Miotto 2019 FASEB J

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Miotto PM, McGlory C, Bahniwal R, Kamal M, Phillips SM, Holloway GP (2019) Supplementation with dietary ω-3 mitigates immobilization-induced reductions in skeletal muscle mitochondrial respiration in young women. FASEB J 33:8232-40.

» PMID: 30970218

Miotto PM, McGlory C, Bahniwal R, Kamal M, Phillips SM, Holloway GP (2019) FASEB J

Abstract: Omega-3 (ω-3) supplementation attenuates immobilization-induced atrophy; however, the underlying mechanisms remain unclear. Since mitochondrial dysfunction and oxidative stress have been implicated in muscle atrophy, we examined whether ω-3 supplementation could mitigate disuse-mediated mitochondrial dysfunction. Healthy young women (age = 22 ± 3 yr) randomly received control ( n = 9) or ω-3 supplementation ( n = 11; 3 g eicosapentaenoic acid, 2 g docosahexaenoic acid) for 4 wk prior to and throughout 2 wk of single-limb immobilization. Biopsies were performed before and after 3 and 14 d of immobilization for the assessment of mitochondrial respiration, H2O2 emission, and markers of ADP transport/lipid metabolism. In controls, immobilization rapidly (3 d) reduced (∼20%) ADP-stimulated mitochondrial respiration without altering ADP sensitivity or the abundance of mitochondrial proteins. Extending immobilization to 14 d did not further reduce mitochondrial coupled respiration; however, unlike following 3 d, mitochondrial proteins were reduced ∼20%. In contrast, ω-3 supplementation prevented immobilization-induced reductions in mitochondrial content and respiration throughout the immobilization period. Regardless of dietary supplement, immobilization did not alter mitochondrial H2O2 emission in the presence or absence of ADP, markers of cellular redox state, mitochondrial lipid-supported respiration, or lipid-related metabolic proteins. These data highlight the rapidity of mitochondrial adaptations in response to muscle disuse, challenge the necessity for increased oxidative stress during inactivity, and establish that ω-3 supplementation preserves oxidative phosphorylation function and content during immobilization.

Keywords: Metabolism, Mitochondrial function, Oxidative stress, Buffer Z, Blebbistatin, Amplex Red in muscle fibers Bioblast editor: Plangger M O2k-Network Lab: CA Guelph Holloway GP


Labels: MiParea: Respiration, Exercise physiology;nutrition;life style 


Organism: Human  Tissue;cell: Skeletal muscle  Preparation: Permeabilized tissue  Enzyme: Complex I, Complex II;succinate dehydrogenase, Complex III, Complex V;ATP synthase  Regulation: ADP  Coupling state: LEAK, OXPHOS  Pathway: F, N, NS  HRR: Oxygraph-2k, O2k-Fluorometer 

2019-04, Amplex UltraRed