Silencing of α-complex protein-2 reverses alcohol- and cytokine-induced fibrogenesis in hepatic stellate cells

Abstract

Background and aim: α-complex protein-2 (αCP2) encoded by the poly (rC) binding protein 2(PCBP2) gene is responsible for the accumulation of type I collagen in fibrotic livers. In this study, we silenced the PCBP2 gene using a small interfering RNA (siRNA) to reverse alcohol- and cytokine-induced profibrogenic effects on hepatic stellate cells (HSCs). Methods: Primary rat HSCs and the HSC-T6 cell line were used as fibrogenic models to mimic the initiation and perpetuation stages of fibrogenesis, respectively. We previously found that a PCBP2 siRNA, which efficiently silences expression of αCP2, reduces the stability of type I collagen mRNA. We investigated the effects of the PCBP2 siRNA on cell proliferation and migration. Expression of type I collagen in HSCs was analyzed by quantitative real-time PCR and western blotting. In addition, we evaluated the effects of the PCBP2 siRNA on apoptosis and the cell cycle. Results: PCBP2 siRNA reversed multiple alcohol- and cytokine-induced profibrogenic effects on primary rat HSCs and HSC-T6 cells. The PCBP2 siRNA also reversed alcohol- and cytokine-induced accumulation of type I collagen as well as cell proliferation and migration. Moreover, the combination of LY2109761, a transforming growth factor-β1 inhibitor, and the PCBP2 siRNA exerted a synergistic inhibitive effect on the accumulation of type I collagen in HSCs. Conclusions: Silencing of PCBP2 using siRNA could be a potential therapeutic strategy for alcoholic liver fibrosis. Keywords: Hepatic stellate cells, Primary HSC, Myofibroblast, Liver fibrosis, Poly (rC) binding protein (PCBP)2, Transforming growth factor(TGF)-β, Platelet-derived growth factor (PDGF), Epidermal growth factor (EGF), LY2a09761, Migration