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Beiter T, Zügel M, Hudemann J, Schild M, Fragasso A, Burgstahler C, Krüger K, Mooren FC, Steinacker JM, Nieß AM. The Acute, Short-, and Long-Term Effects of Endurance Exercise on Skeletal Muscle Transcriptome Profiles. Int J Mol Sci 2024; 25:2881. [PMID: 38474128 DOI: 10.3390/ijms25052881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/14/2024] Open
Abstract
A better understanding of the cellular and molecular mechanisms that are involved in skeletal muscle adaptation to exercise is fundamentally important to take full advantage of the enormous benefits that exercise training offers in disease prevention and therapy. The aim of this study was to elucidate the transcriptional signatures that distinguish the endurance-trained and untrained muscles in young adult males (24 ± 3.5 years). We characterized baseline differences as well as acute exercise-induced transcriptome responses in vastus lateralis biopsy specimens of endurance-trained athletes (ET; n = 8; VO2max, 67.2 ± 8.9 mL/min/kg) and sedentary healthy volunteers (SED; n = 8; VO2max, 40.3 ± 7.6 mL/min/kg) using microarray technology. A second cohort of SED volunteers (SED-T; n = 10) followed an 8-week endurance training program to assess expression changes of selected marker genes in the course of skeletal muscle adaptation. We deciphered differential baseline signatures that reflected major differences in the oxidative and metabolic capacity of the endurance-trained and untrained muscles. SED-T individuals in the training group displayed an up-regulation of nodal regulators of oxidative adaptation after 3 weeks of training and a significant shift toward the ET signature after 8 weeks. Transcriptome changes provoked by 1 h of intense cycling exercise only poorly overlapped with the genes that constituted the differential baseline signature of ETs and SEDs. Overall, acute exercise-induced transcriptional responses were connected to pathways of contractile, oxidative, and inflammatory stress and revealed a complex and highly regulated framework of interwoven signaling cascades to cope with exercise-provoked homeostatic challenges. While temporal transcriptional programs that were activated in SEDs and ETs were quite similar, the quantitative divergence in the acute response transcriptomes implicated divergent kinetics of gene induction and repression following an acute bout of exercise. Together, our results provide an extensive examination of the transcriptional framework that underlies skeletal muscle plasticity.
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Affiliation(s)
- Thomas Beiter
- Department of Sports Medicine, Medical Clinic, Eberhard-Karls-University of Tübingen, 72076 Tübingen, Germany
| | - Martina Zügel
- Department of Sport and Rehabilitation Medicine, University of Ulm, 89075 Ulm, Germany
| | - Jens Hudemann
- Department of Sports Medicine, Medical Clinic, Eberhard-Karls-University of Tübingen, 72076 Tübingen, Germany
| | - Marius Schild
- Department of Exercise Physiology and Sports Therapy, University of Gießen, 35394 Gießen, Germany
| | - Annunziata Fragasso
- Department of Sports Medicine, Medical Clinic, Eberhard-Karls-University of Tübingen, 72076 Tübingen, Germany
| | - Christof Burgstahler
- Department of Sports Medicine, Medical Clinic, Eberhard-Karls-University of Tübingen, 72076 Tübingen, Germany
| | - Karsten Krüger
- Department of Exercise Physiology and Sports Therapy, University of Gießen, 35394 Gießen, Germany
| | - Frank C Mooren
- Department of Medicine, Faculty of Health, University of Witten/Herdecke, 58455 Witten, Germany
| | - Jürgen M Steinacker
- Department of Sport and Rehabilitation Medicine, University of Ulm, 89075 Ulm, Germany
| | - Andreas M Nieß
- Department of Sports Medicine, Medical Clinic, Eberhard-Karls-University of Tübingen, 72076 Tübingen, Germany
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2
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Dong H, Tsai SY. Mitochondrial Properties in Skeletal Muscle Fiber. Cells 2023; 12:2183. [PMID: 37681915 PMCID: PMC10486962 DOI: 10.3390/cells12172183] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 08/16/2023] [Accepted: 08/24/2023] [Indexed: 09/09/2023] Open
Abstract
Mitochondria are the primary source of energy production and are implicated in a wide range of biological processes in most eukaryotic cells. Skeletal muscle heavily relies on mitochondria for energy supplements. In addition to being a powerhouse, mitochondria evoke many functions in skeletal muscle, including regulating calcium and reactive oxygen species levels. A healthy mitochondria population is necessary for the preservation of skeletal muscle homeostasis, while mitochondria dysregulation is linked to numerous myopathies. In this review, we summarize the recent studies on mitochondria function and quality control in skeletal muscle, focusing mainly on in vivo studies of rodents and human subjects. With an emphasis on the interplay between mitochondrial functions concerning the muscle fiber type-specific phenotypes, we also discuss the effect of aging and exercise on the remodeling of skeletal muscle and mitochondria properties.
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Affiliation(s)
- Han Dong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore;
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117593, Singapore;
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore
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3
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Liu H, Wang J. The Effects of Incorporating Dry-land Short Intervals to Long Aerobic-dominant In-Water Swimming Training on Physiological Parameters, Hormonal Factors, and Performance: A Randomized-Controlled Intervention Study. J Sports Sci Med 2023; 22:329-337. [PMID: 37293428 PMCID: PMC10244997 DOI: 10.52082/jssm.2023.329] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/21/2023] [Indexed: 06/10/2023]
Abstract
This study investigated the impact of a 4-week dry-land short sprint interval program (sSIT) on a swim ergometer, when incorporated into long aerobic-dominant in-water swimming training, on the physiological parameters, hormonal factors, and swimming performance of well-trained swimmers. Sixteen participants (age = 25 ± 6 years, height = 183 ± 6 cm, weight 78 ± 6 kg, body fat = 10.6 ± 3.1%) were randomized to either a long aerobic-dominant in-pool training plus three sessions/week of sSIT or a control group (CON) who didn't engage in SIT. sSIT consisted of 3 sets of 10 × 4 s, 10 × 6 s, and 10 × 8 s all-out sprints interspersed by 15, 60, and 40 s recovery between each sprint, respectively. Pre- and post-training assessments included peak oxygen uptake (V̇O2peak), O2pulse (V̇O2/HR), ventilation at V̇O2peak (V̇E@V̇O2peak), peak and average power output, and freestyle swim performance at 50, 100, and 200-m distances, stroke rate, as well as testosterone and cortisol. sSIT resulted in significant improvements in V̇O2peak (5.8%), O2pulse (4.7%), V̇E@V̇O2peak (7.1%), peak and average power output (6.7% and 13.8%, respectively), total testosterone (20%), testosterone to cortisol ratio (16.1%), and 50, 100, and 200-m freestyle swimming performance (-2.2%, -1.2%, and -1.1%, respectively). Furthermore, the observed alterations in the physiological, biochemical, and performance adaptations were significantly more substantial in the sSIT group than the CON group (p ≤ 0.05), demonstrating no modifications during the 4-week long aerobic-dominant in-water swimming without sSIT. The current research effectively established that supplementing standard long aerobic-dominant in-water swim training with three weekly dry-land sSIT sessions triggers adaptive mechanisms that foster enhancements in the aerobic and anaerobic capacity and swimming performance in well-trained swimmers.
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Affiliation(s)
- Huan Liu
- Woosuk University, 443, Samnye-ro, Samnye-eup, Wanju-gun, Jeollabuk-do, 55338, South Korea
| | - Jue Wang
- Kookmin University, 77 Jeongeung-ro, Seongbuk-gu, Seoul, 02707, South Korea
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4
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Boullosa D, Dragutinovic B, Feuerbacher J, Benítez-Flores S, Coyle E, Schumann M. Effects of short sprint interval training on aerobic and anaerobic indices: A systematic review and meta-analysis. Scand J Med Sci Sports 2022; 32:810-820. [PMID: 35090181 DOI: 10.1111/sms.14133] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 11/26/2022]
Abstract
The effects of short sprint interval training (sSIT) with efforts of ≤10 seconds on maximal oxygen consumption (V̇O2 max), aerobic and anaerobic performances remain unknown. To verify the effectiveness of sSIT in physically active adults and athletes, a systematic literature search was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The databases PubMed/MEDLINE, ISI Web of Science, SPORTDiscus were systematically searched on the 9th of May 2020 and updated on the 14th of September 2021. Inclusion criteria were based on PICO and included healthy athletes and active adults of any sex (≤40 years), performing supervised sSIT (≤10 s of "all out" and non "all out" efforts) of at least 2 weeks, with a minimum of 6 sessions. As a comparator, a non-sSIT control group, another high-intensity interval training (HIIT) group, or a continuous training (CT) group were required. A total of 18 studies was deemed eligible. The estimated SMDs based on the random-effects model were -0.56 (95% CI: -0.79, -0.33, p < 0.001) for V̇O2 max, -0.43 (95% CI: -0.67, -0.20, p < 0.001) for aerobic performance, and -0.44 (95% CI: -0.70, -0.18, p < 0.001) for anaerobic performance after sSIT vs. no exercise/usual training. However, there were no significant differences (p > 0.05) for all outcomes when comparing sSIT vs. HIIT/CT. Our findings indicate a very high effectiveness of sSIT protocols in different exercise modes (e.g. cycling, running, paddling, punching) to improve V̇O2 max, aerobic and anaerobic performances in physically active young healthy adults and athletes.
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Affiliation(s)
- Daniel Boullosa
- Integrated Institute of Health, Federal University of Mato Grosso do Sul, Campo Grande, Brazil
| | - Boris Dragutinovic
- Department of Molecular and Cellular Sports Medicine, German Sport University, Cologne, Germany
| | - Joshua Feuerbacher
- Department of Molecular and Cellular Sports Medicine, German Sport University, Cologne, Germany
| | - Stefano Benítez-Flores
- Department of Physical Education and Health, Higher Institute of Physical Education, University of the Republic, Montevideo, Uruguay
| | - Edward Coyle
- Human Performance Laboratory, University of Texas at Austin, Austin, USA
| | - Moritz Schumann
- Department of Molecular and Cellular Sports Medicine, German Sport University, Cologne, Germany
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Perelló-Amorós M, Fernández-Borràs J, Sánchez-Moya A, Vélez EJ, García-Pérez I, Gutiérrez J, Blasco J. Mitochondrial Adaptation to Diet and Swimming Activity in Gilthead Seabream: Improved Nutritional Efficiency. Front Physiol 2021; 12:678985. [PMID: 34220544 PMCID: PMC8249818 DOI: 10.3389/fphys.2021.678985] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 05/21/2021] [Indexed: 01/09/2023] Open
Abstract
Sustained exercise promotes growth in different fish species, and in gilthead seabream we have demonstrated that it improves nutrient use efficiency. This study assesses for differences in growth rate, tissue composition and energy metabolism in gilthead seabream juveniles fed two diets: high-protein (HP; 54% protein, 15% lipid) or high energy (HE; 50% protein, 20% lipid), under voluntary swimming (VS) or moderate-to-low-intensity sustained swimming (SS) for 6 weeks. HE fed fish under VS conditions showed lower body weight and higher muscle lipid content than HP fed fish, but no differences between the two groups were observed under SS conditions. Irrespective of the swimming regime, the white muscle stable isotopes profile of the HE group revealed increased nitrogen and carbon turnovers. Nitrogen fractionation increased in the HP fed fish under SS, indicating enhanced dietary protein oxidation. Hepatic gene expression markers of energy metabolism and mitochondrial biogenesis showed clear differences between the two diets under VS: a significant shift in the COX/CS ratio, modifications in UCPs, and downregulation of PGC1a in the HE-fed fish. Swimming induced mitochondrial remodeling through upregulation of fusion and fission markers, and removing almost all the differences observed under VS. In the HE-fed fish, white skeletal muscle benefited from the increased energy demand, amending the oxidative uncoupling produced under the VS condition by an excess of lipids and the pro-fission state observed in mitochondria. Contrarily, red muscle revealed more tolerant to the energy content of the HE diet, even under VS conditions, with higher expression of oxidative enzymes (COX and CS) without any sign of mitochondrial stress or mitochondrial biogenesis induction. Furthermore, this tissue had enough plasticity to shift its metabolism under higher energy demand (SS), again equalizing the differences observed between diets under VS condition. Globally, the balance between dietary nutrients affects mitochondrial regulation due to their use as energy fuels, but exercise corrects imbalances allowing practical diets with lower protein and higher lipid content without detrimental effects.
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Affiliation(s)
- Miquel Perelló-Amorós
- Department of Cell Biology, Physiology, and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Jaume Fernández-Borràs
- Department of Cell Biology, Physiology, and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Albert Sánchez-Moya
- Department of Cell Biology, Physiology, and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Emilio J Vélez
- Université de Pau et des Pays de l'Adour, E2S UPPA, INRAE, UMR 1419 Nutrition Métabolisme et Aquaculture, Saint-Pée-sur-Nivelle, France
| | - Isabel García-Pérez
- Department of Cell Biology, Physiology, and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Joaquin Gutiérrez
- Department of Cell Biology, Physiology, and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Josefina Blasco
- Department of Cell Biology, Physiology, and Immunology, Faculty of Biology, University of Barcelona, Barcelona, Spain
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6
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Bartlett MF, Fitzgerald LF, Kent JA. Rates of oxidative ATP synthesis are not augmented beyond the pH threshold in human vastus lateralis muscles during a stepwise contraction protocol. J Physiol 2021; 599:1997-2013. [PMID: 33576028 DOI: 10.1113/jp280851] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 02/05/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The oxygen cost of high-intensity exercise at power outputs above an individual's lactate threshold (LT) is greater than would be predicted by the linear oxygen consumption-power relationship observed below the LT. However, whether these augmentations are caused by an increased ATP cost of force generation (ATPCOST ) or an increased oxygen cost of ATP synthesis is unclear. We used 31 P-MRS to measure changes in cytosolic [ADP] (intramyocellular marker of oxidative metabolism), oxidative ATP synthesis (ATPOX ) and ATPCOST during a 6-stage, stepwise knee extension protocol. ATPCOST was unchanged across stages. The relationship between [ADP] and muscle power output was augmented at workloads above the pH threshold (pHT ; proxy for LT), whereas increases in ATPOX were attenuated. These results suggest the greater oxygen cost of contractions at workloads beyond the pHT is not caused by mechanisms that increase ATPCOST , but rather mechanisms that alter intrinsic mitochondrial function or capacity. ABSTRACT Increases in skeletal muscle metabolism and oxygen consumption are linearly related to muscle power output for workloads below the lactate threshold (LT), but are augmented (i.e. greater rate of increase relative to workload) thereafter. Presently, it is unclear whether these metabolic augmentations are caused by increases in the ATP cost of force generation (ATPCOST ) or changes in the efficiency of mitochondrial oxygen consumption and oxidative ATP synthesis (ATPOX ). To partition these two hypotheses in vivo, we used 31 P-MRS to calculate slopes relating step-changes in muscle work to concurrent changes in cytosolic phosphates and ATPOX before and after the pH threshold (pHT ; used here as a proxy for LT) within the vastus lateralis muscle of eight young adults during a stepwise knee extension test. Changes in muscle phosphates and ATPOX were linearly related to workload below the pHT . However, slopes above the pHT were greater for muscle phosphates (P < 0.05) and lower for ATPOX (P < 0.05) than were the slopes observed below the pHT . The maximal capacity for ATPOX ( V ̇ max ) and ADP-specific ATPOX also declined beyond the pHT (P < 0.05), whereas ATPCOST was unchanged (P = 0.10). These results oppose the hypothesis that high-intensity contractions increase ATPCOST and suggest that greater oxidative metabolism at workloads beyond the pHT is caused by mechanisms that affect intrinsic mitochondrial function or capacity, such as alterations in substrate selection or electron entry into the electron transport chain, temperature-mediated changes in mitochondrial permeability to protons, or stimulation of mitochondrial uncoupling by reactive oxygen species generation.
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Affiliation(s)
- Miles F Bartlett
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Liam F Fitzgerald
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA
| | - Jane A Kent
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA
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7
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Skelly LE, Gillen JB, Frankish BP, MacInnis MJ, Godkin FE, Tarnopolsky MA, Murphy RM, Gibala MJ. Human skeletal muscle fiber type-specific responses to sprint interval and moderate-intensity continuous exercise: acute and training-induced changes. J Appl Physiol (1985) 2021; 130:1001-1014. [PMID: 33630680 DOI: 10.1152/japplphysiol.00862.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
There are limited and equivocal data regarding potential fiber type-specific differences in the human skeletal muscle response to sprint interval training (SIT), including how this compares with moderate-intensity continuous training (MICT). We examined mixed-muscle and fiber type-specific responses to a single session (study 1) and to 12 wk (study 2) of MICT and SIT using Western blot analysis. MICT consisted of 45 min of cycling at ∼70% of maximal heart rate, and SIT involved 3 × 20-s "all-out" sprints interspersed with 2 min of recovery. Changes in signaling proteins involved in mitochondrial biogenesis in mixed-muscle and pooled fiber samples were similar after acute MICT and SIT. This included increases in the ratios of phosphorylated to total acetyl-CoA carboxylase and p38 mitogen-activated protein kinase protein content (main effects, P < 0.05). Following training, mitochondrial content markers including the protein content of cytochrome c oxidase subunit IV and NADH:ubiquinone oxidoreductase subunit A9 were increased similarly in mixed-muscle and type IIa fibers (main effects, P < 0.05). In contrast, only MICT increased these markers of mitochondrial content in type I fibers (interactions, P < 0.05). MICT and SIT also similarly increased the content of mitochondrial fusion proteins optic atrophy 1 (OPA1) and mitofusin 2 in mixed-muscle, and OPA1 in pooled fiber samples (main effects, P < 0.02). In summary, acute MICT and SIT elicited similar fiber type-specific responses of signaling proteins involved in mitochondrial biogenesis, whereas 12 wk of training revealed differential responses of mitochondrial content markers in type I but not type IIa fibers.NEW & NOTEWORTHY We examined mixed-muscle and fiber type-specific responses to a single session and to 12 wk of moderate-intensity continuous training (MICT) and sprint interval training (SIT) in humans. Both interventions elicited generally similar responses, although the training-induced increases in type I fiber-specific markers of mitochondrial content were greater in MICT than in SIT. These findings advance our understanding of the potential role of fiber type-specific changes in determining the human skeletal muscle response to intermittent and continuous exercise.
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Affiliation(s)
- Lauren E Skelly
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Jenna B Gillen
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.,Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
| | - Barnaby P Frankish
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, Melbourne, Victoria, Australia
| | - Martin J MacInnis
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.,Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - F Elizabeth Godkin
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Mark A Tarnopolsky
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada.,Department of Pediatrics, McMaster University, Hamilton, Ontario, Canada
| | - Robyn M Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, Melbourne, Victoria, Australia.,Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - Martin J Gibala
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
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8
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Bartlett MF, Fitzgerald LF, Nagarajan R, Hiroi Y, Kent JA. Oxidative ATP synthesis in human quadriceps declines during 4 minutes of maximal contractions. J Physiol 2020; 598:1847-1863. [PMID: 32045011 DOI: 10.1113/jp279339] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/30/2020] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS During maximal exercise, skeletal muscle metabolism and oxygen consumption remain elevated despite precipitous declines in power. Presently, it is unclear whether these responses are caused by an increased ATP cost of force generation (ATPCOST ) or mitochondrial uncoupling; a process that reduces the efficiency of oxidative ATP synthesis (ATPOX ). To address this gap, we used 31-phosphorus magnetic resonance spectroscopy to measure changes in ATPCOST and ATPOX in human quadriceps during repeated trials of maximal intensity knee extensions lasting up to 4 min. ATPCOST remained unchanged. In contrast, ATPOX plateaued by ∼2 min and then declined (∼15%) over the final 2 min. The maximal capacity for ATPOX (Vmax ), as well as ADP-specific rates of ATPOX , were also significantly diminished. Collectively, these results suggest that mitochondrial uncoupling, and not increased ATPCOST , is responsible for altering the regulation of skeletal muscle metabolism and oxygen consumption during maximal exercise. ABSTRACT The relationship between skeletal muscle oxygen consumption and power output is augmented during exercise at workloads above the lactate threshold. Potential mechanisms for this response have been hypothesized, including increased ATP cost of force generation (ATPCOST ) and mitochondrial uncoupling, a process that reduces the efficiency of oxidative ATP synthesis (ATPOX ). To test these hypotheses, we used phosphorus magnetic resonance spectroscopy to non-invasively measure changes in phosphate concentrations and pH in the vastus lateralis muscle of nine young adults during repeated trials of maximal, all-out dynamic knee extensions (120°s-1 , 1 every 2 s) lasting 24, 60, 120, and 240 s. ATPOX was measured at each time point from the initial velocity of PCr resynthesis, and ATPCOST was calculated as the sum of ATP synthesized by the creatine and adenylate kinase reactions, non-oxidative glycolysis, ATPOX and net changes in [ATP]. Power output declined in a reproducible manner for all four trials. ATPCOST did not change over time (main effect P = 0.45). ATPOX plateaued from 60 to 120 s and then decreased over the final 120 s (main effect P = 0.001). The maximal capacity for oxidative ATP synthesis (Vmax ), as well as ADP-specific rates of ATPOX , also decreased over time (main effect P = 0.001, both). Collectively, these results demonstrate that prolonged maximal contraction protocols impair oxidative energetics and implicate mitochondrial uncoupling as the mechanism for this response. The causes of mitochondrial uncoupling are presently unknown but may offer a potential explanation for the dissociation between skeletal muscle power output and oxygen consumption during maximal, all-out exercise protocols.
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Affiliation(s)
- Miles F Bartlett
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, 01003.,Department of Kinesiology, University of Texas, Arlington, Texas, 76019
| | - Liam F Fitzgerald
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, 01003
| | - Rajakumar Nagarajan
- Human Magnetic Resonance Center, Institute for Applied Life Sciences (IALS), University of Massachusetts, Amherst, Massachusetts, 01003
| | - Yeun Hiroi
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, 01003
| | - Jane A Kent
- Muscle Physiology Laboratory, Department of Kinesiology, University of Massachusetts, Amherst, Massachusetts, 01003
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9
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Zhang Y, Yan H, Zhou P, Zhang Z, Liu J, Zhang H. MicroRNA-152 Promotes Slow-Twitch Myofiber Formation via Targeting Uncoupling Protein-3 Gene. Animals (Basel) 2019; 9:ani9090669. [PMID: 31509946 PMCID: PMC6769457 DOI: 10.3390/ani9090669] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 08/11/2019] [Accepted: 09/05/2019] [Indexed: 11/16/2022] Open
Abstract
The differences of pork quality characteristics among different pig breeds mainly came from the differences in myofiber type compositions. Growing evidence indicated the key role of miRNAs in myofiber specification. In the present study, we found that miR-152 is more abundant in the slow-twitch myofiber-enriched muscles. However, its role in myofiber type transformation and myogenesis is largely unknown. Overexpression of miR-152 in porcine myotubes promoted the formation of slow-twitch myofibers and myogenesis. While, inhibition of miR-152 expression showed the opposite effect to miR-152 mimics transfection. The luciferase reporter analysis confirmed that miR-152 straightly targets the 3'-untranslated region (3'-UTR) of uncoupling protein 3 (UCP3) to cause its post-transcriptional inhibition in the protein level. The knockdown of UCP3 by siRNA showed the similar effect of miR-152 on myofiber type transition. Furthermore, the rescue experiment in the porcine myotube transfected with miR-152 mimics or/and UCP3 overexpression plasmid with or without the 3'UTR revealed that UCP3 mediates the action of miR-152 in slow-twitch myofiber formation. Taken together, our findings proposed a novel molecular mechanism through which miR-152 epigenetically regulates meat quality via promoting slow-twitch myofiber formation and skeletal myogenesis.
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Affiliation(s)
- Yong Zhang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Honglin Yan
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Pan Zhou
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Zhenzhen Zhang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
| | - Jingbo Liu
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
| | - Hongfu Zhang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China
- State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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10
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Fiorenza M, Lemminger AK, Marker M, Eibye K, Iaia FM, Bangsbo J, Hostrup M. High-intensity exercise training enhances mitochondrial oxidative phosphorylation efficiency in a temperature-dependent manner in human skeletal muscle: implications for exercise performance. FASEB J 2019; 33:8976-8989. [PMID: 31136218 DOI: 10.1096/fj.201900106rrr] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The purpose of the present study was to investigate whether exercise training-induced adaptations in human skeletal muscle mitochondrial bioenergetics are magnified under thermal conditions resembling sustained intense contractile activity and whether training-induced changes in mitochondrial oxidative phosphorylation (OXPHOS) efficiency influence exercise efficiency. Twenty healthy men performed 6 wk of high-intensity exercise training [i.e., speed endurance training (SET; n = 10)], or maintained their usual lifestyle (n = 10). Before and after the intervention, mitochondrial respiratory function was determined ex vivo in permeabilized muscle fibers under experimentally-induced normothermia (35°C) and hyperthermia (40°C) mimicking in vivo muscle temperature at rest and during intense exercise, respectively. In addition, activity and content of muscle mitochondrial enzymes and proteins were quantified. Exercising muscle efficiency was determined in vivo by measurements of leg hemodynamics and blood parameters during one-legged knee-extensor exercise. SET enhanced maximal OXPHOS capacity and OXPHOS efficiency at 40°C, but not at 35°C, and attenuated hyperthermia-induced decline in OXPHOS efficiency. Furthermore, SET increased expression of markers of mitochondrial content and up-regulated content of MFN2, DRP1, and ANT1. Also, SET improved exercise efficiency and capacity. These findings indicate that muscle mitochondrial bioenergetics adapts to high-intensity exercise training in a temperature-dependent manner and that enhancements in mitochondrial OXPHOS efficiency may contribute to improving exercise performance.-Fiorenza, M., Lemminger, A. K., Marker, M., Eibye, K., Iaia, F. M., Bangsbo, J., Hostrup, M. High-intensity exercise training enhances mitochondrial oxidative phosphorylation efficiency in a temperature-dependent manner in human skeletal muscle: implications for exercise performance.
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Affiliation(s)
- Matteo Fiorenza
- Section of Integrative Physiology, Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark.,Department of Neurosciences, Biomedicine, and Movement Sciences, University of Verona, Verona, Italy
| | - Anders K Lemminger
- Section of Integrative Physiology, Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Mathias Marker
- Section of Integrative Physiology, Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Eibye
- Section of Integrative Physiology, Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - F Marcello Iaia
- Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
| | - Jens Bangsbo
- Section of Integrative Physiology, Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise, and Sports, University of Copenhagen, Copenhagen, Denmark
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TaheriChadorneshin H, Rostamkhani F, Shirvani H. Long-term effects of sprint interval training on expression of cardiac genes involved in energy efficiency. SPORT SCIENCES FOR HEALTH 2019. [DOI: 10.1007/s11332-018-0480-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Eigendorf J, May M, Friedrich J, Engeli S, Maassen N, Gros G, Meissner JD. High Intensity High Volume Interval Training Improves Endurance Performance and Induces a Nearly Complete Slow-to-Fast Fiber Transformation on the mRNA Level. Front Physiol 2018; 9:601. [PMID: 29897050 PMCID: PMC5987183 DOI: 10.3389/fphys.2018.00601] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/03/2018] [Indexed: 12/29/2022] Open
Abstract
We present here a longitudinal study determining the effects of two 3 week-periods of high intensity high volume interval training (HIHVT) (90 intervals of 6 s cycling at 250% maximum power, Pmax/24 s) on a cycle ergometer. HIHVT was evaluated by comparing performance tests before and after the entire training (baseline, BSL, and endpoint, END) and between the two training sets (intermediate, INT). The mRNA expression levels of myosin heavy chain (MHC) isoforms and markers of energy metabolism were analyzed in M. vastus lateralis biopsies by quantitative real-time PCR. In incremental tests peak power (Ppeak) was increased, whereas V ˙ O2peak was unaltered. Prolonged time-to-exhaustion was found in endurance tests with 65 and 80% Pmax at INT and END. No changes in blood levels of lipid metabolites were detected. Training-induced decreases of hematocrit indicate hypervolemia. A shift from slow MHCI/β to fast MHCIIa mRNA expression occurred after the first and second training set. The mRNA expression of peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), a master regulator of oxidative energy metabolism, decreased after the second training set. In agreement, a significant decrease was also found for citrate synthase mRNA after the second training set, indicating reduced oxidative capacity. However, mRNA expression levels of glycolytic marker enzyme glyceraldehyde-3-phosphate dehydrogenase did not change after the first and second training set. HIHVT induced a nearly complete slow-to-fast fiber type transformation on the mRNA level, which, however, cannot account for the improvements of performance parameters. The latter might be explained by the well-known effects of hypervolemia on exercise performance.
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Affiliation(s)
- Julian Eigendorf
- Institute of Sports Medicine, Hannover Medical School, Hannover, Germany
| | - Marcus May
- Clinical Research Center Hannover, Hannover Medical School, Hannover, Germany
| | - Jan Friedrich
- Institute of Sports Medicine, Hannover Medical School, Hannover, Germany
| | - Stefan Engeli
- Institute of Clinical Pharmacology, Hannover Medical School, Hannover, Germany
| | - Norbert Maassen
- Institute of Sports Medicine, Hannover Medical School, Hannover, Germany
- Institute of Sports Science, Leibniz University Hannover, Hannover, Germany
| | - Gerolf Gros
- Molecular and Cell Physiology, AG Vegetative Physiology, Hannover Medical School, Hannover, Germany
| | - Joachim D. Meissner
- Molecular and Cell Physiology, AG Vegetative Physiology, Hannover Medical School, Hannover, Germany
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Miller VJ, Villamena FA, Volek JS. Nutritional Ketosis and Mitohormesis: Potential Implications for Mitochondrial Function and Human Health. J Nutr Metab 2018; 2018:5157645. [PMID: 29607218 PMCID: PMC5828461 DOI: 10.1155/2018/5157645] [Citation(s) in RCA: 113] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 12/27/2017] [Indexed: 02/07/2023] Open
Abstract
Impaired mitochondrial function often results in excessive production of reactive oxygen species (ROS) and is involved in the etiology of many chronic diseases, including cardiovascular disease, diabetes, neurodegenerative disorders, and cancer. Moderate levels of mitochondrial ROS, however, can protect against chronic disease by inducing upregulation of mitochondrial capacity and endogenous antioxidant defense. This phenomenon, referred to as mitohormesis, is induced through increased reliance on mitochondrial respiration, which can occur through diet or exercise. Nutritional ketosis is a safe and physiological metabolic state induced through a ketogenic diet low in carbohydrate and moderate in protein. Such a diet increases reliance on mitochondrial respiration and may, therefore, induce mitohormesis. Furthermore, the ketone β-hydroxybutyrate (BHB), which is elevated during nutritional ketosis to levels no greater than those resulting from fasting, acts as a signaling molecule in addition to its traditionally known role as an energy substrate. BHB signaling induces adaptations similar to mitohormesis, thereby expanding the potential benefit of nutritional ketosis beyond carbohydrate restriction. This review describes the evidence supporting enhancement of mitochondrial function and endogenous antioxidant defense in response to nutritional ketosis, as well as the potential mechanisms leading to these adaptations.
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Affiliation(s)
- Vincent J. Miller
- Department of Human Sciences, College of Education and Human Ecology, The Ohio State University, Columbus, OH, USA
| | - Frederick A. Villamena
- Department of Biological Chemistry and Pharmacology, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Jeff S. Volek
- Department of Human Sciences, College of Education and Human Ecology, The Ohio State University, Columbus, OH, USA
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Skovgaard C, Christiansen D, Christensen PM, Almquist NW, Thomassen M, Bangsbo J. Effect of speed endurance training and reduced training volume on running economy and single muscle fiber adaptations in trained runners. Physiol Rep 2018; 6:e13601. [PMID: 29417745 PMCID: PMC5803184 DOI: 10.14814/phy2.13601] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 01/07/2018] [Accepted: 01/09/2018] [Indexed: 12/03/2022] Open
Abstract
The aim of the present study was to examine whether improved running economy with a period of speed endurance training and reduced training volume could be related to adaptations in specific muscle fibers. Twenty trained male (n = 14) and female (n = 6) runners (maximum oxygen consumption (VO2 -max): 56.4 ± 4.6 mL/min/kg) completed a 40-day intervention with 10 sessions of speed endurance training (5-10 × 30-sec maximal running) and a reduced (36%) volume of training. Before and after the intervention, a muscle biopsy was obtained at rest, and an incremental running test to exhaustion was performed. In addition, running at 60% vVO2 -max, and a 10-km run was performed in a normal and a muscle slow twitch (ST) glycogen-depleted condition. After compared to before the intervention, expression of mitochondrial uncoupling protein 3 (UCP3) was lower (P < 0.05) and dystrophin was higher (P < 0.05) in ST muscle fibers, and sarcoplasmic reticulum calcium ATPase 1 (SERCA1) was lower (P < 0.05) in fast twitch muscle fibers. Running economy at 60% vVO2 -max (11.6 ± 0.2 km/h) and at v10-km (13.7 ± 0.3 km/h) was ~2% better (P < 0.05) after the intervention in the normal condition, but unchanged in the ST glycogen-depleted condition. Ten kilometer performance was improved (P < 0.01) by 3.2% (43.7 ± 1.0 vs. 45.2 ± 1.2 min) and 3.9% (45.8 ± 1.2 vs. 47.7 ± 1.3 min) in the normal and the ST glycogen-depleted condition, respectively. VO2 -max was the same, but vVO2 -max was 2.0% higher (P < 0.05; 19.3 ± 0.3 vs. 18.9 ± 0.3 km/h) after than before the intervention. Thus, improved running economy with intense training may be related to changes in expression of proteins linked to energy consuming processes in primarily ST muscle fibers.
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Affiliation(s)
- Casper Skovgaard
- Department of Nutrition, Exercise and SportsSection of Integrative PhysiologyUniversity of CopenhagenCopenhagenDenmark
- Team Danmark (Danish Elite Sports Organization)CopenhagenDenmark
| | - Danny Christiansen
- Institute of Sport, Exercise and Active Living (ISEAL)Victoria UniversityMelbourneAustralia
| | - Peter M. Christensen
- Department of Nutrition, Exercise and SportsSection of Integrative PhysiologyUniversity of CopenhagenCopenhagenDenmark
- Team Danmark (Danish Elite Sports Organization)CopenhagenDenmark
| | - Nicki W. Almquist
- Department of Nutrition, Exercise and SportsSection of Integrative PhysiologyUniversity of CopenhagenCopenhagenDenmark
| | - Martin Thomassen
- Department of Nutrition, Exercise and SportsSection of Integrative PhysiologyUniversity of CopenhagenCopenhagenDenmark
| | - Jens Bangsbo
- Department of Nutrition, Exercise and SportsSection of Integrative PhysiologyUniversity of CopenhagenCopenhagenDenmark
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15
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Endurance training increases the efficiency of rat skeletal muscle mitochondria. Pflugers Arch 2016; 468:1709-24. [PMID: 27568192 PMCID: PMC5026720 DOI: 10.1007/s00424-016-1867-9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 08/04/2016] [Accepted: 08/08/2016] [Indexed: 11/18/2022]
Abstract
Endurance training enhances mitochondrial oxidative capacity, but its effect on mitochondria functioning is poorly understood. In the present study, the influence of an 8-week endurance training on the bioenergetic functioning of rat skeletal muscle mitochondria under different assay temperatures (25, 35, and 42 °C) was investigated. The study was performed on 24 adult 4-month-old male Wistar rats, which were randomly assigned to either a treadmill training group (n = 12) or a sedentary control group (n = 12). In skeletal muscles, endurance training stimulated mitochondrial biogenesis and oxidative capacity. In isolated mitochondria, endurance training increased the phosphorylation rate and elevated levels of coenzyme Q. Moreover, a decrease in mitochondrial uncoupling, including uncoupling protein-mediated proton leak, was observed after training, which could explain the increased reactive oxygen species production (in nonphosphorylating mitochondria) and enhanced oxidative phosphorylation efficiency. At all studied temperatures, endurance training significantly augmented H2O2 production (and coenzyme Q reduction level) in nonphosphorylating mitochondria and decreased H2O2 production (and coenzyme Q reduction level) in phosphorylating mitochondria. Endurance training magnified the hyperthermia-induced increase in oxidative capacity and attenuated the hyperthermia-induced decline in oxidative phosphorylation efficiency and reactive oxygen species formation of nonphosphorylating mitochondria via proton leak enhancement. Thus, endurance training induces both quantitative and qualitative changes in muscle mitochondria that are important for cell signaling as well as for maintaining muscle energy homeostasis, especially at high temperatures.
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16
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Nabben M, van Bree BWJ, Lenaers E, Hoeks J, Hesselink MKC, Schaart G, Gijbels MJJ, Glatz JFC, da Silva GJJ, de Windt LJ, Tian R, Mike E, Skapura DG, Wehrens XHT, Schrauwen P. Lack of UCP3 does not affect skeletal muscle mitochondrial function under lipid-challenged conditions, but leads to sudden cardiac death. Basic Res Cardiol 2014; 109:447. [PMID: 25344084 DOI: 10.1007/s00395-014-0447-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 10/07/2014] [Accepted: 10/15/2014] [Indexed: 12/29/2022]
Abstract
UCP3's exact physiological function in lipid handling in skeletal and cardiac muscle remains unknown. Interestingly, etomoxir, a fat oxidation inhibitor and strong inducer of UCP3, is proposed for treating both diabetes and heart failure. We hypothesize that the upregulation of UCP3 upon etomoxir serves to protect mitochondria against lipotoxicity. To evaluate UCP3's role in skeletal muscle (skm) and heart under lipid-challenged conditions, the effect of UCP3 ablation was examined in a state of dysbalance between fat availability and oxidative capacity. Wild type (WT) and UCP3(-/-) mice were subjected to high-fat feeding for 14 days. From day 6 onwards, they were given either saline or etomoxir. Etomoxir treatment induced an increase in markers of lipotoxicity in skm compared to saline. This increase upon etomoxir was similar for both, WT and UCP3(-/-) mice, suggesting that UCP3 does not play a role in protection against lipotoxicity. Interestingly, we observed 25 % mortality in UCP3(-/-)s upon etomoxir administration vs. 11 % in WTs. This increased mortality in UCP3(-/-) compared to WT mice could not be explained by differences in cardiac lipotoxicity, apoptosis, fibrosis (histology, immunohistochemistry), oxidative capacity (respirometry) or function (echocardiography). Electrophysiology demonstrated, however, prolonged QRS and QTc intervals and greater susceptibility to ventricular tachycardia upon programmed electrical stimulation in etomoxir-treated UCP3(-/-)s versus WTs. Isoproterenol administration after pacing resulted in 75 % mortality in UCP3(-/-)s vs. 14 % in WTs. Our results argue against a protective role for UCP3 on skm metabolism under lipid overload, but suggest UCP3 to be crucial in prevention of arrhythmias upon lipid-challenged conditions.
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Affiliation(s)
- Miranda Nabben
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Bianca W J van Bree
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Ellen Lenaers
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Joris Hoeks
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, PO Box 616, 6200 MD Maastricht, The Netherlands
| | - Matthijs K C Hesselink
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Gert Schaart
- Department of Human Movement Sciences, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Marion J J Gijbels
- Department of Molecular Genetics, CARIM School for Cardiovascular Research, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Jan F C Glatz
- Department of Molecular Genetics, CARIM School for Cardiovascular Research, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Gustavo J J da Silva
- Department of Cardiology, CARIM School for Cardiovascular Research, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Leon J de Windt
- Department of Cardiology, CARIM School for Cardiovascular Research, Maastricht University Medical Centre, Maastricht, The Netherlands
| | - Rong Tian
- Department of Anesthesiology and Pain Medicine, Mitochondria and Metabolism Center, University of Washington, Seattle, WA, USA
| | - Elise Mike
- Department of Molecular Physiology and Biophysics and Medicine (Cardiology), Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Darlene G Skapura
- Department of Molecular Physiology and Biophysics and Medicine (Cardiology), Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Xander H T Wehrens
- Department of Molecular Physiology and Biophysics and Medicine (Cardiology), Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - Patrick Schrauwen
- Department of Human Biology, NUTRIM School for Nutrition, Toxicology and Metabolism, Maastricht University Medical Centre, PO Box 616, 6200 MD Maastricht, The Netherlands
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Frankenberg NT, Lamb GD, Vissing K, Murphy RM. Subcellular fractionation reveals HSP72 does not associate with SERCA in human skeletal muscle following damaging eccentric and concentric exercise. J Appl Physiol (1985) 2014; 116:1503-11. [DOI: 10.1152/japplphysiol.00161.2013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Through its upregulation and/or translocation, heat shock protein 72 (HSP72) is involved in protection and repair of key proteins after physiological stress. In human skeletal muscle we investigated HSP72 protein after eccentric (ECC1) and concentric (CONC) exercise and repeated eccentric exercise (ECC2; 8 wk later) and whether it translocated from its normal cytosolic location to membranes/myofibrils. HSP72 protein increased ∼2-fold 24 h after ECC1, with no apparent change after CONC or ECC2. In resting (nonstressed) human skeletal muscle the total pool of HSP72 protein was present almost exclusively in the cytosolic fraction, and after each exercise protocol the distribution of HSP72 protein remained unaltered. Overall, the amount of HSP72 protein in the cytosol increased 24 h after ECC1, matching the fold increase that was measured in total HSP72 protein. To better ascertain the capabilities and limitations of HSP72, using quantitative Western blotting we determined the HSP72 protein content to be 11.4 μmol/kg wet weight in resting human vastus lateralis muscle, which is comprised of Type I (slow-twitch) and Type II (fast-twitch) fibers. HSP72 protein content was similar in individual Type I or II fiber segments. After physiological stress, HSP72 content can increase and, although the functional consequences of increased amounts of HSP72 protein are poorly understood, it has been shown to bind to and protect protein pumps like SERCA and Na+-K+-ATPase. Given no translocation of cytosolic HSP72, these findings suggest eccentric contractions, unlike other forms of stress such as heat, do not trigger tight binding of HSP72 to its primary membrane-bound target proteins, in particular SERCA.
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Affiliation(s)
- Noni T. Frankenberg
- Department of Zoology, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Graham D. Lamb
- Department of Zoology, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Kristian Vissing
- Section of Sport Science, Dept. of Public Health, Aarhus University, DK-8000 Aarhus, Denmark
| | - Robyn M. Murphy
- Department of Zoology, La Trobe University, Melbourne, Victoria, 3086, Australia
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18
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Da Boit M, Bailey SJ, Callow S, Dimenna FJ, Jones AM. Effects of interval and continuous training on O2 uptake kinetics during severe-intensity exercise initiated from an elevated metabolic baseline. J Appl Physiol (1985) 2014; 116:1068-77. [DOI: 10.1152/japplphysiol.01365.2013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to test the hypothesis that V̇o2 kinetics would be speeded to a greater extent following repeated sprint training (RST), compared with continuous endurance training (ET), in the transition from moderate- to severe-intensity exercise. Twenty-three recreationally active subjects were randomly assigned to complete six sessions of ET (60–110 min of moderate-intensity cycling) or RST (four to seven 30-s all-out Wingate tests) over a 2-wk period. Subjects completed three identical work-to-work cycling exercise tests before and after the intervention period, consisting of baseline cycling at 20 W followed by sequential step increments to moderate- and severe-intensity work rates. The severe-intensity bout was continued to exhaustion on one occasion and was followed by a 60-s all-out sprint on another occasion. Phase II pulmonary V̇o2 kinetics were speeded by a similar magnitude in both the lower (ET pre, 28 ± 4; ET post, 22 ± 4 s; RST pre, 25 ± 8; RST post, 20 ± 7 s) and upper (ET pre, 50 ± 10; ET post, 39 ± 11 s; RST pre, 54 ± 7; RST post, 40 ± 11 s) steps of the work-to-work test following ET and RST ( P < 0.05). The tolerable duration of exercise and the total amount of sprint work completed in the exercise performance test were also similarly enhanced by ET and RST ( P < 0.05). Therefore, ET and RST provoked comparable improvements in V̇o2 kinetics and exercise performance in the transition from an elevated baseline work rate, with RST being a more time-efficient approach to elicit these adaptations.
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Affiliation(s)
- Mariasole Da Boit
- School of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, United Kingdom
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19
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Abstract
Cancer biologists seem to have overlooked tumor metabolism in their research endeavors over the last 80 years of the last century, only to have "rediscovered Warburg" (Warburg et al. 1930; Warburg, Science 123(3191):309-314, 1956) within the first decade of the twenty-first century, as well as to suggest the importance of other, non-glucose-dependent, metabolic pathways such as such as fatty acid de novo synthesis and catabolism (β-oxidation) (Mashima et al., Br J Cancer 100:1369-1372, 2009) and glutamine catabolism (glutaminolysis) (DeBerardinis et al., Proc Nat Acad Sci 104(49):19345-19350, 2007). These non-glucose metabolic pathways seem to be just as important as the Warburg effect, if not potentially more so in human cancer. The purpose of this review is to highlight the importance of fatty acid metabolism in cancer cells and, where necessary, identify gaps in current knowledge and postulate hypothesis based upon findings in the cellular physiology of metabolic diseases and normal cells.
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Affiliation(s)
- Swethajit Biswas
- Sarcoma Research Group, Northern Institute for Cancer Research & North of England Bone & Soft Tissue Sarcoma Service, Paul O'Gorman Building, Newcastle University, Framlington Place, Newcastle-Upon-Tyne NE2 4HH, UK.
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20
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Gohil R, Lane TRA, Coughlin P. Review of the adaptation of skeletal muscle in intermittent claudication. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/wjcd.2013.34055] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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21
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Human skeletal muscle fiber type specific protein content. Anal Biochem 2012; 425:175-82. [PMID: 22469996 DOI: 10.1016/j.ab.2012.03.018] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 02/28/2012] [Accepted: 03/22/2012] [Indexed: 01/20/2023]
Abstract
The aim of this project was to develop a method to assess fiber type specific protein content across the continuum of human skeletal muscle fibers. Individual vastus lateralis muscle fibers (n = 264) were clipped into two portions: one for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) fiber typing and one for Western blot protein identification. Following fiber type determination, fiber segments were combined into fiber type specific pools (∼20 fibers/pool) and measured for total protein quantity, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), citrate synthase (CS), and total p38 content. GAPDH content was 64, 54, 160, and 138% more abundant in myosin heavy chain (MHC) I/IIa, MHC IIa, MHC IIa/IIx, and MHC IIx fibers, respectively, when compared with MHC I. Inversely, CS content was 528, 472, 242, and 47% more abundant in MHC I, MHC I/IIa, MHC IIa, and MHC IIa/IIx fibers, respectively, when compared with MHC IIx. Total p38 content was 87% greater in MHC IIa versus MHC I fibers. These data and this approach establish a reliable method for human skeletal muscle fiber type specific protein analysis. Initial results show that particular proteins exist in a hierarchal fashion throughout the continuum of human skeletal muscle fiber types, further highlighting the necessity of fiber type specific analysis.
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Saraslanidis P, Petridou A, Bogdanis GC, Galanis N, Tsalis G, Kellis S, Mougios V. Muscle metabolism and performance improvement after two training programmes of sprint running differing in rest interval duration. J Sports Sci 2011; 29:1167-74. [PMID: 21777153 DOI: 10.1080/02640414.2011.583672] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Repeated-sprint training often involves short sprints separated by inadequate recovery intervals. The effects of interval duration on metabolic and performance parameters are unclear. We compared the effects of two training programmes, differing in rest interval duration, on muscle (vastus lateralis) metabolism and sprint performance. Sixteen men trained three times a week for 8 weeks, each training session comprising 2-3 sets of two 80-m sprints. Sprints were separated by 10 s (n = 8) or 1 min (n = 8). Both training programmes improved performance in the 100-, 200-, and 300-m sprints, but the improvement was greater in the 10-s group during the final 100 m of the 200- and 300-m runs. Independent of interval duration, training mitigated the drop of muscle ATP after two 80-m sprints. The drop in phosphocreatine and the increases in glucose-6-phosphate and fructose-6-phosphate after two 80-m sprints were greater in the 10-s group. In conclusion, training with a limited number of repeated short sprints (≤10 s) may be more effective in improving speed maintenance in 200- and 300-m runs when performed with a 1:1 rather than a 1:6 exercise-to-rest ratio. This may be due to a greater activation of glycolysis caused, in part, by the limited resynthesis of phosphocreatine during the very short rest interval.
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Affiliation(s)
- Ploutarchos Saraslanidis
- Department of Physical Education and Sport Science, Aristotle University of Thessaloniki, Thessaloniki, Greece
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23
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Mitochondrial dysfunction and lipotoxicity. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1801:266-71. [PMID: 19782153 DOI: 10.1016/j.bbalip.2009.09.011] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 08/28/2009] [Accepted: 09/13/2009] [Indexed: 12/25/2022]
Abstract
Mitochondrial dysfunction in skeletal muscle has been suggested to underlie the development of insulin resistance and type 2 diabetes mellitus. Reduced mitochondrial capacity will contribute to the accumulation of lipid intermediates, desensitizing insulin signaling and leading to insulin resistance. Why mitochondrial function is reduced in the (pre-)diabetic state is, however, so far unknown. Although it is tempting to suggest that skeletal muscle insulin resistance may result from an inherited or acquired reduction in mitochondrial function in the pre-diabetic state, it cannot be excluded that mitochondrial dysfunction may in fact be the consequence of the insulin-resistant/diabetic state. Lipotoxicity, the deleterious effects of accumulating fatty acids in skeletal muscle cells, may lie at the basis of mitochondrial dysfunction: next to producing energy, mitochondria are also the major source of reactive oxygen species (ROS). Fatty acids accumulating in the vicinity of mitochondria are vulnerable to ROS-induced lipid peroxidation. Subsequently, these lipid peroxides could have lipotoxic effects on mtDNA, RNA and proteins of the mitochondrial machinery, leading to mitochondrial dysfunction. Indeed, increased lipid peroxidation has been reported in insulin resistant skeletal muscle and the mitochondrial uncoupling protein-3, which has been suggested to prevent lipid-induced mitochondrial damage, is reduced in subjects with an impaired glucose tolerance and in type 2 diabetic patients. These findings support the hypothesis that fat accumulation in skeletal muscle may precede the reduction in mitochondrial function that is observed in type 2 diabetes mellitus.
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Lumini JA, Magalhães J, Oliveira PJ, Ascensão A. Beneficial effects of exercise on muscle mitochondrial function in diabetes mellitus. Sports Med 2009; 38:735-50. [PMID: 18712941 DOI: 10.2165/00007256-200838090-00003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The physiopathology of diabetes mellitus has been closely associated with a variety of alterations in mitochondrial histology, biochemistry and function. Generally, the alterations comprise increased mitochondrial reactive oxygen and nitrogen species (RONS) generation, resulting in oxidative stress and damage; decreased capacity to metabolize lipids, leading to intramyocyte lipid accumulation; and diminished mitochondrial density and reduced levels of uncoupling proteins (UCPs), with consequent impairment in mitochondrial function. Chronic physical exercise is a physiological stimulus able to induce mitochondrial adaptations that can counteract the adverse effects of diabetes on muscle mitochondria. However, the mechanisms responsible for mitochondrial adaptations in the muscles of diabetic patients are still unclear. The main mechanisms by which exercise may be considered an important non-pharmacological strategy for preventing and/or attenuating diabetes-induced mitochondrial impairments may involve (i) increased mitochondrial biogenesis, which is dependent on the increased expression of some important proteins, such as the 'master switch' peroxisome proliferator-activated receptor (PPAR)-gamma-coactivator-1alpha (PGC-1alpha) and heat shock proteins (HSPs), both of which are severely downregulated in the muscles of diabetic patients; and (ii) the restoration or attenuation of the low UCP3 expression in skeletal muscle mitochondria of diabetic patients, which is suggested to play a pivotal role in mitochondrial dysfunction.There is evidence that chronic exercise and lifestyle interventions reverse impairments in mitochondrial density and size, in the activity of respiratory chain complexes and in cardiolipin content; however, the mechanisms by which chronic exercise alters mitochondrial respiratory parameters, mitochondrial antioxidant systems and other specific proteins involved in mitochondrial metabolism in the muscles of diabetic patients remain to be elucidated.
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Affiliation(s)
- José A Lumini
- Research Centre in Physical Activity, Health and Leisure, University of Porto, Porto, Portugal
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Iaia FM, Hellsten Y, Nielsen JJ, Fernström M, Sahlin K, Bangsbo J. Four weeks of speed endurance training reduces energy expenditure during exercise and maintains muscle oxidative capacity despite a reduction in training volume. J Appl Physiol (1985) 2008; 106:73-80. [PMID: 18845781 DOI: 10.1152/japplphysiol.90676.2008] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We studied the effect of an alteration from regular endurance to speed endurance training on muscle oxidative capacity, capillarization, as well as energy expenditure during submaximal exercise and its relationship to mitochondrial uncoupling protein 3 (UCP3) in humans. Seventeen endurance-trained runners were assigned to either a speed endurance training (SET; n = 9) or a control (Con; n = 8) group. For a 4-wk intervention (IT) period, SET replaced the ordinary training ( approximately 45 km/wk) with frequent high-intensity sessions each consisting of 8-12 30-s sprint runs separated by 3 min of rest (5.7 +/- 0.1 km/wk) with additional 9.9 +/- 0.3 km/wk at low running speed, whereas Con continued the endurance training. After the IT period, oxygen uptake was 6.6, 7.6, 5.7, and 6.4% lower (P < 0.05) at running speeds of 11, 13, 14.5, and 16 km/h, respectively, in SET, whereas remained the same in Con. No changes in blood lactate during submaximal running were observed. After the IT period, the protein expression of skeletal muscle UCP3 tended to be higher in SET (34 +/- 6 vs. 47 +/- 7 arbitrary units; P = 0.06). Activity of muscle citrate synthase and 3-hydroxyacyl-CoA dehydrogenase, as well as maximal oxygen uptake and 10-km performance time, remained unaltered in both groups. In SET, the capillary-to-fiber ratio was the same before and after the IT period. The present study showed that speed endurance training reduces energy expenditure during submaximal exercise, which is not mediated by lowered mitochondrial UCP3 expression. Furthermore, speed endurance training can maintain muscle oxidative capacity, capillarization, and endurance performance in already trained individuals despite significant reduction in the amount of training.
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Affiliation(s)
- F Marcello Iaia
- Dept. of Exercise and Sport Sciences, University of Copenhagen, Copenhagen, Denmark
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Costford SR, Seifert EL, Bézaire V, F Gerrits M, Bevilacqua L, Gowing A, Harper ME. The energetic implications of uncoupling protein-3 in skeletal muscle. Appl Physiol Nutr Metab 2008; 32:884-94. [PMID: 18059613 DOI: 10.1139/h07-063] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Despite almost a decade of research since the identification of uncoupling protein-3 (UCP3), the molecular mechanisms and physiological functions of this mitochondrial anion carrier protein are not well understood. Because of its highly selective expression in skeletal muscle and the existence of mitochondrial proton leak in this tissue, early reports proposed that UCP3 caused a basal proton leak and increased thermogenesis. However, gene expression data and results from knockout and overexpression studies indicated that UCP3 does not cause basal proton leak or physiological thermogenesis. UCP3 expression is associated with increases in circulating fatty acids and in fatty acid oxidation (FAO) in muscle. Fatty acids are also well recognized as activators of the prototypic UCP1 in brown adipose tissue. This has led to hypotheses implicating UCP3 in mitochondrial fatty acid translocation. The corresponding hypothesized physiological roles include facilitated FAO and protection from the lipotoxic effects of fatty acids. Recent in vitro studies of physiological increases in UCP3 in muscle cells demonstrate increased FAO, and decreased reactive oxygen species (ROS) production. Detailed mechanistic studies indicate that ROS or lipid by-products of ROS can activate a UCP3-mediated proton leak, which in turn acts in a negative feedback loop to mitigate ROS production. Altogether, UCP3 appears to play roles in muscle FAO and mitigated ROS production. Future studies will need to elucidate the molecular mechanisms underlying increased FAO, as well as the physiological relevance of ROS-activated proton leak.
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Affiliation(s)
- Sheila R Costford
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
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Mensink M, Hesselink MKC, Borghouts LB, Keizer H, Moonen-Kornips E, Schaart G, Blaak EE, Schrauwen P. Skeletal muscle uncoupling protein-3 restores upon intervention in the prediabetic and diabetic state: implications for diabetes pathogenesis? Diabetes Obes Metab 2007; 9:594-6. [PMID: 17587402 DOI: 10.1111/j.1463-1326.2006.00628.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
AIM Skeletal muscle uncoupling protein-3 (UCP3) is reduced in type 2 diabetes, and in the pre-diabetic condition of impaired glucose tolerance (IGT). Here we examined whether intervention programs known to improve insulin sensitivity are paralleled by an increase in skeletal muscle UCP3 protein levels. METHODS Skeletal muscle UCP3 protein content was measured before and after one year of an exercise intervention in muscle biopsies of eight diabetic subjects. In addition, UCP3 was measured in IGT subjects before and after 1 year of following a lifestyle-intervention program or serving as control. RESULTS In the diabetic patients a significant increase of approximately 75% in UCP3 protein was found after 1 year of exercise training (P < 0.05). In IGT subjects UCP3 protein increased in the intervention group (P = 0.02), while UCP3 remained unaltered in the control group (P = 0.64). CONCLUSION Both, exercise training and a lifestyle-intervention program increase UCP3 protein content in skeletal muscle of subjects with reduced glycaemic control, indicating a restoration towards normal UCP3 levels. These data support the idea that UCP3 has a role in the aetiology of type 2 diabetes mellitus.
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Affiliation(s)
- M Mensink
- Department of Human Biology, Nutrition and Toxicology Research Institute NUTRIM, Maastricht University, Maastricht, The Netherlands.
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Larsson BW, Kadi F, Ulfberg J, Aulin KP. Skeletal Muscle Morphology in Patients with Restless Legs Syndrome. Eur Neurol 2007; 58:133-7. [PMID: 17622717 DOI: 10.1159/000104712] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Accepted: 02/05/2007] [Indexed: 11/19/2022]
Abstract
AIM The aim of the study was to assess the cellular and structural properties of skeletal muscle in restless legs syndrome (RLS). METHOD Twenty patients and 16 controls were included. Aerobic performance was assessed using a submaximal test. On muscle biopsies taken from the tibialis anterior, fiber distribution and fiber area were analyzed together with parameters surveying the microvascularization, especially the tortuosity, which is expressed as a percent of muscle fiber perimeter in contact with the wall of the microvessel, length of capillary/perimeter of fiber (LC/PF) index. RESULTS The RLS group had significantly lower predicted maximal oxygen uptake (p = 0.01) and significantly higher LC/PF index (p = 0.01) compared to the controls. CONCLUSION The higher capillary tortuosity in RLS patients indicates the occurrence of significant remodeling in capillary geometry in RLS.
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Winder WW, Taylor EB, Thomson DM. Role of AMP-Activated Protein Kinase in the Molecular Adaptation to Endurance Exercise. Med Sci Sports Exerc 2006; 38:1945-9. [PMID: 17095928 DOI: 10.1249/01.mss.0000233798.62153.50] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
What are the molecular signals induced by muscle contraction that result in an increase in GLUT4, hexokinase 2, mitochondrial oxidative enzymes, and other adaptations to endurance exercise training? Could repetitive activation of AMP-activated protein kinase (AMPK) be responsible in part? There is substantial evidence for a role of AMPK in inducing adaptations to endurance training: 1) AMPK is activated in response to muscle contraction; 2) chronic chemical activation of AMPK results in increases in GLUT4, hexokinase 2, UCP-3, and citric acid cycle enzymes; 3) muscle contraction and chemical activation of AMPK both result in increases in PGC-1alpha, a transcriptional coactivator involved in stimulation of mitochondrial biogenesis; and 4) increases in muscle PGC-1 alpha, delta-aminolevulinic acid synthetase, and mitochondrial DNA induced by chronic creatine phosphate depletion in wild-type mice are not observed in dominant-negative AMPK mice. These observations lend credence to the hypothesis that AMPK activation induced by muscle contraction is responsible in part for adaptations to endurance exercise training.
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Affiliation(s)
- William W Winder
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA.
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Gosker HR, Schrauwen P, Broekhuizen R, Hesselink MKC, Moonen-Kornips E, Ward KA, Franssen FME, Wouters EFM, Schols AMWJ. Exercise training restores uncoupling protein-3 content in limb muscles of patients with chronic obstructive pulmonary disease. Am J Physiol Endocrinol Metab 2006; 290:E976-81. [PMID: 16352674 DOI: 10.1152/ajpendo.00336.2005] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxidative capacity and uncoupling protein-3 (UCP3) content are reduced in limb muscles of patients with chronic obstructive pulmonary disease (COPD). It has been hypothesized that the physiological role of UCP3 is to protect mitochondria against lipotoxicity in cases where fatty acid influx exceeds the capacity to oxidize them. Exercise training improves oxidative capacity and reduces UCP3 protein content in healthy subjects, but the response of UCP3 to training in COPD is unknown. We studied the effect of exercise training on UCP3 content in limb muscles of COPD patients. For this, seven healthy age-matched subjects and thirteen patients with COPD were studied. All patients were admitted to an 8-wk exercise training intervention. Exercise capacity was assessed by means of an incremental cycle ergometry test. Biopsies were taken from the vastus lateralis in which UCP3 and lipid peroxidation levels were determined by Western blotting. Citrate synthase and 3-hydroxyacyl-CoA dehydrogenase (HAD; an enzyme involved in fatty acid oxidation) were measured as indexes of muscle oxidative capacity. UCP3 in COPD was approximately 50% lower compared with healthy age-matched controls. In COPD, training induced upregulation of UCP3 [from 67.7 (SD 41.8) to 113.8 (SD 104.2) arbitrary units (AU), P = 0.062], especially in the patients who showed no increase in HAD activity [from 80.9 (SD 52.6) to 167.9 (SD 109.1) AU, P = 0.028], whereas lipid peroxidation levels remained unaltered. We conclude that exercise-training can restore muscle UCP3 protein level in COPD, and the nature of this response complies with the hypothesis that UCP3 may protect against lipotoxicity.
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Affiliation(s)
- Harry R Gosker
- Dept. of Respiratory Medicine, Maastricht Univ., Nutrition and Toxicology Research Institute Maastricht, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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Schrauwen P, Mensink M, Schaart G, Moonen-Kornips E, Sels JP, Blaak EE, Russell AP, Hesselink MKC. Reduced skeletal muscle uncoupling protein-3 content in prediabetic subjects and type 2 diabetic patients: restoration by rosiglitazone treatment. J Clin Endocrinol Metab 2006; 91:1520-5. [PMID: 16384852 DOI: 10.1210/jc.2005-1572] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The mitochondrial uncoupling protein-3 (UCP3) has been implicated in the protection of the mitochondrial matrix against lipid-induced mitochondrial damage. Recent evidence points toward mitochondrial aberrations as a major contributor to the development of insulin resistance and diabetes, and UCP3 is reduced in diabetes. OBJECTIVE We compared skeletal muscle UCP3 protein levels in prediabetic subjects [i.e. impaired glucose tolerance (IGT)], diabetic patients, and healthy controls and examined whether rosiglitazone treatment was able to restore UCP3. PATIENTS, DESIGN, INTERVENTION: Ten middle-aged obese men with type 2 diabetes mellitus [age, 61.4 +/- 3.1 yr; body mass index (BMI), 29.8 +/- 2.9 kg/m(2)], nine IGT subjects (age, 59.0 +/- 6.6 yr; BMI, 29.7 +/- 3.0 kg/m(2)), and 10 age- and BMI-matched healthy controls (age, 57.3 +/- 7.4 yr; BMI, 30.1 +/- 3.9 kg/m(2)) participated in this study. After baseline comparisons, diabetic patients received rosiglitazone (2 x 4 mg/d) for 8 wk. MAIN OUTCOME MEASURES Muscle biopsies were sampled to determine UCP3 and mitochondrial protein (complex I-V) content. RESULTS UCP3 protein content was significantly lower in prediabetic IGT subjects and in diabetic patients compared with healthy controls (39.0 +/- 28.5, 47.2 +/- 24.7, and 72.0 +/- 23.7 arbitrary units, respectively; P < 0.05), whereas the levels of the mitochondrial protein complex I-V were similar between groups. Rosiglitazone treatment for 8 wk significantly increased insulin sensitivity and muscle UCP3 content (from 53.2 +/- 29.9 to 66.3 +/- 30.9 arbitrary units; P < 0.05). CONCLUSION We show that UCP3 protein content is reduced in prediabetic subjects and type 2 diabetic patients. Eight weeks of rosiglitazone treatment restores skeletal muscle UCP3 protein in diabetic patients.
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Affiliation(s)
- Patrick Schrauwen
- Nutrition and Toxicology Research Institute Maastricht, Department of Human Biology, Maastricht University, P.O. Box 616, NL-6200 MD Maastricht, The Netherlands.
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Hoeks J, Hesselink MKC, Sluiter W, Schaart G, Willems J, Morrisson A, Clapham JC, Saris WHM, Schrauwen P. The effect of high-fat feeding on intramuscular lipid and lipid peroxidation levels in UCP3-ablated mice. FEBS Lett 2006; 580:1371-5. [PMID: 16455084 DOI: 10.1016/j.febslet.2006.01.059] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Revised: 01/11/2006] [Accepted: 01/13/2006] [Indexed: 01/06/2023]
Abstract
Uncoupling protein-3 (UCP3) has been suggested to protect against lipid-induced oxidative damage. Therefore, we studied intramuscular lipid peroxide levels and high-fat diet induced alterations in muscle lipid metabolism of UCP3-ablated mice. UCP3-/- mice showed approximately 3-fold higher levels of intramuscular lipid peroxides upon standard chow feeding, compared to wild-type littermates. Remarkably, this difference was no longer apparent on the high-fat diet. However, upon high-fat feeding, intramuscular triacylglycerol levels were approximately 50% lower in UCP3-/- mice, in comparison to UCP3+/+ animals. Succinate dehydrogenase activity, and total protein content of the muscle fatty acid transporter FAT/CD36 were however similar between UCP3-/- and UCP3+/+ mice.
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Affiliation(s)
- Joris Hoeks
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands.
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Taylor EB, Lamb JD, Hurst RW, Chesser DG, Ellingson WJ, Greenwood LJ, Porter BB, Herway ST, Winder WW. Endurance training increases skeletal muscle LKB1 and PGC-1alpha protein abundance: effects of time and intensity. Am J Physiol Endocrinol Metab 2005; 289:E960-8. [PMID: 16014350 DOI: 10.1152/ajpendo.00237.2005] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Recent research suggests that LKB1 is the major AMP-activated protein kinase kinase (AMPKK). Peroxisome-proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) is a master coordinator of mitochondrial biogenesis. Previously we reported that skeletal muscle LKB1 protein increases with endurance training. The purpose of this study was to determine whether training-induced increases in skeletal muscle LKB1 and PGC-1alpha protein exhibit a time course and intensity-dependent response similar to that of citrate synthase. Male Sprague-Dawley rats completed endurance- and interval-training protocols. For endurance training, rats trained for 4, 11, 25, or 53 days. Interval-training rats trained identically to endurance-trained rats, except that after 25 days interval training was combined with endurance training. Time course data were collected from endurance-trained red quadriceps (RQ) after each time point. Interval training data were collected from soleus, RQ, and white quadriceps (WQ) muscle after 53 days only. Mouse protein 25 (MO25) and PGC-1alpha protein increased significantly after 4 days. Increased citrate synthase activity, increased LKB1 protein, and decreased AMPKK activity were found after 11 days. Maximal increases occurred after 4 days for hexokinase II, 25 days for MO25, and 53 days for citrate synthase, LKB1, and PGC-1alpha. In WQ, but not RQ or soleus, interval training had an additive effect to endurance training and induced significant increases in all proteins measured. These results demonstrate that LKB1 and PGC-1alpha protein abundances increase with endurance and interval training similarly to citrate synthase. The increase in LKB1 and PGC-1alpha with endurance and interval training may function to maintain the training-induced increases in mitochondrial mass.
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Affiliation(s)
- Eric B Taylor
- Department of Physiology and Developmental Biology, 545 WIDB, Brigham Young University, Provo, UT 84602, USA
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Schrauwen P, Russell AP, Moonen-Kornips E, Boon N, Hesselink MKC. Effect of 2 weeks of endurance training on uncoupling protein 3 content in untrained human subjects. ACTA ACUST UNITED AC 2005; 183:273-80. [PMID: 15743387 DOI: 10.1111/j.1365-201x.2004.01393.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM The mitochondrial uncoupling protein-3 (UCP3) is able to lower the proton gradient across the inner mitochondrial membrane, thereby uncoupling substrate oxidation from ATP production and dissipating energy as heat. What the effect of endurance training on UCP3 is, is still controversial. Endurance-trained athletes are characterized by lower levels of UCP3, but longitudinal studies in rodents reported no effect of endurance training on muscular UCP3 levels. Here, we examined the effect of a 2-week training programme on skeletal muscle UCP3 protein content in untrained human subjects, and hypothesized that UCP3 will be reduced after the training programme. METHODS Nine untrained men [age: 23.3 +/- 3.2 years; BMI: 22.6 +/- 2.6 kg m(-2); maximal power output (W(max)): 3.8 +/- 0.6 W kg(-1) body weight] trained for 2 weeks. Before and at least 72 h after the training period, muscle biopsies were taken for determination of UCP3 protein content. RESULTS UCP3 protein content tended to be lower after the training programme [95 +/- 10 vs. 109 +/- 12 arbitrary units (AU), P = 0.08]. Cytochrome c content tended to increase with 33% in response to endurance training (52 +/- 6 vs. 39 +/- 6 AU, P = 0.08). The ratio UCP3 relative to cytochrome c tended to decrease significantly upon endurance training (2.0 +/- 0.4 vs. 3.2 +/- 0.6 AU, P = 0.01). CONCLUSION A short-term (2-week) endurance training programme decreased UCP3 protein levels and significantly reduced the ratio of UCP3 to cytochrome c.
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Affiliation(s)
- P Schrauwen
- Department of Human Biology, Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Maastricht University, PO Box 616, NL-6200 MD Maastricht, The Netherlands
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De Bock K, Richter EA, Russell AP, Eijnde BO, Derave W, Ramaekers M, Koninckx E, Léger B, Verhaeghe J, Hespel P. Exercise in the fasted state facilitates fibre type-specific intramyocellular lipid breakdown and stimulates glycogen resynthesis in humans. J Physiol 2005; 564:649-60. [PMID: 15705646 PMCID: PMC1464435 DOI: 10.1113/jphysiol.2005.083170] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The effects were compared of exercise in the fasted state and exercise with a high rate of carbohydrate intake on intramyocellular triglyceride (IMTG) and glycogen content of human muscle. Using a randomized crossover study design, nine young healthy volunteers participated in two experimental sessions with an interval of 3 weeks. In each session subjects performed 2 h of constant-load bicycle exercise ( approximately 75% ), followed by 4 h of controlled recovery. On one occasion they exercised after an overnight fast (F), and on the other (CHO) they received carbohydrates before ( approximately 150 g) and during (1 g (kg bw)(-1) h(-1)) exercise. In both conditions, subjects ingested 5 g carbohydrates per kg body weight during recovery. Fibre type-specific relative IMTG content was determined by Oil red O staining in needle biopsies from m. vastus lateralis before, immediately after and 4 h after exercise. During F but not during CHO, the exercise bout decreased IMTG content in type I fibres from 18 +/- 2% to 6 +/- 2% (P = 0.007) area lipid staining. Conversely, during recovery, IMTG in type I fibres decreased from 15 +/- 2% to 10 +/- 2% in CHO, but did not change in F. Neither exercise nor recovery changed IMTG in type IIa fibres in any experimental condition. Exercise-induced net glycogen breakdown was similar in F and CHO. However, compared with CHO (11.0 +/- 7.8 mmol kg(-1) h(-1)), mean rate of postexercise muscle glycogen resynthesis was 3-fold greater in F (32.9 +/- 2.7 mmol kg(-1) h(-1), P = 0.01). Furthermore, oral glucose loading during recovery increased plasma insulin markedly more in F (+46.80 microU ml(-1)) than in CHO (+14.63 microU ml(-1), P = 0.02). We conclude that IMTG breakdown during prolonged submaximal exercise in the fasted state takes place predominantly in type I fibres and that this breakdown is prevented in the CHO-fed state. Furthermore, facilitated glucose-induced insulin secretion may contribute to enhanced muscle glycogen resynthesis following exercise in the fasted state.
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Affiliation(s)
- K De Bock
- Exercise Physiology and Biomechanics Laboratory, Faculty of Kinesiology and Rehabilitation Sciences, K.U.Leuven, Tervuursevest 101, B-3001 Leuven (Heverlee), Belgium
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Abstract
The potential lipotoxic effect of intramyocellular triglyceride (IMTG) accumulation has been suggested to be a major component in the development of insulin resistance. Increased levels of IMTGs correlate with insulin resistance in both obese and diabetic patients, but this relationship does not exist in endurance trained (ETr) subjects. This may be, in part, related to differences in the gene expression and activities of key enzymes involved in fatty acid transport and oxidation as well as in the perodixation status of the IMTGs in obese/diabetic patients as compared with ETr subjects. Disruptions in fat and lipid homeostasis in skeletal muscle have been shown to activate protein kinase C (PKC), which acts on several downstream signalling pathways, including the insulin and the IkappaB kinase (IKK)/NFkappaB signalling pathways. Additionally, an increased peroxidation of IMTGs may reduce insulin sensitivity by increasing TNFalpha, which is known to increase the expression of suppressor of cytokine signalling proteins (SOCS). A common characteristic observed when activating both PKC and TNFalpha/SOCS3 is the inhibition of tyrosine phosphorylation of IRS-1 and subsequently an inhibition of its activation of downstream signalling molecules. These may be important players in the development of insulin resistance and understanding their activation and expression in both obese and ETr humans should assist in understanding how and why IMTGs become lipotoxic.
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Affiliation(s)
- A P Russell
- Clinique romande de réadaptation SUVA Care, Sion, Switzerland.
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Korzeniewski B, Zoladz JA. Factors determining the oxygen consumption rate (VO2) on-kinetics in skeletal muscles. Biochem J 2004; 379:703-10. [PMID: 14744260 PMCID: PMC1224118 DOI: 10.1042/bj20031740] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2003] [Revised: 01/13/2004] [Accepted: 01/26/2004] [Indexed: 10/26/2022]
Abstract
Using a computer model of oxidative phosphorylation developed previously [Korzeniewski and Mazat (1996) Biochem. J. 319, 143-148; Korzeniewski and Zoladz (2001) Biophys. Chem. 92, 17-34], we analyse the effect of several factors on the oxygen-uptake kinetics, especially on the oxygen consumption rate (VO2) and half-transition time t(1/2), at the onset of exercise in skeletal muscles. Computer simulations demonstrate that an increase in the total creatine pool [PCr+/-Cr] (where Cr stands for creatine and PCr for phosphocreatine) and in glycolytic ATP supply lengthen the half-transition time, whereas increase in mitochondrial content, in parallel activation of ATP supply and ATP usage, in oxygen concentration, in proton leak, in resting energy demand, in resting cytosolic pH and in initial alkalization decrease this parameter. Theoretical studies show that a decrease in the activity of creatine kinase (CK) [displacement of this enzyme from equilibrium during on-transient (rest-to-work transition)] accelerates the first stage of the VO2 on-transient, but slows down the second stage of this transient. It is also demonstrated that a prior exercise terminated a few minutes before the principal exercise shortens the transition time. Finally, it is shown that at a given ATP demand, and under conditions where CK works near the thermodynamic equilibrium, the half-transition time of VO2 kinetics is determined by the amount of PCr that has to be transformed into Cr during rest-to-work transition; therefore any factor that diminishes the difference in [PCr] between rest and work at a given energy demand will accelerate the VO2 on-kinetics. Our conclusions agree with the general idea formulated originally by Easterby [(1981) Biochem. J. 199, 155-161] that changes in metabolite concentrations determine the transition times between different steady states in metabolic systems.
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Affiliation(s)
- Bernard Korzeniewski
- Institute of Molecular Biology and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Kraków, Poland.
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Russell AP, Somm E, Debigaré R, Hartley O, Richard D, Gastaldi G, Melotti A, Michaud A, Giacobino JP, Muzzin P, LeBlanc P, Maltais F. COPD Results in a Reduction in UCP3 Long mRNA and UCP3 Protein Content in Types I and IIa Skeletal Muscle Fibers. ACTA ACUST UNITED AC 2004; 24:332-9. [PMID: 15602154 DOI: 10.1097/00008483-200409000-00009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Findings recently have shown coupling protein-3 (UCP3) content to be decreased in the skeletal muscle of patients with chronic obstructive pulmonary disease (COPD). Uncoupling protein-3 mRNA exists as two isoforms: long (UCP3L) and short (UCP3S). The UCP3 protein is expressed the least in oxidative and the most in glycolytic muscle fibers. Levels of UCP3 have been associated positively with intramyocellular triglyceride (IMTG) contents in conditions of altered fatty acid metabolism. As a source for muscle free fatty acid metabolism, IMTG is decreased in COPD. The current study completely characterized all the parameters of UCP3 expression (ie, UCP3L and UCP3S mRNA expression in whole muscle samples) and UCP3 protein content as well as IMTG content in the different fiber types in patients with COPD and healthy control subjects. METHODS Using real-time polymerase chain reaction, UCP3 gene expression was quantified. Skeletal muscle fiber type and UCP3 protein and IMTG content were measured using immunofluorescence and Oil red oil staining, respectively. RESULTS The findings showed that UCP3L mRNA expression was 44% lower (P < .005) in the patients with COPD than in the control subjects, whereas the UCP3S mRNA content was similar in the two groups. As compared with control subjects, UCP3 protein content was decreased by 89% and 83% and the IMTG content by 64% and 54%, respectively, in types I and IIa fibers (P < .0167) of patients with COPD, whereas they were unchanged in IIx fibers. CONCLUSIONS The reduced UCP3 and IMTG content in the more oxidative fibers may be linked to the altered muscle fatty acid metabolism associated with COPD. Further studies are required to determine the exact role and clinical relevance of the reduced UCP3 content in patients with COPD.
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Affiliation(s)
- Aaron P Russell
- Clinique Romande de Réadaptation SUVA Care, Sion, Switzerland.
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Ljubicic V, Adhihetty PJ, Hood DA. Role of UCP3 in state 4 respiration during contractile activity-induced mitochondrial biogenesis. J Appl Physiol (1985) 2004; 97:976-83. [PMID: 15145919 DOI: 10.1152/japplphysiol.00336.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In an effort to better characterize uncoupling protein-3 (UCP3) function in skeletal muscle, we assessed basal UCP3 protein content in rat intermyofibrillar (IMF) and subsarcolemmal (SS) mitochondrial subfractions in conjunction with measurements of state 4 respiration. UCP3 content was 1.3-fold ( P < 0.05) greater in IMF compared with SS mitochondria. State 4 respiration was 2.6-fold greater ( P < 0.05) in the IMF subfraction than in SS mitochondria. GDP attenuated state 4 respiration by ∼40% ( P < 0.05) in both subfractions. The UCP3 activator oleic acid (OA) significantly increased state 4 respiration in IMF mitochondria only. We used chronic electrical stimulation (3 h/day for 7 days) to investigate the relationship between changes in UCP3 protein expression and alterations in state 4 respiration during contractile activity-induced mitochondrial biogenesis. UCP3 content was increased by 1.9- and 2.3-fold in IMF and SS mitochondria, respectively, which exceeded the concurrent 40% ( P < 0.05) increase in cytochrome- c oxidase activity. Chronic contractile activity increased state 4 respiration by 1.4-fold ( P < 0.05) in IMF mitochondria, but no effect was observed in the SS subfraction. The uncoupling function of UCP3 accounted for 50–57% of the OA-induced increase in state 4 respiration in IMF mitochondria, which was independent of the induced twofold difference in UCP3 content due to chronic contractile activity. Thus modifications in UCP3 function are more important than changes in UCP3 expression in modifying state 4 respiration. This effect is evident in IMF but not SS mitochondria. We conclude that UCP3 at physiological concentrations accounts for a significant portion of state 4 respiration in both IMF and SS mitochondria, with the contribution being greater in the IMF subfraction. In addition, the contradiction between human and rat training studies with respect to UCP3 protein expression may partly be explained by the greater than twofold difference in mitochondrial UCP3 content between rat and human skeletal muscle.
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Affiliation(s)
- Vladimir Ljubicic
- School of Kinesiology and Health Science, York University, Toronto, Ontario, Canada M3J 1P3
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Putman CT, Dixon WT, Pearcey JA, Maclean IM, Jendral MJ, Kiricsi M, Murdoch GK, Pette D. Chronic low-frequency stimulation upregulates uncoupling protein-3 in transforming rat fast-twitch skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2004; 287:R1419-26. [PMID: 15308491 DOI: 10.1152/ajpregu.00421.2004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this investigation was to examine the temporal changes in uncoupling protein (UCP)-3 expression, as well as related adaptive changes in mitochondrial density and fast-to-slow fiber type transitions during chronically enhanced contractile activity. We examined the effects of 1-42 days of chronic low-frequency electrical stimulation (CLFS), applied to rat tibialis anterior (TA) for 10 h/day, on the expression of UCP-3 and concomitant changes in myosin heavy chain (MHC) protein expression and increases in oxidative capacity. UCP-3 protein content increased from 1 to 12 days, reaching 1.5-fold over control (P < 0.0005); it remained elevated for up to 42 days. In contrast, UCP-3 mRNA decreased in response to CLFS, reaching a level that was threefold lower than control (P < 0.0007). The activities of the mitochondrial reference enzymes citrate synthase (EC 4.1.3.7) and 3-hydroxyacyl-CoA-dehydrogenase (EC 1.1.1.35), which are known to increase in proportion to mitochondrial density, progressively increased up to an average of 2.3-fold (P < 0.00001). These changes were accompanied by fast-to-slow fiber type transitions, characterized by a shift in the pattern of MHC expression (P <0.0002): MHCI and MHCIIa expression increased by 1.7- and 4-fold, whereas MHCIIb displayed a 2.4-fold reduction. We conclude that absolute increases in UCP-3 protein content in the early adaptive phase were associated with the genesis of mitochondria containing a normal complement of UCP-3. However, during exposure to long-term CLFS, mitochondria were generated with a lower complement of UCP-3 and coincided with the emergence of a growing population of oxidative type IIA fibers.
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Affiliation(s)
- Charles T Putman
- Exercise Biochemsitry Laboratory, Faculty of Physical Education and Recreation, University of Alberta, Edmonton, Alberta, Canada T6G 2H9.
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Mahoney DJ, Carey K, Fu MH, Snow R, Cameron-Smith D, Parise G, Tarnopolsky MA. Real-time RT-PCR analysis of housekeeping genes in human skeletal muscle following acute exercise. Physiol Genomics 2004; 18:226-31. [PMID: 15161965 DOI: 10.1152/physiolgenomics.00067.2004] [Citation(s) in RCA: 163] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Studies examining gene expression with RT-PCR typically normalize their mRNA data to a constitutively expressed housekeeping gene. The validity of a particular housekeeping gene must be determined for each experimental intervention. We examined the expression of various housekeeping genes following an acute bout of endurance (END) or resistance (RES) exercise. Twenty-four healthy subjects performed either a interval-type cycle ergometry workout to exhaustion (∼75 min; END) or 300 single-leg eccentric contractions (RES). Muscle biopsies were taken before exercise and 3 h and 48 h following exercise. Real-time RT-PCR was performed on β-actin, cyclophilin (CYC), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and β2-microglobulin (β2M). In a second study, 10 healthy subjects performed 90 min of cycle ergometry at ∼65% of V̇o2 max, and we examined a fifth housekeeping gene, 28S rRNA, and reexamined β2M, from muscle biopsy samples taken immediately postexercise. We showed that CYC increased 48 h following both END and RES exercise (3- and 5-fold, respectively; P < 0.01), and 28S rRNA increased immediately following END exercise (2-fold; P = 0.02). β-Actin trended toward an increase following END exercise (1.85-fold collapsed across time; P = 0.13), and GAPDH trended toward a small yet robust increase at 3 h following RES exercise (1.4-fold; P = 0.067). In contrast, β2M was not altered at any time point postexercise. We conclude that β2M and β-actin are the most stably expressed housekeeping genes in skeletal muscle following RES exercise, whereas β2M and GAPDH are the most stably expressed following END exercise.
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Affiliation(s)
- Douglas J Mahoney
- Department of Medical Sciences, McMaster University, Hamilton, Ontario, Canada L8N 3Z5
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Abstract
Acute endurance exercise results in the oxidation of several amino acids. The total amount of amino acid oxidation during endurance exercise amounts to only 1-6% of the total energy cost of exercise. The branched chain amino acid, leucine, has been most often studied in relation to endurance exercise. Leucine is oxidized by the enzyme, branched-chain oxo-acid dehydrogenase (BCOAD). BCOAD is relatively inactive at rest ( approximately 4-7%) and is activated at the onset of exercise by dephosphorylation (to about 25%). After a period of endurance exercise training, the activation of BCOAD and amino acid oxidation are attenuated, however the total amount of BCOAD enzyme is up-regulated. A low energy and/or carbohydrate intake will increase amino acid oxidation and total protein requirements. With adequate energy and carbohydrate intake, low to moderate intensity endurance activity has little impact on dietary protein requirements and 1.0 gPRO/kg/d is sufficient. The only situation where dietary protein requirements exceed those for relatively sedentary individuals is in top sport athletes where the maximal requirement is approximately 1.6 gPRO/kg/d. Although most endurance athletes get enough protein to support any increased requirements, those with low energy or carbohydrate intakes may require nutritional advice to optimize dietary protein intake.
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Affiliation(s)
- Mark Tarnopolsky
- Department of Pediatrics and Medicine, McMaster University, Hamilton, Ontario, Canada.
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Mitchell TW, Turner N, Hulbert AJ, Else PL, Hawley JA, Lee JS, Bruce CR, Blanksby SJ. Exercise alters the profile of phospholipid molecular species in rat skeletal muscle. J Appl Physiol (1985) 2004; 97:1823-9. [PMID: 15208292 DOI: 10.1152/japplphysiol.00344.2004] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have determined the effect of two exercise-training intensities on the phospholipid profile of both glycolytic and oxidative muscle fibers of female Sprague-Dawley rats using electrospray-ionization mass spectrometry. Animals were randomly divided into three training groups: control, which performed no exercise training; low-intensity (8 m/min) treadmill running; or high-intensity (28 m/min) treadmill running. All exercise-trained rats ran 1,000 m/session for 4 days/wk for 4 wk and were killed 48 h after the last training bout. Exercise training was found to produce no novel phospholipid species but was associated with significant alterations in the relative abundance of a number of phospholipid molecular species. These changes were more prominent in glycolytic (white vastus lateralis) than in oxidative (red vastus lateralis) muscle fibers. The largest observed change was a decrease of approximately 20% in the abundance of 1-stearoyl-2-docosahexaenoyl-phosphatidylethanolamine [PE(18:0/22:6); P < 0.001] ions in both the low- and high-intensity training regimes in glycolytic fibers. Increases in the abundance of 1-oleoyl-2-linoleoyl phopshatidic acid [PA(18:1/18:2); P < 0.001] and 1-alkenylpalmitoyl-2-linoleoyl phosphatidylethanolamine [plasmenyl PE (16:0/18:2); P < 0.005] ions were also observed for both training regimes in glycolytic fibers. We conclude that exercise training results in a remodeling of phospholipids in rat skeletal muscle. Even though little is known about the physiological or pathophysiological role of specific phospholipid molecular species in skeletal muscle, it is likely that this remodeling will have an impact on a range of cellular functions.
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Affiliation(s)
- Todd W Mitchell
- Metabolic Research Centre,University of Wollongong, Wollongong, New South Wales 2522.
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