EphB2 and EphB4 receptors forward signaling promotes SDF-1-induced endothelial cell chemotaxis and branching remodeling.
The complex molecular mechanisms that drive endothelial cell movement and the formation of new vessels are poorly understood and require further investigation. Eph receptor tyrosine kinases and their membrane-anchored ephrin ligands regulate cell movements mostly by cell-cell contact, whereas the G-protein-coupled receptor CXCR4 and its unique SDF-1 chemokine ligand regulate cell movement mostly through soluble gradients. By using biochemical and functional approaches, we investigated how ephrinB and SDF-1 orchestrate endothelial cell movement and morphogenesis into capillary-like structures. We describe how endogenous EphB2 and EphB4 signaling are required for the formation of extracellular matrix-dependent capillary-like structures in primary human endothelial cells. We further demonstrate that EphB2 and EphB4 activation enhance SDF-1-induced signaling and chemotaxis that are also required for extracellular matrix-dependent endothelial cell clustering. These results support a model in which SDF-1 gradients first promote endothelial cell clustering and then EphB2 and EphB4 critically contribute to subsequent cell movement and alignment into cord-like structures. This study reveals a requirement for endogenous Eph signaling in endothelial cell morphogenic processes, uncovers a novel link between EphB forward signaling and SDF-1-induced signaling, and demonstrates a mechanism for cooperative regulation of endothelial cell movement.
Salvucci
Ombretta
O
Basic Research Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
de la Luz Sierra
Maria
M
Martina
Jose A
JA
McCormick
Peter J
PJ
Tosato
Giovanna
G
D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000494:pharmacology*; D002633:Chemotaxis / Q000187:drug effects / Q000502:physiology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D008833:Microcirculation; D012313:RNA / Q000302:isolation & purification; D036224:Receptor, EphB4 / Q000235:genetics / Q000502:physiology*; D036201:Receptor, EphB5 / Q000235:genetics / Q000502:physiology*; D036081:Receptors, Eph Family / Q000235:genetics; D011994:Recombinant Proteins / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D012867:Skin / Q000098:blood supply; D014471:Umbilical Veins
C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D011994:Recombinant Proteins; D012313:RNA; D036224:Receptor, EphB4; D036201:Receptor, EphB5; D036081:Receptors, Eph Family