Suppressive effect of interferon γ on IL-13-induced fibrosis in fibroblasts

AIM:To investigate the suppressive effect of interferon γ(IFN-γ) on fibrosis induced by interleukin 13(IL-13) in fibroblasts.METHODS:The fibroblasts were divided into IFN-γ(4×105U/L) group,IL-13(100 μg/L) group,IFN-γ+IL-13 group and blank control group.At 24 h,48 h and 72 h,the secreted collagen from fibroblasts was measured by hydroxyproline release assay.The mRNA expression of collagen type I α1(Col1A1) in fibroblasts was examined by RT-PCR.The protein level of collagen type I synthesized in fibroblasts was analyzed by Western blotting.RESULTS:IFN-γ at 4×105U/ L significantly inhibited the proliferation of fibroblasts and down-regulated Col1A1 mRNA and cellular collagen.The mRNA expression of Col1A1 and the protein level of collagen type I in IFN-γ group were lower than those in blank control group at 48 h and 72 h.At 72 h,the mRNA expression of Col1A1 and the protein level of collagen type I in IL-13 group were substantially higher than those in blank control group,those in IFN-γ + IL-13 group were remarkable lower than those in blank control group,and those in IFN-γ group were also lower than those in blank control group.CONCLUSION:IFN-γ inhibits the fibrotic effect of IL-13 in fibroblasts.