Overexpression of Numb gene can inhibit the progression of biliary liver fibrosis in adult liver

Abstract

Objective: To investigate whether the overexpression of Numb gene can effectively intervene the progression of cholestatic liver fibrosis (CLF) in adult liver. Methods: Twenty-four SD rats were randomly divided into sham operation (Sham, n=6), common bile duct ligation (BDL, n=6), empty vector plasmid (Numb-EV, n=6) and numb gene overexpression group (Numb-OE, n=6). The CLF model was prepared by common bile duct ligation. Simultaneously, the model was established, and the adeno-associated virus (AAV) carrying the cloned numb gene was injected into the rats' spleens. Samples were collected at the end of four weeks. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (Alb), serum total bilirubin (TBil), serum total bile acid (TBA), liver histopathology, liver tissue hydroxyproline (Hyp) content, and alpha smooth muscle actin (α-SMA), cytokeratin (CK) 7, and CK19 expression conditions were determined in liver tissue. An analysis of variance was used to compare the means of multiple groups. Results: Compared with the Sham group, the Numb mRNA level in the rat liver tissue was significantly decreased in the BDL group (0.872±0.237 vs. 0.452±0.147, P=0.003). Compared with the Numb-EV group, the Numb mRNA level in the liver tissue was significantly increased in the Numb-OE group (0.487±0.122 vs. 1.094±0.345, P＜0.01). Compared with the Sham group, the Hyp content (μg/L) (288.46±49.49 vs. 901.98±271.85, P＜0.01) and the α-SMA mRNA level (0.858±0.234 vs. 8.976±1.398, P＜0.01) were significantly higher in the BDL group. Compared with the Numb-EV group, the Hyp content (864.32±113.54 vs. 580.44±171.77, P=0.039), the α-SMA mRNA level (6.138±1.443 vs. 1.322±0.859, P＜0.01) and the protein levels were significantly reduced in the Numb-OE group. Compared with the Sham group, the serum ALT, AST, TBil, and TBA levels were significantly increased in the BDL group (P＜0.01), and the ALB content was significantly decreased (P＜0.01). Compared with the Numb-EV group, AST and TBil levels were significantly reduced in the Numb-OE group (P＜0.01), as were the ALT and TBA levels (P＜0.05); however, the ALB content was significantly increased (P＜0.01), and the differences were statistically significant. Compared with the Sham group, the mRNA expression levels of CK7 and CK19 were significantly increased in the BDL group (1.40±0.42 vs. 43.78±7.56; 1.11±0.51 vs. 363.81±134.84, P＜0.01). The mRNA expression levels of CK7 and CK19 were significantly reduced in the OE group (343.19±81.22 vs. 3.22±2.34; 40.53±14.02 vs. 15.68±9.36,P＜0.01). Conclusion: Overexpression of the Numb gene can inhibit CLF progression in the adult liver, which may become a new target for CLF therapy.