Journal
FREE RADICAL BIOLOGY AND MEDICINE
Volume 38, Issue 10, Pages 1382-1391Publisher
ELSEVIER SCIENCE INC
DOI: 10.1016/j.freeradbiomed.2005.02.003
Keywords
adaptive response; retinal pigment epithelium; oxidative stress; antioxidant enzymes; DNA damage; DNA repair; free radicals
Funding
- Wellcome Trust Funding Source: Medline
Ask authors/readers for more resources
Cells are armed with a vast repertoire of antioxidant defense mechanisms to help prevent the accumulation of oxidative damage. It is becoming increasingly apparent that the cellular adaptive response has an important antioxidant function to counteract oxidative stress. To investigate this adaptive response we assessed the effect of sublethal H2O2 on cell viability, enzymatic activity, and nuclear (nDNA) and mitochondrial DNA (mtDNA) susceptibility to damage and repair in cultured human retinal pigment epithelium (PPE) cells. This nondividing cell type exists in a highly oxidizing microenviromment in vivo. Prior exposure to sublethal H2O2 confirmed an adaptive response, resulting in a greater cellular resistance to subsequent toxic exposures compared to nonadapted RPE (p < 0.05). A greater CAT, GPX, and CuZnSOD enzymatic activity (p < 0.05) and increased nDNA protection (p < 0.05) were also observed. However, there was no adaptive benefit for mtDNA protection or repair in response to oxidative stress. This study confirms a role for the adaptive response as an important antioxidant defense for cells located in inherently oxidizing microenvironments. Furthermore, it identifies that the mitochondria, are a weak link in otherwise efficient oxidative stress defenses and that this may contribute to aging and age-related disease. (c) 2005 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available