Increased susceptibility of late passage human diploid fibroblasts to oxidative stress

Exp Gerontol. Jul-Aug 1996;31(4):465-74. doi: 10.1016/0531-5565(96)00001-0.

Abstract

Three strains of human diploid fibroblasts, TIG-3, TIG-7, and MRC-5, were serially cultivated. The susceptibility of early-passage and late-passage cells at 20-30 and 60-70 population doubling levels, respectively, to hydrogen peroxide, the superoxide radical (exposure to the hypoxanthine-xanthine oxidase system), or linoleic acid hydroperoxide was examined for lactate dehydrogenase release. The susceptibility of late-passage cells to such oxidative stress was considerably enhanced compared with early-passage cells. The concentration of reduced glutathione in late-passage cells was lower by 24-44% on a per-cell-number basis and by 86.0-94.5% on a per-protein-quantity basis than in early-passage cells. In addition, the activity of catalase in late-passage cells was lower by 19-46% compared with early-passage cells. There was, however, no difference between the mRNA levels of catalase in early-passage and late-passage cells. The activities and mRNA levels of copper/zinc superoxide dismutase, manganese superoxide dismutase, and glutathione peroxidase in late-passage cells were all higher than in early-passage cells. These results suggest that late-passage cells are more susceptible to oxidative stress than early-passage cells presumably because of decreases in cellular reduced glutathione concentration and catalase activity, and that their primary defense against oxidative stress is reduced glutathione.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalase / metabolism
  • Cellular Senescence*
  • Fibroblasts / physiology
  • Glutathione / metabolism
  • Humans
  • Oxidative Stress*
  • Superoxide Dismutase / metabolism

Substances

  • Catalase
  • Superoxide Dismutase
  • Glutathione