Figure 1

Effect of monosodium urate (MSU) crystals on CCL2 production in cultured fibroblast-like synoviocytes (FLS). (a) FLS were treated with increasing concentrations of MSU crystals for 24 hours. (b) Synoviocytes were incubated in the presence (black circles) or absence (white circles) of 50 μg/ml MSU crystals for the indicated time. CCL2 was measured in culture supernatants with ELISA. Results are presented as mean ± SD of three separate experiments. (c) FLS were stimulated (grey columns) or not (white columns) for 24 hours with 50 μg/ml MSU crystals in the presence or absence of 250 ng/ml IL-1Ra. IL-1Ra was either added with MSU crystals (MSU + IL-1Ra) or added to FLS 1 hour before activation by MSU crystals (IL-1Ra + MSU). (d) FLS were stimulated (black columns) or not (white columns) for 24 hours with 125 pg/ml IL-1β in the presence or absence of 250 ng/ml of IL-1Ra. IL-1Ra was either added with IL-1β (IL-1β + IL-1Ra) or added to FLS 1 hour before activation by IL-1β (IL-1Ra + IL-1β). (c, d) Culture supernatants were analyzed for the production of CCL2. Results are presented as mean ± SD of three separate experiments.