Fig. 4.

MG132 increases protein misfolding stress and upregulates Hsp70 and HO1 levels. Astrocytes were treated with indicated concentrations of MG132 (1^st hit) and probed for a number of stress-sensitive proteins 24h later (A, C–L). Astrocytes were treated with single or dual hits of MG132 and assayed for levels of ubiquitinated proteins and heat shock proteins Hsp70 and HO1 24h after the 2^nd hit (B, M–N). *** p ≤ 0.001 vs 0 μM 2^nd MG132 hit; + p ≤ 0.05, ++ p ≤ 0.01 vs 0 μM 1^st MG132 hit, two-way ANOVA followed by Bonferroni post hoc correction for B, M, and N. The one-tailed, paired Student’s t-test was used for A, C–L