title: Protective effect of canolol from oxidative stress-induced cell damage in ARPE-19 cells via an ERK mediated antioxidative pathway.
abstract: OBJECTIVE
  Oxidative stress damage to retinal pigment epithelial (RPE) cells is thought to play a critical role in the pathogenesis of age-related macular degeneration (AMD). This study was conducted to investigate the protective effect of canolol against oxidative stress-induced cell death in ARPE-19 cells and its underlying mechanism.
  
  
  METHODS
  ARPE-19 cells, a human retinal pigment epithelial cell line, were subjected to oxidative stress with 150 μM t-butyl hydroxide (t-BH) in the presence/absence of canolol in different concentrations. Cell viabilities were monitored by a 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyl tetrazolium bromide (MTT) assay. The apoptosis was measured by flow cytometry using Annexin V-FITC and PI staining and intracellular reactive oxygen species (ROS) levels were measured by a fluorescence spectrophotometer. Gene expression of NF-E2-related factor (Nrf-2), heme oxygenase-1 (HO-1), catalase and glutathione S-transferase-pi (GST-pi) were measured by a reverse transcription polymerase chain reaction (RT-PCR) assay. Activation of the extracellular signal regulated kinase (ERK) protein was evaluated by western blot analysis.
  
  
  RESULTS
  Canolol showed relatively high safety for ARPE-19 cells and recovered the cell death caused by t-BH dose-dependently at a concentration of 50-200 μM. Canolol also reduced t-BH-induced intracellular ROS generation and thus protected ARPE-19 cells from cell apoptosis. HO-1, catalase, GST-pi, and Nrf-2 were elevated in ARPE-19 cells after treatment with different concentrations of canolol for 24 h. Finally, canolol was found to activate extracellular signal regulated kinase (ERK) phosphorylation in ARPE-19 cells under the condition, with or without t-BH.
  
  
  CONCLUSIONS
  Canolol protected ARPE-19 cells from t-BH-induced oxidative damage and the protective mechanism was associated, at least partly, with the upregulation (activation) of antioxidative enzymes, probably through an ERK mediated pathway. This suggests that canolol offers a remarkable protective effect against oxidative damage of RPE cells and may have a therapeutic effect on AMD and other oxidative stress-related retinal diseases.
authors.affiliation: Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, P.R. China.
authors.forename: Xin
authors.initials: X
authors.lastname: Dong
authors.forename: Zhongrui
authors.initials: Z
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zhang
authors.forename: Shuizhong
authors.initials: S
authors.lastname: Liu
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Fang
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Maeda
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsukura
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D019610:Cytoprotection / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D051267:NF-E2-Related Factor 2 / Q000235:genetics / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology* / Q000627:therapeutic use; D010766:Phosphorylation / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors* / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013050:Spectrometry, Fluorescence; D015854:Up-Regulation; D014753:Vinyl Compounds / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D010636:Phenols; D017382:Reactive Oxygen Species; D014753:Vinyl Compounds; D002374:Catalase; D051547:Heme Oxygenase-1; D005982:Glutathione Transferase; D048049:Extracellular Signal-Regulated MAP Kinases; C488411:4-vinyl-2,6-dimethoxyphenol