Figure 6.

Bile acids downregulate human apoA-I promoter activity by FXR acting on the C site. (a) Schematic representation of the human apoA-I promoter constructs. (b) HepG2 cells were transfected with the indicated human apoA-I promoter-driven luciferase (Luc) reporter plasmid (1 μg) in the presence of either the empty pcDNA3 or FXR- and RXR-containing expression vectors (300 ng). Cells were subsequently treated with CDCA (75 μM) or vehicle for 36 hours. Values are expressed as percentage of control set at 100% normalized to internal control β-galactosidase activity as described in Methods.