Proteomics of Pancreatic Islet Beta Cells

Abstract

The pancreatic islets of Langerhans are clusters of endocrine cells responsible for hormone secretion. These islets comprise five distinct cell types, α, β, δ, ε, and pancreatic polypeptide (PP) cells, each producing specific hormones. Among them, β cells constitute approximately 50–80% of the islet cell population and play a central role in regulating blood glucose levels through insulin secretion. In addition to their metabolic function, β cells are involved in cellular growth and transcriptional regulation. Recent advances in proteomic technologies have significantly enhanced our understanding of the β-cell proteome. Comprehensive proteomic profiling has revealed the molecular landscape of β cells, providing insights into their physiological roles and disease associations. In particular, the identification of proteins expressed in human, mouse, and rat islets, as well as those specifically enriched in β cells, has contributed to elucidating the molecular mechanisms underlying β-cell function. This review summarizes current research trends on proteins expressed in pancreatic islets and β cells, focusing on their types, abundance, molecular functions, and physiological characteristics. Special attention is given to proteins that are functionally important for β-cell activity and those implicated in the pathogenesis of diabetes.