Scientific article
OA Policy
English

Mitochondrial carriers regulating insulin secretion profiled in human islets upon metabolic stress

Published inBiomolecules, vol. 10, no. 11, 1543
Publication date2020
Abstract

Chronic exposure of β-cells to nutrient-rich metabolic stress impairs mitochondrial metabolism and its coupling to insulin secretion. We exposed isolated human islets to different metabolic stresses for 3 days: 0.4 mM oleate or 0.4 mM palmitate at physiological 5.5 mM glucose (lipotoxicity), high 25 mM glucose (glucotoxicity), and high 25 mM glucose combined with 0.4 mM oleate and/or palmitate (glucolipotoxicity). Then, we profiled the mitochondrial carriers and associated genes with RNA-Seq. Diabetogenic conditions, and in particular glucotoxicity, increased expression of several mitochondrial solute carriers in human islets, such as the malate carrier DIC, the α-ketoglutarate-malate exchanger OGC, and the glutamate carrier GC1. Glucotoxicity also induced a general upregulation of the electron transport chain machinery, while palmitate largely counteracted this effect. Expression of different components of the TOM/TIM mitochondrial protein import system was increased by glucotoxicity, whereas glucolipotoxicity strongly upregulated its receptor subunit TOM70. Expression of the mitochondrial calcium uniporter MCU was essentially preserved by metabolic stresses. However, glucotoxicity altered expression of regulatory elements of calcium influx as well as the Na+/Ca2+ exchanger NCLX, which mediates calcium efflux. Overall, the expression profile of mitochondrial carriers and associated genes was modified by the different metabolic stresses exhibiting nutrient-specific signatures.

Funding
  • Swiss National Science Foundation - 166625
  • Autre - Hjelt Diabetes Foundation
Citation (ISO format)
JIMÉNEZ-SÁNCHEZ, Cecilia, BRUN, Thierry, MAECHLER, Pierre. Mitochondrial carriers regulating insulin secretion profiled in human islets upon metabolic stress. In: Biomolecules, 2020, vol. 10, n° 11, p. 1543. doi: 10.3390/biom10111543
Main files (1)
Article (Published version)
Secondary files (1)
Identifiers
Additional URL for this publicationhttps://www.mdpi.com/2218-273X/10/11/1543
Journal ISSN2218-273X
201views
68downloads

Technical informations

Creation27/11/2020 11:15:00
First validation27/11/2020 11:15:00
Update time15/03/2023 23:36:25
Status update15/03/2023 23:36:24
Last indexation31/10/2024 20:37:30
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack