Fig. 5.

Effects of COX-2 inhibition on MLO-Y4 cell responses to MSU crystal-stimulated RAW264.7 macrophage conditioned medium. 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. A cyclooxygenase-2 (COX-2)-specific inhibitor (SC-236) was added to MLO-Y4 cells for 1 h prior to the addition of 40% conditioned medium for 24 h. MLO-Y4 cells were then harvested for mRNA gene expression analysis and supernatants harvested for protein quantification. a Changes in mRNA expression of inflammatory genes: tumor necrosis factor (TNF)-α, COX-2, interleukin (IL)-6, and IL-11; and bone-related genes: receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG). b Changes in TNF-α, prostaglandin E₂ (PGE₂), and IL-6 protein levels in MLO-Y4 cell supernatants. Data shown are pooled from five biological repeats and are presented as (SEM); one-way analysis of variance (ANOVA) with post-hoc Sidak’s test between groups as indicated. NS no significant difference