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Espinosa A, Casas M, Jaimovich E. Energy (and Reactive Oxygen Species Generation) Saving Distribution of Mitochondria for the Activation of ATP Production in Skeletal Muscle. Antioxidants (Basel) 2023; 12:1624. [PMID: 37627619 PMCID: PMC10451830 DOI: 10.3390/antiox12081624] [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: 06/14/2023] [Revised: 07/27/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Exercise produces oxidants from a variety of intracellular sources, including NADPH oxidases (NOX) and mitochondria. Exercise-derived reactive oxygen species (ROS) are beneficial, and the amount and location of these ROS is important to avoid muscle damage associated with oxidative stress. We discuss here some of the evidence that involves ROS production associated with skeletal muscle contraction and the potential oxidative stress associated with muscle contraction. We also discuss the potential role of H2O2 produced after NOX activation in the regulation of glucose transport in skeletal muscle. Finally, we propose a model based on evidence for the role of different populations of mitochondria in skeletal muscle in the regulation of ATP production upon exercise. The subsarcolemmal population of mitochondria has the enzymatic and metabolic components to establish a high mitochondrial membrane potential when fissioned at rest but lacks the capacity to produce ATP. Calcium entry into the mitochondria will further increase the metabolic input. Upon exercise, subsarcolemmal mitochondria will fuse to intermyofibrillar mitochondria and will transfer the mitochondria membrane potential to them. These mitochondria are rich in ATP synthase and will subsequentially produce the ATP needed for muscle contraction in long-term exercise. These events will optimize energy use and minimize mitochondria ROS production.
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Affiliation(s)
- Alejandra Espinosa
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8320000, Chile; (A.E.)
- San Felipe Campus, School of Medicine, Faculty of Medicine, Universidad de Valparaiso, San Felipe 2172972, Chile
| | - Mariana Casas
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8320000, Chile; (A.E.)
| | - Enrique Jaimovich
- Center for Studies of Exercise, Metabolism and Cancer (CEMC), Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8320000, Chile; (A.E.)
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Abrigo J, Olguín H, Tacchi F, Orozco-Aguilar J, Valero-Breton M, Soto J, Castro-Sepúlveda M, Elorza AA, Simon F, Cabello-Verrugio C. Cholic and deoxycholic acids induce mitochondrial dysfunction, impaired biogenesis and autophagic flux in skeletal muscle cells. Biol Res 2023; 56:30. [PMID: 37291645 DOI: 10.1186/s40659-023-00436-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 04/27/2023] [Indexed: 06/10/2023] Open
Abstract
BACKGROUND Skeletal muscle is sensitive to bile acids (BA) because it expresses the TGR5 receptor for BA. Cholic (CA) and deoxycholic (DCA) acids induce a sarcopenia-like phenotype through TGR5-dependent mechanisms. Besides, a mouse model of cholestasis-induced sarcopenia was characterised by increased levels of serum BA and muscle weakness, alterations that are dependent on TGR5 expression. Mitochondrial alterations, such as decreased mitochondrial potential and oxygen consumption rate (OCR), increased mitochondrial reactive oxygen species (mtROS) and unbalanced biogenesis and mitophagy, have not been studied in BA-induced sarcopenia. METHODS We evaluated the effects of DCA and CA on mitochondrial alterations in C2C12 myotubes and a mouse model of cholestasis-induced sarcopenia. We measured mitochondrial mass by TOM20 levels and mitochondrial DNA; ultrastructural alterations by transmission electronic microscopy; mitochondrial biogenesis by PGC-1α plasmid reporter activity and protein levels by western blot analysis; mitophagy by the co-localisation of the MitoTracker and LysoTracker fluorescent probes; mitochondrial potential by detecting the TMRE probe signal; protein levels of OXPHOS complexes and LC3B by western blot analysis; OCR by Seahorse measures; and mtROS by MitoSOX probe signals. RESULTS DCA and CA caused a reduction in mitochondrial mass and decreased mitochondrial biogenesis. Interestingly, DCA and CA increased LC3II/LC3I ratio and decreased autophagic flux concordant with raised mitophagosome-like structures. In addition, DCA and CA decreased mitochondrial potential and reduced protein levels in OXPHOS complexes I and II. The results also demonstrated that DCA and CA decreased basal, ATP-linked, FCCP-induced maximal respiration and spare OCR. DCA and CA also reduced the number of cristae. In addition, DCA and CA increased the mtROS. In mice with cholestasis-induced sarcopenia, TOM20, OXPHOS complexes I, II and III, and OCR were diminished. Interestingly, the OCR and OXPHOS complexes were correlated with muscle strength and bile acid levels. CONCLUSION Our results showed that DCA and CA decreased mitochondrial mass, possibly by reducing mitochondrial biogenesis, which affects mitochondrial function, thereby altering potential OCR and mtROS generation. Some mitochondrial alterations were also observed in a mouse model of cholestasis-induced sarcopenia characterised by increased levels of BA, such as DCA and CA.
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Affiliation(s)
- Johanna Abrigo
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile
| | - Hugo Olguín
- Laboratory of Tissue Repair and Adult Stem Cells, Department of Cellular and Molecular Biology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Franco Tacchi
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile
| | - Josué Orozco-Aguilar
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile
- Laboratorio de Ensayos Biológicos (LEBi), Universidad de Costa Rica, San José, Costa Rica
- Facultad de Farmacia, Universidad de Costa Rica, San José, Costa Rica
| | - Mayalen Valero-Breton
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile
| | - Jorge Soto
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Millennium Institute on Immunology and Immunotherapy, Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Mauricio Castro-Sepúlveda
- Exercise Physiology and Metabolism Laboratory, School of Kinesiology, Faculty of Medicine, Finis Terrae University, Santiago, Chile
| | - Alvaro A Elorza
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
- Institute of Biomedical Sciences, Faculty of Medicine, and Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile
| | - Felipe Simon
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago, Chile.
- Laboratory of Integrative Physiopathology, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.
| | - Claudio Cabello-Verrugio
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.
- Millennium Institute on Immunology and Immunotherapy, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile.
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Clemente-Suárez VJ, Martín-Rodríguez A, Yáñez-Sepúlveda R, Tornero-Aguilera JF. Mitochondrial Transfer as a Novel Therapeutic Approach in Disease Diagnosis and Treatment. Int J Mol Sci 2023; 24:ijms24108848. [PMID: 37240194 DOI: 10.3390/ijms24108848] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/12/2023] [Accepted: 05/14/2023] [Indexed: 05/28/2023] Open
Abstract
Mitochondrial dysfunction is a hallmark of numerous diseases, including neurodegenerative disorders, metabolic disorders, and cancer. Mitochondrial transfer, the transfer of mitochondria from one cell to another, has recently emerged as a potential therapeutic approach for restoring mitochondrial function in diseased cells. In this review, we summarize the current understanding of mitochondrial transfer, including its mechanisms, potential therapeutic applications, and impact on cell death pathways. We also discuss the future directions and challenges in the field of mitochondrial transfer as a novel therapeutic approach in disease diagnosis and treatment.
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Affiliation(s)
| | | | - Rodrigo Yáñez-Sepúlveda
- Faculty of Education and Social Sciences, Universidad Andres Bello, Viña del Mar 2520000, Chile
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Willingham TB, Ajayi PT, Glancy B. Subcellular Specialization of Mitochondrial Form and Function in Skeletal Muscle Cells. Front Cell Dev Biol 2021; 9:757305. [PMID: 34722542 PMCID: PMC8554132 DOI: 10.3389/fcell.2021.757305] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/27/2021] [Indexed: 11/22/2022] Open
Abstract
Across different cell types and within single cells, mitochondria are heterogeneous in form and function. In skeletal muscle cells, morphologically and functionally distinct subpopulations of mitochondria have been identified, but the mechanisms by which the subcellular specialization of mitochondria contributes to energy homeostasis in working muscles remains unclear. Here, we discuss the current data regarding mitochondrial heterogeneity in skeletal muscle cells and highlight potential new lines of inquiry that have emerged due to advancements in cellular imaging technologies.
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Affiliation(s)
- T. Bradley Willingham
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Peter T. Ajayi
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
| | - Brian Glancy
- National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, United States
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD, United States
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Wahwah N, Kras KA, Roust LR, Katsanos CS. Subpopulation-specific differences in skeletal muscle mitochondria in humans with obesity: insights from studies employing acute nutritional and exercise stimuli. Am J Physiol Endocrinol Metab 2020; 318:E538-E553. [PMID: 31990577 DOI: 10.1152/ajpendo.00463.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Mitochondria from skeletal muscle of humans with obesity often display alterations with respect to their morphology, proteome, biogenesis, and function. These changes in muscle mitochondria are considered to contribute to metabolic abnormalities observed in humans with obesity. Most of the evidence describing alterations in muscle mitochondria in humans with obesity, however, lacks reference to a specific subcellular location. This is despite data over the years showing differences in the morphology and function of subsarcolemmal (found near the plasma membrane) and intermyofibrillar (nested between the myofibrils) mitochondria in skeletal muscle. Recent studies reveal that impairments in mitochondrial function in obesity with respect to the subcellular location of the mitochondria in muscle are more readily evident following exposure of the skeletal muscle to physiological stimuli. In this review, we highlight the need to understand skeletal muscle mitochondria metabolism in obesity in a subpopulation-specific manner and in the presence of physiological stimuli that modify mitochondrial function in vivo. Experimental approaches employed under these conditions will allow for more precise characterization of impairments in skeletal muscle mitochondria and their implications in inducing metabolic dysfunction in human obesity.
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Affiliation(s)
- Nisreen Wahwah
- Center for Metabolic and Vascular Biology and School of Life Sciences, Arizona State University, Scottsdale, Arizona
| | - Katon A Kras
- Center for Metabolic and Vascular Biology and School of Life Sciences, Arizona State University, Scottsdale, Arizona
| | - Lori R Roust
- College of Medicine, Mayo Clinic in Arizona, Scottsdale, Arizona
| | - Christos S Katsanos
- Center for Metabolic and Vascular Biology and School of Life Sciences, Arizona State University, Scottsdale, Arizona
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Groennebaek T, Billeskov TB, Schytz CT, Jespersen NR, Bøtker HE, Olsen RKJ, Eldrup N, Nielsen J, Farup J, de Paoli FV, Vissing K. Mitochondrial Structure and Function in the Metabolic Myopathy Accompanying Patients with Critical Limb Ischemia. Cells 2020; 9:cells9030570. [PMID: 32121096 PMCID: PMC7140415 DOI: 10.3390/cells9030570] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 02/20/2020] [Accepted: 02/26/2020] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction has been implicated as a central mechanism in the metabolic myopathy accompanying critical limb ischemia (CLI). However, whether mitochondrial dysfunction is directly related to lower extremity ischemia and the structural and molecular mechanisms underpinning mitochondrial dysfunction in CLI patients is not understood. Here, we aimed to study whether mitochondrial dysfunction is a distinctive characteristic of CLI myopathy by assessing mitochondrial respiration in gastrocnemius muscle from 14 CLI patients (65.3 ± 7.8 y) and 15 matched control patients (CON) with a similar comorbidity risk profile and medication regimen but without peripheral ischemia (67.4 ± 7.4 y). Furthermore, we studied potential structural and molecular mechanisms of mitochondrial dysfunction by measuring total, sub-population, and fiber-type-specific mitochondrial volumetric content and cristae density with transmission electron microscopy and by assessing mitophagy and fission/fusion-related protein expression. Finally, we asked whether commonly used biomarkers of mitochondrial content are valid in patients with cardiovascular disease. CLI patients exhibited inferior mitochondrial respiration compared to CON. This respiratory deficit was not related to lower whole-muscle mitochondrial content or cristae density. However, stratification for fiber types revealed ultrastructural mitochondrial alterations in CLI patients compared to CON. CLI patients exhibited an altered expression of mitophagy-related proteins but not fission/fusion-related proteins compared to CON. Citrate synthase, cytochrome c oxidase subunit IV (COXIV), and 3-hydroxyacyl-CoA dehydrogenase (β-HAD) could not predict mitochondrial content. Mitochondrial dysfunction is a distinctive characteristic of CLI myopathy and is not related to altered organelle content or cristae density. Our results link this intrinsic mitochondrial deficit to dysregulation of the mitochondrial quality control system, which has implications for the development of therapeutic strategies.
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Affiliation(s)
- Thomas Groennebaek
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark; (T.G.); (C.T.S.)
| | - Tine Borum Billeskov
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (T.B.B.); (J.F.)
- Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, 8200 Aarhus, Denmark
| | - Camilla Tvede Schytz
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark; (T.G.); (C.T.S.)
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5230 Odense, Denmark;
| | - Nichlas Riise Jespersen
- Department of Cardiology, Aarhus University Hospital, 8200 Aarhus, Denmark; (N.R.J.); (H.E.B.)
| | - Hans Erik Bøtker
- Department of Cardiology, Aarhus University Hospital, 8200 Aarhus, Denmark; (N.R.J.); (H.E.B.)
| | | | - Nikolaj Eldrup
- Department Vascular Surgery, Rigshospitalet, Copenhagen University, 2100 Copenhagen, Denmark;
| | - Joachim Nielsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, 5230 Odense, Denmark;
| | - Jean Farup
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (T.B.B.); (J.F.)
| | - Frank Vincenzo de Paoli
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark; (T.B.B.); (J.F.)
- Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, 8200 Aarhus, Denmark
- Correspondence: (F.V.d.P.); (K.V.); Tel.: +45-87168173
| | - Kristian Vissing
- Department of Public Health, Aarhus University, 8000 Aarhus, Denmark; (T.G.); (C.T.S.)
- Correspondence: (F.V.d.P.); (K.V.); Tel.: +45-87168173
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Kras KA, Hoffman N, Roust LR, Benjamin TR, DE Filippis EA, Katsanos CS. Adenosine Triphosphate Production of Muscle Mitochondria after Acute Exercise in Lean and Obese Humans. Med Sci Sports Exerc 2019; 51:445-453. [PMID: 30363008 DOI: 10.1249/mss.0000000000001812] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Current evidence indicates mitochondrial dysfunction in humans with obesity. Acute exercise appears to enhance mitochondrial function in the muscle of nonobese humans, but its effects on mitochondrial function in muscle of humans with obesity are not known. We sought to determine whether acute aerobic exercise stimulates mitochondrial function in subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria in humans with obesity. METHODS We assessed maximal adenosine triphosphate production rate (MAPR) and citrate synthase (CS) activity in isolated SS and IMF mitochondria from subjects with body mass index < 27 kg·m (median age, 25 yr; interquartile range, 22-39 yr) and subjects with body mass index > 32 kg·m (median age, 29 yr; interquartile range, 20-39 yr) before and 3 h after a 45-min cycling exercise at an intensity corresponding to 65% HR reserve. The SS and IMF mitochondria were isolated from muscle biopsies using differential centrifugation. Maximal adenosine triphosphate production rate and CS activities were determined using luciferase-based and spectrophotometric enzyme-based assays, respectively. RESULTS Exercise increased MAPR in IMF mitochondria in both nonobese subjects and subjects with obesity (P < 0.05), but CS-specific activity did not change in either group (P > 0.05). Exercise increased MAPR supported by complex II in SS mitochondria, in both groups (P < 0.05), but MAPR supported by complex I or palmitate did not increase by exercise in the subjects with obesity (P > 0.05). Citrate synthase-specific activity increased in SS mitochondria in response to exercise only in nonobese subjects (P < 0.05). CONCLUSIONS In nonobese humans, acute aerobic exercise increases MAPR in both SS and IMF mitochondria. In humans with obesity, the exercise increases MAPR in IMF mitochondria, but this response is less evident in SS mitochondria.
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Affiliation(s)
- Katon A Kras
- Center for Metabolic and Vascular Biology, Arizona State University, Scottsdale, AZ
| | - Nyssa Hoffman
- Center for Metabolic and Vascular Biology, Arizona State University, Scottsdale, AZ
| | - Lori R Roust
- College of Medicine, Mayo Clinic in Arizona, Scottsdale, AZ
| | | | | | - Christos S Katsanos
- Center for Metabolic and Vascular Biology, Arizona State University, Scottsdale, AZ.,College of Medicine, Mayo Clinic in Arizona, Scottsdale, AZ
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Hingst JR, Bjerre RD, Wojtaszewski JFP, Jensen J. Rapid radiochemical filter paper assay for determination of hexokinase activity and affinity for glucose-6-phosphate. J Appl Physiol (1985) 2019; 127:661-667. [DOI: 10.1152/japplphysiol.00207.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Glucose phosphorylation by hexokinase (HK) is a rate-limiting step in glucose metabolism. Regulation of HK includes feedback inhibition by its product glucose-6-phosphate (G6P) and mitochondria binding. HK affinity for G6P is difficult to measure because its natural product (G6P) inhibits enzyme activity. HK phosphorylates several hexoses, and we have taken advantage of the fact that 2-deoxyglucose (2-DG)-6-phosphate does not inhibit HK activity. By this, we have developed a new method for rapid radiochemical analysis of HK activity with 2-DG as a substrate, which allows control of the concentrations of G6P to investigate HK affinity for inhibition by G6P. We verified that 2-DG serves as a substrate for the HK reaction with linear time and concentration dependency as well as expected maximal velocity and KM. This is the first simple assay that evaluates feedback inhibition of HK by its product G6P and provides a unique technique for future research evaluating the regulation of glucose phosphorylation under various physiological conditions.NEW & NOTEWORTHY Traditionally, hexokinase activity has been analyzed spectrophotometrically in which the product formation of glucose-6-phosphate (G6P) is analyzed by an indirect reaction coupled to NADPH formation during conversion of G6P to 6-P gluconolactone. By nature, this assay prevents measurements of hexokinase (HK) affinity for inhibition by G6P. We have developed a rapid radiochemical filter paper assay to study HK affinity for G6P by use of radiolabeled 2-deoxyglucose as substrate to study physiological regulation of HK affinity for G6P-induced inhibition.
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Affiliation(s)
- Janne R. Hingst
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Rie D. Bjerre
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen F. P. Wojtaszewski
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen Jensen
- Department of Physical Performance, Norwegian School of Sports Sciences, Oslo, Norway
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Hart CR, Layec G, Trinity JD, Kwon OS, Zhao J, Reese VR, Gifford JR, Richardson RS. Increased skeletal muscle mitochondrial free radical production in peripheral arterial disease despite preserved mitochondrial respiratory capacity. Exp Physiol 2018; 103:838-850. [PMID: 29604234 DOI: 10.1113/ep086905] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/23/2018] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the central question of this study? What is the degree to which skeletal muscle mitochondria-derived reactive oxygen species (ROS) production is linked to impaired skeletal muscle function in patients with early-stage peripheral arterial disease (PAD) and what is the impact on mitochondrial respiratory capacity? What is the main finding and its importance? This is the first study to document increased mitochondria-derived reactive oxygen species production associated with elevated intramuscular oxidative stress, despite preserved mitochondrial respiratory function, in patients with PAD. Furthermore, systemic inflammation, mitochondria-derived ROS production and skeletal muscle oxidative stress were strongly correlated to disease severity, as indicated by ankle-brachial index, in patients with PAD. ABSTRACT Skeletal muscle mitochondrial dysfunction, which is not fully explained by disease-related arterial occlusion, has been implicated in the pathophysiology of peripheral arterial disease (PAD). Therefore, this study comprehensively assessed mitochondrial respiratory function in biopsies from the gastrocnemius of 10 patients with PAD (Fontaine Stage II) and 12 healthy controls (HC). Intramuscular and systemic inflammation, mitochondria-derived reactive oxygen species (ROS) production, and oxidative stress were also assessed to better understand the mechanisms responsible for the proposed PAD-induced mitochondrial dysfunction. Interestingly, mitochondrial respiratory capacity, assessed as complex I (CI) and complex II (CII)-driven State 3 respiration, measured separately and in combination (State 3 CI+II), revealed no difference between the patients with PAD and the HC. However, mitochondria-derived ROS production was significantly elevated in PAD (HC: 1.0 ± 0.9; PAD: 4.3 ± 1.0 AU (mg tissue)-1 ). Furthermore, patients with PAD exhibited significantly greater concentrations of the pro-inflammatory markers tumour necrosis factor α in plasma (HC: 0.9 ± 0.4; PAD: 2.0 ± 0.3 pg ml-1 ) and interleukin 6 in both plasma (HC: 2.3 ± 0.4; PAD: 4.3 ± 0.5 pg ml-1 ) and muscle (∼75% greater). Intramuscular oxidative stress, assessed by protein carbonyls and 4-hydroxynonenal, was significantly greater in PAD compared to HC. Ankle brachial index was significantly correlated with intramuscular inflammation, oxidative stress and mitochondria-derived ROS production. Thus, elevated intramuscular inflammation, oxidative stress and mitochondria-derived ROS production are likely to contribute to the pathophysiology of the skeletal muscle dysfunction associated with PAD, even in the presence of preserved mitochondrial respiratory function in this population.
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Affiliation(s)
- Corey R Hart
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Exercise and Sport Science, University of Utah, Salt Lake City, UT, USA
| | - Gwenael Layec
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA
| | - Joel D Trinity
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA
| | - Oh Sung Kwon
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA
| | - Jia Zhao
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA
| | - Van R Reese
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA
| | - Jayson R Gifford
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA
| | - Russell S Richardson
- Geriatric Research, Education, and Clinical Center, George E. Whalen VA Medical Center, Salt Lake City, UT, USA.,Department of Medicine, Division of Geriatrics, University of Utah, Salt Lake City, UT, USA.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
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10
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Rontoyanni VG, Nunez Lopez O, Fankhauser GT, Cheema ZF, Rasmussen BB, Porter C. Mitochondrial Bioenergetics in the Metabolic Myopathy Accompanying Peripheral Artery Disease. Front Physiol 2017; 8:141. [PMID: 28348531 PMCID: PMC5346567 DOI: 10.3389/fphys.2017.00141] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/23/2017] [Indexed: 11/14/2022] Open
Abstract
Peripheral artery disease (PAD) is a serious but relatively underdiagnosed and undertreated clinical condition associated with a marked reduction in functional capacity and a heightened risk of morbidity and mortality. The pathophysiology of lower extremity PAD is complex, and extends beyond the atherosclerotic arterial occlusion and subsequent mismatch between oxygen demand and delivery to skeletal muscle mitochondria. In this review, we evaluate and summarize the available evidence implicating mitochondria in the metabolic myopathy that accompanies PAD. Following a short discussion of the available in vivo and in vitro methodologies to quantitate indices of muscle mitochondrial function, we review the current evidence implicating skeletal muscle mitochondrial dysfunction in the pathophysiology of PAD myopathy, while attempting to highlight questions that remain unanswered. Given the rising prevalence of PAD, the detriment in quality of life for patients, and the associated significant healthcare resource utilization, new alternate therapies that ameliorate lower limb symptoms and the functional impairment associated with PAD are needed. A clear understanding of the role of mitochondria in the pathophysiology of PAD may contribute to the development of novel therapeutic interventions.
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Affiliation(s)
- Victoria G. Rontoyanni
- Metabolism Unit, Shriners Hospitals for ChildrenGalveston, TX, USA
- Department of Surgery, University of Texas Medical BranchGalveston, TX, USA
| | - Omar Nunez Lopez
- Metabolism Unit, Shriners Hospitals for ChildrenGalveston, TX, USA
- Department of Surgery, University of Texas Medical BranchGalveston, TX, USA
| | | | - Zulfiqar F. Cheema
- Department of Surgery, University of Texas Medical BranchGalveston, TX, USA
| | - Blake B. Rasmussen
- Department of Nutrition and Metabolism, University of Texas Medical BranchGalveston, TX, USA
| | - Craig Porter
- Metabolism Unit, Shriners Hospitals for ChildrenGalveston, TX, USA
- Department of Surgery, University of Texas Medical BranchGalveston, TX, USA
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Brass EP, Hiatt WR, Green S. Skeletal muscle metabolic changes in peripheral arterial disease contribute to exercise intolerance: a point-counterpoint discussion. Vasc Med 2016; 9:293-301. [PMID: 15678622 DOI: 10.1191/1358863x04vm572ra] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Patients with claudication have a marked impairment in exercise performance. Several factors contribute to this limitation, including reductions in large vessel blood flow and oxygen delivery as well as metabolic abnormalities in skeletal muscle. The relative contribution of these factors and their role in the pathophysiology of the exercise limitation is discussed using a point-counterpoint approach. Future directions for research conclude the discussion.
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Affiliation(s)
- Eric P Brass
- Center for Clinical Pharmacology, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA, USA
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12
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Baum O, Torchetti E, Malik C, Hoier B, Walker M, Walker PJ, Odriozola A, Graber F, Tschanz SA, Bangsbo J, Hoppeler H, Askew CD, Hellsten Y. Capillary ultrastructure and mitochondrial volume density in skeletal muscle in relation to reduced exercise capacity of patients with intermittent claudication. Am J Physiol Regul Integr Comp Physiol 2016; 310:R943-51. [DOI: 10.1152/ajpregu.00480.2015] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 03/17/2016] [Indexed: 01/26/2023]
Abstract
Intermittent claudication (IC) is the most commonly reported symptom of peripheral arterial disease (PAD). Impaired limb blood flow is a major casual factor of lower exercise tolerance in PAD but cannot entirely explain it. We hypothesized that IC is associated with structural changes of the capillary-mitochondria interface that could contribute to the reduction of exercise tolerance in IC patients. Capillary and mitochondrial morphometry were performed after light and transmission electron microscopy using vastus lateralis muscle biopsies of 14 IC patients and 10 age-matched controls, and peak power output (PPO) was determined for all participants using an incremental single-leg knee-extension protocol. Capillary density was lower (411 ± 90 mm−2 vs. 506 ± 95 mm−2; P ≤ 0.05) in the biopsies of the IC patients than in those of the controls. The basement membrane (BM) around capillaries was thicker (543 ± 82 nm vs. 423 ± 97 nm; P ≤ 0.01) and the volume density of mitochondria was lower (3.51 ± 0.56% vs. 4.60 ± 0.74%; P ≤ 0.01) in the IC patients than the controls. In the IC patients, a higher proportion of capillaries appeared with collapsed slit-like lumen and/or swollen endothelium. PPO was lower (18.5 ± 9.9 W vs. 33.5 ± 9.4 W; P ≤ 0.01) in the IC patients than the controls. We suggest that several structural alterations in skeletal muscle, either collectively or separately, contribute to the reduction of exercise tolerance in IC patients.
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Affiliation(s)
- Oliver Baum
- Institute of Physiology, CharitéCrossOver (CCO), Berlin, Germany
- Institute of Anatomy, University of Bern, Switzerland
| | | | - Corinna Malik
- Institute of Anatomy, University of Bern, Switzerland
| | - Birgitte Hoier
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Meegan Walker
- School of Health and Sport Sciences, University of the Sunshine Coast, Australia
| | - Philip J. Walker
- Discipline of Surgery, School of Medicine and Centre for Clinical Research, The University of Queensland, Australia; and
- National Health and Medical Research Council, Centre of Research Excellence for Peripheral Arterial Diseases, Australia
| | | | | | | | - Jens Bangsbo
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Hans Hoppeler
- Institute of Anatomy, University of Bern, Switzerland
| | - Christopher D. Askew
- School of Health and Sport Sciences, University of the Sunshine Coast, Australia
- National Health and Medical Research Council, Centre of Research Excellence for Peripheral Arterial Diseases, Australia
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
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13
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Elustondo PA, White AE, Hughes ME, Brebner K, Pavlov E, Kane DA. Physical and functional association of lactate dehydrogenase (LDH) with skeletal muscle mitochondria. J Biol Chem 2013; 288:25309-25317. [PMID: 23873936 PMCID: PMC3757195 DOI: 10.1074/jbc.m113.476648] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 07/09/2013] [Indexed: 11/06/2022] Open
Abstract
The intracellular lactate shuttle hypothesis posits that lactate generated in the cytosol is oxidized by mitochondrial lactate dehydrogenase (LDH) of the same cell. To examine whether skeletal muscle mitochondria oxidize lactate, mitochondrial respiratory oxygen flux (JO2) was measured during the sequential addition of various substrates and cofactors onto permeabilized rat gastrocnemius muscle fibers, as well as isolated mitochondrial subpopulations. Addition of lactate did not alter JO2. However, subsequent addition of NAD(+) significantly increased JO2, and was abolished by the inhibitor of mitochondrial pyruvate transport, α-cyano-4-hydroxycinnamate. In experiments with isolated subsarcolemmal and intermyofibrillar mitochondrial subpopulations, only subsarcolemmal exhibited NAD(+)-dependent lactate oxidation. To further investigate the details of the physical association of LDH with mitochondria in muscle, immunofluorescence/confocal microscopy and immunoblotting approaches were used. LDH clearly colocalized with mitochondria in intact, as well as permeabilized fibers. LDH is likely localized inside the outer mitochondrial membrane, but not in the mitochondrial matrix. Collectively, these results suggest that extra-matrix LDH is strategically positioned within skeletal muscle fibers to functionally interact with mitochondria.
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Affiliation(s)
- Pia A Elustondo
- From the Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 4R2 and
| | | | | | - Karen Brebner
- Psychology, St. Francis Xavier University, Antigonish, Nova Scotia B2G 2W5, Canada
| | - Evgeny Pavlov
- From the Department of Physiology and Biophysics, Dalhousie University, Halifax, NS B3H 4R2 and
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14
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Jonkers RAM, Dirks ML, Nabuurs CIHC, De Feyter HM, Praet SFE, Nicolay K, van Loon LJC, Prompers JJ. Myofibrillar distribution of succinate dehydrogenase activity and lipid stores differs in skeletal muscle tissue of paraplegic subjects. Am J Physiol Endocrinol Metab 2012; 302:E365-73. [PMID: 22068603 DOI: 10.1152/ajpendo.00270.2011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Lack of physical activity has been related to an increased risk of developing insulin resistance. This study aimed to assess the impact of chronic muscle deconditioning on whole body insulin sensitivity, muscle oxidative capacity, and intramyocellular lipid (IMCL) content in subjects with paraplegia. Nine subjects with paraplegia and nine able-bodied, lean controls were recruited. An oral glucose tolerance test was performed to assess whole body insulin sensitivity. IMCL content was determined both in vivo and in vitro using (1)H-magnetic resonance spectroscopy and fluorescence microscopy, respectively. Muscle biopsy samples were stained for succinate dehydrogenase (SDH) activity to measure muscle fiber oxidative capacity. Subcellular distributions of IMCL and SDH activity were determined by defining subsarcolemmal and intermyofibrillar areas on histological samples. SDH activity was 57 ± 14% lower in muscle fibers derived from subjects with paraplegia when compared with controls (P < 0.05), but IMCL content and whole body insulin sensitivity did not differ between groups. In muscle fibers taken from controls, both SDH activity and IMCL content were higher in the subsarcolemmal region than in the intermyofibrillar area. This typical subcellular SDH and IMCL distribution pattern was lost in muscle fibers collected from subjects with paraplegia and had changed toward a more uniform distribution. In conclusion, the lower metabolic demand in deconditioned muscle of subjects with paraplegia results in a significant decline in muscle fiber oxidative capacity and is accompanied by changes in the subcellular distribution patterns of SDH activity and IMCL. However, loss of muscle activity due to paraplegia is not associated with substantial lipid accumulation in skeletal muscle tissue.
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Affiliation(s)
- Richard A M Jonkers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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15
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MacPherson REK, Herbst EAF, Reynolds EJ, Vandenboom R, Roy BD, Peters SJ. Subcellular localization of skeletal muscle lipid droplets and PLIN family proteins OXPAT and ADRP at rest and following contraction in rat soleus muscle. Am J Physiol Regul Integr Comp Physiol 2011; 302:R29-36. [PMID: 22012700 DOI: 10.1152/ajpregu.00163.2011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Skeletal muscle lipid droplet-associated proteins (PLINs) are thought to regulate lipolysis through protein-protein interactions on the lipid droplet surface. In adipocytes, PLIN2 [adipocyte differentiation-related protein (ADRP)] is found only on lipid droplets, while PLIN5 (OXPAT, expressed only in oxidative tissues) is found both on and off the lipid droplet and may be recruited to lipid droplet membranes when needed. Our purpose was to determine whether PLIN5 is recruited to lipid droplets with contraction and to investigate the myocellular location and colocalization of lipid droplets, PLIN2, and PLIN5. Rat solei were isolated, and following a 30-min equilibration period, they were assigned to one of two groups: 1) 30 min of resting incubation and 2) 30 min of stimulation (n = 10 each). Immunofluorescence microscopy was used to determine subcellular content, distribution, and colocalization of lipid droplets, PLIN2, and PLIN5. There was a main effect for lower lipid and PLIN2 content in stimulated compared with rested muscles (P < 0.05). Lipid droplet distribution declined exponentially from the sarcolemma to the fiber center in the rested muscles (P = 0.001, r(2) = 0.99) and linearly in stimulated muscles (slope = -0.0023 ± 0.0006, P < 0.001, r(2) = 0.93). PLIN2 distribution declined exponentially from the sarcolemma to the fiber center in both rested and stimulated muscles (P < 0.0001, r(2) = 0.99 rest; P = 0.0004, r(2) = 0.98 stimulated), while PLIN5 distribution declined linearly (slope = -0.0085 ± 0.0009, P < 0.0001, r(2) = 0.94 rest; slope=-0.0078 ± 0.0010, P = 0.0003, r(2) = 0.91 stimulated). PLIN5-lipid droplets colocalized at rest with no difference poststimulation (P = 0.47; rest r(2) = 0.55 ± 0.02, stimulated r(2) = 0.58 ± 0.03). PLIN2-lipid droplets colocalized at rest with no difference poststimulation (P = 0.48; rest r(2) = 0.66 ± 0.02, stimulated r(2) = 0.65 ± 0.02). Contrary to our hypothesis, these results show that PLIN5 is not recruited to lipid droplets with contraction in isolated skeletal muscle.
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Affiliation(s)
- Rebecca E K MacPherson
- Brock University, Department of Kinesiology, Centre for Muscle Metabolism and Biophysics, Faculty of Applied Health Sciences, St. Catharines, Ontario, Canada.
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16
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Abstract
Mitochondria play a pivotal role in cellular function, not only as a major site of ATP production, but also by regulating energy expenditure, apoptosis signaling, and production of reactive oxygen species. Altered mitochondrial function is reported to be a key underlying mechanism of many pathological states and in the aging process. Functional measurements of intact mitochondria isolated from fresh tissue provides distinct information regarding the function of these organelles that complements conventional mitochondrial assays using previously frozen tissue as well as in vivo assessment using techniques such as magnetic resonance and near-infrared spectroscopy. This chapter describes the process by which mitochondria are isolated from small amounts of human skeletal muscle obtained by needle biopsy and two approaches used to assess mitochondrial oxidative capacity and other key components of mitochondrial physiology. We first describe a bioluminescent approach for measuring the rates of mitochondrial ATP production. Firefly luciferase catalyzes a light-emitting reaction whereby the substrate luciferin is oxidized in an ATP-dependent manner. A luminometer is used to quantify the light signal, which is proportional to ATP concentration. We also review a method involving polarographic measurement of oxygen consumption. Measurements of oxygen consumption, which previously required large amounts of tissue, are now feasible with very small amounts of sample obtained by needle biopsy due to recent advances in the field of high-resolution respirometry. We illustrate how careful attention to substrate combinations and inhibitors allows an abundance of unique functional information to be obtained from isolated mitochondria, including function at various energetic states, oxidative capacity with electron flow through distinct complexes, coupling of oxygen consumption to ATP production, and membrane integrity. These measurements, together with studies of mitochondrial DNA abundance, mRNA levels, protein expression, and synthesis rates of mitochondrial proteins provide insightful mechanistic information about mitochondria in a variety of tissue types.
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Affiliation(s)
- Ian R Lanza
- Division of Endocrinology, Endocrinology Research Unit, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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17
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Stellingwerff T, Boon H, Jonkers RAM, Senden JM, Spriet LL, Koopman R, van Loon LJC. Significant intramyocellular lipid use during prolonged cycling in endurance-trained males as assessed by three different methodologies. Am J Physiol Endocrinol Metab 2007; 292:E1715-23. [PMID: 17299080 DOI: 10.1152/ajpendo.00678.2006] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intramyocellular triacylglycerol (IMTG) has been suggested to represent an important substrate source during exercise. In the present study, IMTG utilization during exercise is assessed through the use of various methodologies. In addition, we identified differences in the use of intramyocellular lipids deposited in the immediate subsarcolemmal (SS) area and those stored in the more central region of the fiber. Contemporary stable isotope technology was applied in combination with muscle tissue sampling before and immediately after 3 h of moderate-intensity cycling exercise (62 +/- 2% Vo(2 max)) in eight well-trained male cyclists. Continuous infusions with [U-13C]palmitate and [6,6-(2)H2]glucose were applied to quantify plasma free fatty acid (FFA) and glucose oxidation rates and to estimate whole body IMTG and glycogen use. Both immunohistochemical analyses of oil red O (ORO)-stained muscle cross sections and biochemical triacylglycerol (TG) extraction were performed to assess muscle lipid content. During exercise, plasma FFA, muscle (and/or lipoprotein)-derived TG, plasma glucose, and muscle glycogen oxidation contributed 24 +/- 2, 22 +/- 3, 11 +/- 1, and 43 +/- 3% to total energy expenditure, respectively. In accordance, a significant net decline in muscle lipid content was observed following exercise as assessed by ORO staining (67 +/- 8%) and biochemical TG extraction (49 +/- 8%), and a positive correlation was observed between methods (r = 0.56; P < 0.05). Lipid depots located in the SS area were utilized to a greater extent than the more centrally located depots. This is the first study to show significant use of IMTG as a substrate source during exercise in healthy males via the concurrent implementation of three major methodologies. In addition, this study shows differences in resting subcellular intramyocellular lipid deposit distribution and in the subsequent net use of these deposits during exercise.
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Affiliation(s)
- Trent Stellingwerff
- Department of Movement Science, Maastricht University, Maastricht, The Netherlands.
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18
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Menshikova EV, Ritov VB, Fairfull L, Ferrell RE, Kelley DE, Goodpaster BH. Effects of exercise on mitochondrial content and function in aging human skeletal muscle. J Gerontol A Biol Sci Med Sci 2006; 61:534-40. [PMID: 16799133 PMCID: PMC1540458 DOI: 10.1093/gerona/61.6.534] [Citation(s) in RCA: 252] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Skeletal muscle mitochondria are implicated with age-related loss of function and insulin resistance. We examined the effects of exercise on skeletal muscle mitochondria in older (age = 67.3 +/- 0.6 years) men (n = 5) and women (n = 3). Similar increases in (p <.01) cardiolipin (88.2 +/- 9.0 to 130.6 +/- 7.5 microg/mU creatine kinase activity [CK]) and the total mitochondrial DNA (1264 +/- 170 to 1895 +/- 273 copies per diploid of nuclear genome) reflected increased mitochondria content. Succinate oxidase activity, complexes 2-4 of the electron transport chain (ETC), increased from 0.13 +/- 0.02 to 0.20 +/- 0.02 U/mU CK (p <.01). This improvement was more pronounced (p <.05) in subsarcolemmal (127 +/- 48%) compared to intermyofibrillar (56 +/- 12%) mitochondria. NADH oxidase activity, representing total ETC activity, increased from 0.51 +/- 0.09 to 1.00 +/- 0.09 U/mU CK (p <.01). In conclusion, exercise enhances mitochondria ETC activity in older human skeletal muscle, particularly in subsarcolemmal mitochondria, which is likely related to the concomitant increases in mitochondrial biogenesis.
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Affiliation(s)
- Elizabeth V. Menshikova
- Division of Endocrinology and Metabolism, Department of Medicine; University of Pittsburgh School of Medicine, and the
| | - Vladimir B. Ritov
- Division of Endocrinology and Metabolism, Department of Medicine; University of Pittsburgh School of Medicine, and the
| | - Liane Fairfull
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh; Pittsburgh, PA
| | - Robert E. Ferrell
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh; Pittsburgh, PA
| | - David E. Kelley
- Division of Endocrinology and Metabolism, Department of Medicine; University of Pittsburgh School of Medicine, and the
| | - Bret H. Goodpaster
- Division of Endocrinology and Metabolism, Department of Medicine; University of Pittsburgh School of Medicine, and the
- Address for Correspondence: Bret H. Goodpaster, PhD, University of Pittsburgh, 3459 Fifth Avenue, MUH N807, Pittsburgh, PA 15213.
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19
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Gueguen N, Lefaucheur L, Fillaut M, Vincent A, Herpin P. Control of skeletal muscle mitochondria respiration by adenine nucleotides: differential effect of ADP and ATP according to muscle contractile type in pigs. Comp Biochem Physiol B Biochem Mol Biol 2005; 140:287-97. [PMID: 15649776 DOI: 10.1016/j.cbpc.2004.10.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 10/22/2004] [Accepted: 10/26/2004] [Indexed: 12/01/2022]
Abstract
Skeletal muscle exhibits considerable variation in mitochondrial content among fiber types, but it is less clear whether mitochondria from different fiber types also present specific functional and regulatory properties. The present experiment was undertaken on ten 170-day-old pigs to compare functional properties and control of respiration by adenine nucleotides in mitochondria isolated from predominantly slow-twitch (Rhomboideus (RM)) and fast-twitch (Longissimus (LM)) muscles. Mitochondrial ATP synthesis, respiratory control ratio (RCR) and ADP-stimulated respiration with either complex I or II substrates were significantly higher (25-30%, P<0.05) in RM than in LM mitochondria, whereas no difference was observed for basal respiration. Based on mitochondrial enzyme activities (cytochrome c oxidase [COX], F0F1-ATPase, mitochondrial creatine kinase [mi-CK]), the higher ADP-stimulated respiration rate of RM mitochondria appeared mainly related to a higher maximal oxidative capacity, without any difference in the maximal phosphorylation potential. Mitochondrial K(m) for ADP was similar in RM (4.4+/-0.9 microM) and LM (5.9+/-1.2 microM) muscles (P>0.05) but the inhibitory effect of ATP was more marked in LM (P<0.01). These findings demonstrate that the regulation of mitochondrial respiration by ATP differs according to muscle contractile type and that absolute muscle oxidative capacity not only relies on mitochondrial density but also on mitochondrial functioning per se.
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Affiliation(s)
- N Gueguen
- INRA, Unité Mixte de Recherche sur le Veau et le Porc, Domaine de la Prise, 35590 Saint-Gilles, France.
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20
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Menshikova EV, Ritov VB, Toledo FGS, Ferrell RE, Goodpaster BH, Kelley DE. Effects of weight loss and physical activity on skeletal muscle mitochondrial function in obesity. Am J Physiol Endocrinol Metab 2005; 288:E818-25. [PMID: 15585590 DOI: 10.1152/ajpendo.00322.2004] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The current study was undertaken to address responsiveness of skeletal muscle mitochondrial electron transport chain (ETC) activity to weight loss (WL) and exercise in overweight or obese, sedentary volunteers. Fourteen middle-aged participants (7 male/7 female) had assessments of mitochondrial ETC activity and mitochondrial (mt)DNA in vastus lateralis muscle, obtained by percutaneous biopsy, before and after a 16-wk intervention. Mean WL was 9.7 (1.5%) and the mean increase in Vo(2 max) was [means (SD)] 21.7 (3.7)%. Total ETC activity increased significantly, from 0.13 (0.02) to 0.19 (0.03) U/mU creatine kinase (CK; P < 0.001). ETC activity was also assessed in mitochondria isolated into subsarcolemmal (SSM) and intermyofibrillar (IMF-M) fractions. In response to intervention, there was a robust increase of ETC activity in SSM (0.028 (0.007) to 0.046 (0.011) U/mU CK, P < 0.001), and in IMF-M [0.101 (0.015) to 0.148 (0.018) U/mU CK, P < 0.005]. At baseline, the percentage of ETC activity contained in the SSM fraction was low and remained unchanged following intervention [19 (3) vs. 22 (2)%], despite the increase in ETC activity. Also, muscle mtDNA content did not change significantly [1665 (213) vs. 1874 (214) mtDNA/nuclear DNA], denoting functional improvement rather than proliferation of mitochondria as the principal mechanism of enhanced ETC activity. Increases in ETC activity were correlated with energy expenditure during exercise sessions, and ETC activity in SSM correlated with insulin sensitivity after adjustment for Vo(2 max). In summary, skeletal muscle ETC activity is increased by WL and exercise in previously sedentary obese men and women. We conclude that improved skeletal muscle ETC activity following moderate WL and improved aerobic capacity contributes to associated alleviation of insulin resistance.
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Affiliation(s)
- Elizabeth V Menshikova
- Division of Endocrinology and Metabolism, Department of Medicine, University of Pittsburgh, School of Medicine, Pennsylvania, USA
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21
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Ritov VB, Menshikova EV, Kelley DE. High-performance liquid chromatography-based methods of enzymatic analysis: electron transport chain activity in mitochondria from human skeletal muscle. Anal Biochem 2005; 333:27-38. [PMID: 15351277 DOI: 10.1016/j.ab.2004.05.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Indexed: 11/18/2022]
Abstract
This study addresses an application of pyridine nucleotide enzymatic analyses to evaluate the activity of the mitochondrial electron transport chain (reduced nicotinamide adenine dinucleotide (NADH) oxidase) and Complexes I and II in samples of human muscle as small as approximately 10 mg wet weight. Key aspects in this adaptation are the use of high-performance liquid chromatography with fluorescence detection of NADH and use of alamethicin, a channel-forming antibiotic that enables an unrestricted access of substrates into the mitochondrial matrix. The procedure includes disintegration of tissue by Polytron homogenizer, extraction of myosin from myofibrillar fragments by KCl/pyrophosphate to facilitate release of mitochondria, and preparation of fractions of subsarcolemmal and intermyofibrillar mitochondria. Oxidation of NADH or succinate is assayed in the presence of 40 microg/ml alamethicin and the reaction is terminated by H(2)SO(4), which also destroys the remaining NADH. Nicotinamide adenine dinucleotide (NAD) or fumarate concentrations are measured using alcohol dehydrogenase or fumarase plus malic dehydrogenase reactions, respectively. Generation of NADH, assessed in auxiliary reactions in the presence of hydrazine, is strictly proportional to NAD or fumarate content across a concentration range of 1-20 microM. NADH is quantitatively analyzed with a detection limit of 3-5 pmol by HPLC using a reverse-phase Hypersil ODS column connected to a fluorescence detector.
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Affiliation(s)
- Vladimir B Ritov
- Department of Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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22
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Ritov VB, Menshikova EV, He J, Ferrell RE, Goodpaster BH, Kelley DE. Deficiency of subsarcolemmal mitochondria in obesity and type 2 diabetes. Diabetes 2005; 54:8-14. [PMID: 15616005 DOI: 10.2337/diabetes.54.1.8] [Citation(s) in RCA: 622] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The current study addresses a novel hypothesis of subcellular distribution of mitochondrial dysfunction in skeletal muscle in type 2 diabetes. Vastus lateralis muscle was obtained by percutaneous biopsy from 11 volunteers with type 2 diabetes; 12 age-, sex-, and weight-matched obese sedentary nondiabetic volunteers; and 8 lean volunteers. Subsarcolemmal and intermyofibrillar mitochondrial fractions were isolated by differential centrifugation and digestion techniques. Overall electron transport chain activity was similar in type 2 diabetic and obese subjects, but subsarcolemmal mitochondria electron transport chain activity was reduced in type 2 diabetic subjects (0.017 +/- 0.003 vs. 0.034 +/- 0.007 units/mU creatine kinase [CK], P = 0.01) and sevenfold reduced compared with lean subjects (P < 0.01). Electron transport chain activity in intermyofibrillar mitochondria was similar in type 2 diabetic and obese subjects, though reduced compared with lean subjects. A reduction in subsarcolemmal mitochondria was confirmed by transmission electron microscopy. Although mtDNA was lower in type 2 diabetic and obese subjects, the decrement in electron transport chain activity was proportionately greater, indicating functional impairment. Because of the potential importance of subsarcolemmal mitochondria for signal transduction and substrate transport, this deficit may contribute to the pathogenesis of muscle insulin resistance in type 2 diabetes.
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Affiliation(s)
- Vladimir B Ritov
- Division of Endocrinology and Metabolism, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
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23
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Hou XY, Green S, Askew CD, Barker G, Green A, Walker PJ. Skeletal muscle mitochondrial ATP production rate and walking performance in peripheral arterial disease. Clin Physiol Funct Imaging 2002; 22:226-32. [PMID: 12076351 DOI: 10.1046/j.1475-097x.2002.00423.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study tested the hypotheses that skeletal muscle mitochondrial ATP production rate (MAPR) is impaired in patients with peripheral arterial disease (PAD) and that it relates positively to their walking performances. Seven untrained patients, eight exercise-trained patients and 11 healthy controls completed a maximal walking test and had muscle sampled from the gastrocnemius medialis muscle. Muscle was analysed for its MAPR in the presence of pyruvate, palmitoyl-L-carnitine or both, as well as citrate synthase (CS) activity. MAPRs were not different between untrained PAD and controls. In contrast, MAPRs (pyruvate) were significantly higher in trained PAD vs. controls. MAPR (pyruvate combinations) was also significantly higher in trained than untrained PAD muscle. MAPR and CS activity were highly correlated with walking performance in patients, but not in controls. These data do not support the hypothesis that isolated mitochondria are functionally impaired in PAD and demonstrate that the muscle mitochondrial capacity to oxidize carbohydrate is positively related to walking performance in these patients.
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Affiliation(s)
- X-Y Hou
- School of Human Movement Studies, Queensland University of Technology, Brisbane, Australia
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24
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Kemp GJ, Roberts N, Bimson WE, Bakran A, Harris PL, Gilling-Smith GL, Brennan J, Rankin A, Frostick SP. Mitochondrial function and oxygen supply in normal and in chronically ischemic muscle: a combined 31P magnetic resonance spectroscopy and near infrared spectroscopy study in vivo. J Vasc Surg 2001; 34:1103-10. [PMID: 11743568 DOI: 10.1067/mva.2001.117152] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE We used (31)P magnetic resonance spectroscopy (MRS) and near-infrared spectroscopy (NIRS) as a means of quantifying abnormalities in calf muscle oxygenation and adenosine triphosphate (ATP) turnover in peripheral vascular disease (PVD). METHODS Eleven male patients with PVD (mean age, 65 years; range, 55-76 years) and nine male control subjects of similar age were observed in a case-control study in vascular outpatients. Inclusion criteria were more than 6 months' calf claudication (median, 1.5 years; range, 0.6-18 years); proven femoropopliteal or iliofemoral occlusive or stenotic disease; maximum treadmill walking distance (2 km/h, 10 degrees gradient) of 50 to 230 m (mean, 112 m); ankle-brachial pressure index of 0.8 or less during exercise (mean, 0.47; range, 0.29-0.60). Exclusion criteria included diabetes mellitus, anemia, and magnet contraindications. Simultaneous (31)P MRS and NIRS of lateral gastrocnemius was conducted during 2 to 4 minutes of voluntary 0.5 Hz isometric plantarflexion at 50% and 75% maximum voluntary contraction force (MVC), followed by 5 minutes recovery. Each subject was studied three times, and the results were combined. RESULTS Compared with control subjects, patients with PVD showed (1) normal muscle cross-sectional area, MVC, ATP turnover, and contractile efficiency (ATP turnover per force/area); (2) larger phosphocreatine (PCr) changes during exercise (ie, increased shortfall of oxidative ATP synthesis) and slower PCr recovery (47% +/- 7% [mean +/- SEM] decrease in functional capacity for oxidative ATP synthesis, P = .001); (3) faster deoxygenation during exercise and slower postexercise reoxygenation (59% +/- 7% decrease in rate constant, P = .0009), despite reduced oxidative ATP synthesis; (4) correlation between PCr and NIRS recovery rate constants (P < .02); and (5) correlations between smaller walking distance, slower PCr recovery, and reduced MVC (P < .001). The precision of the key measurements (rate constants and contractile efficiency) was 12% to 18% interstudy and 30% to 40% intersubject. CONCLUSION The primary lesion in oxygen supply dominates muscle metabolism. Reduced force-generation in patients who are affected more may protect muscle from metabolic stress.
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Affiliation(s)
- G J Kemp
- Department of Musculoskeletal Science, University of Liverpool, UK.
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25
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Rasmussen UF, Rasmussen HN. Human quadriceps muscle mitochondria: a functional characterization. Mol Cell Biochem 2000; 208:37-44. [PMID: 10939626 DOI: 10.1023/a:1007046028132] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Human quadriceps mitochondria were isolated from ca. 80 mg tissue in ca. 45% yield. The preparation is described with respect to content of mitochondrial markers and nine different respiratory activities. The specific state 3 activities were high in comparison with literature data, indicating high integrity and purity of the preparation. Examples of state 3 rates, in micromol O min(-1) g protein(-1) (25 degrees C): pyruvate + malate, 400; succinate, 514; malate + glutamate, 444. The notion of high integrity was also supported by the reproducibility of the preparation and the magnitude of the respiratory control ratios and the P/O ratios. The mitochondria most likely had lost ca. 30% of their cytochrome c upon isolation, but it was substantiated that this loss had not influenced the state 3 rates. Functional assays of single reactions or groups of reactions could be based on respiration experiments. The respiratory chain activity, for instance, was measured as respiration of NADH in freeze-permeabilized mitochondria (1263 micromol O min(-1) g protein(-1)). Comparison of uncoupled rates of respiration and state 3 rates indicated that the ATP synthesis exerted major flux control over respiration of succinate + glutamate, malate + glutamate and pyruvate + malate. These reactions, showing very similar rates of ATP synthesis, could be used as a functional assay of ATP synthesis (1200 micromol ATP min(-1) g protein(-1)). Respiration of succinate, palmitoyl-carnitine + malate, or glutamate could not support the maximal rate of ATP synthesis and the upstream reactions probably exerted major flux control in these cases. The specific activities appeared very constant in this group of young men, only the respiratory activity with glutamate might show biological variation.
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Affiliation(s)
- U F Rasmussen
- Department of Biochemistry, August Krogh Institute, University of Copenhagen, Denmark
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26
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Abstract
BACKGROUND Conservative management is advocated as a treatment of choice for patients with intermittent claudication. This is a review of the mechanisms behind the improvement following an exercise rehabilitation programme. METHODS All Medline articles from the National Library of Medicine, USA containing the text words 'claudication' or 'peripheral vascular disease' and 'exercise' were reviewed. Cross-referencing from relevant articles was carried out. RESULTS AND CONCLUSION The poor physical status of a patient with intermittent claudication is not solely due to a reduction in blood flow to the lower limbs; associated factors, such as metabolic inefficiency, poor cardiorespiratory reserve and exercise-induced inflammation contribute. An exercise programme frequently improves both the physical aspect and quality of life, and the success of such exercise is multifactorial. An increase in the blood flow to the lower extremity is uncommon. Other factors, such as a redistribution of blood flow, changes in oxidative capacity of the skeletal muscles and greater utilization of oxygen, occur and the associated metabolic dysfunction of the skeletal muscles is rectified. Following exercise training, blood rheology improves and exercise-induced inflammation is ameliorated; cardiorespiratory status also benefits and the oxygen cost of exercise decreases.
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Affiliation(s)
- K H Tan
- Department of Surgery, Countess of Chester Hospital, Liverpool Road, Chester CH2 1UL, UK
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27
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Starritt EC, Angus D, Hargreaves M. Effect of short-term training on mitochondrial ATP production rate in human skeletal muscle. J Appl Physiol (1985) 1999; 86:450-4. [PMID: 9931175 DOI: 10.1152/jappl.1999.86.2.450] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Seven untrained volunteers [3 men, 4 women, 20.1 +/- 2.0 (SD) yr, 66. 0 +/- 11.0 kg, 171 +/- 13 cm] participated in a 10-day cycle exercise training program. Resting muscle samples were obtained from vastus lateralis before and after 5 and 10 days of training. Mitochondrial ATP production rate (MAPR) was assayed in isolated mitochondria by using a bioluminescence technique and referenced to the activity of glutamate dehydrogenase in the muscle sample. MAPR increased 136 and 161% after 10 days of training for the mitochondrial substrate combinations pyruvate + palmitoyl-L-carnitine + alpha-ketoglutarate + malate and palmitoyl-L-carnitine + malate, respectively. Total muscle glutamate dehydrogenase and citrate synthase activity increased 53 and 16%, respectively, after 5 days but did not significantly increase further after 10 days. The results from the present study indicate that MAPR, measured by using the substrate combinations pyruvate + palmitoyl-L-carnitine + alpha-ketoglutarate + malate and palmitoyl-L-carnitine + malate, can rapidly increase in response to endurance training.
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Affiliation(s)
- E C Starritt
- Department of Physiology, The University of Melbourne, Parkville 3052, Australia
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28
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Bizeau ME, Willis WT, Hazel JR. Differential responses to endurance training in subsarcolemmal and intermyofibrillar mitochondria. J Appl Physiol (1985) 1998; 85:1279-84. [PMID: 9760317 DOI: 10.1152/jappl.1998.85.4.1279] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To examine the effect of endurance training (6 wk of treadmill running) on regional mitochondrial adaptations within skeletal muscle, subsarcolemmal (SS) and intermyofibrillar (IMF) mitochondria were isolated from trained and control rat hindlimb muscles. Mitochondrial oxygen consumption (VO2) was measured polarographically by using the following substrates: 1 mM pyruvate + 1 mM malate (P+M), 10 mM 2-oxoglutarate, 45 microM palmitoyl-DL-carnitine + 1 mM malate, and 10 mM glutamate. Spectrophotometric assays of cytochrome-c reductase and NAD-specific isocitrate dehydrogenase (IDH) activity were also performed. Maximal (state III) and resting (state IV) VO2 were lower in SS than in IMF mitochondria in both trained and control groups. In SS mitochondria, training elicited significant 36 and 20% increases in state III VO2 with P+M and glutamate, respectively. In IMF mitochondria, training resulted in a smaller (20%), yet significant, increase in state III VO2 with P+M as a substrate, whereas state III VO2 increased 33 and 27% with 2-oxoglutarate and palmitoyl-DL-carnitine + malate, respectively. Within groups, cytochrome-c reductase and IDH activities were lower in SS when compared with IMF mitochondria. Training increased succinate-cytochrome-c reductase in both SS (30%) and IMF mitochondria (28%). IDH activity increased 32% in the trained IMF but remained unchanged in SS mitochondria. We conclude that endurance training promotes substantial changes in protein stoichiometry and composition of both SS and IMF mitochondria.
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Affiliation(s)
- M E Bizeau
- Exercise and Sport Research Institute and Department of Biology, Arizona State University, Tempe, Arizona 85287-0404, USA.
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29
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Rasmussen HN, Andersen AJ, Rasmussen UF. Optimization of preparation of mitochondria from 25-100 mg skeletal muscle. Anal Biochem 1997; 252:153-9. [PMID: 9324953 DOI: 10.1006/abio.1997.2304] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A method for isolation of mitochondria from 25-100 mg skeletal muscle is described. The instrumental developments include a refined homogenization setup, special handling techniques, and equipment for biopsy storage. The preparation medium was a standard ionic medium. All fractions were assayed for marker enzymes and the data used in optimization of the yield. It was observed that the homogenization procedure exerts strong control on the integrity of the isolated mitochondria. The method was developed with pigeon breast muscle as the model tissue and used virtually unaltered for preparation from muscles of pigs, rats, and humans. The relative yield was 40-50% and the mitochondria were well coupled and showed high rates of phosphorylating respiration.
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Affiliation(s)
- H N Rasmussen
- August Krogh Institute, Department of Biochemistry, University of Copenhagen, Denmark
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30
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Takahashi M, Hood DA. Protein import into subsarcolemmal and intermyofibrillar skeletal muscle mitochondria. Differential import regulation in distinct subcellular regions. J Biol Chem 1996; 271:27285-91. [PMID: 8910303 DOI: 10.1074/jbc.271.44.27285] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
To date, no studies have described the import of proteins in mitochondria obtained from skeletal muscle. In this tissue, mitochondria consist of the functionally and biochemically distinct intermyofibrillar (IMF) and subsarcolemmal (SS) subfractions, which are localized in specialized cellular compartments. This mitochondrial heterogeneity in muscle could be due, in part, to differential rates of protein import. To evaluate this possibility, the import of precursor malate dehydrogenase and ornithine carbamyltransferase proteins was investigated in isolated IMF and SS mitochondria in vitro. Import of these was 3-4-fold greater in IMF compared with SS mitochondria as a function of time. This could account for the higher malate dehydrogenase enzyme activity in IMF mitochondria. Divergent import rates in IMF and SS mitochondria likely result from a differential reliance on various components of the import pathway. SS mitochondria possess a greater content of the molecular chaperones hsp60 and Grp75, yet import is lower than in IMF mitochondria. On the other hand, adriamycin inhibition studies illustrated a greater reliance on acidic phospholipids (i.e. cardiolipin) for the import process in SS mitochondria. Matrix ATP levels were 3-fold higher in IMF mitochondria, but experiments in which ATP depletion was performed with atractyloside and oligomycin illustrated a dissociation between import rates and levels of ATP. In contrast, a close relationship was found between the rate of ATP production (i.e. mitochondrial respiration) and protein import. When respiratory rates in IMF and SS mitochondria were equalized, import rates in both subfractions were similar. These data indicate that 1) import rates are more closely related to the rate of ATP production than the steady state ATP level, 2) import into IMF and SS mitochondrial subfractions is regulated differently, and 3) mitochondrial heterogeneity within a cell type can be due to differences in the rates of protein import, suggesting that this step is a potentially regulatable event in determining the final mitochondrial phenotype.
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Affiliation(s)
- M Takahashi
- Departments of Biology and Kinesiology, York University, North York, Ontario M3J 1P3, Canada.
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31
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Daneryd P, Westin T, Edström S, Soussi B. Tumour purine nucleotides and cell proliferation in response to exercise in rats. Eur J Cancer 1995; 31A:2309-12. [PMID: 8652261 DOI: 10.1016/0959-8049(95)00441-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Voluntary physical exercise can delay the onset of anorexia and cachexia in tumour-bearing rats. A substrate deviation in the host which has been hypothesised as tumour burden is reduced despite an increase in food intake. Therefore, we determined the levels of purine nucleotides, the energy charge and the cell division rate in tumours from exercising animals in the postexercise period. Tumour content of purine nucleotides was analysed by HPLC. Tumour cell kinetics was studied by flow cytometry after incorporation of bromodeoxyuridine (BrdU) into DNA. Exercising animals demonstrated a 34.4% reduction in tumour volume (P < 0.05) but a 1.31-fold increase in energy charge in tumour tissue (P < 0.05). Labelling index (LI), DNA synthesis time (Ts) and potential doubling time (Tpot) were not significantly altered. These results suggest that the influence on tumour growth is closely related to the exercise period.
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Affiliation(s)
- P Daneryd
- Department of Surgery, Sahlgrenska University Hospital, Göteborg, Sweden
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32
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Cirillo R, Aliev G, Hornby EJ, Prosdocimi M. Endothelium as a therapeutical target in peripheral occlusive arterial diseases: consideration for pharmacological interventions. Pharmacol Res 1994; 29:293-311. [PMID: 7971683 DOI: 10.1016/1043-6618(94)80053-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The aim of this review is to consider the role of endothelium in the establishment of injury induced by ischaemia and reperfusion with particular emphasis on the vascular beds of the legs. We review the main abnormalities found in the macro- and microcirculation in these conditions and discuss the various theories put forward to explain the mechanism by which endothelial injury is induced. Endothelial cells play a key role in maintaining patent and functional capillaries. When blood vessels are damaged they become unresponsive to vasodilatory stimuli and intraluminal thrombosis may occur. The relative contribution of platelets and leukocytes in the formation of final ischaemic damage is widely discussed. Furthermore, the role of reperfusion in causing damage to post-ischaemic vascular beds is considered as well. The degree to which post-ischaemic injury is reversible might define the opportunity for therapeutic interventions.
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Affiliation(s)
- R Cirillo
- Department of Vascular Biology, Fidia Research Laboratories, UK
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33
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Daneryd P, Karlberg I, Scherstén T, Soussi B. Cytochrome c oxidase and purine nucleotides in skeletal muscle in tumour-bearing exercising rats. Eur J Cancer 1992; 28A:773-7. [PMID: 1326306 DOI: 10.1016/0959-8049(92)90113-g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We have previously shown that spontaneous physical exercise can delay the onset of experimental anorexia and cachexia and retard tumour growth and we now report the effects on the energy metabolism in skeletal muscle. Exercising tumour-bearing animals (TBE) had an increased maximal capacity for oxygen uptake expressed as Vmax of the cytochrome c oxidase compared with their tumour-bearing sedentary controls (TBS) [mean (S.E.) 289.9 (30.7) vs. 141.6 (11.0); P less than 0.05] but an unchanged Km value. The TBS animals had a depressed Vmax as compared with non-tumour-bearing sedentary controls (CS) [141.6 (11.0) vs. 210.1 (15.1); P less than 0.05]. Most of the purine nucleotides in the 'glycolytic' anterior tibial muscle were significantly altered in the TBE animals compared with the TBS animals, but in the mainly 'oxidative' soleus muscle only the level of inosine monophosphate (IMP) was changed. The results indicate that physical exercise can normalise the oxidative capacity and improve the energy state in skeletal muscle in the tumour-bearing host.
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Affiliation(s)
- P Daneryd
- Wallenberg Laboratory, Department of Surgery, University of Göteborg, Sahlgrenska Hospital, Sweden
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34
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van Ekeren GJ, Cornelissen EA, Stadhouders AM, Sengers RC. Increased volume density of peripheral mitochondria in skeletal muscle of children with exercise intolerance. Eur J Pediatr 1991; 150:744-50. [PMID: 1915491 DOI: 10.1007/bf01958770] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Muscle biopsies from 17 children with exercise intolerance and other miscellaneous symptoms and signs showed changes in mitochondrial content. The patients could not be classified according to known criteria. The histopathological changes were quantified by morphometric analysis and the clinical data were statistically analysed to detect intercorrelations. After a mean follow up period of 6.8 years (range 0.5-13.6), patients were re-examined and the course of the disease was determined. No clinical entity could be established. None of the patients showed aggravation of the exercise intolerance, but 71% noted no improvement. An increased volume density of peripheral mitochondria was shown in 59%. Based on clinical history, histopathological changes and course we suggest that some of these patients suffer from a yet unknown disturbance in energy metabolism. Recognition of these patients is important for appropriate counselling.
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Affiliation(s)
- G J van Ekeren
- Department of Cell Biology and Histology, University of Nijmegen, The Netherlands
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35
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Egginton S, Hudlická O. The effect of torbafylline on enzyme activities in fast and slow muscles with limited blood supply. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. C, COMPARATIVE PHARMACOLOGY AND TOXICOLOGY 1991; 99:163-8. [PMID: 1675966 DOI: 10.1016/0742-8413(91)90094-a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
1. Activities of a glycolytic enzyme--lactate dehydrogenase, LDH, and two oxidative enzymes--citrate synthase (CS), a marker for TCA cycle entry, and 3-hydroxyacyl-CoA dehydrogenase (HAD), which indicates the capacity for beta-oxidation of endogenous lipids, were measured in fast (tibialis anterior, TA, and extensor digitorum longus, EDL) and slow (soleus, SOL) muscles of Sprague-Dawley rats with intact and limited blood supply, and following treatment with the xanthine derivative torbafylline (Hoechst, Werk Albert, Wiesbaden). 2. Limitation of blood supply by unilateral ligation of the common iliac artery increased activity of LDH in fast muscles, and activity of CS and HAD in soleus. 3. Torbafylline treatment caused an increased LDH activity in intact fast muscles and decreased it in soleus, although the relative capacity for anaerobic and aerobic metabolism (indicated by the ratio of LDH and CS activities) remained unchanged in all cases. 4. Whilst having little effect on oxidative enzyme activity of fast muscles, torbafylline decreased the activity of CS but increased activity of HAD in soleus, suggesting a greater reliance on lipid metabolism. 5. The effect of arterial ligation on enzyme activity was ameliorated by treatment with torbafylline, possibly due to its effect on the microcirculation.
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Affiliation(s)
- S Egginton
- Department of Physiology, University of Birmingham Medical School, U.K
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36
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Wibom R, Hultman E. ATP production rate in mitochondria isolated from microsamples of human muscle. THE AMERICAN JOURNAL OF PHYSIOLOGY 1990; 259:E204-9. [PMID: 2382713 DOI: 10.1152/ajpendo.1990.259.2.e204] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mitochondrial ATP production (MAPR) was determined using a bioluminescence method in mitochondrial preparations of human skeletal muscle. We obtained muscle samples from 21 healthy subjects using the percutaneous muscle biopsy technique. The subjects were grouped according to their degree of physical activity, i.e., from sedentary to highly active. The MAPR for each subject was related to the mitochondrial protein content and to the activity of glutamate dehydrogenase (GDH) estimated in muscle homogenates and in isolated mitochondria. With the use of GDH as a reference base, the MAPR could be expressed per muscle mass. MAPR was determined for different individual substrates and also for the combination of pyruvate, palmitoyl-carnitine, alpha-ketoglutarate, and malate (MAPRPPKM). The MAPR observed was higher for the combination of substrates than for any individual substrate tested. The relation between mitochondrial ATP production rate and GDH activity was the same for all subjects irrespective of physical activity status, but MAPRPPKM/kg muscle varied from 6.6 +/- 1.3 mmol.min-1.kg-1 in sedentary subjects to 11.0 +/- 2.2 in highly active subjects. The present method, which uses 50 mg of muscle tissue, enables mitochondrial function to be estimated in healthy subjects or patients with mitochondrial disorders.
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Affiliation(s)
- R Wibom
- Department of Clinical Chemistry II, Huddinge University Hospital, Karolinska Institutet, Sweden
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37
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Soussi B, Idström JP, Scherstén T, Bylund-Fellenius AC. Cytochrome c oxidase and cardiolipin alterations in response to skeletal muscle ischaemia and reperfusion. ACTA PHYSIOLOGICA SCANDINAVICA 1990; 138:107-14. [PMID: 2156404 DOI: 10.1111/j.1748-1716.1990.tb08822.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of 2 and 4 h of tourniquet ischaemia followed by 1 h of reperfusion on the major mitochondrial phospholipids and on the cytochrome c oxidase kinetic parameters has been investigated in rat skeletal muscle. There was no change either in the mitochondrial phospholipid content or in the Vmax and the Km of the enzyme after 2 h of ischaemia with and without subsequent reperfusion. Four hours of ischaemia had no effect on the lecithin and the cephalin content, while the cardiolipin content decreased as well as the Vmax of the enzyme (P less than 0.05). Tissue reperfusion caused a dramatic decrease in both cardiolipin (55% of the control, P less than 0.001) and Vmax (38% of the control, P less than 0.001). The corresponding reduction in lecithin and cephalin contents was 12% and 14% respectively (P less than 0.05). The Km remained unchanged at all conditions. These findings suggest that mitochondrial dysfunction in response to ischaemia and reperfusion could be a consequence of the reperfusion itself following severe ischaemia. The results are discussed in terms of cardiolipin peroxidation and cytochrome oxidase as a functional parameter.
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Affiliation(s)
- B Soussi
- Department of Surgery, University of Gothenburg, Sweden
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38
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Lundgren F, Dahllöf AG, Lundholm K, Scherstén T, Volkmann R. Intermittent claudication--surgical reconstruction or physical training? A prospective randomized trial of treatment efficiency. Ann Surg 1989; 209:346-55. [PMID: 2647051 PMCID: PMC1493950 DOI: 10.1097/00000658-198903000-00016] [Citation(s) in RCA: 172] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This study reports the initial evaluation of treatment efficiency in 75 patients with intermittent claudication who were randomized to three treatment groups: 1) reconstructive surgery, 2) reconstructive surgery with subsequent physical training, and 3) physical training alone. Before treatment, there were no statistically significant differences between the groups in age, sex, smoking habits, symptom duration of claudication, ankle-arm blood pressure quotient (ankle-index), maximal plethysmographic calf blood flow, symptom-free and maximal walking distance, the history of other atherosclerotic manifestations or in the medical treatment. The walking performance was improved in all three groups at follow-up 13 +/- 0.5 months after randomization. Surgery was most effective, but the addition of training to surgery improved the symptom-free walking distance even further. In pooled observations of the three groups, age, symptom duration, and a history of myocardial ischemic disease correlated negatively with walking performance after treatment. In the operated group, the duration of claudication and a history of myocardial ischemic disease correlated negatively with the walking performance. This was not the case when patients were censored if limited by other symptoms than intermittent claudication after treatment. In the trained group, the duration of claudication correlated negatively to symptom-free and maximal walking distance. Ankle-index and maximal plethysmographic calf blood flow after treatment and the change of these variables with treatment correlated positively with both symptom-free and maximal walking distance when results were pooled for all patients. Although this mainly was a consequence of the improved blood flow after surgery, the change of maximal plethysmographic calf blood flow also correlated with symptom-free but not with maximal walking distance in the trained group. The results demonstrate that, compared with physical training alone, operation alone or in combination with subsequent training are superior treatment modalities in patients with intermittent claudication.
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Affiliation(s)
- F Lundgren
- Department of Surgery, Sahlgrenska Sjukhuset, University of Göteborg, Sweden
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39
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Soussi B, Idström JP, Schersten T, Bylund-Fellenius AC. Kinetic parameters of cytochrome c oxidase in rat skeletal muscle: effect of endurance training. ACTA PHYSIOLOGICA SCANDINAVICA 1989; 135:373-9. [PMID: 2538997 DOI: 10.1111/j.1748-1716.1989.tb08590.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The kinetic properties of cytochrome c oxidase (EC 1.9.3.1) in skeletal muscle tissue of sedentary and endurance-trained rats were studied. The initial velocity of the cytochrome c oxidase reaction was determined polarographically over a large range of cytochrome c concentrations and the maximal velocity (Vmax) and the Michaelis constant (Km) were calculated. The catalytic activity of cytochrome c oxidase in isolated mitochondria was also investigated. The training programme consisted of treadmill running for 2 h a day, 6 days a week, at a speed of 30 m min-1 and 30 degrees elevation, for 4 weeks. Vmax of cytochrome oxidase with respect to cytochrome c increased significantly from 254 to 310 mumol O2 min-1 g-1 protein in response to training (P less than 0.001), whereas Km remained unchanged (18.9 and 18.7 microM). The turnover number (TN) increased from 11.1 S-1 in sedentary rats to 16.6 S-1 in trained rats (P less than 0.001). The results suggest a qualitative change in the enzyme molecule in addition to a true Vmax change of cytochrome c oxidase in response to endurance training.
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Affiliation(s)
- B Soussi
- Wallenberg Laboratory, University of Göteborg, Department of Surgery, Sahlgrenska Hospital, Sweden
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40
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Lundgren F, Zachrisson H, Emery P, Bylund-Fellenius AC, Elander A, Bennegård K, Scherstén T, Lundholm K. Leg exchange of amino acids during exercise in patients with arterial insufficiency. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1988; 8:227-41. [PMID: 3402184 DOI: 10.1111/j.1475-097x.1988.tb00267.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Intermittent claudication is associated with adaptation in muscle metabolism. This study has evaluated the metabolism of amino acids at rest and during non-steady state exercise in patients with arterial insufficiency of at least six months duration in comparison with matched control individuals. The exchange of amino acids were measured during two periods of acute exercise; one initial exercise period with a standardized work load and exercise time and a second exercise period which continued until further exercise was impossible due to pain in the patients and exhaustion in the controls. The maximum blood flow was reduced by 40% in the patients but the maximum oxygen uptake per unit power developed was almost the same in patients and controls. The patients had significantly lower concentrations of glutamine, lysine and taurine at rest compared with the controls. The exchange of amino acids across the resting leg did not differ between the two groups. Exercise increased the efflux of amino acids in both patients and controls. The efflux of glutamine (896 +/- 205 vs. 48 +/- 359 nmol/100 ml/min/watt) was higher in the patients compared to the controls at the first exercise period with inverse changes in the opposite direction of asparagine (149 +/- 105 vs. 799 +/- 121 and 27 +/- 70 vs. 633 +/- 334 nmol/100 ml/min/watt at the first and second exercise, respectively. Alanine release did not differ between the groups. The complementary patterns of glutamine and asparagine during hypoxic exercise in the patients may reflect the fact that these amino acids share a common carrier system. The similarity in the efflux of non-metabolized amino acids, such as methionine, phenylalanine, tyrosine and 3-methylhistidine, indicated that muscle hypoxia in claudication patients did not promote net degradation of either globular or myofibrillar proteins, although exercise increased the efflux of 3-methylhistidine three- to fourfold in both patients and control individuals (from 1 +/- 0.4 to 4 +/- 1.8 and from 0 +/- 0.7 to 6 +/- 2.5 nmol/100 ml/min/watt, respectively). The exercise-induced alterations in leg exchange of amino acids were restored within 10-20 min following exercise regardless of hypoxia. The results demonstrate that patients with arterial insufficiency have altered intermediary metabolism of amino acids during exercise. However, muscle hypoxia in such patients does not seem to promote a negative protein balance or induce serious alterations in cell membrane integrity.
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Affiliation(s)
- F Lundgren
- Department of Surgery, Sahlgrenska Sjukhuset, Göteborg, Sweden
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