LncRNA-ATB/microRNA-200a/β-catenin regulatory axis involved in the progression of HCV-related hepatic fibrosis

Abstract

Objective(s): Long noncoding RNAs (lncRNAs)-activated by transforming growth factor beta (lncRNA-ATB) is known to be involved in the invasion of hepatocellular carcinoma by regulating target genes of miR-200a. However, the role and molecular mechanisms of lncRNA-ATB/miR-200a in HCV-related liver fibrosis remains unclear. In this study, we examined the expression of lncRNA-ATB/miR-200a, and their target gene β-Catenin in liver tissues of HCV patients and hepatic stellate cells (HSCs) to elucidate the possible role of lncRNA-ATB/miR-200a axis in HSC activation and development of liver fibrosis.

Materials and methods: Liver tissues were obtained by biopsy or surgery from eighteen HCV patients with severe liver fibrosis and six healthy subjects (control). Conditioned media (CM) from cultured HepG2-CORE cells (HepG2 cells stably expressing HCV core protein) were used to treat LX-2 cells. The binding sites between lncRNA-ATB/miR-200a and β-catenin were predicted and then verified by a dual luciferase reporter assay. The effect of lncRNA-ATB/miR-200a/β-catenin on HSC activation was assessed by examining the expression of alpha-smooth muscle actin (α-SMA) and collagen type 1 alpha 1 (Col1A1) in HSCs. Further, the regulatory role of lncRNA-ATB on HSC activation and miR-200a/β-catenin expression was assessed by using siRNA-mediated knockdown of lncRNA-ATB.

Results: LncRNA-ATB was up-regulated in fibrotic liver tissues and activated LX-2 cells treated with CM from HepG2-CORE cells. Dual luciferase reporter assays confirmed that lncRNA-ATB contained common binding sites for miR-200a and β-catenin. Decreased expression of miR-200a and increased expression of β-catenin were observed in liver tissues of patients with HCV-related hepatic fibrosis and activated HSCs. Knockdown of lncRNA-ATB could down-regulate β-catenin expression by up-regulating the endogenous miR-200a and suppress the activation of LX-2 cells.

Conclusion: LncRNA-ATB/miR-200a/β-catenin regulatory axis likely contributed to the development of liver fibrosis in HCV patients. Knockdown of lncRNA-ATB might be a novel therapeutic target for HCV-related liver fibrosis.

Keywords: Hepatic stellate cells; Liver fibrosis; Long noncoding RNA; Long noncoding RNA-activated by transforming growth factor beta; microRNA-200a; β-Catenin.