Mesenchymal stem-derived exosomes enhance therapeutic benefits of exercise in isoproterenol-induced myocardial ischemia: Targeting ERK and Akt/mTOR signaling.

BACKGROUND

Myocardial infarction (MI) is a significant global cause of chronic heart failure. In post-ischemic cardiac hypertrophy, multiple molecular targets and signals within the cardiac tissue are evident. Mesenchymal stem cell-derived exosomes (MSC-EXO) and exercise (EXE) showed promise in enhancing post-ischemic cardiac repair.

AIM: To investigate how the exosomes released by stem cells and/or EXE can promote cardiac repair and improve isoproterenol (ISO)-induced post-ischemic hypertrophy.

METHODS

The enrolled animals were divided into 8 control rats and 32 experimental rats. Induction of MI was performed using ISO. Then, the experimental rats were divided into 4 groups: Rats subjected to 4 weeks of swimming EXE, rats treated with exosomes, and the combined treatment. Additionally, functional and interactional exploration of targeted proteins was conducted using Gene Ontology, Kyoto Encyclopedia of Genes and Genomes analysis, and STRING database, along with histological examination.

RESULTS

Both MSC-EXO or EXE significantly improved ISO induced elevation of cardiac enzymes, oxidative stress, and inflammatory markers, as well as the degenerative changes of the cardiac muscles, fibrosis, and apoptosis. Meanwhile, the combined treatment of EXE and MSC-EXO resulted in a significant improvement in cardiac function and structure as compared to all groups that synchronized with dual inhibition of extracellular signal-regulated kinase and protein kinase B/mammalian target of rapamycin (P < 0.01) signaling and modulation of matrix metalloproteinase 9 and sarcoplasmic endoplasmic reticulum calcium ATPase type 2a, with significant improved angiogenesis.

CONCLUSION

Functional and structural cardiac improvements are accompanied by reduced inflammation, oxidative stress, and apoptosis. Both MSC-EXO and EXE exert cardio-protection by upregulating sarcoplasmic endoplasmic reticulum calcium ATPase, the critical pump for normal calcium handling.