FIG. 11.

Activation of the FAS promoter by LXRs and their ligands. A luciferase reporter construct containing the rat FAS promoter (31) and reference plasmid pSV-βgal with empty plasmid pCMV7 or expression plasmids pCMV-LXR and pRXR were transfected into HepG2 cells. After the transfection, ligands for LXR and RXR or ethanol (used as a negative control) was added to the cells, followed by a 24-h incubation in the medium with 10% fetal bovine serum. In some sets, 25-HC at 1 μg/ml and cholesterol at 10 μg/ml were also added to the medium to suppress the sterol-regulatory cleavage activity of SREBPs (sterol-suppressed condition). Luciferase activity was measured and normalized to β-galactosidase activity. Fold induction (means ± standard deviations) by LXRs is shown. pCMV-nSREBP-1c, an expression plasmid of human nuclear SREBP-1c was used as a positive control for FAS promoter activation (BP-1c). Lα+R, LXRα plus RXR; 22+9, 22(R)-HC plus 9CRA.