Please use this identifier to cite or link to this item:
Title: Synaptotagmin-7 as a positive regulator of glucose-induced glucagon-like peptide-1 secretion in mice
Authors: Gustavsson, N.
Wang, Y. 
Kang, Y.
Seah, T.
Chua, S.
Radda, G.K.
Han, W.
Keywords: Calcium sensor
Knockout mice
Issue Date: Jul-2011
Citation: Gustavsson, N., Wang, Y., Kang, Y., Seah, T., Chua, S., Radda, G.K., Han, W. (2011-07). Synaptotagmin-7 as a positive regulator of glucose-induced glucagon-like peptide-1 secretion in mice. Diabetologia 54 (7) : 1824-1830. ScholarBank@NUS Repository.
Abstract: Aims/hypothesis: Glucagon-like peptide-1 (GLP-1), a hormone with potent antihyperglycaemic effects, is produced and secreted from highly specialised gut endocrine L-cells. It regulates glucose homeostasis by promoting glucose-dependent insulin secretion, suppressing glucagon secretion and enhancing insulin sensitivity. Similar to islet alpha and beta cells, L-cells are electrically excitable, and express calcium channels and ATP-sensitive potassium channels. GLP-1 is also stored in secretory granules, the exocytosis of which is triggered by increased intracellular calcium levels. Although the calcium dependence of GLP-1 granule exocytosis is well established, the identities of calcium-sensing proteins in GLP-1 secretion remain elusive. Here we tested whether synaptotagmin-7, a calcium sensor in pancreatic alpha and beta cells, regulates GLP-1 secretion. Methods: We studied GLP-1 secretion using synaptotagmin-7 knockout (KO) mice and GLUTag cells with lentiviral-mediated synaptotagmin-7 silencing. Results: We found that synaptotagmin-7 was co-localised with GLP-1 in intestinal L-cells. GLP-1 secretion was impaired in synaptotagmin-7 KO mice when they were challenged by glucose ingestion. Lentiviral knockdown (KD) of synaptotagmin-7 in GLUTag cells led to similar reductions in GLP-1 secretion, as determined by biochemical assays and by membrane capacitance measurements. Calcium response was not altered in synaptotagmin-7 KD cells. Conclusions/interpretation: These results demonstrate that synaptotagmin-7 functions as a positive regulator of GLP-1 secretion in intestinal L-cells and GLUTag cells, consistent with its proposed role as a calcium sensor in GLP-1 secretion. © 2011 Springer-Verlag.
Source Title: Diabetologia
ISSN: 0012186X
DOI: 10.1007/s00125-011-2119-3
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.


checked on Apr 21, 2021


checked on Apr 21, 2021

Page view(s)

checked on Apr 11, 2021

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.