title: Effects of microRNA-139 on myocardial cell injury induced by oxidative stress.
abstract: OBJECTIVE
  This study aims to explore the effects of miR-139 on myocardial cell injury induced by oxidative stress and its mechanisms.
  
  
  METHODS
  H9c2 cells were used in this study. They were divided into control group, H2O2 group, H2O2+miR-139-5-p NC group and H2O2+miR-139-5-p mimics group. Cell activity was detected by MTT method. ROS level was detected by DCFH-DA probe method. MDA and SOD levels and Caspase 3 activity were detected by spectrophotometry. The cell apoptosis was detected by Hoechst 33342 and Annexin V-FITC/PI staining methods. The expression levels of AKT, GSK-3β, Bax and Bcl-2 were determined by Western blotting methods.
  
  
  RESULTS
  It showed that the activity of H9c2 cells decreased with the increase of the dose of H2O2. The activity of miR-139-5-p in H9c2 cells decreased after treatment of H2O2 for 6 h (P<0.01). Compared with control group, cell activity in H2O2 group and H2O2+miR-139-5-p NC group decreased (P<0.01), ROS fluorescence intensity increased (P<0.01), MDA content increased (P<0.01), SOD content decreased (P<0.01), apoptosis degree, Caspase 3 activity and Bax levels increased (P<0.01), Bcl-2, AKT and GSK-3β decreased (P<0.01). However, they were opposite in H2O2+miR-139-5-p mimics compared with H2O2 group and H2O2+miR-139-5-p NC group.
  
  
  CONCLUSIONS
  miR-139-5-p expressed low in oxidative stress of H9c2 cells induced by H2O2 and the oxidative stress injury could be inhibited after increasing the expression of miR-139-5-p, which could be related with the elimination of intracellular oxidative stress products and the resistance to apoptosis through AKT/GSK-3β signaling pathway.
authors.affiliation: Department of Cardiology, Army General Hospital in Lanzhou Lanzhou 730050, Gansu, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Department of Cardiology, Army General Hospital in Lanzhou Lanzhou 730050, Gansu, China.
authors.forename: Sumei
authors.initials: S
authors.lastname: Liang
authors.affiliation: Department of Cardiology, Army General Hospital in Lanzhou Lanzhou 730050, Gansu, China.
authors.forename: Yuxiu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, Army General Hospital in Lanzhou Lanzhou 730050, Gansu, China.
authors.forename: Yongqing
authors.initials: Y
authors.lastname: Chen
keywords: AKT/GSK-3β signaling pathway; H9c2 cells; Oxidative stress; ROS; apoptosis; miR-139-5-p