Hypoxia Inducible Factor-1α Overexpression Enhances the Efficacy of Mesenchymal Stem Cells Derived Extracellular Vesicles for Cardiac Repair After Myocardial Infarction
Abstract Aims Naturally secreted extracellular vesicles (EVs) play important roles in stem-mediated cardioprotection. This study aimed to investigate the cardioprotective function and underlying mechanisms of EVs derived from HIF-1a engineered mesenchymal stem cells (MSCs) in a rat model of AMI.Methods and Results EVs isolated from HIF-1a engineered MSCs (HIF-1a-EVs) and control MSCs (MSCs-EVs) were prepared. In in vitro experiments, the EVs were incubated with cardiomyocytes and endothelial cells exposed to hypoxia and serum deprivation (H/SD); in in vivo experiments, the EVs were injected in the acutely infarcted hearts of Sprague-Dawley rats. Compared with MSCs-EVs, HIF-1a-EVs significantly inhibited the apoptosis of cardiomyocytes and enhanced angiogenesis of endothelial cells; meanwhile, HIF-1a-EVs also significantly shrunk fibrotic area and strengthened cardiac function in infarcted rats. After treatment with EVs/RGD-biotin hydrogels, we observed longer retention, higher stability in HIF-1a-EVs, and stronger cardiac function in the rats. Quantitative real-time PCR (qRT-PCR) displayed that miRNA-221-3p was highly expressed in HIF-1a-EVs. After miR-221-3p was inhibited in HIF-1a-EVs, the biological effects of HIF-1a EVs on apoptosis and angiogenesis were attenuated.Conclusion EVs released by MSCs with HIF-1a overexpression can promote the angiogenesis of endothelial cells and the apoptosis of cardiomyocytes via upregulating the expression of miR-221-3p. RGD hydrogels can enhance the therapeutic efficacy of HIF-1a engineered MSC-derived EVs.