Labelling and Characterization of Human GLP-1 Secreting L-Cells in Primary Ileal Organoid Culture

Abstract

GLP-1 from intestinal L-cells stimulates insulin secretion and reduces appetite after food ingestion, and is the basis for drugs against type-2 diabetes and obesity. Drugs targeting L- and other enteroendocrine cells are under development, aiming to mimic endocrine effects of gastric bypass surgery, but are difficult to develop without human L-cell models. We engineered human ileal organoids by CRISPR-Cas9 to express the fluorescent protein Venus in the proglucagon locus, enabling maintenance of live identifiable human L-cells in culture. FACS-purified organoid-derived L-cells, analysed by RNAseq, expressed hormones, receptors and ion channels, largely typical of their murine counterparts. L-cells were electrically active and exhibited membrane depolarization and calcium elevations in response to G-protein coupled receptor ligands. Organoids secreted hormones in response to glucose and other stimuli. The ability to label and maintain human L-cells in organoid culture opens new avenues to explore L-cell function and develop drugs targeting the human enteroendocrine system.