Friederich-Persson 2012 Diabetologia

Friederich-Persson M, Franzén S, Catrina SB, Dallner G, Hansell P, Brismar K, Palm F (2012) Coenzyme Q10 prevents GDP-sensitive mitochondrial uncoupling, glomerular hyperfiltration and proteinuria in kidneys from db/db mice as a model of type 2 diabetes. Diabetologia 55:1535-43.

» PMID: 22311417

Friederich-Persson M, Franzen S, Catrina SB, Dallner G, Hansell P, Brismar K, Palm F (2012) Diabetologia

Abstract: AIMS/HYPOTHESIS: Increased oxygen consumption results in kidney tissue hypoxia, which is proposed to contribute to the development of diabetic nephropathy. Oxidative stress causes increased oxygen consumption in type 1 diabetic kidneys, partly mediated by uncoupling protein-2 (UCP-2)-induced mitochondrial uncoupling. The present study investigates the role of UCP-2 and oxidative stress in mitochondrial oxygen consumption and kidney function in db/db mice as a model of type 2 diabetes.

METHODS: Mitochondrial oxygen consumption, glomerular filtration rate and proteinuria were investigated in db/db mice and corresponding controls with and without coenzyme Q10 (CoQ10) treatment.

RESULTS: Untreated db/db mice displayed mitochondrial uncoupling, manifested as glutamate-stimulated oxygen consumption (2.7 ± 0.1 vs 0.2 ± 0.1 pmol O(2) s(-1) [mg protein](-1)), glomerular hyperfiltration (502 ± 26 vs 385 ± 3 μl/min), increased proteinuria (21 ± 2 vs 14 ± 1, μg/24 h), mitochondrial fragmentation (fragmentation score 2.4 ± 0.3 vs 0.7 ± 0.1) and size (1.6 ± 0.1 vs 1 ± 0.0 μm) compared with untreated controls. All alterations were prevented or reduced by CoQ10 treatment. Mitochondrial uncoupling was partly inhibited by the UCP inhibitor GDP (-1.1 ± 0.1 pmol O(2) s(-1) [mg protein](-1)). UCP-2 protein levels were similar in untreated control and db/db mice (67 ± 9 vs 67 ± 4 optical density; OD) but were reduced in CoQ10 treated groups (43 ± 2 and 38 ± 7 OD).

CONCLUSIONS/INTERPRETATION: db/db mice displayed oxidative stress-mediated activation of UCP-2, which resulted in mitochondrial uncoupling and increased oxygen consumption. CoQ10 prevented altered mitochondrial function and morphology, glomerular hyperfiltration and proteinuria in db/db mice, highlighting the role of mitochondria in the pathogenesis of diabetic nephropathy and the benefits of preventing increased oxidative stress. • Keywords: db/db mice, Kidney, Mitochondria, Type2 diabetes, Uncoupling protein-2

• O2k-Network Lab: SE Uppsala Liss P

Labels: MiParea: Respiration, Genetic knockout;overexpression  Pathology: Diabetes  Stress:Ischemia-reperfusion, Oxidative stress;RONS  Organism: Mouse  Tissue;cell: Kidney  Preparation: Isolated mitochondria 

Coupling state: LEAK, OXPHOS  Pathway: N, ROX  HRR: Oxygraph-2k 

Mitochondrial respiration medium for kidney

The intracellular milieu of kidney has a low [K⁺]. Kidney mitochondria are inhibited by the high [K⁺] of MiR06.

>> MiPMap - Is this a general issue for the organ, or is it in addition also a species issue?