miR-200c Accelerates Hepatic Stellate Cell-Induced Liver Fibrosis via Targeting the FOG2/PI3K Pathway

Background. Although expression of miR-200s is aberrant in liver fibrosis, its role in liver fibrogenesis still remains unknown. Here, we investigated the role of miR-200c in the activation of human hepatic stellate cells (HSCs) and induction of liver fibrosis. Methods. We engineered human HSCs (LX2 cell line) to stably express miR-200c (LX2-200c) or empty vector control (LX2-nc). Results. miR-200c expression upregulated alpha-smooth muscle actin (SMA) and vimentin, enhanced HSCs growth and migration, increased expression of collagen type I (a main component of ECM) gene and secretion of epidermal growth factor (EGF), and upregulated the phosphorylation of Akt, a downstream effector of the PI3K pathway. As a target of miR-200s and inhibitor of PI3K pathway, FOG2 protein expression was significantly suppressed in LX2-200c cells. Moreover, LY294002, a highly selective inhibitor of PI3K, blocked phosphorylation of Akt and the effects of miR-200c. Conclusions. These data suggest that miR-200c activates HSCs in liver fibrosis possibly by downregulating FOG2 protein expression and upregulating PI3K/Akt signaling. Autocrine activation of EGF signaling may also be a mechanism of miR-200c-mediated HSCs activation. So miR-200c can be a potential marker for HSCs activation and liver fibrosis progression, as well as a potential target to attenuate liver fibrosis.