Suppression of α Smooth Muscle Actin Expression by IFN- γ in Established Myofibroblast Cell Lines

Abstract

The purpose of this study is to investigate the effect of interferon-γ (IFN-γ) on myofibroblast generation using four myofibroblast cell lines that we established from Dupuytren's nodules. Cells were cultured in Earl's medium with 15% fetal bovine serum (FBS) and plated on a microplate at a density of 10⁴ cells/well. These cells were treated with various concentrations of IFN-γ (0–1000 U/mL) for 3 days. By cell-capture enzyme immunoassay (CC-EIA), immunofluorescence staining, and reverse transcriptase polymerase chain reaction (RT-PCR) analysis, we evaluated the effect of IFN-γ on the expression of α smooth muscle actin (αSMA) in these cells. CC-EIA and RT-PCR analysis showed that IFN-γ suppressed αSMA expression, and immunofluorescence microscopy demonstrated that IFN-γ markedly decreased the number of αSMA-positive cells. These results showed that IFN-γ strongly inhibits myofibroblast generation in established myofibroblast cell lines and suggest the possibility of using IFN-γ therapy for contractile disease.