Institute for Bio-Medical Convergence, College of Medicine, Catholic Kwandong University, Gangneung-si, Gangwon-do 210-701, Republic of Korea; Catholic Kwandong University, International St. Mary's Hospital, Incheon Metropolitan City 404-834, Republic of Korea. Electronic address: [Email]
Recent studies have shown that several upstream signaling elements of apoptosis and necroptosis are closely associated with acute injury in the heart. In our study, we observed that miR-105 was notably dysregulated in rat hearts with myocardial infarction (MI). Thus, the purpose of this study was to test the hypothesis that miR-105 participates in the regulation of RIP3/p-MLKL- and BNIP3-dependent necroptosis/apoptosis in H9c2 cells and MI rat hearts. Our results show that the RIP3/p-MLKL necroptotic pathway and BNIP3-dependent apoptosis signaling are enhanced in H9c2 cells under hypoxic conditions, whereas, compared with these pathways in the controls, those in miR-105-treated H9c2 cells are suppressed. Mechanistically, we identified miR-105 as the miRNA directly suppressing the expression of RIP3 and BNIP3, two important mediators involved in cell necroptosis and apoptosis. Furthermore, MI rat hearts injected with miR-105 had decreased infarct sizes, indicating that miR-105 is among three miRNAs that function simultaneously to suppress necroptotic/apoptotic cell death pathways and to inhibit MI-induced cardiomyocyte cell death at multiple levels. Taken together, miR-105 may constitute a new therapeutic strategy for cardioprotection in ischemic heart disease.