PMEPA1 attenuates myocardial ischemia-reperfusion injury via interaction with NEDD4 and involvement of the TGF-β/SMAD pathway

Abstract

Myocardial ischemia-reperfusion injury (MIRI) remains a significant challenge in cardiovascular medicine, and its molecular mechanisms are not yet fully elucidated. In the present study, integrated transcriptomic analysis combined with machine learning identified PMEPA1 as a key gene consistently downregulated in both rat models of MIRI and H9c2 cardiomyocytes subjected to ischemia –reperfusion injury. A series of in vivo and in vitro experiments, including gene overexpression and knockdown, cell viability and proliferation assays, flow cytometry, Western blot, co-immunoprecipitation, and immunofluorescence, were performed to investigate the role and underlying mechanism of PMEPA1 in MIRI. Overexpression of PMEPA1 enhanced cardiomyocyte proliferation, reduced apoptosis, and inhibited activation of the TGF-β/SMAD signaling pathway. Further investigation revealed a direct interaction between PMEPA1 and the E3 ubiquitin ligase NEDD4. Both NEDD4 overexpression and PMEPA1 knockdown aggravated cardiomyocyte injury and increased activation of the TGF-β/SMAD pathway. Notably, the detrimental effects of NEDD4 overexpression were attenuated in the absence of PMEPA1, suggesting a PMEPA1-dependent mechanism. These findings highlight a novel NEDD4–PMEPA1 axis in the regulation of TGF-β/SMAD signaling during myocardial injury and provide new insights into potential molecular targets for the treatment of cardiovascular disease.