HISTOLOGY OF THE ENDOCRINE PANCREAS: MODERN APPROACHES TO THE ISLETS OF LANGERHANS AND THEIR HORMONE-PRODUCING CELLS

Abstract

This article presents modern perspectives on the histology of the endocrine portion of the pancreas and the hormone-producing cell types of the Langerhans islets. The pancreas consists of exocrine and endocrine components, which are closely interconnected (crosstalk) and form a complex functional system. During embryonic development, both components originate from a common source, and in some cases, cells retain the ability to transdifferentiate into one another. The endocrine portion is organized into Langerhans islets composed of α, β, D, D1, and PP cells, each synthesizing specific hormones and regulating one another through paracrine signaling.

The article highlights diseases associated with dysfunction of endocrine cells, particularly type 1 and type 2 diabetes, somatostatinoma, and vasoactive intestinal peptide–producing tumors. Globally, diabetes affects 11.1% of the population. It is also noted that long-standing type 2 diabetes may impair β-cell function and potentially contribute to the development of pancreatic cancer (pancreatic adenocarcinoma).

Recent studies have demonstrated that extracellular matrix (ECM) proteins — nidogen-1 (NID1) and decorin (DCN) — reduce β-cell death under hypoxic conditions and help preserve their hormone-producing capacity during transplantation of donor Langerhans islets. In addition, CRISPR-Cas9, RNA-seq, and in vitro 3D models are being used to investigate intercellular interactions and regenerative potential. These approaches offer promising new strategies in endocrine histology, diabetes research, and cellular transplantation.