Vascular endothelial growth factor receptor-2 activates ADP-ribosylation factor 1 to promote endothelial nitric-oxide synthase activation and nitric oxide release from endothelial cells.
Vascular endothelial growth factor (VEGF) induces angiogenesis and regulates endothelial function via production and release of nitric oxide (NO), an important signaling molecule. The molecular basis leading to NO production involves phosphatidylinositiol-3 kinase (PI3K), Akt, and endothelial nitric-oxide synthase (eNOS) activation. In this study, we have examined whether small GTP-binding proteins of the ADP-ribosylation factor (ARF) family act as molecular switches to regulate signaling cascades activated by VEGF in endothelial cells. Our results show that this growth factor can promote the rapid and transient activation of ARF1. In endothelial cells, this GTPase is present on dynamic plasma membrane ruffles. Inhibition of ARF1 expression, using RNA interference, markedly impaired VEGF-dependent eNOS phosphorylation and NO production by preventing the activation of the PI3K/Akt signaling axis. Furthermore, our data indicate that phosphorylation of Tyr(801), on VEGF receptor 2, is essential for activating Src- and ARF1-dependent signaling events leading to NO release from endothelial cells. Lastly, this mediator is known to regulate a broad variety of endothelial cell functions. Depletion of ARF1 markedly inhibits VEGF-dependent increase of vascular permeability as well as capillary tubule formation, a process important for angiogenesis. Taken together, our data indicate that ARF1 is a novel modulator of VEGF-stimulated NO release and signaling in endothelial cells.
Department of Biochemistry, Faculty of Medicine, University of Montréal, Montréal, Quebec H3C 3J7, Canada.
Zeinab
Z
Daher
Pierre-Luc
PL
Boulay
Fanny
F
Desjardins
Jean-Philippe
JP
Gratton
Audrey
A
Claing
D020823:ADP-Ribosylation Factor 1 / Q000378:metabolism*; D000818:Animals; D001011:Aorta / Q000166:cytology; D002417:Cattle; D042783:Endothelial Cells / Q000378:metabolism*; D004789:Enzyme Activation; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D020935:MAP Kinase Signaling System; D009569:Nitric Oxide / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
D042461:Vascular Endothelial Growth Factor A; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D019869:Phosphatidylinositol 3-Kinases; D040301:Vascular Endothelial Growth Factor Receptor-2; D020823:ADP-Ribosylation Factor 1