-------------------------------------------------------------------------JOURNEES SCIENTIFIQUES DE L'ECOLE DOCTORALE BIOLOGIE-SANTE -------------------------------------------------------------------------WESTOTEL 9 ET 10 DECEMBRE 2014 & 1 PROGRAMME 9 DECEMBRE 2014: 09H15 ACCUEIL DES DOCTORANTS 09H30: INTRODUCTION / PRESENTATION LESCAUDRON / PEIGNE Cassie-Marie). ADN-BIOSANTE (Laurent SESSION 1 : "NUTRITION / METABOLISME / SIGNALISATION" 10H00-10H30: CONFERENCE (20 + 5MIN) MARIE-CÉCILE ALEXANDRE: PHAN-NANTES «Perinatal maternal protein restriction impacts milk composition and offspring metabolomic trajectory in a rodent model of metabolic programming. » 10H30-12H00: PRESENTATIONS DES DOCTORANTS (4 PRESENTATIONS DE 10 + 5 MIN) MME. YAMADA AMI – 2 ème ANNEE – LABERCA - ONIRIS CONTRIBUTION TO THE HUMAN PFAS EXPOSURE ASSESSMENT FOR TWO FRENCH SUB POPULATIONS. MME. HALLOUM WAFAA – 2 ème ANNEE – LABERCA - ONIRIS DEVELOPMENT OF ANALYTICAL STRATEGIES DEDICATED FOR THE ANALYSIS OF ORGANOPHOSPHOSPHORUS FLAME RETARDANTS IN BIOLOGICAL SAMPLES. MME. LECLERC LUCIE - 2 ème ANNEE – ONIRIS MOTHER BODY WEIGHT AT CONCEPTION AND ENERGY INTAKE ARE THE MAIN FACTORS THAT EXPLAIN WEIGHT GAIN DURING GROWTH IN DOGS MME. MARTINEAU ANNE-SOPHIE – 3 ème ANNEE –UNITE NUTRITION ET ENDOCRINOLOGIE THE CONSUMPTION OF A GRAPE AND BLUEBERRY POLYPHENOL-RICH MIXTURE IS SAFE IN DOGS SÉANCE “SPEED-POSTER 1” (DE 1 A 15) 11H40-12H00: PRESENTATIONS ORALES (15 (.PPT) ORDRE DE PASSAGE DANS LE LIVRET POSTERS *2 MINUTES) PRESENTATION 12H15 – 13H15: PAUSE DEJEUNER SESSION 2 : " PATHOLOGIES INFECTIEUSES / IMMUNOLOGIE" 13H15-13H45: CONFERENCE (20’ +5’) ELISE CHIFFOLEAU: « Induction of allograft tolerance in transplantation » 13H50-15H30: PRESENTATIONS DES DOCTORANTS (6 PRESENTATIONS DE 10 + 5 MIN) MME. CANO CAMILLE - 2 ème ANNEE - INSERM U892, EQUIPE 7B SPONTANEOUS WOUND HEALING IN A MOUSE MODEL OF M. ULCERANS INFECTION: A HOST-PATHOGEN CROSS-TALK. M. FOUCHER ETIENNE – 3 ème ANNEE – U892 EQ7 IL-34 AND M-CSF INDUCE MACROPHAGES THAT PROMOTE THE GENERATION OF TH17 CELLS VIA MEMBRANE IL-1Α 2 MME. BACOU ELODIE – 2 ème ANNEE – IECM ANALYSIS OF MIXING-INDUCED STRESS CONSEQUENCES ON IMMUNE TRAITS IN PIGS. MME. YAP MICHELLE – 3 ème ANNEE – UMR 1064 AN INCREASE OF HIGHLY DIFFERENTIATED TEMRA CD8 T CELLS WITH POTENT EFFECTOR FUNCTION IN KIDNEY TRANSPLANT RECIPIENTS WITH STABLE GRAFT FUNCTION REVEALED PATIENTS WITH AT-RISK OF LONG-TERM GRAFT FUNCTION. M. LAPERINE OLIVIER - 3 ème ANNÉE – UMR 791 ROLES OF INTERLEUKINS 33 AND 36 IN THE PATHOGENESIS OF PERIODONTAL DISEASE IN MICE M. PATINEC ALLAN - 3 ème ANNEE –UMR 892 MODULATION DE L'IMMUNITE ANTI-INFECTIEUSE PAR STIMULATION DES POPULATIONS INKT CIRCULANTES DANS UN CONTEXTE DE TRAUMATISME CRANIEN. 15H30-15H50: PAUSE-CAFE SÉANCE “SPEED-POSTER 2” (DE 16 A 40) 15H50-16H50: PRESENTATIONS ORALES (25 (.PPT) ORDRE DE PASSAGE DANS LE LIVRET POSTERS *2 MINUTES) PRESENTATION 16H50-18H15: VISITE POSTERS SESSION 3 : "IMMUNOLOGIE ET CANCEROLOGIE" 18H15-18H50: CONFERENCE (20 + 5’) CATHERINE IBISCH «The bone marrow and the cancer patient: contribution of animal models to hematopoietic stem cell transplantation in oncology » 18H50-19H45 : PRESENTATIONS MIN) DES DOCTORANTS (3 PRESENTATIONS DE 10 + 5 M. D’ALMEIDA Sènan – 3ème année – Inserm U892 THE ECTO-NUCLEOTIDASE CD39 IS INVOLVED IN THE ACQUISITION OF AN IMMUNOSUPPRESSIVE PHENOTYPE BY TUMOR-ASSOCIATED MACROPHAGES. MME. RUGGERI Tiphaine – 2 ème année – EA 3826 Post-Traumatic Immunosuppression in a Mouse Model of Spinal Cord Injury M. AVRIL Pierre - 3 ème année – UMR 957 EFFECT OF SOLUBLE FACTORS PRODUCED BY FAT ON CARCINOLOGICAL RISK 20H00-21H00: DINER A L’HOTEL 21H00-2H: SOIREE DANSANTE (SALLE PAQUEBOT) ANIMATION PAR ASSOCIATION DES DOCTEURS 3 PROGRAMME 10 DECEMBRE 2014: SÉANCE “SPEED-POSTER 3” (DE 41 A 65) 09H30-10H20: PRESENTATIONS ORALES (25 (.PPT) ORDRE DE PASSAGE DANS LE LIVRET. POSTERS *2 MINUTES) PRESENTATION 10H20-10H40 : PAUSE-CAFÉ 10H40-11H40 : VISITE POSTERS 12H00-13H15: DEJEUNER SESSION 4 : " PHYSIOLOGIE / PATHOLOGIES CARDIO-VASCULAIRE / SIGNALISATION" 13H15-13H45: CONFERENCE (20’ +5’) BENJAMIN LAUZIER « Hexosamine biosynthetic pathway stimulation, a new strategy to improve survival during sepsis» 13H45-15H00: PRESENTATIONS DES DOCTORANTS (5 PRESENTATIONS DE 10 + 5 MIN) MME. MONTAUDON ELODIE – 3 ème ANNÉE – PAPF - ONIRIS CARDIOVASCULAR EFFECTS OF ANTI- Β1– AND Β3–ADRENERGIC RECEPTOR ANTIBODIES IN LEWIS RAT MME. BICHON Emmanuelle – 2 ème – LABERCA - ONIRIS GC-APCI-MS/MS for making natural steroids analysis more comprehensive and compatible with ultra-trace detection . MME. COLIN ESTELLE - 3 ème ANNEE – UMR 1083 LOSS OF FUNCTION MUTATIONS IN WDR73 ARE RESPONSIBLE FOR MICROCEPHALY AND STEROID RESISTANT NEPHROTIC SYNDROME : GALLOWAY-MOWAT SYNDROME. MME. BON Nina – 2ème année – INSERM UMRS791 Insight into the extracellular phosphate sensing mechanism, the key step for an appropriate FGF23 secretion M. CLAIREMBAULT THOMAS - 3 ème ANNÉE – UMR 913 STRUCTURAL ALTERATIONS OF THE INTESTINAL EPITHELIAL BARRIER IN PARKINSON’S DISEASE 15H00-15H25: PAUSE-CAFÉ 4 SESSION 5 : "NANO MEDECINE / VECTORISATION / BIOMATERIAUX /THERAPIE GENIQUE MEDECINE REGENERATRICE" 15H30-17H00: PRESENTATIONS DES DOCTORANTS (6 PRESENTATIONS DE 10 + 5 MIN) MME. ANDRE Emilie – 3ème année – Inserm U1066 Neuronal commitment of mesenchymal stem cells with nanoparticles transporting si-RNA M. Kizito-Tshitoko TSHILENGE - 2ème année UMR 1089 Gene transfer in retinal ganglion cell MME. HENRY Nina – 2 ème année – U791 Nano-reinforced hydrogel and protein release in the context of regenerative medicine of the intervertebral disc M.HUET Simon -3 ème année – Affilogic SAS UMR CNRS 6286 Rational design of Nanofitins targeting a defined epitope MME. Vandamme Céline – 2ème année – Inserm UMR 1089 Detection and Characterisation of Human anti-AAV CD8+ T Cells using MHC class I Multimer-based Magnetic Enrichment MME. MALHAIRE Hélène -3 ème année – UMR 1066 ORAL FORMULATION OF PROTEINS: DEVELOPMENT AND CHARACTERIZATION OF AQUEOUS CORE NANOCAPSULES 17H05: CONFERENCE (20’ +5’) JEAN CHRISTOPHE GIMEL: «Brownian diffusion of nanomedicines in complex biological media» 17H35: RETOUR SUR NANTES OU ANGERS 5 SOMMAIRE COMMUNICATIONS ORALES POSTERS 6 MME. YAMADA Ami – 2ème année – LABERCA ONIRIS Session 1 Contribution to the human PFAS exposure assessment for two French sub-populations Ami YAMADA*1, Jean-Philippe ANTIGNAC1, Bruno LE BIZEC1, Jean-Charles LEBLANC2 1 Oniris, Laboratoire d’études des résidus et contaminants dans les aliments (LABERCA), Route de Gachet – Site de la Chantrerie – CS 50707, 44307 Nantes Cedex 3, France 2 Food and Agricultural Organization of the United Nations (FAO), Viale delle Terme di Caracalla, 00153 Rome, Italie Since first synthesis in the early 1940’s and introduction on market in the 1950’s, the use of poly- and perfluoroalkylated substances (PFAS) is now widespread in various applications such as fire-fighting foams, aviation hydraulic fluids, medical devices and pesticides but also in consumer products as water- and stain-repellents for anti-sticking coating of pans, cleaning products and waterproof clothing as instance. Due to a high thermal and chemical resistance, these compounds are hardly, if ever, degraded. High thermal and chemical resistance, adsorption to particles and long-range atmospheric transport explain their ubiquitous presence even in remote areas such as in Arctic where neither use nor production of PFAS is known. Since last decade, the risk assessors and managers saw these compounds as a matter of public health interest when toxicity concerns were associated with PFAS exposure and found in the blood of the general population. The main suspected health effects are neurotoxicity, hepatotoxicity, developmental toxicity, immunotoxicity as well as effects on thyroid. The aim of this PhD thesis is to characterise the aggregated external exposure of two possibly at risk sub-populations to PFAS found at the highest concentration in serum, namely the perfluorooctanesulphonate (PFOS), the perfluorooctanoic acid (PFOA), the perfluorohexanesulphonate (PFHxS) and the perfluorononanoic acid (PFNA). Populations of interest are pregnant women and their newborn as this population is potentially the most sensitive to the effects of PFAS during this critical period of time and high fish consumers (sea and freshwater) as this population is potentially the most exposed via the diet considering that fishes are reported as being the highest contaminated foods to PFAS. The considered external exposure includes diet, indoor and outdoor air as well as settled dust and soil excluding dermal pathway as it was shown that at a physiologically relevant pH, PFOS and PFOA were unable to penetrate through the skin. As part of the work, a link of the external exposure versus internal exposure considering the serum level of PFOS and PFOA reported in the two sub-populations with the use of a physiologically based toxicokinetic model is proposed. 7 MME. HALLOUM Wafaa – 2ème année – LABERCA ONIRIS Session 1 DEVELOPMENT OF ANALYTICAL STRATEGIES DEDICATED FOR THE ANALYSIS OF ORGANOPHOSPHOSPHORUS FLAME RETARDANTS IN BIOLOGICAL SAMPLES Halloum W1, 2, Cariou R1, Dervilly-Pinel G1, Jaber F2, Le Bizec B1 1LUNAM Université, Oniris, USC INRA 1329 Laboratoire d’Etude des Résidus et Contaminants dans les Aliments (LABERCA), F-44307, Nantes, France. 2Lebanese University - Faculty of Sciences I, Laboratory of Analysis of Organic Compounds (LACO) - 508 - Hadath, Beirut, Lebanon Abstract Flame retardants (FRs) are human-made chemicals added to consumer and industrial products for the purpose of reducing flammability1. Among FRs, there are the halogenated FRs that may be divided into brominated and chlorinated flame retardants (BFRs and CFRs), and phosphorus-containing flame retardants (PFRs)2. The market for flame retardant chemicals is being driven by globally tightening fire safety regulations. In this context, some halogenated FRs, such as BFRs, have proven to be persistent, bioaccumulative and toxic to environment, animals and humans. This led governments to adopt restrictions which phase out the production and use of some BFRs3. On the other hand, organophosphorus flame retardants (OPFRs) are proposed as alternatives for BFRs and their use shows a continuous increase4,5. However, most OPFRs are introduced as additives and not chemically bound to the polymer; hence they are slowly released in the environment by abrasion and volatilization. Some of these chemicals are suspected to be neurotoxic, particularly triphenyl phosphate (TPP), tri-n-butyl phosphate (TnBP) and tri-cresyl phosphate (TCP)6. Furthermore, halogenated alkyl phosphates have low degradation potential and thus may be persistent7. As a result, OPFRs are considered as reemerging pollutants because of their increased use after BFR bans and their ubiquitous occurrence in both indoor and outdoor environments 3. The aim of this work was to develop an analytical method including sample preparation and detection techniques enabling the extraction of 19 OPFRs from complex biological matrices, and their subsequent identification and quantification at trace levels by using gas chromatography and/or liquid chromatography coupled to tandem mass spectrometry (GCMS/MS and LC-MS/MS). For this purpose, an instrumental method was developed on GCMS/MS with satisfactory performances in terms of detection limits and linearity of calibration curves. Another instrumental method is on its way of development on LC-MS/MS. On the other hand, solid- phase extraction (SPE) along with a number of parameters was investigated as a suitable purification technique. The work will extend to optimize the extraction procedure and to implement the whole strategy for the analysis of fish samples as well as other foodstuffs in order to analyze these contaminants at trace levels and hence to contribute to the evaluation of Human dietary exposure. References 1.U.S. Department of health and human services. (2012); Agency for Toxic Substances and Disease Registry 2. Bergman A, Ryden A, J.Law R, de Boer J, Covaci A, Alaee M, Birnbaum L, Petreas M, Rose M, Sakai S, Van den Eede N, Van der Veen N. (2012); Environ Int. 49: 57-82 3. Cristale J, Lacorte S. (2013); Journal of Chromato A.1305 : 267-275 4. Van der Veen I, De Boer J. (2012); Chemosphere. 88: 1119-1153 5. Brandsma S.H, De Boer J, Cofino W.P, Covaki A, Leonard P.E.G. (2013); Trends in Analytical Chemistry. 43: 217-228 6. Ma Y, Cui K, Zeng F, Wen J, Liu H, Zhu F, Ouyang G, Luan T, Zeng Z. (2013); Analytica Chemica Acta; 786:47-53 7. Van den Eede N, Dirtu A.C, Neels H, Covaci A. (2011); Environ Int.37: 454-461 8 MME. LECLERC LUCIE - 2ème année – ONIRIS session 1 Mother body weight at conception and energy intake are the main factors that explain weight gain during growth in dogs L. Leclerc1, 3, C. Thorin2, S. Serisier1, P. Nguyen3 1 Royal Canin Research Center, Aimargues, France 2 UPSP 5304 de Physiopathologie Animale et Pharmacologie Fonctionnelle, 3Unité de Nutrition et Endocrinologie Ecole Nationale Vétérinaire, Agroalimentaire et de l'alimentation Nantes Atlantique, ONIRIS, Nantes, France lucie.leclerc@oniris-nantes.fr Introduction: In humans, it has been shown that overweight in adulthood could be predicted early in childhood. Serisier et al. showed that a higher growth rate could be a risk factor for later overweight in cats. The aim of our study is to identify early risk factors (from the conception to the end of growth) to become overweight in adulthood for dogs and cats. The preliminary results in dogs are presented here. Animals, material and methods: Twenty-four female Beagle dogs were studied from birth to the age of twenty-nine weeks. They were weighed weekly. After weaning at 10 weeks of age, they were fed ad libitum every day for 3.5 hours. Individual food intake was recorded daily on business days, and mean energy intake (MEI) was calculated from weaning to the age of 29 weeks. Early-life data were provided by the breeding centre, including number of previous litters (NbPL), mother’s age and body weight at conception (MBWc), weight gain during gestation, litter size and body weight at birth of each puppy as well as father body weight at mating. The effect of early-life factors on body weight at weaning and at 29 weeks of age (BW29) was assessed by a multilinear model analysis. The effect of early-life factors on weight gain before and after weaning were also assessed with the same statistical test. However, individual energy intake as well as weaning BW has been added to the statistical model after weaning. Results: No variable explained birth body weight. However, interestingly, weaning body weight and weight gain from birth to weaning significantly depended on MBWc (P<0.001) which was itself strongly associated with NbPL (P=0.003). BW29 and weight gain from weaning to 29 weeks of age were associated with MEI (P<0.001). In addition, BW29 depended on weaning BW (P<0.001). Discussion and Conclusion: Before weaning, mother body weight at conception has a significant impact on weaning BW and body weight gain from birth to weaning. Once dogs started to consume manufactured diets, energy intake became the most significant parameter which explained BW29 and body weight gain after weaning. Since mother body weight at conception impacted weaning body weight which itself impacted BW29, mother body weight at conception indirectly impacted BW29. These results suggest a cumulative effect of MBWc before weaning and energy intake after weaning on final body weight. Many complementary data, including resting energy expenditure, digestibility, inflammatory factors and hormone levels should enable to better explain weight and fat gain during growth and the risk of becoming overweight. Serisier, Samuel, Alexandre Feugier, Claudie Venet, Vincent Biourge, and Alexander J. German. 2013. “Faster Growth Rate in Ad Libitum-Fed Cats: A Risk Factor Predicting the Likelihood of Becoming Overweight during Adulthood.” Journal of Nutritional Science 2 (April). doi:10.1017/jns.2013.10. 9 MME. MARTINEAU Anne-Sophie – 3ème année –Unité Nutrition et Endocrinologie Session 1 The consumption of a grape and blueberry polyphenol-rich mixture is safe in dogs AS Martineau1,4, V Leray1,4, D Gaudout2,4, A Lepoudère3,4, K Ouguerram1,4 and P Nguyen1,4 1 Nutrition and Endocrinology Unit, Oniris, Vet School and CRNH Nantes 2 Activ’Inside, Libourne 3 SPF, ElvenFrance 4On behalf of Neurophenols® consortium Grape polyphenols have beneficial health effects, but grape ingestion has been associated with acute renal failure leading most often to fatal issue in dogs. The responsible factors are unknown. Our aim was to check the safety of a supplement of polyphenol-rich mixture (grape and blueberry extracts (specific pet Neurophenols® blend)) in dogs. Seventeen dogs were given, for 12 wks, capsules containing 4 (n=5) or 20 (n=6) or 40 (n=6) mg/kg/d of the polyphenol mixture. Five control dogs were given maltodextrin capsules. Blood and 24-h urine were taken before the beginning of the study (W0), then after 4 wks and 12 wks of supplementation. Plasma standard analysis (creatinine (Creat), urea, minerals (Na, K, Ca, P), total protein, hepatic biomarkers (ALT, ALP)) were assayed. New biomarkers that reveal early renal damage were measured : plasma and urinary cystatin C (CysC), clusterin (Clu), neutrophil gelatinase-associated lipocalin (NGAL). Urinary biomarkers/Creat ratios were calculated. Data were compared with limits of reference intervals or with the highest values from our control dogs and experimental dogs at W0. Whatever the week, plasma standard analysis were below high limits of reference intervals. Plasma CysC concentration was below our own high limit. Plasma Clu and NGAL concentrations were below limits of reference intervals. Urinary CysC/Creat, Clu/Creat, NGAL/Creat ratios were below our own limit. Grape extract and blueberry extract (specific pet Neurophenols® blend) consumption was not associated with any sign of renal failure and can be consumed safely in dogs. MME. CANO Camille - 2ème année - INSERM U892, équipe 7b Session 2 Spontaneous wound healing in a mouse model of M. ulcerans infection: A hostpathogen cross-talk Mycobacterium ulcerans infection or Buruli ulcer is a skin disease mainly affecting children. In 1998, The World Health Organization (WHO) recognized it as an emerging infectious disease in West and Central Africa with an important public health impact and classified it as a neglected tropical disease. Buruli ulcer is the third most common mycobacterial disease after tuberculosis and leprosy. Classically, Buruli ulcer is a necrotising skin disease characterized by an indolent painless course leading to extensive cutaneous and subcutaneous destruction, functional limitations and disabilities. These lesions are due to mycolactone, the main virulence factor of M. ulcerans, which has cytotoxic, immunomodulatory and analgesic properties. Since 2005, WHO recommends the use of antibiotherapy (streptomycin and rifampicin) associated or not with surgery. Several months after the onset of clinical signs, in the lack of treatment, lesions may evolve into a process of spontaneous wound healing. This "cure", which however has important irreversible functional consequences, demonstrates a control of infection by the host. Understanding the mechanism involved in the process of spontaneous wound healing, both at the cellular and molecular levels, will pave the way to new therapeutic strategies. For ethical reasons, the work on human samples is impossible. However the commonly used mouse models to study the pathophysiology of M. ulcerans infection show no spontaneous wound healing stage, thus excluding the possibility to identify the involved mechanisms. In this context, a screening on 10 different mouse strains allowed us to identify a strain mimicking all stages of infection, including spontaneous wound healing. Genomic and transcriptional studies in these mice demonstrate a deficiency of a cell surface receptor mainly expressed by neutrophils and macrophages. Functional tests demonstrate an antagonistic role of mycolactone on this receptor, assuming its involvement in the pathophysiology of infection. These results open the way toward the identification of the toxin / receptor interaction mechanisms and the clarification of their involvement in the healing phenomenon. M. FOUCHER Etienne – 3ème année – U892 Eq7 Session 2 IL-34 and M-CSF induce macrophages that promote the generation of Th17 cells via membrane IL-1α Depending on their environment, and especially the nature of the cytokines, monocytes can differentiate into macrophages (M) or dendritic cells (DC). In the past, we have demonstrated that M-CSF induce the differentiation of human monocytes into immunoregulatory M. We have recently reported that IL-34, a second ligand of the M-CSF receptor (c-fms or CD115), induces the differentiation of monocytes into CD14 high CD163high CD1a- Mφ (IL-34-Mφ) that exhibit potent immunosuppressive properties (IL-10high IL-12low profile) and decrease the proliferation of stimulated T cells. Interestingly, for all the parameters analyzed, IL-34-M are phenotypically and functionally similar to M-CSF-Mφ. Moreover, the generation of IL-34-Mφ is not dependent of endogenous M-CSF consumption. As Mφ orchestrate the immune response, we evaluated the capacity of M-CSF-Mφ and IL-34-Mφ to polarize human CD4+ T cells. Results showed that, unexpectedly, M-CSF-Mφ and IL-34-M promote the generation of IL-17-producing Th cells, contrary to the pro-inflammatory IL-12high IL-10low GM-CSF-Mφ which favour the generation of Th1 cells. More precisely, these M subsets switch non-Th17 memory CD4+ T cells into conventional CCR4+ CCR6+ CD161+ Th17 cells, expressing or not IFN-. Finally, we have demonstrated that the generation of Th17 cells is mediated via membrane IL-1α which is constitutively expressed by the two M subsets. In an attempt to identify strategies to prevent a deleterious accumulation of immunoregulatory M in some pathological situations, we have shown that (i) IFN- and GM-CSF prevent IL-34-induced monocyte differentiation into immunosuppressive Mφ and (ii) that IFN- switches established IL-34-Mφ into immunostimulatory Mφ. In conclusion, this study demonstrates that human M-CSF-Mφ, IL-34-Mφ, initially considered as antiinflammatory cells, induce in vitro Th17 cells via a constitutive expression of membrane IL-1α. This process may contribute to maintain locally a restrained and smoldering inflammation required for angiogenesis and metastasis in tumors. MME. BACOU Elodie – 2ème année –IECM Session 2 Analysis of mixing-induced stress consequences on immune traits in pigs. Elodie Bacou*a,b, Karine Haurognéa,b, Marie Allarda,b, Jordan Marchandb,a, Grégoire Mignotb,a, Yvon Billonc, Jean-Marie Bachb,a, Pierre Mormèded, Julie Hervéb,a and Blandine Lieubeaua,b. a INRA USC 1383, IECM, Nantes F-44300 France LUNAM University, Oniris University Nantes EA 4644, IECM, Nantes F-44300 France c INRA UE 1372, GenESI, Saint-Pierre-d’Amilly F-17700 France d INRA UMR 1388, GenPhySe, Castanet-Tolosan F-31426 France b 11 Pig husbandry is known as an intensive breeding system, piglets being submitted to multiple stressful events such as early weaning, successive mixing and crowding. We hypothesize that these events can affect pig health by increasing their sensitivity to bacterial infections while decreasing their robustness. Immune traits were recently described as descriptive indicators of pig health. Among them, the whole blood assay, which measures cytokine release in whole blood in response to LPS stimulation, was proposed to predict individual susceptibility to infectious diseases. In this context, we aimed to analyse the effects of an acute stress, ie a one-hour mixing, on several immune traits in 90 pigs: white blood cell count, lymphocyte subsets, phagocytosis and ex-vivo production of cytokines (IL-8, IL-10, IL-12 and TNFcortisol and catecholamines are known as the main mediators of stress responses, we will measure their levels in plasma samples and correlate them to immune traits. We first demonstrated an increase in circulating white blood cell number associated to an altered lymphocyte subset repartition (decrease in B and CD4+ T cells and increase in CD8+ and CD4+CD8+ T cells). Furthermore, one-hour mixing induced significant decrease in IL-8 and IL-10 ex-vivo productions while having no effect on IL-12 and TNFas on phagocytosis. Cortisol and catecholamine levels remain to be measured. Altogether, our data already link a stressful event to altered immune responses in pigs, although mediators still remain to be determined. A better understanding of intensive farming practice consequences on immunity is mandatory to increase pig robustness required for antibiotic use reduction (Plan Ecoantibio 2012-2016). 12 MME. YAP Michelle – 3ème année – UMR 1064 session 2 An increase of highly differentiated TEMRA CD8 T cells with potent effector function in kidney transplant recipients with stable graft function revealed patients with at-risk of long-term graft function. Michelle Yap1 2 3, Françoise Boeffard1 2 3, AnnaickPallier1 2 3, Richard Danger1 2 3, Magali Giral1 2 3 , Jacques Dantal1 2 3, Yohann Foucher2 4, Cécile Guillot-Gueguen2, Jean-Paul Soulillou1 2 3, Sophie Brouard1 2 3, and Nicolas Degauque1 2 3 1 INSERM, UMR 1064, Nantes, France 2 CHU de Nantes, ITUN, Nantes, France 3 Université de Nantes, Faculté de Médecine, Nantes, France. 4 Université de Nantes, EA 4275, Nantes, France. Introduction: Kidney transplantation is considered the best treatment for patients with end-stage renal disease; however it is still necessary to improve long term graft survival. While T lymphocytes have been shown to be implicated in acute graft rejection, there is still little information regarding the role of CD8 T cells in long term graft survival. We took advantage of a large group of kidney transplant recipients enrolled in a prospective study to investigate the role of CD8 T cells in long-term graft outcome. Methods: 131 kidney graft recipients with a stable graft were enrolled into the prospective study. Patients were enrolled at least 5 years post-transplant. At the time of inclusion, the TCR Vβ repertoire (CDR3 length) was characterized using TcLandscape and a detailed profile of CD8 T cells was obtained through multicolor flow cytometry. Patients were followed for more than 6 additional years, during which 47 patients had undergone kidney graft degradation. In addition, the functional properties of a sub-group of 32 patients who were matched for clinical parameters (time post-transplantation, recipient and donor age) and selected according to the CD8 phenotype (high vs. low TEMRA CD27-CD28-CD57+TBET+) were analyzed through the secretion of pro-inflammatory cytokines IFNγ and TNFα and the expression of cytotoxic surrogate marker CD107a upon polyclonal stimulation with plate bound αCD3 and αCD28.2 mAbs. Results: 86 patients were identified to have an altered TCR Vβ repertoire and 45 patients had an unaltered TCR Vβ repertoire. Accumulation of alteration in the TCR Vβ repertoire was associated with an increase of TEMRA (CD45RA+CCR7-) CD8 T cells. Those CD8 T cells displayed an activated phenotype (CD27-CD28-CD127-) and potent effector functions characterized by an upregulation of cytotoxic molecules (PERFhiGZMB+) and effectorassociated molecules (TBEThi and CD57+). In patients with an increase of TEMRA CD27CD28-CD57+TBET+, short-term polyclonal stimulation of PBMC results in an increased secretion of TNFα and IFNγ by CD8+TBET+ T cells and a vigorous cytotoxic function, as exemplified by the expression of CD107a. Finally, the increase of highly differentiated TEMRA CD8 T cells was associated with 1.96 high risk of kidney dysfunction (multivariate model). Conclusion: Despite our cohort of kidney graft recipients appeared to be stable and homogeneous from a clinical perspective at the time of enrollment, the monitoring of CD8 T cell phenotype and function and the characterization of the TCR Vβ repertoire reveals major differences in the homeostasis of the CD8 T cell populations and in the long term outcome of the kidney graft. 13 M. LAPERINE Olivier - 3ème année – UMR 791 Session 2 Roles of interleukins 33 and 36 in the pathogenesis of periodontal disease in mice LAPERINE Olivier1,2, CLOITRE Alexandra1,3, CAILLON Jocelyne4, DAVIDEAU Jean-Luc5, PALMER Gaby6, SOURICE Sophie1, PILET Paul1,2, GUICHEUX Jérôme1 ,2,3, BECKCORMIER Sarah1, LESCLOUS Philippe1,2,3 1 INSERM UMRS 791 – Laboratoire d’Ingénierie Ostéo-Articulaire et Dentaire « LIOAD » STEP « Skeletal Tissue Engineering and Physiopathology » group ; 2Université de Nantes, UFR Odontologie ; 3CHU de Nantes, Pôle Hospitalo-Universitaire 4 OTONN : 1 place Alexis Ricordeau » - 44042 NANTES CEDEX 1 France 4UPRES EA 3826, Faculté de médecine, Université de Nantes, Nantes France 5INSERM UMR 1109, “Osteoarticular and Dental Regenerative NanoMedicine” Laboratory, Strasbourg, France 6Division of Rheumatology, Department of Internal Medicine, University Hospital of Geneva, Geneva, Switzerland Keywords: Periodontal disease, Interleukins, Bone loss Periodontitis is an inflammatory disease of bacterial origin, triggering tissues surrounding the tooth i.e. gingiva, periodontal ligament and alveolar bone. This disease is a major public health issue. In France, nearly 85 % of the adult population is affected by periodontal disease whose 10% presented a refractory type to the mechanical and / or medical treatments, leading to the loss of many teeth. Actually, its immunopathogenic mechanisms remained poorly understood. Following the bacterial stimulus, an inflammatory cascade is initiated via Tolllike receptors (mainly 2 and 4) to ultimately activate osteoclast function. Interleukin 33 (IL33) and IL-36 are new members of the IL-1 cytokine family of particular interest because of their involvement in an inflammatory pathology showing immunosimilarities with periodontitis, the rheumatoid arthritis. The objective of this study is to validate a mouse model for periodontal bone loss and to investigate the potential involvement of IL-33 and IL-36 in the pathogenesis of this disease. To this aim, we performed a mouse model of alveolar bone loss by local bacterial infection (Porphyromonas gingivalis i.e Pg). The jaws of these mice were analyzed by micro computed tomography, real-time RT-PCR and conventional histological approaches (HES staining, immunohistochemistry). We validated this model since we recorded a significant alveolar bone loss one month after induction of periodontal disease. Interestingly, preliminary results showed an expression of IL-33 in the gingival epithelium in affected animals whereas no labeling was discernible in controls. We also recorded an increase of IL-33 expression in the connective tissue of affected animals compared to the control mice. The real-time RT-PCR experiments showed an overexpression of IL-36 mRNA in the gingiva of affected animals. Taken together, these data suggested a potential role of these two interleukins in the immunopathogenesis of periodontitis. To further investigate the molecular mechanisms of these two cytokines, we are now developing an in vitro approach using gingival cells stimulated with LPS from Pg. Finally, we would like to use this periodontal model in knockout mice for genes encoding IL-33 or its receptor IL1RL1. Altogether, these approaches would allow a better understanding for a role of IL-33 and IL-36 in periodontal disease. 14 M. PATINEC Allan - 3ème année –UMR 892 session 2 Modulation of anti-infectious immunity by stimulation of circulating iNKT populations in head trauma context. In this study we focuse on the mechanisms that allow the establishment of anti-infectious immunodeficiency in a context of head trauma. An article published in Science on November 2011 (1) indicated that the loss of antiinfectious immunity observed after brain lesions could be associated with the direct action of neurotransmitters, such as catecholamines, on lymphocyte populations. The authors established in a mouse model that the iNKT population was the cornerstone of the phenomenon leading to a switch in cytokinine secretion, towards an pro-infectious phenotype. Our goal is to check if these results are revelant to the human situation. The chosen axis is the study of the capacity of the different sub populations of iNKT cells to respond to various stimuli, whether glycolipid or catecholinergic. We were able to highlight a significant effect of the action of epinephrine on cytokinine secretion on PBMC, with a decrease in the IFN-g secretion and an increase of the IL-10 level, in agreement with the establishment of a regulatory pro-infectious state. Very interestingly, an endogenous ligand of human iNKT cells, the β-glucosylceramid significantly increased the IFN-γ/IL-10 ratio compared to the canonical ligand KRN7000 (αgalactosylceramide), suggesting a potential for reversion of the phenomenon induced by epinephrine. Preliminary experiments using sera from patients after cardiac arrest enabled us to observe a change in iNKT cytokine secretion compatible with the establishment of a pro-infectious profile, and concordant with the effects highlighted with epinephrine. These results are consistent with the presence of catecholinergic molecules in the serum of patients after brain-injury that may contribute to the loss of anti-infectious immunity through their effect on the balance of cytokine secretion. (1) Wong CH, Jenne CN, Lee WY, Léger C, Kubes P. Functional innervation of hepatic iNKT cells is immunosuppressive following stroke. Science 2011;334:101-5. M. D’ALMEIDA Sènan – 3ème année – Inserm U892 Session 3 THE ECTO-NUCLEOTIDASE CD39 IS INVOLVED IN THE ACQUISITION OF AN IMMUNOSUPPRESSIVE PHENOTYPE BY TUMOR -ASSOCIATED MACROPHAGES Tumor-associated macrophages (TAMs) are the main immunosuppressive myeloid cells in the tumor microenvironment. To date, the mechanisms involved in their generation remain largely unknown. It has been shown that ATP, shown to recruit myeloid cells into the tumor, became an immunosuppressive tool in cancer due to its rapid catabolism into adenosine by ectonucleotidases. Previous studies have also underlined the role of the ectonucleoside triphosphate diphosphohydrolase-1 (NTPDase1 or CD39) in the biology of regulatory T cells [1]. Thus, they represent therapeutic targets to overcome tumor-associated immunosuppression. OBJECTIVE: To investigate the role of CD39 and ATP metabolism in the biology of TAM. METHODS: TAMs were purified from ovarian cancer patients. By performing a robust functional assay, mature IL-1 production by macrophages reflected the presence of extracellular ATP. RESULTS: In this study, we showed that TAM purified from ovarian cancer patients and immunosuppressive macrophages generated in vitro express high levels of membrane CD39 compared to immune-stimulatory macrophages. Furthermore, we evidenced the ability for the pharmacological inhibition of CD39 (POM-1), to potentiate expression of IL15 immunosuppressive macrophages generated in vitro, while decreasing their immunosuppressive functions (IL-10 secretion, IL-27 secretion, specific CD163 markers and their ability to phagocyte). Among the several cytokines tested, it was of note that the blockade of the cytokine IL-27, by down-modulating the surface expression of CD39, was of particular importance for IL-1 and IL-10 secretion. CONCLUSION: As a matter of fact, this study underlines the pivotal role of CD39 via ATP metabolism and/or via the adenosine pathway in the acquisition of an immunosuppressive phenotype by TAM and in vitro generated immunosuppressive M that their blockade could be used as an anti-tumoral therapy. Collectively, these data suggest that CD39 maintains the immunosuppressive phenotype of TAM from ovarian cancer. This work brings new information on the nature and profile of tumor-infiltrating immune cells. KEY-WORDS: Tumor-Associated Macrophages, NLR, inflammasome, IL-1, ATP, purinergic signaling, CD39, IL-27, ovarian cancer 1. Antonioli, L., et al., CD39 and CD73 in immunity and inflammation. Trends Mol Med, 2013. 19(6): p. 355-67. MME. RUGGERI Tiphaine – 2ème année – EA 3826 Session 3 1,2 Tiphaine RUGGERI, 1 University of Nantes faculty of medicine unit EA3826 2 Regional center for cancer research Nantes/Angers INSERM UMR-892, 2nd year of thesis Post-Traumatic Immunosuppression in a Mouse Model of Spinal Cord Injury Introduction. High level Spinal Cord injuries (SCI) lead to an immunosuppression that sensibilizes individuals to nosocomial infection. Mechanisms involved in immunosuppression after nosocomial infection following a severe trauma of SCI are still poorly understood. Our study aims to validate a spinal cord injury (SCI) model in terms of susceptibility of SCI mice to Staphylococcus aureus (S. aureus) pneumonia, a common bacteria involved in nosocomial infections after acute immunosuppression. Methods. A surgical procedure involving a medullary dislocation between thoracic vertebra T3 and T8 was established. This dislocation led to a dysregulation of the sympathetic nervous system in the spleen, a major lymphoid organ in mice. 3 groups were studied: control group (without anesthesia and dislocation), Sham group (with anesthesia but without dislocation) and SCI group (with anesthesia and dislocation). First we analyzed consequences on weihg spleen after trauma. Then, mortality (survival curves) of S. aureus infected mice was observed for 10 days to study susceptibility of mice to S. aureus. Mice were infected at different days, post-operatively at D1, D3 or D8. In parallel, inflammatory cells infiltration into the lungs was assessed by histology and SIOX analysis (Fiji software) to confirm infection lungs mice. Second, we studied immunosuppression by level of TNF-α determined by ELISA after LPS stimulation of blood samples were evaluated. And also by expression of inflammatory cytokines, TNF-α and IL1β, were determined in lungs, as well as pro or anti-inflammatory cytokines, IFN-γ and IL-10, in spleen. Results. First, after medullary dislocation, we observed a decrease of spleen weight in SCI mice 48h post-operative as compared to Sham mice that confirm interaction between nervous system and immune system. Three days post-operative, SCI mice were more susceptible to infection than the Sham mice: 50% mortality was observed in SCI group (48h after the bacterial challenge) as compared to a 25% mortality rate for Sham animals. No difference of cells infiltration after infection in Sham and SCI was observed. In infected lungs, TNF- α and IL-1β concentrations increased in Sham and even more in SCI group. Second, as previously demonstrated in other acute stresses (Asehnoune et al., 2006), a hyporeactivity after LPS stimulation of whole blood culture (a classical marker of immunosuppression) was observed (an increase of TNF-α was observed in blood samples stimulated with LPS from Sham mice, but not in SCI mice). After infection, expression of IFN-γ increased in spleen for Sham mice but not for SCI mice. On the other hand, an increase 16 of IL-10 was observed in SCI group but remained at a basal level in Sham group. Finally, studies on marker cells showed an increase of PD1 expression on lymphocytes T at 16h postoperative for SCI animals as compared to Sham mice in spleen. Conclusion. SCI mice show an immunosuppression state as compared to Sham mice. SCI mice seem more susceptible to S. aureus infection than Sham mice that confirm immunosuppression presence. After infection, SCI animals highly express IL-10 in spleen, which confers anti-inflammatory state, whereas Sham mice highly express IFN-γ, which confers pro-inflammatory state. These results show that SCI mice are in anti-inflammatory state favorable for immunosuppression. We will continue our project in study of interactions between dendritic cells, Natural Killer cells and lymphocytes T, to understand mechanisms lead immunosuppression and found therapeutic method against immunosuppression. Asehnoune, K., Fitting, C., Edouard, A.R., Cosson, C., Benhamou, D., Cavaillon, J.-M., and Moine, P. (2006). Influence of resuscitation volume on blood cells TNF production in a murine model of haemorrhage. Resuscitation 68, 127–133. M. AVRIL Pierre - 3ème année – UMR 957 Session 3 EFFECT OF SOLUBLE FACTORS PRODUCED BY FAT ON CARCINOLOGICAL RISK In a clinical case, a late and local recurrence of osteosarcoma has been observed following autologous fat graft. The involvement of the adipose tissue in this recurrence has been demonstrated in murine models of osteosarcoma [1]. Autologous fat grafting-or-lipofilling- is more widely used in reconstructive procedures following breast cancer. In the case of highgrade breast carcinomas, a recent retrospective study showed that lipofilling was a potential risk of local recurrence in young patients with a high mitotic index (Ki-67> = 14%) [2] .Proliferation assays and flow cytometry analyzes performed on these cells have demonstrated a pro-tumor effect in vitro characterized by an accelerated cell cycle of adipose tissue mediated by cell-free fraction containing fat soluble factors (= fat-CM). Tumor recurrence can occur from residual cancer stem cells (CSC) characterized by a low rate of proliferation and by their ability to form a complete tumor. In order to reproduce the acquisition of a CSC-like phenotype, tumor cells were cultured in oncospheres and qPCR analyses were performed. In conditions of loss of adhesion, proliferation of osteosarcoma cells was decreased while their stemness marker levels were increased. Mammary carcinoma cells cultivated in oncosphere showed the acquisition of epithelial to mesenchymal transition markers. In these culturing conditions, fat-CM could partially modulate these phenotypic changes. Identify the soluble factor(s) responsible of the pro-tumor effect of adipose tissue should lead to a better understanding the interactions between tumor cells and their environment. This could help to establish new therapeutic targets for cancer treatment and to secure the lipofilling procedure, a main reconstructive surgical technical for patients. REFERENCES [1] Perrot P, Rousseau J, Bouffaut AL, et al. PLoS One. 2010; 5: e10999 [2] Petit JY, Rietjens M, Botteri E, et al. Ann Oncol. 2013 17 MME. MONTAUDON Elodie – 3ème année – PAPF ONIRIS Session 4 Cardiovascular effects of anti- β1– and β3–adrenergic receptor antibodies in Lewis rat E. MONTAUDON*, J-C. DESFONTIS, L. DUBREUIL, Y. MALLEM. LUNAM Université, Oniris, «UPSP 5304 de physiopathologie animale et pharmacologie fonctionnelle», Atlanpole La Chantrerie, BP 40706, Nantes, F-44307, France. β1– and β3–adrenerdic receptor (AR) autoantibodies (AABs) were detected in patients with dilated cardiomyopathy (DCM). Many studies have shown that β1–AABs play an important role in the pathogenesis of DCM. Our previous work has shown that the immunization of rats for 3 months with the second extracellular loop (ECII) of β1–AR induced endothelial dysfunction in aorta. Those results suggest that β1–AABs could have a vascular pathogenic action. However, until now, no study has explored the cardiovascular effects of β3–AABs. The aims of this sudy was to evaluate whether β3-antibodies (Abs) possess β3-AR agonistic effect and whether active immunization producing β3-ABs or β1-ABs has deleterious effects on cardiac and vascular reactivity in Lewis rats. Lewis rats were immunized for 6 months with peptidic sequences corresponding to the ECII of β3-AR or β1-AR. Agonistic effect of β3-AABs was evaluated on electrically fieldstimulated isolated cardiomyocytes from adult rabbit by measuring the cell shortening. Echocardiographies and ex vivo studies on isolated perfused heart and isolated thoracic aorta were conducted on immunized rats. Finally, the expression of β-AR was quantified by immunofluorescence approach. SR58611A (10 nM), a preferential β3–AR agonist and purified β3-ABs (25 g/mL) induced a decrease of cell shortening (-39.64.4% (n=11) and -18.53.9% (n=10) respectively). This decrease was significantly inhibited when the cardiomyocytes were preincubated with the L-748337 (1 M), a selective β3-AR antagonist (p<0.05), and with pertussis toxin (0.3 g/ml), a Gi protein inhibitor (p<0.05). Echocardiographies revealed a decrease of the fractional shortening and ejection fraction only in rats immunized against β1–AR. However, the study on isolated heart showed a decrease of the isoprenaline-induced lusitropic and inotropic effects in both animals immunized against the β1– and β3–AR. These systolic and diastolic dysfunctions are correlated with a decrease in the expression of β1–AR and an increase of β3–AR in rats immunized against the β1–AR and an increase of both β3– and β1–AR in rats immunized against β3–AR. In thoracic aorta, β1–AR relaxation was impaired in rats immunized against β1–AR while it was improved in those immunized against β3–AR. Those results show for the first time that β3–ABs induced a β3–AR partial agonist-like activity. In the heart, they would have a pathogenic action while in blood vessels, they would have a protective effect offsetting the endothelial dysfunction caused by β1–ABs. 18 MME. BICHON Emmanuelle – 2ème année – LABERCA/ONIRIS Session 4 GC-APCI-MS/MS for making natural steroids analysis more comprehensive and compatible with ultra trace detection Authors: E. Bichon, S.Prevost, K. Hening, F. Monteau, B. Le Bizec. To understand the mechanism of action of certain chemical endocrine disrupters on the human steroidome, an amazing effort is still today necessary so that the measurement of a wide range of gonadic steroids become possible and compatible with the ultra trace amounts of these substances in –sometimes- very complex biological matrices (available in very limited amount). For androgens, analytical strategies rely in general on gas chromatography coupled to mass spectrometry mainly using triple quadrupole technologies and electron ionization. Because of the high energy involved, steroid fragmentation is extensive and often leads to unsatisfactory results. To improve the signal specificity and eventually the quality of the delivered signals, soft ionization strategies must be envisaged. Potentialities of atmospheric pressure chemical ionization (APCI) have been investigated in this project. An exhaustive comparison of the physical conditions, e.g. corona discharge, interface temperature and gas flow, as well as different way of preparing target steroids (i.e. derivatization reaction) has been conducted. Observed performances will be discussed with regard to current classical analytical strategies used in clinical chemistry. Perspectives given by the significant improvement of the performance will be discussed. MME. COLIN Estelle -3ème année –UMR 1083 Session 4 Loss of function mutations in WDR73 are responsible for microcephaly and steroid resistant nephrotic syndrome : Galloway-Mowat syndrome. Estelle Colin*, Evelyne Huynh Cong, Géraldine Mollet, Agnès Guichet, Olivier Gribouval, Christelle Arrondel, Olivia Boyer, Laurent Daniel, Marie-Claire Gubler, Zelal Ekinci, Michel Tsimaratos, Brigitte Chabrol, Nathalie Boddaert, Alain Verloes, Arnaud Chevrollier, Naig Gueguen, Valérie Desquiret-Dumas, Marc Ferré, Vincent Procaccio, Laurence Richard, Benoit Funalot, Anne Moncla, Dominique Bonneau, Corinne Antignac Laboratoire: UMR INSERM 1083 – CNRS 6214 – BNMI Galloway-Mowat syndrome (MIM 251300) is a rare autosomal recessive condition characterized by nephrotic syndrome associated with microcephaly and neurological impairment. Through a combination of autozygosity mapping and whole exome sequencing, we identified WDR73 as a Galloway-Mowat causing gene in two unrelated families. WDR73 encodes a WD40-repeat containing protein of unknown function. Here, we show that the WDR73 protein is expressed in the brain and in the kidney, and is located diffusely in the cytoplasm during interphase but relocalizes to spindle poles and astral microtubules during mitosis. Mutant fibroblasts from patients and WDR73-depleted podocytes displayed abnormal nuclear morphology, low cell viability and alterations of the microtubule network. These data suggest that WDR73 plays a crucial role in the maintenance of cell architecture and cell survival. Altogether, WDR73 mutations cause Galloway-Mowat syndrome in a particular subset of patients presenting with late-onset nephrotic syndrome, post-natal microcephaly, severe intellectual disability and homogenous brain MRI features. WDR73 is another example of a gene involved in a disease affecting both the kidney glomerulus and the central nervous system. 19 MME. BON Nina – 2ème année – INSERM UMRS791 Session 4 Insight into the extracellular phosphate sensing mechanism, the key step for an appropriate FGF23 secretion BON Nina (2nd year PhD student)1, 2, BOURGINE Annabelle1, 2, COUASNAY Greig1, 2 , WEISS Pierre1, 2, GUICHEUX Jérôme1, 2, BECK-CORMIER Sarah1, 2, BECK Laurent1, 2 1 2 INSERM UMRS791, Laboratoire d’Ingénierie Ostéo-Articulaire et Dentaire, Nantes Université de Nantes, UFR Odontologie, Nantes Phosphate (Pi) is known to be a vital ion involved in structural and metabolic functions. More recently, several studies have suggested that Pi is a signaling molecule. Notably, we have shown in pre-osteoblasts (MC3T3-E1), in chondrocytes (MC615) and in odontoblasts (MO6-G3) that an increase in extracellular Pi concentration leads to the ERK1/2 MAPK pathway activation. This pathway notably allows the upregulation of genes involved in bone mineralization. However, the mechanism underlying the sensing of extracellular Pi variations is still unclear. Recently, we have shown in vitro in MC3T3E1 or MC615 cells that both PiT1 and PiT2 proteins are likely to be involved in this process. PiT proteins are multifunctional proteins originally described as retroviral receptors and sodium-Pi cotransporters. Additional experiments have shown that PiT2 could oligomerize in response to extracellular Pi variations. Considering the strong similarity between PiT1 and PiT2 we hypothesize that a PiT1-PiT2 interaction could underlie the mechanism whereby the ERK1/2 pathway is activated. To investigate this interaction, we are using a Bioluminescence Resonance Energy Transfer (BRET) approach. To this end, we have fused the coding sequence of YFP or Renilla luciferase on PiT proteins using the Fast Cloning method. To assess the interaction of PiT proteins, we are also using co-immunoprecipitation upon Pi stimulation with a BS3-based crosslinking approach. In vivo, an increase in serum Pi concentration was shown to stimulate the secretion of Fibroblast Growth Factor 23 (FGF23). FGF23 is produced and secreted by the osteocytes and is the main hormone controlling the Pi homeostasis. Therefore to study the physiological relevance of the involvement of PiT proteins in Pi sensing, we have developed new mouse models carrying specific PiT1 and/or PiT2 deletions in osteocytes. To this aim, we have generated PiT1lox/lox, PiT2lox/lox and PiT1lox/lox;PiT2lox/lox mice using homologous recombination, and crossed them with Dentin Matrix Protein 1 (DMP1)-Cre transgenic mice. When the Pi food supply is normal, the gross phenotype of these mice is not affected. However, feeding mice with low- or high-Pi diets resulted in aberrant regulation of FGF23 secretion in mutant mice. This study will unravel the molecular mechanisms whereby Pi informs the cell of its own extracellular variation which will lead to an appropriate FGF23 secretion resulting in a normal regulation of Pi homeostasis. M. CLAIREMBAULT Thomas - 3ème année – UMR 913 Session 4 Title: Structural alterations of the intestinal epithelial barrier in Parkinson’s disease Abstract Functional and morphological alterations of the intestinal epithelial barrier (IEB) have been 20 consistently reported in digestive disorders such as irritable bowel syndrome and inflammatory bowel disease. There is mounting evidence that Parkinson’s disease (PD) is not only a brain disease but also a digestive disorder. Gastrointestinal involvement is a frequent and early event in the course of PD, and it may be critically involved in the early development of the disease. We therefore undertook the present survey to investigate whether changes in the IEB function and/or morphology occur in PD. Colonic biopsies were performed in 31 PD patients and 11 age-matched healthy controls. The para- and transcellular permeability were evaluated by measuring sulfonic acid andhorseradish peroxidase fluxrespectively, in colonic biopsies mounted in Ussing chambers. The expression and localization of the two tight junctions proteins ZO-1 and occluding were analyzed by Western blot and immunofluorescence, respectively. The para- and transcellular permeability were not different between PD patients and controls. The expression of occludin, but not ZO-1, was significantly lower in colonic samples from PD patients as compared to controls and the cellular distribution of both proteins was altered in colonic mucosal specimens from PD patients. Our findings provide evidence that the IEB is morphologically altered in PD and further reinforce possible the role of the gastrointestinal tract in the initiation and/or the progression of the disease. MME. ANDRE Emilie – 3ème année – Inserm U1066 Session 5 Neuronal commitment of mesenchymal stem cells with nanoparticles transporting siRNA André E. 1,2 ; Seijo B 3,4 ;Sindji L 1,2; Resnier P. 1,2 ; Pensado A.3,4 ; Schiller PC. 5 ; Passirani C. 1,2 ; Sanchez A. 3,4 and Montero-Menei CN.1,2 * 1 PRES LUNAM – University of Angers, F-49933 Angers, France 2 INSERM U1066 – Micro et Nanomédecines Biomimétiques, 4 rue larrey, F-49933 Angers, France 3 Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, University of Santiago de Compostela, Campus Vida, 15782 Santiago de Compostela, Spain. 4 Molecular Image Group, University of Santiago de Compostela Clinical Hospital, Travesía da Choupana, 15706 Santiago de Compostela, Spain. 5 Department of Orthopaedics, University of Miami Miller School of Medicine, FL, USA emilie.andre01@gmail.com Abstract Introduction : Hungtington’s disease (HD) is an autosomal dominant genetic disease, associated with the progressive loss of the GABAergic neurons in the striatum. Cellular transplantation is the only therapeutic demonstrated a benefit to restore lost cells. Clinical studies with foetal GABAergic precursors have shown promising results, but problems with availability and ethical issues limit their use. Mesenchymal stem cells (MSC) are an interesting source of cells for brain regenerative medicine and more particularly the “Marrow-Isolated Adult Multilineage Inducible” (MIAMI) cells a homogeneous subpopulation, which express several pluripotency markers (Oct4, Sox2, Nanog), may differentiate toward a neuronal phenotype and secrete tissue repair factors (1)(2). In order to enhance their neuronal differentiation, we chose to use small interfering RNA (siRNA) against the neuronal inhibitory factor REST to commit them toward a neural/neuronal phenotype(3). Non-viral nanoparticle-based vectors, which have an efficient transfection level, associated to low toxicity, have been developed for this neuronal programming purpose. Materials and methods: Two different novel systems have been formulated for 21 neuronal programming: lipid nanocapsules (LNC) and nanoparticles based on sorbitan esters (Span). Adapting the method by Heurtault et al (4), we optimized basic lipid nanocapsules (LNC) associating siRNA (size: 95nm and ζ potential : +10mV). On the other hand, we developed nanoparticles based on sorbitan esters (Span) (5) and pullulan associating siRNA (size: 200 nm, ζ potential: - 43 mV). Results: Both systems provide an efficient siRNA association (around 50%) determined by UV spectrophotometer, showing appropriate stability during storage (1 month) and a good efficiency of transfection performed by RT-qPCR and microscopy confocal. An important down-regulation was achieved using the siRNA-LNC even at lower concentrations to those described for a transfection reagent such as Oligofectamine in the the manufacturer’s recommendations (Oligofectamine was used with 250ng and we observed 85% of downregulation with 50ng of siRNA-LNCs)Gene expression analysis revealed that mainly MIAMI cells are able to differentiate into neuron-like cells, expressing β3-tubulin and tyrosine hydroxylase, 48h after transfection. Additionally, Span based nanosystems showed a more favourable cytotoxicity profile when compared to the other nanosytem. Conclusion: These results show the potential interest of this approach for tissue engineering strategies and we will graft neuronal committed cells in the ex vivo models developed in our laboratory. 1. Tatard VM,et al. Bone. 2007 Feb;40(2):360–73. 2. Roche S, et al. Int J Pharm. 2013 Jan;440(1):72–82. 3. Yang Y,et al. Exp Cell Res. 2008 Jul;314(11-12):2257–65. 4. Heurtault B, et al. Pharm Res. 2002;19:875–80. 5. Sánchez, A.; Seijo, B.; Zorzi, G.K.; Calvalho, E.S.; Pensado, A. Sistemas nanoparticulares elaborados a base de ésteres de sorbitán. P201131812 WO : 2013068625 A1 PCT: ES2012/070774 M. Kizito-Tshitoko TSHILENGE - 2ème année - UMR 1089 Session 5 Gene transfer in retinal ganglion cell Recombinant adeno-associated viral (rAAV) are powerful and promising vectors to treat IRD patients because its tropism and transduction pattern are well characterized in retina. Two modes of vector injection are well characterized as function of retinal layer targeted: (i) Subretinal injection to transduce cells localized in outer retinal layers such as photoreceptors and RPE cells and (ii) Intravitreal injection to transduce cells localized in inner retinal layers such as retinal ganglion cells (RGCs), amacrine and Müller cells. Nevertheless, rAAVmediated gene transfer in RGCs following intravitreal injection in dog eyes is poorly characterized. This present study was designed in the effort to optimize and characterize rAAV2/2 transduction in RGCs of dog. Here, we describe for the first time that rAAV2/2 is able to mediate a strong and efficient transduction of RGCs in dog retina. MME. HENRY Nina – 2ème année – U791 Session 5 Nano-reinforced hydrogel and protein release in the context of regenerative medicine of the intervertebral disc Nina Henry1,2,3, Johann Clouet1,3,5,6, Catherine Le Visage1,3, Jean Le Bideau2, Jérôme Guicheux1,3,4 1 INSERM, UMRS 791, LIOAD, Equipe STEP, Nantes, France ; 2 CNRS, UMR 6502, IMN, Equipe PMN, Nantes, France ; 3 Université de Nantes, UFR Odontologie, Nantes, 22 France ; 4 CHU Nantes, PHU 4 OTONN, Nantes, France ; 5 CHU Nantes, PHU 7 BiologiePharmacie, Pharmacie Centrale, Nantes, France ; 6 Université de Nantes, UFR Sciences Biologiques et Pharmaceutiques, Nantes, France. Intervertebral disc (IVD) degeneration is one of the major causes of low back pain (LBP)1. Currently, LBP is mainly managed by pharmacological treatments and, if unsuccessful, by surgical procedures. During IVD degeneration the Nucleus pulposus (NP, inner part of the IVD) is particularly impacted by dehydration and cell loss. In this context, regenerative medicine and particularly tissue engineering disc repair strategies clinically address early disc degeneration and could offer less invasive and etiological alternatives to spinal reconstructive surgery2,3. Our laboratory developed an injectable, self-crosslinking silanized hydroxypropylmethylcellulose (Si-HPMC) based hydrogel in order to restore the hydration of the NP and provide a 3D micro-environment beneficial for cell proliferation4. The hydrogel was further reinforced by mesoporous silica nanofibers (MSNF)5 synthesized by the co-condensation of silica precursors6. To optimize stem cell differentiation and enhance synthesis of an appropriate in situ extracellular matrix, a bioactive hydrogel was designed via growth factor addition to the MSNF. Lysozyme was chosen for preliminary MSNF adsorption/desorption assays. It was added to a MSNF suspension in various pH conditions (4, 7 and 10), concentrations (1, 10 and 25 mg/ml) and stirring time (1h to 48h). Release tests were performed in PBS, pH 7.2 at 37°C during 20 days. Lysozyme concentrations were determined by a colorimetric method and its activity detected enzymatically. In this study, we demonstrated that lysozyme can be adsorbed on MSNF. The highest lysozyme adsorption was obtained at pH 10, concentration of 25 mg/ml and after 48h of stirring, corresponding to a 50% adsorption efficiency. Interestingly, adsorption efficiency reached 95-100% for lower concentrations (1 mg/ml to 10 mg/ml). This information will be of particular importance when using expensive molecules i.e. growth factors. Following incubation experiments under physiological conditions, a burst release was observed after 1h. In subsequent time points, desorption rate was stabilized at 25%. At all time points, the released lysozyme was enzymatically active. These preliminary experiments demonstrated the adsorption/release capacity of the MSNF. The next step of this project will consist in the use of Growth Differentiation Factor-5 whose pivotal role in the differentiation of stem cells into IVD cells has been demonstrated7. Its physicochemical properties, close to those of lysozyme, allow us to hypothesize a similar behavior in terms of adsorption/release. M.HUET Simon - 3ème année – Affilogic SAS UMR CNRS 6286 Session 5 Rational design of Nanofitins targeting a defined epitope Nanofitins belongs to the family of affinity protein scaffold, and constitutes as such an alternative to antibodies. They offer the advantages of being small, single chain, extremely stable to both temperature and pH, as well as being highly expressed in simple expression systems like E. coli. Their generation using in vitro selection system allows to obtain hits from large numbers of variants, which need then to be screened out for the desired properties. This screening effort can be further densified when the targeting of a very defined epitope is required. Assisted-generation of Nanofitins through the computated design of interaction surfaces would be useful to complement this approach and maximize the screening outputs since it would allow to target specific regions of the protein of interest, generally leading to predictable effect of the designed binder. 23 We describe a computational method for the rational design of Nanofitins binding a targeted surface patch of interest on a macromolecule. Prediction algorithms enforced by published datas are used to identify favorable regions of the target surface for protein-protein interaction. Complexes generated in this way are used as a starting point from which the Nanofitin interaction surface is subjected to de novo protein design, and sequences providing the highest complex stability are sorted out. The method was successfully used to perform the entire in silico design of Nanofitins binding a selected surface patch of the Green Fluorescent Protein, as confirmed by in vitro assay. This work provides a promising method to generate designed binding proteins that, if combining high affinity for their target and strong specificity of the interaction region, would narrow down the screening effort to generate therapeutically relevant Nanofitins. 24 MME. Vandamme Céline – 2ème année – Inserm UMR 1089 Session 5 Detection and Characterisation of Human anti-AAV CD8+ T Cells using MHC class I Multimer-based Magnetic Enrichment Vandamme Céline, Hesnard Leslie, Guilbaud Mickaël, Devaux Marie, Jaulin Nicolas, Le Duff Johanne, Bonneville Marc, Moullier Philippe, Saulquin Xavier and Adjali Oumeya. Recombinant Adeno-Associated Virus vectors (rAAV) represent the most largely used platform for in vivo gene therapy. Despite promising results in large animal models and clinical trials, pre-existing antibody and memory CD8+ T cell responses directed against the capsid of rAAV remain one of the major hurdles to the safety and efficiency of in vivo rAAV-mediated gene transfer. Particularly, the impact of pre-existing capsid-specific CD8+ T lymphocytes on gene transfer remains elusive, all the more so since their detection and subsequent evaluation have proven to be a challenge with currently available tools (such as ELISpot or intracellular cytokine staining assays) because of their scarcity. Combining major histocompatibility complex class I (MHC I) multimer staining with magnetic enrichment, we were able to detect AAV2 and AAV8 capsid-specific CD8+ T cells ex vivo, among peripheral blood mononuclear cells from healthy donors (at frequencies ranging from 1e-5 to 7e-4 among CD8+ T cells). Using flow cytometry, we could further sort AAV8 capsid-specific CD8+ T cells and generate their corresponding clones. Undergoing characterisation and functional studies of the clones generated suggest a variety of activation profiles in terms of degranulation activity, IFN-γ and TNF-α expression. Evaluation of AAV8specific T cell clones’ killing activity on rAAV8-transduced target cells is currently under investigation, as is a most comprehensive study of their cytokine secretion profiles. Elucidating the different activation patterns of AAV capsid-specific CD8+ T lymphocytes will be important for the understanding of the onset of pre-existing anti-AAV immunity on rAAV-based gene transfer and its impact on clinical outcome. MME. MALHAIRE Hélène - 3ème année – UMR 1066 ORAL FORMULATION OF PROTEINS: DEVELOPMENT CHARACTERIZATION OF AQUEOUS CORE NANOCAPSULES AND Hélène Malhaire a,b*, Jean-Pierre Benoîta,b and Frédéric Lagarcea,b,c a LUNAM – Université d’Angers, F-49933 Angers, France b INSERM U1066 – Micro et Nanomédecines Biomimétiques, 4 rue Larrey, Angers, France c Centre Hospitalier Universitaire Angers, Pôle Pharmaceutique, Angers Cedex, France * 3rd year PhD student The oral route is easy, convenient and comfortable for patient. Unfortunately, since the main role of the gastrointestinal tract is the digestion of nutrients, it is also the worst way for a protein to achieve the blood pool. The challenge is thus to protect the therapeutic protein against this harsh environment and to carry it until the blood pool to enable the cure of common chronic disease. Aqueous core nanocapsules were prepared according to a phase inversion method and therapeutic protein was introduced right before a quench with isopentane (1, 2). Size, PDI and zeta potential (ZP) were assessed up to 21 days after preparation. Encapsulation efficiency and isopentane residue were determined by high performance liquid chromatography and gas chromatography, respectively. Stability in fasted and fed state simulated intestinal fluids was also performed (3). Structure, shape and size were confirmed by imaging in SEM, cryo-TEM and AFM. These monodispersed 200 nm nanocapsules exhibit a negative zeta potential and good encapsulation efficiency (EE=90%) with a protein pay-load of 1.8 µg/mL. Isopentane residue is 25 below 10 ppm, which is much less than the minimum toxic threshold of a class 2 solvent according to the international conference of harmonization. Good shelf-life stability is highlighted by the consistency of size, PDI and ZP up to 21 days. Moreover, no change of these parameters over the 6 hours study in simulated fluids lets expect good stability in small intestine, whether at fasted or fed state. Images are pending. Nanocapsules are thus able to efficiently encapsulate a therapeutic protein. Their stability in storage and in simulated media lets expect a promising future. Toxicity assays and mechanistic studies to estimate oral absorption will be shortly performed before an evaluation of the therapeutic efficiency in rat. 1. 2. 3. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 281035. References: N. Anton, J.-P. Benoit, P. Saulnier, J. Drug Deliv. Sci. Technol. 18, 95–99 (2008). N. Anton et al., Langmuir. 25, 11413–11419 (2009). E. Jantratid et al., Eur. J. Pharm. Sci. 37, 434–441 (2009). 26 POSTERS 27 1- Marie-Astrid BOUTET - 2ème année - Inserm UMR 957 Expression of IL-36, and in inflammatory diseases: example of rheumatoid arthritis M-A. Boutet*, M. Gahier, C. Darrieutort, C. Charrier, R. Brion, M. Berreur, J. Chesneau, D. Heymann, B. Le Goff, F. Blanchard The IL-1 family comprises 11 proteins including three recently discovered cytokines encoded by three different genes: IL-36, and . These molecules bind the same receptor IL-36R (or IL-1Rrp2 or IL-1RL2) inducing the dimerisation with the co-receptor IL-1RAcP and signaling via NFB and MAPK pathways. IL-36, and are over-expressed in psoriatic lesional skin and in mouse models of psoriasis and could be induced by inflammatory cytokines (TNF, IL-17, IL-22) in keratinocytes. In rheumatoid arthritis (RA), it has been shown that IL-36 is produced by plasmocytes and that IL-36 is over-expressed in serum of RA patients but no comparative and complete study exists about expression of IL-36, and in RA. Here, using three mouse models of arthritis, synovial fluid and synovial membranes from RA patients and primary culture of fibroblast like synovioctes (FLS) and CD14+ monocytes differenciated into M0 (control), M1 (inflammatory macrophages), M2c (anti inflammatory macrophages), dendritic cells (antigen presenting cells) and osteoclasts (bone resorbing cells), we shown that IL-36, and are over-expressed in rheumatoid arthritis and that inflammatory macrophages (M1) seem to be the major source of these cytokines. 2- IDRISS Salam - 2ème année - Institut du Thorax INSERM UMR 1087 / CNRS UMR 6291 Urine Sample-derived Human Induced Pluripotent Stem Cells As A Model To Study PCSK9-mediated Autosomal Dominant Hypercholesterolemia. Karim Si-Tayeb, Salam Idriss, Benoite Champon, Amandine Caillaud, Matthieu Pichelin, Lucie Arnaud, Kazem Zibara, Bertrand Cariou, l'institut du thorax, Nantes, France Introduction. Human induced pluripotent stem cells (hiPSC) are becoming a relevant model for the study of liver metabolic diseases once differentiated into hepatocyte-like cells (HLC), and it has been shown that they can faithfully recapitulate autosomal dominant hypercholesterolemia (ADH). PCSK9 is a critical modulator of cholesterol homeostasis, and quickly became a hot target for ADH pharmacological treatment strategies. However, current cellular models to further decipher the role of PCSK9 in ADH are limited, especially to study the PCSK9 gain of function mutation S127R, which seems to interfere with LDL cholesterol homeostasis intracellularly by still unknown mechanisms. Hypothesis. Human iPS cells will provide an appropriate tool to model PCSK9-mediated ADH and screen molecules with pharmacological properties. Methods. We used urine samples as a source of somatic cells in order to obtain hiPSC upon episomal vectors-mediated reprogramming (UhiPSC). After characterization and validation, UhiPS control or carrying the S127R mutation were differentiated into HLC. Results. Compared to control cells, HLC-S127R secreted less PCSK9 in the media (-38.5 ± 47.2%; p=0.08), and had a 3.5 fold (±0.17; p<0.05) decrease of dil-LDL uptake. Pravastatin treatments (10µM for 24h) significantly enhanced LDL receptor (LDLR) and PCSK9 gene expression and PCSK9 secretion in both control and S127R HLC. Finally, pravastatin treatments induced a 3.2 fold (±0.84; p<0.05) increase of dil-LDL uptake in HLC-S127R compared to only a 1.3 fold (±0.09; p<0.05) increase in control HLC. This in vitro induction of HLC-S127R LDLR activity correlated with the good response of patients to statin treatment. 28 Conclusions. Our study demonstrates that not only patient’s urine samples provide an attractive source of somatic cells for reprogramming and hepatocyte differentiation but also a powerful tool to further study PCSK9 functions and test new therapeutic approaches. 3- DALLET LAURENCE – 2ème année – Institut du thorax Cell delivery mechanism of protein/lipid complexes studied by correlative microscopy Laurence Dallet1,2, Pauline Peuziat1, Marion Decossas2, Bruno Pitard1, Olivier Lambert2 1 Institut du Thorax, UMR 1087 INSERM, 8 Quai Moncousu, 44000 NANTES 2 CBMN, UMR 5248 CNRS, Allée Geoffroy Saint Hilaire, 33600 PESSAC The development of effective carriers is an emerging field for delivering therapeutic molecules (DNA, RNA, protein). Since large proteins do not spontaneously cross the plasma membrane, development of nanocarriers enabling their transport into the cytoplasm is required. To date, many studies have investigated the use of cationic lipids for gene delivery or DNA vaccination more recently, those cationic lipids may also be efficient for cellular uptake of proteins [1] [2]. Thus, taking advantage of the capability of cationic lipids, original therapy involving antibody represents a new approach to treat some diseases such as cystic Regulator) causing its retention in endoplasmic reticulum (ER) seem responsible for CF. Recently, it has been shown that keratin 8 (K8), component of intermediate filaments, was involved in this retention by interacting with the domain of mutated CFTR [3]. The intracellular delivery of antibodies against K8 may prevent the interaction between mutated CFTR and K8 and then changes the intracellular trafficking of CFTR. In this context, this study aims at understanding the cellular trafficking of complexes (cationic lipid/protein) and the mechanisms governing the internalization process. To ensure that the cells analyzed by electron microscopy to contain fluorescent anti-K8 antibody, correlative microscopy approach (CLEM: Correlative Light and Electron Microscopy) has been performed. This technique is based on the analysis by fluorescence microscopy and electron microscopy of the same cell, grown on adequate support (MaTtek support). Among a variety of tested cationic lipid, the formulation DOSP/MM27 has been identify as the most effective lipid formulation for intracellular delivery of K8 antibody. EM characterization showed a unique organization forming clusters of onion-like structures exposing antibodies at their surfaces. Using CLEM, the intracellular delivery of K8 antibody complexed with multilamellar structures has been observed in living cells. These first results are in the early stages of proof of concept CLEM studies and are promising for the future. To further decipher the mechanisms of action of K8 antibody, its attachment to intermediate filaments will be studied using a confocal microscopy combined with immunogold labeling. Next, the methodology will be transposed on HeLa cells expressing CFTR WT and mutated CFTR to analyze the localization of CFTR. [1] D. McIlroy, B. Barteau, J. Cany, P. Richard, C. Gourden, S. Conchon, and B. Pitard, “DNA/Amphiphilic Block Copolymer Nanospheres Promote Low-dose DNA Vaccination,” Mol. Ther., vol. 17, no. 8, pp. 1473–1481, Aug. 2009. [2] O. Le Bihan, R. Chèvre, S. Mornet, B. Garnier, B. Pitard, and O. Lambert, “Probing the in vitro mechanism of action of cationic lipid/DNA lipoplexes at a nanometric scale,” Nucleic Acids Res., vol. 39, no. 4, pp. 1595–1609, Mar. 2011. [3] J. Colas, G. Faure, E. Saussereau, S. Trudel, W. M. Rabeh, S. Bitam, I. C. Guerrera, J. Fritsch, I. Sermet-Gaudelus, N. Davezac, F. Brouillard, G. L. Lukacs, H. Herrmann, M. Ollero, and A. Edelman, “Disruption of cytokeratin-8 interaction with F508del-CFTR corrects its functional defect,” Hum. Mol. Genet., vol. 21, no. 3, pp. 623–634, Feb. 2012. 29 4- JACQUES Camille – 2ème année – UMR 957 BET Bromodomain implication in Ewing Sarcoma carcinogenesis Camille JACQUES*, François LAMOUREUX, Marc BAUD’HUIN, Franck TIRODE, Dominique HEYMANN, Françoise REDINI, Benjamin ORY LPRO UMR 957, Faculté de Médecine, 1 rue Gaston Veil, 44035 Nantes cedex 1 With an annual incidence of 2 cases per million, Ewing sarcoma is the second most common primitive malignant bone tumor after osteosarcoma. This aggressive cancer mainly affects adolescents and young adults and is characterized by an ectopic tumor bone formation associated or not with osteolysis, at the diaphysis of the long bones and at the pelvis principally. Ewing sarcomas are often characterized by a chromosomal translocation leading to the production of a chimerical transcription factor, EWS-Fli1, which is implicated in the progression of this malignancy. Current treatments noticeably improve the outcome of this pathology, but unfortunately, therapeutic resistances and pulmonary metastasis remain and reduce the survival rates. Despite of the protocols’ optimization efforts, and regarding the fact that some patients still relapse after treatment, it is important to develop new therapeutic approaches. This study is based on collaboration with the American laboratory of the Dr. James BRADNER, which synthesized a new molecule, called JQ1, and which could be a new original weapon against this cancer. JQ1 is indeed a potent inhibitor of the epigenetic regulators family of BET proteins. This protein family interacts with acetylated histones through its bromodomains, and is able to regulate the chromatin accessibility to transcription factors and RNA polymerases. This project aims to elucidate what is the exact role of the BET proteins in the Ewing sarcoma carcinogenesis, and notably their implication in the proper regulation of this pathology-related oncogene, EWS-Fli1. The inhibition of such proteins in the Ewing sarcoma context could allow in the future considering the use of the epigenetic-regulators molecules like JQ1 as powerful chemotherapy drug. 5- MME. KERVOELEN Charlotte – 3ème année – Inserm U892 Equipe 10 The pro-apoptotic effect of Dexamethasone mediated by GILZ and Bim up-regulation is related to genetic heterogeneity of multiple myeloma Kervoëlen C 1,2, Ménoret E 1, Gomez-Bougie P 2,3, Bataille R 2, Moreau P 3, PellatDeceunynck C 2,3 and Amiot M 2, 3. 1. Myelomax, IRS-UN, Nantes, F-44000, France 2. Inserm, U892, Université de Nantes, CNRS, UMR 6299, Nantes, F-44000, France. 3. Service d’Hématologie Clinique, CHU de Nantes, Nantes, France Multiple myeloma (MM) is heterogeneous with respect to its causative molecular abnormalities and the treatment response of patients. Briefly, MM that are hyperdiploid or have a t(11;14) translocation have a better prognosis than those with t(4;14) or t(14;16) translocations. Dexamethasone (Dex) is widely used in all phases of MM treatment as induction, consolidation or maintenance. However, the mechanism of Dex sensitivity still remains elusive. In the present study, we analyzed the ability of Dex to induce cell death by Apo-2.7 staining in 33 human myeloma cell lines (HMCLs) representative of the molecular subsets carrying t(11;14), t(4;14) or t(14;16) translocations, which deregulate CCND1, MMSET and c-MAF, 30 respectively. The mechanisms controlling Dex-induced apoptosis were evaluated by analyzing glucocorticoid receptor (GR), glucocorticoid-induced leucin zipper (GILZ) and Bcl-2 protein family expression in the different MM molecular subtypes. Transient knock-down of glucocorticoid-responsive proteins were performed to define their role in the pro-apoptotic effect of Dex. We first demonstrated that direct pro-apoptotic effect of Dex was related to the genetic heterogeneity of MM, since sensitive cell lines were restricted to t(14;16) and t(4;14) subgroups. We next demonstrated by transcriptomic Affymetrix analysis that GR expression was heterogeneous among the different molecular subtypes of HMCLs. MAF subgroup significantly expressed higher levels of GR than all other subgroups (p=0.02). This result was also confirmed on 300 newly diagnosed MM patients (p<.0001). We also demonstrated that Dex sensitivity was associated with its ability to down-regulate MAF protein level and its well-known target CCND2. This result was in agreement with the fact that elevated levels of MAF were associated not only with t(14;16) translocation but also with MMSET overexpression, which is a characteristic of t(4;14) subgroup. We next demonstrated that Dex induced an up-regulation of GILZ, a glucocorticoid-responsive molecule, in dex-sensitive and insensitive HMCLs. Nevertheless, resistant HMCLs, which expressed low levels of GR, failed to up-regulate GILZ to the same extent than sensitive HMCLs, suggesting that GR levels could be an important limiting factor for GILZ up-regulation. Of note, GILZ silencing induced a strong reduction of Dex-induced cell death. These results suggest that transactivation has a pivotal role in the induction of cell death by Dex in myeloma cells. Dex also induced an up-regulation of Bim isoforms and a down-regulation of Bcl-xL in all sensitive cell lines. We further demonstrated that Bim up-regulation is required for the apoptotic program in response to Dex. Finally, the silencing of GILZ impaired the upregulation of Bim and the down-regulation of Bcl-xL under Dex treatment. In conclusion, Dex exerted a direct anti-tumor effect on HMCLs of t(14;16) and t(4;14) molecular subgroups while t(11;14) subgroup was insensitive to it. This result suggested that conventional therapeutic approaches should be re-evaluated within molecular subgroups of MM patients to favor potential molecular subtype therapy based on rational preclinical data. Finally, while Dex interferes with multiple pathways, we begin to unravel its complex mechanism of action demonstrating that transactivation, inducing GILZ up-regulation, plays a pivotal role in Dex induced cell death through the regulation of the Bcl-2 protein network. 6- MME. KERMARREC Laetitia – 2ème année - INSERM, UMR 913; CHU de Nantes, IMAD Regulation of T cell proliferation by enteric glial cells Laëtitia Kermarrec, Tony Durand, Michel Neunlist, Isabelle Neveu, Philippe Naveilhan The enteric nervous system (ENS), also called the second brain, controls various intestinal functions such as motility, secretion and absorption. Composed of neurons and enteric glial cells (EGC), the ENS may have a critical role in inflammatory bowel diseases. To study the impact of EGC on immune cells, increasing number of EGC isolated from the myenteric plexus of the rat digestive tract was added to spleen-derived rat T lymphocytes stimulated by anti-CD3 and anti-CD28 antibodies. Analyses by flow cytometry show that EGC inhibit the proliferation of activated T cells, as do astrocytes, their central counterpart. Pretreatment of 31 rEGC with pro-inflammatory stimuli does not modify their immunomodulatory effects. Preliminary experiments with human EGC indicate a similar impact on activated human peripheral blood mononuclear cells. The molecules implicated in this regulatory mechanism are currently under investigation. 7- MME. RETTMAN Pauline – 3ème année – EA 4271 Immunovirologie et Polymorphisme Génétique Use of Killer cell Immunoglobulin-like Receptor (KIR) genes as markers of haematopoietic chimerism in double-unit cord blood transplantation Pauline Rettman1, Nolwenn Legrand1, Catherine Willem1, Laurence Lodé2, Patrice Chevallier1,3, Anne Cesbron4, 5 , David Senitzer6, Christelle Retière1 and Katia Gagne1,4,5 1 Etablissement Français du Sang, Université de Nantes, Immunovirologie et Polymorphisme Génétique, EA4271, Nantes, France; 2Laboratoire d’Hématologie Biologique, CHU Hotel Dieu, Nantes, France; 3Service d’Hématologie Clinique, CHU Hotel Dieu, Nantes, France; 4 Laboratoire d’Histocompatibilité et d’Immunogénétique, EFS Nantes, France; 5LabEx Transplantex, Université de Strasbourg, France; 6Division of Hematology and Bone Marrow Transplantation, City of Hope, National Medical Center, Duarte, CA, USA. Double umbilical cord blood transplantation (dUCBT) is an efficient alternative for adult patients with haematological malignancies when fully HLA-matched related or unrelated donors are unavailable. Interestingly, when full chimerism is obtained after dUCBT, it is usually derived from only one of the two UCB units infused. Up to now, real-time SNP-based PCR has been considered as the best method to assess and quantify chimerism allowing the monitoring of engraftment and prediction of relapse after dUCBT. We previously reported that cord blood NK KIR+ reconstitute the patient immune system early after dUCBT impacting on engraftment with one full UCB unit dominance and that KIR were expressed as soon as day 14 after dUCBT. In this study, we therefore propose the use of KIR genes as complementary chimerism markers. Fourteen functional KIR genes, located on chromosome 19, were typed using multiplex KIR PCR both in patients and UCB units before dUCBT and in recipients after dUCBT (days+15, +30, +90). Analysis of KIR genotyping post-dUCBT was concordant with KIR+ NK cell phenotype performed at days+15, +30, +60 post-dUCBT and permit to differentiate patients with engraftment with full or mixed chimerism from autologous recovery in 41 consecutive dUCBT. Activating KIR genes were in particular more relevant than inhibitory ones in this assessment. Lastly, comparison of dUCBT engraftment by KIR genotyping post-dUCBT with conventional SNP-based chimerism method showed concordance for the majority of cases. Overall, our data suggest that KIR genes may be considered as complementary markers to assess hematopoietic chimerism status early postdUCBT. 8- MME PRAT Valentine -2ème année – UMR 1087 Transgenic rat model overexpressing endothelial β3-adrenoceptor: a new model for heart failure with preserved ejection fraction. Heart failure with preserved ejection fraction (HFpEF) is a growing health burden affecting the elderly. Patients with HF are classically divided into two groups: those with HF with preserved ejection fraction (HFpEF), and those with HF and reduced ejection fraction (HFrEF). In the last two decades, the proportion of patients with HFpEF over HFrEF has increased from 38% to 54% out of cases of HF, a proportion that will continue to rise due to the progressive aging of population and expected increase in the prevalence of hypertension, obesity and diabetes. Altered cardiac relaxation 32 and filling play a crucial roles in HFpEF, and are partially due to an increase in myocardial stiffness. Due to the lack of patient biopsies and accurate animal models, its physiopathology remains unclear and no specific treatment is currently available. In this context, our team developed a transgenic rat model (Tgβ3) overexpressing human β3-adrenoceptor upon ICAM2 promoter, leading to a specific endothelial expression. At 45 weeks of age, Tgβ3 males rats presented an increase in left ventricle end diastolic pressure (LVEDP; WT: 5.57±1.23; Tgβ3: 11.68±1.12; p<0.01) and in dP/dtmax (WT: 6333±370; Tgβ3: 7808±191; p<0.01), characteristic of an increase in LV stiffness and in peripheral resistances. Echographic investigation showed an altered filling pattern with an increase in early-tolate filling (E/A) ratio (WT:1.139±0.017; Tgβ3: 1.319±0.044; p<0.01), with a pEF but without macroscopic cardiac remodeling. These results showed that aged Tgβ3 rats presented a restrictive cardiac filling, representative of the HFpEF phenotype. Further studies, such as fibrosis quantification and calcium cycle study, are needed to determine the underlying mechanisms of the diastolic impairment, as well as molecular targets altered in the disease in order to develop a new therapeutic strategy for HFpEF treatment. 9- MME. CORBILLE Anne-Gaëlle – 2ème année U913 Appraisal of the dopaminergic and noradrenergic innervation of the submucosal plexus in Parkinson's disease. Abstract Background: The principal components of the enteric nervous system (ENS) are two neuronal networks, the myenteric and submucosal plexus (SMP), which are primarily involved in the regulation of gastrointestinal (GI) motility and secretion, respectively. These two plexus are made up of intrinsic neurons receiving input from the extrinsic sympathetic and parasympathetic innervation of the gut. Both the intrinsic and extrinsic innervations of the gut are affected by Lewy pathology in Parkinson's disease (PD). A recent autopsy survey indicated that there was no global or dopaminergic loss in the myenteric plexus in PD but the SMP was not examined. Objective: The aim of the present work was to compare the relative abundance of dopaminergic and noradrenergic neurons in colonic biopsies between PD patients and control individuals. Methods: Colonic biopsies were taken during the course of a colonoscopy in 35 PD patients and 10 control subjects. Density of dopaminergic neurons and expression of the dopaminergic and noradrenergic markers were analyzed by tyrosine hydroxylase (TH) immunofluorescence and Western blot using anti-dopaminetransporter (DAT) and anti-dopamine beta-hydroxylase (DBH), respectively. Results: No significant differences were observed in the density of dopaminergic neurons and in the expression levels of dopaminergic and noradrenergic markers in colonic biopsies from PD patients as compared to controls. Conclusion: Our results indicate that there is no evidence of dopaminergic and noradrenergic neuronal loss in the SMP in PD, thereby suggesting that neuropathology in submucosal neurons is unlikely to be a causative factor for GI dysfunction in PD. Keywords : Parkinson's disease; autonomic nervous system; dopamine; enteric nervous system 10- M. COLOMBANI Thibault – 2ème année – UMR 1087 Lipoaminoglycosides : Immuno-understanding and biological receptor investigation My PhD revolves around the cationic lipids, usually, used as transfection reagent and considered as a safe alternative to viral vectors as nanocarrier for gene therapy or drug intracellular delivery. My results provide evidence that they do not behave as inert material but do activate cellular signaling pathways implicated in innate immune response. I show that 33 the cationic lipids belonging to the family of lipoaminoglycosides induce the production of IFNβ1, IL-6, CXCL10, and DNA-sensors interferon-inducible by mouse myoblast cell lines or mouse embryonic cell lines. Further, I demonstrate that the activation of this pathways is structure-dependent, with a huge implication of the head polar group and we made the hypothesis that the endocytosis is necessary to the stimulation of the pathways. My results suggest that lipoaminoglycosides because of their ability to stimulate the innate immune system can be used as a new class of synthetic and save “adjuvants vectors” for vaccination. 11- M. FLEURENCE Julien – 2ème année – U892 Title: Targeting and killing glioblastoma with monoclonal antibody to O-acetyl-GD2 ganglioside. Denis Cochonneau1,2, Fleurence Julien*, Lisa Oliver1,2, Arulraj Nadaradjane1,2, Mickaël Terme3, Dorvillius Mylène3, Jihane Frikeche1,2,4, Delphine Loussouarn4, François Valette1,2, François Paris1,2, Stéphane Birklé1,2,4 1 INSERM U.892, Centre de Recherche en Cancérologie de Nantes-Angers, Institut de Recherche en Santé de l’Université de Nantes, 8 quai Moncousu, 44007 Nantes, France. 2 CNRS 6299, Centre de Recherche en Cancérologie de Nantes-Angers, Institut de Recherche en Santé de l’Université de Nantes, 8 quai Moncousu, 44007 Nantes, France. 3 ATLAB Pharma, Institut de Recherche en Santé de l’Université de Nantes, 8 quai Moncousu, 44007 Nantes, France. 4 Université de Nantes, UFR des Sciences Pharmaceutiques et Biologiques, 9 rue Bias, 44035 Nantes, France. Abstract Purpose: High-grade gliomas including glioblastoma multiforme are the most common and most devastating brain tumors. The impact of current treatments is unfortunately small, highlighting the need for new and novel therapies. Our objective was to determine whether Oacetylated GD2-specific antibody therapy may be explored for the treatment for High-grade gliomas. Experiment design: To test this hypothesis, we studied O-acetylated GD2 expression on a panel of surgically resected human glioma tissues, glioma cell lines and primary glioma biopsy-derived tumor lines. Results: We found that O-acetylated-GD2 is expressed on surgically resected human glioma tissues, glioma cell lines and glioma primo-cultures. In addition, mAb 8B6-IgG2a specific for Oacetylated-GD2 can inhibit the proliferation of glioma cell lines and and primary glioma cells and can target the glioma tumor to reduce tumor growth in vivo. Conclusion: Our findings suggest that gliomas are suitable for specific targeting by mAbs specific for Oacetylated GD2. In addition, they provided the preclinical support for the use of anti-Oactylated GD2 mAbs as a valuable addition to current therapeutics. 12- MME. LABBE Pauline – 2ème année – U1087 LRRFip1 and Wnt pathway involvement in mitral valve prolapse Pauline Labbé* (1), Florence Kyndt (1), Thierry Le Tourneau (1), Stéphane Zaffran (2), Cécile Duplaà (3), Jean-Jacques Schott (1), Jean Mérot (1) (1) Inserm U1087, Institut du Thorax, Nantes, France – (2) Inserm UMR S910, Marseille, 34 France – (3) Inserm U1034, Pessac, France Heart valves diseases affect 3% of world population, and surgery is often the only therapeutic mean. A genetic study performed on a family in which several members exhibited a mitral valve prolapse (MVP) identified a mutation on LRRFip1 gene. LRRFip1 undergoes extensive alternative transcription splicing giving rise to 5 isoforms in humans and the mutation we identified results in R94G substitution in three (Iso1, 3 and 4) out of the five isoforms. Previous studies essentially focused on LRRFip1-iso5 that was first described as a transcription factor interacting with positive (Dishevelled) and negative (Flightless-1) regulators of the canonical Wnt β-catenin dependant pathway. LRRFip1 thus appeared as an interesting gene in MVP as it may regulate two crucial events of cardiac valve development and homeostasis involving Wnt pathway: epithelial to mesenchymal transition and cell proliferation. Interestingly, we showed by RNA sequencing and RT-PCR that LRRFip1-iso1 is expressed in human valves. Furthermore, LRRFip1-iso1 has poor homology with the other isoforms and nothing is known about its function, we thus focused on it. In HEK 293 cells, fractionation experiments revealed a nuclear localization of LRRFip1-iso1 while other isoforms are strictly cytoplasmic. We then showed by Luciferase-based Wnt reporter assays that out of the five isoforms, LRRFip1-iso1 activates the canonical Wnt pathway at the highest levels. This activation requires beta-catenin, but no increase in active or total betacatenin expression was observed. Furthermore, the R94G mutation decreases Wnt activation. We then identified a disordered region in LRRFip1-iso1 (25 amino-acids around the R94G mutation) responsible for this strong activation and comprising predicted signalling or structural sites which can be perturbed by the mutation. Thus, our studies suggest that LRRFip1-iso1 may activate the canonical Wnt pathway by participating in a beta-catenin dependent transcription complex. R94G mutation may deregulate gene transcription and consequently alter valvulogenesis and/or valve homeostasy. 13- M. NAVET Benjamin – 2ème année – UMR 957 Dlx homeobox genes involvement in osteosarcoma Benjamin NAVET*, Frédéric LEZOT, INSERM UMR 957, University of Nantes, France The osteosarcoma is a bone primitive tumor from osteoblastic origin that mainly affects children and young adult. Dlx homeobox genes are implicated in early development, bone growth and osteoblastogenesis. So an implication of these genes in osteosarcoma physiopathology has been proposed. Recently, an abnormal expression of Dlx4 has been evidenced in different osteosarcoma cell-lines with a potential implication in proliferation, osteolysis and osteo-formation processes. Dlx4 over-expression and inhibition with shRNA has been induced in sub-clones of the MOS-J cell evidencing different expression levels of Dlx4. To date, results do not implicate Dlx4 in the proliferation process of osteosarcoma, both in vivo and in vitro. Concerning the osteolysis process, results validate the previously described positive impact through the stimulation of RANKL secretion into the tumor microenvironment by a cell that may be from the lymphocyte lineage. However, more refined analysis of the system need to be realized, since it appears that the Dlx4 gene would encode for another transcript named BP1. Specific invalidations of each transcripts should enable to understand in depth the part of Dlx4 homeobox gene in osteosarcoma. 35 14- M. DAVID Benoît – 2ème année – UFIP CNRS 6286 Turning glycoside hydrolases into transglycosidases: a theoretical study of the internal water dynamics in the Thermus thermophilus β-glycosidase (2° année) Benoît David *, Johann Hendrickx, Yves-Henri Sanejouand, Charles Tellier UFIP UMR-CNRS 6286, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes, France Mostly known for their ability to hydrolyze glycosidic linkages, numerous glycoside hydrolases are also able to catalyze reverse hydrolysis (transglycosylation) which can be harnessed for the synthesis of complex oligosaccharides. Although hydrolysis usually prevails over the reverse reaction, transglycosylation propensity has already been increased through mutagenesis and directed evolution experiments [1, 2]. However, little is known about the regulation of the balance between both activities. A previous experimental study on the β-glycosidase de Thermus thermophilus (Ttβgly) using deuterium exchange mass spectrometry has shown that amide hydrogens from a buried part of the protein were able to exchange with the solvent's []. The discovery via molecular dynamic (MD) simulation of a potential water channel connecting the bulk to the active site along this peptide has supported a possible role of internal water dynamics on the hydrolytic acivity of Ttβgly [3]. Using an improved simulation protocol, new MD simulations up to 500 ns have been conducted in order to extensively probe the internal water dynamics in Ttβgly. Analysis of the internal water molecules trajectories allowed to characterized a total of six new potential water channels. Distant residues previously known for playing a role in influencing the balance between hydrolysis and transglycosylation were also identified in the vicinity of five water channels. Computation of the water molecule exchange rate at each position explored by a water molecule in the protein has shown that only three water channels showed a significant water exchange at the interface of the active site. Within this context, it is tempting to speculate that those characterized water channels could be involved in supplying water molecules to the active site and potentially regulating the hydrolytic activity of Ttβgly. 1. Feng, H.-Y. Converting a -Glycosidase into a -Transglycosidase by Directed Evolution. Journal of Biological Chemistry 280, 37088–37097 (2005). 2. Teze, D. et al. Semi-rational approach for converting a GH1 -glycosidase into a transglycosidase. Protein Engineering Design and Selection 27, 13–19 (2014). 3. Teze, D. et al. Conserved Water Molecules in Family 1 Glycosidases: A DXMS and Molecular Dynamics Study. Biochemistry 52, 5900–5910 (2013). 15- MME. BESBES ANISSA – 2ème année – EA 3826 Role of NK cells in a Post-haemorrhage immunosuppression mouse model. Impact of glucocorticoid treatment efficacy. Besbes A.1, Broquet A.1, Jacqueline C.1, Vourc’H M.1, Potel G.1, Caillon J.1, Asehnoune K.1,2 1 Laboratoire EA3826. Thérapeutiques cliniques et expérimentales des infections. Faculté de médecine. Université de Nantes. Nantes. France. 2 CHU de Nantes, Pôle Anesthésie Réanimation, Service d’anesthésie réanimation 36 chirurgicale, Hôtel Dieu, 44093 Nantes, France. Abstract Haemorrhage is a trauma leading an immune dysfunction phenotype. This immune failure altered survival rate of patients, as it increases their susceptibility to nosocomial infections. Recent works from the laboratory strongly suggest an alteration of the function of central cell of the innate immune system: NK cells. (1-3). NK cells play a crucial role in controlling infection, and depleted mice show more susceptibility to a secondary Pseudomonas aeruginosa pneumonia. (2) In a murine haemorrhagic shock model routinely used in the laboratory, we observed modifications in the NK cells phenotype and function. Following haemorrhage, NK cells turn to an anti-inflammatory phenotype by secreting IL-10 impairing dendritic cells maturation and functions. A recent clinical study strongly suggested that Hydrocortisone may prevent immunosuppression severity, which increase survival rate of patients treated after haemorrhage trauma. In our mice model, we demonstrated that in concordance with this clinical result, Hydrocortisone restored partially the NK cells functions and decreased significantly the mice susceptibility to a secondary infection (1). The aim of our study is: 1) To characterize the NK cell change of phenotype and to characterize the cell subset responsible for the immunosuppression state. 2) To compare two corticoid treatments frequently used in emergency in preventing nosocomial infection: Hydrocortisone and Solumédrol. This work will be done on a murine model of heamorrhagic shock. This volume controlled haemorrhagic shock is routinely used in our laboratory. Keywords: Haemorrhage, Immunosuppression, NK cells, Hydrocortisone, Solumédrol (1) Hydrocortisone Prevents Immunosuppression by Interleukin-10+ Natural Killer Cells After Trauma-Hemorrhage.Roquilly A, Broquet A, Jacqueline C, Masson D, Segain JP, Braudeau C, Vourc'h M, Caillon J, Altare F, Josien R, Retière C, Villadangos J, Asehnoune K. Crit Care Med. 2014 Oct 6. (2) Depletion of natural killer cells increases mice susceptibility in a Pseudomonas aeruginosa pneumonia model. Broquet A, Roquilly A, Jacqueline C, Potel G, Caillon J, Asehnoune K. Crit Care Med. 2014 Jun;42(6):e441-50. (3) CpG-ODN and MPLA prevent mortality in a murine model of post-hemorrhageStaphyloccocusaureus pneumonia.Roquilly A, Gautreau L, Segain JP, de Coppet P, Sebille V, Jacqueline C, Caillon J, Potel G, Lejus C, Josien R, Asehnoune K. PLoS One. 2010 Oct 16- MME. FIGUEIREDO Lara -2ème année – Lioad UMR 791 Oxygen diffusion in Si-HPMC scaffolds as stem cell niche in vitro models Figueiredo, L ; Réthoré, G ; Le Visage, C and Weiss, P 1 LIOAD, INSERM U791, Nantes University lara.martins-figueiredo@etu.univ-nantes.fr Introduction Despite stem cell niche being characterized by low oxygen content, anoxia at the core of cellularized scaffolds has long been associated with poor in vivo results of stem cell transplantation. Oxygen diffusion is of outmost importance, since it influences cell metabolism and has a great impact on stem-cell fate. Hence, a detailed characterization of oxygen diffusion profiles in hydrogels could provide useful insights for the development of stem cell niche models. 37 Objectives We investigated the oxygen diffusion properties in self-setting Si-HPMC hydrogels reinforced or not with laponites and their related cell viability. Methods Hydrogel preparation One volume of 4 wt % Si-HPMC was mixed with half volume of acidic buffer and half volume of XLG laponite (Rockwood, GmbH) solution or water. Oxygen measurements Core oxygen partial pressure in the 3D constructs was monitored with a needle type oxygen microsensor (PreSens, Germany). For determination of oxygen content kinetics in acellular hydrogels, ten millimeter-high constructs with and without laponite reinforcement, were equilibrated at 0.1% oxygen. De-oxygenation and re-oxygenation of the hydrogel was followed. In a separate experiment, same type constructs, seeded or not with (hASC) were incubated in normoxic conditions (20% O2). Cell viability measurements Staining of live hASCs inside hydrogel constructs was performed at 24, 48, 72 and 144 hours after cell seeding using a Calcein-AM Assay kit. Samples were collected from the center of constructs and imaged using confocal microscopy. Results De-oxygenation profiles of Si-HPMC and Si-HPMC+XLG acellular constructs in an anoxia environment were almost superimposed, showing a slow decrease of their oxygen content. For cellularized constructs in normoxic conditions, there was a fast decrease of the oxygen contents at the center of constructs in the first 12h of the experiment. In addition, hydrogels loaded with laponites reached a significantly lower value of oxygen content. Then, we identified a re-oxygenation profile of both constructs. Cell density at the core of the Si-HPMC construct significantly increased after 48 hours of culture, indicating that cells proliferated during that time. On the contrary, in presence of laponites, the number of live cells per mm3 at the center of the constructs remained stable. At all time points (except 24 hours), there was a significant difference in cell density between hydrogels with and without laponites Discussion Due to its ability to form a physical network, laponites act as oxygen transport barrier. However, in this study, superimposition of de-oxygenation and re-oxygenation profiles suggests that laponites addition to Si-HMPC hydrogel has no obvious effect on oxygen diffusion per se. In addition, the lowest oxygen level after 12h of normoxic incubation and reduced cell viability after 24h suggests interference of laponites with cell metabolism. Conclusion Hydrogel re-inforcement with laponites does not seem to have an impact on oxygen diffusion per se. On the other hand, laponites clearly have an impact on cellular oxygen consumption and viability. 17 - M. KAMBAREV Stanimir – 2ème année –UMR 892 A whole-genome approach to study host-pathogen interactions. Stanimir Kambarev1*, Laurent Marsollier2, Stéphane Corvec 3, 4, Frédéric Pecorari1 1 Recherche en oncologie Nucléaire, Centre de recherche en cancérologie de Nantes-Angers, INSERM UMR 892, CNRS 6299, Université de Nantes 2 Inserm Avenir ATOMycA, Centre de recherche en cancérologie de Nantes-Angers, INSERM UMR 892, CNRS 6299, Université de Nantes 38 3 Service de Bactériologie et Hygiène hospitalière , CHU de Nantes Université de Nantes, EA3826 Thérapeutiques cliniques et expérimentales des infections, UFR de Médecine, Nantes 4 During infection, pathogens utilize a multitude of virulence factors to adhere to the host, to evade its immune responses and to disseminate. The host’s immune system responds to the invasion by development of specific humoral and cellular responses. The understanding of these interactions at molecular level is essential for the development of new prevention, diagnosis and therapeutic strategies. In this context, we study the interactions of two pathogenic bacteria with their host at humoral level. Streptococcus gallolyticus ssp. gallolyticus is known for its close association with the incidence of colorectal cancer (CRC). Despite the extensive research on the topic it is still not certain if the bacterium is only an opportunist, successfully growing in the setting of compromised mucosal barrier or whether it contributes, via specific virulence features, to the development of colonic malignancy. Mycobacterium ulcerans causes the third most common mycobacterial disease worldwide- Buruli ulcer, which is associated with severe skin mutilation. Early diagnosis and treatment are considered to be the only ways to reduce morbidity. However, no field-friendly diagnostic test is available up to now. ANTIGENome is a whole-genome combinatorial approach allowing for serological identification of the pathogen’s immune-relevant proteome, independently of its growth conditions and gene regulation. By development of a fully in vitro ribosome display-based version of the method, we seek to identify protein virulence factors of S. gallolyticus, associated with CRC development or immunodominant biomarkers of M. ulcerans for development of diagnostic tools. 18- MME. KALICHUK Valentina – 2ème année – UMR 892 AFFITIN-FUNCTIONALIZED NANOPARTICLES FOR TARGETED DELIVERY TO COLORECTAL TUMORS Kalichuk, V. (1,2,*); Béhar, G. (1); Mouratou B. (1); Preat, V. (2); Pecorari, F. (1). 1 Université de Nantes, Institut de Recherche en Santé de l'Université de Nantes, INSERM U892 - CNRS 6299 – CRCNA, Nuclear Oncology Research, Nantes, France. 2 Université Catholique de Louvain, Louvain Drug Research Institute, Pharmaceutics and Drug Delivery, Brussels, Belgium. *Contact e-mail: valentina.kalichuk@univ-nantes.fr Colorectal cancer (CRC) is the second most common cancer in women and third in men. Despite the progress of the medicine during the last decades, further progress in CRC treatment is needed. Conventional chemo- and radiotherapies lack selectivity, thus they are toxic for normal tissues as well as for cancerous ones. Therefore, there is a need of targeted and controlled delivery system that may reduce dose and duration of the therapy. Nanoparticles (NPs) have the potential to improve current chemotherapies or radiotherapies by increasing efficacy, lowering toxicity while maintaining a high concentration of therapeutic compounds at the site of interest. Promising approach is the active targeting, in which targeting ligands are attached to the NPs. Although monoclonal antibodies (mAbs) are the most used targeting ligands in cancer therapy, they possess several limitations such as their cost, large size and instability. Affitins are artificial affinity proteins, derived from the archaeal polypeptide Sac7d and its homologs. These non-antibody binders show comparable affinity and specificity to those of antibodies, but are thermally and chemically stable, cheaper to produce and have a size 39 compatible with chemical synthesis (7 kDa) while they have a less complex structure. The goal of the project is to combine the advantages of both Affitins and NPs for active targeting in cancer therapy. Affitins directed against CRC biomarkers will be used for the development of highly stable Affitin-functionalized nanoparticles for targeted delivery to colorectal tumors. 19- M. DION Johann – 2ème année – UFIP /UMR 6286 SYNTHESIS OF DERIVATIVES GALECTIN INHIBITORS BASED ON LACTOSAMINE J. Dion*, S. Dahbi, N. Storozhylova, C. Grandjean Unité Fonctionnalité et Ingénierie des Protéines (UMR6286) University of Nantes, 2 rue de la Houssinière, 44322 Nantes, France. E-mail: johann.dion@univ-nantes.fr Galectins are a family of lectin, very conserved in the mammal species (15 members known), which are able to recognize -galactoside sugar motifs1. These galectins are multifunctional proteins which are involved in a lot of biological processes like cellular cycle, apoptosis, cell trafficking and cell-cell or cell-matrix interaction. Key unit of cell development, inflammatory and immune response, the deregulation of these proteins seems to be associated with more than one hundred pathologies2. Therefore, galectins have been identified as potential therapeutic targets. However, there is still a lot of difficulties to understand mechanisms of action of galectins. We have embarked in a program aimed at preparing specific inhibitors of the galectin-3 to study its role in cell migration and cell division in the skin and, at term, to propose novel therapeutic strategies. We have elected to work on type I (1-3) and type II (1-4) lactosamine, two natural disaccharides recognized by the galectin-3, as scaffolds and to introduce pharmacophores at 40 defined positions to further improve their binding, according to a drug design approach. A first generation of C2 aromatic derivatives, displaying better affinity thanks to -cation3 or interactions4, has been prepared.5 For instance, in the case of type II compounds, the derivative with 3-methoxyphenylamide group increase binding by a factor six (Fig. 1). Kd = 36 M 1-4 = Kd = 6 Figure 1. Example of substitution on type II lactosamine In the case of type II compounds, as shown on Figure 1, we want to target the best linkage (in green) between aromatic ring and sugar. We have first kept the aromatic ring constant to make possible comparison. We selected 3-methoxyphenyl ring (in blue) known to increase affinity. By changing the amide function by another link (urea, sulfonamide, methylamine, ...) we will be able to select the best one by correlation with Kd value. In a second part of our work, we have also synthesized several inhibitors with constant amide link and different aromatic rings in order to see effect of the aryl group on the binding. References: 1. S.H. Barondes, D.N. Cooper, M.A. Gitt, H. Leffler, J. Biol. Chem., 1994, 269, 20807 2. Klyosov, A.A., Chapter 2 in Glycobiology and Drug Design, 2012, 25 3. I. Cumpstey, E. Salomonsson, A. Sundin, H. Leffler, U.J. Nilsson, ChemBioChem, 2007, 8, 1389 4. S. Fort, H.S. Kim, O. Hindsgaul, J. Org. Chem., 2006, 71, 7146 5. S. André, C. Grandjean, F.-M. Gautier, S. Bernardi, F. Sansone, H.-J. Gabius, R. Ungaro, Chem. Commun., 2011, 47, 6126 20- MME. MISME-AUCOUTURIER Barbara -2ème année -EA1155-IICiMed Département de Parasitologie et de Mycologie Médicale, Université de Nantes Granulomes fongiques : caractérisation cellulaire et moléculaire de l’interaction hôtepathogène. Subject During chronic disseminated candidiasis (CDC) and chronic mucocutaneous candidiasis disease (CMCD) the physiopathological response is characterized by the persistence of Candida inside granulomas due to an impaired cell mediated immunity against infection. In this context, host-fungal interactions within the granulomas have not been well described to date. Then EA1155 IICiMed laboratory have recently developed the first human model of in vitro Candida albicans persistence within granuloma allowing describing the kinetic of fungal granuloma formation behind human Peripheral Blood Mononuclear Cells infection (PBMC). This study aimed at comparing the granuloma response for eight Candida species. Method We compared the capability of eight Candida species (C. albicans, C. dubliniensis, C. 41 tropicalis, C. lusitaniae, C. glabrata, C. parapsilosis, C. kefyr and C. krusei, 4 clinical isolates by species) to form granulomas in vitro. The kinetics of granuloma formation was studied during the infection of ten immunocompetent healthy donors through the number and size variations of granuloma structures, and the fungal load evolution. Results The infection of the immune cells from healthy donors induced the formation of a granulomatous response for all Candida species used in the assay. An increase of the average of granuloma number and size was observed between day 4 and 6 post infection. However, the average of granuloma size was different between species. For C. albicans and C. dubliniensis the median was 170 ± 18 μm on day 6 whereas for the other species granuloma size was 63 ± 8 μm. Then, the fungal loads inside the granuloma were compared to the corresponding granuloma sizes exhibiting a strong positive correlation at day 6 post-infection (r = 0,84). Besides, while the fungal multiplication is controlled during the two first days for all species, the fungal load evolution further followed two distinct profiles according to species. The first one was characterized by an increase of the fungal loads from day 2 to day 6, whereas the second showed a progressive clearance of the pathogen by the granulomatous reaction. A multiparametric comparative analysis of these profiles taking into account the levels of fungal load at day 6, allowed to highlight four species clusters. Three clusters were related to the first profile with high (C. albicans: cluster 1) moderate (C. dubliniensis and C. tropicalis: cluster 2) and low (C. lusitaniae, C. glabrata and C. parapsilosis: cluster 3) fungal loads. The cluster 4 (C. krusei and C. kefyr) corresponds to the second clearance profile Conclusion Under our conditions, results indicated that the interaction between Candida and the immune cells from immunocompetent donors, lead to the formation of granuloma structures. Differences were highlighted in term of evolution of granulomatous response depending on the Candida species. The capacity of Candida spp to form hyphae, the production of virulence factors such as the granuloma response variability between healthy individuals are key factors that are under progress investigation 21- M.MOREAU François – 2ème année – UMR 1087 Title: Effect of bariatric surgery on cholesterol metabolism. Authors : François Moreau*, Claire Blanchard, Audrey Ayer, Veronique Ferchaud, Michel Krempf, Bertrand Cariou & Cédric Le May Introduction : Hypercholesterolemia affect 37,4 % of the 65-74 years old and is a major risk factor for cardiovascular diseases. Current guidelines highlight the need for new treatment options able to decrease plasma cholesterol levels beyond those presently achieved. Recently, a new way called the Trans Intestinal Cholesterol Excretion (TICE) emerged as a new druggable metabolic pathway. TICE allows direct plasma cholesterol elimination through the small intestine and represents a potential therapeutic target to reduce cardiovascular events. Obesity is frequently associated with metabolic dysfunction such as diabetes and dyslipidemia. In absence of pharmaceutical treatments, bariatric surgeries represent the more efficient therapy to reduce obesity and its associated metabolic complications such as hypercholesterolemia. However, the molecular mechanisms involved in the hypocholesterolemic effect of bariatric surgeries are poorly characterized. Objectifs : Our goal is to measure the effect of bariatric surgery on cholesterol metabolism. Methods: 10 weeks-old C57BL6J mice received a high fat diet (35% Kcal from fat). After 8 weeks, mice were randomized on 3 experimental groups: 1) in the first group, a laparotomy was performed and then mice received food ad libitum (group Sham); 2) in the second group, mice were also laparatomized but then received the same amount of food consumed by mice in group 3 (group sham 42 pair-fed); 3) a sleeve gastrectomy was performed on the third group (60% of the stomach was removed) and then mice had free access on food (group sleeve). We next tested several weeks after surgery the consequence on intestinal functions and on glucose & lipid homeostasis. We first measured the effect of the sleeve on the body weight and the daily food intake. We next performed an oral glucose test tolerance 2 weeks after surgery. Finally, we measured plasma cholesterol and biliary, fecal and transintestinal cholesterol excretion. The intestinal function was analyzed by assessing intestinal transit and intestinal barrier permeability. Results: Our data showed that body weight from group 3 mice was significantly reduced compared to mice from sham/sham pair-fed group. We did not measure significant effect of sleeve on daily food intake. Two weeks post-surgery, the glucose tolerance was significantly improved in the sleeve group. Plasma cholesterol tends to be reduced in sleeve group compared to cham pair-fed group. However, this hypocholesterolemic effect was modest and transient. Consistently, fecal, biliary and transintestinal cholesterol excretion were comparable between group 1, 2 & 3 five weeks after the surgery. Finally, we did not observe major differences of intestinal transit or barrier permeability after surgery. Interestingly, we notice that the stomach weight in the sleeve group was similar to the mice of group 1 & 2 suggesting that gastric cells from rumen (upper part of the murine stomach) proliferate to restore the organ. Conclusions: Our results confirmed that sleeve surgery have beneficial effects on body weight and glucose homeostasis. By contrast, the hypocholesterolemic effect was modest and transient. Our next steps will be 1) to perform a more restrictive sleeve (by removing the rumen); 2) to test the effect of a second currently used surgery method, the gastric by-pass. Keywords: Baratric surgery, Sleeve, TICE, hypercholesterolemia, Gas chromatography coupled with mass spectrometry. 22- MME. CHARPENTIER Maud – 2ème année – UMR 892 CHARACTERIZATION AND CONTROL OF THE EXPRESSION OF MELOE DERIVED MELANOMA ANTIGENS Charpentier M. 1,2,3, Florenceau L. 1,2, Carbonnelle D. 1,2,3 , Labarrière N. 1,2, Lang F.1,2,3 1 CRCNA INSERM UMR 892 Equipe 3 CNRS UMR 6299 3 University of Nantes 2 Our group has been working for many years on the characterization of melanoma antigens relevant for adoptive T cell therapy. We identified MELOE-1, an antigen implicated in melanoma immunosurveillance translated from the meloe mRNA, the transcription of which is restrained to the melanocytic lineage. This mRNA is polycistronic and also encodes another antigen named MELOE-2. MELOE-1 and -2 specific T lymphocytes have been identified and are activated by melanoma cells but not by normal melanocytes. It suggests a specific translation regulation that occurs only in tumor cells and makes MELOE-1 and -2 interesting targets for immunotherapy. Studying the underlying translation mechanisms we identified two IRES sequences upstream each ORF. First described in prokaryotic organisms IRES mediated translation is also documented for eukaryotic mRNA as an unconventional translation pathway that may be activated during cellular stress and malignant transformation. More recently, the translation of two additional ORFs, MELOE-3 and MELOE-4 close to the 5’ end of the mRNA have been documented. Using bicistronic constructs we proved that MELOE-4 is translated through the canonical cap dependent pathway. As expected, in experiments performed using the EGFP reporter protein fused to our peptides of interest, the expression of MELOE-4 is much higher than that of other proteins of the MELOE family in 43 melanoma cells. Regarding MELOE-3, our results suggest that its translation is due to defective ribosome scanning. Our hypothesis is that MELOE-4 is the physiological product of meloe and should thus also be expressed in normal melanocytes. On the other hand, MELOE-1 and -2 expression would depend on IRES sequences promoted by IRES trans-acting factors specifically expressed or recruited to the translation site in tumor cells. In order to validate this hypothesis we initiated the generation of a MELOE-4 specific monoclonal antibody and already started the characterization of ITAFs implicated in MELOE-1 translation. REFERENCES [1] Carbonnelle D, Vignard V, Sehedic D, Moreau-Aubry A, Florenceau L, et al. (2013) The Melanoma Antigens MELOE-1 and MELOE-2 Are Translated from a Bona Fide Polycistronic mRNA Containing Functional IRES Sequences. PLoS ONE 23- MME. SALOU Laetitia - 3ème année – UMR 957 Histomorphometric analysis of Ti dental implant ossointegration in a rabbit model: Nanostructured surface versus sand-blasted acid-etched surface Laëtitia Salou*,1,2,3, Alain Hoornaert4, Julien Stanovici1, Guy Louarn2, Pierre Layrolle1 1 Inserm U957, Lab. Pathophysiology of bone resorption, University of Nantes, France 2 CNRS –Institut des Matériaux, Nantes, France 3 Biomedical Tissues, Nantes, France 4 Academic Hospital of Nantes, France *Laetitia.salou@univ-nantes.fr Background: Titanium and alloys are widely used for dental implants. Osseointegration is critical for long term implant stability as well as to ensure a tissue barrier for preventing bacterial infiltration and thus clinical success. Conventional treatments of dental implants to improve their osseointegration consist of roughening their surface by grit-blasting and acid etching. However, these treatments only modify the surface at the micrometer-scale while proteins and cells interact in the nanometer-scale. For instance, modification of implant at nanoscale could promote cell adhesion and behaviour by mechanotranduction. Series of in vitro and vivo investigations have shown that nanoporous structure increased osteoblastic differentiation, bone apposition and bone strength of titanium implants [1, 2]. However, there is no study that has yet compared the biocompatibility of this nanostructured surface versus commercialized micro-rough surface usually use for dental implants. Aim: This study aims at comparing the osseointegration of dental implants with smooth and rough surfaces with nanostructure to a conventional grit-blasted and acid-etched surface at 2 different time of healing in femoral condyles of rabbits. Material and methods: Fourty-two dental implants from 6 to 10 mm long and 4 mm of diameter were surface modified following different methods. TiO2 nanostructure were fabricated on TA6V smooth (S-NANO) and grit-blasted (R-NANO) implants using potentiostatic anodization at 20 V in 1 wt. % HF and 1M of acetic acid. The micro-rough surfaces (SBAE) were treated by alumina grit blasting and etched in warm hydrochloric and sulfuric acids. Both surface groups were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman analysis and X-ray spectrometry (XPS). The three different implant surfaces were placed in the femoral condyles of 24 female New Zealand White rabbits under general anaesthesia. After healing periods of 2 and 4 weeks, animals were sacrificed and specimens were fixed, dehydrated and processed for nondecalcified histology. Percentage of bone-to-implant contact [%BIC], percentage of bone surface at 0.5 mm around the implant [%BS/0.5mm] were determined on back-scattered electron microscopy images. Statistical analysis was performing with the non-parametric test of Mann Whitney at the 95% confidence level. 44 Results: Nanostructrured implant were homogeneously colour coded by the process of anodization. SEM images showed a regular array of nanotubes of 60 nm in diameter on both S-Nano and R-Nano surfaces. Micro roughness was also observed on R-Nano surface while typical random hilly topography covered the SBAE surface. AFM topography measurements confirmed this observation with average roughness of 0.1 µm, 0.4 µm and 1.0 µm for the SNano, the R-Nano and the SBAE control group, respectively. Raman analysis revealed a high crystalline phase of Anatase and Rutile for the Nano surface while amorphous structure was observed on the control implant. After two weeks of implantation in rabbit femur, histomorphometry analysis indicated S-Nano surface improve bone bonding such as the control and is significantly higher than the R-Nano surface ( 54% vs 43%; P = 0,04). After 4 weeks, both the BIC and BS/TS 0.5mm values of the Nano surfaces were similar to the control. Conclusions and clinical implications: Histological data from our study confirm that nanosurface could favor bone and soft tissues integration [1, 2]. Results show that S-Nano surface improved the osseointegration as good as the commercialized micro-rough surface usually uses in implantology. This smooth Nano-surfaces is also functional by its possibility of color-coding and easely cleaned. Further clinical investigation will be realised. [1] Lavenus S. et al. Eur Cells & Materials (2011), [2] Lavenus S. et al. Nanomedicine (2012) 24- M. GUIHO Romain - 3ème année – UMR 957 TRAIL-based therapeutics in pediatric bone tumors: resistance of in vitro and in vivo models to TRAIL pro -apoptotic effects and sensitization approaches. Romain GUIHO 1, Kévin BITEAU1, Julien TAURELLE 1, Valérie TRICHET 1, Franck TIRODE 2, Dominique HEYMANN 1, Françoise REDINI 1 1 INSERM UMR 957 - Laboratoire de Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives Université de Nantes, Faculté de Médecine, 1 rue Gaston Veil, 44 035 Nantes - France 2 Institut Curie, INSERM U830, 26 rue d'Ulm - 75248 Paris Cedex 05 – France Osteosarcoma (OS) and Ewing's sarcoma (EWS) are the two most common pediatric bone tumors. Patients with these diseases have not seen major therapeutic advances these last thirty years and the survival rate of 70 % at five years for a localized tumor still fall to around 20 % in the case of a metastatic tumor or a resistance to chemotherapy. Pro-apoptotic cytokine TNF-Related Apoptosis Inducing Ligand (TRAIL) can selectively kill tumor cells and could be a new therapeutic approach for patients at high risk. However, the study of several OS and EWS cell lines for TRAIL sensitivity, showed the existence of resistance phenomena. Our objective is to identify the molecular mechanisms involved in TRAIL resistance in these particular pathologies to consider therapeutics support strategies by in vitro and in vivo approaches. Different levels of TRAIL regulation signaling pathways are explored: expression of death receptors (DR4 and DR5) and decoy receptors (DcR1, DcR2, Osteoprotegerin), importance of inhibitory proteins of apoptosis (cFLIP; IAP1/2), activation of TRAIL-induce surviving, migration or invasion pathways (NFkB, MAPK, PI3K/Akt…). Even if OS and EWS present similar clinical features, these pathologies differ in response to TRAIL pro -apoptotic effects: the importance of death receptor expression profile was demonstrated in the EWS with a very strong correlation between the expression of DR4 and TRAIL sensitivity, whereas strong resistance of OS cell lines was observed, independent of receptor balance between decoy and death receptors. Our sensitization efforts in OS models, in vitro and in vivo are based on use of potentially sensitizing molecules such as chemotherapeutic agents, with particular attention to the bone microenvironment in these pathologies. In vitro synergy studies show encouraging results, particularly with cisplatin that seems to sensitize to TRAIL via down expression of cFLIP and the removal of the inhibition of the intrinsic pathway of apoptosis. Zoledronic acid, already used as antiresorptive agent in 45 OS, also shows a sensitizing effect by inhibition of IAPs. The transition of these observations to nude mice models is in progress. 25- MME. GUILLONNEAU Maëva – 3ème année – UMR 892 ROLE AND REGULATION OF NUCLEOPHOSMIN IN ENDOTHELIAL CELLS RESPONSE TO OXIDATIVE STRESS AND INVOLVEMENT OF THE p38 MAPK PATHWAY Guillonneau Maëva1-2*, Bénéteau Elise1, Paris François1, Huot Jacques2, Corre Isabelle1-2 1- Centre de Recherche en Cancérologie Nantes Anger, Inserm U892-CNRS 6299-Université de Nantes, Nantes, France 2- Centre de Recherche du CHU de Québec, Centre de recherche sur le cancer de l’Université Laval, Québec, Canada The endothelium is an essential cellular compartment involved in vascular and tissues homeostasis. Importantly, endothelial deregulation can lead to significant dysfunctions such as atherosclerosis, inflammation and metastasis. Oxidative stress (either exogenous or endogenous) through the production of reactive oxygen species (ROS) is an important factor of endothelial deregulation. To limit oxidative stress damaging effects to the endothelium and to surrounding tissues, it is important to understand the molecular signaling pathways involved. p38 MAPKs family is among the key intracellular signaling proteins in oxidative stress cellular response. By a proteomic approach, we identified nucleophosmin (NPM) as a new partner of p38 in endothelial cells exposed to oxidative stress such as 500 µM of H2O2. p38/NPM interaction exists in the cytoplasm of resting endothelial cell and is decreased upon oxidative stress. NPM is phosphorylated on threonine 199 (T199) in basal condition but is dephosphorylated in response to oxidative stress, through the activity of PP1/PP2 phosphatases. However, NPM does not affect the kinase activity of p38 and p38 does not phosphorylate NPM. Nevertheless, knockdown of p38 affects the status of NPM phosphorylation on T199. Additionally, increased phosphorylation of NPM at T199 enhances its interaction with p38. One of the functions rapidly regulated in stressed endothelial cells is the reorganization of the actin cytoskeleton with the formation of stress fibers. We showed implication of NPM and of its status of phosphorylation in oxidative stress-induced actin reorganisation. Our results identify a new p38/NPM signaling pathway, relying on the phosphorylation status of NPM through a PP1/PP2 phosphatase activity. We describe for the first time a role of NPM in the regulation of endothelial cell cytoskeleton dynamics. This work will allow better understanding of the role of the p38/NPM pathway in regulating the endothelial cell response to oxidative stress and, by extension, to ionizing radiation. 46 26- MME. DIAB Maya - 3ème année –UMR 892 Production and characterization of monoclonal antibodies specific for dog and cat syndecan-1 for nuclear medicine preclinical trial on spontaneous tumors DIAB M.1, DAVODEAU F.1,CHEREL M.1,2 1 Nantes-Angers Cancer Research Center CRCNA/ INSERM UMR892 ,Nantes,France. 2ICO cancer center,nantes,France maya.diab@univ-nantes.fr BACKGROUND: Syndecan-1 (CD138) is a cell surface heparane sulfate bearing proteoglycane, over expressedin multiple myelomaand in a wide spectrum of carcinomas. In the case of breast cancer, the expression of CD138 correlateswith apoorprognosis. We have shown, on a xenogenic mouse model of triple negativebreast cancer (TNBC) that CD138 is a relevant target for imaging (immuno-PET) andfradioimmunotherapy (RIT). The objective of this study was to produce a monoclonal antibodies targeting canine CD138 in order to evaluate their usefulness forimmune-TEP and RIT on dogs with spontaneous carcinoma. METHOD:Hybridomas were produced through immunization of mice with the recombinantectodomainof canine syndecan 1 (residues 1 to 251) and fusion of spleen cells with Sp2/o cells. Screening of positivehybridomas by FACS was performed usingcanin CD138 transfected CHO cells. Isotypes, affinity and epitopes mapping were determined and Monoclonal antibodies were characterized using immunohistochemistry. RESULTS:We selected twenty fourhybridomas producing antibodies reacting with our CD138c transfected CHO cells. Only eleven hybridomas were isolated after subclonning allowing us to produce eleven differents antibodies. All of them are IgG1 kappa except one which is IgG2b kappa.Theiraffinity for canine CD138 are of the order of nano molar and four distinct epitopes of CD138c are recognized by theseantibodies.. Immunohistochemistry analysis showed that all antibodies recognize caninesyndecanon healthy tissues and on canine mammary cancers. CONCLUSION :These monoclonal antibodies could be a powerful tools to assess canine syndecan-1 targeting by Imaging and radioimmunotherapy in clinically relevant large animal model.The validation of RIT targeting CD138 on spontaneousmammarytumorsexhibitinghighhomologywithhuman TNBC would propose in womena newtherapeuticapproches for the management of relapsedTNBC thatcan’tbenefitfrom hormone therapy or immunotherapyusingantibodiestargeting Her2 / Neu. 27- MME. PARROT Tiphaine - 3ème année – UMR 892 “INTRA-TUMOR CD4+CD8+ DOUBLE-POSITIVE T CELLS: A NEW TARGET FOR IL-9 “ T. Parrot1, M. Allard1, J. Desfrançois2, R. Oger1, H. Benlalam1, D. Raingeard de la Blétière1, 3 , L. Pressier1, N. Labarrière1, Y. Delneste1, P. Guardiola1, 3, N. Gervois1 1 UMR 892 INSERM / 6299 CNRS / Université Nantes - CRCNA 2 Cytometry Facility “CytoCell”, SFR François Bonamy, Nantes 3 SNP Transcriptome & Epigenomics Facility, CHU, Angers The study of the tumor infiltrate composition in melanomas enabled us to identify a nonconventional CD4+CD8+ double positive T lymphocyte sub-population (double-positive (DP) T cells) characterized by the stable co-expression of the CD4 and CD8 molecules. DP T cell frequency can reach up to 10% of tumor infiltrating lymphocytes and increases with advanced cancer stage, which suggests a role of these cells in anti-tumor immune responses [1]. 47 Similarly to the conventional effector CD8+ lymphocytes, DP T cells recognize tumor cells in an HLA-I restricted context and in a CD8 dependent way. However, DP T cells exert a poor cytotoxic activity and differ from CD8 T cells by their strong ability to produce diverse Th1 and Th2 cytokines. In order to delineate the functions of DP T cells, their transcriptome profile was documented and compared with the one of CD8 infiltrating lymphocytes. It appeared that DP T cells overexpress the IL-9 receptor raising the question of the impact of IL-9 on the biology of these cells. We showed, that IL-9 enhances the survival of DP T cells by protecting them from apoptosis, and, to a lesser extent, favors their proliferation. In addition, IL-9 increases in a dose-dependent manner the cytokine production of DP T cells. In particular, the amount of IL13 secreted in presence of IL-9 is liable to exert biological effects on macrophages polarization, dendritic cells maturation or on tumor cells themselves. Finally, IL-9 increases granzyme B production and degranulation of DP T cells leading to an enhanced cytotoxic capacity against melanoma cell line. To conclude, IL-9 would take part in the maintenance of DP T cells within the tumor infiltrate and favors their functional activity. Our results extend the pleiotropic effect of IL-9 already described for mast cells, T reg, Th17 and monocytes, to intra-tumor DP T cells [2]. REFERENCES [1] Desfrancois J, Moreau-Aubry A, Vignard V, Godet Y, Khammari A, et al. (2010) Double positive CD4CD8 alphabeta T cells: a new tumor-reactive population in human melanomas. PLoS One 5(1): e8437. [2] Noelle RJ, Nowak EC. Cellular sources and immune functions of interleukin-9. Nat Rev Immunol. 2010;10:683–687. 28- MME. BUREL Sophie - 3ème année – UMR 1087 Identification of Two Native Nav1.5 Phosphorylation Sites As Potential Determinants of the Increased Late Na+ Current in Heart Failure Sophie Burel1, Fabien Coyan1, Matthew R Meyer2, Cheryl F Lichti3, Joan H Brown4, Flavien Charpentier1, Jeanne M Nerbonne5, R Reid Townsend6,7, Lars S Maier8 and Céline Marionneau1. 1Institut du Thorax, INSERM UMR1087, CNRS UMR6291, Nantes, France, Departments of 2Medicine, 5Developmental Biology, 6Internal Medicine and 7Cell Biology and Physiology, Washington University Medical School, Saint Louis, MO, USA, 3Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA, 4 Department of Pharmacology, University of California, San Diego, CA, USA, and 8 University Hospital Regensburg, Regensburg, Germany. Voltage-gated Na+ (Nav) channels are key determinants of myocardial excitability and defects in Nav channel functioning or regulation, associated with inherited and acquired cardiac disease, increase the risk of life-threatening arrhythmias. In heart failure, the inactivation properties of Nav1.5 channels are altered, resulting in decreased channel availability and increased late Na+ current. Although previous studies have suggested roles for CaMKII and CaMKII-dependent Nav1.5 phosphorylation, the global native phosphorylation pattern of Nav1.5 channels associated with these alterations is unknown. Phosphoproteomic analyses were undertaken to identify and quantify in situ the native phosphorylation sites on the Nav1.5 proteins purified from wild-type and CaMKIIc-overexpressing (CaMKIIc-Tg) mouse ventricles. A total of 18 phosphosites were identified, 8 of which are novel compared with our previous MS analyses. Of these 18 phosphosites, the C-terminal phosphoserines pS1937/pS1938 are present in the CaMKIIc-Tg IPs (n=3/4) and absent in the WT IPs (n=0/4). In addition, pS1989 is 9-fold more represented (p<0.05, n=4 in each condition) in the CaMKIIc-Tg, than in the WT, IPs. To explore the possibility that phosphorylation at these Cterminal sites regulates the gating properties of Nav1.5 channels, the orthologous human 48 (serine to glutamate) double phosphomutant Nav1.5-S1933E-S1984E was generated and investigated by whole cell voltage-clamp analyses in HEK293 cells. These analyses revealed that the relative percentage of the TTX-sensitive late Na+ current, compared with the peak Na+ current, is significantly (p<0.01) higher for the double phosphomutant (0.07 ± 0.007%, n=24), compared with the WT (0.04 ± 0.004%, n=20), currents. In addition, although the fast and slow time constants of inactivation are similar, the relative contribution of the fast inactivating component of the peak Na+ current is significantly (p<0.05) lower with the phosphomutant, compared with the WT channels. Together, these analyses provide 8 novel native cardiac Nav1.5 phosphorylation sites, 2 of which are in the C-terminus of Nav1.5 and selectively modulate the late component of Na+ current, suggesting a role for modulation at these sites in heart failure. 29- M. POGU Julien - 3ème année – ITUN Tolerization of ongoing CTL response by monocyte derived dendritic cells expressing heme oxygenase-1 One barrier to prevention and treatment of autoimmune diseases is the difficulty of antigen specific tolerization of ongoing T-cell responses. We developed a protocol to tolerize β-cell-specific cytotoxic T cells (CTLs) in type 1 diabetes (T1D) model mice by intradermal co-injection of an HO-1 inducer and a β-cell antigen. This treatment induced recruitment in the draining lymph node of an HO-1-overexpressing monocyte-derived DC (MoDC) population that tolerized autoreactive CTLs. CTL tolerization was associated with lower β-actin expression, and reduced CTL velocity and response to chemokines. Intradermal injection of a clinically approved HO-1 inducer in baboons led to HO-1+ MoDC appearance in draining lymph nodes. Furthermore, in human T-cell clones, β-actin expression was reduced upon incubation with HO-1+ monocytes. Overall, HO-1 inducers represent a promising approach for clinical induction of antigen-specific tolerance. 30- MME. DRUJONT Lucile - 3ème année –UMR 1064 Role of ion fluxes in Th17 biology and autoimmune diseases L. Drujont, A. Lemoine, M.-C. Cuturi, C. Louvet The nuclear hormone receptor ROR t is the key transcription factor that orchestrates the differentiation of Th17 cells but also defines T cells and various Innate Lymphoid Cells (ILCs). It is challenging to decipher the contribution of each ROR t+ cell type during the development of pathological responses and to identify the mechanisms involved beyond IL-17 and few other cytokines. Our group identified TMEM176B, a four-span transmembrane protein that interacts with its structurally identical homolog protein TMEM176A. Electrophysiological experiments revealed that TMEM176A and B function as cation channels and can heteromerize to exert their function. Interestingly, these two homologs are among the few direct targets of ROR t. We observed that both genes are highly expressed in in vitro-generated mouse Th17 compared to Th1, Th2 or iTregs. We also observed that human Th17 cells strongly expressed TMEM176A and B mRNA, correlating with the level of RORC. Thus, we hypothesize that these genes could play a crucial role in the development of a variety of autoimmune diseases. Preliminary results showed that Tmem176b-/- mice were partially protected from psoriasis-like lesions when compared to control mice. These results 49 suggest that the deletion of both genes may be required to clearly elucidate their role in autoimmunity. We have now successfully generated double KO mice and we aim to assess the impact of these deficiencies on different models of autoimmunity. In addition, we aim to link TMEM176A and B intracellular localization to his cation channel function in Th17 cells. We believe that the study of TMEM176A and B will help decipher novel specific pathways of the Th17 cell biology. 31- MME. LAMORA Audrey – 3ème année – UMR 957 LPRO Inhibition of TGF-beta signaling pathway blocks the development of osteosarcoma lung metastasis *Audrey Lamora1-4, Julie Talbot1-3, Gwenola Bougras1-3, Jérôme Amiaud1-3,Marion Leduc1-3, Julie Chesneau1-3, Julien Taurelle1-3, Verena Stresing1-3, Marie Cécile Le Deley5, Marie Françoise Heymann1-3,Dominique Heymann1-3, Françoise Redini1-3 and Franck Verrecchia1-3 1 INSERM, UMR 957, Equipe labellisée Ligue contre le Cancer 2012, Nantes, France; Université de Nantes, Laboratoire de Physiopathologie de la Résorption Osseuse et Thérapie des Tumeurs Osseuses Primitives, Nantes, France; 3CHU Hôtel Dieu, Nantes, France;4Inserm Liliane Bettencourt School, Pharm.D-PhD student;5Institut Gustave Roussy, Villejuif, France 2 Background: Osteosarcoma is the main malignant primary bone tumor in children and adolescents for whom the prognosis remains poor, especially when metastases are present at diagnosis (survival rate drops to 20% when lung metastases were detected). Aim: Because TGF-beta has been shown to promote metastases in many solid tumors, we investigated the effects of inhibition of the TGF-beta/Smad cascade on osteosarcoma behavior. Material and methods: To this end, two independent procedures, a pharmacological approach with TGF-beta Receptor I inhibitor (SD-208) and a molecular approach using the natural Smad inhibitor (Smad7), was used. The impact of these procedures was assessed on tumor growth, tumor microenvironment, bone remodeling and lung metastases development by using a mouse model of osteosarcoma induced by paratibial injection of osteosarcoma cells. Results: We first demonstrated that TGF-beta levels are higher in the serum of osteosarcoma patients compared to healthy volunteers. We also showed that Smad7 slows the growth of the primary tumor and increases mice survival. In this context, we demonstrated that Smad7 expression does not affect osteosarcoma cell proliferation but affects the microarchitectural parameters of bone. In addition, Smad7-osteosarcoma bone tumors expressed lower levels of osteolytic factor RANKL, suggesting that Smad7 overexpression affects the "vicious cycle" established between tumor cells and bone cells by its ability to decrease osteoclast activity. Interestingly, we finaly showed that Smad7 overexpression in osteosarcoma cells and SD-208 inhibits the development of lung metastasis. In this context, we demonstrated that Smad7 and SD-208 reduced the capacity of osteosarcoma cells to invade Matrigel in Boyden migration chambers and gelatin zymography identified reduced MMP-2 secretion by osteosarcoma cells. Conclusions and clinical implications: These results suggest that the inhibition of TGFbeta/Smad signaling pathway could be a promising therapeutic strategy against the tumor progression of osteosarcoma Acknowledgments : Ligue contre le cancer, Fondation Bettencourt Schueller-Ecole de l’INSERM 50 32- M. AMELINE Baptiste – 2ème année – UMR 1089 Title : Evaluation of AAV-based OPN4 transfer for the treatment of inherited retinal dystrophies Inherited retinal diseases (IRD) affect about 2 million people worldwide, leading to severe visual impairment. Specific gene addition therapy is one of the most promising strategies to treat these patients. However many of them are not eligible for specific gene therapy, such as patients with unknown deficient genes. Therefore, the aim of this project is to develop an alternative strategy, independent of the mutation and the retinal degeneration kinetic: The optogene transfer. In context of IRD, it will consist to convert surviving retinal ganglion cells into sensitive light cells following the transfer of ChR2 optogene. Several rodent models of IRD have been successfully treated using the ChR2 optogene. Nevertheless, this approach has never been evaluated in large animal models. The general objective of our study will be to define the feasibility of optogenetic therapy to restore vision in blind patients by evaluating the safety and the efficacy of AAV-mediated gene transfer of ChR2 in surviving ganglion cells of a canine model of IRD (Rpe65-/- dogs). Moreover, two other canine models of IRD could be injected to make the proof of the universality of this approach. 33- MME. CHESNEAU Coraline – 3ème année – UMR 1064 Characterization of molecular interactions between HCMV and dendritic cells: impact of glycosylations on viral tropism. Dendritic cells (DCs) are prone to sense and alert the immune system after intrusion of pathogens. Those cells are mostly localized in skin and mucosa which are gateways for pathogens such as viruses. Components of viral origin, mostly envelope glycoproteins, are recognized by DC-specific lectins. Previously we have shown that the lectin domain or CRD (Carbohydrate Recognition Domain) of DC-SIGN can interact with an envelope glycoprotein of the human cytomegalovirus (HCMV), the glycoprotein B (gB) (Halary et al, 2002). This interaction allows for the internalization of the virus and promoted cis- and transinfection. However, our knowledge of this interaction is currently insufficient to develop new antiHCMV therapies whose design should take into account the blockade of the DC-SIGN/gB interaction.To finely characterize this interaction we proposed to generate and/or to use deletional mutants of DC-SIGN (full length versus d-CRD and d-neck) as well as gB mutants (i.e. selective mutation of each of the 18 potential N-glycosylation sites). Preliminary results, show that CRD part of DC-SIGN is the unique part to be involved in gB interaction. Furthermore, on the 18 potential gB glycosylation sites, only 4/5 seem to have a role in the binding to DC-SIGN. Based on these experiments, we would like to develop a 3D model of the DC-SIGN/gB complex. This one could be used to rationally design competitive inhibitors of this interaction which is probably determinant for the virus to establish a long life persistence. 51 34- M. CARRADORI Dario -2ème année – EA 3143 LNBT PEPTIDE FUNCTIONALIZED NANOVECTORS FOR TARGETING STEM CELLS IN THE SUBVENTRICULAR ZONE Carradori D. 1,2 ; Saulnier P. 2 ; Benoit J .P. 2 ; Eyer J. 1 1 4, Rue Larrey, LNBT EA 3143, Université d'Angers, Angers, France. Tel : 02 44 68 84 88; E-mail: joel.eyer@univ-angers.fr 2 4, Rue Larrey, U646 MINT, Université d'Angers, Angers, France Introduction. Stem cells have the ability to self renew and to differentiate into different cell types, depending on their origin 1. This property is promising for their potential application in therapy, especially in the treatment of neurodegenerative disorders 2. Goal. The aim of this work is to functionalize nanovectors with a peptide (PNs) able to target stem cells of the subventicular zone (SCs SVZ). Fluorescent lipid nanocapsules 3 (fLNCs) were chosen as nanovectors, thanks to their favorable biochemical profile. A 24 amino acid long peptide was chosen as a targeting peptide, because work in progress in our laboratory showed its capacity to enter specifically in SCs SVZ (Lepinoux-Chambaud C. and Eyer J., LNBT). The fLNCs were functionalized with the peptide to obtain the PNs. Then, PNs were incubated with SCs SVZ to investigate their toxicity, their mechanism of cell penetration and their pharmacokinetics. Treated SCs SVZ were analysed by flow cytofluometry and confocal imaging. Materials & Methods. The peptide was purchased from different companies (Millegen, Eurogentec and GeneCust). Labrafac® was purchased from Gattefosse SA (Saint-Priest, France). Lipoïd® came from Lipod Gmbh (Ludwigshafen, Germany). Solutol HS was purchased from BASF (Ludwigshafen, Germany ), NaCl from Prolabo (Fontenay-sousbois, France), and deionized water was acquired from MilliQ system Millipore (Paris, France). DiD' solid; DiIC18(5) solid (1,1'-Dioctadecyl-3,3,3',3'Tetramethylindodicarbocyanine, 4-Chlorobenzenesulfonate Salt) was purchased from Molecular Probes® (Life Technologies). Primary antibodies: anti-α-tubulin, anti-Nestin, anti-GFAP, and anti-Vimentin were purchased from Sigma. Secondary antibodies labelled with Alexa-Fluor-488 or Alexa-Fluor-568, and DAPI were purchased from Molecular Probes® (Life Technologies). The SVZ was dissected from new-born rat according to Directive 2010/63/EU, and SCs were cultivate as floating cell culture to finally obtain neurospheres 4. 7 days old neurospheres were incubated with the PN at different conditions (time, concentration and energy conditions) and then analysed by flow cytofluometry and by confocal microscopy. Results & Discussion. Flow cytofluometry: the SCs incubated with PNs showed a significantly higher fluorescent than SCs incubated with fLNCs (control). Low-energy conditions during incubation didn’t influence significantly the amount of fluores cent cells compared to normal conditions. Confocal microscopy: neurospheres incubated with PN and fLNCs confirmed the flow cytofluometry results. Conclusion. The results showed that the peptide plays an important role in SVZ SCs targeting. The combination of the peptide with fLNCs leads to a PN with high SVZ SCs selectivity. It could be used as a vector for drugs able to induce a therapeutic effect, through SVZ SCs interaction, in the case of neurodegenerative diseases. This work was supported by Nanofar to Carradori D. It was also supported by AFM (Association Française contre les Myopathies), by CIMATH (Région des Pays-de-laLoire), and by MAWTIN to Eyer J.. References 1 FM Watt and BLM Hogan, Science, 2000, 287, 1427-1430. 2 O Lindvall and Z Kokaia, Nature, 2006, 441, 1094-1096. 3 B Heurtault, P Saulnier, B Pech, JE Proust and JP Benoit, Pharmaceutical Research, 2002, 19, 875-880 4 W Guo, NE Patzlaff, EM Jobe and X Zhao, Nature Protocols, 2012, 11, 2005-2012. 52 35- M.RECOQUILLON Sylvain – 3ème année –U1063 Role of non-muscular myosin light chain kinase (nmMLCK) in the inflammation associated with a model of intermittent hypoxia Sylvain Recoquillon, Manuel Gómez-Guzmán, Frédéric Gagnadoux, Ramaroson Andriantsitohaina, M. Carmen Martínez INSERM U1063 « Stress Oxydant et Pathologies Métaboliques », Université d’Angers, France Obstructive Sleep Apnea Syndrome (OSAS) is characterized by repetitive obstructions of the upper airway during sleep, inducing intermittent diminution in oxygen saturation, or intermittent hypoxia (IH). IH alters endothelial function favoring inflammation and could accelerate atherosclerosis-induced cardiovascular diseases. A protein that may play a role in this process is the non-muscular myosin light chain kinase (nmMLCK). The deficiency of this kinase protects mice from death in septic choc models and prevents the atherosclerosis in mice fed with a high fat dietary. The aim of this study was to analyze the implication of nmMLCK in the vascular effects and the inflammation induced by IH. Human aortic endothelial cells (HAoECs) and aortas isolated from C57BL6 mice were exposed to 6h of IH, which include 30 min of hypoxia (O2 5%) followed by 30 min of normoxia (O2 21%), in the absence or the presence of ML-7 (5µM), a nmMLCK inhibitor. After the stimulation, we measured nitric oxide (NO), superoxide anion production and the endothelium-dependent acetylcholine-induced relaxation in order to evaluate endothelial function. We also investigated inflammatory process by evaluating p65-NF-κB pathway and the expression of IL-6 in the supernatant of cells. The results show that IH treatment increased superoxide anion, NO and IL-6 productions in HAoECs. However, while the nmMLCK inhibitor ML-7 had no effect on the IH-induced superoxide anion increase, it decreased both NO and IL-6 production. Furthermore, p65-NF-κB pathway was activated by IH in a ML-7-insensitive manner in HAoECs. IH also decreased acetylcholine-dependent relaxation of mice aortas, suggesting an IH-induced endothelial dysfunction. These results suggest that IH impairs vascular reactivity associated with an IH-induced inflammatory activation in endothelial cells in which nmMLCK may participate. 36- M. KANDALAM Saikrishna – 2ème année – Inserm U1066 NANO AND MICRO TAILORING OF BIOMIMETIC AND PHARMACOLOGICALLY ACTIVE BIOMATERIALS COMBINED TO ADULT STEM CELLS FOR SPINAL CORD INJURY REPAIR Saikrishna KANDALAM 1,2,3 * ; Anne des Rieux 3 ; Laurence Sindji1,2, Jerome Guicheux4,5,6 ; Montero-Menei CN.1,2 1 LUNAM Universite, UMR S-1066 F-49933 Angers, France. INSERM U1066, MINT "Micro et nanomedecines biomimetiques "F-49933 Angers, France. 3 Louvain Drug Research Institute, Pharmaceutics and Drug Delivery Research group, Université Catholique de Louvain, Belgium. 4 INSERM, UMR 791, Skeletal Tissue Engineering and Physiopathology team LIOAD, Nantes, France. 5 Université de Nantes, UFR Odontologie, Nantes, France. 6 CHU Nantes, PHU 4 OTONN, Nantes, France 2 SUMMARY Introduction: During the last few years it has been shown that adult stem cells are strong candidates for cell-based therapy in Spinal cord injury (SCI). Studies shows that, pre53 treatment of Marrow-isolated adult multi-lineage inducible (MIAMI) cells (mesenchymal stromal cells expressing typical embryonic stem cell markers) with epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) enhances neural specification and response to neuronal commitment. Recent studies depicts that brain derived neutrophic factor (BDNF) directly enhanced the differentiation of stem cells to neuronal precursors, and promotes supraspinal axonal regeneration and restoration of motor neuron exitability in spinal cord. Fibronectin an extracellular protein will enhance mesenchymal stem cell survival, cell adhesion. An injectable hydrogels provide elastic properties and enhancing stem cell specification. Objectives: MIAMI cells transported by fibronectin-covered pharmacologically active microcarriers (PAMs) delivering BDNF within a silated hydroxypropyl methylcellulose (SIHPMC) hydrogel [9] matrix to repair neural tissue and promote functional recovery after SCI. Methods: PAM’s preparation involves nanoprecipitation of BDNF and encapsulation in PLGA–P188–PLGA polymeric microspheres. PAM’s characterization includes size (Coulter Counter Multisizer), shape (scanning electron microscope), encapsulation yield (ELISA), release kinetics and bio assay (ELISA & rat dorsal root ganglia). Results: Nanoprecipitation yield of α-chymotrypsin (model protein) was performed using an experimental design was found to be 74±4.3%. BDNF nanoprecipitation yeild, mean size and encapsulation yield in PAMs was determined as 92.2±10.3 %, 33.8±12.7µm and 91.39 % respectively. Conclusion: PAMs are successfully formulated with nanoprecipitated BDNF and surface coated with fibronectin. Further studies on release kinetics of BDNF from fibronectin-BDNFPAMs and characterization of MIAMI cells along with fibronectin-BDNF-PAMs in Si-HPMC hydrogel has to be performed. 37- MME ROY Charlotte – 2ème année -UMR CNRS 6214 INSERM U1083 (BNMI) Protective role of nucleotidases against the development of hypertension Arterial hypertension is a major risk factor for cardiovascular complications such as myocardial infarction or stroke. In hypertension, vascular tone is exacerbated, accompanied by an hypertrophic remodeling of vessel wall (oxidative stress, endothelial dysfunction, fibrosis). Extracellular nucleotides are released under conditions of cellular stress (myogenic tone, shear stress) and promote deleterious responses in pathological context (vasoconstriction, inflammation, promotion of vascular permeability) via activation of purinergic (P2) receptors. Although signaling by extracellular nucleotides are important in vascular homeostasis its contribution to vascular pathologies remains poorly understood. The bioavailability of these nucleotides is controlled by ectonucleotidases, especially NTPDase1 (CD39) highly expressed in the arterial wall. These enzymes not only scavenge nucleotides but, in concert with ecto-5’nucleotidase (CD73), contribute to generation of vasoprotective adenosine (anti inflammatory, vasodilatory). We evaluated here the role of nucleotide degrading enzymes in the development of hypertension. #1 We treated mice with Angiotensin II (AngII, 1mg/kg/day) with or without potatoe Apyrase (AngII/APY), a soluble nucleotidase with similar activity to CD39 (45U in osmotic pumps + 15U ip every 3 days) during 12 days. We observed a reduced systolic blood pressure (SBP) increase (7±5 vs 21±7 mmHg) in the AngII/APY group compared to AngII alone and diminished hypertrophic arterial (aorta) remodeling (2±4 vs 11±3 µm of thickness). The efficacy of the treatment was performed by measuring fluorescent derivative etheno ADP hydrolysis by HPLC. #2 The protective effect provided by the enzyme is certainly affected in hypertension since RT-qPCR experiments showed a decreased of transcript encoding CD39 in resistance arteries in AngII-dependent hypertension. #3 The absence of CD39 should have an impact on the development of hypertension. Entpd1+/+ and Entpd1-/- mice were treated with AngII (0.5 mg/kg/day) during 54 21 days. Results show that SBP was significantly higher (43±5 vs 18±5 mmHg) and associated to an exacerbated hypertrophic arterial remodeling (19±8 vs 3±5 µm) in Entpd1-/compared to Entpd1+/+ mice. This protective role of CD39 remains to be investigated; this is may be due to its vascular component, regulating vasoconstrictor P2 receptor, but also due to its immune component, exerting its anti-inflammatory function. Consequently, nucleotidases confer resistance to high blood pressure and may represent new therapeutic targets in the treatment of hypertension. 38- M. RIDEAU Alexis – 2ème année - Cancer Center, Inserm U892 team 12, CNRS 6299 Identification and Quantification of the Secreted Protein OLFM4, involved in AnchorageIndependant Growth, by a Multi-Technique Approach in Colorectal and Breast Cancer. The proteomic approach is a powerful tool used to study tumoral cell lines or tumoral tissue samples. In order to understand the tumoral development, it is necessary to know fondamental cellular mechanisms. The major actors regulating these mechanisms are the proteins. Proteins enriched from a shotgun proteomic approach can be identified and quantified by mass spectrometry. In a previous study, we have analyzed the proteome of different stages of colorectal tumor and determined Olfactomedine-4 (OLFM4) as a potential biomarker. In this study, we have classified these proteomes in subproteomes. In our laboratory, we investigate the senescence escape during tumor development that is why the subproteome involves in cell death was identified through global colorectal proteome. For few years, the interest in proteins of the SASP (Senescence Associated Secreted Proteins) increased ans especially the ones involved in senescence escape. Thus, the colorectal subproteome secreted was described in this study. Among these secreted proteins, one of them, OLFM4, is very interesting in early clinical diagnosis. This secreted protein is overexpressed in early stage of colorectal and breast cancer and is measurable in blood of patients. Functions of OLFM4 are described only as potential cell survival protein. This study associate OLFM4 to anchorage-independant growth and anoikis resistance through Soft Agar assay. Indeed, OLFM4 increases the growth of colorectal and mammary cell lines in low adhesion conditions. In order to generate subproteomes, the adhesion colorectal proteome was identified. Insterestingly, the OLFM4 overexpression is correlated with a loss of cadherin and an overexpression of vimentin proteins involved in cell adhesion and migration. These data reveal a relationship between a potential biomarker measurable in blood of patients and an agressive phenotype acquired. 39- M. LEGEAY Samuel - 2ème année – Inserm U1063 M3 receptor as a key target for DEET-induced angiogenesis. The insect repellent N,N-diethyl-m-toluamide (DEET) recently proposed as an inhibitor of human acetylcholinesterase has been reported to potentiate tumor development. As angiogenesis is a critical step in tumorigenesis, the present study was designed to test the potential effect of DEET on different processes leading to neovascularisation on human endothelial cells (HUVECs). These primary cells were incubated for 24h with DEET at concentrations similar to that found in plasma of exposed individuals (10-5M) or in the environment (10-8M). Both concentrations of DEET increased proliferation, migration and adhesion of cultured endothelial cells, in vitro capillary length of HUVECS in culture on matrigel and in vivo vascularization of Matrigel Plug. These cellular processes were 55 associated with focal adhesion kinase (FAK) phosphorylation and stress fibers. Both concentrations of DEET also stimulated NO production through an increase of peNOSSer/peNOS-Thr ratio. Moreover, DEET potentiates carbachol-induced calcium signaling in human embryonic kidney (HEK) 293 cells expressing recombinant Galpha(q/11)-coupled muscarinic M3 receptors. Inhibition or silencing M3 muscarinic receptor subtype either with the pharmacological antagonist parafluorohexahydrosiladiphenidol (pFHHSiD) or siRNA, respectively abolished the pro-angiogenic properties of DEET in both in vitro and in vivo conditions. These data underscore a novel property of DEET as a pro-angiogenic toxic, via the involvement of M3 muscarinic receptor subtype, that probably explains its potentiating effect on tumor development. 40- M.FRIFRA Mehdi – 2ème année – Inserm U1063 Impact of nutrients in metabolic diseases: characterization of vegetal samples on different cell lines. FRIFRA Mehdi*, SOLETI Raffaella, CLERE Nicolas, RENOU Jean-Pierre & ANDRIANTSITOHAINA Ramaroson Unité INSERM U1063 SOPAM, Stress Oxydant et Pathologies Métaboliques, University of Angers, France Obesity incidence is associated with an increased risk of disorders, such as metabolic syndrome, diabetes and cardiovascular disease. Nutritional approach is essential to prevent or correct obesity associated disorders and can be achieved by the quality vegetable and fruit consumption. We studied the influence of apple according to the genetic variability, the conditions of production and post-harvest preservation on cells implicated in development of obesity-related diseases. Hepatocytes (HepG2) and adipocytes (3T3-L1) are treated 24 hours with two different concentrations (10-2 and 10-5 g/L) of 31 lyophilisate samples of apples from different genetic variability, culture conditions and conservations, solubilized in DMSO or ethanol with respect to lipid accumulation. The two solvents at used concentrations did not modify basal lipid accumulation and that induced either by oleic acid or cocktail of differentiation medium in HepG2 and 3T3-L1 cell lines, respectively. In HepG2, the four varieties of apples did not modify basal lipid accumulation. Among these varieties, high concentration of Golden and Pink lady decreased lipid accumulation induced by oleic acid when they are solubilized in ethanol. Any of the 31 lyophilisate samples of apples tested solubilized with either DMSO or ethanol and at any concentration used did not affect lipid accumulation in 3T3-L1 adipocytes. These results under score the cellular specificity action of apple on lipid accumulation with special tropism on HepG2 with Golden and Pink lady varieties. They also validate the technological strategies used for cellular screening of vegetable and fruit to sort beneficial products against obesity-related disease. Further studies are ongoing in endothelial and smooth muscle cells and macrophages. 41- M. MILBANK Edward – 2ème année – Inserm UMR 1063 EXTRACELLULAR MICROVESICLES AS A THERAPEUTIC STRATEGY TO PREVENT OR REVERT OBESITY AND ITS METABOLIC COMPLICATIONS IN THE FIELD OF NANOMEDICINE E. MILBANK [1] [2]; M. LOPEZ [1] [2], R. ANDRIANTSITOHAINA [1] [1] INSERM U1063, SOPAM - Stress Oxydant et Pathologies Métaboliques - University of Angers, France. 56 [2] Department of Physiology, CIMUS, University of Santiago de Compostela - Instituto de Investigacion Sanitaria, Santiago de Compostela, 15782, Spain Correspondence should be addressed to E. MILBANK (edward.milbank@etud.univ-angers.fr) Introduction : The central nervous system (CNS) receives multiple inputs of information as diverse as the sensory of eating, metabolism and levels of energy storage. Integrative member of the CNS, the hypothalamus is a well known crucial regulator of both energy intake and energy expenditure. One of the main energy-regulatory factors within the hypothalamus is the AMP-activated protein kinase (AMPK), which is involved in a large number of biological actions including the modulation of energy balance (Lopez et al , Cell Metab 2008, Nat Med. 2010). The use of modified DNA sequence to induce protein inactivation has opened a new avenue in drug discovery. However, their therapeutic potential is hampered by inadequate tissuespecific delivery. Thus, using isolated extracellular microvesicles - vesicles released by activated cells - loaded with a dominant negative isoform of AMPK (AMPK DN), would allow the specific targeting of hypothalamic neurons and the inhibition of AMPK central activity. Objective : Developing structure-modified dendritic cell derived exosomes loaded with an AMPK DN. Methods : Transfection protocol was optimized using JetPei as transfection reagent and green fluorescent protein (GFP) as control. Dendritic cells (DC) viability and immunophenotype were analyzed by flow cytometry. Exosomes morphological analyses were performed using electron microscopy and size distribution methods. Results : DC transfection provided a good efficiency and did not alter the viability and the immunophenotype of the cells. The morphological analysis of the dendritic cell-derived microvesicles confirmed that they harbored the principal properties of the exosomes. Conclusion : Once structure-modified exosomes purified, their abilities to target hypothalamic neurons after systemic and intranasal deliveries will have to be analyzed through in vivo studies. The last step will be to incorporate a AMPK DN within these exosomes and analyze their effects directly on the central regulation of obesity. 42- MME. MOREAU Marie -2ème année – Inserm U892 E12 /CNRS 6299 Secretome of persistent colorectal cancer cells conferes an agressive phenotype which may promote metastasis development. Induction of senescence by chemotherapy was initially characterized as a suppressive response that prevents tumor cell proliferation. However, in response to treatment, it is not really known how cells can survive senescence and how irreversible this pathway is. We analyzed cell escape in response to irinotecan (sn38), a first line treatment used in colorectal cancer that induced senescence. A previous study showed that malignant cells which resisted senescence relied on survival pathways induced by Mcl-1 signaling and to a lesser extent of Bcl-xL. Depletion of Mcl-1 increased irinotecan efficiency, induced the death of polyploid cells, prevented cell emergence and inhibited growth in low-adhesion conditions. In this case, we wanted to know what is effect of the secretome of the cells that escaped cellular senescence. Indeed, one of the caracteristics of cellular senescence is the appearance of the senescence-associated secretory phenotype (SASP) which has different roles autocrine and paracrine in inflammation, angiogenesis or senescence reinforcement. Many studies showed that secretome of senescent cells gave an agressive phenotype to neighboring cells. In our model, we detected subpopulations of cells that adapted to chemotherapy and resumed proliferation. These cells were called Persistent LS174T Cells (PLCs). PLCs are heterogenous 57 populations composed by proliferating and senescent cells. Thus, the secretome analysis could help us to understand the differences between parental LS174T cells ans PLCs. In this context, we collected different samples of conditioned media after starvation from LS174T and PLCs. Then, we analyzed the effect of these supernatants on parental LS174T cells behavior. We showed that conditioned media of PLCs, unlike LS174T cells, induced cell proliferation, growth in low adhesion conditions, emergence, migration and angiogenesis by the formation of a tubing network of endothelial cells. Together, these results suggest that the secretome of persistent colorectal cancer cells to chemotherapy, makes agressive cells and promotes metastasis development. 43- M.DIB Abdallah – 2ème année – U1083 Effect of maternal diabetes on fetal programming of vascular remodeling mechanisms in adult rats Abdallah Dib, Jennifer Bourreau, Daniel Henrion, Céline Fassot UMR CNRS 6214 / INSERM U1083, Faculté de Médecine, Rue Haute de Reculée, 49045 Angers Numerous studies have shown that adult diseases may have their origins in fetal life. Indeed, modifications of the intra-uterine environment during specific windows of fetal development are now recognized as an important cause of fetal stress, leading to several responses such as loss of structure/function and pre-emptive adaptations to an adverse postnatal environment, and finally to adult diseases such as metabolic abnormalities and hypertension. In this way, it has been demonstrated that children of diabetic mothers have an increased risk of developing cardiovascular disease and insulin resistance during adulthood. In our laboratory, we developed an animal model of rats exposed in utero to maternal diabetes (DMO). A first study showed that DMO developped hypertension at 6 months of age. In a second study, specific modifications of aortic gene expression profile were revealed in DMO at a pre-hypertensive stage (3 months) in favor of a vasoconstrictor phenotype. Moreover, a lack of vascular remodeling in response to high blood pressure (hypertension) in old DMO (18 months) was observed. This new project aims to study fetal programming of vascular remodeling mechanisms in response to maternal diabetes. To induce the remodeling process, a mesenteric artery ligation model was used to modify flow (remodeling aimed at normalizing wall stress and restoring optimal blood flow). Briefly, mesenteric arteries of 3 months-old animals issued from control mothers (CMO) or diabetic mothers (DMO) were ligated in order to decreased blood flow (LF). Proximal arteries had an increased blood flow (HF) and distant arteries were used at control (NF). Diameter of vessels were then analyzed by arteriography. Interestingly, we observed that at 7 or 21 days after ligation, DMO did not exhibit constrictive remodeling in LF although expansive remodeling in response to increased flow is maintained. These results show that in utero exposure to maternal diabetes induces a fetal reprogramming of vascular function of the newborn. 44- M. GAY Swann -2ème année – UMR 1066 Elaboration of polymers biobased foams using carbone dioxide a,b Swann Gay* a b a b a , Frank Boury , Alain Gibaud , Brice Calvignac Université d’Angers – Laboratoire MINT/INSERM 1066 Université du Maine – Laboratoire IMMM/CNRS 6283 58 The development of efficient and environmentally friendly materials is a major challenge nowadays. Supercritical fluid (SCF) processes provide clean and efficient alternatives to several technologies such as extraction, chromatography, crystallization and material processing. Carbon dioxide (CO2) is widely used as a SCF due to its non-toxicity and its easy reachable critical properties (Pc=73.8 bars, Tc=31.3 K). Moreover, modifications in CO2 temperature and pressure allow changing its physical properties, an interesting characteristic for plastic materials processing. Thus the development of porous polymeric materials using clean processes fits perfectly with this approach. Moreover polymeric foams are ever widely used in several applications such as transports, phonic or thermic insulation, filtration membrane or medical implant. So the manufacture of bio-based foams with green processes should be promising. In this way, this study has been dedicated to the foaming of polylactic acid (PLA) using supercritical CO2 (SC-CO2) . The PLA was chosen for its good environmental impact: biobased biocompatible, compostable. Two process approaches have been developed to produce PLA foams: one High Temperature Method (HTM) and low Temperature Methods (LTM). The first method uses SC-CO2 as a physical blowing agent. A PLA film is heated in a vessel and SC-CO2 is introduced and is dissolved into the polymer. Pressure and temperature are regulated during a fixed time and then the autoclave is depressurized at a constant rate until the ambient conditions. Hence, the CO2 contained into the PLA expands and induces the foaming. This method is solvent-free but it is necessary to heat at relative high temperatures (between 130 and 165 °C). The second approach is based on phase separation techniques at relatively low temperature (35-40°C). Two techniques of phase separation were investigated. In both methods, a solution of PLA (5 to 20% w/v) in an organic solvent is prepared. First method consists to induce the phase separation in the PLA solution with the introduction of SC-CO2, which acts as antisolvent, and involves the polymer precipitation and extraction of the solvent. In the second method, the phase separation was obtained when the polymer solution is soaked into liquid nitrogen, which freezes the PLA and solvent. Then the organic solvent is extracted with ethanol and an alcohol gel composed of PLA is obtained. Finally the gel is exposed to SCCO2 in order to extract ethanol and dry the PLA foam obtained. This work shows that the different processes permit to produce porous samples of PLA with tunable morphologies. The foams obtained were observed by scanning electron microscopy (SEM). Observations showed different cellular structures ranging from macro scale to micro scale with specific density included between 50 to 750 kg/m3. The PLA crystallinity was determined by X-ray diffraction (XRD), which varies according to the process and induces different foam morphologies. LTM HTM 59 45- MME. GRENIER Céline – 3ème année – CNRS 6214 Inserm 1083 Role of Thrombospondin -1 in the Remodeling Induced by a Chronic Increase in Flow in Resistance Arteries. Celine Grenier1, Antoine Caillon1, Linda Grimaud1, Audrey Ayer1, Bertrand Toutain1,Vincent Sauzeau2, Gervaise Loirand2, Olivier Blanc-Brude3, Daniel Henrion1, Laurent Loufrani1. 1 UMR Inserm 1083 UMR CNRS 6214 Department of Integrated Neurovascular and Mitochondrial Biology, Angers, France. 2 UMR Inserm 1087 CNRS UMR 6291 IRT-UN, NANTES, France 3 UMR Inserm 970 Paris-Cardiovascular research Center at HEGP, Paris, France Background : Chronic increases in blood flow in resistance arteries induce outward vascular remodeling due to increases NO-dependant dilation and MMP activation. Although thrombospondin-1 (TSP-1) interacts with matrix proteins and cell-surface receptors, controversy remains about its vascular functions. We investigate the role of TSP-1 in high flow (HF)-mediated remodeling of resistance arteries. Material and methods: Mesenteric arteries were ligated in vivo to generate HF arteries compared with normal flow (NF) vessels on wild type (WT) and TSP-1 deleted (KO) mice. Arteries were isolated from 4 days to 1 month after ligature. Arteries diameter and reactivity were studied in vitro in an arteriograph. Genes and proteins implicated in inflammation, remodeling, and immune cells recruitment were determined in HF and NF arteries. Results: Increases in diameter found between WT NF and WT HF arteries were not significant in KO arteries. Contrary to KO arteries the diameter increase in WT arteries were correlated to an increase in wall thickness. Furthermore KO arteries were less responsive to Ach induced dilation than WT arteries. After 4 days of ligature, we observed an increase in pro-inflammatory (CD68, Cox2, Gp91 phox, p47 phox, p22phox) gene expression between NF and HF WT arteries which was not observed in KO arteries. Moreover we also saw a rise in leukocytes number in response to chronic increase in blood flow in WT arteries, which was less important in KO arteries, suggesting a role of TSP-1 in the recruitment of immune cells allowing the inflammatory response leading to hypertrophic outward remodeling. In bone marrow cells transfer experiments, we also demonstrated that circulating cells secreted TSP-1 and vascular cells secreted TSP-1 are implicated differently in artery flowinduced remodeling (wall hypertrophy and diameter). Conclusion: The absence of TSP-1 leaded to a decrease in flow-induced dilation remodeling with a reduction of the inflammatory response and of the endothelium-mediated dilation involved in HF remodeling. The deficiency in remodeling was also associated with a decrease in the immune cells recruitment involved in the initiation of the remodeling. 46- MME. MONTAGU Angélique – 3ème année – U1066 Evaluation of interaction mechanisms between Acinetobacter baumannii bacteria and lipidic nanocapsules by flow cytometry. *A. Montagua,b, M-L. Joly-Guillouc, C. Guillet,, J. Bejauda,b, C. Gaillardd , E. Rossinese, and P. Saulniera,b Acinetobacter baumannii is an important nosocomial pathogen, resistant to many commonlyused antibiotics. Considering the limited number of antibiotics in development, interesting strategies could lay on the use of natural resources especially essential oils (EOs). An 60 interesting strategy underlined the antibacterial potential of EO components (carvacrol, cinnamaldehyde) loaded lipid nanocapsules (LNCs) against A. baumannii. The aim of this study was to produce and characterize DiO-LNCs loaded with antibacterial actives. The antibacterial activity of these nano-carriers was evaluated in vitro against A. baumannii. Finally, we determined the interactions between bacteria and LNCs over time thanks to the fluorescence of DiO-LNCs and the properties of trypan blue in order to precise the physicochemical mechanisms occurring at the level of the biological membrane. The results underlined the attractiveness of the encapsulated actives compared to unloaded-LNCs. These results demonstrated the capacity of carvacrol-loaded-LNCs to interact and penetrate the bacterial membrane in comparison with cinnamaldehyde-LNCs and unloaded-LNCs. Moreover, the fluorescence of bacteria remained constant after contact with carvacrol-loadedLNCs and cinnamaldehyde-LNCs whereas the fluorescence of the blank-LNCs decreased over time. This phenomenon could be explained by the release of these blank-LNCs by efflux pumps. Thereafter, modifications of carvacrol after substitution of hydroxyl functions by fatty acids (acetic acid, palmitic acid) demonstrated the crucial role of these latter for antibacterial activity. Finally, after contact with an efflux pump inhibitor CCCP (carbonylcyanide-3chlorophenyl hydrazine), the results underlined a total synergistic effect for Car-LNCs showing that the CCCP is associated with action mechanism of carvacrol especially at the level of efflux pump mechanism. 47- MME. MOUZOUVI Celia Rosemonde -3ème année –U1066 Use of Lipid Nanocapsules for air bubbles stabilization CRM MOUZOUVI1, 2*, KA BIGOT1, P SAULNIER2 1. UFR Pharmacie, Faculté des Sciences de la Santé, Université d’Abomey-calavi, Campus du Champ, 01 BP 188 Bénin. 2. INSERM U1066 – IBS-CHU, 4 rue Larrey 49933 Angers Cedex 9, France. Background: Lipid NanoCapsules (LNC), nano drug carriers, formulated by a phase inversion method are characterized by a shell constituted with two surfactants, Solutol® and Lipoïd®. After their formulation, their film properties at the air/water interface had been highlighted. Based on the findings of this study, our research wants to use these LNC film properties to produce gas bubbles for therapeutic applications. But before this application, the ability of LNC to decrease a surface tension at air/water interface must to be studied. Methods The drop tensiometer was used to measure a surface tension at the air/water interface. Different dilutions of the related suspensions have been prepared. . Interfacial stabilization by LNCs have been compared to interfacial stabilization by Solutol® alone. Results Lipid NanoCapsules decreased the surface tension from 72mN/m to 35mN/m. This action was better than the one induced by surfactants taken directly.. The particles size does not influence significantly the obtained values. The adsorption time of Lipid NanoCapsules was in the range, 1 hour and twenty minutes and 2 hours depending on the dilution factor. Conclusion The use of Lipid NanoCapsules instead of surfactants offers a possibility to stabilize air bubbles and to localize at their surface cargo systems that can be loaded with therapeutic agents. Key Words: Lipid NanoCapsules, surface tension, air bubbles. 61 48- M. FLEURY Audrey – 3ème année – U 1063 Microvesicles harboring Sonic Hedgehog suppress adipocyte differentiation via a noncanonical pathway. Sonic Hedgehog (Shh) is a morphogen that belongs to the highly conserved Hedgehog family proteins. Long-range signaling of Hedgehog can occur via secretion of dual-lipid modified proteins transported via extracellular vesicles. Our previous work has established the ability of a particular group of extracellular vesicles, microvesicles harboring Shh (MVsShh+), to correct endothelial dysfunctions, usually related to cardiovascular diseases. Non-lipid modified Recombinant Shh (RecShh) is also known as a potent anti-adipogenic factor. Here, we investigate the consequences of microvesicles harboring Shh (MVsShh+) on adipocyte differentiation. Methods: This study was carried out with a murine preadipocyte cell line, 3T3-L1, treated with RecShh or MVs specifically enriched with Shh (MVsShh+) or not (MVsShh-). MVs were retrieved from the lymphocytic cell line (T-CEM) conditioned media. Results: Incubation of preadipocytes with RecShh or MVsShh+ prevented adipocyte diffe C/EBPa). RecShh or MVsShh+ could no longer inhibit adipocyte differentiation in preadipocytes defective for the transmembrane receptor Smoothened (SMO), a critical transducer of Hedgehog signaling. However, downstream of SMO, factors involved in the inhibitory properties of RecShh or MVsShh+ were different. Treatment with RecShh induced a ciliary translocation of SMO leading to the induction of Gli factors expression whereas MVs inhibition properties were independent of SMO translocation and Gli expression. Furthermore, preincubation of preadipocytes with a SMO antagonist, cyclopamine, did not allow to reverse the MVsShh+ effects. These results revealed that Shh triggers different downstream pathways to inhibit adipogenesis depending on its association, or lack thereof, with microvesicles. Of particular interest, MVsShh+ stimulate a non-canonical Hedgehog signaling pathway in preadipocytes, which could participate in the regulation of body fat mass by modulating the pool of preadipocytes. 49- MME. VERGER Elise – 3ème année –U1066 Development of a new selective internal radiation therapy and diagnostic tool for Hepatocellular Carcinoma: the Starch-Based Microspheres E.Verger* [1,4,8] ; A. Cikankowitz [1,8] ; A. Bouvier [2] ; N. Lepareur [5,8] ; J. Benoit [1,8] ; J. Deloye [6] ; C. Aubé [2] ; O. Couturier [1,3,8] ; F. Lacoeuille [1,3,7,8] ; R. Hustinx [4] ; F. Hindré [1,7,8]. [1] INSERM U1066 MINT (Micro et Nanomédecines Biomimétiques), University of Angers, FRANCE ; [2] Radiology department, CHU d'Angers, University of Angers, FRANCE ; [3] Nuclear medicine department, CHU d'Angers, University of Angers, FRANCE ; [4] Nuclear medicine department, CHU de Liège, University of Liège, BELGIUM ; [5] Centre Régional de Lutte Contre le Cancer (CRLCC) Eugène Marquis, Rennes, FRANCE ; [6] Cyclopharma Laboratoires, Saint-Beauzire, FRANCE ; [7] PRIMEX (Plateforme de Radiobiologie et d'IMagerie EXpérimentale), University of Angers, FRANCE ; [8] Labex IRON, NantesAngers, FRANCE. Contact email: elise.verger@etud.univ-angers.fr ; Abstract: 62 The HepatoCellular Carcinoma (HCC) is the 2nd leading cause of cancer death. The internal radiation therapy (SIRT) of HCC can be realized by the injection of yttrium-90 microspheres (90YMS). This technique requires a pre-therapeutic step with an angiography and a scintigraphy realized by the injection of 99m-Technetium labelled macroaggregated albumin (99mTc-MAA). However the difference in size and morphology between the 99mTcMAA and the 90YMS can lead to a divergence in the biodistribution and an approximate tumour dosimetry. In order to overcome this problem, our aim is to develop a microparticulate system usable for both the pre-therapeutic step and the treatment itself: the Starch-Based Microparticles (SBMP). They were first developed in our laboratory (UMR-S1066) for lung scintigraphy by the optimization of ready-to-use 99mTc-radiollabeling kits1,2. As 99mTc a pure gamma-emitter and rhenium-188 (188Re) a beta and gamma emitter have similar physical chemical properties, both of them can label the SBMP with the advantage of a unique system for diagnosis purpose and therapy of HCC. The aim of this work is to develop and optimize a ready-to-use kit allowing the fast and stable labelling of SMBP with 188Re. SBMP are obtained by the modification of native starch particles in order to graft a ligand on their surface that will allow the labelling by 99mTc or 188Re. Different parameters like amount of microparticles, of reducing agent, of perrhenate activity or reaction’s volume were changed to optimize the radiolabelling reaction. The efficiency of the radiolabelling is assessed with measure of the radiochemical purity (RCP) by filtration (5µm filter). Also stability studies were performed following the RCP up to 24h. In comparison with 99mTc, the 188Re needs strengthened reducing conditions for a complete complexation onto the SBMP. Reducing agent and amount of microparticles are major influencing factors. At this stage of optimization we obtained a RCP around 90% (±5%) and a 24h stability. SBMPs show promising characteristics as a single agent for the diagnosis and SIRT therapy of HCC. References: 1. Lacoeuille, F. et al. European journal of nuclear medicine and molecular imaging 37, 146–55 (2010). 2. Lacoeuille, F. et al. Biomaterials 32, 7999–8009 (2011). 50- M. VETILLARD Alexandra – 3ème année – ICO Paul Papin Inserm U892 The Akt pathway as a target to prevent tumor escape and irinotecan resistance in colorectal cancer via regulation of BH3-only proteins. Alexandra Vétillard, Simon Fontanel, Anne-Charlotte Bernard, Barbara Jonchère, Zeina Antoun and Olivier Coqueret. ICO Paul Papin/INSERM U892, 2 rue Moll, 49033 Angers, France. Glaxo Smith Kline, 100 route de Versailles - 78163 Marly le Roi Cedex Reducing drug resistance and tumor escape in response to chemotherapy is a major goal of cancer research. Since cell transformation induces an intrinsic drug resistance program, it is essential to understand the link between oncogenic signaling and cell cycle and death pathways. Actually, most clinical trials define the best treatment for the average patient without taking into account tumor heterogeneity. Such unselected approaches represent a major limitation for the development and the success of new targeted therapies. Providing a strong knowledge of the oncogenic pathways potentially involved in drug resistance should improve therapy. We have focused on the role of Akt pathway in drug resistance in colorectal cancer. The Akt role in tumor escape is widely described by its many substrates involved in the cell growth and survival mechanisms. In our model, we have shown that the Akt pathway 63 was activated in response to irinotecan, the main treatment of colorectal cells. This activation of Akt suggested to us that this pathway might be used as a rescue signaling by cells in response to irinotecan. Using clonogenic assays, we showed that the use of the Akt inhibitor (GSK690693) in combination with sn38 induces a further enhancement of cell death. We and others have shown that genotoxic treatments such as topoisomerase inhibitors induce the upregulation of the p21waf1 cell cycle inhibitor and senescence. In this study, the use of GSK690693 in association with sn38 prevented this upregulation of p21waf1 and decreased senescence induction in response to treatment. No modification of p21waf1 localization was noticed. Moreover, GSK690693 limits the emergence of clones that escape senescence induced by sn38. Following the combination of treatments, we also detected an increase in the percentage of SubG1 cells and in caspase3 activation. This induction of apoptosis was explained by an upregulation of the proapoptotic Noxa protein. These results indicate the combined use of GSK690693 and sn38 induced an enhancement of cell death that can be explained by apoptosis induction. Thus, we propose that Akt targeting should be considered in the future to reduce senescence escape in colorectal cancer and improve the treatment of irinotecan-refractory cancers. 51- M. DAYOUB Ousama – 3ème année – U1063 Delphinidin and calcium signaling in human T lymphocytes: a basis to elucidate pathways leading to proliferation and apoptosis *Ousama DAYOUB, Nicolas CLERE, Ramaroson ANDRIANTSITOHAINA INSERM 1063, Oxidative Stress and Metabolic Pathologies (SOPAM), Angers, France The present study was designed to analyze the effect of delphinidin, an anthocyanin known to possess vasculo-protection properties, on T lymphocytes functions such as proliferation and apoptosis with respect to calcium signaling. Human T cells were isolated from blood of healthy patients. Proliferation was assessed using CyQUANT® NF Cell Proliferation Assay Kit and apoptosis by flow cytometry. Calcium signaling was analyzed using Fluo-4 probe and the mechanisms were depicted using appropriate pharmacological drugs. Delphinidin did not modify basal proliferation but it was able to decrease the phytohemagglutinin (PHA)-induced proliferation. Inhibitors of capacitative entry and estrogen receptor antagonist, fulvestrant, but not the NO-synthase inhibitor prevented the effect of delphinidin. In addition, delphinidin reduced actinomycin D - induced apoptosis via a mechanism sensitive to capacitative entry inhibitors. Interestingly, delphinidin decreased the ability of thapsigargin to increase both calcium release and entry. The effect of delphinidin was insensitive to the NO synthase inhibitor but partially prevented by fulvestrant. Together, these data suggest that delphinidin attenuates T lymphocyte activation via multiple cellular targets on the regulation of calcium signaling via estrogen antagonist sensitive and insensitive pathways. The consequence of which results in inhibition of both proliferation and apoptosis. These effects concur to the protective effect of delphinidin on processes leading to inflammation associated with T lymphocyte activation. 64 52- MME. SAFIEDEEN Zainab – 2ème année – SOPAM 1063 Stress du réticulum endoplasmique et syndrome métabolique : rôle de la mitochondrie et du stress oxydant Membrane microparticles (MPs), small vesicles with a diameter ranging between 0.05 and 1µm, are released from activated and/or apoptotic cells. MPs are considered as biomarkers but also as vectors of intercellular communication. Interestingly, elevated levels of MPs occur in many cardiovascular diseases and their levels usually correlated with the severity of the pathologies (Martinez et al., Trends Pharmacol Sci. 2011). We have previously shown that MPs from apoptotic T cells decreased nitric oxide production inducing endothelial dysfunction (Martin et al., Circulation 2004). Recent studies showed a relation between endoplasmic reticulum (ER) stress and endothelial dysfunction via the increase of oxidative stress in cardiovascular diseases (Galan et al. Biochim Biophys Acta. 2014). Moreover, ER stress can increase mitochondrial dysfunction and increase mitochondrial reactive oxygen species (ROS) production (Cao & Kaufman, Antioxid Redox Signal. 2014). Thus, the objectives of my Thesis are to study the link between ER stress components and endothelial dysfunction induced by MPs from metabolic syndrome patients, and to proceed to analyze the potential implication of ROS and mitochondria. For this, human aortic endothelial cells (HAOECs) were incubated with MPs. Western blot, RT q PCR & semi quantitative PCR were made for ER stress components, in the absence or in the presence of TUDCA (ER stress inhibitor). MPs induced increased eIF2 phosphorylation and, BIP and CHOP expressions. Also, splicing of XBP-1 was enhanced. All of these effects were prevented by TUDCA. These results suggest that MPs induce ER stress. Further experiments are needed to determine the implication of mitochondria in the effects induced by MPs. 53- MME. TERRANOVA Lisa – 2ème année - GEROM DEVELOPMENT AND CHARACTERIZATION OF POLYMER SCAFFOLDS BASED ON NANOFIBERS Terranova L* a ; Mallet R a,b ; Perrot R a,b ; Pascaretti-Grizon F a ; D Chappard a,b a GEROM laboratory, University of Angers, Institut de Biologie en Santé, Angers, France b SCIAM - University of Angers, Institut de Biologie en Santé, Angers, France INTRODUCTION: The occurrence of large bone defects after hip revision or cancer surgery requires massive bone grafts to compensate the massive bone loss mass. Currently, there are many synthetic bone substitutes (resorbable polymers, ceramics). However, they are limited in the case of large bone defects due to insufficient biomechanical properties in weight bearing sites. The aim of this study was to create non-resorbable porous scaffolds of a synthetic polymer. These scaffolds are intended to provide large surface areas suitable for the development of vascularization, osteoprogenitor cell migration and ingrowth. METHODS: Polymer solutions were prepared by dissolving polymer beads (polystyrene) in dimethylformamide at a concentration of 20% and 30% (w/v). The scaffolds were prepared by electrospinning. Several parameters control the electrospinning process such as the polymer solvent, concentration of polymer solution, flow rate of the solution, voltage applied to the injector and the collector… Scaffolds with random fibers or aligned fibers were synthesized. Fractal dimensions (Dsky, Dcross, D|,D ̶) of the two types of scaffolds were determined to compare the spatial arrangement of the fibers. In vitro experiment: osteoblast-like cells (SAOS-2) were seeded on the scaffolds at a density of 1 x 104 cells/cm² and incubated at 37°C with 5% CO2 for 14 days. Two types of scaffolds were prepared with ~1.5 and 4.5µm aligned thick fibers and two types with ~1.5 and 3µm 65 random thick fibers. Scaffolds seeded with cells were fixed and dehydrated. DAPI was used to stain the nucleus of the cells under UV microscopy. Scaffolds were characterized by SEM after carbon sputtering. Confocal microscopy of the scaffolds was possible after adding a fluorescent dye (Nile Red) to the polymer solution. RESULTS: Fractal dimensions of random fibers were higher than those of aligned fibers indicating that random fibers significantly occupy more space. In cell culture, a dense layer of cells was observed in each scaffold. Cells were aligned along the long axis of the fibers. CONCLUSION: Electrospinning produced different types of polymer scaffolds with random or aligned fibers of different diameters. The next steps of the study will comprise alkaline phosphatase assay and total protein dosage to evaluate cell density on the scaffolds. This will clarify the influence of fiber distribution and fiber diameter in cell adhesion and proliferation. 54- MME. CEBRON Nora – 2ème année – LABERCA - ONIRIS SELECTIVE ANDROGEN RECEPTOR MODULATORS : ZOOTECHNICAL EFFECTS AND ANALYTICAL STRATEGIES TO DETECT THEIR ADMINISTRATION IN BOVINES N. CESBRON*1, G. DERVILLY-PINEL1, C. VERNET1, M. PENOT1, A. GICQUIAU1, F. MONTEAU1 AND B. LE BIZEC1 1: LUNAM Université, ONIRIS, Laboratoire d’Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France Selective androgen receptor modulators (SARMs) are a novel class of androgen receptor ligands. They are intended to exhibit the same kind of effects as androgenic drugs, like anabolic steroids, but be much more selective in their action, targeting particular tissues (muscle for example) without any undesirable effects on other tissues. While main applications of these synthetic substances are for therapeutic purposes, they will also have a high potential for misuse in veterinary practice and the sporting world. In order to guaranty the consumers with food from animal origin free from any residues of such compounds, analytical strategies are required to ensure safe food and also enable fair trade between producers. First objective of the present study was to investigate zootechnical performances associated to an oral administration of enobosarm (MK-2866/GTX-024/Ostarine®) in calves through the assessment of various parameters of growth (liveweight gain, growth rate, intake efficiency) and development (widtht of hips, girth circonference, pelvis muscle depth, size, BCS). Second objective was to study SARMs kinetics of elimination and metabolism for further development and implementation of a dedicated analytical strategy to detect such practice. No significant zootechnical effect in favour of treated animals versus control after an oral administration of enobosarm could be observed. Such a result may be explained by either the design of the administration (low dose, treatment lenght) or the animal physiology (ineffectiveness to the young entire male calf...). After an oral administration, enobosarm are eliminated within a week in urine. Extensive metabolism occurs under phases I and II metabolites. LC-ESI(-)-MS/MS enables efficient detection over a long period after treatment. 66 55- DUVAL Julie – 2ème année –UMR Bio Epar Can a participatory approach adapting a structured framework for disease monitoring and prevention to farm-specific situations improve animal health in organic dairy farms? – An intervention study. Today tools to improve animal health are often available in the format of ‘Good practices protocols’ which are inconsistently implemented on farms. Innovative methods have to be designed to improve compliance, effectiveness of health plans and finally animal health. We hypothesize that this can be achieved by a more thorough understanding of the farming system and farmer’s specific situation. This is possibly even more important in organic dairy production systems where production specifications induce more constraints in herd and animal health management compared to conventional systems. We aim to evaluate the effectiveness of a participatory approach that adapts a systematic structured framework for disease monitoring and prevention to farm-specific situations in French organic dairy farms. Twenty-one organic dairy farmers and their advisors in animal health will implement the protocol; five farm visits are planned in a period of 12 months on each farm. The objective of the first visit is introducing the disease monitoring and prevention protocols. Secondly, selecting farm specific indicators for the monitoring of the main production diseases (mastitis, lameness, reproductive failure, metabolic disease and calf health) and define farm specific herd health alert thresholds. During the visits 2 to 5, in absence of the researcher, herd health will be monitored using the chosen indicators and alert thresholds. Preventive protocols are reinforced if the animal health situation requires. The design of the preventive protocols is as such that it lists the objectives to attain to prevent disease. This approach will provoke a discussion between the farmer and his advisor on the farmer’s animal management practices. The discussion is essential to be able to identify objectives that are not attainted and thus the risk factors for disease present on the farm. The epidemiological design of the study will allow to show the effectiveness of the intervention in terms of compliance of farmers to corrective measures proposed by advisors and improvement of animal health compared to control farms. Control farms are located in the same geographic area, with comparable feeding practices, herd size and milk production level. We expect to demonstrate high compliance of the farmer to proposed corrective measures by the advisors and consequently an improved animal health situation compared to control farms. We will also gain insight in the objectives of organic dairy farmers and advisors regarding herd health by using the data of the identified herd health indicators and alert thresholds. Furthermore the described measures and constraints in the preventive protocols will provide insight on ‘good practices’ that are used and applicable to organic dairy farms. The results of this study could be the first step in developing an innovative and effective disease monitoring and prevention protocol for dairy farms. And the protocol could be applied in conventional dairy farms as well. 56- MME. LORANT Judith – 2ème année – UMR 703 – PanTher INRA/ONIRIS In vitro and in vivo characterization of immunomodulatory properties of MuStem cells Judith LORANT*1,2,3 Nicolas JAULIN3,4, Thibaut LARCHER1,2,3, Benoit HEDAN5, Jack-Yves DESCHAMPS1,2,3,6, Isabelle LEROUX1,2,3, Céline ZUBER1,2,3, Cindy SCHLEDER1,2,3, Mireille LEDEVIN1,2,3, Maéva DUTILLEUL1,2,3, Hélicia GOUBIN1,2,3, Corinne JOUNIER2,3,6, Sophie MOULLEC2,3,6, Catherine ANDRE5, Yan CHEREL1,2,3, Oumeya ADJALI3,4 and Karl ROUGER1,2,3 67 1 INRA UMR703 PAnTher, F-44307 Nantes, France LUNAM Université, Oniris, École nationale vétérinaire, agro-alimentaire et de l’alimentation Nantes-Atlantique, Nantes, F-44307, France 3 Atlantic Gene Therapies, F-44000 Nantes, France 4 INSERM UMR1089, Nantes University Hospital, F-44000 Nantes, France 5 Institut de Génétique et Développement UMR 6290 CNRS-Université de Rennes1, F-35043 Rennes, France 6 Boisbonne gene and cell therapy Center, F-44307 Nantes, France Contact: judith.lorant@oniris-nantes.fr 2 Duchenne Muscular Dystrophy (DMD) is a genetic muscle disease caused by mutations in the dystrophin gene. To date, no curative treatment is available but adult stem cell-based therapy is one promising therapeutic strategy. We have already demonstrated that allogeneic musclederived delayed adherent stem cells (that we called MuStem) are able to phenotypically correct at clinical and tissue levels the Golden Retriever Muscular Dystrophy (GRMD) dog model (Rouger et al., 2011). Recently, some tissue-specific stem cell populations were shown to exhibit immunomodulatory properties that could increase their ability to engraft in an allogeneic recipient despite the absence of strong immunosuppression and improve their regenerative potential. To explore whether MuStem cells also exhibit such immunoregulatory properties, we transplanted dog leukocyte antigen-identical MuStem cells from healthy donors in GRMD dogs, under an immunosuppressive regimen, which was arrested two weeks after intra-arterial cell delivery. Monitoring of host humoral and cellular immune responses against transplanted MuStem cells and neosynthetized dystrophin protein are in progress. Concomitantly and from a clinical perspective, we have generated human MuStem cells. Interestingly, our preliminary data show the ability of MuStem cells from different donors to modulate allogeneic T cell proliferation and to express immunomodulatory molecules such as prostaglandin-E2 and indoleamin-2,3-deoxygenase-1. In conclusion, our study is critical for the understanding of the crosstalk between MuStem cells and the immune system, as well as the design of safe and efficient allogeneic stem cellbased therapy for the treatment of DMD patients. 57- MME. JALOVECKA Marie -3ème année – UMR ONIRIS/INRABIOEPAR 1300/IPTH Molecular interactions between the immune system of the tick Ixodes ricinus and the protozoan parasite Babesia spp. My doctoral thesis aims to study of multiple molecular interactions between Babesia parasite and tick as its vector. Babesia spp. are apicomplexan protozoa responsible for babesiosis, malaria-like disease of various vertebrate hosts. Despite a growing attention paid to babesiosis as an emerging disease from the aspects of veterinary and human medicine, the knowledge of interactions of Babesia and tick is still insufficient. To study these interactions, the first and necessary target of my thesis is the development of an effective transmission model of a selected Babesia strain to the tick vector and the model mammalian hosts in laboratory conditions. So far, two laboratory in vivo and in vitro babesiosis transmission models were established, between two important emergent zoonotic babesiosis agents, B. microti and B. divergens, and their vector Ixodes ricinus.To simulate natural transmission cycle of B. microti, the primary cause of human babesiosis in the United States, we established an in vivo transmission model based on infected laboratory mice and immature tick stages. On the contrary, for B. divergens, the principal agent of European bovine as well as human disease, we implemented an artificial feeding technique of tick females using an in vitro culture of B. divergens in bovine red blood cells, which desirably imitates the natural transmission cycle. Introduction of both laboratory models enables investigation of mutual molecular interactions 68 of Babesia and ticks, the second aim of my thesis. In order to identify candidate molecules involved in immune response of tick to Babesia infection, the bioinformatical analyses is being performed in cooperation with other laboratories. Based on transcriptome results, the genes with putative roles in Babesia transmission and survival will be evaluated using the technique of tick genes silencing (RNA interference). The result of the thesis will then be the identification and characterization of tick immune molecules which can reduce the burden of Babesia infection. Acknowledgement: Grant Agency CR No. 13-11043S, 13-27630P, 13-12816P and INRA, France. M. J. is supported by the Dual Czech-French PhD. program. 58- MME.ZEYNEP ERGUL – 3ème année –UMR 1066 DOUBLE HYDROPHILIC POLYPHOSPHOESTER CONTAINING COPOLYMERS AS EFFICIENT TEMPLATING AGENTS FOR CALCIUM CARBONATE MICROPARTICLES Ergul Yilmaz Zeynep1*; Debuigne Antoine 1; Calvignac Brice2; Boury Frank2; Jerome Christine1 1 Center for Education and Research on Macromolecules (CERM), Chemistry Department, University of Liège (ULg), Sart Tilman, B-4000, Liège, Belgium 2 INSERM U1066, Micro-Nanomedécines Biomimétiques, University of Angers, 4 rue Larrey, Cedex 9, 49933, Angers, France Drug delivery systems (DDS), often require biodegradable and biocompatible materials that permit safe retention as well as controlled delivery of a drug. CaCO3 particles are safe and biodegradable drug carriers that have excellent properties such as low density, high specific surface areas and porosity for drugs microencapsulation. [1] The formulation of particles always requires a templating agent which influences the particle size, shape and porosity. Mostly, hyaluronic acid (HA) is used as a templating agent for the synthesis of CaCO 3 particles but the search for new efficient candidates able to adjust and decrease the size of the particles is still relevant. In this context, we develop a novel class of polyphosphoesters (PPE) based copolymers dedicated to the structuration of the CaCO3 particles. PPE was considered because of its biocompatibility, biodegradability. We introduced acid functions or negatively charged oxygen atoms along the PPE segment to enhance its calcium affinity and so its ability to tune the morphology of the CaCO 3 particles. PPE copolymers with acid pendant groups 3 and the negatively charged polyphosphodiester-based copolymers 6 were prepared by organocatalyzed ring opening polymerization (ROP), initiated from poly(ethylene oxide) PEO-OH (see scheme).[2] The alkyne functions of the PPE copolymers 2 functionalized by the thiol-yne addition of carboxylic acid containing thiol derivatives under UV irradiation. [3] The negatively charged polyphosphodiester-based copolymers 6 were synthesized by nucleophilic deprotection of the allylic group. Scheme: General strategy for the synthesis of PEO-b-PBYPCOO- (3) and PEO-b-PDPO- (6) Copolymers 3 and 6 were then tested as templating agents for the preparation of CaCO 3 particles by the classical chemical pathway and the supercritical CO2 (Sc-CO2) route [4]. The morphology of the resulting particles was then compared to the one of particles obtained with the HA. The synthesis involving Sc-CO2 and 69 the copolymer 3 with pendant carboxylic groups was particularly interesting and led to smaller (~1.5 µm) and non-aggregated particles. In the future, the impact of the copolymer structure and of the particle size on the encapsulation and release processes will be investigated. References 1. T. Beuvier et al., J. Mater. Chem., 2011, 21, 9757. 2. B. Clément et al., Macromolecules, 2012, 45, 4476. 3. S. Zhang et al., J. Am. Chem. Soc., 2012, 134, 18467. 4. L.Hassani et al., J. Mater. Chem., 2013, 1, 4011. 59- M. PACAUD ROMAIN – 3ème année – CRCNA / LAB CT Demethylation-associated proteins interact with transcription factors to promote targeted DNA demethylation Romain PACAUD1-2-3 *, Mathilde CHERAY1-2, Arulraj NADARADJANE1-2, François M. VALLETTE1-2-3, Pierre-François CARTRON1-2-3 1 Centre de Recherche en Cancérologie Nantes-Angers, INSERM, U892, Team Apoptosis and tumor progression, 8 quai Moncousu, BP7021, 44007 Nantes, France 2 Université de Nantes, Faculté de Médecine, Département de Recherche en Cancérologie, IFR26, F-4400, Nantes, France 3 LaBCT, Institut de Cancérologie de l'Ouest, Boulevard J Monod, 44805 Nantes, Saint Herblain Cedex, Nantes The description of direct interaction between DNMT and transcription factors (TFs) provides a rational molecular explanation to the mechanisms of targeted DNA (hyper)methylation, and to the mechanisms by which transcription factors repress genes expression (Hervouet & al. 2009, Epigenetics; Hervouet & al., 2010., Genes & Cancer; Pacaud & al. 2014, Biochimie). On contrary, the molecular mechanisms involved in the site-specific DNA demethylation are not fully elucidated. By focusing on TRAF1 promoter, MeDIP, hMeDIP and TAB-seq experiments indicated that TRAF1 is subject to a dynamic methylation/demethylation process. Indeed, our data revealed that the methylation of TRAF1 promoter is mediated by a DNMT3B/p65-NFkB/DNMT3L complex (Pacaud & al. 2014, Biochimie), while the demethylation of this promoter is mediated by multiprotein complexes including the TET3, AID or SMUG1 proteins. ReChIP and co-immunoprecipitation experiments suggested that TET3, AID and SMUG1 were recruited on TRAF1 promoter by composing complex with Sp4, cETS1 and RXRa, respectively. The fact that siRNA directed against these TFs decreasing the recruitment of TET3, AID and SMUG1 on TRAF1 promoters, reinforces the idea that TFs could play the role of anchor for the recruitment of TET3, AID and SMUG1 on TRAF1 promoters (data not shown). TF array experiments indicated that TET3, AID and SMUG1 (i.e. three demethylationassociated proteins - DAP) could interact with certain TFs: 23/42 for TET3, 6/42 for AID and 5/42 for SMUG1. P-LISA and co-immunoprecipitation experiments have confirmed these results (data not shown). As illustrated for TET3, we finally noted that certain TFs interacting with DAP have also the ability to interact with DNMTs. Consequently, it seems that the DNMT/TF complexes and DAP/TF complexes could form a system able to regulate the methylation status of the specific CpG dinucleotide (a system comparable to the regulation of the phosphorylation level of proteins by the kinase/phosphatase system). 70 60- M. HIVERNAUD Vincent - 2ème année – UMR 791 Comparison of current protocols for Autologous Fat Grafting Vincent Hivernaud1, 2, 3, Bruno Lefourn5, Jérôme Guicheux2, 3, 4, Anne-Claire Girard1, Pierre Weiss2, 3, 4, Régis Roche1 1 STEMCIS, Plateforme CYROI, Sainte Clotilde, Ile de la Réunion, France Université de Nantes, Faculté de Chirurgie Dentaire, Nantes, France 3 INSERM, UMRS 791, LIOAD Nantes, France 4 CHU Nantes, Pole Hospitalo-universitaire 4 OTONN, Nantes, France 5 Département de Chirurgie Plastique et Reconstructive, Clinique Bretéché, Nantes, France 2 Background: Autologous fat grafting (AFG) is used for aesthetic (volume augmentation) and reconstruction purposes to treat adipose tissue defects (lipodystrophies) or injuries (burn scars, mastectomy…). Despite great interest for these procedures, the major limit of AFG is the important graft resorption that occurs several weeks after injection (from 10% to 60% depending on injection site, volume and protocols). Furthermore, there is still no consensus concerning the way to process fat from liposuction to injection, leading to highly variable results. Several studies tried to determine the impact of each steps but have failed to investigate the whole protocol and therefore usually conclude on partial recommendations. Methods: This study aimed to compare 5 clinically available protocols: (1) Coleman protocol, (2) Water Assisted Lipoaspiration (WAL), (3-4) Micro and Macrofill kits and (5) Power Assisted Lipoaspiration (PAL) combined with a filtration. An in vitro model of tissue culture was used to evaluate oil formation (caused by adipocyte death) and pro-inflammatory cytokine secretion (IL6 and MCP1). Then, tissues obtained and processed with the 5 protocols were grafted subcutaneously in immunocompromised mice. Animals were sacrificed after 4 weeks, and histological analyses of the tissue were done (oil cysts, necrosis and fibrosis). Results: The in vitro model of tissue culture showed a greater amount of remaining tissue at 48h with protocols using a centrifugation to remove the liquid phase before reinjection (Coleman, Macrofill and Microfill). The oil formed during this two days remains under 2% of the initial volume in all tested protocols. Concerning cytokines implicated in inflammation, the IL6 secretion seems to be correlated with the tissue manipulation and the MCP1 secretion appears to be lowered after a washing step. The animal model results are in concordance with the in vitro observations in term of resorption. The histological analyses will allow a greater comprehension of the tissue formed with each protocols. Conclusions: Those preliminary results highlight the benefit of centrifugation to concentrate the adipose tissue before reinjection to discard all the liquid phase which will be resorbed. Moreover, it seems that protocols with a washing step removing dead cells fragments can lead to a less inflammatory secretome. Histological results will determine the real fate of reinjected tissue in a living recipient site. 61- MME. BEUCHER Laure – 3ème année – LABERCA- ONIRIS New technologies to face challenges in the detection of growth promoters’ abuse Laure Beucher*, Gaud Dervilly-Pinel, Fabrice Monteau, Bruno Le Bizec LUNAM Université, Oniris, Laboratoire d’Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France Abstract: 71 Because they enhance feed conversion efficiency and induce animal weight gain, some veterinary drugs can be used as growth promoters on farm animals. However, their welldocumented adverse effects on human health (food poisoning, cardiovascular and central nervous diseases) together with unfair trade issues have led some countries or part of the world (e.g. Europe) to ban their use over the past decades. Therefore, to comply the ban and ensure the consumers with safe food, monitoring rearing practices but also the products of animal origin are necessary. According to the European regulation in force highly sensitive and specific analytical methods for identification of residues at trace levels in animal tissues or fluids have to be continuously improved to face new practices (low dose cocktails, natural hormones …). Monitoring such practices is generally achieved targeting residues of interest by liquid or gas chromatography associated to electrospray ionization mass spectrometry (Q-q-Q in selected ion of multiple reactions monitoring mode). Alternative analytical strategies however have to be developed for continuous and improved efficiency of the detection. Among the latest innovations, traveling-wave ion mobility separation (TWIMS) coupled to Quadrupole-Timeof-Flight mass spectrometer (Q-TOF MS) has been investigated to tackle major analytical issues such as co-eluted compounds, related ion suppression, closed mass-to-charge ratios and sensitivity limits. The idea behind is to obtain a signal cleaning based on an extra TWIMS dimension of separation in gas phase. Such an additional dimension, called drift time, is closely related to the unique physiochemical properties of each molecule in its ionized form (size, charge and conformation). Based on calculated drift times, Collision cross sections (CCS) can subsequently be determined to provide valuable information on ions’ spatial arrangement. As a consequence, such a technology provides an additional criterion for the characterization of target compounds. Ions are finally defined by their retention time, their mass-to-charge ratio, their fragments AND their CCS for unique and unambiguous determination. In this research work, we have assessed this innovative technology for different anabolic compounds chemistry, different introduction modes (Direct injection, Liquid Chromatography and/or Supercritical Fluid Chromatography), but also different biological matrices (urine, meat, retina and feeds). Results will be presented showing the matrix effect on ion mobility separation and the interest of the strategy in terms of sensitivity, specificity and repeatability of the Ion-Mobility mass spectrometry results. Keywords: Growth promoters, food safety, ion mobility separation *Corresponding authors: laure.beucher@oniris-nantes.fr Tel.:+33 658 634 112 Fax: +33 240 687 878 62- MME. VALCOURT Chantal – 3ème année –Inserm U1066 Synergistic interaction between the terpenic components of essential oils and ATB01 against Acinetobacter baumannii. Objectives Antibiotic resistance has become a major clinical and public health problem. Essential oils (EO) are odorous substances contained in plants. Some of them have antibacterial properties. We have selected a mixture of three major constituents of different EO. We have selected a mixture of three major components of different EO: EP1010 (a methoxyphenol), EP1011 (an aldehyde) and EP1012 (a phenol), and an antibiotic of the glycopeptide class (ATB01). ATB01 is not effective against Gram-negative bacteria because their intrinsic resistance against this antibiotic is mediated by porins. The use of ATB01 in combination with EO which have the ability to destabilize the membrane of bacteria might facilitate the passage of 72 the former so that it can pursue its action. The aim of this work was to combine ATB01 with essential oils in order to make the former effective against a multiresistant gram negative bacteria, e.g. Acinetobacter baumannii. Methods A mixture of equal amounts of EP1012, EP1010 and EP1011 was encapsulated in the core of lipid nanocapsules (LNC) formulated via a phase inversion method in order to make the EO suitable for injection. The fractional inhibitory concentration index (FICI) was determined using the checkerboard method. Synergy was studied via a time-kill assay. The LNCs, the non-encapsulated EP1012-EP1010-EP1011 and the ATB01 were tested at concentrations of 425μg/mL, 310μg/mL and 2μg/mL, respectively. The samples were collected after 0, 3, 6 and 24 hours. Scanning electron microscopy (SEM) was used to visualize the changes in the bacterial membrane. Results The results of bactericidal kinetics are presented in Figure. The combination of ATB01 and loaded LNCs showed a synergistic and bactericidal effect. A 3 log difference between the combination and the LNCs (bacteriostatic effect) was found, whereas in the presence of ATB01 alone, bacteria had the same growth as the control. A synergistic effect (a 3 log difference) was also observed for the combination of non-encapsulated compounds and ATB01. The FICI values obtained via a checkerboard method were of 0.32. The results were supported by the SEM showing a bacterial lysis more pronounced for the combination of ATB01 with EO. Conclusion The combination of ATB01 with EOs-loaded LNCs allowed the use of antibiotic doses which are not active when used alone. The active agents that were used (especially EP1012), which destabilize the bacterial membrane, allowed the passage of ATB01 which inhibits the synthesis of the peptidoglycan. The use of the EO with antibacterial activity and the antibiotics in a combination offers an excellent opportunity for the use of the antibiotics otherwise inactive against certain bacteria. 63 - M. LE GUEN Valentin – 3ème année – UMR 1064 Liver gene transfer induces tolerance toward allogeneic MHC I molecule Valentin Le Guen1, Jean-Paul Judor1, Vanessa Gauttier1, Nicolas Ferry2, Sophie Brouard1 & Sophie Conchon1 1INSERM UMR1064, Centre for Research in Transplantation and Immunology, ITUN, CHU Hotel Dieu, Nantes, France. 2UMR 948 Biothérapies Hépatiques, INSERM, Nantes, France The liver presents unique immunological properties. Gene therapy studies have demonstrated that liver-targeted expression of a therapeutic transgene with viral vectors can result in tolerance induction and long-term expression of the product of the transgene. Our aim was to study whether these observations could be extended in an allogeneic context. C57Bl/6 mice (H-2b) were injected with an adeno associated virus (scAAV) encoding the allogeneic MHC class I molecule H-2K(d) under a liver-specific promoter (scAAV H-2K(d), or control scAAV ct, 1012 vg/kg, i.v.). Time course of H-2K(d) expression in the liver was studied by RT-qPCR, and immunofluorescence. Sera were studied to follow the appearance of allo-specific antibodies. Liver non parenchymal cells (NPCs) were isolated at different time points to characterize the immune cell populations. High level of expression of H-2K(d) was detected in the liver of the mice for at least 150 days after AAV injection. No H-2K(d) specific antibodies could be detected. As soon as 2 weeks after AAV injection, a strong leukocyte infiltration was specifically observed in the liver of the AAV H-2K(d) injected mice. Among them, there was an increased population of CD8+ T 73 cells positive for the activation markers CD44 and CD69, and CD62L negative. These activated CD8 T cells have an exhausted phenotype and express high levels of PD-1, Lag3 and CTLA-4 but low level of IL-7R. Liver targeted expression of H-2K(d) via AAV gene transfer induced a dramatic decrease in the humoral and cellular immune response triggered by intramuscular immunization with an adenovirus encoding H-2K(d) : low level of H-2K(d) specific antibodies, decreased IFNγ secretion and proliferation of liver and splenic CD4 and CD8 T cells compared to Ad H-2K(d) immunized mice. Together, these results give strong evidence that AAV mediated liver expression of H-2K(d) induces tolerance toward the alloantigen. The tolerogenic potential of allogeneic MHC class I molecule expression in the liver is currently tested in a fully allogeneic transplantation model in mice 64- MME. JOUNI Mariam – 2ème année – Institut du thorax Cardiac arrhythmias modeling using hiPSC-derived cardiomyocytes Mariam Jouni1,2, Karim Si-Tayeb1, Zeineb Es-Salah-Lamoureux1, Xénia Martin-Latypova1, Anaïs Rungoat1, Flavien Charpentier1, Gildas Loussouarn1, Kazem Zibara2, Patricia Lemarchand1, Nathalie Gaborit1. 1- L’institut du thorax – UMR INSERM 1087/CNRS 6291 – IRS UN, 8 quai Moncousu, BP70721 44007 Nantes Cedex 1, France 2- Doctoral School of Science and Technology (DSST-PRASE), Lebanese university (UL), Hadath-Lebanon. Purpose: Channelopathies associated with cardiac arrhythmias have essentially been studied in heterologous systems or animal models, independently of the patients’ genetic background. However, the alteration of channel functions may lead to remodelling of other proteins, which would be missed in such models. Because sources for human cardiomyocytes are extremely limited, the use of urine samples to derive cardiomyocytes would be a non-invasive and elegant way to get a clearer overview of the affected cardiac electrical functions that lead to pathologies, while expressing the patient gene pool. We set up an experimental approach to obtain and characterize cardiomyocytes differentiated from urine-derived pluripotent stem cells (UiPS-CMs), from a patient with Long QT syndrome. This patient presents a mutation on hERG KCNH2 gene (p.A561P). Methods: Cells obtained from urine sample from the A561P patient and his asymptomatic (not mutated) mother were reprogrammed using the episomal-based method. Urine-derived iPS cells were then differentiated into cardiomyocytes using the matrix sandwich method with modifications. Gene and protein expressions of ventricular-specific markers were analyzed, and optical recording of Action Potentials was performed using the high throughput CellOptiq system. Voltage-clamp and current-clamp experiments were also conducted to record hERG ionic currents as well as action potentials from UiPS-CMs. Results: UiPS cells could be differentiated into functional cardiomyocytes with proper expression of ventricular cytoskeletal proteins and ion channels. These UiPS-CMs were electrically functional, with nodal-, atrial- and ventricular-like action potentials recorded using both CellOptiq and patch-clamp techniques. Application of ajmaline, 4-aminopyridine, nifedipine, 293B or E-4031 to the differentiated cardiomyocytes confirmed the contribution of INa, Ito, ICa, IKs and IKr currents, respectively, to shape the action potentials. Comparing hERG channels expression from the patient’s UiPS-CMs to those from the mother’s allowed to establish that the mutation led to a trafficking defect that resulted in a reduced IKr current. This phenotype was accompanied by lengthened action potentials that sometimes resulted in observable arrhythmias (early afterdepolarizations). 74 Conclusion: Urine-derived pluripotent stem cells from ion channels mutation-bearing patients can be used as novel models to differentiate functional cardiomyocytes that recapitulate cardiac arrhythmia phenotypes. 65- SCARLATA Clara Maria – 3ème année – UMR 1102 Differential expression of the immunosuppressive enzyme IL4I1 in human induced Aiolos+, but not natural Helios+, FOXP3+ Treg Clara-Maria Scarlata 1, Clothilde Celse 1, Pascale Pignon 1, Maha Ayyoub 1 and Danila Valmori 1,2 1 Institut National de la Santé et de la Recherche Médicale, Unité 1102, Equipe Labelissée Ligue Contre le Cancer, Institut de Cancérologie de l’Ouest, Nantes-Saint Herblain, France 2 Faculty of Medicine, Universityt of Nantes, Nantes, France Abstract IL4I1 codes for an L-phenylalanine oxidase that inhibits T cell proliferation. It has been recently reported that the IL4I1 is expressed in TH17 as part of a mechanism that limits their pathogenicity. Based on our previous identification of a population of human FOXP3+ Treg that secrete IL-17 ex vivo, here, we addressed the expression of IL4I1 in Treg. We found that the IL4I1 expression is induced by stimulation in ex vivo isolated circulating Treg, and is restricted to cells that do not express Helios, a transcription factor that characterizes natural Treg (nTreg), but express Aiolos, that is involved in the differentiation of TH17 and induced Treg (iTreg). We also found that stimulation of Treg under inflammatory conditions increases IL4I1 expression, likely as a part of a regulatory loop that attempts to limit the pathogenicity resulting from their conversion into TH17 . 66- M.DUPONT Jean-Baptiste - 2ème année –UMR 1089 Short Persistence of rAAV transgene expression in dystrophic mice correlates with oxidative damage to transgene mRNA Jean-Baptiste Dupont*,1, Benoit Tournaire1, Laurence Jeanson-Leh2, Laurence Dubreil3, Christophe Georger2, Pierre Lindenbaum4, Béatrice Marolleau2, Mireille Ledevin, Emilie Lecomte1, Benjamin Cogné1, Thibaut Larcher3, Bernard Gjata2, Laetitia Van Wittenberghe2, Richard O. Snyder1,5,6, Philippe Moullier1,4 and Adrien Léger1. 1 UMR INSERM 1089, Nantes, France, 2 GENETHON, Evry, France; 3 UMR INRA ONIRIS 703, Nantes, France; 4 Inserm UMR 1087 / CNRS UMR 6291, Nantes, France; 5 Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, United States and 6 CERHB, University of Florida, Gainesville, United States. Duchenne Muscular Dystrophy (DMD) is an X-linked recessive illness for which there is no definitive treatment. Preclinical gene therapy strategies using recombinant Adeno-Associated Virus (rAAV) vectors to deliver therapeutic transgenes in animal models of DMD have shown dramatic phenotype improvements but long-lasting efficiency remains questionable. Long term post rAAV delivery, recent studies reported a progressive reduction of transgene expression which was solely attributed to the loss of vector genomes resulting from the destruction of dystrophic muscle fibers. However, the impact of intracellular metabolic perturbations on transgene mRNA stability was not investigated. In this study, we precisely characterized the contribution of rAAV genome loss, transcriptional and post-transcriptional regulations on the reduction of transgene mRNA level after rAAV injection in DMD mice. 75 Thanks to robust quantitative PCR experiments, we showed that rAAV genome loss cannot fully explain the reduction of transgene mRNA level. We ruled out the implication of epigenetic silencing mechanisms and further demonstrated that rAAV inhibition occurred at the post-transcriptional level. Since DMD physiopathology involves the deregulation of oxidative metabolic pathways, we used RNA Immunoprecipitation to measure the level of Guanine hydroxylation along transgene mRNA, an oxidative damage known to inhibit translation and alter RNA metabolism. We found that rAAV-derived mRNA oxidation was significantly enhanced in dystrophic muscles compared with healthy controls. Altogether these findings provide new insights into host-vector interactions at the RNA level which are likely to help the development of dedicated methods to improve the safety and efficiency of rAAV vectors in dystrophic muscles. 67- MME. DOMENGER Claire – 4ème année –UMR 1089 Off-target analysis of a rAAV-U7snRNA optimized for DMD exon skipping Claire Domenger1*, Aurélie Lardenois3, Caroline Le Guiner1.2 and Philippe Moullier1.2.4 claire.domenger@univ-nantes.fr 1 Atlantic Gene Therapies, INSERM UMR 1089, Université de Nantes, CHU de Nantes, Nantes, France 2 Généthon, Evry, France 3 Atlantic Gene Therapies, INRA UMR 703, ONIRIS, Nantes, France 4 Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA Duchenne muscular dystrophy (DMD) is a degenerative muscular disease affecting 1 male in 3500 and due to mutations in the dmd gene coding for the Dystrophin protein. The absence of Dystrophin causes a progressive degeneration of all muscles including the heart and the diaphragm, leading to the death of patients before their fourth decade. No corrective treatment is yet available. Among therapeutic strategies for DMD, exon skipping has shown encouraging results in animals and more recently in human using chemically modified antisens oligonucleotides (AO). Exon skipping can also be achieved using modified small nuclear RNAs like U7snRNAs in which the therapeutic AO is cloned. Such optimized U7snRNA, called U7OPT, can be packaged in recombinant AAV vectors allowing a long-lasting repair after a single administration. In collaboration with a large network of laboratories, we evaluated the efficacy of a rAAV8-U7-OPT vector injected by locoregional injection of the forelimb of GRMD dogs and we are now moving towards a Phase I/II clinical trial on DMD patients, planned for 2016. Within this project, our team is particularly interested in the characterization of the molecular activity of the U7-OPT. We have already characterized the expression pattern of the U7-OPT in animals’ tissues (GRMD dogs and nonhuman primates) injected during the pre-clinical step of the project. Now we are developing in vitro models of human cells (primary human myotubes and hepatocytes, transduced or not with rAAV-U7-OPT). Our preliminary results suggest that the U7-OPT can be expressed in human muscular cells but also in liver cells, these results encouraged us to anticipate the impact of U7-OPT ectopic expression by considering the potential off-target effects of our treatment. To identify off-target effects due to U7-OPT expression in human context, we plan a 4 steps strategy: (i) A bioinformatic approach related to prediction patterns will allow the identification of the potential targets of U7-OPT antisens sequence on all the known exons of the human genome. 76 (ii) As the in silico approach will probably generate a lot of false positive results, we also plan to extend our work on U7-OPT off-target definition, using a global transcriptomic analysis by RNA sequencing. (iii) The intersection of in silico (i) and RNAseq (ii) approaches will allow us to identify a set of off-targets differentially expressed after a direct action of the U7OPT RNA. (iv) Finally, these off-targets will be all validated by specific RTqPCR. Depending on the identified targets, an evaluation of the impact of the transcriptomic patterns modifications in human cells will also be done. 68- MME. ACHARD Carole – 3ème année – UMR 892 ONCOLYTIC ACTIVITY OF SCHWARZ MEASLES VIRUS AGAINST PLEURAL MESOTHELIOMA Carole Achard1, Mariana Mesel-Lemoine2, Mallory Pain3, Antoine Magnan3, Frédéric Tangy2, Marc Grégoire1 and Jean-François Fonteneau1 1 INSERM UMR 892/CNRS UMR 6299, Institut de Recherche en Santé de l’Université de Nantes, E-mail address : jfontene@nantes.inserm.fr, Phone Number +33 228080236, Nantes, France. 2 CNRS, URA3015, Institut Pasteur, Unité de Génomique Virale et Vaccination, Paris, France. 3 INSERM UMR 1087/CNRS UMR 6291, Institut du thorax, Institut de Recherche en Santé de l’Université de Nantes, Nantes, France. Malignant pleural mesothelioma (MPM) is an aggressive cancer of the pleura mainly due to exposure to asbestos. There is an urgent need for new therapeutic strategies. We work on the development of antitumor virotherapy, based on the use of the live attenuated Schwarz strain of measles virus (MV). This oncolytic virus infects preferentially tumor cells overexpressing the MV receptor CD46, and triggers their apoptosis. With the aim of developing a phase I clinical trial of antitumor virotherapy for MPM, we have conducted an in vitro pre-clinical study on 22 MPM cell lines, allowing us to determine the fraction of MPM patients which are sensitive to this approach. We have also measured the sensitivity to MV infection of healthy cells present in the pleura environment. We show that 70% of tumor cell lines are infected and killed efficiently by MV, whereas the different types of healthy cells exhibit no or low sensitivity. We also observe CD46 overexpression by the majority of MPM cell lines compared to healthy cells. However, the sensitivity of MPM cell lines to the infection cannot be explained only by the expression level of the CD46 molecules. Thus, we analyzed the type I IFN response of MPM cell lines exposed to MV and we found that infection depends on the level and completion of the type I IFN response. Our study confirms the oncolytic potential of MV for antitumoral virotherapy of MPM. 69- M. BEY Karim – 2ème année – UMR 703 INRA / ONIRIS Characterization of a moderate SMA A2G mouse model for intrathecal gene transfer therapy using rAAV9 vector. Karim Bey 1, 2, Johan Deniaud 1, 2, Carine Ciron 1, 2, Corinne Huchet 3, Patrick Aubourg4 and Marie-Anne Colle 1, 2 77 1 INRA UMR U703, Physiopathologie Animale et bioThérapie du muscle et du système nerveux, Nantes, F-44307, France. marie-anne.colle@oniris-nantes.fr; karim.bey@onirisnantes.fr 2 LUNAM université, Oniris, Nantes-Atlantic national college of veterinary medicine, food science and engineering, CS 44706, Nantes, F-44307, France. 3 INSERM UMR1087/ CNRS UMR6291, l’Institut du Thorax, Nantes, F-44322, France. 4 INSERM U986, Génomique, facteurs environnementaux et biothérapie des maladie endocriniennes et neurologiques, Université Paris Sud, Le Kremlin Bicêtre, France. Spinal muscular atrophy (SMA) is an autosomal recessive disease caused by a genetic defect in the survival of motor neuron 1 gene (SMN1). The disease is characterized by degeneration of spinal motor neurons, atrophy of skeletal muscles, and generalized weakness. There are four clinic forms of SMA based on the age of onset and the severity of the symptoms. SMA type 1 is the most severe form, affecting new-borns whereas SMA type 4 is the less severe form, beginning during adulthood. Currently, no curative treatment exists for SMA, although it represents a leading genetic cause of infantile death. Gene therapy, restoring SMN1 activity in MNs, is a promising therapeutic strategy for SMA. Several studies have shown an extension of the survival in severe SMA mice after intravenous delivery of rAAV9 coding for SMN1. Intravenous injection leads to a systemic expression of SMN1 in MNs, but also in peripheral organs, which may be of interest to correct the peripheral and central lesions of SMA, observed in the most severe form (type 1). In the moderate form of the disease, no lesion is found in peripheral organs. Thus, a targeted therapy directly into the CNS should be more appropriate. We have, recently, demonstrated that a single intrathecal administration of an AAV9 vector leads to an efficient transduction of motor neurons in all parts of spinal cord from non-human primates. The main goal of our project is to evaluate the transduction efficiency of an AAV9 coding for SMN1 and its therapeutic effects, following an intrathecal administration, in A2G murine model of moderate SMA. A2G mice were assessed for neurologic and motor deficits using the clasping reflex, swimming tank and pen tests from 6 to 44 weeks of age. Histological and western blot analyses were also performed to determine markers of SMA pathology. At 3 weeks old, SMA mice are statistically and significantly smaller than healthy littermates. A significant neurologic defect is observed at 6 weeks of age in SMA mice using the clasping reflex test. SMA mice show motor alterations at 10 weeks using the swimming tank test and at 26 weeks with the pen test. We demonstrate, a decrease of SMN protein level in spinal cord from SMA affected mice. Some heterotopic MNs are also observed in lumbar spinal cord, a characteristic hallmark of SMA pathology. The next step is to assess the therapeutic benefit of intrathecal AAV serotype 9 mediated delivery to restore SMN protein level in the CNS and to recover neurologic and motor functions in SMA mice. Keywords: moderate SMA, intrathecal delivery, rAAV9, SMN1, motor neurons. 70- MME. MEGHNEM DIHIA – 2ème année –UMR 892 NANT-IL-15 a novel antagonist of IL-15 D. MEGHNEM, S. MORISSEAU, G. TEPPAZ, M. FRUTOSO, I. BARBIEUX, A.QUEMENER, Y. JACQUES, E. MORTIER. Cytokines are key molecules involved in a wide variety of lymphocyte functions, including differentiation, proliferation, activation and survival. The way they are regulated impacts on the cell responses and its consequences on the immune system. IL-15 is a pleiotropic cytokine, physiological inducer of innate immune cells (NK, NK-T and Tγδ). The role of IL78 15 is important in the early steps of T and NK cell activation and the survival of memory CD8+ T cells. IL-15 is structurally related to IL-2 and both cytokines share common chains, IL2/15Rβ and common gamma chain. Specific IL-15 binding and signaling is conferred by the IL-15Rα chain. Defect in IL-15 signalisation affects the survival and function of NK and CD8+ T cells. By contrast, its excess is involved in uncontroled NK and CD8+ cells proliferation and inflammatory disorders. Several studies have shown an increase of IL-15 activity during inflammatory conditions. To inhibit IL-15 function, we have generated an IL-15 antagonist named NANT-IL-15 preventing interaction of IL-15 with its receptor. In vitro, this molecule inhibits specifically the proliferation of IL-15 dependent cells. In vivo, NANT-IL-15 inhibits NK cell proliferation in an IL-15 up-regulated system without any effect on NK and CD8+ T cells homeostasis. Finally preliminary results show the efficacy of NANT-IL-15 in reducing paw inflammation in a collagen induced arthritis mouse model. Thus, NANT-IL-15 represents a promising candidate for the treatment of inflammatory diseases. However, further studies are needed to improve NANT-IL-15 efficacy in different models of inflammation. 71- PEIGNE Cassie-Marie- – 3ème année – Inserm U892/CNRS 6299 Investigation of intracellular proteins interacting with butyrophylin BTN3A1 (CD277) molecule and their implication in antigenic activation process of human Vγ9Vδ2 T lymphocytes Cassie-Marie Peigné (doctorante 3ème année), Alexandra Léger, Marie-Claude Gesnel, Fabienne Konczack, Richard Breathnach, Marc Bonneville, Emmanuel Scotet. Equipe 1, CRCNA, INSERM UMR892 Nantes, France. Human Vγ9Vδ2 T-Cells represent the major peripheral γδ T-Cell subset. They detect a wide range of tumor cells and microbial infections via small non-peptidic phosphorylated compounds (phosphoantigens, PAg), and the butyrophilin3A1 (BTN3A1) protein expressed by target cells. The precise mechanisms implicated in this exquisite cell stress sensing process involving these molecules remain unclear. However, we have evidenced the critical role played by the intracellular domain of the BTN3A1 isoform in the activation of Vγ9Vδ2 TCells induced by PAg. To decipher BTN3A1 contribution in the antigenic activation of Vγ9Vδ2 T-Cells, we aimed at identifying binding partner proteins of BTN3A1 intracellular domain, which may affect Vγ9Vδ2 T-Cell-stimulatory function. We used a yeast-two-hybrid system to select binding candidate proteins in human cDNA libraries using the intracellular domain of BTN3A1. The screening revealed 6 “positive” binding candidates that were further analyzed and confirmed for their interactions with BTN3A1 in human HEK293 cells, by CoIP and Western blot approaches. In order to determine the role played by these intracellular interactants in Vγ9Vδ2 T-Cell antigenic activation process, we analyzed the impact of a targeted downregulation of their expression in HEK293 cells and its specificity. The results of our study show the unexpected and important role played by RhoGEF molecules and two zinc finger proteins in human Vγ9Vδ2 T-Cell antigenic activation process, via interaction with the intracellular region of BTN3A1. Altogether these studies do not only confirm the critical contribution of BTN3A1, and its intracellular part, in the antigenic activation of human Vγ9Vδ2 T-Cells but also bring new insights on partner molecules that tightly regulate this process. 72- MME. DOLLET Lucile - 3ème année –UMR 1087 (confidentiel) FGF21 improves the metabolic complications associated with lipodystrophy in Bscl2-/- mice 79 73- MME. OIZEL Kristell – 3ème année – UMR 892 Manipulating metabolism to overcome radio- and chemo-resistance in glioma CSCs Kristell Oizel, Claire Pecqueur, Lisa Oliver, Emeline Brocard, Denis Cochonneau, François Vallette CRCNA - INSERM UMR 892 - CNRS UMR 6299, Nantes Glioblastoma multiforme (GBM) is the most common malignant brain tumor in adults. Current treatments such as surgical resection, chemotherapy and radiotherapy are inefficient and the median survival does not exceed 15 months. This tumor contains a small number of cancer stem cells (CSCs) that could be responsible for tumor resurgence. In order to better understand the biology of glioma CSCs, we use several glioblastoma primary cultures grown under media conditions favoring the proliferation of CSCs. We show that all primary cultures are resistant to cell death upon irradiation, etoposide or TMZ and that they have heterogeneous phenotypes for their stemness and differentiation markers, their proliferation rate under normoxia and hypoxia, and also for their metabolic needs. In terms of metabolism, most primary cultures exhibit a significant use of both glycolysis and oxidative phosphorylation. Interestingly, the measure of O2 consumption upon chemically-induced uncoupling showed no mitochondrial reserve capacity. Furthermore, increased channeling of pyruvate into mitochondria after PDH inhibition changed metabolic flux while inducing differentiation and sensitivity to cell death. Taken together, these results suggest that CSCs within the tumor could be responsible for the regrowth of the primary tumor after chemo- and radio-therapy. Thus, a better characterization of the tumor subpopulations would provide new insights to our understanding of cell death sensitivity and tumoral metabolic alterations. 80