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Lin L, Wang P, Zheng H, Zhong Z, Zhuansun Y, Yang Z, Chen R. RESPIRATORY MECHANICS AND NEURAL RESPIRATORY DRIVE OF UNTREATED GASPING DURING CARDIAC ARREST IN A PORCINE MODEL. Shock 2023; 59:948-954. [PMID: 37018832 DOI: 10.1097/shk.0000000000002127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
ABSTRACT Introduction: Although the effects on hemodynamics of gasping during cardiac arrest (CA) have received a lot of attention, less is known about the respiratory mechanics and physiology of respiration in gasping. This study aimed to investigate the respiratory mechanics and neural respiratory drive of gasping during CA in a porcine model. Method: Pigs weighing 34.9 ± 5.7 kg were anesthetized intravenously. Ventricular fibrillation (VF) was electrically induced and untreated for 10 min. Mechanical ventilation (MV) was ceased immediately after the onset of VF. Hemodynamic and respiratory parameters, pressure signals, diaphragmatic electromyogram data, and blood gas analysis data were recorded. Results: Gasping was observed in all the animals at a significantly lower rate (2-5 gaps/min), with higher tidal volume ( VT ; 0.62 ± 0.19 L, P < 0.01), and with lower expired minute volume (2.51 ± 1.49 L/min, P < 0.001) in comparison with the baseline. The total respiratory cycle time and the expiratory time tended to be lengthened. Statistically significant elevations in transdiaphragmatic pressure, the pressure-time product of diaphragmatic pressure, and the mean of root mean square diaphragmatic electromyogram values (RMSmean) were observed ( P < 0.05, P < 0.05, and P < 0.001, respectively); however, VT /RMSmean and transdiaphragmatic pressure/RMSmean were reduced at all time points. The partial pressure of oxygen showed a continuous decline after VF to reach statistical significance in the 10th minute (9.46 ± 0.96 kPa, P < 0.001), whereas the partial pressure of carbon dioxide tended to first rise and then fall. Conclusions: Gasping during CA was characterized by high VT , extremely low frequency, and prolonged expiratory time, which may improve hypercapnia. During gasping, increased work of breathing and insufficient neuromechanical efficacy of neural respiratory drive suggested the necessity of MV and appropriate management strategies for MV during resuscitation after CA.
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Affiliation(s)
- Lin Lin
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou
| | - Pengfei Wang
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou
| | | | - Zheye Zhong
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou
| | - Yongxun Zhuansun
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou
| | - Zhengfei Yang
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou
| | - Rui Chen
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou
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2
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Olsson K, Cheng AJ, Al-Ameri M, Tardif N, Melin M, Rooyackers O, Lanner JT, Westerblad H, Gustafsson T, Bruton JD, Rullman E. Sphingomyelinase activity promotes atrophy and attenuates force in human muscle fibres and is elevated in heart failure patients. J Cachexia Sarcopenia Muscle 2022; 13:2551-2561. [PMID: 35852046 PMCID: PMC9530516 DOI: 10.1002/jcsm.13029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 01/26/2022] [Accepted: 05/30/2022] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Activation of sphingomyelinase (SMase) as a result of a general inflammatory response has been implicated as a mechanism underlying disease-related loss of skeletal muscle mass and function in several clinical conditions including heart failure. Here, for the first time, we characterize the effects of SMase activity on human muscle fibre contractile function and assess skeletal muscle SMase activity in heart failure patients. METHODS The effects of SMase on force production and intracellular Ca2+ handling were investigated in single intact human muscle fibres. Additional mechanistic studies were performed in single mouse toe muscle fibres. RNA sequencing was performed in human muscle bundles exposed to SMase. Intramuscular SMase activity was measured from heart failure patients (n = 61, age 69 ± 0.8 years, NYHA III-IV, ejection fraction 25 ± 1.0%, peak VO2 14.4 ± 0.6 mL × kg × min) and healthy age-matched control subjects (n = 10, age 71 ± 2.2 years, ejection fraction 60 ± 1.2%, peak VO2 25.8 ± 1.1 mL × kg × min). SMase activity was related to circulatory factors known to be associated with progression and disease severity in heart failure. RESULTS Sphingomyelinase reduced muscle fibre force production (-30%, P < 0.05) by impairing sarcoplasmic reticulum (SR) Ca2+ release (P < 0.05) and reducing myofibrillar Ca2+ sensitivity. In human muscle bundles exposed to SMase, RNA sequencing analysis revealed 180 and 291 genes as up-regulated and down-regulated, respectively, at a FDR of 1%. Gene-set enrichment analysis identified 'proteasome degradation' as an up-regulated pathway (average fold-change 1.1, P = 0.008), while the pathway 'cytoplasmic ribosomal proteins' (average fold-change 0.8, P < 0.0001) and factors involving proliferation of muscle cells (average fold-change 0.8, P = 0.0002) where identified as down-regulated. Intramuscular SMase activity was ~20% higher (P < 0.05) in human heart failure patients than in age-matched healthy controls and was positively correlated with markers of disease severity and progression, and with several circulating inflammatory proteins, including TNF-receptor 1 and 2. In a longitudinal cohort of heart failure patients (n = 6, mean follow-up time 2.5 ± 0.2 years), SMase activity was demonstrated to increase by 30% (P < 0.05) with duration of disease. CONCLUSIONS The present findings implicate activation of skeletal muscle SMase as a mechanism underlying human heart failure-related loss of muscle mass and function. Moreover, our findings strengthen the idea that SMase activation may underpin disease-related loss of muscle mass and function in other clinical conditions, acting as a common patophysiological mechanism for the myopathy often reported in diseases associated with a systemic inflammatory response.
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Affiliation(s)
- Karl Olsson
- Department of Laboratory Medicine, Section of Clinical Physiology, Karolinska Institutet, Huddinge, Sweden
| | - Arthur J Cheng
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden.,Muscle Health Research Centre, School of Kinesiology and Health Science, Faculty of Health, York University, Toronto, Ontario, Canada
| | - Mamdoh Al-Ameri
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Nicolas Tardif
- Division of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Huddinge, Sweden.,Anesthesiology and intensive care, Department of Clinical Science Intervention and Technology (CLINTEC), Karolinska Institutet, Huddinge, Sweden
| | - Michael Melin
- Department of Laboratory Medicine, Section of Clinical Physiology, Karolinska Institutet, Huddinge, Sweden
| | - Olav Rooyackers
- Division of Perioperative Medicine and Intensive Care, Karolinska University Hospital, Huddinge, Sweden.,Anesthesiology and intensive care, Department of Clinical Science Intervention and Technology (CLINTEC), Karolinska Institutet, Huddinge, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden
| | - Thomas Gustafsson
- Department of Laboratory Medicine, Section of Clinical Physiology, Karolinska Institutet and Department of Clinical Physiology Karolinska Univ Hospital, Huddinge, Sweden
| | - Joseph D Bruton
- Department of Physiology and Pharmacology, Biomedicum C5, Karolinska Institutet, Solna, Sweden
| | - Eric Rullman
- Department of Laboratory Medicine, Section of Clinical Physiology, Karolinska Institutet and Department of Clinical Physiology Karolinska Univ Hospital, Huddinge, Sweden
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3
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Eshima H. Influence of Obesity and Type 2 Diabetes on Calcium Handling by Skeletal Muscle: Spotlight on the Sarcoplasmic Reticulum and Mitochondria. Front Physiol 2021; 12:758316. [PMID: 34795598 PMCID: PMC8592904 DOI: 10.3389/fphys.2021.758316] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/14/2021] [Indexed: 12/25/2022] Open
Abstract
Obesity and diabetes have been shown to interfere with energy metabolism and cause peripheral insulin resistance in skeletal muscle. However, recent studies have focused on the effect metabolic insult has on the loss of muscle size, strength, and physical function. Contractile dysfunction has been linked to impaired intracellular Ca2+ concentration ([Ca2+]i) regulation. In skeletal muscle, [Ca2+]i homeostasis is highly regulated by Ca2+ transport across the sarcolemma/plasma membrane, the golgi apparatus, sarcoplasmic reticulum (SR), and mitochondria. Particularly, the SR and or mitochondria play an important role in the fine-tuning of this metabolic process. Recent studies showed that obesity and insulin resistance are associated with interactions between the SR and mitochondrial networks (the dynamic tubular reticulum formed by mitochondria), suggesting that metabolic disorders alter Ca2+ handling by these organelles. These interactions are facilitated by specific membrane proteins, including ion channels. This review considers the impact of metabolic disorders, such as obesity and type 2 diabetes, on the regulation of [Ca2+]i in skeletal muscle. It also discusses the mechanisms by which this occurs, focusing chiefly on the SR and mitochondria networks. A deeper understanding of the effect of metabolic disorders on calcium handling might be useful for therapeutic strategies.
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Affiliation(s)
- Hiroaki Eshima
- Department of International Tourism, Nagasaki International University, Nagasaki, Japan
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Chung HY, Claus RA. Keep Your Friends Close, but Your Enemies Closer: Role of Acid Sphingomyelinase During Infection and Host Response. Front Med (Lausanne) 2021; 7:616500. [PMID: 33553211 PMCID: PMC7859284 DOI: 10.3389/fmed.2020.616500] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022] Open
Abstract
Breakdown of the inert and constitutive membrane building block sphingomyelin to the highly active lipid mediator ceramide by extracellularly active acid sphingomyelinase is tightly regulated during stress response and opens the gate for invading pathogens, triggering the immune response, development of remote organ failure, and tissue repair following severe infection. How do one enzyme and one mediator manage all of these affairs? Under physiological conditions, the enzyme is located in the lysosomes and takes part in the noiseless metabolism of sphingolipids, but following stress the protein is secreted into circulation. When secreted, acid sphingomyelinase (ASM) is able to hydrolyze sphingomyelin present at the outer leaflet of membranes to ceramide. Its generation troubles the biophysical context of cellular membranes resulting in functional assembly and reorganization of proteins and receptors, also embedded in highly conserved response mechanisms. As a consequence of cellular signaling, not only induction of cell death but also proliferation, differentiation, and fibrogenesis are affected. Here, we discuss the current state of the art on both the impact and function of the enzyme during host response and damage control. Also, the potential role of lysosomotropic agents as functional inhibitors of this upstream alarming cascade is highlighted.
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Affiliation(s)
- Ha-Yeun Chung
- Section Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Jena, Germany.,Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Ralf A Claus
- Department for Anaesthesiology and Intensive Care, Jena University Hospital, Jena, Germany
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Straight CR, Toth MJ, Miller MS. Current perspectives on obesity and skeletal muscle contractile function in older adults. J Appl Physiol (1985) 2020; 130:10-16. [PMID: 33211593 DOI: 10.1152/japplphysiol.00739.2020] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Obesity has become one of the most pressing public health issues of the 21st century and currently affects a substantial proportion of the older adult population. Although the cardiometabolic complications are well documented, research from the past 20 years has drawn attention to the detrimental effects of obesity on physical performance in older adults. Obesity-related declines in physical performance are due, in part, to compromised muscle strength and power. Recent evidence suggests there are a number of mechanisms potentially underlying reduced whole muscle function, including alterations in myofilament protein function and cellular contractile properties, and these may be related to morphological adaptations, such as shifts in fiber type composition and increased intramyocellular lipid content within skeletal muscle. To date, even less research has focused on how exercise and weight loss interventions for obese older adults affect these mechanisms. In light of this work, we provide an update on the current knowledge related to obesity and skeletal muscle contractile function and highlight a number of questions to address potential etiologic mechanisms as well as intervention strategies, which may help advance our understanding of how physical performance can be improved among obese older adults.
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Affiliation(s)
- Chad R Straight
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts
| | - Michael J Toth
- Departments of Medicine, Molecular Physiology and Biophysics, and Orthopaedics and Rehabilitation, University of Vermont, Burlington, Vermont
| | - Mark S Miller
- Department of Kinesiology, University of Massachusetts Amherst, Amherst, Massachusetts
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6
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Henríquez-Olguín C, Boronat S, Cabello-Verrugio C, Jaimovich E, Hidalgo E, Jensen TE. The Emerging Roles of Nicotinamide Adenine Dinucleotide Phosphate Oxidase 2 in Skeletal Muscle Redox Signaling and Metabolism. Antioxid Redox Signal 2019; 31:1371-1410. [PMID: 31588777 PMCID: PMC6859696 DOI: 10.1089/ars.2018.7678] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Significance: Skeletal muscle is a crucial tissue to whole-body locomotion and metabolic health. Reactive oxygen species (ROS) have emerged as intracellular messengers participating in both physiological and pathological adaptations in skeletal muscle. A complex interplay between ROS-producing enzymes and antioxidant networks exists in different subcellular compartments of mature skeletal muscle. Recent evidence suggests that nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (NOXs) are a major source of contraction- and insulin-stimulated oxidants production, but they may paradoxically also contribute to muscle insulin resistance and atrophy. Recent Advances: Pharmacological and molecular biological tools, including redox-sensitive probes and transgenic mouse models, have generated novel insights into compartmentalized redox signaling and suggested that NOX2 contributes to redox control of skeletal muscle metabolism. Critical Issues: Major outstanding questions in skeletal muscle include where NOX2 activation occurs under different conditions in health and disease, how NOX2 activation is regulated, how superoxide/hydrogen peroxide generated by NOX2 reaches the cytosol, what the signaling mediators are downstream of NOX2, and the role of NOX2 for different physiological and pathophysiological processes. Future Directions: Future research should utilize and expand the current redox-signaling toolbox to clarify the NOX2-dependent mechanisms in skeletal muscle and determine whether the proposed functions of NOX2 in cells and animal models are conserved into humans.
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Affiliation(s)
- Carlos Henríquez-Olguín
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports (NEXS), Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Muscle Cell Physiology Laboratory, Center for Exercise, Metabolism, and Cancer, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Susanna Boronat
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Claudio Cabello-Verrugio
- Laboratory of Muscle Pathology, Fragility and Aging, Department of Biological Sciences, Faculty of Life Sciences, Universidad Andres Bello, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy, Santiago, Chile.,Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago, Chile
| | - Enrique Jaimovich
- Muscle Cell Physiology Laboratory, Center for Exercise, Metabolism, and Cancer, Instituto de Ciencias Biomédicas, Universidad de Chile, Santiago, Chile
| | - Elena Hidalgo
- Oxidative Stress and Cell Cycle Group, Universitat Pompeu Fabra, Barcelona, Spain
| | - Thomas E Jensen
- Section of Molecular Physiology, Department of Nutrition, Exercise and Sports (NEXS), Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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Coblentz PD, Ahn B, Hayward LF, Yoo JK, Christou DD, Ferreira LF. Small-hairpin RNA and pharmacological targeting of neutral sphingomyelinase prevent diaphragm weakness in rats with heart failure and reduced ejection fraction. Am J Physiol Lung Cell Mol Physiol 2019; 316:L679-L690. [PMID: 30702345 DOI: 10.1152/ajplung.00516.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Heart failure with reduced ejection fraction (HFREF) increases neutral sphingomyelinase (NSMase) activity and mitochondrial reactive oxygen species (ROS) emission and causes diaphragm weakness. We tested whether a systemic pharmacological NSMase inhibitor or short-hairpin RNA (shRNA) targeting NSMase isoform 3 (NSMase3) would prevent diaphragm abnormalities induced by HFREF caused by myocardial infarction. In the pharmacological intervention, we used intraperitoneal injection of GW4869 or vehicle. In the genetic intervention, we injected adeno-associated virus serotype 9 (AAV9) containing shRNA targeting NSMase3 or a scrambled sequence directly into the diaphragm. We also studied acid sphingomyelinase-knockout mice. GW4869 prevented the increase in diaphragm ceramide content, weakness, and tachypnea caused by HFREF. For example, maximal specific forces (in N/cm2) were vehicle [sham 31 ± 2 and HFREF 26 ± 2 ( P < 0.05)] and GW4869 (sham 31 ± 2 and HFREF 31 ± 1). Respiratory rates were (in breaths/min) vehicle [sham 61 ± 3 and HFREF 84 ± 11 ( P < 0.05)] and GW4869 (sham 66 ± 2 and HFREF 72 ± 2). AAV9-NSMase3 shRNA prevented heightening of diaphragm mitochondrial ROS and weakness [in N/cm2, AAV9-scrambled shRNA: sham 31 ± 2 and HFREF 27 ± 2 ( P < 0.05); AAV9-NSMase3 shRNA: sham 30 ± 1 and HFREF 30 ± 1] but displayed tachypnea. Both wild-type and ASMase-knockout mice with HFREF displayed diaphragm weakness. Our study suggests that activation of NSMase3 causes diaphragm weakness in HFREF, presumably through accumulation of ceramide and elevation in mitochondrial ROS. Our data also reveal a novel inhibitory effect of GW4869 on tachypnea in HFREF likely mediated by changes in neural control of breathing.
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Affiliation(s)
- Philip D Coblentz
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida , Gainesville, Florida
| | - Bumsoo Ahn
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida , Gainesville, Florida
| | - Linda F Hayward
- Department of Physiological Sciences, College of Veterinary Medicine, University of Florida , Gainesville, Florida
| | - Jeung-Ki Yoo
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida , Gainesville, Florida
| | - Demetra D Christou
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida , Gainesville, Florida
| | - Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida , Gainesville, Florida
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Diaphragm abnormalities in heart failure and aging: mechanisms and integration of cardiovascular and respiratory pathophysiology. Heart Fail Rev 2018; 22:191-207. [PMID: 27000754 DOI: 10.1007/s10741-016-9549-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Inspiratory function is essential for alveolar ventilation and expulsive behaviors that promote airway clearance (e.g., coughing and sneezing). Current evidence demonstrates that inspiratory dysfunction occurs during healthy aging and is accentuated by chronic heart failure (CHF). This inspiratory dysfunction contributes to key aspects of CHF and aging cardiovascular and pulmonary pathophysiology including: (1) impaired airway clearance and predisposition to pneumonia; (2) inability to sustain ventilation during physical activity; (3) shallow breathing pattern that limits alveolar ventilation and gas exchange; and (4) sympathetic activation that causes cardiac arrhythmias and tissue vasoconstriction. The diaphragm is the primary inspiratory muscle; hence, its neuromuscular integrity is a main determinant of the adequacy of inspiratory function. Mechanistic work within animal and cellular models has revealed specific factors that may be responsible for diaphragm neuromuscular abnormalities in CHF and aging. These include phrenic nerve and neuromuscular junction alterations as well as intrinsic myocyte abnormalities, such as changes in the quantity and quality of contractile proteins, accelerated fiber atrophy, and shifts in fiber type distribution. CHF, aging, or CHF in the presence of aging disturbs the dynamics of circulating factors (e.g., cytokines and angiotensin II) and cell signaling involving sphingolipids, reactive oxygen species, and proteolytic pathways, thus leading to the previously listed abnormalities. Exercise-based rehabilitation combined with pharmacological therapies targeting the pathways reviewed herein hold promise to treat diaphragm abnormalities and inspiratory muscle dysfunction in CHF and aging.
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9
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Gandra PG, Shiah AA, Nogueira L, Hogan MC. A mitochondrial-targeted antioxidant improves myofilament Ca 2+ sensitivity during prolonged low frequency force depression at low PO2. J Physiol 2018; 596:1079-1089. [PMID: 29334129 DOI: 10.1113/jp275470] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 01/08/2018] [Indexed: 12/22/2022] Open
Abstract
KEY POINTS Skeletal muscle contractile activity is associated with an enhanced reactive oxygen species (ROS) generation. At very low PO2, ROS generation by mitochondria can be elevated in intact cells. An elevated intracellular oxidant activity may affect muscle force development and recovery from fatigue. We treated intact single muscle fibres with a mitochondrial antioxidant and stimulated the fibres to contract at a low extracellular PO2 that is similar to the intracellular PO2 that is observed during moderate to intense exercise in vivo. The mitochondrial antioxidant prevented a sustained decrease in the myofibrillar Ca2+ sensitivity and improved muscle submaximal force development after fatigue at low extracellular PO2. ABSTRACT Skeletal muscle can develop a prolonged low frequency-stimulation force depression (PLFFD) following fatigue-inducing contractions. Increased levels of reactive oxygen species (ROS) have been implicated in the development of PLFFD. During exercise the skeletal muscle intracellular PO2 decreases to relatively low levels, and can be further decreased when there is an impairment in O2 diffusion or availability, such as in certain chronic diseases and during exercise at high altitude. Since ROS generation by mitochondria is elevated at very low PO2 in cells, we tested the hypothesis that treatment of muscle fibres with a mitochondrial-targeted antioxidant at a very low, near hypoxic, PO2 can attenuate PLFFD. We treated intact single fibres from mice with the mitochondrial-specific antioxidant SS31, and measured force development and intracellular [Ca2+ ] 30 min after fatigue at an extracellular PO2 of ∼5 Torr. After 30 min following the end of the fatiguing contractions, fibres treated with SS31 showed significantly less impairment in force development compared to untreated fibres at submaximal frequencies of stimulation. The cytosolic peak [Ca2+ ] transients (peak [Ca2+ ]c ) were equally decreased in both groups compared to pre-fatigue values. The combined force and peak [Ca2+ ]c data demonstrated that myofibrillar Ca2+ sensitivity was diminished in the untreated fibres 30 min after fatigue compared to pre-fatigue values, but Ca2+ sensitivity was unaltered in the SS31 treated fibres. These results demonstrate that at a very low PO2, treatment of skeletal muscle fibres with a mitochondrial antioxidant prevents a decrease in the myofibrillar Ca2+ sensitivity, which alleviates the fatigue induced PLFFD.
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Affiliation(s)
- Paulo G Gandra
- Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (Unicamp), Campinas, Brazil.,Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Amy A Shiah
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Leonardo Nogueira
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Department of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Michael C Hogan
- Department of Medicine, University of California San Diego, La Jolla, CA, USA
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10
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Powers SK, Lynch GS, Murphy KT, Reid MB, Zijdewind I. Disease-Induced Skeletal Muscle Atrophy and Fatigue. Med Sci Sports Exerc 2017; 48:2307-2319. [PMID: 27128663 DOI: 10.1249/mss.0000000000000975] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Numerous health problems, including acute critical illness, cancer, diseases associated with chronic inflammation, and neurological disorders, often result in skeletal muscle weakness and fatigue. Disease-related muscle atrophy and fatigue is an important clinical problem because acquired skeletal muscle weakness can increase the duration of hospitalization, result in exercise limitation, and contribute to a poor quality of life. Importantly, skeletal muscle atrophy is also associated with increased morbidity and mortality of patients. Therefore, improving our understanding of the mechanism(s) responsible for skeletal muscle weakness and fatigue in patients is a required first step to develop clinical protocols to prevent these skeletal muscle problems. This review will highlight the consequences and potential mechanisms responsible for skeletal muscle atrophy and fatigue in patients experiencing acute critical illness, cancer, chronic inflammatory diseases, and neurological disorders.
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Affiliation(s)
- Scott K Powers
- 1Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL; 2Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Victoria, AUSTRALIA; and 3Medical Physiology, Department of Neuroscience, University Medical Center Groningen, Groningen, THE NETHERLANDS
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11
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Loell I, Raouf J, Chen YW, Shi R, Nennesmo I, Alexanderson H, Dastmalchi M, Nagaraju K, Korotkova M, Lundberg IE. Effects on muscle tissue remodeling and lipid metabolism in muscle tissue from adult patients with polymyositis or dermatomyositis treated with immunosuppressive agents. Arthritis Res Ther 2016; 18:136. [PMID: 27287443 PMCID: PMC4902919 DOI: 10.1186/s13075-016-1033-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 05/25/2016] [Indexed: 12/24/2022] Open
Abstract
Background Polymyositis (PM) and dermatomyositis (DM) are autoimmune muscle diseases, conventionally treated with high doses of glucocorticoids in combination with immunosuppressive drugs. Treatment is often dissatisfying, with persisting muscle impairment. We aimed to investigate molecular mechanisms that might contribute to the persisting muscle impairment despite immunosuppressive treatment in adult patients with PM or DM using gene expression profiling of repeated muscle biopsies. Methods Paired skeletal muscle biopsies from six newly diagnosed adult patients with DM or PM taken before and after conventional immunosuppressive treatment were examined by gene expression microarray analysis. Selected genes that displayed changes in expression were analyzed by Western blot. Muscle biopsy sections were evaluated for inflammation, T lymphocytes (CD3), macrophages (CD68), major histocompatibility complex (MHC) class I expression and fiber type composition. Results After treatment, genes related to immune response and inflammation, including inflammasome pathways and interferon, were downregulated. This was confirmed at the protein level for AIM-2 and caspase-1 in the inflammasome pathway. Changes in genes involved in muscle tissue remodeling suggested a negative effect on muscle regeneration and growth. Gene markers for fast type II fibers were upregulated and fiber composition was switched towards type II fibers in response to treatment. The expression of genes involved in lipid metabolism was altered, suggesting a potential lipotoxic effect on muscles of the immunosuppressive treatment. Conclusion The anti-inflammatory effect of immunosuppressive treatment was combined with negative effects on genes involved in muscle tissue remodeling and lipid metabolism, suggesting a negative effect on recovery of muscle performance which may contribute to persisting muscle impairment in adult patients with DM and PM.
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Affiliation(s)
- Ingela Loell
- Karolinska Institutet, Department of Medicine, Rheumatology Unit, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Joan Raouf
- Karolinska Institutet, Department of Medicine, Rheumatology Unit, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Yi-Wen Chen
- Childrens National Medical Center, Research Center for Genetic Medicine, Washington, DC, USA
| | - Rongye Shi
- Center for Human Immunology, Autoimmunity and Inflammation, National Heart/Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Inger Nennesmo
- Karolinska University Hospital Huddinge, Institution for Laboratory Medicine (LABMED), Stockholm, Sweden
| | - Helene Alexanderson
- Karolinska Institutet, Department of NVS, Division of Physical Therapy and Karolinska University Hospital Solna, Physical Therapy Clinic, Stockholm, Sweden
| | - Maryam Dastmalchi
- Karolinska Institutet, Department of Medicine, Rheumatology Unit, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Kanneboyina Nagaraju
- Childrens National Medical Center, Research Center for Genetic Medicine, Washington, DC, USA
| | - Marina Korotkova
- Karolinska Institutet, Department of Medicine, Rheumatology Unit, Karolinska University Hospital Solna, Stockholm, Sweden
| | - Ingrid E Lundberg
- Karolinska Institutet, Department of Medicine, Rheumatology Unit, Karolinska University Hospital Solna, Stockholm, Sweden.
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McDonagh B. Editorial: Redox Regulation in Skeletal Muscle Aging and Exercise. Front Physiol 2016; 7:5. [PMID: 26834647 PMCID: PMC4722430 DOI: 10.3389/fphys.2016.00005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/08/2016] [Indexed: 12/21/2022] Open
Affiliation(s)
- Brian McDonagh
- MRC-Arthritis Research UK Centre for Integrated Research into Musculoskeletal Aging, Institute of Ageing and Chronic Disease, University of Liverpool Liverpool, UK
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13
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Gillis TE, Klaiman JM, Foster A, Platt MJ, Huber JS, Corso MY, Simpson JA. Dissecting the role of the myofilament in diaphragm dysfunction during the development of heart failure in mice. Am J Physiol Heart Circ Physiol 2015; 310:H572-86. [PMID: 26702144 DOI: 10.1152/ajpheart.00773.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/21/2015] [Indexed: 11/22/2022]
Abstract
Dyspnea and reduced exercise capacity, caused, in part, by respiratory muscle dysfunction, are common symptoms in patients with heart failure (HF). However, the etiology of diaphragmatic dysfunction has not been identified. To investigate the effects of HF on diaphragmatic function, models of HF were surgically induced in CD-1 mice by transverse aortic constriction (TAC) and acute myocardial infarction (AMI), respectively. Assessment of myocardial function, isolated diaphragmatic strip function, myofilament force-pCa relationship, and phosphorylation status of myofilament proteins was performed at either 2 or 18 wk postsurgery. Echocardiography and invasive hemodynamics revealed development of HF by 18 wk postsurgery in both models. In vitro diaphragmatic force production was preserved in all groups while morphometric analysis revealed diaphragmatic atrophy and fibrosis in 18 wk TAC and AMI groups. Isometric force-pCa measurements of myofilament preparations revealed reduced Ca(2+) sensitivity of force generation and force generation at half-maximum and maximum Ca(2+) activation in 18 wk TAC. The rate of force redevelopment (ktr) was reduced in all HF groups at high levels of Ca(2+) activation. Finally, there were significant changes in the myofilament phosphorylation status of the 18 wk TAC group. This includes a decrease in the phosphorylation of troponin T, desmin, myosin light chain (MLC) 1, and MLC 2 as well as a shift in myosin isoforms. These results indicate that there are multiple changes in diaphragmatic myofilament function, which are specific to the type and stage of HF and occur before overt impairment of in vitro force production.
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Affiliation(s)
- Todd E Gillis
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada; Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and
| | - Jordan M Klaiman
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada; Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and
| | - Andrew Foster
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mathew J Platt
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jason S Huber
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Melissa Y Corso
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Jeremy A Simpson
- Cardiovascular Research Center, University of Guelph, Guelph, Ontario, Canada; and Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
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14
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Frati A, Landi D, Marinelli C, Gianni G, Fontana L, Migliorini M, Pierucci F, Garcia-Gil M, Meacci E. Nutraceutical properties of chestnut flours: beneficial effects on skeletal muscle atrophy. Food Funct 2015; 5:2870-82. [PMID: 25183412 DOI: 10.1039/c4fo00353e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Plants contain a wide range of non-nutritive phytochemicals, many of which have protective or preventive properties for human diseases. The aim of the present work has been to investigate the nutraceutical properties of sweet chestnut flour extracts obtained from fruits collected from 7 geographic areas of Tuscany (Italy), and their ability in modulating skeletal muscle atrophy. We found that the cultivars from different geographic areas are characterized by the composition and quantity of various nutrients and specific bioactive components, such as tocopherols, polyphenols and sphingolipids. The nutraceutical properties of chestnut sweet flours have been evaluated in C2C12 myotubes induced to atrophy by serum deprivation or dexamethasone. We found that the pretreatment with both total extracts of tocopherols and sphingolipids is able to counterbalance cell atrophy, reducing the decrease in myotube size and myonuclei number, and attenuating protein degradation and the increase in expression of MAFbx/atrogin-1 (a muscle-specific atrophy marker). By contrast, polyphenol extracts were not able to prevent atrophy. Since we also found that γ-tocopherol is the major form of tocopherol in sweet flour and its content differs depending on the procedure of sweet flour preparation, the mechanisms by which γ-tocopherol as well as sphingolipids affect skeletal muscle cell atrophy have been also investigated. This is the first evidence that chestnut sweet flour is a natural source of specific bioactive components with a relevant role in the prevention of cell degeneration and maintenance of skeletal muscle mass, opening important implications in designing appropriate nutritional therapeutic approaches to skeletal muscle atrophy.
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Affiliation(s)
- Alessia Frati
- Dept. of Experimental Clinical and Biomedical Sciences, Unit of Biochemical Sciences, University of Florence, Viale GB Morgagni 50, 50134 Florence, Italy.
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15
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Lamboley CR, Wyckelsma VL, Dutka TL, McKenna MJ, Murphy RM, Lamb GD. Contractile properties and sarcoplasmic reticulum calcium content in type I and type II skeletal muscle fibres in active aged humans. J Physiol 2015; 593:2499-514. [PMID: 25809942 DOI: 10.1113/jp270179] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/23/2015] [Indexed: 01/25/2023] Open
Abstract
KEY POINTS Muscle weakness in old age is due in large part to an overall loss of skeletal muscle tissue, but it remains uncertain how much also stems from alterations in the properties of the individual muscle fibres. This study examined the contractile properties and amount of stored intracellular calcium in single muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) adults. The maximum level of force production (per unit cross-sectional area) in fast twitch fibres in Old subjects was lower than in Young subjects, and the fibres were also less sensitive to activation by calcium. The amount of calcium stored inside muscle fibres and available to trigger contraction was also lower in both fast- and slow-twitch muscle fibres in the Old subjects. These findings indicate that muscle weakness in old age stems in part from an impaired capacity for force production in the individual muscle fibres. ABSTRACT This study examined the contractile properties and sarcoplasmic reticulum (SR) Ca(2+) content in mechanically skinned vastus lateralis muscle fibres of Old (70 ± 4 years) and Young (22 ± 3 years) humans to investigate whether changes in muscle fibre properties contribute to muscle weakness in old age. In type II fibres of Old subjects, specific force was reduced by ∼17% and Ca(2+) sensitivity was also reduced (pCa50 decreased ∼0.05 pCa units) relative to that in Young. S-Glutathionylation of fast troponin I (TnIf ) markedly increased Ca(2+) sensitivity in type II fibres, but the increase was significantly smaller in Old versus Young (+0.136 and +0.164 pCa unit increases, respectively). Endogenous and maximal SR Ca(2+) content were significantly smaller in both type I and type II fibres in Old subjects. In fibres of Young, the SR could be nearly fully depleted of Ca(2+) by a combined caffeine and low Mg(2+) stimulus, whereas in fibres of Old the amount of non-releasable Ca(2+) was significantly increased (by > 12% of endogenous Ca(2+) content). Western blotting showed an increased proportion of type I fibres in Old subjects, and increased amounts of calsequestrin-2 and calsequestrin-like protein. The findings suggest that muscle weakness in old age is probably attributable in part to (i) an increased proportion of type I fibres, (ii) a reduction in both maximum specific force and Ca(2+) sensitivity in type II fibres, and also a decreased ability of S-glutathionylation of TnIf to counter the fatiguing effects of metabolites on Ca(2+) sensitivity, and (iii) a reduction in the amount of releasable SR Ca(2+) in both fibre types.
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Affiliation(s)
- C R Lamboley
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia
| | - V L Wyckelsma
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia.,La Trobe Rural Health School, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - T L Dutka
- School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - M J McKenna
- Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, PO Box 14428, Melbourne, Victoria, 8001, Australia
| | - R M Murphy
- School of Molecular Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - G D Lamb
- School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
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16
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Loehr JA, Abo-Zahrah R, Pal R, Rodney GG. Sphingomyelinase promotes oxidant production and skeletal muscle contractile dysfunction through activation of NADPH oxidase. Front Physiol 2015; 5:530. [PMID: 25653619 PMCID: PMC4300905 DOI: 10.3389/fphys.2014.00530] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 12/27/2014] [Indexed: 11/13/2022] Open
Abstract
Elevated concentrations of sphingomyelinase (SMase) have been detected in a variety of diseases. SMase has been shown to increase muscle derived oxidants and decrease skeletal muscle force; however, the sub-cellular site of oxidant production has not been elucidated. Using redox sensitive biosensors targeted to the mitochondria and NADPH oxidase (Nox2), we demonstrate that SMase increased Nox2-dependent ROS and had no effect on mitochondrial ROS in isolated FDB fibers. Pharmacological inhibition and genetic knockdown of Nox2 activity prevented SMase induced ROS production and provided protection against decreased force production in the diaphragm. In contrast, genetic overexpression of superoxide dismutase within the mitochondria did not prevent increased ROS production and offered no protection against decreased diaphragm function in response to SMase. Our study shows that SMase induced ROS production occurs in specific sub-cellular regions of skeletal muscle; however, the increased ROS does not completely account for the decrease in muscle function.
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Affiliation(s)
- James A Loehr
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine Houston, TX, USA
| | - Reem Abo-Zahrah
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine Houston, TX, USA
| | - Rituraj Pal
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine Houston, TX, USA
| | - George G Rodney
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine Houston, TX, USA
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17
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Bost ER, Frye GS, Ahn B, Ferreira LF. Diaphragm dysfunction caused by sphingomyelinase requires the p47(phox) subunit of NADPH oxidase. Respir Physiol Neurobiol 2014; 205:47-52. [PMID: 25448394 DOI: 10.1016/j.resp.2014.10.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 10/19/2014] [Accepted: 10/20/2014] [Indexed: 10/24/2022]
Abstract
Sphingomyelinase (SMase) activity is elevated in inflammatory states and may contribute to muscle weakness in these conditions. Exogenous SMase depresses muscle force in an oxidant-dependent manner. However, the pathway stimulated by SMase that leads to muscle weakness is unclear. In non-muscle cells, SMase activates the Nox2 isoform of NADPH oxidase, which requires the p47(phox) subunit for enzyme function. We targeted p47(phox) genetically and pharmacologically (apocynin) to examine the role of NADPH oxidase on SMase-induced increase in oxidants and diaphragm weakness. SMase increased cytosolic oxidants (arbitrary units: control 203±15, SMase 276±22; P<0.05) and depressed maximal force in wild type mice (N/cm(2): control 20±1, SMase 16±0.6; P<0.05). However, p47(phox) deficient mice were protected from increased oxidants (arbitrary units: control 217±27, SMase 224±17) and loss of force elicited by SMase (N/cm(2): control 20±1, SMase 19±1). Apocynin appeared to partially prevent the decrease in force caused by SMase (n=3 mice/group). Thus, our study suggests that NADPH oxidase plays an important role on oxidant-mediated diaphragm weakness triggered by SMase. These observations provide further evidence that NADPH oxidase modulates skeletal muscle function.
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Affiliation(s)
- Elaina R Bost
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Rd, Rm 100FLG, Gainesville, FL 32611, United States
| | - Gregory S Frye
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Rd, Rm 100FLG, Gainesville, FL 32611, United States
| | - Bumsoo Ahn
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Rd, Rm 100FLG, Gainesville, FL 32611, United States
| | - Leonardo F Ferreira
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, 1864 Stadium Rd, Rm 100FLG, Gainesville, FL 32611, United States.
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18
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Simon JN, Chowdhury SAK, Warren CM, Sadayappan S, Wieczorek DF, Solaro RJ, Wolska BM. Ceramide-mediated depression in cardiomyocyte contractility through PKC activation and modulation of myofilament protein phosphorylation. Basic Res Cardiol 2014; 109:445. [PMID: 25280528 DOI: 10.1007/s00395-014-0445-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 09/25/2014] [Accepted: 09/26/2014] [Indexed: 12/16/2022]
Abstract
Although ceramide accumulation in the heart is considered a major factor in promoting apoptosis and cardiac disorders, including heart failure, lipotoxicity and ischemia-reperfusion injury, little is known about ceramide's role in mediating changes in contractility. In the present study, we measured the functional consequences of acute exposure of isolated field-stimulated adult rat cardiomyocytes to C6-ceramide. Exogenous ceramide treatment depressed the peak amplitude and the maximal velocity of shortening without altering intracellular calcium levels or kinetics. The inactive ceramide analog C6-dihydroceramide had no effect on myocyte shortening or [Ca(2+)]i transients. Experiments testing a potential role for C6-ceramide-mediated effects on activation of protein kinase C (PKC) demonstrated evidence for signaling through the calcium-independent isoform, PKCε. We employed 2-dimensional electrophoresis and anti-phospho-peptide antibodies to test whether treatment of the cardiomyocytes with C6-ceramide altered myocyte shortening via PKC-dependent phosphorylation of myofilament proteins. Compared to controls, myocytes treated with ceramide exhibited increased phosphorylation of myosin binding protein-C (cMyBP-C), specifically at Ser273 and Ser302, and troponin I (cTnI) at sites apart from Ser23/24, which could be attenuated with PKC inhibition. We conclude that the altered myofilament response to calcium resulting from multiple sites of PKC-dependent phosphorylation contributes to contractile dysfunction that is associated with cardiac diseases in which elevations in ceramides are present.
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Affiliation(s)
- Jillian N Simon
- Department of Physiology and Biophysics and Center for Cardiovascular Research, College of Medicine, University of Illinois, Chicago, IL, 60612, USA
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19
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ROS and RNS signaling in skeletal muscle: critical signals and therapeutic targets. ANNUAL REVIEW OF NURSING RESEARCH 2014; 31:367-87. [PMID: 24894146 DOI: 10.1891/0739-6686.31.367] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The health of skeletal muscle is promoted by optimal nutrition and activity/exercise through the activation of molecular signaling pathways. Reactive oxygen species (ROS) or reactive nitrogen species (RNS) have been shown to modulate numerous biochemical processes including glucose uptake, gene expression, calcium signaling, and contractility. In pathological conditions, ROS/RNS signaling excess or dysfunction contributes to contractile dysfunction and myopathy in skeletal muscle. Here we provide a brief review of ROS/RNS chemistry and discuss concepts of ROS/RNS signaling and its role in physiological and pathophysiological processes within striated muscle.
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20
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Defour A, Van der Meulen JH, Bhat R, Bigot A, Bashir R, Nagaraju K, Jaiswal JK. Dysferlin regulates cell membrane repair by facilitating injury-triggered acid sphingomyelinase secretion. Cell Death Dis 2014; 5:e1306. [PMID: 24967968 PMCID: PMC4079937 DOI: 10.1038/cddis.2014.272] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 05/08/2014] [Accepted: 05/20/2014] [Indexed: 01/17/2023]
Abstract
Dysferlin deficiency compromises the repair of injured muscle, but the underlying cellular mechanism remains elusive. To study this phenomenon, we have developed mouse and human myoblast models for dysferlinopathy. These dysferlinopathic myoblasts undergo normal differentiation but have a deficit in their ability to repair focal injury to their cell membrane. Imaging cells undergoing repair showed that dysferlin-deficit decreased the number of lysosomes present at the cell membrane, resulting in a delay and reduction in injury-triggered lysosomal exocytosis. We find repair of injured cells does not involve formation of intracellular membrane patch through lysosome-lysosome fusion; instead, individual lysosomes fuse with the injured cell membrane, releasing acid sphingomyelinase (ASM). ASM secretion was reduced in injured dysferlinopathic cells, and acute treatment with sphingomyelinase restored the repair ability of dysferlinopathic myoblasts and myofibers. Our results provide the mechanism for dysferlin-mediated repair of skeletal muscle sarcolemma and identify ASM as a potential therapy for dysferlinopathy.
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Affiliation(s)
- A Defour
- Center for Genetic Medicine Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - J H Van der Meulen
- Center for Genetic Medicine Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - R Bhat
- Center for Genetic Medicine Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
| | - A Bigot
- Institut de Myologie, UM76 Université Pierre et Marie Curie, U974 INSERM, UMR7215 CNRS, GH Pitié-Salpétrière, 47 bd de l'Hôpital, Paris, France
| | - R Bashir
- School of Biological and Biochemical Sciences, University of Durham, Durham, UK
| | - K Nagaraju
- Center for Genetic Medicine Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
- Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
| | - J K Jaiswal
- Center for Genetic Medicine Research, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC, USA
- Department of Integrative Systems Biology, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
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21
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Empinado HM, Deevska GM, Nikolova-Karakashian M, Yoo JK, Christou DD, Ferreira LF. Diaphragm dysfunction in heart failure is accompanied by increases in neutral sphingomyelinase activity and ceramide content. Eur J Heart Fail 2014; 16:519-25. [PMID: 24596158 DOI: 10.1002/ejhf.73] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 01/18/2014] [Accepted: 01/31/2014] [Indexed: 12/21/2022] Open
Abstract
AIMS Chronic heart failure (CHF) causes inspiratory (diaphragm) muscle weakness and fatigue that contributes to dyspnoea and limited physical capacity in patients. However, the mechanisms that lead to diaphragm dysfunction in CHF remain poorly understood. Cytokines and angiotensin II are elevated in CHF and stimulate the activity of the enzyme sphingomyelinase (SMase) and accumulation of its reaction product ceramide. In the diaphragm, SMase or ceramide exposure in vitro causes weakness and fatigue. Thus, elevated SMase activity and ceramide content have been proposed as mediators of diaphragm dysfunction in CHF. In the present study, we tested the hypotheses that diaphragm dysfunction was accompanied by increases in diaphragm SMase activity and ceramide content. METHODS AND RESULTS Myocardial infarction was used to induce CHF in rats. We measured diaphragm isometric force, SMase activity by high-performance liquid chromatography, and ceramide subspecies and total ceramide using mass spectrometry. Diaphragm force was depressed and fatigue accelerated by CHF. Diaphragm neutral SMase activity was increased by 20% in CHF, while acid SMase activity was unchanged. We also found that CHF increased the content of C18 -, C20 -, and C24 -ceramide subspecies and total ceramide. Downstream of ceramide degradation, diaphragm sphingosine was unchanged, and sphingosine-1-phosphate level was increased in CHF. CONCLUSION Our major novel finding was that diaphragm dysfunction in CHF rats was accompanied by higher diaphragm neutral SMase activity, which is expected to cause the observed increase in diaphragm ceramide content.
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Affiliation(s)
- Hyacinth M Empinado
- Department of Applied Physiology and Kinesiology, College of Health and Human Performance, University of Florida, Gainesville, FL
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22
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Fry CS, Lee JD, Jackson JR, Kirby TJ, Stasko SA, Liu H, Dupont-Versteegden EE, McCarthy JJ, Peterson CA. Regulation of the muscle fiber microenvironment by activated satellite cells during hypertrophy. FASEB J 2013; 28:1654-65. [PMID: 24376025 DOI: 10.1096/fj.13-239426] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Our aim in the current study was to determine the necessity of satellite cells for long-term muscle growth and maintenance. We utilized a transgenic Pax7-DTA mouse model, allowing for the conditional depletion of > 90% of satellite cells with tamoxifen treatment. Synergist ablation surgery, where removal of synergist muscles places functional overload on the plantaris, was used to stimulate robust hypertrophy. Following 8 wk of overload, satellite cell-depleted muscle demonstrated an accumulation of extracellular matrix (ECM) and fibroblast expansion that resulted in reduced specific force of the plantaris. Although the early growth response was normal, an attenuation of hypertrophy measured by both muscle wet weight and fiber cross-sectional area occurred in satellite cell-depleted muscle. Isolated primary myogenic progenitor cells (MPCs) negatively regulated fibroblast ECM mRNA expression in vitro, suggesting a novel role for activated satellite cells/MPCs in muscle adaptation. These results provide evidence that satellite cells regulate the muscle environment during growth.
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Affiliation(s)
- Christopher S Fry
- 1900 S. Limestone, CTW 105, University of Kentucky, Lexington, KY 40536, USA.
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23
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Russ DW, Wills AM, Boyd IM, Krause J. Weakness, SR function and stress in gastrocnemius muscles of aged male rats. Exp Gerontol 2013; 50:40-4. [PMID: 24316040 DOI: 10.1016/j.exger.2013.11.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 11/08/2013] [Accepted: 11/26/2013] [Indexed: 10/25/2022]
Abstract
Aging is associated with a decline in muscle force that exceeds loss of muscle mass, suggesting that factors other than sarcopenia affect age-related muscle weakness. Here, we investigate in situ muscle force and sarcoplasmic reticulum (SR) properties in gastrocnemius muscles of adult (6-8 months) and aged (24 months) rats. Despite minimal loss of muscle mass, peak tetanic force was significantly reduced (-28%) in aged muscles. Adjusting for differences in muscle cross-sectional area mitigated the age difference (-23%), but it remained significant. The SR calcium release function was also impaired (-17%) with aging, although calcium uptake was not, and SR-associated glycogen increased (+30%) with aging. Western blotting revealed age related increases in Grp78, serinepalmitoyltransferase and neutral sphingomyelinase, suggesting that age increased the stress response and ceramide metabolism in the SR. In contrast Parkin, a protein associated with autophagic signaling, was reduced in the aged SR. These findings are consistent with a hypothesis that age-related impairments of the SR, possibly due to impaired autophagy and/or altered membrane metabolism, contribute to age-related muscle weakness, independent of changes in muscle mass.
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Affiliation(s)
- David W Russ
- Division of Physical Therapy, Ohio University, Athens, OH, USA; Ohio Musculoskeletal and Neurological Institute (OMNI), Heritage College of Osteopathic Medicine, Athens, OH, USA.
| | - Allison M Wills
- Division of Physical Therapy, Ohio University, Athens, OH, USA
| | - Iva M Boyd
- Division of Physical Therapy, Ohio University, Athens, OH, USA
| | - Jodi Krause
- Division of Physical Therapy, Ohio University, Athens, OH, USA
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24
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Roberts BM, Ahn B, Smuder AJ, Al-Rajhi M, Gill LC, Beharry AW, Powers SK, Fuller DD, Ferreira LF, Judge AR. Diaphragm and ventilatory dysfunction during cancer cachexia. FASEB J 2013; 27:2600-10. [PMID: 23515443 DOI: 10.1096/fj.12-222844] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cancer cachexia is characterized by a continuous loss of locomotor skeletal muscle mass, which causes profound muscle weakness. If this atrophy and weakness also occurs in diaphragm muscle, it could lead to respiratory failure, which is a major cause of death in patients with cancer. Thus, the purpose of the current study was to determine whether colon-26 (C-26) cancer cachexia causes diaphragm muscle fiber atrophy and weakness and compromises ventilation. All diaphragm muscle fiber types were significantly atrophied in C-26 mice compared to controls, and the atrophy-related genes, atrogin-1 and MuRF1, significantly increased. Maximum isometric specific force of diaphragm strips, absolute maximal calcium activated force, and maximal specific calcium-activated force of permeabilized diaphragm fibers were all significantly decreased in C-26 mice compared to controls. Further, isotonic contractile properties of the diaphragm were affected to an even greater extent than isometric function. Ventilation measurements demonstrated that C-26 mice have a significantly lower tidal volume compared to controls under basal conditions and, unlike control mice, an inability to increase breathing frequency, tidal volume, and, thus, minute ventilation in response to a respiratory challenge. These data demonstrate that C-26 cancer cachexia causes profound respiratory muscle atrophy and weakness and ventilatory dysfunction.
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Affiliation(s)
- Brandon M Roberts
- Department of Physical Therapy, University of Florida, Gainesville, FL 32611, USA
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25
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Lefta M, Campbell KS, Feng HZ, Jin JP, Esser KA. Development of dilated cardiomyopathy in Bmal1-deficient mice. Am J Physiol Heart Circ Physiol 2012; 303:H475-85. [PMID: 22707558 PMCID: PMC3423146 DOI: 10.1152/ajpheart.00238.2012] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Accepted: 06/09/2012] [Indexed: 12/21/2022]
Abstract
Circadian rhythms are approximate 24-h oscillations in physiology and behavior. Circadian rhythm disruption has been associated with increased incidence of hypertension, coronary artery disease, dyslipidemia, and other cardiovascular pathologies in both humans and animal models. Mice lacking the core circadian clock gene, brain and muscle aryl hydrocarbon receptor nuclear translocator (ARNT)-like protein (Bmal1), are behaviorally arrhythmic, die prematurely, and display a wide range of organ pathologies. However, data are lacking on the role of Bmal1 on the structural and functional integrity of cardiac muscle. In the present study, we demonstrate that Bmal1(-/-) mice develop dilated cardiomyopathy with age, characterized by thinning of the myocardial walls, dilation of the left ventricle, and decreased cardiac performance. Shortly after birth the Bmal1(-/-) mice exhibit a transient increase in myocardial weight, followed by regression and later onset of dilation and failure. Ex vivo working heart preparations revealed systolic ventricular dysfunction at the onset of dilation and failure, preceded by downregulation of both myosin heavy chain isoform mRNAs. We observed structural disorganization at the level of the sarcomere with a shift in titin isoform composition toward the stiffer N2B isoform. However, passive tension generation in single cardiomyocytes was not increased. Collectively, these findings suggest that the loss of the circadian clock gene, Bmal1, gives rise to the development of an age-associated dilated cardiomyopathy, which is associated with shifts in titin isoform composition, altered myosin heavy chain gene expression, and disruption of sarcomere structure.
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MESH Headings
- ARNTL Transcription Factors/deficiency
- ARNTL Transcription Factors/genetics
- Age Factors
- Aging
- Animals
- Cardiomyopathy, Dilated/diagnostic imaging
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/physiopathology
- Connectin
- Disease Progression
- Gene Expression Regulation
- Heart Failure/metabolism
- Heart Failure/physiopathology
- Hypertrophy, Left Ventricular/metabolism
- Hypertrophy, Left Ventricular/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle Proteins/metabolism
- Myocardial Contraction
- Myocardium/metabolism
- Myocardium/pathology
- Myosin Heavy Chains/genetics
- Myosin Heavy Chains/metabolism
- Protein Kinases/metabolism
- RNA, Messenger/metabolism
- Sarcomeres/metabolism
- Sarcomeres/pathology
- Stroke Volume
- Ultrasonography
- Ventricular Dysfunction, Left/metabolism
- Ventricular Dysfunction, Left/physiopathology
- Ventricular Function, Left
- Ventricular Pressure
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Affiliation(s)
- Mellani Lefta
- Center for Muscle Biology, University of Kentucky, Lexington, Kentucky 40536, USA
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