CTGF increases IL-6 expression in human synovial fibroblasts through αvβ5 integrin.

<p>(A) Total protein were extracted from normal synovial fibroblasts and OASFs, and subjected to western blotting for CTGF. (B) Human synovial fibroblasts were cultured for 48 h, and media were collected to measure CTGF. Synovial fluid was obtained from normal or osteoarthritis patients and examined with ELISA for the expression of CTGF. (C&D) OASFs were incubated with various concentrations of CTGF for 24 h. The IL-6 expression was examined by qPCR and ELISA. (E) OASFs were pretreated with αvβ3, αvβ5, α5β1, and α6β1 integrin antibody (5 µg/ml) for 30 min and then incubated with CTGF (10 ng/ml) for 24 h, the IL-6 expression was examined by ELISA. Results are expressed as the mean ± S.E. *: p<0.05 as compared with basal level. #: p<0.05 as compared with CTGF-treated group.