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Ovsepian SV, O'Leary VB, Martinez S. Selective vulnerability of motor neuron types and functional groups to degeneration in amyotrophic lateral sclerosis: review of the neurobiological mechanisms and functional correlates. Brain Struct Funct 2024; 229:1-14. [PMID: 37999738 PMCID: PMC10827929 DOI: 10.1007/s00429-023-02728-6] [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: 07/04/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative condition characterised by a progressive loss of motor neurons controlling voluntary muscle activity. The disease manifests through a variety of motor dysfunctions related to the extent of damage and loss of neurons at different anatomical locations. Despite extensive research, it remains unclear why some motor neurons are especially susceptible to the disease, while others are affected less or even spared. In this article, we review the neurobiological mechanisms, neurochemical profiles, and morpho-functional characteristics of various motor neuron groups and types of motor units implicated in their differential exposure to degeneration. We discuss specific cell-autonomous (intrinsic) and extrinsic factors influencing the vulnerability gradient of motor units and motor neuron types to ALS, with their impact on disease manifestation, course, and prognosis, as revealed in preclinical and clinical studies. We consider the outstanding challenges and emerging opportunities for interpreting the phenotypic and mechanistic variability of the disease to identify targets for clinical interventions.
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Affiliation(s)
- Saak V Ovsepian
- Faculty of Engineering and Science, University of Greenwich London, Chatham Maritime, Kent, ME4 4TB, UK.
| | - Valerie B O'Leary
- Department of Medical Genetics, Third Faculty of Medicine, Charles University, Ruská 87, 10000, Prague, Czech Republic
| | - Salvador Martinez
- Instituto de Neurociencias UMH-CSIC, Avda. Ramon y Cajal, 03550, San Juan de Alicante, Spain.
- Center of Biomedical Network Research on Mental Health (CIBERSAM), ISCIII, Madrid, Spain.
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2
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Rochat C, Bernard-Marissal N, Källstig E, Pradervand S, Perrin FE, Aebischer P, Raoul C, Schneider BL. Astrocyte-targeting RNA interference against mutated superoxide dismutase 1 induces motoneuron plasticity and protects fast-fatigable motor units in a mouse model of amyotrophic lateral sclerosis. Glia 2022; 70:842-857. [PMID: 34978340 PMCID: PMC9303637 DOI: 10.1002/glia.24140] [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: 09/23/2021] [Revised: 12/19/2021] [Accepted: 12/22/2021] [Indexed: 11/22/2022]
Abstract
In amyotrophic lateral sclerosis (ALS) caused by SOD1 gene mutations, both cell‐autonomous and noncell‐autonomous mechanisms lead to the selective degeneration of motoneurons (MN). Here, we evaluate the therapeutic potential of gene therapy targeting mutated SOD1 in mature astrocytes using mice expressing the mutated SOD1G93A protein. An AAV‐gfaABC1D vector encoding an artificial microRNA is used to deliver RNA interference against mutated SOD1 selectively in astrocytes. The treatment leads to the progressive rescue of neuromuscular junction occupancy, to the recovery of the compound muscle action potential in the gastrocnemius muscle, and significantly improves neuromuscular function. In the spinal cord, gene therapy targeting astrocytes protects a small pool of the most vulnerable fast‐fatigable MN until disease end stage. In the gastrocnemius muscle of the treated SOD1G93A mice, the fast‐twitch type IIB muscle fibers are preserved from atrophy. Axon collateral sprouting is observed together with muscle fiber type grouping indicative of denervation/reinnervation events. The transcriptome profiling of spinal cord MN shows changes in the expression levels of factors regulating the dynamics of microtubules. Gene therapy delivering RNA interference against mutated SOD1 in astrocytes protects fast‐fatigable motor units and thereby improves neuromuscular function in ALS mice.
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Affiliation(s)
- Cylia Rochat
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Brain Mind Institute, Lausanne
| | - Nathalie Bernard-Marissal
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Brain Mind Institute, Lausanne.,INSERM, MMG, Aix-Marseille University, Marseille, France
| | - Emma Källstig
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Brain Mind Institute, Lausanne.,Bertarelli Platform for Gene Therapy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva
| | - Sylvain Pradervand
- Genomic Technologies Facility, University of Lausanne, Lausanne, Switzerland
| | | | - Patrick Aebischer
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Brain Mind Institute, Lausanne
| | - Cédric Raoul
- INM, Université Montpellier, INSERM, Montpellier, France
| | - Bernard L Schneider
- Ecole Polytechnique Fédérale de Lausanne (EPFL), Brain Mind Institute, Lausanne.,Bertarelli Platform for Gene Therapy, Ecole Polytechnique Fédérale de Lausanne (EPFL), Geneva
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3
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Pikatza-Menoio O, Elicegui A, Bengoetxea X, Naldaiz-Gastesi N, López de Munain A, Gerenu G, Gil-Bea FJ, Alonso-Martín S. The Skeletal Muscle Emerges as a New Disease Target in Amyotrophic Lateral Sclerosis. J Pers Med 2021; 11:671. [PMID: 34357138 PMCID: PMC8307751 DOI: 10.3390/jpm11070671] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/09/2021] [Accepted: 07/14/2021] [Indexed: 01/02/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder that leads to progressive degeneration of motor neurons (MNs) and severe muscle atrophy without effective treatment. Most research on ALS has been focused on the study of MNs and supporting cells of the central nervous system. Strikingly, the recent observations of pathological changes in muscle occurring before disease onset and independent from MN degeneration have bolstered the interest for the study of muscle tissue as a potential target for delivery of therapies for ALS. Skeletal muscle has just been described as a tissue with an important secretory function that is toxic to MNs in the context of ALS. Moreover, a fine-tuning balance between biosynthetic and atrophic pathways is necessary to induce myogenesis for muscle tissue repair. Compromising this response due to primary metabolic abnormalities in the muscle could trigger defective muscle regeneration and neuromuscular junction restoration, with deleterious consequences for MNs and thereby hastening the development of ALS. However, it remains puzzling how backward signaling from the muscle could impinge on MN death. This review provides a comprehensive analysis on the current state-of-the-art of the role of the skeletal muscle in ALS, highlighting its contribution to the neurodegeneration in ALS through backward-signaling processes as a newly uncovered mechanism for a peripheral etiopathogenesis of the disease.
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Affiliation(s)
- Oihane Pikatza-Menoio
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
| | - Amaia Elicegui
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
| | - Xabier Bengoetxea
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
| | - Neia Naldaiz-Gastesi
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
| | - Adolfo López de Munain
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014 Donostia/San Sebastián, Spain
- Department of Neurosciences, Faculty of Medicine and Nursery, University of the Basque Country UPV-EHU, 20014 Donostia/San Sebastián, Spain
| | - Gorka Gerenu
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
- Department of Physiology, University of the Basque Country UPV-EHU, 48940 Leioa, Spain
| | - Francisco Javier Gil-Bea
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
| | - Sonia Alonso-Martín
- Neuromuscular Diseases Group, Neurosciences Area, Biodonostia Health Research Institute, 20014 Donostia/San Sebastián, Spain; (O.P.-M.); (A.E.); (X.B.); (N.N.-G.); (A.L.d.M.); (G.G.); (F.J.G.-B.)
- CIBERNED, Carlos III Institute, Spanish Ministry of Economy & Competitiveness, 28031 Madrid, Spain
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Harrison JM, Rafuse VF. Muscle fiber-type specific terminal Schwann cell pathology leads to sprouting deficits following partial denervation in SOD1 G93A mice. Neurobiol Dis 2020; 145:105052. [PMID: 32827689 DOI: 10.1016/j.nbd.2020.105052] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/20/2020] [Accepted: 08/13/2020] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an adult-onset disease characterized by the progressive death of motoneurons and denervation of muscle fibers. To restore motor function, surviving motoneurons in partially denervated muscles typically sprout axons to reinnervate denervated endplates. However, studies on the SOD1G93A rodent models of ALS indicate that sprouting is significantly limited in fast, but not slow, twitch muscles after disease onset. This limitation hastens the rate of muscle weakness and loss of motor function. The causes of this limitation are currently unknown. Sprouting could be limited because the SOD1G93A mutation weakens motoneurons making them incapable of expanding their field of innervation. Alternatively, motoneurons may be capable of sprouting, but unable to do so due to the loss of a permissive sprouting environment. To distinguish between the two possibilities, we compared the sprouting capacity of motoneuron subtypes by partially denervating the fast twitch plantaris (composed of type IIa/IIb muscle fibers) and slow twitch soleus muscles (type I/IIa fibers) prior to disease onset and weakening in SOD1G93A and WT mice. We found that only motoneurons innervating the SOD1G93A plantaris had a limited sprouting capacity. This was correlated with the selective loss of terminal Schwann cells (TSCs) at IIb fibers and an increase in macrophage infiltration. Treating SOD1G93A mice with the tyrosine kinase inhibitor, masitinib, significantly reduced infiltration, prevented TSC loss, and increased the sprouting capacity to near normal. These results suggest that TSCs at denervated type IIb muscle fibers are aberrantly targeted by infiltrating macrophages in SOD1G93A mice, and their loss accounts, at least in part, for the compromised sprouting capacity of the largest motoneurons during early stages of ALS.
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Affiliation(s)
- Julia M Harrison
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada; Brain Repair Centre, Life Sciences Research Institute, Halifax, Nova Scotia B3H 4R2, Canada
| | - Victor F Rafuse
- Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada; Brain Repair Centre, Life Sciences Research Institute, Halifax, Nova Scotia B3H 4R2, Canada.
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Just-Borràs L, Hurtado E, Cilleros-Mañé V, Biondi O, Charbonnier F, Tomàs M, Garcia N, Tomàs J, Lanuza MA. Running and swimming prevent the deregulation of the BDNF/TrkB neurotrophic signalling at the neuromuscular junction in mice with amyotrophic lateral sclerosis. Cell Mol Life Sci 2020; 77:3027-3040. [PMID: 31646358 PMCID: PMC11104938 DOI: 10.1007/s00018-019-03337-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/30/2019] [Accepted: 10/04/2019] [Indexed: 12/12/2022]
Abstract
Nerve-induced muscle contraction regulates the BDNF/TrkB neurotrophic signalling to retrogradely modulate neurotransmission and protect the neuromuscular junctions and motoneurons. In muscles with amyotrophic lateral sclerosis, this pathway is strongly misbalanced and neuromuscular junctions are destabilized, which may directly cause the motoneuron degeneration and muscular atrophy observed in this disease. Here, we sought to demonstrate (1) that physical exercise, whose recommendation has been controversial in amyotrophic lateral sclerosis, would be a good option for its therapy, because it normalizes and improves the altered neurotrophin pathway and (2) a plausible molecular mechanism underlying its positive effect. SOD1-G93A mice were trained following either running or swimming-based protocols since the beginning of the symptomatic phase (day 70 of age) until day 115. Next, the full BDNF pathway, including receptors, downstream kinases and proteins related with neurotransmission, was characterized and motoneuron survival was analysed. The results establish that amyotrophic lateral sclerosis-induced damaging molecular changes in the BDNF/TrkB pathway are reduced, prevented or even overcompensated by precisely defined exercise protocols that modulate TrkB isoforms and neurotransmission regulatory proteins and reduce motoneuron death. Altogether, the maintenance of the BDNF/TrkB signalling and the downstream pathway, particularly after the swimming protocol, adds new molecular evidence of the benefits of physical exercise to reduce the impact of amyotrophic lateral sclerosis. These results are encouraging since they reveal an improvement even starting the therapy after the onset of the disease.
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Affiliation(s)
- Laia Just-Borràs
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain
| | - Erica Hurtado
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain
| | - Víctor Cilleros-Mañé
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain
| | - Olivier Biondi
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, 45 Rue des Saints-Pères, 75006, Paris, France
| | - Frédéric Charbonnier
- UMR-S1124, INSERM, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, 45 Rue des Saints-Pères, 75006, Paris, France
| | - Marta Tomàs
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain
| | - Neus Garcia
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain
| | - Josep Tomàs
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain.
| | - Maria A Lanuza
- Unitat d'Histologia i Neurobiologia (UHNEUROB), Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili. Sant Llorenç 21, 43201, Reus, Spain.
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Darroudi S, Tajbakhsh A, Esmaily H, Ghazizadeh H, Zamani P, Sadabadi F, Tayefi M, Tayefi B, Fereydouni N, Mouhebati M, Akbari Sark N, Avan A, Ferns GA, Mohammadpour AH, Asadi Z, Ghayour-Mobarhan M. 50 bp deletion in promoter superoxide dismutase 1 gene and increasing risk of cardiovascular disease in Mashhad stroke and heart atherosclerotic disorder cohort study. Biofactors 2020; 46:55-63. [PMID: 31670860 DOI: 10.1002/biof.1575] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 08/20/2019] [Indexed: 12/14/2022]
Abstract
Cardiovascular disease (CVD), one of the main mortality causes worldwide is considered to be affected by general oxidative stress and inadequacy antioxidant system. Superoxide dismutase 1 (SOD1), a cytosolic antioxidant enzyme has a key role in neutralizing the excessive prooxidant by scavenging the super oxide anions. SOD1 polymorphic variants exhibit the altered activity properties. In the current study, we are aimed to investigate the association between the SOD1 polymorphism and CVD prevalence. A 6-years case control follow up study was designed to genotype the 526 participants (311 controls and 215 cases) for studying the 50 bp INS/DEL polymorphism at SOD1 promoter gene and analyze their blood lipid profile and anthropometric characteristics. Among the two possible alleles of the SOD1 gene (Wild [W] and Mutant [M]) the meaningful association was detected between the Mutants' frequency and the prevalence of CVD patients (p-value <.001). The W and M allele refer to inserted and deleted 50 bp in the polymorphic site of the SOD1 promoter, respectively. The WM and MM genotypes' frequency which indicate the wild heterozygotes and Mutant homozygotes, respectively, were significantly correlated with the prevalence of cardiovascular disease (p-value <.001). The present study has the potential to introduce the 50 bp INS/DEL polymorphism of SOD1 genotyping as a novel unique diagnostic approach for screening the high risk CVD.
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Affiliation(s)
- Susan Darroudi
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amir Tajbakhsh
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Habibollah Esmaily
- Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hamideh Ghazizadeh
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Parvin Zamani
- Department of Medical Biotechnology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Sadabadi
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Maryam Tayefi
- Maryam Tayefi change to Norwegian Center for e-health Research, University hospital of North Norway, Tromsø, Norway
| | - Batool Tayefi
- Preventive Medicine and Public Health Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Narges Fereydouni
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohsen Mouhebati
- Cardiovascular Research Center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Noushin Akbari Sark
- Social Determinants of Health Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amir Avan
- Student Research Committee, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Gordon A Ferns
- Brighton & Sussex Medical School, Division of Medical Education, Brighton, Sussex, UK
| | - Amir H Mohammadpour
- Pharmaceutical Research Center, Pharmaceutical Institute Technology, Mashhad University of Medical Sciences, Mashhad, Iran
- Department of Clinical Pharmacy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra Asadi
- Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Metabolic Syndrome research center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Majid Ghayour-Mobarhan
- Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
- Metabolic Syndrome research center, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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The Impact of Kinases in Amyotrophic Lateral Sclerosis at the Neuromuscular Synapse: Insights into BDNF/TrkB and PKC Signaling. Cells 2019; 8:cells8121578. [PMID: 31817487 PMCID: PMC6953086 DOI: 10.3390/cells8121578] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 11/19/2019] [Accepted: 12/03/2019] [Indexed: 12/14/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) promotes neuron survival in adulthood in the central nervous system. In the peripheral nervous system, BDNF is a contraction-inducible protein that, through its binding to tropomyosin-related kinase B receptor (TrkB), contributes to the retrograde neuroprotective control done by muscles, which is necessary for motor neuron function. BDNF/TrkB triggers downstream presynaptic pathways, involving protein kinase C, essential for synaptic function and maintenance. Undeniably, this reciprocally regulated system exemplifies the tight communication between nerve terminals and myocytes to promote synaptic function and reveals a new view about the complementary and essential role of pre and postsynaptic interplay in keeping the synapse healthy and strong. This signaling at the neuromuscular junction (NMJ) could establish new intervention targets across neuromuscular diseases characterized by deficits in presynaptic activity and muscle contractility and by the interruption of the connection between nervous and muscular tissues, such as amyotrophic lateral sclerosis (ALS). Indeed, exercise and other therapies that modulate kinases are effective at delaying ALS progression, preserving NMJs and maintaining motor function to increase the life quality of patients. Altogether, we review synaptic activity modulation of the BDNF/TrkB/PKC signaling to sustain NMJ function, its and other kinases’ disturbances in ALS and physical and molecular mechanisms to delay disease progression.
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24S-hydroxycholesterol suppresses neuromuscular transmission in SOD1(G93A) mice: A possible role of NO and lipid rafts. Mol Cell Neurosci 2018; 88:308-318. [PMID: 29550246 DOI: 10.1016/j.mcn.2018.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 02/08/2018] [Accepted: 03/12/2018] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the initial denervation of skeletal muscle and subsequent death of motor neurons. A dying-back pattern of ALS suggests a crucial role for neuromuscular junction dysfunction. In the present study, microelectrode recording of postsynaptic currents and optical detection of synaptic vesicle traffic (FM1-43 dye) and intracellular NO levels (DAF-FM DA) were used to examine the effect of the major brain-derived cholesterol metabolite 24S-hydroxycholesterol (24S-HC, 0.4 μM) on neuromuscular transmission in the diaphragm of transgenic mice carrying a mutant superoxide dismutase 1 (SODG93A). We found that 24S-HC suppressed spontaneous neurotransmitter release and neurotransmitter exocytosis during high-frequency stimulation. The latter was accompanied by a decrease in both the rate of synaptic vesicle recycling and activity-dependent enhancement of NO production. Inhibition of NO synthase with L-NAME also attenuated synaptic vesicle exocytosis during high-frequency stimulation and completely abolished the effect of 24S-HC itself. Of note, 24S-HC enhanced the labeling of synaptic membranes with B-subunit of cholera toxin, suggesting an increase in lipid ordering. Lipid raft-disrupting agents (methyl-β-cyclodextrin, sphingomyelinase) prevented the action of 24S-HC on both lipid raft marker labeling and NO synthesis. Together, these experiments indicate that 24S-HC is able to suppress the exocytotic release of neurotransmitter in response to intense activity via a NO/lipid raft-dependent pathway in the neuromuscular junctions of SODG93A mice.
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What is "Hyper" in the ALS Hypermetabolism? Mediators Inflamm 2017; 2017:7821672. [PMID: 29081604 PMCID: PMC5610793 DOI: 10.1155/2017/7821672] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/03/2017] [Indexed: 12/11/2022] Open
Abstract
The progressive and fatal loss of upper (brain) and lower (spinal cord) motor neurons and muscle denervation concisely condenses the clinical picture of amyotrophic lateral sclerosis (ALS). Despite the multiple mechanisms believed to underlie the selective loss of motor neurons, ALS aetiology remains elusive and obscure. Likewise, there is also a cluster of alterations in ALS patients in which muscle wasting, body weight loss, eating dysfunction, and abnormal energy dissipation coexist. Defective energy metabolism characterizes the ALS progression, and such paradox of energy balance stands as a challenge for the understanding of ALS pathogenesis. The hypermetabolism in ALS will be examined from tissue-specific energy imbalance (e.g., skeletal muscle) to major energetic pathways (e.g., AMP-activated protein kinase) and whole-body energy alterations including glucose and lipid metabolism, nutrition, and potential involvement of interorgan communication. From the point of view here expressed, the hypermetabolism in ALS should be evaluated as a magnifying glass through which looking at the ALS pathogenesis is from a different perspective in which defective metabolism can disclose novel mechanistic interpretations and lines of intervention.
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Udina E, Putman CT, Harris LR, Tyreman N, Cook VE, Gordon T. Compensatory axon sprouting for very slow axonal die-back in a transgenic model of spinal muscular atrophy type III. J Physiol 2017; 595:1815-1829. [PMID: 27891608 PMCID: PMC5330916 DOI: 10.1113/jp273404] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/15/2016] [Indexed: 01/13/2023] Open
Abstract
KEY POINTS Smn+/- transgenic mouse is a model of the mildest form of spinal muscular atrophy. Although there is a loss of spinal motoneurons in 11-month-old animals, muscular force is maintained. This maintained muscular force is mediated by reinnervation of the denervated fibres by surviving motoneurons. The spinal motoneurons in these animals do not show an increased susceptibility to death after nerve injury and they retain their regenerative capacity. We conclude that the hypothesized immaturity of the neuromuscular system in this model cannot explain the loss of motoneurons by systematic die-back. ABSTRACT Spinal muscular atrophy (SMA) is a common autosomal recessive disorder in humans and is the leading genetic cause of infantile death. Patients lack the SMN1 gene with the severity of the disease depending on the number of copies of the highly homologous SMN2 gene. Although motoneuron death in the Smn+/- transgenic mouse model of the mildest form of SMA, SMA type III, has been reported, we have used retrograde tracing of sciatic and femoral motoneurons in the hindlimb with recording of muscle and motor unit isometric forces to count the number of motoneurons with intact neuromuscular connections. Thereby, we investigated whether incomplete maturation of the neuromuscular system induced by survival motoneuron protein (SMN) defects is responsible for die-back of axons relative to survival of motoneurons. First, a reduction of ∼30% of backlabelled motoneurons began relatively late, at 11 months of age, with a significant loss of 19% at 7 months. Motor axon die-back was affirmed by motor unit number estimation. Loss of functional motor units was fully compensated by axonal sprouting to retain normal contractile force in four hindlimb muscles (three fast-twitch and one slow-twitch) innervated by branches of the sciatic nerve. Second, our evaluation of whether axotomy of motoneurons in the adult Smn+/- transgenic mouse increases their susceptibility to cell death demonstrated that all the motoneurons survived and they sustained their capacity to regenerate their nerve fibres. It is concluded the systematic die-back of motoneurons that innervate both fast- and slow-twitch muscle fibres is not related to immaturity of the neuromuscular system in SMA.
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Affiliation(s)
- Esther Udina
- Neuroscience and Mental Health Institute, Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
- Institute of Neurosciences and Department of Cell Biology, Physiology and ImmunologyUniversitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)BellaterraSpain
| | - Charles T. Putman
- Neuroscience and Mental Health Institute, Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
- Exercise Biochemistry Laboratory, Faculty of Physical Education and RecreationUniversity of AlbertaEdmontonABCanadaT6G 2H9
| | - Luke R. Harris
- Neuroscience and Mental Health Institute, Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
- Exercise Biochemistry Laboratory, Faculty of Physical Education and RecreationUniversity of AlbertaEdmontonABCanadaT6G 2H9
| | - Neil Tyreman
- Neuroscience and Mental Health Institute, Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
| | - Victoria E. Cook
- Neuroscience and Mental Health Institute, Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
- Exercise Biochemistry Laboratory, Faculty of Physical Education and RecreationUniversity of AlbertaEdmontonABCanadaT6G 2H9
| | - Tessa Gordon
- Neuroscience and Mental Health Institute, Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
- Division of Rehabilitation and Physical Medicine of the Faculty of Medicine and DentistryUniversity of AlbertaEdmontonABCanadaT6G 2S2
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11
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Yamashita T, Hatakeyama T, Sato K, Fukui Y, Hishikawa N, Ohta Y, Nishiyama Y, Kawai N, Tamiya T, Abe K. Flow-metabolism uncoupling in the cervical spinal cord of ALS patients. Neurol Sci 2017; 38:659-665. [PMID: 28120243 DOI: 10.1007/s10072-017-2823-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 01/16/2017] [Indexed: 12/27/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease. In ALS, both glucose consumption and neuronal intensity reportedly decrease in the cerebral motor cortex when measured by positron emission tomography (PET). In this study, we evaluated cervical spinal glucose metabolism, blood flow, and neuronal intensity of 10 ALS patients with upper extremity (U/E) atrophy both with 18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) PET and 11C-flumazenil (11C-FMZ) PET. On the ipsilateral side of C5 and T1 levels, 18F-FDG uptake increased significantly (*p < 0.05), and was correlated with the rate of progression of the ALS FRS-R-U/E score (R = 0.645, *p = 0.041). Despite this hyperglucose metabolism, the 11C-FMZ PET study did not show a coupled increase of spinal blood flow even though neuronal intensity did not decrease. These results indicate a strong correlation between hyperglucose metabolism and ALS progression alongside the uncoupling of flow-metabolism. This mechanism, which could result in subsequent motor neuronal death, may be a potential therapeutic target for ALS.
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Affiliation(s)
- Toru Yamashita
- Department of Neurology, Graduate School of Medicine, Dentistry and Pharmacy, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Tetsuhiro Hatakeyama
- Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Kota Sato
- Department of Neurology, Graduate School of Medicine, Dentistry and Pharmacy, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Yusuke Fukui
- Department of Neurology, Graduate School of Medicine, Dentistry and Pharmacy, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Nozomi Hishikawa
- Department of Neurology, Graduate School of Medicine, Dentistry and Pharmacy, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Yasuyuki Ohta
- Department of Neurology, Graduate School of Medicine, Dentistry and Pharmacy, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Yoshihiro Nishiyama
- Department of Radiology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Nobuyuki Kawai
- Department of Neurological Surgery, Kagawa General Rehabilitation Hospital, Kagawa, Japan
| | - Takashi Tamiya
- Department of Neurological Surgery, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Koji Abe
- Department of Neurology, Graduate School of Medicine, Dentistry and Pharmacy, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan.
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12
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Mancuso R, Navarro X. Sigma-1 Receptor in Motoneuron Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 964:235-254. [PMID: 28315275 DOI: 10.1007/978-3-319-50174-1_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyotrophic Lateral Sclerosis (ALS ) is a neurodegenerative disease affecting spinal cord and brain motoneurons , leading to paralysis and early death. Multiple etiopathogenic mechanisms appear to contribute in the development of ALS , including glutamate excitotoxicity, oxidative stress , protein misfolding, mitochondrial defects, impaired axonal transport, inflammation and glial cell alterations. The Sigma-1 receptor is highly expressed in motoneurons of the spinal cord, particularly enriched in the endoplasmic reticulum (ER) at postsynaptic cisternae of cholinergic C-terminals. Several evidences point to participation of Sigma-1R alterations in motoneuron degeneration. Thus, mutations of the transmembrane domain of the Sigma-1R have been described in familial ALS cases. Interestingly, Sigma-1R KO mice display muscle weakness and motoneuron loss. On the other hand, Sigma-1R agonists promote neuroprotection and neurite elongation through activation of protein kinase C on motoneurons in vitro and in vivo after ventral root avulsion. Remarkably, treatment of SOD1 mice, the most usual animal model of ALS , with Sigma-1R agonists resulted in significantly enhanced motoneuron function and preservation, and increased animal survival. Sigma-1R activation also reduced microglial reactivity and increased the glial expression of neurotrophic factors. Two main interconnected mechanisms seem to underlie the effects of Sigma-1R manipulation on motoneurons: modulation of neuronal excitability and regulation of calcium homeostasis. In addition, Sigma-1R also contributes to regulating protein degradation, and reducing oxidative stress. Therefore, the multi-functional nature of the Sigma-1R represents an attractive target for treating aspects of ALS and other motoneuron diseases .
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Affiliation(s)
- Renzo Mancuso
- Center for Biological Sciences, University of Southampton, Southampton General Hospital, SO16 6YD, Southampton, UK
| | - Xavier Navarro
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain.
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13
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Loeffler JP, Picchiarelli G, Dupuis L, Gonzalez De Aguilar JL. The Role of Skeletal Muscle in Amyotrophic Lateral Sclerosis. Brain Pathol 2016; 26:227-36. [PMID: 26780251 PMCID: PMC8029271 DOI: 10.1111/bpa.12350] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal adult‐onset disease primarily characterized by upper and lower motor neuron degeneration, muscle wasting and paralysis. It is increasingly accepted that the pathological process leading to ALS is the result of multiple disease mechanisms that operate within motor neurons and other cell types both inside and outside the central nervous system. The implication of skeletal muscle has been the subject of a number of studies conducted on patients and related animal models. In this review, we describe the features of ALS muscle pathology and discuss on the contribution of muscle to the pathological process. We also give an overview of the therapeutic strategies proposed to alleviate muscle pathology or to deliver curative agents to motor neurons. ALS muscle mainly suffers from oxidative stress, mitochondrial dysfunction and bioenergetic disturbances. However, the way by which the disease affects different types of myofibers depends on their contractile and metabolic features. Although the implication of muscle in nourishing the degenerative process is still debated, there is compelling evidence suggesting that it may play a critical role. Detailed understanding of the muscle pathology in ALS could, therefore, lead to the identification of new therapeutic targets.
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Affiliation(s)
- Jean-Philippe Loeffler
- Université de Strasbourg, UMR_S 1118, Strasbourg, France.,INSERM, U1118, Mécanismes Centraux et Péripheriques de la Neurodégénérescence, Strasbourg, France
| | - Gina Picchiarelli
- Université de Strasbourg, UMR_S 1118, Strasbourg, France.,INSERM, U1118, Mécanismes Centraux et Péripheriques de la Neurodégénérescence, Strasbourg, France
| | - Luc Dupuis
- Université de Strasbourg, UMR_S 1118, Strasbourg, France.,INSERM, U1118, Mécanismes Centraux et Péripheriques de la Neurodégénérescence, Strasbourg, France
| | - Jose-Luis Gonzalez De Aguilar
- Université de Strasbourg, UMR_S 1118, Strasbourg, France.,INSERM, U1118, Mécanismes Centraux et Péripheriques de la Neurodégénérescence, Strasbourg, France
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14
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Arbour D, Vande Velde C, Robitaille R. New perspectives on amyotrophic lateral sclerosis: the role of glial cells at the neuromuscular junction. J Physiol 2016; 595:647-661. [PMID: 27633977 DOI: 10.1113/jp270213] [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: 06/27/2016] [Accepted: 09/12/2016] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a disease leading to the death of motor neurons (MNs). It is also recognized as a non-cell autonomous disease where glial cells in the CNS are involved in its pathogenesis and progression. However, although denervation of neuromuscular junctions (NMJs) represents an early and major event in ALS, the importance of glial cells at this synapse receives little attention. An interesting possibility is that altered relationships between glial cells and MNs in the spinal cord in ALS may also take place at the NMJ. Perisynaptic Schwann cells (PSCs), which are glial cells at the NMJ, show great morphological and functional adaptability to ensure NMJ stability, maintenance and repair. More specifically, PSCs change their properties according to the state of innervation. Hence, abnormal changes or lack of changes can have detrimental effects on NMJs in ALS. This review will provide an overview of known and hypothesized interactions between MN nerve terminals and PSCs at NMJs during development, aging and ALS-induced denervation. These neuron-PSC interactions may be crucial to the understanding of how degenerative changes begin and progress at NMJs in ALS, and represent a novel therapeutic target.
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Affiliation(s)
- Danielle Arbour
- Département de neurosciences, Université de Montréal, Montréal, Québec, Canada, H3C 3J7.,Groupe de recherche sur le système nerveux central, Université de Montréal, Montréal, Québec, Canada, H3C 3J7
| | - Christine Vande Velde
- Département de neurosciences, Université de Montréal, Montréal, Québec, Canada, H3C 3J7.,Groupe de recherche sur le système nerveux central, Université de Montréal, Montréal, Québec, Canada, H3C 3J7.,Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada, H2X 0A9
| | - Richard Robitaille
- Département de neurosciences, Université de Montréal, Montréal, Québec, Canada, H3C 3J7.,Groupe de recherche sur le système nerveux central, Université de Montréal, Montréal, Québec, Canada, H3C 3J7
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15
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Tsitkanou S, Della Gatta PA, Russell AP. Skeletal Muscle Satellite Cells, Mitochondria, and MicroRNAs: Their Involvement in the Pathogenesis of ALS. Front Physiol 2016; 7:403. [PMID: 27679581 PMCID: PMC5020084 DOI: 10.3389/fphys.2016.00403] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 08/29/2016] [Indexed: 12/14/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS), also known as motor neuron disease (MND), is a fatal motor neuron disorder. It results in progressive degeneration and death of upper and lower motor neurons, protein aggregation, severe muscle atrophy and respiratory insufficiency. Median survival with ALS is between 2 and 5 years from the onset of symptoms. ALS manifests as either familial ALS (FALS) (~10% of cases) or sporadic ALS (SALS), (~90% of cases). Mutations in the copper/zinc (CuZn) superoxide dismutase (SOD1) gene account for ~20% of FALS cases and the mutant SOD1 mouse model has been used extensively to help understand the ALS pathology. As the precise mechanisms causing ALS are not well understood there is presently no cure. Recent evidence suggests that motor neuron degradation may involve a cell non-autonomous phenomenon involving numerous cell types within various tissues. Skeletal muscle is now considered as an important tissue involved in the pathogenesis of ALS by activating a retrograde signaling cascade that degrades motor neurons. Skeletal muscle heath and function are regulated by numerous factors including satellite cells, mitochondria and microRNAs. Studies demonstrate that in ALS these factors show various levels of dysregulation within the skeletal muscle. This review provides an overview of their dysregulation in various ALS models as well as how they may contribute individually and/or synergistically to the ALS pathogenesis.
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Affiliation(s)
- Stavroula Tsitkanou
- Athletics Laboratory, School of Physical Education and Sport Science, University of Athens Athens, Greece
| | - Paul A Della Gatta
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University Geelong, VIC, Australia
| | - Aaron P Russell
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University Geelong, VIC, Australia
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16
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Mancuso R, Martínez-Muriana A, Leiva T, Gregorio D, Ariza L, Morell M, Esteban-Pérez J, García-Redondo A, Calvo AC, Atencia-Cibreiro G, Corfas G, Osta R, Bosch A, Navarro X. Neuregulin-1 promotes functional improvement by enhancing collateral sprouting in SOD1(G93A) ALS mice and after partial muscle denervation. Neurobiol Dis 2016; 95:168-78. [PMID: 27461051 DOI: 10.1016/j.nbd.2016.07.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 06/23/2016] [Accepted: 07/22/2016] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of motoneurons, which is preceded by loss of neuromuscular connections in a "dying back" process. Neuregulin-1 (Nrg1) is a neurotrophic factor essential for the development and maintenance of neuromuscular junctions, and Nrg1 receptor ErbB4 loss-of-function mutations have been reported as causative for ALS. Our main goal was to investigate the role of Nrg1 type I (Nrg1-I) in SOD1(G93A) mice muscles. We overexpressed Nrg1-I by means of an adeno-associated viral (AAV) vector, and investigated its effect by means of neurophysiological techniques assessing neuromuscular function, as well as molecular approaches (RT-PCR, western blot, immunohistochemistry, ELISA) to determine the mechanisms underlying Nrg1-I action. AAV-Nrg1-I intramuscular administration promoted motor axon collateral sprouting by acting on terminal Schwann cells, preventing denervation of the injected muscles through Akt and ERK1/2 pathways. We further used a model of muscle partial denervation by transecting the L4 spinal nerve. AAV-Nrg1-I intramuscular injection enhanced muscle reinnervation by collateral sprouting, whereas administration of lapatinib (ErbB receptor inhibitor) completely blocked it. We demonstrated that Nrg1-I plays a crucial role in the collateral reinnervation process, opening a new window for developing novel ALS therapies for functional recovery rather than preservation.
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Affiliation(s)
- Renzo Mancuso
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain; Biological Sciences, University of Southampton, Southampton General Hospital, Southampton, UK
| | - Anna Martínez-Muriana
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Tatiana Leiva
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - David Gregorio
- Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Lorena Ariza
- Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Marta Morell
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Jesús Esteban-Pérez
- Unidad de ELA, Servicio de Neurología, Instituto de Investigación Biomédica, Hospital 12 de Octubre "i+12", Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Alberto García-Redondo
- Unidad de ELA, Servicio de Neurología, Instituto de Investigación Biomédica, Hospital 12 de Octubre "i+12", Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Ana C Calvo
- Department of Otolaryngology - Head and Neck Surgery, Kresgae Hearing Research Institute, University of Michigan, Michigan, US
| | - Gabriela Atencia-Cibreiro
- Unidad de ELA, Servicio de Neurología, Instituto de Investigación Biomédica, Hospital 12 de Octubre "i+12", Madrid, Spain; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Gabriel Corfas
- Department of Otolaryngology - Head and Neck Surgery, Kresgae Hearing Research Institute, University of Michigan, Michigan, US
| | - Rosario Osta
- Laboratorio de Genética y Bioquímica (LAGENBIO), Facultad de Veterinaria, Instituto Agroalimentario de Aragón (IA2), Instituto de Investigación Sanitaria Aragón, Universidad de Zaragoza, Zaragoza, Spain
| | - Assumpció Bosch
- Center of Animal Biotechnology and Gene Therapy and Department of Biochemistry and Molecular Biology, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Xavier Navarro
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain.
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17
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Kaus A, Sareen D. ALS Patient Stem Cells for Unveiling Disease Signatures of Motoneuron Susceptibility: Perspectives on the Deadly Mitochondria, ER Stress and Calcium Triad. Front Cell Neurosci 2015; 9:448. [PMID: 26635528 PMCID: PMC4652136 DOI: 10.3389/fncel.2015.00448] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/02/2015] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a largely sporadic progressive neurodegenerative disease affecting upper and lower motoneurons (MNs) whose specific etiology is incompletely understood. Mutations in superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TARDBP/TDP-43) and C9orf72, have been identified in subsets of familial and sporadic patients. Key associated molecular and neuropathological features include ubiquitinated TDP-43 inclusions, stress granules, aggregated dipeptide proteins from mutant C9orf72 transcripts, altered mitochondrial ultrastructure, dysregulated calcium homeostasis, oxidative and endoplasmic reticulum (ER) stress, and an unfolded protein response (UPR). Such impairments have been documented in ALS animal models; however, whether these mechanisms are initiating factors or later consequential events leading to MN vulnerability in ALS patients is debatable. Human induced pluripotent stem cells (iPSCs) are a valuable tool that could resolve this “chicken or egg” causality dilemma. Relevant systems for probing pathophysiologically affected cells from large numbers of ALS patients and discovering phenotypic disease signatures of early MN susceptibility are described. Performing unbiased ‘OMICS and high-throughput screening in relevant neural cells from a cohort of ALS patient iPSCs, and rescuing mitochondrial and ER stress impairments, can identify targeted therapeutics for increasing MN longevity in ALS.
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Affiliation(s)
- Anjoscha Kaus
- Board of Governors-Regenerative Medicine Institute, Cedars-Sinai Medical Center Los Angeles, CA, USA ; Department of Biomedical Sciences, Cedars-Sinai Medical Center Los Angeles, CA, USA
| | - Dhruv Sareen
- Board of Governors-Regenerative Medicine Institute, Cedars-Sinai Medical Center Los Angeles, CA, USA ; Department of Biomedical Sciences, Cedars-Sinai Medical Center Los Angeles, CA, USA ; iPSC Core, The David and Janet Polak Stem Cell Laboratory, Cedars-Sinai Medical Center Los Angeles, CA, USA
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18
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Mancuso R, Navarro X. Amyotrophic lateral sclerosis: Current perspectives from basic research to the clinic. Prog Neurobiol 2015; 133:1-26. [PMID: 26253783 DOI: 10.1016/j.pneurobio.2015.07.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 07/30/2015] [Accepted: 07/31/2015] [Indexed: 02/07/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of upper and lower motoneurons, leading to muscle weakness and paralysis, and finally death. Considerable recent advances have been made in basic research and preclinical therapeutic attempts using experimental models, leading to increasing clinical and translational research in the context of this disease. In this review we aim to summarize the most relevant findings from a variety of aspects about ALS, including evaluation methods, animal models, pathophysiology, and clinical findings, with particular emphasis in understanding the role of every contributing mechanism to the disease for elucidating the causes underlying degeneration of motoneurons and the development of new therapeutic strategies.
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Affiliation(s)
- Renzo Mancuso
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Xavier Navarro
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain.
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19
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Homeostatic dysregulation in membrane properties of masticatory motoneurons compared with oculomotor neurons in a mouse model for amyotrophic lateral sclerosis. J Neurosci 2015; 35:707-20. [PMID: 25589764 DOI: 10.1523/jneurosci.1682-14.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative motoneuron disease with presently no cure. Motoneuron (MN) hyperexcitability is commonly observed in ALS and is suggested to be a precursor for excitotoxic cell death. However, it is unknown whether hyperexcitability also occurs in MNs that are resistant to degeneration. Second, it is unclear whether all the MNs within homogeneous motor pools would present similar susceptibility to excitability changes since high-threshold MNs innervating fast fatigable muscle fibers selectively degenerate compared with low-threshold MNs innervating fatigue resistant slow muscle fibers. Therefore, we concurrently examined the excitability of ALS-vulnerable trigeminal motoneurons (TMNs) controlling jaw musculature and ALS-resistant oculomotor neurons (OMNs) controlling eye musculature in a well studied SOD1(G93A) ALS mouse model using in vitro patch-clamp electrophysiology at presymptomatic ages P8-P12. Our results show that hyperexcitability is not a global change among all the MNs, although mutant SOD1 is ubiquitously expressed. Instead, complex changes occur in ALS-vulnerable TMNs based on motor unit type and discharge characteristics. Firing threshold decreases among high-threshold TMNs and increases in a subpopulation of low-threshold TMNs. The latter group was identified based on their linear frequency-current responses to triangular ramp current injections. Such complex changes in MN recruitment were absent in ALS-resistant OMNs. We simulated the observed complex changes in TMN excitability using a computer-based jaw closer motor pool model. Model results suggest that hypoexcitability may indeed represent emerging disease symptomology that causes resistance in muscle force initiation. Identifying the cellular and molecular properties of these hypoexcitable cells may guide effective therapeutic strategies in ALS.
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20
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Brown R, Hynes-Allen A, Swan AJ, Dissanayake KN, Gillingwater TH, Ribchester RR. Activity-dependent degeneration of axotomized neuromuscular synapses in Wld S mice. Neuroscience 2015; 290:300-20. [PMID: 25617654 PMCID: PMC4362769 DOI: 10.1016/j.neuroscience.2015.01.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/10/2015] [Accepted: 01/12/2015] [Indexed: 12/12/2022]
Abstract
Use and disuse may influence synaptic maintenance but so far evidence for this has been indirect. We tested whether stimulation or disuse of neuromuscular junctions in adult WldS mice altered vulnerability to axotomy. Moderate activity optimized resistance to axotomy while disuse or stimulation increased the rate of synaptic degeneration.
Activity and disuse of synapses are thought to influence progression of several neurodegenerative diseases in which synaptic degeneration is an early sign. Here we tested whether stimulation or disuse renders neuromuscular synapses more or less vulnerable to degeneration, using axotomy as a robust trigger. We took advantage of the slow synaptic degeneration phenotype of axotomized neuromuscular junctions in flexor digitorum brevis (FDB) and deep lumbrical (DL) muscles of Wallerian degeneration-Slow (WldS) mutant mice. First, we maintained ex vivo FDB and DL nerve-muscle explants at 32 °C for up to 48 h. About 90% of fibers from WldS mice remained innervated, compared with about 36% in wild-type muscles at the 24-h checkpoint. Periodic high-frequency nerve stimulation (100 Hz: 1 s/100 s) reduced synaptic protection in WldS preparations by about 50%. This effect was abolished in reduced Ca2+ solutions. Next, we assayed FDB and DL innervation after 7 days of complete tetrodotoxin (TTX)-block of sciatic nerve conduction in vivo, followed by tibial nerve axotomy. Five days later, only about 9% of motor endplates remained innervated in the paralyzed muscles, compared with about 50% in 5 day-axotomized muscles from saline-control-treated WldS mice with no conditioning nerve block. Finally, we gave mice access to running wheels for up to 4 weeks prior to axotomy. Surprisingly, exercising WldS mice ad libitum for 4 weeks increased about twofold the amount of subsequent axotomy-induced synaptic degeneration. Together, the data suggest that vulnerability of mature neuromuscular synapses to axotomy, a potent neurodegenerative trigger, may be enhanced bimodally, either by disuse or by hyperactivity.
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Affiliation(s)
- R Brown
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - A Hynes-Allen
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - A J Swan
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - K N Dissanayake
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - T H Gillingwater
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK
| | - R R Ribchester
- Euan MacDonald Centre for Motor Neurone Disease Research, Hugh Robson Building, University of Edinburgh, George Square, Edinburgh EH8 9XD, UK.
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Moloney EB, de Winter F, Verhaagen J. ALS as a distal axonopathy: molecular mechanisms affecting neuromuscular junction stability in the presymptomatic stages of the disease. Front Neurosci 2014; 8:252. [PMID: 25177267 PMCID: PMC4132373 DOI: 10.3389/fnins.2014.00252] [Citation(s) in RCA: 217] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/29/2014] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is being redefined as a distal axonopathy, in that many molecular changes influencing motor neuron degeneration occur at the neuromuscular junction (NMJ) at very early stages of the disease prior to symptom onset. A huge variety of genetic and environmental causes have been associated with ALS, and interestingly, although the cause of the disease can differ, both sporadic and familial forms of ALS show a remarkable similarity in terms of disease progression and clinical manifestation. The NMJ is a highly specialized synapse, allowing for controlled signaling between muscle and nerve necessary for skeletal muscle function. In this review we will evaluate the clinical, animal experimental and cellular/molecular evidence that supports the idea of ALS as a distal axonopathy. We will discuss the early molecular mechanisms that occur at the NMJ, which alter the functional abilities of the NMJ. Specifically, we focus on the role of axon guidance molecules on the stability of the cytoskeleton and how these molecules may directly influence the cells of the NMJ in a way that may initiate or facilitate the dismantling of the neuromuscular synapse in the presymptomatic stages of ALS.
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Affiliation(s)
- Elizabeth B. Moloney
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and ScienceAmsterdam, Netherlands
| | - Fred de Winter
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and ScienceAmsterdam, Netherlands
- Department of Neurosurgery, Leiden University Medical CentreLeiden, Netherlands
| | - Joost Verhaagen
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and ScienceAmsterdam, Netherlands
- Centre for Neurogenomics and Cognitive Research, Vrije Universiteit AmsterdamAmsterdam, Netherlands
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Kryściak K, Grieb P, Celichowski J. Changes in motor unit properties in SOD1 (G93A) rats. Muscle Nerve 2014; 50:577-86. [PMID: 24488615 DOI: 10.1002/mus.24196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 01/13/2014] [Accepted: 01/29/2014] [Indexed: 12/11/2022]
Abstract
INTRODUCTION In amyotrophic lateral sclerosis (ALS), progressive death of motor neurons results in denervation and reinnervation of muscles. It is not clear how ALS affects the properties of motor units (MUs). METHODS Properties of single MUs in the medial gastrocnemius (MG) muscle of rats bearing the human mutated superoxide dismutase gene type 1 (SOD1) were determined at 3 stages: asymptomatic (ALS I); early symptomatic (ALS II); and terminal (ALS III). RESULTS In ALS II, higher proportions of FF (fast fatigable) and S (slow) MUs were observed, whereas in ALS III higher percentages of S and lower percentages of FF MUs were noted compared with controls. S motor neurons reinnervated fast muscle fibers, and those MUs gained some properties of fast MUs, including lower fatigue resistance, greater force generation, and higher action potential amplitudes. CONCLUSION Changes in MU properties of SOD1 rats have progressive and multidirectional character and speed depending on the MU type.
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Affiliation(s)
- Katarzyna Kryściak
- Department of Neurobiology, University School of Physical Education, 27/39 Królowej Jadwigi Street, 61-871, Poznań, Poland
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Schmitt F, Hussain G, Dupuis L, Loeffler JP, Henriques A. A plural role for lipids in motor neuron diseases: energy, signaling and structure. Front Cell Neurosci 2014; 8:25. [PMID: 24600344 PMCID: PMC3929843 DOI: 10.3389/fncel.2014.00025] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 01/17/2013] [Indexed: 12/12/2022] Open
Abstract
Motor neuron diseases (MNDs) are characterized by selective death of motor neurons and include mainly adult-onset amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA). Neurodegeneration is not the single pathogenic event occurring during disease progression. There are multiple lines of evidence for the existence of defects in lipid metabolism at peripheral level. For instance, hypermetabolism is well characterized in ALS, and dyslipidemia correlates with better prognosis in patients. Lipid metabolism plays also a role in other MNDs. In SMA, misuse of lipids as energetic nutrients is described in patients and in related animal models. The composition of structural lipids in the central nervous system is modified, with repercussion on membrane fluidity and on cell signaling mediated by bioactive lipids. Here, we review the main epidemiologic and mechanistic findings that link alterations of lipid metabolism and motor neuron degeneration, and we discuss the rationale of targeting these modifications for therapeutic management of MNDs.
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Affiliation(s)
- Florent Schmitt
- Mécanismes Centraux et Périphériques de la Neurodégénerescence, INSERM U1118 Strasbourg, France ; UMRS1118, Fédération de Médecine Translationnelle de Strasbourg Université de Strasbourg, France
| | - Ghulam Hussain
- Mécanismes Centraux et Périphériques de la Neurodégénerescence, INSERM U1118 Strasbourg, France ; UMRS1118, Fédération de Médecine Translationnelle de Strasbourg Université de Strasbourg, France
| | - Luc Dupuis
- Mécanismes Centraux et Périphériques de la Neurodégénerescence, INSERM U1118 Strasbourg, France ; UMRS1118, Fédération de Médecine Translationnelle de Strasbourg Université de Strasbourg, France
| | - Jean-Philippe Loeffler
- Mécanismes Centraux et Périphériques de la Neurodégénerescence, INSERM U1118 Strasbourg, France ; UMRS1118, Fédération de Médecine Translationnelle de Strasbourg Université de Strasbourg, France
| | - Alexandre Henriques
- Mécanismes Centraux et Périphériques de la Neurodégénerescence, INSERM U1118 Strasbourg, France ; UMRS1118, Fédération de Médecine Translationnelle de Strasbourg Université de Strasbourg, France
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Saxena S, Roselli F, Singh K, Leptien K, Julien JP, Gros-Louis F, Caroni P. Neuroprotection through Excitability and mTOR Required in ALS Motoneurons to Delay Disease and Extend Survival. Neuron 2013; 80:80-96. [DOI: 10.1016/j.neuron.2013.07.027] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2013] [Indexed: 12/13/2022]
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Power GA, Dalton BH, Behm DG, Doherty TJ, Vandervoort AA, Rice CL. Motor unit survival in lifelong runners is muscle dependent. Med Sci Sports Exerc 2012; 44:1235-42. [PMID: 22246219 DOI: 10.1249/mss.0b013e318249953c] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
UNLABELLED A contributing factor to the loss of muscle mass and strength with adult aging is the reduction in the number of functioning motor units (MUs). Recently, we reported that lifelong competitive runners (master runners = ~66 yr) had greater numbers of MUs in a leg muscle (tibialis anterior) than age-matched recreationally active controls. This suggested that long-term exposure to high levels of physical activity may limit the loss of MU numbers with adult aging. However, it is unknown if this finding is the result of long-term activation of the specifically exercised motoneuron pool (i.e., tibialis anterior) or an overall systemic neuroprotective effect of high levels of physical activity. PURPOSE The purpose was to estimate the number of functioning MUs (MUNEs) in the biceps brachii (an upper body muscle not directly loaded by running) of nine young (27 ± 5 yr) and nine old (70 ± 5 yr) men and nine lifelong competitive master runners (67 ± 4 yr). METHODS Decomposition-enhanced spike-triggered averaging was used to measure surface and intramuscular EMG signals during elbow flexion at 10% of maximum voluntary isometric contraction. RESULTS Derived MUNEs were lower in the biceps brachii of runners (185 ± 69 MUs) and old men (133 ± 69 MUs) than the young (354 ± 113 MUs), but the old and master runners were similar. CONCLUSIONS Although there were no significant differences in MUNE between both older groups in the biceps brachii muscle, with the number of subjects tested here, we cannot eliminate the possibility of some whole-body neuroprotective effect. However, when compared with the remote biceps muscle, a greater influence on age-related spinal motoneuron survival was found in a chronically activated MN pool specific to the exercised muscle.
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Affiliation(s)
- Geoffrey A Power
- Canadian Centre for Activity and Aging, School of Kinesiology, Faculty of Health Sciences, The University of Western Ontario, London, Ontario, Canada
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Nguyen KT, Zhang Z, Barrett EF, David G. Morphological and functional changes in innervation of a fast forelimb muscle in SOD1-G85R mice. Neurobiol Dis 2012; 48:399-408. [PMID: 22813866 DOI: 10.1016/j.nbd.2012.07.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 06/15/2012] [Accepted: 07/09/2012] [Indexed: 01/05/2023] Open
Abstract
Muscle endplates become denervated in mice that express mutations of human superoxide dismutase 1 (hSOD1), models of familial amyotrophic lateral sclerosis. This denervation is especially marked in fast limb muscles, and precedes death of motor neuron somata. This study used mice that expressed yellow fluorescent protein (YFP) in neurons to investigate changes in the morphology and function of axons and motor terminals innervating a fast forelimb muscle (epitrochleoanconeus, ETA) in presymptomatic and symptomatic hSOD1-G85R mice, compared to those in mice that express wild-type (wt) hSOD1. The percentage of endplates (identified using fluorescently-labeled α-bungarotoxin) innervated by motor terminals remained high in presymptomatic SOD1-G85R mice, but fell to ~50% in symptomatic mice. The number of large diameter (≥4 μm) axons in the ETA nerve also decreased as mice became symptomatic, and endplate innervation correlated best with the number of large diameter axons. Motor terminal function was assessed using changes in terminal YFP fluorescence evoked by trains of action potentials; different components of the pH-dependent YFP signals reflect stimulation-induced Ca2+ entry and vesicular exo/endocytosis. Most visible motor terminals (>90%) remained capable of responding to nerve stimulation in both pre- and symptomatic hSOD1-G85R mice, but with functional alterations. Responses in presymptomatic terminals suggested reduced acidification and increased vesicular release, whereas symptomatic terminals exhibited increased acidification and reduced vesicular release. The fact that most remaining terminals were able to respond to nerve stimulation suggests that motor terminal-protective therapies might contribute to preserving neuromuscular function in fALS mice.
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Affiliation(s)
- Khanh T Nguyen
- Department of Physiology and Biophysics, University of Miami Miller School of Medicine, P.O. Box 016430, Miami, FL 33101, USA
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Carrasco DI, Bichler EK, Rich MM, Wang X, Seburn KL, Pinter MJ. Motor terminal degeneration unaffected by activity changes in SOD1(G93A) mice; a possible role for glycolysis. Neurobiol Dis 2012; 48:132-40. [PMID: 22750521 DOI: 10.1016/j.nbd.2012.06.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2012] [Revised: 06/06/2012] [Accepted: 06/22/2012] [Indexed: 12/13/2022] Open
Abstract
This study examined whether activity is a contributing factor to motor terminal degeneration in mice that overexpress the G93A mutation of the SOD1 enzyme found in humans with inherited motor neuron disease. Previously, we showed that overload of muscles accomplished by synergist denervation accelerated motor terminal degeneration in dogs with hereditary canine spinal muscular atrophy (HCSMA). In the present study, we found that SOD1 plantaris muscles overloaded for 2months showed no differences of neuromuscular junction innervation status when compared with normally loaded, contralateral plantaris muscles. Complete elimination of motor terminal activity using blockade of sciatic nerve conduction with tetrodotoxin cuffs for 1month also produced no change of plantaris innervation status. To assess possible effects of activity on motor terminal function, we examined the synaptic properties of SOD1 soleus neuromuscular junctions at a time when significant denervation of close synergists had occurred as a result of natural disease progression. When examined in glucose media, SOD1 soleus synaptic properties were similar to wildtype. When glycolysis was inhibited and ATP production limited to mitochondria, however, blocking of evoked synaptic transmission occurred and a large increase in the frequency of spontaneous mEPCs was observed. Similar effects were observed at neuromuscular junctions in muscle from dogs with inherited motor neuron disease (HCSMA), although significant defects of synaptic transmission exist at these neuromuscular junctions when examined in glucose media, as reported previously. These results suggest that glycolysis compensates for mitochondrial dysfunction at motor terminals of SOD1 mice and HCSMA dogs. This compensatory mechanism may help to support resting and activity-related metabolism in the presence of dysfunctional mitochondria and prolong the survival of SOD1 motor terminals.
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Affiliation(s)
- Dario I Carrasco
- Department of Physiology, Emory University, Atlanta, GA 30322, USA
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Miyazaki K, Masamoto K, Morimoto N, Kurata T, Mimoto T, Obata T, Kanno I, Abe K. Early and progressive impairment of spinal blood flow-glucose metabolism coupling in motor neuron degeneration of ALS model mice. J Cereb Blood Flow Metab 2012; 32:456-67. [PMID: 22068226 PMCID: PMC3293114 DOI: 10.1038/jcbfm.2011.155] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Revised: 09/09/2011] [Accepted: 09/26/2011] [Indexed: 12/11/2022]
Abstract
The exact mechanism of selective motor neuron death in amyotrophic lateral sclerosis (ALS) remains still unclear. In the present study, we performed in vivo capillary imaging, directly measured spinal blood flow (SBF) and glucose metabolism, and analyzed whether if a possible flow-metabolism coupling is disturbed in motor neuron degeneration of ALS model mice. In vivo capillary imaging showed progressive decrease of capillary diameter, capillary density, and red blood cell speed during the disease course. Spinal blood flow was progressively decreased in the anterior gray matter (GM) from presymptomatic stage to 0.80-fold of wild-type (WT) mice, 0.61 at early-symptomatic, and 0.49 at end stage of the disease. Local spinal glucose utilization (LSGU) was transiently increased to 1.19-fold in anterior GM at presymptomatic stage, which in turn progressively decreased to 0.84 and 0.60 at early-symptomatic and end stage of the disease. The LSGU/SBF ratio representing flow-metabolism uncoupling (FMU) preceded the sequential pathological changes in the spinal cord of ALS mice and was preferentially found in the affected region of ALS. The present study suggests that this early and progressive FMU could profoundly involve in the whole disease process as a vascular factor of ALS pathology, and could also be a potential target for therapeutic intervention of ALS.
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Affiliation(s)
- Kazunori Miyazaki
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
| | - Kazuto Masamoto
- Department of Biophysics, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
- Education and Research Center for Frontier Science and Engineering, University of Electro-Communications, Tokyo, Japan
| | - Nobutoshi Morimoto
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
| | - Tomoko Kurata
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
| | - Takahumi Mimoto
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
| | - Takayuki Obata
- Department of Biophysics, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Iwao Kanno
- Department of Biophysics, Molecular Imaging Center, National Institute of Radiological Sciences, Chiba, Japan
| | - Koji Abe
- Department of Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
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Elbasiouny SM, Schuster JE. The Effect of Training on Motoneuron Survival in Amyotrophic Lateral Sclerosis: Which Motoneuron Type is Saved? Front Physiol 2011; 2:18. [PMID: 21541255 PMCID: PMC3083714 DOI: 10.3389/fphys.2011.00018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Accepted: 04/12/2011] [Indexed: 12/04/2022] Open
Affiliation(s)
- Sherif M Elbasiouny
- Heckman Lab, Department of Physiology, Feinberg School of Medicine, Northwestern University Chicago, IL, USA
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Abstract
Although often considered as a group, spinal motor neurons are highly diverse in terms of their morphology, connectivity, and functional properties and differ significantly in their response to disease. Recent studies of motor neuron diversity have clarified developmental mechanisms and provided novel insights into neurodegeneration in amyotrophic lateral sclerosis (ALS). Motor neurons of different classes and subtypes--fast/slow, alpha/gamma--are grouped together into motor pools, each of which innervates a single skeletal muscle. Distinct mechanisms regulate their development. For example, glial cell line-derived neurotrophic factor (GDNF) has effects that are pool-specific on motor neuron connectivity, column-specific on axonal growth, and subtype-specific on survival. In multiple degenerative contexts including ALS, spinal muscular atrophy (SMA), and aging, fast-fatigable (FF) motor units degenerate early, whereas motor neurons innervating slow muscles and those involved in eye movement and pelvic sphincter control are strikingly preserved. Extrinsic and intrinsic mechanisms that confer resistance represent promising therapeutic targets in these currently incurable diseases.
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Affiliation(s)
- Kevin C Kanning
- Department of Pathology, Center for Motor Neuron Biology and Disease, Columbia University Medical Center, New York, NY 10032, USA
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Evidence from computer simulations for alterations in the membrane biophysical properties and dendritic processing of synaptic inputs in mutant superoxide dismutase-1 motoneurons. J Neurosci 2010; 30:5544-58. [PMID: 20410108 DOI: 10.1523/jneurosci.0434-10.2010] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A critical step in improving our understanding of the development of amyotrophic lateral sclerosis (ALS) is to identify the factors contributing to the alterations in the excitability of motoneurons and assess their individual contributions. Here we investigated the early alterations in the passive electrical and morphological properties of neonatal spinal motoneurons that occur by 10 d after birth, long before disease onset. We identified some of the factors contributing to these alterations, and estimated their individual contributions. To achieve this goal, we undertook a computer simulation analysis using realistic morphologies of reconstructed wild-type (WT) and mutant superoxide dismutase-1 (mSOD1) motoneurons. Ion channel parameters of these models were then tuned to match the experimental data on electrical properties obtained from these same motoneurons. We found that the reduced excitability of mSOD1 models was accompanied with decreased specific membrane resistance by approximately 25% and efficacy of synaptic inputs (slow and fast) by 12-22%. Linearity of summation of synaptic currents was similar to WT. We also assessed the contribution of the alteration in dendritic morphology alone to this decreased excitability and found that it reduced the input resistance by 10% and the efficacy of synaptic inputs by 7-15%. Our results were also confirmed in models with dendritic active conductances. Our simulations indicated that the alteration in passive electrical properties of mSOD1 models resulted from concurrent alterations in their morphology and membrane biophysical properties, and consequently altered the motoneuronal dendritic processing of synaptic inputs. These results clarify new aspects of spinal motoneurons malfunction in ALS.
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