Acetylation of NF-κB p65 and histone H4 in INS-1E cells. INS-1 E cells were exposed to IL-1β (12.5 pg/ml) for 1 h and/or butyrate (0.4 mM) for 2 h or left unexposed (Ctr). A, acetylation of NF-κB p65. Nuclear extracts were immunoprecipitated using an anti-p65 antibody. Immunoprecipitated extracts were analyzed by Western blotting using an antibody directed against acetylated lysines (A) or p65 (B). The ratio of acetylated p65 over total nuclear p65 is shown in C. Representative blots are shown, and band intensities were quantified using Image Studio. Data are shown as fold increase relative to Ctr, and bars show means ± SEM of n = 4. ∗p < 0.05. D–E, acetylation of histone H4 at the Nos2 (D) and Cxcl1 (E) promoters. ChIP assays were performed with an antibody that immunoprecipitated acetylated (K5, K8, K12, K16) histone H4 or IgG as a negative control. For the IgG control, data were pooled from three independent experiments. Data are shown as percentage of input DNA and bars show means ± SEM of n = 4. ∗p < 0.05, ∗∗p < 0.01. NF-κB, nuclear factor-κB.