Fig. 3

Epigenetic markings favor chromatin accessibility and gene expression during TD. The trimethylation of histone H3 lysines 4 and 9 modulate chromatin accessibility increasing or inhibiting gene expression, respectively. A, C Sum of the fluorescence intensity of the brand H3K4me3 (A) and H3K9me3 (B) normalized by the number of mature neurons identified with these markings, after 4, 7 and 10 days of culture with or without B1. The means of the CT (controls) and TD (thiamine deficiency) groups were compared with the bidirectional analysis of variance (ANOVA) test followed by the Tukey’s multiple comparisons test. Data were expressed as ± standard deviation (****P ≤ 0.0001). The statistical differences represented by red horizontal bars and asterisks refer to the variation in the TD group between the different timepoints. Gray vertical bars and asterisks refer to the intergroup differences (CT versus TD) at the same timepoint. B, D Confocal microscopy images (×60) of COH with markings of mature neurons (NeuN+) in red, cell nucleus (DAPI) in blue and epigenetic markings H3K4me3 (B) or H3K9me3 (D) in green after 7 days of culture with or without B1 (scale bar = 50 μm)