Heterogeneity of the Human Pancreatic Islet.

Pancreatic β-cells play a pivotal role in maintaining normoglycemia. Recent studies have revealed that the β-cell is not a homogeneous cell population but, rather, is heterogeneous in a number of properties such as electrical activity, gene expression, and cell surface markers. Identification of specific β-cell subpopulations altered in diabetic conditions would open a new avenue to develop targeted therapeutic interventions. As intense studies of β-cell heterogeneity are anticipated in the next decade, it is important that heterogeneity of the islet be recognized. Many studies in the past were undertaken with a small sample of islets, which might overlook important individual variance. In this study, by systematic analyses of the human islet in two and three dimensions, we demonstrate islet heterogeneity in size, number, architecture, cellular composition, and capillary density. There is no stereotypic human islet, and thus, a sufficient number of islets should be examined to ensure study reproducibility.