TY - JOUR

T1 - Time-resolved metabolomics analysis of β-cells implicates the pentose phosphate pathway in the control of insulin release

AU - Spégel, Peter

AU - Sharoyko, Vladimir V.

AU - Goehring, Isabel

AU - Danielsson, Anders P.H.

AU - Malmgren, Siri

AU - Nagorny, Cecilia L.F.

AU - Andersson, Lotta E.

AU - Koeck, Thomas

AU - Sharp, Geoffrey W.G.

AU - Straub, Susanne G.

AU - Wollheim, Claes B.

AU - Mulder, Hindrik

PY - 2013/3/15

Y1 - 2013/3/15

N2 - Insulin secretion is coupled with changes in β-cell metabolism. To define this process, 195 putative metabolites, mitochondrial respiration, NADP+, NADPH and insulin secretion were measured within 15 min of stimulation of clonal INS-1 832/13 β-cells with glucose. Rapid responses in the major metabolic pathways of glucose occurred, involving several previously suggested metabolic coupling factors. The complexity of metabolite changes observed disagreed with the concept of one single metabolite controlling insulin secretion. The complex alterations in metabolite levels suggest that a coupling signal should reflect large parts of the β-cell metabolic response. This was fulfilled by the NADPH/NADP+ ratio, which was elevated (8-fold; P<0.01) at 6 min after glucose stimulation. The NADPH/NADP+ ratio paralleled an increase in ribose 5-phosphate (>2.5-fold; P<0.001). Inhibition of the pentose phosphate pathway by trans-dehydroepiandrosterone (DHEA) suppressed ribose 5-phosphate levels and production of reduced glutathione, as well as insulin secretion in INS-1 832/13 β-cells and rat islets without affecting ATP production. Metabolite profiling of rat islets confirmed the glucose-induced rise in ribose 5-phosphate, which was prevented by DHEA. These findings implicate the pentose phosphate pathway, and support a role for NADPH and glutathione, in β-cell stimulus-secretion coupling.

AB - Insulin secretion is coupled with changes in β-cell metabolism. To define this process, 195 putative metabolites, mitochondrial respiration, NADP+, NADPH and insulin secretion were measured within 15 min of stimulation of clonal INS-1 832/13 β-cells with glucose. Rapid responses in the major metabolic pathways of glucose occurred, involving several previously suggested metabolic coupling factors. The complexity of metabolite changes observed disagreed with the concept of one single metabolite controlling insulin secretion. The complex alterations in metabolite levels suggest that a coupling signal should reflect large parts of the β-cell metabolic response. This was fulfilled by the NADPH/NADP+ ratio, which was elevated (8-fold; P<0.01) at 6 min after glucose stimulation. The NADPH/NADP+ ratio paralleled an increase in ribose 5-phosphate (>2.5-fold; P<0.001). Inhibition of the pentose phosphate pathway by trans-dehydroepiandrosterone (DHEA) suppressed ribose 5-phosphate levels and production of reduced glutathione, as well as insulin secretion in INS-1 832/13 β-cells and rat islets without affecting ATP production. Metabolite profiling of rat islets confirmed the glucose-induced rise in ribose 5-phosphate, which was prevented by DHEA. These findings implicate the pentose phosphate pathway, and support a role for NADPH and glutathione, in β-cell stimulus-secretion coupling.

KW - Glutathione

KW - Islets

KW - Mass spectrometry

KW - NADPH

KW - Ribose 5-phosphate

KW - Type 2 diabetes

UR - http://www.scopus.com/inward/record.url?scp=84874587805&partnerID=8YFLogxK

U2 - 10.1042/BJ20121349

DO - 10.1042/BJ20121349

M3 - Article

C2 - 23282133

VL - 450

SP - 595

EP - 605

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 3

ER -