Salmon 2023 Geroscience
SalmΓ³n P, Millet C, Selman C, Monaghan P, Dawson NJ (2023) Tissue-specific reductions in mitochondrial efficiency and increased ROS release rates during ageing in zebra finches, Taeniopygia guttata. https://doi.org/10.1007/s11357-022-00624-1 |
Β» Geroscience 45:265-76. PMID: 35986126 Open Access
Salmon Pablo, Millet Caroline, Selman Colin, Monaghan Pat, Dawson Neal J (2023) Geroscience
Abstract: Mitochondrial dysfunction and oxidative damage have long been suggested as critically important mechanisms underlying the ageing process in animals. However, conflicting data exist on whether this involves increased production of mitochondrial reactive oxygen species (ROS) during ageing. We employed high-resolution respirometry and fluorometry on flight muscle (pectoralis major) and liver mitochondria to simultaneously examine mitochondrial function and ROS (H2O2) release rates in young (3 months) and old (4 years) zebra finches (Taeniopygia guttata). Respiratory capacities for oxidative phosphorylation did not differ between the two age groups in either tissue. Respiratory control ratios (RCR) of liver mitochondria also did not differ between the age classes. However, RCR in muscle mitochondria was 55% lower in old relative to young birds, suggesting that muscle mitochondria in older individuals are less efficient. Interestingly, this observed reduction in muscle RCR was driven almost entirely by higher mitochondrial LEAK-state respiration. Maximum mitochondrial ROS release rates were found to be greater in both flight muscle (1.3-fold) and the liver (1.9-fold) of old birds. However, while maximum ROS (H2O2) release rates from mitochondria increased with age across both liver and muscle tissues, the liver demonstrated a proportionally greater age-related increase in ROS release than muscle. This difference in age-related increases in ROS release rates between muscle and liver tissues may be due to increased mitochondrial leakiness in the muscle, but not the liver, of older birds. This suggests that age-related changes in cellular function seem to occur in a tissue-specific manner in zebra finches, with flight muscle exhibiting signs of minimising age-related increase in ROS release, potentially to reduce damage to this crucial tissue in older individuals. β’ Keywords: Ageing, Birds, Mitochondrial physiology, Proton leak, Reactive oxygen species, Senescence β’ Bioblast editor: Plangger M β’ O2k-Network Lab: DE Wilhelmshaven Salmon P, UK Glasgow Metcalfe NB
Labels: MiParea: Respiration
Pathology: Aging;senescence
Stress:Oxidative stress;RONS
Organism: Birds
Tissue;cell: Skeletal muscle, Liver
Preparation: Homogenate
Coupling state: LEAK, OXPHOS
Pathway: N, CIV, NS, ROX
HRR: Oxygraph-2k, O2k-Fluorometer
2023-04, AmR