Upregulation of miR-29b-3p protects cardiomyocytes from hypoxia-induced apoptosis by targeting TRAF5

BACKGROUND: MicroRNAs (miRNAs) are pivotal regulators in regulating hypoxia-induced cardiomyocyte injury. This study was designed to evaluate the effects of miR-29b-3p on hypoxic cardiomyocytes. METHODS: Human AC16 cells were cultured under normoxic or hypoxic conditions. Hypoxic injury was confirmed based on alterations in cell viability using CCK-8 assay and apoptosis using flow cytometry and Hoechst staining. Bioinformatics analyses and the dual-luciferase reporter assay were performed to predict and validate the target gene of miR-29b-3p. RESULTS: We found that hypoxia suppressed cell viability and promoted apoptosis. TNF receptor-associated factor 5 (TRAF5) was a potential target gene of miR-29b-3p. Our in vitro experiments revealed that miR-29b-3p overexpression or TRAF6 knockdown significantly protected cardiomyocytes against hypoxia-induced injury. Moreover, knockdown of TRAF5 knockdown potentiated the protective effects of miR-29b-3p against hypoxia-induced cell injury. CONCLUSION: These findings suggest that upregulation of miR-29b-3p could protect cardiomyocytes against hypoxia-induced injury through downregulation of TRAF5. Targeting TRAF5 with miR-29b-3p might be a potential therapeutic method for AMI.