Fig. 6.

Effects of TGF-β1 on PPAR-γ mRNA and transcriptional activity. A: quiescent rat PASMCs were treated with TGF-β1 (2 ng/ml) or vehicle for 24 h. The PPAR-γ mRNA level was determined by quantitative RT-PCR and normalized using 18S rRNA levels as an internal control. B: rat PASMCs were cotransfected with pGL3-hPPAR-γ promoter-Luc and pRL-TK plasmid and then exposed to TGF-β1 (2 ng/ml) or vehicle for 24 h. Luciferase activity was measured by luminescence. C and D: chromatin immunoprecipitation (IP) analyses for detection of Smad2/3, Smad4 and histone deacetylase 1 (HDAC1) at the PPAR-γ promoter. Quiescent PASMCs were treated with TGF-β1 (2 ng/ml) or vehicle for 1 h. The Smad2/3, Smad4, and HDAC1 binding levels at the PPAR-γ promoter were determined by specifically amplified PPAR-γ promoter fragment with PCR. A representative set of results from 3 independent assays is shown. Results are means ± SE. n = number of wells. *P < 0.05 compared with respective vehicle controls.