Background: The aetiology of inflammatory bowel disease (IBD) is related to genetics and epigenetics. Epigenetic regulation of the pathogenesis of IBD has not been well defined. Here, we investigated the role of H3K27ac events in the pathogenesis of IBD. Based on previous ChIP-seq and RNA-seq assays, we studied signal transducer and activator of transcription 1 (STAT1) as a transcription factor (TF) and investigated whether the STAT1-EP300-H3K27ac axis contributes to the development of IBD. We performed ChIP-PCR to investigate the interaction between STAT1 and H3K27ac, and co-IP assays were performed to investigate the crosstalk between STAT1 and EP300.
Results: Lymphocyte cytosolic protein 2 (LCP2) and TNF-α-inducible protein 2 (TNFAIP2) are target genes of STAT1. p-STAT1 binds to the enhancer loci of the two genes where H3K27ac is enriched, and EP300 subsequently binds to regulate their expression. In mice with dextran sulfate sodium (DSS)-induced acute colitis, an EP300 inhibitor significantly inhibited colitis.
Conclusions: p-STAT1 and EP300 promote TNFAIP2 and LCP2 expression through an increase in H3K27ac enrichment on their enhancers and contribute to the pathogenesis of chronic inflammation.
Keywords: EP300; Enhancer; H3K27ac; IBD; STAT1.