ABSTRACT
BACKGROUND: Liver cirrhosis is characterized by fibrous scarring and hepatocellular regeneration. Matrix metalloproteinases (MMPs) comprise a family of zinc-dependent enzymes that degrade the extracellular matrix (ECM) components. This study examined whether or not gene delivery of human MMP-3 can attenuate established liver cirrhosis in a rat. METHODS: Rat liver cirrhosis was induced by an intraperitoneal injection of dimethylnitrosamine (DMN) three times a week for 8 weeks. The rats were infected once with either a recombinant adenovirus, AdMMP3.GFP, or a control adenovirus, Ad.GFP, into a portal vein and followed up for 3 weeks. In the rat liver tissues, the collagen content, histopathology and immunohistochemical staining were measured. RESULTS: Liver fibrosis in the DMN induced cirrhotic rat was attenuated along with a diminished hydroxyproline content and increased dried liver weight after the gene delivery of AdMMP3.GFP. In addition, the number of activated hepatic stellate cells was lower whereas the proliferation of hepatocytes, which was confirmed by immunohistochemical staining using anti-proliferating cell nuclear antigen (PCNA) antibody, was observed in the AdMMP3.GFP infected rats, suggesting that human MMP-3 stimulated hepatocyte proliferation. CONCLUSIONS: These results suggest that the gene transfer of human MMP-3 in the liver attenuates established fibrosis and induces hepatocyte proliferation. Therefore, gene therapy using MMP-3 in liver cirrhosis might be a promising therapeutic option in the future.
Subject(s)
Animals , Humans , Rats , Adenoviridae , Cicatrix , Collagen , Dimethylnitrosamine , Extracellular Matrix , Fibrosis , Genetic Therapy , Hepatic Stellate Cells , Hepatocytes , Hydroxyproline , Injections, Intraperitoneal , Liver Cirrhosis , Liver , Matrix Metalloproteinases , Models, Animal , Portal Vein , RegenerationABSTRACT
BACKGROUND/AIMS: The study of liver fibrogenesis by hepatitis C virus (HCV) has been limited due to the lack of an efficiency in vitro culture systems. In the present study, we investigated whether or not HCV core protein is directly related to liver fibrogenesis through stimulation of hepatic stellate cells (HSC). METHODS: Human and rat HSC were isolated and we established an in vitro co-culture system of a stable HepG2-HCV core cell line which was transfected with HCV core gene and primary HSC. We performed immunocytochemical staining and Western and Northern blot analysis in the stimulated HSC by HCV ocre protein to identify the expression of transforming growth factor beta1 (TGF-beta1), transforming growth factor beta receptor II (TGFbeta R II), alpha-smooth muscle actin (alpha-SMA) and connective tissue growth factor (CTGF). The expression of matrix metaloprotinase-2 (MMP-2) and collagen type I (Col I) in the culture media were measured by zymogram and ELISA, respectively. RESULTS: The expression of TGF-beta1 and CTGF was significantly higher in the stable HepG2-HCV core cell line than in HepG2 cells. Furthermore, the makers related to fibrosis such as alpha-SMA, TGF-beta1, Col I, TGFRII and MMP-2 were highly experssed in the co-culture of stable HepG2-HCV core with HSC. CONCLUSIONS: HCV core protein may play a direct role in the fibrogenesis of chronic liver disease with HCV infection.