title: A Transcriptome-Led Exploration of Molecular Mechanisms Regulating Somatostatin-Producing D-Cells in the Gastric Epithelium.
abstract: The stomach epithelium contains a myriad of enteroendocrine cells that modulate a range of physiological functions, including postprandial secretion of regulatory peptides, gastric motility, and nutrient absorption. Somatostatin (SST)-producing D-cells are present in the oxyntic and pyloric regions of the stomach, and provide a tonic inhibitory tone that regulates activity of neighboring enteroendocrine cells and gastric acid secretion. Cellular mechanisms underlying the effects of regulatory factors on gastric D-cells are poorly defined due to problems in identifying primary D-cells, and uncertainty remains about which stimuli influence D-cells directly. In this study, we introduce a transgenic mouse line, SST-Cre, which upon crossing with Cre reporter strains, facilitates the identification and purification of gastric D-cells, or cell-specific expression of genetically encoded calcium indicators. Populations of D-cells from the gastric antrum and corpus were isolated and analyzed by RNA sequencing and quantitative RT-PCR. The expression of hormones, hormone receptors, neurotransmitter receptors, and nutrient receptors was quantified. Pyy, Gipr, Chrm4, Calcrl, Taar1, and Casr were identified as genes that are highly enriched in D-cells compared with SST-negative cells. Hormone secretion assays performed in mixed gastric epithelial cultures confirmed that SST secretion is regulated by incretin hormones, cholecystokinin, acetylcholine, vasoactive intestinal polypeptide, calcitonin gene-related polypeptide, oligopetides, and trace amines. Cholecystokinin and oligopeptides elicited increases in intracellular calcium in single-cell imaging experiments performed using cultured D-cells. Our data provide the first transcriptomic analysis and functional characterization of gastric D-cells, and identify regulatory pathways that underlie the direct detection of stimuli by this cell type.
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Alice
authors.initials: A
authors.lastname: Adriaenssens
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Brian Yee Hong
authors.initials: BY
authors.lastname: Lam
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Billing
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Katie
authors.initials: K
authors.lastname: Skeffington
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Sewing
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Frank
authors.initials: F
authors.lastname: Reimann
authors.affiliation: Metabolic Research Laboratories (A.A., B.Y.H.L., L.B., K.S., F.R., F.G.), Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge CB2 0QQ, United Kingdom; and Pharma Research and Early Development (S.S.), Roche Innovation Center Basel, F. Hoffmann-La Roche AG, 4070 Basel, Switzerland.
authors.forename: Fiona
authors.initials: F
authors.lastname: Gribble
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism*; D006728:Hormones / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D016688:Mice, Inbred NOD; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D011956:Receptors, Cell Surface / Q000145:classification / Q000235:genetics / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000145:classification / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017423:Sequence Analysis, RNA / Q000379:methods; D059010:Single-Cell Analysis / Q000379:methods; D013004:Somatostatin / Q000235:genetics* / Q000378:metabolism; D019864:Somatostatin-Secreting Cells / Q000378:metabolism*; D013270:Stomach / Q000166:cytology; D059467:Transcriptome
chemical_list: D006728:Hormones; D008164:Luminescent Proteins; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D013004:Somatostatin; D002118:Calcium