1
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Deutsch AJ, Elbasiouny SM. Dysregulation of persistent inward and outward currents in spinal motoneurons of symptomatic SOD1-G93A mice. J Physiol 2024. [PMID: 38924530 DOI: 10.1113/jp286032] [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: 11/25/2023] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
Persistent inward currents (PICs) and persistent outward currents (POCs) regulate the excitability and firing behaviours of spinal motoneurons (MNs). Given their potential role in MN excitability dysfunction in amyotrophic lateral sclerosis (ALS), PICs have been previously studied in superoxide dismutase 1 (SOD1)-G93A mice (the standard animal model of ALS); however, conflicting results have been reported on how the net PIC changes during disease progression. Also, individual PICs and POCs have never been examined before in symptomatic ALS. To fill this gap, we measured the net and individual PIC and POC components of wild-type (WT) and SOD MNs in current clamp and voltage clamp during disease progression (assessed by neuroscores). We show that SOD MNs of symptomatic mice experience a much larger net PIC, relative to WT cells from age-matched littermates. Specifically, the Na+ and Ca2+ PICs are larger, whereas the lasting SK-mediated (SKL) POC is smaller than WT (Na+ PIC is the largest and SKL POC is the smallest components in SOD MNs). We also show that PIC dysregulation is present at symptom onset, is sustained throughout advanced disease stages and is proportional to SOD MN cell size (largest dysregulation is in the largest SOD cells, the most vulnerable in ALS). Additionally, we show that studying disease progression using neuroscores is more accurate than using SOD mouse age, which could lead to misleading statistics and age-based trends. Collectively, this study contributes novel PIC and POC data, reveals ionic mechanisms contributing to the vulnerability differential among MN types/sizes, and provides insights on the roles PIC and POC mechanisms play in MN excitability dysfunction in ALS. KEY POINTS: Individual persistent inward currents (PICs) and persistent outward currents (POCs) have never been examined before in spinal motoneurons (MNs) of symptomatic amyotrophic lateral sclerosis (ALS) mice. Thus, we contribute novel PIC and POC data to the ALS literature. Male SOD MNs of symptomatic mice have elevated net PIC, with larger Na+ and Ca2+ PICs but reduced SKL POC vs. wild-type littermates. Na+ PIC is the largest and SKL POC is the smallest current in SOD cells. The PIC/POC dysregulation is present at symptom onset. PIC dysregulation is sustained throughout advanced disease, and is proportional to SOD MN size (largest dysregulation is in the largest cells, the most vulnerable in ALS). Thus, we reveal ionic mechanisms contributing to the vulnerability differential among MN types/sizes in ALS. Studying disease progression using SOD mice neuroscores is more accurate than using age, which could distort the statistical differences between SOD and WT PIC/POC data and the trends during disease progression.
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Affiliation(s)
- Andrew J Deutsch
- Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, OH, USA
| | - Sherif M Elbasiouny
- Department of Biomedical, Industrial, and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, OH, USA
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, College of Science and Mathematics, Wright State University, Dayton, OH, USA
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2
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Odierna GL, Vucic S, Dyer M, Dickson T, Woodhouse A, Blizzard C. How do we get from hyperexcitability to excitotoxicity in amyotrophic lateral sclerosis? Brain 2024; 147:1610-1621. [PMID: 38408864 PMCID: PMC11068114 DOI: 10.1093/brain/awae039] [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: 07/17/2023] [Revised: 11/15/2023] [Accepted: 12/10/2023] [Indexed: 02/28/2024] Open
Abstract
Amyotrophic lateral sclerosis is a devastating neurodegenerative disease that, at present, has no effective cure. Evidence of increased circulating glutamate and hyperexcitability of the motor cortex in patients with amyotrophic lateral sclerosis have provided an empirical support base for the 'dying forward' excitotoxicity hypothesis. The hypothesis postulates that increased activation of upper motor neurons spreads pathology to lower motor neurons in the spinal cord in the form of excessive glutamate release, which triggers excitotoxic processes. Many clinical trials have focused on therapies that target excitotoxicity via dampening neuronal activation, but not all are effective. As such, there is a growing tension between the rising tide of evidence for the 'dying forward' excitotoxicity hypothesis and the failure of therapies that target neuronal activation. One possible solution to these contradictory outcomes is that our interpretation of the current evidence requires revision in the context of appreciating the complexity of the nervous system and the limitations of the neurobiological assays we use to study it. In this review we provide an evaluation of evidence relevant to the 'dying forward' excitotoxicity hypothesis and by doing so, identify key gaps in our knowledge that need to be addressed. We hope to provide a road map from hyperexcitability to excitotoxicity so that we can better develop therapies for patients suffering from amyotrophic lateral sclerosis. We conclude that studies of upper motor neuron activity and their synaptic output will play a decisive role in the future of amyotrophic lateral sclerosis therapy.
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Affiliation(s)
- G Lorenzo Odierna
- Tasmanian School of Medicine, University of Tasmania, Hobart, TAS 7000, Australia
| | - Steve Vucic
- Brain and Nerve Research Center, The University of Sydney, Sydney 2050, Australia
| | - Marcus Dyer
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
- Department of Pharmaceutical and Pharmacological Sciences, Center for Neurosciences, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Adele Woodhouse
- The Wicking Dementia Centre, University of Tasmania, Hobart, TAS 7000, Australia
| | - Catherine Blizzard
- Tasmanian School of Medicine, University of Tasmania, Hobart, TAS 7000, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
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3
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Nascimento F, Özyurt MG, Halablab K, Bhumbra GS, Caron G, Bączyk M, Zytnicki D, Manuel M, Roselli F, Brownstone R, Beato M. Spinal microcircuits go through multiphasic homeostatic compensations in a mouse model of motoneuron degeneration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.10.588918. [PMID: 38645210 PMCID: PMC11030447 DOI: 10.1101/2024.04.10.588918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
In neurological conditions affecting the brain, early-stage neural circuit adaption is key for long-term preservation of normal behaviour. We tested if motoneurons and respective microcircuits also adapt in the initial stages of disease progression in a mouse model of progressive motoneuron degeneration. Using a combination of in vitro and in vivo electrophysiology and super-resolution microscopy, we found that, preceding muscle denervation and motoneuron death, recurrent inhibition mediated by Renshaw cells is reduced in half due to impaired quantal size associated with decreased glycine receptor density. Additionally, higher probability of release from proprioceptive Ia terminals leads to increased monosynaptic excitation to motoneurons. Surprisingly, the initial impairment in recurrent inhibition is not a widespread feature of inhibitory spinal circuits, such as group I inhibitory afferents, and is compensated at later stages of disease progression. We reveal that in disease conditions, spinal microcircuits undergo specific multiphasic homeostatic compensations to preserve force output.
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Affiliation(s)
- Filipe Nascimento
- Department of Neuroscience Physiology and Pharmacology (NPP), Gower Street, University College London, WC1E 6BT, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - M. Görkem Özyurt
- Department of Neuroscience Physiology and Pharmacology (NPP), Gower Street, University College London, WC1E 6BT, UK
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Kareen Halablab
- Department of Neurology, Ulm University, Ulm, Germany
- German Centre for Neurodegenerative Diseases-Ulm (DZNE-Ulm), Ulm, Germany
| | - Gardave Singh Bhumbra
- Department of Neuroscience Physiology and Pharmacology (NPP), Gower Street, University College London, WC1E 6BT, UK
| | - Guillaume Caron
- Saints-Pères Paris Institute for the Neurosciences (SPPIN), Université Paris Cité, Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Marcin Bączyk
- Department of Neurobiology, Poznań University of Physical Education, Poznań, Poland
| | - Daniel Zytnicki
- Saints-Pères Paris Institute for the Neurosciences (SPPIN), Université Paris Cité, Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Marin Manuel
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, USA
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
| | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany
- German Centre for Neurodegenerative Diseases-Ulm (DZNE-Ulm), Ulm, Germany
| | - Rob Brownstone
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Marco Beato
- Department of Neuroscience Physiology and Pharmacology (NPP), Gower Street, University College London, WC1E 6BT, UK
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4
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Antonucci S, Caron G, Dikwella N, Krishnamurty SS, Harster A, Zarrin H, Tahanis A, Heuvel FO, Danner SM, Ludolph A, Grycz K, Baczyk M, Zytnicki D, Roselli F. Non-canonical adrenergic neuromodulation of motoneuron intrinsic excitability through β-receptors in wild-type and ALS mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.25.586570. [PMID: 38585891 PMCID: PMC10996613 DOI: 10.1101/2024.03.25.586570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Altered neuronal excitability and synaptic inputs to motoneurons are part of the pathophysiology of Amyotrophic Lateral Sclerosis. The cAMP/PKA pathway regulates both of them but therapeutic interventions at this level are limited by the lack of knowledge about suitable pharmacological entry points. Here we used transcriptomics on microdissected and in situ motoneurons to reveal the modulation of PKA-coupled receptorome in SOD1(G93A) ALS mice, vs WT, demonstrating the dysregulation of multiple PKA-coupled GPCRs, in particular on vulnerable MNs, and the relative sparing of β-adrenergic receptors. In vivo MN electrophysiology showed that β2/β3 agonists acutely increase excitability, in particular the input/output relationship, demonstrating a non-canonical adrenergic neuromodulation mediated by β2/β3 receptors both in WT and SOD1 mice. The excitability increase corresponds to the upregulation of immediate-early gene expression and dysregulation of ion channels transcriptome. However the β2/β3 neuromodulation is submitted to a strong homeostasis, since a ten days delivery of β2/β3 agonists results in an abolition of the excitability increase. The homeostatic response is largely caused by a substantial downregulation of PKA-coupled GPCRs in MNs from WT and SOD1 mice. Thus, β-adrenergic receptors are physiologically involved in the regulation of MN excitability and transcriptomics, but, intriguingly, a strong homeostatic response is triggered upon chronic pharmacologic intervention.
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Affiliation(s)
| | - Guillaume Caron
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | | | | | - Anthony Harster
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | | | | | | | - Simon M. Danner
- Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, United States
| | - Albert Ludolph
- Dept. of Neurology, Ulm University, Ulm, DE
- German Center for Neurodegenerative Diseases (DZNE)-Ulm, DE
| | - Kamil Grycz
- Dept. of Neurobiology, Poznan University of Physical Education, Poland
| | - Marcin Baczyk
- Dept. of Neurobiology, Poznan University of Physical Education, Poland
| | - Daniel Zytnicki
- Université Paris Cité, CNRS, Saints-Pères Paris Institute for the Neurosciences, Paris, France
| | - Francesco Roselli
- Dept. of Neurology, Ulm University, Ulm, DE
- German Center for Neurodegenerative Diseases (DZNE)-Ulm, DE
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5
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Costa-Pinto S, Gonçalves-Ribeiro J, Tedim-Moreira J, Socodato R, Relvas JB, Sebastião AM, Vaz SH. Communication defects with astroglia contribute to early impairments in the motor cortex plasticity of SOD1 G93A mice. Neurobiol Dis 2024; 193:106435. [PMID: 38336279 DOI: 10.1016/j.nbd.2024.106435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, involving the selective degeneration of cortical upper synapses in the primary motor cortex (M1). Excitotoxicity in ALS occurs due to an imbalance between excitation and inhibition, closely linked to the loss/gain of astrocytic function. Using the ALS SOD1G93A mice, we investigated the astrocytic contribution for the electrophysiological alterations observed in the M1 of SOD1G93A mice, throughout disease progression. Results showed that astrocytes are involved in synaptic dysfunction observed in presymptomatic SOD1G93A mice, since astrocytic glutamate transport currents are diminished and pharmacological inhibition of astrocytes only impaired long-term potentiation and basal transmission in wild-type mice. Proteomic analysis revealed major differences in neuronal transmission, metabolism, and immune system in upper synapses, confirming early communication deficits between neurons and astroglia. These results provide valuable insights into the early impact of upper synapses in ALS and the lack of supportive functions of cortical astrocytes, highlighting the possibility of manipulating astrocytes to improve synaptic function.
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Affiliation(s)
- Sara Costa-Pinto
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Joana Gonçalves-Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Joana Tedim-Moreira
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto 4200-135, Portugal; Department of Biomedicine, Faculty of Medicine, University of Porto, Porto 4200-135, Portugal
| | - Renato Socodato
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto 4200-135, Portugal
| | - João B Relvas
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto 4200-135, Portugal; Department of Biomedicine, Faculty of Medicine, University of Porto, Porto 4200-135, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Sandra H Vaz
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal.
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6
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Lépine S, Nauleau-Javaudin A, Deneault E, Chen CXQ, Abdian N, Franco-Flores AK, Haghi G, Castellanos-Montiel MJ, Maussion G, Chaineau M, Durcan TM. Homozygous ALS-linked mutations in TARDBP/TDP-43 lead to hypoactivity and synaptic abnormalities in human iPSC-derived motor neurons. iScience 2024; 27:109166. [PMID: 38433895 PMCID: PMC10905001 DOI: 10.1016/j.isci.2024.109166] [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: 08/28/2023] [Revised: 11/21/2023] [Accepted: 02/05/2024] [Indexed: 03/05/2024] Open
Abstract
Cytoplasmic mislocalization and aggregation of the RNA-binding protein TDP-43 is a pathological hallmark of the motor neuron (MN) disease amyotrophic lateral sclerosis (ALS). Furthermore, while mutations in TARDBP (encoding TDP-43) have been associated with ALS, the pathogenic consequences of these mutations remain poorly understood. Using CRISPR-Cas9, we engineered two homozygous knock-in induced pluripotent stem cell lines carrying mutations in TARDBP encoding TDP-43A382T and TDP-43G348C, two common yet understudied ALS TDP-43 variants. Motor neurons (MNs) differentiated from knock-in iPSCs had normal viability and displayed no significant changes in TDP-43 subcellular localization, phosphorylation, solubility, or aggregation compared with isogenic control MNs. However, our results highlight synaptic impairments in both TDP-43A382T and TDP-43G348C MN cultures, as reflected in synapse abnormalities and alterations in spontaneous neuronal activity. Collectively, our findings suggest that MN dysfunction may precede the occurrence of TDP-43 pathology and neurodegeneration in ALS and further implicate synaptic and excitability defects in the pathobiology of this disease.
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Affiliation(s)
- Sarah Lépine
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
- Faculty of Medicine and Health Sciences, McGill University, Montreal, QC H3G 2M1, Canada
| | - Angela Nauleau-Javaudin
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
- Faculty of Medicine, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Eric Deneault
- Centre for Oncology, Radiopharmaceuticals and Research; Biologic and Radiopharmaceutical Drugs Directorate, Health Products and Food Branch, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Carol X.-Q. Chen
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Narges Abdian
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Anna Krystina Franco-Flores
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Ghazal Haghi
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - María José Castellanos-Montiel
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Gilles Maussion
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Mathilde Chaineau
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
| | - Thomas Martin Durcan
- Early Drug Discovery Unit (EDDU), The Neuro-Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, QC H3A 1A1, Canada
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Di Lazzaro V, Ranieri F, Bączyk M, de Carvalho M, Dileone M, Dubbioso R, Fernandes S, Kozak G, Motolese F, Ziemann U. Novel approaches to motoneuron disease/ALS treatment using non-invasive brain and spinal stimulation: IFCN handbook chapter. Clin Neurophysiol 2024; 158:114-136. [PMID: 38218077 DOI: 10.1016/j.clinph.2023.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/28/2023] [Accepted: 12/17/2023] [Indexed: 01/15/2024]
Abstract
Non-invasive brain stimulation techniques have been exploited in motor neuron disease (MND) with multifold objectives: to support the diagnosis, to get insights in the pathophysiology of these disorders and, more recently, to slow down disease progression. In this review, we consider how neuromodulation can now be employed to treat MND, with specific attention to amyotrophic lateral sclerosis (ALS), the most common form with upper motoneuron (UMN) involvement, taking into account electrophysiological abnormalities revealed by human and animal studies that can be targeted by neuromodulation techniques. This review article encompasses repetitive transcranial magnetic stimulation methods (including low-frequency, high-frequency, and pattern stimulation paradigms), transcranial direct current stimulation as well as experimental findings with the newer approach of trans-spinal direct current stimulation. We also survey and discuss the trials that have been performed, and future perspectives.
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Affiliation(s)
- Vincenzo Di Lazzaro
- Department of Medicine and Surgery, Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Università Campus Bio-Medico di Roma, Via Alvaro del Portillo, 21, 00128 Roma, Italy; Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, 200, 00128 Roma, Italy.
| | - Federico Ranieri
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, P.Le L.A. Scuro 10, 37134 Verona, Italy
| | - Marcin Bączyk
- Department of Neurobiology, Poznań University of Physical Education, Królowej Jadwigi Street 27/39, 61-871 Poznań, Poland
| | - Mamede de Carvalho
- Institute of Physiology, Institute of Molecular Medicine-JLA, Egas Moniz Study Centre, Faculty of Medicine, University of Lisbon, Lisbon 1649-028, Portugal; Department of Neurosciences and Mental Health, CHULN, Lisbon, Portugal
| | - Michele Dileone
- Faculty of Health Sciences, UCLM Talavera de la Reina, Toledo, Spain; Neurology Department, Hospital Nuestra Señora del Prado, Talavera de la Reina, Toledo, Spain
| | - Raffaele Dubbioso
- Neurophysiology Unit, Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Napoli, Italy
| | - Sofia Fernandes
- Instituto de Biofísica e Engenharia Biomédica, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016-Lisboa, Portugal
| | - Gabor Kozak
- Department of Neurology and Stroke, University of Tübingen, Tübingen, Germany; Hertie-Institute of Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Francesco Motolese
- Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, 200, 00128 Roma, Italy
| | - Ulf Ziemann
- Department of Neurology and Stroke, University of Tübingen, Tübingen, Germany; Hertie-Institute of Clinical Brain Research, University of Tübingen, Tübingen, Germany.
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8
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Kang Q, Jiang S, Min J, Hu F, Xu R. Parvalbumin interneurons dysfunction is potentially associated with FαMNs decrease and NRG1-ErbB4 signaling inhibition in spinal cord in amyotrophic lateral sclerosis. Aging (Albany NY) 2023; 15:15324-15339. [PMID: 38157256 PMCID: PMC10781496 DOI: 10.18632/aging.205351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Accepted: 11/06/2023] [Indexed: 01/03/2024]
Abstract
OBJECTIVE To investigate the alteration of PV interneurons in ALS mainly focusing its dynamic changes and its relationship with motor neurons and ErbB4 signaling. METHODS SOD1G93A mice were used as ALS model. ALS animals were divided into different groups according to birth age: symptomatic prophase (50~60 days), symptomatic phase (90~100 days), and symptomatic progression (130~140 days). Immunofluorescence was performed for measurement of PV-positive interneurons, MMP-9, ChAT, NeuN and ErbB4. RT-qPCR and western blot were used to determine the expression of PV and MMP-9. RESULTS PV expression was remarkably higher in the anterior horn of gray matter compared with posterior horn and area in the middle of gray matter in control mice. In ALS mice, PV, MMP-9 and ErbB4 levels were gradually decreased along with onset. PV, MMP-9 and ErbB4 levels in ALS mice were significantly down-regulated than control mice after onset, indicating the alteration of PV interneurons, FαMNs and ErbB4. SαMNs levels only decreased remarkably at symptomatic progression in ALS mice compared with control mice, while γMNs levels showed no significant change during whole period in all mice. MMP-9 and ErbB4 were positively correlated with PV. NRG1 treatment significantly enhanced the expression of ErBb4, PV and MMP-9 in ALS mice. CONCLUSION PV interneurons decrease is along with FαMNs and ErbB4 decrease in ALS mice.
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Affiliation(s)
- Qin Kang
- Department of Neurology, Medical College of Nanchang University, Nanchang 330006, Jiangxi, P.R. China
- Department of Neurology, Jiangxi Provincial People’s Hospital, First Affiliated Hospital of Nanchang Medical College, Clinical College of Nanchang Medical College, Nanchang 330006, Jiangxi, P.R. China
| | - Shishi Jiang
- Department of Neurology, Medical College of Nanchang University, Nanchang 330006, Jiangxi, P.R. China
| | - Jun Min
- Department of Neurology, The Second Affiliated Hospital of Nanchang University, Nanchang 330006, Jiangxi, P.R. China
| | - Fan Hu
- Department of Neurology, Jiangxi Provincial People’s Hospital, First Affiliated Hospital of Nanchang Medical College, Clinical College of Nanchang Medical College, Nanchang 330006, Jiangxi, P.R. China
| | - Renshi Xu
- Department of Neurology, Medical College of Nanchang University, Nanchang 330006, Jiangxi, P.R. China
- Department of Neurology, Jiangxi Provincial People’s Hospital, First Affiliated Hospital of Nanchang Medical College, Clinical College of Nanchang Medical College, Nanchang 330006, Jiangxi, P.R. China
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9
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Stringer RN, Weiss N. Pathophysiology of ion channels in amyotrophic lateral sclerosis. Mol Brain 2023; 16:82. [PMID: 38102715 PMCID: PMC10722804 DOI: 10.1186/s13041-023-01070-6] [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: 08/22/2023] [Accepted: 12/11/2023] [Indexed: 12/17/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) stands as the most prevalent and severe form of motor neuron disease, affecting an estimated 2 in 100,000 individuals worldwide. It is characterized by the progressive loss of cortical, brainstem, and spinal motor neurons, ultimately resulting in muscle weakness and death. Although the etiology of ALS remains poorly understood in most cases, the remodelling of ion channels and alteration in neuronal excitability represent a hallmark of the disease, manifesting not only during the symptomatic period but also in the early pre-symptomatic stages. In this review, we delve into these alterations observed in ALS patients and preclinical disease models, and explore their consequences on neuronal activities. Furthermore, we discuss the potential of ion channels as therapeutic targets in the context of ALS.
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Affiliation(s)
- Robin N Stringer
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Norbert Weiss
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czech Republic.
- Center of Biosciences, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovakia.
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10
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Drouillas B, Brocard C, Zanella S, Bos R, Brocard F. Persistent Nav1.1 and Nav1.6 currents drive spinal locomotor functions through nonlinear dynamics. Cell Rep 2023; 42:113085. [PMID: 37665666 DOI: 10.1016/j.celrep.2023.113085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 06/29/2023] [Accepted: 08/16/2023] [Indexed: 09/06/2023] Open
Abstract
Persistent sodium current (INaP) in the spinal locomotor network promotes two distinct nonlinear firing patterns: a self-sustained spiking triggered by a brief excitation in bistable motoneurons and bursting oscillations in interneurons of the central pattern generator (CPG). Here, we identify the NaV channels responsible for INaP and their role in motor behaviors. We report the axonal Nav1.6 as the main molecular player for INaP in lumbar motoneurons. The inhibition of Nav1.6, but not of Nav1.1, in motoneurons impairs INaP, bistability, postural tone, and locomotor performance. In interneurons of the rhythmogenic CPG region, both Nav1.6 and Nav1.1 equally mediate INaP. Inhibition of both channels is required to abolish oscillatory bursting activities and the locomotor rhythm. Overall, Nav1.6 plays a significant role both in posture and locomotion by governing INaP-dependent bistability in motoneurons and working in tandem with Nav1.1 to provide INaP-dependent rhythmogenic properties of the CPG.
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Affiliation(s)
- Benoît Drouillas
- Institut de Neurosciences de la Timone, UMR 7289, Aix-Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Cécile Brocard
- Institut de Neurosciences de la Timone, UMR 7289, Aix-Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Sébastien Zanella
- Institut de Neurosciences de la Timone, UMR 7289, Aix-Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Rémi Bos
- Institut de Neurosciences de la Timone, UMR 7289, Aix-Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France
| | - Frédéric Brocard
- Institut de Neurosciences de la Timone, UMR 7289, Aix-Marseille Université and Centre National de la Recherche Scientifique (CNRS), Marseille, France.
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11
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Song J, Dikwella N, Sinske D, Roselli F, Knöll B. SRF deletion results in earlier disease onset in a mouse model of amyotrophic lateral sclerosis. JCI Insight 2023; 8:e167694. [PMID: 37339001 PMCID: PMC10445689 DOI: 10.1172/jci.insight.167694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 06/16/2023] [Indexed: 06/22/2023] Open
Abstract
Changes in neuronal activity modulate the vulnerability of motoneurons (MNs) in neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). So far, the molecular basis of neuronal activity's impact in ALS is poorly understood. Herein, we investigated the impact of deleting the neuronal activity-stimulated transcription factor (TF) serum response factor (SRF) in MNs of SOD1G93A mice. SRF was present in vulnerable MMP9+ MNs. Ablation of SRF in MNs induced an earlier disease onset starting around 7-8 weeks after birth, as revealed by enhanced weight loss and decreased motor ability. This earlier disease onset in SRF-depleted MNs was accompanied by a mild elevation of neuroinflammation and neuromuscular synapse degeneration, whereas overall MN numbers and mortality were unaffected. In SRF-deficient mice, MNs showed impaired induction of autophagy-encoding genes, suggesting a potentially new SRF function in transcriptional regulation of autophagy. Complementary, constitutively active SRF-VP16 enhanced autophagy-encoding gene transcription and autophagy progression in cells. Furthermore, SRF-VP16 decreased ALS-associated aggregate induction. Chemogenetic modulation of neuronal activity uncovered SRF as having important TF-mediating activity-dependent effects, which might be beneficial to reduce ALS disease burden. Thus, our data identify SRF as a gene regulator connecting neuronal activity with the cellular autophagy program initiated in degenerating MNs.
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Affiliation(s)
- Jialei Song
- Institute of Neurobiochemistry and
- Department of Neurology, Ulm University, Ulm, Germany
| | - Natalie Dikwella
- Institute of Neurobiochemistry and
- Department of Neurology, Ulm University, Ulm, Germany
| | | | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany
- German Center for Neurodegenerative Diseases-Ulm (DZNE-Ulm), Ulm, Germany
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12
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Venugopal S, Ghulam-Jhelani Z, Ahn IS, Yang X, Wiedau M, Simmons D, Chandler SH. Early deficits in GABA inhibition parallels an increase in L-type Ca 2+ currents in the jaw motor neurons of SOD1 G93A mouse model for ALS. Neurobiol Dis 2023; 177:105992. [PMID: 36623607 DOI: 10.1016/j.nbd.2023.105992] [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: 01/11/2022] [Revised: 12/21/2022] [Accepted: 01/05/2023] [Indexed: 01/09/2023] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) involves protracted pre-symptomatic periods of abnormal motor neuron (MN) excitability occurring in parallel with central and peripheral synaptic perturbations. Focusing on inhibitory control of MNs, we first compared longitudinal changes in pre-synaptic terminal proteins for GABA and glycine neurotransmitters around the soma of retrogradely identified trigeminal jaw closer (JC) MNs and ChAT-labeled midbrain extraocular (EO) MNs in the SOD1G93A mouse model for ALS. Fluorescence immunocytochemistry and confocal imaging were used to quantify GAD67 and GlyT2 synaptic bouton density (SBD) around MN soma at pre-symptomatic ages ∼P12 (postnatal), ∼P50 (adult) and near disease end-stage (∼P135) in SOD1G93A mice and age-matched wild-type (WT) controls. We noted reduced GAD67 innervation in the SOD1G93A trigeminal jaw closer MNs around P12, relative to age-matched WT and no significant difference around P50 and P135. In contrast, both GAD67 and GlyT2 innervation were elevated in the SOD1G93A EO MNs at the pre-symptomatic time points. Considering trigeminal MNs are vulnerable in ALS while EO MNs are spared, we suggest that upregulation of inhibition in the latter might be compensatory. Notable contrast also existed in the innate co-expression patterns of GAD67 and GlyT2 with higher mutual information (co-dependency) in EO MNs compared to JC in both SOD1G93A and WT mice, especially at adult stages (P50 and P135). Around P12 when GAD67 terminals expression was low in the mutant, we further tested for persistent GABA inhibition in those MNs using in vitro patch-clamp electrophysiology. Our results show that SOD1G93A JC MNs have reduced persistent GABA inhibition, relative to WT. Pharmacological blocking of an underlying tonically active GABA conductance using the GABA-α5 subunit inverse agonist, L-655-708, disinhibited WT JC MNs and lowered their recruitment threshold, suggesting its role in the control of intrinsic MN excitability. Quantitative RT-PCR in laser dissected JC MNs further supported a reduction in GABA-α5 subunit mRNA expression in the mutant. In light of our previous report that JC MNs forming putative fast motor units have lower input threshold in the SOD1G93A mice, we suggest that our present result on reduced GABA-α5 tonic inhibition provides for a mechanism contributing to such imbalance. In parallel with reduced GABA inhibition, we noted an increase in voltage-gated L-type Ca2+ currents in the mutant JC MNs around P12. Together these results support that, early modifications in intrinsic properties of vulnerable MNs could be an adaptive response to counter synaptic deficits.
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Affiliation(s)
- Sharmila Venugopal
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Neurology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Zohal Ghulam-Jhelani
- Undergraduate Interdepartmental Program for Neuroscience, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - In Sook Ahn
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xia Yang
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Martina Wiedau
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Dwayne Simmons
- Department of Biology, Baylor University, Waco, TX 76798, USA
| | - Scott H Chandler
- Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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13
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Cavarsan CF, Steele PR, Genry LT, Reedich EJ, McCane LM, LaPre KJ, Puritz AC, Manuel M, Katenka N, Quinlan KA. Inhibitory interneurons show early dysfunction in a SOD1 mouse model of amyotrophic lateral sclerosis. J Physiol 2023; 601:647-667. [PMID: 36515374 PMCID: PMC9898203 DOI: 10.1113/jp284192] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022] Open
Abstract
Few studies in amyotrophic lateral sclerosis (ALS) measure effects of the disease on inhibitory interneurons synapsing onto motoneurons (MNs). However, inhibitory interneurons could contribute to dysfunction, particularly if altered before MN neuropathology, and establish a long-term imbalance of inhibition/excitation. We directly assessed excitability and morphology of glycinergic (GlyT2 expressing) ventral lumbar interneurons from SOD1G93AGlyT2eGFP (SOD1) and wild-type GlyT2eGFP (WT) mice on postnatal days 6-10. Patch clamp revealed dampened excitability in SOD1 interneurons, including depolarized persistent inward currents (PICs), increased voltage and current threshold for firing action potentials, along with a marginal decrease in afterhyperpolarization duration. Primary neurites of ventral SOD1 inhibitory interneurons were larger in volume and surface area than WT. GlyT2 interneurons were then divided into three subgroups based on location: (1) interneurons within 100 μm of the ventral white matter, where Renshaw cells (RCs) are located, (2) interneurons interspersed with MNs in lamina IX, and (3) interneurons in the intermediate ventral area including laminae VII and VIII. Ventral interneurons in the RC area were the most profoundly affected, exhibiting more depolarized PICs and larger primary neurites. Interneurons in lamina IX had depolarized PIC onset. In lamina VII-VIII, interneurons were least affected. In summary, inhibitory interneurons show very early region-specific perturbations poised to impact excitatory/inhibitory balance of MNs, modify motor output and provide early biomarkers of ALS. Therapeutics like riluzole that universally reduce CNS excitability could exacerbate the inhibitory dysfunction described here. KEY POINTS: Spinal inhibitory interneurons could contribute to amyotrophic lateral sclerosis (ALS) pathology, but their excitability has never been directly measured. We studied the excitability and morphology of glycinergic interneurons in early postnatal transgenic mice (SOD1G93A GlyT2eGFP). Interneurons were less excitable and had marginally smaller somas but larger primary neurites in SOD1 mice. GlyT2 interneurons were analysed according to their localization within the ventral spinal cord. Interestingly, the greatest differences were observed in the most ventrally located interneurons. We conclude that inhibitory interneurons show presymptomatic changes that may contribute to excitatory/inhibitory imbalance in ALS.
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Affiliation(s)
- Clarissa F Cavarsan
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - Preston R Steele
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - Landon T Genry
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - Emily J Reedich
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - Lynn M McCane
- Interdisciplinary Neuroscience Program, University of Rhode Island, Kingston, RI, USA
| | - Kay J LaPre
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - Alyssa C Puritz
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Marin Manuel
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
| | - Natallia Katenka
- Department of Computer Science and Statistics, University of Rhode Island, Kingston, RI, USA
| | - Katharina A Quinlan
- George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
- Department of Biomedical and Pharmaceutical Sciences, College of Pharmacy, University of Rhode Island, Kingston, RI, USA
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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14
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Elbasiouny SM. Motoneuron excitability dysfunction in ALS: Pseudo-mystery or authentic conundrum? J Physiol 2022; 600:4815-4825. [PMID: 36178320 PMCID: PMC9669170 DOI: 10.1113/jp283630] [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: 07/21/2022] [Accepted: 08/24/2022] [Indexed: 01/12/2023] Open
Abstract
In amyotrophic lateral sclerosis (ALS), abnormalities in motoneuronal excitability are seen in early pathogenesis and throughout disease progression. Fully understanding motoneuron excitability dysfunction may lead to more effective treatments. Yet decades of research have not produced consensus on the nature, role or underlying mechanisms of motoneuron excitability dysfunction in ALS. For example, contrary to Ca excitotoxicity theory, predictions of motoneuronal hyper-excitability, normal and hypo-excitability have also been seen at various disease stages and in multiple ALS lines. Accordingly, motoneuron excitability dysfunction in ALS is a disputed topic in the field. Specifically, the form (hyper, hypo or unchanged) and what role excitability dysfunction plays in the disease (pathogenic or downstream of other pathologies; neuroprotective or detrimental) are currently unclear. Although several motoneuron properties that determine cellular excitability change in the disease, some of these changes are pro-excitable, whereas others are anti-excitable, making dynamic fluctuations in overall 'net' excitability highly probable. Because various studies assess excitability via differing methods and at differing disease stages, the conflicting reports in the literature are not surprising. Hence, the overarching process of excitability degradation and motoneuron degeneration is not fully understood. Consequently, the discrepancies on motoneuron excitability dysfunction in the literature represent a substantial barrier to our understanding of the disease. Emerging studies suggest that biological variables, variations in experimental protocols, issues of rigor and sampling/analysis strategies are key factors that may underlie conflicting data in the literature. This review highlights potential confounding factors for researchers to consider and also offers ideas on avoiding pitfalls and improving robustness of data.
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Affiliation(s)
- Sherif M. Elbasiouny
- Department of NeuroscienceCell Biology, and PhysiologyBoonshoft School of Medicine and College of Science and MathematicsWright State UniversityDaytonOHUSA,Department of BiomedicalIndustrial, and Human Factors EngineeringCollege of Engineering and Computer ScienceWright State UniversityDaytonOHUSA
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15
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Fajardo ME, Jenz S, Heckman C. The excitable motor unit: a powerful diagnostic and pathophysiological marker for ALS? Clin Neurophysiol 2022; 142:256-257. [DOI: 10.1016/j.clinph.2022.07.498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 07/28/2022] [Indexed: 02/03/2023]
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16
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Differential effects of invasive anodal trans-spinal direct current stimulation on monosynaptic EPSPs, Ia afferents excitability, and motoneuron intrinsic properties between SOD1 G93A and WT mice. Neuroscience 2022; 498:125-143. [DOI: 10.1016/j.neuroscience.2022.06.035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/27/2022] [Accepted: 06/25/2022] [Indexed: 01/06/2023]
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17
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Sommer D, Rajkumar S, Seidel M, Aly A, Ludolph A, Ho R, Boeckers TM, Catanese A. Aging-Dependent Altered Transcriptional Programs Underlie Activity Impairments in Human C9orf72-Mutant Motor Neurons. Front Mol Neurosci 2022; 15:894230. [PMID: 35774867 PMCID: PMC9237792 DOI: 10.3389/fnmol.2022.894230] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 05/09/2022] [Indexed: 12/14/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is an incurable neurodegenerative disease characterized by dysfunction and loss of upper and lower motor neurons (MN). Despite several studies identifying drastic alterations affecting synaptic composition and functionality in different experimental models, the specific contribution of impaired activity to the neurodegenerative processes observed in ALS-related MN remains controversial. In particular, contrasting lines of evidence have shown both hyper- as well as hypoexcitability as driving pathomechanisms characterizing this specific neuronal population. In this study, we combined high definition multielectrode array (HD-MEA) techniques with transcriptomic analysis to longitudinally monitor and untangle the activity-dependent alterations arising in human C9orf72-mutant MN. We found a time-dependent reduction of neuronal activity in ALSC9orf72 cultures occurring as synaptic contacts undergo maturation and matched by a significant loss of mutant MN upon aging. Notably, ALS-related neurons displayed reduced network synchronicity most pronounced at later stages of culture, suggesting synaptic imbalance. In concordance with the HD-MEA data, transcriptomic analysis revealed an early up-regulation of synaptic terms in ALSC9orf72 MN, whose expression was decreased in aged cultures. In addition, treatment of older mutant cells with Apamin, a K+ channel blocker previously shown to be neuroprotective in ALS, rescued the time-dependent loss of firing properties observed in ALSC9orf72 MN as well as the expression of maturity-related synaptic genes. All in all, this study broadens the understanding of how impaired synaptic activity contributes to MN degeneration in ALS by correlating electrophysiological alterations to aging-dependent transcriptional programs.
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Affiliation(s)
- Daniel Sommer
- Institute of Anatomy and Cell Biology, Ulm University School of Medicine, Ulm, Germany
| | - Sandeep Rajkumar
- Institute of Anatomy and Cell Biology, Ulm University School of Medicine, Ulm, Germany
| | - Mira Seidel
- Institute of Anatomy and Cell Biology, Ulm University School of Medicine, Ulm, Germany
| | - Amr Aly
- Institute of Anatomy and Cell Biology, Ulm University School of Medicine, Ulm, Germany
| | - Albert Ludolph
- Department of Neurology, Ulm University School of Medicine, Ulm, Germany
- German Center for Neurodegenerative Diseases (DZNE), Ulm, Germany
| | - Ritchie Ho
- Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Tobias M. Boeckers
- Institute of Anatomy and Cell Biology, Ulm University School of Medicine, Ulm, Germany
- German Center for Neurodegenerative Diseases (DZNE), Ulm, Germany
| | - Alberto Catanese
- Institute of Anatomy and Cell Biology, Ulm University School of Medicine, Ulm, Germany
- German Center for Neurodegenerative Diseases (DZNE), Ulm, Germany
- *Correspondence: Alberto Catanese,
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18
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Liang B, Thapa R, Zhang G, Moffitt C, Zhang Y, Zhang L, Johnston A, Ruby HP, Barbera G, Wong PC, Zhang Z, Chen R, Lin DT, Li Y. Aberrant Neural Activity in Prefrontal Pyramidal Neurons Lacking TDP-43 Precedes Neuron loss. Prog Neurobiol 2022; 215:102297. [PMID: 35667630 PMCID: PMC9258405 DOI: 10.1016/j.pneurobio.2022.102297] [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: 01/23/2022] [Revised: 04/25/2022] [Accepted: 05/31/2022] [Indexed: 11/16/2022]
Abstract
Mislocalization of TAR DNA binding protein 43 kDa (TARDBP, or TDP-43) is a principal pathological hallmark identified in cases of neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). As an RNA binding protein, TDP-43 serves in the nuclear compartment to repress non-conserved cryptic exons to ensure the normal transcriptome. Multiple lines of evidence from animal models and human studies support the view that loss of TDP-43 leads to neuron loss, independent of its cytosolic aggregation. However, the underlying pathogenic pathways driven by the loss-of-function mechanism are still poorly defined. We employed a genetic approach to determine the impact of TDP-43 loss in pyramidal neurons of the prefrontal cortex (PFC). Using a custom-built miniscope imaging system, we performed repetitive in vivo calcium imaging from freely behaving mice for up to 7 months. By comparing calcium activity in PFC pyramidal neurons between TDP-43 depleted and TDP-43 intact mice, we demonstrated remarkably increased numbers of pyramidal neurons exhibiting hyperactive calcium activity after short-term TDP-43 depletion, followed by rapid activity declines prior to neuron loss. Our results suggest aberrant neural activity driven by loss of TDP-43 as the pathogenic pathway at early stage in ALS and FTD.
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Affiliation(s)
- Bo Liang
- School of Electrical Engineering & Computer Science, College of Engineering & Mines, University of North Dakota, 243 Centennial Drive Stop 7165, Grand Forks, ND 58202, USA.
| | - Rashmi Thapa
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Gracie Zhang
- Laramie High School, 1710 Boulder Drive, Laramie, WY 82070, USA.
| | - Casey Moffitt
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Yan Zhang
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Lifeng Zhang
- School of Electrical Engineering & Computer Science, College of Engineering & Mines, University of North Dakota, 243 Centennial Drive Stop 7165, Grand Forks, ND 58202, USA; Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA; Laramie High School, 1710 Boulder Drive, Laramie, WY 82070, USA; Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA; Department of Pathology, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA; Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 100N. Greene St., Baltimore, MD 21201, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Amanda Johnston
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Hyrum P Ruby
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Giovanni Barbera
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA.
| | - Philip C Wong
- Department of Pathology, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Zhaojie Zhang
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
| | - Rong Chen
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 100N. Greene St., Baltimore, MD 21201, USA.
| | - Da-Ting Lin
- Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, 333 Cassell Drive, Baltimore, MD 21224, USA; The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, 725N. Wolfe Street, Baltimore, MD 21205, USA.
| | - Yun Li
- Department of Zoology and Physiology, University of Wyoming, 1000 E University Avenue, Laramie, WY 82071, USA.
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19
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Salvany S, Casanovas A, Piedrafita L, Gras S, Calderó J, Esquerda JE. Accumulation of misfolded SOD1 outlines distinct patterns of motor neuron pathology and death during disease progression in a SOD1 G93A mouse model of amyotrophic lateral sclerosis. Brain Pathol 2022; 32:e13078. [PMID: 35584812 PMCID: PMC9616096 DOI: 10.1111/bpa.13078] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 04/11/2022] [Indexed: 12/12/2022] Open
Abstract
Early misfolded superoxide dismutase 1 (mfSOD1) accumulation, motor neuron (MN) degeneration, and microgliosis are hallmark pathological features in SOD1G93A amyotrophic lateral sclerosis (ALS) mice. Because of the different vulnerabilities of distinct MN subtypes, degenerating and surviving MNs coexist in different proportions during disease progression. By examining the expression of misfolded conformers of SOD1 using specific antibodies, we defined distinct MN phenotypes that were evaluated during disease progression and the local neuroinflammatory reaction. The most severe phenotype corresponded to somata of fast‐twitch subtype MNs, which exhibited highly positive mfSOD1 immunostaining and an extreme degree of vacuolar degeneration. Vacuoles, which are of mitochondrial origin, contain mfSOD1 in conjunction with nonmitochondrial proteins, such as chromogranin, CD81, and flotillin. The fusion of ER‐derived vesicles enriched in mfSOD1 with outer mitochondrial membranes is thought to be the primary mechanism for vacuole formation. In addition, the ulterior coalescence of enlarged mitochondria may lead to the formation of giant vacuoles. Vacuolar degeneration is a transient degenerative process occurring early during the presymptomatic stages of the disease in ALS mice. Some vacuolated MNs are also positive for pMLKL, the effector protein of necroptosis. This indicates a newly described mechanism in which extracellular vesicles derived from damaged MNs, via cellular secretion or necroptotic disruption, may be the triggers for initiating neuroinflammation, glial‐mediated neurotoxicity, and disease spreading. Furthermore, as MN degeneration in mutant SOD1 mice is noncell autonomous, the effects of experimentally increasing or decreasing the microglial response on the expression of MN phenotypes were also evaluated, demonstrating bidirectional cross talk signaling between the degree of expression of mfSOD1 and local neuroinflammation. More detailed knowledge regarding these processes occurring long before the end stages of the disease is necessary to identify novel molecular targets for future preclinical testing.
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Affiliation(s)
- Sara Salvany
- Patologia Neuromuscular Experimental, Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Anna Casanovas
- Patologia Neuromuscular Experimental, Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Lídia Piedrafita
- Patologia Neuromuscular Experimental, Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Sílvia Gras
- Patologia Neuromuscular Experimental, Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Jordi Calderó
- Patologia Neuromuscular Experimental, Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
| | - Josep E Esquerda
- Patologia Neuromuscular Experimental, Departament de Medicina Experimental, Facultat de Medicina, Universitat de Lleida and Institut de Recerca Biomèdica de Lleida (IRBLleida), Lleida, Catalonia, Spain
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20
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Sangari S, Peyre I, Lackmy‐Vallée A, Bayen E, Pradat P, Marchand‐Pauvert V. Transient increase in recurrent inhibition in amyotrophic lateral sclerosis as a putative protection from neurodegeneration. Acta Physiol (Oxf) 2022; 234:e13758. [PMID: 34981890 DOI: 10.1111/apha.13758] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 12/15/2021] [Accepted: 01/01/2022] [Indexed: 11/28/2022]
Abstract
AIM Adaptive mechanisms in spinal circuits are likely involved in homeostatic responses to maintain motor output in amyotrophic lateral sclerosis. Given the role of Renshaw cells in regulating the motoneuron input/output gain, we investigated the modulation of heteronymous recurrent inhibition. METHODS Electrical stimulations were used to activate recurrent collaterals resulting in the Hoffmann reflex depression. Inhibitions from soleus motor axons to quadriceps motoneurons, and vice versa, were tested in 38 patients and matched group of 42 controls. RESULTS Compared with controls, the mean depression of quadriceps reflex was larger in patients, while that of soleus was smaller, suggesting that heteronymous recurrent inhibition was enhanced in quadriceps but reduced in soleus. The modulation of recurrent inhibition was linked to the size of maximal direct motor response and lower limb dysfunctions, suggesting a significant relationship with the integrity of the target motoneuron pool and functional abilities. No significant link was found between the integrity of motor axons activating Renshaw cells and the level of inhibition. Enhanced inhibition was particularly observed in patients within the first year after symptom onset and with slow progression of lower limb dysfunctions. Normal or reduced inhibitions were mainly observed in patients with motor weakness first in lower limbs and greater dysfunctions in lower limbs. CONCLUSION We provide the first evidence for enhanced recurrent inhibition and speculate that Renshaw cells might have transient protective role on motoneuron by counteracting hyperexcitability at early stages. Several mechanisms likely participate including cortical influence on Renshaw cell and reinnervation by slow motoneurons.
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Affiliation(s)
- Sina Sangari
- Laboratoire d’Imagerie Biomédicale Sorbonne Université INSERM CNRS Paris France
- Shirley Ryan AbilityLab Chicago Illinois USA
- Department of Physical Medicine and Rehabilitation Northwestern University Chicago Illinois USA
| | - Iseline Peyre
- Laboratoire d’Imagerie Biomédicale Sorbonne Université INSERM CNRS Paris France
| | | | - Eléonore Bayen
- Laboratoire d’Imagerie Biomédicale Sorbonne Université INSERM CNRS Paris France
- Pôle MSN, Hôpital Pitié‐Salpêtrière AP‐HP Paris France
| | - Pierre‐François Pradat
- Laboratoire d’Imagerie Biomédicale Sorbonne Université INSERM CNRS Paris France
- Pôle MSN, Hôpital Pitié‐Salpêtrière AP‐HP Paris France
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21
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Verma S, Khurana S, Vats A, Sahu B, Ganguly NK, Chakraborti P, Gourie-Devi M, Taneja V. Neuromuscular Junction Dysfunction in Amyotrophic Lateral Sclerosis. Mol Neurobiol 2022; 59:1502-1527. [PMID: 34997540 DOI: 10.1007/s12035-021-02658-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 11/18/2021] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurological disorder characterized by progressive degeneration of motor neurons leading to skeletal muscle denervation. Earlier studies have shown that motor neuron degeneration begins in motor cortex and descends to the neuromuscular junction (NMJ) in a dying forward fashion. However, accumulating evidences support that ALS is a distal axonopathy where early pathological changes occur at the NMJ, prior to onset of clinical symptoms and propagates towards the motor neuron cell body supporting "dying back" hypothesis. Despite several evidences, series of events triggering NMJ disassembly in ALS are still obscure. Neuromuscular junction is a specialized tripartite chemical synapse which involves a well-coordinated communication among the presynaptic motor neuron, postsynaptic skeletal muscle, and terminal Schwann cells. This review provides comprehensive insight into the role of NMJ in ALS pathogenesis. We have emphasized the molecular alterations in cellular components of NMJ leading to loss of effective neuromuscular transmission in ALS. Further, we provide a preview into research involved in exploring NMJ as potential target for designing effective therapies for ALS.
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Affiliation(s)
- Sagar Verma
- Department of Research, Sir Ganga Ram Hospital, Delhi, India.,Department of Biotechnology, Jamia Hamdard, Delhi, India
| | - Shiffali Khurana
- Department of Research, Sir Ganga Ram Hospital, Delhi, India.,Department of Biomedical Science, Bhaskaracharya College of Applied Sciences, University of Delhi, Delhi, India
| | - Abhishek Vats
- Department of Ophthalmology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bandana Sahu
- Department of Research, Sir Ganga Ram Hospital, Delhi, India
| | | | | | | | - Vibha Taneja
- Department of Research, Sir Ganga Ram Hospital, Delhi, India.
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22
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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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23
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Chalif JI, Mentis GZ. Normal Development and Pathology of Motoneurons: Anatomy, Electrophysiological Properties, Firing Patterns and Circuit Connectivity. ADVANCES IN NEUROBIOLOGY 2022; 28:63-85. [PMID: 36066821 DOI: 10.1007/978-3-031-07167-6_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This chapter will provide an introduction into motoneuron anatomy, electrophysiological properties, firing patterns focusing on development and also describing several pathological conditions that affect mononeurons. It starts with a historical retrospective describing the early landmark work into motoneurons. The next section lays out the various types of motoneurons (alpha, beta, and gamma) and their subclasses (fast-twitch fatigable, fast-twitch fatigue-resistant, and slow-twitch fatigue resistant), highlighting the functional relevance of this classification scheme. The third section describes the development of motoneurons' passive and active electrophysiological properties. This section also defines the major terms one uses in describing how a neuron functions electrophysiologically. The electrophysiological aspects of a neuron is critical to understanding how it behaves within a circuit and contributes to behavior since the firing of an action potential is how neurons communicate with each other and with muscles. The electrophysiological changes of motoneurons over development underlies how their function changes over the lifetime of an organism. After describing the properties of individual motoneurons, the chapter then turns to revealing how motoneurons interact within complex neural circuits, with other motoneurons as well as sensory neurons, and how these circuits change over development. Finally, this chapter ends with highlighting some recent advances made in motoneuron pathology, focusing on spinal muscular atrophy, amyotrophic lateral sclerosis, and axotomy.
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Affiliation(s)
- Joshua I Chalif
- Departments of Neurology and Pathology & Cell Biology, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard University, Boston, MA, USA
| | - George Z Mentis
- Departments of Neurology and Pathology & Cell Biology, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, USA.
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24
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Bączyk M, Manuel M, Roselli F, Zytnicki D. From Physiological Properties to Selective Vulnerability of Motor Units in Amyotrophic Lateral Sclerosis. ADVANCES IN NEUROBIOLOGY 2022; 28:375-394. [PMID: 36066833 DOI: 10.1007/978-3-031-07167-6_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Spinal alpha-motoneurons are classified in several types depending on the contractile properties of the innervated muscle fibers. This diversity is further displayed in different levels of vulnerability of distinct motor units to neurodegenerative diseases such as Amyotrophic Lateral Sclerosis (ALS). We summarize recent data suggesting that, contrary to the excitotoxicity hypothesis, the most vulnerable motor units are hypoexcitable and experience a reduction in their firing prior to symptoms onset in ALS. We suggest that a dysregulation of activity-dependent transcriptional programs in these motoneurons alter crucial cellular functions such as mitochondrial biogenesis, autophagy, axonal sprouting capability and re-innervation of neuromuscular junctions.
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Affiliation(s)
- Marcin Bączyk
- Department of Neurobiology, Poznań University of Physical Education, Poznań, Poland
| | - Marin Manuel
- SPPIN - Saints-Pères Paris Institute for the Neurosciences, CNRS, Université de Paris, Paris, France.
| | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany
- Institute of Anatomy and Cell Biology, Ulm University, Ulm, Germany
- German Center for Neurodegenerative Diseases (DZNE)-Ulm, Ulm, Germany
- Neurozentrum Ulm, Ulm, Germany
| | - Daniel Zytnicki
- SPPIN - Saints-Pères Paris Institute for the Neurosciences, CNRS, Université de Paris, Paris, France
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25
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Sharples SA, Miles GB. Maturation of persistent and hyperpolarization-activated inward currents shapes the differential activation of motoneuron subtypes during postnatal development. eLife 2021; 10:e71385. [PMID: 34783651 PMCID: PMC8641952 DOI: 10.7554/elife.71385] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/15/2021] [Indexed: 12/15/2022] Open
Abstract
The size principle underlies the orderly recruitment of motor units; however, motoneuron size is a poor predictor of recruitment amongst functionally defined motoneuron subtypes. Whilst intrinsic properties are key regulators of motoneuron recruitment, the underlying currents involved are not well defined. Whole-cell patch-clamp electrophysiology was deployed to study intrinsic properties, and the underlying currents, that contribute to the differential activation of delayed and immediate firing motoneuron subtypes. Motoneurons were studied during the first three postnatal weeks in mice to identify key properties that contribute to rheobase and may be important to establish orderly recruitment. We find that delayed and immediate firing motoneurons are functionally homogeneous during the first postnatal week and are activated based on size, irrespective of subtype. The rheobase of motoneuron subtypes becomes staggered during the second postnatal week, which coincides with the differential maturation of passive and active properties, particularly persistent inward currents. Rheobase of delayed firing motoneurons increases further in the third postnatal week due to the development of a prominent resting hyperpolarization-activated inward current. Our results suggest that motoneuron recruitment is multifactorial, with recruitment order established during postnatal development through the differential maturation of passive properties and sequential integration of persistent and hyperpolarization-activated inward currents.
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Affiliation(s)
- Simon A Sharples
- School of Psychology and Neuroscience, University of St AndrewsSt AndrewsUnited Kingdom
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St AndrewsSt AndrewsUnited Kingdom
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26
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Elucidating the Role of Cerebellar Synaptic Dysfunction in C9orf72-ALS/FTD - a Systematic Review and Meta-Analysis. THE CEREBELLUM 2021; 21:681-714. [PMID: 34491551 PMCID: PMC9325807 DOI: 10.1007/s12311-021-01320-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 08/16/2021] [Indexed: 12/28/2022]
Abstract
A hexanucleotide repeat expansion in the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) with synaptic dysfunction identified as an early pathological hallmark. Although TDP-43 pathology and overt neurodegeneration are largely absent from the cerebellum, the pathological hallmarks of RNA foci and dipeptide repeat protein (DPR) inclusions are most abundant. Here, we present a systematic literature search in the databases of PubMed, Scopus, Embase, Web of Science and Science Direct up until March 5, 2021, which yielded 19,515 publications. Following the exclusion criteria, 72 articles were included having referred to C9orf72, synapses and the cerebellum. Meta-analyses were conducted on studies which reported experimental and control groups with means and standard deviations extracted from figures using the online tool PlotDigitizer. This revealed dendritic defects (P = 0.03), reduced C9orf72 in human patients (P = 0.005) and DPR-related neuronal loss (P = 0.0006) but no neuromuscular junction abnormalities (P = 0.29) or cerebellar neuronal loss (P = 0.23). Our results suggest that dendritic arborisation defects, synaptic gene dysregulation and altered synaptic neurotransmission may drive cerebellar synaptic dysfunction in C9-ALS/FTD. In this review, we discuss how the chronological appearance of the different pathological hallmarks alters synaptic integrity which may have profound implications for disease progression. We conclude that a reduction in C9orf72 protein levels combined with the accumulation of RNA foci and DPRs act synergistically to drive C9 synaptopathy in the cerebellum of C9-ALS/FTD patients.
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27
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Jensen DB, Kadlecova M, Allodi I, Meehan CF. Response to Letter to Editor on the article Jensen DB, Kadlecova M, Allodi I, Meehan CF (2020). J Physiol 2021; 599:4233-4236. [PMID: 34254695 DOI: 10.1113/jp281539] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Dennis B Jensen
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
| | - Marion Kadlecova
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
| | - Ilary Allodi
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
| | - Claire F Meehan
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
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28
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Catanese A, Rajkumar S, Sommer D, Freisem D, Wirth A, Aly A, Massa‐López D, Olivieri A, Torelli F, Ioannidis V, Lipecka J, Guerrera IC, Zytnicki D, Ludolph A, Kabashi E, Mulaw MA, Roselli F, Böckers TM. Synaptic disruption and CREB-regulated transcription are restored by K + channel blockers in ALS. EMBO Mol Med 2021; 13:e13131. [PMID: 34125498 PMCID: PMC8261490 DOI: 10.15252/emmm.202013131] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 11/15/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, which is still missing effective therapeutic strategies. Although manipulation of neuronal excitability has been tested in murine and human ALS models, it is still under debate whether neuronal activity might represent a valid target for efficient therapies. In this study, we exploited a combination of transcriptomics, proteomics, optogenetics and pharmacological approaches to investigate the activity-related pathological features of iPSC-derived C9orf72-mutant motoneurons (MN). We found that human ALSC9orf72 MN are characterized by accumulation of aberrant aggresomes, reduced expression of synaptic genes, loss of synaptic contacts and a dynamic "malactivation" of the transcription factor CREB. A similar phenotype was also found in TBK1-mutant MN and upon overexpression of poly(GA) aggregates in primary neurons, indicating a strong convergence of pathological phenotypes on synaptic dysregulation. Notably, these alterations, along with neuronal survival, could be rescued by treating ALS-related neurons with the K+ channel blockers Apamin and XE991, which, respectively, target the SK and the Kv7 channels. Thus, our study shows that restoring the activity-dependent transcriptional programme and synaptic composition exerts a neuroprotective effect on ALS disease progression.
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Affiliation(s)
- Alberto Catanese
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Sandeep Rajkumar
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Daniel Sommer
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Dennis Freisem
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Alexander Wirth
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Amr Aly
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - David Massa‐López
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
| | - Andrea Olivieri
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Federica Torelli
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Valentin Ioannidis
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Joanna Lipecka
- Proteomics platform NeckerINSERM US24/CNRS UMS3633Université de Paris – Structure Fédérative de Recherche NeckerParisFrance
| | - Ida Chiara Guerrera
- Proteomics platform NeckerINSERM US24/CNRS UMS3633Université de Paris – Structure Fédérative de Recherche NeckerParisFrance
| | - Daniel Zytnicki
- SPPIN ‐ Saints‐Pères Paris Institute for the NeurosciencesCNRSUniversité de ParisParis, Paris
| | - Albert Ludolph
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
- Department of NeurologyUlm University School of MedicineUlmGermany
| | - Edor Kabashi
- Institute of Translational Research for Neurological DisordersINSERM UMR 1163Imagine InstituteParisFrance
| | - Medhanie A Mulaw
- Internal Medicine I and Institute of Molecular Medicine and Stem Cell AgingMedical FacultyUniversity Hospital UlmUniversity of Ulm UniversityUlmGermany
| | - Francesco Roselli
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
- Department of NeurologyUlm University School of MedicineUlmGermany
| | - Tobias M Böckers
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
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29
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Affiliation(s)
- Marin Manuel
- SPPIN - Saints-Pères Paris Institute for the Neurosciences, Université de Paris, CNRS, Paris, F-75006, France
| | - Daniel Zytnicki
- SPPIN - Saints-Pères Paris Institute for the Neurosciences, Université de Paris, CNRS, Paris, F-75006, France
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30
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Durand J, Filipchuk A, Pambo-Pambo A, Gaudel F, Liabeuf S, Brocard C, Guéritaud JP. Hypoexcitability of Motoneurons: An Early Pathological Sign in ALS. Neuroscience 2021; 465:233-234. [PMID: 34053506 DOI: 10.1016/j.neuroscience.2021.03.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 10/21/2022]
Affiliation(s)
- J Durand
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France
| | - A Filipchuk
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France; Paris-Saclay Institute of Neuroscience (NeuroPSI), Department of Integrative and Computational Neuroscience (ICN), Centre National de la Recherche Scientifique (CNRS), 91198 Gif-sur-Yvette, France
| | - A Pambo-Pambo
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France
| | - F Gaudel
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France
| | - S Liabeuf
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France
| | - C Brocard
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France
| | - J P Guéritaud
- Institut de Neurosciences de la Timone, Equipe P3M, UMR 7289 CNRS-AMU, Aix Marseille Université, 27 Bd Jean Moulin, 13585 Marseille Cedex 20, France
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31
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Fogarty MJ. Neuronal Hypoexcitability and Dendritic Overbranching - The Case for Failed Compensatory Mechanisms in ALS Aetiology. Neuroscience 2021; 465:231-232. [PMID: 34053505 DOI: 10.1016/j.neuroscience.2021.02.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 02/28/2021] [Indexed: 12/15/2022]
Affiliation(s)
- Matthew J Fogarty
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA; School of Biomedical Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
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32
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Huang X, Roet KCD, Zhang L, Brault A, Berg AP, Jefferson AB, Klug-McLeod J, Leach KL, Vincent F, Yang H, Coyle AJ, Jones LH, Frost D, Wiskow O, Chen K, Maeda R, Grantham A, Dornon MK, Klim JR, Siekmann MT, Zhao D, Lee S, Eggan K, Woolf CJ. Human amyotrophic lateral sclerosis excitability phenotype screen: Target discovery and validation. Cell Rep 2021; 35:109224. [PMID: 34107252 PMCID: PMC8209673 DOI: 10.1016/j.celrep.2021.109224] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 10/14/2020] [Accepted: 05/13/2021] [Indexed: 12/12/2022] Open
Abstract
Drug development is hampered by poor target selection. Phenotypic screens using neurons differentiated from patient stem cells offer the possibility to validate known and discover novel disease targets in an unbiased fashion. To identify targets for managing hyperexcitability, a pathological feature of amyotrophic lateral sclerosis (ALS), we design a multi-step screening funnel using patient-derived motor neurons. High-content live cell imaging is used to evaluate neuronal excitability, and from a screen against a chemogenomic library of 2,899 target-annotated compounds, 67 reduce the hyperexcitability of ALS motor neurons carrying the SOD1(A4V) mutation, without cytotoxicity. Bioinformatic deconvolution identifies 13 targets that modulate motor neuron excitability, including two known ALS excitability modulators, AMPA receptors and Kv7.2/3 ion channels, constituting target validation. We also identify D2 dopamine receptors as modulators of ALS motor neuron excitability. This screen demonstrates the power of human disease cell-based phenotypic screens for identifying clinically relevant targets for neurological disorders. Motor neuron hyperexcitability is observed in both ALS patients and their iPSC-derived neurons. Combining a high-content live imaging excitability phenotypic assay, high-throughput screening against a cross-annotated chemogenomic library, and bioinformatic enrichment analysis, Huang et al. identify targets modulating the hyperexcitability of ALS patient-derived motor neurons in an unbiased manner.
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Affiliation(s)
- Xuan Huang
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Kasper C D Roet
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Liying Zhang
- Medicine Design, Pfizer, Cambridge, MA 02139, USA
| | - Amy Brault
- Medicine Design, Pfizer, Groton, CT 06340, USA
| | - Allison P Berg
- Rare Disease Research Unit, Pfizer, Cambridge, MA 02139, USA
| | - Anne B Jefferson
- Pfizer Centers for Therapeutic Innovation (CTI), San Francisco, CA 94080, USA
| | | | - Karen L Leach
- Pfizer Centers for Therapeutic Innovation (CTI), Cambridge, MA 02139, USA
| | | | - Hongying Yang
- Pfizer Centers for Therapeutic Innovation (CTI), Cambridge, MA 02139, USA
| | - Anthony J Coyle
- Pfizer Centers for Therapeutic Innovation (CTI), Cambridge, MA 02139, USA
| | - Lyn H Jones
- Medicine Design, Pfizer, Cambridge, MA 02139, USA
| | - Devlin Frost
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Ole Wiskow
- Department of Stem Cell and Regenerative Biology, Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Kuchuan Chen
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Rie Maeda
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Alyssa Grantham
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Mary K Dornon
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Joseph R Klim
- Department of Stem Cell and Regenerative Biology, Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Marco T Siekmann
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Dongyi Zhao
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Seungkyu Lee
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
| | - Kevin Eggan
- Department of Stem Cell and Regenerative Biology, Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, and Department of Neurology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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33
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Neurophysiological Mechanisms Underlying Cortical Hyper-Excitability in Amyotrophic Lateral Sclerosis: A Review. Brain Sci 2021; 11:brainsci11050549. [PMID: 33925493 PMCID: PMC8145013 DOI: 10.3390/brainsci11050549] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neuromotor disease characterized by the loss of upper and lower motor neurons (MNs), resulting in muscle paralysis and death. Early cortical hyper-excitability is a common pathological process observed clinically and in animal disease models. Although the mechanisms that underlie cortical hyper-excitability are not completely understood, the molecular and cellular mechanisms that cause enhanced neuronal intrinsic excitability and changes in excitatory and inhibitory synaptic activity are starting to emerge. Here, we review the evidence for an anterograde glutamatergic excitotoxic process, leading to cortical hyper-excitability via intrinsic cellular and synaptic mechanisms and for the role of interneurons in establishing disinhibition in clinical and experimental settings. Understanding the mechanisms that lead to these complex pathological processes will likely produce key insights towards developing novel therapeutic strategies to rescue upper MNs, thus alleviating the impact of this fatal disease.
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34
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Bączyk M, Alami NO, Delestrée N, Martinot C, Tang L, Commisso B, Bayer D, Doisne N, Frankel W, Manuel M, Roselli F, Zytnicki D. Synaptic restoration by cAMP/PKA drives activity-dependent neuroprotection to motoneurons in ALS. J Exp Med 2021; 217:151829. [PMID: 32484501 PMCID: PMC7398175 DOI: 10.1084/jem.20191734] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/03/2020] [Accepted: 05/01/2020] [Indexed: 12/26/2022] Open
Abstract
Excessive excitation is hypothesized to cause motoneuron (MN) degeneration in amyotrophic lateral sclerosis (ALS), but actual proof of hyperexcitation in vivo is missing, and trials based on this concept have failed. We demonstrate, by in vivo single-MN electrophysiology, that, contrary to expectations, excitatory responses evoked by sensory and brainstem inputs are reduced in MNs of presymptomatic mutSOD1 mice. This impairment correlates with disrupted postsynaptic clustering of Homer1b, Shank, and AMPAR subunits. Synaptic restoration can be achieved by activation of the cAMP/PKA pathway, by either intracellular injection of cAMP or DREADD-Gs stimulation. Furthermore, we reveal, through independent control of signaling and excitability allowed by multiplexed DREADD/PSAM chemogenetics, that PKA-induced restoration of synapses triggers an excitation-dependent decrease in misfolded SOD1 burden and autophagy overload. In turn, increased MN excitability contributes to restoring synaptic structures. Thus, the decrease of excitation to MN is an early but reversible event in ALS. Failure of the postsynaptic site, rather than hyperexcitation, drives disease pathobiochemistry.
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Affiliation(s)
- Marcin Bączyk
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Najwa Ouali Alami
- Department of Neurology, Ulm University, Ulm, Germany.,International Graduate School in Molecular Medicine Ulm, Ulm University, Ulm, Germany
| | - Nicolas Delestrée
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Clémence Martinot
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Linyun Tang
- Department of Neurology, Ulm University, Ulm, Germany.,Institute of Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - Barbara Commisso
- Department of Neurology, Ulm University, Ulm, Germany.,Institute of Anatomy and Cell Biology, Ulm University, Ulm, Germany
| | - David Bayer
- Department of Neurology, Ulm University, Ulm, Germany.,Cellular and Molecular Mechanisms in Aging Research Training Group, Ulm University, Ulm, Germany
| | - Nicolas Doisne
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Wayne Frankel
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY
| | - Marin Manuel
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
| | - Francesco Roselli
- Department of Neurology, Ulm University, Ulm, Germany.,Institute of Anatomy and Cell Biology, Ulm University, Ulm, Germany.,German Center for Neurodegenerative Diseases, Ulm, Germany.,Neurozentrum Ulm, Ulm, Germany
| | - Daniel Zytnicki
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique (CNRS), Paris, France
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35
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Huh S, Heckman CJ, Manuel M. Time Course of Alterations in Adult Spinal Motoneuron Properties in the SOD1(G93A) Mouse Model of ALS. eNeuro 2021; 8:ENEURO.0378-20.2021. [PMID: 33632815 PMCID: PMC8009670 DOI: 10.1523/eneuro.0378-20.2021] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 01/02/2023] Open
Abstract
Although amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease, motoneuron electrical properties are already altered during embryonic development. Motoneurons must therefore exhibit a remarkable capacity for homeostatic regulation to maintain a normal motor output for most of the life of the patient. In the present article, we demonstrate how maintaining homeostasis could come at a very high cost. We studied the excitability of spinal motoneurons from young adult SOD1(G93A) mice to end-stage. Initially, homeostasis is highly successful in maintaining their overall excitability. This initial success, however, is achieved by pushing some cells far above the normal range of passive and active conductances. As the disease progresses, both passive and active conductances shrink below normal values in the surviving cells. This shrinkage may thus promote survival, implying the previously large values contribute to degeneration. These results support the hypothesis that motoneuronal homeostasis may be "hypervigilant" in ALS and a source of accumulating stress.
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Affiliation(s)
- Seoan Huh
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago 60611, IL
| | - Charles J Heckman
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago 60611, IL
- Department of Physical Medicine and Rehabilitation, Northwestern University, Feinberg School of Medicine, Chicago 60611, IL
- Department of Physical Therapy and Human Movement Science, Northwestern University, Feinberg School of Medicine, Chicago 60611, IL
| | - Marin Manuel
- Department of Physiology, Northwestern University, Feinberg School of Medicine, Chicago 60611, IL
- Université de Paris, Saints-Pères Paris Institute for the Neurosciences (SPPIN), Centre National de la Recherche Scientifique, Paris 75006, France
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36
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Early Hypoexcitability in a Subgroup of Spinal Motoneurons in Superoxide Dismutase 1 Transgenic Mice, a Model of Amyotrophic Lateral Sclerosis. Neuroscience 2021; 463:337-353. [PMID: 33556455 DOI: 10.1016/j.neuroscience.2021.01.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/22/2021] [Accepted: 01/31/2021] [Indexed: 11/24/2022]
Abstract
In amyotrophic lateral sclerosis (ALS), large motoneurons degenerate first, causing muscle weakness. Transgenic mouse models with a mutation in the gene encoding the enzyme superoxide dismutase 1 (SOD1) revealed that motoneurons innervating the fast-fatigable muscular fibres disconnect very early. The cause of this peripheric disconnection has not yet been established. Early pathological signs were described in motoneurons during the postnatal period of SOD1 transgenic mice. Here, we investigated whether the early changes of electrical and morphological properties previously reported in the SOD1G85R strain also occur in the SOD1G93A-low expressor line with particular attention to the different subsets of motoneurons defined by their discharge firing pattern (transient, sustained, or delayed-onset firing). Intracellular staining and recording were performed in lumbar motoneurons from entire brainstem-spinal cord preparations of SOD1G93A-low transgenic mice and their WT littermates during the second postnatal week. Our results show that SOD1G93A-low motoneurons exhibit a dendritic overbranching similar to that described previously in the SOD1G85R strain at the same age. Further we found an hypoexcitability in the delayed-onset firing SOD1G93A-low motoneurons (lower gain and higher voltage threshold). We conclude that dendritic overbranching and early hypoexcitability are common features of both low expressor SOD1 mutants (G85R and G93A-low). In the high-expressor SOD1G93A line, we found hyperexcitability in the sustained firing motoneurons at the same period, suggesting a delay in compensatory mechanisms. Overall, our results suggest that the hypoexcitability indicate an early dysfunction of the delayed-onset motoneurons and could account as early pathological signs of the disease.
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37
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Suboptimal Discontinuous Current-Clamp Switching Rates Lead to Deceptive Mouse Neuronal Firing. eNeuro 2021; 8:ENEURO.0461-20.2020. [PMID: 33446514 PMCID: PMC7901151 DOI: 10.1523/eneuro.0461-20.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/01/2020] [Accepted: 12/06/2020] [Indexed: 12/03/2022] Open
Abstract
Intracellular recordings using sharp microelectrodes often rely on a technique called discontinuous current-clamp (DCC) to accurately record the membrane potential while injecting current through the same microelectrode. It is well known that a poor choice of DCC switching rate can lead to underestimation or overestimation of the cell potential; however, its effect on the cell firing is rarely discussed. Here, we show that suboptimal switching rates lead to an overestimation of cell excitability. We performed intracellular recordings of mouse spinal motoneurons and recorded their firing in response to pulses and ramps of current in Bridge and DCC mode at various switching rates. We demonstrate that using an incorrect (too low) DCC frequency leads not only to an underestimation of the input resistance, but also, paradoxically, to an artificial overestimation of the firing of these cells: neurons fire at lower current, and at higher frequencies than at higher DCC rates, or than the same neuron recorded in Bridge mode. These effects are dependent on the membrane time constant of the recorded cell, and special care needs to be taken in large cells with very short time constants. Our work highlights the importance of choosing an appropriate DCC switching rate to obtain not only accurate membrane potential readings but also an accurate representation of the firing of the cell.
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38
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Deardorff AS, Romer SH, Fyffe RE. Location, location, location: the organization and roles of potassium channels in mammalian motoneurons. J Physiol 2021; 599:1391-1420. [DOI: 10.1113/jp278675] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 01/08/2021] [Indexed: 11/08/2022] Open
Affiliation(s)
- Adam S. Deardorff
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine Dayton OH 45435 USA
- Department of Neurology and Internal Medicine, Wright State University Boonshoft School of Medicine Dayton OH 45435 USA
| | - Shannon H. Romer
- Odyssey Systems Environmental Health Effects Laboratory, Navy Medical Research Unit‐Dayton Wright‐Patterson Air Force Base OH 45433 USA
| | - Robert E.W. Fyffe
- Department of Neuroscience, Cell Biology and Physiology, Wright State University Boonshoft School of Medicine Dayton OH 45435 USA
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39
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Bączyk M, Krutki P, Zytnicki D. Is there hope that transpinal direct current stimulation corrects motoneuron excitability and provides neuroprotection in amyotrophic lateral sclerosis? Physiol Rep 2021; 9:e14706. [PMID: 33463907 PMCID: PMC7814489 DOI: 10.14814/phy2.14706] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 12/14/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease of largely unknown pathophysiology, characterized by the progressive loss of motoneurons (MNs). We review data showing that in presymptomatic ALS mice, MNs display reduced intrinsic excitability and impaired level of excitatory inputs. The loss of repetitive firing specifically affects the large MNs innervating fast contracting muscle fibers, which are the most vulnerable MNs in ALS. Interventions that aimed at restoring either the intrinsic excitability or the synaptic excitation result in a decrease of disease markers in MNs and delayed neuromuscular junction denervation. We then focus on trans‐spinal direct current stimulation (tsDCS), a noninvasive tool, since it modulates the activity of spinal neurons and networks. Effects of tsDCS depend on the polarity of applied current. Recent work shows that anodal tsDCS induces long‐lasting enhancement of MN excitability and synaptic excitation of spinal MNs. Moreover, we show preliminary results indicating that anodal tsDCS enhances the excitatory synaptic inputs to MNs in ALS mice. In conclusion, we suggest that chronic application of anodal tsDCS might be useful as a complementary method in the management of ALS patients.
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Affiliation(s)
- Marcin Bączyk
- Department of Neurobiology, Poznan University of Physical Education, Poznań, Poland
| | - Piotr Krutki
- Department of Neurobiology, Poznan University of Physical Education, Poznań, Poland
| | - Daniel Zytnicki
- Université de Paris, Centre National de la Recherche Scientifique (CNRS), Saints-Pères Paris Institute for the Neurosciences (SPPIN), Paris, France
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40
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Liu J, Wang Z, Shen D, Yang X, Liu M, Cui L. Split phenomenon of antagonistic muscle groups in amyotrophic lateral sclerosis: relative preservation of flexor muscles. Neurol Res 2020; 43:372-380. [PMID: 33372862 DOI: 10.1080/01616412.2020.1866354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Objective: In addition to the split hand sign, other split phenomena of different muscles also exist in amyotrophic lateral sclerosis (ALS). We analyzed the incidence of split phenomena in multiple antagonistic muscle groups in ALS patients and explored whether clinical factors affected their occurrence.Methods: 618 ALS patients were included from a single ALS center. Muscle strength in upper and lower limbs was evaluated using the modified Medical Research Council (MRC) scoring system (range from 1 to 13). Split phenomena between different antagonistic muscle groups were summarized, and the correlations with clinical factors were analyzed.Results: Split phenomena were detected in 22.3% antagonistic muscles for flexion and extension of the elbow, 11.9% for the wrist, 23.9% for fingers, 18.2% for the ankle, and 14.7% for toes. These manifestations were characterized by preferential wasting of the elbow, wrist, and finger extensor muscles compared with the flexor muscles, and the ankle and toe dorsiflexor muscles compared with the plantar flexor muscles. The presence of muscle wasting was more common when the muscle strength was stronger than a modified MRC grade 6. No definite correlation was found between split phenomena and clinical factors, including age-at-onset, gender, disease duration, the region of onset, and pyramidal tract damage.Discussion: Split phenomena of antagonistic muscle groups widely exist in ALS patients. No definitive and consistent clinical factors were observed that affected the occurrence of these phenomena.
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Affiliation(s)
- Jingwen Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Zhili Wang
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Dongchao Shen
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xunzhe Yang
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Mingsheng Liu
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Liying Cui
- Department of Neurology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Neurosciences Center, Chinese Academy of Medical Sciences, Beijing, China
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41
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Jørgensen HS, Jensen DB, Dimintiyanova KP, Bonnevie VS, Hedegaard A, Lehnhoff J, Moldovan M, Grondahl L, Meehan CF. Increased Axon Initial Segment Length Results in Increased Na + Currents in Spinal Motoneurones at Symptom Onset in the G127X SOD1 Mouse Model of Amyotrophic Lateral Sclerosis. Neuroscience 2020; 468:247-264. [PMID: 33246068 DOI: 10.1016/j.neuroscience.2020.11.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 10/22/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease preferentially affecting motoneurones. Transgenic mouse models have been used to investigate the role of abnormal motoneurone excitability in this disease. Whilst an increased excitability has repeatedly been demonstrated in vitro in neonatal and embryonic preparations from SOD1 mouse models, the results from the only studies to record in vivo from spinal motoneurones in adult SOD1 models have produced conflicting findings. Deficits in repetitive firing have been reported in G93A SOD1(high copy number) mice but not in presymptomatic G127X SOD1 mice despite shorter motoneurone axon initial segments (AISs) in these mice. These discrepancies may be due to the earlier disease onset and prolonged disease progression in G93A SOD1 mice with recordings potentially performed at a later sub-clinical stage of the disease in this mouse. To test this, and to explore how the evolution of excitability changes with symptom onset we performed in vivo intracellular recording and AIS labelling in G127X SOD1 mice immediately after symptom onset. No reductions in repetitive firing were observed showing that this is not a common feature across all ALS models. Immunohistochemistry for the Na+ channel Nav1.6 showed that motoneurone AISs increase in length in G127X SOD1 mice at symptom onset. Consistent with this, the rate of rise of AIS components of antidromic action potentials were significantly faster confirming that this increase in length represents an increase in AIS Na+ channels occurring at symptom onset in this model.
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Affiliation(s)
- H S Jørgensen
- Department of Neuroscience, University of Copenhagen, Denmark
| | - D B Jensen
- Department of Neuroscience, University of Copenhagen, Denmark
| | | | - V S Bonnevie
- Department of Neuroscience, University of Copenhagen, Denmark
| | - A Hedegaard
- Department of Neuroscience, University of Copenhagen, Denmark
| | - J Lehnhoff
- Department of Neuroscience, University of Copenhagen, Denmark
| | - M Moldovan
- Department of Neuroscience, University of Copenhagen, Denmark
| | - L Grondahl
- Department of Neuroscience, University of Copenhagen, Denmark
| | - C F Meehan
- Department of Neuroscience, University of Copenhagen, Denmark.
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42
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Jensen DB, Kadlecova M, Allodi I, Meehan CF. Spinal motoneurones are intrinsically more responsive in the adult G93A SOD1 mouse model of amyotrophic lateral sclerosis. J Physiol 2020; 598:4385-4403. [PMID: 32716521 DOI: 10.1113/jp280097] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 07/17/2020] [Indexed: 12/17/2022] Open
Abstract
KEY POINTS Although in vitro recordings using neonatal preparations from mouse models of amyotrophic lateral sclerosis (ALS) suggest increased motoneurone excitability, in vivo recordings in adult ALS mouse models have been conflicting. In adult G93A SOD1 models, spinal motoneurones have previously been shown to have deficits in repetitive firing, in contrast to the G127X SOD1 mouse model. Our in vivo intracellular recordings in barbiturate-anaesthetized adult male G93A SOD1 mice reveal that the incidence of failure to fire with current injection was equally low in control and ALS mice (∼2%). We show that failure to fire repetitively can be a consequence of experimental protocol and should not be used alone to classify otherwise normal motoneurones as hypo-excitable. Motoneurones in the G93A SOD1 mice showed an increased response to inputs, with lower rheobase, higher input-output gains and increased activation of persistent inward currents. ABSTRACT In vitro studies from transgenic amyotrophic lateral sclerosis models have suggested an increased excitability of spinal motoneurones. However, in vivo intracellular recordings from adult amyotrophic lateral sclerosis mice models have produced conflicting findings. Previous investigations using barbiturate anaesthetized G93A SOD1 mice have suggested that some motoneurones are hypo-excitable, defined by deficits in repetitive firing. Our own previous recordings in G127X SOD1 mice using different anaesthesia, however, showed no repetitive firing deficits and increased persistent inward currents at symptom onset. These discrepancies may be a result of differences between models, symptomatic stage, anaesthesia or technical differences. To investigate this, we repeated our original experiments, but in adult male G93A SOD1 mice, at both presymptomatic and symptomatic stages, under barbiturate anaesthesia. In vivo intracellular recordings from antidromically identified spinal motoneurones revealed that the incidence of failure to fire with current injection was equally low in control and G93A SOD1 mice (∼2%). Motoneurones in G93A SOD1 mice fired significantly more spontaneous action potentials. Rheobase was significantly lower and the input resistance and input-output gain were significantly higher in both presymptomatic and symptomatic G93A SOD1 mice. This was despite a significant increase in the duration of the post-spike after-hyperpolarization in both presymptomatic and symptomatic G93A SOD1 mice. Finally, evidence of increased activation of persistent inward currents was seen in both presymptomatic and symptomatic G93A SOD1 mice. Our results do not confirm previous reports of hypo-excitability of spinal motoneurones in the G93A SOD1 mouse and demonstrate that the motoneurones show an increased response to inputs.
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Affiliation(s)
- Dennis B Jensen
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
| | - Marion Kadlecova
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
| | - Ilary Allodi
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
| | - Claire F Meehan
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, Copenhagen N, Denmark
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43
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Gunes ZI, Kan VWY, Ye X, Liebscher S. Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology. Front Neurosci 2020; 14:573. [PMID: 32625051 PMCID: PMC7311855 DOI: 10.3389/fnins.2020.00573] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/11/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysiology, genetic manipulations and molecular characterizations in animal models and culture experiments, which argue for a causal involvement of complex alterations of structure, function and connectivity of different neuronal subtypes within the cortical and spinal cord motor circuitries. We also summarize the current knowledge regarding the detrimental role of astrocytes and reassess the frequently proposed hypothesis of glutamate-mediated excitotoxicity with respect to changes in neuronal excitability. Together, these findings suggest multifaceted cell type-, brain area- and disease stage- specific disturbances of the excitation/inhibition balance as a cardinal aspect of ALS pathophysiology.
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Affiliation(s)
- Zeynep I Gunes
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Vanessa W Y Kan
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - XiaoQian Ye
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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44
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Excessive Homeostatic Gain in Spinal Motoneurons in a Mouse Model of Amyotrophic Lateral Sclerosis. Sci Rep 2020; 10:9049. [PMID: 32493926 PMCID: PMC7271238 DOI: 10.1038/s41598-020-65685-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 05/05/2020] [Indexed: 02/08/2023] Open
Abstract
In the mSOD1 model of ALS, the excitability of motoneurons is poorly controlled, oscillating between hyperexcitable and hypoexcitable states during disease progression. The hyperexcitability is mediated by excessive activity of voltage-gated Na+ and Ca2+ channels that is initially counteracted by aberrant increases in cell size and conductance. The balance between these opposing actions collapses, however, at the time that the denervation of muscle fibers begins at about P50, resulting in a state of hypo-excitability and cell death. We propose that this process of neurodegeneration ensues from homeostatic dysregulation of excitability and have tested this hypothesis by perturbing a signal transduction pathway that plays a major role in controlling biogenesis and cell size. Our 『homeostatic dysregulation hypothesis' predicted that neonatal mSOD1 motoneurons would be much more sensitive to such perturbations than wild type controls and our results strongly support this hypothesis. Our results have important implications for therapeutic approaches to ALS.
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45
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Jara JH, Sheets PL, Nigro MJ, Perić M, Brooks C, Heller DB, Martina M, Andjus PR, Ozdinler PH. The Electrophysiological Determinants of Corticospinal Motor Neuron Vulnerability in ALS. Front Mol Neurosci 2020; 13:73. [PMID: 32508590 PMCID: PMC7248374 DOI: 10.3389/fnmol.2020.00073] [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: 11/26/2019] [Accepted: 04/15/2020] [Indexed: 12/12/2022] Open
Abstract
The brain is complex and heterogeneous. Even though numerous independent studies indicate cortical hyperexcitability as a potential contributor to amyotrophic lateral sclerosis (ALS) pathology, the mechanisms that are responsible for upper motor neuron (UMN) vulnerability remain elusive. To reveal the electrophysiological determinants of corticospinal motor neuron (CSMN, a.k.a UMN in mice) vulnerability, we investigated the motor cortex of hSOD1G93A mice at P30 (postnatal day 30), a presymptomatic time point. Glutamate uncaging by laser scanning photostimulation (LSPS) revealed altered dynamics especially within the inhibitory circuitry and more specifically in L2/3 of the motor cortex, whereas the excitatory microcircuits were unchanged. Observed microcircuitry changes were specific to CSMN in the motor column. Electrophysiological evaluation of the intrinsic properties in response to the microcircuit changes, as well as the exon microarray expression profiles of CSMN isolated from hSOD1G93A and healthy mice at P30, revealed the presence of a very dynamic set of events, ultimately directed to establish, maintain and retain the balance at this early stage. Also, the expression profile of key voltage-gated potassium and sodium channel subunits as well as of the inhibitory GABA receptor subunits and modulatory proteins began to suggest the challenges CSMN face at this early age. Since neurodegeneration is initiated when neurons can no longer maintain balance, the complex cellular events that occur at this critical time point help reveal how CSMN try to cope with the challenges of disease manifestation. This information is critically important for the proper modulation of UMNs and for developing effective treatment strategies.
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Affiliation(s)
- Javier H Jara
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Patrick L Sheets
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Maximiliano José Nigro
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Mina Perić
- Institute for Physiology and Biochemistry "Ivan Djaja", Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Carolyn Brooks
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Daniel B Heller
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Pavle R Andjus
- Institute for Physiology and Biochemistry "Ivan Djaja", Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - P Hande Ozdinler
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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46
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Howells J, Sangari S, Matamala JM, Kiernan MC, Marchand-Pauvert V, Burke D. Interrogating interneurone function using threshold tracking of the H reflex in healthy subjects and patients with motor neurone disease. Clin Neurophysiol 2020; 131:1986-1996. [PMID: 32336595 DOI: 10.1016/j.clinph.2020.03.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/21/2020] [Accepted: 03/15/2020] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The excitability of the lower motoneurone pool is traditionally tested using the H reflex and a constant-stimulus paradigm, which measures changes in the amplitude of the reflex response. This technique has limitations because reflex responses of different size must involve the recruitment or inhibition of different motoneurones. The threshold-tracking technique ensures that the changes in excitability occur for an identical population of motoneurones. We aimed to assess this technique and then apply it in patients with motor neurone disease (MND). METHODS The threshold-tracking approach was assessed in 17 healthy subjects and 11 patients with MND. The soleus H reflex was conditioned by deep peroneal nerve stimulation producing reciprocal Ia and so-called D1 and D2 inhibitions, which are believed to reflect presynaptic inhibition of soleus Ia afferents. RESULTS Threshold tracking was quicker than the constant-stimulus technique and reliable, properties that may be advantageous for clinical studies. D1 inhibition was significantly reduced in patients with MND. CONCLUSIONS Threshold tracking is useful and may be preferable under some conditions for studying the excitability of the motoneurone pool. The decreased D1 inhibition in the patients suggests that presynaptic inhibition may be reduced in MND. SIGNIFICANCE Reduced presynaptic inhibition could be evidence of an interneuronopathy in MND. It is possible that the hyperreflexia is a spinal pre-motoneuronal disorder, and not definitive evidence of corticospinal involvement in MND.
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Affiliation(s)
- James Howells
- Brain & Mind Centre, The University of Sydney, N.S.W. 2006, Australia
| | - Sina Sangari
- Sorbonne Université, INSERM, CNRS, Laboratoire d'Imagerie Biomédicale, LIB, F-75006 Paris, France
| | - José Manuel Matamala
- Department of Neurological Science and Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
| | - Matthew C Kiernan
- Brain & Mind Centre, The University of Sydney, N.S.W. 2006, Australia; Department of Neurology, Royal Prince Alfred Hospital and The University of Sydney, N.S.W. 2006, Australia
| | | | - David Burke
- Department of Neurology, Royal Prince Alfred Hospital and The University of Sydney, N.S.W. 2006, Australia.
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47
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Highlander MM, Allen JM, Elbasiouny SM. Meta-analysis of biological variables' impact on spinal motoneuron electrophysiology data. J Neurophysiol 2020; 123:1380-1391. [PMID: 32073942 DOI: 10.1152/jn.00378.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Experimental, methodological, and biological variables must be accounted for statistically to maximize accuracy and comparability of published neuroscience data. However, accounting for all variables is nigh impossible. Thus we aimed to identify particularly influential variables within published neurological data, from cat, rat, and mouse studies, via a robust statistical process. Our goal was to develop tools to improve rigor in the collection and analysis of data. We strictly constrained experimental and methodological variables and then assessed four key biological variables within motoneuron research: species, age, sex, and cell type. We quantified intraexperimental and interexperimental variances in 11 commonly reported electrophysiological properties of spinal motoneurons. We first assessed variances without accounting for biological variables and then reassessed them while accounting for all four variables. We next assessed variances with all possible combinations of these four variables. We concluded that some motoneuron properties have low intraexperimental, but high interexperimental, variance; that individual motoneuron properties are impacted differently by biological variables; and that some unexplained variances still remain. We report here the optimal combinations of biological variables to reduce interexperimental variance for all 11 parameters. We also rank each parameter by intra- and interexperimental consistency. We expect these results to assist with design of experimental and analytical methods, and to support accuracy in simulations. Furthermore, although demonstrated on spinal motoneuron electrophysiology literature, our approach is applicable to biological data from all fields of neuroscience. This approach represents an important aid to experimental design, comparison of reported data, and reduction of unexplained variance in neuroscience data.NEW & NOTEWORTHY Our meta-analysis shows the impact of species, age, sex, and cell type on lumbosacral motoneuron electrophysiological properties by thoroughly quantifying variances across literature for the first time. We quantify the variances of 11 motoneuron properties with consideration of biological variables, thus providing specific insights for motoneuron modelers and experimenters, and providing a general methodological template for the quantification of variance in neurological data with the consideration of any experimental, methodological, or biological variables of interest.
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Affiliation(s)
- Morgan M Highlander
- Department of Biomedical, Industrial and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, Ohio
| | - John M Allen
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, Ohio
| | - Sherif M Elbasiouny
- Department of Neuroscience, Cell Biology and Physiology, Boonshoft School of Medicine and College of Science and Mathematics, Wright State University, Dayton, Ohio.,Department of Biomedical, Industrial and Human Factors Engineering, College of Engineering and Computer Science, Wright State University, Dayton, Ohio
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48
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Bonnevie VS, Dimintiyanova KP, Hedegaard A, Lehnhoff J, Grøndahl L, Moldovan M, Meehan CF. Shorter axon initial segments do not cause repetitive firing impairments in the adult presymptomatic G127X SOD-1 Amyotrophic Lateral Sclerosis mouse. Sci Rep 2020; 10:1280. [PMID: 31992746 PMCID: PMC6987224 DOI: 10.1038/s41598-019-57314-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 12/19/2019] [Indexed: 12/13/2022] Open
Abstract
Increases in axonal sodium currents in peripheral nerves are some of the earliest excitability changes observed in Amyotrophic Lateral Sclerosis (ALS) patients. Nothing is known, however, about axonal sodium channels more proximally, particularly at the action potential initiating region - the axon initial segment (AIS). Immunohistochemistry for Nav1.6 sodium channels was used to investigate parameters of AISs of spinal motoneurones in the G127X SOD1 mouse model of ALS in adult mice at presymptomatic time points (~190 days old). In vivo intracellular recordings from lumbar spinal motoneurones were used to determine the consequences of any AIS changes. AISs of both alpha and gamma motoneurones were found to be significantly shorter (by 6.6% and 11.8% respectively) in G127X mice as well as being wider by 9.8% (alpha motoneurones). Measurements from 20–23 day old mice confirmed that this represented a change during adulthood. Intracellular recordings from motoneurones in presymptomatic adult mice, however, revealed no differences in individual action potentials or the cells ability to initiate repetitive action potentials. To conclude, despite changes in AIS geometry, no evidence was found for reduced excitability within the functional working range of firing frequencies of motoneurones in this model of ALS.
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Affiliation(s)
- V S Bonnevie
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - K P Dimintiyanova
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - A Hedegaard
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - J Lehnhoff
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - L Grøndahl
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - M Moldovan
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark
| | - C F Meehan
- Department of Neuroscience, University of Copenhagen, Panum Institute, Blegdamsvej 3, DK-2200, Copenhagen N, Denmark.
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49
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Zhao C, Devlin AC, Chouhan AK, Selvaraj BT, Stavrou M, Burr K, Brivio V, He X, Mehta AR, Story D, Shaw CE, Dando O, Hardingham GE, Miles GB, Chandran S. Mutant C9orf72 human iPSC-derived astrocytes cause non-cell autonomous motor neuron pathophysiology. Glia 2019; 68:1046-1064. [PMID: 31841614 PMCID: PMC7078830 DOI: 10.1002/glia.23761] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022]
Abstract
Mutations in C9orf72 are the most common genetic cause of amyotrophic lateral sclerosis (ALS). Accumulating evidence implicates astrocytes as important non‐cell autonomous contributors to ALS pathogenesis, although the potential deleterious effects of astrocytes on the function of motor neurons remains to be determined in a completely humanized model of C9orf72‐mediated ALS. Here, we use a human iPSC‐based model to study the cell autonomous and non‐autonomous consequences of mutant C9orf72 expression by astrocytes. We show that mutant astrocytes both recapitulate key aspects of C9orf72‐related ALS pathology and, upon co‐culture, cause motor neurons to undergo a progressive loss of action potential output due to decreases in the magnitude of voltage‐activated Na+ and K+ currents. Importantly, CRISPR/Cas‐9 mediated excision of the C9orf72 repeat expansion reverses these phenotypes, confirming that the C9orf72 mutation is responsible for both cell‐autonomous astrocyte pathology and non‐cell autonomous motor neuron pathophysiology.
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Affiliation(s)
- Chen Zhao
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Anna-Claire Devlin
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | - Amit K Chouhan
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | - Bhuvaneish T Selvaraj
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK.,Dementia Research Institute at the University of Edinburgh, Edinburgh, UK
| | - Maria Stavrou
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK.,Dementia Research Institute at the University of Edinburgh, Edinburgh, UK
| | - Karen Burr
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK.,Dementia Research Institute at the University of Edinburgh, Edinburgh, UK
| | - Veronica Brivio
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | - Xin He
- Dementia Research Institute at the University of Edinburgh, Edinburgh, UK.,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Arpan R Mehta
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK.,Dementia Research Institute at the University of Edinburgh, Edinburgh, UK
| | - David Story
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK.,Dementia Research Institute at the University of Edinburgh, Edinburgh, UK
| | - Christopher E Shaw
- MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, London, UK.,Dementia Research Institute at Kings College London, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Owen Dando
- Dementia Research Institute at the University of Edinburgh, Edinburgh, UK.,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Giles E Hardingham
- Dementia Research Institute at the University of Edinburgh, Edinburgh, UK.,Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Gareth B Miles
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,School of Psychology and Neuroscience, University of St Andrews, St Andrews, Fife, UK
| | - Siddharthan Chandran
- Euan MacDonald Centre for MND Research, The University of Edinburgh, Edinburgh, UK.,Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK.,Dementia Research Institute at the University of Edinburgh, Edinburgh, UK.,Centre for Brain Development and Repair, Institute for Stem Cell Biology and Regenerative Medicine, Bangalore, India
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50
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Valbuena GN, Cantoni L, Tortarolo M, Bendotti C, Keun HC. Spinal Cord Metabolic Signatures in Models of Fast- and Slow-Progressing SOD1 G93A Amyotrophic Lateral Sclerosis. Front Neurosci 2019; 13:1276. [PMID: 31920474 PMCID: PMC6914819 DOI: 10.3389/fnins.2019.01276] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/11/2019] [Indexed: 12/11/2022] Open
Abstract
The rate of disease progression in amyotrophic lateral sclerosis (ALS) is highly variable, even between patients with the same genetic mutations. Metabolic alterations may affect disease course variability in ALS patients, but challenges in identifying the preclinical and early phases of the disease limit our understanding of molecular mechanisms underlying differences in the rate of disease progression. We examined effects of SOD1G93A on thoracic and lumbar spinal cord metabolites in two mouse ALS models with different rates of disease progression: the transgenic SOD1G93A-C57BL/6JOlaHsd (C57-G93A, slow progression) and transgenic SOD1G93A-129SvHsd (129S-G93A, fast progression) strains. Samples from three timepoints (presymptomatic, disease onset, and late stage disease) were analyzed using Gas Chromatography-Mass Spectrometry metabolomics. Tissue metabolome differences in the lumbar spinal cord were driven primarily by mouse genetic background, although larger responses were observed in metabolic trajectories after the onset of symptoms. The significantly affected lumbar spinal cord metabolites were involved in energy and lipid metabolism. In the thoracic spinal cord, metabolic differences related to genetic background, background-SOD1 genotype interactions, and longitudinal SOD1G93A effects. The largest responses in thoracic spinal cord metabolic trajectories related to SOD1G93A effects before onset of visible symptoms. More metabolites were significantly affected in the thoracic segment, which were involved in energy homeostasis, neurotransmitter synthesis and utilization, and the oxidative stress response. We find evidence that initial metabolic alterations in SOD1G93A mice confer disadvantages for maintaining neuronal viability under ALS-related stressors, with slow-progressing C57-G93A mice potentially having more favorable spinal cord bioenergetic profiles than 129S-G93A. These genetic background-associated metabolic differences together with the different early metabolic responses underscore the need to better characterize the impact of germline genetic variation on cellular responses to ALS gene mutations both before and after the onset of symptoms in order to understand their impact on disease development.
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Affiliation(s)
- Gabriel N Valbuena
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Lavinia Cantoni
- Department of Molecular Biochemistry and Pharmacology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Massimo Tortarolo
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Caterina Bendotti
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy
| | - Hector C Keun
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
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