Effect of nuclear receptor downregulation on hepatic expression of cytochrome P450 and transporters in chronic hepatitis C in association with fibrosis development.

Analysis of mRNAs from liver biopsy samples of patients with chronic hepatitis C revealed that the levels of nuclear receptor expression were correlated with those of drug-metabolizing enzymes and transporters in relation to the development of fibrosis. Overall, the median mRNA level was largely dependent on fibrosis stage (F), and that for stage 3 patients (F3) was about 50% less than that for F1 patients. Levels of expression of AhR, together with CAR and PXR, were lowest in livers of F3 patients. Multivariate linear regression analysis revealed that AhR expression appeared to be involved in the regulation of CYP1A2, 2E1, 2D6, UGT1A, MDR1/3, MRP2/3, NTCP and OCT1 in the livers of patients with chronic hepatitis C. These results suggest that downregulation of AhR during the progression of liver fibrosis is associated with decreased expression levels of these phase I and II enzymes and drug transporters during inflammation-related signal transduction between AhR and other nuclear receptors.