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

Fig. 1. Isolation and identification of exosomes derived from BM-MSCs A. The morphology of BM-MSCs was characterized as being spindle-shaped under a light microscope ( × 200); B. The morphology of BM-MSCs exos was identified by a transmission electron microscope ( × 60000); C. The count and size distribution of BM-MSCs exos was detected by Nanoparticle tracking analysis (NTA); D. The exosomal marker protein CD9 was confirmed by Western blot.

Fig. 2. Intramuscular injection of BM-MSCsDSY exos can improve post-MI cardiac function A-E. The CK, LDH, α-HBDH, ALT, and AST levels in serum on the 7th, 14th, and 28th days after MI; F-G. Cardiac function was evaluated by electrocardiogram. Data are presented as Mean ± SEM, n = 6, ∗∗P < 0.01, ∗P < 0.05.

Fig. 3. Intramuscular injection of BM-MSCsDSY exos can reduce infarction area and fibrosis, and can improve post-MI cardiac morphology, histopathology and cardiomyocyte ultrastructure A-B. TTC staining for infarction area on the 7th, 14th, and 28th days after MI; C. Representative MASSON staining for collagen on the 7th, 14th, and 28th days after MI ( × 200); D. Cardiac morphology on the 7th, 14th, and 28th days after MI; E. Representative HE staining for cardiac histopathology on the 7th, 14th, and 28th days after MI ( × 200); F. Representative cardiomyocytes' ultrastructure on the 7th, 14th, and 28th days after MI ( × 25000). Data are presented as Mean ± SEM, n = 3, ∗∗P < 0.01, ∗P < 0.05.

Fig. 4. Intramuscular injection of BM-MSCsDSY exos inhibits post-MI cardiomyocyte apoptosis A. Representative TUNEL staining for apoptotic cardiomyocytes on the 7th, 14th, and 28th days after MI; B-C. Gene expression levels of p53 and BAK1 mRNA on the 7th, 14th, and 28th days after MI; D-G. Expression levels of the Bax/Bcl-2 ratio, Cleaved Caspase-3, and p-GSK-3β on the 7th, 14th, and 28th days after MI. Data are presented as Mean ± SEM, n = 3, ∗∗P < 0.01, ∗P < 0.05.

Fig. 5. Intramuscular injection of BM-MSCsDSY exos promotes post-MI autophagy in myocardial cells A-B. Gene expression levels of p62 and LC3 mRNA on the 7th, 14th, and 28th days after MI; D-G. Expression levels of p62 and LC3II on the 7th, 14th, and 28th days after MI. Data are presented as Mean ± SEM, n = 3, ∗∗P < 0.01, ∗P < 0.05.