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Hayden CMT, Nagarajan R, Smith ZH, Gilmore S, Kent JA. Postcontraction [acetylcarnitine] reflects interindividual variation in skeletal muscle ATP production patterns in vivo. Am J Physiol Regul Integr Comp Physiol 2024; 326:R66-R78. [PMID: 37955131 DOI: 10.1152/ajpregu.00027.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 11/02/2023] [Accepted: 11/02/2023] [Indexed: 11/14/2023]
Abstract
In addition to its role in substrate selection (carbohydrate vs. fat) for oxidative metabolism in muscle, acetylcarnitine production may be an important modulator of the energetic pathway by which ATP is produced. A combination of noninvasive magnetic resonance spectroscopy measures of cytosolic acetylcarnitine and ATP production pathways was used to investigate the link between [acetylcarnitine] and energy production in vivo. Intracellular metabolites were measured in the vastus lateralis muscle of eight males (mean: 28.4 yr, range: 25-35) during 8 min of incremental, dynamic contractions (0.5 Hz, 2-min stages at 6%, 9%, 12%, and 15% maximal torque) that increased [acetylcarnitine] approximately fivefold from resting levels. ATP production via oxidative phosphorylation, glycolysis, and the creatine kinase reaction was calculated based on phosphorus metabolites and pH. Spearman rank correlations indicated that postcontraction [acetylcarnitine] was positively associated with both absolute (mM) and relative (% total ATP) glycolytic ATP production (rs = 0.95, P = 0.001; rs = 0.93, P = 0.002), and negatively associated with relative (rs = -0.81, P = 0.02) but not absolute (rs = -0.14, P = 0.75) oxidative ATP production. Thus, acetylcarnitine accumulated more when there was a greater reliance on "nonoxidative" glycolysis and a relatively lower contribution from oxidative phosphorylation, reflecting the fate of pyruvate in working skeletal muscle. Furthermore, these data indicate striking interindividual variation in responses to the energy demand of submaximal contractions. Overall, the results of this preliminary study provide novel evidence of the coupling in vivo between ATP production pathways and the carnitine system.NEW & NOTEWORTHY Production of acetylcarnitine from acetyl-CoA and free carnitine may be important for energy pathway regulation in contracting skeletal muscle. Noninvasive magnetic resonance spectroscopy was used to investigate the link between acetylcarnitine and energy production in the vastus lateralis muscle during dynamic contractions (n = 8 individuals). A positive correlation between acetylcarnitine accumulation and "nonoxidative" glycolysis and an inverse relationship with oxidative phosphorylation, provides novel evidence of the coupling between ATP production and the carnitine system in vivo.
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Affiliation(s)
- Christopher M T Hayden
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, United States
| | - Rajakumar Nagarajan
- Human Magnetic Resonance Center, Institute for Applied Life Sciences, University of Massachusetts, Amherst, Massachusetts, United States
| | - Zoe H Smith
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, United States
| | - Samantha Gilmore
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, United States
| | - Jane A Kent
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, United States
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2
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Long J, Xia Y, Qiu H, Xie X, Yan Y. Respiratory substrate preferences in mitochondria isolated from different tissues of three fish species. FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:1555-1567. [PMID: 36472706 DOI: 10.1007/s10695-022-01137-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/30/2022] [Indexed: 06/17/2023]
Abstract
Energy requirements of tissues vary greatly and exhibit different mitochondrial respiratory activities with variable participation of both substrates and oxidative phosphorylation. The present study aimed to (1) compare the substrate preferences of mitochondria from different tissues and fish species with different ecological characteristics, (2) identify an appropriate substrate for comparing metabolism by mitochondria from different tissues and species, and (3) explore the relationship between mitochondrial metabolism mechanisms and ecological energetic strategies. Respiration rates and cytochrome c oxidase (CCO) activities of mitochondria isolated from heart, brain, kidney, and other tissues from Silurus meridionalis, Carassius auratus, and Megalobrama amblycephala were measured using succinate (complex II-linked substrate), pyruvate (complex I-linked), glutamate (complex I-linked), or combinations. Mitochondria from all tissues and species exhibited substrate preferences. Mitochondria exhibited greater coupling efficiencies and lower leakage rates using either complex I-linked substrates, whereas an opposite trend was observed for succinate (complex II-linked). Furthermore, maximum mitochondrial respiration rates were higher with the substrate combinations than with individual substrates; therefore, state III respiration rates measured with substrate combinations could be effective indicators of maximum mitochondrial metabolic capacity. Regardless of fish species, both state III respiration rates and CCO activities were the highest in heart mitochondria, followed by red muscle mitochondria. However, differences in substrate preferences were not associated with species feeding habit. The maximum respiration rates of heart mitochondria with substrate combinations could indicate differences in locomotor performances, with higher metabolic rates being associated with greater capacity for sustained swimming.
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Affiliation(s)
- Jing Long
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Science, Southwest University, Chongqing, 400715, China
| | - Yiguo Xia
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Science, Southwest University, Chongqing, 400715, China
| | - Hanxun Qiu
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Science, Southwest University, Chongqing, 400715, China
| | - Xiaojun Xie
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Science, Southwest University, Chongqing, 400715, China
| | - Yulian Yan
- Key Laboratory of Freshwater Fish Reproduction and Development, Ministry of Education, School of Life Science, Southwest University, Chongqing, 400715, China.
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3
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Kuzmiak-Glancy S, Glancy B, Kay MW. Ischemic damage to every segment of the oxidative phosphorylation cascade elevates ETC driving force and ROS production in cardiac mitochondria. Am J Physiol Heart Circ Physiol 2022; 323:H499-H512. [PMID: 35867709 PMCID: PMC9448280 DOI: 10.1152/ajpheart.00129.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Myocardial ischemia has long-lasting negative impacts on cardiomyocyte mitochondrial ATP production. However, the location(s) of damage to the oxidative phosphorylation pathway responsible for altered mitochondrial function is unclear. Mitochondrial reactive oxygen species (ROS) production increases following ischemia, but the specific factors controlling this increase are unknown. To determine how ischemia affects the mitochondrial energy conversion cascade and ROS production, mitochondrial driving forces [redox potential and membrane potential (ΔΨ)] were measured at resting, intermediate, and maximal respiration rates in mitochondria isolated from rat hearts after 60 min of control flow (control) or no-flow ischemia (ischemia). The effective activities of the dehydrogenase enzymes, the electron transport chain (ETC), and ATP synthesis and transport were computed using the driving forces and flux. Ischemia lowered maximal mitochondrial respiration rates and diminished the responsiveness of respiration to both redox potential and ΔΨ. Ischemia decreased the activities of every component of the oxidative phosphorylation pathway: the dehydrogenase enzymes, the ETC, and ATP synthesis and transport. ROS production was linearly related to driving force down the ETC; however, ischemia mitochondria demonstrated a greater driving force down the ETC and higher ROS production. Overall, results indicate that ischemia ubiquitously damages the oxidative phosphorylation pathway, reduces mitochondrial sensitivity to driving forces, and augments the propensity for electrons to leak from the ETC. These findings underscore that strategies to improve mitochondrial function following ischemia must target the entire mitochondrial energy conversion cascade. NEW & NOTEWORTHY This integrative analysis is the first to assess how myocardial ischemia alters the mitochondrial driving forces and the degree to which individual segments of the mitochondrial energy transduction pathway contribute to diminished function following ischemia. This investigation demonstrates that increased reactive oxygen species production following ischemia is related to a lower effective activity of the electron transport chain and a greater driving force down the electron transport chain.
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Affiliation(s)
- Sarah Kuzmiak-Glancy
- Department of Kinesiology, School of Public Health, University of Maryland, College Park, MD, United States
| | - Brian Glancy
- Laboratory of Muscle Energetics, National Heart, Lung, and Blood Institute and National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Matthew W Kay
- Department of Biomedical Engineering, The George Washington University, Washington, DC, United States
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4
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Hernández-Camacho JD, Fernández-Ayala DJM, Vicente-García C, Navas-Enamorado I, López-Lluch G, Oliva C, Artuch R, Garcia-Villoria J, Ribes A, de Cabo R, Carvajal JJ, Navas P. Calorie Restriction Rescues Mitochondrial Dysfunction in Adck2-Deficient Skeletal Muscle. Front Physiol 2022; 13:898792. [PMID: 35936917 PMCID: PMC9351392 DOI: 10.3389/fphys.2022.898792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 06/22/2022] [Indexed: 11/20/2022] Open
Abstract
ADCK2 haploinsufficiency-mediated mitochondrial coenzyme Q deficiency in skeletal muscle causes mitochondrial myopathy associated with defects in beta-oxidation of fatty acids, aged-matched metabolic reprogramming, and defective physical performance. Calorie restriction has proven to increase lifespan and delay the onset of chronic diseases associated to aging. To study the possible treatment by food deprivation, heterozygous Adck2 knockout mice were fed under 40% calorie restriction (CR) and the phenotype was followed for 7 months. The overall glucose and fatty acids metabolism in muscle was restored in mutant mice to WT levels after CR. CR modulated the skeletal muscle metabolic profile of mutant mice, partially rescuing the profile of WT animals. The analysis of mitochondria isolated from skeletal muscle demonstrated that CR increased both CoQ levels and oxygen consumption rate (OCR) based on both glucose and fatty acids substrates, along with mitochondrial mass. The elevated aerobic metabolism fits with an increase of type IIa fibers, and a reduction of type IIx in mutant muscles, reaching WT levels. To further explore the effect of CR over muscle stem cells, satellite cells were isolated and induced to differentiate in culture media containing serum from animals in either ad libitum or CR diets for 72 h. Mutant cells showed slower differentiation alongside with decreased oxygen consumption. In vitro differentiation of mutant cells was increased under CR serum reaching levels of WT isolated cells, recovering respiration measured by OCR and partially beta-oxidation of fatty acids. The overall increase of skeletal muscle bioenergetics following CR intervention is paralleled with a physical activity improvement, with some increases in two and four limbs strength tests, and weights strength test. Running wheel activity was also partially improved in mutant mice under CR. These results demonstrate that CR intervention, which has been shown to improve age-associated physical and metabolic decline in WT mice, also recovers the defective aerobic metabolism and differentiation of skeletal muscle in mice caused by ADCK2 haploinsufficiency.
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Affiliation(s)
- Juan Diego Hernández-Camacho
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
| | - Daniel J. M. Fernández-Ayala
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
| | - Cristina Vicente-García
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
| | - Ignacio Navas-Enamorado
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
- Atsena Therapeutics, Durham, NC, United States
| | - Guillermo López-Lluch
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
| | - Clara Oliva
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Rafael Artuch
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
- Clinical Biochemistry Department, Institut de Recerca Sant Joan de Déu, Barcelona, Spain
| | - Judith Garcia-Villoria
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
- Inborn Errors of Metabolism Section, Biochemistry and Molecular Genetics Department, Hospital Clinic, Barcelona, Spain
| | - Antonia Ribes
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
- Inborn Errors of Metabolism Section, Biochemistry and Molecular Genetics Department, Hospital Clinic, Barcelona, Spain
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD, United States
| | - Jaime J. Carvajal
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
| | - Plácido Navas
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, Madrid, Spain
- *Correspondence: Plácido Navas,
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5
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Flight muscle and heart phenotypes in the high-flying ruddy shelduck. J Comp Physiol B 2021; 191:563-573. [PMID: 33591404 DOI: 10.1007/s00360-020-01326-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 10/12/2020] [Accepted: 11/01/2020] [Indexed: 01/21/2023]
Abstract
Ruddy shelduck migrate from wintering grounds in lowland India and Myanmar to breeding grounds in central China and Mongolia, sustaining flight over the Himalayas, where oxygen availability is greatly reduced. We compared phenotypes of the pectoralis muscle and the ventricle of the heart from ruddy shelduck and common shelduck (a closely related low-altitude congener) that were raised in common conditions at sea level, predicting that oxidative capacity would be greater in ruddy shelduck to support high-altitude migration. Fibre-type composition of the pectoralis and the maximal activity of eight enzymes involved in mitochondrial energy metabolism in the pectoralis and heart, were compared between species. Few differences distinguished ruddy shelduck from common shelduck in the flight muscle, with the exception that ruddy shelduck had higher activities of complex II and higher ratios of complex IV (cytochrome c oxidase) and complex II when expressed relative to citrate synthase activity. There were no species differences in fibre-type composition, so these changes in enzyme activity may reflect an evolved modification in the functional properties of muscle mitochondria, potentially influencing mitochondrial respiratory capacity and/or oxygen affinity. Ruddy shelduck also had higher lactate dehydrogenase activity concurrent with lower pyruvate kinase and hexokinase activity in the left ventricle, which likely reflects an increased capacity for lactate oxidation by the heart. We conclude that changes in pathways of mitochondrial energy metabolism in the muscle and heart may contribute to the ability of ruddy shelduck to fly at high altitude.
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Willis W, Willis E, Kuzmiak-Glancy S, Kras K, Hudgens J, Barakati N, Stern J, Mandarino L. Oxidative phosphorylation K 0.5ADP in vitro depends on substrate oxidative capacity: Insights from a luciferase-based assay to evaluate ADP kinetic parameters. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148430. [PMID: 33887230 DOI: 10.1016/j.bbabio.2021.148430] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 03/30/2021] [Accepted: 04/07/2021] [Indexed: 12/21/2022]
Abstract
The K0.5ADP of oxidative phosphorylation (OxPhos) identifies the cytosolic ADP concentration which elicits one-half the maximum OxPhos rate. This kinetic parameter is commonly measured to assess mitochondrial metabolic control sensitivity. Here we describe a luciferase-based assay to evaluate the ADP kinetic parameters of mitochondrial ATP production from OxPhos, adenylate kinase (AK), and creatine kinase (CK). The high sensitivity, reproducibility, and throughput of the microplate-based assay enabled a comprehensive kinetic assessment of all three pathways in mitochondria isolated from mouse liver, kidney, heart, and skeletal muscle. Carboxyatractyloside titrations were also performed with the assay to estimate the flux control strength of the adenine nucleotide translocase (ANT) over OxPhos in human skeletal muscle mitochondria. ANT flux control coefficients were 0.91 ± 0.07, 0.83 ± 0.06, and 0.51 ± 0.07 at ADP concentrations of 6.25, 12.5, and 25 μM, respectively, an [ADP] range which spanned the K0.5ADP. The oxidative capacity of substrate combinations added to drive OxPhos was found to dramatically influence ADP kinetics in mitochondria from several tissues. In mouse skeletal muscle ten different substrate combinations elicited a 7-fold range of OxPhos Vmax, which correlated positively (R2 = 0.963) with K0.5ADP values ranging from 2.3 ± 0.2 μM to 11.9 ± 0.6 μM. We propose that substrate-enhanced capacity to generate the protonmotive force increases the OxPhos K0.5ADP because flux control at ANT increases, thus K0.5ADP rises toward the dissociation constant, KdADP, of ADP-ANT binding. The findings are discussed in the context of top-down metabolic control analysis.
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Affiliation(s)
- Wayne Willis
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States; Center for Disparities in Diabetes, Obesity, and Metabolism, University of Arizona, Tucson, AZ, United States.
| | - Elizabeth Willis
- College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Sarah Kuzmiak-Glancy
- Department of Kinesiology, University of Maryland, College Park, MD, United States
| | - Katon Kras
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States
| | - Jamie Hudgens
- College of Pharmacy, Midwestern University, Glendale, AZ, United States
| | - Neusha Barakati
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States
| | - Jennifer Stern
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States; Center for Disparities in Diabetes, Obesity, and Metabolism, University of Arizona, Tucson, AZ, United States
| | - Lawrence Mandarino
- Department of Medicine, Division of Endocrinology, University of Arizona, Tucson, AZ, United States; Center for Disparities in Diabetes, Obesity, and Metabolism, University of Arizona, Tucson, AZ, United States
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7
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Damal Villivalam S, Ebert SM, Lim HW, Kim J, You D, Jung BC, Palacios HH, Tcheau T, Adams CM, Kang S. A necessary role of DNMT3A in endurance exercise by suppressing ALDH1L1-mediated oxidative stress. EMBO J 2021; 40:e106491. [PMID: 33847380 DOI: 10.15252/embj.2020106491] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/25/2020] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
Exercise can alter the skeletal muscle DNA methylome, yet little is known about the role of the DNA methylation machinery in exercise capacity. Here, we show that DNMT3A expression in oxidative red muscle increases greatly following a bout of endurance exercise. Muscle-specific Dnmt3a knockout mice have reduced tolerance to endurance exercise, accompanied by reduction in oxidative capacity and mitochondrial respiration. Moreover, Dnmt3a-deficient muscle overproduces reactive oxygen species (ROS), the major contributors to muscle dysfunction. Mechanistically, we show that DNMT3A suppresses the Aldh1l1 transcription by binding to its promoter region, altering its epigenetic profile. Forced expression of ALDH1L1 elevates NADPH levels, which results in overproduction of ROS by the action of NADPH oxidase complex, ultimately resulting in mitochondrial defects in myotubes. Thus, inhibition of ALDH1L1 pathway can rescue oxidative stress and mitochondrial dysfunction from Dnmt3a deficiency in myotubes. Finally, we show that in vivo knockdown of Aldh1l1 largely rescues exercise intolerance in Dnmt3a-deficient mice. Together, we establish that DNMT3A in skeletal muscle plays a pivotal role in endurance exercise by controlling intracellular oxidative stress.
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Affiliation(s)
- Sneha Damal Villivalam
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
| | - Scott M Ebert
- Departments of Internal Medicine and Molecular Physiology and Biophysics and Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA.,Emmyon, Inc., Coralville, IA, USA
| | - Hee Woong Lim
- Division of Biomedical Informatics, Cincinnati Children's Hospital Medical Center, Department of Pediatrics & Biomedical Informatics, University of Cincinnati, Cincinnati, OH, USA
| | - Jinse Kim
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
| | - Dongjoo You
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
| | - Byung Chul Jung
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
| | - Hector H Palacios
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
| | - Tabitha Tcheau
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
| | - Christopher M Adams
- Departments of Internal Medicine and Molecular Physiology and Biophysics and Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA.,Emmyon, Inc., Coralville, IA, USA.,Iowa City Department of Veterans Affairs Medical Center, Iowa City, IA, USA
| | - Sona Kang
- Nutritional Sciences and Toxicology Department, University of California Berkeley, Berkeley, CA, USA
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8
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McCue A, Munten S, Herzig KH, Gagnon DD. Metabolic flexibility is unimpaired during exercise in the cold following acute glucose ingestion in young healthy adults. J Therm Biol 2021; 98:102912. [PMID: 34016339 DOI: 10.1016/j.jtherbio.2021.102912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 02/05/2021] [Accepted: 03/11/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE Metabolic flexibility is compromised in individuals suffering from metabolic diseases, lipo- and glucotoxicity, and mitochondrial dysfunctions. Exercise studies performed in cold environments have demonstrated an increase in lipid utilization, which could lead to a compromised substrate competition, glycotoxic-lipotoxic state, or metabolic inflexibility. Whether metabolic flexibility is altered during incremental maximal exercise to volitional fatigue in a cold environment remains unclear. METHODS Ten young healthy participants performed four maximal incremental treadmill tests to volitional fatigue, in a fasted state, in a cold (0 °C) or a thermoneutral (22.0 °C) environment, with and without a pre-exercise ingestion of a 75-g glucose solution. Metabolic flexibility was assessed via indirect calorimetry using the change in respiratory exchange ratio (ΔRER), maximal fat oxidation (ΔMFO), and where MFO occurred along the exercise intensity spectrum (ΔFatmax), while circulating lactate and glucose levels were measured pre and post exercise. RESULTS Multiple linear mixed-effects regressions revealed an increase in glucose oxidation from glucose ingestion and an increase in lipid oxidation from the cold during exercise (p < 0.001). No differences were observed in metabolic flexibility as assessed via ΔRER (0.05 ± 0.03 vs. 0.05 ± 0.03; p = 0.734), ΔMFO (0.21 ± 0.18 vs. 0.16 ± 0.13 g min-1; p = 0.133) and ΔFatmax (13.3 ± 19.0 vs. 0.6 ± 21.3 %V̇O2peak; p = 0.266) in cold and thermoneutral, respectively. CONCLUSIONS Following glucose loading, metabolic flexibility was unaffected during exercise to volitional fatigue in a cold environment, inducing an increase in lipid oxidation. These results suggest that competing pathways responsible for the regulation of fuel selection during exercise and cold exposure may potentially be mechanistically independent. Whether long-term metabolic influences of high-fat diets and acute lipid overload in cold and warm environments would impact metabolic flexibility remain unclear.
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Affiliation(s)
- Alexus McCue
- Laboratory of Environmental Exercise Physiology, School of Kinesiology and Health Sciences, Laurentian University, Sudbury, Ontario, Canada; Center of Research in Occupational Health and Safety, Laurentian University, Sudbury, Ontario, Canada
| | - Stephanie Munten
- Laboratory of Environmental Exercise Physiology, School of Kinesiology and Health Sciences, Laurentian University, Sudbury, Ontario, Canada; Center of Research in Occupational Health and Safety, Laurentian University, Sudbury, Ontario, Canada
| | - Karl-Heinz Herzig
- Institute of Biomedicine, Medical Research Center, Faculty of Medicine, University of Oulu, Oulu University Hospital, Oulu, Finland; Department of Gastroenterology and Metabolism, Poznan University of Medical Sciences, Poznan, Poland
| | - Dominique D Gagnon
- Laboratory of Environmental Exercise Physiology, School of Kinesiology and Health Sciences, Laurentian University, Sudbury, Ontario, Canada; Center of Research in Occupational Health and Safety, Laurentian University, Sudbury, Ontario, Canada.
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9
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Young KG, Vanderboor CM, Regnault TRH, Guglielmo CG. Species-specific metabolic responses of songbird, shorebird, and murine cultured myotubes to n-3 polyunsaturated fatty acids. Am J Physiol Regul Integr Comp Physiol 2020; 320:R362-R376. [PMID: 33356878 DOI: 10.1152/ajpregu.00249.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Migratory birds may benefit from diets rich in polyunsaturated fatty acids (PUFAs) that could improve exercise performance. Previous investigations suggest that different types of birds may respond differently to PUFA. We established muscle myocyte cell culture models from muscle satellite cells of a migratory passerine songbird (yellow-rumped warbler, Setophaga coronata coronata) and a nonpasserine shorebird (sanderling, Calidris alba). We differentiated and treated avian myotubes and immortalized murine C2C12 myotubes with n-3 PUFA docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and with monounsaturated oleic acid (OA) to compare effects on aerobic performance, metabolic enzyme activities, key fatty acid (FA) transporters, and expression of peroxisome proliferator-activated receptors (PPARs). Sanderling and C2C12 myotubes increased expression of PPARs with n-3 PUFA treatments, whereas expression was unchanged in yellow-rumped warblers. Both sanderlings and yellow-rumped warblers increased expression of fatty acid transporters, whereas C2C12 cells decreased expression following n-3 PUFA treatments. Only yellow-rumped warbler myotubes increased expression of some metabolic enzymes, whereas the sanderling and C2C12 cells were unchanged. PUFA supplementation in C2C12 myotubes increased mitochondrial respiratory chain efficiency, whereas sanderlings increased proton leak-associated respiration and maximal respiration (measurements were not made in warblers). This research indicates that songbirds and shorebirds respond differently to n-3 PUFA and provides support for the hypothesis that n-3 PUFA increase the aerobic capacity of migrant shorebird muscle, which may improve overall endurance flight performance.
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Affiliation(s)
- Kevin G Young
- Department of Biology, Advanced Facility for Avian Research, Western University, London, Ontario, Canada
| | - Christina M Vanderboor
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada
| | - Timothy R H Regnault
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Department of Obstetrics and Gynaecology, Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.,Children's Health Research Institute, Lawson Health Research Institute, London, Ontario, Canada
| | - Christopher G Guglielmo
- Department of Biology, Advanced Facility for Avian Research, Western University, London, Ontario, Canada
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10
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Lai N, Fealy CE, Kummitha CM, Cabras S, Kirwan JP, Hoppel CL. Mitochondrial Utilization of Competing Fuels Is Altered in Insulin Resistant Skeletal Muscle of Non-obese Rats (Goto-Kakizaki). Front Physiol 2020; 11:677. [PMID: 32612543 PMCID: PMC7308651 DOI: 10.3389/fphys.2020.00677] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/26/2020] [Indexed: 12/25/2022] Open
Abstract
Aim Insulin-resistant skeletal muscle is characterized by metabolic inflexibility with associated alterations in substrate selection, mediated by peroxisome-proliferator activated receptor δ (PPARδ). Although it is established that PPARδ contributes to the alteration of energy metabolism, it is not clear whether it plays a role in mitochondrial fuel competition. While nutrient overload may impair metabolic flexibility by fuel congestion within mitochondria, in absence of obesity defects at a mitochondrial level have not yet been excluded. We sought to determine whether reduced PPARδ content in insulin-resistant rat skeletal muscle of a non-obese rat model of T2DM (Goto-Kakizaki, GK) ameliorate the inhibitory effect of fatty acid (i.e., palmitoylcarnitine) on mitochondrial carbohydrate oxidization (i.e., pyruvate) in muscle fibers. Methods Bioenergetic function was characterized in oxidative soleus (S) and glycolytic white gastrocnemius (WG) muscles with measurement of respiration rates in permeabilized fibers in the presence of complex I, II, IV, and fatty acid substrates. Mitochondrial content was measured by citrate synthase (CS) and succinate dehydrogenase activity (SDH). Western blot was used to determine protein expression of PPARδ, PDK isoform 2 and 4. Results CS and SDH activity, key markers of mitochondrial content, were reduced by ∼10-30% in diabetic vs. control, and the effect was evident in both oxidative and glycolytic muscles. PPARδ (p < 0.01), PDK2 (p < 0.01), and PDK4 (p = 0.06) protein content was reduced in GK animals compared to Wistar rats (N = 6 per group). Ex vivo respiration rates in permeabilized muscle fibers determined in the presence of complex I, II, IV, and fatty acid substrates, suggested unaltered mitochondrial bioenergetic function in T2DM muscle. Respiration in the presence of pyruvate was higher compared to palmitoylcarnitine in both animal groups and fiber types. Moreover, respiration rates in the presence of both palmitoylcarnitine and pyruvate were reduced by 25 ± 6% (S), 37 ± 6% (WG) and 63 ± 6% (S), 57 ± 8% (WG) compared to pyruvate for both controls and GK, respectively. The inhibitory effect of palmitoylcarnitine on respiration was significantly greater in GK than controls (p < 10-3). Conclusion With competing fuels, the presence of fatty acids diminishes mitochondria ability to utilize carbohydrate derived substrates in insulin-resistant muscle despite reduced PPARδ content.
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Affiliation(s)
- Nicola Lai
- Department of Electrical and Computer Engineering, Old Dominion University, Norfolk, VA, United States.,Biomedical Engineering Institute, Old Dominion University, Norfolk, VA, United States.,Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, Cagliari, Italy.,Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Center for Mitochondrial Disease, Case Western Reserve University, Cleveland, OH, United States
| | - Ciarán E Fealy
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Chinna M Kummitha
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - Silvia Cabras
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States
| | - John P Kirwan
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.,Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, United States.,Pennington Biomedical Research Center, Baton Rouge, LA, United States
| | - Charles L Hoppel
- Center for Mitochondrial Disease, Case Western Reserve University, Cleveland, OH, United States.,Department of Pharmacology, Case Western Reserve University, Cleveland, OH, United States.,Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
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11
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Sweazea KL, Tsosie KS, Beckman EJ, Benham PM, Witt CC. Seasonal and elevational variation in glucose and glycogen in two songbird species. Comp Biochem Physiol A Mol Integr Physiol 2020; 245:110703. [PMID: 32283178 DOI: 10.1016/j.cbpa.2020.110703] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 03/10/2020] [Accepted: 04/06/2020] [Indexed: 12/27/2022]
Abstract
Birds naturally maintain high glucose concentrations in the blood and tissues, even when relying on fat to meet the metabolic demands of flight or thermogenesis. One possibility is that high glucose levels might be needed to deal with these metabolic demands. Thus, we hypothesized that birds chronically exposed to colder temperatures and higher elevations have higher circulating glucose and tissue free glucose and glycogen compared to conspecifics living at warmer temperatures and lower elevations. Adult House Sparrows (Passer domesticus) and House Finches (Haemorhous mexicanus) were captured from Phoenix, AZ (340 m elevation), and Albuquerque, NM (1600 m elevation), during the summer and winter months. We measured plasma glucose, as well as free glucose and glycogen from multiple tissues. In general, high elevation and colder temperatures were associated with higher tissue glycogen and higher free glucose concentrations in the brain. These findings indicate that glucose and glycogen are subject to seasonal phenotypic flexibility as well as geographic variations that may relate to local food availability and abundance.
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Affiliation(s)
- Karen L Sweazea
- College of Health Solutions, Arizona State University, United States of America; School of Life Sciences, Arizona State University, United States of America.
| | - Krystal S Tsosie
- School of Life Sciences, Arizona State University, United States of America
| | - Elizabeth J Beckman
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, United States of America
| | - Phred M Benham
- Department of Integrative Biology and Museum of Vertebrate Zoology, University of California, Berkeley, United States of America
| | - Christopher C Witt
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, United States of America
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12
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Vázquez-Fonseca L, Schaefer J, Navas-Enamorado I, Santos-Ocaña C, Hernández-Camacho JD, Guerra I, Cascajo MV, Sánchez-Cuesta A, Horvath Z, Siendones E, Jou C, Casado M, Gutiérrez P, Brea-Calvo G, López-Lluch G, Fernández-Ayala DJM, Cortés-Rodríguez AB, Rodríguez-Aguilera JC, Matté C, Ribes A, Prieto-Soler SY, Dominguez-Del-Toro E, Francesco AD, Aon MA, Bernier M, Salviati L, Artuch R, Cabo RD, Jackson S, Navas P. ADCK2 Haploinsufficiency Reduces Mitochondrial Lipid Oxidation and Causes Myopathy Associated with CoQ Deficiency. J Clin Med 2019; 8:jcm8091374. [PMID: 31480808 PMCID: PMC6780728 DOI: 10.3390/jcm8091374] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 08/28/2019] [Accepted: 08/29/2019] [Indexed: 01/27/2023] Open
Abstract
Fatty acids and glucose are the main bioenergetic substrates in mammals. Impairment of mitochondrial fatty acid oxidation causes mitochondrial myopathy leading to decreased physical performance. Here, we report that haploinsufficiency of ADCK2, a member of the aarF domain-containing mitochondrial protein kinase family, in human is associated with liver dysfunction and severe mitochondrial myopathy with lipid droplets in skeletal muscle. In order to better understand the etiology of this rare disorder, we generated a heterozygous Adck2 knockout mouse model to perform in vivo and cellular studies using integrated analysis of physiological and omics data (transcriptomics–metabolomics). The data showed that Adck2+/− mice exhibited impaired fatty acid oxidation, liver dysfunction, and mitochondrial myopathy in skeletal muscle resulting in lower physical performance. Significant decrease in Coenzyme Q (CoQ) biosynthesis was observed and supplementation with CoQ partially rescued the phenotype both in the human subject and mouse model. These results indicate that ADCK2 is involved in organismal fatty acid metabolism and in CoQ biosynthesis in skeletal muscle. We propose that patients with isolated myopathies and myopathies involving lipid accumulation be tested for possible ADCK2 defect as they are likely to be responsive to CoQ supplementation.
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Affiliation(s)
- Luis Vázquez-Fonseca
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- Clinical Genetics Unit, Department of Women and Children's Health, University of Padova, and IRP Città della Speranza, 35100 Padova, Italy
| | - Jochen Schaefer
- Department of Neurology, Carl Gustav Carus University Dresden, 01307 Dresden, Germany
| | - Ignacio Navas-Enamorado
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- Boston University School of Medicine, Boston, MA 02118, USA
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 20201, USA
| | - Carlos Santos-Ocaña
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Juan D Hernández-Camacho
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Ignacio Guerra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
| | - María V Cascajo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Ana Sánchez-Cuesta
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Zoltan Horvath
- Department of Neurology, Carl Gustav Carus University Dresden, 01307 Dresden, Germany
| | - Emilio Siendones
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
| | - Cristina Jou
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
- Clinical Chemistry and Pathology Departments, Institut de Recerca Sant Joan de Déu, 08000 Barcelona, Spain
| | - Mercedes Casado
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
- Clinical Chemistry and Pathology Departments, Institut de Recerca Sant Joan de Déu, 08000 Barcelona, Spain
| | - Purificación Gutiérrez
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
| | - Gloria Brea-Calvo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Guillermo López-Lluch
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Daniel J M Fernández-Ayala
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Ana B Cortés-Rodríguez
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Juan C Rodríguez-Aguilera
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
| | - Cristiane Matté
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul. CEP 90035-003, Porto Alegre, RS, Brazil
| | - Antonia Ribes
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
- Secciód'Errors Congènits del Metabolisme-IBC, Servei de Bioquímica I Genètica Molecular, Hospital Clinic, 08000 Barcelona, Spain
| | | | | | - Andrea di Francesco
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 20201, USA
| | - Miguel A Aon
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 20201, USA
| | - Michel Bernier
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 20201, USA
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Women and Children's Health, University of Padova, and IRP Città della Speranza, 35100 Padova, Italy
| | - Rafael Artuch
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain
- Clinical Chemistry and Pathology Departments, Institut de Recerca Sant Joan de Déu, 08000 Barcelona, Spain
| | - Rafael de Cabo
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, 251 Bayview Boulevard, Suite 100, Baltimore, MD 20201, USA
| | - Sandra Jackson
- Department of Neurology, Carl Gustav Carus University Dresden, 01307 Dresden, Germany
| | - Plácido Navas
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain.
- CIBERER, Instituto de Salud Carlos III, 28000 Madrid, Spain.
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13
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Paglietti A. Limit to steady-state aerobic power of skeletal muscles. J Biol Phys 2018; 44:619-646. [PMID: 30280281 DOI: 10.1007/s10867-018-9510-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 08/30/2018] [Indexed: 11/24/2022] Open
Abstract
Like any other kind of cell, muscle cells produce energy by oxidizing the fuel substrate that they absorb together with the needed oxygen from the surroundings. Oxidation occurs entirely within the cell. It means that the reactants and products of reaction must at some time be dissolved in the cell's cytosol. If a cell operates at steady state, its cytosol composition remains constant. Therefore, the cytosol in a muscle that produces work at steady state must contain a constant amount of fuel, oxygen, and product of reaction dissolved in it. The greater the power produced, the higher the concentration of these solutes. There is a limit, however, to the maximum amount of solutes that the cytosol can contain without damaging the cell. General thermodynamic arguments, which are reviewed in this paper, help relate this limit to the dehydration and overhydration limits of the cell. The present analysis shows that the same limits entail a limit to the maximum power that a muscle can produce at steady state. This limit depends on the composition of the fuel mixture used by the muscle. The analysis also determines the number of fuel carbon atoms that must be oxidized in parallel within a cell to produce a given power. It may well happen that a muscle cannot reach the maximum attainable power because it cannot activate all the parallel oxidation paths that are needed to produce it. This may be due to a series of reasons ranging from health issues to a lack of training. The paper shows how the methods of indirect calorimetry can provide all the experimental data needed to determine the actual number of parallel oxidation paths that at steady state must be active in a muscle in a given exercise. A diagram relating muscle power to the number of parallel oxidation paths and fuel composition is finally presented. It provides a means to assess the power capacity of animal muscles and can be applied to evaluate their fitness, stamina, margins for improvement, and athletic potential.
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Affiliation(s)
- A Paglietti
- Department of Mechanical, Chemical and Materials Engineering, University of Cagliari, 09123, Cagliari, Italy.
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14
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Smith RL, Soeters MR, Wüst RCI, Houtkooper RH. Metabolic Flexibility as an Adaptation to Energy Resources and Requirements in Health and Disease. Endocr Rev 2018; 39:489-517. [PMID: 29697773 PMCID: PMC6093334 DOI: 10.1210/er.2017-00211] [Citation(s) in RCA: 332] [Impact Index Per Article: 55.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2017] [Accepted: 04/19/2018] [Indexed: 12/15/2022]
Abstract
The ability to efficiently adapt metabolism by substrate sensing, trafficking, storage, and utilization, dependent on availability and requirement, is known as metabolic flexibility. In this review, we discuss the breadth and depth of metabolic flexibility and its impact on health and disease. Metabolic flexibility is essential to maintain energy homeostasis in times of either caloric excess or caloric restriction, and in times of either low or high energy demand, such as during exercise. The liver, adipose tissue, and muscle govern systemic metabolic flexibility and manage nutrient sensing, uptake, transport, storage, and expenditure by communication via endocrine cues. At a molecular level, metabolic flexibility relies on the configuration of metabolic pathways, which are regulated by key metabolic enzymes and transcription factors, many of which interact closely with the mitochondria. Disrupted metabolic flexibility, or metabolic inflexibility, however, is associated with many pathological conditions including metabolic syndrome, type 2 diabetes mellitus, and cancer. Multiple factors such as dietary composition and feeding frequency, exercise training, and use of pharmacological compounds, influence metabolic flexibility and will be discussed here. Last, we outline important advances in metabolic flexibility research and discuss medical horizons and translational aspects.
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Affiliation(s)
- Reuben L Smith
- Laboratory of Genetic Metabolic Diseases, Academic Medical Center, AZ Amsterdam, Netherlands.,Amsterdam Gastroenterology and Metabolism, Academic Medical Center, AZ Amsterdam, Netherlands
| | - Maarten R Soeters
- Amsterdam Gastroenterology and Metabolism, Academic Medical Center, AZ Amsterdam, Netherlands.,Department of Endocrinology and Metabolism, Internal Medicine, Academic Medical Center, AZ Amsterdam, Netherlands
| | - Rob C I Wüst
- Laboratory of Genetic Metabolic Diseases, Academic Medical Center, AZ Amsterdam, Netherlands.,Amsterdam Cardiovascular Sciences, Academic Medical Center, AZ Amsterdam, Netherlands.,Amsterdam Movement Sciences, Academic Medical Center, AZ Amsterdam, Netherlands
| | - Riekelt H Houtkooper
- Laboratory of Genetic Metabolic Diseases, Academic Medical Center, AZ Amsterdam, Netherlands.,Amsterdam Gastroenterology and Metabolism, Academic Medical Center, AZ Amsterdam, Netherlands.,Amsterdam Cardiovascular Sciences, Academic Medical Center, AZ Amsterdam, Netherlands
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15
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Willis WT, Miranda-Grandjean D, Hudgens J, Willis EA, Finlayson J, De Filippis EA, Zapata Bustos R, Langlais PR, Mielke C, Mandarino LJ. Dominant and sensitive control of oxidative flux by the ATP-ADP carrier in human skeletal muscle mitochondria: Effect of lysine acetylation. Arch Biochem Biophys 2018; 647:93-103. [PMID: 29653079 DOI: 10.1016/j.abb.2018.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/29/2018] [Accepted: 04/08/2018] [Indexed: 02/01/2023]
Abstract
The adenine nucleotide translocase (ANT) of the mitochondrial inner membrane exchanges ADP for ATP. Mitochondria were isolated from human vastus lateralis muscle (n = 9). Carboxyatractyloside titration of O2 consumption rate (Jo) at clamped [ADP] of 21 μM gave ANT abundance of 0.97 ± 0.14 nmol ANT/mg and a flux control coefficient of 82% ± 6%. Flux control fell to 1% ± 1% at saturating (2 mM) [ADP]. The KmADP for Jo was 32.4 ± 1.8 μM. In terms of the free (-3) ADP anion this KmADP was 12.0 ± 0.7 μM. A novel luciferase-based assay for ATP production gave KmADP of 13.1 ± 1.9 μM in the absence of ATP competition. The free anion KmADP in this case was 2.0 ± 0.3 μM. Targeted proteomic analyses showed significant acetylation of ANT Lysine23 and that ANT1 was the most abundant isoform. Acetylation of Lysine23 correlated positively with KmADP, r = 0.74, P = 0.022. The findings underscore the central role played by ANT in the control of oxidative phosphorylation, particularly at the energy phosphate levels associated with low ATP demand. As predicted by molecular dynamic modeling, ANT Lysine23 acetylation decreased the apparent affinity of ADP for ANT binding.
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Affiliation(s)
- W T Willis
- University of Arizona, College of Medicine, Department of Medicine, 1501 N. Campbell Avenue, P.O. Box 245099, Tucson, AZ 85724-5099, USA.
| | - D Miranda-Grandjean
- Mayo Clinic, Division of Endocrinology, East Shea Boulevard and 134th Street, Scottsdale, AZ 85259, USA.
| | - J Hudgens
- Mayo Clinic, Division of Endocrinology, East Shea Boulevard and 134th Street, Scottsdale, AZ 85259, USA.
| | - E A Willis
- Mayo Clinic, Division of Endocrinology, East Shea Boulevard and 134th Street, Scottsdale, AZ 85259, USA.
| | - J Finlayson
- University of Arizona, College of Medicine, Department of Medicine, 1501 N. Campbell Avenue, P.O. Box 245099, Tucson, AZ 85724-5099, USA.
| | - E A De Filippis
- Mayo Clinic, Division of Endocrinology, East Shea Boulevard and 134th Street, Scottsdale, AZ 85259, USA.
| | - R Zapata Bustos
- University of Arizona, College of Medicine, Department of Medicine, 1501 N. Campbell Avenue, P.O. Box 245099, Tucson, AZ 85724-5099, USA.
| | - P R Langlais
- University of Arizona, College of Medicine, Department of Medicine, 1501 N. Campbell Avenue, P.O. Box 245099, Tucson, AZ 85724-5099, USA.
| | - C Mielke
- Mayo Clinic, Division of Endocrinology, East Shea Boulevard and 134th Street, Scottsdale, AZ 85259, USA.
| | - L J Mandarino
- University of Arizona, College of Medicine, Department of Medicine, 1501 N. Campbell Avenue, P.O. Box 245099, Tucson, AZ 85724-5099, USA.
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16
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Hawkes LA, Batbayar N, Butler PJ, Chua B, Frappell PB, Meir JU, Milsom WK, Natsagdorj T, Parr N, Scott GR, Takekawa JY, WikeIski M, Witt MJ, Bishop CM. Do Bar-Headed Geese Train for High Altitude Flights? Integr Comp Biol 2018; 57:240-251. [PMID: 28859401 DOI: 10.1093/icb/icx068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
SYNOPSIS Exercise at high altitude is extremely challenging, largely due to hypobaric hypoxia (low oxygen levels brought about by low air pressure). In humans, the maximal rate of oxygen consumption decreases with increasing altitude, supporting progressively poorer performance. Bar-headed geese (Anser indicus) are renowned high altitude migrants and, although they appear to minimize altitude during migration where possible, they must fly over the Tibetan Plateau (mean altitude 4800 m) for much of their annual migration. This requires considerable cardiovascular effort, but no study has assessed the extent to which bar-headed geese may train prior to migration for long distances, or for high altitudes. Using implanted loggers that recorded heart rate, acceleration, pressure, and temperature, we found no evidence of training for migration in bar-headed geese. Geese showed no significant change in summed activity per day or maximal activity per day. There was also no significant change in maximum heart rate per day or minimum resting heart rate, which may be evidence of an increase in cardiac stroke volume if all other variables were to remain the same. We discuss the strategies used by bar-headed geese in the context of training undertaken by human mountaineers when preparing for high altitude, noting the differences between their respective cardiovascular physiology.
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Affiliation(s)
- Lucy A Hawkes
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10?9FE, UK
| | - Nyambayar Batbayar
- Wildlife Science and Conservation Center, Bayanzurkh District, Ulaanbataar 210351, Mongolia
| | - Patrick J Butler
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15?2TT, UK
| | - Beverley Chua
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4
| | - Peter B Frappell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania 7001, Australia
| | | | - William K Milsom
- Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4
| | | | - Nicole Parr
- Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn Campus, Cornwall TR10?9FE, UK
| | - Graham R Scott
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 3K1
| | - John Y Takekawa
- Audubon California, Richardson Bay Audubon Center and Sanctuary, Tiburon, CA 94920, USA
| | - Martin WikeIski
- Max Planck Institute for Ornithology, D-82319 Seewiesen, Germany.,Department of Biology, University of Konstanz, Konstanz D-78457, Germany
| | - Matthew J Witt
- College of Life and Environmental Sciences, University of Exeter, Environment and Sustainability Institute, Penryn Campus, Cornwall TR10?9FE, UK
| | - Charles M Bishop
- School of Biological Sciences, Bangor University, Bangor, Gwynedd LL57?2UW, UK
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17
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Willis WT, Jackman MR, Messer JI, Kuzmiak-Glancy S, Glancy B. A Simple Hydraulic Analog Model of Oxidative Phosphorylation. Med Sci Sports Exerc 2017; 48:990-1000. [PMID: 26807634 DOI: 10.1249/mss.0000000000000884] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mitochondrial oxidative phosphorylation is the primary source of cellular energy transduction in mammals. This energy conversion involves dozens of enzymatic reactions, energetic intermediates, and the dynamic interactions among them. With the goal of providing greater insight into the complex thermodynamics and kinetics ("thermokinetics") of mitochondrial energy transduction, a simple hydraulic analog model of oxidative phosphorylation is presented. In the hydraulic model, water tanks represent the forward and back "pressures" exerted by thermodynamic driving forces: the matrix redox potential (ΔGredox), the electrochemical potential for protons across the mitochondrial inner membrane (ΔGH), and the free energy of adenosine 5'-triphosphate (ATP) (ΔGATP). Net water flow proceeds from tanks with higher water pressure to tanks with lower pressure through "enzyme pipes" whose diameters represent the conductances (effective activities) of the proteins that catalyze the energy transfer. These enzyme pipes include the reactions of dehydrogenase enzymes, the electron transport chain (ETC), and the combined action of ATP synthase plus the ATP-adenosine 5'-diphosphate exchanger that spans the inner membrane. In addition, reactive oxygen species production is included in the model as a leak that is driven out of the ETC pipe by high pressure (high ΔGredox) and a proton leak dependent on the ΔGH for both its driving force and the conductance of the leak pathway. Model water pressures and flows are shown to simulate thermodynamic forces and metabolic fluxes that have been experimentally observed in mammalian skeletal muscle in response to acute exercise, chronic endurance training, and reduced substrate availability, as well as account for the thermokinetic behavior of mitochondria from fast- and slow-twitch skeletal muscle and the metabolic capacitance of the creatine kinase reaction.
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Affiliation(s)
- Wayne T Willis
- 1Center for Metabolic and Vascular Biology, Arizona State University at Mayo Clinic, Scottsdale, AZ; 2Division of Endocrinology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO; 3Exercise Science Department, Mesa Community College, Mesa, AZ; 4Department of Biomedical Engineering, The George Washington University, Washington, DC; and 5Laboratory of Cardiac Energetics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
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18
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Soman SS, Tinson A. Development and evaluation of a simple and effective real time PCR assay for mitochondrial quantification in racing camels. Mol Cell Probes 2016; 30:326-330. [PMID: 27475303 DOI: 10.1016/j.mcp.2016.07.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 07/26/2016] [Accepted: 07/26/2016] [Indexed: 10/21/2022]
Abstract
Camel racing is a popular sport in the Middle East region, where the demand is high for racing camels with higher stamina and endurance. Devising a technique to measure oxidative capacity and endurance in camels should be useful. Mitochondria are highly specialized organelles involved in metabolism in all higher organisms for sustaining life and providing energy for physical functions. The ratio of mitochondrial DNA (mtDNA) to nuclear DNA (nDNA) is often used as an estimate for the metabolic status of the tissue. A greater quantity of mitochondria per unit of tissue translates into greater oxidative capacity and endurance. In this report, we describe a simple, sensitive and efficient real-time PCR assay for the quantification of blood mitochondria in racing camels. The primer sequences selected for the SYBR green-based PCR assay included mitochondrial D-loop region, mitochondrial ATP6ase gene and the nuclear β-actin gene. The assay was validated using two groups of camels comprising racing and dairy camels. The racing camels demonstrated a higher mtDNA/nDNA ratio compared with dairy camels based on the ΔΔCt values, with a higher variability among racing camels. The mean ΔΔCt values of adult and young racing camels did not vary considerably. The findings show that the present assay can be used as an evaluative tool for racing camels.
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Affiliation(s)
- Soja Saghar Soman
- Hilli Embryo Transfer Center, Management of Scientific Centers and Presidential Camels, Department of President's Affairs, Al Ain, United Arab Emirates.
| | - Alex Tinson
- Hilli Embryo Transfer Center, Management of Scientific Centers and Presidential Camels, Department of President's Affairs, Al Ain, United Arab Emirates
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Stager M, Swanson DL, Cheviron ZA. Regulatory mechanisms of metabolic flexibility in the dark-eyed junco (Junco hyemalis). J Exp Biol 2015; 218:767-77. [DOI: 10.1242/jeb.113472] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
ABSTRACT
Small temperate birds reversibly modify their aerobic performance to maintain thermoregulatory homeostasis under seasonally changing environmental conditions and these physiological adjustments may be attributable to changes in the expression of genes in the underlying regulatory networks. Here, we report the results of an experimental procedure designed to gain insight into the fundamental mechanisms of metabolic flexibility in the dark-eyed junco (Junco hyemalis). We combined genomic transcriptional profiles with measures of metabolic enzyme activities and whole-animal thermogenic performance from juncos exposed to four 6-week acclimation treatments that varied in temperature (cold, 3°C; warm, 24°C) and photoperiod (short day, 8 h light:16 h dark; long day, 16 h light:8 h dark). Cold-acclimated birds increased thermogenic capacity compared with warm-acclimated birds, and this enhanced performance was associated with upregulation of genes involved in muscle hypertrophy, angiogenesis, and lipid transport and oxidation, as well as with catabolic enzyme activities. These physiological changes occurred over ecologically relevant timescales, suggesting that birds make regulatory adjustments to interacting, hierarchical pathways in order to seasonally enhance thermogenic capacity.
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Affiliation(s)
- Maria Stager
- Department of Animal Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - David L. Swanson
- Department of Biology, University of South Dakota, Vermillion, SD 57069, USA
| | - Zachary A. Cheviron
- Department of Animal Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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