Figure 5

Cell cycle distribution of nucleus pulposus cells. Serum-deprived nucleus pulposus cells were cultured with no supplements for 24 h (a). The cells were treated with 5 ng/mL transforming growth factor β1 (TGFβ1) for 24 h (b). At 2 h before the addition of TGFβ1, the cells were treated with 16 μM 10058-F4 (c), or with 30 μM PD98059 (d). The cells were harvested 24 h after the addition of TGFβ1 and the nuclei were stained with propidium iodide. DNA histograms were generated using flow cytometry. Each plot represents the analysis of 10,000 events. The histograms present typical results and the percentage of cells in G₀/G₁, S and G₂/M phases are shown as the average of duplicated measurements.