1
|
Kamal KY, Othman MA, Kim JH, Lawler JM. Bioreactor development for skeletal muscle hypertrophy and atrophy by manipulating uniaxial cyclic strain: proof of concept. NPJ Microgravity 2024; 10:62. [PMID: 38862543 PMCID: PMC11167039 DOI: 10.1038/s41526-023-00320-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 08/15/2023] [Indexed: 06/13/2024] Open
Abstract
Skeletal muscles overcome terrestrial, gravitational loading by producing tensile forces that produce movement through joint rotation. Conversely, the microgravity of spaceflight reduces tensile loads in working skeletal muscles, causing an adaptive muscle atrophy. Unfortunately, the design of stable, physiological bioreactors to model skeletal muscle tensile loading during spaceflight experiments remains challenging. Here, we tested a bioreactor that uses initiation and cessation of cyclic, tensile strain to induce hypertrophy and atrophy, respectively, in murine lineage (C2C12) skeletal muscle myotubes. Uniaxial cyclic stretch of myotubes was conducted using a StrexCell® (STB-1400) stepper motor system (0.75 Hz, 12% strain, 60 min day^-1). Myotube groups were assigned as follows: (a) quiescent over 2- or (b) 5-day (no stretch), (c) experienced 2-days (2dHY) or (d) 5-days (5dHY) of cyclic stretch, or (e) 2-days of cyclic stretch followed by a 3-day cessation of stretch (3dAT). Using ß-sarcoglycan as a sarcolemmal marker, mean myotube diameter increased significantly following 2dAT (51%) and 5dAT (94%) vs. matched controls. The hypertrophic, anabolic markers talin and Akt phosphorylation (Thr308) were elevated with 2dHY but not in 3dAT myotubes. Inflammatory, catabolic markers IL-1ß, IL6, and NF-kappaB p65 subunit were significantly higher in the 3dAT group vs. all other groups. The ratio of phosphorylated FoxO3a/total FoxO3a was significantly lower in 3dAT than in the 2dHY group, consistent with elevated catabolic signaling during unloading. In summary, we demonstrated proof-of-concept for a spaceflight research bioreactor, using uniaxial cyclic stretch to produce myotube hypertrophy with increased tensile loading, and myotube atrophy with subsequent cessation of stretch.
Collapse
Affiliation(s)
- Khaled Y Kamal
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Graduate Faculty of Nutrition, Texas A&M University, College Station, TX, USA.
| | - Mariam Atef Othman
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Graduate Faculty of Nutrition, Texas A&M University, College Station, TX, USA
| | - Joo-Hyun Kim
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Graduate Faculty of Nutrition, Texas A&M University, College Station, TX, USA
| | - John M Lawler
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Graduate Faculty of Nutrition, Texas A&M University, College Station, TX, USA
- Department of Nutrition, Texas A&M University, College Station, TX, USA
| |
Collapse
|
2
|
Jang BC, Kwon ES, Lee YJ, Jung JI, Moon YS, Kwon DR. Comparison of Muscle Regeneration Effects at Different Melittin Concentrations in Rabbit Atrophied Muscle. Int J Mol Sci 2024; 25:5035. [PMID: 38732255 PMCID: PMC11084904 DOI: 10.3390/ijms25095035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 04/18/2024] [Accepted: 05/04/2024] [Indexed: 05/13/2024] Open
Abstract
This research aimed to explore the healing impacts of Melittin treatment on gastrocnemius muscle wasting caused by immobilization with a cast in rabbits. Twenty-four rabbits were randomly allocated to four groups. The procedures included different injections: 0.2 mL of normal saline to Group 1 (G1-NS); 4 μg/kg of Melittin to Group 2 (G2-4 μg/kg Melittin); 20 μg/kg of Melittin to Group 3 (G3-20 μg/kg Melittin); and 100 μg/kg of Melittin to Group 4 (G4-100 μg/kg Melittin). Ultrasound was used to guide the injections into the rabbits' atrophied calf muscles following two weeks of immobilization via casting. Clinical measurements, including the length of the calf, the compound muscle action potential (CMAP) of the tibial nerve, and the gastrocnemius muscle thickness, were assessed. Additionally, cross-sectional slices of gastrocnemius muscle fibers were examined, and immunohistochemistry and Western blot analyses were performed following two weeks of therapy. The mean regenerative changes, as indicated by clinical parameters, in Group 4 were significantly more pronounced than in the other groups (p < 0.05). Furthermore, the cross-sectional area of the gastrocnemius muscle fibers and immunohistochemical indicators in Group 4 exceeded those in the remaining groups (p < 0.05). Western blot analysis also showed a more significant presence of anti-inflammatory and angiogenic cytokines in Group 4 compared to the others (p < 0.05). Melittin therapy at a higher dosage can more efficiently activate regeneration in atrophied gastrocnemius muscle compared to lower doses of Melittin or normal saline.
Collapse
Affiliation(s)
- Byeong-Churl Jang
- Department of Molecular Medicine, College of Medicine, Keimyung University, Daegu 42601, Republic of Korea;
| | - Eun Sang Kwon
- Department of Medicine, College of Medicine, Keimyung University, Daegu 42601, Republic of Korea
| | - Yoon-Jin Lee
- Department of Biochemistry, College of Medicine, Soonchunhyang University, Cheonan 31151, Republic of Korea;
| | - Jae Ik Jung
- Department of Rehabilitation Medicine, Catholic University of Daegu School of Medicine, Daegu 42472, Republic of Korea;
| | - Yong Suk Moon
- Department of Anatomy, Catholic University of Daegu School of Medicine, Daegu 42472, Republic of Korea;
| | - Dong Rak Kwon
- Department of Rehabilitation Medicine, Catholic University of Daegu School of Medicine, Daegu 42472, Republic of Korea;
| |
Collapse
|
3
|
Martins EJ, Serrão P, Leonardi-Figueiredo MM, Ravanelli LS, Serenza FS, Mattiello S, Aagaard P, Mattiello-Sverzut A. Isokinetic arm and shoulder muscle torque-velocity characteristics in mobility limited children and adolescents with spina bifida. Physiother Theory Pract 2024; 40:962-972. [PMID: 36482746 DOI: 10.1080/09593985.2022.2150529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 10/28/2022] [Accepted: 11/14/2022] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Propulsive wheelchair capacity may be influenced by arm muscle performance.Objectives: To determine whether children and adolescent wheelchair-users with spina bifida show reduced arm muscle strength compared to their typically developing peers and to compare muscle strength data obtained by isokinetic and handheld dynamometry (HHD). METHODS Participants (mean age 12.5 ± 2.5 years) were assigned to spina bifida (SB; n = 11) or control (n = 22) groups. Isokinetic dynamometry was used to measure peak torque (PT) during dynamic (60°s-1 and 120°s-1) and isometric strength testing (MVIC) for shoulder and elbow flexors and extensors. HHD was used to measure MVIC of the same muscle groups. RESULTS SB showed reduced isokinetic PT for shoulder extensors at 60°s-1 and 120°s-1, shoulder flexor MVIC, and elbow flexors at 60°s-1 and MVIC; higher PT for shoulder flexors and elbow flexors at 120°s-1; and decreased MVIC for elbow flexors but not extensors compared to controls when assessed by HHD. The SB and control groups showed strong positive correlations between MVIC data obtained by the two devices for all muscle groups (r ≥ 0.81; p < .01), except for shoulder flexor MVIC in controls (r = 0.68; p < .01). CONCLUSION SB presented reduced levels of dynamic slow-speed and isometric shoulder and elbow muscle strength and greater dynamic high-speed shoulder and elbow flexor strength than controls possibly due to the exposure to self-sustained wheelchair ambulation. Exercise-based intervention protocols to increase slow-speed arm muscle strength should be considered in youth with SB. Strong positive correlations observed between muscle strength assessed by isokinetic dynamometry and HHD support the use of HHD in this clinical population.
Collapse
Affiliation(s)
- Emanuela J Martins
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Paula Serrão
- Department of Physiotherapy, Federal University of São Carlos, São Carlos, Brazil
| | | | - Letícia S Ravanelli
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Felipe S Serenza
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Stela Mattiello
- Department of Physiotherapy, Federal University of São Carlos, São Carlos, Brazil
| | - Per Aagaard
- Institute of Sports Science and Clinical Biomechanics, Muscle Physiology and Biomechanics Research Unit, University of Southern Denmark, Odense, Denmark
| | - Ana Mattiello-Sverzut
- Department of Health Sciences, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| |
Collapse
|
4
|
Plantarflexor neuromuscular performance in Insertional Achilles tendinopathy. Musculoskelet Sci Pract 2022; 62:102671. [PMID: 36219920 DOI: 10.1016/j.msksp.2022.102671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 09/08/2022] [Accepted: 09/30/2022] [Indexed: 12/12/2022]
Abstract
BACKGROUND Insertional Achilles tendinopathy (IAT) is a common and painful musculoskeletal condition. The management of IAT commonly involves strengthening of the plantarflexors, although there is currently a paucity of research investigating plantarflexor neuromuscular performance specific to people with IAT. OBJECTIVES To compare plantarflexor neuromuscular performance between men with IAT and controls, and to investigate the relationship between plantarflexor neuromuscular performance and patient reported outcome measures for men with IAT. DESIGN Case control. METHOD 34 men with IAT (age 43.7 years [SD 10.02], weight 89.6 kg [16.3]) were matched with 34 healthy men (age 42.8 years [SD 8.9], weight 87.2 kg [9.7]). Participants underwent a plantarflexion maximal voluntary isometric contraction (MVIC) task, and a target force matching task. Neuromuscular variables from these tasks include; MVIC, rate of torque development (RTD), electromechanical delay (EMD), and muscle force steadiness. Participants also completed questionnaires regarding; pain and function, and psychological factors. RESULTS The IAT group had reduced MVIC (p < 0.01) and RTD, (p < 0.01) compared to controls, however no significant difference in plantarflexor force steadiness (p = 0.08), or EMD (p = 0.71) was observed. Low strength correlations were detected between the VISA-A and RTD (r = 0.37, p = 0.04), kinesiophobia and EMD (r = 0.45, p = 0.03). CONCLUSIONS This study established impairments in plantarflexor strength and RTD among people with IAT. Plantarflexor force steadiness and EMD is not altered in IAT, which is in contrast to evidence from mid-portion Achilles tendinopathy. Plantarflexor RTD was the only neuromuscular outcome measure linked to symptom severity, which may indicate it is an important rehabilitation finding.
Collapse
|
5
|
Combination Therapy of Polydeoxyribonucleotide and Microcurrent in Muscle Regeneration on Cast-Induced Muscle Atrophy in Rabbit. BIOMED RESEARCH INTERNATIONAL 2022; 2022:7469452. [DOI: 10.1155/2022/7469452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/12/2022] [Indexed: 11/18/2022]
Abstract
Background. The aim of this study was to evaluate how polydeoxyribonucleotide (PDRN) and microcurrent therapy (MT) functioned synergistically in a cast-immobilized rabbit model with an atrophied calf muscle. Methods. At the age of 12 weeks, 32 male New Zealand rabbits were enrolled in four groups. After 2 weeks of cast-immobilization, 4 procedures were performed on atrophied calf muscle [weekly two injections normal saline 0.2 ml injection group 1 (G1-NS), weekly two injections 0.2 ml PDRN injection group 2 (G2-PDRN), MT group 3 (G3-MT), and 0.2 ml PDRN injection with MT group 4 (G4-PDRN+MT)]. For 2 weeks, MT was used for 60 minutes each day. The calf circumference (CC), the thickness of gastrocnemius muscle (TGCM), and the tibial nerve compound muscle action potential (CMAP) were evaluated using ultrasound before and after 2 weeks of treatment. Proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor, and platelet endothelial cell adhesion molecule-1 (PECAM-1) of GCM fibers (type I, type II, and total) were measured. Statistical analyses were performed using ANOVA. Results. The mean atrophic alterations of right CC, CMAP, and TGCM (medial/lateral) were substantially lower in G4-PDRN+MT than in the G1-NS, G2-PDRN, and G3-MT, respectively (
). Furthermore, mean CSAs (type I, type II, and total) of medial and lateral GCM muscle fibers in G4-PDRN+MT were significantly higher when compared to other three groups (
). In terms of the PCNA-, VEGF-, and PECAM-1-positive cell ratio of medial and lateral GCM muscle fibers, G4-PDRN+MT was considerably higher than G1-NS, G2-PDRN, and G3-MT (
). Conclusions. On the atrophied calf muscle of the rabbit model, PDRN injection combined with MT was more effective than PDRN injection alone, MT alone, and normal saline injection separately.
Collapse
|
6
|
Klein CS, Liu H, Zhao CN, Yang X. Quantitative ultrasound imaging of intrinsic hand muscles after traumatic cervical spinal cord injury. Spinal Cord 2022; 60:199-209. [PMID: 34172926 DOI: 10.1038/s41393-021-00653-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 02/06/2023]
Abstract
STUDY DESIGN This is a cross-sectional descriptive study. OBJECTIVES To quantify differences in hand muscle morphology between persons with cervical spinal cord injury (SCI) and uninjured adults. SETTING The study was performed at the Guangdong Work Injury Rehabilitation Hospital. METHODS We quantified hand muscle cross-sectional area (CSA), thickness, and echo intensity (EI) in 18 persons with subacute to chronic SCI and 23 controls using ultrasound imaging. RESULTS Mean SCI abductor pollicis brevis (APB), abductor digiti minimi (ADM), and first dorsal interosseous (FDI) CSA were ~26%, 43%, and 37% smaller than the control means, the deficit in the APB being less than the ADM (P < 0.05). Muscle thickness was also smaller after SCI, but deficits in ADM (31%) and FDI (20%) thickness were less than the CSA deficits (P < 0.05). In five SCI persons, APB CSA and/or opponens pollicis (OP) thickness were normal despite complete motor paralysis. Mean longitudinal image EI was 40% higher in the OP and 15% higher in the flexor pollicis brevis (FPB) after SCI (P < 0.05), suggesting denervation-induced infiltration of fat and fibrous tissues. OP EI was related to OP thickness (r = -0.6, P = 0.007, n = 18). Mean axial image EI was 10% higher in the APB and ADM after SCI (P < 0.05). There were no significant correlations between muscle morphological properties and clinical features in the SCI participants. CONCLUSION Our results indicate significant SCI atrophy and elevated EI that are muscle dependent.
Collapse
Affiliation(s)
- Cliff S Klein
- Guangdong Work Injury Rehabilitation Center, Guangzhou, China.
| | - Hui Liu
- Guangdong Work Injury Rehabilitation Center, Guangzhou, China
| | - Chen Ning Zhao
- Guangdong Work Injury Rehabilitation Center, Guangzhou, China
| | - Xinghua Yang
- Guangdong Work Injury Rehabilitation Center, Guangzhou, China
| |
Collapse
|
7
|
Rare tremors and tremors occurring in other neurological disorders. J Neurol Sci 2022; 435:120200. [DOI: 10.1016/j.jns.2022.120200] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/07/2022] [Accepted: 02/17/2022] [Indexed: 12/21/2022]
|
8
|
Geist Hauserman J, Stavusis J, Joca HC, Robinett JC, Hanft L, Vandermeulen J, Zhao R, Stains JP, Konstantopoulos K, McDonald KS, Ward C, Kontrogianni-Konstantopoulos A. Sarcomeric deficits underlie MYBPC1-associated myopathy with myogenic tremor. JCI Insight 2021; 6:e147612. [PMID: 34437302 PMCID: PMC8525646 DOI: 10.1172/jci.insight.147612] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 08/25/2021] [Indexed: 12/02/2022] Open
Abstract
Myosin binding protein-C slow (sMyBP-C) comprises a subfamily of cytoskeletal proteins encoded by MYBPC1 that is expressed in skeletal muscles where it contributes to myosin thick filament stabilization and actomyosin cross-bridge regulation. Recently, our group described the causal association of dominant missense pathogenic variants in MYBPC1 with an early-onset myopathy characterized by generalized muscle weakness, hypotonia, dysmorphia, skeletal deformities, and myogenic tremor, occurring in the absence of neuropathy. To mechanistically interrogate the etiologies of this MYBPC1-associated myopathy in vivo, we generated a knock-in mouse model carrying the E248K pathogenic variant. Using a battery of phenotypic, behavioral, and physiological measurements spanning neonatal to young adult life, we found that heterozygous E248K mice faithfully recapitulated the onset and progression of generalized myopathy, tremor occurrence, and skeletal deformities seen in human carriers. Moreover, using a combination of biochemical, ultrastructural, and contractile assessments at the level of the tissue, cell, and myofilaments, we show that the loss-of-function phenotype observed in mutant muscles is primarily driven by disordered and misaligned sarcomeres containing fragmented and out-of-register internal membranes that result in reduced force production and tremor initiation. Collectively, our findings provide mechanistic insights underscoring the E248K-disease pathogenesis and offer a relevant preclinical model for therapeutic discovery.
Collapse
Affiliation(s)
- Janelle Geist Hauserman
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Janis Stavusis
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Humberto C. Joca
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Joel C. Robinett
- Department of Medical Pharmacology and Physiology, University of Missouri, School of Medicine Columbia, Missouri, USA
| | - Laurin Hanft
- Department of Medical Pharmacology and Physiology, University of Missouri, School of Medicine Columbia, Missouri, USA
| | - Jack Vandermeulen
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Runchen Zhao
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Joseph P. Stains
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri, School of Medicine Columbia, Missouri, USA
| | - Christopher Ward
- Department of Orthopedics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | |
Collapse
|
9
|
Henson DP, Edgar C, Ding Z, Sivapuratharasu B, Le Feuvre P, Finnegan ME, Quest R, McGregor AH, Bull AMJ. Understanding lower limb muscle volume adaptations to amputation. J Biomech 2021; 125:110599. [PMID: 34265657 DOI: 10.1016/j.jbiomech.2021.110599] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 06/18/2021] [Accepted: 06/24/2021] [Indexed: 10/21/2022]
Abstract
Amputation of a major limb, and the subsequent return to movement with a prosthesis, requires the development of compensatory strategies to account for the loss. Such strategies, over time, lead to regional muscle atrophy and hypertrophy through chronic under or overuse of muscles compared to uninjured individuals. The aim of this study was to quantify the lower limb muscle parameters of persons with transtibial and transfemoral amputations using high resolution MRI to ascertain muscle volume and to determine regression equations for predicting muscle volume using femur- and tibia-length, pelvic-width, height, and mass. Twelve persons with limb loss participated in this study and their data were compared to six matched control subjects. Subjects with unilateral transtibial amputation showed whole-limb muscle volume loss in the residual-limb, whereas minor volume changes in the intact limb were found, providing evidence for a compensation strategy that is dominated by the intact-limb. Subjects with bilateral-transfemoral amputations showed significant muscle volume increases in the short adductor muscles with an insertion not affected by the amputation, the hip flexors, and the gluteus medius, and significant volume decreases in the longer adductor muscles, rectus femoris, and hamstrings. This study presents a benchmark measure of muscle volume discrepancies in persons with limb-loss, and can be used to understand the compensation strategies of persons with limb-loss and the impact on muscle volume, thus enabling the development of optimised intervention protocols, conditioning therapies, surgical techniques, and prosthetic devices that promote and enhance functional capability within the population of persons with limb loss.
Collapse
Affiliation(s)
- David P Henson
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Bioengineering, Imperial College London, UK.
| | - Caitlin Edgar
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Bioengineering, Imperial College London, UK
| | - Ziyun Ding
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Bioengineering, Imperial College London, UK; The Department of Mechanical Engineering, University of Birmingham, UK
| | - Biranavan Sivapuratharasu
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Bioengineering, Imperial College London, UK; The Department of Surgery and Cancer, Imperial College London, UK
| | - Peter Le Feuvre
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Surgery and Cancer, Imperial College London, UK
| | - Mary E Finnegan
- The Department of Bioengineering, Imperial College London, UK; The Department of Imaging, Imperial College Healthcare NHS Trust, Imperial College London, UK
| | - Rebecca Quest
- The Department of Bioengineering, Imperial College London, UK; The Department of Imaging, Imperial College Healthcare NHS Trust, Imperial College London, UK
| | - Alison H McGregor
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Surgery and Cancer, Imperial College London, UK
| | - Anthony M J Bull
- The Royal British Legion Centre for Blast Injury Studies, Imperial College London, UK; The Department of Bioengineering, Imperial College London, UK
| |
Collapse
|
10
|
Memme JM, Slavin M, Moradi N, Hood DA. Mitochondrial Bioenergetics and Turnover during Chronic Muscle Disuse. Int J Mol Sci 2021; 22:ijms22105179. [PMID: 34068411 PMCID: PMC8153634 DOI: 10.3390/ijms22105179] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/07/2021] [Accepted: 05/11/2021] [Indexed: 12/15/2022] Open
Abstract
Periods of muscle disuse promote marked mitochondrial alterations that contribute to the impaired metabolic health and degree of atrophy in the muscle. Thus, understanding the molecular underpinnings of muscle mitochondrial decline with prolonged inactivity is of considerable interest. There are translational applications to patients subjected to limb immobilization following injury, illness-induced bed rest, neuropathies, and even microgravity. Studies in these patients, as well as on various pre-clinical rodent models have elucidated the pathways involved in mitochondrial quality control, such as mitochondrial biogenesis, mitophagy, fission and fusion, and the corresponding mitochondrial derangements that underlie the muscle atrophy that ensues from inactivity. Defective organelles display altered respiratory function concurrent with increased accumulation of reactive oxygen species, which exacerbate myofiber atrophy via degradative pathways. The preservation of muscle quality and function is critical for maintaining mobility throughout the lifespan, and for the prevention of inactivity-related diseases. Exercise training is effective in preserving muscle mass by promoting favourable mitochondrial adaptations that offset the mitochondrial dysfunction, which contributes to the declines in muscle and whole-body metabolic health. This highlights the need for further investigation of the mechanisms in which mitochondria contribute to disuse-induced atrophy, as well as the specific molecular targets that can be exploited therapeutically.
Collapse
Affiliation(s)
| | | | | | - David A. Hood
- Correspondence: ; Tel.: +1-(416)-736-2100 (ext. 66640)
| |
Collapse
|
11
|
Nox2 Inhibition Regulates Stress Response and Mitigates Skeletal Muscle Fiber Atrophy during Simulated Microgravity. Int J Mol Sci 2021; 22:ijms22063252. [PMID: 33806917 PMCID: PMC8005132 DOI: 10.3390/ijms22063252] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 01/25/2023] Open
Abstract
Insufficient stress response and elevated oxidative stress can contribute to skeletal muscle atrophy during mechanical unloading (e.g., spaceflight and bedrest). Perturbations in heat shock proteins (e.g., HSP70), antioxidant enzymes, and sarcolemmal neuronal nitric oxidase synthase (nNOS) have been linked to unloading-induced atrophy. We recently discovered that the sarcolemmal NADPH oxidase-2 complex (Nox2) is elevated during unloading, downstream of angiotensin II receptor 1, and concomitant with atrophy. Here, we hypothesized that peptidyl inhibition of Nox2 would attenuate disruption of HSP70, MnSOD, and sarcolemmal nNOS during unloading, and thus muscle fiber atrophy. F344 rats were divided into control (CON), hindlimb unloaded (HU), and hindlimb unloaded +7.5 mg/kg/day gp91ds-tat (HUG) groups. Unloading-induced elevation of the Nox2 subunit p67phox-positive staining was mitigated by gp91ds-tat. HSP70 protein abundance was significantly lower in HU muscles, but not HUG. MnSOD decreased with unloading; however, MnSOD was not rescued by gp91ds-tat. In contrast, Nox2 inhibition protected against unloading suppression of the antioxidant transcription factor Nrf2. nNOS bioactivity was reduced by HU, an effect abrogated by Nox2 inhibition. Unloading-induced soleus fiber atrophy was significantly attenuated by gp91ds-tat. These data establish a causal role for Nox2 in unloading-induced muscle atrophy, linked to preservation of HSP70, Nrf2, and sarcolemmal nNOS.
Collapse
|
12
|
Nakada S, Yamashita Y, Machida S, Miyagoe-Suzuki Y, Arikawa-Hirasawa E. Perlecan Facilitates Neuronal Nitric Oxide Synthase Delocalization in Denervation-Induced Muscle Atrophy. Cells 2020; 9:cells9112524. [PMID: 33238404 PMCID: PMC7700382 DOI: 10.3390/cells9112524] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/17/2020] [Accepted: 11/19/2020] [Indexed: 01/01/2023] Open
Abstract
Perlecan is an extracellular matrix molecule anchored to the sarcolemma by a dystrophin–glycoprotein complex. Perlecan-deficient mice are tolerant to muscle atrophy, suggesting that perlecan negatively regulates mechanical stress-dependent skeletal muscle mass. Delocalization of neuronal nitric oxide synthase (nNOS) from the sarcolemma to the cytosol triggers protein degradation, thereby initiating skeletal muscle atrophy. We hypothesized that perlecan regulates nNOS delocalization and activates protein degradation during this process. To determine the role of perlecan in nNOS-mediated mechanotransduction, we used sciatic nerve transection as a denervation model of gastrocnemius muscles. Gastrocnemius muscle atrophy was significantly lower in perinatal lethality-rescued perlecan-knockout (Hspg2−/−-Tg) mice than controls (WT-Tg) on days 4 and 14 following surgery. Immunofluorescence microscopy showed that cell membrane nNOS expression was reduced by denervation in WT-Tg mice, with marginal effects in Hspg2−/−-Tg mice. Moreover, levels of atrophy-related proteins—i.e., FoxO1a, FoxO3a, atrogin-1, and Lys48-polyubiquitinated proteins—increased in the denervated muscles of WT-Tg mice but not in Hspg2−/−-Tg mice. These findings suggest that during denervation, perlecan promotes nNOS delocalization from the membrane and stimulates protein degradation and muscle atrophy by activating FoxO signaling and the ubiquitin–proteasome system.
Collapse
Affiliation(s)
- Satoshi Nakada
- Japanese Center for Research on Women in Sport, Juntendo University Graduate School of Health and Sports Science, Chiba 270-1695, Japan; (S.N.); (S.M.)
| | - Yuri Yamashita
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan;
| | - Shuichi Machida
- Japanese Center for Research on Women in Sport, Juntendo University Graduate School of Health and Sports Science, Chiba 270-1695, Japan; (S.N.); (S.M.)
| | - Yuko Miyagoe-Suzuki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Tokyo 187-8502, Japan;
| | - Eri Arikawa-Hirasawa
- Japanese Center for Research on Women in Sport, Juntendo University Graduate School of Health and Sports Science, Chiba 270-1695, Japan; (S.N.); (S.M.)
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan;
- Correspondence: ; Tel.: +81-3-3813-3111
| |
Collapse
|
13
|
Pádua da Silva G, Palinkas M, Tosta Lopes RF, Vallin Fabrin SC, Ferreira B, Donizetti Verri E, Roza Gonçalves C, Stamato Taube OL, Siéssere S, Hallak Regalo SC. Effects of relapsing-remitting multiple sclerosis on the stomatognathic system: preliminary findings. GAZZETTA MEDICA ITALIANA ARCHIVIO PER LE SCIENZE MEDICHE 2020. [DOI: 10.23736/s0393-3660.19.04104-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
14
|
Passiatore M, De Vitis R, Perna A, D'Orio M, Cilli V, Taccardo G. Extraphyseal distal radius fracture in children: is the cast always needed? A retrospective analysis comparing Epibloc system and K-wire pinning. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2020; 30:1243-1250. [PMID: 32405758 DOI: 10.1007/s00590-020-02698-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/07/2020] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Closed reduction and internal fixation are a widespread surgical treatment for pediatrics displaced extraphyseal distal radius fractures. Post-surgical cast immobilization is usually needed. Epibloc system (ES) is a device used to fix Colles fractures in adults, not requiring post-surgical immobilization. The aim of the study is to investigate the effectiveness of ES in a pediatric population suffering from displaced extraphyseal distal radius fractures. METHODS We retrospectively analyzed 52 patients (age 8-12 years) who underwent CRIF. Patients were divided into two groups. Group A (25 patients): ES osteosynthesis. Group B (27 patients): K-wires and short arm cast osteosynthesis. The primary outcome is the maintenance of reduction in radiographs (displacement on frontal and lateral view). The secondary outcome is the reaching of the complete active range of motion recovery (compared with the contralateral side) and the time needed to obtain it. The need of further additional treatment (physiotherapy) and the presence of complication were also assessed. RESULTS Reduction was equally maintained in both groups (p > 0.05). Physiotherapy was mandatory for 11 patients in group B; only for 3 patients in group A, the difference was statistically significant (p = 0.03) according to Fisher test. Otherwise, the difference was not statistically significant regarding complications. (p > 0.05). At the last follow-up, complete functional recovery was reached in all patients. CONCLUSIONS Functional recovery is faster, and postoperative physiotherapy is rarely required with ES. This device allows us to go beyond the traditional concept of mandatory postoperative immobilization after pediatric wrist fractures surgery.
Collapse
Affiliation(s)
- Marco Passiatore
- Istituto Di Clinica Ortopedica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Via Giuseppe Moscati 31, 00168, Roma, Italia.
| | - Rocco De Vitis
- Istituto Di Clinica Ortopedica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Roma, Italia
| | - Andrea Perna
- Istituto Di Clinica Ortopedica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Via Giuseppe Moscati 31, 00168, Roma, Italia
| | - Marco D'Orio
- Istituto Di Clinica Ortopedica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Via Giuseppe Moscati 31, 00168, Roma, Italia
| | - Vitale Cilli
- Chirurgie de La Main, CHIREC Site Delta, Bruxelles, Belgium
| | - Giuseppe Taccardo
- Istituto Di Clinica Ortopedica, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Roma, Italia
| |
Collapse
|
15
|
Sarcomeric myopathies associated with tremor: new insights and perspectives. J Muscle Res Cell Motil 2019; 41:285-295. [PMID: 31620961 DOI: 10.1007/s10974-019-09559-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 10/05/2019] [Indexed: 12/21/2022]
Abstract
Myopathies are a large and heterogeneous group of disorders associated with mutations in structural and regulatory genes responsible for proper muscle assembly, organization and function. Despite the molecular diversity of inherited myopathies, they have historically been classified by the phenotypic traits observed in affected patients. It is therefore common for myopathies originating from mutations in different genes to be grouped together due to similar physical manifestations, and conversely myopathies resulting from mutations in the same gene to be considered separately due to disparate symptoms. Herein, we focus on an early onset myopathy linked to inherited or de novo mutations in sarcomeric genes that is characterized by muscle weakness, hypotonia and tremor, and further highlight that it may constitute a new form of myopathy, with tremor as its defining feature. Based on recent reports, we also discuss the possible myogenic origin of the tremor that may start at the level of the sarcomere due to structural and/or contractile alterations occurring as a result of the identified mutations. It is our hope that establishment of this form of myopathy accompanied by myogenic tremor as a new disease entity will have important diagnostic and therapeutic implications.
Collapse
|
16
|
McAuliffe S, Tabuena A, McCreesh K, O'Keeffe M, Hurley J, Comyns T, Purtill H, O'Neill S, O'Sullivan K. Altered Strength Profile in Achilles Tendinopathy: A Systematic Review and Meta-Analysis. J Athl Train 2019; 54:889-900. [PMID: 31386582 DOI: 10.4085/1062-6050-43-18] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Persistent strength deficits secondary to Achilles tendinopathy (AT) have been postulated to account for difficulty engaging in tendon-loading movements, such as running and jumping, and may contribute to the increased risk of recurrence. To date, little consensus exists on the presence of strength deficits in AT. Consequently, researchers are uncertain about the appropriate methods of assessment that may inform rehabilitation in clinical practice. OBJECTIVE To evaluate and synthesize the literature investigating plantar-flexion (PF) strength in individuals with AT. STUDY SELECTION Two independent reviewers searched 9 electronic databases using an agreed-upon set of key words. DATA EXTRACTION Data were extracted from studies comparing strength measures (maximal, reactive, and explosive strength) between individuals with AT and healthy control participants or between the injured and uninjured sides of people with AT. The Critical Appraisal Skills Programme Case-Control Study Checklist was used to assess the risk of bias for the included studies. DATA SYNTHESIS A total of 19 studies were eligible. Pooled meta-analyses for isokinetic dynamometry demonstrated reductions in maximal strength (concentric PF peak torque [PT] slow [Hedges g = 0.52, 44% deficit], concentric PF PT fast [Hedges g = 0.61, 38% deficit], and eccentric PF PT slow [Hedges g = 0.26, 18% deficit]). Reactive strength, particularly during hopping, was also reduced (Hedges g range = 0.32-2.61, 16%-35% deficit). For explosive strength, reductions in the rate of force development (Hedges g range = 0.31-1.73, 10%-21% deficit) were observed, whereas the findings for ground reaction force varied but were not consistently altered. CONCLUSIONS Individuals with AT demonstrated strength deficits compared with the uninjured side or with asymptomatic control participants. Deficits were reported across the strength spectrum for maximal, reactive, and explosive strength. Clinicians and researchers may need to adapt their assessment of Achilles tendon function, which may ultimately help to optimize rehabilitation outcomes.
Collapse
Affiliation(s)
- Seán McAuliffe
- Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Ariane Tabuena
- School of Allied Health, University of Limerick, Ireland
| | - Karen McCreesh
- School of Allied Health, University of Limerick, Ireland
| | - Mary O'Keeffe
- School of Allied Health, University of Limerick, Ireland
| | - John Hurley
- School of Allied Health, University of Limerick, Ireland
| | - Tom Comyns
- Department of Physical Education and Sports Science, University of Limerick, Ireland
| | - Helen Purtill
- Department of Mathematics & Statistics, University of Limerick, Ireland
| | - Seth O'Neill
- Department of Medical & Social Care Education, University of Leicester, United Kingdom
| | - Kieran O'Sullivan
- Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.,School of Allied Health, University of Limerick, Ireland
| |
Collapse
|
17
|
Wang Z, Jiang S, Cao J, Liu K, Xu S, Arfat Y, Guo Q, Chang H, Goswami N, Hinghofer‐Szalkay H, Gao Y. Novel findings on ultrastructural protection of skeletal muscle fibers during hibernation of Daurian ground squirrels: Mitochondria, nuclei, cytoskeleton, glycogen. J Cell Physiol 2019; 234:13318-13331. [DOI: 10.1002/jcp.28008] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/18/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Zhe Wang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Shan‐Feng Jiang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
- Laboratory for Bone Metabolism, Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University Xi'an Shaanxi People's Republic of China
| | - Jin Cao
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Kun Liu
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Shen‐Hui Xu
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Yasir Arfat
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Quan‐Ling Guo
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Hui Chang
- Key Laboratory of Resource Biology and Biotechnology in Western China, College of Life Sciences, Northwest University, Ministry of Education Xi'an China
| | - Nandu Goswami
- Physiology Unit, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz Graz Austria
| | - Helmut Hinghofer‐Szalkay
- Physiology Unit, Otto Loewi Research Center for Vascular Biology, Immunology and Inflammation, Medical University of Graz Graz Austria
| | | |
Collapse
|
18
|
Park GY, Kwon DR, Moon YS. Low-intensity microcurrent therapy promotes regeneration of atrophied calf muscles in immobilized rabbits. J Biomed Res 2018; 33:30. [PMID: 30418167 PMCID: PMC6352881 DOI: 10.7555/jbr.32.20180056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 07/05/2018] [Indexed: 11/03/2022] Open
Abstract
The purpose of this study was to investigate the intensity-specific regenerative effects of microcurrent therapy on gastrocnemius muscle atrophy induced by cast-immobilization in rabbits. Fifteen rabbits were randomly allocated to 3 groups after cast removal: cast-immobilization and sham microcurrent therapy for 2 weeks (group 1); cast-immobilization and microcurrent therapy (25 μA) for 2 weeks (group 2); cast-immobilization and microcurrent therapy (5,000 μA) for 2 weeks (group 3). Clinical parameters [calf circumference, compound muscle action potential (CMAP) of the tibial nerve, thickness of gastrocnemius muscle], cross sectional area of gastrocnemius muscle fibres, and immunohistochemistry was evaluated. The clinical parameters representing mean atrophic changes in group 2 were significantly lower than those in group 3. The cross sectional area of the gastrocnemius muscle fibres and immunohistochemical parameters in group 2 were significantly greater than those in group 3. The results showed that low-intensity microcurrent therapy can more effectively promote regeneration in atrophied gastrocnemius muscle than high-intensity microcurrent therapy.
Collapse
Affiliation(s)
- Gi Young Park
- . Department of Rehabilitation Medicine, Muscle Research Center, Catholic University of Daegu School of Medicine, Daegu 42472, Republic of Korea
| | - Dong Rak Kwon
- . Department of Rehabilitation Medicine, Muscle Research Center, Catholic University of Daegu School of Medicine, Daegu 42472, Republic of Korea
| | - Yong Suk Moon
- . Department of Anatomy, Catholic University of Daegu School of Medicine, Daegu 42472, Republic of Korea
| |
Collapse
|
19
|
Maggio ABR, Martin XE, Tabard-Fougère A, Delhumeau C, Ceroni D. What is the real impact of upper limb cast immobilisation on activity-related energy expenditure in children? BMJ Open Sport Exerc Med 2018; 4:e000359. [PMID: 30364617 PMCID: PMC6196977 DOI: 10.1136/bmjsem-2018-000359] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2018] [Indexed: 11/13/2022] Open
Abstract
Background Upper limb fractures and subsequent cast immobilisation constitute a potential cause of reduction in childhood levels of physical activity (PA), with subsequent decrease of energy consumption. The main objective of this study was thus to quantify the decrease of activity-related energy expenditure (AEE) due to upper limb cast immobilisation. Methods We conducted a longitudinal matched case-control study that included 35 children and teenagers with a first episode of upper limb fracture and 35 healthy cases. PA was assessed during cast immobilisation by accelerometer. AEE was the calculated using an equation based on the total counts per day measured by accelerometers. Results AEE in children and teenagers with upper limb fractures was estimated to be 7.4 % lower than healthy controls. The mean difference corresponded to 1.35 kcal/kg per mean valid recorded time (750 min), that is, the waking hours. When converted in kcal per mean subjects’ weight, the difference in AEE amounted 63.5 kcal/day, which corresponds approximately to 26 min of walking at a speed of 4 km/hours. In comparison with the mean AEE in healthy controls (18.2 kcal/kg), the noted decrease (1.35 kcal/kg) represents only 7.4 % of AEE. Conclusion Reduction of AEE in children and teenagers with upper limb fractures may lead to a slight positive energy balance, as there is usually no compensatory reduction of energy intake. An increase of light PA has to be counselled in this situation or patients should be advised to reduce their energy intake during the immobilisation period. Level of evidence Level I: high-quality prospective study (all patients were enrolled at the same point in their disease with ≥80 % follow-up of enrolled patients).
Collapse
Affiliation(s)
- Albane B R Maggio
- Santé et Mouvement Consultation, Service of Paediatric Specialties, Department of Child and Adolescent, UniversityHospitals of Geneva and University of Geneva, Geneva, Switzerland
| | - Xavier Eric Martin
- Pediatric Orthopedic Unit, Department of Child and Adolescent, University of Geneva Hospitals, Geneva, Switzerland.,Clinical Epidemiology Service, Department of Child and Adolescent, University of Geneva Hospitals, Geneva, Switzerland
| | - Anne Tabard-Fougère
- Pediatric Orthopedic Unit, Department of Child and Adolescent, University of Geneva Hospitals, Geneva, Switzerland
| | - Cécile Delhumeau
- Clinical Epidemiology Service, Department of Child and Adolescent, University of Geneva Hospitals, Geneva, Switzerland
| | - Dimitri Ceroni
- Pediatric Orthopedic Unit, Department of Child and Adolescent, University of Geneva Hospitals, Geneva, Switzerland
| |
Collapse
|
20
|
Jagnandan K, Higham TE. How rapid changes in body mass affect the locomotion of terrestrial vertebrates: ecology, evolution and biomechanics of a natural perturbation. Biol J Linn Soc Lond 2018. [DOI: 10.1093/biolinnean/bly056] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Kevin Jagnandan
- Life Sciences Department, San Diego City College, San Diego, CA, USA
| | - Timothy E Higham
- Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA, USA
| |
Collapse
|
21
|
Kuczmarski JM, Hord JM, Lee Y, Guzzoni V, Rodriguez D, Lawler MS, Garcia-Villatoro EL, Holly D, Ryan P, Falcon K, Garcia M, Janini Gomes M, Fluckey JD, Lawler JM. Effect of Eukarion-134 on Akt-mTOR signalling in the rat soleus during 7 days of mechanical unloading. Exp Physiol 2018; 103:545-558. [PMID: 29315934 DOI: 10.1113/ep086649] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 01/02/2018] [Indexed: 12/21/2022]
Abstract
NEW FINDINGS What is the central question of this study? Translocation of nNOSμ initiates catabolic signalling via FoxO3a and skeletal muscle atrophy during mechanical unloading. Recent evidence suggests that unloading-induced muscle atrophy and FoxO3a activation are redox sensitive. Will a mimetic of superoxide dismutase and catalase (i.e. Eukarion-134) also mitigate suppression of the Akt-mTOR pathway? What is the main finding and its importance? Eukarion-134 rescued Akt-mTOR signalling and sarcolemmal nNOSμ, which were linked to protection against the unloading phenotype, muscle fibre atrophy and partial fibre-type shift from slow to fast twitch. The loss of nNOSμ from the sarcolemma appears crucial to Akt phosphorylation and is redox sensitive, although the mechanisms remain unresolved. ABSTRACT Mechanical unloading stimulates rapid changes in skeletal muscle morphology, characterized by atrophy of muscle fibre cross-sectional area and a partial fibre-type shift from slow to fast twitch. Recent studies revealed that oxidative stress contributes to activation of forkhead box O3a (FoxO3a), proteolytic signalling and unloading-induced muscle atrophy via translocation of the μ-splice variant of neuronal nitric oxide synthase (nNOSμ) and activation of FoxO3a. There is limited understanding of the role of reactive oxygen species in the Akt-mammalian target of rapamycin (mTOR) pathway signalling during unloading. We hypothesized that Eukarion-134 (EUK-134), a mimetic of the antioxidant enzymes superoxide dismutase and catalase, would protect Akt-mTOR signalling in the unloaded rat soleus. Male Fischer 344 rats were separated into the following three study groups: ambulatory control (n = 11); 7 days of hindlimb unloading + saline injections (HU, n = 11); or 7 days of HU + EUK-134; (HU + EUK-134, n = 9). EUK-134 mitigated unloading-induced dephosphorylation of Akt, as well as FoxO3a, in the soleus. Phosphorylation of mTOR in the EUK-treated HU rats was not different from that in control animals. However, EUK-134 did not significantly rescue p70S6K phosphorylation. EUK-134 attenuated translocation of nNOSμ from the membrane to the cytosol, reduced nitration of tyrosine residues and suppressed upregulation of caveolin-3 and dysferlin. EUK-134 ameliorated HU-induced remodelling, atrophy of muscle fibres and the 12% increase in type II myosin heavy chain-positive fibres. Attenuation of the unloaded muscle phenotype was associated with decreased reactive oxygen species, as assessed by ethidium-positive nuclei. We conclude that oxidative stress affects Akt-mTOR signalling in unloaded skeletal muscle. Direct linkage of abrogation of nNOSμ translocation with Akt-mTOR signalling during unloading is the subject of future investigation.
Collapse
Affiliation(s)
- J Matthew Kuczmarski
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA.,Heart and Vascular Institute, Penn State College of Medicine, Hershey, PA, USA
| | - Jeff M Hord
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Yang Lee
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Vinicius Guzzoni
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA.,Laboratory of Biochemistry and Molecular Biology, Department of Physiological Science, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
| | - Dinah Rodriguez
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Matthew S Lawler
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA.,Department of Biomedical Engineering, Georgia Tech University, Atlanta, GA, USA
| | - Erika L Garcia-Villatoro
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA.,Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Dylan Holly
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Patrick Ryan
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Kristian Falcon
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Marcela Garcia
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - Mariana Janini Gomes
- Physiopathology Program in Internal Medicine, Botucatu Medical School, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - James D Fluckey
- Muscle Biology Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA
| | - John M Lawler
- Redox Biology & Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, TX, USA.,Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| |
Collapse
|
22
|
Moon YS, Kwon DR, Lee YJ. Therapeutic effect of microcurrent on calf muscle atrophy in immobilized rabbit. Muscle Nerve 2018; 58:270-276. [PMID: 29466826 DOI: 10.1002/mus.26110] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/18/2018] [Indexed: 01/13/2023]
Abstract
INTRODUCTION Immobilization causes significant muscle loss. In this study we assessed the regenerative effect of microcurrent electrical stimulation (MES) on gastrocnemius muscle (GCM) atrophy induced by immobilization by cast (IC) in rabbits. METHODS Fifteen rabbits were divided into 3 groups: IC (group 1); IC and free re-ambulation for 2 weeks after cast removal (CR) (group 2); and IC and MES for 2 weeks after CR (group 3). We evaluated clinical parameters (calf circumference, compound muscle action potential of tibial nerve, and thickness of GCM by ultrasound), histomorphometric data (muscle composition and cross-sectional area), and immunohistochemistry. RESULTS Mean atrophic changes in clinical parameters in group 3 were significantly less than those in groups 1 and 2 (P < 0.05). Histomophometric and immunohistochemical parameters in group 3 were significantly greater than those in groups 1 and 2, respectively (P < 0.05). DISCUSSION MES prevents muscle atrophy and facilitates regeneration of muscle. Muscle Nerve 58: 270-276, 2018.
Collapse
Affiliation(s)
- Yong Suk Moon
- Department of Anatomy, Catholic University of Daegu School of Medicine, Daegu, South Korea
| | - Dong Rak Kwon
- Department of Rehabilitation Medicine, Catholic University of Daegu School of Medicine, 33 Duryugongwon-ro 17-gil Nam-Gu, Daegu, 42472, South Korea
| | - Yoon-Jin Lee
- Department of Biochemistry, College of Medicine, Soonchunhyang University, Cheonan, South Korea
| |
Collapse
|
23
|
Abstract
UNLABELLED Physical inactivity, which may result from immobilization, is recognized as a risk factor for the development of obesity. We aimed to quantify the decrease in activity-related energy expenditure (AEE) because of lower limb cast immobilization. We carried out a longitudinal matched case-control study: 34 adolescents with a first episode of lower limb fracture and 34 healthy cases. Physical activity was assessed during cast immobilization by an accelerometer from which we calculated the decrease in AEE. AEE in adolescents with lower limb fractures was estimated to be 16.0% lower than healthy controls. When converted into kcal per mean participants' weight, the difference in AEE amounted to 125 kcal/day, which corresponds to 5.2 h of slow walking. A significant reduction of AEE in adolescents with lower limb fractures may lead to a significantly positive energy balance as there is usually no compensatory reduction of energy intake. An increase of walking seems unrealistic in this situation and patients should be advised at the emergency unit to reduce their energy intake during the immobilization period. LEVEL OF EVIDENCE Level III, prospective case-control study.
Collapse
|
24
|
Durán-Carabali LE, Sanches EF, Marques MR, Aristimunha D, Pagnussat A, Netto CA. Longer hypoxia-ischemia periods to neonatal rats causes motor impairments and muscular changes. Neuroscience 2016; 340:291-298. [PMID: 27826103 DOI: 10.1016/j.neuroscience.2016.10.068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/21/2016] [Accepted: 10/29/2016] [Indexed: 12/21/2022]
Abstract
Prematurity and hypoxia-ischemia (HI) can lead to movement disorders in infants. Considering that mild-moderate HI induced at postnatal day (PND) 3 has failed to produce motor disabilities similar to those seen in pre-term newborns, the main goal of the present study was to verify whether longer hypoxia periods would mimic motor function impairment, brain and muscle morphological alterations. Forty-nine Wistar rat pups of both sexes were randomly assigned to surgical control (CG) and HI groups. HI animals were submitted to the Levine-Rice model at PND 3, and exposed to 120 (HI-120'), 180 (HI-180') or 210 (HI-210') minutes of hypoxia (FiO2: 0.08). Sensorimotor function was assessed as from PND 35-45, by means of grasping strength, adhesive removal, cylinder and ladder walking tests. Histological staining was used to quantify the striatal volume and the cross-sectional area (CSA) of skeletal muscles. Cylinder and adhesive removal test evidenced that HI-180' and HI-210' groups had asymmetrical use of the forepaws when compared to controls. HI animals showed a decrease in the step placement quality and an increase in step errors when compared to CG (P⩽0.05). Reduction in striatal volume correlates with behavioral assessment, HI-180' and HI-210' groups presented lower biceps brachii and tibialis anterior CSA. These results show that rats exposed to longer hypoxic periods at PND3 have encephalic and sensorimotor impairments that mimic those observed in preterm infants. Morphological changes in muscle tissue evidence a new pathophysiological characteristic of the HI model that might be of relevance for the study of sensorimotor deficits.
Collapse
Affiliation(s)
- L E Durán-Carabali
- Post-graduation Program of Physiology, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil.
| | - E F Sanches
- Post-graduation Program of Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre (UFRGS), RS, Brazil
| | - M R Marques
- Post-graduation Program of Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre (UFRGS), RS, Brazil
| | - D Aristimunha
- Post-graduation Program of Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre (UFRGS), RS, Brazil
| | - A Pagnussat
- Rehabilitation Sciences Graduate Program, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Brazil
| | - C A Netto
- Post-graduation Program of Physiology, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, Brazil; Post-graduation Program of Neuroscience, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre (UFRGS), RS, Brazil
| |
Collapse
|
25
|
Nieuwenhuizen J, Halm JA, Jeekel J, Lange JF. Natural Course of Incisional Hernia and Indications for Repair. Scand J Surg 2016; 96:293-6. [DOI: 10.1177/145749690709600406] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: Incisional hernias and incisional hernia repair can be a significant challenge for both surgeon and patient. Despite the growing amount of literature describing various methods of surgical techniques, little has been published the natural course of an incisional hernia and regarding indications for incisional hernia repair. Methods: An internet database search was performed to identify articles describing symptoms presented by patients and indications for incisional hernia repair. Results: Various symptoms and indications regarding incisional hernia repair and the natural course of an incisional hernia are mentioned in the literature. Nevertheless, published data accurately describing these symptoms and indications are rare. Conclusion: A prospective trial monitoring incisional hernias as well as comparing conservative treatment with repair should be performed.
Collapse
Affiliation(s)
- J. Nieuwenhuizen
- Department of Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - J. A. Halm
- Department of Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - J. Jeekel
- Department of Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - J. F. Lange
- Department of Surgery, Erasmus University Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
26
|
Unexpected Fascicle Length Changes In Denervated Feline Soleus Muscle During Stance Phase Of Walking. Sci Rep 2015; 5:17619. [PMID: 26635206 PMCID: PMC4669439 DOI: 10.1038/srep17619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/03/2015] [Indexed: 11/27/2022] Open
Abstract
After surgical repair of traumatically severed peripheral nerves, associated muscles are paralyzed for weeks. Little is known about fascicle length changes in paralyzed muscles during locomotion. The aim of this study was to investigate to what extent, if any, muscle fascicles of denervated feline soleus (SO) change length during stance of walking when intact SO synergists are actively contracting. Hindlimb kinematics, SO fascicle and muscle-tendon unit (MTU) length, and EMG activity of SO, lateral gastrocnemius (LG) and medial gastrocnemius (MG) were measured during level and slope walking in adult cats. Measurements were taken before and 1–2 weeks following SO-LG denervation. Unexpectedly, SO fascicle lengthening and shortening during stance in all walking conditions were evident after denervation. The greatest SO fascicle shortening (17.3 ± 2.2% of a reference length) and least fascicle lengthening (1.5 ± 0.8%) after denervation were found during upslope walking, where MG EMG activity was greatest across slopes (P < 0.05) and greatest discrepancies between post denervation SO fascicle and MTU length changes occurred. These findings suggest that myofascial linkages between denervated SO and its active synergists might affect its fascicle length changes. Further studies are needed to directly test this suggestion.
Collapse
|
27
|
Kawano F, Nimura K, Ishino S, Nakai N, Nakata K, Ohira Y. Differences in histone modifications between slow- and fast-twitch muscle of adult rats and following overload, denervation, or valproic acid administration. J Appl Physiol (1985) 2015; 119:1042-52. [PMID: 26404615 DOI: 10.1152/japplphysiol.00289.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 09/21/2015] [Indexed: 11/22/2022] Open
Abstract
Numerous studies have reported alterations in skeletal muscle properties and phenotypes in response to various stimuli such as exercise, unloading, and gene mutation. However, a shift in muscle fiber phenotype from fast twitch to slow twitch is not completely induced by stimuli. This limitation is hypothesized to result from the epigenetic differences between muscle types. The main purpose of the present study was to identify the differences in histone modification for the plantaris (fast) and soleus (slow) muscles of adult rats. Genome-wide analysis by chromatin immunoprecipitation followed by DNA sequencing revealed that trimethylation at lysine 4 and acetylation of histone 3, which occurs at transcriptionally active gene loci, was less prevalent in the genes specific to the slow-twitch soleus muscle. Conversely, gene loci specific to the fast-twitch plantaris muscle were associated with the aforementioned histone modifications. We also found that upregulation of slow genes in the plantaris muscle, which are related to enhanced muscular activity, is not associated with activating histone modifications. Furthermore, silencing of muscle activity by denervation caused the displacement of acetylated histone and RNA polymerase II (Pol II) in 5' ends of genes in plantaris, but minor effects were observed in soleus. Increased recruitment of Pol II induced by forced acetylation of histone was also suppressed in valproic acid-treated soleus. Our present data indicate that the slow-twitch soleus muscle has a unique set of histone modifications, which may relate to the preservation of the genetic backbone against physiological stimuli.
Collapse
Affiliation(s)
- Fuminori Kawano
- Graduate School of Health Sciences, Matsumoto University, Matsumoto, Nagano, Japan;
| | - Keisuke Nimura
- Division of Gene Therapy Science, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Saki Ishino
- Center for Medical Research and Education, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Naoya Nakai
- School of Human Cultures, University of Shiga Prefecture, Hikone, Shiga, Japan
| | - Ken Nakata
- Medicine for Sports and Performing Arts, Graduate School of Medicine, Osaka University, Toyonaka, Osaka, Japan; and
| | - Yoshinobu Ohira
- Graduate School of Sports Sciences, Doshisha University, Kyotanabe City, Kyoto, Japan
| |
Collapse
|
28
|
Konrad A, Tilp M. Effects of ballistic stretching training on the properties of human muscle and tendon structures. J Appl Physiol (1985) 2014; 117:29-35. [DOI: 10.1152/japplphysiol.00195.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to investigate the influence of a 6-wk ballistic stretching training program on various parameters of the human gastrocnemius medialis muscle and the Achilles tendon. It is known that ballistic stretching is an appropriate means of increasing the range of motion (RoM), but information in the literature about the mechanical adaptation of the muscle-tendon unit (MTU) is scarce. Therefore, in this study, a total of 48 volunteers were randomly assigned into ballistic stretching and control groups. Before and following the stretching intervention, we determined the maximum dorsiflexion RoM with the corresponding fascicle length and pennation angle. Passive resistive torque (PRT) and maximum voluntary contraction (MVC) were measured with a dynamometer. Muscle-tendon junction (MTJ) displacement allowed us to determine the length changes in tendon and muscle, and hence to calculate stiffness. Mean RoM increased significantly from 33.8 ± 6.3° to 37.8 ± 7.2° only in the intervention group, but other functional (PRT, MVC) and structural (fascicle length, pennation angle, muscle stiffness, tendon stiffness) parameters were unaltered. Thus the increased RoM could not be explained by structural changes in the MTU and was likely due to increased stretch tolerance.
Collapse
Affiliation(s)
- Andreas Konrad
- University of Graz, Institute of Sports Science, Graz, Austria
| | - Markus Tilp
- University of Graz, Institute of Sports Science, Graz, Austria
| |
Collapse
|
29
|
Lawler JM, Kunst M, Hord JM, Lee Y, Joshi K, Botchlett RE, Ramirez A, Martinez DA. EUK-134 ameliorates nNOSμ translocation and skeletal muscle fiber atrophy during short-term mechanical unloading. Am J Physiol Regul Integr Comp Physiol 2014; 306:R470-82. [PMID: 24477538 DOI: 10.1152/ajpregu.00371.2013] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Reduced mechanical loading during bedrest, spaceflight, and casting, causes rapid morphological changes in skeletal muscle: fiber atrophy and reduction of slow-twitch fibers. An emerging signaling event in response to unloading is the translocation of neuronal nitric oxide synthase (nNOSμ) from the sarcolemma to the cytosol. We used EUK-134, a cell-permeable mimetic of superoxide dismutase and catalase, to test the role of redox signaling in nNOSμ translocation and muscle fiber atrophy as a result of short-term (54 h) hindlimb unloading. Fischer-344 rats were divided into ambulatory control, hindlimb-unloaded (HU), and hindlimb-unloaded + EUK-134 (HU-EUK) groups. EUK-134 mitigated the unloading-induced phenotype, including muscle fiber atrophy and muscle fiber-type shift from slow to fast. nNOSμ immunolocalization at the sarcolemma of the soleus was reduced with HU, while nNOSμ protein content in the cytosol increased with unloading. Translocation of nNOS from the sarcolemma to cytosol was virtually abolished by EUK-134. EUK-134 also mitigated dephosphorylation at Thr-32 of FoxO3a during HU. Hindlimb unloading elevated oxidative stress (4-hydroxynonenal) and increased sarcolemmal localization of Nox2 subunits gp91phox (Nox2) and p47phox, effects normalized by EUK-134. Thus, our findings are consistent with the hypothesis that oxidative stress triggers nNOSμ translocation from the sarcolemma and FoxO3a dephosphorylation as an early event during mechanical unloading. Thus, redox signaling may serve as a biological switch for nNOS to initiate morphological changes in skeletal muscle fibers.
Collapse
Affiliation(s)
- John M Lawler
- Redox Biology and Cell Signaling Laboratory, Department of Health and Kinesiology, Texas A&M University, College Station, Texas
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Labruyère R, Zimmerli M, van Hedel HJ. Slowed Down: Response Time Deficits in Well-Recovered Subjects With Incomplete Spinal Cord Injury. Arch Phys Med Rehabil 2013; 94:2020-6. [DOI: 10.1016/j.apmr.2013.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 03/28/2013] [Accepted: 04/04/2013] [Indexed: 10/26/2022]
|
31
|
Adductor squeeze test values and hip joint range of motion in Gaelic football athletes with longstanding groin pain. J Sci Med Sport 2013; 17:155-9. [PMID: 23684372 DOI: 10.1016/j.jsams.2013.04.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 03/27/2013] [Accepted: 04/05/2013] [Indexed: 01/05/2023]
Abstract
OBJECTIVES The objective of the present study was to investigate whether differences exist in adductor squeeze test values and hip joint range of motion between athletes with longstanding groin pain and injury-free controls. DESIGN Observational study with a case control design. METHODS Eighteen Gaelic football players with current longstanding groin pain and 18 matched injury-free controls were assessed on their performance of the adductor squeeze test. Adductor squeeze test values were quantified using a sphygmomanometer. A fluid-filled inclinometer was used to assess hip joint internal and external rotation range of motion. A bent knee fall-out test was also utilised to examine hip joint range of motion. RESULTS A significant difference in adductor squeeze test values was observed between the control group (269 ± 25 mmHg) and longstanding groin pain group (202 ± 36 mmHg; p<0.01). Furthermore the longstanding groin pain group had a decreased bent knee fall-out (p<0.01) bilaterally, as well as decreased hip joint internal rotation (p<0.05) and hip joint external rotation (p<0.05) range of motion bilaterally when compared to the control group. CONCLUSIONS Gaelic football players with longstanding groin pain exhibit decreased adductor squeeze test values and hip joint range of motion when compared to non-injured players. These findings have implications for assessment and rehabilitation practices, as well as return to play criteria.
Collapse
|
32
|
Kim JH, Thompson LV. Inactivity, age, and exercise: single-muscle fiber power generation. J Appl Physiol (1985) 2012; 114:90-8. [PMID: 23104693 DOI: 10.1152/japplphysiol.00525.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We examined the effects of mild therapeutic exercise during a period of inactivity on size and contractile functions of myosin heavy chain (MHC) type I (n = 204) and type II (n = 419) single fibers from the medial gastrocnemius in three age groups. Young adult (5-12 mo), middle-aged (24-31 mo), and old (32-37 mo) F344BNF1 rats were assigned to one of three groups: weight-bearing control, non-weight bearing (NWB), and NWB plus exercise (NWBX). Fourteen days of hindlimb suspension were applied in NWB rats. The NWBX rats exercised on the treadmill for 15 min, four times a day, during the period of NWB. The NWBX did not improve peak power, but increased normalized power of MHC type I fibers in young adult rats. In MHC type II fibers, NWBX did not change peak power, isometric maximal force, V(max), and fiber size from young adult and middle-aged rats. NWBX did not improve peak power and isometric maximal force and showed a dramatic decline in V(max) and normalized power in the old rats. Collectively, mild treadmill exercise during a period of inactivity does not improve peak power of MHC type I or type II fiber from the gastrocnemius in young, middle-aged, and old rats. However, NWBX is beneficial in enhancing normalized power of MHC type I fibers in young adult rats, most likely due to the stimulus intensity and the ability of the individual fibers to adapt to the stimulus. In contrast, several factors, such as impaired adaptation potential, inappropriate exercise intensity, or increased susceptibility to muscle damage, may contribute to the lack of improvement in the older rats.
Collapse
Affiliation(s)
- Jong-Hee Kim
- Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | | |
Collapse
|
33
|
Kim JH, Thompson LV. Differential effects of mild therapeutic exercise during a period of inactivity on power generation in soleus type I single fibers with age. J Appl Physiol (1985) 2012; 112:1752-61. [PMID: 22422796 DOI: 10.1152/japplphysiol.01077.2011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The purpose of this study was to investigate the effects of mild therapeutic exercise (treadmill) in preventing the inactivity-induced alterations in contractile properties (e.g., power, force, and velocity) of type I soleus single fibers in three different age groups. Young adult (5- to 12-mo-old), middle-aged (24- to 31-mo-old), and old (32- to 40-mo-old) F344BNF1 rats were randomly assigned to three experimental groups: weight-bearing control (CON), non-weight bearing (NWB), and NWB with exercise (NWBX). NWB rats were hindlimb suspended for 2 wk, representing inactivity. The NWBX rats were hindlimb suspended for 2 wk and received therapeutic exercise on a treadmill four times a day for 15 min each. Peak power and isometric maximal force were reduced following hindlimb suspension (HS) in all three age groups. HS decreased fiber diameter in young adult and old rats (-21 and -12%, respectively). Specific tension (isometric maximal force/cross-sectional area) was significantly reduced in both the middle-aged (-36%) and old (-23%) rats. The effects of the mild therapeutic exercise program on fiber diameter and contractile properties were age specific. Mild treadmill therapeutic exercise attenuated the HS-induced reduction in fiber diameter (+17%, 93% level of CON group) and peak power (μN·fiber length·s(-1)) (+46%, 63% level of CON group) in young adult rats. In the middle-aged animals, this exercise protocol improved peak power (+60%, 100% level of CON group) and normalized power (kN·m(-2)·fiber length·s(-1)) (+45%, 108% level of CON group). Interestingly, treadmill exercise resulted in a further reduction in shortening velocity (-42%, 67% level of CON group) and specific tension (-29%, 55% level of CON group) in the old animals. These results suggest that mild treadmill exercise is beneficial in attenuating and preventing inactivity-induced decline in peak power of type I soleus single fibers in young adult and middle-aged animals, respectively. However, this exercise program does not prevent the HS-induced decline in muscle function in the old animals.
Collapse
Affiliation(s)
- Jong-Hee Kim
- Department of Physical Medicine and Rehabilitation, Medical School, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | | |
Collapse
|
34
|
|
35
|
Abstract
BACKGROUND Deleterious effects of lower limb immobilization in adults have been well described and suggest that altered muscle strength was not fully recoverable after rehabilitation. In this study, we hypothesized that the same significant differences in strength and power performances between the injured and noninjured leg are foreseeable 18 months after a lower limb fracture in teenagers, and between injured adolescents and healthy controls. METHODS The effects of cast immobilization on the strength and power performance were evaluated 18 months after a lower limb fracture in 39 injured teenagers who were paired with healthy controls. Strength and power performance were assessed during a single-leg vertical jump test using a force platform. RESULTS At 18 months, strength performance in injured teenagers was similar in both lower limbs. A significant difference was found between injured and noninjured legs for maximal muscular power measurement. However, the limb symmetry index was superior to 85% for maximal muscular power, which should be considered as normal. Limb asymmetries greater than 15% for muscular strength and power were more frequent in injured teenagers than in noninjured children and adolescents, but the difference was statistically significant only for the mean muscle power (P=0.0003). CONCLUSIONS These findings show that the recovery of muscular strength and power is foreseeable after a lower limb fracture in the pediatric population, even if a greater percentage of injured teenagers was found to have limb asymmetries greater than 15% for mean muscular power 18 months after trauma compared with the healthy controls. LEVEL OF EVIDENCE Level III, case-control study.
Collapse
|
36
|
Giszter SF, Hockensmith G, Ramakrishnan A, Udoekwere UI. How spinalized rats can walk: biomechanics, cortex, and hindlimb muscle scaling--implications for rehabilitation. Ann N Y Acad Sci 2010; 1198:279-93. [PMID: 20536943 DOI: 10.1111/j.1749-6632.2010.05534.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Neonatal spinalized (NST) rats can achieve autonomous weight-supported locomotion never seen after adult injury. Mechanisms that support function in NST rats include increased importance of cortical trunk control and altered biomechanical control strategies for stance and locomotion. Hindlimbs are isolated from perturbations in quiet stance and act in opposition to forelimbs in locomotion in NST rats. Control of roll and yaw of the hindlimbs is crucial in their locomotion. The biomechanics of the hind limbs of NST rats are also likely crucial. We present new data showing the whole leg musculature scales proportional to normal rat musculature in NST rats, regardless of function. This scaling is a prerequisite for the NST rats to most effectively use pattern generation mechanisms and motor patterns that are similar to those present in intact rats. Pattern generation may be built into the lumbar spinal cord by evolution and matched to the limb biomechanics, so preserved muscle scaling may be essential to the NST function observed.
Collapse
Affiliation(s)
- Simon F Giszter
- Neurobiology and Anatomy, School of Bioengineering, Drexel University College of Medicine, Philadelphia, Pennsylvania, USA.
| | | | | | | |
Collapse
|
37
|
Fujita N, Arakawa T, Matsubara T, Ando H, Miki A. Influence of fixed muscle length and contractile properties on atrophy and subsequent recovery in the rat soleus and plantaris muscles. ACTA ACUST UNITED AC 2010; 72:151-63. [PMID: 20513978 DOI: 10.1679/aohc.72.151] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This study examined muscular atrophy and the recovery process induced by hindlimb unloading and joint immobilization in the rat soleus and plantaris muscles. Rats were divided into control, hindlimb unloading (HU), hindlimb unloading with ankle joint immobilization at the maximum dorsiflexion (HUD), and maximum plantarflexion (HUP) groups. The hindlimb was reloaded after fourteen days of unloading, and muscle atrophy and walking ability were assessed at 0, 3, and 7 days of reloading. A cross sectional area of muscle fibers in the soleus muscle on day 0 of reloading revealed sizes in order from the control, HUD, HUP down to the HU group, indicating that the HU group was the most atrophied among the four groups. These values in the plantaris muscle ranged in order from the control, HU, HUD, to HUP groups, the HUP group being the most atrophied among the four groups. These muscles recovered from atrophy in the same descending order, and the values in the HUD and HUP groups slowly recovered during the reloading periods. The HUD and HUP groups showed a central core lesion and reloading-induced lesions in some type I muscle fibers after the immobilization and reloading, one possible reason for the delayed recovery in these groups. The muscle atrophy in the HU, HUD, and HUP groups remained at day 7 although the walking ability appeared to be normal. Accordingly, further rehabilitation therapy might be necessary even if the functional ability appears to be normal.
Collapse
Affiliation(s)
- Naoto Fujita
- Department of Rehabilitation Sciences, Kobe University Graduate School of Health Sciences, Suma-ku, Kobe, Japan
| | | | | | | | | |
Collapse
|
38
|
Abstract
This series of articles for rehabilitation in practice aims to cover a knowledge element of the rehabilitation medicine curriculum. Nevertheless they are intended to be of interest to a multidisciplinary audience. The competency addressed in this article is ‘The trainee consistently demonstrates a knowledge of the pathophysiology of various specific impairments including lower motor neuron weakness’ and ‘management approaches for specific impairments including lower motor neuron weakness’. This article explores weakness as a lower motor symptom. Weakness as a primary impairment of neuromuscular diseases is addressed, with recognition of the phenomenon of disuse atrophy, and how weakness impacts on the functional abilities of people with myopathy and neuropathy. Interventions to reduce weakness or address the functional consequences of weakness are evaluated with consideration of safety and clinical application. Learning outcomes: This paper will allow readers to: (1) appraise the contribution of research in rehabilitation of lower motor neuron weakness to clinical decision making and (2) engage with the issues that arise when researching rehabilitation interventions for lower motor neuron weakness. Aim of article: Impairments associated with neuromuscular conditions can lead to significant functional difficulties that can impact on a person’s daily participation. This article focuses on the primary impairment of weakness and explores the research evidence for rehabilitation interventions that directly influence weakness or address the impact of weakness on function.
Collapse
Affiliation(s)
- Gita M Ramdharry
- St George's School of Physiotherapy, Faculty of Health and Social Care Sciences, St George's University of London and Kingston University, UK,
| |
Collapse
|
39
|
Xu J, Marzetti E, Seo AY, Kim JS, Prolla TA, Leeuwenburgh C. The emerging role of iron dyshomeostasis in the mitochondrial decay of aging. Mech Ageing Dev 2010; 131:487-93. [PMID: 20434480 DOI: 10.1016/j.mad.2010.04.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Revised: 04/14/2010] [Accepted: 04/21/2010] [Indexed: 11/26/2022]
Abstract
Recent studies show that cellular and mitochondrial iron increases with age. Iron overload, especially in mitochondria, increases the availability of redox-active iron, which may be a causal factor in the extensive age-related biomolecular oxidative damage observed in aged organisms. Such damage is thought to play a major role in the pathogenesis of iron overload diseases and age-related pathologies. Indeed, recent findings of the beneficial effects of iron manipulation in life extension in Caenorhabditis elegans, Drosophila and transgenic mice have sparked a renewed interest in the potential role of iron in longevity. A substantial research effort now focuses on developing and testing safe pharmacologic interventions to combat iron dyshomeostasis in aging, acute injuries and in iron overload disorders.
Collapse
Affiliation(s)
- Jinze Xu
- Department of Aging and Geriatrics Research, Division of Biology of Aging, Genomics, Metabolism and Biomarkers Core of the Institute on Aging, University of Florida, Gainesville, FL 32611, USA
| | | | | | | | | | | |
Collapse
|
40
|
|
41
|
Proteolysis activation and proteome alterations in murine skeletal muscle submitted to 1 week of hindlimb suspension. Eur J Appl Physiol 2009; 107:553-63. [DOI: 10.1007/s00421-009-1151-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2009] [Indexed: 12/16/2022]
|
42
|
Choi H, Selpides PJI, Nowell MM, Rourke BC. Functional overload in ground squirrel plantaris muscle fails to induce myosin isoform shifts. Am J Physiol Regul Integr Comp Physiol 2009; 297:R578-86. [PMID: 19553499 DOI: 10.1152/ajpregu.00236.2009] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We performed 2 wk of mechanical overload by synergist ablation on plantaris muscles from a small rodent hibernator, Spermophilus lateralis. While this muscle displays prominent myosin heavy-chain (MyHC) isoform shifts during hibernation, sensitivity to mechanical loading as a stimulus for muscle mass and isoform plasticity has not been demonstrated. Squirrel muscles, whether during hibernation or not, potentially are less sensitive to mechanical unloading, but we hypothesized that increased loading would produce the typical mammalian response of greater plantaris mass and MyHC shifts. Mechanical overload produced a 50% increase in muscle mass but, surprisingly, no changes in MyHC isoform protein or mRNA expression, despite previously observed fast-to-slow MyHC isoform switching during hibernation. Citrate synthase enzyme activity, as well as mRNA expression of creatine kinase and the muscle growth factor myostatin, were all unchanged. The mRNA expression of critical muscle atrophy genes decreased by 50% during hypertrophy, including ubiquitin ligases MuRF1 and MAFbx, and the related transcription factor FOXO-1a. Insulin-like growth factor (IGF-1) and hypoxia-inducible factor (HIF-1alpha) mRNA expression was elevated by 400% and 150%. Fast-to-slow MyHC isoform shifts appear unnecessary to support the increased recruitment of the plantaris muscle, shifts which are seen in other rodent models. Our results are consistent with muscular activity during interbout arousals as a potential mechanism to preserve muscle mass, but illustrate the primary importance of other seasonal factors besides patterns of muscle activation which must act in concert to alter MyHC isoforms and muscle fiber type during hibernation.
Collapse
Affiliation(s)
- Hyung Choi
- Dept. of Biological Sciences, California State Univ., Long Beach, 1250 Bellflower Blvd, Long Beach, CA 90840, USA
| | | | | | | |
Collapse
|
43
|
Marzetti E, Hwang JCY, Lees HA, Wohlgemuth SE, Dupont-Versteegden EE, Carter CS, Bernabei R, Leeuwenburgh C. Mitochondrial death effectors: relevance to sarcopenia and disuse muscle atrophy. Biochim Biophys Acta Gen Subj 2009; 1800:235-44. [PMID: 19450666 DOI: 10.1016/j.bbagen.2009.05.007] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 05/06/2009] [Accepted: 05/12/2009] [Indexed: 01/07/2023]
Abstract
Accelerated apoptosis in skeletal muscle is increasingly recognized as a potential mechanism contributing to the development of sarcopenia of aging and disuse muscle atrophy. Given their central role in the regulation of apoptosis, mitochondria are regarded as key players in the pathogenesis of myocyte loss during aging and other atrophying conditions. Oxidative damage to mitochondrial constituents, impaired respiration and altered mitochondrial turnover have been proposed as potential triggering events for mitochondrial apoptotic signaling. In addition, iron accumulation within mitochondria may enhance the susceptibility to apoptosis during the development of sarcopenia and possibly acute muscle atrophy, likely through exacerbation of oxidative stress. Mitochondria can induce myocyte apoptosis via both caspase-dependent and independent pathways, although the apoptogenic mediators involved may be different depending on age, muscle type and specific atrophying conditions. Despite the considerable advances made, additional research is necessary to establish a definite causal link between apoptotic signaling and the development of sarcopenia and acute atrophy. Furthermore, a translational effort is required to determine the role played by apoptosis in the pathogenesis of sarcopenia and disuse-induced muscle loss in human subjects.
Collapse
Affiliation(s)
- Emanuele Marzetti
- Department of Aging and Geriatrics, Institute on Aging, Division of Biology of Aging, University of Florida, Gainesville, FL 32610-0143, USA.
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Malatesta M, Perdoni F, Battistelli S, Muller S, Zancanaro C. The cell nuclei of skeletal muscle cells are transcriptionally active in hibernating edible dormice. BMC Cell Biol 2009; 10:19. [PMID: 19284674 PMCID: PMC2663540 DOI: 10.1186/1471-2121-10-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 03/14/2009] [Indexed: 12/18/2022] Open
Abstract
Background Skeletal muscle is able to react in a rapid, dynamic way to metabolic and mechanical stimuli. In particular, exposure to either prolonged starvation or disuse results in muscle atrophy. At variance, in hibernating animals muscle atrophy may be scarce or absent after bouts of hibernation i.e., periods of prolonged (months) inactivity and food deprivation, and muscle function is fully preserved at arousal. In this study, myocytes from the quadriceps muscle of euthermic and hibernating edible dormice were investigated by a combination of morphological, morphometrical and immunocytochemical analyses at the light and electron microscopy level. The focus was on cell nuclei and mitochondria, which are highly sensitive markers of changing metabolic rate. Results Findings presented herein demonstrate that: 1) the general histology of the muscle, inclusive of muscle fibre shape and size, and the ratio of fast and slow fibre types are not affected by hibernation; 2) the fine structure of cytoplasmic and nuclear constituents is similar in euthermia and hibernation but for lipid droplets, which accumulate during lethargy; 3) during hibernation, mitochondria are larger in size with longer cristae, and 4) myonuclei maintain the same amount and distribution of transcripts and transcription factors as in euthermia. Conclusion In this study we demonstrate that skeletal muscle cells of the hibernating edible dormouse maintain their structural and functional integrity in full, even after months in the nest. A twofold explanation for that is envisaged: 1) the maintenance, during hibernation, of low-rate nuclear and mitochondrial activity counterbalancing myofibre wasting, 2) the intensive muscle stimulation (shivering) during periodic arousals in the nest, which would mimic physical exercise. These two factors would prevent muscle atrophy usually occurring in mammals after prolonged starvation and/or inactivity as a consequence of prevailing catabolism. Understanding the mechanisms responsible for skeletal muscle preservation in hibernators could pave the way to prevention and treatment of muscle wasting associated with pathological conditions or ageing as well as life in extreme environments, such as ocean deeps or spaceflights.
Collapse
Affiliation(s)
- Manuela Malatesta
- Dipartimento di Scienze Morfologico-Biomediche, Sezione di Anatomia e Istologia, University of Verona, Italy.
| | | | | | | | | |
Collapse
|
45
|
Nierobisz LS, Felts JV, Mozdziak PE. Apoptosis and macrophage infiltration occur simultaneously and present a potential sign of muscle injury in skeletal muscle of nutritionally compromised, early post-hatch turkeys. Comp Biochem Physiol B Biochem Mol Biol 2009; 153:61-5. [PMID: 19416697 DOI: 10.1016/j.cbpb.2009.01.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/21/2009] [Accepted: 01/21/2009] [Indexed: 12/24/2022]
Abstract
Physical stress and malnutrition may cause elimination of myonuclei and produce inflammatory response in muscle. The objective of this study was to histochemically determine the association of apoptosis and/or macrophage infiltration with changes in muscle satellite cell mitotic activity in pectoralis thoracicus muscle of early post-hatch turkey toms. Feed-deprived birds and birds provided with three different levels of crude protein and amino acids (0.88 NRC, 1.00 NRC, and 1.12 NRC) were used in this model. The number of apoptotic nuclei was significantly elevated (P<0.05) and presence of macrophage infiltration was readily detectable in feed-deprived and 0.88 NRC treatment groups 72 h and 96 h post-hatch suggesting potential muscle injury and/or muscle remodeling. The number of apoptotic nuclei was the same (P>0.05), and there was no detectable macrophage infiltration present in birds placed on 1.00 NRC and 1.12 NRC diet 72 h, 96 h, and 120 h post-hatch. At 120 h post-hatch, feed-deprived and 0.88 NRC birds were characterized by no detectable levels of macrophage infiltration and a significant drop (P<0.05) in apoptotic nuclei. Understanding mechanisms that correlate early nutrition with skeletal muscle growth and development may present a useful tool in optimizing muscle health and improving meat quality and yield.
Collapse
Affiliation(s)
- L S Nierobisz
- Department of Poultry Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC 27695, USA.
| | | | | |
Collapse
|
46
|
Moreau NG, Li L, Geaghan JP, Damiano DL. Fatigue resistance during a voluntary performance task is associated with lower levels of mobility in cerebral palsy. Arch Phys Med Rehabil 2008; 89:2011-6. [PMID: 18722588 DOI: 10.1016/j.apmr.2008.03.012] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 09/14/2006] [Accepted: 03/18/2008] [Indexed: 01/08/2023]
Abstract
OBJECTIVES To investigate muscle fatigue of the knee flexors and extensors in people with cerebral palsy (CP) compared with those without motor disability during performance of a voluntary fatigue protocol and to investigate the relationship with functional mobility. DESIGN A case-control study. SETTING A biomechanics laboratory. PARTICIPANTS Ambulatory subjects with CP (n=18; mean age, 17.5 y) in Gross Motor Function Classification System (GMFCS) levels I, II, and III and a comparison group of age-matched subjects (n=16) without motor disability (mean age, 16.6 y). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES The voluntary muscle fatigue protocol consisted of concentric knee flexion and extension at 60 degrees a second for 35 repetitions on an isokinetic dynamometer. Peak torque for each repetition was normalized by the maximum peak torque value. Muscle fatigue was calculated as the rate of decline in normalized peak torque across all repetitions, represented by the slope of the linear regression. Self-selected and fast gait velocities were measured as well as the Pediatric Outcomes Data Collection Instrument (PODCI). RESULTS Greater fatigability (slope) was observed in the comparison group for both knee flexors and extensors than in the group with CP. Within CP, lower knee extensor fatigue (slope) was associated with lower functioning GMFCS levels and lower levels of activity and participation as measured by the PODCI transfers and basic mobility. CONCLUSIONS Even after adjusting for maximum peak torque, the knee flexors and extensors of participants with CP were observed to be less fatigable than age-matched peers without motor disability. The lower rate of muscle fatigue was also associated with lower functional mobility in CP. These results may be related to strength or activation differences and/or muscle property alterations. Future investigations are warranted.
Collapse
Affiliation(s)
- Noelle G Moreau
- Department of Physical Therapy, Washington University, St. Louis, MO 63108, USA.
| | | | | | | |
Collapse
|
47
|
Bruusgaard JC, Gundersen K. In vivo time-lapse microscopy reveals no loss of murine myonuclei during weeks of muscle atrophy. J Clin Invest 2008; 118:1450-7. [PMID: 18317591 DOI: 10.1172/jci34022] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2007] [Accepted: 01/09/2008] [Indexed: 11/17/2022] Open
Abstract
Numerous studies have suggested that muscle atrophy is accompanied by apoptotic loss of myonuclei and therefore recovery would require replenishment by muscle stem cells. We used in vivo time-lapse microscopy to observe the loss and replenishment of myonuclei in murine muscle fibers following induced muscle atrophy. To our surprise, imaging of single fibers for up to 28 days did not support the concept of nuclear loss during atrophy. Muscles were inactivated by denervation, nerve impulse block, or mechanical unloading. Nuclei were stained in vivo either acutely by intracellular injection of fluorescent oligonucleotides or in time-lapse studies after transfection with a plasmid encoding GFP with a nuclear localization signal. We observed no loss of myonuclei in fast- or slow-twitch muscle fibers despite a greater than 50% reduction in fiber cross-sectional area. TUNEL labeling of fragmented DNA on histological sections revealed high levels of apoptotic nuclei in inactive muscles. However, when costained for laminin and dystrophin, virtually none of the TUNEL-positive nuclei could be classified as myonuclei; apoptosis was confined to stromal and satellite cells. We conclude that disuse atrophy is not a degenerative process, but is rather a change in the balance between protein synthesis and proteolysis in a permanent cell syncytium.
Collapse
Affiliation(s)
- Jo C Bruusgaard
- Department of Molecular Biosciences, University of Oslo, Oslo, Norway
| | | |
Collapse
|
48
|
Chingui LJ, Braquinho RP, Severi MTM, Silva CAD. Comportamento quimiometabólico do músculo sóleo na fase aguda da imobilização articular. FISIOTERAPIA E PESQUISA 2008. [DOI: 10.1590/s1809-29502008000200014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
O objetivo foi avaliar o perfil fisiológico do músculo sóleo na fase aguda da imobilização articular na posição de 90o. Ratos Wistar foram divididos em 4 grupos (n=6 cada): controle (C), imobilizado por 1 (Im1), 2 (Im2) e 3 dias (Im3). Após o período experimental, o músculo sóleo foi retirado e foram mensurados: o peso muscular, o índice de hidratação, a concentração de glicogênio e a concentração de DNA/proteínas totais. Os dados foram submetidos a análise estatística, com nível de significância fixado em p<0,05. No primeiro dia não houve alterações nas reservas glicogênicas, sendo observada redução progressiva das reservas: 53% no segundo dia e 65% no terceiro dia de imobilização. O peso muscular sofreu redução de 28,57% apenas no terceiro dia; o índice de hidratação aumentou 6,44% no segundo e 8,58% no terceiro dia. As concentrações de DNA tiveram elevação de 43,18% no primeiro dia, 59,09% no segundo e 75% no terceiro. Quanto à concentração de proteínas totais, houve elevação de 45,9% no primeiro dia, 32,25% no segundo e 58,95% no terceiro dia. Os resultados sugerem que a hipotrofia muscular é um processo desencadeado precocemente, envolvendo alterações quimiofisiológicas que são deflagradas na fase aguda da imobilização.
Collapse
|
49
|
Structural differentiation of skeletal muscle fibers in the absence of innervation in humans. Proc Natl Acad Sci U S A 2007; 104:19339-44. [PMID: 18042706 DOI: 10.1073/pnas.0709061104] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The relative importance of muscle activity versus neurotrophic factors in the maintenance of muscle differentiation has been greatly debated. Muscle biopsies from spinal cord injury patients, who were trained with an innovative protocol of functional electrical stimulation (FES) for prolonged periods (2.4-9.3 years), offered the unique opportunity of studying the structural recovery of denervated fibers from severe atrophy under the sole influence of muscle activity. FES stimulation induced surprising recovery of muscle structure, mass, and force even in patients whose muscles had been denervated for prolonged periods before the beginning of FES training (up to 2 years) and had almost completely lost muscle-specific internal organization. Ninety percent (or more) of the fibers analyzed by electron microscopy showed a striking recovery of the ultrastructural organization of myofibrils and Ca(2+)-handling membrane systems. This functional/structural restoration follows a pattern that mimics some aspects of normal muscle differentiation. Most importantly, the recovery occurs in the complete absence of motor and sensory innervation and of nerve-derived trophic factors, that is, solely under the influence of muscle activity induced by electrical stimulation.
Collapse
|
50
|
Lee YS, Lin CY, Caiozzo VJ, Robertson RT, Yu J, Lin VW. Repair of spinal cord transection and its effects on muscle mass and myosin heavy chain isoform phenotype. J Appl Physiol (1985) 2007; 103:1808-14. [PMID: 17717118 DOI: 10.1152/japplphysiol.00588.2007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A number of significant advances have been developed for treating spinal cord injury during the past two decades. The combination of peripheral nerve grafts and acidic fibroblast growth factor (hereafter referred to as PNG) has been shown to partially restore hindlimb function. However, very little is known about the effects of such treatments in restoring normal muscle phenotype. The primary goal of the current study was to test the hypothesis that PNG would completely or partially restore 1) muscle mass and muscle fiber cross-sectional area and 2) the slow myosin heavy chain phenotype of the soleus muscle. To test this hypothesis, we assigned female Sprague-Dawley rats to three groups: 1) sham control, 2) spinal cord transection (Tx), and 3) spinal cord transection plus PNG (Tx+PNG). Six months following spinal cord transection, the open-field test was performed to assess locomotor function, and then the soleus muscles were harvested and analyzed. SDS-PAGE for single muscle fiber was used to evaluate the myosin heavy chain (MHC) isoform expression pattern following the injury and treatment. Immunohistochemistry was used to identify serotonin (5-HT) fibers in the spinal cord. Compared with the Tx group, the Tx+PNG group showed 1) significantly improved Basso, Beattie, and Bresnahan scores (hindlimb locomotion test), 2) less muscle atrophy, 3) a higher percentage of slow type I fibers, and 4) 5-HT fibers distal to the lesion site. We conclude that the combined treatment of PNG is partially effective in restoring the muscle mass and slow phenotype of the soleus muscle in a T-8 spinal cord-transected rat model.
Collapse
MESH Headings
- Animals
- Body Weight
- Disease Models, Animal
- Female
- Fibroblast Growth Factor 1/pharmacology
- Fibroblast Growth Factor 1/therapeutic use
- Intercostal Nerves/transplantation
- Motor Activity/drug effects
- Muscle Fibers, Skeletal/drug effects
- Muscle Fibers, Skeletal/metabolism
- Muscle Fibers, Skeletal/pathology
- Muscle Fibers, Slow-Twitch/drug effects
- Muscle Fibers, Slow-Twitch/metabolism
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/innervation
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Myosin Heavy Chains/metabolism
- Nerve Regeneration/drug effects
- Organ Size
- Phenotype
- Protein Isoforms/metabolism
- Rats
- Rats, Sprague-Dawley
- Recovery of Function
- Serotonin/metabolism
- Spinal Cord Injuries/drug therapy
- Spinal Cord Injuries/metabolism
- Spinal Cord Injuries/pathology
- Spinal Cord Injuries/physiopathology
- Spinal Cord Injuries/surgery
- Time Factors
Collapse
Affiliation(s)
- Yu-Shang Lee
- Department of Anatomy & Neurobiology, University of California, Irvine, CA, USA
| | | | | | | | | | | |
Collapse
|