Abstract 12286: A Novel Yap Inhibitor Cbl0137 Protects Against Endothelial Inflammation and Atherosclerosis

Abstract

Background: Endothelial activation is a critical hallmark in the initiation of atherosclerosis. Our previous study found that YAP activation plays a significant role in induction of endothelial inflammation and formation of atherosclerotic plaques, suggesting that targeting YAP signaling pathway might be effective for the treatment of atherosclerotic cardiovascular disease. We have recently set up a reporter gene assay-based drug screening platform and identified CBL0137 as an inhibitor of YAP activity in human endothelial cells. Methods: We used 8*GTIIC luciferase reporter gene assay to screen a drug library and other small molecule compounds. We validated the inhibitory effect of CBL0137 on YAP activity by detecting the expression of YAP target genes and phosphorylation of YAP, which were measured by quantitative real-time polymerase chain reaction and western blotting, respectively. Subsequently, we treated human endothelial cells with CBL0137 (1 μM) for 4 hrs, and then isolated the total RNA and performed transcriptome sequencing. We explored the anti-inflammatory effects and underlying mechanisms of CBL0137 in primary endothelial cells. Moreover, we assessed whether CBL0137 could retard formation of atherosclerotic plaques in ApoE-/- mice using carotid artery partial ligation-induced and chronic western diet-induced atherosclerosis models. Results: We identified CBL0137 as a novel YAP inhibitor through screening the drug library. In human endothelial cells, CBL0137 inhibited the phosphorylation of YAP at Y357 to suppress YAP activity, and therefore repressed the expression of YAP target genes. In addition, CBL0137 restrained endothelial inflammatory response in a YAP-dependent manner. Furthermore, CBL0137 inhibited YAP phosphorylation at Y357 via the tyrosine-protein kinase Src. In animal experiments, administration of low doses of CBL0137 attenuated endothelial inflammation and atherosclerosis induced by disturbed flow or atherogenic diets in both male and female ApoE-/- mice. Conclusions: CBL0137 is a novel YAP inhibitor that protects against endothelial inflammation and atherogenesis. CBL0137 might be a promising anti-atherosclerosis drug, but further investigations including clinical trials are required.