Simvastatin inhibits POVPC-mediated induction of endothelial-to-mesenchymal cell transition

Endothelial-to-mesenchymal transition (EndMT), the process by which an endothelial cell (EC) undergoes a series of molecular events that result in a mesenchymal cell phenotype, plays an important role in atherosclerosis. 1-Palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC), derived from the oxidation of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine, is a proinflammatory lipid found in atherosclerotic lesions. Whether POVPC promotes EndMT and how simvastatin influences POVPC-mediated EndMT remains unclear. Here, we treated human umbilical vein ECs with POVPC, simvastatin, or both, and determined their effect on EC viability, morphology, tube formation, proliferation, and generation of NO and superoxide anion (O-2(center dot-)). Expression of specific endothelial and mesenchymal markers was detected by immunofluorescence and immunoblotting. POVPC did not affect EC viability but altered cellular morphology from cobblestone-like ECs to a spindlelike mesenchymal cell morphology. POVPC increased O-2(-) generation and expression of alpha-smooth muscle actin, vimentin, Snail-1, Twist-1, transforming growth factor-beta (TGF-beta), TGF-beta receptor II, p-Smad2/3, and Smad2/3. POVPC also decreased NO production and expression of CD31 and endothelial NO synthase. Simvastatin inhibited POVPC-mediated effects on cellular morphology, production of O-2(center dot-) and NO, and expression of specific endothelial and mesenchymal markers. These data demonstrate that POVPC induces EndMT by increasing oxidative stress, which stimulates TGF-beta/Smad signaling, leading to Snail-1 and Twist-1 activation. Simvastatin inhibited POVPC-induced EndMT by decreasing oxidative stress, suppressing TGF-beta/Smad signaling, and inactivating Snail-1 and Twist-1. Our findings reveal a novel mechanism of atherosclerosis that can be inhibited by simvastatin.

Automated summary

Endothelial-to-mesenchymal transition (EndMT) is an important process in atherosclerosis, with POVPC playing a role in inducing this transition. Simvastatin was found to inhibit POVPC-induced EndMT by reducing oxidative stress, suppressing TGF-beta/Smad signaling, and deactivating Snail-1 and Twist-1. This reveals a novel mechanism of atherosclerosis that can be targeted by simvastatin.