Fig. 3.

Tgif1 knock-down derepresses Abca1 expression. A: NMuLi cells were transfected with siRNAs targeting Tgif1, and cells were treated with GW3965 for 18 hours as indicated (10⁻⁷ and 10⁻⁶ M). Expression of endogenous Tgif1 mRNA was analyzed by qRT-PCR 72 hours after transfection with siRNAs. B: NMuLi cells transfected with siTgif1 or a control pool were analyzed by western blot for Tgif1 and Smad2/3 as a loading control. Specific bands are indicated, and the relative expression of Tgif1 is shown below. C: The NMuLi knock-down RNAs were analyzed by qRT-PCR for expression of Abca1, Abcg1 and Srebp-1c. Relative expression is shown in arbitrary units, as mean + s.d., as determined by the ΔCt method (significant changes are indicated: * p < 0.05, ** p < 0.01). D: Association of Tgif1 with the DR4 containing regions of the Abca1 and Srebf1 promoters was analyzed by chromatin immunoprecipitation. Tgif1 recruitment to the Gapdh promoter was analyzed as a control. Samples were from NMuLi cells treated with or without GW3965 (10⁻⁶ M), as indicated. Data is shown (in arbitrary units) as relative enrichment in the Tgif-specific precipitation, normalized to input chromatin and precipitation with pre-immune serum. E: HepG2 cells were transfected with siRNAs targeting Tgif1, and cells were treated with GW3965 for 18 hours as indicated. Expression of Abca1, Abcg1 and Srebp1c was analyzed by qRT-PCR 72 hours after transfection, and is shown in arbitrary units (significant changes are: ** p < 0.01, *** p < 0.001).