Distinct roles of ephrin-B2 forward and EphB4 reverse signaling in endothelial cells.
OBJECTIVE
The transmembrane ligand ephrin-B2 and its receptor tyrosine kinase EphB4 are specifically expressed on arterial and venous endothelial cells, respectively, and bidirectional signals mediated by both proteins play an important role in vascular development. However, how such bidirectional signals are required for cell-cell adhesion or repulsion remains unclear.


RESULTS
Using a cell line and sorted primary endothelial cells, we show that ephrin-B2 forward signaling through the EphB4 receptor inhibits cell adhesion, whereas EphB4 reverse signaling by the transmembrane ephrin-B2 ligand does not. Cell migration is also inhibited on immobilized ephrin-B2-Fc but not on EphB4-Fc protein.


CONCLUSIONS
Ephrin-B2 forward signaling and EphB4 reverse signaling differentially affect cell adhesion and migration between arterial and venous endothelial cells.
Hamada
Koichi
K
Department of Cell Differentiation, Institute of Molecular Embryology and Genetics, Kumamoto University School of Medicine, Kumamoto, Japan.
Oike
Yuichi
Y
Ito
Yasuhiro
Y
Maekawa
Hiromitsu
H
Miyata
Keishi
K
Shimomura
Taizo
T
Suda
Toshio
T
D000199:Actins / Q000378:metabolism / Q000502:physiology; D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology; D001921:Brain / Q000098:blood supply; D002196:Capillaries / Q000166:cytology; D002448:Cell Adhesion / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism / Q000502:physiology; D003599:Cytoskeleton / Q000378:metabolism / Q000502:physiology; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology*; D036388:Ephrin-B2 / Q000494:pharmacology / Q000502:physiology*; D007141:Immunoglobulin Fc Fragments / Q000494:pharmacology; D008024:Ligands; D051379:Mice; D036224:Receptor, EphB4 / Q000378:metabolism / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D015398:Signal Transduction / Q000502:physiology*
D000199:Actins; D003598:Cytoskeletal Proteins; D036388:Ephrin-B2; D007141:Immunoglobulin Fc Fragments; D008024:Ligands; D011993:Recombinant Fusion Proteins; D036224:Receptor, EphB4