Figure 3. Plk1 is essential for neuronal cell death. (A) Inhibition of Plk1 reduces Aβ-induced neuronal cell death in PC12 cells. PC12 cells were treated with NGF for 3 d, followed by Aβ25-35 or Aβ25-35 + BI 2536 treatment for 24h. Cells were then incubated with 10 μg/ml propidium iodide (PI) for 10 min at 37–, washed with PBS, and harvested for immunofluorescence (IF). Cell death was assessed based on the principle that only the nuclei of cells with compromised plasma membranes will be stained with PI. (B) Inhibition of Plk1 reduces Aβ-induced DNA replication in PC12 cells. PC12 cells were treated as in (A), and subjected to BrdU incorporation assay to monitor DNA synthesis. * P<0.05.