Noone 2023 J Physiol
| Noone J, Damiot A, Kenny H, Chery I, Zahariev A, Normand S, Crampes F, de Glisezinski I, Rochfort KD, Laurens C, Bareille MP, Simon C, Bergouignan A, Blanc S, O'Gorman DJ (2023) The impact of 60 days of -6° head down tilt bed rest on mitochondrial content, respiration and regulators of mitochondrial dynamics. https://doi.org/10.1113/jp284734 |
» J Physiol [Epub ahead of print]. PMID: 38050414 Open Access
Noone John, Damiot Anthony, Kenny Helena, Chery Isabelle, Zahariev Alexandre, Normand Sylvie, Crampes Francois, de Glisezinski Isabelle, Rochfort Keith D, Laurens Claire, Bareille Marie-Pierre, Simon Chantal, Bergouignan Audrey, Blanc Stephane, O'Gorman Donal J (2023) J Physiol
Abstract: It is unclear how skeletal muscle metabolism and mitochondrial function adapt to long duration bed rest and whether changes can be prevented by nutritional intervention. The present study aimed (1) to assess the effect of prolonged bed rest on skeletal muscle mitochondrial function and dynamics and (2) to determine whether micronutrient supplementation would mitigate the adverse metabolic effect of bed rest. Participants were maintained in energy balance throughout 60 days of bed rest with micronutrient supplementation (INT) (body mass index: 23.747 ± 1.877 kg m-2 ; 34.80 ± 7.451 years; n = 10) or without (control) (body mass index: 24.087 ± 2.088 kg m-2 ; 33.50 ± 8.541 years; n = 10). Indirect calorimetry and dual-energy x-ray absorptiometry were used for measures of energy expenditure, exercise capacity and body composition. Mitochondrial respiration was determined by high-resolution respirometry in permeabilized muscle fibre bundles from vastus lateralis biopsies. Protein and mRNA analysis further examined the metabolic changes relating to regulators of mitochondrial dynamics induced by bed rest. INT was not sufficient in preserving whole body metabolic changes conducive of a decrease in body mass, fat-free mass and exercise capacity within both groups. Mitochondrial respiration, OPA1 and Drp1 protein expression decreased with bed rest, with an increase pDrp1s616 . This reduction in mitochondrial respiration was explained through an observed decrease in mitochondrial content (mtDNA:nDNA). Changes in regulators of mitochondrial dynamics indicate an increase in mitochondrial fission driven by a decrease in inner mitochondrial membrane fusion (OPA1) and increased pDrp1s616 . • Keywords: OPA1, Bed rest, Energy expenditure, Metabolism, Mitochondrial dynamics, Mitochondrial function, Skeletal muscle • Bioblast editor: Plangger M
Labels: MiParea: Respiration
HRR: Oxygraph-2k
2023-12
