Figure 2.

Valproic acid increases protein oxidation in undifferentiated cells but not in differentiated neurons. Undifferentiated P19 cells and P19-derived neurons were treated with D3T and VPA and then labeled with biotinylated iodoacetamide (BIAM), a marker of reduced protein thiols. (a–c) Undifferentiated cells were assessed for BIAM signal intensity (a), normalized to their respective GelCode Blue-stained samples run in parallel (b), and analyzed using the normalized protein signal intensity (n = 3; (c)). (d–f) Differentiated neurons were also assessed for BIAM signal intensity (d), normalized to their respective GelCode Blue-stained samples (e), and analyzed using the normalized protein signal intensity (n = 3; (f)). Normalized BIAM signal intensity is an inverse measure of overall protein oxidation. Brief exposure to H₂O₂ was used as a positive control (a–f). Data are presented as means ± SEM. (c,f). Statistical comparisons were made using a one-way ANOVA followed by a pairwise t-test using the Bonferroni correction (c,f). Asterisks denote a statistically significant difference (** = p < 0.01, and *** = p < 0.001; (c,f)).