Expression of basic fibroblast growth factor in rat liver fibrosis and hepatic stellate cells.

Abstract

The expression of basic fibroblast growth factor (bFGF) in rat liver fibrosis and hepatic stellate cells (HSCs) and the relationship between the expression of bFGF and rat liver fibrogenesis were studied. Sixty male SD rats (230-260 g) were divided into 4 groups randomly (the 0 week group, 1 week group, 4 week group and 8 week group). Liver fibrosis was induced by subcutaneous injection of carbon tetrachloride. The sections of rats' liver in each group were tested by Van-Gieson (V-G) staining and immunohistochemistry. The expression of bFGF mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). HSCs were isolated by the combined methods of collagenase IV perfusion and density gradient centrifugation. The expression of bFGF protein in cultured HSCs was detected by Western blot. Images of immunohistochemistry detection, agarose gel electrophoresis of RT-PCR and SDS-polyacrylamide gel electrophoresis of Western blot were analyzed semiquantitatively by image-analyzing system. The results were analyzed by statistics. The results showed that the fibers were gradually increased in the sections of rat liver with the prolongation of the model induction. At the end of the 8th weeks, liver fibrosis was formed. The expression of bFGF detected by immunohistochemistry showed a similar tendency of gradual increase. At the end of the 8th weeks, the bFGF expression could be observed in many regions in sections and the strongest expression was in interstitial cells including HSCs and some hepatocytes in regions around the portal area and central veins. Also there was moderate expression widely in extracellular matrix (ECM). In RT-PCR detection and Western blot detection of HSCs cultured in vitro, the similar tendency of gradual increase was evident either. It is suggested that bFGF is related with liver fibrosis of rats closely and may be a fibrogenesis factor of liver. bFGF possibly regulates liver fibrogenesis through regulating metabolism of extracellular matrix (ECM) by autocrine and paracrine stimulation.