Pirfenidone inhibits the proliferation of fibroblasts from patients with active Crohn's disease.

OBJECTIVE: One-third of Crohn's disease (CD) patients develop intestinal strictures that require repeated surgical intervention. Current anti-inflammatory therapies have limited effect on stricture development, which necessitates the exploration of new pharmacological approaches. Pirfenidone (PFD), a novel anti-fibrotic agent, was recently approved in Europe for the treatment of idiopathic pulmonary fibrosis (IPF). We hypothesized that observations in IPF could be transferable to intestinal fibrosis and that PFD inhibits the proliferation and extracellular matrix (ECM) turnover of gut-derived fibroblasts from CD patients.
MATERIAL AND METHODS: Fibroblasts were isolated from biopsies of inflamed (n = 8) and non-inflamed (n = 5) colonic mucosa. Expression of CD90 and alpha-smooth muscle actin (αSMA) expression was determined by flow cytometry. The fibroblasts were cultured with PFD (0.5, 1.0 and 2.0 mg/ml). Proliferation was evaluated with CellTiter 96(®) AQueous One Solution Cell Proliferation Assay. Production of matrix metalloproteinase-3 (MMP-3), tissue inhibitor of metalloproteinases-1 (TIMP-1) and collagen were assessed using ELISA and calorimetric assays, respectively.
RESULTS: The majority of the fibroblasts were αSMA-positive myofibroblasts. PFD inhibited fibroblast proliferation [0.94 (PFD 0.5 mg/ml); 0.76 (1.0 mg/ml); 0.58 (2.0 mg/ml)] and production of MMP-3 [0.85 (0.5 mg/ml); 0.74 (1.0 mg/ml); 0.63 (2.0 mg/ml)] dose-dependently (both p = 0.0001). The anti-proliferative effect of PFD was reversible (p = 0.0001), indicating that PFD does not act by an irreversible cytotoxic mechanism. PFD did not influence neither TIMP-1 nor collagen production.
CONCLUSION: PFD inhibited the proliferation and the production of MMP-3 dose-dependently in gut-derived fibroblast from CD patients. Our observations support further studies on PFD in stricturing CD.