Fig. 4.

Transactivation of BSEP promoters by FXRα1 and FXRα2 with various FXR ligands. (A) Human BSEP promoter reporter phBSEP(-2.6kb) and (B) rat bsep promoter reporter prBSEP(-2kb) were cotransfected into human hepatoma Huh 7 cells and rat HCC L0 cells, respectively, with FXRα1 or FXRα2, followed by treatment of transfected cells with various endogenous and exogenous FXR ligands, including CA (10 μM), CDCA (10 μM), DCA (10 μM), LCA (10 μM), UDCA (10 μM), GDCA (10 μM), GW4064 (1 μM), GUG (10 μM), and T0901317 (1 μM). Thirty hours post treatment, reporter transactivation levels as luciferase activities were detected with a dual-luciferase reporter assay system. The firefly luminescence was normalized based on the Renilla luminescence signal. The data are presented as mean ± SD of at least three separate experiments. *P < 0.05 between FXRα1 and FXRα2-transfected cells (Student t-test).