Figure 6. In vitro, the combination of UDCA and dexamethasone upregulates the transcriptional activity of AE2 alternate promoter regions in transfected PLC/PRF/5 cells.

(A) Diagram of AE2 promoter regions (gray arrows indicate the HNF1 site; open rhombuses represent GREcore motifs) and luciferase constructs II-b₂ and I-b₁, with luciferase activities of PLC/PRF/5 cells transiently transfected (0.1 μg of respective construct) and treated for 24 hours either with UDCA plus dexamethasone or with just vehicle. (B) Dose-dependent luciferase activities of PLC/PRF/5 cells transiently transfected with luciferase construct I-b₁ (0.1 μg) and treated for 24 hours with different concentrations of UDCA and/or dexamethasone. Luciferase activities (normalized with Renilla activities) are given as fold activity relative to the activity of construct I-b₁ in the absence of UDCA and DEX. Data are mean ± SD; n = 9 each. *P < 0.05, **P < 0.01, ***P < 0.001 versus vehicle control.