Abstract 242: A Novel Transient Receptor Potential Ion Channel Vanilloid 4 Agonist Inhibits Monocytes Adhesion and Atherosclerosis via eNOS Activation

Abstract

Endothelial nitric oxide (NO) synthase (eNOS/NOS3)-derived NO represents an important vasculoprotective molecule in the cardiovascular system. The transient receptor potential ion channel vanilloid subtype 4 (TRPV4) mediates vascular mechanosensitivity, in part through an increase in blood flow-mediated NO production and endothelium-dependent relaxation. Here, we hypothesized that non-mechanical TRPV4 activation can mimic laminar flow-induced signaling and thereby limits monocyte adhesion and atherosclerosis. We observed that GSK1016790A, a novel, potent and specific agonist of TRPV4, mimics laminar flow, thereby inducing robust phosphorylation (Ser1177) of eNOS in a TRPV4 and calcium-dependent manner. Mechanistically, GSK1016790A induced eNOS phosphorylation, NO production and vasorelaxation via calcium/calmodulin-dependent kinase kinase (CaMKK)/AMP-activated protein kinase (AMPK) pathway. In functional experiments, GSK1016790A inhibited TNFα-induced monocytes adhesion to human endothelial cells by inhibiting the expression of intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1), and this inhibition was abolished by an eNOS inhibitor L-NG-Nitroarginine Methyl Ester (L-NAME) or AMPK inhibitor Compound C. Mice given GSK1016790A showed increased eNOS (2.5- fold increase versus vehicle, n=12, P<0.001) and AMPK phosphorylation (2.1- fold increase versus vehicle, n=12, P<0.01) in the aorta. Finally, we demonstrated that oral administration of GSK1016790A inhibited atherosclerotic plaque formation in ApoE deficient mice fed a Western-type diet (13.27% ± 1.571%, versus vehicle 23.22% ± 1.130%, n=8, P<0.001). In conclusion, our data provide a novel mechanism whereby a TRPV4 agonist triggers NO production and suggests that TRPV4 agonists could be used as innovative vasculoprotective treatments of endothelial dysfunction-related diseases, such as atherosclerosis, hypertension and stroke.