Effect of cannabinoid receptor-2 agonist AM1241 on platelet-derived growth factor expression in the liver tissue of mice with hepatic fibrosis

Abstract

Objective: To investigate the effect of cannabinoid receptor-2 (CB2) agonist AM1241 on the mRNA and protein expression of platelet-derived growth factor (PDGF) and collagen-III (Col-III) in the liver tissue of mice with experimental liver fibrosis induced by carbon tetrachloride (CCl(4)). Methods: Totally 38 8-week-old male C57BL/6J mice were randomly divided into control group, model group, 3 mg/kg CB2 receptor agonist (AM1241) group, and 9 mg/kg AM1241 group. All mice, except for the control group, were treated with 30% CCl(4) (three times a week, 5 ml/kg body weight, 16 weeks) to establish a liver fibrosis model. Meanwhile, 3 and 9 mg/kg AM1421 was intraperitoneally injected for daily intervention, respectively. The dosage was adjusted according to actual body weight. The same solvent was given in the control group. The serum level of aspartate aminotransferase (AST) was measured by serum enzyme digestion. The liver inflammation and fibrosis were observed by HE staining of tissue slices. The mRNA and protein expression of PDGF and Col-III in hepatic tissue was determined by real-time PCR and immunohistochemistry. Results: Compared with the control group, the mice in model group showed severe liver fibrosis, significantly elevated serum AST level (742 ± 300.8 U/L vs 118.1 ± 31.1 U/L, P < 0.05), and significantly increased mRNA and protein expression of PDGF and Col-III in liver tissue (P < 0.05). Compared with the model group, the mice in 3 mg/kg AM1241 group and 9 mg/kg AM1241 group had less severe liver fibrosis, and significantly reduced serum AST levels (116.6 ± 13.68 U/L vs 742 ± 300.8 U/L, P < 0.05; 113.8 ± 16.01 U/L vs 742 ± 300.8 U/L, P < 0.05) and mRNA and protein expression of PDGF and Col-III in liver tissue (P < 0.05). Conclusion: CB2 receptor agonist AM1241 can inhibit the mRNA and protein expression of PDGF in the liver tissue of mice with hepatic fibrosis, and reduce extracellular matrix synthesis.