Vascular endothelial growth factor stimulates prostacyclin production and activation of cytosolic phospholipase A2 in endothelial cells via p42/p44 mitogen‐activated protein kinase

Abstract
Vascular endothelial growth factor (VEGF) stimulated a time‐ and concentration‐dependent increase in PGI2 synthesis in human umbilical vein endothelial cells with a mean maximum increase of 2‐fold above basal levels at 25 ng/ml after 60 min. VEGF also rapidly stimulated the release of arachidonic acid and phosphorylation and activation of cytosolic phospholipase A2 (cPLA2). The VEGF‐related factor, placenta growth factor (PlGF), had little effect on PGI2 synthesis, arachidonic acid release or cPLA2 activation. PD98059, a selective inhibitor of MAP kinase kinase, caused complete inhibition of VEGF‐stimulated MAP kinase activity, PGI2 synthesis and cPLA2 gel retardation, but had no effect on VEGF‐induced vWF secretion. These findings provide the first evidence that VEGF can stimulate PGI2 synthesis via cPLA2‐mediated arachidonic acid release and indicate that VEGF stimulation of this biosynthetic pathway may occur, at least in part, via activation of p42/p44 MAP kinases.