HIF-1α overexpression in mesenchymal stem cell-derived exosome-encapsulated arginine-glycine-aspartate (RGD) hydrogels boost therapeutic efficacy of cardiac repair after myocardial infarction

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-1 alpha engineered mesenchymal stem cells (MSCs) in a rat model of AMI. Methods and results: EVs isolated from HIF-1 alpha engineered MSCs (HIF-1 alpha-EVs) and control MSCs (NC-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 NC-EVs, HIF-1 alpha-EVs significantly inhibited the apoptosis of cardiomyocytes and enhanced angiogenesis of endothelial cells; meanwhile, HIF-1 alpha-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-1 alpha-EVs, and stronger cardiac function in the rats. Quantitative real-time PCR (qRT-PCR) displayed that miRNA-221-3p was highly expressed in HIF-1 alpha-EVs. After miR-221-3p was inhibited in HIF-1 alpha-EVs, the biological effects of HIF-1 alpha EVs on apoptosis and angiogenesis were attenuated. Conclusion EVs released by MSCs with HIF-1 alpha 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-1 alpha engineered MSCs-derived EVs.

Automated summary

EVs derived from HIF-1α-engineered MSCs can promote angiogenesis of endothelial cells and apoptosis of cardiomyocytes through upregulating the expression of miR-221-3p. Additionally, RGD hydrogels can enhance the therapeutic efficacy of these EVs.