[Pirfenidone inhibits proliferation of rabbit tenon fibroblasts by down-regulating TGF-β3 in the TGF-β/Smad pathway].

To investigate the molecular mechanism by which pirfenidone inhibits scar formation through the TGF-β/Smad pathway.Cultured rabbit tenon fibroblasts (RTFs) were treated with different concentrations of pirfenidone to determine its initial active concentration and optimum concentration of pirfenidone for inhibiting RTF proliferation using CCK-8 assay. In RTFs treated with pirfenidone at the initial and optimal concentrations, expressions of TGF-β3, collagen I and collagen III were examined with both immunofluorescence assay and Western blotting, and their mRNA expression levels were detected using RT-PCR.The initial and optimal concentrations of pirfenidone for inhibiting RTF proliferation were 0.1 mg/mL and 0.27 mg/mL, respectively. In RTFs treated with pirfenidone at the two concentrations for 24 h, both immunofluorescence assay and Western blotting showed significantly lowered protein expressions of TGF-β3, collagen I and collagen III as compared with those in the control group (P < 0.05). The mRNA expressions of TGF-β3, collagen I and collagen III in the RTFs were also significantly lowered after treatment with pirfenidone at the initial and optimal concentrations (P < 0.05).Pirfenidone concentration-dependently inhibits the proliferation of RTFs possibly by down-regulating the expression of TGF-β3 in the TGF-β/Smad pathway.