FIG. 9.

Induction of SREBP-1c protein by LXR-RXR ligands in HepG2 cells as measured by immunoblot analysis. HepG2 cells were incubated with the indicated ligands for LXR or RXR for 24 h. In some groups, 1 μg of 25-HC per ml and 10 μg of cholesterol per ml were also added to the medium to suppress sterol-regulatory cleavage activity of SREBPs (sterol-suppressed condition). After the incubation, nuclear extracts and membranes were prepared from the cells and aliquots (30 μg) of protein were subjected to immunoblot analysis using antibodies against SREBP-1c, SREBP-1a and -1c, and SREBP-2. The bands were visualized with the ECL system. The values below the bands refer to relative fold changes in protein levels. Lanes: 1, ethanol; 2, 22(R)-HC; 3, 9CRA; 4, 22(R)-HC plus 9CRA; 5, ethanol in a sterol-suppressed condition; 6, 22(R)-HC plus 9CRA in a sterol-suppressed condition.