Abstract
Recent evidence indicates that exosomes derived from mesenchymal stem cells (MSCs) confer protective effects against myocardial ischemia/reperfusion (I/R) injury. Exosomes are carriers of potentially protective endogenous molecules, including microRNAs (miRNAs/miRs). The current study set out to test the effects of transferring miR-182-5p from MSC-derived exosomes into myocardial cells on myocardial I/R injury. First, an I/R mouse model was developed by left anterior descending coronary artery occlusion, and myocardial cells were exposed to hypoxia/reoxygenation (H/R) for in vitro I/R model establishment. Loss- and gain-of-function experiments of miR-182-5p and GSDMD were conducted to explore the effects of miR-182-5p via MSC-derived exosomes on cell pyroptosis and viability. GSDMD was robustly expressed in I/R-injured myocardial tissues and H/R-exposed myocardial cells. GSDMD upregulation promoted H/R-induced myocardial cell pyroptosis and reduced viability, corresponding to increased lactate dehydrogenase release, reactive oxygen species production, and pyroptosis. A luciferase assay demonstrated GSDMD as a target of miR-182-5p. In addition, exosomal miR-182-5p was found to diminish GSDMD-dependent cell pyroptosis and inflammation induced by H/R. Furthermore, MSC-derived exosomes carrying miR-182-5p improved cardiac function and reduced myocardial infarction, accompanied with reduced inflammation and cell pyroptosis in vivo. Taken together, our findings suggest a cardioprotective effect of exosomal miR-182-5p against myocardial I/R injury, shedding light on an attractive therapeutic strategy.