The enhancing impact of amino termini of hepatitis C virus core protein on activation of hepatic stellate cells

AIM: To investigate the potential effects of carboxyl and amino termini of HCV core protein on the HSCs activation. BACKGROUND: The core protein is recognized as the most important fibrosis inducer of Hepatitis C virus (HCV). While the exogenous fibrotic effect of HCV core protein has been reported earlier, the endogenous effect and the role of two termini must still be investigated. METHODS: Plasmids expressing full length, carboxyl-truncated (T1), or amino-truncated (T3) versions of the core were transfected into LX 2 cells. MTT assay was performed to evaluate the cytotoxicity of the endogenous expression of different regions of core protein on these cells. Afterwards, the total RNA was reversely transcribed and introduced into quantitative polymerase chain reaction (qPCR) to measure the expression level of collagen type I (COL1A1), α-smooth muscle actin (-SMA), tissue metalloproteinase inhibitor 1 (TIMP-1), and transforming growth factor-β1 (TGF-β1). In addition, TGF-β1 as a fibrotic factor, was also assessed in the supernatant of LX-2 cells using ELISA method. RESULTS: The full and T1 versions of the core exhibited a measurable proliferative effect on LX 2 cells (P<0.05). Analysis of the gene expression was also showed that, in spite of amino-truncated version, these constructs represented a significant activation impact compared to the empty plasmid. Moreover, the result of TGF β assay was in agreement with the results of mRNA expression analysis. CONCLUSION: The endogenous expression of the full and carboxyl-truncated versions of the core exhibited a significant activator effect on HSCs. Therefore, it can be concluded that, amino domain of HCV core protein performs a stellate cell activation role.