Effects of JNK inhibitor II and Erk inhibitor on TGF-β and dexamethasone induced CTGF expression in hepatocytes. (A) Three-days old hepatocytes were serum-starved before stimulation. Cells were treated with or without inhibitor and then stimulated for three hours with TGF-β and dexamethasone as indicated and thereafter immediately lysed. Cell lysates have been subjected to electrophoresis and Western blot. Corresponding expression of β-actin is shown as loading control. (B) Densitometrically evaluation of independent cell preparations showed that CTGF expression was not changed in the presence of JNK inhibitor (n = 2; light-grey). In comparison to untreated cells (n = 3; white bars) the addition of Erk inhibitor clearly inhibited TGF-β/dexamethasone induced CTGF expression (n = 2; dark-grey). BLU (Boehringer light units). (C) Just as well, densitometric analysis of PAI-1 demonstrated that the Erk inhibitor repressed TGF-β and dexamethasone induced expression. (Native – n = 4; with Erk inhibitor – n = 2).