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 cytos ol 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.
All Science Journal Classification (ASJC) codes
- Primary biliary cirrhosis
- Quinone oxidoreductase