Effect of peroxisome proliferator-activated receptor gamma agonists on myofibroblast differentiation and collagen production in nasal polyp-derived fibroblasts

Objectives: We investigated the effect of transforming growth factor-β1 (TGF-β1) on the differentiation of nasal polyp-derived fibroblasts (NPDFs) and on their production of collagen, and investigated the effect of peroxisome proliferator-activated receptor γ (PPARγ) agonists on the effects of TGF-β1. Methods: Primary fibroblast lines were established from 5 human nasal polyp tissues. We activated the NPDFs with TGF-β1 and exposed them to the PPARγ agonists ciglitazone and 15-deoxy-Δ-prostaglandin J2. The expression of α-smooth muscle actin (α-SMA) and collagen was measured by reverse transcriptase-polymerase chain reactions, immunocytochemical staining, and collagen assays. Results: The treatment with TGF-β1 increased the expression of α-SMA and collagen, and expression was markedly attenuated by the PPARγ agonists. Conclusions: PPARγ agonists inhibit the differentiation of TGF-β1-activated NPDFs and their production of collagen.