The effect of the presence of PrP^C on transition metals induced cell death.

<p>Cells were tested for cell death after treatment with transition metals for 24 h, cell death was measured by propidium iodide (PI) exclusion assay. (A) Zpl 2–1, ZW 13–2, Zpl 2-1-vector and Zpl 2-1-PrP cells were treated either with 750 μM of Cu²⁺-Gly (1:4 mol/mol), or with 100 μM of Zn²⁺, or 500 μM of Mn²⁺ or 750 μM of Co²⁺. Dead cells were stained with PI, and histograms were obtained by flow cytometric analysis. M1 represents the population of PI positive cells. The bar graphs on the panels b through e indicate the average of PI positive cells in case of 750 μM of Cu²⁺ treatment (B), 100 μM of Zn²⁺ treatment (C), 500 μM of Mn²⁺ treatment (D) and 750 μM of Co²⁺ treatment (E), respectively. Experiments were performed three times in duplicates, and data represent the mean ± standard deviation (S.D.). *p<0.05, **p<0.01 and ***p<0.001 indicate significant differences between treated (+) and untreated (-) cells; ⁺p<0.05, ⁺⁺p<0.01 and ⁺⁺⁺p<0.001 indicate significant differences between the ratios obtained for treated ZW 13–2 cells to treated Zpl 2–1 cells, and treated Zpl 2-1-vector cells to treated Zpl 2-1-PrP cells, respectively.