Regulated and adaptive in vivo insulin secretion from islets only containing β-cells

Research Overview

β-cells are regulated systemically and locally by neighboring α-, δ-, and γ-cells — but whether those non-β-cells are actually required for accurate insulin secretion was unknown. This study examined mice whose adult islets contained only β-cells, alongside human pseudoislets built solely from primary β-cells.

Mice lacking non-β-cells regulated blood glucose optimally, with enhanced glucose tolerance, insulin sensitivity, and restricted weight gain on a high-fat diet; their β-cell-only islets secreted insulin with dynamics comparable to intact islets. Human β-cell pseudoislets likewise retained glucose-regulated mitochondrial respiration, insulin secretion, and exendin-4 responses — indicating non-β-cells are dispensable for regulated insulin secretion.