Effect of taurine chloramine on the expression of MMPs in adiponectin- or IL-β-stimulated FLSs. The expressions of the collagenases (MMP-1 and MMP-13) were determined by ELISA [A], and semi-quantitative RNA analysis [B]. Synovial cells (2.5 × 105 cells/60-mm dish/2-ml serum-free media) were treated with taurine chloramine (TauCl) for 30 min prior to 24 h of adiponectin (10 µg/ml) or IL-1β (10 ng/ml) stimulation for analysis of MMP proteins by ELISA. Supernatants were collected for ELISA and the cells were used for RNA extraction for semi-quantitative RT-PCR. Experiments were performed in quadruplicate with cells from patients. The experiments were repeated with FLSs from three patients. The data shown are representative of 3 independent experiments, and similar results were obtained from all 3. Values are expressed as mean ± S.E.M. *P<0.05, **P<0.01, and *** P<0.001 versus non-treated group.