CaV1.2 rather than CaV1.3 is coupled to glucose-stimulated insulin secretion in INS-1 832/13 cells.
Dekker Nitert, Marloes LU ; Nagorny, Cecilia LU ; Wendt, Anna LU ; Eliasson, Lena LU
and Mulder, Hindrik
LU
(2008)
In Journal of Molecular Endocrinology
41(1).
p.1-11
- Abstract
- In clonal beta-cell lines and islets from different species, a variety of calcium channels are coupled to glucose-stimulated insulin secretion. The aim of this study was to identify the voltage-gated calcium channels that control insulin secretion in insulinoma (INS)-1 832/13 cells. The mRNA level of Ca(V)1.2 exceeded that of Ca(V)1.3 and Ca(V)2.3 two-fold. Insulin secretion, which rose tenfold in response to 16.7 mM glucose, was completely abolished by 5 microM isradipine that blocks Ca(V)1.2 and Ca(V)1.3. Similarly, the increase in intracellular calcium in response to 15 mM glucose was decreased in the presence of 5 microM isradipine, and the frequency of calcium spikes was decreased to the level seen at 2.8 mM glucose. By contrast,... (More)
- In clonal beta-cell lines and islets from different species, a variety of calcium channels are coupled to glucose-stimulated insulin secretion. The aim of this study was to identify the voltage-gated calcium channels that control insulin secretion in insulinoma (INS)-1 832/13 cells. The mRNA level of Ca(V)1.2 exceeded that of Ca(V)1.3 and Ca(V)2.3 two-fold. Insulin secretion, which rose tenfold in response to 16.7 mM glucose, was completely abolished by 5 microM isradipine that blocks Ca(V)1.2 and Ca(V)1.3. Similarly, the increase in intracellular calcium in response to 15 mM glucose was decreased in the presence of 5 microM isradipine, and the frequency of calcium spikes was decreased to the level seen at 2.8 mM glucose. By contrast, inhibition of Ca(V)2.3 with 100 nM SNX-482 did not significantly affect insulin secretion or intracellular calcium. Using RNA interference, Ca(V)1.2 mRNA and protein levels were knocked down by approximately 65% and approximately 34% respectively, which reduced insulin secretion in response to 16.7 mM glucose by 50%. Similar reductions in calcium currents and cell capacitance were seen in standard whole-cell patch-clamp experiments. The remaining secretion of insulin could be reduced to the basal level by 5 microM isradipine. Calcium influx underlying this residual insulin secretion could result from persisting Ca(V)1.2 expression in transfected cells since knock-down of Ca(V)1.3 did not affect glucose-stimulated insulin secretion. In summary, our results suggest that Ca(V)1.2 is critical for insulin secretion in INS-1 832/13 cells. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1168700
- author
- Dekker Nitert, Marloes
LU
; Nagorny, Cecilia
LU
; Wendt, Anna
LU
; Eliasson, Lena
LU
and Mulder, Hindrik
LU
- organization
- publishing date
- 2008
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Molecular Endocrinology
- volume
- 41
- issue
- 1
- pages
- 1 - 11
- publisher
- Society for Endocrinology
- external identifiers
-
- wos:000258750100001
- pmid:18562674
- scopus:48949100588
- pmid:18562674
- ISSN
- 1479-6813
- DOI
- 10.1677/JME-07-0133
- language
- English
- LU publication?
- yes
- id
- 33a70492-e487-4977-86b6-84e4ed25346e (old id 1168700)
- alternative location
- http://www.ncbi.nlm.nih.gov/pubmed/18562674?dopt=Abstract
- date added to LUP
- 2016-04-01 15:03:09
- date last changed
- 2022-02-05 00:11:13
@article{33a70492-e487-4977-86b6-84e4ed25346e,
abstract = {{In clonal beta-cell lines and islets from different species, a variety of calcium channels are coupled to glucose-stimulated insulin secretion. The aim of this study was to identify the voltage-gated calcium channels that control insulin secretion in insulinoma (INS)-1 832/13 cells. The mRNA level of Ca(V)1.2 exceeded that of Ca(V)1.3 and Ca(V)2.3 two-fold. Insulin secretion, which rose tenfold in response to 16.7 mM glucose, was completely abolished by 5 microM isradipine that blocks Ca(V)1.2 and Ca(V)1.3. Similarly, the increase in intracellular calcium in response to 15 mM glucose was decreased in the presence of 5 microM isradipine, and the frequency of calcium spikes was decreased to the level seen at 2.8 mM glucose. By contrast, inhibition of Ca(V)2.3 with 100 nM SNX-482 did not significantly affect insulin secretion or intracellular calcium. Using RNA interference, Ca(V)1.2 mRNA and protein levels were knocked down by approximately 65% and approximately 34% respectively, which reduced insulin secretion in response to 16.7 mM glucose by 50%. Similar reductions in calcium currents and cell capacitance were seen in standard whole-cell patch-clamp experiments. The remaining secretion of insulin could be reduced to the basal level by 5 microM isradipine. Calcium influx underlying this residual insulin secretion could result from persisting Ca(V)1.2 expression in transfected cells since knock-down of Ca(V)1.3 did not affect glucose-stimulated insulin secretion. In summary, our results suggest that Ca(V)1.2 is critical for insulin secretion in INS-1 832/13 cells.}},
author = {{Dekker Nitert, Marloes and Nagorny, Cecilia and Wendt, Anna and Eliasson, Lena and Mulder, Hindrik}},
issn = {{1479-6813}},
language = {{eng}},
number = {{1}},
pages = {{1--11}},
publisher = {{Society for Endocrinology}},
series = {{Journal of Molecular Endocrinology}},
title = {{CaV1.2 rather than CaV1.3 is coupled to glucose-stimulated insulin secretion in INS-1 832/13 cells.}},
url = {{http://dx.doi.org/10.1677/JME-07-0133}},
doi = {{10.1677/JME-07-0133}},
volume = {{41}},
year = {{2008}},
}