Fig. 2.

Regulation of RUT on ABCA1 and SR-BI expression by LXRα and LXRβ. A, B: GAL4 chimeric receptor assay. pBIND-LXRα-LBD (A) or pBIND-LXRβ-LBD (B) was cotransfected with GAL4 reporter vector into HepG2 cells. Experiments were carried out in triplicate wells and repeated at least thrice. Results are expressed in terms of fold induction over control (0.1% DMSO). C, D: HepG2 cells were incubated with or without RUT (0.035, 0.35, 3.48, and 34.80 μM), scrambled siRNA (50 nM), LXRα siRNA (50 nM) (C), or LXRβ siRNA (50 nM) (D) for 18 h, and then the levels of ABCA1 and SR-BI proteins were determined by Western blotting assays. A representative immunoblot of three separate experiments is shown, and the abundances of indicated proteins were normalized to that of GAPDH when treated LXRα siRNA (C) and LXRβ siRNA (D). Data are means ± SEM (* P < 0.05). E, F: TR-FRET assay was used to examine corepressor peptide displacement from or coactivator recruitment to human LXRα (E) or LXRβ (F) LBD in response to T0901317 or RUT. The data were calculated as the ratio of 520 nm/495 nm. Figures are representative of at least two independent experiments.