51
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Mankhong S, Kim S, Moon S, Kwak HB, Park DH, Kang JH. Experimental Models of Sarcopenia: Bridging Molecular Mechanism and Therapeutic Strategy. Cells 2020; 9:E1385. [PMID: 32498474 PMCID: PMC7348939 DOI: 10.3390/cells9061385] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 12/15/2022] Open
Abstract
Sarcopenia has been defined as a progressive decline of skeletal muscle mass, strength, and functions in elderly people. It is accompanied by physical frailty, functional disability, falls, hospitalization, and mortality, and is becoming a major geriatric disorder owing to the increasing life expectancy and growing older population worldwide. Experimental models are critical to understand the pathophysiology of sarcopenia and develop therapeutic strategies. Although its etiologies remain to be further elucidated, several mechanisms of sarcopenia have been identified, including cellular senescence, proteostasis imbalance, oxidative stress, and "inflammaging." In this article, we address three main aspects. First, we describe the fundamental aging mechanisms. Next, we discuss both in vitro and in vivo experimental models based on molecular mechanisms that have the potential to elucidate the biochemical processes integral to sarcopenia. The use of appropriate models to reflect sarcopenia and/or its underlying pathways will enable researchers to understand sarcopenia and develop novel therapeutic strategies for sarcopenia. Lastly, we discuss the possible molecular targets and the current status of drug candidates for sarcopenia treatment. In conclusion, the development of experimental models for sarcopenia is essential to discover molecular targets that are valuable as biochemical biomarkers and/or therapeutic targets for sarcopenia.
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Affiliation(s)
- Sakulrat Mankhong
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
| | - Sujin Kim
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Department of Kinesiology, Inha University, Incheon 22212, Korea; (H.-B.K.); (D.-H.P.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
| | - Sohee Moon
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
| | - Hyo-Bum Kwak
- Department of Kinesiology, Inha University, Incheon 22212, Korea; (H.-B.K.); (D.-H.P.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
| | - Dong-Ho Park
- Department of Kinesiology, Inha University, Incheon 22212, Korea; (H.-B.K.); (D.-H.P.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
| | - Ju-Hee Kang
- Department of Pharmacology, Hypoxia-related Disease Research Center, College of Medicine, Inha University, Incheon 22212, Korea; (S.M.); (S.K.); (S.M.)
- Institute of Sports & Arts Convergence (ISAC), Inha University, Incheon 22212, Korea
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52
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Molecular changes in transcription and metabolic pathways underlying muscle atrophy in the CuZnSOD null mouse model of sarcopenia. GeroScience 2020; 42:1101-1118. [PMID: 32394347 DOI: 10.1007/s11357-020-00189-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/02/2020] [Indexed: 12/19/2022] Open
Abstract
Mice lacking the superoxide anion scavenger CuZn superoxide dismutase (Sod1-/- mice) develop a number of age-related phenotypes, including an early progression of muscle atrophy and weakness (sarcopenia) associated with loss of innervation. The purpose of this study was to delineate the early development of sarcopenia in the Sod1-/- mice and to measure changes in the muscle transcriptome, proteome, and eicosanoid profile at the stage when sarcopenia is markedly induced in this model (7-9 months of age). We found a strong correlation between muscle atrophy and mitochondrial state 1 hydroperoxide production, which was 40% higher in isolated mitochondria from Sod1-/- mouse gastrocnemius muscle by 2 months of age. The primary pathways showing altered gene expression in Sod1-/- mice identified by RNA-seq transcriptomic analysis are protein ubiquitination, synaptic long-term potentiation, calcium signaling, phospholipase C signaling, AMPK, and TWEAK signaling. Targeted proteomics shows elevated expression of mitochondrial proteins, fatty acid metabolism enzymes, tricarboxylic acid (TCA) cycle enzymes, and antioxidants, while enzymes involved in carbohydrate metabolism are downregulated in Sod1-/- mice. LC-MS analysis of lipids in gastrocnemius muscle detected 78 eicosanoids, of which 31 are significantly elevated in muscle from Sod1-/- mice. These data suggest that mitochondrial hydroperoxide generation is elevated prior to muscle atrophy and may be a potential driving factor of changes in the transcriptome, proteome, and eicosanoid profile of the Sod1-/- mice. Together, these analyses revealed important molecular events that occur during muscle atrophy, which will pave the way for future studies using new approaches to treat sarcopenia.
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53
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Qaisar R, Karim A, Elmoselhi AB. Muscle unloading: A comparison between spaceflight and ground-based models. Acta Physiol (Oxf) 2020; 228:e13431. [PMID: 31840423 DOI: 10.1111/apha.13431] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 12/09/2019] [Accepted: 12/12/2019] [Indexed: 12/12/2022]
Abstract
Prolonged unloading of skeletal muscle, a common outcome of events such as spaceflight, bed rest and hindlimb unloading, can result in extensive metabolic, structural and functional changes in muscle fibres. With advancement in investigations of cellular and molecular mechanisms, understanding of disuse muscle atrophy has significantly increased. However, substantial gaps exist in our understanding of the processes dictating muscle plasticity during unloading, which prevent us from developing effective interventions to combat muscle loss. This review aims to update the status of knowledge and underlying mechanisms leading to cellular and molecular changes in skeletal muscle during unloading. We have also discussed advances in the understanding of contractile dysfunction during spaceflights and in ground-based models of muscle unloading. Additionally, we have elaborated on potential therapeutic interventions that show promising results in boosting muscle mass and strength during mechanical unloading. Finally, we have identified key gaps in our knowledge as well as possible research direction for the future.
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Affiliation(s)
- Rizwan Qaisar
- Department of Basic Medical Sciences College of Medicine University of Sharjah Sharjah UAE
| | - Asima Karim
- Department of Basic Medical Sciences College of Medicine University of Sharjah Sharjah UAE
| | - Adel B. Elmoselhi
- Department of Basic Medical Sciences College of Medicine University of Sharjah Sharjah UAE
- Department of Physiology Michigan State University East Lansing MI USA
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54
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Pharaoh G, Owen D, Yeganeh A, Premkumar P, Farley J, Bhaskaran S, Ashpole N, Kinter M, Van Remmen H, Logan S. Disparate Central and Peripheral Effects of Circulating IGF-1 Deficiency on Tissue Mitochondrial Function. Mol Neurobiol 2019; 57:1317-1331. [PMID: 31732912 PMCID: PMC7060968 DOI: 10.1007/s12035-019-01821-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Abstract
Age-related decline in circulating levels of insulin-like growth factor (IGF)-1 is associated with reduced cognitive function, neuronal aging, and neurodegeneration. Decreased mitochondrial function along with increased reactive oxygen species (ROS) and accumulation of damaged macromolecules are hallmarks of cellular aging. Based on numerous studies indicating pleiotropic effects of IGF-1 during aging, we compared the central and peripheral effects of circulating IGF-1 deficiency on tissue mitochondrial function using an inducible liver IGF-1 knockout (LID). Circulating levels of IGF-1 (~ 75%) were depleted in adult male Igf1f/f mice via AAV-mediated knockdown of hepatic IGF-1 at 5 months of age. Cognitive function was evaluated at 18 months using the radial arm water maze and glucose and insulin tolerance assessed. Mitochondrial function was analyzed in hippocampus, muscle, and visceral fat tissues using high-resolution respirometry O2K as well as redox status and oxidative stress in the cortex. Peripherally, IGF-1 deficiency did not significantly impact muscle mass or mitochondrial function. Aged LID mice were insulin resistant and exhibited ~ 60% less adipose tissue but increased fat mitochondrial respiration (20%). The effects on fat metabolism were attributed to increases in growth hormone. Centrally, IGF-1 deficiency impaired hippocampal-dependent spatial acquisition as well as reversal learning in male mice. Hippocampal mitochondrial OXPHOS coupling efficiency and cortex ATP levels (~ 50%) were decreased and hippocampal oxidative stress (protein carbonylation and F2-isoprostanes) was increased. These data suggest that IGF-1 is critical for regulating mitochondrial function, redox status, and spatial learning in the central nervous system but has limited impact on peripheral (liver and muscle) metabolism with age. Therefore, IGF-1 deficiency with age may increase sensitivity to damage in the brain and propensity for cognitive deficits. Targeting mitochondrial function in the brain may be an avenue for therapy of age-related impairment of cognitive function. Regulation of mitochondrial function and redox status by IGF-1 is essential to maintain brain function and coordinate hippocampal-dependent spatial learning. While a decline in IGF-1 in the periphery may be beneficial to avert cancer progression, diminished central IGF-1 signaling may mediate, in part, age-related cognitive dysfunction and cognitive pathologies potentially by decreasing mitochondrial function.
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Affiliation(s)
- Gavin Pharaoh
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Daniel Owen
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Alexander Yeganeh
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Pavithra Premkumar
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Julie Farley
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Shylesh Bhaskaran
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Nicole Ashpole
- Department of Biomolecular Sciences, University of Mississippi, Oxford, MS, USA
| | - Michael Kinter
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Holly Van Remmen
- Aging & Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Sreemathi Logan
- Oklahoma Center for Geroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. .,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA. .,Department of Rehabilitation Sciences, College of Allied Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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55
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Tomiya S, Tamura Y, Kouzaki K, Kotani T, Wakabayashi Y, Noda M, Nakazato K. Cast immobilization of hindlimb upregulates sarcolipin expression in atrophied skeletal muscles and increases thermogenesis in C57BL/6J mice. Am J Physiol Regul Integr Comp Physiol 2019; 317:R649-R661. [PMID: 31433681 DOI: 10.1152/ajpregu.00118.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mechanical unloading impairs cytosolic calcium (Ca2+) homeostasis in skeletal muscles. In this study, we investigated whether sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) itself or one of the regulators of the Ca2+ SERCA pump, sarcolipin (SLN), is altered to deregulate Ca2+ homeostasis in cast immobilized, atrophied muscles. Hindlimb muscles of 8-wk-old male C57BL/6J mice were subjected to bilateral cast immobilization for 2 wk. Two-week-cast immobilization induced both body weight and skeletal muscle loss. Highly phosphorylated Ca2+/calmodulin-dependent protein kinase II in the atrophied muscles suggested that cytosolic Ca2+ concentration was elevated. Extremely high expression levels of SLN mRNA and protein were observed in the atrophied muscles. Upregulation of SLN at the transcriptional level was supported by low RCAN1 expression, which is a negative regulator of SLN. We treated C2C12 cells with dexamethasone to mimic muscle atrophy in vitro and showed a direct relationship between high SLN mRNA expression and low Ca2+ uptake by sarcoplasmic reticulum. Since SLN reportedly plays a role in nonshivering thermogenesis, we performed a cold tolerance test of the whole body. As a result, we found that mice with cast immobilization showed high cold tolerance, suggesting that cast immobilization promoted whole body thermogenesis. Although the activity level was decreased during cast immobilization without change in food intake, adipose tissue weights also decreased significantly after cast immobilization. Concomitantly, we conclude that cast immobilization of hindlimb increased thermogenesis in C57Bl/6J mice, probably via high expression of SLN.
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Affiliation(s)
- Shigeto Tomiya
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Yuki Tamura
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan.,Research Institute for Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Karina Kouzaki
- Research Institute for Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Takaya Kotani
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Yuka Wakabayashi
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Masafumi Noda
- Research Institute for Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan.,Research Institute for Sport Science, Nippon Sport Science University, Tokyo, Japan
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56
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Alcazar J, Losa-Reyna J, Rodriguez-Lopez C, Navarro-Cruz R, Alfaro-Acha A, Ara I, García-García FJ, Alegre LM, Guadalupe-Grau A. Effects of concurrent exercise training on muscle dysfunction and systemic oxidative stress in older people with COPD. Scand J Med Sci Sports 2019; 29:1591-1603. [PMID: 31169924 DOI: 10.1111/sms.13494] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 05/29/2019] [Accepted: 06/04/2019] [Indexed: 12/13/2022]
Abstract
Oxidative stress is associated with disease severity and limb muscle dysfunction in COPD. Our main goal was to assess the effects of exercise training on systemic oxidative stress and limb muscle dysfunction in older people with COPD. Twenty-nine outpatients with COPD (66-90 years) were randomly assigned to a 12-week exercise training (ET; high-intensity interval training (HIIT) plus power training) or a control (CT; usual care) group. We evaluated mid-thigh muscle cross-sectional area (CSA; computed tomography); vastus lateralis (VL) muscle thickness, pennation angle, and fascicle length (ultrasonography); peak VO2 uptake (VO2peak ) and work rate (Wpeak ) (incremental cardiopulmonary exercise test); rate of force development (RFD); maximal muscle power (Pmax ; force-velocity testing); systemic oxidative stress (plasma protein carbonylation); and physical performance and quality of life. ET subjects experienced changes in mid-thigh muscle CSA (+4%), VL muscle thickness (+11%) and pennation angle (+19%), VO2peak (+14%), Wpeak (+37%), RFD (+32% to 65%), Pmax (+38% to 51%), sit-to-stand time (-24%), and self-reported health status (+20%) (all P < 0.05). No changes were noted in the CT group (P > 0.05). Protein carbonylation decreased among ET subjects (-27%; P < 0.05), but not in the CT group (P > 0.05). Changes in protein carbonylation were associated with changes in muscle size and pennation angle (r = -0.44 to -0.57), exercise capacity (r = -0.46), muscle strength (r = -0.45), and sit-to-stand performance (r = 0.60) (all P < 0.05). The combination of HIIT and power training improved systemic oxidative stress and limb muscle dysfunction in older people with COPD. Changes in oxidative stress were associated with exercise-induced structural and functional adaptations.
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Affiliation(s)
- Julian Alcazar
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain
| | - Jose Losa-Reyna
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.,Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain
| | - Carlos Rodriguez-Lopez
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain
| | - Roberto Navarro-Cruz
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain
| | - Ana Alfaro-Acha
- CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.,Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain
| | - Ignacio Ara
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain
| | - Francisco J García-García
- CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.,Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain
| | - Luis M Alegre
- GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.,CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain
| | - Amelia Guadalupe-Grau
- CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.,Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain.,ImFINE Research Group, Universidad Politécnica de Madrid, Madrid, Spain
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57
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Pharaoh G, Sataranatarajan K, Street K, Hill S, Gregston J, Ahn B, Kinter C, Kinter M, Van Remmen H. Metabolic and Stress Response Changes Precede Disease Onset in the Spinal Cord of Mutant SOD1 ALS Mice. Front Neurosci 2019; 13:487. [PMID: 31213966 PMCID: PMC6554287 DOI: 10.3389/fnins.2019.00487] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 04/29/2019] [Indexed: 12/11/2022] Open
Abstract
Many Amyotrophic Lateral Sclerosis (ALS) patients experience hypermetabolism, or an increase in measured vs. calculated metabolic rate. The cause of hypermetabolism and the effects on neuronal metabolism in ALS are currently unknown, but the efficacy of dietary interventions shows promise for metabolism as an ALS therapeutic target. The goal of this study is to measure changes in metabolic pathways as a function of disease progression in spinal cords of the SOD1G93A mouse model of ALS. We conducted a comprehensive assessment of protein expression for metabolic pathways, antioxidants, chaperones, and proteases in lumbar spinal cord from male SOD1G93A mice at pre-onset, onset, and end-stages of the disease using targeted proteomic analysis. These results reveal that protein content of metabolic proteins including proteins involved in glycolysis, β-oxidation, and mitochondrial metabolism is altered in SOD1G93A mouse spinal cord well before disease onset. The changes in mitochondrial metabolism proteins are associated with decreased maximal respiration and glycolytic flux in SOD1G93A dermal fibroblasts and increased hydrogen peroxide and lipid hydroperoxide production in mitochondria from sciatic nerve and gastrocnemius muscle fibers at end stage of disease. Consistent with redox dysregulation, expression of the glutathione antioxidant system is decreased, and peroxiredoxins and catalase expression are increased. In addition, stress response proteases and chaperones, including those involved in the mitochondrial unfolded protein response (UPRmt), are induced before disease onset. In summary, we report that metabolic and stress response changes occur in SOD1G93A lumbar spinal cord before motor symptom onset, and are primarily caused by SOD1G93A expression and do not vary greatly as a function of disease course.
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Affiliation(s)
- Gavin Pharaoh
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States.,Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, United States
| | | | - Kaitlyn Street
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Shauna Hill
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States.,Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Jake Gregston
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Bumsoo Ahn
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Caroline Kinter
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Michael Kinter
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, United States.,Department of Physiology, University of Oklahoma Health Science Center, Oklahoma City, OK, United States.,Oklahoma City VA Medical Center, Oklahoma City, OK, United States
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58
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Abstract
Introduction: Sarcopenia, the age-related loss of skeletal muscle mass and function, is a global health problem that contributes to the development of physical disability, morbidity and mortality in the ageing population. Sarcopenia is now recognised in many countries as a muscle disease with an ICD-10-CM Diagnosis Code for billing care related to this condition, despite no FDA-approved treatments being currently available. Areas covered: This review highlights the current state of knowledge regarding the biological mechanisms contributing to the age-related loss of muscle mass and function and provides a summary of existing and emerging pharmacotherapies in clinical trials for sarcopenia. Expert opinion: While understanding of the pathophysiology of sarcopenia has progressed, rigorous preclinical studies that better inform clinical trials are needed to accelerate drug discovery and identify safe and effective treatments. Few drugs have been developed specifically for sarcopenia and many have failed to meet clinically relevant outcomes related to strength and physical performance. The multifactorial complexity of sarcopenia means that tailored, personalised treatments are more likely to be required than just a single intervention.
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Affiliation(s)
- Justin P Hardee
- Centre for Muscle Research, Department of Physiology, The University of Melbourne , Melbourne , Victoria , Australia
| | - Gordon S Lynch
- Centre for Muscle Research, Department of Physiology, The University of Melbourne , Melbourne , Victoria , Australia
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59
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Ahn B, Ranjit R, Premkumar P, Pharaoh G, Piekarz KM, Matsuzaki S, Claflin DR, Riddle K, Judge J, Bhaskaran S, Satara Natarajan K, Barboza E, Wronowski B, Kinter M, Humphries KM, Griffin TM, Freeman WM, Richardson A, Brooks SV, Van Remmen H. Mitochondrial oxidative stress impairs contractile function but paradoxically increases muscle mass via fibre branching. J Cachexia Sarcopenia Muscle 2019; 10:411-428. [PMID: 30706998 PMCID: PMC6463475 DOI: 10.1002/jcsm.12375] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 11/12/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Excess reactive oxygen species (ROS) and muscle weakness occur in parallel in multiple pathological conditions. However, the causative role of skeletal muscle mitochondrial ROS (mtROS) on neuromuscular junction (NMJ) morphology and function and muscle weakness has not been directly investigated. METHODS We generated mice lacking skeletal muscle-specific manganese-superoxide dismutase (mSod2KO) to increase mtROS using a cre-Lox approach driven by human skeletal actin. We determined primary functional parameters of skeletal muscle mitochondrial function (respiration, ROS, and calcium retention capacity) using permeabilized muscle fibres and isolated muscle mitochondria. We assessed contractile properties of isolated skeletal muscle using in situ and in vitro preparations and whole lumbrical muscles to elucidate the mechanisms of contractile dysfunction. RESULTS The mSod2KO mice, contrary to our prediction, exhibit a 10-15% increase in muscle mass associated with an ~50% increase in central nuclei and ~35% increase in branched fibres (P < 0.05). Despite the increase in muscle mass of gastrocnemius and quadriceps, in situ sciatic nerve-stimulated isometric maximum-specific force (N/cm2 ), force per cross-sectional area, is impaired by ~60% and associated with increased NMJ fragmentation and size by ~40% (P < 0.05). Intrinsic alterations of components of the contractile machinery show elevated markers of oxidative stress, for example, lipid peroxidation is increased by ~100%, oxidized glutathione is elevated by ~50%, and oxidative modifications of myofibrillar proteins are increased by ~30% (P < 0.05). We also find an approximate 20% decrease in the intracellular calcium transient that is associated with specific force deficit. Excess superoxide generation from the mitochondrial complexes causes a deficiency of succinate dehydrogenase and reduced complex-II-mediated respiration and adenosine triphosphate generation rates leading to severe exercise intolerance (~10 min vs. ~2 h in wild type, P < 0.05). CONCLUSIONS Increased skeletal muscle mtROS is sufficient to elicit NMJ disruption and contractile abnormalities, but not muscle atrophy, suggesting new roles for mitochondrial oxidative stress in maintenance of muscle mass through increased fibre branching.
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Affiliation(s)
- Bumsoo Ahn
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Rojina Ranjit
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Pavithra Premkumar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Gavin Pharaoh
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Katarzyna M Piekarz
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Satoshi Matsuzaki
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Dennis R Claflin
- Department of Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, USA
| | - Kaitlyn Riddle
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Jennifer Judge
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, USA
| | - Shylesh Bhaskaran
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | | | - Erika Barboza
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Benjamin Wronowski
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Michael Kinter
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA
| | - Kenneth M Humphries
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Timothy M Griffin
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma Center for Neuroscience, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma City VA Medical Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Willard M Freeman
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Arlan Richardson
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma City VA Medical Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | - Susan V Brooks
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, USA.,Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.,Oklahoma City VA Medical Center, Oklahoma City, USA.,Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, USA
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60
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Steinz MM, Persson M, Aresh B, Olsson K, Cheng AJ, Ahlstrand E, Lilja M, Lundberg TR, Rullman E, Möller KÄ, Sandor K, Ajeganova S, Yamada T, Beard N, Karlsson BC, Tavi P, Kenne E, Svensson CI, Rassier DE, Karlsson R, Friedman R, Gustafsson T, Lanner JT. Oxidative hotspots on actin promote skeletal muscle weakness in rheumatoid arthritis. JCI Insight 2019; 5:126347. [PMID: 30920392 DOI: 10.1172/jci.insight.126347] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Skeletal muscle weakness in patients suffering from rheumatoid arthritis (RA) adds to their impaired working abilities and reduced quality of life. However, little molecular insight is available on muscle weakness associated with RA. Oxidative stress has been implicated in the disease pathogenesis of RA. Here we show that oxidative post-translational modifications of the contractile machinery targeted to actin result in impaired actin polymerization and reduced force production. Using mass spectrometry, we identified the actin residues targeted by oxidative 3-nitrotyrosine (3-NT) or malondialdehyde adduct (MDA) modifications in weakened skeletal muscle from mice with arthritis and patients afflicted by RA. The residues were primarily located to three distinct regions positioned at matching surface areas of the skeletal muscle actin molecule from arthritis mice and RA patients. Moreover, molecular dynamic simulations revealed that these areas, here coined "hotspots", are important for the stability of the actin molecule and its capacity to generate filaments and interact with myosin. Together, these data demonstrate how oxidative modifications on actin promote muscle weakness in RA patients and provide novel leads for targeted therapeutic treatment to improve muscle function.
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Affiliation(s)
- Maarten M Steinz
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
| | - Malin Persson
- Department of Kinesiology and Physical Education, McGill University, Montreal, Canada
| | - Bejan Aresh
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Karl Olsson
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Arthur J Cheng
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
| | - Emma Ahlstrand
- Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden
| | - Mats Lilja
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Tommy R Lundberg
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Eric Rullman
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden
| | | | - Katalin Sandor
- Department of Physiology and Pharmacology, Center for Molecular Medicine, and
| | - Sofia Ajeganova
- Department of Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Takashi Yamada
- Department of Physical Therapy, Sapporo Medical University, Sapporo, Japan
| | - Nicole Beard
- Faculty of Science and Technology, University of Canberra, Australia
| | - Björn Cg Karlsson
- Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden
| | - Pasi Tavi
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden.,A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Ellinor Kenne
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
| | - Camilla I Svensson
- Department of Physiology and Pharmacology, Center for Molecular Medicine, and
| | - Dilson E Rassier
- Department of Kinesiology and Physical Education, McGill University, Montreal, Canada
| | - Roger Karlsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Ran Friedman
- Department of Chemistry and Biomedical Sciences, Linnaeus University, Kalmar, Sweden
| | - Thomas Gustafsson
- Department of Laboratory Medicine, Division of Clinical Physiology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna T Lanner
- Department of Physiology and Pharmacology, Molecular Muscle Physiology and Pathophysiology, Karolinska Institutet, Stockholm, Sweden
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61
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Wier CG, Crum AE, Reynolds AB, Iyer CC, Chugh D, Palettas MS, Heilman PL, Kline DM, Arnold WD, Kolb SJ. Muscle contractility dysfunction precedes loss of motor unit connectivity in SOD1(G93A) mice. Muscle Nerve 2018; 59:254-262. [PMID: 30370671 DOI: 10.1002/mus.26365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/17/2018] [Accepted: 10/22/2018] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Electrophysiological measurements are used in longitudinal clinical studies to provide insight into the progression of amyotrophic lateral sclerosis (ALS) and the relationship between muscle weakness and motor unit (MU) degeneration. Here, we used a similar longitudinal approach in the Cu/Zn superoxide dismutase (SOD1[G93A]) mouse model of ALS. METHODS In vivo muscle contractility and MU connectivity assays were assessed longitudinally in SOD1(G93A) and wild type mice from postnatal days 35 to 119. RESULTS In SOD1(G93A) males, muscle contractility was reduced by day 35 and preceded MU loss. Muscle contractility and motor unit reduction were delayed in SOD1(G93A) females compared with males, but, just as with males, muscle contractility reduction preceded MU loss. DISCUSSION The longitudinal contractility and connectivity paradigm employed here provides additional insight into the SOD1(G93A) mouse model and suggests that loss of muscle contractility is an early finding that may precede loss of MUs and motor neuron death. Muscle Nerve 59:254-262, 2019.
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Affiliation(s)
- Christopher G Wier
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Alexander E Crum
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Anthony B Reynolds
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Chitra C Iyer
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Deepti Chugh
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Marilly S Palettas
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - Patrick L Heilman
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - David M Kline
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - W David Arnold
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA.,Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Stephen J Kolb
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
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62
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Qaisar R, Bhaskaran S, Premkumar P, Ranjit R, Natarajan KS, Ahn B, Riddle K, Claflin DR, Richardson A, Brooks SV, Van Remmen H. Oxidative stress-induced dysregulation of excitation-contraction coupling contributes to muscle weakness. J Cachexia Sarcopenia Muscle 2018; 9:1003-1017. [PMID: 30073804 PMCID: PMC6204588 DOI: 10.1002/jcsm.12339] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 06/25/2018] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND We have previously shown that the deletion of the superoxide scavenger, CuZn superoxide dismutase, in mice (Sod1-/- mice) results in increased oxidative stress and an accelerated loss of skeletal muscle mass and force that mirror the changes seen in old control mice. The goal of this study is to define the effect of oxidative stress and ageing on muscle weakness and the Excitation Contraction (EC) coupling machinery in age-matched adult (8-10 months) wild-type (WT) and Sod1-/- mice in comparison with old (25-28 months) WT mice. METHODS In vitro contractile assays were used to measure muscle contractile parameters. The activity of the sarcoplasmic reticulum Ca2+ ATPase (SERCA) pump was measured using an NADH-linked enzyme assay. Immunoblotting and immunofluorescence techniques were used to measure protein expression, and real-time reverse transcription PCR was used to measure gene expression. RESULTS The specific force generated by the extensor digitorum longus muscle was reduced in the Sod1-/- and old WT mice compared with young WT mice along with significant prolongation of time to peak force, increased half relaxation time, and disruption of intracellular calcium handling. The maximal activity of the SERCA calcium uptake pump was significantly reduced in gastrocnemius muscle from both old WT (≈14%) and adult Sod1-/- (≈33%) mice compared with young WT mice along with increased expression of sarcolipin, a known inhibitor of SERCA activity. Protein levels of the voltage sensor and calcium uptake channel proteins dihydropyridine receptor α1 and SERCA2 were significantly elevated (≈45% and ≈57%, respectively), while the ratio of calstabin, a channel stabilizing protein, to ryanodine receptor was significantly reduced (≈21%) in Sod1-/- mice compared with young WT mice. The changes in calcium handling were accompanied by substantially elevated levels of global protein carbonylation and lipid peroxidation. CONCLUSIONS Our data suggest that the muscle weakness in Sod1-/- and old WT mice is in part driven by reactive oxygen species-mediated EC uncoupling and supports a role for reduced SERCA pump activity in compromised muscle function. The novel quantitative mechanistic data provided here can lead to potential therapeutic interventions of SERCA dysfunction for sarcopenia and muscle diseases.
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Affiliation(s)
- Rizwan Qaisar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Shylesh Bhaskaran
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Pavithra Premkumar
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Rojina Ranjit
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | | | - Bumsoo Ahn
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Kaitlyn Riddle
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA
| | - Dennis R Claflin
- Department of Surgery, Section of Plastic Surgery, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Arlan Richardson
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.,Oklahoma City VA Medical Center, Oklahoma City, OK, USA.,Department of Geriatric Medicine and the Reynolds Oklahoma Center of Aging, Oklahoma University Health Science Center, Oklahoma City, OK, USA
| | - Susan V Brooks
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Holly Van Remmen
- Aging and Metabolism Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK, USA.,Oklahoma City VA Medical Center, Oklahoma City, OK, USA
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