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Chronic high glucose and pyruvate levels differentially affect mitochondrial bioenergetics and fuel-stimulated insulin secretion from clonal INS-1 832/13 cells.

Göhring, Isabel LU ; Sharoyko, Vladimir LU ; Malmgren, Siri LU ; Andersson, Lotta LU ; Spégel, Peter LU ; Nicholls, David LU and Mulder, Hindrik LU (2014) In Journal of Biological Chemistry 289(6). p.3786-3798
Abstract
Glucotoxicity in pancreatic β-cells is a well-established pathogenetic process in Type 2 Diabetes. It has been suggested that metabolism-derived reactive oxygen species perturb the β-cell transcriptional machi-nery. Less is known about altered mitochondrial function in this condition. We used INS-1 832/13 cells cultured for 48 h in 2.8 mM glucose (low-G), 16.7 mM glucose (high-G) or 2.8 mM glucose plus 13.7 mM pyruvate (high-P) to identify metabolic perturbations. High-G cells showed decreased responsiveness, relative to low-G cells, with respect to mitochondrial membrane hyperpolarization, plasma membrane depolarization and insulin secretion, when stimulated acutely with 16.7 mM glucose or 10 mM pyruvate. In contrast, high-P cells were... (More)
Glucotoxicity in pancreatic β-cells is a well-established pathogenetic process in Type 2 Diabetes. It has been suggested that metabolism-derived reactive oxygen species perturb the β-cell transcriptional machi-nery. Less is known about altered mitochondrial function in this condition. We used INS-1 832/13 cells cultured for 48 h in 2.8 mM glucose (low-G), 16.7 mM glucose (high-G) or 2.8 mM glucose plus 13.7 mM pyruvate (high-P) to identify metabolic perturbations. High-G cells showed decreased responsiveness, relative to low-G cells, with respect to mitochondrial membrane hyperpolarization, plasma membrane depolarization and insulin secretion, when stimulated acutely with 16.7 mM glucose or 10 mM pyruvate. In contrast, high-P cells were functionally unimpaired, eliminating chronic provision of saturating mitochondrial substrate as a cause of glucotoxicity. Although cellular insulin content was depleted in high-G cells, relative to low-G and high-P cells, cellular functions were largely recovered following a further 24 h culture in low-G medium. After 2 h at 2.8 mM glucose, high-G cells did not retain increased levels of glycolytic or TCA-cycle intermediates, but nevertheless displayed increased glycolysis, increased respiration and an increased mitochondrial proton leak relative to low-G and high-P cells. This notwithstanding, titration of low-G cells with low protonophore concen-trations, monitoring respiration and insulin secretion in parallel, showed that the perturbed insulin secretion of high-G cells could not be accounted for by increased proton leak. The present study supports the idea that glucose-induced disturbances of stimulus-secretion coupling by extra-mitochondrial metabolism upstream of pyruvate, rather than exhaustion from metabolic overload, underlie glucotoxicity in insulin-producing cells. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
289
issue
6
pages
3786 - 3798
publisher
ASBMB
external identifiers
  • pmid:24356960
  • wos:000331368700058
  • scopus:84893653671
ISSN
1083-351X
DOI
10.1074/jbc.M113.507335
language
English
LU publication?
yes
id
ee6199a2-8c13-412a-b34b-1fcf506483d9 (old id 4223453)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/24356960?dopt=Abstract
date added to LUP
2014-01-05 19:30:05
date last changed
2017-09-24 03:17:10
@article{ee6199a2-8c13-412a-b34b-1fcf506483d9,
  abstract     = {Glucotoxicity in pancreatic β-cells is a well-established pathogenetic process in Type 2 Diabetes. It has been suggested that metabolism-derived reactive oxygen species perturb the β-cell transcriptional machi-nery. Less is known about altered mitochondrial function in this condition. We used INS-1 832/13 cells cultured for 48 h in 2.8 mM glucose (low-G), 16.7 mM glucose (high-G) or 2.8 mM glucose plus 13.7 mM pyruvate (high-P) to identify metabolic perturbations. High-G cells showed decreased responsiveness, relative to low-G cells, with respect to mitochondrial membrane hyperpolarization, plasma membrane depolarization and insulin secretion, when stimulated acutely with 16.7 mM glucose or 10 mM pyruvate. In contrast, high-P cells were functionally unimpaired, eliminating chronic provision of saturating mitochondrial substrate as a cause of glucotoxicity. Although cellular insulin content was depleted in high-G cells, relative to low-G and high-P cells, cellular functions were largely recovered following a further 24 h culture in low-G medium. After 2 h at 2.8 mM glucose, high-G cells did not retain increased levels of glycolytic or TCA-cycle intermediates, but nevertheless displayed increased glycolysis, increased respiration and an increased mitochondrial proton leak relative to low-G and high-P cells. This notwithstanding, titration of low-G cells with low protonophore concen-trations, monitoring respiration and insulin secretion in parallel, showed that the perturbed insulin secretion of high-G cells could not be accounted for by increased proton leak. The present study supports the idea that glucose-induced disturbances of stimulus-secretion coupling by extra-mitochondrial metabolism upstream of pyruvate, rather than exhaustion from metabolic overload, underlie glucotoxicity in insulin-producing cells.},
  author       = {Göhring, Isabel and Sharoyko, Vladimir and Malmgren, Siri and Andersson, Lotta and Spégel, Peter and Nicholls, David and Mulder, Hindrik},
  issn         = {1083-351X},
  language     = {eng},
  number       = {6},
  pages        = {3786--3798},
  publisher    = {ASBMB},
  series       = {Journal of Biological Chemistry},
  title        = {Chronic high glucose and pyruvate levels differentially affect mitochondrial bioenergetics and fuel-stimulated insulin secretion from clonal INS-1 832/13 cells.},
  url          = {http://dx.doi.org/10.1074/jbc.M113.507335},
  volume       = {289},
  year         = {2014},
}