Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
Chronic high Glucose and Pyruvate Levels differentially affect Mitochondrial Bioenergetics and Fuel-stimulated insulin secretion from Clonal INS-1 832/13 Cells. / Göhring, Isabel; Sharoyko, Vladimir V.; Malmgren, Siri; Andersson, Lotta E.; Spégel, Peter; Nicholls, David G.; Mulder, Hindrik.
в: Journal of Biological Chemistry, Том 289, № 6, 07.02.2014, стр. 3786-3798.Результаты исследований: Научные публикации в периодических изданиях › статья › Рецензирование
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TY - JOUR
T1 - Chronic high Glucose and Pyruvate Levels differentially affect Mitochondrial Bioenergetics and Fuel-stimulated insulin secretion from Clonal INS-1 832/13 Cells
AU - Göhring, Isabel
AU - Sharoyko, Vladimir V.
AU - Malmgren, Siri
AU - Andersson, Lotta E.
AU - Spégel, Peter
AU - Nicholls, David G.
AU - Mulder, Hindrik
PY - 2014/2/7
Y1 - 2014/2/7
N2 - Background: Elevated glucose may cause β-cell dysfunction in type 2 diabetes, i.e., glucotoxicity. Results: Elevated glucose, but not pyruvate, perturbed insulin secretion and content, plasma and mitochondrial membrane potentials, and proton leak, while increasing glycolytic metabolites in β-cells. Conclusion: Early metabolism of glucose exerts a toxic effect on clonal insulin-producing cells. Significance: Unraveling these mechanisms may provide protection of β-cells in diabetes. Glucotoxicity in pancreaticβ-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 machinery. 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 13.9 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 concentrations, 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 stimulussecretion coupling by extramitochondrial metabolism upstream of pyruvate, rather than exhaustion from metabolic overload, underlie glucotoxicity in insulin-producing cells.
AB - Background: Elevated glucose may cause β-cell dysfunction in type 2 diabetes, i.e., glucotoxicity. Results: Elevated glucose, but not pyruvate, perturbed insulin secretion and content, plasma and mitochondrial membrane potentials, and proton leak, while increasing glycolytic metabolites in β-cells. Conclusion: Early metabolism of glucose exerts a toxic effect on clonal insulin-producing cells. Significance: Unraveling these mechanisms may provide protection of β-cells in diabetes. Glucotoxicity in pancreaticβ-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 machinery. 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 13.9 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 concentrations, 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 stimulussecretion coupling by extramitochondrial metabolism upstream of pyruvate, rather than exhaustion from metabolic overload, underlie glucotoxicity in insulin-producing cells.
KW - Beta Cell
KW - Bioenergetics
KW - Insulin Secretion
KW - Metabolomics
KW - Mitochondrial Metabolism
KW - Uncoupling Proteins
UR - http://www.scopus.com/inward/record.url?scp=84893653671&partnerID=8YFLogxK
U2 - 10.1074/jbc.M113.507335
DO - 10.1074/jbc.M113.507335
M3 - Article
C2 - 24356960
VL - 289
SP - 3786
EP - 3798
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 6
ER -
ID: 5716033