Fig. 4.

Secretion of proinflammatory mediators by MLO-Y4 cells in response to MSU crystal-stimulated RAW264.7 macrophages. RAW264.7 macrophages were cultured with or without 0.5 mg/mL monosodium urate (MSU) crystals for 24 h for preparation of MSU crystal-stimulated conditioned medium and control conditioned medium, respectively. Conditioned medium preparations were added to MLO-Y4 cells (40% final concentration in a well) for 24 h and supernatants harvested. The concentrations of a tumor necrosis factor (TNF)-α, b prostaglandin E₂ (PGE₂), c interleukin (IL)-6, and d osteoprotegerin (OPG) protein in the RAW264.7 macrophage conditioned medium samples (control and MSU crystal-stimulated) and the MLO-Y4 cell supernatants were measured by ELISA. Data shown are pooled from three biological repeats and are presented as mean (SEM); one-way analysis of variance (ANOVA) with post-hoc Sidak’s test between groups as indicated. NS no significant difference