Inflammatory Bowel Disease and Epigenetics

The term epigenome refers to the complete set of DNA methylation events, histone modifications, and chromatin accessibility and its relation to coding and noncoding RNA molecules. All marks are cell-type specific and are dynamically modulated throughout the lifetime of an individual. Epigenetic processes are critical for regular development of the intestinal mucosa. Important examples include shaping of immune responses and epithelial differentiation. However, specific epigenetic signatures and genetic variants in genes encoding parts of the epigenetic machinery (e.g., DNMT3A/B) have also been associated with inflammatory bowel disease (IBD). Thus, it is well conceivable that such alterations of the epigenome in different cellular compartments may link genetic susceptibility and environmental influences and may determine “decision points” in the progression toward disease onset (i.e., manifestation) and/or progression of IBD. The chapter provides a review of recent advances in epigenetic research in IBD and aims to link general aspects of our understanding of epigenetic processes in the intestine with more specific clinical observations.