ABSTRACT
<p><b>OBJECTIVE</b>To investigate the relationship between connective tissue growth factor (CCN5) and hepatic stellate cell (HSC) activation as well as the mechanism of action.</p><p><b>METHODS</b>As the research object, LX-2 cells were stimulated with transforming growth factor-beta1 ( TGF-(beta1), and the protein expression levels of CCN5 and CCN2 were determined by Western blot; Hepatocyte high expression system of CCN5 was constructed and transfected hepatic stellate cells (HSC) to make CCN5 overexpression; The expression levels of alpha-smooth muscle actin (alpha-SMA) and collagen I were determined by RT-PCR and Western blot. To further study its mechanism of action, Smad2 and phosphorylation level of Smad2 were determined by RT-PCR and Western blot.</p><p><b>RESULTS</b>Under normal circumstances, CCN2 expression levels were much higher than CCN5 in LX-2 cells, while CCN2 expression was significantly higher than CCN5 if LX-2 cells were stimulated by TGF-beta1. However, there was no change for CCN5. Compared with the control group and the vector group, CCN5 was successfully overexpressed in the transfection group, and mRNA and protein levels of alpha-SMA and collagen I were significantly decreased (P < 0.01). Meanwhile, phosphorylation level of Smad2 was also significantly decreased (P < 0.01).</p><p><b>CONCLUSION</b>CCN5, which has the function that inhibits HSC activation, has the opposite role compared with CCN2, therefore, a new idea was proposed for the prevention and treatment of liver fibrosis.</p>