Mitochondrial Superoxide Production Decreases on Glucose-Stimulated Insulin Secretion in Pancreatic beta Cells Due to Decreasing Mitochondrial Matrix NADH/NAD(+) Ratio

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F20%3A00532352" target="_blank" >RIV/61388971:_____/20:00532352 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/67985823:_____/20:00532352

Výsledek na webu

<a href="https://www.liebertpub.com/doi/10.1089/ars.2019.7800" target="_blank" >https://www.liebertpub.com/doi/10.1089/ars.2019.7800</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1089/ars.2019.7800" target="_blank" >10.1089/ars.2019.7800</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mitochondrial Superoxide Production Decreases on Glucose-Stimulated Insulin Secretion in Pancreatic beta Cells Due to Decreasing Mitochondrial Matrix NADH/NAD(+) Ratio

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

Mitochondrial Superoxide Production Decreases on Glucose-Stimulated Insulin Secretion in Pancreatic beta Cells Due to Decreasing Mitochondrial Matrix NADH/NAD(+) Ratio

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10406 - Analytical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Antioxidants & Redox Signaling

ISSN

1523-0864

e-ISSN

—

Svazek periodika

33

Číslo periodika v rámci svazku

12

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

27

Strana od-do

789-815

Kód UT WoS článku

000547812000001

EID výsledku v databázi Scopus

2-s2.0-85091125811