Paracrine signaling by pancreatic delta cells determines the glycemic set point in mice

Abstract

Pancreatic islets contain several endocrine cell types that coordinate to maintain blood glucose homeostasis. While {beta} and cells are thought to be the main drivers of glucose homeostasis through insulin and glucagon secretion respectively, the contribution of {delta} cells and somatostatin (SST) secretion to establishing the glycemic set point remains unresolved. Here we remove local SST signaling from {delta} cells within the pancreatic islet to investigate their contribution to the glycemic set point. Our data demonstrate that ablating {delta} cells or SST leads to a sustained decrease in the glycemic set point. This coincides with a decreased glucose threshold for insulin response from {beta} cells, leading to increased insulin secretion to the same glucose challenge. In contrast, cell ablation had no effect on glycemic set point. Collectively, these data establish the physiological role of {delta} cells in determining the glycemic set point through their interaction with {beta} cells.