Figure 1.

Exposure to high glucose induces osteoblast apoptosis. (A) Osteoblasts were incubated with high glucose (16.5 mM) for 1, 4 or 7 days, and cell viability was examined by MTT assay. (B) Following exposure to high glucose (16.5 mM) for 4 days, the osteoblasts are subjected to flow cytometric analysis with Annexin V/propidium iodide (PI) double staining; upper right and lower right quadrants represent the proportion of late and early apoptotic cells, respectively. (C) The percentage of apoptotic cells was also determined. (D) The protein expression levels of Bcl-2, Bax, caspase-3 and caspase-8 were measured by western blot analysis when the cells were exposed to high glucose for 4 days. Values are expressed as the mean ± SEM, n=3 parallel experiments in each group. ^*P<0.05 vs. control group (normal glucose).