Cytochrome P4502C9-Derived Epoxyeicosatrienoic Acids Induce the Expression of Cyclooxygenase-2 in Endothelial Cells

Abstract
Objective— Cytochrome P450 (CYP) epoxygenases metabolize arachidonic acid to epoxyeicosatrienoic acids (EETs). CYP2C9-derived EETs elicit endothelial cell proliferation and angiogenesis, but the signaling pathways involved are incompletely understood. Because cyclooxygenase-2 (COX-2) is involved in angiogenesis, we determined whether a link exists between CYP2C9 and COX-2 expression. Methods and Results— Human umbilical vein endothelial cells were infected with CYP2C9 sense or antisense adenoviral constructs. Overexpression of CYP2C9 increased COX-2 promoter activity, an effect accompanied by a significant increase in COX-2 protein expression and elevated prostacyclin production. The CYP2C9-induced expression of COX-2 was inhibited by the CYP2C9 inhibitor, sulfaphenazole, whereas 11,12-EET increased COX-2 expression. Overexpression of CYP2C9 and stimulation with 11,12-EET increased intracellular cAMP levels and stimulated DNA-binding of the cAMP-response element-binding protein. The protein kinase A inhib... Overexpression of cytochrome P450 (CYP) 2C9 in endothelial cells increased cAMP levels, stimulated the cAMP-response element-binding protein, and enhanced cyclooxygenase-2 (COX-2) promoter activity, protein expression, and prostacyclin production. CYP2C9 overexpression stimulated endothelial tube formation, which was attenuated by the COX-2 inhibitor celecoxib. Thus, COX-2 contributes to CYP2C9-induced angiogenesis.