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MiR-335 regulates exocytotic proteins and affects glucose-stimulated insulin secretion through decreased Ca2+-dependent exocytosis in beta cells

Salunkhe, V.A. LU ; Ofori, J. LU ; Gandasi, N.R.; Salö, S.A.; Wendt, A. LU ; Barg, S. LU ; Esguerra, J.L.S. LU and Eliasson, L. LU (2015) In Diabetologia 58(Suppl. 1). p.128-128
Abstract
Background and aims: Ca2+-induced exocytosis is essential for insulin to be secreted from beta-cells, and in islets from type-2 diabetic (T2D) donors the expression of several genes coding for exocytotic proteins is reduced. Largely this phenomenon cannot be explained by polymorphism; rather it is likely due to epigenetic factors like microRNAs (miRNAs). Indeed, previous studies have identified a number of miRNAs with differential expression in the islets from T2D donors and the Goto- Kakizaki (GK) rat. One of the upregulatedmiRNAs in the GK rat is miR- 335, predicted to target several exocytotic genes amongst those Stxbp1 is a validated target. Here we aim to investigate whether miR-335 regulates the expression of exocytotic genes and... (More)
Background and aims: Ca2+-induced exocytosis is essential for insulin to be secreted from beta-cells, and in islets from type-2 diabetic (T2D) donors the expression of several genes coding for exocytotic proteins is reduced. Largely this phenomenon cannot be explained by polymorphism; rather it is likely due to epigenetic factors like microRNAs (miRNAs). Indeed, previous studies have identified a number of miRNAs with differential expression in the islets from T2D donors and the Goto- Kakizaki (GK) rat. One of the upregulatedmiRNAs in the GK rat is miR- 335, predicted to target several exocytotic genes amongst those Stxbp1 is a validated target. Here we aim to investigate whether miR-335 regulates the expression of exocytotic genes and affects insulin secretion and exocytosis in beta-cells. Materials and methods: Insulin secretion was measured by radio immuno assay. Exocytosis and docking of insulin granules was studied by capacitance measurements using the patch-clamp technique and by TIRF microscopy. Rat miR-335 was overexpressed using chemicallymodified mature microRNA mimic in INS-1 832/13 beta-cells by transfection. Gene knockdown was performed with RNAi. Protein and mRNA levels were analysed with Western Blot and RT-qPCR, respectively. Results: Overexpression of miR-335 (OE335) in INS-1 832/13 cells reduced insulin secretion at 16.7 mM glucose compared to control cells (SCR) (n=3; p (Less)
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published
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keywords
glucose, protein, insulin, microRNA, synaptotagmin, nitrogen 15, messenger RNA, insulin release, exocytosis, European, diabetes mellitus, gene, microscopy, donor, membrane, Goto Kakizaki rat, rat, genetic transfection, patch clamp technique, immunoassay, gene silencing, pancreas islet beta cell, density, electric potential, Western blotting, adaptation, cell function, telecommunication
in
Diabetologia
volume
58
issue
Suppl. 1
pages
1 pages
publisher
Springer Verlag
ISSN
1432-0428
DOI
10.1007/s00125-015-3687-4
language
English
LU publication?
yes
id
df6afde0-72d7-41c4-9abc-de3eee1d8d19
date added to LUP
2016-08-30 00:20:28
date last changed
2016-12-13 10:48:21
@misc{df6afde0-72d7-41c4-9abc-de3eee1d8d19,
  abstract     = {Background and aims: Ca2+-induced exocytosis is essential for insulin to be secreted from beta-cells, and in islets from type-2 diabetic (T2D) donors the expression of several genes coding for exocytotic proteins is reduced. Largely this phenomenon cannot be explained by polymorphism; rather it is likely due to epigenetic factors like microRNAs (miRNAs). Indeed, previous studies have identified a number of miRNAs with differential expression in the islets from T2D donors and the Goto- Kakizaki (GK) rat. One of the upregulatedmiRNAs in the GK rat is miR- 335, predicted to target several exocytotic genes amongst those Stxbp1 is a validated target. Here we aim to investigate whether miR-335 regulates the expression of exocytotic genes and affects insulin secretion and exocytosis in beta-cells. Materials and methods: Insulin secretion was measured by radio immuno assay. Exocytosis and docking of insulin granules was studied by capacitance measurements using the patch-clamp technique and by TIRF microscopy. Rat miR-335 was overexpressed using chemicallymodified mature microRNA mimic in INS-1 832/13 beta-cells by transfection. Gene knockdown was performed with RNAi. Protein and mRNA levels were analysed with Western Blot and RT-qPCR, respectively. Results: Overexpression of miR-335 (OE335) in INS-1 832/13 cells reduced insulin secretion at 16.7 mM glucose compared to control cells (SCR) (n=3; p},
  author       = {Salunkhe, V.A. and Ofori, J. and Gandasi, N.R. and Salö, S.A. and Wendt, A. and Barg, S. and Esguerra, J.L.S. and Eliasson, L.},
  issn         = {1432-0428},
  keyword      = {glucose,protein,insulin,microRNA,synaptotagmin,nitrogen 15,messenger RNA,insulin release,exocytosis,European,diabetes mellitus,gene,microscopy,donor,membrane,Goto Kakizaki rat,rat,genetic transfection,patch clamp technique,immunoassay,gene silencing,pancreas islet beta cell,density,electric potential,Western blotting,adaptation,cell function,telecommunication},
  language     = {eng},
  month        = {09},
  note         = {Conference Abstract},
  number       = {Suppl. 1},
  pages        = {128--128},
  publisher    = {Springer Verlag},
  series       = {Diabetologia},
  title        = {MiR-335 regulates exocytotic proteins and affects glucose-stimulated insulin secretion through decreased Ca2+-dependent exocytosis in beta cells},
  url          = {http://dx.doi.org/10.1007/s00125-015-3687-4},
  volume       = {58},
  year         = {2015},
}