Fig. 2

Effects of conditioned medium from MSU crystal-stimulated RAW264.7 macrophages on osteoblastic differentiation of MC3T3-E1 cells. RAW264.7 macrophages were cultured with the indicated concentrations of MSU crystals for 24 h. Conditioned medium from the RAW264.7 cultures was added to MC3T3-E1 cells at 40% of the final volume. A Expression of osteoblast marker genes determined by real-time PCR. Means (SEM) of data pooled from three or more biological repeats are presented. Data were analyzed by two-way ANOVA with post hoc Dunnett’s test. *p < 0.05, **p < 0.01, and ***p < 0.001 versus control conditioned medium at that time point. B MC3T3-E1 cells were cultured for 3 weeks in an osteogenic medium supplemented with 40% MSU crystal-stimulated conditioned medium from RAW264.7 cells. The representative photomicrographs show mineralized areas (black) and cells (yellow) in cultures stained with von Kossa stain. The experiment was repeated twice with similar results. MSU CM, concentrations of MSU crystals (mg/mL) used to prepare conditioned medium from RAW264.7 cells