X-Message-Number: 19554
Date: Thu, 18 Jul 2002 05:13:30 -0700 (PDT)
From: Doug Skrecky <>
Subject: antiaging effect of nicotinamide

  Rapid reversion of aging phenotypes by nicotinamide through possible
  modulation of histone acetylation.
  Cellular & Molecular Life
  Sciences.  58(14):2108-16, 2001 Dec.
  Aging appears to be an irreversible process. Here we report that nicotinamide
  (NAA) can induce rapid and reversible reversion of aging phenotypes in human
  diploid fibroblasts in terms of cell morphology and senescence-associated
  beta-galactosidase activity. Although NAA seems to enhance the replicative
  potential of the cells, it has little effect on their growth rate and
  life span, suggesting that NAA action is rather separated
  from the cellular replicative system. The effects are unique
  to NAA: none ofthe NAA-related compounds examined (an NAD precursor/niacin,
  NAD analogs, and poly(ADP-ribose) polymerase inhibitors) exerted similar
  effects. Thus, NAD-related metabolism and poly(ADP-ribosyl)ation are unlikely
  related to the NAA action. On the other hand, histone acetyltransferase (HAT)
  activity was elevated in NAA-exposed cells, while in aged cells, HAT activity
  and histone H4 acetylation were lowered. Taken together, the results suggest
  that NAA may cause rejuvenation by restoring, at least in part, altered gene
  expression in aged cells through its activation of HAT.

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