title: Senescence associated beta galactosidase activity in human retinal pigment epithelial cells exposed to mild hyperoxia in vitro.
abstract: OBJECTIVE
  To determine if mild hyperoxia induces senescence in retinal pigment epithelium (RPE) cells in vitro.
  
  
  METHODS
  RPE340 cells and WI38 cells were grown in 20% oxygen and 40% oxygen until proliferative exhaustion. A combined senescence associated beta galactosidase (SABG) and 5-bromo-2'-deoxyuridine (BrdU) double labelling technique was performed at different times and labelled cells were counted.
  
  
  RESULTS
  Cells grown in 40% oxygen stopped proliferating at an earlier population doubling level than when grown in 20% oxygen. An increase in SABG positive cells and decrease of BrdU positive cells in 40% oxygen developed at an earlier time than when grown in 20% oxygen.
  
  
  CONCLUSIONS
  Mild hyperoxia induces premature senescence in a specific RPE cell line.
authors.affiliation: Department of Ophthalmology, University of California, Davis, CA, USA.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Honda
authors.forename: Leonard M
authors.initials: LM
authors.lastname: Hjelmeland
authors.forename: James T
authors.initials: JT
authors.lastname: Handa
mesh_terms: D015415:Biomarkers / Q000032:analysis; D018929:Cell Culture Techniques; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D016922:Cellular Senescence / Q000187:drug effects* / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D010100:Oxygen / Q000494:pharmacology*; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D001616:beta-Galactosidase / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D001616:beta-Galactosidase; D010100:Oxygen