Pirfenidone inhibits transforming growth factor β1-induced extracellular matrix production in nasal polyp-derived fibroblasts

Am J Rhinol Allergy. 2015 Nov-Dec;29(6):408-13. doi: 10.2500/ajra.2015.29.4221.


Purpose: Pirfenidone has been shown to have antifibrotic and anti-inflammatory effects in the lungs. The purpose of this study was to evaluate the inhibitory effects of pirfenidone on transforming growth factor (TGF)-β1-induced myofibroblast differentiation and extracellular matrix accumulation. We also determined the molecular mechanisms of pirfenidone in nasal polyp-derived fibroblasts (NPDF).

Methods: NPDFs were isolated from nasal polyps from eight patients who had chronic rhinosinusitis with nasal polyp. Pirfenidone was used to treat TGF-β1-induced NPDFs. Cytotoxicity was evaluated by using a 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl-tetrazolium bromide assay. Fibroblast migration was evaluated with scratch assays. Expression levels of α-smooth muscle actin (SMA), fibronectin, and phosphorylated Smad2/3 were determined by Western blot and/or reverse transcription-polymerase chain reaction and immunofluorescent staining. Total collagen production was analyzed with the Sircol collagen assay and contractile activity was measured by a collagen gel contraction assay.

Results: Pirfenidone (0-2 mg/mL) has no significant cytotoxic effects in TGF-β1-induced NPDFs. Migration of NPDFs was significantly inhibited by pirfenidone treatment. The expression levels of α-SMA and fibronectin were significantly reduced in pirfenidone-treated NPDFs. Collagen contraction and production were also significantly decreased by pirfenidone treatment. Finally, pirfenidone significantly inhibited phosphorylation of the Smad2/3 pathway in TGF-β1-induced NPDFs.

Conclusions: Pirfenidone has an inhibitory effect on TGF-β1-induced migration, myofibroblast differentiation (α-SMA), extracellular matrix accumulation, and collagen contraction by blocking the phosphorylation of Smad2/3 pathways in NPDFs. Thus, pirfenidone may inhibit TGF-β1-induced extracellular matrix by regulating Smad2/3.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blotting, Western
  • Cell Differentiation
  • Cell Movement
  • Cells, Cultured
  • Extracellular Matrix / drug effects
  • Extracellular Matrix / metabolism*
  • Female
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Gene Expression Regulation*
  • Humans
  • Male
  • Nasal Polyps / drug therapy
  • Nasal Polyps / genetics*
  • Nasal Polyps / metabolism
  • Pyridones / administration & dosage*
  • RNA / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Transforming Growth Factor beta1 / drug effects
  • Transforming Growth Factor beta1 / genetics*
  • Transforming Growth Factor beta1 / metabolism


  • Pyridones
  • Transforming Growth Factor beta1
  • RNA
  • pirfenidone