Pharmacological HDAC inhibition impairs pancreatic beta cell function through an epigenome-wide reprogramming [ChIP-seq]

Histone deacetylases (HDAC) enzymes are chromatin modifiers which directly regulate gene expression through deacetylation of lysine residues within specific histone and non-histone proteins. A cell-specific gene expression pattern defines the identity of insulin-producing pancreatic b cells, yet molecular networks driving this transcriptional specificity are not fully understood. Here, we investigated the HDAC-dependent molecular mechanisms controlling pancreatic b-cell identity and function using trichostatin A (TSA), a pan-HDAC inhibitor. We observed that TSA alters insulin secretion associated with b-cell specific transcriptome programming in both mouse and human b-cell lines, as well as on human pancreatic islets. We also demonstrated that this alternative b-cell transcriptional program in response to HDAC inhibition is related to an epigenome-wide remodeling at both promoters and enhancers. Our data indicate that full HDAC activity is required to safeguard the epigenome, to protect against loss of β-cell identity with unsuitable expression of genes associated with alternative cell fates. Epigenomic profiling of TSA-treated Min6 cells