Fig. 3

TGF-β1 down-regulated PPARγ expression level in OP9-DL1 cells. a OP9-DL1 cells were treated with various concentrations of TGF-β1 for different intervals, and PPARγ mRNA levels were examined by real-time PCR. GAPDH served as an internal control. b After treatment with TGF-β1 for 72 h, total protein was extracted and PPARγ protein levels were determined by Western blot analysis. Representative blots are shown, and protein size is expressed as kDa. c Quantitative densitometric analysis was performed by using β-actin as a loading control. Quantification data represent results obtained from three independent experiments. ChIP assay was performed in OP9-DL1 cells without treatment (d) and treated with 0.2 ng/mL TGF-β1 or vehicle for 6 h (e). Chromatin was immunoprecipitated with antibodies against Smad 2/3, HDAC1 and H3K14ac, and the PPARγ promoter fragment was amplified by PCR. Densitometric analysis was conducted in comparison to vehicle control. Data are presented as averages from three independent experiments (f). **P < 0.01; *P < 0.05 vs vehicle