Role of mitogen-inducible gene 6 in the activation of human hepatic stellate cells and deposition of extracellular matrix induced by sodium arsenite

[Background] Arsenic is a well-known environmental toxicant. Hepatic fibrosis could occur dueto excessive or long-term exposure to arsenic, while associated molecular mechanisms remain undefined. Mitogen-inducible gene 6 (Mig-6) exhibits a protective effect on numerous diseases or cancers. However, the specific role of Mig-6 in the mechanisms of arsenite-induced hepatic fibrosis remains indistinct. [Objective] To investigate the specific role of Mig-6 in the activation of hepatic stellate cells (HSC) and the deposition of extracellular matrix (ECM) induced by sodium arsenite (NaAsO2). [Methods] Human hepatic stellate cells (Lx-2) were treated with 0, 1.875, 3.75, 7.5, and 15 μmol·L−1 of NaAsO2 for 24 h, or with 7.5 μmol·L−1 NaAsO2 for 0, 12, 24, 48, and 72 h. Additionally, Lx-2 cells were transfected by pcDNA3.1(+)/Mig-6, then treated with 7.5 μmol·L−1 NaAsO2 for 24 h; a blank control group, a pcDNA3.1(+)-control group, a pcDNA3.1(+)/Mig-6 group, and an arsenic (7.5 μmol·L−1 NaAsO2) group were also set up. After transfection, the cells and culture supernatants were collected, and the protein levels of Mig-6, α-smooth muscle actin (α-SMA), and transforming growth factor-β1 (TGF-β1) in Lx-2 cells were identified by Western blotting analysis; moreover, the secretion levels of main ECM components in supernatants such as hyaluronic acid (HA), laminin (LN), collagens IV (COL-IV), and procollagen-III (PIIINP) were tested by ELISA. [Results] The Mig-6 expression decreased in the 3.75, 7.5, and 15 μmol·L−1 NaAsO2 groups (0.561±0.095, 0.695±0.048, and 0.401±0.030) compared to the control group (1.000±0.000) in Lx-2 cells (P