MiR-199a-3p promotes repair of myocardial infarction by targeting NACC2

Objective: Myocardial infarction (MI) has gained widespread interest due to its high death and disability rate worldwide. Some miRNAs are markers of heart disease. Therefore, it is necessary to understand the mechanism for repairing MI injury.

Methods: Here, we evaluated the relative expression levels of miR-199a-3p in mouse and human myocardial cell models of injury, and its effect on myocardial cells viability using Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridline (EdU) assay, and flow cytometry assay as well as western blot in vitro. Furthermore, we performed bioinformatic online analysis to investigate the role that miR-199a-3p plays in cardiomyocyte injury, measured by dual-luciferase reporter assay.

Results: The results showed that miR-199a-3p significantly increased the growth rate of cardiomyocytes after treating them with hydrogen peroxide (H₂O₂). miR-199a-3p also acted as an inhibitor that directly targeted NACC2, resulting in a higher NACC2 expression level in the injury model of cardiomyocytes than normal myocardial cells and thus preventing miR-199a-3p-induced proliferation promotion in model cardiomyocytes.

Conclusion: Our results demonstrate that miR-199a-3p may be a prognostic biomarker in myocardial injury.