Novel insights into pancreatic β-cell glucolipotoxicity from real-time functional analysis of mitochondrial energy metabolism in INS-1E insulinoma cells

被引:42
作者
Barlow, Jonathan [1 ]
Affourtit, Charles [1 ]
机构
[1] Univ Plymouth, Sch Biomed & Healthcare Sci, Plymouth PL4 8AA, Devon, England
基金
英国医学研究理事会;
关键词
glucose-stimulated insulin secretion; mitochondrial dysfunction; oxidative phosphorylation; pancreatic beta-cell glucolipotoxicity; reactive oxygen species; Type; 2; diabetes; UNCOUPLING PROTEIN-2; FATTY-ACIDS; PROTON LEAK; IN-VIVO; DYSFUNCTION; OBESITY; SECRETION; MECHANISMS; FAILURE; LIPOTOXICITY;
D O I
10.1042/BJ20131002
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
High circulating glucose and non-esterified (free) fatty acid levels can cause pancreatic beta-cell failure. The molecular mechanisms of this beta-cell glucolipotoxicity are yet to be established conclusively. In the present paper we report on the involvement of mitochondrial dysfunction in fatty-acid-induced beta-cell failure. We have used state-of-the-art extracellular flux technology to functionally probe mitochondrial energy metabolism in intact INS-1E insulinoma cells in real-time. We show that 24-h palmitate exposure at high glucose attenuates the glucose-sensitivity of mitochondrial respiration and lowers coupling efficiency of glucose-stimulated oxidative phosphorylation. These mitochondrial defects coincide with an increased level of ROS (reactive oxygen species), impaired GSIS (glucose-stimulated insulin secretion) and decreased cell viability. Palmitate lowers absolute glucose-stimulated respiration coupled to ATP synthesis, but does not affect mitochondrial proton leak. Palmitate is not toxic when administered at low glucose unless fatty acid beta-oxidation is inhibited. Palmitoleate, on the other hand, does not affect mitochondrial respiration, ROS levels, GSIS or cell viability. Although palmitoleate protects against the palmitate-induced ROS increase and cell viability loss, it does not protect against respiratory and insulin secretory defects. We conclude that mitochondrial dysfunction contributes to fatty-acid-induced GSIS impairment, and that glucolipotoxic cell viability and GSIS phenotypes are mechanistically distinct.
引用
收藏
页码:417 / 426
页数:10
相关论文
共 50 条
[1]   Stronger control of ATP/ADP by proton leak in pancreatic β-cells than skeletal muscle mitochondria [J].
Affourtit, C ;
Brand, MD .
BIOCHEMICAL JOURNAL, 2006, 393 :151-159
[2]   Uncoupling protein-2 contributes significantly to high mitochondrial proton leak in INS-1E insulinoma cells and attenuates glucose-stimulated insulin secretion [J].
Affourtit, Charles ;
Brand, Martin D. .
BIOCHEMICAL JOURNAL, 2008, 409 (01) :199-204
[3]   Uncoupling protein-2 attenuates glucose-stimulated insulin, secretion in INS-1E insulinoma cells by lowering mitochondrial reactive oxygen species [J].
Affourtit, Charles ;
Jastroch, Martin ;
Brand, Martin D. .
FREE RADICAL BIOLOGY AND MEDICINE, 2011, 50 (05) :609-616
[4]   MEASURING MITOCHONDRIAL BIOENERGETICS IN INS-1E INSULINOMA CELLS [J].
Affourtit, Charles ;
Brand, Martin D. .
METHODS IN ENZYMOLOGY, VOL 457: MITOCHONDRIAL FUNCTION, PARTB MITOCHONDRIAL PROTEIN KINASES, PROTEIN PHOSPHATASES AND MITOCHONDRIAL DISEASES, 2009, 457 :405-424
[5]   Role of inflammatory mechanisms in pathogenesis of type 2 diabetes mellitus [J].
Akash, Muhammad Sajid Hamid ;
Rehman, Kanwal ;
Chen, Shuqing .
JOURNAL OF CELLULAR BIOCHEMISTRY, 2013, 114 (03) :525-531
[6]  
Barlow J., 2013, RES DIABETES
[7]   Measuring Mitochondrial Uncoupling Protein-2 Level and Activity in Insulinoma Cells [J].
Barlow, Jonathan ;
Hirschberg, Verena ;
Brand, Martin D. ;
Affourtit, Charles .
HYDROGEN PEROXIDE AND CELL SIGNALING, PT C, 2013, 528 :257-267
[8]   Assessing mitochondrial dysfunction in cells [J].
Brand, Martin D. ;
Nicholls, David G. .
BIOCHEMICAL JOURNAL, 2011, 435 :297-312
[9]   Endoplasmic reticulum stress, obesity and diabetes [J].
Cnop, Miriam ;
Foufelle, Fabienne ;
Velloso, Licio A. .
TRENDS IN MOLECULAR MEDICINE, 2012, 18 (01) :59-68
[10]   Mechanisms involved in the cytotoxic and cytoprotective actions of saturated versus monounsaturated long-chain fatty acids in pancreatic β-cells [J].
Diakogiannaki, Eleftheria ;
Dhayal, Shalinee ;
Childs, Caroline E. ;
Calder, Philip C. ;
Welters, Hannah J. ;
Morgan, Noel G. .
JOURNAL OF ENDOCRINOLOGY, 2007, 194 (02) :283-291