Myocardial ischemia-reperfusion injury, MicroRNA-214-3p, Lysine demethylase 3A, Apoptosis, Inflammatory response, Oxidative tress, Medicine (General), R5-920, Cytology, QH573-671

Objective: Many studies have explored the roles of microRNAs (miRs) in myocardial ischemia/reperfusion injury (MI/RI), while the function of miR-214-3p in MI/RI remained obscure. This study aims to unravel the regulatory mechanism of miR-214-3p in MI/RI via targeting histone demethylase lysine demethylase 3A (KDM3A). Methods: MI/RI rat model was established by ligating the left anterior descending coronary artery. MiR-214-3p and KDM3A expression in myocardial tissues of MI/RI rats was examined. Then, the serum oxidative stress factors, inflammatory factors, pathological changes of myocardial tissues, cardiomyocyte apoptosis, and fibrosis of myocardial tissues were detected in MI/RI rats intervening with miR-214-3p or KDM3A expression. The targeting relation between miR-214-3p and KDM3A was validated. Results: MiR-214-3p was low-expressed while KDM3A was high-expressed in MI/RI rat model. Up-regulated miR-214-3p or down-regulated KDM3A protected against MI/RI via mitigating serum oxidative response, reducing the levels of inflammatory factors, alleviating the pathological changes of myocardial tissues, and decreasing cardiomyocyte apoptosis and fibrosis of myocardial tissue. KDM3A amplification reversed the therapeutic effects of elevated miR-214-3p on MI/RI. KDM3A was targeted by miR-214-3p. Conclusion: miR-214-3p hinders cardiomyocyte apoptosis and myocardial injury in MI/RI rats via regulating KDM3A. Thus, miR-214-3p may function as a potential candidate for MI/RI treatment.