Hepatic expressions of cannabinoid receptors CB1 and CB2 correlate with the fibrogenesis in patients with chronic hepatitis B.

AIM:

The endocannabinoid system is involved in the pathogenesis of liver fibrosis. However, most of the findings come from experiment researches on animal model or clinical trial on chronic hepatitis C. The roles of cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2) in hepatofibrosis on patients with chronic hepatitis B(CHB) have not been studied universally. This study aimed to explore the relationship between liver fibrosis and expressions of CB1 and CB2 on patients with CHB.

METHODS:

Eighty liver biopsy on patients with CHB (male 52, female 28) were enrolled. Fibrosis was staged on a scale of 1 to 4 (F1 to F4, F4 defining as cirrhosis). There were 20 samples in each fibrosis stage. The expressions of hepatic alpha-smooth muscle actin(α-SMA), CB1 and CB2 were detected by immunohistochemistry.

RESULTS:

Hepatic CB1 and CB2 were expressed in all patients with CHB. The degree of fibrosis was associated with significantly increased CB1 and CB2 expressions in CHB. Furthermore a significant increase of positive cells of both CB1 and CB2 was detected in stage 3 and stage 4 compared to stage1 and stage 2. There was a strong positive association between CB1 expression and α-SMA expression. Moreover, double immunofluorescence staining of CB1 and α-SMA demonstrated that the activated hepatic stellate cells(HSCs) express CB1.

CONCLUSIONS:

The hepatic expressions of CB1 and CB2 play important roles during the progression of fibrosis induced by CHB. Endogenous activation of CB1 receptors in patients with CHB enhances fibrogenesis by direct effect on activated HSCs.

Copyright © 2017. Published by Elsevier Ltd.