Diabetes forum: Extreme makeover of pancreatic alpha-cells

Abstract

Most insulin-secreting pancreatic β-cells are irreplaceably lost in type 1 diabetes. In a mouse model, pancreatic α-cells seem to sacrifice their identity to replenish the low stock of β-cells. Two experts discuss what this means for understanding the basic cell biology involved and its relevance to treating diabetes.

Figure 1. A helping hand from α-cells

The islets of Langerhans in the pancreas contain both insulin-secreting β-cells and glucagon-secreting α-cells. Insulin lowers the level of glucose circulating in the bloodstream, whereas glucagon has the opposite effect. Thorel et al. used diphtheria toxin to destroy almost all pancreatic β-cells in mice. The authors' cell-lineage tracing indicates that, following treatment with insulin over time, a population of α-cells passes through a bihormonal step (producing both insulin and glucagon; green cells) before becoming new β-cells.