2058 Pirfenidone inhibits TGF-b1-induced extracellular matrix production in nasal polyp-derived fibroblasts

Thursday, 15 October 2015
Hall D1 Foyer (Floor 3) (Coex Convention Center)

Jae-MIN SHIN, MD , Department of Otorhinolaryngology, Korea University Guro Hospital, Korea University Guro Hospital, Seoul, South Korea

IL-HO PARK, MD, PhD , Department of Otorhinolaryngology, Korea Universitiy Guro Hospital, College of Medicine, Korea University, Seoul, South Korea

Heung-Man Lee, MD, PhD , Otorhinolaryngology-Head and Neck Surgery, Korea University College of Medicine, Guro Hospital, Seoul, South Korea

Purpose: Pirfenidone has been shown to have anti-fibrotic 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 (NPDFs).

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 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 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.