MiR-134-5p was found to have potential diagnostic value for myocardial infarction (MI), but its biological role in MI has not been reported. In this study, MI mouse model was established. Quantitative real-time PCR (qRT-PCR) and western blot were used to measure the expression of miR-134-5p, lysine demethylase 2A (KDM2A), and vascular endothelial growth factor (VEGF). Dual-Luciferase reporter (DLR) assay was used to explore the relationship between miR-134-5p and KDM2A. The influence of miR-134-5p on cardiomyocytes apoptosis was detected using methyl thiazolyl tetrazolium (MTT) assay. The results revealed that miR-134-5p was highly expressed in infarction tissues of MI mice. Knockdown of miR-134-5p inhibited hypoxia/reoxygenation (H/R) -induced cardiomyocyte apoptosis. In addition, KDM2A was the target gene of miR-134-5p and negatively regulated by miR-134-5p. The promotion effect on the protein level of KDM2A and VEGF induced by miR-134-5p inhibitor can be reversed by shKDM2A in cardiomyocytes. Further, silencing of miR-134-5p promoted myocardial angiogenesis and inhibited myocardial apoptosis via upregulating KDM2A in MI mice. Taken together, our research revealed that knockdown of miR-134-5p increased KDM2A expression, thereby suppressing myocardial apoptosis and promoting myocardial angiogenesis.
Keywords: Cardiomyocyte; Hypoxia/reoxygenation (H/R); Mice; Vascular endothelial growth factor (VEGF).