FIGURE 7.

LXRα activates PPRE by increasing the transcriptional activity of the PPARγ. A, Alexander cells were cotransfected with 100 ng of expression vectors for LXRα, PPARγ, RXRα, and SHP and the luciferase reporter containing the three copies of LGK-PPRE or LGK-LXRE in front of a thymidine kinase minimal promoter, as indicated. The LGK-PPRE construct (which includes the -119/-98 region of the LGK promoter) and LGK-LXRE construct, which includes the -56/-32 region, were transfected into Alexander cells. For SHP, a plus or minus sign indicates the presence or absence of SHP overexpression. For LXRα, PPARγ, and RXRα, a plus sign indicates both overexpression of receptors and treatment of appropriate ligands, and a minus sign indicates without overexpression and no treatment of ligands. Alexander cells (B) or CV-1 cells (C) were cotransfected with 100 ng of expression vector for PPARγ, RXRα, and SHP and luciferase reporter containing the three copies of APRE or GPRE in front of the thymidine kinase minimal promoter. The cells were treated with their respective ligands as indicated. Normalized luciferase activities are shown as the mean ± S.D. of three independent experiments performed in triplicate.