Fig. 1.

Regulation of MIG12 expression by LXR in the liver and identification of an LXRE in the MIG12 promoter. A, Mice (n = 4) were intragastrically administered the vehicle or T0901317 (50 mg/kg) and killed 24 h later. MIG12 mRNA was quantitated by real-time PCR of liver samples using 36B4 mRNA as the internal standard for normalization. B and C, HEK293 cells were transfected with 200 ng of the indicated reporter constructs together with 50 ng of pCMV-β-gal in the presence or absence of 20 ng of expression plasmids for LXRα and RXRα. Twenty-four hours after transfection, cells were placed in medium A containing the vehicle (DMSO) or 10 μm T0901317. After incubation for another 24 h, luciferase assays were performed as described in Materials and Methods. Promoter activity of pMIG12-2.5kb-Luc in the absence of LXRα and RXRα and in the presence of the vehicle is represented as 1. D, Sequences of consensus DR4, mouse MIG12 LXRE3, and LXRE4. For comparison, the MIG12 LXRE4 sequence of the bottom strand is shown. E, Competitive gel mobility-shift assays were performed as described in Materials and Methods using nuclear extracts from HEK293 cells transfected with or without LXRα and /RXRα expression plasmids, ³²P-labeled DR4 (left panel) and MIG12 LXRE3 (right panel) as input probe and unlabeled oligonucleotides as competitors at 50-fold molar excess. F, Pooled livers from four mice treated with either vehicle or 50 mg/kg T0901317 were analyzed by ChIP assays using the antibody for LXRα and an isotype-matched IgG control antibody. Bound DNA was quantitated by real-time PCR and normalized to the input. All results are expressed as mean ± sd of three independent experiments. *, P < 0.05; **, P < 0.01; IP, immunoprecipitation.