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Predominant role of active versus facilitative glucose transport for glucagon-like peptide-1 secretion
Zitieren Sie bitte immer diese URN: urn:nbn:de:bvb:20-opus-125927
- Aims/hypothesis Several glucose-sensing pathways have been implicated in glucose-triggered secretion of glucagon-like peptide-1 (GLP-1) from intestinal L cells. One involves glucose metabolism and closure of ATP-sensitive K\(^+\) channels, and another exploits the electrogenic nature of Na\(^+\)-coupled glucose transporters (SGLTs). This study aimed to elucidate the role of these distinct mechanisms in glucose-stimulated GLP-1 secretion. Methods Glucose uptake into L cells (either GLUTag cells or cells in primary cultures, using a newAims/hypothesis Several glucose-sensing pathways have been implicated in glucose-triggered secretion of glucagon-like peptide-1 (GLP-1) from intestinal L cells. One involves glucose metabolism and closure of ATP-sensitive K\(^+\) channels, and another exploits the electrogenic nature of Na\(^+\)-coupled glucose transporters (SGLTs). This study aimed to elucidate the role of these distinct mechanisms in glucose-stimulated GLP-1 secretion. Methods Glucose uptake into L cells (either GLUTag cells or cells in primary cultures, using a new transgenic mouse model combining proglucagon promoter-driven Cre recombinase with a ROSA26tdRFP reporter) was monitored with the FLII\(_{12}\)Pglu-700μδ6 glucose sensor. Effects of pharmacological and genetic interference with SGLT1 or facilitative glucose transport (GLUT) on intracellular glucose accumulation and metabolism (measured by NAD(P)H autofluorescence), cytosolic Ca\(^{2+}\) (monitored with Fura2) and GLP-1 secretion (assayed by ELISA) were assessed. Results L cell glucose uptake was dominated by GLUT-mediated transport, being abolished by phloretin but not phloridzin. NAD(P)H autofluorescence was glucose dependent and enhanced by a glucokinase activator. In GLUTag cells, but not primary L cells, phloretin partially impaired glucose-dependent secretion, and suppressed an amplifying effect of glucose under depolarising high K\(^+\) conditions. The key importance of SGLT1 in GLUTag and primary cells was evident from the impairment of secretion by phloridzin or Sglt1 knockdown and failure of glucose to trigger cytosolic Ca\(^{2+}\) elevation in primary L cells from Sglt1 knockout mice. Conclusions/interpretation SGLT1 acts as the luminal glucose sensor in L cells, but intracellular glucose concentrations are largely determined by GLUT activity. Although L cell glucose metabolism depends partially on glucokinase activity, this plays only a minor role in glucose-stimulated GLP-1 secretion.…
Autor(en): | H. E. Parker, A. Adriaenssens, G. Rogers, P. Richards, H. Koepsell, F. Reimann, F. M. Gribble |
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URN: | urn:nbn:de:bvb:20-opus-125927 |
Dokumentart: | Artikel / Aufsatz in einer Zeitschrift |
Institute der Universität: | Medizinische Fakultät / Institut für Anatomie und Zellbiologie |
Sprache der Veröffentlichung: | Englisch |
Titel des übergeordneten Werkes / der Zeitschrift (Englisch): | Diabetologia |
Erscheinungsjahr: | 2012 |
Band / Jahrgang: | 55 |
Heft / Ausgabe: | 9 |
Seitenangabe: | 2445-2455 |
Originalveröffentlichung / Quelle: | Diabetologia (2012) 55:2445–2455. DOI 10.1007/s00125-012-2585-2 |
DOI: | https://doi.org/10.1007/s00125-012-2585-2 |
Allgemeine fachliche Zuordnung (DDC-Klassifikation): | 6 Technik, Medizin, angewandte Wissenschaften / 61 Medizin und Gesundheit / 610 Medizin und Gesundheit |
Freie Schlagwort(e): | KATP channel; L cells; SGLT1; glucagon-like peptide-1 (GLP-1); glucokinase |
Datum der Freischaltung: | 12.07.2016 |
Lizenz (Deutsch): | CC BY: Creative-Commons-Lizenz: Namensnennung |