Fig. 4.

K/BxN serum injection increases the density of CD68⁺ osteoclasts in trabecular distal femurs of WT but not Tlr4^−/− mice at 28 days. Representative confocal images of CD68⁺ cells (green) in male (A) and female (B) mice of Sects. (20 μm thick) at the distal femoral metaphysis from WT, WT serum-injected, Tlr4^−/− and Tlr4^−/− serum-injected mice. A significantly greater density of multinucleated cells expressing CD68⁺ was found in male (p = 0.0004) and female (p = 0.04) WT serum injected mice compared with their respective controls (C). However, this increase of CD68⁺ osteoclasts was not observed in Tlr4^−/− serum injected male and female mice (C). *p < 0.05 one-way ANOVA with Tukey post hoc test; n = 5 per group