FIGURE 1.

Preconditioning with nitric oxide donors, DETA-NO, enhances hCSC survival. A, hCSCs were challenged with the indicated dose of H₂O₂ for 3 h and evaluated by LDH assay. B, hCSCs were preconditioned with various concentrations of DETA-NO for 12 h, challenged with H₂O₂, and evaluated by LDH assay. C, hCSCs were preconditioned with 250 μm DETA-NO for the indicated time, challenged with H₂O₂, and evaluated by LDH assay. D, after hCSCs were preconditioned with 250 μm DETA-NO for 12 h, medium was refreshed for a period of time as indicated. Cells were then challenged with H₂O₂ followed by LDH assay. E, hCSCs were pretreated with 250 μm DETA-NO in the presence or absence of 10 μm 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO) for 12 h. Cells were then challenged with H₂O₂ and evaluated by LDH assay. Data are presented as mean ratio of H₂O₂-induced LDH release to total LDH in cells with S.D. (means ± S.D.). Error bars represent S.D. * indicates p < 0.05 versus vehicle; ** indicates p < 0.01 versus vehicle; *** indicates p < 0.001 versus vehicle; n = 4 independent experiments. DMSO, dimethyl sulfoxide.