Western blot analysis of PAI-1 and CTGF expression in hepatocytes. Cells were incubated 6 hours with TGF-β, dexamethasone or both. Afterwards the hepatocytes were harvested and lysates (40 μg) have been subjected to Western blotting and analyzed for PAI-1 and CTGF expression. (A) PAI-1 was significantly induced after co-stimulation with TGF-β and dexamethasone, indicating a synergistic effect in hepatocytes. β-actin was assayed as loading control. (B) Densitometric analysis of PAI-1 expression in hepatocytes and its release into medium. Three independent western blots were analysed; control versus TGF-β and dexamethasone co-treated cells * p < 0.05; BLU (Boehringer light units). (C) A co-treatment with TGF-β and dexamethasone strongly induce CTGF in hepatocytes (PC, day three after plating). A low amount of CTGF could be detected in the supernatant of TGF-β stimulated cells. The same blots were analysed for β-actin as loading control. (D) Densitometric analysis of three independent experiments. CTGF is induced about 50-fold after a TGF-β-dexamethasone co-stimulation (control versus TGF-β and dexamethasone co-treated cells * p < 0.005), but it is hardly secreted.