Figure 6. Impaired coupling function in osteoclast-specific Cthrc1 KO mice.

(A) Cthrc1, Acp5, Calcr, and Ctsk expression at baseline and after RANKL injection in Cthrc1^fl/fl control and ΔOC mice, determined by quantitative RT-PCR. Values were normalized for Gapdh. n = 4. (B) Impaired recovery of 3D BV at 8 weeks after RANKL injection in ΔOC versus Cthrc1^fl/fl control mice. Mice were sacrificed at 10 days and 8 weeks after RANKL injections, and 3D-determined BV relative to tissue volume was determined. Representative μCT images at 8 weeks are also shown. Scale bars: 1 mm. n = 8. (C) Urinary CTX excretion was assessed 1 day before (–1) and 2 and 4 days after RANKL injections. Data are normalized for creatinine (Cr). n = 5. (D) Bone histomorphometric analysis was performed at 10 days after RANKL injections. Osteoblast surface (Ob.S), osteoblast number (Ob.N), osteoid surface, and bone formation rate were corrected for bone surface. n = 8. (E) Serum osteocalcin (Ocn) concentrations were determined 10 days after RANKL injections (n = 8). *P < 0.05; **P < 0.01; ***P < 0.001.