Up-regulation of NAD(P)H quinone oxidoreductase 1 during human liver injury

World J Gastroenterol. 2006 Mar 28;12(12):1937-40. doi: 10.3748/wjg.v12.i12.1937.


Aim: To investigate the expression and activity of NAD(P)H quinone oxidoreductase 1 (NQO1) in human liver specimens obtained from patients with liver damage due to acetaminophen (APAP) overdose or primary biliary cirrhosis (PBC).

Methods: NQO1 activity was determined in cytosol from normal, APAP and PBC liver specimens. Western blot and immunohistochemical staining were used to determine patterns of NQO1 expression using a specific antibody against NQO1.

Results: NQO1 protein was very low in normal human livers. In both APAP and PBC livers, there was strong induction of NQO1 protein levels on Western blot. Correspondingly, significant up-regulation of enzyme activity (16- and 22-fold, P< 0.05) was also observed in APAP and PBC livers, respectively. Immunohistochemical analysis highlighted injury-specific patterns of NQO1 staining in both APAP and PBC livers.

Conclusion: These data demonstrate that NQO1 protein and activity are markedly induced in human livers during both APAP overdose and PBC. Up-regulation of this cytoprotective enzyme may represent an adaptive stress response to limit further disease progression by detoxifying reactive species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetaminophen / adverse effects
  • Adolescent
  • Adult
  • Analgesics, Non-Narcotic / adverse effects
  • Female
  • Gene Expression Regulation, Enzymologic
  • Humans
  • Immunohistochemistry
  • Liver / enzymology
  • Liver / pathology
  • Liver Cirrhosis, Biliary / complications
  • Liver Diseases / enzymology*
  • Liver Diseases / etiology
  • Male
  • Middle Aged
  • NAD(P)H Dehydrogenase (Quinone) / genetics*
  • Up-Regulation


  • Analgesics, Non-Narcotic
  • Acetaminophen
  • NAD(P)H Dehydrogenase (Quinone)
  • NQO1 protein, human