fig6

Figure 6. Ins stimulates α5β1 integrin and its signaling pathway. (A) represents the adhesion assay in primary cultures of HSCs. Ins treatment (5 µmol) significantly increased HSCs adhesion to fibronectin and pretreating with α5Ab countered this effect, suggesting that increased adhesion is mediated by activation of α5β1 integrin; (B) shows Western blot analysis demonstrating increased levels of α5β1 integrin and p-FAK in Ins-treated HSCs; (C) shows that α5 siRNA inhibits the Ins effect on collagen synthesis in HSCs. Following siRNA-mediated downregulation of α5 integrin, cultures were grown in serum-free high glucose medium with Ins. Western blot analysis shows that Ins stimulation of both α5 integrin and COL1 synthesis was blocked in the absence of α5 integrin. HSCs: Hepatic stellate cells; Ins: insulin; α5Ab: α5β1 integrin blocking antibody; p-FAK: phosphorylated form of focal adhesion kinase; COL1: type 1 collagen.