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Tsentsevitsky AN, Sibgatullina GV, Odoshivkina YG, Khuzakhmetova VF, Tokmakova AR, Ponomareva AA, Salnikov VV, Zakirjanova GF, Petrov AM, Bukharaeva EA. Functional and Structural Changes in Diaphragm Neuromuscular Junctions in Early Aging. Int J Mol Sci 2024; 25:8959. [PMID: 39201644 PMCID: PMC11354816 DOI: 10.3390/ijms25168959] [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: 07/24/2024] [Revised: 08/10/2024] [Accepted: 08/15/2024] [Indexed: 09/02/2024] Open
Abstract
Age-related impairment of the diaphragm causes respiratory complications. Neuromuscular junction (NMJ) dysfunction can be one of the triggering events in diaphragm weaknesses in old age. Prominent structural and functional alterations in diaphragm NMJs were described in elderly rodents, but NMJ changes in middle age remain unclear. Here, we compared diaphragm muscles from young adult (3 months) and middle-aged (12 months) BALB/c mice. Microelectrode recordings, immunofluorescent staining, electron microscopy, myography, and whole-body plethysmography were used. We revealed presynaptic (i) and postsynaptic (ii) changes. The former (i) included an increase in both action potential propagation velocity and neurotransmitter release evoked by low-, moderate-, and high-frequency activity but a decrease in immunoexpression of synapsin 1 and synaptic vesicle clustering. The latter (ii) consisted of a decrease in currents via nicotinic acetylcholine receptors and the area of their distribution. These NMJ changes correlated with increased contractile responses to moderate- to high-frequency nerve activation. Additionally, we found alterations in the pattern of respiration (an increase in peak inspiratory flow and a tendency of elevation of the tidal volume), which imply increased diaphragm activity in middle-aged mice. We conclude that enhancement of neuromuscular communication (due to presynaptic mechanism) accompanied by improved contractile responses occurs in the diaphragm in early aging.
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Affiliation(s)
- Andrei N. Tsentsevitsky
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
| | - Guzel V. Sibgatullina
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
| | - Yulia G. Odoshivkina
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
- Department of Normal Physiology, Kazan State Medical University, 49 Butlerova Street, 420012 Kazan, Russia
| | - Venera F. Khuzakhmetova
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
| | - Anna R. Tokmakova
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
| | - Anastasia A. Ponomareva
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
| | - Vadim V. Salnikov
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
| | - Guzalia F. Zakirjanova
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
- Department of Normal Physiology, Kazan State Medical University, 49 Butlerova Street, 420012 Kazan, Russia
| | - Alexey M. Petrov
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
- Department of Normal Physiology, Kazan State Medical University, 49 Butlerova Street, 420012 Kazan, Russia
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia
| | - Ellya A. Bukharaeva
- Kazan Institute of Biochemistry and Biophysics, Federal Research Center “Kazan Scientific Center of RAS”, 2/31 Lobachevsky Street, P.O. Box 30, 420111 Kazan, Russia; (A.N.T.); (G.V.S.); (Y.G.O.); (V.F.K.); (A.R.T.); (A.A.P.); (V.V.S.); (G.F.Z.)
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2
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Xie WQ, He M, Yu DJ, Li HZ, Jin HF, Ji BZ, Yang G, Chen LL, Rahmati M, Li YS. Correlation study between bone metabolic markers, bone mineral density, and sarcopenia. J Endocrinol Invest 2024; 47:1559-1572. [PMID: 38097848 DOI: 10.1007/s40618-023-02252-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/19/2023] [Indexed: 02/21/2024]
Abstract
OBJECTIVE To investigate the correlation between bone metabolism markers, bone mineral density (BMD), and sarcopenia. METHODS A total of 331 consecutive patients aged ≥ 60 years who were hospitalized between November 2020 and December 2021 were enrolled. Participants were divided into sarcopenia and non-sarcopenia groups according to the Asian Working Group on Sarcopenia criteria (AWGS, 2019). The clinical data, bone metabolism markers (β-CTX, N-MID, and TP1NP), and BMD were compared between the two groups. RESULTS Age, β-CTX, and N-MID of the sarcopenia group were higher than those of the non-sarcopenia group (P < 0.05), but the BMD T values were lower than those of the non-sarcopenia group (P < 0.05). Binary logistic regression analysis showed that increased femoral neck BMD (FNBMD) was a protective factor for sarcopenia, while increased β-CTX was a risk factor. Pearson/Spearman correlation analysis showed that the diagnostic indices of sarcopenia were positively correlated with FNBMD and negatively correlated with β-CTX and N-MID. Multiple linear regression analysis revealed that BMI and FNBMD significantly positively affected muscle strength and appendicular skeletal muscle mass (ASM). The FNBMD significantly positively affected physical performance, while β-CTX significantly negatively affected muscle strength, ASM, and physical performance. CONCLUSION Increased FNBMD may be a protective factor against sarcopenia, and increased β-CTX may be a risk factor. The FNBMD significantly positively affected the diagnostic indices of sarcopenia, while β-CTX significantly negatively affected them. BMD and bone metabolism marker levels may be considered in early screening for sarcopenia.
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Affiliation(s)
- W Q Xie
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - M He
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - D J Yu
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - H Z Li
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - H F Jin
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - B Z Ji
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - G Yang
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - L L Chen
- Hunan Key Laboratory for Bioanalysis of Complex Matrix Samples, Changsha, 410000, Hunan, China
| | - M Rahmati
- Department of Physical Education and Sport Sciences, Faculty of Literature and Human Sciences, Lorestan University, Khorramabad, Iran
- Department of Physical Education and Sport Sciences, Faculty of Literature and Humanities, Vali-E-Asr University of Rafsanjan, Rafsanjan, Iran
| | - Y S Li
- Deparment of Orthopedics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
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Wang Q, Cui C, Zhang N, Lin W, Chai S, Chow SKH, Wong RMY, Hu Y, Law SW, Cheung WH. Effects of physical exercise on neuromuscular junction degeneration during ageing: A systematic review. J Orthop Translat 2024; 46:91-102. [PMID: 38817243 PMCID: PMC11137388 DOI: 10.1016/j.jot.2024.03.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/27/2024] [Accepted: 03/31/2024] [Indexed: 06/01/2024] Open
Abstract
The neuromuscular junction (NMJ) is a specialized chemical synapse that converts neural impulses into muscle action. Age-associated NMJ degeneration, which involves nerve terminal and postsynaptic decline, denervation, and loss of motor units, significantly contributes to muscle weakness and dysfunction. Although physical training has been shown to make substantial modifications in NMJ of both young and aged animals, the results are often influenced by methodological variables in existing studies. Moreover, there is still lack of strong consensus on the specific effects of exercise on improving the morphology and function of the ageing NMJ. Consequently, the purpose of this study was to conduct a systematic review to elucidate the effects of exercise training on NMJ compartments in the elderly. We conducted a systematic review using PubMed, Embase, and Web of Science databases, employing relevant keywords. Two independent reviewers selected studies that detailed NMJ changes during exercise in ageing, written in English, and available in full text. In total, 20 papers were included. We examined the altered adaptation of the NMJ to exercise, focusing on presynaptic and postsynaptic structures and myofibers in older animals or humans. Our findings indicated that aged NMJs exhibited different adaptive responses to physical exercise compared to younger counterparts. Endurance training, compared with resistance and voluntary exercise regimens, was found to have a more pronounced effect on NMJ structural remodeling, particularly in fast twitch muscle fibers. Physical exercise was observed to promote the formation and maintenance of acetylcholine receptor (AChR) clusters by increasing the recombinant docking protein 7 (Dok7) expression and stabilizing Agrin and lipoprotein receptor-related protein 4 (LRP4). These insights suggest that research on exercise-related therapies could potentially attenuate the progression of neuromuscular degeneration. Translational potential of this article: This systematic review provides a detailed overview of the effects of different types of physical exercise on improving NMJ in the elderly, providing scientific support for the timely intervention of muscle degeneration in the elderly by physical exercise, and providing help for the development of new therapeutic interventions in the future.
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Affiliation(s)
- Qianjin Wang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Can Cui
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Ning Zhang
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Wujian Lin
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Senlin Chai
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Simon Kwoon-Ho Chow
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Department of Orthopaedic Surgery, Stanford University, Stanford, CA, USA
| | - Ronald Man Yeung Wong
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Yong Hu
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Sheung Wai Law
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Wing-Hoi Cheung
- Musculoskeletal Research Laboratory, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
- Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
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Yamaguchi T, Kouzaki K, Sasaki K, Nakazato K. Alterations in neuromuscular junction morphology with ageing and endurance training modulate neuromuscular transmission and myofibre composition. J Physiol 2024. [PMID: 38173183 DOI: 10.1113/jp285143] [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: 06/18/2023] [Accepted: 12/12/2023] [Indexed: 01/05/2024] Open
Abstract
Both ageing and exercise training affect the neuromuscular junction (NMJ) structure. Morphological alterations in the NMJ have been considered to influence neuromuscular transmission and myofibre properties, but the direct link between the morphology and function has yet to be established. We measured the neuromuscular transmission, myofibre composition and NMJ structure of 5-month-old (young) and 24-month-old untrained (aged control) and trained (aged trained) mice. Aged trained mice were subjected to 2 months of endurance training before the measurement. Neuromuscular transmission was evaluated in vivo as the ratio of ankle plantar flexion torque evoked by the sciatic nerve stimulation to that by direct muscle stimulation. The torque ratio was significantly lower in aged mice than in young and aged trained mice at high-frequency stimulations, showing a significant positive correlation with voluntary grip strength. The degree of pre- to post-synaptic overlap of the NMJ was also significantly lower in aged mice and positively correlated with the torque ratio. We also found that the proportion of fast-twitch fibres in the soleus muscle decreased with age, and that age-related denervation occurred preferentially in fast-twitch fibres. Age-related denervation and a shift in myofibre composition were partially prevented by endurance training. These results suggest that age-related deterioration of the NMJ structure impairs neuromuscular transmission and alters myofibre composition, but these alterations can be prevented by structural amelioration of NMJ with endurance training. Our findings highlight the importance of the NMJ as a major determinant of age-related deterioration of skeletal muscles and the clinical significance of endurance training as a countermeasure. KEY POINTS: The neuromuscular junction (NMJ) plays an essential role in neuromuscular transmission and the maintenance of myofibre properties. We show that neuromuscular transmission is impaired with ageing but recovered by endurance training, which contributes to alterations in voluntary strength. Neuromuscular transmission is associated with the degree of pre- to post-synaptic overlap of the NMJ. Age-related denervation of fast-twitch fibres and a shift in myofibre composition toward a slower phenotype are partially prevented by endurance training. Our study provides substantial evidence that age-related and exercise-induced alterations in neuromuscular transmission and myofibre properties are associated with morphological changes in the NMJ.
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Affiliation(s)
- Tatsuhiro Yamaguchi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
- Japan Society for the Promotion of Science, Tokyo, Japan
| | - Karina Kouzaki
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
| | - Kazushige Sasaki
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan
| | - Koichi Nakazato
- Graduate School of Health and Sport Science, Nippon Sport Science University, Tokyo, Japan
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Li Y, Patel M, Baroudi J, Wu M, Gatti S, Liang M, Wipf P, Badawi Y, Meriney SD. A cross-sectional study of ageing at the mouse neuromuscular junction and effects of an experimental therapeutic approach for dynapenia. J Physiol 2023; 601:4135-4150. [PMID: 37606613 DOI: 10.1113/jp284749] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 08/08/2023] [Indexed: 08/23/2023] Open
Abstract
Despite prior efforts to understand and target dynapenia (age-induced loss of muscle strength), this condition remains a major challenge that reduces the quality of life in the aged population. We have focused on the neuromuscular junction (NMJ) where changes in structure and function have rarely been systematically studied as a dynamic and progressive process. Our cross-sectional study found neurotransmission at the male mouse NMJ to be biphasic, displaying an early increase followed by a later decrease, and this phenotype was associated with structural changes to the NMJ. A cross-sectional characterization showed that age-induced alterations fell into four age groups: young adult (3-6 months), adult (7-18 months), early aged (19-24 months), and later aged (25-30 months). We then utilized a small molecule therapeutic candidate, GV-58, applied acutely during the later aged stage to combat age-induced reductions in transmitter release by increasing calcium influx during an action potential, which resulted in a significant increase in transmitter release. This comprehensive study of neuromuscular ageing at the NMJ will enable future research to target critical time points for therapeutic intervention. KEY POINTS: Age-induced frailty and falls are the leading causes of injury-related death and are caused by an age-induced loss of muscle strength due to a combination of neurological and muscular changes. A cross-sectional approach was used to study age-induced changes to the neuromuscular junction in a mouse model, and physiological changes that were biphasic over the ageing time course were found. Changes in physiology at the neuromuscular junction were correlated with alterations in neuromuscular junction morphology. An acutely applied positive allosteric gating modifier of presynaptic voltage-gated calcium channels was tested as a candidate therapeutic strategy that could increase transmitter release at aged neuromuscular junctions. These results provide a detailed time course of age-induced changes at the neuromuscular junction in a mouse model and test a candidate therapeutic strategy for weakness.
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Affiliation(s)
- Y Li
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Patel
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Baroudi
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Wu
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - S Gatti
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Liang
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - P Wipf
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Y Badawi
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Stephen D Meriney
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
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Chung T, Bopp T, Ward C, Notarangelo FM, Schwarcz R, Westbrook R, Xue Q, Walston J, Hoke A. Deletion of quinolinate phosphoribosyltransferase gene accelerates frailty phenotypes and neuromuscular decline with aging in a sex-specific pattern. Aging Cell 2023; 22:e13849. [PMID: 37078472 PMCID: PMC10352574 DOI: 10.1111/acel.13849] [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: 11/04/2022] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/21/2023] Open
Abstract
Decline in neuromuscular function with aging is known to be a major determinant of disability and all-cause mortality in late life. Despite the importance of the problem, the neurobiology of age-associated muscle weakness is poorly understood. In a previous report, we performed untargeted metabolomics on frail older adults and discovered prominent alteration in the kynurenine pathway, the major route of dietary tryptophan degradation that produces neurotoxic intermediate metabolites. We also showed that neurotoxic kynurenine pathway metabolites are correlated with increased frailty score. For the present study, we sought to further examine the neurobiology of these neurotoxic intermediates by utilizing a mouse model that has a deletion of the quinolinate phosphoribosyltransferase (QPRT) gene, a rate-limiting step of the kynurenine pathway. QPRT-/- mice have elevated neurotoxic quinolinic acid level in the nervous system throughout their lifespan. We found that QPRT-/- mice have accelerated declines in neuromuscular function in an age- and sex-specific manner compared to control strains. In addition, the QPRT-/- mice show premature signs of frailty and body composition changes that are typical for metabolic syndrome. Our findings suggest that the kynurenine pathway may play an important role in frailty and age-associated muscle weakness.
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Affiliation(s)
- Tae Chung
- Department of Physical Medicine and RehabilitationJohns Hopkins University School of MedicineBaltimoreMarylandUSA
- Department of NeurologyNeuromuscular DivisionJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Taylor Bopp
- Department of Physical Medicine and RehabilitationJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Chris Ward
- Department of OrthopedicsUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Francesca M. Notarangelo
- Maryland Psychiatric Research CenterDepartment of PsychiatryUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Robert Schwarcz
- Maryland Psychiatric Research CenterDepartment of PsychiatryUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Reyhan Westbrook
- Department of Geriatric Medicine and GerontologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Qian‐Li Xue
- Department of Geriatric Medicine and GerontologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Jeremy Walston
- Department of Geriatric Medicine and GerontologyJohns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Ahmet Hoke
- Department of NeurologyNeuromuscular DivisionJohns Hopkins University School of MedicineBaltimoreMarylandUSA
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7
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Kitase Y, Vallejo JA, Dallas SL, Xie Y, Dallas M, Tiede-Lewis L, Moore D, Meljanac A, Kumar C, Zhao C, Rosser J, Brotto M, Johnson ML, Liu Z, Wacker MJ, Bonewald L. Body weight influences musculoskeletal adaptation to long-term voluntary wheel running during aging in female mice. Aging (Albany NY) 2022; 15:308-352. [PMID: 36403149 PMCID: PMC9925690 DOI: 10.18632/aging.204390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 11/02/2022] [Indexed: 11/19/2022]
Abstract
Frailty is the hallmark of aging that can be delayed with exercise. The present studies were initiated based on the hypothesis that long-term voluntary wheel running (VWR) in female mice from 12 to 18 or 22 months of age would have beneficial effects on the musculoskeletal system. Mice were separated into high (HBW) and low (LBW) body weight based on final body weights upon termination of experiments. Bone marrow fat was significantly higher in HBW than LBW under sedentary conditions, but not with VWR. HBW was more protective for soleus size and function than LBW under sedentary conditions, however VWR increased soleus size and function regardless of body weight. VWR plus HBW was more protective against muscle loss with aging. Similar effects of VWR plus HBW were observed with the extensor digitorum longus, EDL, however, LBW with VWR was beneficial in improving EDL fatigue resistance in 18 mo mice and was more beneficial with regards to muscle production of bone protective factors. VWR plus HBW maintained bone in aged animals. In summary, HBW had a more beneficial effect on muscle and bone with aging especially in combination with exercise. These effects were independent of bone marrow fat, suggesting that intrinsic musculoskeletal adaptions were responsible for these beneficial effects.
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Affiliation(s)
- Yukiko Kitase
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Julian A. Vallejo
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
- Department of Biomedical Sciences, School of Medicine, University of Missouri, Kansas City, MO 64108, USA
| | - Sarah L. Dallas
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - Yixia Xie
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - Mark Dallas
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - LeAnn Tiede-Lewis
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - David Moore
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - Anthony Meljanac
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - Corrine Kumar
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Carrie Zhao
- Department of Anatomy, Cell Biology and Physiology, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Jennifer Rosser
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - Marco Brotto
- Bone-Muscle Research Center, College of Nursing and Health Innovation, University of Texas, Arlington, TX 76019, USA
| | - Mark L. Johnson
- Department of Oral and Craniofacial Sciences, School of Dentistry, University of Missouri, Kansas City, MO 64108, USA
| | - Ziyue Liu
- Department of Biostatistics and Health Data Science, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
| | - Michael J. Wacker
- Department of Biomedical Sciences, School of Medicine, University of Missouri, Kansas City, MO 64108, USA
| | - Lynda Bonewald
- Department of Orthopaedic Surgery, School of Medicine, Indiana University, Indianapolis, IN 46202, USA
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Triolo M, Bhattacharya D, Hood DA. Denervation induces mitochondrial decline and exacerbates lysosome dysfunction in middle-aged mice. Aging (Albany NY) 2022; 14:8900-8913. [PMID: 36342767 PMCID: PMC9740366 DOI: 10.18632/aging.204365] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/24/2022] [Indexed: 11/06/2022]
Abstract
With age, skeletal muscle undergoes a progressive decline in size and quality. Imbalanced mitochondrial turnover and the resultant dysfunction contribute to these phenotypic alterations. Motor neuron denervation (Den) is a contributor to the etiology of muscle atrophy associated with age. Further, aged muscle exhibits reduced plasticity to both enhanced and suppressed contractile activity. It remains unclear when the onset of this blunted response occurs, and how middle-aged muscle adapts to denervation. The purpose of this study was to compare mitochondrial turnover pathways in young (Y, ~5months) and middle-aged (MA, ~15months) mice, and determine the influence of Den. Transgenic mt-Keima mice were subjected to 1,3 or 7 days of Den. Muscle mass, mitochondrial content, and PGC-1α protein were not different between Y and MA mice. However, indications of enhanced mitochondrial fission and mitophagy were evident in MA muscle which were supported by a greater abundance of lysosome proteins. Den resulted in muscle atrophy and reductions in mitochondrial protein content by 7-days. These changes occurred concomitant with modest decreases in PGC-1α protein, but without further elevations in mitophagy. Although both autophagosomal and lysosomal proteins were elevated, evidence of lysosome dysfunction was present following Den in MA mice. These data suggest that increases in fission drive an acceleration of mitophagy in muscle of MA mice to preserve mitochondrial quality. Den exacerbates the aging phenotype by reducing biogenesis in the absence of a change in mitophagy, perhaps limited by lysosomal capacity, leading to an accumulation of dysfunctional mitochondria with an age-related loss of neuromuscular innervation.
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Affiliation(s)
- Matthew Triolo
- Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada,School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
| | - Debasmita Bhattacharya
- Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada,School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
| | - David A. Hood
- Muscle Health Research Centre, York University, Toronto, Ontario M3J 1P3, Canada,School of Kinesiology and Health Science, York University, Toronto, Ontario M3J 1P3, Canada
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9
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Deschenes MR, Flannery R, Hawbaker A, Patek L, Mifsud M. Adaptive Remodeling of the Neuromuscular Junction with Aging. Cells 2022; 11:cells11071150. [PMID: 35406714 PMCID: PMC8997609 DOI: 10.3390/cells11071150] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/24/2022] [Accepted: 03/24/2022] [Indexed: 02/06/2023] Open
Abstract
Aging is associated with gradual degeneration, in mass and function, of the neuromuscular system. This process, referred to as “sarcopenia”, is considered a disease by itself, and it has been linked to a number of other serious maladies such as type II diabetes, osteoporosis, arthritis, cardiovascular disease, and even dementia. While the molecular causes of sarcopenia remain to be fully elucidated, recent findings have implicated the neuromuscular junction (NMJ) as being an important locus in the development and progression of that malady. This synapse, which connects motor neurons to the muscle fibers that they innervate, has been found to degenerate with age, contributing both to senescent-related declines in muscle mass and function. The NMJ also shows plasticity in response to a number of neuromuscular diseases such as amyotrophic lateral sclerosis (ALS) and Lambert-Eaton myasthenic syndrome (LEMS). Here, the structural and functional degradation of the NMJ associated with aging and disease is described, along with the measures that might be taken to effectively mitigate, if not fully prevent, that degeneration.
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10
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Bannow LI, Bonaterra GA, Bertoune M, Maus S, Schulz R, Weissmann N, Kraut S, Kinscherf R, Hildebrandt W. Effect of chronic intermittent hypoxia (CIH) on neuromuscular junctions and mitochondria in slow- and fast-twitch skeletal muscles of mice—the role of iNOS. Skelet Muscle 2022; 12:6. [PMID: 35151349 PMCID: PMC8841105 DOI: 10.1186/s13395-022-00288-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Accepted: 01/10/2022] [Indexed: 01/17/2023] Open
Abstract
Background Obstructive sleep apnea (OSA) imposes vascular and metabolic risks through chronic intermittent hypoxia (CIH) and impairs skeletal muscle performance. As studies addressing limb muscles are rare, the reasons for the lower exercise capacity are unknown. We hypothesize that CIH-related morphological alterations in neuromuscular junctions (NMJ) and mitochondrial integrity might be the cause of functional disorders in skeletal muscles. Methods Mice were kept under 6 weeks of CIH (alternating 7% and 21% O2 fractions every 30 s, 8 h/day, 5 days/week) compared to normoxia (NOX). Analyses included neuromuscular junctions (NMJ) postsynaptic morphology and integrity, fiber cross-sectional area (CSA) and composition (ATPase), mitochondrial ultrastructure (transmission-electron-microscopy), and relevant transcripts (RT-qPCR). Besides wildtype (WT), we included inducible nitric oxide synthase knockout mice (iNOS−/−) to evaluate whether iNOS is protective or risk-mediating. Results In WT soleus muscle, CIH vs. NOX reduced NMJ size (− 37.0%, p < 0.001) and length (− 25.0%, p < 0.05) together with fiber CSA of type IIa fibers (− 14%, p < 0.05) and increased centronucleated fiber fraction (p < 0.001). Moreover, CIH vs. NOX increased the fraction of damaged mitochondria (1.8-fold, p < 0.001). Compared to WT, iNOS−/− similarly decreased NMJ area and length with NOX (− 55%, p < 0.001 and − 33%, p < 0.05, respectively) or with CIH (− 37%, p < 0.05 and − 29%, p < 0.05), however, prompted no fiber atrophy. Moreover, increased fractions of damaged (2.1-fold, p < 0.001) or swollen (> 6-fold, p < 0.001) mitochondria were observed with iNOS−/− vs. WT under NOX and similarly under CIH. Both, CIH- and iNOS−/− massively upregulated suppressor-of-cytokine-signaling-3 (SOCS3) > 10-fold without changes in IL6 mRNA expression. Furthermore, inflammatory markers like CD68 (macrophages) and IL1β were significantly lower in CIH vs. NOX. None of these morphological alterations with CIH- or iNOS−/− were detected in the gastrocnemius muscle. Notably, iNOS expression was undetectable in WT muscle, unlike the liver, where it was massively decreased with CIH. Conclusion CIH leads to NMJ and mitochondrial damage associated with fiber atrophy/centronucleation selectively in slow-twitch muscle of WT. This effect is largely mimicked by iNOS−/− at NOX (except for atrophy). Both conditions involve massive SOCS3 upregulation likely through denervation without Il6 upregulation but accompanied by a decrease of macrophage density especially next to denervated endplates. In the absence of muscular iNOS expression in WT, this damage may arise from extramuscular, e.g., motoneuronal iNOS deficiency (through CIH or knockout) awaiting functional evaluation. Supplementary Information The online version contains supplementary material available at 10.1186/s13395-022-00288-7.
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11
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Cho YH, Seo TB. Effect of treadmill exercise combined with bone marrow stromal cell transplantation on atrophy-related signaling pathway in the denervated soleus muscle. J Exerc Rehabil 2022; 17:395-402. [PMID: 35036388 PMCID: PMC8743607 DOI: 10.12965/jer.2142618.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 11/09/2021] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to investigate whether combination of low-intensity exercise with bone marrow stromal cell (BMSC) transplantation could regulate protein kinas B (Akt)-mammalian target of rapamycin (mTOR) and Wnt3a-β-catenin signaling pathways for prevention of soleus muscle atrophy after sciatic nerve injury (SNI). The experimental rats divided into 5 groups (n=10): normal control group, SNI+sedentary group (SED), SNI+low-intensity treadmill exercise group (TEX), SNI+BMSC transplantation group (BMSC), SNI+TEX+BMSC transplantation group (TEX+BMSC). Sciatic nerve crush injury was applied into the middle of thigh twice for 1 min and 30 sec at interval. Low-intensity treadmill exercise was comprised of walking at a speed of 4 to 8 m/min for 30 min once a day. cultured BMSC at a density of 5×106 in 50-μL phosphate-buffered saline was injected into the distal portion of the injured sciatic nerves. TEX+BMSC group dramatically up-regulated expression levels of growth-associated protein-43 in the injured sciatic nerve at 2 weeks postinjury. Also, although Akt and mTOR signaling pathway significantly increased in TEX and BMSC groups than SED group, TEX+BMSC group showed more potent increment on this signaling in soleus muscle after SNI. Lastly, Wnt3a and the nuclear translocation of β-catenin and nuclear factor-kappa B in soleus were increased by SNI, but TEX+BMSC group significantly downregulated activity of this signaling pathway in the nuclear cell lysate of soleus muscle. Present findings provide new information that combination of low-intensity treadmill exercise might be effective therapeutic approach on restriction of soleus muscle atrophy after peripheral nerve injury.
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Affiliation(s)
- Yeong-Hyun Cho
- Department of Kinesiology, College of Natural Science, Jeju National University, Jeju, Korea
| | - Tae-Beom Seo
- Department of Kinesiology, College of Natural Science, Jeju National University, Jeju, Korea
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12
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Pratt J, De Vito G, Narici M, Boreham C. Neuromuscular Junction Aging: A Role for Biomarkers and Exercise. J Gerontol A Biol Sci Med Sci 2021; 76:576-585. [PMID: 32832976 DOI: 10.1093/gerona/glaa207] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Indexed: 12/13/2022] Open
Abstract
Age-related skeletal muscle degradation known as "sarcopenia" exerts considerable strain on public health systems globally. While the pathogenesis of such atrophy is undoubtedly multifactorial, disruption at the neuromuscular junction (NMJ) has recently gained traction as a key explanatory factor. The NMJ, an essential communicatory link between nerve and muscle, undergoes profound changes with advancing age. Ascertaining whether such changes potentiate the onset of sarcopenia would be paramount in facilitating a timely implementation of targeted therapeutic strategies. Hence, there is a growing level of importance to further substantiate the effects of age on NMJs, in parallel with developing measures to attenuate such changes. As such, this review aimed to establish the current standpoint on age-related NMJ deterioration and consequences for skeletal muscle, while illuminating a role for biomarkers and exercise in ameliorating these alterations. Recent insights into the importance of key biomarkers for NMJ stability are provided, while the stimulative benefits of exercise in preserving NMJ function are demonstrated. Further elucidation of the diagnostic and prognostic relevance of biomarkers, coupled with the therapeutic benefits of regular exercise may be crucial in combating age-related NMJ and skeletal muscle degradation.
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Affiliation(s)
- Jedd Pratt
- Institute for Sport and Health, University College Dublin, Ireland.,Genuity Science, Dublin, Ireland
| | - Giuseppe De Vito
- Department of Biomedical Sciences, CIR-Myo Myology Centre, Neuromuscular Physiology Laboratory, University of Padua, Italy
| | - Marco Narici
- Department of Biomedical Sciences, CIR-Myo Myology Centre, Neuromuscular Physiology Laboratory, University of Padua, Italy
| | - Colin Boreham
- Institute for Sport and Health, University College Dublin, Ireland
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13
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Sugita S, Tamura K, Yano M, Minegishi Y, Ota N. The Impact of Milk Fat Globule Membrane with Exercise on Age-Related Degeneration of Neuromuscular Junctions. Nutrients 2021; 13:nu13072310. [PMID: 34371820 PMCID: PMC8308682 DOI: 10.3390/nu13072310] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 12/19/2022] Open
Abstract
Morphological changes in neuromuscular junctions (NMJs), which are synapses formed between α-motor neurons and skeletal muscle fibers, are considered to be important in age-related motor dysfunction. We have previously shown that the intake of dietary milk fat globule membrane (MFGM) combined with exercise attenuates age-related NMJ alterations in the early phase of aging. However, it is unclear whether the effect of MFGM with exercise on age-related NMJ alterations persists into old age, and whether intervention from old age is still effective when age-related changes in NMJs have already occurred. In this study, 6- or 18-month-old mice were treated with a 1% MFGM diet and daily running wheel exercise until 23 or 24 months of age, respectively. MFGM treatment with exercise was effective in suppressing the progression of age-related NMJ alterations in old age, and even after age-related changes in NMJs had already occurred. Moreover, the effect of MFGM intake with exercise was not restricted to NMJs but extended to the structure and function of peripheral nerves. This study demonstrates that MFGM intake with exercise may be a novel approach for improving motor function in the elderly by suppressing age-related NMJ alterations.
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14
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Allen MD, Dalton BH, Gilmore KJ, McNeil CJ, Doherty TJ, Rice CL, Power GA. Neuroprotective effects of exercise on the aging human neuromuscular system. Exp Gerontol 2021; 152:111465. [PMID: 34224847 DOI: 10.1016/j.exger.2021.111465] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 05/31/2021] [Accepted: 06/30/2021] [Indexed: 12/23/2022]
Abstract
Human biological aging from maturity to senescence is associated with a gradual loss of muscle mass and neuromuscular function. It is not until very old age (>80 years) however, that these changes often manifest into functional impairments. A driving factor underlying the age-related loss of muscle mass and function is the reduction in the number and quality of motor units (MUs). A MU consists of a single motoneuron, located either in the spinal cord or the brain stem, and all of the muscle fibres it innervates via its peripheral axon. Throughout the adult lifespan, MUs are slowly, but progressively lost. The compensatory process of collateral reinnervation attempts to recapture orphaned muscle fibres following the death of a motoneuron. Whereas this process helps mitigate loss of muscle mass during the latter decades of adult aging, the neuromuscular system has fewer and larger MUs, which have lower quality connections between the axon terminal and innervated muscle fibres. Whether this process of MU death and degradation can be attenuated with habitual physical activity has been a challenging question of great interest. This review focuses on age-related alterations of the human neuromuscular system, with an emphasis on the MU, and presents findings on the potential protective effects of lifelong physical activity. Although there is some discrepancy across studies of masters athletes, if one considers all experimental limitations as well as the available literature in animals, there is compelling evidence of a protective effect of chronic physical training on human MUs. Our tenet is that high-levels of physical activity can mitigate the natural trajectory of loss of quantity and quality of MUs in old age.
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Affiliation(s)
- Matti D Allen
- Department of Physical Medicine and Rehabilitation, School of Medicine, Faculty of Health Sciences, Queen's University, Kingston, ON K7L 4X3, Canada; School of Kinesiology and Health Studies, Faculty of Arts and Sciences, Queen's University, Kingston, ON K7L 4X3, Canada
| | - Brian H Dalton
- School of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
| | - Kevin J Gilmore
- Department of Surgery, Faculty of Medicine, University of Toronto, Toronto, ON M5S 3E1, Canada
| | - Chris J McNeil
- School of Health and Exercise Science, University of British Columbia, Kelowna, BC V1V 1V7, Canada
| | - Timothy J Doherty
- Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada; Department of Physical Medicine and Rehabilitation, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada
| | - Charles L Rice
- School of Kinesiology, The University of Western Ontario, London, ON, Canada; Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, The University of Western Ontario, London, ON, Canada.
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
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15
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Soendenbroe C, Andersen JL, Mackey AL. Muscle-nerve communication and the molecular assessment of human skeletal muscle denervation with aging. Am J Physiol Cell Physiol 2021; 321:C317-C329. [PMID: 34161153 DOI: 10.1152/ajpcell.00174.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Muscle fiber denervation is a major contributor to the decline in physical function observed with aging. Denervation can occur through breakdown of the neuromuscular junctions (NMJ) itself, affecting only that particular fiber, or through the death of a motor neuron, which can lead to a loss of all the muscle fibers in that motor unit. In this review, we discuss the muscle-nerve relationship, where signaling from both the motor neuron and the muscle fiber is required for maximal preservation of neuromuscular function in old age. Physical activity is likely to be the most important single factor that can contribute to this preservation. Furthermore, we propose that inactivity is not an innocent bystander, but plays an active role in denervation through the production of signals hostile to neuron survival. Investigating denervation in human muscle tissue samples is challenging due to the shared protein profile of regenerating and denervated muscle fibers. In this review, we provide a detailed overview of the key traits observed in immunohistochemical preparations of muscle biopsies from healthy, young, and elderly individuals. Overall, a combination of assessing tissue samples, circulating biomarkers, and electrophysiological assessments in humans will prove fruitful in the quest to gain more understanding of denervation of skeletal muscle. In addition, cell culture models represent a valuable tool in the search for key signaling factors exchanged between muscle and nerve, and which exercise has the capacity to alter.
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Affiliation(s)
- Casper Soendenbroe
- Department of Orthopedic Surgery, Institute of Sports Medicine Copenhagen, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark.,Xlab, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Medicine, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Jesper L Andersen
- Department of Orthopedic Surgery, Institute of Sports Medicine Copenhagen, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark.,Department of Clinical Medicine, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Abigail L Mackey
- Department of Orthopedic Surgery, Institute of Sports Medicine Copenhagen, Copenhagen University Hospital - Bispebjerg and Frederiksberg, Copenhagen, Denmark.,Xlab, Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Medicine, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
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16
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NMJ-Analyser identifies subtle early changes in mouse models of neuromuscular disease. Sci Rep 2021; 11:12251. [PMID: 34112844 PMCID: PMC8192785 DOI: 10.1038/s41598-021-91094-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 04/26/2021] [Indexed: 12/21/2022] Open
Abstract
The neuromuscular junction (NMJ) is the peripheral synapse formed between a motor neuron axon terminal and a muscle fibre. NMJs are thought to be the primary site of peripheral pathology in many neuromuscular diseases, but innervation/denervation status is often assessed qualitatively with poor systematic criteria across studies, and separately from 3D morphological structure. Here, we describe the development of ‘NMJ-Analyser’, to comprehensively screen the morphology of NMJs and their corresponding innervation status automatically. NMJ-Analyser generates 29 biologically relevant features to quantitatively define healthy and aberrant neuromuscular synapses and applies machine learning to diagnose NMJ degeneration. We validated this framework in longitudinal analyses of wildtype mice, as well as in four different neuromuscular disease models: three for amyotrophic lateral sclerosis (ALS) and one for peripheral neuropathy. We showed that structural changes at the NMJ initially occur in the nerve terminal of mutant TDP43 and FUS ALS models. Using a machine learning algorithm, healthy and aberrant neuromuscular synapses are identified with 95% accuracy, with 88% sensitivity and 97% specificity. Our results validate NMJ-Analyser as a robust platform for systematic and structural screening of NMJs, and pave the way for transferrable, and cross-comparison and high-throughput studies in neuromuscular diseases.
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17
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Birnbaum S, Porcher R, Portero P, Clair B, Demeret S, Eymard B, Gargiulo M, Louët E, Berrih-Aknin S, Le Panse R, Aegerter P, Hogrel JY, Sharshar T. Home-based exercise in autoimmune myasthenia gravis: A randomized controlled trial. Neuromuscul Disord 2021; 31:726-735. [PMID: 34304969 DOI: 10.1016/j.nmd.2021.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 05/07/2021] [Accepted: 05/11/2021] [Indexed: 10/21/2022]
Abstract
The tolerance of exercise and its effects on quality of life in myasthenia gravis are not currently backed up by strong evidence. The aim of this study was to determine whether exercise as an adjunct therapy is well tolerated and can improve health-related quality of life (HRQoL) in stabilized, generalized autoimmune myasthenia gravis (gMG). We conducted a parallel-group, multi-center prospective RCT using computer-generated block randomization. Adults with stabilized, gMG, and no contra-indication to exercise, were eligible. Participants received usual care alone or usual care and exercise. The exercise intervention consisted of 3-weekly 40 min sessions of an unsupervised, moderate-intensity home rowing program over 3 months. The primary endpoint was the change in HRQoL from randomization to post-intervention. Assessor-blinded secondary endpoints were exercise tolerance and effects on clinical, psychological and immunological status. Of 138 patients screened between October 2014 and July 2017, 45 were randomly assigned to exercise (n = 23) or usual care (n = 20). Although exercise was well tolerated, the intention-to-treat analysis revealed no evidence of improved HRQoL compared to usual care (MGQOL-15-F; mean adjusted between-groups difference of -0.8 points, 95%CI -5.4 to 3.7). Two patients hospitalized for MG exacerbation were from the usual care group.
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Affiliation(s)
| | - R Porcher
- Hotel-Dieu Hospital Clinical Epidemiology Centre, Paris, France
| | - P Portero
- Université Paris-Est, Creteil, France
| | - B Clair
- APHP, Assistance Publique - Hopitaux de Paris, France
| | - S Demeret
- APHP, Assistance Publique - Hopitaux de Paris, France
| | - B Eymard
- Paris Descartes University Institute of Psychology, Paris, France
| | | | - E Louët
- Institute of Myology, Paris, France
| | | | - R Le Panse
- Paris Descartes University Institute of Psychology, Paris, France
| | - P Aegerter
- APHP, Assistance Publique - Hopitaux de Paris, France
| | | | - T Sharshar
- GHU-Psychiatrie & Neurosciences site Sainte-Anne 75014 Paris, France.
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18
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Chugh D, Iyer CC, Bobbili P, Blatnik AJ, Kaspar BK, Meyer K, Burghes AH, Clark BC, Arnold WD. Voluntary wheel running with and without follistatin overexpression improves NMJ transmission but not motor unit loss in late life of C57BL/6J mice. Neurobiol Aging 2021; 101:285-296. [PMID: 33678425 PMCID: PMC8122043 DOI: 10.1016/j.neurobiolaging.2021.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 12/23/2020] [Accepted: 01/16/2021] [Indexed: 01/17/2023]
Abstract
Sarcopenia, or pathological loss of muscle mass and strength during aging, is an important contributor to loss of physical function in older adults. Sarcopenia is a multifactorial syndrome associated with intrinsic muscle and upstream neurological dysfunction. Exercise is well-established as an effective intervention for sarcopenia, but less is known about the long-term neurobiological impact of exercise. The goals of this study were to investigate the effects of exercise, alone or in combination with follistatin (FST) overexpression (antagonist of myostatin), on neuromuscular junction transmission and motor unit numbers in mice between the age of 22 and 27 months, ages at which prior studies have demonstrated that some motor unit loss is already evident. C57BL/6J mice underwent baseline assessment and were randomized to housing with or without voluntary running wheels and injection with adeno-associated virus to overexpress FST or vehicle. Groups for comparison included sedentary and running with and without FST. Longitudinal assessments showed significantly increased muscle mass and contractility in the 'running plus FST' group, but running, with and without FST, showed no effect on motor unit degeneration. In contrast, running, with and without FST, demonstrated marked improvement of neuromuscular junction transmission stability.
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Affiliation(s)
- Deepti Chugh
- Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Chitra C Iyer
- Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Prameela Bobbili
- Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Anton J Blatnik
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Brian K Kaspar
- The Research Institute, Nationwide Children's Hospital, Columbus, OH, USA
| | - Kathrin Meyer
- The Research Institute, Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University, Columbus, OH, USA
| | - Arthur Hm Burghes
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Brian C Clark
- Ohio Musculoskeletal and Neurological Institute & the Department of Biomedical Sciences, Athens, OH, USA
| | - W David Arnold
- Department of Neurology, Neuromuscular Division, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH, USA; Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH, USA.
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19
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Bao Z, Cui C, Chow SKH, Qin L, Wong RMY, Cheung WH. AChRs Degeneration at NMJ in Aging-Associated Sarcopenia-A Systematic Review. Front Aging Neurosci 2020; 12:597811. [PMID: 33362532 PMCID: PMC7759742 DOI: 10.3389/fnagi.2020.597811] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Accepted: 11/19/2020] [Indexed: 12/16/2022] Open
Abstract
Sarcopenia is an aging process with a decline of skeletal muscle mass and function, which is a challenging public health problem with reduced quality of life in patients. The endplate, the post-synaptic part of the neuromuscular junction (NMJ), occupies 0.1% of the myofiber surface area only, but is composed of millions of acetylcholine receptors (AChRs) that are efficient in binding to acetylcholine (ACh) and triggering skeletal muscle contraction. This systematic review aims to examine aging-associated alterations of post-synaptic AChRs, including morphology, function and related gene expression. A systematic literature search was conducted in PubMed, Embase and Web of Science with relevant keywords by two independent reviewers. Original pre-clinical and clinical studies regarding AChRs changes during aging with available full text and written in English were included. Information was extracted from the included studies for further review. In total, 30 articles were included. Various parameters assessing AChRs alterations by radioassay, immunofluorescence, electrophysiology and mechanical test were reported. Endplate fragmentation and denervation were common in old skeletal muscles during aging. To ensure efficient NMJ transmission and force generation, type I or IIb muscle fibers tended to have increased ACh quanta releasing after electrical stimulations, while type IIa muscle fibers tended to have stronger binding between ACh and AChRs, but the overall function of AChRs was reduced during aging. Alterations of AChRs area depended on muscle type, species and the progress of muscle atrophy and type I muscles fibers tended to demonstrate enlarging AChRs areas. Myogenic regulator factors (MRFs) can regulate the expression of AChRs subunits, while decreased MRF4 may lead to expression changes of AChRs subunits during aging. Sarcoglycan-α can delay low-density lipoprotein receptor-related protein 4 (LRP4) degradation. This protein was increased in old muscles but still cannot suppress the degradation of LRP4. Investigating the role of these AChRs-related genes in the process of aging may provide a potential target to treat sarcopenia.
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Affiliation(s)
- Zhengyuan Bao
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Can Cui
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Simon Kwoon-Ho Chow
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.,The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Ling Qin
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Ronald Man Yeung Wong
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China
| | - Wing-Hoi Cheung
- Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China.,The CUHK-ACC Space Medicine Centre on Health Maintenance of Musculoskeletal System, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China
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20
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Badawi Y, Nishimune H. Impairment Mechanisms and Intervention Approaches for Aged Human Neuromuscular Junctions. Front Mol Neurosci 2020; 13:568426. [PMID: 33328881 PMCID: PMC7717980 DOI: 10.3389/fnmol.2020.568426] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 10/16/2020] [Indexed: 12/19/2022] Open
Abstract
The neuromuscular junction (NMJ) is a chemical synapse formed between a presynaptic motor neuron and a postsynaptic muscle cell. NMJs in most vertebrate species share many essential features; however, some differences distinguish human NMJs from others. This review will describe the pre- and postsynaptic structures of human NMJs and compare them to NMJs of laboratory animals. We will focus on age-dependent declines in function and changes in the structure of human NMJs. Furthermore, we will describe insights into the aging process revealed from mouse models of accelerated aging. In addition, we will compare aging phenotypes to other human pathologies that cause impairments of pre- and postsynaptic structures at NMJs. Finally, we will discuss potential intervention approaches for attenuating age-related NMJ dysfunction and sarcopenia in humans.
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Affiliation(s)
- Yomna Badawi
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, KS, United States.,Neurobiology of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi, Japan
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21
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Giorgetti E, Panesar M, Zhang Y, Joller S, Ronco M, Obrecht M, Lambert C, Accart N, Beckmann N, Doelemeyer A, Perrot L, Fruh I, Mueller M, Pierrel E, Summermatter S, Bidinosti M, Shimshek DR, Brachat S, Nash M. Modulation of Microglia by Voluntary Exercise or CSF1R Inhibition Prevents Age-Related Loss of Functional Motor Units. Cell Rep 2020; 29:1539-1554.e7. [PMID: 31693894 DOI: 10.1016/j.celrep.2019.10.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 07/27/2019] [Accepted: 10/01/2019] [Indexed: 01/05/2023] Open
Abstract
Age-related loss of skeletal muscle innervation by motor neurons leads to impaired neuromuscular function and is a well-established clinical phenomenon. However, the underlying pathogenesis remains unclear. Studying mice, we find that the number of motor units (MUs) can be maintained by counteracting neurotoxic microglia in the aged spinal cord. We observe that marked innervation changes, detected by motor unit number estimation (MUNE), occur prior to loss of muscle function in aged mice. This coincides with gene expression changes indicative of neuronal remodeling and microglial activation in aged spinal cord. Voluntary exercise prevents loss of MUs and reverses microglia activation. Depleting microglia by CSF1R inhibition also prevents the age-related decline in MUNE and neuromuscular junction disruption, implying a causal link. Our results suggest that age-related changes in spinal cord microglia contribute to neuromuscular decline in aged mice and demonstrate that removal of aged neurotoxic microglia can prevent or reverse MU loss.
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Affiliation(s)
- Elisa Giorgetti
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland.
| | - Moh Panesar
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Yunyu Zhang
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA
| | - Stefanie Joller
- Neuroscience, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Marie Ronco
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Michael Obrecht
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Christian Lambert
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Nathalie Accart
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Nicolau Beckmann
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Arno Doelemeyer
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Ludovic Perrot
- Global Sci Operations, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Isabelle Fruh
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Matthias Mueller
- Chemical Biology and Therapeutics, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Eliane Pierrel
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Serge Summermatter
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Michael Bidinosti
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Derya R Shimshek
- Neuroscience, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Sophie Brachat
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland
| | - Mark Nash
- Musculoskeletal Diseases Area, Novartis Institutes for BioMedical Research, 4002 Basel, Switzerland.
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22
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Castets P, Ham DJ, Rüegg MA. The TOR Pathway at the Neuromuscular Junction: More Than a Metabolic Player? Front Mol Neurosci 2020; 13:162. [PMID: 32982690 PMCID: PMC7485269 DOI: 10.3389/fnmol.2020.00162] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/05/2020] [Indexed: 12/18/2022] Open
Abstract
The neuromuscular junction (NMJ) is the chemical synapse connecting motor neurons and skeletal muscle fibers. NMJs allow all voluntary movements, and ensure vital functions like breathing. Changes in the structure and function of NMJs are hallmarks of numerous pathological conditions that affect muscle function including sarcopenia, the age-related loss of muscle mass and function. However, the molecular mechanisms leading to the morphological and functional perturbations in the pre- and post-synaptic compartments of the NMJ remain poorly understood. Here, we discuss the role of the metabolic pathway associated to the kinase TOR (Target of Rapamycin) in the development, maintenance and alterations of the NMJ. This is of particular interest as the TOR pathway has been implicated in aging, but its role at the NMJ is still ill-defined. We highlight the respective functions of the two TOR-associated complexes, TORC1 and TORC2, and discuss the role of localized protein synthesis and autophagy regulation in motor neuron terminals and sub-synaptic regions of muscle fibers and their possible effects on NMJ maintenance.
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Affiliation(s)
- Perrine Castets
- Department of Cell Physiology and Metabolism, Faculty of Medicine, University of Geneva, Geneva, Switzerland
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23
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Khosa S, Trikamji B, Khosa GS, Khanli HM, Mishra SK. An Overview of Neuromuscular Junction Aging Findings in Human and Animal Studies. Curr Aging Sci 2020; 12:28-34. [PMID: 31161982 PMCID: PMC6971950 DOI: 10.2174/1874609812666190603165746] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 05/14/2019] [Accepted: 05/14/2019] [Indexed: 12/15/2022]
Abstract
Background: Aging is a complex irreversible process that is not only related to an individual’s genetic make-up but also to lifestyle choices and environmental exposures. Like every other structure in human body, the Neuromuscular Junction (NMJ) is not averse to aging. Objectives: The prime objective is to analyse the microscopic and macroscopic changes at the NMJs with aging. Methods: For the purpose of review we evaluated data from resources like Pubmed, Ovid, UCLA libraries and USC libraries. Results: We review various morphological, physiological, immunological, and biochemical changes in NMJs with aging and their management. Conclusion: The alterations in NMJs secondary to aging are inevitable. It is vital that neurologists clearly understand the pathophysiology of NMJ aging and differentiate between physiological and pathological effects of aging. With the current knowledge of science, the changes in NMJ aging can be better prevented rather than cured.
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Affiliation(s)
- Shaweta Khosa
- Department of Neurology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, United States
| | - Bhavesh Trikamji
- Department of Neurology, Harbor UCLA Medical Center, Torrance, CA 90502, United States
| | - Gurveer S Khosa
- Department of Medicine, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India
| | - Hadi M Khanli
- Department of Neurology, George Washington University, Washington, DC 20052, United States
| | - Shri K Mishra
- Department of Neurology, University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, United States
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24
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DOK7 Gene Therapy Enhances Neuromuscular Junction Innervation and Motor Function in Aged Mice. iScience 2020; 23:101385. [PMID: 32758427 PMCID: PMC7452162 DOI: 10.1016/j.isci.2020.101385] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/21/2020] [Accepted: 07/16/2020] [Indexed: 12/14/2022] Open
Abstract
Muscle denervation at the neuromuscular junction (NMJ), the essential synapse between motor neuron and skeletal muscle, is associated with age-related motor impairment. Therefore, improving muscle innervation at aged NMJs may be an effective therapeutic strategy for treating the impairment. We previously demonstrated that the muscle protein Dok-7 plays an essential role in NMJ formation, and, indeed, its forced expression in muscle enlarges NMJs. Moreover, therapeutic administration of an adeno-associated virus vector encoding human Dok-7 (DOK7 gene therapy) suppressed muscle denervation and enhanced motor activity in a mouse model of amyotrophic lateral sclerosis (ALS). Here, we show that DOK7 gene therapy significantly enhances motor function and muscle strength together with NMJ innervation in aged mice. Furthermore, the treated mice showed greatly increased compound muscle action potential (CMAP) amplitudes compared with the controls, suggesting enhanced neuromuscular transmission. Thus, therapies aimed at enhancing NMJ innervation have potential for treating age-related motor impairment. DOK7 gene therapy enhances motor function and muscle strength in aged (≥2 years) mice DOK7 gene therapy enhances neuromuscular junction (NMJ) innervation in aged mice DOK7 gene therapy increases compound muscle action potential amplitudes in aged mice Enhancing NMJ innervation in the elderly may strengthen muscles and motor activities
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25
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Zullo A, Fleckenstein J, Schleip R, Hoppe K, Wearing S, Klingler W. Structural and Functional Changes in the Coupling of Fascial Tissue, Skeletal Muscle, and Nerves During Aging. Front Physiol 2020; 11:592. [PMID: 32670080 PMCID: PMC7327116 DOI: 10.3389/fphys.2020.00592] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 05/11/2020] [Indexed: 12/18/2022] Open
Abstract
Aging is a one-way process associated with profound structural and functional changes in the organism. Indeed, the neuromuscular system undergoes a wide remodeling, which involves muscles, fascia, and the central and peripheral nervous systems. As a result, intrinsic features of tissues, as well as their functional and structural coupling, are affected and a decline in overall physical performance occurs. Evidence from the scientific literature demonstrates that senescence is associated with increased stiffness and reduced elasticity of fascia, as well as loss of skeletal muscle mass, strength, and regenerative potential. The interaction between muscular and fascial structures is also weakened. As for the nervous system, aging leads to motor cortex atrophy, reduced motor cortical excitability, and plasticity, thus leading to accumulation of denervated muscle fibers. As a result, the magnitude of force generated by the neuromuscular apparatus, its transmission along the myofascial chain, joint mobility, and movement coordination are impaired. In this review, we summarize the evidence about the deleterious effect of aging on skeletal muscle, fascial tissue, and the nervous system. In particular, we address the structural and functional changes occurring within and between these tissues and discuss the effect of inflammation in aging. From the clinical perspective, this article outlines promising approaches for analyzing the composition and the viscoelastic properties of skeletal muscle, such as ultrasonography and elastography, which could be applied for a better understanding of musculoskeletal modifications occurring with aging. Moreover, we describe the use of tissue manipulation techniques, such as massage, traction, mobilization as well as acupuncture, dry needling, and nerve block, to enhance fascial repair.
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Affiliation(s)
- Alberto Zullo
- Department of Sciences and Technologies, University of Sannio, Benevento, Italy
- CEINGE Advanced Biotechnologies, Naples, Italy
| | - Johannes Fleckenstein
- Department of Sports Medicine, Institute of Sports Sciences, Goethe-University Frankfurt, Frankfurt, Germany
| | - Robert Schleip
- Department of Sport and Health Sciences, Technical University Munich, Munich, Germany
- Department of Sports Medicine and Health Promotion, Friedrich-Schiller University Jena, Jena, Germany
| | - Kerstin Hoppe
- Department of Anaesthesiology, Würzburg University, Würzburg, Germany
| | - Scott Wearing
- Department of Sport and Health Sciences, Technical University Munich, Munich, Germany
- Faculty of Health School, Queensland University of Technology, Brisbane, QLD, Australia
| | - Werner Klingler
- Department of Sport and Health Sciences, Technical University Munich, Munich, Germany
- Faculty of Health School, Queensland University of Technology, Brisbane, QLD, Australia
- Fascia Research Group, Department of Experimental Anaesthesiology, Ulm University, Ulm, Germany
- Department of Anaesthesiology, SRH Hospital Sigmaringen, Sigmaringen, Germany
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26
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Multiple MuSK signaling pathways and the aging neuromuscular junction. Neurosci Lett 2020; 731:135014. [PMID: 32353380 DOI: 10.1016/j.neulet.2020.135014] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 12/16/2022]
Abstract
The neuromuscular junction (NMJ) is the vehicle for fast, reliable and robust communication between motor neuron and muscle. The unparalleled accessibility of this synapse to morphological, electrophysiological and genetic analysis has yielded an in depth understanding of many molecular components mediating its formation, maturation and stability. However, key questions surrounding the signaling pathways mediating these events and how they play out across the lifetime of the synapse remain unanswered. Such information is critical since the NMJ is necessary for normal movement and is compromised in several settings including myasthenia gravis, amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), muscular dystrophy, sarcopenia and aging. Muscle specific kinase (MuSK) is a central player in most if not all contexts of NMJ formation and stability. However, elucidating the function of this receptor in this range of settings is challenging since MuSK participates in at least three signaling pathways: as a tyrosine kinase-dependent receptor for agrin-LRP4 and Wnts; and, as a kinase-independent BMP co-receptor. Here we focus on NMJ stability during aging and discuss open questions regarding the molecular mechanisms that govern active maintenance of the NMJ, with emphasis on MuSK and the potential role of its multiple signaling contexts.
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27
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Kravtsova VV, Bouzinova EV, Chibalin AV, Matchkov VV, Krivoi II. Isoform-specific Na,K-ATPase and membrane cholesterol remodeling in motor endplates in distinct mouse models of myodystrophy. Am J Physiol Cell Physiol 2020; 318:C1030-C1041. [PMID: 32293933 DOI: 10.1152/ajpcell.00453.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Na,K-ATPase is a membrane transporter that is critically important for skeletal muscle function. Mdx and Bla/J mice are the experimental models of Duchenne muscular dystrophy and dysferlinopathy that are known to differ in the molecular mechanism of the pathology. This study examines the function of α1- and α2-Na,K-ATPase isozymes in respiratory diaphragm and postural soleus muscles from mdx and Bla/J mice compared with control С57Bl/6 mice. In diaphragm muscles, the motor endplate structure was severely disturbed (manifested by defragmentation) in mdx mice only. The endplate membrane of both Bla/J and mdx mice was depolarized due to specific loss of the α2-Na,K-ATPase electrogenic activity and its decreased membrane abundance. Total FXYD1 subunit (modulates Na,K-ATPase activity) abundance was decreased in both mouse models. However, the α2-Na,K-ATPase protein content as well as mRNA expression were specifically and significantly reduced only in mdx mice. The endplate membrane cholesterol redistribution was most pronounced in mdx mice. Soleus muscles from Bla/J and mdx mice demonstrated reduction of the α2-Na,K-ATPase membrane abundance and mRNA expression similar to the diaphragm muscles. In contrast to diaphragm, the α2-Na,K-ATPase protein content was altered in both Bla/J and mdx mice; membrane cholesterol re-distribution was not observed. Thus, the α2-Na,K-ATPase is altered in both Bla/J and mdx mouse models of chronic muscle pathology. However, despite some similarities, the α2-Na,K-ATPase and cholesterol abnormalities are more pronounced in mdx mice.
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Affiliation(s)
- Violetta V Kravtsova
- Department of General Physiology, St. Petersburg State University, St. Petersburg, Russia
| | | | | | | | - Igor I Krivoi
- Department of General Physiology, St. Petersburg State University, St. Petersburg, Russia
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28
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Tan KT, Ang STJ, Tsai SY. Sarcopenia: Tilting the Balance of Protein Homeostasis. Proteomics 2019; 20:e1800411. [PMID: 31722440 DOI: 10.1002/pmic.201800411] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 11/04/2019] [Indexed: 12/14/2022]
Abstract
Sarcopenia, defined as age-associated decline of muscle mass and function, is a risk factor for mortality and disability, and comorbid with several chronic diseases such as type II diabetes and cardiovascular diseases. Clinical trials showed that nutritional supplements had positive effects on muscle mass, but not on muscle function and strength, demonstrating our limited understanding of the molecular events involved in the ageing muscle. Protein homeostasis, the equilibrium between protein synthesis and degradation, is proposed as the major mechanism underlying the development of sarcopenia. As the key central regulator of protein homeostasis, the mammalian target of rapamycin (mTOR) is proposed to be essential for muscle hypertrophy. Paradoxically, sustained activation of mTOR complex 1 (mTORC1) is associated with a loss of sensitivity to extracellular signaling in the elderly. It is not understood why sustained mTORC1 activity, which should induce muscle hypertrophy, instead results in muscle atrophy. Here, recent findings on the implications of disrupting protein homeostasis on muscle physiology and sarcopenia development in the context of mTOR/protein kinase B (AKT) signaling are reviewed. Understanding the role of these molecular mechanisms during the ageing process will contribute towards the development of targeted therapies that will improve protein metabolism and reduce sarcopenia.
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Affiliation(s)
- Kuan Ting Tan
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Seok-Ting Jamie Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
| | - Shih-Yin Tsai
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, 2 Medical Drive, MD9 Admin Office, Singapore, 117597, Singapore
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29
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Neuromuscular junction transmission failure is a late phenotype in aging mice. Neurobiol Aging 2019; 86:182-190. [PMID: 31866157 DOI: 10.1016/j.neurobiolaging.2019.10.022] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 09/12/2019] [Accepted: 10/29/2019] [Indexed: 12/23/2022]
Abstract
Neurodegeneration has increasingly been considered an important factor in the pathogenesis of sarcopenia or age-related loss of muscle mass and strength. Experiments were designed to investigate the fidelity of neuromuscular junction (NMJ) transmission across the lifespan in hindlimb muscles of male and female C57BL/6J mice (at 12, 20, 24, 27, and 29 months of age). Single-fiber electromyography recordings demonstrated abrupt onset of NMJ transmission failure at 27 months of age. Failed NMJ transmission was a later onset phenotype as compared with other assessments of motor unit numbers, muscle contractility, and frailty which showed alterations at 20 months of age. Ex vivo NMJ recordings demonstrated no reduction of endplate current amplitude in support of reduced muscle fiber excitability as the cause of failed NMJ transmission in aged mice. Improved understanding of age-related neurodegeneration will likely have important implications in designing novel therapeutic interventions specific for different stages of sarcopenia. Our findings suggest reduced muscle excitability may be a potential therapeutic target for improvement of physical function in older adults.
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30
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Vaughan SK, Sutherland NM, Valdez G. Attenuating Cholinergic Transmission Increases the Number of Satellite Cells and Preserves Muscle Mass in Old Age. Front Aging Neurosci 2019; 11:262. [PMID: 31616286 PMCID: PMC6768977 DOI: 10.3389/fnagi.2019.00262] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 09/05/2019] [Indexed: 12/13/2022] Open
Abstract
In addition to driving contraction of skeletal muscles, acetylcholine (ACh) acts as an anti-synaptogenic agent at neuromuscular junctions (NMJs). Previous studies suggest that aging is accompanied by increases in cholinergic activity at the NMJ, which may play a role in neuromuscular degeneration. In this study, we hypothesized that moderately and chronically reducing ACh could attenuate the deleterious effects of aging on NMJs and skeletal muscles. To test this hypothesis, we analyzed NMJs and muscle fibers from heterozygous transgenic mice with reduced expression of the vesicular ACh transporter (VAChT; VKDHet), which present with approximately 30% less synaptic ACh compared to control mice. Because ACh is constitutively decreased in VKDHet, we first analyzed developing NMJs and muscle fibers. We found no obvious morphological or molecular differences between NMJs and muscle fibers of VKDHet and control mice during development. In contrast, we found that moderately reducing ACh has various effects on adult NMJs and muscle fibers. VKDHet mice have significantly larger NMJs and muscle fibers compared to age-matched control mice. They also present with reduced expression of the pro-atrophy gene, Foxo1, and have more satellite cells in skeletal muscles. These molecular and cellular features may partially explain the increased size of NMJs and muscle fibers. Thus, moderately reducing ACh may be a therapeutic strategy to prevent the loss of skeletal muscle mass that occurs with advancing age.
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Affiliation(s)
- Sydney K Vaughan
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States.,Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Blacksburg, VA, United States
| | - Natalia M Sutherland
- Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
| | - Gregorio Valdez
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, United States.,Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States.,Department of Biological Sciences, Virginia Tech, Blacksburg, VA, United States
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31
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Trajanovska S, Ban J, Huang J, Gregorevic P, Morsch M, Allen DG, Phillips WD. Muscle specific kinase protects dystrophic mdx mouse muscles from eccentric contraction-induced loss of force-producing capacity. J Physiol 2019; 597:4831-4850. [PMID: 31340406 DOI: 10.1113/jp277839] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 07/17/2019] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Adeno-associated viral vector was used to elevate the expression of muscle specific kinase (MuSK) and rapsyn (a cytoplasmic MuSK effector protein) in the tibialis anterior muscle of wild-type and dystrophic (mdx) mice. In mdx mice, enhanced expression of either MuSK or rapsyn ameliorated the acute loss of muscle force associated with strain injury. Increases in sarcolemmal immunolabelling for utrophin and β-dystroglycan suggest a mechanism for the protective effect of MuSK in mdx muscles. MuSK also caused subtle changes to the structure and function of the neuromuscular junction, suggesting novel roles for MuSK in muscle physiology and pathophysiology. ABSTRACT Muscle specific kinase (MuSK) has a well-defined role in stabilizing the developing mammalian neuromuscular junction, but MuSK might also be protective in some neuromuscular diseases. In the dystrophin-deficient mdx mouse model of Duchenne muscular dystrophy, limb muscles are especially fragile. We injected the tibialis anterior muscle of 8-week-old mdx and wild-type (C57BL10) mice with adeno-associated viral vectors encoding either MuSK or rapsyn (a cytoplasmic MuSK effector protein) fused to green fluorescent protein (MuSK-GFP and rapsyn-GFP, respectively). Contralateral muscles injected with empty vector served as controls. One month later mice were anaesthetized with isoflurane and isometric force-producing capacity was recorded from the distal tendon. MuSK-GFP caused an unexpected decay in nerve-evoked tetanic force, both in wild-type and mdx muscles, without affecting contraction elicited by direct electrical stimulation of the muscle. Muscle fragility was probed by challenging muscles with a strain injury protocol consisting of a series of four strain-producing eccentric contractions in vivo. When applied to muscles of mdx mice, eccentric contraction produced an acute 27% reduction in directly evoked muscle force output, affirming the susceptibility of mdx muscles to strain injury. mdx muscles overexpressing MuSK-GFP or rapsyn-GFP exhibited significantly milder force deficits after the eccentric contraction challenge (15% and 14%, respectively). The protective effect of MuSK-GFP in muscles of mdx mice was associated with increased immunolabelling for utrophin and β-dystroglycan in the sarcolemma. Elevating the expression of MuSK or rapsyn revealed several distinct synaptic and extrasynaptic effects, suggesting novel roles for MuSK signalling in muscle physiology and pathophysiology.
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Affiliation(s)
- S Trajanovska
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - J Ban
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - J Huang
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - P Gregorevic
- Department of Physiology, The University of Melbourne, Melbourne, Victoria, Australia.,Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.,Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
| | - M Morsch
- Department of Biomedical Sciences, Macquarie University, Sydney, New South Wales, Australia
| | - D G Allen
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
| | - W D Phillips
- Physiology and Bosch Institute, University of Sydney, Sydney, New South Wales, Australia
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32
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Nilsson MI, Bourgeois JM, Nederveen JP, Leite MR, Hettinga BP, Bujak AL, May L, Lin E, Crozier M, Rusiecki DR, Moffatt C, Azzopardi P, Young J, Yang Y, Nguyen J, Adler E, Lan L, Tarnopolsky MA. Lifelong aerobic exercise protects against inflammaging and cancer. PLoS One 2019; 14:e0210863. [PMID: 30682077 PMCID: PMC6347267 DOI: 10.1371/journal.pone.0210863] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 01/03/2019] [Indexed: 12/16/2022] Open
Abstract
Biological aging is associated with progressive damage accumulation, loss of organ reserves, and systemic inflammation ('inflammaging'), which predispose for a wide spectrum of chronic diseases, including several types of cancer. In contrast, aerobic exercise training (AET) reduces inflammation, lowers all-cause mortality, and enhances both health and lifespan. In this study, we examined the benefits of early-onset, lifelong AET on predictors of health, inflammation, and cancer incidence in a naturally aging mouse model (C57BL/J6). Lifelong, voluntary wheel-running (O-AET; 26-month-old) prevented age-related declines in aerobic fitness and motor coordination vs. age-matched, sedentary controls (O-SED). AET also provided partial protection against sarcopenia, dynapenia, testicular atrophy, and overall organ pathology, hence augmenting the 'physiologic reserve' of lifelong runners. Systemic inflammation, as evidenced by a chronic elevation in 17 of 18 pro- and anti-inflammatory cytokines and chemokines (P < 0.05 O-SED vs. 2-month-old Y-CON), was potently mitigated by lifelong AET (P < 0.05 O-AET vs. O-SED), including master regulators of the cytokine cascade and cancer progression (IL-1β, TNF-α, and IL-6). In addition, circulating SPARC, previously known to be upregulated in metabolic disease, was elevated in old, sedentary mice, but was normalized to young control levels in lifelong runners. Remarkably, malignant tumours were also completely absent in the O-AET group, whereas they were present in the brain (pituitary), liver, spleen, and intestines of sedentary mice. Collectively, our results indicate that early-onset, lifelong running dampens inflammaging, protects against multiple cancer types, and extends healthspan of naturally-aged mice.
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Affiliation(s)
- Mats I. Nilsson
- Department of Pathology and Molecular Medicine, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
- Exerkine Corporation, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Jacqueline M. Bourgeois
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Joshua P. Nederveen
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Marlon R. Leite
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Bart P. Hettinga
- Exerkine Corporation, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Adam L. Bujak
- Exerkine Corporation, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Linda May
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Ethan Lin
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Michael Crozier
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Daniel R. Rusiecki
- Exerkine Corporation, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Chris Moffatt
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Paul Azzopardi
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Jacob Young
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Yifan Yang
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Jenny Nguyen
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Ethan Adler
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Lucy Lan
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
| | - Mark A. Tarnopolsky
- Exerkine Corporation, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
- Department of Pediatrics, McMaster University Medical Center (MUMC), Hamilton, Ontario, Canada
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Wier CG, Crum AE, Reynolds AB, Iyer CC, Chugh D, Palettas MS, Heilman PL, Kline DM, Arnold WD, Kolb SJ. Muscle contractility dysfunction precedes loss of motor unit connectivity in SOD1(G93A) mice. Muscle Nerve 2018; 59:254-262. [PMID: 30370671 DOI: 10.1002/mus.26365] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/17/2018] [Accepted: 10/22/2018] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Electrophysiological measurements are used in longitudinal clinical studies to provide insight into the progression of amyotrophic lateral sclerosis (ALS) and the relationship between muscle weakness and motor unit (MU) degeneration. Here, we used a similar longitudinal approach in the Cu/Zn superoxide dismutase (SOD1[G93A]) mouse model of ALS. METHODS In vivo muscle contractility and MU connectivity assays were assessed longitudinally in SOD1(G93A) and wild type mice from postnatal days 35 to 119. RESULTS In SOD1(G93A) males, muscle contractility was reduced by day 35 and preceded MU loss. Muscle contractility and motor unit reduction were delayed in SOD1(G93A) females compared with males, but, just as with males, muscle contractility reduction preceded MU loss. DISCUSSION The longitudinal contractility and connectivity paradigm employed here provides additional insight into the SOD1(G93A) mouse model and suggests that loss of muscle contractility is an early finding that may precede loss of MUs and motor neuron death. Muscle Nerve 59:254-262, 2019.
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Affiliation(s)
- Christopher G Wier
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Alexander E Crum
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Anthony B Reynolds
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Chitra C Iyer
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Deepti Chugh
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - Marilly S Palettas
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - Patrick L Heilman
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
| | - David M Kline
- Center for Biostatistics, Department of Biomedical Informatics, The Ohio State University, Columbus, Ohio, USA
| | - W David Arnold
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA.,Department of Physical Medicine and Rehabilitation, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Stephen J Kolb
- Department of Biological Chemistry and Pharmacology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, 395 West 12th Avenue, Columbus, Ohio, 43210, USA
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Vilchinskaya NA, Krivoi II, Shenkman BS. AMP-Activated Protein Kinase as a Key Trigger for the Disuse-Induced Skeletal Muscle Remodeling. Int J Mol Sci 2018; 19:ijms19113558. [PMID: 30424476 PMCID: PMC6274864 DOI: 10.3390/ijms19113558] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 12/25/2022] Open
Abstract
Molecular mechanisms that trigger disuse-induced postural muscle atrophy as well as myosin phenotype transformations are poorly studied. This review will summarize the impact of 5′ adenosine monophosphate -activated protein kinase (AMPK) activity on mammalian target of rapamycin complex 1 (mTORC1)-signaling, nuclear-cytoplasmic traffic of class IIa histone deacetylases (HDAC), and myosin heavy chain gene expression in mammalian postural muscles (mainly, soleus muscle) under disuse conditions, i.e., withdrawal of weight-bearing from ankle extensors. Based on the current literature and the authors’ own experimental data, the present review points out that AMPK plays a key role in the regulation of signaling pathways that determine metabolic, structural, and functional alternations in skeletal muscle fibers under disuse.
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Affiliation(s)
| | - Igor I Krivoi
- Department of General Physiology, St. Petersburg State University, St. Petersburg 199034, Russia.
| | - Boris S Shenkman
- Myology Laboratory, Institute of Biomedical Problems RAS, Moscow 123007, Russia.
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Sukoff Rizzo SJ, Anderson LC, Green TL, McGarr T, Wells G, Winter SS. Assessing Healthspan and Lifespan Measures in Aging Mice: Optimization of Testing Protocols, Replicability, and Rater Reliability. ACTA ACUST UNITED AC 2018; 8:e45. [DOI: 10.1002/cpmo.45] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Stacey J. Sukoff Rizzo
- Mouse Neurobehavioral Phenotyping Facility, Center for Biometric Analysis, The Jackson Laboratory; Bar Harbor Maine
| | - Laura C. Anderson
- Mouse Neurobehavioral Phenotyping Facility, Center for Biometric Analysis, The Jackson Laboratory; Bar Harbor Maine
| | - Torrian L. Green
- Mouse Neurobehavioral Phenotyping Facility, Center for Biometric Analysis, The Jackson Laboratory; Bar Harbor Maine
| | - Tracy McGarr
- Mouse Neurobehavioral Phenotyping Facility, Center for Biometric Analysis, The Jackson Laboratory; Bar Harbor Maine
| | - Gaylynn Wells
- Mouse Neurobehavioral Phenotyping Facility, Center for Biometric Analysis, The Jackson Laboratory; Bar Harbor Maine
| | - Shawn S. Winter
- Mouse Neurobehavioral Phenotyping Facility, Center for Biometric Analysis, The Jackson Laboratory; Bar Harbor Maine
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Abstract
Age-dependent declines in muscle function are observed across species. The loss of mobility resulting from the decline in muscle function represents an important health issue and a key determinant of quality of life for the elderly. It is believed that changes in the structure and function of the neuromuscular junction are important contributors to the observed declines in motor function with increased age. Numerous studies indicate that the aging muscle is an important contributor to the deterioration of the neuromuscular junction but the cellular and molecular mechanisms driving the degeneration of the synapse remain incompletely described. Importantly, growing data from both animal models and humans indicate that exercise can rejuvenate the neuromuscular junction and improve motor function. In this review we will focus on the role of muscle-derived neurotrophin signaling in the rejuvenation of the aged neuromuscular junction in response to exercise.
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Affiliation(s)
- Tabita Kreko-Pierce
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA.,Barshoph Institute of Longevity and Aging Studies, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA
| | - Benjamin A Eaton
- Department of Cellular and Integrative Physiology, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA.,Barshoph Institute of Longevity and Aging Studies, University of Texas Health Sciences Center at San Antonio, San Antonio, Texas, USA
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Willadt S, Nash M, Slater C. Age-related changes in the structure and function of mammalian neuromuscular junctions. Ann N Y Acad Sci 2017; 1412:41-53. [PMID: 29291259 DOI: 10.1111/nyas.13521] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 09/07/2017] [Accepted: 09/12/2017] [Indexed: 12/17/2022]
Abstract
As mammals age, their neuromuscular junctions (NMJs) change their form, with an increasingly complex system of axonal branches innervating increasingly fragmented regions of postsynaptic differentiation. It has been suggested that this remodeling is associated with impairment of neuromuscular transmission and that this contributes to age-related muscle weakness in mammals, including humans. Here, we review previous work on NMJ aging, most of which has focused on either structure or function, as well as a new study aimed at seeking correlation between the structure and function of individual NMJs. While it is clear that extensive structural changes occur as part of the aging process, it is much less certain how, if at all, these are correlated with an impairment of function. This leaves open the question of whether loss of NMJ function is a significant cause of age-related muscle weakness.
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Affiliation(s)
- Silvia Willadt
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Mark Nash
- Novartis Institutes for Biomedical Research, Basel, Switzerland
| | - Clarke Slater
- Institute of Neuroscience, Newcastle University, Newcastle upon Tyne, UK
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Krause Neto W, Silva WDA, Ciena AP, de Souza RR, Anaruma CA, Gama EF. Aging Induces Changes in the Somatic Nerve and Postsynaptic Component without Any Alterations in Skeletal Muscles Morphology and Capacity to Carry Load of Wistar Rats. Front Neurosci 2017; 11:688. [PMID: 29326543 PMCID: PMC5741656 DOI: 10.3389/fnins.2017.00688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 11/22/2017] [Indexed: 01/09/2023] Open
Abstract
The present study aimed to analyze the morphology of the peripheral nerve, postsynaptic compartment, skeletal muscles and weight-bearing capacity of Wistar rats at specific ages. Twenty rats were divided into groups: 10 months-old (ADULT) and 24 months-old (OLD). After euthanasia, we prepared and analyzed the tibial nerve using transmission electron microscopy and the soleus and plantaris muscles for cytofluorescence and histochemistry. For the comparison of the results between groups we used dependent and independent Student's t-test with level of significance set at p ≤ 0.05. For the tibial nerve, the OLD group presented the following alterations compared to the ADULT group: larger area and diameter of both myelinated fibers and axons, smaller area occupied by myelinated and unmyelinated axons, lower numerical density of myelinated fibers, and fewer myelinated fibers with normal morphology. Both aged soleus and plantaris end-plate showed greater total perimeter, stained perimeter, total area and stained area compared to ADULT group (p < 0.05). Yet, aged soleus end-plate presented greater dispersion than ADULT samples (p < 0.05). For the morphology of soleus and plantaris muscles, density of the interstitial volume was greater in the OLD group (p < 0.05). No statistical difference was found between groups in the weight-bearing tests. The results of the present study demonstrated that the aging process induces changes in the peripheral nerve and postsynaptic compartment without any change in skeletal muscles and ability to carry load in Wistar rats.
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Affiliation(s)
- Walter Krause Neto
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| | - Wellington de Assis Silva
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| | - Adriano P Ciena
- Laboratory of Morphology and Physical Activity, Department of Physical Education, São Paulo State University, Rio Claro, Brazil
| | - Romeu R de Souza
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
| | - Carlos A Anaruma
- Laboratory of Morphology and Physical Activity, Department of Physical Education, São Paulo State University, Rio Claro, Brazil
| | - Eliane F Gama
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Department of Physical Education, São Judas Tadeu University, São Paulo, Brazil
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Bondì M, Germinario E, Pirazzini M, Zanetti G, Cencetti F, Donati C, Gorza L, Betto R, Bruni P, Danieli-Betto D. Ablation of S1P3 receptor protects mouse soleus from age-related drop in muscle mass, force, and regenerative capacity. Am J Physiol Cell Physiol 2017; 313:C54-C67. [DOI: 10.1152/ajpcell.00027.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/11/2017] [Accepted: 04/19/2017] [Indexed: 12/31/2022]
Abstract
We investigated the effects of S1P3 deficiency on the age-related atrophy, decline in force, and regenerative capacity of soleus muscle from 23-mo-old male (old) mice. Compared with muscle from 5-mo-old (adult) mice, soleus mass and muscle fiber cross-sectional area (CSA) in old wild-type mice were reduced by ~26% and 24%, respectively. By contrast, the mass and fiber CSA of soleus muscle in old S1P3-null mice were comparable to those of adult muscle. Moreover, in soleus muscle of wild-type mice, twitch and tetanic tensions diminished from adulthood to old age. A slowing of contractile properties was also observed in soleus from old wild-type mice. In S1P3-null mice, neither force nor the contractile properties of soleus changed during aging. We also evaluated the regenerative capacity of soleus in old S1P3-null mice by stimulating muscle regeneration through myotoxic injury. After 10 days of regeneration, the mean fiber CSA of soleus in old wild-type mice was significantly smaller (−28%) compared with that of regenerated muscle in adult mice. On the contrary, the mean fiber CSA of regenerated soleus in old S1P3-null mice was similar to that of muscle in adult mice. We conclude that in the absence of S1P3, soleus muscle is protected from the decrease in muscle mass and force, and the attenuation of regenerative capacity, all of which are typical characteristics of aging.
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Affiliation(s)
- Michela Bondì
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Elena Germinario
- Department of Biomedical Sciences, University of Padova, Padua, Italy
- Interuniversity Institute of Myology, Italy
| | - Marco Pirazzini
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Giulia Zanetti
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Francesca Cencetti
- Interuniversity Institute of Myology, Italy
- Department of Biomedical, Experimental and Clinical Sciences, Mario Serio, University of Firenze, Florence, Italy; and
| | - Chiara Donati
- Interuniversity Institute of Myology, Italy
- Department of Biomedical, Experimental and Clinical Sciences, Mario Serio, University of Firenze, Florence, Italy; and
| | - Luisa Gorza
- Department of Biomedical Sciences, University of Padova, Padua, Italy
| | - Romeo Betto
- Interuniversity Institute of Myology, Italy
- National Research Council-Institute for Neuroscience, Padua, Italy
| | - Paola Bruni
- Interuniversity Institute of Myology, Italy
- Department of Biomedical, Experimental and Clinical Sciences, Mario Serio, University of Firenze, Florence, Italy; and
| | - Daniela Danieli-Betto
- Department of Biomedical Sciences, University of Padova, Padua, Italy
- Interuniversity Institute of Myology, Italy
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40
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Bartling B, Al-Robaiy S, Lehnich H, Binder L, Hiebl B, Simm A. Sex-related differences in the wheel-running activity of mice decline with increasing age. Exp Gerontol 2017; 87:139-147. [DOI: 10.1016/j.exger.2016.04.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 03/29/2016] [Accepted: 04/18/2016] [Indexed: 01/19/2023]
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White Z, Terrill J, White RB, McMahon C, Sheard P, Grounds MD, Shavlakadze T. Voluntary resistance wheel exercise from mid-life prevents sarcopenia and increases markers of mitochondrial function and autophagy in muscles of old male and female C57BL/6J mice. Skelet Muscle 2016; 6:45. [PMID: 27964759 PMCID: PMC5155391 DOI: 10.1186/s13395-016-0117-3] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 12/01/2016] [Indexed: 12/22/2022] Open
Abstract
Background There is much interest in the capacity of resistance exercise to prevent the age-related loss of skeletal muscle mass and function, known as sarcopenia. This study investigates the molecular basis underlying the benefits of resistance exercise in aging C57BL/6J mice of both sexes. Results This study is the first to demonstrate that long-term (34 weeks) voluntary resistance wheel exercise (RWE) initiated at middle age, from 15 months, prevents sarcopenia in selected hindlimb muscles and causes hypertrophy in soleus, by 23 months of age in both male and female C57BL/6J mice. Compared with 23-month-old sedentary (SED) controls, RWE (0–6 g of resistance) increased intramuscular mitochondrial density and oxidative capacity (measured by citrate synthase and NADH-TR) and increased LC3II/I ratios (a marker of autophagy) in exercised mice of both sexes. RWE also reduced mRNA expression of Gadd45α (males only) and Runx1 (females only) but had no effect on other markers of denervation including Chrng, Chrnd, Musk, and Myog. RWE increased heart mass in all mice, with a more pronounced increase in females. Significant sex differences were also noted among SED mice, with Murf1 mRNA levels increasing in male, but decreasing in old female mice between 15 and 23 months. Conclusions Overall, long-term RWE initiated from 15 month of age significantly improved some markers of the mitochondrial and autophagosomal pathways and prevented age-related muscle wasting. Electronic supplementary material The online version of this article (doi:10.1186/s13395-016-0117-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Zoe White
- School of Anatomy, Physiology and Human Biology, The University of Western Australia (UWA), 35 Stirling Highway, Crawley, WA, 6009, Australia.,Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, UWA and Harry Perkins Institute of Medical Research, Crawley, 6009, WA, Australia
| | - Jessica Terrill
- School of Anatomy, Physiology and Human Biology, The University of Western Australia (UWA), 35 Stirling Highway, Crawley, WA, 6009, Australia.,School of Chemistry and Biochemistry, UWA, Crawley, 6009, WA, Australia
| | - Robert B White
- School of Anatomy, Physiology and Human Biology, The University of Western Australia (UWA), 35 Stirling Highway, Crawley, WA, 6009, Australia
| | | | - Phillip Sheard
- Department of Physiology, University of Otago, Dunedin, 9010, New Zealand
| | - Miranda D Grounds
- School of Anatomy, Physiology and Human Biology, The University of Western Australia (UWA), 35 Stirling Highway, Crawley, WA, 6009, Australia.
| | - Tea Shavlakadze
- School of Anatomy, Physiology and Human Biology, The University of Western Australia (UWA), 35 Stirling Highway, Crawley, WA, 6009, Australia
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Tarantino U, Baldi J, Scimeca M, Piccirilli E, Piccioli A, Bonanno E, Gasbarra E. The role of sarcopenia with and without fracture. Injury 2016; 47 Suppl 4:S3-S10. [PMID: 27496721 DOI: 10.1016/j.injury.2016.07.057] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Bone and muscle tissues are in a close relationship. They are linked from a biological and functional point of view and both are related to an increased fracture risk in the elderly. The aging process is involved in the loss of functionality of both bones and muscles. In particular, aging-induced decline in muscle size and quality accompanies catabolic alterations in bone tissue; furthermore, age-related changes in bone alter its response to muscle-derived stimulation. The increased fracture risk in individuals with sarcopenia and osteoporosis is due to the decline of muscle mass and strength, the decrease in bone mineral density (BMD) and limited mobility. In this study, we investigated the role of sarcopenia and the main age-related bone diseases, osteoporosis (OP) and osteoarthritis (OA). METHODS Muscular performance status was evaluated using the Physical Activity Scale for the Elderly (PASE) test in 27 female patients with OP who underwent total hip arthroplasty for hip fracture, and in 27 age-matched female patients with OA who underwent total hip arthroplasty. Dual-energy X-ray absorptiometry (DEXA) was performed and the T-score values were used to discriminate between OP and OA patients. Body Mass Index (BMI) was calculated. As part of a multiparametric model of evaluation, biopsies of vastus lateralis muscle were analysed by immunohistochemical reaction to find a correlation with the above mentioned functional index. RESULTS The PASE test showed that the OP patients had a low or moderate level of physical activity before fracture occurred, whereas the OA patients had more intensive pre-fracture physical performances. Histological analysis showed that osteoporosis is characterised by a preferential type II fibre atrophy; in particular, data correlation showed that lower PASE test scores were related to lower diameter of type II fibres. No correlation was found between bone mineral density (BMD) and PASE test results. DISCUSSION AND CONCLUSION Osteoporosis is closely related to sarcopenia before and after fracture. Bone remodelling is influenced by muscle morphological and functional impairment and sarcopenia is considered one of the major factors for functional limitation and motor dependency in elderly osteoporotic individuals. Therefore, physical activity should be strongly recommended for OP patients at diagnosis.
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Affiliation(s)
- Umberto Tarantino
- Department of Orthopaedics and Traumatology, "Tor Vergata" University of Rome, "Policlinico Tor Vergata" Foundation, Viale Oxford 1, 00133 Rome, Italy.
| | - Jacopo Baldi
- Department of Orthopaedics and Traumatology, "Tor Vergata" University of Rome, "Policlinico Tor Vergata" Foundation, Viale Oxford 1, 00133 Rome, Italy; School of Specialisation in Orthopaedics and Traumatology, "Tor Vergata" University of Rome, "Policlinico Tor Vergata" Foundation, Viale Oxford 1, 00133 Rome, Italy
| | - Manuel Scimeca
- Anatomic Pathology Section, Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy; "Multidisciplinary Study of the Effects of Microgravity on Bone Cells" Project, Italian Space Agency (ASI), Spatial Biomedicine Center, Via del Politecnico snc, 00133 Rome, Italy
| | - Eleonora Piccirilli
- Department of Orthopaedics and Traumatology, "Tor Vergata" University of Rome, "Policlinico Tor Vergata" Foundation, Viale Oxford 1, 00133 Rome, Italy; School of Specialisation in Orthopaedics and Traumatology, "Tor Vergata" University of Rome, "Policlinico Tor Vergata" Foundation, Viale Oxford 1, 00133 Rome, Italy
| | - Andrea Piccioli
- Oncologic Centre, "Palazzo Baleani", Azienda Policlinico Umberto I, Corso Vittorio Emanuele II 244, Rome, Italy
| | - Elena Bonanno
- Anatomic Pathology Section, Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Via Montpellier 1, 00133 Rome, Italy
| | - Elena Gasbarra
- Department of Orthopaedics and Traumatology, "Tor Vergata" University of Rome, "Policlinico Tor Vergata" Foundation, Viale Oxford 1, 00133 Rome, Italy
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Rogers RS, Nishimune H. The role of laminins in the organization and function of neuromuscular junctions. Matrix Biol 2016; 57-58:86-105. [PMID: 27614294 DOI: 10.1016/j.matbio.2016.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/10/2016] [Accepted: 08/17/2016] [Indexed: 01/11/2023]
Abstract
The synapse between motor neurons and skeletal muscle is known as the neuromuscular junction (NMJ). Proper alignment of presynaptic and post-synaptic structures of motor neurons and muscle fibers, respectively, is essential for efficient motor control of skeletal muscles. The synaptic cleft between these two cells is filled with basal lamina. Laminins are heterotrimer extracellular matrix molecules that are key members of the basal lamina. Laminin α4, α5, and β2 chains specifically localize to NMJs, and these laminin isoforms play a critical role in maintenance of NMJs and organization of synaptic vesicle release sites known as active zones. These individual laminin chains exert their role in organizing NMJs by binding to their receptors including integrins, dystroglycan, and voltage-gated calcium channels (VGCCs). Disruption of these laminins or the laminin-receptor interaction occurs in neuromuscular diseases including Pierson syndrome and Lambert-Eaton myasthenic syndrome (LEMS). Interventions to maintain proper level of laminins and their receptor interactions may be insightful in treating neuromuscular diseases and aging related degeneration of NMJs.
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Affiliation(s)
- Robert S Rogers
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
| | - Hiroshi Nishimune
- Department of Anatomy and Cell Biology, University of Kansas School of Medicine, Kansas City, Kansas, USA.
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Deschenes MR, Kressin KA, Garratt RN, Leathrum CM, Shaffrey EC. Effects of exercise training on neuromuscular junction morphology and pre- to post-synaptic coupling in young and aged rats. Neuroscience 2016; 316:167-77. [PMID: 26711679 PMCID: PMC4724510 DOI: 10.1016/j.neuroscience.2015.12.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/13/2015] [Accepted: 12/02/2015] [Indexed: 11/17/2022]
Abstract
The objective of this study was to determine whether pre- to post-synaptic coupling of the neuromuscular junction (NMJ) could be maintained in the face of significant morphological remodeling brought about by exercise training, and whether aging altered this capacity. Eighteen young adult (8 mo) and eighteen aged (24 mo) Fischer 344 rats were randomly assigned to either endurance trained (treadmill running) or untrained control conditions resulting in four groups (N=9/group). After the 10-week intervention rats were euthanized and hindlimb muscles were surgically removed, quickly frozen at approximate resting length and stored at -85°C. The plantaris and EDL muscles were selected for study as they have different functions (ankle extensor and ankle flexor, respectively) but both are similarly and overwhelmingly comprised of fast-twitch myofibers. NMJs were stained with immunofluorescent procedures and images were collected with confocal microscopy. Each variable of interest was analyzed with a 2-way ANOVA with main effects of age and endurance training; in all cases significance was set at P⩽0.05. Results showed that no main effects of aging were detected in NMJs of either the plantaris or the EDL. Similarly, endurance training failed to alter any synaptic parameters of EDL muscles. The same exercise stimulus in the plantaris however, resulted in significant pre- and post-synaptic remodeling, but without altering pre- to post-synaptic coupling of the NMJs. Myofiber profiles of the same plantaris and EDL muscles were also analyzed. Unlike NMJs, myofibers displayed significant age-related atrophy in both the plantaris and EDL muscles. Overall, these results confirm that despite significant training-induced reconfiguration of NMJs, pre- to post-synaptic coupling remains intact underscoring the importance of maintaining proper apposition of neurotransmitter release and binding sites so that effective nerve to muscle communication is assured.
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Affiliation(s)
- M R Deschenes
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA; Program in Neuroscience, College of William & Mary, Williamsburg, VA 23187-8795, USA.
| | - K A Kressin
- Program in Neuroscience, College of William & Mary, Williamsburg, VA 23187-8795, USA
| | - R N Garratt
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA
| | - C M Leathrum
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA
| | - E C Shaffrey
- Department of Kinesiology & Health Sciences, College of William & Mary, Williamsburg, VA 23187-8795, USA
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Tung VWK, Burton TJ, Quail SL, Mathews MA, Camp AJ. Motor Performance is Impaired Following Vestibular Stimulation in Ageing Mice. Front Aging Neurosci 2016; 8:12. [PMID: 26869921 PMCID: PMC4737917 DOI: 10.3389/fnagi.2016.00012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 01/15/2016] [Indexed: 11/13/2022] Open
Abstract
Balance and maintaining postural equilibrium are important during stationary and dynamic movements to prevent falls, particularly in older adults. While our sense of balance is influenced by vestibular, proprioceptive, and visual information, this study focuses primarily on the vestibular component and its age-related effects on balance. C57Bl/6J mice of ages 1, 5–6, 8–9 and 27–28 months were tested using a combination of standard (such as grip strength and rotarod) and newly-developed behavioral tests (including balance beam and walking trajectory tests with a vestibular stimulus). In the current study, we confirm a decline in fore-limb grip strength and gross motor coordination as age increases. We also show that a vestibular stimulus of low frequency (2–3 Hz) and duration can lead to age-dependent changes in balance beam performance, which was evident by increases in latency to begin walking on the beam as well as the number of times hind-feet slip (FS) from the beam. Furthermore, aged mice (27–28 months) that received continuous access to a running wheel for 4 weeks did not improve when retested. Mice of ages 1, 10, 13 and 27–28 months were also tested for changes in walking trajectory as a result of the vestibular stimulus. While no linear relationship was observed between the changes in trajectory and age, 1-month-old mice were considerably less affected than mice of ages 10, 13 and 27–28 months. Conclusion: this study confirms there are age-related declines in grip strength and gross motor coordination. We also demonstrate age-dependent changes to finer motor abilities as a result of a low frequency and duration vestibular stimulus. These changes showed that while the ability to perform the balance beam task remained intact across all ages tested, behavioral changes in task performance were observed.
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Affiliation(s)
- Victoria W K Tung
- Discipline of Biomedical Science, The University of Sydney Sydney, NSW, Australia
| | - Thomas J Burton
- The Bosch Institute Animal Behavioural Facility, The University of SydneySydney, NSW, Australia; Discipline of Physiology, The University of SydneySydney, NSW, Australia
| | - Stephanie L Quail
- Brain and Mind Centre, The University of Sydney Sydney, NSW, Australia
| | - Miranda A Mathews
- Discipline of Biomedical Science, The University of Sydney Sydney, NSW, Australia
| | - Aaron J Camp
- Discipline of Biomedical Science, The University of Sydney Sydney, NSW, Australia
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Li M, Vienberg SG, Bezy O, O'Neill BT, Kahn CR. Role of PKCδ in Insulin Sensitivity and Skeletal Muscle Metabolism. Diabetes 2015; 64:4023-32. [PMID: 26307588 PMCID: PMC4657586 DOI: 10.2337/db14-1891] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 08/17/2015] [Indexed: 01/06/2023]
Abstract
Protein kinase C (PKC)δ has been shown to be increased in liver in obesity and plays an important role in the development of hepatic insulin resistance in both mice and humans. In the current study, we explored the role of PKCδ in skeletal muscle in the control of insulin sensitivity and glucose metabolism by generating mice in which PKCδ was deleted specifically in muscle using Cre-lox recombination. Deletion of PKCδ in muscle improved insulin signaling in young mice, especially at low insulin doses; however, this did not change glucose tolerance or insulin tolerance tests done with pharmacological levels of insulin. Likewise, in young mice, muscle-specific deletion of PKCδ did not rescue high-fat diet-induced insulin resistance or glucose intolerance. However, with an increase in age, PKCδ levels in muscle increased, and by 6 to 7 months of age, muscle-specific deletion of PKCδ improved whole-body insulin sensitivity and muscle insulin resistance and by 15 months of age improved the age-related decline in whole-body glucose tolerance. At 15 months of age, M-PKCδKO mice also exhibited decreased metabolic rate and lower levels of some proteins of the OXPHOS complex suggesting a role for PKCδ in the regulation of mitochondrial mass at older age. These data indicate an important role of PKCδ in the regulation of insulin sensitivity and mitochondrial homeostasis in skeletal muscle with aging.
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Affiliation(s)
- Mengyao Li
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Sara G Vienberg
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA Novo Nordisk Foundation Center for Basic Metabolic Research, Copenhagen University, Copenhagen, Denmark
| | - Olivier Bezy
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - Brian T O'Neill
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA
| | - C Ronald Kahn
- Section of Integrative Physiology and Metabolism, Joslin Diabetes Center, Harvard Medical School, Boston, MA
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Krause Neto W, Ciena AP, Anaruma CA, de Souza RR, Gama EF. Effects of exercise on neuromuscular junction components across age: systematic review of animal experimental studies. BMC Res Notes 2015; 8:713. [PMID: 26601719 PMCID: PMC4658757 DOI: 10.1186/s13104-015-1644-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/28/2015] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND During almost one-third of our life, maturation of the nervous system promotes strength and muscle mass increase. However, as age advances, the nervous system begins to suffer a slow and continue reduction of its functions. Neuromuscular junction (NMJ) is one of the structures of which change due to aging process. Physical training leads to significant adjustments in NMJs of young and aged animals. Nevertheless, studies that aimed to investigate this effect have, in many cases, methodological variables that may have some influence on the result. Thus, this study aimed to carry out a systematic review about the effects of exercise training on the NMJ compartments of young, adult and aged animals. RESULTS We searched PubMed, Google Scholar, Science Direct, Scielo and Lilacs databases for animal experimental studies that studied exercise effects on the NMJs components across age. After inclusion and exclusion criteria, we included nine articles in systematic review and two for meta-analysis (young/adult NMJ). CONCLUSIONS We identified that exercise training cause NMJ hypertrophy on young animals and NMJ compression on aged ones. However, many methodological issues such as age, skeletal muscle and fibers type, and type of exercise and training protocol might influence the results. Graphical abstract: Flow gram is actually to be show at results section as Fig 1.
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Affiliation(s)
- Walter Krause Neto
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Physical Education Department, São Judas Tadeu University, Unidade Mooca, Rua Taquari, 546, Mooca, P.O Box: 03166-000, São Paulo, SP, Brazil.
| | - Adriano Polican Ciena
- Laboratory of Histology and Electron Microscopy, Physical Education Department, "Julio de Mesquita Filho" São Paulo State University, Rio Claro, SP, Brazil.
| | - Carlos Alberto Anaruma
- Laboratory of Histology and Electron Microscopy, Physical Education Department, "Julio de Mesquita Filho" São Paulo State University, Rio Claro, SP, Brazil.
| | - Romeu Rodrigues de Souza
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Physical Education Department, São Judas Tadeu University, Unidade Mooca, Rua Taquari, 546, Mooca, P.O Box: 03166-000, São Paulo, SP, Brazil.
| | - Eliane Florencio Gama
- Laboratory of Morphoquantitative Studies and Immunohistochemistry, Physical Education Department, São Judas Tadeu University, Unidade Mooca, Rua Taquari, 546, Mooca, P.O Box: 03166-000, São Paulo, SP, Brazil.
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Larroquette F, Seto L, Gaub PL, Kamal B, Wallis D, Larivière R, Vallée J, Robitaille R, Tsuda H. Vapb/Amyotrophic lateral sclerosis 8 knock-in mice display slowly progressive motor behavior defects accompanying ER stress and autophagic response. Hum Mol Genet 2015; 24:6515-29. [PMID: 26362257 DOI: 10.1093/hmg/ddv360] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 09/01/2015] [Indexed: 12/12/2022] Open
Abstract
Missense mutations (P56S) in Vapb are associated with autosomal dominant motor neuron diseases: amyotrophic lateral sclerosis and lower motor neuron disease. Although transgenic mice overexpressing the mutant vesicle-associated membrane protein-associated protein B (VAPB) protein with neuron-specific promoters have provided some insight into the toxic properties of the mutant proteins, their role in pathogenesis remains unclear. To identify pathological defects in animals expressing the P56S mutant VAPB protein at physiological levels in the appropriate tissues, we have generated Vapb knock-in mice replacing wild-type Vapb gene with P56S mutant Vapb gene and analyzed the resulting pathological phenotypes. Heterozygous P56S Vapb knock-in mice show mild age-dependent defects in motor behaviors as characteristic features of the disease. The homozygous P56S Vapb knock-in mice show more severe defects compared with heterozygous mice reflecting the dominant and dose-dependent effects of P56S mutation. Significantly, the knock-in mice demonstrate accumulation of P56S VAPB protein and ubiquitinated proteins in cytoplasmic inclusions, selectively in motor neurons. The mutant mice demonstrate induction of ER stress and autophagic response in motor neurons before obvious onset of behavioral defects, suggesting that these cellular biological defects might contribute to the initiation of the disease. The P56S Vapb knock-in mice could be a valuable tool to gain a better understanding of the mechanisms by which the disease arises.
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Affiliation(s)
- Frédérique Larroquette
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Lesley Seto
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Perrine L Gaub
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Brishna Kamal
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Deeann Wallis
- Department of Biochemistry and Biophysics, Texas A&M University, Cypress, TX, USA and
| | - Roxanne Larivière
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4
| | - Joanne Vallée
- Departement of Neurosciences, University of Montreal, Montreal, Quebec, Canada
| | - Richard Robitaille
- Departement of Neurosciences, University of Montreal, Montreal, Quebec, Canada
| | - Hiroshi Tsuda
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4,
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Tintignac LA, Brenner HR, Rüegg MA. Mechanisms Regulating Neuromuscular Junction Development and Function and Causes of Muscle Wasting. Physiol Rev 2015; 95:809-52. [DOI: 10.1152/physrev.00033.2014] [Citation(s) in RCA: 224] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The neuromuscular junction is the chemical synapse between motor neurons and skeletal muscle fibers. It is designed to reliably convert the action potential from the presynaptic motor neuron into the contraction of the postsynaptic muscle fiber. Diseases that affect the neuromuscular junction may cause failure of this conversion and result in loss of ambulation and respiration. The loss of motor input also causes muscle wasting as muscle mass is constantly adapted to contractile needs by the balancing of protein synthesis and protein degradation. Finally, neuromuscular activity and muscle mass have a major impact on metabolic properties of the organisms. This review discusses the mechanisms involved in the development and maintenance of the neuromuscular junction, the consequences of and the mechanisms involved in its dysfunction, and its role in maintaining muscle mass during aging. As life expectancy is increasing, loss of muscle mass during aging, called sarcopenia, has emerged as a field of high medical need. Interestingly, aging is also accompanied by structural changes at the neuromuscular junction, suggesting that the mechanisms involved in neuromuscular junction maintenance might be disturbed during aging. In addition, there is now evidence that behavioral paradigms and signaling pathways that are involved in longevity also affect neuromuscular junction stability and sarcopenia.
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Affiliation(s)
- Lionel A. Tintignac
- Biozentrum, University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; and INRA, UMR866 Dynamique Musculaire et Métabolisme, Montpellier, France
| | - Hans-Rudolf Brenner
- Biozentrum, University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; and INRA, UMR866 Dynamique Musculaire et Métabolisme, Montpellier, France
| | - Markus A. Rüegg
- Biozentrum, University of Basel, Basel, Switzerland; Department of Biomedicine, University of Basel, Basel, Switzerland; and INRA, UMR866 Dynamique Musculaire et Métabolisme, Montpellier, France
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50
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Soffe Z, Radley-Crabb HG, McMahon C, Grounds MD, Shavlakadze T. Effects of loaded voluntary wheel exercise on performance and muscle hypertrophy in young and old male C57Bl/6J mice. Scand J Med Sci Sports 2015; 26:172-88. [PMID: 25653015 DOI: 10.1111/sms.12416] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2014] [Indexed: 01/05/2023]
Abstract
This study compared the capacity of young and old male C57Bl/6J mice to exercise with increasing resistance over 10 weeks, and its impact on muscle mass. Young mice (aged 15-25 weeks) were subjected to low (LR) and high (HR) resistance exercise, whereas only LR was used for old mice (107-117 weeks). Weekly patterns of voluntary wheel activity, food consumption and body weights were measured. Running patterns changed over time and with age, with two peaks of activity detected for young, but only one for old mice: speed and distance run was also less for old mice. The mass for six limb muscles was measured at the end of the experiment. The most pronounced increase in mass in response to exercise was for the soleus in young and old mice, and also quadriceps and gastrocnemius in young mice. Soleus and quadriceps muscles were analyzed histologically for myofiber number and size. A striking feature was the many small myofibers in response to exercise in young (but not old) soleus, whereas these were not present after exercise in young or old quadriceps. Overall, there was a striking difference in response to exercise between muscles and this was influenced by age.
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Affiliation(s)
- Z Soffe
- School of Anatomy, Physiology and Human Biology, the University of Western Australia, Nedlands, Western Australia, Australia
| | - H G Radley-Crabb
- School of Anatomy, Physiology and Human Biology, the University of Western Australia, Nedlands, Western Australia, Australia.,School of Biomedical Sciences, CHIRI Biosciences Research Precinct, Curtin University, Bentley, Western Australia, Australia
| | - C McMahon
- Developmental Biology Group, Agresearch Ltd, Hamilton, New Zealand
| | - M D Grounds
- School of Anatomy, Physiology and Human Biology, the University of Western Australia, Nedlands, Western Australia, Australia
| | - T Shavlakadze
- School of Anatomy, Physiology and Human Biology, the University of Western Australia, Nedlands, Western Australia, Australia.,Developmental Biology Group, Agresearch Ltd, Hamilton, New Zealand
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