Exosomes derived from Danshen decoction-pretreated bone marrow mesenchymal stem cells alleviate myocardial infarction via anti-apoptosis and up-regulation of autophagy

Cardiomyocyte loss and myocardial fibrosis are major determinants of myocardial infarction (MI) pathological changes. Mesenchymal stem cell (MSC)-derived exosomes (exos) and Danshen decoction (DSY) have been demonstrated to mediate cardiac repair following MI. BM-MSCs exos or BM-MSCsDSY exos were intramuscularly injected into post-MI rats. On the 7th, 14th and 28th days, serum CK, LDH, α-HBDH, ALT, and AST were measured and electrocardiogram changes were monitored to identify cardiac function; Triphenyltetrazolium chloride staining, Hematein&Eosin staining, Masson trichrome staining and Transmission Electron Microscope were adopted to analyze infarct area, cardiac morphology, histopathology, and fibrosis and cardiomyocyte ultrastructure; TUNEL assay, real-time PCR and western blot were performed to detect cardiomyocyte apoptosis and autophagy. As a result, BMMSCsDSY exos are superior to BM-MSCs-exos in improvement of cardiac function, morphology, histopathology and cardiomyocyte ultrastructure, as well as in reduction of infarction area and cardiac fibrosis by inhibiting apoptosis and promoting autophagy of cardiomyocytes.