Figure 3.
Effect of dexamethasone on a TGF-β-Smad 3-sensitive reporter construct [(CAGA)9- MLP-luc]. (A) Dexamethasone inhibits TGF-β-Smad 3-signalling in Hep-G2. Hep-G2 was transfected with (CAGA)9- MLP-luc and stimulated with 1 or 2 ng of TGF-β1. Four hours after incubation with various dexamethasone concentrations, cells were lysed and luciferase reporter gene activity was measured. Results are presented as light units relative to untreated cells. The presented data is the mean ± SD of three independent experiments, each performed in duplicates. (B) TGF-β decreases GR signalling. Hep-G2 cells were co-transfected with GRE4E1b-luc and Smad 3 plasmid. TGF-β decreases and over-expressed Smad 3 abrogates GR signalling. Luciferase activities were measured using the Victor 1420 Multilabel Counter Luminometer (Wallac, Germany).