Focal Adhesion Kinase Regulates Hepatic Stellate Cell Activation and Liver Fibrosis

Understanding the underlying molecular mechanisms of liver fibrosis is important to develop effective therapy. Herein, we show that focal-adhesion-kinse (FAK) plays a key role in promoting hepatic stellate cells (HSCs) activation in vitro and liver fibrosis progression in vivo. FAK activation is associated with increased expression of alpha-smooth muscle actin (alpha-SMA) and collagen in fibrotic live tissues. Transforming growth factor beta-1 (TGF-beta 1) induces FAK activation in a time and dose dependent manner. FAK activation precedes the alpha-SMA expression in HSCs. Inhibition of FAK activation blocks the alpha-SMA and collagen expression, and inhibits the formation of stress fibers in TGF-beta 1 treated HSCs. Furthermore, inhibition of FAK activation significantly reduces HSC migration and small GTPase activation, and induces apoptotic signaling in TGF-beta 1 treated HSCs. Importantly, FAK inhibitor attenuates liver fibrosis in vivo and significantly reduces collagen and alpha-SMA expression in an animal model of liver fibrosis. These data demonstrate that FAK plays an essential role in HSC activation and liver fibrosis progression, and FAK signaling pathway could be a potential target for liver fibrosis.