1. T1R2 receptor-mediated glucose sensing in the upper intestine potentiates glucose absorption through activation of local regulatory pathways
- Author
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Timothy F. Osborne, Elnaz Karimian Azari, Paula P Veldhuis, Traci E. LaMoia, Richard E. Pratley, Veronika Vargova, Kathleen R. Smith, Juan Pablo Arnoletti, Sebastian G. de la Fuente, Katalin Karolyi, Tania Hussain, and George Kyriazis
- Subjects
0301 basic medicine ,EEC, enteroendocrine cells ,Male ,Isc, short-circuit current ,Enteroendocrine cell ,Glucose homeostasis ,Receptors, G-Protein-Coupled ,Papp, apparent permeability coefficient ,Mice ,0302 clinical medicine ,Glucagon-Like Peptide 2 ,Intestinal Mucosa ,Receptor ,3-OMG, 3-O-methylglucose ,Mice, Knockout ,biology ,Chemistry ,digestive, oral, and skin physiology ,WAT, white adipose tissue ,Peptide secretion ,GI, gastrointestinal ,HSD, high sucrose diet ,humanities ,Cell biology ,Jejunum ,Taste ,GLP-1 and GLP-2, glucagon-like peptides-1 and -2 ,Original Article ,Female ,IP, intraperitoneal ,T1R2 ,HPV, hepatic portal vein ,Signal Transduction ,lcsh:Internal medicine ,KO, knock out ,STRs, sweet taste receptors ,Enteroendocrine Cells ,030209 endocrinology & metabolism ,Sweet taste receptors ,03 medical and health sciences ,Downregulation and upregulation ,PYY, peptide YY ,Animals ,Secretion ,TTX, tetrodotoxin ,lcsh:RC31-1245 ,Molecular Biology ,Gcg, pro-glucagon ,Glucose transporter ,Biological Transport ,Cell Biology ,IG.GTT, intragastric glucose tolerance test ,Apical membrane ,Mice, Inbred C57BL ,030104 developmental biology ,Glucose ,Intestinal Absorption ,biology.protein ,GLUT2 ,Energy Metabolism ,GLP-2 ,TER, tissue trans-epithelial resistance - Abstract
Objective Beyond the taste buds, sweet taste receptors (STRs; T1R2/T1R3) are also expressed on enteroendocrine cells, where they regulate gut peptide secretion but their regulatory function within the intestine is largely unknown. Methods Using T1R2-knock out (KO) mice we evaluated the role of STRs in the regulation of glucose absorption in vivo and in intact intestinal preparations ex vivo. Results STR signaling enhances the rate of intestinal glucose absorption specifically in response to the ingestion of a glucose-rich meal. These effects were mediated specifically by the regulation of GLUT2 transporter trafficking to the apical membrane of enterocytes. GLUT2 translocation and glucose transport was dependent and specific to glucagon-like peptide 2 (GLP-2) secretion and subsequent intestinal neuronal activation. Finally, high-sucrose feeding in wild-type mice induced rapid downregulation of STRs in the gut, leading to reduced glucose absorption. Conclusions Our studies demonstrate that STRs have evolved to modulate glucose absorption via the regulation of its transport and to prevent the development of exacerbated hyperglycemia due to the ingestion of high levels of sugars., Highlights • The intestinal T1R2 receptor enhances glucose absorption in vivo and ex vivo. • Pharmacological inhibition of STRs reduces glucose flux in human intestinal preparations. • T1R2 regulates glucose absorption dependent on GLUT2 activity in enterocytes. • GLP-2 mediates the effects of T1R2 signaling through activation of enteric neurons. • High sucrose diet rapidly downregulates STRs leading to reduced glucose absorption.
- Published
- 2018