Abstract 13229: Statins Improve Endothelial Function via Suppression of Epigenetics Driven-EndMT

Introduction and Hypothesis: Statins, a class of HMG-CoA reductase inhibitors that repress the mevalonate pathway, have been increasingly recognized to reduce cardiovascular risks in a pleiotropic manner independent of their lipid-lowering effects. Yet, the precise molecular mechanisms underlying their cardiovascular protection effects remain elusive. As an unlimited alternate source of human primary cells, we sought to use human induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) to tackle this question. Methods: We treated iPSC-ECs with or without statins in both baseline and prodiabetic conditions, and evaluated their biological functions specifically at the transcriptional and epigenetic levels using an array of state-of-the-art technologies, such as transcriptome profiling, ChIP-seq, ATAC-seq, and CRISPR interference (CRISPRi). Results: We observed that, compared to vehicles, statins significantly improved endothelial functions in both baseline and prodiabetic conditions in iPSC-ECs. Mechanistically, statins could reduce chromatin accessibility at TEAD elements and ultimately at endothelial-to-mesenchymal transition (EndMT)-regulating genes in a yes-associated protein (YAP)-dependent manner. Interestingly, inhibition of geranylgeranyltransferase I (GGTase I), a mevalonate pathway intermediate, was able to block YAP nuclear translocation and thereby YAP activity by suppressing RhoA signaling. Based on these observations, we further confirmed that inhibition of any component of the GGTase-RhoA-YAP/TEAD signaling axis using either genetic or pharmacological approaches was effective to rescue EndMT-associated endothelial dysfunction, especially under prodiabetic conditions. Conclusions: Taken together, our study identifies a novel protective role of statins in endothelial dysfunction by epigenetically repressing EndMT, and proposes that GGTase, RhoA, and YAP inhibitors may be tested as potential therapeutic candidates in addition to statins to prevent or treat endothelial dysfunction-associated cardiovascular diseases.