title: MicroRNA-26a overexpression protects RGC-5 cells against H2O2-induced apoptosis.
abstract: BACKGROUND
  We intended to examine the functional role of microRNA 26 (miR-26a) in regulating H2O2-induced cytotoxicity and apoptosis in RGC-5 cells in vitro.
  
  
  METHODS
  Various concentrations of H2O2 (0-1000 μM) were added in RGC-5 culture. Cell cytotoxicity was monitored by viability assay and gene expression level of miR-26a examined by qRT-PCR. MicroRNA-26a mimic was then applied in the RGC-5 culture to examine its effect on upregulating endogenous miR-26a and rescuing H2O2-induced cytotoxicity. TUNEL immunostaining assay was used to further assess the protective effect of upregulating miR-26a on H2O2-induced apoptosis in RGC-5 cells. Direct targeting of miR-26a on Phosphatase and tensin homolog (PTEN) signaling pathway was assessed by luciferase assay and western blotting. PTEN was then ectopically over-expressed in RGC-5. And its effects on miR-26a mediated apoptosis protection in RGC-5 were investigated by western blot and TUNEL assay.
  
  
  RESULTS
  H2O2 induced cytotoxicity and down-regulated miR-26a in dose-dependent manner in RGC-5 cells. MiR-26a-mimic upregulated endogenous miR-26a gene levels, and then reduced H2O2-induced cytotoxicity, as well as H2O2-induced apoptosis in RGC-5 cells. PTEN was directly targeted by miR-26a. PTEN protein was upregulated, and phosphorylated AKT protein down-regulated while miR-26a was upregulated to reduce H2O2-induced apoptosis. Finally, overexpressing PTEN reversed the protective effect of miR-26a upregulation on RGC-5 apoptosis.
  
  
  CONCLUSIONS
  Upregulating miR-26a protects RGC-5 cell against cytotoxicity and apoptosis, probably through down-regulation of PTEN.
authors.affiliation: Department of Ophthalmology, Yantaishan Hospital, 91 Jiefang Road, Yantai, 264000, Shandong, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Kang
authors.affiliation: Department of Ophthalmology, Yantai Development Area Hospital, Yantai, 264006, Shandong, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Jia
authors.affiliation: Department of Ophthalmology, People's Hospital of Cao County, Heze, 274400, Shandong, China.
authors.forename: Huaqi
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Ophthalmology, People's Hospital of Cao County, Heze, 274400, Shandong, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: Hu
authors.affiliation: Department of Ophthalmology, Weihai Municipal Hospital, 70 Heping Road, Weihai, 264200, Shandong, China. Electronic address: xiangzey@aol.com.
authors.forename: Xiangze
authors.initials: X
authors.lastname: Yang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002460:Cell Line; D015536:Down-Regulation / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000633:toxicity*; D035683:MicroRNAs; D051059:PTEN Phosphohydrolase / Q000378:metabolism; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
chemical_list: C556274:MIRN26 microRNA, rat; D035683:MicroRNAs; D006861:Hydrogen Peroxide; D051059:PTEN Phosphohydrolase; C487216:Pten protein, rat
keywords: Apoptosis; Neuroprotection; PTEN; RGC-5; miR-26a