Age-related loss of stress-induced nuclear proteasome activation is due to low PARP-1 activity

Free Radic Biol Med. 2011 Jan 1;50(1):86-92. doi: 10.1016/j.freeradbiomed.2010.10.700. Epub 2010 Oct 23.


Changes in protein turnover are among the dominant metabolic changes during aging. Of special importance is the maintenance of nuclear protein homeostasis to ensure a coordinated cellular metabolism. Therefore, in the nucleus a special PARP-1-mediated mechanism of proteasomal activation exists to ensure a rapid degradation of oxidized nuclear proteins. It was already demonstrated earlier that the cytosolic proteasomal system declines dramatically with aging, whereas the nuclear proteasome remains less affected. We demonstrate here that the stress-mediated proteasomal activation in the nucleus declines during replicative senescence of human fibroblasts. Furthermore, we clearly show that this decline in the PARP-1-mediated proteasomal activation is due to a decline in the expression and activity of PARP-1 in senescent fibroblasts. In a final study we show that this process also happens in vivo, because the protein expression level of PARP-1 is significantly lower in the skin of aged donors compared to that of young ones. Therefore, we conclude that the rate-limiting factor in poly(ADP-ribose)-mediated proteasomal activation in oxidative stress is PARP-1 and not the nuclear proteasome itself.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / physiology
  • Benzamides / pharmacology
  • Biopsy
  • Cell Nucleus / metabolism*
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cellular Senescence / physiology*
  • Down-Regulation
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Humans
  • Hydrogen Peroxide / pharmacology
  • Oxidative Stress / physiology*
  • Poly (ADP-Ribose) Polymerase-1
  • Poly Adenosine Diphosphate Ribose / metabolism
  • Poly Adenosine Diphosphate Ribose / pharmacology
  • Poly(ADP-ribose) Polymerase Inhibitors
  • Poly(ADP-ribose) Polymerases / metabolism*
  • Poly(ADP-ribose) Polymerases / pharmacology
  • Proteasome Endopeptidase Complex / metabolism*


  • Benzamides
  • Enzyme Inhibitors
  • Poly(ADP-ribose) Polymerase Inhibitors
  • Poly Adenosine Diphosphate Ribose
  • 3-aminobenzamide
  • Hydrogen Peroxide
  • PARP1 protein, human
  • Poly (ADP-Ribose) Polymerase-1
  • Poly(ADP-ribose) Polymerases
  • Proteasome Endopeptidase Complex