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Mitochondrial Superoxide Production Decreases on Glucose-Stimulated Insulin Secretion in Pancreatic beta Cells Due to Decreasing Mitochondrial Matrix NADH/NAD(+) Ratio
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SYSNO ASEP 0532352 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Mitochondrial Superoxide Production Decreases on Glucose-Stimulated Insulin Secretion in Pancreatic beta Cells Due to Decreasing Mitochondrial Matrix NADH/NAD(+) Ratio Author(s) Plecitá-Hlavatá, Lydie (FGU-C) RID, ORCID
Engstová, Hana (FGU-C) RID, ORCID
Holendová, Blanka (FGU-C) RID, ORCID, SAI
Tauber, Jan (FGU-C) RID, ORCID
Špaček, Tomáš (FGU-C) RID, ORCID
Petrásková, Lucie (MBU-M) ORCID
Křen, Vladimír (MBU-M) RID, ORCID
Špačková, Jitka (FGU-C) RID, ORCID
Gotvaldová, Klára (FGU-C) RID, ORCID
Ježek, Jan (FGU-C) RID, ORCID
Dlasková, Andrea (FGU-C) RID, ORCID
Smolková, Katarína (FGU-C) RID, ORCID, SAI
Ježek, Petr (FGU-C) RID, ORCIDSource Title Antioxidants & Redox Signaling. - : Mary Ann Liebert - ISSN 1523-0864
Roč. 33, č. 12 (2020), s. 789-815Number of pages 27 s. Language eng - English Country US - United States Keywords mitochondrial superoxide generation ; pancreatic beta cells ; glucose-stimulated insulin secretion ; Complex I ; NADH/NAD(+) ratio ; fluorescence lifetime imaging Subject RIV FB - Endocrinology, Diabetology, Metabolism, Nutrition OECD category Endocrinology and metabolism (including diabetes, hormones) Subject RIV - cooperation Institute of Microbiology - Analytical Chemistry, Separation R&D Projects GA16-06700S GA ČR - Czech Science Foundation (CSF) GA17-01813S GA ČR - Czech Science Foundation (CSF) GA20-00408S GA ČR - Czech Science Foundation (CSF) Method of publishing Open access Institutional support FGU-C - RVO:67985823 ; MBU-M - RVO:61388971 UT WOS 000547812000001 EID SCOPUS 85091125811 DOI 10.1089/ars.2019.7800 Annotation Aims:Glucose-stimulated insulin secretion (GSIS) in pancreatic beta cells was expected to enhance mitochondrial superoxide formation. Hence, we elucidated relevant redox equilibria. Results:Unexpectedly, INS-1E cells at transitions from 3 (11 mM, pancreatic islets from 5 mM) to 25 mM glucose decreased matrix superoxide release rates (MitoSOX Red monitoring validated by MitoB) and H2O2(mitoHyPer, subtracting mitoSypHer emission). Novel double-channel fluorescence lifetime imaging, approximating free mitochondrial matrix NADH(F,)indicated its similar to 20% decrease. Matrix NAD(F)(+)increased on GSIS, indicated by the FAD-emission lifetime decrease, reflecting higher quenching of FAD by NAD(F)(+). The participation of pyruvate/malate and pyruvate/citrate redox shuttles, elevating cytosolic NADPH(F)(iNAP1 fluorescence monitoring) at the expense of matrix NADH(F), was indicated, using citrate (2-oxoglutarate) carrier inhibitors and cytosolic malic enzyme silencing: All changes vanished on these manipulations.C-13-incorporation from C-13-L-glutamine into C-13-citrate reflected the pyruvate/isocitrate shuttle. Matrix NADPH(F)(iNAP3 monitored) decreased. With decreasing glucose, the suppressor of Complex III site Q electron leak (S3QEL) suppressor caused a higher Complex I I(F)site contribution, but a lower superoxide fraction ascribed to the Complex III site IIIQo. Thus, the diminished matrix NADH(F)/NAD(F)(+) decreased Complex I flavin site I(F)superoxide formation on GSIS. Innovation:Mutually validated methods showed decreasing superoxide release into the mitochondrial matrix in pancreatic beta cells on GSIS, due to the decreasing matrix NADH(F)/NAD(F)(+) (NADPH(F)/NADP(F)(+)) at increasing cytosolic NADPH(F) levels. The developed innovative methods enable real-time NADH/NAD(+)and NADPH/NADP(+) monitoring in any distinct cell compartment. Conclusion:The export of reducing equivalents from mitochondria adjusts lower mitochondrial superoxide production on GSIS, but it does not prevent oxidative stress in pancreatic beta cells. Workplace Institute of Physiology Contact Lucie Trajhanová, lucie.trajhanova@fgu.cas.cz, Tel.: 241 062 400 Year of Publishing 2021 Electronic address https://www.liebertpub.com/doi/10.1089/ars.2019.7800
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