Bruno Peault – pericytes and MSCs
• MSCs, MAPCs, MDSCs, ADSCs
– all claimed to be multipotent for mesodermal cells
• Superficial similarities with pericytes – also in many tissues
• CD146/NG2/PDGFRB
• Pericytes express MSC markers in situ and in culture
• Pericytes (from muscle AND elsewhere) can regenerate muscle
• Single cell-derived cultures are multipotent
• MSCs and pericytes are both immunosuppressive in myocardium
i.e. inhibit MF infilt.
• Pericytes promote hematopoiesis in culture
•Ecs inhibit pericyte -> fat differentiation
• There are also different MSC-like cells in adventitium
– different markers
Helmut Augustin – EC quiescence
• Postnatal retina
Tie2
phalanx>stalk>tip
Ang2
tip>stalk>phalanx
• Ang1-Tie2 axis N for quiescence (Q)
• Ang2 Tg phenocopies Ang1 KO
• Loss of Q -> incr. Ang2 expr. In EC
• Ang2 rises during melanoma progression
• Ang2KO Normal devel., v.low response in Miles and ThG assays
Facilitator of TEM
• Ang2 KO NG2 and desmin coverage up, aSMA coverage down
• Phalanx vessels pericytes NG2 hi, desmin hi, aSMA lo
• Ang2 lof -> quiescence
• Ang2 gof -> activation
Helmut Augustin – Part II - CCM
• CCM – loss of quiescence (Q)
• oxpr CCM1 -> reduced sprouting & migration
reduced apoptosis & proliferation, PAkt up
• CCM1 KD -> increased sprouting & migration
increased apoptosis & proliferation
• CCM1 oxpr – Dll4, Hey1/2 up ie N signaling up
• CCM1KD – Dll4, Hey1/2 down
• DAPT blunts CCM1 effects
CCM1
N
Ang
Erk
Akt
proliferation
• Can reduce xs angiogenesis with sorafenib (broad tyrK inhibitor)
Amin Ghabrial
• Junctions between seamless and seamed vessels – HOW?
• Heart-of-glass – CCM1/2/3
• D.mel has CCM3 – it binds GC kinaseIII
– KD of either -> junction defects
Suk-Won Jin - VEGF or BMP?
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VEGF MO blocks arterial sprouts but not venous
BMP2a/2b expr. in V; BMP2b expr. around V
Oxpr Noggin3 interferes selectively with CV plexus
Oxpr BMP2b -> incr. V sprouting but no response in arteries
BMP2a MO -> plexus defects
flk1-DN BMPR1 inhibits V connections (no effect in DA)
i.e. R is N in ECs
• BMP effects are not VEGF-dependent
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Mouse EBs – noggin inhibits ang. while BMP2 enhances
Christer Betsholtz
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Wallgard et al ATVB 2008 – 58 EC-specific genes
a couple are Adh. GPCRs (Eldt1, GPR116) – both KOs viable
Eldt1 KO – nothing obvious
GPR116 KO – capillary dilation, lung enlargement, MF infilt.
• SphR1 (Edg1) – KO shows xs sprouting and glomeruli around aorta
Nick Gale – organ-specific vasculature
• TEM5/GPR124 – KO shows forebrain hemorrhage sim. to avKO
but not quite the same (also less severe in SC)
• pericytes are around tufts but are aSMA+
• GPR124 expr in ECs and pericytes.
• LCM shows tufts expr. Hypoxia, TGFB, hemorrhage, EC, peri genes
Mark Kahn
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ITAMs -> Syk-> SLP76 -> PLCg
SLP76 KO – vessel-lymphatic connections. No SLP76 in LECs
BMT recapitulates defect – can rescue with GATA1-GFP-SLP
Use Vav-Cre to turn on YFP and KO SLP76
– no contrib. of EC to lymphatics
Podoplanin +/- enhances Vav-Cre SLP76 cKO
PDPN-Fc binds platelets
PF4Cre SLP76 cKO – reproduces phenotype – SO PLATELETS
CLEC2 is podoplanin receptor – restricted to MKs
CLEC2 KO mice reproduce phenotype
Can activate WT but not CLEC-KO plts with PDPN-Fc
See small plt aggs on neoLEC in WT – plts bind LEC, not BEC
No obvious effects of plts on LEC
Aniket Gore - Wnt
• down the tubes mutant – no ISVs – R-spondin – enhances Wnt
FU-FU-TSP - mutant is S>L in TSP
• MO phenocopies mutant
• Interacts with Kremen (KR-WSC-CUB-TM)
• Sign. Looks autocrine
• VEGFC is down in mutant
• Can restore by inh. GSK3 or by VEGFC mRNA
R-spondin
Dkk
Kremen
LRP5/6
VEGF-C
Wnt
Frz
Kareen Kreutziger
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hESC-derived cardiomyocyte patches
tri-cell constructs – CMyo + HUVEC + MEF/HDF/hMSC
two MSC lines differ in their effectiveness
difference is in N/DLL4 and some other N/delta
Ying Wang - moesin
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MoesinP during EC migration and tube formation
In Zf ISV moesin enriched at lumenal membrane and vesicles
Colocation of moesin and VEcad is not complete
Vecad MO -> no lumens – still lots of vacuoles and moesin
Moesin also N for ISV formation and
Vecad not org to CCJs or vacuoles