“…Exosomes released by chronically hypoxic cardiac precursor cells deliver a pool of miRNAs (miR-15b, miR-17, miR-20a, miR-103, miR-199a, miR-210, and miR-292) that enhance angiogenesis, reduce profibrotic gene expression, preserve myocardial contractile function, and improve cardiac function in the early hours after the onset of acute myocardial infarction [ 90 ]. Heart failure is the end-stage state of various cardiovascular diseases [ 91 , 92 ], and heart failure pathological condition altered the miRNA cargos of cardiac-derived exosomes and impaired their regenerative activities. It may be related to miR-21-5p, the exosome released from explant-derived cardiac stromal cells, contributing to heart repair by enhancing angiogenesis and cardiomyocyte survival through the phosphatase and tensin homolog/Akt pathway [ 93 ].…”