Molecular mechanisms underlying glucose-dependent insulinotropic polypeptide secretion in human duodenal organoids

• DOI: 10.1007/s00125-024-06293-3
• Publication Date: 2024-10-23T06:02:59Z
• Authors: Nunzio Guccio; Constanza Alcaino; Emily L. Miedzybr...; Marta Santos-Hern...; Christopher A. Smith; Adam Davison; Rula Bany Bakar; Richard G. Kay; Frank Reimann; Fiona M. Gribble
• Keywords: Incretin; Gastric inhibitory polypeptide; Enteroendocrine cell; Organoid; HEK 293 cells

Abstract Aims/hypothesis Glucose-dependent insulinotropic polypeptide (GIP) is an incretin hormone secreted by enteroendocrine K cells in the proximal small intestine. This study aimed to explore function of human at molecular and cellular levels. Methods CRISPR-Cas9 homology-directed repair was used insert transgenes encoding a yellow fluorescent protein (Venus) or Epac-based cAMP sensor (Epac-S-H187) GIP locus duodenal-derived organoids. Fluorescently labelled were purified FACS for RNA-seq peptidomic analysis. reporter organoids employed secretion assays, live-cell imaging Ca 2+ using Fura-2 Epac-S-H187, basic electrophysiological characterisation. The G protein-coupled receptor genes GPR142 CASR knocked out evaluate roles amino acid sensing. Results duodenal revealed enrichment several receptors involved nutrient sensing, including FFAR1 , GPBAR1 GPR119 . Glucose induced action potential firing cytosolic elevation caused 1.8-fold increase secretion, which inhibited sodium glucose co-transporter 1/2 (SGLT1/2) blocker sotagliflozin. Activation long-chain fatty free 1 (FFAR1) 2.7-fold while tryptophan phenylalanine stimulated 2.8- 2.1-fold, respectively. While knockout blunted intracellular responses, / double needed reduce secretory responses aromatic acids. Conclusions/interpretation newly generated organoid cell model enables transcriptomic functional characterisation nutrient-sensing pathways secretion. Both calcium-sensing (CASR) 142 (GPR142) contribute protein-stimulated will be further identify targets modulation native diabetes obesity. Graphical