Figure 3: Osteoporotic phenotype in accordance with autoimmune disease in Fcgr2b^−/− mice.

(a) μCT of the femur of 12-week-old female Fcgr2b^+/− and Fcgr2b^−/− mice (see Fig. 1b legend for the details). Representative data of 10 mice are shown. Bone volume and degree of trabecular separation were determined with the μCT analysis (right, n=10). (b) Bone histomorphometric analysis of the tibiae of 12-week-old female Fcgr2b^+/− and Fcgr2b^−/− mice and the parameters for osteoclastic bone resorption, as determined by the bone morphometric analysis (n=10). (c) Osteoclast differentiation in Fcgr2b^+/− and Fcgr2b^−/− cells cultured in 10% fetal bovine serum (upper) or 5% mouse serum isolated from WT mice (lower). Representative data (left) and quantification (n=3) are shown. (d) Effect of IgGs in mouse serum isolated from WT mice (upper) or Fcgr2b^−/− mice (lower) on osteoclast differentiation in Fcgr2b^+/+ and Fcgr2b^−/− cells. (e) The μCT analysis of the femur of 12-week-old female Fcgr2b^+/−Fcer1g^+/− (Control), Fcgr2b^−/−Fcer1g^+/− and Fcgr2b^−/−Fcer1g^−/− (DKO) mice. Representative data of nine mice are shown. Bone volume was determined with the μCT analysis (right, n=9). (f) Osteoclast differentiation in Fcgr2b^+/−Fcer1g^+/−, Fcgr2b^−/−Fcer1g^+/− and Fcgr2b^−/−Fcer1g^−/− cells cultured in WT mouse serum. All quantification experiments were performed using triplicate culture wells. All data are representative of more than three independent experiments and are shown as the mean±s.e.m. Statistical analyses were performed using unpaired two-tailed Student’s t-test (*P<0.05; **P<0.01; n.s., not significant).