Suppression of microRNA-101 attenuates hypoxia-induced myocardial H9c2 cell injury by targeting DIMT1-Sp1/survivin pathway.

OBJECTIVE: MicroRNAs (miRNAs) are small single-stranded RNAs in eukaryotic cells, which play important regulatory roles in the pathogenesis of various diseases. We aimed to investigate the effects of miRNA-101 (miR-101) on hypoxia-induced myocardial infarction (MI) cell injury model (myocardial H9c2 cell injury model). The possible target gene of miR-101 was also analyzed. MATERIALS AND METHODS: H9c2 cells were exposed to hypoxia treatment. Cell viability, migration, invasion, apoptosis and the expression of miR-101 were detected using CCK-8 assay, transwell assay, flow cytometer analysis, Western blotting and qRT-PCR, respectively. Then, the effects of miR-101 overexpression or suppression on the cell injury induced by hypoxia were assessed. Dual luciferase reporter assay was used to analyze the possible target gene of miR-101. Finally, the effects of dimethyladenosine transferase 1 homolog (DIMT1), the possible target gene of miR-101, on H9c2 cell injury were investigated. RESULTS: Hypoxia significantly induced H9c2 cell injury. miR-101 was up-regulated after hypoxia induction. Hypoxia-induced cell injury was significantly reversed by miR-101 suppression and exacerbated by miR-101 overexpression. DIMT1 was a direct target gene of miR-101. Knockdown of DIMT1 markedly inhibited the protective effects of miR-101 suppression on hypoxia-induced cell injury by suppressing specific protein 1 (Sp1)/Survivin pathway. CONCLUSIONS: We verified the critical roles of miR-101 in regulating myocardial cell injury induced by hypoxia. DIMT1-mediated the Sp1/Survivin pathway was also involved in this process. Our findings replenished the understanding of the regulatory roles of miRNAs in hypoxia-induced MI cell injury and provided new molecular target for therapy and diagnosis of MI.