title: Age-related loss of the DNA repair response following exposure to oxidative stress.
abstract: Young (4- to 6-month-old) and aged (24- to 28-month-old) mice were exposed to 2-nitropropane (2-NP), a DNA oxidizing agent, and the ability to induce DNA polymerase beta (beta-pol) and AP endonuclease (APE) was determined. In contrast to the inducibility of these gene products in response to oxidative damage in young mice, aged mice showed a lack of inducibility of beta-pol and APE. APE protein level and endonuclease activity were both reduced 40% (p<.01) in response to 2-NP. Accordingly, the accumulation of DNA repair intermediates in response to 2-NP differed with age. Young animals accumulated 3'OH-containing DNA strand breaks, whereas the aged animals did not. A role for p53 in the difference in DNA damage response with age is suggested by the observation that the accumulation of p53 protein in response to DNA damage in young animals was absent in the aged animals. Our results are consistent with a reduced ability to process DNA damage with age.
authors.affiliation: Developmental Therapeutics Program, Wayne State University School of Medicine, Detroit, MI 48201, USA. d.cabelof@wayne.edu
authors.forename: Diane C
authors.initials: DC
authors.lastname: Cabelof
authors.forename: Julian J
authors.initials: JJ
authors.lastname: Raffoul
authors.forename: Yubin
authors.initials: Y
authors.lastname: Ge
authors.forename: Holly
authors.initials: H
authors.lastname: Van Remmen
authors.forename: Larry H
authors.initials: LH
authors.lastname: Matherly
authors.forename: Ahmad R
authors.initials: AR
authors.lastname: Heydari
mesh_terms: D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D015153:Blotting, Western; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects / Q000502:physiology*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase / Q000187:drug effects / Q000378:metabolism*; D004195:Disease Models, Animal; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009595:Nitroparaffins / Q000494:pharmacology; D018384:Oxidative Stress; D011336:Probability; D011407:Propane / Q000031:analogs & derivatives / Q000494:pharmacology; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: D009595:Nitroparaffins; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; C016617:2-nitropropane; D011407:Propane