TRPV4-Mediated Mitochondrial Dynamics: A Novel Mechanism Regulating Endothelial Function and Angiogenesis

Transient receptor potential vanilloid type 4 (TRPV4) is a mechanosensitive ion channel involved in the regulation of endothelial cell (EC) functions, including proliferation, migration, and angiogenesis. However, the molecular mechanisms underlying TRPV4-mediated regulation of EC activity remain inadequately understood. In this study, we explored whether TRPV4 channels influence endothelial function through modulation of mitochondrial dynamics. Confocal microscopy revealed a peri-nuclear localization of mitochondria in normal endothelial cells (NEC), whereas mitochondria in TRPV4 knockout endothelial cells (KOEC) were diffusely distributed throughout the cytoplasm. Transmission electron microscopy further confirmed the presence of rounded mitochondria in NEC, in contrast to elongated mitochondria with distinct cristae in KOEC. Notably, the distribution of mitochondria in KOEC increased in response to varying matrix stiffness, as observed when cells were cultured on extracellular matrix (ECM) gels with stiffness values mimicking pathological conditions (0.2, 8, and 50 kPa). At the molecular level, western blot analysis revealed an elevated ratio of fusion to fission proteins (Optic Atrophy 1 (OPA1)/mitochondrial fission factor (MFF)) in KOEC compared to NEC. Furthermore, seahorse flux analysis indicated significantly higher basal oxygen consumption rate (OCR), maximal OCR, ATP-linked OCR, and spare capacity in KOEC relative to NEC, all of which were notably reduced upon treatment with the small molecule OPA1 inhibitor MYLS22. Importantly, MYLS22 restored TRPV4 knockout-associated defects in proliferation, migration, and angiogenesis in ex vivo models. In vivo, MYLS22 treatment significantly impaired tumor angiogenesis and growth in endothelial-specific TRPV4 knockout mice. Collectively, these findings demonstrate that TRPV4 channels regulate angiogenesis by modulating mitochondrial dynamics through OPA1 and highlight endothelial TRPV4 as a novel therapeutic target for the regulation of mitochondrial function in endothelial cells. This work was supported by the National Institutes of Health (R01HL148585) and AHA-TPA-971237 to CKT, and AHA Pre-Doc to KD. 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.