Global Epigenomic Analysis of Primary Human Pancreatic Islets Provides Insights into Type 2 Diabetes Susceptibility Loci

Michael L. Stitzel, Praveen Sethupathy, Daniel S. Pearson, Peter S. Chines, Lingyun Song, Michael R. Erdos, Ryan Welch, Stephen C.J. Parker, Alan P. Boyle, Laura J. Scott, NISC Comparative Sequencing Program, Elliott H. Margulies, Michael Boehnke, Terrence S. Furey, Gregory E. Crawford, Francis S. Collins.
Cell Metabolism. 2010-11-03;12(5):443-455.
Abstract
Identifying cis-regulatory elements is important to understanding how human pancreatic islets modulate gene expression in physiologic or pathophysiologic (e.g., diabetic) conditions. We conducted genome-wide analysis of DNase I hypersensitive sites, histone H3 lysine methylation modifications (K4me1, K4me3, K79me2), and CCCTC factor (CTCF) binding in human islets. This identified ∼18,000 putative promoters (several hundred unannotated and islet-active). Surprisingly, active promoter modifications were absent at genes encoding islet-specific hormones, suggesting a distinct regulatory mechanism. Of 34,039 distal (nonpromoter) regulatory elements, 47% are islet unique and 22% are CTCF bound. In the 18 type 2 diabetes (T2D)-associated loci, we identified 118 putative regulatory elements and confirmed enhancer activity for 12 of 33 tested. Among six regulatory elements harboring T2D-associated variants, two exhibit significant allele-specific differences in activity. These findings present a global snapshot of the human islet epigenome and should provide functional context for noncoding variants emerging from genetic studies of T2D and other islet disorders.
Consortium data used in this publication
GSE23784