Mesenchymal Stem Cell-derived Exosomal Mir-21-5p Inhibits YAP1 Expression and Improves Outcomes in Myocardial Infarction

Background: Myocardial infarction (MI) remains a significant global health concern, characterized by cardiomyocyte apoptosis and adverse ventricular remodeling. Nevertheless, the interplay between exosomal miR-21-5p and Yes-associated protein 1 (YAP1) in the context of MI remains unexplored.

Methods: Rat mesenchymal stem cells (MSCs) and H9c2 cardiomyocytes were cultured, characterized, and instrumental in our experiments. Exosomes were meticulously isolated, and their identity confirmed. The internalization of these exosomes by H9c2 cells was assessed, while RNA and protein expression were quantified using Quantitative Real-Time PCR and Western blot, respectively. MTT assay was implemented for cell viability, and apoptosis was evaluated via flow cytometric analysis. To elucidate gene interactions, we conducted microarray profiling of miRNA expression, dual luciferase reporter assays, and RNA Immunoprecipitation.

Results: MSC-derived exosomes exhibited a remarkable capacity to attenuate hypoxia-induced inflammation and apoptosis in H9c2 cells. Notably, these exosomes significantly upregulated miR-21-5p levels within H9c2 cells, and the abrogation of miR-21-5p function abated their protective effects. Through computational analysis, we unveiled a miR-21-5p binding site in the 3'UTR of YAP1, which directly inhibited YAP1 expression. Importantly, the inhibition of YAP1 effectively reinstated the protective effects of exosomes in cells with impaired exosomal miR-21-5p.

Conclusion: This study underscores the pivotal role played by MSC-derived exosomes in safeguarding against MI, primarily by mediating the transfer of miR-21-5p, which targets YAP1 signaling pathways.

Clinical Trial Number: N/A.