Fig. 4

Pharmacologic inhibition of NF-κB in glia protects N2A neuronal cells from apoptosis induced by Mn-exposed glial conditioned media. Pharmacologic inhibition of NF-κB with Bay-11 in mixed glial cultures preserves N2A viability following treatment with 100 μM MnCl₂ GCM (a) and ACM (b). Direct treatment of N2A cells with Mn causes a dose-dependent decrease in viability (c). Flow cytometry analysis of apoptotic N2A cells indicated that direct treatment with 100 μM MnCl₂ (d, e) results in fewer Annexin V+ and PI+ cells compared to GCM (f, h) and ACM (g, i) and that pretreatment of glial cultures with Bay-11 prior to Mn exposure decreases the number of Annexin V+ and PI+ cells in both GCM- and ACM-treated N2A cells. One-way ANOVA analyses performed for experiments comparing three or more treatment groups and T test in those comparing two treatment groups. Data depicted as ± S.E.M. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001 (n ≥ 4 per treatment group; across ≥ 3 independent experiments)