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Galli RA, Borsboom TC, Gineste C, Brocca L, Rossi M, Hwee DT, Malik FI, Bottinelli R, Gondin J, Pellegrino MA, de Winter JM, Ottenheijm CA. Tirasemtiv enhances submaximal muscle tension in an Acta1:p.Asp286Gly mouse model of nemaline myopathy. J Gen Physiol 2024; 156:e202313471. [PMID: 38376469 PMCID: PMC10876480 DOI: 10.1085/jgp.202313471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 12/01/2023] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Nemaline myopathies are the most common form of congenital myopathies. Variants in ACTA1 (NEM3) comprise 15-25% of all nemaline myopathy cases. Patients harboring variants in ACTA1 present with a heterogeneous disease course characterized by stable or progressive muscle weakness and, in severe cases, respiratory failure and death. To date, no specific treatments are available. Since NEM3 is an actin-based thin filament disease, we tested the ability of tirasemtiv, a fast skeletal muscle troponin activator, to improve skeletal muscle function in a mouse model of NEM3, harboring the patient-based p.Asp286Gly variant in Acta1. Acute and long-term tirasemtiv treatment significantly increased muscle contractile capacity at submaximal stimulation frequencies in both fast-twitch extensor digitorum longus and gastrocnemius muscle, and intermediate-twitch diaphragm muscle in vitro and in vivo. Additionally, long-term tirasemtiv treatment in NEM3 mice resulted in a decreased respiratory rate with preserved minute volume, suggesting more efficient respiration. Altogether, our data support the therapeutic potential of fast skeletal muscle troponin activators in alleviating skeletal muscle weakness in a mouse model of NEM3 caused by the Acta1:p.Asp286Gly variant.
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Affiliation(s)
- Ricardo A. Galli
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health and Tissue Function and Regeneration, Amsterdam, The Netherlands
| | - Tamara C. Borsboom
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
| | | | - Lorenza Brocca
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Maira Rossi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Darren T. Hwee
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA, USA
| | - Fady I. Malik
- Research and Early Development, Cytokinetics Inc., South San Francisco, CA, USA
| | - Roberto Bottinelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- IRCCS Mondino Foundation, Pavia, Italy
| | - Julien Gondin
- Aix-Marseille University, CNRS, CRMBM, Marseille, France
- Institut NeuroMyoGène, Unité Physiopathologie et Génétique du Neurone et du Muscle, Université Claude Bernard Lyon 1, CNRS UMR 5261, INSERM U1315, Université Lyon, Lyon, France
| | | | - Josine M. de Winter
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health and Tissue Function and Regeneration, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure and Arrhythmias, Amsterdam, The Netherlands
| | - Coen A.C. Ottenheijm
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Physiology, Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Pulmonary Hypertension and Atherosclerosis, Amsterdam, The Netherlands
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, USA
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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] [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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Poole DC, Ferguson SK, Musch TI, Porcelli S. Role of nitric oxide in convective and diffusive skeletal microvascular oxygen kinetics. Nitric Oxide 2022; 121:34-44. [PMID: 35123062 DOI: 10.1016/j.niox.2022.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 12/29/2021] [Accepted: 01/27/2022] [Indexed: 10/19/2022]
Abstract
Progress in understanding physiological mechanisms often consists of discrete discoveries made across different models and species. Accordingly, understanding the mechanistic bases for how altering nitric oxide (NO) bioavailability impacts exercise tolerance (or not) depends on integrating information from cellular energetics and contractile regulation through microvascular/vascular control of O2 transport and pulmonary gas exchange. This review adopts state-of-the-art concepts including the intramyocyte power grid, the Wagner conflation of perfusive and diffusive O2 conductances, and the Critical Power/Critical Speed model of exercise tolerance to address how altered NO bioavailability may, or may not, affect physical performance. This question is germane from the elite athlete to the recreational exerciser and particularly the burgeoning heart failure (and other clinical) populations for whom elevating O2 transport and/or exercise capacity translates directly to improved life quality and reduced morbidity and mortality. The dearth of studies in females is also highlighted, and areas of uncertainty and questions for future research are identified.
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Affiliation(s)
- David C Poole
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Scott K Ferguson
- Department of Kinesiology and Exercise Science, University of Hawaii, Hilo, HI, 96720, USA
| | - Timothy I Musch
- Departments of Kinesiology and Anatomy and Physiology, Kansas State University, Manhattan, KS, 66506, USA
| | - Simone Porcelli
- Department of Molecular Medicine, University of Pavia, Pavia, Italy.
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Zhang B, Li P, Li J, Liu X, Wu W. Effect of Oxidative Stress on Diaphragm Dysfunction and Exercise Intervention in Chronic Obstructive Pulmonary Disease. Front Physiol 2021; 12:684453. [PMID: 34163375 PMCID: PMC8215263 DOI: 10.3389/fphys.2021.684453] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 05/10/2021] [Indexed: 11/13/2022] Open
Abstract
Chronic obstructive pulmonary disease (COPD) can cause extrapulmonary injury such as diaphragm dysfunction. Oxidative stress is one of the main factors causing diaphragm dysfunction in COPD. Exercise plays a positive role in the prevention and treatment of diaphragm dysfunction in COPD, and the changes in diaphragm structure and function induced by exercise are closely related to the regulation of oxidative stress. Therefore, on the basis of the review of oxidative stress and the changes in diaphragm structure and function in COPD, this article analyzed the effects of exercise on oxidative stress and diaphragm dysfunction in COPD and explored the possible mechanism by which exercise improves oxidative stress. Studies have found that diaphragm dysfunction in COPD includes the decline of muscle strength, endurance, and activity. Oxidative stress mainly affects the structure and function of the diaphragm in COPD through protein oxidation, protease activation and calcium sensitivity reduction. The effects of exercise on oxidative stress level and diaphragm dysfunction may differ depending on the intensity, duration, and style of exercise. The mechanism of exercise on oxidative stress in the diaphragm of COPD may include improving antioxidant capacity, reducing oxidase activity and improving mitochondrial function.
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Affiliation(s)
- Bingzhi Zhang
- Department of Sports Medicine, Shanghai University of Sport, Shanghai, China
| | - Peijun Li
- Department of Sports Medicine, Shanghai University of Sport, Shanghai, China
| | - Jian Li
- Department of Sports Medicine, Shanghai University of Sport, Shanghai, China
| | - Xiaodan Liu
- School of Rehabilitation Science, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Weibing Wu
- Department of Sports Medicine, Shanghai University of Sport, Shanghai, China
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Olsson H, Al-Saadi J, Oehler D, Pergolizzi J, Magnusson P. Physiological Effects of Beetroot in Athletes and Patients. Cureus 2019; 11:e6355. [PMID: 31938641 PMCID: PMC6952046 DOI: 10.7759/cureus.6355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Dietary supplementation with beetroot juice (BRJ), a naturally rich source of nitrate, is an area of considerable interest to elite athletes as well as recreational exercisers. Nitrate and nitrite have previously been thought of as mainly final elimination products of nitric oxide (NO), but this view has been challenged and evidence indicates that these compounds can be converted to NO in vivo. We conducted a narrative review summarizing the literature regarding evidence of beetroot used as dietary supplement and its effects on training physiology and athletic performance in healthy and diseased populations. The databases PubMed and Web of Science were used to obtain articles. It was evident that BRJ supplementation had an effect on oxygen cost and consumption during exercise by more efficient adenosine triphosphate (ATP) production in combination with lower ATP consumption. However, the effect seems to be dependent on dose and duration. Effect on exercise performance is conflicting, time to exhaustion seems to increase but its effect on time-trial performance needs further elucidation. Ergogenic benefits might depend on individual aerobic fitness level, where individuals with lower fitness level may gain higher benefits regarding athletic performance. Dietary nitrate supplementation appears to have some effect on training performance in patients with peripheral artery disease, heart failure, and chronic pulmonary obstructive disease. However, larger randomized controlled trials are necessary to determine the overall utility of beetroot as a dietary supplement.
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Affiliation(s)
- Hanna Olsson
- Cardiology, Centre for Research and Development Region Gävleborg/Uppsala University, Gävle, SWE
| | - Jonathan Al-Saadi
- Cardiology, Centre for Research and Development Region Gävleborg/Uppsala University, Gävle, SWE
| | - Daniel Oehler
- Cardiology, Pulmonology and Vascular Medicine, University Hospital Düsseldorf, Düsseldorf, DEU
| | | | - Peter Magnusson
- Medicine, Cardiology Research Unit, Karolinska Institutet, Stockholm, SWE
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Lee S, Abel MG, Thomas T, Symons TB, Yates JW. Acute beetroot juice supplementation does not attenuate knee extensor exercise muscle fatigue in a healthy young population. J Exerc Nutrition Biochem 2019; 23:55-62. [PMID: 31010275 PMCID: PMC6477801 DOI: 10.20463/jenb.2019.0008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 03/15/2019] [Accepted: 03/26/2019] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The effect of acute nitrate supplementation on muscle fatigue is largely unknown. This study aimed to evaluate the effect of acute nitrate supplementation on muscle fatigue. METHODS Thirty-five recreationally active subjects consumed 140 ml of beetroot (BR) juice (nitrate: 8 mmol·d-1) or placebo (PL) 12 and 2.5 hours before two exercise sessions. Peak torque was measured during 50 repetitions, at maximal effort, and during concentric knee extensions at 90°·s-1. Blood pressure (BP) was recorded pre- and post-exercise. RESULTS Peak torque, maximum work, rate of fatigue, and rate of work fatigue were similar between the BR and PL conditions. Post-exercise diastolic BP (BR: 67.2 ± 9.8 vs. PL: 64.5 ± 7.9 mmHg, p < 0.05) and mean arterial pressure (BR: 91.6 ± 9.3 vs. PL: 88.8 ± 8.2 mmHg, p < 0.05) were higher with BR supplementation. CONCLUSION These findings suggest that the acute intake of BR juice had no effect on knee extensor muscle strength or fatigue but increased BP in a healthy recreationally active population.
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Affiliation(s)
- Seungyong Lee
- Department of Pathology, Johns Hopkins University School of Medicine, BaltimoreUSA
- Department of Kinesiology and Health Promotion, University of Kentucky, LexingtonUSA
| | - Mark G. Abel
- Department of Kinesiology and Health Promotion, University of Kentucky, LexingtonUSA
| | - Travis Thomas
- College of Health Sciences, University of Kentucky, LexingtonUSA
| | - T. Brock Symons
- Department of Health & Sports Sciences, University of Louisville, LouisvilleUSA
| | - James W. Yates
- Department of Kinesiology and Health Promotion, University of Kentucky, LexingtonUSA
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de Castro TF, de Assis Manoel F, Figueiredo DH, Figueiredo DH, Machado FA. Effects of chronic beetroot juice supplementation on maximum oxygen uptake, velocity associated with maximum oxygen uptake, and peak velocity in recreational runners: a double-blinded, randomized and crossover study. Eur J Appl Physiol 2019; 119:1043-1053. [DOI: 10.1007/s00421-019-04094-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 02/06/2019] [Indexed: 12/17/2022]
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8
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Shannon OM, McGawley K, Nybäck L, Duckworth L, Barlow MJ, Woods D, Siervo M, O'Hara JP. "Beet-ing" the Mountain: A Review of the Physiological and Performance Effects of Dietary Nitrate Supplementation at Simulated and Terrestrial Altitude. Sports Med 2018; 47:2155-2169. [PMID: 28577258 PMCID: PMC5633647 DOI: 10.1007/s40279-017-0744-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Exposure to altitude results in multiple physiological consequences. These include, but are not limited to, a reduced maximal oxygen consumption, drop in arterial oxygen saturation, and increase in muscle metabolic perturbations at a fixed sub-maximal work rate. Exercise capacity during fixed work rate or incremental exercise and time-trial performance are also impaired at altitude relative to sea level. Recently, dietary nitrate (NO3−) supplementation has attracted considerable interest as a nutritional aid during altitude exposure. In this review, we summarise and critically evaluate the physiological and performance effects of dietary NO3− supplementation during exposure to simulated and terrestrial altitude. Previous investigations at simulated altitude indicate that NO3− supplementation may reduce the oxygen cost of exercise, elevate arterial and tissue oxygen saturation, improve muscle metabolic function, and enhance exercise capacity/performance. Conversely, current evidence suggests that NO3− supplementation does not augment the training response at simulated altitude. Few studies have evaluated the effects of NO3− at terrestrial altitude. Current evidence indicates potential improvements in endothelial function at terrestrial altitude following NO3− supplementation. No effects of NO3− supplementation have been observed on oxygen consumption or arterial oxygen saturation at terrestrial altitude, although further research is warranted. Limitations of the present body of literature are discussed, and directions for future research are provided.
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Affiliation(s)
- Oliver Michael Shannon
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK.
| | - Kerry McGawley
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Linn Nybäck
- Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden
| | - Lauren Duckworth
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK
| | - Matthew John Barlow
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK
| | - David Woods
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK.,Defence Medical Services, Royal Centre for Defence Medicine, Birmingham, B152TH, UK
| | - Mario Siervo
- Institute of Cellular Medicine, University of Newcastle, Newcastle upon Tyne, NE45PL, UK
| | - John Paul O'Hara
- Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, LS6 3QS, UK
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Dutka TL, Mollica JP, Lamboley CR, Weerakkody VC, Greening DW, Posterino GS, Murphy RM, Lamb GD. S-nitrosylation and S-glutathionylation of Cys134 on troponin I have opposing competitive actions on Ca2+ sensitivity in rat fast-twitch muscle fibers. Am J Physiol Cell Physiol 2017; 312:C316-C327. [DOI: 10.1152/ajpcell.00334.2016] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 11/22/2022]
Abstract
Nitric oxide is generated in skeletal muscle with activity and decreases Ca2+ sensitivity of the contractile apparatus, putatively by S-nitrosylation of an unidentified protein. We investigated the mechanistic basis of this effect and its relationship to the oxidation-induced increase in Ca2+ sensitivity in mammalian fast-twitch (FT) fibers mediated by S-glutathionylation of Cys134 on fast troponin I (TnIf). Force-[Ca2+] characteristics of the contractile apparatus in mechanically skinned fibers were assessed by direct activation with heavily Ca2+-buffered solutions. Treatment with S-nitrosylating agents, S-nitrosoglutathione (GSNO) or S-nitroso- N-acetyl-penicillamine (SNAP), decreased pCa50 ( = −log10 [Ca2+] at half-maximal activation) by ~−0.07 pCa units in rat and human FT fibers without affecting maximum force, but had no effect on rat and human slow-twitch fibers or toad or chicken FT fibers, which all lack Cys134. The Ca2+ sensitivity decrease was 1) fully reversed with dithiothreitol or reduced glutathione, 2) at least partially reversed with ascorbate, indicative of involvement of S-nitrosylation, and 3) irreversibly blocked by low concentration of the alkylating agent, N-ethylmaleimide (NEM). The biotin-switch assay showed that both GSNO and SNAP treatments caused S-nitrosylation of TnIf. S-glutathionylation pretreatment blocked the effects of S-nitrosylation on Ca2+ sensitivity, and vice-versa. S-nitrosylation pretreatment prevented NEM from irreversibly blocking S-glutathionylation of TnIf and its effects on Ca2+ sensitivity, and likewise S-glutathionylation pretreatment prevented NEM block of S-nitrosylation. Following substitution of TnIf into rat slow-twitch fibers, S-nitrosylation treatment caused decreased Ca2+ sensitivity. These findings demonstrate that S-nitrosylation and S-glutathionylation exert opposing effects on Ca2+ sensitivity in mammalian FT muscle fibers, mediated by competitive actions on Cys134 of TnIf.
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Affiliation(s)
- T. L. Dutka
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - J. P. Mollica
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - C. R. Lamboley
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Melbourne, Victoria, Australia; and
| | - V. C. Weerakkody
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - D. W. Greening
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - G. S. Posterino
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
| | - R. M. Murphy
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - G. D. Lamb
- School of Life Sciences, La Trobe University, Melbourne, Victoria, Australia
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Shannon OM, Duckworth L, Barlow MJ, Woods D, Lara J, Siervo M, O'Hara JP. Dietary nitrate supplementation enhances high-intensity running performance in moderate normobaric hypoxia, independent of aerobic fitness. Nitric Oxide 2016; 59:63-70. [DOI: 10.1016/j.niox.2016.08.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/25/2016] [Accepted: 08/11/2016] [Indexed: 12/31/2022]
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Singh A, Verma S, Singh V, jappa C, Roopa N, Raju P, Singh S. Beetroot Juice Supplementation Increases High Density Lipoprotein-Cholesterol and Reduces Oxidative Stress in Physically Active Individuals. ACTA ACUST UNITED AC 2015. [DOI: 10.6000/1927-5951.2015.05.03.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Abstract
The ability of cells to sense and respond to physical forces has been recognized for decades, but researchers are only beginning to appreciate the fundamental importance of mechanical signals in biology. At the larger scale, there has been increased interest in the collective organization of cells and their ability to produce complex, "emergent" behaviors. Often, these complex behaviors result in tissue-level control mechanisms that manifest as biological oscillators, such as observed in fireflies, heartbeats, and circadian rhythms. In many cases, these complex, collective behaviors are controlled--at least in part--by physical forces imposed on the tissue or created by the cells. Here, we use mathematical simulations to show that two complementary mechanobiological oscillators are sufficient to control fluid transport in the lymphatic system: Ca(2+)-mediated contractions can be triggered by vessel stretch, whereas nitric oxide produced in response to the resulting fluid shear stress causes the lymphatic vessel to relax locally. Our model predicts that the Ca(2+) and NO levels alternate spatiotemporally, establishing complementary feedback loops, and that the resulting phasic contractions drive lymph flow. We show that this mechanism is self-regulating and robust over a range of fluid pressure environments, allowing the lymphatic vessels to provide pumping when needed but remain open when flow can be driven by tissue pressure or gravity. Our simulations accurately reproduce the responses to pressure challenges and signaling pathway manipulations observed experimentally, providing an integrated conceptual framework for lymphatic function.
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13
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Irie T, Sips PY, Kai S, Kida K, Ikeda K, Hirai S, Moazzami K, Jiramongkolchai P, Bloch DB, Doulias PT, Armoundas AA, Kaneki M, Ischiropoulos H, Kranias E, Bloch KD, Stamler JS, Ichinose F. S-Nitrosylation of Calcium-Handling Proteins in Cardiac Adrenergic Signaling and Hypertrophy. Circ Res 2015; 117:793-803. [PMID: 26259881 DOI: 10.1161/circresaha.115.307157] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/10/2015] [Indexed: 01/08/2023]
Abstract
RATIONALE The regulation of calcium (Ca(2+)) homeostasis by β-adrenergic receptor (βAR) activation provides the essential underpinnings of sympathetic regulation of myocardial function, as well as a basis for understanding molecular events that result in hypertrophic signaling and heart failure. Sympathetic stimulation of the βAR not only induces protein phosphorylation but also activates nitric oxide-dependent signaling, which modulates cardiac contractility. Nonetheless, the role of nitric oxide in βAR-dependent regulation of Ca(2+) handling has not yet been explicated fully. OBJECTIVE To elucidate the role of protein S-nitrosylation, a major transducer of nitric oxide bioactivity, on βAR-dependent alterations in cardiomyocyte Ca(2+) handling and hypertrophy. METHODS AND RESULTS Using transgenic mice to titrate the levels of protein S-nitrosylation, we uncovered major roles for protein S-nitrosylation, in general, and for phospholamban and cardiac troponin C S-nitrosylation, in particular, in βAR-dependent regulation of Ca(2+) homeostasis. Notably, S-nitrosylation of phospholamban consequent upon βAR stimulation is necessary for the inhibitory pentamerization of phospholamban, which activates sarcoplasmic reticulum Ca(2+)-ATPase and increases cytosolic Ca(2+) transients. Coincident S-nitrosylation of cardiac troponin C decreases myocardial sensitivity to Ca(2+). During chronic adrenergic stimulation, global reductions in cellular S-nitrosylation mitigate hypertrophic signaling resulting from Ca(2+) overload. CONCLUSIONS S-Nitrosylation operates in concert with phosphorylation to regulate many cardiac Ca(2+)-handling proteins, including phospholamban and cardiac troponin C, thereby playing an essential and previously unrecognized role in cardiac Ca(2+) homeostasis. Manipulation of the S-nitrosylation level may prove therapeutic in heart failure.
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Affiliation(s)
- Tomoya Irie
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Patrick Y Sips
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Shinichi Kai
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Kotaro Kida
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Kohei Ikeda
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Shuichi Hirai
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Kasra Moazzami
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Pawina Jiramongkolchai
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Donald B Bloch
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Paschalis-Thomas Doulias
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Antonis A Armoundas
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Masao Kaneki
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Harry Ischiropoulos
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Evangelia Kranias
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Kenneth D Bloch
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Jonathan S Stamler
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.)
| | - Fumito Ichinose
- From the Anesthesia Center for Critical Care Research, Department of Anesthesia, Critical Care and Pain Medicine (T.I., P.Y.S., S.K., K.K., K.I., S.H., P.J., D.B.B., M.K., K.D.B., F.I.), Cardiovascular Research Center, Division of Cardiology, Department of Medicine (K.M., A.A.A., K.D.B.), and Division of Rheumatology Allergy and Immunology, Department of Medicine (D.B.B.), Massachusetts General Hospital and Harvard Medical School, Boston; Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA (P.Y.S.); Children's Hospital of Philadelphia Research Institute, Department of Pediatrics and Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine at the University of Pennsylvania (P.-T.D., H.I.); Department of Research, Shriners Hospitals for Children (M.K.) and Department of Pharmacology (E.K.), University of Cincinnati College of Medicine, OH; and Institute for Transformative Molecular Medicine, Case Western Reserve University, Harrington Discovery Institute University Hospitals, Cleveland, OH (J.S.S.).
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14
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Miller MS, Callahan DM, Toth MJ. Skeletal muscle myofilament adaptations to aging, disease, and disuse and their effects on whole muscle performance in older adult humans. Front Physiol 2014; 5:369. [PMID: 25309456 PMCID: PMC4176476 DOI: 10.3389/fphys.2014.00369] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 09/07/2014] [Indexed: 12/02/2022] Open
Abstract
Skeletal muscle contractile function declines with aging, disease, and disuse. In vivo muscle contractile function depends on a variety of factors, but force, contractile velocity and power generating capacity ultimately derive from the summed contribution of single muscle fibers. The contractile performance of these fibers are, in turn, dependent upon the isoform and function of myofilament proteins they express, with myosin protein expression and its mechanical and kinetic characteristics playing a predominant role. Alterations in myofilament protein biology, therefore, may contribute to the development of functional limitations and disability in these conditions. Recent studies suggest that these conditions are associated with altered single fiber performance due to decreased expression of myofilament proteins and/or changes in myosin-actin cross-bridge interactions. Furthermore, cellular and myofilament-level adaptations are related to diminished whole muscle and whole body performance. Notably, the effect of these various conditions on myofilament and single fiber function tends to be larger in older women compared to older men, which may partially contribute to their higher rates of disability. To maintain functionality and provide the most appropriate and effective countermeasures to aging, disease, and disuse in both sexes, a more thorough understanding is needed of the contribution of myofilament adaptations to functional disability in older men and women and their contribution to tissue level function and mobility impairment.
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Affiliation(s)
- Mark S Miller
- Department of Kinesiology, School of Public Health and Health Sciences, University of Massachusetts Amherst, MA, USA
| | - Damien M Callahan
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont Burlington, VT, USA
| | - Michael J Toth
- Department of Molecular Physiology and Biophysics, College of Medicine, University of Vermont Burlington, VT, USA ; Department of Medicine, College of Medicine, University of Vermont Burlington, VT, USA
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Muggeridge DJ, Howe CCF, Spendiff O, Pedlar C, James PE, Easton C. A single dose of beetroot juice enhances cycling performance in simulated altitude. Med Sci Sports Exerc 2014; 46:143-50. [PMID: 23846159 DOI: 10.1249/mss.0b013e3182a1dc51] [Citation(s) in RCA: 106] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Increasing nitric oxide bioavailability via supplementation with nitrate-rich beetroot juice (BR) has been shown to attenuate the negative effect of hypoxia on peripheral oxygen saturation and exercise tolerance. PURPOSE We investigated the effects of a single dose of concentrated BR on the physiological responses to submaximal exercise and time trial (TT) performance in trained cyclists exposed to moderate simulated altitude (approximately 2500 m). METHODS Nine competitive amateur male cyclists (age, 28 ± 8 yr; V˙O2peak at altitude, 51.9 ± 5.8 mL·kg·min) completed four exercise trials consisting of an initial graded test to exhaustion and three performance trials on a cycle ergometer. The performance trials comprised 15 min of submaximal steady-state exercise at 60% maximum work rate and a 16.1-km TT. The second and third trials were preceded by ingestion of either 70 mL of BR or nitrate-depleted BR (PLA) 3 h before exercise. RESULTS Plasma nitrate (PLA, 39.1 ± 3.5 µM; BR, 150.5 ± 9.3 µM) and nitrite (PLA, 289.8 ± 27.9 nM; BR, 678.1 ± 103.5 nM) measured immediately before exercise were higher after ingestion of BR compared with that after PLA (P < 0.001, P = 0.004). V˙O2 during steady-state exercise was lower in the BR trial (2542 ± 114 mL·min) than that in the PLA trial (2727 ± 85 mL·min, P = 0.049). TT performance was significantly faster after BR (1664 ± 14 s) than that after PLA (1702 ± 15 s, P = 0.021). CONCLUSION A single dose of BR lowered V˙O2 during submaximal exercise and enhanced TT performance of trained cyclists in normobaric hypoxia. Consequently, ingestion of BR may be a practical and effective ergogenic aid for endurance exercise at altitude.
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Affiliation(s)
- David J Muggeridge
- 1Institute for Clinical Exercise and Health Science, University of the West of Scotland, Hamilton, Scotland, UNITED KINGDOM; 2School of Life Sciences, Kingston University, Kingston upon Thames, England, UNITED KINGDOM; 3School of Sport, Health and Applied Science, St Mary's University College, Twickenham, England, UNITED KINGDOM; and 4Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, Wales, UNITED KINGDOM
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16
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Toth MJ, Miller MS, Callahan DM, Sweeny AP, Nunez I, Grunberg SM, Der-Torossian H, Couch ME, Dittus K. Molecular mechanisms underlying skeletal muscle weakness in human cancer: reduced myosin-actin cross-bridge formation and kinetics. J Appl Physiol (1985) 2013; 114:858-68. [PMID: 23412895 DOI: 10.1152/japplphysiol.01474.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Many patients with cancer experience physical disability following diagnosis, although little is known about the mechanisms underlying these functional deficits. To characterize skeletal muscle adaptations to cancer in humans, we evaluated skeletal muscle structure and contractile function at the molecular, cellular, whole-muscle, and whole-body level in 11 patients with cancer (5 cachectic, 6 noncachectic) and 6 controls without disease. Patients with cancer showed a 25% reduction in knee extensor isometric torque after adjustment for muscle mass (P < 0.05), which was strongly related to diminished power output during a walking endurance test (r = 0.889; P < 0.01). At the cellular level, single fiber isometric tension was reduced in myosin heavy chain (MHC) IIA fibers (P = 0.05) in patients with cancer, which was explained by a reduction (P < 0.05) in the number of strongly bound cross-bridges. In MHC I fibers, myosin-actin cross-bridge kinetics were reduced in patients, as evidenced by an increase in myosin attachment time (P < 0.01); and reductions in another kinetic parameter, myosin rate of force production, predicted reduced knee extensor isometric torque (r = 0.689; P < 0.05). Patients with cancer also exhibited reduced mitochondrial density (-50%; P < 0.001), which was related to increased myosin attachment time in MHC I fibers (r = -0.754; P < 0.01). Finally, no group differences in myofilament protein content or ultrastructure were noted that explained the observed functional alterations. Collectively, our results suggest reductions in myofilament protein function as a potential molecular mechanism contributing to muscle weakness and physical disability in human cancer.
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Affiliation(s)
- Michael J Toth
- Department of Medicine, University of Vermont, College of Medicine, Burlington, VT, USA.
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17
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Fulford J, Winyard PG, Vanhatalo A, Bailey SJ, Blackwell JR, Jones AM. Influence of dietary nitrate supplementation on human skeletal muscle metabolism and force production during maximum voluntary contractions. Pflugers Arch 2013; 465:517-28. [PMID: 23354414 DOI: 10.1007/s00424-013-1220-5] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 01/07/2013] [Accepted: 01/14/2013] [Indexed: 10/27/2022]
Abstract
Dietary nitrate supplementation, which enhances nitric oxide (NO) bioavailability, has previously been shown to contribute to improved exercise performance by reducing both oxygen cost and energy expenditure. In contrast, previous studies have indicated that NO can lower force production in vitro. To examine the role of dietary nitrates in regulating force generation under normal physiological conditions, we undertook an extended nitrate supplementation regime and determined force output and energy cost with a repeated isometric maximum voluntary contraction (MVC) protocol. In a double-blind, randomized, crossover design, eight participants received 0.5 l/day of nitrate-rich (BR) or nitrate-depleted (PL) beetroot juice for 15 days and completed an exercise protocol consisting of 50 MVCs at 2.5 h, 5 days and 15 days after the beginning of the supplementation period. No significant reduction in force output was determined for BR relative to PL for the peak contraction, the mean or the end force, and no significant time effect was found over the course of the supplementation period. There was a reduction in the mean PCr cost of exercise averaged over the BR supplementation trials, but this did not reach statistical significance for end exercise (BR 15.10 ± 4.14 mM, PL 17.10 ± 5.34 mM, P = 0.06) or the mean throughout the protocol (BR 15.96 ± 4.14 mM, PL 17.79 ± 4.51 mM, P = 0.06). However, a significant reduction in PCr cost per unit force output was found for BR at end exercise (P = 0.04). These results indicate that, under normal physiological conditions, increased NO bioavailability is not associated with a reduction of force-generating capability in human skeletal muscle and confirm that nitrate supplementation reduces the PCr cost of force production.
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Affiliation(s)
- Jonathan Fulford
- NIHR Exeter Clinical Research Facility, University of Exeter Medical School, Exeter, UK.
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Sigala I, Zacharatos P, Boulia S, Toumpanakis D, Michailidou T, Parthenis D, Roussos C, Papapetropoulos A, Hussain SN, Vassilakopoulos T. Nitric oxide regulates cytokine induction in the diaphragm in response to inspiratory resistive breathing. J Appl Physiol (1985) 2012; 113:1594-603. [PMID: 22961265 DOI: 10.1152/japplphysiol.00233.2012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Resistive breathing (encountered in chronic obstructive pulmonary disease and asthma) results in cytokine upregulation and decreased nitric oxide (NO) levels in the strenuously contracting diaphragm. NO can regulate gene expression. We hypothesized that endogenously produced NO downregulates cytokine production triggered by strenuous diaphragmatic contraction. Wistar rats treated with vehicle, the nonselective NO synthase inhibitor NG-nitro-l-arginine-methylester (l-NAME), or the NO donor diethylenetriamine-NONOate (DETA) were subjected to inspiratory resistive breathing (IRB; 50% of maximal inspiratory pressure) for 6 h or sham operation. Additional groups of rats were subjected to IRB for 6 h with concurrent administration of l-NAME and inhibitors of NF-κB (BAY-11-7082), ERK1/2 (PD98059), or P38 (SB203580). Inhibition of NO production (with l-NAME) resulted in upregulation of IRB-induced diaphragmatic IL-6, IL-10, IL-2, TNF-α, and IL-1β levels by 50%, 53%, 60%, 47%, and 45%, respectively. In contrast, the NO donor (DETA) attenuated the IRB-induced cytokine upregulation to levels characteristic of quietly breathing animals. l-NAME augmented IRB-induced activation of MAPKs (P38 and ERK1/2) and NF-κB, whereas DETA triggered the opposite effect. NF-κB and ERK1/2 inhibition in l-NAME-treated animals blunted the l-NAME-induced cytokine upregulation except IL-6, whereas P38 inhibition blunted all (including IL-6) cytokine upregulation. NO downregulates IRB-induced cytokine production in the strenuously contracting diaphragm through its action on MAPKs and NF-κB.
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Affiliation(s)
- Ioanna Sigala
- Department of Critical Care and Pulmonary Services, University of Athens Medical School, Evangelismos Hospital, 45-47 Ipsilandou Str., Athens, Greece
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Dutka TL, Verburg E, Larkins N, Hortemo KH, Lunde PK, Sejersted OM, Lamb GD. ROS-mediated decline in maximum Ca2+-activated force in rat skeletal muscle fibers following in vitro and in vivo stimulation. PLoS One 2012; 7:e35226. [PMID: 22629297 PMCID: PMC3358267 DOI: 10.1371/journal.pone.0035226] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/13/2012] [Indexed: 11/22/2022] Open
Abstract
We hypothesised that normal skeletal muscle stimulated intensely either in vitro or in situ would exhibit reactive oxygen species (ROS)-mediated contractile apparatus changes common to many pathophysiological conditions. Isolated soleus (SOL) and extensor digitorum longus (EDL) muscles of the rat were bubbled with 95% O2 and stimulated in vitro at 31°C to give isometric tetani (50 Hz for 0.5 s every 2 s) until maximum force declined to ≤30%. Skinned superficial slow-twitch fibers from the SOL muscles displayed a large reduction (∼41%) in maximum Ca2+-activated specific force (Fmax), with Ca2+-sensitivity unchanged. Fibers from EDL muscles were less affected. The decrease in Fmax in SOL fibers was evidently due to oxidation effects on cysteine residues because it was reversed if the reducing agent DTT was applied prior to activating the fiber. The GSH∶GSSG ratio was ∼3-fold lower in the cytoplasm of superficial fibers from stimulated muscle compared to control, confirming increased oxidant levels. The presence of Tempol and L-NAME during in vitro stimulation prevented reduction in Fmax. Skinned fibers from SOL muscles stimulated in vivo at 37°C with intact blood supply also displayed reduction in Fmax, though to a much smaller extent (∼12%). Thus, fibers from muscles stimulated even with putatively adequate O2 supply display a reversible oxidation-induced decrease in Fmax without change in Ca2+-sensitivity, consistent with action of peroxynitrite (or possibly superoxide) on cysteine residues of the contractile apparatus. Significantly, the changes closely resemble the contractile deficits observed in a range of pathophysiological conditions. These findings highlight how readily muscle experiences ROS-related deficits, and also point to potential difficulties when defining muscle performance and fatigue.
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Affiliation(s)
- Travis L Dutka
- Department of Zoology, La Trobe University, Melbourne, Australia.
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Radak Z, Naito H, Taylor AW, Goto S. Nitric oxide: Is it the cause of muscle soreness? Nitric Oxide 2012; 26:89-94. [DOI: 10.1016/j.niox.2011.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Revised: 12/14/2011] [Accepted: 12/21/2011] [Indexed: 11/25/2022]
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21
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LANSLEY KATHERINEE, WINYARD PAULG, BAILEY STEPHENJ, VANHATALO ANNI, WILKERSON DARYLP, BLACKWELL JAMIER, GILCHRIST MARK, BENJAMIN NIGEL, JONES ANDREWM. Acute Dietary Nitrate Supplementation Improves Cycling Time Trial Performance. Med Sci Sports Exerc 2011; 43:1125-31. [DOI: 10.1249/mss.0b013e31821597b4] [Citation(s) in RCA: 250] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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22
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Makris AC, Sotzios Y, Zhou Z, Makropoulou M, Papapetropoulos N, Zacharatos P, Pyriochou A, Roussos C, Papapetropoulos A, Vassilakopoulos T. Nitric oxide stimulates interleukin-6 production in skeletal myotubes. J Interferon Cytokine Res 2010; 30:321-7. [PMID: 20035621 DOI: 10.1089/jir.2009.0022] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Strenuous exercise leads to the up-regulation of interleukin-6 (IL-6) production and enhanced nitric oxide (NO) release within the contracting skeletal muscles. In this study, we investigated whether NO regulates IL-6 production in C2C12 myotubes. These cells exhibited a concentration-dependent increase in IL-6 production upon stimulation with NO donors (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NONOate), (Z)-1-[N-(3-aminopropyl)-N-(n-propyl)amino]diazen-1-ium-1,2-diolate (PAPA-NONOate), and sodium nitroprusside (SNP). This treatment did not alter cGMP levels nor did the soluble guanylyl cyclase (sGC) inhibitor, 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one(ODQ), alter this response. The NO-independent sGC activator 5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine (BAY41-2272) and cyclic guanosine monophosphate (cGMP) analog 8Br-cGMP failed to induce IL-6 production. Upon exposure to NO donors, we observed an increase in Erk1/2 and p38 MAPK phosphorylation but not in SAPK/JNK. In addition, NO-induced IL-6 release was inhibited in a concentration-dependent fashion by the MEK1/2 inhibitor PD98059 and the p38 MAPK inhibitor SB203580 but not by the SAPK/JNK inhibitor SP600125. We conclude that NO-stimulated IL-6 production in differentiated C2C12 myotubes is cGMP-independent and mediated by activation of MAPK pathways.
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Affiliation(s)
- Anastasia C Makris
- George P. Livanos and Marianthi Simou Laboratories, Department of Critical Care and Pulmonary Services, Evangelismos Hospital, University of Athens Medical School , Athens, Greece
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23
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Changes in contractile properties of skinned single rat soleus and diaphragm fibres after chronic hypoxia. Pflugers Arch 2010; 460:863-73. [PMID: 20697736 DOI: 10.1007/s00424-010-0866-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 07/08/2010] [Accepted: 07/20/2010] [Indexed: 01/03/2023]
Abstract
Hypoxia may be one of the factors underlying muscle dysfunction during ageing and chronic lung and heart failure. Here we tested the hypothesis that chronic hypoxia per se affects contractile properties of single fibres of the soleus and diaphragm muscle. To do this, the force-velocity relationship, rate of force redevelopment and calcium sensitivity of single skinned fibres from normoxic rats and rats exposed to 4 weeks of hypobaric hypoxia (410 mmHg) were investigated. The reduction in maximal force (P(0)) after hypoxia (p=0.031) was more pronounced in type IIa than type I fibres and was mainly attributable to a reduction in fibre cross-sectional area (p=0.044). In type IIa fibres this was aggravated by a reduction in specific tension (p=0.001). The maximal velocity of shortening (V (max)) and shape of the force velocity relation (a/P(0)), however, did not differ between normoxic and hypoxic muscle fibres and the reduction in maximal power of hypoxic fibres (p=0.012) was mainly due to a reduction in P(0). In conclusion, chronic hypoxia causes muscle fibre dysfunction which is not only due to a loss of muscle mass, but also to a diminished force generating capacity of the remaining contractile material. These effects are similar in the soleus and diaphragm muscle, but more pronounced in type IIa than I fibres.
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Bailey SJ, Fulford J, Vanhatalo A, Winyard PG, Blackwell JR, DiMenna FJ, Wilkerson DP, Benjamin N, Jones AM. Dietary nitrate supplementation enhances muscle contractile efficiency during knee-extensor exercise in humans. J Appl Physiol (1985) 2010; 109:135-48. [DOI: 10.1152/japplphysiol.00046.2010] [Citation(s) in RCA: 407] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to elucidate the mechanistic bases for the reported reduction in the O2cost of exercise following short-term dietary nitrate (NO3−) supplementation. In a randomized, double-blind, crossover study, seven men (aged 19–38 yr) consumed 500 ml/day of either nitrate-rich beetroot juice (BR, 5.1 mmol of NO3−/day) or placebo (PL, with negligible nitrate content) for 6 consecutive days, and completed a series of low-intensity and high-intensity “step” exercise tests on the last 3 days for the determination of the muscle metabolic (using31P-MRS) and pulmonary oxygen uptake (V̇o2) responses to exercise. On days 4–6, BR resulted in a significant increase in plasma [nitrite] (mean ± SE, PL 231 ± 76 vs. BR 547 ± 55 nM; P < 0.05). During low-intensity exercise, BR attenuated the reduction in muscle phosphocreatine concentration ([PCr]; PL 8.1 ± 1.2 vs. BR 5.2 ± 0.8 mM; P < 0.05) and the increase in V̇o2(PL 484 ± 41 vs. BR 362 ± 30 ml/min; P < 0.05). During high-intensity exercise, BR reduced the amplitudes of the [PCr] (PL 3.9 ± 1.1 vs. BR 1.6 ± 0.7 mM; P < 0.05) and V̇o2(PL 209 ± 30 vs. BR 100 ± 26 ml/min; P < 0.05) slow components and improved time to exhaustion (PL 586 ± 80 vs. BR 734 ± 109 s; P < 0.01). The total ATP turnover rate was estimated to be less for both low-intensity (PL 296 ± 58 vs. BR 192 ± 38 μM/s; P < 0.05) and high-intensity (PL 607 ± 65 vs. BR 436 ± 43 μM/s; P < 0.05) exercise. Thus the reduced O2cost of exercise following dietary NO3−supplementation appears to be due to a reduced ATP cost of muscle force production. The reduced muscle metabolic perturbation with NO3−supplementation allowed high-intensity exercise to be tolerated for a greater period of time.
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Affiliation(s)
| | - Jonathan Fulford
- Peninsula College of Medicine and Dentistry, St. Luke's Campus, University of Exeter, Exeter, United Kingdom
| | | | - Paul G. Winyard
- Peninsula College of Medicine and Dentistry, St. Luke's Campus, University of Exeter, Exeter, United Kingdom
| | | | | | | | - Nigel Benjamin
- Peninsula College of Medicine and Dentistry, St. Luke's Campus, University of Exeter, Exeter, United Kingdom
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Spencer T, Posterino GS. Sequential effects of GSNO and H2O2 on the Ca2+ sensitivity of the contractile apparatus of fast- and slow-twitch skeletal muscle fibers from the rat. Am J Physiol Cell Physiol 2009; 296:C1015-23. [DOI: 10.1152/ajpcell.00251.2008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reactive oxygen species (ROS), such as hydrogen peroxide (H2O2) and nitric oxide (NO), have been shown to differentially alter the Ca2+ sensitivity of the contractile apparatus of fast-twitch skeletal muscle, leading to the proposal that normal muscle function is controlled by perturbations in the amounts of these two groups of molecules ( 28 ). However, no previous studies have examined whether these opposing actions are retained when the contractile apparatus is subjected to both molecule types. Using mechanically skinned fast- and slow-twitch skeletal muscle fibers of the rat, we compared the effects of sequential addition of nitrosoglutathione (GSNO), a NO donor, and H2O2 on the Ca2+ sensitivity of the contractile apparatus. As expected from previous reports in fast-twitch fibers, when added separately, GSNO (1 mM) reduced the Ca2+ sensitivity of the contractile apparatus, whereas H2O2 (10 mM; added during contractions) increased the Ca2+ sensitivity of the contractile apparatus. When added sequentially to the same fiber, such that the oxidation by one molecule (e.g., GSNO) preceded the oxidation by the other (e.g., H2O2), and vice versa, the individual effects of both molecules on the Ca2+ sensitivity were retained. Interestingly, neither molecule had any effect on the Ca2+ sensitivity of slow-twitch skeletal muscle. The data show that H2O2 and GSNO retain the capacity to independently affect the contractile apparatus to modulate force. Furthermore, the absence of effects in slow-twitch muscle may further explain why this fiber type is relatively insensitive to fatigue.
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Powers SK, Jackson MJ. Exercise-induced oxidative stress: cellular mechanisms and impact on muscle force production. Physiol Rev 2008; 88:1243-76. [PMID: 18923182 DOI: 10.1152/physrev.00031.2007] [Citation(s) in RCA: 1477] [Impact Index Per Article: 92.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The first suggestion that physical exercise results in free radical-mediated damage to tissues appeared in 1978, and the past three decades have resulted in a large growth of knowledge regarding exercise and oxidative stress. Although the sources of oxidant production during exercise continue to be debated, it is now well established that both resting and contracting skeletal muscles produce reactive oxygen species and reactive nitrogen species. Importantly, intense and prolonged exercise can result in oxidative damage to both proteins and lipids in the contracting myocytes. Furthermore, oxidants can modulate a number of cell signaling pathways and regulate the expression of multiple genes in eukaryotic cells. This oxidant-mediated change in gene expression involves changes at transcriptional, mRNA stability, and signal transduction levels. Furthermore, numerous products associated with oxidant-modulated genes have been identified and include antioxidant enzymes, stress proteins, DNA repair proteins, and mitochondrial electron transport proteins. Interestingly, low and physiological levels of reactive oxygen species are required for normal force production in skeletal muscle, but high levels of reactive oxygen species promote contractile dysfunction resulting in muscle weakness and fatigue. Ongoing research continues to probe the mechanisms by which oxidants influence skeletal muscle contractile properties and to explore interventions capable of protecting muscle from oxidant-mediated dysfunction.
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Affiliation(s)
- Scott K Powers
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida 32611, USA.
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van Hees HWH, Li YP, Ottenheijm CAC, Jin B, Pigmans CJC, Linkels M, Dekhuijzen PNR, Heunks LMA. Proteasome inhibition improves diaphragm function in congestive heart failure rats. Am J Physiol Lung Cell Mol Physiol 2008; 294:L1260-8. [PMID: 18424622 DOI: 10.1152/ajplung.00035.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In congestive heart failure (CHF), diaphragm weakness is known to occur and is associated with myosin loss and activation of the ubiquitin-proteasome pathway. The effect of modulating proteasome activity on myosin loss and diaphragm function is unknown. The present study investigated the effect of in vivo proteasome inhibition on myosin loss and diaphragm function in CHF rats. Coronary artery ligation was used as an animal model for CHF. Sham-operated rats served as controls. Animals were treated with the proteasome inhibitor bortezomib (intravenously) or received saline (0.9%) injections. Force generating capacity, cross-bridge cycling kinetics, and myosin content were measured in diaphragm single fibers. Proteasome activity, caspase-3 activity, and MuRF-1 and MAFbx mRNA levels were determined in diaphragm homogenates. Proteasome activities in the diaphragm were significantly reduced by bortezomib. Bortezomib treatment significantly improved diaphragm single fiber force generating capacity (approximately 30-40%) and cross-bridge cycling kinetics (approximately 20%) in CHF. Myosin content was approximately 30% higher in diaphragm fibers from bortezomib-treated CHF rats than saline. Caspase-3 activity was decreased in diaphragm homogenates from bortezomib-treated rats. CHF increased MuRF-1 and MAFbx mRNA expression in the diaphragm, and bortezomib treatment diminished this rise. The present study demonstrates that treatment with a clinically used proteasome inhibitor improves diaphragm function by restoring myosin content in CHF.
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Affiliation(s)
- Hieronymus W H van Hees
- Deptartment of Pulmonary Diseases, Radboud University Medical Centre, Nijmegen, The Netherlands.
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28
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Prochniewicz E, Lowe DA, Spakowicz DJ, Higgins L, O'Conor K, Thompson LV, Ferrington DA, Thomas DD. Functional, structural, and chemical changes in myosin associated with hydrogen peroxide treatment of skeletal muscle fibers. Am J Physiol Cell Physiol 2007; 294:C613-26. [PMID: 18003749 DOI: 10.1152/ajpcell.00232.2007] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To understand the molecular mechanism of oxidation-induced inhibition of muscle contractility, we have studied the effects of hydrogen peroxide on permeabilized rabbit psoas muscle fibers, focusing on changes in myosin purified from these fibers. Oxidation by 5 mM peroxide decreased fiber contractility (isometric force and shortening velocity) without significant changes in the enzymatic activity of myofibrils and isolated myosin. The inhibitory effects were reversed by treating fibers with dithiothreitol. Oxidation by 50 mM peroxide had a more pronounced and irreversible inhibitory effect on fiber contractility and also affected enzymatic activity of myofibrils, myosin, and actomyosin. Peroxide treatment also affected regulation of contractility, resulting in fiber activation in the absence of calcium. Electron paramagnetic resonance of spin-labeled myosin in muscle fibers showed that oxidation increased the fraction of myosin heads in the strong-binding structural state under relaxing conditions (low calcium) but had no effect under activating conditions (high calcium). This change in the distribution of structural states of myosin provides a plausible explanation for the observed changes in both contractile and regulatory functions. Mass spectroscopy analysis showed that 50 mM but not 5 mM peroxide induced oxidative modifications in both isoforms of the essential light chains and in the heavy chain of myosin subfragment 1 by targeting multiple methionine residues. We conclude that 1) inhibition of muscle fiber contractility via oxidation of myosin occurs at high but not low concentrations of peroxide and 2) the inhibitory effects of oxidation suggest a critical and previously unknown role of methionines in myosin function.
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Affiliation(s)
- Ewa Prochniewicz
- Department of Biochemistry, University of Minnesota, Jackson Hall 6-155, 321 Church St., Minneapolis, MN 55455, USA.
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Zhu X, Heunks LMA, Ennen L, Machiels HA, Van Der Heijden HFM, Dekhuijzen PNR. Nitric oxide modulates neuromuscular transmission during hypoxia in rat diaphragm. Muscle Nerve 2006; 33:104-12. [PMID: 16247767 DOI: 10.1002/mus.20445] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Hypoxia impairs neuromuscular transmission in the rat diaphragm. In previous studies, we have shown that nitric oxide (NO) plays a role in force modulation of the diaphragm under hypoxic conditions. The role of NO, a neurotransmitter, on neurotransmission in skeletal muscle under hypoxic conditions is unknown. The effects of the NO synthase (NOS) inhibitor nomega-nitro-L-arginine (L-NNA, 1 mM) and the NO donor spermine NONOate (Sp-NO, 1 mM) were evaluated on neurotransmission failure during nonfatiguing and fatiguing contractions of the rat diaphragm under hypoxic (PO2 approximately 5.8 kPa) and hyperoxic conditions (PO2 approximately 64.0 kPa). Hypoxia impaired force generated by both muscle stimulation at 40 HZ (P40M) and by nerve stimulation at 40 HZ (P40N). The effect of hypoxia in the latter was more pronounced. L-NNA increased P40N whereas Sp-NO decreased P40N during hypoxia. In contrast, neither L-NNA nor Sp-NO affected P40N during hyperoxia. L-NNA only slightly reduced neurotransmission failure during fatiguing contractions under hyperoxic conditions. Consequently, neurotransmission failure assessed by comparing force loss during repetitive nerve simulation and superimposed direct muscle stimulation was more pronounced in hypoxia, which was alleviated by L-NNA and aggravated by Sp-NO. These data provide insight in the underlying mechanisms of hypoxia-induced neurotransmission failure. This is important as respiratory muscle failure may result from hypoxia in vivo.
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Affiliation(s)
- Xiaoping Zhu
- Department of Pulmonary Diseases, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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Baker DJ, Krause DJ, Howlett RA, Hepple RT. Nitric oxide synthase inhibition reduces O2 cost of force development and spares high-energy phosphates following contractions in pump-perfused rat hindlimb muscles. Exp Physiol 2006; 91:581-9. [PMID: 16469818 DOI: 10.1113/expphysiol.2005.032698] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The purpose of the present experiments was to test the hypotheses that: (i) nitric oxide synthase (NOS) inhibition reduces the O2 cost of force development across a range of contractile demands; and (ii) this reduced O2 cost of force development would be reflected in a sparing of intramuscular higher energy phosphates. Rat distal hindlimb muscles were pump perfused in situ and electrically stimulated (200 ms trains with pulses at 100 Hz, each pulse 0.05 ms duration) for 1 min each at 15, 30 and 60 tetani min(-1) and for 2 min at 90 tetani min(-1) in three groups: 0.01 mM adenosine; 1 mM D-NAME and 0.01 mM adenosine (D-NAME); and 1 mM L-NAME and 0.01 mM adenosine (L-NAME). The gastrocnemius-plantaris-soleus muscle group was freeze clamped post-contractions for metabolite analyses. Force was 19% higher and oxygen uptake (VO2) was 20% lower with L-NAME versus adenosine, and there was a 35% reduction in VO2/time-integrated tension versus adenosine and 24% versus D-NAME that was independent of contraction frequency. L-NAME treatment produced a 33% sparing of muscle phosphocreatine (PCr), and intramuscular lactate was no different between groups. In contrast, D-NAME reduced force by 30%, VO2 by 29% and the O2 cost of force development by 15% compared with adenosine, but had no effect on the degree of intramuscular ATP and PCr depletion. These results show that NOS inhibition improved the metabolic efficiency of force development, either by improving the ATP yield for a given O2 consumption or by reducing the ATP cost of force development. In addition, these effects were independent of contraction frequency.
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Affiliation(s)
- David J Baker
- Faculty of Kinesiology, University of Calgary, 2500 University Drive NW, Calgary, Alberta, T2N 1N4, Canada
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Ottenheijm CAC, Heunks LMA, Geraedts MCP, Dekhuijzen PNR. Hypoxia-induced skeletal muscle fiber dysfunction: role for reactive nitrogen species. Am J Physiol Lung Cell Mol Physiol 2005; 290:L127-35. [PMID: 16113049 DOI: 10.1152/ajplung.00073.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Hypoxia impairs skeletal muscle function, but the precise mechanisms are incompletely understood. In hypoxic rat diaphragm muscle, generation of peroxynitrite is elevated. Peroxynitrite and other reactive nitrogen species have been shown to impair contractility of skinned muscle fibers, reflecting contractile protein dysfunction. We hypothesized that hypoxia induces contractile protein dysfunction and that reactive nitrogen species are involved. In addition, we hypothesized that muscle reoxygenation reverses contractile protein dysfunction. In vitro contractility of rat soleus muscle bundles was studied after 30 min of hyperoxia (Po2 approximately 90 kPa), hypoxia (Po2 approximately 5 kPa), hypoxia + 30 microM N(G)-monomethyl-L-arginine (L-NMMA, a nitric oxide synthase inhibitor), hyperoxia + 30 microM L-NMMA, and hypoxia (30 min) + reoxygenation (15 min). One part of the muscle bundle was used for single fiber contractile measurements and the other part for nitrotyrosine detection. In skinned single fibers, maximal Ca2+-activated specific force (Fmax), fraction of strongly attached cross bridges (alphafs), rate constant of force redevelopment (ktr), and myofibrillar Ca2+ sensitivity were determined. Thirty minutes of hypoxia reduced muscle bundle contractility. In the hypoxic group, single fiber Fmax, alphafs, and ktr were significantly reduced compared with hyperoxic, L-NMMA, and reoxygenation groups. Myofibrillar Ca2+ sensitivity was not different between groups. Nitrotyrosine levels were increased in hypoxia compared with all other groups. We concluded that acute hypoxia induces dysfunction of skinned muscle fibers, reflecting contractile protein dysfunction. In addition, our data indicate that reactive nitrogen species play a role in hypoxia-induced contractile protein dysfunction. Reoxygenation of the muscle bundle partially restores bundle contractility but completely reverses contractile protein dysfunction.
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Affiliation(s)
- Coen A C Ottenheijm
- Department of Pulmonary Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
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32
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Ottenheijm CAC, Heunks LMA, Sieck GC, Zhan WZ, Jansen SM, Degens H, de Boo T, Dekhuijzen PNR. Diaphragm dysfunction in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2005; 172:200-5. [PMID: 15849324 PMCID: PMC2718467 DOI: 10.1164/rccm.200502-262oc] [Citation(s) in RCA: 159] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Hypercapnic respiratory failure because of inspiratory muscle weakness is the most important cause of death in chronic obstructive pulmonary disease (COPD). However, the pathophysiology of failure of the diaphragm to generate force in COPD is in part unclear. OBJECTIVES The present study investigated contractile function and myosin heavy chain content of diaphragm muscle single fibers from patients with COPD. METHODS Skinned muscle fibers were isolated from muscle biopsies from the diaphragm of eight patients with mild to moderate COPD and five patients without COPD (mean FEV(1) % predicted, 70 and 100%, respectively). Contractile function of single fibers was assessed, and afterwards, myosin heavy chain content was determined in these fibers. In diaphragm muscle homogenates, the level of ubiquitin-protein conjugation was determined. RESULTS Diaphragm muscle fibers from patients with COPD showed reduced force generation per cross-sectional area, and reduced myosin heavy chain content per half sarcomere. In addition, these fibers had decreased Ca2+ sensitivity of force generation, and slower cross-bridge cycling kinetics. Our observations were present in fibers expressing slow and 2A isoforms of myosin heavy chain. Ubiquitin-protein conjugation was increased in diaphragm muscle homogenates of patients with mild to moderate COPD. CONCLUSIONS Early in the development of COPD, diaphragm fiber contractile function is impaired. Our data suggest that enhanced diaphragm protein degradation through the ubiquitin-proteasome pathway plays a role in loss of contractile protein and, consequently, failure of the diaphragm to generate force.
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Affiliation(s)
- Coen A C Ottenheijm
- Department of Pulmonary Diseases, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands
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Corr DT, Herzog W. Force recovery after activated shortening in whole skeletal muscle: transient and steady-state aspects of force depression. J Appl Physiol (1985) 2005; 99:252-60. [PMID: 15746298 DOI: 10.1152/japplphysiol.00509.2004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The depression of isometric force after active shortening is a well-accepted characteristic of skeletal muscle, yet its mechanisms remain unknown. Although traditionally analyzed at steady state, transient phenomena caused, at least in part, by cross-bridge kinetics may provide novel insight into the mechanisms associated with force depression (FD). To identify the transient aspects of FD and its relation to shortening speed, shortening amplitude, and muscle mechanical work, in situ experiments were conducted in soleus muscle-tendon units of anesthetized cats. The period immediately after shortening, in which force recovers toward steady state, was fit by using an exponential recovery function (R2 > 0.99). Statistical analyses revealed that steady-state FD (FD(ss)) increased with shortening amplitude and mechanical work. This FD(ss) increase was always accompanied by a significant decrease in force recovery rate. Furthermore, a significant reduction in stiffness was observed after all activated shortenings, presumably because of a reduced proportion of attached cross bridges. These results were interpreted with respect to the two most prominent proposed mechanisms of force depression: sarcomere length nonuniformity theory (7, 32) and a stress-induced inhibition of cross-bridge binding in the newly formed actin-myosin overlap zone (14, 28). We hypothesized that the latter could describe both steady-state and transient aspects of FD using a single scalar variable, the mechanical work done during shortening. As either excursion (overlap) or force (stress) is increased, mechanical work increases, and cross-bridge attachment would become more inhibited, as supported by this study in which an increase in mechanical work resulted in a slower recovery to a more depressed steady-state force.
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Affiliation(s)
- David T Corr
- Human Performance Laboratory, Univ. of Calgary, Calgary, AB, Canada.
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Jones AM, Wilkerson DP, Campbell IT. Nitric oxide synthase inhibition with L-NAME reduces maximal oxygen uptake but not gas exchange threshold during incremental cycle exercise in man. J Physiol 2004; 560:329-38. [PMID: 15284344 PMCID: PMC1665192 DOI: 10.1113/jphysiol.2004.065664] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Accepted: 07/28/2004] [Indexed: 12/25/2022] Open
Abstract
We hypothesized that the effective inhibition of nitric oxide synthase (NOS), achieved via systemic infusion of N(G)-nitro-l-arginine methyl ester (l-NAME), would reduce the gas exchange threshold (GET) and the maximal oxygen uptake (V(.)(O(2)max)) during incremental cycle exercise in man if NO is important in the regulation of muscle vasodilatation. Seven healthy males, aged 18-34 years, volunteered to participate in this ethically approved study. On two occasions, the subjects completed an incremental exercise test to exhaustion on an electrically braked cycle ergometer following the infusion of either l-NAME (4 mg kg(-1) in 50 ml saline) or placebo (50 ml saline, CON). At rest, the infusion of l-NAME resulted in a significant increase in mean arterial pressure (MAP; CON vs. l-NAME, 89 +/- 8 vs. 103 +/- 11 mmHg (mean +/- s.d.; P < 0.05)) and a significant reduction in heart rate (HR; CON vs. l-NAME, 60 +/- 12 vs. 51 +/- 8 beats min(-1); P < 0.01). At submaximal work rates, there was no significant difference in V(.)(O(2)) between the conditions and no difference in the GET (CON vs. l-NAME, 1.94 +/- 0.47 vs. 2.01 +/- 0.41 l min(-1)). However, at higher work rates, differences in V(.)(O(2)) between the conditions became more pronounced such that V(.)(O(2)max) was significantly lower with l-NAME (CON vs. l-NAME, 4.02 +/- 0.41 vs. 3.80 +/- 0.34 l min(-1); P < 0.05). The reduction in V(.)(O(2)max) was associated with a reduction in HR(max) (CON vs. l-NAME, 186 +/- 10 vs. 178 +/- 7 beats min(-1); P < 0.01). These results demonstrate that NOS inhibition with l-NAME has no effect on GET but reduces V(.)(O(2)max) during large muscle group exercise in man, presumably by direct or indirect effects on cardiac output and muscle blood flow.
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Affiliation(s)
- Andrew M Jones
- Department of Exercise and Sport Science, Manchester Metropolitan University, Hassall Road, Alsager, ST7 2HL, UK.
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Zhu X, Heunks LMA, Machiels HA, Ennen L, Dekhuijzen PNR. Effects of modulation of nitric oxide on rat diaphragm isotonic contractility during hypoxia. J Appl Physiol (1985) 2003; 94:612-20. [PMID: 12391124 DOI: 10.1152/japplphysiol.00441.2002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Nitric oxide (NO) is essential for optimal myofilament function of the rat diaphragm in vitro during active shortening. Little is known about the role of NO in muscle contraction under hypoxic conditions. Hypoxia might increase the NO synthase (NOS) activity within the rat diaphragm. We hypothesized that NO plays a protective role in isotonic contractile and fatigue properties during hypoxia in vitro. The effects of the NOS inhibitor N(G)-monomethyl-l-arginine (l-NMMA), the NO scavenger hemoglobin, and the NO donor spermine NONOate on shortening velocity, power generation, and isotonic fatigability during hypoxia were evaluated (Po(2) approximately 7 kPa). l-NMMA and hemoglobin slowed the shortening velocity, depressed power generation, and increased isotonic fatigability during hypoxia. The effects of l-NMMA were prevented by coadministration with the NOS substrate l-arginine. Spermine NONOate did not alter isotonic contractile and fatigue properties during hypoxia. These results indicate that endogenous NO is needed for optimal muscle contraction of the rat diaphragm in vitro during hypoxia.
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Affiliation(s)
- Xiaoping Zhu
- Department of Pulmonary Diseases, University Medical Centre Nijmegen, The Netherlands
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