Figure 6. Osteoclast activity is increased in Hdac4^ob−/− mice.

(A) TRAP staining of tibiae of female 10-week-old Hdac4^fl/fl and Hdac4^ob−/− mice treated with PTH or vehicle is shown. 20X. (B) Quantification of osteoclast number and (C) osteoclast surface % in the animals in (A). Data shown as means ± SE. Different letters indicate p<0.05 vs. one another. (Hdac4 ^fl/fl; n=4, Hdac4 ^fl/fl with PTH; n=5, Hdac4^ob−/−; n=−5, Hdac4^ob−/−; with PTH; n=4). (D) Serum CTX levels (Hdac4 ^fl/fl; n=9, Hdac4 ^fl/fl with PTH; n=10, Hdac4^ob−/−; n=10, Hdac4^ob−/− with PTH; n=10), data shown as means ± SE and different letters indicate p<0.05 vs. one another. (E) The relative levels of Mmp13 mRNA normalized to β-actin (Hdac4 ^fl/fl; n=7, Hdac4 ^fl/fl with PTH; n=7, Hdac4^ob−/−; n=6, Hdac4^ob−/− with PTH; n=8). Total RNA was extracted from distal femurs of 10-week-old females and measured using real time RT-PCR. Data are shown as fold change to vehicle-treated Hdac4^fl/fl and as means ± SE. Different letters indicate p<0.05 vs. one another.