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Hoecht EM, Budd JM, Notaro NM, Holloway GP, Dyck DJ. Stimulation of fat oxidation in rat muscle by unacylated ghrelin persists for 2-3 hours, but is independent of fatty acid transporter translocation. Physiol Rep 2023; 11:e15815. [PMID: 37726258 PMCID: PMC10509152 DOI: 10.14814/phy2.15815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/01/2023] [Accepted: 08/11/2023] [Indexed: 09/21/2023] Open
Abstract
While a definitive mechanism-of-action remains to be identified, recent findings indicate that ghrelin, particularly the unacylated form (UnAG), stimulates skeletal muscle fatty acid oxidation. The biological importance of UnAG-mediated increases in fat oxidation remains unclear, as UnAG peaks in the circulation before mealtimes, and decreases rapidly during the postprandial situation before increases in postabsorptive circulating lipids. Therefore, we aimed to determine if the UnAG-mediated stimulation of fat oxidation would persist long enough to affect the oxidation of meal-derived fatty acids, and if UnAG stimulated the translocation of fatty acid transporters to the sarcolemma as a mechanism-of-action. In isolated soleus muscle strips from male rats, short-term pre-treatment with UnAG elicited a persisting stimulus on fatty acid oxidation 2 h after the removal of UnAG. UnAG also caused an immediate phosphorylation of AMPK, but not an increase in plasma membrane FAT/CD36 or FABPpm. There was also no increase in AMPK signaling or increased FAT/CD36 or FABPpm content at the plasma membrane at 2 h which might explain the sustained increase in fatty acid oxidation. These findings confirm UnAG as a stimulator of fatty acid oxidation and provide evidence that UnAG may influence the handling of postprandial lipids. The underlying mechanisms are not known.
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Affiliation(s)
- Evan M. Hoecht
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Joshua M. Budd
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Nicole M. Notaro
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - Graham P. Holloway
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
| | - David J. Dyck
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphOntarioCanada
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2
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Frangos SM, DesOrmeaux GJ, Holloway GP. Acidosis attenuates CPT-I-supported bioenergetics as a potential mechanism limiting lipid oxidation. J Biol Chem 2023; 299:105079. [PMID: 37482278 PMCID: PMC10469998 DOI: 10.1016/j.jbc.2023.105079] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 07/25/2023] Open
Abstract
Fuel interactions in contracting muscle represent a complex interplay between enzymes regulating carbohydrate and fatty acid catabolism, converging in the mitochondrial matrix. While increasing exercise intensity promotes carbohydrate use at the expense of fatty acid oxidation, the mechanisms underlying this effect remain poorly elucidated. As a potential explanation, we investigated whether exercise-induced reductions in intramuscular pH (acidosis) attenuate carnitine palmitoyltransferase-I (CPT-I)-supported bioenergetics, the rate-limiting step for fatty acid oxidation within mitochondria. Specifically, we assessed the effect of a physiologically relevant reduction in pH (pH 7.2 versus 6.8) on single and mixed substrate respiratory responses in murine skeletal muscle isolated mitochondria and permeabilized fibers. While pH did not influence oxidative phosphorylation stoichiometry (ADP/O ratios), coupling efficiency, oxygen affinity, or ADP respiratory responses, acidosis impaired lipid bioenergetics by attenuating respiration with L-carnitine and palmitoyl-CoA, while enhancing the inhibitory effect of malonyl-CoA on CPT-I. These acidotic effects were largely retained following a single bout of intense exercise. At rest, pyruvate and succinate-supported respiration were also impaired by acidosis. However, providing more pyruvate and ADP at pH 6.8 to model increases in glycolytic flux and ATP turnover with intense exercise overcame the acidotic attenuation of carbohydrate-linked oxidative phosphorylation. Importantly, this situation is fundamentally different from lipids where CPT-I substrate sensitivity and availability is impaired at higher power outputs suggesting lipid metabolism may be more susceptible to the effects of acidosis, possibly contributing to fuel shifts with increasing exercise intensity.
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Affiliation(s)
- Sara M Frangos
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
| | - Geneviève J DesOrmeaux
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada.
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3
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Cal K, Leyva A, Rodríguez-Duarte J, Ruiz S, Santos L, Colella L, Ingold M, Vilaseca C, Galliussi G, Ziegler L, Peclat TR, Bresque M, Handy RM, King R, dos Reis LM, Espasandin C, Breining P, Dapueto R, Lopez A, Thompson KL, Agorrody G, DeVallance E, Meadows E, Lewis SE, Barbosa GCS, de Souza LOL, Chichierchio MS, Valez V, Aicardo A, Contreras P, Vendelbo MH, Jakobsen S, Kamaid A, Porcal W, Calliari A, Verdes JM, Du J, Wang Y, Hollander JM, White TA, Radi R, Moyna G, Quijano C, O’Doherty R, Moraes-Vieira P, Holloway GP, Leonardi R, Mori MA, Camacho-Pereira J, Kelley EE, Duran R, Lopez GV, Batthyány C, Chini EN, Escande C. A nitroalkene derivative of salicylate alleviates diet-induced obesity by activating creatine metabolism and non-shivering thermogenesis. Res Sq 2023:rs.3.rs-3101395. [PMID: 37502859 PMCID: PMC10371099 DOI: 10.21203/rs.3.rs-3101395/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Obesity-related type II diabetes (diabesity) has increased global morbidity and mortality dramatically. Previously, the ancient drug salicylate demonstrated promise for the treatment of type II diabetes, but its clinical use was precluded due to high dose requirements. In this study, we present a nitroalkene derivative of salicylate, 5-(2-nitroethenyl)salicylic acid (SANA), a molecule with unprecedented beneficial effects in diet-induced obesity (DIO). SANA reduces DIO, liver steatosis and insulin resistance at doses up to 40 times lower than salicylate. Mechanistically, SANA stimulated mitochondrial respiration and increased creatine-dependent energy expenditure in adipose tissue. Indeed, depletion of creatine resulted in the loss of SANA action. Moreover, we found that SANA binds to creatine kinases CKMT1/2, and downregulation CKMT1 interferes with the effect of SANA in vivo. Together, these data demonstrate that SANA is a first-in-class activator of creatine-dependent energy expenditure and thermogenesis in adipose tissue and emerges as a candidate for the treatment of diabesity.
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Affiliation(s)
- Karina Cal
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
- Unidad Biofísica, Departamento de Biociencias, Facultad de Veterinaria, Udelar, Uruguay
| | - Alejandro Leyva
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, IIBCE, Uruguay
| | - Jorge Rodríguez-Duarte
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
| | - Santiago Ruiz
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
| | - Leonardo Santos
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
| | - Lucía Colella
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Departamento de Química Orgánica, Facultad de Química, Udelar, Uruguay
| | - Mariana Ingold
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Departamento de Química Orgánica, Facultad de Química, Udelar, Uruguay
| | - Cecilia Vilaseca
- Departamento de Fisiología, Facultad de Medicina, Udelar, Uruguay
| | - German Galliussi
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Laboratory of Immunoregulation and Inflammation; Institut Pasteur Montevideo, Uruguay
| | - Lucía Ziegler
- Departamento de Ecología y Gestión Ambiental, Centro Universitario Regional del Este, Udelar, Maldonado, Uruguay
| | - Thais R. Peclat
- Mayo Clinic Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Physiology and Biomedical Engineering; Mayo Clinic, Rochester, MN, USA
| | - Mariana Bresque
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
| | - Rachel M Handy
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Rachel King
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown WV, USA
| | - Larissa Menezes dos Reis
- Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, SP, Brazil; Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, SP, Brazil; Obesity and Comorbidities Research Center (OCRC), University of Campinas, SP, Brazil; Experimental Medicine Research Cluster (EMRC), University of Campinas, SP, Brazil
| | - Camila Espasandin
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
- Unidad Bioquìmica, Facultad de Veterinaria, Udelar, Uruguay
| | | | - Rosina Dapueto
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Área I+D Biomédico, CUDIM, Uruguay
| | - Andrés Lopez
- Laboratorio de Fisicoquímica Orgánica, Departamento de Química del Litoral, CENUR Litoral Norte, Udelar, Uruguay
| | - Katie L. Thompson
- Mayo Clinic Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Physiology and Biomedical Engineering; Mayo Clinic, Rochester, MN, USA
| | - Guillermo Agorrody
- Departamento de Fisiopatología, Hospital de Clínicas, Facultad de Medicina, Udelar, Uruguay
| | - Evan DeVallance
- Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV, USA
| | - Ethan Meadows
- Mitochondria, Metabolism and Bioenergetics Working Group; School of Medicine, West Virginia University, Morgantown, WV, USA
| | - Sara E. Lewis
- Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV, USA
- Mitochondria, Metabolism and Bioenergetics Working Group; School of Medicine, West Virginia University, Morgantown, WV, USA
- Center for Inhalation Toxicology (iTOX), School of Medicine, West Virginia University, Morgantown, USA
| | - Gabriele Catarine Santana Barbosa
- Laboratory of Bioenergetics and Mitochondrial Physiology, Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Brazil
| | - Leonardo Osbourne Lai de Souza
- Laboratory of Bioenergetics and Mitochondrial Physiology, Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Brazil
| | - Marina Santos Chichierchio
- Laboratory of Bioenergetics and Mitochondrial Physiology, Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Brazil
| | - Valeria Valez
- Cátedra de Bioquímica y Biofísica, Facultad de Odontología, Udelar, Uruguay
- Centro de Investigaciones Biomédicas (CEINBIO), Udelar, Uruguay
- Departamento de Bioquímica, Facultad de Medicina, Udelar, Uruguay
| | - Adrián Aicardo
- Centro de Investigaciones Biomédicas (CEINBIO), Udelar, Uruguay
- Departamento de Bioquímica, Facultad de Medicina, Udelar, Uruguay
- Departamento de Nutrición Clínica, Escuela de Nutrición, Udelar, Uruguay
| | - Paola Contreras
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
- Departamento de Fisiología, Facultad de Medicina, Udelar, Uruguay
| | - Mikkel H. Vendelbo
- Department of Biomedicine, Aarhus University, Denmark
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Denmark
| | - Steen Jakobsen
- Department of Nuclear Medicine and PET, Aarhus University Hospital, Denmark
| | - Andrés Kamaid
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, IIBCE, Uruguay
- Unidad de Bioimagenología Avanzada. Institut Pasteur de Montevideo, Uruguay
| | - Williams Porcal
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Departamento de Química Orgánica, Facultad de Química, Udelar, Uruguay
| | - Aldo Calliari
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
- Unidad Biofísica, Departamento de Biociencias, Facultad de Veterinaria, Udelar, Uruguay
| | - José Manuel Verdes
- Unidad Patología, Departamento de Patobiología; Facultad de Veterinaria, Udelar, Uruguay
| | - Jianhai Du
- Mitochondria, Metabolism and Bioenergetics Working Group; School of Medicine, West Virginia University, Morgantown, WV, USA
- Department of Ophthalmology and Visual Sciences, Department of Biochemistry, West Virginia University, Morgantown, USA
| | - Yekai Wang
- Department of Ophthalmology and Visual Sciences, Department of Biochemistry, West Virginia University, Morgantown, USA
| | - John M Hollander
- Mitochondria, Metabolism and Bioenergetics Working Group; School of Medicine, West Virginia University, Morgantown, WV, USA
- Division of Exercise Physiology, West Virginia University, Morgantown, USA
| | - Thomas A. White
- Mayo Clinic Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Rafael Radi
- Centro de Investigaciones Biomédicas (CEINBIO), Udelar, Uruguay
- Departamento de Bioquímica, Facultad de Medicina, Udelar, Uruguay
| | - Guillermo Moyna
- Laboratorio de Fisicoquímica Orgánica, Departamento de Química del Litoral, CENUR Litoral Norte, Udelar, Uruguay
| | - Celia Quijano
- Centro de Investigaciones Biomédicas (CEINBIO), Udelar, Uruguay
- Departamento de Bioquímica, Facultad de Medicina, Udelar, Uruguay
| | - Robert O’Doherty
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pennsylvania
- Department of Microbiology and Molecular Genetics; University of Pittsburgh, Pennsylvania
| | - Pedro Moraes-Vieira
- Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, SP, Brazil; Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, SP, Brazil; Obesity and Comorbidities Research Center (OCRC), University of Campinas, SP, Brazil; Experimental Medicine Research Cluster (EMRC), University of Campinas, SP, Brazil
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Roberta Leonardi
- Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown WV, USA
- Mitochondria, Metabolism and Bioenergetics Working Group; School of Medicine, West Virginia University, Morgantown, WV, USA
| | - Marcelo A Mori
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, SP, Brazil; Obesity and Comorbidities Research Center (OCRC), Campinas, SP, Brazil; Experimental Medicine Research Cluster (EMRC), Campinas, SP, Brazil; Instituto Nacional de Obesidade e Diabetes, Campinas, SP, Brazil
| | - Juliana Camacho-Pereira
- Laboratory of Bioenergetics and Mitochondrial Physiology, Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Brazil
| | - Eric E. Kelley
- Department of Physiology and Pharmacology, School of Medicine, West Virginia University, Morgantown, WV, USA
- Mitochondria, Metabolism and Bioenergetics Working Group; School of Medicine, West Virginia University, Morgantown, WV, USA
- Center for Inhalation Toxicology (iTOX), School of Medicine, West Virginia University, Morgantown, USA
| | - Rosario Duran
- Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, IIBCE, Uruguay
| | - Gloria V. Lopez
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
- Departamento de Química Orgánica, Facultad de Química, Udelar, Uruguay
| | - Carlos Batthyány
- Laboratory of Vascular Biology and Drug Development, Institut Pasteur Montevideo, Uruguay
| | - Eduardo N. Chini
- Mayo Clinic Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
- Department of Anesthesiology, Mayo Clinic, Rochester, MN, USA
- Department of Physiology and Biomedical Engineering; Mayo Clinic, Rochester, MN, USA
- Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Jacksonville, Florida, USA
| | - Carlos Escande
- Laboratory of Metabolic Diseases and Aging, Institut Pasteur Montevideo, Uruguay
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4
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Wang D, Townsend LK, DesOrmeaux GJ, Frangos SM, Batchuluun B, Dumont L, Kuhre RE, Ahmadi E, Hu S, Rebalka IA, Gautam J, Jabile MJT, Pileggi CA, Rehal S, Desjardins EM, Tsakiridis EE, Lally JSV, Juracic ES, Tupling AR, Gerstein HC, Paré G, Tsakiridis T, Harper ME, Hawke TJ, Speakman JR, Blondin DP, Holloway GP, Jørgensen SB, Steinberg GR. GDF15 promotes weight loss by enhancing energy expenditure in muscle. Nature 2023; 619:143-150. [PMID: 37380764 PMCID: PMC10322716 DOI: 10.1038/s41586-023-06249-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 05/23/2023] [Indexed: 06/30/2023]
Abstract
Caloric restriction that promotes weight loss is an effective strategy for treating non-alcoholic fatty liver disease and improving insulin sensitivity in people with type 2 diabetes1. Despite its effectiveness, in most individuals, weight loss is usually not maintained partly due to physiological adaptations that suppress energy expenditure, a process known as adaptive thermogenesis, the mechanistic underpinnings of which are unclear2,3. Treatment of rodents fed a high-fat diet with recombinant growth differentiating factor 15 (GDF15) reduces obesity and improves glycaemic control through glial-cell-derived neurotrophic factor family receptor α-like (GFRAL)-dependent suppression of food intake4-7. Here we find that, in addition to suppressing appetite, GDF15 counteracts compensatory reductions in energy expenditure, eliciting greater weight loss and reductions in non-alcoholic fatty liver disease (NAFLD) compared to caloric restriction alone. This effect of GDF15 to maintain energy expenditure during calorie restriction requires a GFRAL-β-adrenergic-dependent signalling axis that increases fatty acid oxidation and calcium futile cycling in the skeletal muscle of mice. These data indicate that therapeutic targeting of the GDF15-GFRAL pathway may be useful for maintaining energy expenditure in skeletal muscle during caloric restriction.
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Affiliation(s)
- Dongdong Wang
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Logan K Townsend
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Geneviève J DesOrmeaux
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Sara M Frangos
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Battsetseg Batchuluun
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Lauralyne Dumont
- Department of Pharmacology-Physiology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Rune Ehrenreich Kuhre
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk, Maaloev, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elham Ahmadi
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Sumei Hu
- Key Laboratory of Geriatric Nutrition and Health, Ministry of Education, Beijing Technology and Business University, Beijing, China
- Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Irena A Rebalka
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Jaya Gautam
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Maria Joy Therese Jabile
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Chantal A Pileggi
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Sonia Rehal
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Eric M Desjardins
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Evangelia E Tsakiridis
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - James S V Lally
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Emma Sara Juracic
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - A Russell Tupling
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, Canada
| | - Hertzel C Gerstein
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario, Canada
| | - Guillaume Paré
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Population Health Research Institute, Hamilton Health Sciences and McMaster University, Hamilton, Ontario, Canada
- Thrombosis and Atherosclerosis Research Institute, McMaster University, Hamilton Health Sciences, Hamilton, Ontario, Canada
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, Ontario, Canada
| | - Theodoros Tsakiridis
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
- Department of Oncology, McMaster University, Hamilton, Ontario, Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Thomas J Hawke
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada
| | - John R Speakman
- Shenzhen Key Laboratory of Metabolic Health, Center for Energy Metabolism and Reproduction, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- CAS Center for Excellence in Animal Evolution and Genetics (CCEAEG), Kunming, China
| | - Denis P Blondin
- Department of Pharmacology-Physiology, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
- Division of Neurology, Department of Medicine, Centre de Recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Sebastian Beck Jørgensen
- Global Obesity and Liver Disease Research, Global Drug Discovery, Novo Nordisk, Maaloev, Denmark
- Bio Innovation Hub Transformational Research Unit, Novo Nordisk, Boston, MA, USA
| | - Gregory R Steinberg
- Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada.
- Division of Endocrinology and Metabolism, Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
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5
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Petrick HL, Handy RM, Vachon B, Frangos SM, Holwerda AM, Gijsen AP, Senden JM, van Loon LJC, Holloway GP. Dietary nitrate preserves mitochondrial bioenergetics and mitochondrial protein synthesis rates during short-term immobilization in mice. J Physiol 2023. [PMID: 37293995 DOI: 10.1113/jp284701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Accepted: 06/02/2023] [Indexed: 06/10/2023] Open
Abstract
Skeletal muscle disuse reduces muscle protein synthesis rates and induces atrophy, events associated with decreased mitochondrial respiration and increased reactive oxygen species (ROS). Since dietary nitrate can improve mitochondrial bioenergetics, we examined whether nitrate supplementation attenuates disuse-induced impairments in mitochondrial function and muscle protein synthesis rates. Female C57Bl/6N mice were subject to single-limb casting (3 or 7 days) and consumed drinking water with or without 1 mM sodium nitrate. Compared to the contralateral control limb, 3 days of immobilization lowered myofibrillar fractional synthesis rates (FSR, p<0.0001), resulting in muscle atrophy. While FSR and mitophagy-related proteins were higher in subsarcolemmal (SS) compared to intermyofibrillar (IMF) mitochondria, immobilization for 3 days decreased FSR in both SS (p = 0.009) and IMF (p = 0.031) mitochondria. Additionally, 3 days of immobilization reduced maximal mitochondrial respiration and protein content, and increased maximal mitochondrial ROS emission without altering mitophagy-related proteins in muscle homogenate or isolated mitochondria (SS, IMF). While nitrate consumption did not attenuate the decline in muscle mass or myofibrillar FSR, intriguingly, nitrate completely prevented immobilization-induced reductions in SS and IMF mitochondrial FSR. In addition, nitrate prevented alterations in mitochondrial content and bioenergetics following both 3 and 7 days of immobilization. However, in contrast to 3 days of immobilization, nitrate did not prevent the decline in SS and IMF mitochondrial FSR following 7 days. Therefore, while nitrate supplementation was not sufficient to prevent muscle atrophy, nitrate may represent a promising therapeutic strategy to maintain mitochondrial bioenergetics and transiently preserve mitochondrial protein synthesis rates during short-term muscle disuse. KEY POINTS: Alterations in mitochondrial bioenergetics (decreased respiration and increased reactive oxygen species) are thought to contribute to muscle atrophy and reduced protein synthesis rates during muscle disuse. Since dietary nitrate can improve mitochondrial bioenergetics, we examined if nitrate supplementation could attenuate immobilization-induced skeletal muscle impairments in female mice. Dietary nitrate prevented short-term (3 day) immobilization-induced declines in mitochondrial protein synthesis rates, reductions in markers of mitochondrial content, and alterations in mitochondrial bioenergetics. Despite these benefits, and the preservation of mitochondrial content and bioenergetics during more prolonged (7 day) immobilization, nitrate consumption did not preserve skeletal muscle mass or myofibrillar protein synthesis rates. Overall, while dietary nitrate did not prevent atrophy, nitrate supplementation represents a promising nutritional approach to preserve mitochondrial function during muscle disuse. Abstract figure legend In female mice consuming standard drinking water (H2 O), 3 and 7 days of single-limb immobilization decreased mitochondrial (mito) protein fractional synthesis rate (FSR), myofibrillar (myofib) protein FSR, and mitochondrial respiration, and increased mitochondrial reactive oxygen species (ROS). In contrast, sodium nitrate (NO3 ) prevented the immobilization-induced alterations in mitochondrial bioenergetics (respiration, ROS) at both timepoints (3- and 7-day). In addition, mitochondrial protein FSR was transiently (3 day) preserved in the immobilized limb of nitrate-consuming mice. Combined, while dietary nitrate was not sufficient to prevent muscle atrophy, nitrate preserved mitochondrial bioenergetics and mitochondrial protein synthesis rates during short-term muscle disuse in mice. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Rachel M Handy
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Bayley Vachon
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Sara M Frangos
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Andrew M Holwerda
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Annemarie P Gijsen
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Joan M Senden
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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6
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Pignanelli C, Holloway GP, Burr JF. Blood flow restriction does not alter the early hypertrophic signaling and short-term adaptive response to resistance exercise when performed to task failure. J Appl Physiol (1985) 2023; 134:1265-1277. [PMID: 37055038 DOI: 10.1152/japplphysiol.00529.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023] Open
Abstract
Previous research supports that low-load resistance exercise with BFR (LL-BFR) acutely increases physiological responses and muscle mass accrual compared to low-load resistance exercise (LL-RE) alone. However, most studies have work-matched LL-BFR and LL-RE. Completing sets to similar perceived efforts, thereby allowing for a variable amount of work, may provide a more ecologically valid approach to compare LL-BFR and LL-RE. This study aimed to examine acute signaling and training responses following LL-RE or LL-BFR performed to task failure. Ten participants had each leg randomly assigned to perform LL-RE or LL-BFR. Muscle biopsies were obtained before and two-hours after the first exercise bout and after 6-weeks of training for Western blot and immunohistochemistry analyses. Repeated measure ANOVA and intraclass coefficients (ICC) were used to compare responses of each condition. After exercise, AKT(T308) phosphorylation increased after LL-RE and LL-BFR (both ~145% of baseline, p<0.05) and trended for p70 S6K(T389) (LL-RE: ~158% and LL-BFR: ~137%, p=0.06). BFR did not alter these responses, resulting in fair-excellent ICCs for signaling proteins involved in anabolism (ICCAKT(T308)=0.889, p=0.001; ICCAKT(S473) =0.519, p=0.074; ICCp70 S6K(T389)=0.514, p=0.105). After training, muscle fiber cross-sectional area and vastus lateralis whole-muscle thickness were similar between conditions (ICC≥ 0.637, p≤0.031). Similar acute and chronic responses between conditions and high ICC values between legs suggest that both LL-BFR and LL-RE performed by the same person result in similar adaptations. These data support the concept that sufficient muscular exertion is a key factor for training-induced muscle hypertrophy with low-load resistance exercise independent of total work and blood flow.
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Affiliation(s)
- Christopher Pignanelli
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jamie F Burr
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Handy RM, DesOrmeaux GJ, Barbeau PA, Frangos SM, Holloway GP. Independent, but not co-supplementation, with nitrate and resveratrol improves glucose tolerance and reduces markers of cellular stress in high-fat-fed male mice. Am J Physiol Regul Integr Comp Physiol 2023; 324:R317-R328. [PMID: 36622081 DOI: 10.1152/ajpregu.00196.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Independent supplementation with nitrate (NIT) and resveratrol (RSV) enriches various aspects of mitochondrial biology in key metabolic tissues. Although RSV is known to activate Sirt1 and initiate mitochondrial biogenesis, the metabolic benefits elicited by dietary nitrate appear to be dependent on 5'-adenosine monophosphate-activated protein kinase (AMPK)-mediated signaling events, a process also linked to the activation of Sirt1. Although the benefits of individual supplementation with these compounds have been characterized, it is unknown if co-supplementation may produce superior metabolic adaptations. Thus, we aimed to determine if treatment with combined +NIT and +RSV (+RN) could additively alter metabolic adaptations in the presence of a high-fat diet (HFD). Both +RSV and +NIT improved glucose tolerance compared with HFD (P < 0.05); however, this response was attenuated following combined +RN supplementation. Within skeletal muscle, all supplements increased mitochondrial ADP sensitivity compared with HFD (P < 0.05), without altering mitochondrial content. Although +RSV and +NIT decreased hepatic lipid deposition compared with HFD (P < 0.05), this effect was abolished with +RN, which aligned with significant reductions in Sirt1 protein content (P < 0.05) after combined treatment, in the absence of changes to mitochondrial content or function. Within epididymal white adipose tissue (eWAT), all supplements reduced crown-like structure accumulation compared with HFD (P < 0.0001) and mitochondrial reactive oxygen species (ROS) emission (P < 0.05), alongside reduced adipocyte cross-sectional area (CSA) (P < 0.05), with the greatest effect observed after +RN treatment (P = 0.0001). Although the present data suggest additive changes in adipose tissue metabolism after +RN treatment, concomitant impairments in hepatic lipid homeostasis appear to prevent improvements in whole body glucose homeostasis observed with independent treatment, which may be Sirt1 dependent.
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Affiliation(s)
- Rachel M Handy
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Geneviève J DesOrmeaux
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Pierre-Andre Barbeau
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Sara M Frangos
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Petrick HL, Ogilvie LM, Brunetta HS, Robinson A, Kirsh AJ, Barbeau PA, Handy RM, Coyle-Asbil B, Gianetto-Hill C, Dennis KMJH, van Loon LJC, Chabowski A, Schertzer JD, Allen-Vercoe E, Simpson JA, Holloway GP. Dietary nitrate and corresponding gut microbiota prevent cardiac dysfunction in obese mice. Diabetes 2023:148499. [PMID: 36812497 DOI: 10.2337/db22-0575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 02/12/2023] [Indexed: 02/24/2023]
Abstract
Impaired heart function can develop in diabetic individuals in the absence of coronary artery disease or hypertension, suggesting mechanisms beyond hypertension/increased afterload contribute to diabetic cardiomyopathy. Identifying therapeutic approaches that improve glycemia and prevent cardiovascular disease are clearly required for clinical management of diabetes-related comorbidities. Since intestinal bacteria are important for metabolism of nitrate, we examined if dietary nitrate and fecal microbial transplantation (FMT) from nitrate-fed mice could prevent high-fat diet (HFD)-induced cardiac abnormalities. Male C57Bl/6N mice were fed an 8-week low-fat diet (LFD), HFD, or HFD+Nitrate (4mM sodium nitrate). HFD-fed mice presented with pathological left ventricular (LV) hypertrophy, reduced stroke volume and increased end diastolic pressure, in association with increased myocardial fibrosis, glucose intolerance, adipose inflammation, serum lipids, LV mitochondrial reactive oxygen species (ROS), and gut dysbiosis. In contrast, dietary nitrate attenuated these detriments. In HFD-fed mice, FMT from HFD+Nitrate donors did not influence serum nitrate, blood pressure, adipose inflammation, or myocardial fibrosis. However, microbiota from HFD+Nitrate mice decreased serum lipids, LV ROS, and similar to FMT from LFD donors, prevented glucose intolerance and cardiac morphology changes. Therefore, the cardioprotective effects of nitrate are not dependent on reducing blood pressure, but rather mitigating gut dysbiosis, highlighting a nitrate-gut-heart axis.
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Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Leslie M Ogilvie
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Henver S Brunetta
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Avery Robinson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Aleah J Kirsh
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Pierre-Andre Barbeau
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Rachel M Handy
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Bridget Coyle-Asbil
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Connor Gianetto-Hill
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Kaitlyn M J H Dennis
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Adrian Chabowski
- Department of Physiology, Medical University of Bialystok, Bialystok, Poland
| | - Jonathan D Schertzer
- Department of Biochemistry and Biomedical Sciences, Farncombe Family Digestive Health Research Institute, and Centre for Metabolism, Obesity and Diabetes Research, McMaster University, Hamilton, Ontario, Canada
| | - Emma Allen-Vercoe
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Handy RM, Holloway GP. Insights into the development of insulin resistance: Unraveling the interaction of physical inactivity, lipid metabolism and mitochondrial biology. Front Physiol 2023; 14:1151389. [PMID: 37153211 PMCID: PMC10157178 DOI: 10.3389/fphys.2023.1151389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/07/2023] [Indexed: 05/09/2023] Open
Abstract
While impairments in peripheral tissue insulin signalling have a well-characterized role in the development of insulin resistance and type 2 diabetes (T2D), the specific mechanisms that contribute to these impairments remain debatable. Nonetheless, a prominent hypothesis implicates the presence of a high-lipid environment, resulting in both reactive lipid accumulation and increased mitochondrial reactive oxygen species (ROS) production in the induction of peripheral tissue insulin resistance. While the etiology of insulin resistance in a high lipid environment is rapid and well documented, physical inactivity promotes insulin resistance in the absence of redox stress/lipid-mediated mechanisms, suggesting alternative mechanisms-of-action. One possible mechanism is a reduction in protein synthesis and the resultant decrease in key metabolic proteins, including canonical insulin signaling and mitochondrial proteins. While reductions in mitochondrial content associated with physical inactivity are not required for the induction of insulin resistance, this could predispose individuals to the detrimental effects of a high-lipid environment. Conversely, exercise-training induced mitochondrial biogenesis has been implicated in the protective effects of exercise. Given mitochondrial biology may represent a point of convergence linking impaired insulin sensitivity in both scenarios of chronic overfeeding and physical inactivity, this review aims to describe the interaction between mitochondrial biology, physical (in)activity and lipid metabolism within the context of insulin signalling.
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Petrick HL, Brownell S, Vachon B, Brunetta HS, Handy RM, van Loon LJC, Murrant CL, Holloway GP. Dietary nitrate increases submaximal SERCA activity and ADP transfer to mitochondria in slow-twitch muscle of female mice. Am J Physiol Endocrinol Metab 2022; 323:E171-E184. [PMID: 35732003 DOI: 10.1152/ajpendo.00371.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rapid oscillations in cytosolic calcium (Ca2+) coordinate muscle contraction, relaxation, and physical movement. Intriguingly, dietary nitrate decreases ATP cost of contraction, increases force production, and increases cytosolic Ca2+, which would seemingly necessitate a greater demand for sarcoplasmic reticulum Ca2+ ATPase (SERCA) to sequester Ca2+ within the sarcoplasmic reticulum (SR) during relaxation. As SERCA is highly regulated, we aimed to determine the effect of 7-day nitrate supplementation (1 mM via drinking water) on SERCA enzymatic properties and the functional interaction between SERCA and mitochondrial oxidative phosphorylation. In soleus, we report that dietary nitrate increased force production across all stimulation frequencies tested, and throughout a 25 min fatigue protocol. Mice supplemented with nitrate also displayed an ∼25% increase in submaximal SERCA activity and SERCA efficiency (P = 0.053) in the soleus. To examine a possible link between ATP consumption and production, we established a methodology coupling SERCA and mitochondria in permeabilized muscle fibers. The premise of this experiment is that the addition of Ca2+ in the presence of ATP generates ADP from SERCA to support mitochondrial respiration. Similar to submaximal SERCA activity, mitochondrial respiration supported by SERCA-derived ADP was increased by ∼20% following nitrate in red gastrocnemius. This effect was fully attenuated by the SERCA inhibitor cyclopiazonic acid and was not attributed to differences in mitochondrial oxidative capacity, ADP sensitivity, protein content, or reactive oxygen species emission. Overall, these findings suggest that improvements in submaximal SERCA kinetics may contribute to the effects of nitrate on force production during fatigue.NEW & NOTEWORTHY We show that nitrate supplementation increased force production during fatigue and increased submaximal SERCA activity. This was also evident regarding the high-energy phosphate transfer from SERCA to mitochondria, as nitrate increased mitochondrial respiration supported by SERCA-derived ADP. Surprisingly, these observations were only apparent in muscle primarily expressing type I (soleus) but not type II fibers (EDL). These findings suggest that alterations in SERCA properties are a possible mechanism in which nitrate increases force during fatiguing contractions.
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Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Stuart Brownell
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Bayley Vachon
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Henver S Brunetta
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Physiological Sciences, Federal University of Santa Catarina, Santa Catarina, Brazil
| | - Rachel M Handy
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Coral L Murrant
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Politis-Barber V, Petrick HL, Raajendiran A, DesOrmeaux GJ, Brunetta HS, dos Reis LM, Mori MA, Wright DC, Watt MJ, Holloway GP. Ckmt1 is Dispensable for Mitochondrial Bioenergetics Within White/Beige Adipose Tissue. Function (Oxf) 2022; 3:zqac037. [PMID: 37954502 PMCID: PMC10633789 DOI: 10.1093/function/zqac037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 07/05/2022] [Accepted: 07/07/2022] [Indexed: 11/14/2023] Open
Abstract
Within brown adipose tissue (BAT), the brain isoform of creatine kinase (CKB) has been proposed to regulate the regeneration of ADP and phosphocreatine in a futile creatine cycle (FCC) that stimulates energy expenditure. However, the presence of FCC, and the specific creatine kinase isoforms regulating this theoretical model within white adipose tissue (WAT), remains to be fully elucidated. In the present study, creatine did not stimulate respiration in cultured adipocytes, isolated mitochondria or mouse permeabilized WAT. Additionally, while creatine kinase ubiquitous-type, mitochondrial (CKMT1) mRNA and protein were detected in human WAT, shRNA-mediated reductions in Ckmt1 did not decrease submaximal respiration in cultured adipocytes, and ablation of CKMT1 in mice did not alter energy expenditure, mitochondrial responses to pharmacological β3-adrenergic activation (CL 316, 243) or exacerbate the detrimental metabolic effects of consuming a high-fat diet. Taken together, these findings solidify CKMT1 as dispensable in the regulation of energy expenditure, and unlike in BAT, they do not support the presence of FCC within WAT.
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Affiliation(s)
- Valerie Politis-Barber
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada
| | - Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada
| | - Arthe Raajendiran
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Genevieve J DesOrmeaux
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada
| | - Henver S Brunetta
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas - SP 13083-970, Brazil
| | - Larissa M dos Reis
- Department of Genetics, Evolution, Microbiology and Immunology, University of Campinas, Campinas - SP 13083-970, Brazil
| | - Marcelo A Mori
- Department of Biochemistry and Tissue Biology, University of Campinas, Campinas - SP 13083-970, Brazil
| | - David C Wright
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada
| | - Matthew J Watt
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd E, Guelph, ON N1G 2W1, Canada
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Brunetta HS, Petrick HL, Momken I, Handy RM, Pignanelli C, Nunes EA, Piquereau J, Mericskay M, Holloway GP. Nitrate consumption preserves HFD-induced skeletal muscle mitochondrial ADP sensitivity and lysine acetylation: A potential role for SIRT1. Redox Biol 2022; 52:102307. [PMID: 35398714 PMCID: PMC9006675 DOI: 10.1016/j.redox.2022.102307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 03/28/2022] [Indexed: 11/26/2022] Open
Abstract
Dietary nitrate supplementation, and the subsequent serial reduction to nitric oxide, has been shown to improve glucose homeostasis in several pre-clinical models of obesity and insulin resistance. While the mechanisms remain poorly defined, the beneficial effects of nitrate appear to be partially dependent on AMPK-mediated signaling events, a central regulator of metabolism and mitochondrial bioenergetics. Since AMPK can activate SIRT1, we aimed to determine if nitrate supplementation (4 mM sodium nitrate via drinking water) improved skeletal muscle mitochondrial bioenergetics and acetylation status in mice fed a high-fat diet (HFD: 60% fat). Consumption of HFD induced whole-body glucose intolerance, and within muscle attenuated insulin-induced Akt phosphorylation, mitochondrial ADP sensitivity (higher apparent Km), submaximal ADP-supported respiration, mitochondrial hydrogen peroxide (mtH2O2) production in the presence of ADP and increased cellular protein carbonylation alongside mitochondrial-specific acetylation. Consumption of nitrate partially preserved glucose tolerance and, within skeletal muscle, normalized insulin-induced Akt phosphorylation, mitochondrial ADP sensitivity, mtH2O2, protein carbonylation and global mitochondrial acetylation status. Nitrate also prevented the HFD-mediated reduction in SIRT1 protein, and interestingly, the positive effects of nitrate ingestion on glucose homeostasis and mitochondrial acetylation levels were abolished in SIRT1 inducible knock-out mice, suggesting SIRT1 is required for the beneficial effects of dietary nitrate. Altogether, dietary nitrate preserves mitochondrial ADP sensitivity and global lysine acetylation in HFD-fed mice, while in the absence of SIRT1, the effects of nitrate on glucose tolerance and mitochondrial acetylation were abrogated.
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Goudie L, Mancini NL, Shutt TE, Holloway GP, Mu C, Wang A, McKay DM, Shearer J. Impact of experimental colitis on mitochondrial bioenergetics in intestinal epithelial cells. Sci Rep 2022; 12:7453. [PMID: 35523978 PMCID: PMC9076608 DOI: 10.1038/s41598-022-11123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 04/18/2022] [Indexed: 11/18/2022] Open
Abstract
Intestinal homeostasis is highly dependent on optimal epithelial barrier function and permeability. Intestinal epithelial cells (IEC) regulate these properties acting as cellular gatekeepers by selectively absorbing nutrients and controlling the passage of luminal bacteria. These functions are energy demanding processes that are presumably met through mitochondrial-based processes. Routine methods for examining IEC mitochondrial function remain sparse, hence, our objective is to present standardized methods for quantifying mitochondrial energetics in an immortalized IEC line. Employing the murine IEC4.1 cell line, we present adapted methods and protocols to examine mitochondrial function using two well-known platforms: the Seahorse Extracellular Flux Analyzer and Oxygraph-2 k. To demonstrate the applicability of these protocols and instruments, IEC were treated with and without the murine colitogenic agent, dextran sulfate sodium (DSS, 2% w/v). Profound impairments with DSS treatment were found with both platforms, however, the Oxygraph-2 k allowed greater resolution of affected pathways including short-chain fatty acid metabolism. Mitochondrial functional analysis is a novel tool to explore the relationship between IEC energetics and functional consequences within the contexts of health and disease. The outlined methods offer an introductory starting point for such assessment and provide the investigator with insights into platform-specific capabilities.
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Affiliation(s)
- Luke Goudie
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Alberta, Canada
| | - Nicole L Mancini
- Gastrointestinal Research Group and Inflammation Research Network, Department of Physiology and Pharmacology, Calvin, Joan and Phoebe Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Timothy E Shutt
- Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Departments of Medical Genetics and Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, HMRB 228, Alberta, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Chunlong Mu
- Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Departments of Medical Genetics and Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, HMRB 228, Alberta, Canada
| | - Arthur Wang
- Gastrointestinal Research Group and Inflammation Research Network, Department of Physiology and Pharmacology, Calvin, Joan and Phoebe Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Derek M McKay
- Gastrointestinal Research Group and Inflammation Research Network, Department of Physiology and Pharmacology, Calvin, Joan and Phoebe Snyder Institute for Chronic Diseases, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Jane Shearer
- Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Alberta, Canada. .,Alberta Children's Hospital Research Institute, Hotchkiss Brain Institute, Departments of Medical Genetics and Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, HMRB 228, Alberta, Canada.
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Holloway GP, Nickerson JG, Lally JSV, Petrick HL, Dennis KMJH, Jain SS, Alkhateeb H, Bonen A. Co-overexpression of CD36 and FABPpm increases fatty acid transport additively, not synergistically, within muscle. Am J Physiol Cell Physiol 2022; 322:C546-C553. [PMID: 35138177 DOI: 10.1152/ajpcell.00435.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We aimed to determine the combined effects of over-expressing FABPpm and CD36 on skeletal muscle fatty acid transport to establish if these transport proteins function collaboratively. Electrotransfection with either FABPpm or CD36 increased their protein content at the plasma membrane (+75% and +64%), increased fatty acid transport rates +24% for FABPpm and +62% for CD36, resulting in a calculated transport efficiency of ~0.019 and ~0.053 per unit protein change for FABPpm and CD36, respectively. We subsequently used these data to determine if increasing both proteins additively or synergistically increased fatty acid transport. Co-transfection of FABPpm and CD36 simultaneously increased protein content in whole muscle (FABPpm, +46%; CD36, +45%) and at the sarcolemma (FABPpm, +41% and CD36, +42%), as well as fatty acid transport rates (+50%). Since the relative effects of changing FABPpm and CD36 content had been independently determined, we were able to a predict a change in fatty acid transport based on the overexpression of plasmalemmal transporters in the co-transfection experiments. This prediction yielded an increase in fatty acid transport of +0.984 and +1.722 pmol/mg prot/15sec for FABPpm and CD36, respectively, for a total increase of +2.96 pmol/mg prot/15sec. This calculated determination was remarkably consistent with the measured change in transport, namely +2.89 pmol/mg prot/15sec. Altogether, these data indicate that increasing CD36 and FABPpm alters fatty acid transport rates additively, but not synergistically, suggesting an independent mechanism-of-action within muscle for each transporter. This conclusion was further supported by the observation that plasmalemmal CD36 and FABPpm did not co-immunoprecipitate.
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Affiliation(s)
- Graham P Holloway
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canad
| | | | - James S V Lally
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Heather L Petrick
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canad
| | - Kaitlyn M J H Dennis
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canad
| | - Swati S Jain
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canad
| | | | - Arend Bonen
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canad
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15
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DesOrmeaux GJ, Petrick HL, Brunetta HS, Holloway GP. Independent of mitochondrial respiratory function, dietary nitrate attenuates HFD-induced lipid accumulation and mitochondrial ROS emission within the liver. Am J Physiol Endocrinol Metab 2021; 321:E217-E228. [PMID: 34229472 DOI: 10.1152/ajpendo.00610.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 06/14/2021] [Indexed: 11/22/2022]
Abstract
The liver is particularly susceptible to the detrimental effects of a high-fat diet (HFD), rapidly developing lipid accumulation and impaired cellular homeostasis. Recently, dietary nitrate has been shown to attenuate HFD-induced whole body glucose intolerance and liver steatosis, however, the underlying mechanism(s) remain poorly defined. In the current study, we investigated the ability of dietary nitrate to minimize possible impairments in liver mitochondrial bioenergetics following 8 wk of HFD (60% fat) in male C57BL/6J mice. Consumption of a HFD caused whole body glucose intolerance (P < 0.0001), and within the liver, increased lipid accumulation (P < 0.0001), mitochondrial-specific reactive oxygen species emission (P = 0.007), and markers of oxidative stress. Remarkably, dietary nitrate attenuated almost all of these pathological responses. Despite the reduction in lipid accumulation and redox stress (reduced TBARS and nitrotyrosine), nitrate did not improve insulin signaling within the liver or whole body pyruvate tolerance (P = 0.313 HFD vs. HFD + nitrate). Moreover, the beneficial effects of nitrate were independent of changes in weight gain, 5' AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) signaling, mitochondrial content, mitochondrial respiratory capacity and ADP sensitivity or antioxidant protein content. Combined, these data suggest nitrate supplementation represents a potential therapeutic strategy to attenuate hepatic lipid accumulation and decrease mitochondrial ROS emission following HFD, processes linked to improvements in whole body glucose tolerance. However, the beneficial effects of nitrate within the liver do not appear to be a result of increased oxidative capacity or mitochondrial substrate sensitivity.NEW & NOTEWORTHY The mechanism(s) for how dietary nitrate prevents high-fat diet (HFD)-induced glucose intolerance remain poorly defined. We show that dietary nitrate attenuates HFD-induced increases in lipid accumulation, mitochondrial-specific reactive oxygen species (ROS) emission, and markers of oxidative stress within the liver. The beneficial effects of nitrate were independent of changes 5' AMP-activated protein kinase signaling, mitochondrial content/respiratory capacity, or lipid-supported respiratory sensitivity. Combined, these data provide potential mechanisms underlying the therapeutic potential of dietary nitrate.
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Affiliation(s)
| | - Heather L Petrick
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Henver S Brunetta
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Graham P Holloway
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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16
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Petrick HL, King TJ, Pignanelli C, Vanderlinde TE, Cohen JN, Holloway GP, Burr JF. Endurance and Sprint Training Improve Glycemia and V˙O2peak but only Frequent Endurance Benefits Blood Pressure and Lipidemia. Med Sci Sports Exerc 2021; 53:1194-1205. [PMID: 33315809 DOI: 10.1249/mss.0000000000002582] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Sprint interval training (SIT) has gained popularity as a time-effective alternative to moderate-intensity endurance training (END). However, whether SIT is equally effective for decreasing cardiometabolic risk factors remains debatable, as many beneficial effects of exercise are thought to be transient, and unlike END, SIT is not recommended daily. Therefore, in line with current exercise recommendations, we examined the ability of SIT and END to improve cardiometabolic health in overweight/obese males. METHODS Twenty-three participants were randomized to perform 6 wk of constant workload SIT (3 d·wk-1, 4-6 × 30 s ~170% Wpeak, 2 min recovery, n = 12) or END (5 d·wk-1, 30-40 min, ~60% Wpeak, n = 11) on cycle ergometers. Aerobic capacity (V˙O2peak), body composition, blood pressure (BP), arterial stiffness, endothelial function, glucose and lipid tolerance, and free-living glycemic regulation were assessed pre- and posttraining. RESULTS Both END and SIT increased V˙O2peak (END ~15%, SIT ~5%) and glucose tolerance (~20%). However, only END decreased diastolic BP, abdominal fat, and improved postprandial lipid tolerance, representing improvements in cardiovascular risk factors that did not occur after SIT. Although SIT, but not END, increased endothelial function, arterial stiffness was not altered in either group. Indices of free-living glycemic regulation were improved after END and trended toward an improvement after SIT (P = 0.06-0.09). However, glycemic control was better on exercise compared with rest days, highlighting the importance of exercise frequency. Furthermore, in an exploratory nature, favorable individual responses (V˙O2peak, BP, glucose tolerance, lipidemia, and body fat) were more prevalent after END than low-frequency SIT. CONCLUSION As only high-frequency END improved BP and lipid tolerance, free-living glycemic regulation was better on days that participants exercised, and favorable individual responses were consistent after END, high-frequency END may favorably improve cardiometabolic health.
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Affiliation(s)
| | - Trevor J King
- Human Performance and Health Research Laboratory, Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Christopher Pignanelli
- Human Performance and Health Research Laboratory, Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Tara E Vanderlinde
- Human Performance and Health Research Laboratory, Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Jeremy N Cohen
- Human Performance and Health Research Laboratory, Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Graham P Holloway
- Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Jamie F Burr
- Human Performance and Health Research Laboratory, Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
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17
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Thornton E, Robinson E, Templeman JR, Bruggink L, Bower M, Cant JP, Holloway GP, Swanson KS, Squires EJ, Shoveller AK. Supplemental Fiber Affects Body Temperature and Fecal Metabolites but Not Respiratory Rate or Body Composition in Mid-Distance Training Sled Dogs. Front Vet Sci 2021; 8:639335. [PMID: 33996969 PMCID: PMC8116954 DOI: 10.3389/fvets.2021.639335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/09/2021] [Indexed: 11/13/2022] Open
Abstract
Dietary fiber affects canine physiology in many ways, such as increasing colonic absorption of water and improving gut health, both of which may positively impact exercise performance. The objectives of this study were to investigate the effects of increased dietary soluble fiber and incremental training on respiratory rate (RR), internal body temperature (BT), body composition, and fecal metabolites in mid-distance training sled dogs. Fourteen dogs (12 Siberian and 2 Alaskan Huskies) were blocked by age, sex, and body weight (BW) and then randomly allocated into one of two diet groups. Seven dogs were fed a dry extruded control diet (Ctl) with an insoluble:soluble fiber ratio of 4:1 (0.74% soluble fiber on a dry-matter basis), and seven dogs were fed a dry extruded treatment diet (Trt) with an insoluble:soluble fiber ratio of 3:1 (2.12% soluble fiber on a dry-matter basis). Fecal samples were taken once a week. All dogs underwent 9 weeks of incremental exercise conditioning where the running distance was designed to increase each week. Every 3 weeks, external telemetry equipment was used to non-invasively measure and record RR and internal BT at resting, working, and post-exercise recovery states. Body composition was measured on weeks −1 and 9 using quantitative magnetic resonance. Body composition, RR, BT, and fecal metabolites were analyzed using a mixed model with dog as a random effect and week and diet group as fixed effects. Dogs on Trt had lower working and post-exercise BT than Ctl (P < 0.05). In addition, Trt dogs had lower recovery BT at weeks 2 and 5 than Ctl dogs (P < 0.05). Treatment dogs had greater fecal short-chain fatty acid concentrations than Ctl (P < 0.05). Diet had no effect on RR or body composition (P > 0.10), but exercise resulted in an overall 7% increase in lean and 3.5% decrease in fat mass (P < 0.05). These data suggest that increasing dietary soluble fiber may positively influence BT and gut health; however, it has no effect on RR or body composition. Soluble fiber did not negatively impact any measures of overall health and performance and should be considered for use in performance dogs.
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Affiliation(s)
- Emma Thornton
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Eve Robinson
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - James R Templeman
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Lindy Bruggink
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | | | - John P Cant
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Kelly S Swanson
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - E James Squires
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Anna K Shoveller
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
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18
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Petrick HL, Holloway GP. Revisiting Mitochondrial Bioenergetics: Experimental Considerations for Biological Interpretation. Function (Oxf) 2020; 2:zqaa044. [PMID: 35330971 PMCID: PMC8788803 DOI: 10.1093/function/zqaa044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 12/15/2020] [Accepted: 12/22/2020] [Indexed: 01/06/2023]
Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Canada,Address correspondence to G.P.H. (e-mail: )
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19
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Genders AJ, Holloway GP, Bishop DJ. Are Alterations in Skeletal Muscle Mitochondria a Cause or Consequence of Insulin Resistance? Int J Mol Sci 2020; 21:ijms21186948. [PMID: 32971810 PMCID: PMC7554894 DOI: 10.3390/ijms21186948] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 12/14/2022] Open
Abstract
As a major site of glucose uptake following a meal, skeletal muscle has an important role in whole-body glucose metabolism. Evidence in humans and animal models of insulin resistance and type 2 diabetes suggests that alterations in mitochondrial characteristics accompany the development of skeletal muscle insulin resistance. However, it is unclear whether changes in mitochondrial content, respiratory function, or substrate oxidation are central to the development of insulin resistance or occur in response to insulin resistance. Thus, this review will aim to evaluate the apparent conflicting information placing mitochondria as a key organelle in the development of insulin resistance in skeletal muscle.
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Affiliation(s)
- Amanda J. Genders
- Institute for Health and Sport (iHeS), Victoria University, Melbourne 8001, Australia;
- Correspondence: ; Tel.: +61-3-9919-9556
| | - Graham P. Holloway
- Dept. Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada;
| | - David J. Bishop
- Institute for Health and Sport (iHeS), Victoria University, Melbourne 8001, Australia;
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20
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Petrick HL, Foley KP, Zlitni S, Brunetta HS, Paglialunga S, Miotto PM, Politis-Barber V, O’Dwyer C, Philbrick DJ, Fullerton MD, Schertzer JD, Holloway GP. Adipose Tissue Inflammation Is Directly Linked to Obesity-Induced Insulin Resistance, while Gut Dysbiosis and Mitochondrial Dysfunction Are Not Required. Function (Oxf) 2020; 1:zqaa013. [PMID: 34278304 PMCID: PMC8276887 DOI: 10.1093/function/zqaa013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/17/2020] [Accepted: 08/21/2020] [Indexed: 01/06/2023]
Abstract
Obesity is associated with adipose tissue hypertrophy, systemic inflammation, mitochondrial dysfunction, and intestinal dysbiosis. Rodent models of high-fat diet (HFD)-feeding or genetic deletion of multifunctional proteins involved in immunity and metabolism are often used to probe the etiology of obesity; however, these models make it difficult to divorce the effects of obesity, diet composition, or immunity on endocrine regulation of blood glucose. We, therefore, investigated the importance of adipose inflammation, mitochondrial dysfunction, and gut dysbiosis for obesity-induced insulin resistance using a spontaneously obese mouse model. We examined metabolic changes in skeletal muscle, adipose tissue, liver, the intestinal microbiome, and whole-body glucose control in spontaneously hyperphagic C57Bl/6J mice compared to lean littermates. A separate subset of lean and obese mice was subject to 8 weeks of obesogenic HFD feeding, or to pair feeding of a standard rodent diet. Hyperphagia, obesity, adipose inflammation, and insulin resistance were present in obese mice despite consuming a standard rodent diet, and these effects were blunted with caloric restriction. However, hyperphagic obese mice had normal mitochondrial respiratory function in all tissues tested and no discernable intestinal dysbiosis relative to lean littermates. In contrast, feeding mice an obesogenic HFD altered the composition of the gut microbiome, impaired skeletal muscle mitochondrial bioenergetics, and promoted poor glucose control. These data show that adipose inflammation and redox stress occurred in all models of obesity, but gut dysbiosis and mitochondrial respiratory dysfunction are not always required for obesity-induced insulin resistance. Rather, changes in the intestinal microbiome and mitochondrial bioenergetics may reflect physiological consequences of HFD feeding.
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Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Kevin P Foley
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Soumaya Zlitni
- Departments of Genetics and Medicine, Stanford University, Stanford, 94305, CA, USA
| | - Henver S Brunetta
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada,Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
| | - Sabina Paglialunga
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Valerie Politis-Barber
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Conor O’Dwyer
- Department of Biochemistry, Microbiology and Immunology, Centre for Inflammation, Infection and Immunity, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, Canada
| | - Diana J Philbrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Morgan D Fullerton
- Department of Biochemistry, Microbiology and Immunology, Centre for Inflammation, Infection and Immunity, Centre for Catalysis Research and Innovation, University of Ottawa, Ottawa, ON, Canada
| | - Jonathan D Schertzer
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada,Address correspondence to G.P.H. (e-mail: )
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21
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Petrick HL, Brunetta HS, Pignanelli C, Nunes EA, van Loon LJC, Burr JF, Holloway GP. In vitro ketone-supported mitochondrial respiration is minimal when other substrates are readily available in cardiac and skeletal muscle. J Physiol 2020; 598:4869-4885. [PMID: 32735362 DOI: 10.1113/jp280032] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/28/2020] [Indexed: 12/30/2022] Open
Abstract
KEY POINTS Ketone bodies are proposed to represent an alternative fuel source driving energy production, particularly during exercise. Biologically, the extent to which mitochondria utilize ketone bodies compared to other substrates remains unknown. We demonstrate in vitro that maximal mitochondrial respiration supported by ketone bodies is low when compared to carbohydrate-derived substrates in the left ventricle and red gastrocnemius muscle from rodents, and in human skeletal muscle. When considering intramuscular concentrations of ketone bodies and the presence of other carbohydrate and lipid substrates, biological rates of mitochondrial respiration supported by ketone bodies are predicted to be minimal. At the mitochondrial level, it is therefore unlikely that ketone bodies are an important source for energy production in cardiac and skeletal muscle, particularly when other substrates are readily available. ABSTRACT Ketone bodies (KB) have recently gained popularity as an alternative fuel source to support mitochondrial oxidative phosphorylation and enhance exercise performance. However, given the low activity of ketolytic enzymes and potential inhibition from carbohydrate oxidation, it remains unknown if KBs can contribute to energy production. We therefore determined the ability of KBs (sodium dl-β-hydroxybutyrate, β-HB; lithium acetoacetate, AcAc) to stimulate in vitro mitochondrial respiration in the left ventricle (LV) and red gastrocnemius (RG) of rats, and in human vastus lateralis. Compared to pyruvate, the ability of KBs to maximally drive respiration was low in isolated mitochondria and permeabilized fibres (PmFb) from the LV (∼30-35% of pyruvate), RG (∼10-30%), and human vastus lateralis (∼2-10%). In PmFb, the concentration of KBs required to half-maximally drive respiration (LV: 889 µm β-HB, 801 µm AcAc; RG: 782 µm β-HB, 267 µm AcAc) were greater than KB content representative of the muscle microenvironment (∼100 µm). This would predict low rates (∼1-4% of pyruvate) of biological KB-supported respiration in the LV (8-14 pmol s-1 mg-1 ) and RG (3-6 pmol s-1 mg-1 ) at rest and following exercise. Moreover, KBs did not increase respiration in the presence of saturating pyruvate, submaximal pyruvate (100 µm) reduced the ability of physiological β-HB to drive respiration, and addition of other intracellular substrates (succinate + palmitoylcarnitine) decreased maximal KB-supported respiration. As a result, product inhibition is likely to limit KB oxidation. Altogether, the ability of KBs to drive mitochondrial respiration is minimal and they are likely to be outcompeted by other substrates, compromising their use as an important energy source.
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Affiliation(s)
- Heather L Petrick
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Henver S Brunetta
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada.,Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
| | - Chris Pignanelli
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Everson A Nunes
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil.,Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Jamie F Burr
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Science, University of Guelph, Guelph, Ontario, Canada
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22
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Brunetta HS, Politis-Barber V, Petrick HL, Dennis KMJH, Kirsh AJ, Barbeau PA, Nunes EA, Holloway GP. Nitrate attenuates high fat diet-induced glucose intolerance in association with reduced epididymal adipose tissue inflammation and mitochondrial reactive oxygen species emission. J Physiol 2020; 598:3357-3371. [PMID: 32449521 DOI: 10.1113/jp279455] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 05/19/2020] [Indexed: 12/20/2023] Open
Abstract
KEY POINTS Dietary nitrate is a prominent therapeutic strategy to mitigate some metabolic deleterious effects related to obesity. Mitochondrial dysfunction is causally linked to adipose tissue inflammation and insulin resistance. Whole-body glucose tolerance is prevented by nitrate independent of body weight and energy expenditure. Dietary nitrate reduces epididymal adipose tissue inflammation and mitochondrial reactive oxygen species emission while preserving insulin signalling. Metabolic beneficial effects of nitrate consumption are associated with improvements in mitochondrial redox balance in hypertrophic adipose tissue. ABSTRACT Evidence has accumulated to indicate that dietary nitrate alters energy expenditure and the metabolic derangements associated with a high fat diet (HFD), but the mechanism(s) of action remain incompletely elucidated. Therefore, we aimed to determine if dietary nitrate (4 mm sodium nitrate via drinking water) could prevent HFD-mediated glucose intolerance in association with improved mitochondrial bioenergetics within both white (WAT) and brown (BAT) adipose tissue in mice. HFD feeding caused glucose intolerance (P < 0.05) and increased body weight. As a result of higher body weight, energy expenditure increased proportionally. HFD-fed mice displayed greater mitochondrial uncoupling and a twofold increase in uncoupling protein 1 content within BAT. Within epididymal white adipose tissue (eWAT), HFD increased cell size (i.e. hypertrophy), mitochondrial H2 O2 emission, oxidative stress, c-Jun N-terminal kinase phosphorylation and leucocyte infiltration, and induced insulin resistance. Remarkably, dietary nitrate consumption attenuated and/or mitigated all these responses, including rendering mitochondria more coupled within BAT, and normalizing mitochondrial H2 O2 emission and insulin-mediated Akt-Thr308 phosphorylation within eWAT. Intriguingly, the positive effects of dietary nitrate appear to be independent of eWAT mitochondrial respiratory capacity and content. Altogether, these data suggest that dietary nitrate attenuates the development of HFD-induced insulin resistance in association with attenuating WAT inflammation and redox balance, independent of changes in either WAT or BAT mitochondrial respiratory capacity/content.
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Affiliation(s)
- Henver S Brunetta
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
| | - Valerie Politis-Barber
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Kaitlyn M J H Dennis
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Aleah J Kirsh
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Pierre-Andre Barbeau
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Everson A Nunes
- Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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23
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Politis-Barber V, Brunetta HS, Paglialunga S, Petrick HL, Holloway GP. Long-term, high-fat feeding exacerbates short-term increases in adipose mitochondrial reactive oxygen species, without impairing mitochondrial respiration. Am J Physiol Endocrinol Metab 2020; 319:E376-E387. [PMID: 32543945 PMCID: PMC7473917 DOI: 10.1152/ajpendo.00028.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
White adipose tissue (WAT) dysfunction in obesity is implicated in the onset of whole body insulin resistance. Alterations in mitochondrial bioenergetics, namely impaired mitochondrial respiration and increased mitochondrial reactive oxygen species (mtROS) production, have been suggested to contribute to this metabolic dysregulation. However, techniques investigating mitochondrial function are classically normalized to tissue weight, which may be confounding when considering obesity-related adipocyte hypertrophy. Furthermore, the effect of long-term high-fat diet (HFD) on mtROS in WAT has yet to be elucidated. Therefore, we sought to determine the HFD-mediated temporal changes in mitochondrial respiration and mtROS emission in WAT. C57BL/6N mice received low-fat diet or HFD for 1 or 8 wk and changes in inguinal WAT (iWAT) and epididymal WAT (eWAT) were assessed. While tissue weight-normalized mitochondrial respiration was reduced in iWAT following 8-wk HFD-feeding, this effect was mitigated when adipocyte cell size and/or number were considered. These data suggest HFD does not impair mitochondrial respiratory capacity per adipocyte within WAT. In support of this assertion, within eWAT compensatory increases in lipid-supported and maximal succinate-supported respiration occurred at 8 wk despite cell hypertrophy and increases in WAT inflammation. Although these data suggest impairments in mitochondrial respiration do not contribute to HFD-mediated WAT phenotype, lipid-supported mtROS emission increased following 1-wk HFD in eWAT, while both lipid and carbohydrate-supported mtROS were increased at 8 wk in both depots. Combined, these data establish that while HFD does not impair adipocyte mitochondrial respiratory capacity, increased mtROS is an enduring physiological occurrence within WAT in HFD-induced obesity.
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Affiliation(s)
| | - Henver S. Brunetta
- 1Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
- 2Department of Physiological Sciences, Federal University of Santa Catarina, Florianopolis, Brazil
| | - Sabina Paglialunga
- 1Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Heather L. Petrick
- 1Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P. Holloway
- 1Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Miotto PM, Petrick HL, Holloway GP. Acute insulin deprivation results in altered mitochondrial substrate sensitivity conducive to greater fatty acid transport. Am J Physiol Endocrinol Metab 2020; 319:E345-E353. [PMID: 32543943 PMCID: PMC7473910 DOI: 10.1152/ajpendo.00495.2019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Type 1 and type 2 diabetes are both tightly associated with impaired glucose control. Although both pathologies stem from different mechanisms, a reduction in insulin action coincides with drastic metabolic dysfunction in skeletal muscle and metabolic inflexibility. However, the underlying explanation for this response remains poorly understood, particularly since it is difficult to distinguish the role of attenuated insulin action from the detrimental effects of reactive lipid accumulation, which impairs mitochondrial function and promotes reactive oxygen species (ROS) emission. We therefore utilized streptozotocin to examine the effects of acute insulin deprivation, in the absence of a high-lipid/nutrient excess environment, on the regulation of mitochondrial substrate sensitivity and ROS emission. The ablation of insulin resulted in reductions in absolute mitochondrial oxidative capacity and ADP-supported respiration and reduced the ability for malonyl-CoA to inhibit carnitine palmitoyltransferase I (CPT-I) and suppress fatty acid-supported respiration. These bioenergetic responses coincided with increased mitochondrial-derived H2O2 emission and lipid transporter content, independent of major mitochondrial substrate transporter proteins and enzymes involved in fatty acid oxidation. Together, these data suggest that attenuated/ablated insulin signaling does not affect mitochondrial ADP sensitivity, whereas the increased reliance on fatty acid oxidation in situations where insulin action is reduced may occur as a result of altered regulation of mitochondrial fatty acid transport through CPT-I.
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Affiliation(s)
- Paula M Miotto
- Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Heather L Petrick
- Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health & Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Jannas-Vela S, Brownell S, Petrick HL, Heigenhauser GJF, Spriet LL, Holloway GP. Assessment of Na+/K+ ATPase Activity in Small Rodent and Human Skeletal Muscle Samples. Med Sci Sports Exerc 2020; 51:2403-2409. [PMID: 31634296 DOI: 10.1249/mss.0000000000002063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION In skeletal muscle, the Na/K ATPase (NKA) plays essential roles in processes linked to muscle contraction, fatigue, and energy metabolism; however, very little information exists regarding the regulation of NKA activity. The scarcity of information regarding NKA function in skeletal muscle likely stems from methodological constraints, as NKA contributes minimally to total cellular ATP utilization, and therefore contamination from other ATPases prevents the assessment of NKA activity in muscle homogenates. Here we introduce a method that improves accuracy and feasibility for the determination of NKA activity in small rodent muscle samples (5-10 mg) and in human skeletal muscle. METHODS Skeletal muscle homogenates from mice (n = 6) and humans (n = 3) were used to measure NKA and sarcoplasmic reticulum Ca ATPase (SERCA) activities with the addition of specific ATPase inhibitors to minimize "background noise." RESULTS We observed that myosin ATPase activity was the major interfering factor for estimation of NKA activity in skeletal muscle homogenates, as the addition of 25 μM of blebbistatin, a specific myosin ATPase inhibitor, considerably minimized "background noise" (threefold) and enabled the determination of NKA maximal activity with values three times higher than previously reported. The specificity of the assay was demonstrated after the addition of 2 mM ouabain, which completely inhibited NKA. On the other hand, the addition of blebbistatin did not affect the ability to measure SERCA function. The coefficient of variation for NKA and SERCA assays were 6.2% and 4.4%, respectively. CONCLUSION The present study has improved the methodology to determine NKA activity. We further show the feasibility of measuring NKA and SERCA activities from a common muscle homogenate. This methodology is expected to aid in our long-term understanding of how NKA affects skeletal muscle metabolic homeostasis and contractile function in diverse situations.
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Affiliation(s)
- Sebastian Jannas-Vela
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA.,Exercise Science Laboratory, Faculty of Medicine, School of Kinesiology, Universidad Finis Terrae, Santiago, CHILE
| | - Stuart Brownell
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | | | - Lawrence L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, CANADA
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Kirsh AJ, Juracic ES, Petrick HL, Monaco CMF, Barbeau PA, Tupling AR, Holloway GP. Dietary nitrate does not alter cardiac function, calcium handling proteins, or SERCA activity in the left ventricle of healthy rats. Appl Physiol Nutr Metab 2020; 45:1049-1053. [PMID: 32379978 DOI: 10.1139/apnm-2020-0078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dietary nitrate has been shown to increase cytosolic calcium concentrations within the heart, which would necessitate greater calcium sequestration for relaxation. In the present study we demonstrate that while nitrate supplementation reduced blood pressure, calcium-handling protein content, sarco(endo)plasmic reticulum Ca-ATPase 2a (SERCA) enzymatic properties, and left ventricular function were not altered. In addition, nitrite did not alter in vitro SERCA activity. Combined, these data suggest that in healthy rats, dietary nitrate does not increase left ventricle SERCA-related calcium-handling properties. Novelty Dietary nitrate decreases blood pressure but does not alter left ventricular calcium-handling protein content or SERCA activity in healthy rats.
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Affiliation(s)
- Aleah J Kirsh
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Emma S Juracic
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Cynthia M F Monaco
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Pierre-Andre Barbeau
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - A Russell Tupling
- Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
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Jannas‐Vela S, Klingel SL, Cervone DT, Wickham KA, Heigenhauser GJF, Mutch DM, Holloway GP, Spriet LL. Resting metabolic rate and skeletal muscle SERCA and Na + /K + ATPase activities are not affected by fish oil supplementation in healthy older adults. Physiol Rep 2020; 8:e14408. [PMID: 32342642 PMCID: PMC7186565 DOI: 10.14814/phy2.14408] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/11/2020] [Accepted: 02/13/2020] [Indexed: 11/25/2022] Open
Abstract
Omega-3 polyunsaturated fatty acids (PUFAs) have unique properties purported to influence several aspects of metabolism, including energy expenditure and protein function. Supplementing with n-3 PUFAs may increase whole-body resting metabolic rate (RMR), by enhancing Na+ /K+ ATPase (NKA) activity and reducing the efficiency of sarcoplasmic reticulum (SR) Ca2+ ATPase (SERCA) activity by inducing a Ca2+ leak-pump cycle. The purpose of this study was to examine the effects of fish oil (FO) on RMR, substrate oxidation, and skeletal muscle SERCA and NKA pump function in healthy older individuals. Subjects (n = 16 females; n = 8 males; 65 ± 1 years) were randomly assigned into groups supplemented with either olive oil (OO) (5 g/day) or FO (5 g/day) containing 2 g/day eicosapentaenoic acid and 1 g/day docosahexaenoic acid for 12 weeks. Participants visited the laboratory for RMR and substrate oxidation measurements after an overnight fast at weeks 0 and 12. Skeletal muscle biopsies were taken during weeks 0 and 12 for analysis of NKA and SERCA function and protein content. There was a main effect of time with decrease in RMR (5%) and fat oxidation (18%) in both the supplementation groups. The kinetic parameters of SERCA and NKA maximal activity, as well as the expression of SR and NKA proteins, were not affected after OO and FO supplementation. In conclusion, these results suggest that FO supplementation is not effective in altering RMR, substrate oxidation, and skeletal muscle SERCA and NKA protein levels and activities, in healthy older men and women.
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Affiliation(s)
- Sebastian Jannas‐Vela
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
- Exercise Science LaboratorySchool of KinesiologyFaculty of MedicineUniversidad Finis TerraeSantiagoChile
| | - Shannon L. Klingel
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
| | - Daniel T. Cervone
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
| | - Kate A. Wickham
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
| | | | - David M. Mutch
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
| | - Graham P. Holloway
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
| | - Lawrence L. Spriet
- Department of Human Health and Nutritional SciencesUniversity of GuelphGuelphONCanada
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Barbeau PA, Houad JM, Huber JS, Paglialunga S, Snook LA, Herbst EAF, Dennis KMJH, Simpson JA, Holloway GP. Ablating the Rab-GTPase activating protein TBC1D1 predisposes rats to high-fat diet-induced cardiomyopathy. J Physiol 2020; 598:683-697. [PMID: 31845331 DOI: 10.1113/jp279042] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2019] [Accepted: 12/12/2019] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS Although the role of TBC1D1 within the heart remains unknown, expression of TBC1D1 increases in the left ventricle following an acute infarction, suggesting a biological importance within this tissue. We investigated the mechanistic role of TBC1D1 within the heart, aiming to establish the consequences of attenuating TBC1D1 signalling in the development of diabetic cardiomyopathy, as well as to determine potential sex differences. TBC1D1 ablation increased plasma membrane fatty acid binding protein content and myocardial palmitate oxidation. Following high-fat feeding, TBC1D1 ablation dramatically increased fibrosis and induced end-diastolic dysfunction in both male and female rats in the absence of changes in mitochondrial bioenergetics. Altogether, independent of sex, ablating TBC1D1 predisposes the left ventricle to pathological remodelling following high-fat feeding, and suggests TBC1D1 protects against diabetic cardiomyopathy. ABSTRACT TBC1D1, a Rab-GTPase activating protein, is involved in the regulation of glucose handling and substrate metabolism within skeletal muscle, and is essential for maintaining pancreatic β-cell mass and insulin secretion. However, the function of TBC1D1 within the heart is largely unknown. Therefore, we examined the role of TBC1D1 in the left ventricle and the functional consequence of ablating TBC1D1 on the susceptibility to high-fat diet-induced abnormalities. Since mutations within TBC1D1 (R125W) display stronger associations with clinical parameters in women, we further examined possible sex differences in the predisposition to diabetic cardiomyopathy. In control-fed animals, TBC1D1 ablation did not alter insulin-stimulated glucose uptake, or echocardiogram parameters, but increased accumulation of a plasma membrane fatty acid transporter and the capacity for palmitate oxidation. When challenged with an 8 week high-fat diet, TBC1D1 knockout rats displayed a four-fold increase in fibrosis compared to wild-type animals, and this was associated with diastolic dysfunction, suggesting a predisposition to diet-induced cardiomyopathy. Interestingly, high-fat feeding only induced cardiac hypertrophy in male TBC1D1 knockout animals, implicating a possible sex difference. Mitochondrial respiratory capacity and substrate sensitivity to pyruvate and ADP were not altered by diet or TBC1D1 ablation, nor were markers of oxidative stress, or indices of overt heart failure. Altogether, independent of sex, ablation of TBC1D1 not only increased the susceptibility to high-fat diet-induced diastolic dysfunction and left ventricular fibrosis, independent of sex, but also predisposed male animals to the development of cardiac hypertrophy. These data suggest that TBC1D1 may exert cardioprotective effects in the development of diabetic cardiomyopathy.
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Affiliation(s)
- Pierre-Andre Barbeau
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Jacy M Houad
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Jason S Huber
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Sabina Paglialunga
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Laelie A Snook
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Eric A F Herbst
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Kaitlyn M J H Dennis
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health & Nutritional Sciences, University of Guelph, Ontario, Canada
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Pignanelli C, Petrick HL, Keyvani F, Heigenhauser GJF, Quadrilatero J, Holloway GP, Burr JF. Low-load resistance training to task failure with and without blood flow restriction: muscular functional and structural adaptations. Am J Physiol Regul Integr Comp Physiol 2020; 318:R284-R295. [PMID: 31823670 DOI: 10.1152/ajpregu.00243.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The application of blood flow restriction (BFR) during resistance exercise is increasingly recognized for its ability to improve rehabilitation and for its effectiveness in increasing muscle hypertrophy and strength among healthy populations. However, direct comparison of the skeletal muscle adaptations to low-load resistance exercise (LL-RE) and low-load BFR resistance exercise (LL-BFR) performed to task failure is lacking. Using a within-subject design, we examined whole muscle group and skeletal muscle adaptations to 6 wk of LL-RE and LL-BFR training to repetition failure. Muscle strength and size outcomes were similar for both types of training, despite ~33% lower total exercise volume (load × repetition) with LL-BFR than LL-RE (28,544 ± 1,771 vs. 18,949 ± 1,541 kg, P = 0.004). After training, only LL-BFR improved the average power output throughout the midportion of a voluntary muscle endurance task. Specifically, LL-BFR training sustained an 18% greater power output from baseline and resulted in a greater change from baseline than LL-RE (19 ± 3 vs. 3 ± 4 W, P = 0.008). This improvement occurred despite histological analysis revealing similar increases in capillary content of type I muscle fibers following LL-RE and LL-BFR training, which was primarily driven by increased capillary contacts (4.53 ± 0.23 before training vs. 5.33 ± 0.27 and 5.17 ± 0.25 after LL-RE and LL-BFR, respectively, both P < 0.05). Moreover, maximally supported mitochondrial respiratory capacity increased only in the LL-RE leg by 30% from baseline (P = 0.006). Overall, low-load resistance training increased indexes of muscle oxidative capacity and strength, which were not further augmented with the application of BFR. However, performance on a muscle endurance test was improved following BFR training.
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Affiliation(s)
- Christopher Pignanelli
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Heather L Petrick
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Fatemeh Keyvani
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | | | - Joe Quadrilatero
- Department of Kinesiology, University of Waterloo, Waterloo, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jamie F Burr
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Dirks ML, Miotto PM, Goossens GH, Senden JM, Petrick HL, Kranenburg J, Loon LJ, Holloway GP. Short‐term bed rest‐induced insulin resistance cannot be explained by increased mitochondrial H2O2emission. J Physiol 2019; 598:123-137. [DOI: 10.1113/jp278920] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/11/2019] [Indexed: 12/16/2022] Open
Affiliation(s)
- Marlou L. Dirks
- NUTRIM School of Nutrition and Translational Research in MetabolismMaastricht University Medical Centre+ the Netherlands
| | - Paula M. Miotto
- Human Health & Nutritional SciencesUniversity of Guelph Guelph Ontario Canada
| | - Gijs H. Goossens
- NUTRIM School of Nutrition and Translational Research in MetabolismMaastricht University Medical Centre+ the Netherlands
| | - Joan M. Senden
- NUTRIM School of Nutrition and Translational Research in MetabolismMaastricht University Medical Centre+ the Netherlands
| | - Heather L. Petrick
- Human Health & Nutritional SciencesUniversity of Guelph Guelph Ontario Canada
| | - Janneau Kranenburg
- NUTRIM School of Nutrition and Translational Research in MetabolismMaastricht University Medical Centre+ the Netherlands
| | - Luc J.C. Loon
- NUTRIM School of Nutrition and Translational Research in MetabolismMaastricht University Medical Centre+ the Netherlands
| | - Graham P. Holloway
- Human Health & Nutritional SciencesUniversity of Guelph Guelph Ontario Canada
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Townsend LK, Weber AJ, Barbeau PA, Holloway GP, Wright DC. Reactive oxygen species-dependent regulation of pyruvate dehydrogenase kinase-4 in white adipose tissue. Am J Physiol Cell Physiol 2019; 318:C137-C149. [PMID: 31721616 DOI: 10.1152/ajpcell.00313.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Reactive oxygen species (ROS) are important signaling molecules mediating the exercise-induced adaptations in skeletal muscle. Acute exercise also drives the expression of genes involved in reesterification and glyceroneogenesis in white adipose tissue (WAT), but whether ROS play any role in this effect has not been explored. We speculated that exercise-induced ROS would regulate acute exercise-induced responses in WAT. To address this question, we utilized various models to alter redox signaling in WAT. We examined basal and exercise-induced gene expression in a genetically modified mouse model of reduced mitochondrial ROS emission [mitochondrial catalase overexpression (MCAT)]. Additionally, H2O2, various antioxidants, and the β3-adrenergic receptor agonist CL316243 were used to assess gene expression in white adipose tissue culture. MCAT mice have reduced ROS emission from WAT, enlarged WAT depots and adipocytes, and greater pyruvate dehydrogenase kinase-4 (Pdk4) gene expression. In WAT culture, H2O2 reduced glyceroneogenic gene expression. In wild-type mice, acute exercise induced dramatic but transient increases in Pdk4 and phosphoenolpyruvate carboxykinase (Pck1) mRNA in both subcutaneous inguinal WAT and epididymal WAT depots, which was almost completely absent in MCAT mice. Furthermore, the induction of Pdk4 and Pck1 in WAT culture by CL316243 was markedly reduced in the presence of antioxidants N-acetyl-cysteine or vitamin E. Genetic and nutritional approaches that attenuate redox signaling prevent exercise- and β-agonist-induced gene expression within WAT. Combined, these data suggest that ROS represent important mediators of gene expression within WAT.
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Affiliation(s)
- Logan K Townsend
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Alyssa J Weber
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Pierre-Andre Barbeau
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - David C Wright
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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Holloway GP, Holwerda AM, Miotto PM, Dirks ML, Verdijk LB, van Loon LJC. Age-Associated Impairments in Mitochondrial ADP Sensitivity Contribute to Redox Stress in Senescent Human Skeletal Muscle. Cell Rep 2019. [PMID: 29539414 DOI: 10.1016/j.celrep.2018.02.069] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
It remains unknown if mitochondrial bioenergetics are altered with aging in humans. We established an in vitro method to simultaneously determine mitochondrial respiration and H2O2 emission in skeletal muscle tissue across a range of biologically relevant ADP concentrations. Using this approach, we provide evidence that, although the capacity for mitochondrial H2O2 emission is not increased with aging, mitochondrial ADP sensitivity is impaired. This resulted in an increase in mitochondrial H2O2 and the fraction of electron leak to H2O2, in the presence of virtually all ADP concentrations examined. Moreover, although prolonged resistance training in older individuals increased muscle mass, strength, and maximal mitochondrial respiration, exercise training did not alter H2O2 emission rates in the presence of ADP, the fraction of electron leak to H2O2, or the redox state of the muscle. These data establish that a reduction in mitochondrial ADP sensitivity increases mitochondrial H2O2 emission and contributes to age-associated redox stress.
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Affiliation(s)
- Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Andrew M Holwerda
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
| | - Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Marlou L Dirks
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
| | - Lex B Verdijk
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
| | - Luc J C van Loon
- NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, 6200 Maastricht, the Netherlands
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Petrick HL, Pignanelli C, Barbeau PA, Churchward-Venne TA, Dennis KMJH, van Loon LJC, Burr JF, Goossens GH, Holloway GP. Blood flow restricted resistance exercise and reductions in oxygen tension attenuate mitochondrial H 2 O 2 emission rates in human skeletal muscle. J Physiol 2019; 597:3985-3997. [PMID: 31194254 DOI: 10.1113/jp277765] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Accepted: 06/07/2019] [Indexed: 12/23/2022] Open
Abstract
KEY POINTS Blood flow restricted resistance exercise (BFR-RE) is capable of inducing comparable adaptations to traditional resistance exercise (RE), despite a lower total exercise volume. It has been suggested that an increase in reactive oxygen species (ROS) production may be involved in this response; however, oxygen partial pressure ( P O 2 ) is reduced during BFR-RE, and the influence of P O 2 on mitochondrial redox balance remains poorly understood. In human skeletal muscle tissue, we demonstrate that both maximal and submaximal mitochondrial ROS emission rates are acutely decreased 2 h following BFR-RE, but not RE, occurring along with a reduction in tissue oxygenation during BFR-RE. We further suggest that P O 2 is involved in this response because an in vitro analysis revealed that reducing P O 2 dramatically decreased mitochondrial ROS emissions and electron leak to ROS. Altogether, these data indicate that mitochondrial ROS emission rates are attenuated following BFR-RE, and such a response is likely influenced by reductions in P O 2 . ABSTRACT Low-load blood flow restricted resistance exercise (BFR-RE) training has been proposed to induce comparable adaptations to traditional resistance exercise (RE) training, however, the acute signalling events remain unknown. Although a suggested mechanism of BFR-RE is an increase in reactive oxygen species (ROS) production, oxygen partial pressure ( P O 2 ) is reduced during BFR-RE, and the influence of O2 tension on mitochondrial redox balance remains ambiguous. We therefore aimed to determine whether skeletal muscle mitochondrial bioenergetics were altered following an acute bout of BFR-RE or RE, and to further examine the role of P O 2 in this response. Accordingly, muscle biopsies were obtained from 10 males at rest and 2 h after performing three sets of single-leg squats (RE or BFR-RE) to failure at 30% one-repetition maximum. We determined that mitochondrial respiratory capacity and ADP sensitivity were not altered in response to RE or BFR-RE. Although maximal (succinate) and submaximal (non-saturating ADP) mitochondrial ROS emission rates were unchanged following RE, BFR-RE attenuated these responses by ∼30% compared to pre-exercise, occurring along with a reduction in skeletal muscle tissue oxygenation during BFR-RE (P < 0.01 vs. RE). In a separate cohort of participants, evaluation of mitochondrial bioenergetics in vitro revealed that mild O2 restriction (50 µm) dramatically attenuated maximal (∼4-fold) and submaximal (∼50-fold) mitochondrial ROS emission rates and the fraction of electron leak to ROS compared to room air (200 µm). Combined, these data demonstrate that mitochondrial ROS emissions are attenuated following BFR-RE, a response which may be mediated by a reduction in skeletal muscle P O 2 .
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Affiliation(s)
- Heather L Petrick
- Human Health & Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | | | - Pierre-Andre Barbeau
- Human Health & Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Tyler A Churchward-Venne
- Department of Kinesiology and Physical Education, McGill University, Montreal, Quebec, Canada.,Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Kaitlyn M J H Dennis
- Human Health & Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Jamie F Burr
- Human Health & Nutritional Science, University of Guelph, Guelph, Ontario, Canada
| | - Gijs H Goossens
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, the Netherlands
| | - Graham P Holloway
- Human Health & Nutritional Science, University of Guelph, Guelph, Ontario, Canada
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Barbeau PA, Houad JM, Huber JS, Paglialunga S, Snook LA, Herbst EA, Chorner Z, Simpson JA, Holloway GP. Ablating The Rab-GTPase Activating Protein TBC1D1 Predisposes Rats To High Fat Diet-Induced Cardiomyopathy. Med Sci Sports Exerc 2019. [DOI: 10.1249/01.mss.0000562454.58203.4f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Petrick HL, Pignanelli C, Churchward-Venne TA, van Loon LJ, Burr JF, Goossens GH, Holloway GP. Blood Flow Restricted Exercise and Reduced Oxygen Tension Decrease Mitochondrial ROS Emission in Human Muscle. Med Sci Sports Exerc 2019. [DOI: 10.1249/01.mss.0000563416.30599.18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Miotto PM, McGlory C, Bahniwal R, Kamal M, Phillips SM, Holloway GP. Supplementation with dietary ω-3 mitigates immobilization-induced reductions in skeletal muscle mitochondrial respiration in young women. FASEB J 2019; 33:8232-8240. [PMID: 30970218 DOI: 10.1096/fj.201900095r] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Omega-3 (ω-3) supplementation attenuates immobilization-induced atrophy; however, the underlying mechanisms remain unclear. Since mitochondrial dysfunction and oxidative stress have been implicated in muscle atrophy, we examined whether ω-3 supplementation could mitigate disuse-mediated mitochondrial dysfunction. Healthy young women (age = 22 ± 3 yr) randomly received control (n = 9) or ω-3 supplementation (n = 11; 3 g eicosapentaenoic acid, 2 g docosahexaenoic acid) for 4 wk prior to and throughout 2 wk of single-limb immobilization. Biopsies were performed before and after 3 and 14 d of immobilization for the assessment of mitochondrial respiration, H2O2 emission, and markers of ADP transport/lipid metabolism. In controls, immobilization rapidly (3 d) reduced (∼20%) ADP-stimulated mitochondrial respiration without altering ADP sensitivity or the abundance of mitochondrial proteins. Extending immobilization to 14 d did not further reduce mitochondrial coupled respiration; however, unlike following 3 d, mitochondrial proteins were reduced ∼20%. In contrast, ω-3 supplementation prevented immobilization-induced reductions in mitochondrial content and respiration throughout the immobilization period. Regardless of dietary supplement, immobilization did not alter mitochondrial H2O2 emission in the presence or absence of ADP, markers of cellular redox state, mitochondrial lipid-supported respiration, or lipid-related metabolic proteins. These data highlight the rapidity of mitochondrial adaptations in response to muscle disuse, challenge the necessity for increased oxidative stress during inactivity, and establish that ω-3 supplementation preserves oxidative phosphorylation function and content during immobilization.-Miotto, P. M., McGlory, C., Bahniwal, R., Kamal, M., Phillips, S. M., Holloway, G. P. Supplementation with dietary ω-3 mitigates immobilization-induced reductions in skeletal muscle mitochondrial respiration in young women.
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Affiliation(s)
- Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Chris McGlory
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Ravninder Bahniwal
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Michael Kamal
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University, Hamilton, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada
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Gerling CJ, Mukai K, Chabowski A, Heigenhauser GJF, Holloway GP, Spriet LL, Jannas-Vela S. Incorporation of Omega-3 Fatty Acids Into Human Skeletal Muscle Sarcolemmal and Mitochondrial Membranes Following 12 Weeks of Fish Oil Supplementation. Front Physiol 2019; 10:348. [PMID: 30984028 PMCID: PMC6449797 DOI: 10.3389/fphys.2019.00348] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/14/2019] [Indexed: 11/13/2022] Open
Abstract
Fish oil (FO) supplementation in humans results in the incorporation of omega-3 fatty acids (FAs) eicosapentaenoic acid (EPA; C20:5) and docosahexaenoic acid (DHA; C20:6) into skeletal muscle membranes. However, despite the importance of membrane composition in structure–function relationships, a paucity of information exists regarding how different muscle membranes/organelles respond to FO supplementation. Therefore, the purpose of the present study was to determine the effects 12 weeks of FO supplementation (3g EPA/2g DHA daily) on the phospholipid composition of sarcolemmal and mitochondrial fractions, as well as whole muscle responses, in healthy young males. FO supplementation increased the total phospholipid content in whole muscle (57%; p < 0.05) and the sarcolemma (38%; p = 0.05), but did not alter the content in mitochondria. The content of omega-3 FAs, EPA and DHA, were increased (+3-fold) in whole muscle, and mitochondrial membranes, and as a result the omega-6/omega-3 ratios were dramatically decreased (-3-fold), while conversely the unsaturation indexes were increased. Intriguingly, before supplementation the unsaturation index (UI) of sarcolemmal membranes was ∼3 times lower (p < 0.001) than either whole muscle or mitochondrial membranes. While supplementation also increased DHA within sarcolemmal membranes, EPA was not altered, and as a result the omega-6/omega-3 ratio and UI of these membranes were not altered. All together, these data revealed that mitochondrial and sarcolemmal membranes display unique phospholipid compositions and responses to FO supplementation.
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Affiliation(s)
- Christopher J Gerling
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Kazutaka Mukai
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Adrian Chabowski
- Department of Physiology, Medical University of Białystok, Białystok, Poland
| | | | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Lawrence L Spriet
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
| | - Sebastian Jannas-Vela
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada.,Exercise Science Laboratory, School of Kinesiology, Faculty of Medicine, Universidad Finis Terrae, Santiago, Chile
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38
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Dirks ML, Smeets JSJ, Holwerda AM, Kouw IWK, Marzuca-Nassr GN, Gijsen AP, Holloway GP, Verdijk LB, van Loon LJC. Dietary feeding pattern does not modulate the loss of muscle mass or the decline in metabolic health during short-term bed rest. Am J Physiol Endocrinol Metab 2019; 316:E536-E545. [PMID: 30645176 DOI: 10.1152/ajpendo.00378.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Short periods of bed rest lead to the loss of muscle mass and quality. It has been speculated that dietary feeding pattern may have an impact upon muscle protein synthesis rates and, therefore, modulate the loss of muscle mass and quality. We subjected 20 healthy men (age: 25 ± 1 yr, body mass index: 23.8 ± 0.8 kg/m2) to 1 wk of strict bed rest with intermittent (4 meals/day) or continuous (24 h/day) enteral tube feeding. Participants consumed deuterium oxide for 7 days before bed rest and throughout the 7-day bed rest period. Prior to and immediately after bed rest, lean body mass (dual energy X-ray absorptiometry), quadriceps cross-sectional area (CSA; CT), maximal oxygen uptake capacity (V̇o2peak), and whole body insulin sensitivity (hyperinsulinemic-euglycemic clamp) were assessed. Muscle biopsies were collected 7 days before, 1 day before, and immediately after bed rest to assess muscle tracer incorporation. Bed rest resulted in 0.3 ± 0.3 vs. 0.7 ± 0.4 kg lean tissue loss and a 1.1 ± 0.6 vs. 0.8 ± 0.5% decline in quadriceps CSA in the intermittent vs. continuous feeding group, respectively (both P < 0.05), with no differences between groups (both P > 0.05). Moreover, feeding pattern did not modulate the bed rest-induced decline in insulin sensitivity (-46 ± 3% vs. 39 ± 3%; P < 0.001) or V̇o2peak (-2.5 ± 2.2 vs. -8.6 ± 2.2%; P < 0.010) (both P > 0.05). Myofibrillar protein synthesis rates during bed rest did not differ between the intermittent and continuous feeding group (1.33 ± 0.07 vs. 1.50 ± 0.13%/day, respectively; P > 0.05). In conclusion, dietary feeding pattern does not modulate the loss of muscle mass or the decline in metabolic health during 1 wk of bed rest in healthy men.
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Affiliation(s)
- Marlou L Dirks
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Joey S J Smeets
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Andrew M Holwerda
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Imre W K Kouw
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Gabriel N Marzuca-Nassr
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Annemie P Gijsen
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Graham P Holloway
- Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Lex B Verdijk
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
| | - Luc J C van Loon
- Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+ , The Netherlands
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39
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Miotto PM, LeBlanc PJ, Holloway GP. High-Fat Diet Causes Mitochondrial Dysfunction as a Result of Impaired ADP Sensitivity. Diabetes 2018; 67:2199-2205. [PMID: 29980534 DOI: 10.2337/db18-0417] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 06/26/2018] [Indexed: 11/13/2022]
Abstract
Although molecular approaches altering mitochondrial content have implied a direct relationship between mitochondrial bioenergetics and insulin sensitivity, paradoxically, consumption of a high-fat (HF) diet increases mitochondrial content while inducing insulin resistance. We hypothesized that despite the induction of mitochondrial biogenesis, consumption of an HF diet would impair mitochondrial ADP sensitivity in skeletal muscle of mice and therefore manifest in mitochondrial dysfunction in the presence of ADP concentrations indicative of skeletal muscle biology. We found that HF consumption increased mitochondrial protein expression; however, absolute mitochondrial respiration and ADP sensitivity were impaired across a range of biologically relevant ADP concentrations. In addition, HF consumption attenuated the ability of ADP to suppress mitochondrial H2O2 emission, further suggesting impairments in ADP sensitivity. The abundance of ADP transport proteins were not altered, but the sensitivity to carboxyatractyloside-mediated inhibition was attenuated after HF consumption, implicating alterations in adenine nucleotide translocase (ANT) ADP sensitivity in these observations. Moreover, palmitoyl-CoA is known to inhibit ANT, and modeling intramuscular palmitoyl-CoA concentrations that occur after HF consumption exacerbated the deficiency in ADP sensitivity. Altogether, these data suggest that an HF diet induces mitochondrial dysfunction secondary to an intrinsic impairment in mitochondrial ADP sensitivity that is magnified by palmitoyl-CoA.
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Affiliation(s)
- Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Paul J LeBlanc
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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40
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Baaten CCFMJ, Moenen FCJI, Henskens YMC, Swieringa F, Wetzels RJH, van Oerle R, Heijnen HFG, Ten Cate H, Holloway GP, Beckers EAM, Heemskerk JWM, van der Meijden PEJ. Impaired mitochondrial activity explains platelet dysfunction in thrombocytopenic cancer patients undergoing chemotherapy. Haematologica 2018; 103:1557-1567. [PMID: 29880611 PMCID: PMC6119160 DOI: 10.3324/haematol.2017.185165] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 06/05/2018] [Indexed: 01/07/2023] Open
Abstract
Severe thrombocytopenia (≤50×109 platelets/L) due to hematological malignancy and intensive chemotherapy is associated with an increased risk of clinically significant bleeding. Since the bleeding risk is not linked to the platelet count only, other hemostatic factors must be involved. We studied platelet function in 77 patients with acute leukemia, multiple myeloma or malignant lymphoma, who experienced chemotherapy-induced thrombocytopenia. Platelets from all patients - independent of disease or treatment type - were to a variable extent compromised in Ca2+ flux, integrin a β activation and P-selectin expression when stimulated with a panelIIbof3 agonists. The patients' platelets were also impaired in spreading on fibrinogen. Whereas the Ca2+ store content was unaffected, the patients' platelets showed ongoing phosphatidylserine exposure, which was not due to apoptotic caspase activity. Interestingly, mitochondrial function was markedly reduced in platelets from a representative subset of patients, as evidenced by a low mitochondrial membrane potential (P<0.001) and low oxygen consumption (P<0.05), while the mitochondrial content was normal. Moreover, the mitochondrial impairments coincided with elevated levels of reactive oxygen species (Spearman's rho=-0.459, P=0.012). Markedly, the impairment of platelet function only appeared after two days of chemotherapy, suggesting origination in the megakaryocytes. In patients with bone marrow recovery, platelet function improved. In conclusion, our findings disclose defective receptor signaling related to impaired mitochondrial bioenergetics, independent of apoptosis, in platelets from cancer patients treated with chemotherapy, explaining the low hemostatic potential of these patients.
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Affiliation(s)
- Constance C F M J Baaten
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, the Netherlands
| | - Floor C J I Moenen
- Department of Hematology, Maastricht University Medical Centre, the Netherlands
| | - Yvonne M C Henskens
- Central Diagnostic Laboratory, Maastricht University Medical Centre, the Netherlands
| | - Frauke Swieringa
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, the Netherlands.,Department of Protein Dynamics, Leibniz Institute for Analytical Sciences - ISAS-e.V., Dortmund, Germany
| | - Rick J H Wetzels
- Central Diagnostic Laboratory, Maastricht University Medical Centre, the Netherlands
| | - René van Oerle
- Central Diagnostic Laboratory, Maastricht University Medical Centre, the Netherlands.,Laboratory for Clinical Thrombosis and Hemostasis, Department of Internal Medicine, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, the Netherlands
| | - Harry F G Heijnen
- Department of Cell Biology and Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, the Netherlands
| | - Hugo Ten Cate
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, the Netherlands.,Laboratory for Clinical Thrombosis and Hemostasis, Department of Internal Medicine, Cardiovascular Research Institute Maastricht, Maastricht University Medical Center, the Netherlands
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Ontario, Canada
| | - Erik A M Beckers
- Department of Hematology, Maastricht University Medical Centre, the Netherlands
| | - Johan W M Heemskerk
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, the Netherlands
| | - Paola E J van der Meijden
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University Medical Centre, the Netherlands
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41
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Abstract
Since the seminal finding almost 50 years ago that exercise training increases mitochondrial content in skeletal muscle, a considerable amount of research has been dedicated to elucidate the mechanisms inducing mitochondrial biogenesis. The discovery of peroxisome proliferator-activated receptor γ co-activator 1α as a major regulator of exercise-induced gene transcription was instrumental in beginning to understand the signals regulating this process. However, almost two decades after its discovery, our understanding of the signals inducing mitochondrial biogenesis remain poorly defined, limiting our insights into possible novel training modalities in elite athletes that can increase the oxidative potential of muscle. In particular, the role of mitochondrial reactive oxygen species has received very little attention; however, several lifestyle interventions associated with an increase in mitochondrial reactive oxygen species coincide with the induction of mitochondrial biogenesis. Furthermore, the diminishing returns of exercise training are associated with reductions in exercise-induced, mitochondrial-derived reactive oxygen species. Therefore, research focused on altering redox signaling in elite athletes may prove to be effective at inducing mitochondrial biogenesis and augmenting training regimes. In the context of exercise performance, the biological effect of increasing mitochondrial content is an attenuated rise in free cytosolic adenosine diphosphate (ADP), and subsequently decreased carbohydrate flux at a given power output. Recent evidence has shown that mitochondrial ADP sensitivity is a regulated process influenced by nutritional interventions, acute exercise, and exercise training. This knowledge raises the potential to improve mitochondrial bioenergetics in the absence of changes in mitochondrial content. Elucidating the mechanisms influencing the acute regulation of mitochondrial ADP sensitivity could have performance benefits in athletes, especially as these individuals display high levels of mitochondria, and therefore are subjects in whom it is notoriously difficult to further induce mitochondrial adaptations. In addition to changes in ADP sensitivity, an increase in mitochondrial coupling would have a similar bioenergetic response, namely a reduction in free cytosolic ADP. While classically the stoichiometry of the electron transport chain has been considered rigid, recent evidence suggests that sodium nitrate can improve the efficiency of this process, creating the potential for dietary sources of nitrate (e.g., beetroot juice) to display similar improvements in exercise performance. The current review focuses on these processes, while also discussing the biological relevance in the context of exercise performance.
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Affiliation(s)
- Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, 491 Gordon St., Guelph, ON, N1G 2W1, Canada.
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42
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Rajna A, Gibling H, Sarr O, Matravadia S, Holloway GP, Mutch DM. Alpha-linolenic acid and linoleic acid differentially regulate the skeletal muscle secretome of obese Zucker rats. Physiol Genomics 2018; 50:580-589. [PMID: 29727591 DOI: 10.1152/physiolgenomics.00038.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Evidence shows that proteins secreted from skeletal muscle influence a broad range of metabolic signaling pathways. We previously reported that essential polyunsaturated fatty acids (PUFA) improved whole-body glucose homeostasis in obese Zucker rats; however, the mechanisms underlying these benefits remain enigmatic. While PUFA and obesity influence skeletal muscle function, their effects on the secretome are unknown. The aim of this work was to determine if improvements in whole-body glucose homeostasis in obese Zucker rats fed diets supplemented with either linoleic acid (LA) or alpha-linolenic acid (ALA) for 12 wk are related to changes in the skeletal muscle secretome. Secreted proteins were identified with a predictive bioinformatic analysis of microarray gene expression from red tibialis anterior skeletal muscle. Approximately 130 genes were differentially expressed (false discovery rate = 0.05) in obese rats compared with lean controls. The expression of 15 genes encoding secreted proteins was differentially regulated in obese controls, obese LA-supplemented, and obese ALA-supplemented rats compared with lean controls. Five secreted proteins ( Col3a1, Col15a1, Pdgfd, Lyz2, and Angptl4) were differentially regulated by LA and ALA. Most notably, ALA supplementation reduced Angptl4 gene expression compared with obese control and obese-LA supplemented rats and reduced circulating ANGPTL4 serum concentrations. ALA also influenced Angptl4 gene expression and ANGPTL4 secretion from differentiated rat L6 myotubes. Altogether, the present data indicate that obesity has a greater global impact on skeletal muscle gene expression than either essential PUFA; however, LA and ALA may exert their metabolic benefits in part by regulating the skeletal muscle secretome.
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Affiliation(s)
- Alex Rajna
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Heather Gibling
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Ousseynou Sarr
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Sarthak Matravadia
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - David M Mutch
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
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43
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Miotto PM, Holloway GP. Exercise-induced reductions in mitochondrial ADP sensitivity contribute to the induction of gene expression and mitochondrial biogenesis through enhanced mitochondrial H 2O 2 emission. Mitochondrion 2018; 46:116-122. [PMID: 29588219 DOI: 10.1016/j.mito.2018.03.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/23/2018] [Accepted: 03/21/2018] [Indexed: 01/04/2023]
Abstract
Acute exercise rapidly induces mitochondrial gene expression, however, the intracellular events regulating this process remain incompletely understood. The purpose of this study was to determine whether reductions in mitochondrial ADP sensitivity during exercise have a biological role in regulating mitochondrial-derived reactive oxygen species (ROS) production and the induction of mitochondrial biogenesis. Mitochondrial creatine kinase wildtype (WT) and knockout (KO) mice have divergent responses in ADP sensitivity during exercise, and we therefore used these mice to determine the relationship between mitochondrial ADP sensitivity, ROS production, and mitochondrial adaptations to exercise. In WT mice, acute exercise reduced mitochondrial ADP respiratory sensitivity and the ability of ADP to suppress ROS production, while increasing mitochondrial gene transcription (PGC-1α, PGC-1β and PDK4). In stark contrast, in KO mice, exercise increased ADP sensitivity, reduced mitochondrial ROS emission, and did not induce gene transcription. Despite the divergence in mRNA responses, exercise similarly induced calcium/calmodulin-dependent protein kinase II (CaMKII) and AMP-activated protein kinase (AMPK) phosphorylation in WT and KO mice, however only WT mice were associated with redox stress (4HNE). These data implicate acute changes in ADP sensitivity in mitochondrial adaptations to exercise. To further examine this we chronically exercise trained mice. While training increased mitochondrial content and reduced ADP sensitivity in WT mice, KO mice did not exhibit adaptations to exercise. Combined, these data suggest that exercise-induced attenuations in mitochondrial ADP sensitivity mediate redox signals that contribute to the induction of acute and chronic mitochondrial adaptations.
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Affiliation(s)
- Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, ON, Canada.
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph N1G 2W1, ON, Canada.
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44
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Whitfield J, Heigenhauser GJF, van Loon LJC, Spriet LL, Tupling AR, Holloway GP. Response. Med Sci Sports Exerc 2018; 50:875. [PMID: 29547496 DOI: 10.1249/mss.0000000000001490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- Jamie Whitfield
- Mary Mackillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, AUSTRALIA Department of Medicine, McMaster University, Hamilton, ON, CANADA Department of Human Movement Sciences, Nutrition and Toxicology Research Institute, Maastricht University, Maastricht, the NETHERLANDS Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA Department of Kinesiology, University of Waterloo, Waterloo, ON, CANADA Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, CANADA
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45
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Miotto PM, McGlory C, Holloway TM, Phillips SM, Holloway GP. Sex differences in mitochondrial respiratory function in human skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2018. [PMID: 29513564 DOI: 10.1152/ajpregu.00025.2018] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mitochondrial bioenergetic contributions to sex differences in human skeletal muscle metabolism remain poorly defined. The primary aim of this study was to determine whether mitochondrial respiratory kinetics differed between healthy young men and women in permeabilized skeletal muscle fibers. While men and women displayed similar ( P > 0.05) maximal respiration rates and abundance of mitochondrial/adenosine diphosphate (ADP) transport proteins, women had lower ( P < 0.05) mitochondrial ADP sensitivity (+30% apparent Km) and absolute respiration rates at a physiologically relevant ADP concentration (100 μM). Moreover, although men and women exhibited similar carnitine palmitoyl transferase-I protein content- and palmitoyl-CoA-supported respiration, women displayed greater sensitivity to malonyl-CoA-mediated respiratory inhibition. These data establish baseline sex differences in mitochondrial bioenergetics and provide the foundation for studying mitochondrial function within the context of metabolic perturbations and diseases that affect men and women differently.
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Affiliation(s)
- Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Chris McGlory
- Department of Kinesiology, McMaster University , Hamilton, Ontario , Canada
| | - Tanya M Holloway
- Department of Kinesiology, McMaster University , Hamilton, Ontario , Canada
| | - Stuart M Phillips
- Department of Kinesiology, McMaster University , Hamilton, Ontario , Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
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46
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Monaco CMF, Miotto PM, Huber JS, van Loon LJC, Simpson JA, Holloway GP. Sodium nitrate supplementation alters mitochondrial H 2O 2 emission but does not improve mitochondrial oxidative metabolism in the heart of healthy rats. Am J Physiol Regul Integr Comp Physiol 2018. [PMID: 29513565 DOI: 10.1152/ajpregu.00275.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Supplementation with dietary inorganic nitrate ([Formula: see text]) is increasingly recognized to confer cardioprotective effects in both healthy and clinical populations. While the mechanism(s) remains ambiguous, in skeletal muscle oral consumption of NaNO3 has been shown to improve mitochondrial efficiency. Whether NaNO3 has similar effects on mitochondria within the heart is unknown. Therefore, we comprehensively investigated the effect of NaNO3 supplementation on in vivo left ventricular (LV) function and mitochondrial bioenergetics. Healthy male Sprague-Dawley rats were supplemented with NaNO3 (1 g/l) in their drinking water for 7 days. Echocardiography and invasive hemodynamics were used to assess LV morphology and function. Blood pressure (BP) was measured by tail-cuff and invasive hemodynamics. Mitochondrial bioenergetics were measured in LV isolated mitochondria and permeabilized muscle fibers by high-resolution respirometry and fluorometry. Nitrate decreased ( P < 0.05) BP, LV end-diastolic pressure, and maximal LV pressure. Rates of LV relaxation (when normalized to mean arterial pressure) tended ( P = 0.13) to be higher with nitrate supplementation. However, nitrate did not alter LV mitochondrial respiration, coupling efficiency, or oxygen affinity in isolated mitochondria or permeabilized muscle fibers. In contrast, nitrate increased ( P < 0.05) the propensity for mitochondrial H2O2 emission in the absence of changes in cellular redox state and decreased the sensitivity of mitochondria to ADP (apparent Km). These results add to the therapeutic potential of nitrate supplementation in cardiovascular diseases and suggest that nitrate may confer these beneficial effects via mitochondrial redox signaling.
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Affiliation(s)
- Cynthia M F Monaco
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Jason S Huber
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Luc J C van Loon
- Department of Human Movement Sciences, Nutrition, and Toxicology, Research Institute Maastricht (NUTRIM), Maastricht University , Maastricht , The Netherlands
| | - Jeremy A Simpson
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
| | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph , Guelph, Ontario , Canada
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47
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Monaco CMF, Proudfoot R, Miotto PM, Herbst EAF, MacPherson REK, Holloway GP. α-linolenic acid supplementation prevents exercise-induced improvements in white adipose tissue mitochondrial bioenergetics and whole-body glucose homeostasis in obese Zucker rats. Diabetologia 2018; 61:433-444. [PMID: 28965129 DOI: 10.1007/s00125-017-4456-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 08/21/2017] [Indexed: 12/15/2022]
Abstract
AIMS/HYPOTHESIS While the underlying mechanisms in the development of insulin resistance remain inconclusive, metabolic dysfunction in both white adipose tissue (WAT) and skeletal muscle have been implicated in the process. Therefore, we investigated the independent and combined effects of α-linolenic acid (ALA) supplementation and exercise training on whole-body glucose homeostasis and mitochondrial bioenergetics within the WAT and skeletal muscle of obese Zucker rats. METHODS We randomly assigned obese Zucker rats to receive a control diet alone or supplemented with ALA and to remain sedentary or undergo exercise training for 4 weeks (CON-Sed, ALA-Sed, CON-Ex and ALA-Ex groups). Whole-body glucose tolerance was determined in response to a glucose load. Mitochondrial content and bioenergetics were examined in skeletal muscle and epididymal WAT (eWAT). Insulin sensitivity and cellular stress were assessed by western blot. RESULTS Exercise training independently improved whole-body glucose tolerance as well as insulin-induced signalling in muscle and WAT. However, the consumption of ALA during exercise training prevented exercise-mediated improvements in whole-body glucose tolerance. ALA consumption did not influence exercise-induced adaptations within skeletal muscle, insulin sensitivity and mitochondrial bioenergetics. In contrast, within eWAT, ALA supplementation attenuated insulin signalling, decreased mitochondrial respiration and increased the fraction of electron leak to reactive oxygen species (ROS). CONCLUSIONS/INTERPRETATION These findings indicate that, in an obese rodent model, consumption of ALA attenuates the favourable adaptive changes of exercise training within eWAT, which consequently impacts whole-body glucose homeostasis. The direct translation to humans, however, remains to be determined.
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Affiliation(s)
- Cynthia M F Monaco
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd East, Guelph, ON, N1G 2W1, Canada
| | - Ross Proudfoot
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd East, Guelph, ON, N1G 2W1, Canada
| | - Paula M Miotto
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd East, Guelph, ON, N1G 2W1, Canada
| | - Eric A F Herbst
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd East, Guelph, ON, N1G 2W1, Canada
| | | | - Graham P Holloway
- Department of Human Health and Nutritional Sciences, University of Guelph, 50 Stone Rd East, Guelph, ON, N1G 2W1, Canada.
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Herbst EAF, George MAJ, Brebner K, Holloway GP, Kane DA. Lactate is oxidized outside of the mitochondrial matrix in rodent brain. Appl Physiol Nutr Metab 2017; 43:467-474. [PMID: 29206478 DOI: 10.1139/apnm-2017-0450] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The nature and existence of mitochondrial lactate oxidation is debated in the literature. Obscuring the issue are disparate findings in isolated mitochondria, as well as relatively low rates of lactate oxidation observed in permeabilized muscle fibres. However, respiration with lactate has yet to be directly assessed in brain tissue with the mitochondrial reticulum intact. To determine if lactate is oxidized in the matrix of brain mitochondria, oxygen consumption was measured in saponin-permeabilized mouse brain cortex samples, and rat prefrontal cortex and hippocampus (dorsal) subregions. While respiration in the presence of ADP and malate increased with the addition of lactate, respiration was maximized following the addition of exogenous NAD+, suggesting maximal lactate metabolism involves extra-matrix lactate dehydrogenase. This was further supported when NAD+-dependent lactate oxidation was significantly decreased with the addition of either low-concentration α-cyano-4-hydroxycinnamate or UK-5099, inhibitors of mitochondrial pyruvate transport. Mitochondrial respiration was comparable between glutamate, pyruvate, and NAD+-dependent lactate oxidation. Results from the current study demonstrate that permeabilized brain is a feasible model for assessing lactate oxidation, and support the interpretation that lactate oxidation occurs outside the mitochondrial matrix in rodent brain.
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Affiliation(s)
- Eric A F Herbst
- a Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Mitchell A J George
- b Department of Human Kinetics, St. Francis Xavier University, Antigonish, NS B2G 2W5, Canada
| | - Karen Brebner
- c Department of Psychology, St. Francis Xavier University, Antigonish, NS B2G 2W5, Canada
| | - Graham P Holloway
- a Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Daniel A Kane
- b Department of Human Kinetics, St. Francis Xavier University, Antigonish, NS B2G 2W5, Canada
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Whitfield J, Paglialunga S, Smith BK, Miotto PM, Simnett G, Robson HL, Jain SS, Herbst EAF, Desjardins EM, Dyck DJ, Spriet LL, Steinberg GR, Holloway GP. Ablating the protein TBC1D1 impairs contraction-induced sarcolemmal glucose transporter 4 redistribution but not insulin-mediated responses in rats. J Biol Chem 2017; 292:16653-16664. [PMID: 28808062 DOI: 10.1074/jbc.m117.806786] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/10/2017] [Indexed: 12/28/2022] Open
Abstract
TBC1 domain family member 1 (TBC1D1), a Rab GTPase-activating protein and paralogue of Akt substrate of 160 kDa (AS160), has been implicated in both insulin- and 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase-mediated glucose transporter type 4 (GLUT4) translocation. However, the role of TBC1D1 in contracting muscle remains ambiguous. We therefore explored the metabolic consequence of ablating TBC1D1 in both resting and contracting skeletal muscles, utilizing a rat TBC1D1 KO model. Although insulin administration rapidly increased (p < 0.05) plasma membrane GLUT4 content in both red and white gastrocnemius muscles, the TBC1D1 ablation did not alter this response nor did it affect whole-body insulin tolerance, suggesting that TBC1D1 is not required for insulin-induced GLUT4 trafficking events. Consistent with findings in other models of altered TBC1D1 protein levels, whole-animal and ex vivo skeletal muscle fat oxidation was increased in the TBC1D1 KO rats. Although there was no change in mitochondrial content in the KO rats, maximal ADP-stimulated respiration was higher in permeabilized muscle fibers, which may contribute to the increased reliance on fatty acids in resting KO animals. Despite this increase in mitochondrial oxidative capacity, run time to exhaustion at various intensities was impaired in the KO rats. Moreover, contraction-induced increases in sarcolemmal GLUT4 content and glucose uptake were lower in the white gastrocnemius of the KO animals. Altogether, our results highlight a critical role for TBC1D1 in exercise tolerance and contraction-mediated translocation of GLUT4 to the plasma membrane in skeletal muscle.
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Affiliation(s)
- Jamie Whitfield
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Sabina Paglialunga
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Brennan K Smith
- Division of Endocrinology and Metabolism, Department of Medicine, and
| | - Paula M Miotto
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Genevieve Simnett
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Holly L Robson
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Swati S Jain
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Eric A F Herbst
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Eric M Desjardins
- Division of Endocrinology and Metabolism, Department of Medicine, and
| | - David J Dyck
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Lawrence L Spriet
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Gregory R Steinberg
- Division of Endocrinology and Metabolism, Department of Medicine, and.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario L8N 3Z5, Canada
| | - Graham P Holloway
- From the Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
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Paglialunga S, Simnett G, Robson H, Hoang M, Pillai R, Arkell AM, Simpson JA, Bonen A, Huising M, Joseph JW, Holloway GP. The Rab-GTPase activating protein, TBC1D1, is critical for maintaining normal glucose homeostasis and β-cell mass. Appl Physiol Nutr Metab 2017; 42:647-655. [DOI: 10.1139/apnm-2016-0585] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Tre-2/USP6, BUB2, cdc16 domain family, member 1 (TBC1D1), a Rab-GTPase activating protein, is a paralogue of AS160, and has been implicated in the canonical insulin-signaling cascade in peripheral tissues. More recently, TBC1D1 was identified in rat and human pancreatic islets; however, the islet function of TBC1D1 remains not fully understood. We examined the role of TBC1D1 in glucose homeostasis and insulin secretion utilizing a rat knockout (KO) model. Chow-fed TBC1D1 KO rats had improved insulin action but impaired glucose-tolerance tests (GTT) and a lower insulin response during an intraperitoneal GTT compared with wild-type (WT) rats. The in vivo data suggest there may be an islet defect. Glucose-stimulated insulin secretion was higher in isolated KO rat islets compared with WT animals, suggesting TBC1D1 is a negative regulator of insulin secretion. Moreover, KO rats displayed reduced β-cell mass, which likely accounts for the impaired whole-body glucose homeostasis. This β-cell mass reduction was associated with increased active caspase 3, and unaltered Ki67 or urocortin 3, suggesting the induction of apoptosis rather than decreased proliferation or dedifferentiation may account for the decline in islet mass. A similar phenotype was observed in TBC1D1 heterozygous animals, highlighting the sensitivity of the pancreas to subtle reductions in TBC1D1 protein. An 8-week pair-fed high-fat diet did not further alter β-cell mass or apoptosis in KO rats, suggesting that dietary lipids per se, do not lead to a further impairment in glucose homeostasis. The present study establishes a fundamental role for TBC1D1 in maintaining in vivo β-cell mass.
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Affiliation(s)
- Sabina Paglialunga
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Genevieve Simnett
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Holly Robson
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Monica Hoang
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Renjitha Pillai
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Alicia M. Arkell
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Jeremy A. Simpson
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Arend Bonen
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
| | - Mark Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences & Department of Physiology & Membrane Biology, School of Medicine, University of California, Davis, California, USA
| | - Jamie W. Joseph
- School of Pharmacy, University of Waterloo, 10A Victoria Street South, Kitchener, ON N2G 1C5, Canada
| | - Graham P. Holloway
- Department of Human Health & Nutritional Sciences, University of Guelph, 50 Stone Rd. East, Guelph, ON N1G 2W1, Canada
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