A, cells were immunostained with antibodies against p22phox. B, cells received either ASO or ScO at 1 μm against p22phox, and after 40 h of incubation, the cells were treated with 1 μm fibrillar Aβ1–42. At different intervals (measured in seconds), superoxide production was assayed in whole cells using the LumiMax™ superoxide anion detection kit (Stratagene). Results are the mean of two separate experiments. C, after 30 min of treatment with Aβ1–42, activities of N-SMase and A-SMase were assayed. D, after 18 h of stimulation with Aβ1–42, cell viability was examined by the metabolism of MTT and the release of LDH. Control group served as 100%, and data from other groups were expressed as percent of control. Results are mean ± S.D. of three different experiments. a, p < 0.001 versus control. b, p < 0.001 versus Aβ1–42.