Calcium-independent phospholipase A2 mediates CREB phosphorylation in double-stranded RNA-stimulated endothelial cells

One of the products of a calcium-independent phospholipase A(2) (iPLA(2)) attack of plasmenylcholine, lysoplasmenylcholine, has previously been shown to activate cAMP-dependent protein kinase (PKA). Because endothelial cells respond to some agonists in part by the activation of iPLA(2), the present study was designed to determine whether double-stranded RNA (dsRNA), the primary activator of the antiviral response in endothelial cells, elicits cAMP response element binding protein (CREB) phosphorylation through a mechanism mediated by iPLA(2). dsRNA stimulated CREB phosphorylation in bovine pulmonary artery endothelial cells that was inhibited by the iPLA(2) inhibitor, bromoenol lactone, and the PKA inhibitor, H-89. Additionally, the product of iPLA(2) hydrolysis of plasmenylcholine and lysoplasmenylcholine elicited CREB phosphorylation in bovine pulmonary endothelial cells. Taken together, the present studies suggest that dsRNA as well as other agonists of endothelial cells elicit signaling mechanisms that include in part CREB phosphorylation mediated by iPLA(2).