1. The Intestinal Glucose–Apelin Cycle Controls Carbohydrate Absorption in Mice
- Author
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Isabelle Castan-Laurell, Bernard Masri, Estelle Wanecq, Yassine Sakar, Cédric Dray, Sylvain Galvani, Philippe Valet, Larry S. Barak, Anne Nègre-Salvayre, Robert Ducroc, Luc Garrigues, Danièle Daviaud, Bernard Monsarrat, Odile Burlet-Schiltz, Claire Vinel, Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de recherche biomédicale Bichat-Beaujon (CRB3), Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de Recherches en Cancérologie de Toulouse (CRCT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut de pharmacologie et de biologie structurale (IPBS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Department of Cell Biology, Duke University Medical Center, This work was funded by Inserm, Université Paris Diderot Paris 7 and Université Paul 19 Sabatier. Y.S. was a recipient of Fondation pour la Recherche Médicale (FRM)., Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Hormones, facteurs de croissance et physiopathologie vasculaire, IFR 31 Louis Bugnard (IFR 31), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Toulouse [Toulouse]-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Toulouse [Toulouse]-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-IFR 31 Louis Bugnard (IFR 31), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)
- Subjects
Male ,[SDV]Life Sciences [q-bio] ,Mass Spectrometry ,Intestinal absorption ,Mice ,Random Allocation ,0302 clinical medicine ,AMP-activated protein kinase ,Reference Values ,Glucose homeostasis ,Sodium-Glucose Transporter 1 ,ComputingMilieux_MISCELLANEOUS ,Glucose Transporter Type 2 ,0303 health sciences ,Microscopy, Confocal ,diabetes ,biology ,Gastroenterology ,[SDV.MHEP.EM]Life Sciences [q-bio]/Human health and pathology/Endocrinology and metabolism ,Immunohistochemistry ,Apelin ,apelin ,Intercellular Signaling Peptides and Proteins ,medicine.medical_specialty ,mouse model ,Blotting, Western ,Carbohydrates ,030209 endocrinology & metabolism ,Carbohydrate metabolism ,03 medical and health sciences ,Internal medicine ,medicine ,Animals ,030304 developmental biology ,Analysis of Variance ,adipokine ,Hepatology ,Glucose transporter ,Biological Transport ,Mice, Inbred C57BL ,Disease Models, Animal ,Glucose ,Endocrinology ,Intestinal Absorption ,biology.protein ,GLUT2 ,Calorie intake ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology ,Chromatography, Liquid - Abstract
International audience; BACKGROUND & AIMS: Glucose is absorbed into intestine cells via the sodium glucose transporter 1 (SGLT-1) and glucose transporter 2 (GLUT2); various peptides and hormones control this process. Apelin is a peptide that regulates glucose homeostasis and is produced by proximal digestive cells; we studied whether glucose modulates apelin secretion by enterocytes and the effects of apelin on intestinal glucose absorption. METHODS: We characterized glucose-related luminal apelin secretion in vivo and ex vivo by mass spectroscopy and immunologic techniques. The effects of apelin on (14)C-labeled glucose transport were determined in jejunal loops and in mice following apelin gavage. We determined levels of GLUT2 and SGLT-1 proteins and phosphorylation of AMPKα2 by immunoblotting. The net effect of apelin on intestinal glucose transepithelial transport was determined in mice. RESULTS: Glucose stimulated luminal secretion of the pyroglutaminated apelin-13 isoform ([Pyr-1]-apelin-13) in the small intestine of mice. Apelin increased specific glucose flux through the gastric epithelial barrier in jejunal loops and in vivo following oral glucose administration. Conversely, pharmacologic apelin blockade in the intestine reduced the increased glycemia that occurs following oral glucose administration. Apelin activity was associated with phosphorylation of AMPKα2 and a rapid increase of the GLUT2/SGLT-1 protein ratio in the brush border membrane. CONCLUSIONS: Glucose amplifies its own transport from the intestinal lumen to the bloodstream by increasing luminal apelin secretion. In the lumen, active apelin regulates carbohydrate flux through enterocytes by promoting AMPKα2 phosphorylation and modifying the ratio of SGLT-1:GLUT2. The glucose-apelin cycle might be pharmacologically handled to regulate glucose absorption and assess better control of glucose homeostasis.
- Published
- 2013
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