VEGF-induced activation of phosphoinositide 3-kinase is dependent on focal adhesion kinase

JH Qi, L Claesson-Welsh - Experimental cell research, 2001 - Elsevier
Experimental cell research, 2001Elsevier
Vascular endothelial growth factor (VEGF)-A stimulates formation of new blood vessels
(angiogenesis). This process includes migration of endothelial cells from the preexisting
vessel toward the source of the growth factor. We show that VEGF-A-induced migration of
porcine aortic endothelial cells expressing VEGF receptor-2 (VEGFR-2) is dependent on
activation of phosphoinositide 3-kinase (PI3-kinase). There is no direct interaction between
VEGF receptor-2 and PI3-kinase; instead PI3-kinase is activated downstream of focal …
Vascular endothelial growth factor (VEGF)-A stimulates formation of new blood vessels (angiogenesis). This process includes migration of endothelial cells from the preexisting vessel toward the source of the growth factor. We show that VEGF-A-induced migration of porcine aortic endothelial cells expressing VEGF receptor-2 (VEGFR-2) is dependent on activation of phosphoinositide 3-kinase (PI3-kinase). There is no direct interaction between VEGF receptor-2 and PI3-kinase; instead PI3-kinase is activated downstream of focal adhesion kinase (FAK) in VEGF-A-stimulated cells. Thus, VEGF-A stimulation leads to complex formation between FAK and PI3-kinase and overexpression of dominant-negative FAK decreases VEGF-A-induced PI3-kinase activation. FAK activation by VEGF-A increases with increasing concentration of growth factor, without apparent collapse of the cytoskeleton, in contrast to the effect of platelet-derived growth factor. FAK activation is mediated via the C-terminal tail of VEGFR-2 and loss of VEGF-A-induced FAK activation in cells expressing mutant VEGFR-2 correlates with loss of migration capacity. These data show that VEGF-A-induced FAK and PI3-kinase activation are required for migration of cells expressing VEGFR-2, via a pathway independent of direct interaction with the receptor.
Elsevier