Figure 5.

p38 MAPK phosphorylation increased in cultured neurons exposed to a nontoxic concentration of Aβ42. A, Effect of Aβ42 (200 nm) on p38 phosphorylation at different incubation times (n = 6 experiments for each group; *p < 0.05 vs control untreated cells). B, Effect of increasing concentrations of Aβ42 on p38 phosphorylation; 200 nm Aβ42 significantly increased phospho-p38 levels (n = 6 experiments in each group, *p < 0.001 vs control untreated). No additional increase was induced by higher concentrations Aβ42 (2 and 20 μm). C, Aβ42 (200 nm, 10 min incubation) or H₂O₂ (100 μm, 10 min) increased p38 phosphorylation compared with anti-RAGE IgG. Levels of p38 phosphorylation in cultures exposed to Aβ42 in the presence of anti-RAGE IgG were similar to those observed in cultures not exposed to Aβ42 and incubated with control IgG or in control cells (^#p < 0.001). Anti-RAGE IgG pretreatment of neuronal cultures significantly reduced Aβ-, but not H₂O₂-induced increase in phospho-p38 (*p < 0.05 vs Aβ42 200 nm; n = 6 experiments for each group). Error bars indicate SEM.