Wogonin inhibits transforming growth factor beta 1-induced extracellular matrix production via the p38/activator protein 1 signaling pathway in nasal polyp-derived fibroblasts

Abstract

Background: Wogonin has been shown to have antifibrotic and anti-inflammatory effects in the lower airway. The purpose of this study was to evaluate the effects of wogonin on transforming growth factor (TGF) beta 1-induced myofibroblast differentiation, extracellular matrix production, migration, and collagen contraction, and to determine the molecular mechanisms of wogonin in nasal polyp-derived fibroblasts (NPDF). Methods: NPDFs were isolated from nasal polyps from eight patients. TGF-beta 1-induced NPDFs were treated with wogonin. Cytotoxicity was evaluated by using a 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide assay. Fibroblast migration was evaluated with transwell and scratch migration assays. The expression levels of beta-smooth muscle actin, fibronectin, phosphorylated-p38, and c-Fos were determined by Western blot and/or reverse transcription-polymerase chain reaction. The total collagen amount was analyzed with the Sircol collagen assay, and contractile activity was measured by a collagen gel contraction assay. Results: Wogonin (0-60 mu M) had no significant cytotoxic effects on TGF-beta 1-induced NPDFs. Migration of NPDFs was significantly inhibited by wogonin treatment. The expression levels of alpha-smooth muscle actin and fibronectin were significantly reduced in wogonin-treated NPDFs. Collagen production and contraction were also significantly decreased by wogonin treatment. Wogonin markedly inhibited activation of the p38/activator protein 1 pathway in TGF-beta 1-induced NPDFs. Conclusion: These results indicated that wogonin may inhibit TGF-beta 1-induced myofibroblast differentiation, extracellular matrix production, migration, and collagen contraction through the p38/activator protein-1 pathway in NPDFs.