Fig. 3.

l-cysteine and d-cysteine, but not NMC protect astrocytes against proteotoxicity. Primary cortical astrocytes were treated with MG132 or vehicle and with l-cysteine (A), d-cysteine (B), NMC (C), or vehicle. Viability was measured 48 hours later by blinded counts of the number of Hoechst⁺ nuclei (A–C) or DRAQ5 nuclear staining (D). **P ≤ 0.01; ***P ≤ 0.001 versus 0 µM MG132; ⁺P ≤ 0.05; ⁺⁺P ≤ 0.01; ⁺⁺⁺P ≤ 0.001 versus 0 mM d-cysteine, l-cysteine, or NMC, two-way analysis of variance followed by the Bonferroni post hoc test.