Inhibition of focal adhesion kinase on hepatic stellate cell adhesion and migration

Abstract Objective Hepatic fibrosis is characterized by the activation of hepatic stellate cells. Focal adhesion kinase (FAK)–phosphatidylinositol 3-kinase (PI3K) signals participate in the activation of hepatic stellate cells. We evaluated the effect of FAK-related nonkinase (FRNK) on the adhesion and migration of hepatic stellate cells. Materials and Methods Hepatic fibrosis was induced in Sprague-Dawley rats by means of bile-duct ligation. Livers were harvested at 1 week, 2 week, 3 week, and 4 week after the ligation; livers of sham-operated animals were harvested at 4 week after ligation. Histopathological features were evaluated in liver sections stained with hematoxylin-eosin and Sirius Red stain. Hepatic stellate cells were transfected with FRNK plasmid. The adhesion of hepatic stellate cells was examined with a toluidine blue colorimetric assay. The migration of hepatic stellate cells was evaluated by use of an improved Boyden double-chamber method. Protein and mRNA levels in the liver and the hepatic stellate cells were determined by Western blot analysis and real-time PCR respectively. Results Hematoxylin-eosin staining of liver documented the presence of fibrosis in the rats. Actin and PI3K expression was increased in parallel with the development of hepatic fibrosis. At the same time, activator protein-1 (AP-1) ( c-fos , c-jun ) mRNA in the livers was increased. Overexpression of FRNK inhibited the adhesion and migration of hepatic stellate cells time-dependently. Simultaneously, FRNK inhibited PI3K mRNA and protein expression and c-jun mRNA expression. Conclusions FRNK inhibited the adhesion and migration of hepatic stellate cells by decreasing the expressions of the FAK-PI3K-AP-1 signal pathway.