The expression of Connective Tissue Growth Factor and Cyr61 gene on cultured rat hepatic stellate cells

Connective Tissue Growth Factor (CTGF) and cystein-rich protein (Cyr61) are the secreted proteins expressed as an immediate-early gene response in fib roblasts after the growth stimulation. Both proteins are overexpressed duri ng wound repair, and are known to stimulate the extracellular matrix (ECM) production and the growth of ECM cells as ECM-associated signaling molecule s. In this study, we found that the expression of CTGF and Cyr61 genes was enh anced in culture hepatic stellate cells as well as in regenerating liver af ter the administration of galactosamine (GalN). The expression of CTGF and Cyr 61 genes were increasingly up-regulated for 3 weeks and their kinetics were similar to those of type I collagen and biglycan genes in culture hepa tic stellate cells. The expression of Transforming growth factor beta-1 (TG F-beta 1) gene was more enhanced in the initial few days than the later day s. Whereas, in the post-injury regeneration, the expression of CTGF Cyr 61, type I collagen, biglycan, and TGF-beta 1 genes was up-regulated at 2 h af ter GalN administration, reached a peak at 48 h with a shoulder peak at 6-1 2 h, and then returned to the pre-injury level. These results suggest that CTGF and Cyr 61 are involved in ECM remodeling occurring after liver injury , and are produced in hepatic stellate cells.