title: β-catenin is overexpressed in hepatic fibrosis and blockage of Wnt/β-catenin signaling inhibits hepatic stellate cell activation.
abstract: β-catenin, a core component of Wnt/β-catenin signaling, has been shown to be an important regulator of cellular proliferation and differentiation. Abnormal activation of Wnt/β-catenin signaling promotes tissue fibrogenesis. In the present study, the role of β-catenin during liver fibrogenesis was analyzed and the functional effects of β-catenin gene silencing in hepatic stellate cells (HSCs) using small interfering (si)RNA were investigated. The expression of β-catenin in human hepatic fibrosis tissues of different grades and normal human hepatic tissues was examined using immunohistochemistry. To inhibit the Wnt/β-catenin signaling pathway, siRNA for β-catenin was developed and transiently transfected into HSC-T6 cells using Lipofectamine 2000. β-catenin expression was evaluated by quantitative polymerase chain reaction (qPCR) and western blot analysis. The expression of collagen types Ⅰ and Ⅲ was evaluated by qPCR and immunofluorescent staining. Cellular proliferation and the cell cycle were analyzed using a methyl thiazolyl tetrazolium assay. Apoptosis was assessed by Annexin V staining. A higher expression level of β-catenin was identified in the patients with high-grade hepatic fibrosis in comparison with that of the normal controls. Additionally, β-catenin siRNA molecules were successfully transfected into HSCs and induced inhibition of β-catenin expression in a time-dependent manner. β-catenin siRNA treatment also inhibited synthesis of collagen types Ⅰ and Ⅲ in transfected HSCs. Furthermore, compared with those of the control group, siRNA-mediated knockdown of β-catenin in HSC-T6 cells inhibited cell proliferation and resulted in cell apoptosis. This study suggests a significant functional role for β-catenin in the development of liver fibrosis and demonstrates that downregulation of the Wnt/β-catenin signaling pathway inhibits HSC activation. Thus, this study provides a novel strategy for the treatment of hepatic fibrosis.
authors.affiliation: Department of Gastroenterology, Shanghai Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Wen-Song
authors.initials: WS
authors.lastname: Ge
authors.affiliation: Department of Gastroenterology, General Hospital of Jinan Military Command, Jinan, Shandong 250031, P.R. China.
authors.forename: Yao-Jun
authors.initials: YJ
authors.lastname: Wang
authors.affiliation: Department of Gastroenterology, Shanghai Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Wu
authors.affiliation: Department of Gastroenterology, Shanghai Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Jian-Gao
authors.initials: JG
authors.lastname: Fan
authors.affiliation: Department of Gastroenterology, Shanghai Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, P.R. China.
authors.forename: Ying-Wei
authors.initials: YW
authors.lastname: Chen
authors.affiliation: Department of Gastroenterology, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai 200003, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024061:Collagen Type III / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation; D055166:Hepatic Stellate Cells / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008103:Liver Cirrhosis / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D060449:Wnt Signaling Pathway; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D034741:RNA, Small Interfering; D051176:beta Catenin