Up-regulation of matrix metalloproteinase expression in synovial fibroblasts from knee OA with flexion contracture using adenovirus-mediated relaxin gene therapy

Abstract

The aim of this study was to investigate the effect of the RLN gene on the inhibition of fibrosis in Synovial fibroblasts. Synovial fibroblast cells with adenovirus LacZ (Ad-LacZ) as a marker gene or adenovirus relaxin (Ad-RLN) as therapeutic gene showed transgene expressions in beta-galactosidase assay and Western blot analysis. Synovial fibroblasts with Ad-RLN demonstrated a 22% and 48% reduction in collagen I and III mRNA expressions respectively, a 50% decrease in MMP-1, 70% decrease in MMP-2, 80% decrease in MMP-9, and a 15% reduction in MMP-13 protein expression compared with cultures with viral control and saline control. In addition, the synovial fibroblasts with Ad-RLN showed a 40% decrease in TIMP 1 and a 15% increase in TIMP 2 protein expression at 48 h compared to cultures with viral control and saline control. Also, synovial fibroblasts with Ad-RLN demonstrated a 74% inhibition of fibronectin and a 52% decrease in total collagen synthesis at 48 h compared with cultures with viral control and saline control. In conclusion, the RLN gene render antifibrogenic effect on synovial fibroblasts from osteoarthritis with flexion contracture via direct inhibition of collagen synthesis not through collagenolytic pathway such as MMP-1, -13, TIMP 1, and 2. Therefore relaxin can be an alternative therapeutic strategy in initial stage of osteoarthritis with flexion contracture by its antifibrogenic effect.