Figure 3. Inhibition of osteoblast proliferation and expression of CBS and CSE by Dex. (A) Cell viability of rat primary osteoblasts was measured by MTT after cells were treated with 10−7 and 10−6 M Dex for 48 h. n=3, **p<0.01. (B) Representative photomicrographs (x200) of EdU staining and corresponding total cell photomicrographs. Blue: Hoechst labeling of cell nuclei; red: EdU labeling of nuclei of proliferative cells. (C) Quantitative data showing the percentage of EdU-positive cells in different treatment groups (number of red vs number of blue nuclei). n=3, *p<0.05, **p<0.01. (D) Dex inhibited osteogenic differentiation of primary osteoblasts in a dose-dependent manner, as evidenced by changes in mineralized matrix formation (ARS staining, day 14) (x100). (E–G) Western blot analysis showing that Dex decreased the levels of CBS and CSE in primary osteoblasts in a dose-dependent manner. n=3, *p<0.05, **p<0.01.