Cellular fibronectin stimulates hepatocytes to produce factors that promote alcohol-induced liver injury

Figure 4 Effect of cellular fibronectin on the secretion of pro- and active-matrix metalloproteinase-2 by cultured hepatocytes isolated from control and ethanol-fed rats. Protein and activity levels of pro- and active-matrix metalloproteinase-2 (MMP-2) in the cell culture media of hepatocytes after 20 h of treatment with cellular fibronectin (cFn) were determined as described in Material and Methods. In the presence of higher concentrations of exogenous cFn (4 μg/mL and 7.5 μg/mL), cells from both control and ethanol-fed animals released elevated levels of pro- and active-MMP-2 (A) with corresponding higher MMP-2 activity (B). Plasma fibronectin treatment produced no effect on either cell type (C). GZ: gel zymography; WB: western blot. Data are represented as means ± SEM. Ethanol values significantly different from those of the control are expressed as ^aP < 0.05, and treatment significantly different from untreated cultures is expressed as ^bP < 0.05. (n = 3 - 11 experiments).