Regulation of glucagon secretion by glucose transporter type 2 (glut2) and astrocyte-dependent glucose sensors.

Détails

ID Serval
serval:BIB_899311492768
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Regulation of glucagon secretion by glucose transporter type 2 (glut2) and astrocyte-dependent glucose sensors.
Périodique
Journal of Clinical Investigation
Auteur(s)
Marty N., Dallaporta M., Foretz M., Emery M., Tarussio D., Bady I., Binnert C., Beermann F., Thorens B.
ISSN
0021-9738
Statut éditorial
Publié
Date de publication
2005
Peer-reviewed
Oui
Volume
115
Numéro
12
Pages
3545-3553
Langue
anglais
Résumé
Ripglut1;glut2-/- mice have no endogenous glucose transporter type 2 (glut2) gene expression but rescue glucose-regulated insulin secretion. Control of glucagon plasma levels is, however, abnormal, with fed hyperglucagonemia and insensitivity to physiological hypo- or hyperglycemia, indicating that GLUT2-dependent sensors control glucagon secretion. Here, we evaluated whether these sensors were located centrally and whether GLUT2 was expressed in glial cells or in neurons. We showed that ripglut1;glut2-/- mice failed to increase plasma glucagon levels following glucoprivation induced either by i.p. or intracerebroventricular 2-deoxy-D-glucose injections. This was accompanied by failure of 2-deoxy-D-glucose injections to activate c-Fos-like immunoreactivity in the nucleus of the tractus solitarius and the dorsal motor nucleus of the vagus. When glut2 was expressed by transgenesis in glial cells but not in neurons of ripglut1;glut2-/- mice, stimulated glucagon secretion was restored as was c-Fos-like immunoreactive labeling in the brainstem. When ripglut1;glut2-/- mice were backcrossed into the C57BL/6 genetic background, fed plasma glucagon levels were also elevated due to abnormal autonomic input to the alpha cells; glucagon secretion was, however, stimulated by hypoglycemic stimuli to levels similar to those in control mice. These studies identify the existence of central glucose sensors requiring glut2 expression in glial cells and therefore functional coupling between glial cells and neurons. These sensors may be activated at different glycemic levels depending on the genetic background.
Mots-clé
Animals, Astrocytes, Blood Glucose, Blotting, Northern, Blotting, Southern, Blotting, Western, DNA, Complementary, Deoxyglucose, Gene Expression Regulation, Glucagon, Glucagon-Secreting Cells, Glucose, Glucose Transporter Type 2, Hypoglycemia, Immunohistochemistry, Insulin, Mice, Mice, Inbred C57BL, Mice, Transgenic, Models, Biological, Models, Genetic, Neuroglia, Neurons, Proto-Oncogene Proteins c-fos, Time Factors, Transgenes
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 14:41
Dernière modification de la notice
08/05/2019 21:36
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