TRPV4 channels mediate TGF-β2-induced endothelial-to-mesenchymal transition (EndMT) via Rho/Snail mechanotransduction pathway

Endothelial-to-mesenchymal transition (EndMT) is a critical cellular differentiation process implicated in embryonic development and cardiovascular diseases including atherosclerosis and cardiac fibrosis. Although soluble factors such as TGF-β are major mediators of EndMT, mechanical forces such as substrate stiffness, stretch and shear stress also play equally important role in EndMT. However, the mechanotransduction mechanisms in EndMT are not well known. Here, we investigated the role of a mechanically activated ion channel, TRPV4 in EndMT. First, we found that TGF-β2 but not TGF-β1 induced EndMT of human microvascular endothelial cells (HMEC-1; human EC) as measured by increased expression of α-SMA and reduction in CD31. Next, we found that pharmacological inhibition of TRPV4 with GSK2193874 or genetic deletion of TRPV4 (TRPV4KOEC) significantly inhibited TGF-β2-induced EndMT. Importantly, TGF-β2 treatment significantly enhanced TRPV4 protein expression and TRPV4 mediated calcium influx in human EC. Mechanistically, TRPV4 inhibition attenuated TGF-β2-induced expression of EndMT transcription factor, Snail. Finally, TGF-β2-treatment decreased expression of p190RhoGAP that is attenuated by TRPV4 blockade. Our results thus suggest that TRPV4 channels mediate TGF-β2-induced EndMT via Rho/Snail mechanotransduction pathway. This work was supported by the National Institutes of Health and American Heart Association (R01HL148585 and AHA-TPA-971237) to CKT. This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.