TGF-β enhances binding of Smad2 and Smad3 to the CXCL1 promoter.

<p>Genomic DNA was isolated from 41CAFs treated with 5 ng/ml of TGF-β for 6 hours, and immunoprecipated with: control IgG, or antibodies to Smad2 or Smad3. Samples were analyzed by real-time PCR analysis for (A) Smad2 or (B) Smad3 binding to SBE1 and SBE2 or SBE2 alone on the CXCL1 promoter. Smad2/3 binding to the PAI1 promoter was evaluated as a positive control for TGF-β responsiveness. Background from IgG control was subtracted from samples. Left panels show fraction of Smad2 or 3 binding to DNA relative to input control. Right panel shows Smad2 or Smad3 binding normalized to (-) TGF-β group for each promoter region. Statistical analysis was performed using Two Tailed T-test. Statistical significance was determined by p<0.05; *p<0.05, **p<0.01. Values are expressed as Mean ± SEM.