Fig. 2
KD increases NRG1 expression via histone acetylation. A Representative Western blots showing H3, H4 proteins and their acetylation levels in the hippocampus of CD or KD-fed mice. GAPDH serves as a loading control. B Quantitative analysis of data in A. n = 4 mice per group. Student’s t test, for H3, t(6) = 0.2343, P = 0.8225; for H3k18ac, t(6) = 0.9896, P = 0.3606; for H3k27ac, t(6) = 3.816, P = 0.0088; for H4, t(6) = 0.6188, P = 0.5588; for H4k8ac, t(6) = 3.378, P = 0.0149; for H4k12ac, t(6) = 4.479, P = 0.0042. C Hippocampal samples from CD and KD groups were subjected to Chromatin Immunoprecipitation (CHIP). Shown was the CHIP procedure workflow. D Agarose gel electrophoresis of CHIP-qPCR products. E Increased level of H4 acetylation at Nrg1 promoter in KD-fed mice. n = 4 mice per group. Student’s t test, t(6) = 4.698, P = 0.0033. F TSA treatment increased hippocampal Nrg1 mRNA level and diminished the difference between CD and KD groups. n = 5 mice per group except that n = 6 mice for CD + TSA group. Two-way ANOVA with sidak’s multiple comparison tests. F(1,17) = 12.71, P = 0.0024; CD + vehicle vs KD + vehicle, P = 0.0008; CD + vehicle vs CD + TSA, P < 0.0001; CD + TSA vs KD + TSA, P > 0.9999. G NRG1 level in the hippocampus was increased by TSA treatment. Shown were representative western blot images. GAPDH serves as a loading control. H Quantitative analysis of western blot data in G. One-way ANOVA, for H3, F(3,12) = 0.4619, P = 0.7141; for H3K27ac, F(3,12) = 15.9, P = 0.0002. CD + vehicle vs KD + vehicle, P = 0.0469; CD + vehicle vs CD + TSA, P = 0.0004; CD + TSA vs KD + TSA, P > 0.9999; for H4, F(3,12) = 0.5403, P = 0.6637; for H4K12ac, F(3,12) = 17.86, P = 0.0001. CD + vehicle vs KD + vehicle, P = 0.0012; CD + vehicle vs CD + TSA, P = 0.0003; CD + TSA vs KD + TSA, P > 0.9999; For NRG1, F(3,12) = 29.81, P < 0.0001. CD + vehicle vs KD + vehicle, P = 0.0072; CD + vehicle vs CD + TSA, P < 0.0001; CD + TSA vs KD + TSA, P = 0.7846. * indicates p < 0.05; ** indicates p < 0.01; *** indicates p < 0.001