title: Insulin protects H9c2 rat cardiomyoblast cells against hydrogen peroxide-induced injury through upregulation of microRNA-210.
abstract: BACKGROUND
  Insulin protects cardiomyocytes from reactive oxygen species (ROS)-induced apoptosis after ischemic/reperfusion injury, but the mechanism is not clear. This study investigated the protective mechanism of insulin in preventing cardiomyocyte apoptosis from ROS injury.
  
  
  METHODS
  Rat cardiomyoblast H9c2 cells were treated with hydrogen peroxide (H2O2) or insulin at various concentrations for various periods of time, or with insulin and H2O2 for various periods of time. Cell viability was measured by the methylthiazolydiphenyl-tetrazolium bromide method. Cellular miR-210 levels were quantified using real-time RT-PCR. MiR-210 expression was also manipulated through lentivirus-mediated transfection. LY294002 was used to investigate involvement of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway.
  
  
  RESULTS
  The percentage of viable cells was significantly and inversely associated with H2O2 concentration, an effect that was seemingly attenuated by insulin pretreatment. Treatments with H2O2 or insulin were associated with a significant increase in miR-210 levels. Manipulation of miR-210 expression by gene transfection showed that miR-210 could attenuate H2O2-induced cellular injury. Inhibition of the PI3K/Akt pathway by the Akt inhibitor LY294002 was associated with a decrease in miR-210 expression.
  
  
  CONCLUSIONS
  Insulin stimulated the expression of miR-210 through the PI3K/Akt pathway, resulting in a protective effect against cardiomyocyte injury that had been induced by H2O2/oxygen species. Our results provide novel evidence regarding the mechanism underlying the protective effect of insulin.
authors.affiliation: Department of Cardiology, The Second Hospital of Jilin University, Jilin University , Changchun , China.
authors.forename: Y-F
authors.initials: YF
authors.lastname: Shi
authors.forename: N
authors.initials: N
authors.lastname: Liu
authors.forename: Y-X
authors.initials: YX
authors.lastname: Li
authors.forename: C-L
authors.initials: CL
authors.lastname: Song
authors.forename: X-J
authors.initials: XJ
authors.lastname: Song
authors.forename: Z
authors.initials: Z
authors.lastname: Zhao
authors.forename: B
authors.initials: B
authors.lastname: Liu
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival; D002867:Chromones / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007328:Insulin / Q000737:chemistry; D035683:MicroRNAs / Q000378:metabolism*; D009025:Morpholines / Q000737:chemistry; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D018384:Oxidative Stress; D010100:Oxygen / Q000737:chemistry; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D051381:Rats; D015854:Up-Regulation
chemical_list: D002867:Chromones; D007328:Insulin; C546388:MIRN210 microRNA, rat; D035683:MicroRNAs; D009025:Morpholines; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D006861:Hydrogen Peroxide; D019869:Phosphatidylinositol 3-Kinases; D010100:Oxygen
keywords: Akt; H2O2; Insulin; microRNA-210; oxidative stress