Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
http://www.ojrd.com/supplements/10/S2
MEETING ABSTRACTS
Open Access
Proceedings of the 1st French-Italian meeting on
laminopathies and other nuclear envelope-related
diseases
Marseille, France. 15-16 January 2015
Published: 11 November 2015
These abstracts are available online at http://www.ojrd.com/supplements/10/S2
INTRODUCTION
I1
An overview of new translational, clinical and therapeutic perspectives
in laminopathies and other nuclear envelope-related diseases
Annachiara De Sandre-Giovannoli1, Nicolas Levy1, Rabah Ben Yaou2,3,
France Leturcq4, Giovanna Lattanzi5,6, Gisèle Bonne2,3*
1
Aix Marseille Université, INSERM, GMGF UMR_S 910 & Department of
Medical Genetics and Cell Biology, La Timone Children’s hospital, APHM,
13385, Marseille, France; 2Sorbonne Universités, UPMC Univ Paris 06, INSERM
UMRS974, CNRS FRE3617, Center for Research in Myology, F-75013 Paris,
France; 3Institut de Myologie, F-75013, Paris, France; 4AP-HP, Groupe
Hospitalier Cochin-Broca-Hôtel Dieu, Laboratoire de biochimie et génétique
moléculaire, Paris, France; 5CNR Institute for Molecular Genetics, Unit of
Bologna, Bologna, Italy; 6Rizzoli Orthopedic Institute, Laboratory of
Musculoskeletal Cell Biology, Bologna, Italy
E-mail: g.bonne@institut-myologie.org
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):I1
Introduction: Defects of proteins of the nuclear envelope are now
recognized as a vast group of heterogeneous rare inherited diseases. The
first reported nuclear envelope-related disease, has been the X-linked form
of the Emery-Dreifuss muscular dystrophy (EDMD1, OMIM#310300), a
condition characterized by muscle weakness and wasting usually with a
humeroperoneal distribution in the first stages, early joint contractures of
Achilles tendons, elbows, neck and spine, and cardiac involvement featuring
conduction defects, arrhythmias, subsequent dilated cardiomyopathy and
frequently responsible of sudden death. EDMD1 is due to mutation of the
EMD gene encoding emerin. Defects of A-type lamins (or Lamin A and C),
two other nuclear envelope proteins were identified shortly after
as being responsible of the autosomal form of EDMD (EDMD2,
OMIM#181350). The same gene, LMNA was then found mutated in a large
spectrum of disorders, now called Laminopathies, affecting the skeletal
and cardiac striated muscles, the peripheral nerves, the adipose tissue or
leading to segmental premature ageing syndromes. These discoveries
have shed light on the nuclear envelope, and mutations in genes
encoding other nuclear envelope proteins were regularly reported in
cascade during the last 15 years.
The French network on ‘EDMD & other nuclear envelope related diseases’
directed by Drs. Gisèle Bonne, Rabah Ben Yaou and France Leturcq (Paris),
organizes annual meetings since it has been created in 2000. The Italian
Network for Laminopathies, directed by Dr Giovanna Lattanzi (Bologna)
and established in 2009, convene meetings twice a year. On January,
15-16, 2015, for the first time, the two networks held a joint meeting in
Marseille at La Timone Adults’ Hospital: The 1st French-Italian meeting on
laminopathies & other nuclear envelope-related diseases. This meeting was
organized by Dr. Annachiara De Sandre-Giovannoli and Pr. Nicolas Lévy
and the directors of the French and Italian networks. The meeting aimed
to provide an update of recently acquired knowledge on: i) preclinical
researches, ii) clinical researches, iii) patient registry and databases and
iv) clinical trials in some of these rare diseases. The meeting also provided
an understanding of the current state of the art on laminopathies and
other nuclear envelope related diseases across France, Italy and the Iberian
Peninsula and an opportunity to exchange ideas to improve patients’
healthcare organization in the future in a larger European/international
context. The meeting has gathered 108 participants during two days. The
first day was dedicated to communications among professionals involved
in diagnosis, research and treatment of laminopathies and related diseases,
and open to industrial partners, and the second day was dedicated to
communications and view exchanges among professionals and patients’
families, aiming to inform them of the state of the art concerning their
disease in terms of research and treatment. Among the invited speakers,
Dr. Carlos Lopez-Otin, a leading scientist in the field of Progeria research,
Dr. Raoul Hennekam, an expert clinician in the diagnosis and follow up of
progeroid laminopathies and lipodystrophies, Dr. David Araujo-Vilar, the
coordinator of the European consortium on lipodystrophies. These two
days have been rich of view exchanges and informative for professionals
and patients’ families, and have helped to further develop novel as well as
already established fruitful collaborations.
It is planned not only to organize a second joint meeting between the
French and Italian networks, but also to more widely open these meetings
to other European colleagues, since already for this first edition, the Iberian
community was largely represented. No doubt that this first edition will be
the first one of a long series, since nuclear envelope proteins and their
related diseases are extremely diverse and in continuous evolution.
Acknowledgments: We thank the patients, their families and the patient
associations: the Associazione Alessandra Proietti onlus, the Associazione
Italiana Distrofia Muscolare di Emery Dreifuss (AIDMED Onlus), the
Associazione Italiana Progeria Sammy Basso (AIProSaB Onlus), the Progeria
Family Circle for their participation. We thank “MCO congrès” for organizing
the logistics of the meeting.
This meeting was made possible thanks to the financial supports of the
Association Française contre les Myopathies (AFM), Associazione Italiana
Progeria Sammy Basso (AIProSaB onlus), Diatheva Srl (http://www.diatheva.
com), the Assistance Publique-Hôpitaux de Marseille and Assistance
Publique-Hôpitaux de Paris, the Institut National de la Santé et de la
Recherche Médicale (INSERM), the Aix-Marseille University, the Progeria
family Circle.
© 2015 various authors. All articles published in this supplement are distributed under the terms of the Creative Commons Attribution
License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium,
provided the original work is properly cited.
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
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1. PRECLINICAL RESEARCH ON
LAMINOPATHIES
O1
Molecular mechanisms of normal and pathological aging
Carlos López-Otín
Departamento de Bioquímica y Biología Molecular, IUOPA, Universidad de
Oviedo, Oviedo, Spain
E-mail: clo@uniovi.es
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O1
We have recently defined nine molecular and cellular hallmarks that represent
common denominators of aging in different organisms. These hallmarks are:
genomic instability, telomere attrition, epigenetic alterations, loss of
proteostasis, deregulated nutrient-sensing, mitochondrial dysfunction, cellular
senescence, stem cell exhaustion, and altered intercellular communication.
On the other hand, parallel studies of our laboratory on accelerated aging
syndromes, including Hutchinson-Gilford Progeria Syndrome (HGPS) and
Nestor-Guillermo Progeria Syndrome (NGPS), have provided relevant
information about these hallmarks of aging. HGPS is caused by a point
mutation in the LMNA gene that yields a truncated form of prelamin A called
progerin, which is also produced during normal aging. Over the last years,
the generation of mouse models of HGPS and other progeroid laminopathies
has shed light on the molecular alterations functionally involved in these
diseases. Thus, knock-out mice deficient in Zmpste24 metalloproteinase
implicated in prelamin A maturation, mosaic mice containing Zmpste24deficient and Zmpste24-proficient cells, and knock-in mice carrying the human
HGPS mutation which causes progerin accumulation, have allowed us to
demonstrate that progeroid laminopathies result from the combined action
of both cell-autonomous and systemic factors. Accordingly, we have shown
that nuclear envelope defects causative of these complex diseases lead to
alterations in stem cell functionality, epigenetic abnormalities, perturbations
in cell senescence pathways, metabolic changes and chronic activation of
inflammatory responses. We have also demonstrated that the genetic or
pharmacological blockade of these altered pathways prevents the
development of many age-associated features of these progeroid mice and
extends their longevity. On this basis, we have developed therapeutic
strategies for progeroid laminopathies which are now in clinical trials
coordinated by Pr. Nicolas Lévy for the treatment of HGPS patients. These
findings illustrate the importance of mouse models for designing therapeutic
strategies to treat rare and dramatic progeroid syndromes as well as for
improving our knowledge of the universal and complex process of human
aging.
1.1 IPS CELLS AND OTHER IN VITRO
MODELS OF LAMINOPATHIES
O2
Pluripotent stem cells for pathological modelling of Hutchinson-Gilford
Progeria Syndrome (HGPS) and drug discovery
Xavier Nissan
CECS, I-STEM, AFM, Institute for Stem cell Therapy and Exploration of
Monogenic diseases, Evry, France
E-mail: xnissan@istem.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O2
Progeria, also known as HGPS, is a rare, fatal genetic disease characterized
by an appearance of accelerated aging in children. This syndrome is
typically caused by mutations in codon 608 (p.G608G) of the LMNA leading
to the production of a mutated form of Lamin A precursor called progerin.
In HGPS, progerin accumulates in cells causing progressive molecular
defects including nuclear shape abnormalities, chromatin disorganization,
DNA damages and delay in cell proliferation. Although two clinical trials
have recently produced promising results, as well as in vitro and in vivo,
there is currently no cure for HGPS patients. In collaboration with the
teams of Dr Nicolas Lévy (UMR_S 910) and Dr Lino Ferreira (University of
Coimbra), we have addressed this challenge by developing two high
throughput screenings using the unique self-renewal and pluripotency
properties induced pluripotent stem cells (iPS cells). Accordingly, these
Page 2 of 12
studies revealed the potential therapeutic effect of two new classes of
compounds rescuing both nuclear shape abnormalities and defects of
differentiation through on one hand, an inhibition of the prenylation
process and on the other hand, a decrease of progerin expression.
O3
Development of a SMCs model from HGPS-iPS and proofs of principle
Lino Ferreira
Center of Neurosciences and Cell Biology, University of Coimbra, Portugal
E-mail: lino@biocant.pt
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O3
HGPS is a rare, progressive aging disease in children that leads to
premature death. Vascular smooth muscle cells (SMCs) are the most
affected cells in HGPS patients, although the reason for such sensitivity
remains poorly understood. Induced pluripotent stem cells (iPSCs) offer an
unlimited source of SMCs to study the disease. iPSCs are also an important
tool to study the molecular mechanisms of the disease from a
developmental point of view. In this work, we study the reasons of HGPSSMCs vulnerability using iPSCs obtained from HGPS fibroblast patients. We
have evaluated the differentiation profile of HGPS-iPSCs and normal iPSCs
into SMCs. We showed that HGPS-iPSC SMCs shared similar features
observed on progerin-expressing cells. We have identified and characterize
drugs that prevent SMC loss. Our findings open new opportunities for the
treatment of HGPS disease and diseases related to vascular ageing.
O4
3D culture system of muscle precursor cell to reveal mechanosensing
defects in nuclear envelope related disorders
Catherine Coirault
Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617,
Center for Research in Myology, Paris, France
E-mail: c.coirault@institut-myologie.org
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O4
Mutations in the LInker of the Nucleoskeleton and Cytoskeleton (LINC)complex associated proteins, including lamins and nesprins cause human
muscular dystrophies but disease mechanisms still remain to be elucidated.
We aim to determine whether human muscular dystrophies resulting from
mutations in A-type lamin and nesprin1 affected the capacity of myoblasts
to sense the stiffness of the extracellular matrix. Human myoblasts with
various mutations in the A-type lamins encoded by LMNA (LMNA), nesprin1
mutant (SYNE1), and control (WT) myoblasts were cultured in 3D soft matrix
(1-10 kPa) or on 2D conventional glass (~ 106 kPa) surfaces. Focal adhesion
(vinculin), actin cytoskeleton, and YAP signaling pathway, a particularly
important regulator of the mechano-response, were investigated. On 2D
hard surface, there was no obvious difference in actin cytoskeleton and focal
adhesion between WT, LMNA and SYNE1 myoblasts. In contrast, LMNA and
SYNE1 myoblasts cultured in soft matrix exhibited enlarged focal adhesions
and stress fibers compared with WT. Cytoplasmic translocation of YAP
observed in WT in response to reduced stiffness matrix was absent in LMNA
and SYNE1 cells, suggesting a permanent activation of YAP in mutant cells.
In conclusion, our data indicate that cell culture matrix stiffness is critical to
reveal mechanosensing defects in dystrophic muscle cells.
O5
Prelamin accumulation in primary endothelial cells induces premature
senescence and activation
Nathalie Bonello-Palot, Catherine Badens*
Aix Marseille Université, INSERM, GMGF UMR_S 910 & Department of Medical
Genetics and Cell Biology, La Timone Children’s hospital, APHM, 13385,
Marseille, France
E-mail: catherine.badens@univ-amu.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O5
Defects in lamin A maturation result in premature aging syndromes and
severe atherosclerosis as observed in Hutchinson-Gilford Progeria
Syndrome. In age-related atherosclerosis, several features of cells
senescence have been characterized in endothelial cells lamin A
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alterations. We propose a cellular model to study lamin A-related
senescence in primary endothelial cells. In this model, lamin A defects
were induced by protease inhibitor (PI: Atazanavir) treatment during 48h
on normal cells issued from placenta (human umbilical vein (HUVEC) or
cord blood (ECFC)). We showed that PI treatment led to the accumulation
of farnesylated prelamin A and induced nuclear shape abnormalities and
premature senescence in both HUVEC and ECFC. ICAM-1-dependent
activation was present and monocytes adhesion was increased in HUVEC
whereas ability to generate microvascular network in matrigel was
decreased for ECFC. The effects of PI treatment on nuclei shape were
reversed when cells were PI-treated in combination with Pravastatin and
Zoledronate in both mature and progenitor endothelial cells. Reversion also
was demonstrated with 2 antisens-oligonucleotides targeted toward lamin A
specific splice sites. This study confirms that PI treatment reproduces
premature senescence due to lamin A maturation defects in primary
endothelial cells after a 2 days exposure. The cells used were extracted from
full term and healthy neonates i.e. from individuals of age 0. This allows us
to consider that other senescence pathways were not activated and that the
observed alterations were specific of prelamin A accumulation. This model
constitutes a valuable tool to test different approaches aimed at reversing
specifically lamin A-related cells senescence.
1.2. IN VIVO MODELS OF
LAMINOPATHIES
O6
Hypothalamic involvement in premature aging laminopathies
Claudia Cavadas
CNC – Center for Neuroscience and Cell Biology, University of Coimbra,
Coimbra, Portugal, Faculty of Pharmacy, University of Coimbra, Coimbra,
Portugal
E-mail: cavadas@ci.uc.pt
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O6
Caloric restriction (CR), the reduced intake of calories without malnutrition,
extends lifespan of many organisms, from yeast to mammals, and delays
the progression of age-related diseases. Evidence show that hypothalamus
is a crucial brain region for the progress of whole-body aging [1] and the
beneficial effects induced by CR are regulated by nutrient-sensing neurons
located in the hypothalamus [2]. Although CR’s beneficial effects
in delaying human aging are promising, its application for long periods
is very difficult to maintain and not feasible to apply to fragile children
with progeria. To overcome this problem, the induction of protective
endogenous mechanisms, or pharmacological agents, could theoretically
be used to mimic the beneficial effects of CR without its discomfort. Our
group showed that hypothalamus of Zmpste24-/- mouse has lower levels of
Neuropeptide Y, comparing to wild-type animals. Moreover, they showed
that targeting the Neuropeptide Y system in hypothalamus, as a CR mimetic
strategy, delays or reverts some ageing features of Zmpste24-/- mice.
Further studies are needed to confirm this innovative approach and if it
could be translational to progeria children.
References
1. Zhang G, Li J, Purkayastha S, Tang Y, Zhang H, Yin Y, et al: Hypothalamic
programming of systemic ageing involving IKK-beta, NF-kappaB and
GnRH. Nature 2013, 497(7448):211-6.
2. Dacks PA, Moreno CL, Kim ES, Marcellino BK, Mobbs CV: Role of the
hypothalamus in mediating protective effects of dietary restriction
during aging. Frontiers in neuroendocrinology 2013, 34(2):95-106.
O7
Investigation of pathomechanisms of ventricular arrhythmias in cardiac
laminopathies
Antoine Muchir
Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617,
Center for Research in Myology, Paris, France
E-mail: a.muchir@institut-myolgie.org
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O7
Page 3 of 12
Mutations in LMNA are responsible for an aggressive form of dilated
cardiomyopathy due to a high rate of malignant ventricular arrhythmias.
Inter-cellular communication is essential for proper cardiac function.
Mechanical and electrical activities must synchronize so that the work of
individual cardiomyocytes transforms into the pumping function of the
heart. This well-coordinated excitation-contraction coupling of the heart
relies on an efficient inter-cellular communication, which is under the
regulation of the intercalated discs. We focused on the understanding of
the molecular mechanisms of components of intercalated disc relocalization in pathological context. For this, we investigated disease
mechanisms and identify novel therapeutic targets, using an integrated
series of models in cultured cells, mice and humans. Positive results will
break new ground for future work towards developing novel treatment
for malignant arrhythmias.
1.3 NOVEL THERAPEUTIC
APPROACHES, PROOFS OF
PRINCIPLE IN LAMINOPATHIES
O8
New therapeutic approaches to HGPS based on progerin inhibition
Camilla Pellegrini
CNR Institute for Molecular Genetics, Unit of Bologna, Bologna, Italy, Rizzoli
Orthopedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna,
Italy
E-mail: camilla.pellegrini@ior.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O8
Hutchinson-Gilford Progeria Syndrome (HGPS) is caused by a de novo
heterozygous mutation on LMNA gene that leads to accumulation of
progerin, a mutant form of prelamin A. HGPS skin fibroblasts are
characterized by multiple nuclear defects: nuclear shape abnormalities
chromatin structure alterations, increased DNA damage and cell cycle
alterations.
Retinoic acid may modulate LMNA gene transcription, due to the presence
of a retinoic acid responsive element (L-RARE) in the LMNA promoter. Based
on this knowledge, we investigated if all trans retinoic acid (ATRA) could
lower progerin levels in HGPS fibroblasts. We also evaluated the effects of a
combined treatment with rapamycin, a drug known to promote autophagy
and reduce both farnesylated prelamin A and progerin amount.
We demonstrate a surprising effect of ATRA to repress Lamin A/C gene
transcription and we show that the combined treatment with ATRA and
rapamycin has a synergistic effect: it dramatically lowers progerin levels,
restores both heterochromatin organization and nuclear shape, reduces
DNA damage markers and improves cell viability. These promising results
could open the way to a new therapeutic approach for HGPS.
O9
Efficient progerin clearance through autophagy induction and SRSF-1
downregulation in Hutchinson-Gilford Progeria Syndrome
Karim Harhouri
Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France
E-mail: karim.harhouri@univ-amu.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O9
Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare premature
and accelerated aging disease caused by a de novo point mutation in LMNA
encoding A-type lamins. Progerin, a truncated and toxic form of prelamin A,
accumulates in HGPS cells nuclei and is a hallmark of the disease. We show
that progerin is sequestered, together with other proteins (lamins B1/B2,
emerin), into abnormally shaped nuclear organelles, identified as novel
biomarkers in Progeria. We identified a novel compound that led to effective
progerin degradation and clearance from patients’ fibroblasts. This
compound induces progerin nucleocytoplasmic translocation, and progerin
degradation through macroautophagy. It also strongly reduces progerin
production through caspase-linked cleavage of SRSF-1 controlling prelamin A
mRNA splicing. In vivo, upon treatment with the compound, progerin
expression decreases in skeletal muscle of LmnaG609G/G609G mice. Altogether,
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
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we demonstrate increased progerin clearance based on the dual action of a
novel compound and shed light on a novel promising class of molecules
towards a therapy for Progeria and related diseases.
O10
Impairment of Lamin A/C-Polycomb crosstalk as a possible epigenetic
cause of Emery Dreifuss Muscular Dystrophy (EDMD)
Chiara Lanzuolo
Institute of Cell Biology and Neurobiology (IBCN)-CNR Epigenetics and
Nuclear structure Laboratory at Santa Lucia Foundation, Roma, Italy
E-mail: chiara.lanzuolo@cnr.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O10
Traditionally, studies on EDMD have focused on genetic changes affecting
molecules involved in the development of pathology. However, emerging
findings indicate that a single genetic mutation can be accompanied by a
range of different phenotypes, suggesting a contribution of the epigenetic
background to the disease progression. This is in line with recent works
showing that changes in chromatin architecture are peculiar of several
laminopathies [1,2]. Despite much effort has been done to understand the
regulation of the complex networks of gene expression that govern
muscle differentiation and that is affected in EDMD, little is known
about the epigenetic players and molecular mechanisms involved
in pathogenesis and progression. Key epigenetic regulators of chromatin
architecture are Polycomb group (PcG) of proteins, epigenetic
transcriptional repressors of genes primarily involved in differentiation and
development [3]. In particular, during myogenesis, modulation of Ezh2
levels, the catalytic subunit of the Polycomb Repressive Complex 2 (PRC2)
ensures the correct muscle differentiation [4]. In the nucleus, PcG proteins
form microscopically visible foci and high-through-put data together with
microscopy analysis revealed that their targets are organized in chromatin
loops [5,6]. We have shown that Lamin A/C sustains PcG foci influencing
PcG nuclear compartmentalization and modulating their repressive
functions. During myogenesis, Lamin A/C depletion leads to an altered
timing of muscle differentiation due to the aberrant expression of PcGregulated genes.
References
1. McCord RP, Nazario-Toole A, Zhang H, Chines PS, Zhan Y, Erdos MR, et al:
Correlated alterations in genome organization, histone methylation, and
DNA-lamin A/C interactions in Hutchinson-Gilford progeria syndrome.
Genome research 2013, 23(2):260-9.
2. Shumaker DK, Dechat T, Kohlmaier A, Adam SA, Bozovsky MR, Erdos MR,
et al: Mutant nuclear lamin A leads to progressive alterations of
epigenetic control in premature aging. Proceedings of the National
Academy of Sciences of the United States of America 2006, 103(23):8703-8.
3. Lanzuolo C, Orlando V: Memories from the polycomb group proteins.
Annual review of genetics 2012, 46:561-89.
4. Caretti G, Di Padova M, Micales B, Lyons GE, Sartorelli V: The Polycomb
Ezh2 methyltransferase regulates muscle gene expression and skeletal
muscle differentiation. Genes & development 2004, 18(21):2627-38.
5. Bantignies F, Roure V, Comet I, Leblanc B, Schuettengruber B, Bonnet J,
et al: Polycomb-dependent regulatory contacts between distant Hox loci
in Drosophila. Cell 2011, 144(2):214-26.
6. Lanzuolo C, Roure V, Dekker J, Bantignies F, Orlando V: Polycomb response
elements mediate the formation of chromosome higher-order structures
in the bithorax complex. Nature cell biology 2007, 9(10):1167-74.
O11
Gene Therapy for LMNA-related Congenital Muscular Dystrophy (LCMD) by Trans-Splicing
Feriel Azibani*, Anne T Bertrand
Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617,
Center for Research in Myology, Paris, France
E-mail: f.azibani@institut-myologie.org
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O11
LMNA-related Congenital Muscular Dystrophy (L-CMD) is a rare genetic
disorder characterized by the onset of selective axial weakness and
Page 4 of 12
wasting in the first year of life with limited motor achievements, associated
with multiple severe contractures and frequent respiratory failure requiring
early ventilatory support. We identified heterozygous de novo mutations in
LMNA, encoding lamins A/C, as responsible for this sub-group of CMD in
which no therapeutic treatment is available [1]. Lamins A/C are nuclear
envelope proteins, ubiquitously expressed in all post mitotic cells, which
play essential roles in the nucleus structure and in the regulation of gene
expression. We generated the first Knock-In mouse model of L-CMD
(KI-LmnadelK32) reproducing a LMNA mutation identified in L-CMD patients.
Homozygous mice die within the first 3 weeks of life from striated muscles
maturation delay and severe metabolic defects [2]. Heterozygous mice
develop an isolated dilated cardiomyopathy and die by one year of age
[3]. We aim to assess the possibility of LMNA-mRNA repair by spliceosomemediated RNA trans-splicing (SMarT) as a potential therapeutic approach
for L-CMD. This gene therapy strategy will allow inhibition of mutated
LMNA transcript expression for the benefit of corresponding wild type
transcripts. We developed 5’-RNA pre-trans-splicing molecules (PTM)
capable of repairing the murine LMNA transcripts. Efficiency of these PTM
was assessed in vitro in C2C12 cells and in vivo using Adeno-Associated
Virus (AAV) transduction in tibialis anterior of WT mice. We will now
determine the ability of the best PTM to restore normal muscular
phenotype, in vitro in KI myoblasts/myotubes and in vivo after injection of
AAV-PTM vectors in new born homozygous and adult heterozygous mice.
Histological and metabolic parameters will be monitored to evaluate the
degree of phenotype rescue.
References
1. Quijano-Roy S, Mbieleu B, Bonnemann CG, Jeannet PY, Colomer J,
Clarke NF, et al: De novo LMNA mutations cause a new form of
congenital muscular dystrophy. Annals of neurology 2008, 64(2):177-86.
2. Bertrand AT, Renou L, Papadopoulos A, Beuvin M, Lacene E, Massart C, et al:
DelK32-lamin A/C has abnormal location and induces incomplete tissue
maturation and severe metabolic defects leading to premature death.
Human molecular genetics 2012, 21(5):1037-48.
3. Cattin ME, Bertrand AT, Schlossarek S, Le Bihan MC, Skov Jensen S,
Neuber C, et al: Heterozygous LmnadelK32 mice develop dilated
cardiomyopathy through a combined pathomechanism of
haploinsufficiency and peptide toxicity. Human molecular genetics 2013,
22(15):3152-64.
1.4 NOVEL BIOMARKERS IN
LAMINOPATHIES
O12
Chromatin dynamics and in vitro biomarkers in laminopathies: an
overview
Giovanna Lattanzi
CNR Institute for Molecular Genetics, Unit of Bologna and Rizzoli Orthopedic
Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
E-mail: giovanna.lattanzi@cnr.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O12
Chromatin regulation in eukaryotes occurs through complex and
interconnected mechanisms that ensure heterochromatin maintenance and
compartmentalization of chromosome domains, genome stability, chromatin
conformational changes before and after mitosis, gene silencing and
transcriptional activation and chromatin remodeling at specific promoters.
We refer to these events as a whole using the term “chromatin dynamics.”
Chromatin dynamics involves a number of protein families including
epigenetic enzymes, DNA repair factors, heterochromatin proteins,
transcription factors and transcriptional regulators. Although lamins have
been involved in almost all the processes that regulate chromatin dynamics
[1], three main functions link lamins to chromatin regulation: recruitment of
the DNA damage response proteins [2], transcription factor binding [3,4]
and modulation and maintenance of heterochromatin domains [5]. Our
preliminary data have shown that lamin A/C plays a major role in anchorage
of epigenetic enzymes in nuclei and loss of lamin A/C- histone deacetylase
(HDAC) binding, as occurs in Hutchinson-Gilford progeria (HGPS) cells,
affects enzyme activity and histone acetylation. These results may explain
our previously published data [6] showing that the heterochromatin defects
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of HGPS cells can be rescued by combined inhibition of prelamin A
farnesylation and HDAC activity and pave the way to new therapeutic
perspectives. Moreover, altered lamin A/C-HDAC interaction and histone
acetylation patterns can be explored as potential biomarkers for
laminopathies.
References
1. Camozzi D, Capanni C, Cenni V, Mattioli E, Columbaro M, Squarzoni S, et al:
Diverse lamin-dependent mechanisms interact to control chromatin
dynamics. Focus on laminopathies. Nucleus 2014, 5(5):427-40.
2. Lattanzi G, Ortolani M, Columbaro M, Prencipe S, Mattioli E, Lanzarini C,
et al: Lamins are rapamycin targets that impact human longevity: a
study in centenarians. Journal of cell science 2014, 127(Pt 1):147-57.
3. Capanni C, Mattioli E, Columbaro M, Lucarelli E, Parnaik VK, Novelli G, et al:
Altered pre-lamin A processing is a common mechanism leading to
lipodystrophy. Human molecular genetics 2005, 14(11):1489-502.
4. Columbaro M, Mattioli E, Maraldi NM, Ortolani M, Gasparini L, D’Apice MR,
et al: Oct-1 recruitment to the nuclear envelope in adult-onset
autosomal dominant leukodystrophy. Biochimica et biophysica acta 2013,
1832(3):411-20.
5. Lattanzi G, Columbaro M, Mattioli E, Cenni V, Camozzi D, Wehnert M, et al:
Pre-Lamin A processing is linked to heterochromatin organization.
Journal of cellular biochemistry 2007, 102(5):1149-59.
6. Columbaro M, Capanni C, Mattioli E, Novelli G, Parnaik VK, Squarzoni S, et al:
Rescue of heterochromatin organization in Hutchinson-Gilford progeria
by drug treatment. Cellular and molecular life sciences: CMLS 2005,
62(22):2669-78.
O13
LMNA p.R482W mutation related to FPLD2 alters SREBP1-A type lamin
interactions in human fibroblasts and adipose stem cells
Brigitte Buendia
Unité de Biologie Fonctionnelle et Adaptative (BFA), Université Paris DiderotParis 7, CNRS, UMR 8251, Paris, France
E-mail: brigitte.buendia@univ-paris-diderot.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O13
SREBP1 (Sterol regulatory element binding protein 1), transcription factor
that regulates hundreds of genes involved in lipid metabolism and
adipocyte differentiation, is a direct partner of A-type lamins. We show
that i) in vitro, the tail regions of prelamin A, lamin A and lamin C bind a
polypeptide of SREBP1 and ii) within cells, interactions between wild-type
A-type lamins and SREBP1 occur mainly at the nuclear periphery but also
within the nucleoplasm. While A-type lamin R482W mutation is responsible
for Dunnigan type familial partial lipodystrophy (FPLD2), we show that
both overexpression of LMNA p.R482W in primary human preadipocytes
and endogenous expression of A-type lamins p.R482W in FPLD2 patient
fibroblasts, reduce A-type lamins-SREBP1 in situ interactions and
upregulates a large number of SREBP1 target genes [1]. As this LMNA
mutant was previously shown to inhibit adipogenic differentiation, we
propose that deregulation of SREBP1 by mutated A-type lamins constitutes
one underlying mechanism of the physiopathology of FPLD2.
Reference
1. Vadrot N, Duband-Goulet I, Cabet E, Attanda W, Barateau A, Vicart P, et al:
The p.R482W substitution in A-type lamins deregulates SREBP1 activity
in Dunnigan-type familial partial lipodystrophy. Human molecular genetics
2015, 24(7):2096-109.
O14
Altered cytokine profiles in laminopathic patients
Pia Bernasconi
Neurology IV Unit - Neuroimmunology and Neuromuscular Diseases Unit,
Foundation IRCCS Neurological Institute “Carlo Besta”, Milan, Italy
E-mail: pbernasconi@istituto-besta.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O14
Prelamin A accumulation is known to dysregulate the NF-B signaling
cascade, causing a secretion of high levels of proinflammatory cytokines,
which in turn might contribute to the pathologic aging observed in
Page 5 of 12
laminopathies, and in particular in HGPS [1]. In collaboration with
researchers and clinicians of the Italian network for Laminopathies, we
wondered whether it was possible to identify a pattern of cytokine
expression that could discriminate laminopathy from other forms of
muscular dystrophy and/or cardiomyopathy and a laminopathy with a
cardiac involvement from one with only muscle involvement, with the
final goal to identify biomarker(s) helpful for diagnosis, prognosis and
evaluation of therapy efficacy. We analysed the cytokine profiles of sera
collected from 37 patients affected by different forms of laminopathy
(all LMNA mutations), 9 patients affected by genetically defined nonLMNA muscular dystrophy and 27 healthy individuals. Sera
were screened for the expression levels of 16 cytokines, 6 chemokines,
5 growth factors and TGF-beta1, 2 and 3 by Luminex technology. Some
pro-inflammatory cytokines were found to be differentially expressed
in cardiopathic and non-cardiopathic patients compared to healthy
controls, and among laminopathies with muscle and cardiac
involvement, laminopathies without myopathy and muscular
dystrophies. Interestingly, TGF-beta2 serum levels were higher in the
LMNA patients than in healthy individuals and in patients with nonLMNA muscular dystrophy, suggesting a direct link between LMNA
mutations and dysregulation of TGFbeta2 pathway, as indicated by
previous and recent experimental studies [2,3].
References
1. Osorio FG, Barcena C, Soria-Valles C, Ramsay AJ, de Carlos F, Cobo J, et al:
Nuclear lamina defects cause ATM-dependent NF-kappaB activation and
link accelerated aging to a systemic inflammatory response. Genes &
development 2012, 26(20):2311-24.
2. Avnet S, Pallotta R, Perut F, Baldini N, Pittis MG, Saponari A, et al:
Osteoblasts from a mandibuloacral dysplasia patient induce human
blood precursors to differentiate into active osteoclasts. Biochimica et
biophysica acta 2011, 1812(7):711-8.
3. Evangelisti C, Bernasconi P, Cavalcante P, Cappelletti C, D’Apice MR,
Sbraccia P, et al: Modulation of TGFbeta 2 levels by lamin A in U2-OS
osteoblast-like cells: understanding the osteolytic process triggered by
altered lamins. Oncotarget 2015, 6(10):7424-37.
O15
microRNA deregulation in Hutchinson-Gilford Progeria
Patrice Roll
Aix Marseille Université, INSERM, GMGF UMR_S 910 & Department of Medical
Genetics and Cell Biology, La Timone Children’s hospital, APHM, 13385,
Marseille, France
E-mail: patrice.roll@univ-amu.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O15
The Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare genetic
disease characterized by an accelerated aging, due to the accumulation
in nucleus of a toxic protein called progerin, leading to abnormal gene
expression and potential microRNA (miRNA) deregulation. To evaluate the
role of miRNAs in HGPS, we conducted an in vitro miRNome analysis by
RT-qPCR on dermal fibroblasts of 5 patients and 5 healthy individuals at
early (P12+/-2) and for 5 individuals at late passages (P22+/-2). We found
29 deregulated miRNAs in more than 50% of patients (15 overexpressed,
14 underexpressed) presenting different deregulation profiles depending
on their age and passage in vitro. We identified 4 interesting potential
targeted pathways linked to aging/Progeria: cell cycle and proliferation,
senescence, inflammation and autophagy for which 3 miRNAs target
central actors of this pathway. No significant difference between patients
and controls was detected for 3 autophagy makers on western blotting.
However, using flow cytometry, allowing quantification of autophagy
level cell by cell, we observed in a 14 yo patient exhibiting the most
miRNA deregulated profile, a majority of cells presenting no autophagy.
Our hypothesis is that the combined overexpression of the 3 autophagy
inhibitor miRNAs acts as a “brake” on autophagy, leading to a decrease of
progerin degradation, and finally to a pathophysiological vicious cycle.
We are now confirming this hypothesis by transfecting antagomiRs on
cellular model. We will also evaluate this mechanism in our HGPS LAKI
mouse model and in the context of physiological aging, during which
progerin is also produced at lower levels.
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
http://www.ojrd.com/supplements/10/S2
2 . CLINICAL RESEARCH ON NUCLEAR
ENVELOPE RELATED DISEASES
2.1 CASE REPORTS, NOVEL
MUTATIONS & PHENOTYPES,
OTHER NUCLEAR ENVELOPATHIES
O16
Update of Emerinopathies’ clinical-genetic spectrum: the French
network experience
France Leturcq*, Rabah Ben Yaou*
AP-HP, Groupe Hospitalier Cochin-Broca-Hôtel Dieu, Laboratoire de
biochimie et génétique moléculaire (LBGM), Paris, France
E-mail: france.leturcq@inserm.fr; r.benyaou@institut-myologie.org
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O16
Emerinopathies include diseases caused by EMD gene mutations localized
on chromosome X and encoding emerin, an integral protein of the nuclear
envelope. The most frequent emerinopathy is the X-linked Emery-Dreifuss
muscular dystrophy (X-EDMD) that was first reported in the 60ths by
Emery and Dreifuss [1]. The disease is characterized by muscle weakness
and wasting usually with a humeroperoneal distribution in the first stages,
early joint contractures involving Achilles tendons, elbows, neck and the
whole spine, and cardiac involvement featuring conduction defects,
arrhythmias, subsequent cardiomyopathy (usually dilated) and frequently
responsible of sudden death. Bione et al. [2] identified the first mutations
of EMD gene encoding emerin to be responsible of X-EDMD. These
mutations usually lead to absence or reduced level of emerin in different
tissues of affected males including skeletal muscle, skin, oral mucosa cells
and lymphocytes as it is demonstrated by immunocytochemical and
histochemical methods [3,4]. Female carriers exhibit mosaic expression
patterns with usually normal emerin amounts [3]. These methods may thus
be used in the diagnostic strategy of X-EDMD prior to EMD gene analysis.
In a recent study (unpublished work from the French network and LBGM)
aiming to assess the diagnostic utility of emerin study by western blot on
lymphoblastoïd cell lines, we looked at EMD mutation rate observed in a
cohort of 269 male and female patients with variable emerin amounts. In
male patients, absence or severe reduction of emerin (<5%) lead to EMD
mutation identification in all cases, while moderate emerin amount
reduction revealed EMD mutation in 75% of the patients. Interestingly, in
all cases where emerin amounts were considered as normal, no EMD
mutations were found. In female cases, all cases with emerin moderate or
severe reduction harbored EMD mutation. When emerin is normal, EMD
mutation was found in 58% of female cases. These results suggest that a
diagnostic rate of 100% may be reached if emerin study by western blot is
performed prior to EMD gene screening in male patients. Moreover,
emerin gene mutations have been rarely observed in rare cases of isolated
cardiac disease [5,6] and limb girdle muscular dystrophies with cardiac
disease and without joint contractures [7,8].
We reported of a new family with an unusual type of X-linked fatal isolated
cardiac disease. The family included 9 affected male subjects with early death
within the 4th to 6th decades and suffering from dilated cardiomyopathy
(DCM) with arrhythmias requiring ICD implantation and or heart
transplantation in some cases. Two surviving brothers were assessed. The first
brother had DCM since 49 years old, ICD implantation at 51, additional
Pacemaker at 52. His neurological assessment as well as CPK and EMG were
normal at 53. His young brother had also DCM since 38 years old and
his neurological assessment was normal at 45. Muscle biopsy performed in
the oldest brother was considered as normal. Emerin protein analysis on
muscle by Western blot using MANEM8 antibodies showed normal amounts
while emerin immunostaining studies on muscle cryosections using NCLEmerin antibodies showed complete absence of emerin. Subsequent EMD
gene analysis revealed a missense mutation within exon 1.
By using the UMD-EMD locus specific database (http://www.umd.be/EMD/)
gathering all published EMD gene mutations as well as those found in LBGM
(more than 200 families), authors looked at EMD mutation spectrum. It was
found that truncating mutations leading to absence or highly decreased
emerin represent more than 65% of probands, while non-truncating
Page 6 of 12
mutations, including missense ones and leading to either absence or
abnormal emerin, represents 21,5% of probands. The remaining probands
(13.5%) carry intronic mutations with variable emerin amounts according to
alternative splicing. There are no clear phenotype/genotype correlations due
to high intra- and inter-familial variability. Truncating mutations may lead to
classical forms of EDMD as well as severe forms with early ambulation loss
and moderate forms with benign skeletal muscle involvement.
References
1. Emery AE, Dreifuss FE: Unusual type of benign x-linked muscular
dystrophy. Journal of neurology, neurosurgery, and psychiatry 1966,
29(4):338-42.
2. Bione S, Maestrini E, Rivella S, Mancini M, Regis S, Romeo G, et al:
Identification of a novel X-linked gene responsible for Emery-Dreifuss
muscular dystrophy. Nature genetics 1994, 8(4):323-7.
3. Manilal S, Recan D, Sewry CA, Hoeltzenbein M, Llense S, Leturcq F, et al:
Mutations in Emery-Dreifuss muscular dystrophy and their effects on
emerin protein expression. Human molecular genetics 1998, 7(5):855-64.
4. Nagano A, Koga R, Ogawa M, Kurano Y, Kawada J, Okada R, et al: Emerin
deficiency at the nuclear membrane in patients with Emery-Dreifuss
muscular dystrophy. Nature genetics 1996, 12(3):254-9.
5. Ben Yaou R, Toutain A, Arimura T, Demay L, Massart C, Peccate C, et al:
Multitissular involvement in a family with LMNA and EMD mutations:
Role of digenic mechanism? Neurology 2007, 68(22):1883-94.
6. Karst ML, Herron KJ, Olson TM: X-linked nonsyndromic sinus node
dysfunction and atrial fibrillation caused by emerin mutation. Journal of
cardiovascular electrophysiology 2008, 19(5):510-5.
7. Muntoni F, Lichtarowicz-Krynska EJ, Sewry CA, Manilal S, Recan D, Llense S,
et al: Early presentation of X-linked Emery-Dreifuss muscular dystrophy
resembling limb-girdle muscular dystrophy. Neuromuscular disorders: NMD
1998, 8(2):72-6.
8. Ura S, Hayashi YK, Goto K, Astejada MN, Murakami T, Nagato M, et al: Limbgirdle muscular dystrophy due to emerin gene mutations. Archives of
neurology 2007, 64(7):1038-41.
O17
Emerin oligomerisation properties, impact on lamin and actin
recognition
Isaline Herrada*, Sophie Zinn-Justin
Institut de Biologie Intégrative de la Cellule, CEA, CNRS, Université Paris Sud,
Gif-sur-Yvette, France
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O17
Since a few years, several studies have revealed the essential role played by
the nuclear envelope in the cell response to mechanical demands of their
immediate surroundings. A systematic scaling between the concentration of
lamins within the nucleoskeleton and tissue elasticity was observed. This
tuning in the nuclear lamina composition was associated to changes in
nuclear mechanical properties. In addition to the lamin expression level, the
phosphorylation states of lamins A and C and of their partner emerin might
contribute to the transmission of a mechanical signal. In particular, in
response to a force applied on nesprin-1 in isolated nuclei, emerin is
phosphorylated on tyrosine residues Tyr74 and Tyr95, and these
phosphorylation events are essential to trigger a nuclear mechanical
response to tension. We have evaluated the capacity of the nucleoplasmic
region of emerin to oligomerize, in the wild-type case as well as in emerin
with mutations causing EDMD. We report large structural differences
between wild-type emerin and several mutants. The impact of these
structural differences on lamin and actin recognition is currently being
studied. The role of emerin phosphorylation on emerin structure and
binding properties is also being characterized, in order to reveal defects due
to mutations causing EDMD.
O18
FHL1 protein isoforms in Emery-Dreifuss muscular dystrophy
Esma Ziat*, Anne T Bertrand
Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617,
Center for Research in Myology, Paris, France
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O18
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
http://www.ojrd.com/supplements/10/S2
Emery-Dreifuss muscular dystrophy (EDMD) is a hereditary muscular
disorder characterized by early joint contractures, progressive muscular
wasting and weakness of scapuloperoneal distribution, and at adult age,
patients develop cardiac abnormalities with a high risk of sudden death
[1]. EDMD encompasses both X-linked and autosomal inheritance due to
mutations in the genes encoding the nuclear envelope proteins emerin,
lamin A/C [2-4]. First mutations in the Four-and-a-half LIM domain 1 gene
(FHL1) being responsible for X-linked EDMD were described by Gueneau
et al. [5]. The human FHL1 gene encodes three alternatively spliced
isoforms, named FHL1A, FHL1B and FHL1C, with FHL1A being the most
abundantly expressed protein isoform in striated muscle. There is still
little known about the precise localization and functions of the three
different FHL1 isoforms in human skeletal muscle. Here, we describe for
the first time the subcellular localization of FHL1A, FHL1B, and FHL1C
in vitro in differentiating human primary myoblasts.
Localization of FHL1 protein isoforms was studied at the myoblast and
myotube stages by confocal microscope analysis. Endogenous FHL1B
protein localization was detected by an anti-FHL1B specific antibody, while
for FHL1A and FHL1C, as no efficient isoform-specific antibodies were
available, an anti-Flag antibody was used to follow Flag-tagged FHL1A and
Flag-tagged FHL1C protein expression, after lentiviral transduction of
human primary myoblasts. Successful transduction was confirmed by
western blotting of whole extracts from myoblasts and myotubes using an
anti-Flag antibody. In human myoblasts, Flag-FHL1A and Flag-FHL1C
showed both a cytoplasmic and a nuclear distribution, while the nuclear
staining was more pronounced in Flag-FHL1C transduced myoblasts.
Endogenous FHL1B protein gave a moderate cytoplasmic and a strong
nuclear staining. During 6- and 12-days of human myoblast differentiation,
localization of all three FHL1 protein isoforms shifted from the nucleus to
the cytoplasm. In addition, all FHL1 protein isoforms were observed to colocalize with phalloidin-stained actin fibers. Collectively, these results
indicate differentiation-related changes in expression and subcellular
localization of the human FHL1 protein isoforms.
References
1. Emery AE: Emery-Dreifuss muscular dystrophy - a 40 year retrospective.
Neuromuscular disorders: NMD 2000, 10(4-5):228-32.
2. Bione S, Maestrini E, Rivella S, Mancini M, Regis S, Romeo G, et al:
Identification of a novel X-linked gene responsible for Emery-Dreifuss
muscular dystrophy. Nature genetics 1994, 8(4):323-7.
3. Bonne G, Di Barletta MR, Varnous S, Becane HM, Hammouda EH, Merlini L,
et al: Mutations in the gene encoding lamin A/C cause autosomal
dominant Emery-Dreifuss muscular dystrophy. Nature genetics 1999,
21(3):285-8.
4. Di Barletta Raffaele M, Ricci E, Galluzzi G, Tonali P, Mora M, Morandi L, et al:
Different mutations in the LMNA gene cause autosomal dominant and
autosomal recessive Emery-Dreifuss muscular dystrophy. American journal
of human genetics 2000, 66(4):1407-12.
5. Gueneau L, Bertrand AT, Jais JP, Salih MA, Stojkovic T, Wehnert M, et al:
Mutations of the FHL1 gene cause Emery-Dreifuss muscular dystrophy.
American journal of human genetics 2009, 85(3):338-53.
O19
LMNA-associated myopathies: the Italian experience in a large cohort
of patients
Lorenzo Maggi
Neuromuscular Diseases and Neuroimmunology Unit, Fondazione IRCCS
Istituto Neurologico Carlo Besta, Milan, Italy
E-mail: lorenzo.maggi@istituto-besta.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O19
We conducted a retrospective study in a large cohort of myopathic
patients carrying LMNA gene mutations to evaluate clinical and molecular
features associated with different phenotypes. To this purpose we included
90 LMNA-mutated myopathic patients and 36 LMNA-mutated familial cases
without muscle involvement. Among the myopathic patients LGMD1B was
by far the most frequent phenotype, observed in 43 (48%) patients,
followed by L-CMD in 21 (23%), EDMD2 in 20 (22%) and an atypical
myopathy in 6 (7%). The different myopathic phenotypes shared a similar
cardiac impairment. On the other hand comparing cardiac features
between myopathic and familial cases without muscle involvement we
observed that cardioverter defibrillator or pacemaker were implanted more
Page 7 of 12
frequently in myopathic patients (n=43) (p=0.006). In addition heart
transplantation and death were observed only in myopathic subgroup,
respectively in 8 (9%) and 10 (11%) patients. In conclusion LMNA-related
myopathies represent a continuum clinical spectrum; their clinical course
appears to be dominated by cardiac involvement, considering the
relatively low frequency of other complications, including loss of
ambulation, assisted ventilation, surgery for scoliosis or gastrostomy.
Longitudinal studied are needed to better investigate their natural history
and provide indications for early management of heart involvement, in
particular in first decades of life, to prevent the risk of fatal events.
O20
Limb-girdle muscular dystrophy 1F is caused by a microdeletion in the
transportin 3 gene
Saida Ortolano
Group of Neonatal and Pediatric Pathology/Rare Diseases, Instituto de
Investigación Biomédica de Ourense-Pontevedra-Vigo (IBI) Hospital Rebullón,
Vigo Spain
E-mail: saida.ortolano@sergas.es
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O20
Whole genome sequencing strategy allowed identifying the gene
responsible for autosomal dominant limb-girdle muscular dystrophy 1F,
which was previously linked to locus 7q32.1-32.2. A large Spanish family
spanning six generations with limb girdle muscular weakness and distal
involvement was find to present a mutation in the stop codon of TNPO3
gene (c.2771delA). The mutation segregates with the clinical phenotype, and
is absent in healthy relatives of the family as well as in genomic sequence
databases. Histological abnormalities of the nuclei and altered TNPO3
expression assessed in muscle biopsy of the patients indicate impaired
TNPO3 function. TNPO3 encodes transportin-3, a serine/arginine rich protein
carrier through nuclear membrane. The function of transportin-3 in skeletal
muscle has not been thoroughly characterized. The identification of this
mutation as the cause of autosomal dominant limb-girdle muscular
dystrophy highlights the importance of defects of nuclear envelope proteins
as causes of inherited myopathies [1].
Reference
1. Melia MJ, Kubota A, Ortolano S, Vilchez JJ, Gamez J, Tanji K, et al: Limbgirdle muscular dystrophy 1F is caused by a microdeletion in the
transportin 3 gene. Brain: a journal of neurology 2013, 136(Pt 5):1508-17.
O21
Irisin levels in LMNA-mutated lipodystrophic syndromes
Faiza Bensmaine1, Marie-Christine Vantyghem1,2*
1
Endocrinology and Metabolism Department, Lille Nord de France University
Hospital, Lille, France; 2Inserm U1190, Lille University Hospital, Lille, France
E-mail: mc-vantyghem@chru-lille.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O21
Sarcopenia is defined by decreased muscle mass and impaired muscle
function, which may be associated with frailty and eventually higher
mortality rates. It is physiologically induced by aging but also related to
obesity by different mechanisms such as 1) diminished physical activity;
2) elevated oxidative stress; 3) inflammatory cytokines; 4) increased
catabolic state, through hypothalamo-pituitary axis; 5) muscle insulin
resistance; 6) abnormal muscle progenitor cells differentiation to an
adipocyte-like phenotype as a result of paracrine signals from (adipo)
cytokines.
Adipose tissue is classified as white adipose tissue (WAT), the major energy
storing tissue, brown adipose tissue (BAT), which mediates non-shivering
thermogenesis and brite adipocytes (brown in white). Increasing BAT and
energy expenditure in adult humans could be a therapeutic strategy to
combat obesity. Brown adipocytes are thought to originate from a
precursor shared with skeletal muscle that expresses Myf5-Cre, while white
adipocytes originate from a Myf5-negative precursors. This provides a
rational explanation to why BAT is more metabolically favorable than WAT,
even if the situation is more complex because subsets of white adipocytes
also arise from Myf5-Cre expressing precursors. Differences in origin
between adipocytes could explain metabolic heterogeneity between
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
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depots and/or influence body fat patterning particularly in lipodystrophic
disorders.
Irisin is a newly discovered myokine, associated with ‘browning’ of the
WAT. It displays a day-night rhythm, is correlated with lean body mass, and
increases after exercise in healthy young individuals, despite an association
with major adverse cardiovascular events and polycystic ovary disease [1].
Deficiency of myostatin, and thus stimulation of muscle growth, has also
been reported to induce irisin and its precursor FNDC5 expression in
muscle and drive the browning of WAT in mice.
Familial partial lipodystrophy, Dunnigan variety (FPLD2), an autosomal
dominant disorder caused by LMNA mutations, is characterized by fat loss
from the extremities and apparent muscular hypertrophy. However, it is
unclear whether these patients appear muscular because of a lack of
subcutaneous fat or have an actual increase in muscle mass [2]. Moreover
adipose tissue mitochondrial dysfunction triggers a lipodystrophic
syndrome with insulin resistance, hepatosteatosis, and cardiovascular
complications [3,4].
Therefore, our objective was to identify the status of lean mass in LMNAmutated lipodystrophic syndromes and to determine simple biomarkers to
differentiate LMNA-mutated and acquired lipodystrophies. To do so, we
assessed the lean (as a surrogate of muscle mass) and fat mass with
absorptiometry in FPLD2 patients, non-diabetic obese and control subjects
using dual-emission x-ray absorptiometry and magnetic resonance imaging,
and measured the myokine irisin and the adipokine leptin blood levels . Our
hypothesis is that the rupture of balance between physiological lean and fat
mass in lipodystrophic syndromes could explain the evolution towards insulinresistance (Trial registration: Clin.gov2009-AO-1169-48/PHRC2009 09/094).
References
1. Bostrom PA, Fernandez-Real JM, Mantzoros C: Irisin in humans: recent
advances and questions for future research. Metab: Clin & Exp 2014,
63:178-80.
2. Ji H, Weatherall P, Adams-Huet B, Garg A: Increased skeletal muscle
volume in women with familial partial lipodystrophy, Dunnigan variety.
J Clin Endocrinol Metab 2013, 98:E1410-3.
3. Strickland LR, Guo F, Lok K, Garvey WT: Type 2 diabetes with partial
lipodystrophy of the limbs: a new lipodystrophy phenotype. Diabetes
Care 2013, 36:2247-53.
4. Vernochet C, Damilano F, Mourier A, Bezy O, Mori MA, Smyth G, et al:
Adipose tissue mitochondrial dysfunction triggers a lipodystrophic
syndrome with insulin resistance, hepatosteatosis, and cardiovascular
complications. FASEB 2014, 28:4408-19.
O22
The nuclear lamina during human spermiogenesis
Michael Mitchell
Aix Marseille Université, INSERM, GMGF UMR_S 910 13385, Marseille, France
E-mail: michael.mitchell@univ-amu.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O22
The nuclear lamina takes centre stage during spermiogenesis, the postmeiotic phase of spermatogenesis, when haploid round spermatids
differentiate into spermatozoa: the acrosome and flagellum develop at
opposite nuclear poles, the nucleus elongates and, as the nuclear histones
are replaced with protamines, the chromatin condenses, to produce the
highly compacted pyriform nucleus of the mature spermatozoa. In rodent
spermatids, the nuclear lamina contains lamin B1 and lamin B3 a specific
isoform of lamin B2 with a shortened rod domain, and A-type lamins are
absent [1,2], but nothing is known about the structure of the nuclear
lamina during human spermiogenesis. We are studying the nuclear lamina
during human spermiogenesis. We have shown that the human nuclear
lamina contains lamin B1 and, distinct from rodents, lamin B2. We also
described a transcript potentially encoding a human lamin B3 that, like its
mouse counterpart [3], induces severe nuclear deformation when
expressed in HeLa cells [4]. In human, lamin B1 and B2 localise to the
nuclear periphery in spermatids except in the region covered by the
acrosome. They are seen to recede to the posterior pole of the nucleus as
the spermatids progress through spermiogenesis. Lamin B1 was observed
on 30-40% of ejaculated spermatozoa, while lamin B2 was not detected.
The percentage of B1-labelled spermatozoa dropped at least 6-fold when
spermatozoa with normal head density were selected, indicating that
lamin B1 labels immature spermatozoa lacking a fully compacted nucleus,
Page 8 of 12
and may therefore be a marker of poor sperm quality. The comparison of
the human nuclear lamina with that of the mouse suggests that lamin B1
and B3 have critical roles during mammalian spermiogenesis.
References
1. Schutz W, Alsheimer M, Ollinger R, Benavente R: Nuclear envelope
remodeling during mouse spermiogenesis: postmeiotic expression and
redistribution of germline lamin B3. Experimental cell research 2005,
307(2):285-91.
2. Vester B, Smith A, Krohne G, Benavente R: Presence of a nuclear lamina in
pachytene spermatocytes of the rat. Journal of cell science 1993, 104(Pt
2):557-63.
3. Schutz W, Benavente R, Alsheimer M: Dynamic properties of germ linespecific lamin B3: the role of the shortened rod domain. European journal
of cell biology 2005, 84(7):649-62.
4. Elkhatib R, Longepied G, Paci M, Achard V, Grillo JM, Levy N, et al: Nuclear
envelope remodelling during human spermiogenesis involves somatic
B-type lamins and a spermatid-specific B3 lamin isoform. Molecular
human reproduction 2015, 21(3):225-36.
2.2 ADVANCES IN THERAPEUTIC
APPROACHES FOR LAMINOPATHIES
O23
Laminopathies: clinical presentations and management
Raoul CM Hennekam
Department of Paediatrics, Academic Medical Centre, Amsterdam,
Netherlands
E-mail: r.c.hennekam@amc.uva.nl
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O23
The number of laminopathies is large, and the variability is equally wide.
OMIM mentions 10 different entities, but there are several additional
reports of individuals with a lamin A/C mutation who have phenotypes
that are still at variance of these.
This variability can be explained in two ways. One is the widespread
dissemination of the lamin A/C protein within our bodies and indeed
within individual cells and the many functions that is has. The function of
providing firmness to the nuclear envelop is a major function. A lack of
that firmness due to the abnormal protein causes all structures and
proteins in the envelope potentially to be disturbed. These have all kind of
functions, sometimes also completely unrelated, and all can be disturbed
by the abnormal lamin A/C only. The other explanation is the variability
between individuals with changes in the same gene in general. Even
brothers and sisters with exactly the same mutation in exactly the same
gene can still show very different phenotypes. The background is that it
will not be a single gene that explains the phenotype but also the
background of genetic information of each person, and the exogenous
influences on this, are important. Indeed, “monogenic disorder do not
exist” [1]. So variability should in fact be expected and also explained to
patients.
One can evaluate all laminopathies for their major manifestations, which
are the heart, muscles, nerves, joints, fat tissue, skin, bone, morphology of
the face, growth and endocrine functioning. Some laminopathies are
explained by mainly heart and muscle abnormalities, other mainly by
bone, fat, skin, growth and face abnormalities. However, it may be this
distinction is artificial. It may be that in fact (almost) all laminopathies
show signs or symptoms in all of the above tissues, but we fail to
recognize this either because we haven’t looked carefully enough, or
because patients die for one particularly affected tissue and therefore
don’t have the time to show the other manifestations in other tissues. This
can be important in evaluating patients with the various laminopathies, in
providing optimal care to them, and in considerations if a management if
applied for one of the consequences of an lamin A/C, as one cannot
exclude others will then arise that have been unknown until then.
Some may argue that this means in fact all patients with a laminopathy
might be better put under a single diagnosis. That seems not right.
Detailed discussions about this are available in literature [2]. In addition,
the WHO has decided in the development of the upcoming new
International Classification of Diseases that what really counts is what a
patient experiences from an entity. And surely it does make a difference if
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one has an entity that leads to demise already around birth (restrictive
dermopathy), leads to significant problems that will be fatal in puberty
(Hutchinson-Gilford progeria), or allow you to live well into adulthood at
least with only limited restrictions in well-being (mandibulo-acral
dysostosis). So grouping all disorders under the umbrella laminopathy is
very useful for our insights, but for patients subdivision into individual
entities is still essential.
The grouping into laminopathy has also advantages in considering various
management strategies. In a very basic way one can divide management
into influencing the abnormal DNA (gene therapy), influencing the
abnormal RNA (mainly through morpholinos and other small molecules),
decreasing the amount of abnormal protein and/or increasing the amount
of normal protein (by farnesylation inhibition or increasing turnover of
proteins), and by influencing the consequences on a cell or tissue level (for
instance by statins). Gradually it becomes clear that the most effective way
must be influencing the abnormal RNA as the other ways are either
undesirable (gene therapy) or lack true, curative effectivity (FTIs and
statins). The advantage by working in this way is that studies for one
laminopathy might have benefits for the other laminopathies as well, and
in the end also for all patients.
References
1. Hennekam RC, Biesecker LG: Next-generation sequencing demands nextgeneration phenotyping. Human mutation 2012, 33(5):884-6.
2. Hennekam RC: What to call a syndrome. American journal of medical
genetics Part A 2007, 143A(10):1021-4.
O24
Management of congenital muscular dystrophies related to defects in
the LMNA gene
Susana Quijano-Roy1*, Adele D’Amico2
1
AP-HP, Service de Pédiatrie, Pôle Pédiatrique, Hôpital R. Poincaré, Garches.
Hôpitaux Universitaires Paris-Ile-de-France Ouest; GNMH, UVSQ, France; 2Unit
of Neuromuscular and Neurodegenerative Disorders, Bambino Gesù
Children’s Hospital, Rome
E-mail: susana.quijano-roy@rpc.aphp.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O24
Congenital Muscular Dystrophies are a heterogeneous group of muscular
disorders defined as early onset muscle weakness and progressive course
associated to dystrophic features at muscle biopsy. CMDs related to lamina
A/C gene (LMNA) defect include different phenotypes that can be classified
as i) severe phenotype with generalized muscular weakness and
contractures by birth, ii) ‘dropped head’ phenotype with prominent
involvement of axial muscles that generally evolves to rigid spine
phenotype and iii) early Emery-Dreifuss phenotype. All these condition
generally lead in the first 2 decades to cardiac disturbances, respiratory
insufficiency, orthopedic complication and metabolic disorders. The clinical
management requires a multidisciplinary and rigorous approach focused
on early medical and rehabilitative interventions with the main aims to
prevent ‘fatal heart event’, to cure co-morbidities (pulmonary insufficiency
and spinal and joint contractures) and to improve the quality of life of
these children.
O25
Cardiac involvement in laminopathies
Giuseppe Boriani1*, Elena Biagini1*, Karim Wahbi2, Denis Duboc2
1
Institute of Cardiology, Department of Experimental, Diagnostic and
Specialty Medicine, University of Bologna, S. Orsola-Malpighi University
Hospital, Bologna, Italy; 2Service de cardiologie, Hopital Cochin, Paris, and
Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617,
Center for Research in Myology, Paris, France
E-mail: giuseppe.boriani@unibo.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O25
Lamin A/C gene mutations can be associated with myocardial diseases,
usually characterized by dilated cardiomyopathy and/or arrhythmic
disorders. Phenotypic penetrance is age-related but expression is
extremely heterogeneous, so that muscular and arrhythmic disease can be
present in combination in the same patient, or one phenotypic
manifestation can appear earlier than the other or even not become overt
Page 9 of 12
Figure 1(abstract O25) Spectrum of cardiac involvement in
cardiolaminopathies, with regard to arrhythmic disturbances and heart
failure. Legend: AV: atrio-ventricular, LV: left ventricular
for a long time period [1]. From a cardiological point of view, aetiological
diagnosis in dilated cardiomyopathy, and specifically the diagnosis of
cardiolaminopathy, is relevant, since clinical and prognostic implications as
well as specific management strategies can be different, particularly with
regard to prevention of sudden cardiac death.
Patients can be diagnosed as being affected by a cardiolaminopathy as
a result of a cardiological workup performed for symptoms of heart
failure or for arrhythmic events or can be diagnosed incidentally or
during family screening. Family history, physical examination, laboratory
findings (specifically serum creatine kinase values) and ECG findings are
important “red flags” to diagnose a cardiolaminopathy. Patients with
cardiolaminopathies may present a wide range of arrhythmic
disturbances, which include either bradyarrhythmias (conduction
disturbances and ario-ventricular blocks, sinus node dysfunction, atrial
standstill) or tachyarrhyhmias (atrial fibrillation, ventricular tachycardia
and ventricular fibrillation), in variable combinations, and with frequent
association with left ventricular dysfunction and heart failure (Figure 1).
The presence and severity of arrhythmic disturbances is usually not
related to the presence and degree of neuromuscular impairment [2-4].
The most common clinical manifestations are lightheadedness, syncope,
palpitations, or even ischemic stroke due to cardioembolism (in case of
atrial fibrillation or atrial standstill) or sudden death [2-5]. Implantation
of a pacemaker protects form the consequences of bradyarrhythmias,
while an implantable cardioverter defibrillator (ICD) is able to interrupt
malignant ventricular tachyarrhythmias, thus preventing sudden cardiac
death [6]. Biventricular pacing is a form of cardiac stimulation, referred
as cardiac resynchronization therapy (CRT) that may improve cardiac
function in case of heart failure, low ejection fraction and ventricular
dyssynchrony [7]. Clinical decision making has to consider the risk and
benefit of brady- and tachyarrhythmias, taking into account presence/
absence of ventricular dysfunction, and the decision to implant a
cardiac electrical device (pacemaker, ICD, with/without CRT) should
consider potential risks and benefits (brignole EP). In a multicenter
study a series of risk factors emerged as predictors of the occurrence of
ventricular tachyarrhythmias (male gender, non-sustained ventricular
tachycardia, left ventricular ejection fraction < 45% and non-missense
mutation) and their presence or combination and should help for the
decision to implant an ICD [8].
References
1. Pasotti M, Klersy C, Pilotto A, Marziliano N, Rapezzi C, Serio A, et al: Longterm outcome and risk stratification in dilated cardiolaminopathies.
Journal of the American College of Cardiology 2008, 52(15):1250-60.
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
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2.
3.
4.
5.
6.
7.
8.
Ben Yaou R, Gueneau L, Demay L, Stora S, Chikhaoui K, Richard P, et al:
Heart involvement in lamin A/C related diseases. Archives des maladies du
coeur et des vaisseaux 2006, 99(9):848-55.
Bonne G, Yaou RB, Beroud C, Boriani G, Brown S, de Visser M, et al: 108th
ENMC International Workshop, 3rd Workshop of the MYO-CLUSTER
project: EUROMEN, 7th International Emery-Dreifuss Muscular Dystrophy
(EDMD) Workshop, 13-15 September 2002, Naarden, The Netherlands.
Neuromuscular disorders : NMD 2003, 13(6):508-15.
Boriani G, Gallina M, Merlini L, Bonne G, Toniolo D, Amati S, et al: Clinical
relevance of atrial fibrillation/flutter, stroke, pacemaker implant, and
heart failure in Emery-Dreifuss muscular dystrophy: a long-term
longitudinal study. Stroke; a journal of cerebral circulation 2003, 34(4):901-8.
van Berlo JH, de Voogt WG, van der Kooi AJ, van Tintelen JP, Bonne G,
Yaou RB, et al: Meta-analysis of clinical characteristics of 299 carriers of
LMNA gene mutations: do lamin A/C mutations portend a high risk of
sudden death? Journal of molecular medicine 2005, 83(1):79-83.
Meune C, Van Berlo JH, Anselme F, Bonne G, Pinto YM, Duboc D: Primary
prevention of sudden death in patients with lamin A/C gene mutations.
The New England journal of medicine 2006, 354(2):209-10.
Bertini M, Ziacchi M, Biffi M, Biagini E, Rocchi G, Martignani C, et al: Effects
of cardiac resynchronisation therapy on dilated cardiomyopathy with
isolated ventricular non-compaction. Heart 2011, 97(4):295-300.
van Rijsingen IA, Arbustini E, Elliott PM, Mogensen J, Hermans-van Ast JF,
van der Kooi AJ, et al: Risk factors for malignant ventricular arrhythmias
in lamin a/c mutation carriers a European cohort study. Journal of the
American College of Cardiology 2012, 59(5):493-500.
O26
Advances in muscle imaging for Emery-Dreifuss muscular dystrophy
Nicola Carboni
Division of Neurology, San Francesco Hospital of Nuoro, Nuoro, Italy
E-mail: nikola.carboni@tiscali.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O26
Laminopathies are a heterogeneous group of disorders related to alterations
on genes coding for proteins of the nuclear envelope. Among these clinical
entities, there are several diseases affecting mainly the cardiac and skeletal
muscles. These disorders include forms with a selective cardiac compromise
and muscular dystrophies (autosomal and X-linked forms of Emery-Dreifuss
muscular dystrophy, Limb girdle muscular dystrophy 1B, LMNA-related
congenital muscular dystrophy and other rare clinical entities). We performed
imaging studies on a large cohort of subjects bearing either LMNA or EMD
gene mutations; each patient enrolled displayed variable compromise on
posterior legs’ muscles, ranging from mild compromise on soleus and medial
head of gastrocnemius to overt alterations on soleus, medial head of
gastrocnemius [1,3]. Of note, we saw that even subjects presenting with
clinically selective cardiac compromise displayed, on imaging studies,
variable alterations on skeletal muscles. This findings showed a continuum in
skeletal muscles compromise among different phenotypes related to LMNA
or EMD gene mutations and lead to hypothesize a common mechanism in
the process of damage of skeletal muscles fibers.
References
1. Carboni N, Mura M, Mercuri E, Marrosu G, Manzi RC, Cocco E, et al: Cardiac
and muscle imaging findings in a family with X-linked Emery-Dreifuss
muscular dystrophy. Neuromuscul Disord 2012, 22(2):152-8.
2. Carboni N, Mura M, Marrosu G, Cocco E, Marini S, Solla E, et al: Muscle
imaging analogies in a cohort of patients with different clinical phenotypes
caused by LMNA gene mutations. Muscle Nerve 2010, 41(4):458-63.
3. Carboni N, Mura M, Marrosu G, Cocco E, Ahmad M, Solla E, et al: Muscle MRI
findings in patients with an apparently exclusive cardiac phenotype due to
a novel LMNA gene mutation. Neuromuscul Disord 2008, 18(4):291-8.
O27
Metreleptin therapy in LMNA-linked lipodystrophies
Camille Vatier*, Corinne Vigouroux*
INSERM UMR_S938, Centre de Recherche Saint-Antoine, Sorbonne
Universités UPMC Univ Paris 06, ICAN, Institute of Cardiometabolism and
Nutrition, Paris, France
E-mail: corinne.vigouroux@inserm.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O27
Page 10 of 12
Lipodystrophic syndromes are rare diseases of acquired or genetic origin,
associating a decreased amount of fat (with an altered distribution of body
fat in partial forms) and the metabolic alterations usually observed in
obesity, i.e. insulin resistance leading to diabetes, hypertriglyceridemia with
the risk of acute pancreatitis, fatty liver with risk of cirrhosis, and precocious
atherosclerosis. Mutations in more than 15 genes, including LMNA, have
been shown to be responsible of monogenic forms of lipodystrophies. The
decreased capacity of adipocytes to store excess energy as lipids and to
perform physiological endocrine functions, is considered as the main
pathophysiological determinant of lipodystrophies. The low circulating levels
of leptin lead to an increased appetite and participate in the ectopic storage
of lipids in the muscle and liver, which aggravates the metabolic alterations.
Replacement leptin therapy was shown to strikingly improve insulin
resistance, dyslipidemia and liver steatosis in patients with generalized form
of lipoatrophy, associated with very low endogenous secretion of leptin [1].
Recombinant leptin (metreleptin), administrated in one daily subcutaneous
injection, is well-tolerated, and, although it did not improve lipoatrophy
itself, demonstrated metabolic benefits in 55 lipodystrophic patients during
a 3-year therapy [2]. Regarding laminopathies, two studies evaluated
metreleptin therapy in 6 then 24 patients with the Dunnigan-type familial
partial lipodystrophy [3,4]. Although metreleptin was efficient in decreasing
circulating triglycerides and liver steatosis, the effects on glucose
homeostasis did not reach statistical significance. Metreleptin, which is the
first specific therapy for lipodystrophies, was approved in 2014 by the FDA
for generalized forms, and is available in selected European centers through
compassionate programs. Further studies are needed to clarify the
therapeutic indications of metreleptin in partial lipodystrophies including
laminopathies.
References
1. Oral EA, Simha V, Ruiz E, Andewelt A, Premkumar A, Snell P, et al: Leptinreplacement therapy for lipodystrophy. The New England journal of
medicine 2002, 346(8):570-8.
2. Chan JL, Lutz K, Cochran E, Huang W, Peters Y, Weyer C, et al: Clinical
effects of long-term metreleptin treatment in patients with
lipodystrophy. Endocrine practice : official journal of the American College of
Endocrinology and the American Association of Clinical Endocrinologists 2011,
17(6):922-32.
3. Park JY, Javor ED, Cochran EK, DePaoli AM, Gorden P: Long-term efficacy
of leptin replacement in patients with Dunnigan-type familial partial
lipodystrophy. Metabolism: clinical and experimental 2007, 56(4):508-16.
4. Simha V, Subramanyam L, Szczepaniak L, Quittner C, Adams-Huet B, Snell P,
et al: Comparison of efficacy and safety of leptin replacement therapy in
moderately and severely hypoleptinemic patients with familial partial
lipodystrophy of the Dunnigan variety. The Journal of clinical
endocrinology and metabolism 2012, 97(3):785-92.
O28
Round Table: Discussion with families and lay associations
Tiziana Mongini1*, Alessandra Gambineri2*
1
Neuromuscular Center, Department of Neurosciences ‘Rita Levi Montalcini’,
University of Turin, Turin, Italy; 2Division of Endocrinology, Department of
Medical and Surgical Science (DIMEC), S. Orsola-Malpighi Hospital, Bologna, Italy
E-mail: tizianaenrica.mongini@unito.it; alessandra.gambineri@aosp.bo.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O28
This session was dedicated to patients, their relatives and delegates of
Family Associations (the Progeria Family Circle, the European Association of
Progeria Families; AIProSaB, the Italian Association for Progeria, Sammy
Basso; AIDMED, the Italian Association for Emery-Dreifuss Muscular
Dystrophy; the Associazione Alessandra Proietti for Emery-Dreifuss Muscular
Dystrophy), with the main objective to establish for the first time a direct
interaction with the scientific international community working on
laminopathies. Since the patient number is very low, and the clinical
presentations of laminopathies vary greatly among the different subgroups,
this was a good opportunity to confront the whole community to identify
the ‘unmet needs’; besides the therapy to cure the disease, they include all
the complementary aspects of the disease that worsen the patient quality of
life. With the help of patients, the researchers may plan adequate strategies
to address all the issues related to the disease and to give a ‘priority’ to each
of them. Some examples of such positive interactions are the primary role of
Patients Association in the production of the Standards of Care for a group
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of neuromuscular disorders by TREAT-NMD, an European Organization, the
involvement of Parent Project in DMD clinical trials planning by Pharma
Industries and their inclusion in the process of drug approval by American
and European Drug Agencies (FDA and EMA). In Italy, the Italian Association
of Myology produced two consensus conferences, on vaccinations and on
anesthesia procedures in neuromuscular patients, on the suggestion of
Italian Neuromuscular Associations.
With the exception of patients with Progeria, who already benefit from a
good network of expert that cover their needs, the other patients, in
particular those with muscular dystrophy, are less characterized and their
clinical protocols are less standardized.
Future possible areas of common interests, to be prioritized and supported
by Patients Association, may include a consensus on precise criteria to
define the different phenotypes; protocols to reduce diagnostic delay or
misdiagnoses; physiotherapy indications; pain relevance and management;
nutritional issues.
Patient participation during the round table allowed us to focus on their
main issues: the need to spread knowledge on laminopathies and to
foster research activity in the field (mentioned by an EDMD parent and
by an HGPS patient); the need of clear indications for follow-up reference
centers (mentioned by an EDMD patient); concerns about dietary advices
for muscular and progeroid laminopathies (mentioned by an EDMD
parent with reference to the talk by Dr. Quijano-Roy and comments by
Dr. D’Amico and by an HGPS parent).
2.3 FOCUS ON REGISTRIES AND
DATABASES
O29
Utility of patients’ registries to gather clinical, epidemiological and
molecular information
Gaëlle Blandin*, Christophe Béroud
Aix Marseille Université, INSERM, GMGF UMR_S 910, 13385, Marseille, France
E-mail: gaelle.blandin@univ-amu.fr
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O29
Rare disease patient registries are indispensable tools for translating
research into improved care and therapeutic solutions. During the race to
identify a safe and effective treatment, they come into play at many stages
of the translational research cycle: collection of mutational data,
description of the disease, support for patient recruitment for clinical trials
and scientific studies (such as natural history studies), collection of
epidemiological data, evaluation/monitoring of the efficacy/safety of a
treatment, elaboration of guidelines for diagnosis and management of the
disease, etc.
In the field of rare disease, the main challenges that patient registries face
are sustainability, better interoperability with the establishment of
common data standards (for data collection, data quality, data security,
legal and ethical issues) and support for translational collaborations to
constitute large cohorts of patients. To work out these questions, the
IRDiRC (International Rare Disease Research Consortium) initiative is a
major force to encourage cooperation at international level. In this process,
patients and families are becoming more active participants and must
continue to raise their voice to drive innovation in collaboration with all
stakeholders.
O30
Clinical aspects of cardiolaminopathies and prospects for a
cardiolaminopathy registry
Sara Benedetti
Laboratory of Clinical Molecular Biology and Cytogenetics, San Raffaele
Scientific Institute, Milano, Italy
E-mail: benedetti.sara@hsr.it
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O30
Mutations in the LMNA gene, encoding nuclear proteins lamin A/C, have
been associated with neurological and cardiac disease and a high risk of
sudden death. The implant of a cardioverter defibrillator (ICD) is to date
the only effective intervention, but no specific guidelines are available. We
Page 11 of 12
decided to create a common Italian database integrating clinical and
genetic data of patients bearing LMNA gene mutations to improve
knowledge of natural history of cardiopathy, define a risk stratification
protocol for ICD implant and investigate genotype/phenotype correlations.
To date, 113 patients (age 47±18) from 11 Italian centers have been
included in our database and followed for 7±11 years. We evaluated age
at onset of different phenotypes. 70% developed cardiac symptoms,
including both rhythm (atrial fibrillation, atrio-ventricular block, ventricular
tachycardias) and structural defects (dilated cardiomyopathy, mitral
insufficiency), which may or may not be preceded by neurological signs.
Cardiac magnetic resonance was pathologic in 2/3 of studied patients.
We also evaluated the occurrence of ICD implantation, appropriate
shocks, cardiac transplantation and heart failure. Open questions include
the identification of predictors of arrhythmias to allow early diagnosis
and improve risk stratification and management of asymptomatic
patients.
O31
A common French-Italian laminopathy registry – update & future
prospects
Gisèle Bonne*, Rabah Ben Yaou
Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617,
Center for Research in Myology, Paris, France
E-mail: g.bonne@institut-myologie.org
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O31
In front of the wide clinical and genetic heterogeneity of the laminopathies,
the first task of the French Network on EDMD and other related nuclear
envelope related diseases, has been to set up in 2000, a mutation database
for LMNA and EMD mutations. We selected the Universal Mutation Database
tool (UMD) developed by Christophe Beroud (http://www.umd.be, [1]) and
set up the UMD-LMNA database that compiles genetic and associated main
clinical features of both in-house identified cases, those submitted to us by
other partners involved in LMNA gene analysis, and also all mutated subjects
reported in the literature (http://www.umd.be/LMNA/). To date, the UMDLMNA database comprises 510 different LMNA mutations identified in over
2700 individuals, out of which 60% presenting with a laminopathy of the
striated muscles (cardiomyopathies+/-muscular dystrophies), 14% with a
laminopathy affecting the adipose tissue (metabolic syndromes +/- partial
lipodystrophies) and 5.2% with premature ageing syndrome.
For rare diseases, a major hurdle in clinical translation of basic science
research results is the difficulty in identifying appropriate patient cohorts.
Prospective data on patient clinical characteristics, specific biomarkers
and outcome measures are also frequently unavailable. With the aim to
obtain longitudinal clinical data on patients with laminopathy or
emerinopathy (as well as asymptomatic carriers at the time of genetic
diagnosis) and create corresponding “trial-readiness” patient registries, we
set-up in 2013 a prospective patient registry, the OPALE registry (for
“Observatoire des Patients Atteints de Laminopathie et Emerinopathie”).
This registry will allow precise characterization of the disease natural
history, identification of specific outcome measures and further
evaluation of the prognostic value of various biomarkers. The overall
goals of OPALE are 1) a better follow-up and management of the
patients and 2) the identification of specific parameters to monitor
treatments in the perspective of future clinical trials. OPALE has been
initiated within 3 pilot centers (neuromuscular reference center at the
Myology Institute, cardiology department of Cochin university hospital in
Paris, neuropediatric department of Raymond Poincaré university hospital
in Garches) and thanks to the strong links within the French Networks of
“EDMD & other nuclear envelope related diseases”, OPALE is now
progressively opened to other French reference centers, once the
approvals of IRB/ethics committee and other regulatory authority have
been obtained. To date, 78 patients have been included in this registry
among 170 followed within the 3 pilot centers. Regular update of the
collected data are planned. We plan to open the registry to international
colleagues via our interaction with the Italian network for Laminopathies,
with the TREAT-NMD networks as well as any other center interested in
this initiative. We hope the OPALE registry will become rapidly an
international interactive tool for the benefit of laminopathy and
emerinopathy patients.
Orphanet Journal of Rare Diseases 2015, Volume 10 Suppl 2
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Reference
1. Beroud C, Hamroun D, Collod-Beroud G, Boileau C, Soussi T, Claustres M:
UMD (Universal Mutation Database): 2005 update. Human mutation 2005,
26(3):184-91.
O32
ECLip-the European consortium on lipodystrophies: an update
David Araújo-Vilar
Member of ECLip Executive Board, Division of Endocrinology and Nutrition,
University Clinical Hospital of Santiago de Compostela, Santiago de
Compostela, Spain
E-mail: david.araujo@usc.es
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O32
The European Consortium of Lipodystrophies (ECLip) is a network of
relevant clinical and basic-science research groups in Europe involved in
investigation of Lipodystrophic Syndromes (LS).
The goal of this Consortium is to enable intensive and effective collaboration
among the various high-quality European research groups in order to
promote the free exchange of ideas and information concerning research
and clinical care among LS researchers. The principal benefit will be the
advancement of patient care. It will also promote the public understanding
of LS and its consequences in affected individuals. On the other hand, ECLip
will lead to further growth and inclusion of novel aspects of LS research,
making European investigators the leaders in this important but still poorly
explored research area. Likewise, ECLip will try to give visibility and
recognition of LS in society and among policy makers, and will help the
promotion of advocacy groups in Europe and worldwide.
To date, ECLip is formed by 38 research groups coming from 15 European
countries.
The ECLip website (http://www.european-lipodystrophies.org) provides
information on all groups involved in the consortium, with information
about the researchers, the main research lines of each group, their clinical
and basic research facilities, and contact details.
2.4 CLINICAL TRIAL FOR RARE DISEASES
O33
Which support from the French Foundation of rare disease towards
clinical trial set up in rare diseases?
Luigi Ravagnan
French Foundation for rare diseases, Paris, France
E-mail: contact@fondation-maladiesrares.com
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O33
The French Foundation for rare diseases (Fondation maladies rares) is a new
private non-profit organisation started in 2012 by Pr. Nicolas Lévy and Céline
Hubert, which pooled together their complementary experiences in the field
of rare diseases, from academia and the pharmaceutical industry
respectively. Headquartered in Paris at the heart of the ‘Rare Diseases
Platform’, the Foundation reaches out to the whole national territory with its
network of regional delegates. The team is now composed of 14 dedicated
professionals.
Page 12 of 12
The Foundation was foreseen in the 2nd French National Rare Diseases Plan,
as the flagship measure of the research axis. It was created and financially
supported by 5 founders representing the patients, the research sector and
the medical sector (AFM-Téléthon, Alliance Maladies Rares, National Institute
of Health and Medical Research - Inserm, Conference of University Presidents
– CPU and Conference of University Hospitals Directors-General).
The Foundation carries out a mission of general interest: it aims at accelerating
rare diseases research programs by improving the coordination among rare
diseases players, contributing to the understanding of rare diseases, the
development of new treatments and the improvement of patient’s care and
lives.
Since its creation, 168 research projects were funded, for an amount
granted in excess of €4M, and over 100 ‘proofs of concepts’ detected,
half of which actively followed to help fill the gaps towards clinical
development (e.g. strengthening of the proof of concept, orphan drug
designation, agreement with a private partner, European funding, etc.).
O34
Applications of the PMO platform to genetic diseases
Ryszard Kole
Sarepta Therapeutics, Cambridge, MA 02142, USA
E-mail: RKole@Sarepta.com
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O34
Genetic diseases are caused by a variety of mutations some of which lead to
aberrant splicing of pre- mRNA and prevent proper mRNA translation of
essential proteins or lead to translation of undesirable proteins. Such mRNA
defects can be frequently repaired by appropriate targeting of
oligonucleotides to modify splicing pathways and restore correct translation
of desirable proteins.
Hutchinson-Gilford progeria syndrome (HGPS), the main topic of this
conference, other laminopathies, as well as diseases such as Duchenne
muscular dystrophy (DMD) and thalassemia, are amenable to splicing
manipulation or exon skipping. It has been shown in cell culture, in animal
disease models or in case of DMD in clinical trials that oligonucleotides
targeted to appropriate pre- mRNA splicing elements can restore correct
splicing and allow production of desirable proteins, i.e. dystrophin in DMD,
beta-globin in thalassemia, or reduce the level of harmful proteins, such as
progerin in HGPS.
Sarepta Therapeutics develops phosphorodiamidate morpholino oligomers
(PMOs) and their derivatives as potential drugs for the treatment of rare
diseases. After more than three years of treatment with PMO drug candidate,
eteplirsen, stability of respiratory functions was observed and the results of
the 6-minute walk test (6MWT) at 168 weeks showed continued ambulation
across all patients evaluable on the test. Some decline in distance walked was
observed since the week 144 time point. No significant treatment related
adverse events were observed over the three-year course of this study.
Cite abstracts in this supplement using the relevant abstract number,
e.g.: Kole: Applications of the PMO platform to genetic diseases.
Orphanet Journal of Rare Diseases 2015, 10(Suppl 2):O34