1
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Rida Zainab S, Zeb Khan J, Khalid Tipu M, Jahan F, Irshad N. A review on multiple sclerosis: Unravelling the complexities of pathogenesis, progression, mechanisms and therapeutic innovations. Neuroscience 2024; 567:133-149. [PMID: 39709058 DOI: 10.1016/j.neuroscience.2024.12.029] [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: 10/24/2024] [Revised: 11/25/2024] [Accepted: 12/14/2024] [Indexed: 12/23/2024]
Abstract
Multiple sclerosis (MS) is a chronic, inflammatory demyelinating disorder of the central nervous system (CNS) targeting myelinated axons. Pathogenesis of MS entails an intricate genetic, environmental, and immunological interaction. Dysregulation of immune response i.e. autoreactive T & B-Cells and macrophage infiltration into the CNS leads to inflammation, demyelination, and neurodegeneration. Disease progression of MS varies among individuals transitioning from one form of relapsing-remitting to secondary progressive MS (SPMS). Research advances have unfolded various molecular targets involved in MS from oxidative stress to blood-brain barrier (BBB) disruption. Different pathways are being targeted so far such as inflammatory and cytokine signaling pathways to overcome disease progression. Therapeutic innovations have significantly transformed the management of MS, especially the use of disease-modifying therapies (DMTs) to reduce relapse rates and control disease progression. Advancements in research, neuroprotective strategies, and remyelination strategies hold promising results in reversing CNS damage. Various mice models are being adopted for testing new entities in MS research.
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Affiliation(s)
- Syeda Rida Zainab
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
| | - Jehan Zeb Khan
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
| | - Muhammad Khalid Tipu
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
| | - Faryal Jahan
- Shifa College of Pharmaceutical Sciences, STMU, Islamabad, Pakistan.
| | - Nadeem Irshad
- Department of Pharmacy, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, Pakistan.
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2
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Boccuni I, Bas-Orth C, Bruehl C, Draguhn A, Fairless R. Glutamate transporter contribution to retinal ganglion cell vulnerability in a rat model of multiple sclerosis. Neurobiol Dis 2023; 187:106306. [PMID: 37734623 DOI: 10.1016/j.nbd.2023.106306] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 09/05/2023] [Accepted: 09/18/2023] [Indexed: 09/23/2023] Open
Abstract
Glial glutamate transporters actively participate in neurotransmission and have a fundamental role in determining the ambient glutamate concentration in the extracellular space. Their expression is dynamically regulated in many diseases, including experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. In EAE, a downregulation has been reported which may render neurons more susceptible to glutamate excitotoxicity. In this study, we have investigated the expression of GLAST (EAAT1) and GLT-1 (EAAT2) in the retina of Brown Norway rats following induction of myelin oligodendrocyte glycoprotein (MOG)-EAE, which results in retinal ganglion cell (RGC) degeneration and dysfunction. In addition, we tested whether AAV-mediated overexpression of GLAST in the retina can protect RGCs from degeneration. To address the impact of glutamate transporter modulation on RGCs, we performed whole-cell recordings and measured tonic NMDA receptor-mediated currents in the absence and presence of a glutamate-uptake blocker. We report that αOFF-RGCs show larger tonic glutamate-induced currents than αON-RGCs, in line with their greater vulnerability under neuroinflammatory conditions. We further show that increased AAV-mediated expression of GLAST in the retina does indeed protect RGCs from degeneration during the inflammatory disease. Collectively, our study highlights the neuroprotective role of glutamate transporters in the EAE retina and provides a characterization of tonic glutamate-currents of αRGCs. The larger effects of increased extracellular glutamate concentration on the αOFF-subtype may underlie its enhanced vulnerability to degeneration.
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Affiliation(s)
- Isabella Boccuni
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Carlos Bas-Orth
- Institute of Anatomy and Cell Biology, University of Heidelberg, Heidelberg 69120, Germany
| | - Claus Bruehl
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Andreas Draguhn
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg 69120, Germany
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, Heidelberg 69120, Germany; Clinical Cooperation Unit (CCU) Neurooncology, German Cancer Consortium (DKTK), German Cancer Research Center (DFKZ), Heidelberg 69120, Germany.
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3
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Nimgampalle M, Chakravarthy H, Sharma S, Shree S, Bhat AR, Pradeepkiran JA, Devanathan V. Neurotransmitter systems in the etiology of major neurological disorders: Emerging insights and therapeutic implications. Ageing Res Rev 2023; 89:101994. [PMID: 37385351 DOI: 10.1016/j.arr.2023.101994] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/21/2023] [Accepted: 06/25/2023] [Indexed: 07/01/2023]
Abstract
Neurotransmitters serve as chemical messengers playing a crucial role in information processing throughout the nervous system, and are essential for healthy physiological and behavioural functions in the body. Neurotransmitter systems are classified as cholinergic, glutamatergic, GABAergic, dopaminergic, serotonergic, histaminergic, or aminergic systems, depending on the type of neurotransmitter secreted by the neuron, allowing effector organs to carry out specific functions by sending nerve impulses. Dysregulation of a neurotransmitter system is typically linked to a specific neurological disorder. However, more recent research points to a distinct pathogenic role for each neurotransmitter system in more than one neurological disorder of the central nervous system. In this context, the review provides recently updated information on each neurotransmitter system, including the pathways involved in their biochemical synthesis and regulation, their physiological functions, pathogenic roles in diseases, current diagnostics, new therapeutic targets, and the currently used drugs for associated neurological disorders. Finally, a brief overview of the recent developments in neurotransmitter-based therapeutics for selected neurological disorders is offered, followed by future perspectives in that area of research.
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Affiliation(s)
- Mallikarjuna Nimgampalle
- Department of Biology, Indian Institute of Science Education and Research Tirupati (IISER T), Transit campus, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India
| | - Harshini Chakravarthy
- Department of Biology, Indian Institute of Science Education and Research Tirupati (IISER T), Transit campus, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India.
| | - Sapana Sharma
- Department of Biology, Indian Institute of Science Education and Research Tirupati (IISER T), Transit campus, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India
| | - Shruti Shree
- Department of Biology, Indian Institute of Science Education and Research Tirupati (IISER T), Transit campus, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India
| | - Anoop Ramachandra Bhat
- Department of Biology, Indian Institute of Science Education and Research Tirupati (IISER T), Transit campus, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India
| | | | - Vasudharani Devanathan
- Department of Biology, Indian Institute of Science Education and Research Tirupati (IISER T), Transit campus, Karakambadi Road, Mangalam, Tirupati 517507, Andhra Pradesh, India.
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4
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Schwarz K, Schmitz F. Synapse Dysfunctions in Multiple Sclerosis. Int J Mol Sci 2023; 24:ijms24021639. [PMID: 36675155 PMCID: PMC9862173 DOI: 10.3390/ijms24021639] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the central nervous system (CNS) affecting nearly three million humans worldwide. In MS, cells of an auto-reactive immune system invade the brain and cause neuroinflammation. Neuroinflammation triggers a complex, multi-faceted harmful process not only in the white matter but also in the grey matter of the brain. In the grey matter, neuroinflammation causes synapse dysfunctions. Synapse dysfunctions in MS occur early and independent from white matter demyelination and are likely correlates of cognitive and mental symptoms in MS. Disturbed synapse/glia interactions and elevated neuroinflammatory signals play a central role. Glutamatergic excitotoxic synapse damage emerges as a major mechanism. We review synapse/glia communication under normal conditions and summarize how this communication becomes malfunctional during neuroinflammation in MS. We discuss mechanisms of how disturbed glia/synapse communication can lead to synapse dysfunctions, signaling dysbalance, and neurodegeneration in MS.
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5
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Antunes FTT, De Souza AH, Figueira J, Binda NS, Carvalho VPR, Vieira LB, Gomez MV. Targeting N-type calcium channels in young-onset of some neurological diseases. Front Cell Dev Biol 2022; 10:1090765. [PMID: 36601540 PMCID: PMC9806183 DOI: 10.3389/fcell.2022.1090765] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 12/08/2022] [Indexed: 12/24/2022] Open
Abstract
Calcium (Ca 2+) is an important second messenger in charge of many critical processes in the central nervous system (CNS), including membrane excitability, neurotransmission, learning, memory, cell proliferation, and apoptosis. In this way, the voltage-gated calcium channels (VGCCs) act as a key supply for Ca2+ entry into the cytoplasm and organelles. Importantly, the dysregulation of these channels has been reported in many neurological diseases of young-onset, with associated genetic factors, such as migraine, multiple sclerosis, and Huntington's disease. Notably, the literature has pointed to the role of N-type Ca2+ channels (NTCCs) in controlling a variety of processes, including pain, inflammation, and excitotoxicity. Moreover, several Ca2+ channel blockers that are used for therapeutic purposes have been shown to act on the N-type channels. Therefore, this review provides an overview of the NTCCs in neurological disorders focusing mainly on Huntington's disease, multiple sclerosis, and migraine. It will discuss possible strategies to generate novel therapeutic strategies.
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Affiliation(s)
- Flavia Tasmin Techera Antunes
- Department of Physiology and Pharmacology, University of Calgary, Calgary, AB, Canada,Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Alessandra Hubner De Souza
- Post-Graduate Program of Health Sciences, Faculdade de Ciências Médicas de, Belo Horizonte, Minas Gerais, Brazil,*Correspondence: Alessandra Hubner De Souza, ; Marcus Vinícius Gomez,
| | - Juliana Figueira
- Pharmacology Department, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Nancy Scardua Binda
- Pharmacology Department, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | | | - Luciene Bruno Vieira
- Pharmacology Departament, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Marcus Vinícius Gomez
- Graduate Program in Health Sciences, Faculty Santa Casa BH, Belo Horizonte, Minas Gerais, Brazil,*Correspondence: Alessandra Hubner De Souza, ; Marcus Vinícius Gomez,
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6
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Kunkl M, Amormino C, Tedeschi V, Fiorillo MT, Tuosto L. Astrocytes and Inflammatory T Helper Cells: A Dangerous Liaison in Multiple Sclerosis. Front Immunol 2022; 13:824411. [PMID: 35211120 PMCID: PMC8860818 DOI: 10.3389/fimmu.2022.824411] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/13/2022] [Indexed: 11/15/2022] Open
Abstract
Multiple Sclerosis (MS) is a neurodegenerative autoimmune disorder of the central nervous system (CNS) characterized by the recruitment of self-reactive T lymphocytes, mainly inflammatory T helper (Th) cell subsets. Once recruited within the CNS, inflammatory Th cells produce several inflammatory cytokines and chemokines that activate resident glial cells, thus contributing to the breakdown of blood-brain barrier (BBB), demyelination and axonal loss. Astrocytes are recognized as key players of MS immunopathology, which respond to Th cell-defining cytokines by acquiring a reactive phenotype that amplify neuroinflammation into the CNS and contribute to MS progression. In this review, we summarize current knowledge of the astrocytic changes and behaviour in both MS and experimental autoimmune encephalomyelitis (EAE), and the contribution of pathogenic Th1, Th17 and Th1-like Th17 cell subsets, and CD8+ T cells to the morphological and functional modifications occurring in astrocytes and their pathological outcomes.
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Affiliation(s)
- Martina Kunkl
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
| | - Carola Amormino
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
| | - Valentina Tedeschi
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy
| | - Maria Teresa Fiorillo
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy
| | - Loretta Tuosto
- Department of Biology and Biotechnology Charles Darwin, Sapienza University, Rome, Italy.,Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University, Rome, Italy
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7
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Todd AC, Hardingham GE. The Regulation of Astrocytic Glutamate Transporters in Health and Neurodegenerative Diseases. Int J Mol Sci 2020; 21:E9607. [PMID: 33348528 PMCID: PMC7766851 DOI: 10.3390/ijms21249607] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/04/2020] [Accepted: 12/11/2020] [Indexed: 12/24/2022] Open
Abstract
The astrocytic glutamate transporters excitatory amino acid transporters 1 and 2 (EAAT1 and EAAT2) play a key role in nervous system function to maintain extracellular glutamate levels at low levels. In physiology, this is essential for the rapid uptake of synaptically released glutamate, maintaining the temporal fidelity of synaptic transmission. However, EAAT1/2 hypo-expression or hypo-function are implicated in several disorders, including epilepsy and neurodegenerative diseases, as well as being observed naturally with aging. This not only disrupts synaptic information transmission, but in extremis leads to extracellular glutamate accumulation and excitotoxicity. A key facet of EAAT1/2 expression in astrocytes is a requirement for signals from other brain cell types in order to maintain their expression. Recent evidence has shown a prominent role for contact-dependent neuron-to-astrocyte and/or endothelial cell-to-astrocyte Notch signalling for inducing and maintaining the expression of these astrocytic glutamate transporters. The relevance of this non-cell-autonomous dependence to age- and neurodegenerative disease-associated decline in astrocytic EAAT expression is discussed, plus the implications for disease progression and putative therapeutic strategies.
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Affiliation(s)
- Alison C. Todd
- UK Dementia Research Institute at the University of Edinburgh, Chancellor’s Building, Edinburgh Medical School, Edinburgh EH16 4SB, UK;
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Giles E. Hardingham
- UK Dementia Research Institute at the University of Edinburgh, Chancellor’s Building, Edinburgh Medical School, Edinburgh EH16 4SB, UK;
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
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8
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das Neves SP, Sousa JC, Sousa N, Cerqueira JJ, Marques F. Altered astrocytic function in experimental neuroinflammation and multiple sclerosis. Glia 2020; 69:1341-1368. [PMID: 33247866 DOI: 10.1002/glia.23940] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 12/11/2022]
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) that affects about 2.5 million people worldwide. In MS, the patients' immune system starts to attack the myelin sheath, leading to demyelination, neurodegeneration, and, ultimately, loss of vital neurological functions such as walking. There is currently no cure for MS and the available treatments only slow the initial phases of the disease. The later-disease mechanisms are poorly understood and do not directly correlate with the activity of immune system cells, the main target of the available treatments. Instead, evidence suggests that disease progression and disability are better correlated with the maintenance of a persistent low-grade inflammation inside the CNS, driven by local glial cells, like astrocytes and microglia. Depending on the context, astrocytes can (a) exacerbate inflammation or (b) promote immunosuppression and tissue repair. In this review, we will address the present knowledge that exists regarding the role of astrocytes in MS and experimental animal models of the disease.
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Affiliation(s)
- Sofia Pereira das Neves
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - João José Cerqueira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal.,Clinical Academic Center, Braga, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Braga, Portugal.,ICVS/3B's - PT Government Associate Laboratory, Braga, Portugal
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9
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Bozic I, Savic D, Lavrnja I. Astrocyte phenotypes: Emphasis on potential markers in neuroinflammation. Histol Histopathol 2020; 36:267-290. [PMID: 33226087 DOI: 10.14670/hh-18-284] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes, the most abundant glial cells in the central nervous system (CNS), have numerous integral roles in all CNS functions. They are essential for synaptic transmission and support neurons by providing metabolic substrates, secreting growth factors and regulating extracellular concentrations of ions and neurotransmitters. Astrocytes respond to CNS insults through reactive astrogliosis, in which they go through many functional and molecular changes. In neuroinflammatory conditions reactive astrocytes exert both beneficial and detrimental functions, depending on the context and heterogeneity of astrocytic populations. In this review we profile astrocytic diversity in the context of neuroinflammation; with a specific focus on multiple sclerosis (MS) and its best-described animal model experimental autoimmune encephalomyelitis (EAE). We characterize two main subtypes, protoplasmic and fibrous astrocytes and describe the role of intermediate filaments in the physiology and pathology of these cells. Additionally, we outline a variety of markers that are emerging as important in investigating astrocytic biology in both physiological conditions and neuroinflammation.
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Affiliation(s)
- Iva Bozic
- Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Danijela Savic
- Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Irena Lavrnja
- Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia.
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10
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How Repair-or-Dispose Decisions Under Stress Can Initiate Disease Progression. iScience 2020; 23:101701. [PMID: 33235980 PMCID: PMC7670198 DOI: 10.1016/j.isci.2020.101701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 07/17/2020] [Accepted: 10/15/2020] [Indexed: 11/20/2022] Open
Abstract
Glia, the helper cells of the brain, are essential in maintaining neural resilience across time and varying challenges: By reacting to changes in neuronal health glia carefully balance repair or disposal of injured neurons. Malfunction of these interactions is implicated in many neurodegenerative diseases. We present a reductionist model that mimics repair-or-dispose decisions to generate a hypothesis for the cause of disease onset. The model assumes four tissue states: healthy and challenged tissue, primed tissue at risk of acute damage propagation, and chronic neurodegeneration. We discuss analogies to progression stages observed in the most common neurodegenerative conditions and to experimental observations of cellular signaling pathways of glia-neuron crosstalk. The model suggests that the onset of neurodegeneration can result as a compromise between two conflicting goals: short-term resilience to stressors versus long-term prevention of tissue damage.
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11
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Sheng L, Stewart T, Yang D, Thorland E, Soltys D, Aro P, Khrisat T, Xie Z, Li N, Liu Z, Tian C, Bercow M, Matsumoto J, Zabetian CP, Peskind E, Quinn JF, Shi M, Zhang J. Erythrocytic α-synuclein contained in microvesicles regulates astrocytic glutamate homeostasis: a new perspective on Parkinson's disease pathogenesis. Acta Neuropathol Commun 2020; 8:102. [PMID: 32641150 PMCID: PMC7346449 DOI: 10.1186/s40478-020-00983-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 06/29/2020] [Indexed: 02/07/2023] Open
Abstract
Parkinson's disease is a neurodegenerative disorder characterized by the transmission and accumulation of toxic species of α-synuclein (α-syn). Extracellular vesicles (EVs) are believed to play a vital role in the spread of toxic α-syn species. Recently, peripheral α-syn pathology has been investigated, but little attention has been devoted to erythrocytes, which contain abundant α-syn. In this study, we first demonstrated that erythrocyte-derived EVs isolated from Parkinson's disease patients carried elevated levels of oligomeric α-syn, compared to those from healthy controls. Moreover, human erythrocyte-derived EVs, when injected into peripheral blood in a mouse model of Parkinson's disease, were found to readily cross the blood-brain barrier (BBB). These EVs accumulated in astrocyte endfeet, a component of the BBB, where they impaired glutamate uptake, likely via interaction between excitatory amino acid transporter 2 (EAAT2) and oligomeric α-syn. These data suggest that erythrocyte-derived EVs and the oligomeric α-syn carried in them may play critical roles in the progression or even initiation of Parkinson's disease. Additionally, the mechanisms involved are attributable at least in part to dysfunction of astrocytes induced by these EVs. These observations provide new insight into the understanding of the mechanisms involved in Parkinson's disease.
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Affiliation(s)
- Lifu Sheng
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Tessandra Stewart
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Dishun Yang
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
- Department of Pathology, Peking University Health Science Centre and Third Hospital, Beijing, China
| | - Eric Thorland
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - David Soltys
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Patrick Aro
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Tarek Khrisat
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Zhiying Xie
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Na Li
- Department of Pathology, Peking University Health Science Centre and Third Hospital, Beijing, China
| | - Zongran Liu
- Department of Pathology, Peking University Health Science Centre and Third Hospital, Beijing, China
| | - Chen Tian
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Matthew Bercow
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Junichi Matsumoto
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA
| | - Cyrus P Zabetian
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
- Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
| | - Elaine Peskind
- Mental Illness Research Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, USA
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Joseph F Quinn
- Department of Neurology, Oregon Health and Science University, Portland, OR, USA
| | - Min Shi
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA.
| | - Jing Zhang
- Department of Pathology, University of Washington School of Medicine, Seattle, Washington, USA.
- Department of Pathology, the First Affiliated Hospital and School of Medicine, Zhejiang University, Hangzhou, 310003, China.
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12
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Evonuk KS, Doyle RE, Moseley CE, Thornell IM, Adler K, Bingaman AM, Bevensee MO, Weaver CT, Min B, DeSilva TM. Reduction of AMPA receptor activity on mature oligodendrocytes attenuates loss of myelinated axons in autoimmune neuroinflammation. SCIENCE ADVANCES 2020; 6:eaax5936. [PMID: 31934627 PMCID: PMC6949032 DOI: 10.1126/sciadv.aax5936] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 11/08/2019] [Indexed: 06/10/2023]
Abstract
Glutamate dysregulation occurs in multiple sclerosis (MS), but whether excitotoxic mechanisms in mature oligodendrocytes contribute to demyelination and axonal injury is unexplored. Although current treatments modulate the immune system, long-term disability ensues, highlighting the need for neuroprotection. Glutamate is elevated before T2-visible white matter lesions appear in MS. We previously reported that myelin-reactive T cells provoke microglia to release glutamate from the system xc - transporter promoting myelin degradation in experimental autoimmune encephalomyelitis (EAE). Here, we explore the target for glutamate in mature oligodendrocytes. Most glutamate-stimulated calcium influx into oligodendrocyte somas is AMPA receptor (AMPAR)-mediated, and genetic deletion of AMPAR subunit GluA4 decreased intracellular calcium responses. Inducible deletion of GluA4 on mature oligodendrocytes attenuated EAE and loss of myelinated axons was selectively reduced compared to unmyelinated axons. These data link AMPAR signaling in mature oligodendrocytes to the pathophysiology of myelinated axons, demonstrating glutamate regulation as a potential neuroprotective strategy in MS.
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Affiliation(s)
- Kirsten S. Evonuk
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Ryan E. Doyle
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Carson E. Moseley
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
- University of California, San Francisco, CA, USA
| | - Ian M. Thornell
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Keith Adler
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Amanda M. Bingaman
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Mark O. Bevensee
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Casey T. Weaver
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Booki Min
- Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Tara M. DeSilva
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
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13
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Malik AR, Willnow TE. Excitatory Amino Acid Transporters in Physiology and Disorders of the Central Nervous System. Int J Mol Sci 2019; 20:ijms20225671. [PMID: 31726793 PMCID: PMC6888459 DOI: 10.3390/ijms20225671] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 11/07/2019] [Accepted: 11/11/2019] [Indexed: 12/12/2022] Open
Abstract
Excitatory amino acid transporters (EAATs) encompass a class of five transporters with distinct expression in neurons and glia of the central nervous system (CNS). EAATs are mainly recognized for their role in uptake of the amino acid glutamate, the major excitatory neurotransmitter. EAATs-mediated clearance of glutamate released by neurons is vital to maintain proper glutamatergic signalling and to prevent toxic accumulation of this amino acid in the extracellular space. In addition, some EAATs also act as chloride channels or mediate the uptake of cysteine, required to produce the reactive oxygen speciesscavenger glutathione. Given their central role in glutamate homeostasis in the brain, as well as their additional activities, it comes as no surprise that EAAT dysfunctions have been implicated in numerous acute or chronic diseases of the CNS, including ischemic stroke and epilepsy, cerebellar ataxias, amyotrophic lateral sclerosis, Alzheimer’s disease and Huntington’s disease. Here we review the studies in cellular and animal models, as well as in humans that highlight the roles of EAATs in the pathogenesis of these devastating disorders. We also discuss the mechanisms regulating EAATs expression and intracellular trafficking and new exciting possibilities to modulate EAATs and to provide neuroprotection in course of pathologies affecting the CNS.
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Affiliation(s)
- Anna R. Malik
- Nencki Institute of Experimental Biology, 02-093 Warsaw, Poland
- Correspondence:
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Belozor OS, Yakovleva DA, Potapenko IV, Shuvaev AN, Smolnikova MV, Vasilev A, Pozhilenkova EA, Shuvaev AN. Extracellular S100β Disrupts Bergman Glia Morphology and Synaptic Transmission in Cerebellar Purkinje Cells. Brain Sci 2019; 9:brainsci9040080. [PMID: 31013844 PMCID: PMC6523464 DOI: 10.3390/brainsci9040080] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 04/08/2019] [Accepted: 04/10/2019] [Indexed: 12/24/2022] Open
Abstract
Astrogliosis is a pathological process that affects the density, morphology, and function of astrocytes. It is a common feature of brain trauma, autoimmune diseases, and neurodegeneration including spinocerebellar ataxia type 1 (SCA1), a poorly understood neurodegenerative disease. S100β is a Ca2+ binding protein. In SCA1, excessive excretion of S100β by reactive astrocytes and its uptake by Purkinje cells has been demonstrated previously. Under pathological conditions, excessive extracellular concentration of S100β stimulates the production of proinflammatory cytokines and induces apoptosis. We modeled astrogliosis by S100β injections into cerebellar cortex in mice. Injections of S100β led to significant changes in Bergmann glia (BG) cortical organization and affected their processes. S100β also changed morphology of the Purkinje cells (PCs), causing a significant reduction in the dendritic length. Moreover, the short-term synaptic plasticity and depolarization-induced suppression of synaptic transmission were disrupted after S100β injections. We speculate that these effects are the result of Ca2+-chelating properties of S100β protein. In summary, exogenous S100β induced astrogliosis in cerebellum could lead to neuronal dysfunction, which resembles a natural neurodegenerative process. We suggest that astrocytes play an essential role in SCA1 pathology, and that astrocytic S100β is an important contributor to this process.
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Affiliation(s)
- Olga S Belozor
- Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky, Department of Biological Chemistry, Medical Pharmaceutical and Toxicological Chemistry, Partizan Zheleznyak st. 1, 660022 Krasnoyarsk, Russia.
| | - Dariya A Yakovleva
- Siberian Federal University, Svobodny pr., 79, 660041 Krasnoyarsk, Russia.
| | - Ilya V Potapenko
- Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky, Research Institute of Molecular Medicine and Pathobiochemistry, Partizan Zheleznyak st. 1, 660022 Krasnoyarsk, Russia.
| | - Andrey N Shuvaev
- Siberian Federal University, Svobodny pr., 79, 660041 Krasnoyarsk, Russia.
| | - Marina V Smolnikova
- Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky, Research Institute of Molecular Medicine and Pathobiochemistry, Partizan Zheleznyak st. 1, 660022 Krasnoyarsk, Russia.
- Federal Research Center "Krasnoyarsk Science Center" of the Siberian Branch of the Russian Academy of Sciences, Scientific Research Institute of Medical Problems of the North, Partizan Zheleznyak st., 3G, 660022 Krasnoyarsk, Russia.
| | - Alex Vasilev
- Institute of Living Systems, Immanuel Kant Baltic Federal University, Universitetskaya st., 2, 236041 Kaliningrad, Russia.
| | - Elena A Pozhilenkova
- Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky, Department of Biological Chemistry, Medical Pharmaceutical and Toxicological Chemistry, Partizan Zheleznyak st. 1, 660022 Krasnoyarsk, Russia.
- Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky, Research Institute of Molecular Medicine and Pathobiochemistry, Partizan Zheleznyak st. 1, 660022 Krasnoyarsk, Russia.
| | - Anton N Shuvaev
- Krasnoyarsk State Medical University named after Prof. V.F. Voino-Yasenetsky, Research Institute of Molecular Medicine and Pathobiochemistry, Partizan Zheleznyak st. 1, 660022 Krasnoyarsk, Russia.
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Kuzmina US, Zainullina LF, Vakhitov VA, Bakhtiyarova KZ, Vakhitova YV. The role of glutamate in the pathogenesis of multiple sclerosis. Zh Nevrol Psikhiatr Im S S Korsakova 2019; 119:160-167. [DOI: 10.17116/jnevro2019119081160] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Laquinimod ameliorates excitotoxic damage by regulating glutamate re-uptake. J Neuroinflammation 2018; 15:5. [PMID: 29304807 PMCID: PMC5756343 DOI: 10.1186/s12974-017-1048-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 12/21/2017] [Indexed: 11/10/2022] Open
Abstract
Background Laquinimod is an immunomodulatory drug under clinical investigation for the treatment of the progressive form of multiple sclerosis (MS) with both anti-inflammatory and neuroprotective effects. Excitotoxicity, a prominent pathophysiological feature of MS and of its animal model, experimental autoimmune encephalomyelitis (EAE), involves glutamate transporter (GluT) dysfunction in glial cells. The aim of this study was to assess whether laquinimod might exert direct neuroprotective effects by interfering with the mechanisms of excitotoxicity linked to GluT function impairments in EAE. Methods Osmotic minipumps allowing continuous intracerebroventricular (icv) infusion of laquinimod for 4 weeks were implanted into C57BL/6 mice before EAE induction. EAE cerebella were taken to perform western blot and qPCR experiments. For ex vivo experiments, EAE cerebellar slices were incubated with laquinimod before performing electrophysiology, western blot, and qPCR. Results In vivo treatment with laquinimod attenuated EAE clinical score at the peak of the disease, without remarkable effects on inflammatory markers. In vitro application of laquinimod to EAE cerebellar slices prevented EAE-linked glutamatergic alterations without mitigating astrogliosis and inflammation. Moreover, such treatment induced an increase of Slcla3 mRNA coding for the glial glutamate–aspartate transporter (GLAST) without affecting the protein content. Concomitantly, laquinimod significantly increased the levels of the glial glutamate transporter 1 (GLT-1) protein and pharmacological blockade of GLT-1 function fully abolished laquinimod anti-excitotoxic effect. Conclusions Overall, our results suggest that laquinimod protects against glutamate excitotoxicity of the cerebellum of EAE mice by bursting the expression of glial glutamate transporters, independently of its anti-inflammatory effects.
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miR-142-3p Is a Key Regulator of IL-1β-Dependent Synaptopathy in Neuroinflammation. J Neurosci 2017; 37:546-561. [PMID: 28100738 DOI: 10.1523/jneurosci.0851-16.2016] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 10/21/2016] [Accepted: 10/24/2016] [Indexed: 12/21/2022] Open
Abstract
MicroRNAs (miRNA) play an important role in post-transcriptional gene regulation of several physiological and pathological processes. In multiple sclerosis (MS), a chronic inflammatory and degenerative disease of the CNS, and in its mouse model, the experimental autoimmune encephalomyelitis (EAE), miRNA dysregulation has been mainly related to immune system dysfunction and white matter (WM) pathology. However, little is known about their role in gray matter pathology. Here, we explored miRNA involvement in the inflammation-driven alterations of synaptic structure and function, collectively known as synaptopathy, a neuropathological process contributing to excitotoxic neurodegeneration in MS/EAE. Particularly, we observed that miR-142-3p is increased in the CSF of patients with active MS and in EAE brains. We propose miR-142-3p as a molecular mediator of the IL-1β-dependent downregulation of the glial glutamate-aspartate transporter (GLAST), which causes an enhancement of the glutamatergic transmission in the EAE cerebellum. The synaptic abnormalities mediated by IL-1β and the clinical and neuropathological manifestations of EAE disappeared in miR-142 knock-out mice. Furthermore, we observed that in vivo miR-142-3p inhibition, either by a preventive and local treatment or by a therapeutic and systemic strategy, abolished IL-1β- and GLAST-dependent synaptopathy in EAE wild-type mice. Consistently, miR-142-3p was responsible for the glutamatergic synaptic alterations caused by CSF of patients with MS, and CSF levels of miR-142-3p correlated with prospective MS disease progression. Our findings highlight miR-142-3p as key molecular player in IL-1β-mediated synaptic dysfunction, possibly leading to excitotoxic damage in both EAE and MS diseases. Inhibition of miR-142-3p could be neuroprotective in MS. SIGNIFICANCE STATEMENT Current studies suggest the role of glutamate excitotoxicity in the development and progression of multiple sclerosis (MS) and of its mouse model experimental autoimmune encephalomyelitis (EAE). The molecular mechanisms linking inflammation and synaptic alterations in MS/EAE are still unknown. Here, we identified miR-142-3p as a determinant molecular actor in inflammation-dependent synaptopathy typical of both MS and EAE. miR-142-3p was upregulated in the CSF of MS patients and in EAE cerebellum. Inhibition of miR-142-3p, locally in EAE brain and in a MS chimeric ex vivo model, recovered glutamatergic synaptic enhancement typical of EAE/MS. We proved that miR-142-3p promoted the IL-1β-dependent glutamate dysfunction by targeting glutamate-aspartate transporter (GLAST), a crucial glial transporter involved in glutamate homeostasis. Finally, we suggest miR-142-3p as a negative prognostic factor in patients with relapsing-remitting multiple sclerosis.
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Rajda C, Pukoli D, Bende Z, Majláth Z, Vécsei L. Excitotoxins, Mitochondrial and Redox Disturbances in Multiple Sclerosis. Int J Mol Sci 2017; 18:ijms18020353. [PMID: 28208701 PMCID: PMC5343888 DOI: 10.3390/ijms18020353] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/20/2017] [Accepted: 01/22/2017] [Indexed: 01/03/2023] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). There is increasing evidence that MS is not only characterized by immune mediated inflammatory reactions, but also by neurodegenerative processes. There is cumulating evidence that neurodegenerative processes, for example mitochondrial dysfunction, oxidative stress, and glutamate (Glu) excitotoxicity, seem to play an important role in the pathogenesis of MS. The alteration of mitochondrial homeostasis leads to the formation of excitotoxins and redox disturbances. Mitochondrial dysfunction (energy disposal failure, apoptosis, etc.), redox disturbances (oxidative stress and enhanced reactive oxygen and nitrogen species production), and excitotoxicity (Glu mediated toxicity) may play an important role in the progression of the disease, causing axonal and neuronal damage. This review focuses on the mechanisms of mitochondrial dysfunction (including mitochondrial DNA (mtDNA) defects and mitochondrial structural/functional changes), oxidative stress (including reactive oxygen and nitric species), and excitotoxicity that are involved in MS and also discusses the potential targets and tools for therapeutic approaches in the future.
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Affiliation(s)
- Cecilia Rajda
- Department of Neurology, University of Szeged, 6725 Szeged, Hungary.
| | - Dániel Pukoli
- Department of Neurology, University of Szeged, 6725 Szeged, Hungary.
- Department of Neurology, Vaszary Kolos Hospital, 2500 Esztergom, Hungary.
| | - Zsuzsanna Bende
- Department of Neurology, University of Szeged, 6725 Szeged, Hungary.
| | - Zsófia Majláth
- Department of Neurology, University of Szeged, 6725 Szeged, Hungary.
| | - László Vécsei
- Department of Neurology, University of Szeged, 6725 Szeged, Hungary.
- MTA-SZTE Neuroscience Research Group, 6725 Szeged, Hungary.
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Merckx E, Albertini G, Paterka M, Jensen C, Albrecht P, Dietrich M, Van Liefferinge J, Bentea E, Verbruggen L, Demuyser T, Deneyer L, Lewerenz J, van Loo G, De Keyser J, Sato H, Maher P, Methner A, Massie A. Absence of system x c- on immune cells invading the central nervous system alleviates experimental autoimmune encephalitis. J Neuroinflammation 2017; 14:9. [PMID: 28086920 PMCID: PMC5237180 DOI: 10.1186/s12974-016-0787-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 12/28/2016] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Multiple sclerosis (MS) is an autoimmune demyelinating disease that affects the central nervous system (CNS), leading to neurodegeneration and chronic disability. Accumulating evidence points to a key role for neuroinflammation, oxidative stress, and excitotoxicity in this degenerative process. System xc- or the cystine/glutamate antiporter could tie these pathological mechanisms together: its activity is enhanced by reactive oxygen species and inflammatory stimuli, and its enhancement might lead to the release of toxic amounts of glutamate, thereby triggering excitotoxicity and neurodegeneration. METHODS Semi-quantitative Western blotting served to study protein expression of xCT, the specific subunit of system xc-, as well as of regulators of xCT transcription, in the normal appearing white matter (NAWM) of MS patients and in the CNS and spleen of mice exposed to experimental autoimmune encephalomyelitis (EAE), an accepted mouse model of MS. We next compared the clinical course of the EAE disease, the extent of demyelination, the infiltration of immune cells and microglial activation in xCT-knockout (xCT-/-) mice and irradiated mice reconstituted in xCT-/- bone marrow (BM), to their proper wild type (xCT+/+) controls. RESULTS xCT protein expression levels were upregulated in the NAWM of MS patients and in the brain, spinal cord, and spleen of EAE mice. The pathways involved in this upregulation in NAWM of MS patients remain unresolved. Compared to xCT+/+ mice, xCT-/- mice were equally susceptible to EAE, whereas mice transplanted with xCT-/- BM, and as such only exhibiting loss of xCT in their immune cells, were less susceptible to EAE. In none of the above-described conditions, demyelination, microglial activation, or infiltration of immune cells were affected. CONCLUSIONS Our findings demonstrate enhancement of xCT protein expression in MS pathology and suggest that system xc- on immune cells invading the CNS participates to EAE. Since a total loss of system xc- had no net beneficial effects, these results have important implications for targeting system xc- for treatment of MS.
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Affiliation(s)
- Ellen Merckx
- Center for Neurosciences (C4N), Department of Pharmaceutical Biotechnology and Molecular Biology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Giulia Albertini
- Center for Neurosciences (C4N), Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Brussels, Belgium
| | - Magdalena Paterka
- Department of Neurology, University Medical Center of the Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Cathy Jensen
- Center for Neurosciences (C4N), Department of Pharmaceutical Biotechnology and Molecular Biology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Philipp Albrecht
- Department of Neurology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Michael Dietrich
- Department of Neurology, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Joeri Van Liefferinge
- Center for Neurosciences (C4N), Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Brussels, Belgium
| | - Eduard Bentea
- Center for Neurosciences (C4N), Department of Pharmaceutical Biotechnology and Molecular Biology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Lise Verbruggen
- Center for Neurosciences (C4N), Department of Pharmaceutical Biotechnology and Molecular Biology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Thomas Demuyser
- Center for Neurosciences (C4N), Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Brussels, Belgium
| | - Lauren Deneyer
- Center for Neurosciences (C4N), Department of Pharmaceutical Biotechnology and Molecular Biology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium
| | - Jan Lewerenz
- Department of Neurology, University of Ulm, Ulm, Germany
| | - Geert van Loo
- Inflammation Research Center, VIB and Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jacques De Keyser
- Center for Neurosciences (C4N), Department of Neurology, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Hideyo Sato
- Department of Medical Technology, Faculty of Medicine, Niigata University, Niigata, Japan
| | - Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Axel Methner
- Department of Neurology, University Medical Center of the Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Ann Massie
- Center for Neurosciences (C4N), Department of Pharmaceutical Biotechnology and Molecular Biology, Vrije Universiteit Brussel, Laarbeeklaan 103, 1090, Brussels, Belgium.
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Kostic M, Zivkovic N, Cvetanovic A, Stojanovic I, Colic M. IL-17 signalling in astrocytes promotes glutamate excitotoxicity: Indications for the link between inflammatory and neurodegenerative events in multiple sclerosis. Mult Scler Relat Disord 2016; 11:12-17. [PMID: 28104249 DOI: 10.1016/j.msard.2016.11.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/24/2016] [Accepted: 11/13/2016] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Th-17 cells have been exclusively referred to inflammatory events in multiple sclerosis (MS), while their importance in the development of glutamate excitotoxicity and the consequent neurodegeneration has been a completely unexplored concept. Accordingly, the objective of our study was to assess IL-17A effect on astrocyte ability to metabolize and release glutamate, considering that astrocytes had the central role in glutamate homeostasis. METHODS By using primary rat astrocyte cultures, astrocyte ability to uptake glutamate was estimated by the alterations of glutamate transporters (GLAST and GLT-1) expression, whereas changes in glutamine synthetase expression were used to estimate the ability to metabolize glutamate. Gene expression was determined by real time polymerase chain reaction (rtPCR). IL-17A effect on astrocyte ability to produce glutamate was investigated directly, by measuring the level of released glutamate using high performance liquid chromatography (HPLC). RESULTS Lower concentrations of IL-17A reduced the expressions of both glutamate transporters and glutamine synthetase; however, this effect was lost when IL-17A was applied in a higher dose. IL-17A did not significantly modify glutamate release from astrocyte in basal conditions, but following Ca2+ stimulation, as well as Ca2+ removal from the culture medium, IL-17A stimulated glutamate release in dose-dependent manner. CONCLUSION Together, these results support that IL-17A could promote glutamate excitotoxicity by decreasing astrocyte ability to uptake and convert glutamate to non-toxic glutamine, but also by stimulating Ca2+ dependent glutamate release. Such interactions between IL-17A and glutamate excitotoxicity implicate the potential link between inflammation and neurodegeneration during MS pathogenesis, and identify astrocytes as a potential target in achieving neuroprotective effects in MS.
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Affiliation(s)
- Milos Kostic
- Department of Immunology, Medical Faculty, University of Nis, Blvd. dr Zorana Djindjica 81, 18000 Nis, Serbia.
| | - Nikola Zivkovic
- Department of Pathology, Medical Faculty, University of Nis, Blvd. dr Zorana Djindjica 81, 18000 Nis, Serbia
| | - Ana Cvetanovic
- Clinic of Oncology, Clinical Center Nis, Blvd. dr Zorana Djindjica 48, 18000 Nis, Serbia
| | - Ivana Stojanovic
- Department of Biochemistry, Medical Faculty, University of Nis, Blvd. dr Zorana Djindjica 81, 18000 Nis, Serbia
| | - Miodrag Colic
- Department of Immunology, Medical Faculty, University of Nis, Blvd. dr Zorana Djindjica 81, 18000 Nis, Serbia
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Grygorowicz T, Wełniak-Kamińska M, Strużyńska L. Early P2X7R-related astrogliosis in autoimmune encephalomyelitis. Mol Cell Neurosci 2016; 74:1-9. [PMID: 26921791 DOI: 10.1016/j.mcn.2016.02.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 01/22/2016] [Accepted: 02/22/2016] [Indexed: 01/16/2023] Open
Abstract
Astrocytes are the main cells responsible for maintenance of brain homeostasis. Undisturbed action and signaling with other cells are crucial for proper functioning of the central nervous system (CNS). Dysfunctional astrocytes may determine the degree of neuronal injury and are associated with several brain pathologies, among which are multiple sclerosis (MS) and the animal model of this disease which is known as experimental autoimmune encephalomyelitis (EAE). One of the many functions of astrocytes is their response to CNS damage when they undergo reactive gliosis. Our data reveal that activation of astrocytes occurs in forebrains of immunized rats at a very early stage of EAE, well before the symptomatic phase of the disease. We have noted enhanced expression of GFAP and S100β starting from day 4 post-immunization. Temporal coincidence between the expression of astrocyte activation markers and the expression of connexin 43 and purinergic P2X7 receptor (P2X7R) was also observed. Administration of Brilliant blue G, an antagonist of P2X7R, significantly decreases astrogliosis as confirmed by immunohistochemical analysis and observation of decreased levels of GFAP and S100β. The condition of the treated animals was improved and the neurological symptoms of the disease were alleviated. With the knowledge that cerebral astroglia represent the main source of ATP and glutamate which are potentially neurotoxic substances released through P2X7R and connexin hemichannels, we suggest that astroglia may be involved in pathogenesis of MS/EAE at a very early stage through the purinergic/glutamatergic mechanisms.
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Affiliation(s)
- Tomasz Grygorowicz
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego St., 02-106 Warsaw, Poland
| | - Marlena Wełniak-Kamińska
- Department of Experimental Pharmacology, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego St., 02-106 Warsaw, Poland
| | - Lidia Strużyńska
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, 5 Pawińskiego St., 02-106 Warsaw, Poland.
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Mandolesi G, Gentile A, Musella A, Fresegna D, De Vito F, Bullitta S, Sepman H, Marfia GA, Centonze D. Synaptopathy connects inflammation and neurodegeneration in multiple sclerosis. Nat Rev Neurol 2015; 11:711-24. [PMID: 26585978 DOI: 10.1038/nrneurol.2015.222] [Citation(s) in RCA: 181] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Multiple sclerosis (MS) has long been regarded as a chronic inflammatory disease of the white matter that leads to demyelination and eventually to neurodegeneration. In the past decade, several aspects of MS pathogenesis have been challenged, and degenerative changes of the grey matter, which are independent of demyelination, have become a topic of interest. CNS inflammation in MS and experimental autoimmune encephalomyelitis (EAE; a disease model used to study MS in rodents) causes a marked imbalance between GABAergic and glutamatergic transmission, and a loss of synapses, all of which leads to a diffuse 'synaptopathy'. Altered synaptic transmission can occur early in MS and EAE, independently of demyelination and axonal loss, and subsequently causes excitotoxic damage. Inflammation-driven synaptic abnormalities are emerging as a prominent pathogenic mechanism in MS-importantly, they are potentially reversible and, therefore, represent attractive therapeutic targets. In this Review, we focus on the connection between inflammation and synaptopathy in MS and EAE, which sheds light not only on the pathophysiology of MS but also on that of primary neurodegenerative disorders in which inflammatory processes contribute to disease progression.
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Affiliation(s)
- Georgia Mandolesi
- IRCCS Fondazione Santa Lucia/Centro Europeo per la Ricerca sul Cervello (CERC), Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Antonietta Gentile
- Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Alessandra Musella
- IRCCS Fondazione Santa Lucia/Centro Europeo per la Ricerca sul Cervello (CERC), Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Diego Fresegna
- IRCCS Fondazione Santa Lucia/Centro Europeo per la Ricerca sul Cervello (CERC), Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Francesca De Vito
- Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Silvia Bullitta
- IRCCS Fondazione Santa Lucia/Centro Europeo per la Ricerca sul Cervello (CERC), Via del Fosso di Fiorano 64, 00143 Rome, Italy
| | - Helena Sepman
- IRCCS Fondazione Santa Lucia/Centro Europeo per la Ricerca sul Cervello (CERC), Via del Fosso di Fiorano 64, 00143 Rome, Italy.,Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Girolama A Marfia
- Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Diego Centonze
- IRCCS Istituto Neurologico Mediterraneo (INM) Neuromed, Via Atinense 18, 86077 Pozzilli, Italy
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Feng D, Guo B, Liu G, Wang B, Wang W, Gao G, Qin H, Wu S. FGF2 alleviates PTSD symptoms in rats by restoring GLAST function in astrocytes via the JAK/STAT pathway. Eur Neuropsychopharmacol 2015; 25:1287-99. [PMID: 25979764 DOI: 10.1016/j.euroneuro.2015.04.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 04/06/2015] [Accepted: 04/24/2015] [Indexed: 12/18/2022]
Abstract
In our previous study, we demonstrated that fibroblast growth factor 2 (FGF2) administration alleviated posttraumatic stress disorder (PTSD) symptoms via an "astrocyte-related" mechanism. We further investigated the changes in the astrocytic glutamate transporters GLAST and GLT-1 and in JAK/STAT3 signaling (which is involved in astrocyte activation and GLAST/GLT-1 function) in single prolonged stress (SPS) model rats. High-performance liquid chromatography (HPLC), Western blot and immunohistochemistry analyses revealed a significant SPS-induced increase in the concentration of glutamate in the cerebrospinal fluid and decrease in GLAST/GLT-1 expression and JAK/STAT3 signaling. Treatment with FGF2 significantly alleviated GLAST/GLT-1 dysfunction, JAK/STAT3 signaling inhibition, and the behavioral abnormalities. The administration of the JAK/STAT pathway inhibitor AG490 blocked the effects of FGF2 on PTSD symptoms, astrocyte activation, and GLAST, but not GLT-1, expression in vivo and in vitro. Our findings suggest that astrocytic JAK/STAT signaling is associated with SPS-induced GLAST dysfunction and that FGF2 protects against PTSD symptoms by restoring astrocytic glutamate uptake via the JAK/STAT signaling pathway.
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Affiliation(s)
- Dayun Feng
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an 710032, PR China; Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Baolin Guo
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an 710032, PR China
| | - Gaohua Liu
- Department of Psychosomatics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Bao Wang
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Wen Wang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an 710032, PR China
| | - Guodong Gao
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an 710032, PR China
| | - Huaizhou Qin
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an 710032, PR China.
| | - Shengxi Wu
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an 710032, PR China.
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Adenosine Monophosphate-activated Protein Kinase Regulates Interleukin-1β Expression and Glial Glutamate Transporter Function in Rodents with Neuropathic Pain. Anesthesiology 2015; 122:1401-13. [PMID: 25710409 DOI: 10.1097/aln.0000000000000619] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Neuroinflammation and dysfunctional glial glutamate transporters (GTs) in the spinal dorsal horn are implicated in the genesis of neuropathic pain. The authors determined whether adenosine monophosphate-activated protein kinase (AMPK) in the spinal dorsal horn regulates these processes in rodents with neuropathic pain. METHODS Hind paw withdrawal responses to radiant heat and mechanical stimuli were used to assess nociceptive behaviors. Spinal markers related to neuroinflammation and glial GTs were determined by Western blotting. AMPK activities were manipulated pharmacologically and genetically. Regulation of glial GTs was determined by measuring protein expression and activities of glial GTs. RESULTS AMPK activities were reduced in the spinal dorsal horn of rats (n = 5) with thermal hyperalgesia induced by nerve injury, which were accompanied with the activation of astrocytes, increased production of interleukin-1β and activities of glycogen synthase kinase 3β, and suppressed protein expression of glial glutamate transporter-1. Thermal hyperalgesia was reversed by spinal activation of AMPK in neuropathic rats (n = 10) and induced by inhibiting spinal AMPK in naive rats (n = 7 to 8). Spinal AMPKα knockdown (n = 6) and AMPKα1 conditional knockout (n = 6) induced thermal hyperalgesia and mechanical allodynia. These genetic alterations mimicked the changes of molecular markers induced by nerve injury. Pharmacological activation of AMPK enhanced glial GT activity in mice with neuropathic pain (n = 8) and attenuated glial glutamate transporter-1 internalization induced by interleukin-1β (n = 4). CONCLUSIONS These findings suggest that enhancing spinal AMPK activities could be an effective approach for the treatment of neuropathic pain.
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Modulation of glutamate transport and receptor binding by glutamate receptor antagonists in EAE rat brain. PLoS One 2014; 9:e113954. [PMID: 25426719 PMCID: PMC4245246 DOI: 10.1371/journal.pone.0113954] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 11/01/2014] [Indexed: 12/02/2022] Open
Abstract
The etiology of multiple sclerosis (MS) is currently unknown. However, one potential mechanism involved in the disease may be excitotoxicity. The elevation of glutamate in cerebrospinal fluid, as well as changes in the expression of glutamate receptors (iGluRs and mGluRs) and excitatory amino acid transporters (EAATs), have been observed in the brains of MS patients and animals subjected to experimental autoimmune encephalomyelitis (EAE), which is the predominant animal model used to investigate the pathophysiology of MS. In the present paper, the effects of glutamatergic receptor antagonists, including amantadine, memantine, LY 367583, and MPEP, on glutamate transport, the expression of mRNA of glutamate transporters (EAATs), the kinetic parameters of ligand binding to N-methyl-D-aspartate (NMDA) receptors, and the morphology of nerve endings in EAE rat brains were investigated. The extracellular level of glutamate in the brain is primarily regulated by astrocytic glutamate transporter 1 (GLT-1) and glutamate-aspartate transporter (GLAST). Excess glutamate is taken up from the synaptic space and metabolized by astrocytes. Thus, the extracellular level of glutamate decreases, which protects neurons from excitotoxicity. Our investigations showed changes in the expression of EAAT mRNA, glutamate transport (uptake and release) by synaptosomal and glial plasmalemmal vesicle fractions, and ligand binding to NMDA receptors; these effects were partially reversed after the treatment of EAE rats with the NMDA antagonists amantadine and memantine. The antagonists of group I metabotropic glutamate receptors (mGluRs), including LY 367385 and MPEP, did not exert any effect on the examined parameters. These results suggest that disturbances in these mechanisms may play a role in the processes associated with glutamate excitotoxicity and the progressive brain damage in EAE.
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Kan QC, Zhang S, Xu YM, Zhang GX, Zhu L. Matrine regulates glutamate-related excitotoxic factors in experimental autoimmune encephalomyelitis. Neurosci Lett 2014; 560:92-7. [PMID: 24368216 DOI: 10.1016/j.neulet.2013.12.031] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 12/12/2013] [Accepted: 12/14/2013] [Indexed: 01/20/2023]
Abstract
It is increasingly accepted that glutamate excitotoxicity contributes to the death of nerve cells in multiple sclerosis (MS). Matrine (MAT) is a quinolizidine alkaloid that has long been used in the treatment of hepatitis B without obvious side effects. Previous reports have shown that MAT suppresses central nervous system inflammation and demyelination in experimental autoimmune encephalomyelitis (EAE), an animal model of MS; however whether MAT effectively inhibits excitotoxic molecules, such as glutamate-related factors, is still unclear. In this study, we provide data showing that MAT attenuated EAE disease severity, accompanied by downregulated glutamate and upregulated GABA levels, as well as enhanced expression of two dependent glutamate transporters (GLT-1 and GLAST). In addition, MAT treatment significantly reduced the level of the NMDA- and AMPA-glutamate receptor in EAE rats. Taken together, our data indicate that MAT treatment regulates glutamate-related molecules, and suggests that the neuroprotective role of MAT is a novel mechanism underlying its therapeutic effect in EAE.
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MESH Headings
- Alkaloids/pharmacology
- Alkaloids/therapeutic use
- Animals
- Cerebral Cortex/metabolism
- Encephalomyelitis, Autoimmune, Experimental/drug therapy
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Excitatory Amino Acid Transporter 1/genetics
- Excitatory Amino Acid Transporter 1/metabolism
- Excitatory Amino Acid Transporter 2/genetics
- Excitatory Amino Acid Transporter 2/metabolism
- Female
- Glutamic Acid/metabolism
- Quinolizines/pharmacology
- Quinolizines/therapeutic use
- RNA, Messenger/metabolism
- Rats, Wistar
- Receptors, AMPA/metabolism
- Receptors, N-Methyl-D-Aspartate/metabolism
- Spinal Cord/immunology
- gamma-Aminobutyric Acid/metabolism
- Matrines
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Affiliation(s)
- Quan-Cheng Kan
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Su Zhang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Yu-Ming Xu
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China
| | - Guang-Xian Zhang
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| | - Lin Zhu
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan, China.
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Interleukin-1β alters glutamate transmission at purkinje cell synapses in a mouse model of multiple sclerosis. J Neurosci 2013; 33:12105-21. [PMID: 23864696 DOI: 10.1523/jneurosci.5369-12.2013] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Cerebellar deficit contributes significantly to disability in multiple sclerosis (MS). Several clinical and experimental studies have investigated the pathophysiology of cerebellar dysfunction in this neuroinflammatory disorder, but the cellular and molecular mechanisms are still unclear. In experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, proinflammatory cytokines, together with a degeneration of inhibitory neurons, contribute to impair GABAergic transmission at Purkinje cells (PCs). Here, we investigated glutamatergic transmission to gain insight into the pathophysiology of cerebellar dysfunction in EAE. Electrophysiological recordings from PCs showed increased duration of spontaneous excitatory postsynaptic currents (EPSCs) during the symptomatic phase of EAE, suggesting an alteration of glutamate uptake played by Bergmann glia. We indeed observed an impaired functioning of the glutamate-aspartate transporter/excitatory amino acid transporter 1 (GLAST/EAAT1) in EAE cerebellum caused by protein downregulation and in correlation with prominent astroglia activation. We have also demonstrated that the proinflammatory cytokine interleukin-1β (IL-1β), released by a subset of activated microglia/macrophages and infiltrating lymphocytes, was involved directly in such synaptic alteration. In fact, brief incubation of IL-1β in normal cerebellar slices replicated EAE modifications through a rapid GLAST/EAAT1 downregulation, whereas incubation of an IL-1 receptor antagonist (IL-1ra) in EAE slices reduced spontaneous EPSC alterations. Finally, EAE mice treated with intracerebroventricular IL-1ra showed normal glutamatergic and GABAergic transmissions, along with GLAST/EAAT1 normalization, milder inflammation, and reduced motor deficits. These results highlight the crucial role played by the proinflammatory IL-1β in triggering molecular and synaptic events involved in neurodegenerative processes that characterize neuroinflammatory diseases such as MS.
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Rossi S, Motta C, Studer V, Barbieri F, Buttari F, Bergami A, Sancesario G, Bernardini S, De Angelis G, Martino G, Furlan R, Centonze D. Tumor necrosis factor is elevated in progressive multiple sclerosis and causes excitotoxic neurodegeneration. Mult Scler 2013; 20:304-12. [PMID: 23886826 DOI: 10.1177/1352458513498128] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Chronic inflammation leads to gray matter damage in progressive multiple sclerosis (MS), but the mechanism linking inflammation and neurodegeneration is unclear. OBJECTIVE The objective of this paper is to investigate the synaptic mechanism of inflammatory neurodegeneration in progressive forms of MS. METHODS Cytokine and neurofilament-light were determined in cerebrospinal fluid (CSF) of MS patients. In vitro electrophysiology and cell swelling experiments were performed to measure the effects of inflammatory cytokines in the CSF of MS patients on synaptic transmission and neuronal integrity. RESULTS Tumor necrosis factor-α (TNF) was higher in CSF of progressive MS subjects, and caused excitotoxic neuronal death in vitro. In murine brain slices incubated in the presence of CSF from progressive MS, in fact, we observed increased spontaneous excitatory postsynaptic currents (sEPSCs) and glutamate-mediated neuronal swelling through a mechanism dependent on enhanced TNF signaling. We also suggested a pathogenic role of B cells in TNF CSF increase, exacerbation of glutamatergic transmission and neuronal damage, since CNS depletion of B cells with intrathecal rituximab caused a dramatic reduction of TNF levels, of TNF-induced sEPSC alterations, and of neurofilament CSF concentrations in a patient with progressive MS. CONCLUSION Our results point to TNF as a primary neurotoxic molecule in progressive forms of MS.
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Affiliation(s)
- Silvia Rossi
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Italy
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Modulation of neurological deficits and expression of glutamate receptors during experimental autoimmune encephalomyelitis after treatment with selected antagonists of glutamate receptors. BIOMED RESEARCH INTERNATIONAL 2013; 2013:186068. [PMID: 23936777 PMCID: PMC3722774 DOI: 10.1155/2013/186068] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 06/02/2013] [Indexed: 12/02/2022]
Abstract
The aim of our investigation was to characterize the role of group I mGluRs and NMDA receptors in pathomechanisms of experimental autoimmune encephalomyelitis (EAE), the rodent model of MS. We tested the effects of LY 367385 (S-2-methyl-4-carboxyphenylglycine, a competitive antagonist of mGluR1), MPEP (2-methyl-6-(phenylethynyl)-pyridine, an antagonist of mGluR5), and the uncompetitive NMDA receptor antagonists amantadine and memantine on modulation of neurological deficits observed in rats with EAE. The neurological symptoms of EAE started at 10-11 days post-injection (d.p.i.) and peaked after 12-13 d.p.i. The protein levels of mGluRs and NMDA did not increase in early phases of EAE (4 d.p.i.), but starting from 8 d.p.i. to 25 d.p.i., we observed a significant elevation of mGluR1 and mGluR5 protein expression by about 20% and NMDA protein expression by about 10% over the control at 25 d.p.i. The changes in protein levels were accompanied by changes in mRNA expression of group I mGluRs and NMDARs. During the late disease phase (20–25 d.p.i.), the mRNA expression levels reached 300% of control values. In contrast, treatment with individual receptor antagonists resulted in a reduction of mRNA levels relative to untreated animals.
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Sulkowski G, Dąbrowska-Bouta B, Chalimoniuk M, Strużyńska L. Effects of antagonists of glutamate receptors on pro-inflammatory cytokines in the brain cortex of rats subjected to experimental autoimmune encephalomyelitis. J Neuroimmunol 2013; 261:67-76. [PMID: 23746391 DOI: 10.1016/j.jneuroim.2013.05.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 04/18/2013] [Accepted: 05/10/2013] [Indexed: 10/26/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Inflammatory cytokines and glutamate neurotoxicity have been proposed as major determinants accompanying the demyelination and axonal degeneration observed during the course of MS. The present study using the animal model of MS known as experimental autoimmune encephalomyelitis (EAE) demonstrates that pharmacological inhibition of ionotropic NMDA glutamate receptors by their antagonists (amantadine and memantine) suppresses neurological symptoms of disease in EAE rats and reduces expression of pro-inflammatory cytokines in the brain. Conversely, antagonists of group I metabotropic glutamate receptors, mGluRs (LY 367385 and MPEP), do not affect the inflammatory process and the neurological condition of EAE rats.
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Affiliation(s)
- Grzegorz Sulkowski
- Laboratory of Pathoneurochemistry, Department of Neurochemistry, Mossakowski Medical Research Centre Polish Academy of Sciences, 5 Pawińskiego str., 02-106 Warsaw, Poland.
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Olechowski CJ, Tenorio G, Sauve Y, Kerr BJ. Changes in nociceptive sensitivity and object recognition in experimental autoimmune encephalomyelitis (EAE). Exp Neurol 2013; 241:113-21. [PMID: 23291347 DOI: 10.1016/j.expneurol.2012.12.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 11/28/2012] [Accepted: 12/18/2012] [Indexed: 11/25/2022]
Abstract
Multiple sclerosis is associated with a high incidence of depression, cognitive impairments and neuropathic pain. Previously, we demonstrated that tactile allodynia is present at disease onset in an animal model of MS, experimental autoimmune encephalomyelitis (EAE). We have now monitored changes in object recognition in mice with EAE to determine if altered nociceptive sensitivity is also associated with behavioral signs indicative of cognitive impairment in this model. At the onset of clinical signs, mice with EAE showed impairments in the novel object recognition (NOR) assay, indicative of deficits in cognitive functioning early in the disease course. At the spinal level, we found increased gene expression for the cytokines IL-1β, IL-6 and the glutamate transporter EAAT-2 that coincide with increased nociceptive sensitivity and deficits in object recognition. Increased levels of EAAT-2 mRNA appear to be a response to perturbed protein levels of the transporter as we found a loss of EAAT-2 protein levels in the spinal cord of EAE mice. To determine if changes in the levels of EAAT-2 were responsible for the observed changes in nociceptive sensitivity and cognitive deficits, we treated EAE mice with the β-lactam antibiotic ceftriaxone, an agent known to increase glutamate transporter levels in vivo. Ceftriaxone prevented tactile hypersensitivity and normalized performance in the NOR assay in EAE mice. These findings highlight the important interrelationship between pain and cognitive function in the disease and suggest that targeting spinally mediated pain hypersensitivity is a novel therapeutic avenue to treat impairments in other higher order cortical processes.
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Fang J, Han D, Hong J, Tan Q, Tian Y. The chemokine, macrophage inflammatory protein-2γ, reduces the expression of glutamate transporter-1 on astrocytes and increases neuronal sensitivity to glutamate excitotoxicity. J Neuroinflammation 2012; 9:267. [PMID: 23234294 PMCID: PMC3545864 DOI: 10.1186/1742-2094-9-267] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 11/26/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Changes in glutamatergic neurotransmission via decreased glutamate transporter (GLT) activity or expression contributes to multiple neurological disorders. Chemokines and their receptors are involved in neurological diseases but the role of chemokines in the expression of glutamate transporters is unclear. METHODS Primary astrocytes were prepared from neonatal (<24 hours old) SJL/J mouse brains and incubated with 5 μg/ml lipopolysaccharide (LPS) or 50 ng/ml tumor necrosis factor α (TNF-α) for 24 hours. Soluble macrophage inflammatory protein-2γ (MIP-2γ) in culture supernatants was determined using a sandwich ELISA. The MIP-2γ effect on the expression of GLT-1 was measured by quantitative RT-PCR, flow cytometric analysis or western blot assay. Detergent-resistant membranes from astrocytes were isolated on the basis of their ability to float in density gradients. Raft-containing fractions were tracked by the enrichment of caveolin-1 and the dendritic lipid raft marker, flotillin-1. Cell viability was determined by measuring either the leakage of lactate dehydrogenase or the reduction of 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide by viable cells and confirmed by visual inspection. RESULTS The production of the chemokine MIP-2γ by mouse cortical astrocytes increased significantly after stimulation with LPS or TNF-α in vitro. Astrocytes over-expressing MIP-2γ down-regulated the expression of GLT-1 at the mRNA and protein level and caused redistribution of GLT-1 out of the lipid rafts that mediate glutamate uptake. We used pharmacological inhibitors to identify the downstream signaling pathways underlying MIP-2γ activity. We also found complementary results by knocking down MIP-2γ activity in astrocytes with MIP-2γ small interfering RNA (siRNA). MIP-2γ overexpression in astrocytes enhanced the neuronal toxicity of glutamate by decreasing GLT-1 activity, but MIP-2γ itself was not toxic to neurons. CONCLUSIONS These results suggest that MIP-2γ mediates the pathogenesis of central nervous system disorders associated with neutrophil infiltration in the brain and decreased GLT-1 activity.
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Affiliation(s)
- Jie Fang
- First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian, 350005, China
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Lin CLG, Kong Q, Cuny GD, Glicksman MA. Glutamate transporter EAAT2: a new target for the treatment of neurodegenerative diseases. Future Med Chem 2012; 4:1689-700. [PMID: 22924507 PMCID: PMC3580837 DOI: 10.4155/fmc.12.122] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Glutamate is the primary excitatory amino acid neurotransmitter in the CNS. The concentration of glutamate in the synaptic cleft is tightly controlled by interplay between glutamate release and glutamate clearance. Abnormal glutamate release and/or dysfunction of glutamate clearance can cause overstimulation of glutamate receptors and result in neuronal injury known as excitotoxicity. The glial glutamate transporter EAAT2 plays a major role in glutamate clearance. Dysfunction or reduced expression of EAAT2 has been documented in many neurodegenerative diseases. In addition, many studies in animal models of disease indicate that increased EAAT2 expression provides neuronal protection. Here, we summarize these studies and suggest that EAAT2 is a potential target for the prevention of excitotoxicity. EAAT2 can be upregulated by transcriptional or translational activation. We discuss current progress in the search for EAAT2 activators, which is a promising direction for the treatment of neurodegenerative diseases.
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Mandolesi G, Grasselli G, Musella A, Gentile A, Musumeci G, Sepman H, Haji N, Fresegna D, Bernardi G, Centonze D. GABAergic signaling and connectivity on Purkinje cells are impaired in experimental autoimmune encephalomyelitis. Neurobiol Dis 2012; 46:414-24. [PMID: 22349452 DOI: 10.1016/j.nbd.2012.02.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Revised: 01/30/2012] [Accepted: 02/04/2012] [Indexed: 12/25/2022] Open
Abstract
A significant proportion of multiple sclerosis (MS) patients have functionally relevant cerebellar deficits, which significantly contribute to disability. Although clinical and experimental studies have been conducted to understand the pathophysiology of cerebellar dysfunction in MS, no electrophysiological and morphological studies have investigated potential alterations of synaptic connections of cerebellar Purkinje cells (PC). For this reason we analyzed cerebellar PC GABAergic connectivity in mice with MOG((35-55))-induced experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. We observed a strong reduction in the frequency of the spontaneous inhibitory post-synaptic currents (IPSCs) recorded from PCs during the symptomatic phase of the disease, and in presence of prominent microglia activation not only in the white matter (WM) but also in the molecular layer (ML). The massive GABAergic innervation on PCs from basket and stellate cells was reduced and associated to a decrease of the number of these inhibitory interneurons. On the contrary no significant loss of the PCs could be detected. Incubation of interleukin-1beta (IL-1β) was sufficient to mimic the electrophysiological alterations observed in EAE mice. We thus suggest that microglia and pro-inflammatory cytokines, together with a degeneration of basket and stellate cells and their synaptic terminals, contribute to impair GABAergic transmission on PCs during EAE. Our results support a growing body of evidence that GABAergic signaling is compromised in EAE and in MS, and show a selective susceptibility to neuronal and synaptic degeneration of cerebellar inhibitory interneurons.
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Affiliation(s)
- Georgia Mandolesi
- Fondazione Santa Lucia/Centro Europeo per la Ricerca sul Cervello, 00143 Rome, Italy
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de Lago E, Moreno-Martet M, Cabranes A, Ramos JA, Fernández-Ruiz J. Cannabinoids ameliorate disease progression in a model of multiple sclerosis in mice, acting preferentially through CB1 receptor-mediated anti-inflammatory effects. Neuropharmacology 2012; 62:2299-308. [PMID: 22342378 DOI: 10.1016/j.neuropharm.2012.01.030] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Revised: 01/26/2012] [Accepted: 01/30/2012] [Indexed: 11/18/2022]
Abstract
Multiple sclerosis (MS) is an autoimmune disease that affects the CNS and it is characterized by inflammation, demyelination, remyelination, gliosis and axonal damage that occur mainly in the spinal cord. Cannabinoids have been proposed as promising therapeutic agents in MS given their capability to alleviate specific MS symptoms (e.g., spasticity, pain). Although MS has been considered mainly an inflammatory disorder, recent evidence, however, revealed the importance of neurodegenerative events, opening the possibility that cannabinoid agonists, given their cytoprotective properties, may also serve to reduce oligodendrocyte death and axonal damage in MS. Thus, the treatment with WIN55,512-2, a potent CB(1) and CB(2) agonist, was reported to be effective to ameliorate tremor and spasticity in mice with chronic relapsing experimental autoimmune encephalomyelitis, a murine model of MS, but also to delay disease progression in this and other murine models of MS. The purpose of this investigation was to further explore the mechanism(s) underlying the amelioration in disease progression caused by WIN55,212-2. We have particularly focused on anti-glutamatergic and anti-inflammatory effects of this cannabinoid agonist. In this study, we used mice treated with myelin oligodendrocyte glycoprotein (MOG) that induces a progressive pattern of EAE and conducted the pharmacological experiments in early stages of the disease. As expected, the administration of WIN55,512-2 (5 mg/kg, i.p) had a positive effect in reducing neurological disability and improving motor coordination of EAE mice. Levels of glutamate and GABA in the spinal cord and also in the brainstem of EAE mice were similar to control animals, and, accordingly, they were not altered by the treatment with WIN55,212-2. However, EAE mice showed some subtle alterations in mRNA levels for the glutamate transporter GLT1 and, to a lesser extent, GLAST too, changes that were altered by the treatment with WIN55,212-2 in the spinal cord, but not in the brainstem. Regarding to inflammatory responses, EAE mice showed a marked up-regulation in mRNA levels for COX-2, inducible NOS and TNF-α in the spinal cord and the brainstem, these responses being attenuated after the treatment with WIN55,212-2. We also observed the presence of cell aggregates in the spinal cord of EAE mice that were significantly attenuated by the treatment with WIN55,212-2. Immunohistochemical analysis (with Iba-1 and Cd11b) of these aggregates indicated that they corresponded to microglia (resident macrophages) and peripheral macrophages. Lastly, experiments conducted with selective antagonists for the CB(1) (e.g. rimonabant) or CB(2) (e.g. AM-630) receptors revealed that WIN55,212-2 effects in EAE mice were mediated by the activation of CB(1) but not CB(2) receptors, as reflected the reversion of positive effects of this cannabinoid on neurological decline, TNF-α generation and accumulation of cell aggregates in the spinal cord with rimonabant, but not with AM-630. This was concordant with the lack of positive effects on neurological decline observed in EAE mice when they received HU-308, a selective CB(2) receptor agonist, instead WIN55,212-2. In summary, the treatment of EAE mice with the cannabinoid agonist WIN55,512-2 reduced their neurological disability and the progression of the disease. This effect was exerted through the activation of CB(1) receptors, which would exert a positive influence in the reduction of inflammatory events linked to the pathogenesis of this disease.
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Affiliation(s)
- Eva de Lago
- Departamento de Bioquímica y Biología Molecular, Instituto Universitario de Investigación en Neuroquímica, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain
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Musgrave T, Tenorio G, Rauw G, Baker GB, Kerr BJ. Tissue concentration changes of amino acids and biogenic amines in the central nervous system of mice with experimental autoimmune encephalomyelitis (EAE). Neurochem Int 2011; 59:28-38. [PMID: 21672584 DOI: 10.1016/j.neuint.2011.03.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Revised: 03/03/2011] [Accepted: 03/22/2011] [Indexed: 12/31/2022]
Abstract
We have characterized the changes in tissue concentrations of amino acids and biogenic amines in the central nervous system (CNS) of mice with MOG(35-55)-induced experimental autoimmune encephalomyelitis (EAE), an animal model commonly used to study multiple sclerosis (MS). High performance liquid chromatography was used to analyse tissue samples from five regions of the CNS at the onset, peak and chronic phase of MOG(35-55) EAE. Our analysis includes the evaluation of several newly examined amino acids including d-serine, and the inter-relations between the intraspinal concentration changes of different amino acids and biogenic amines during EAE. Our results confirm many of the findings from similar studies using different variants of the EAE model as well as those examining changes in amino acid and biogenic amine levels in the cerebrospinal fluid (CSF) of MS patients. However, several notable differences were observed between mice with MOG(35-55)-induced EAE with findings from human studies and other EAE models. In addition, our analysis has identified strong correlations between different amino acids and biogenic amines that appear to change in two distinct groups during EAE. Group I analyte concentrations are increased at EAE onset and peak but then decrease in the chronic phase with a large degree of variability. Group II is composed of amino acids and biogenic amines that change in a progressive manner during EAE. The altered levels of these amino acids and biogenic amines in the disease may represent a critical pathway leading to neurodegenerative processes that are now recognized to occur in EAE and MS.
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Affiliation(s)
- Travis Musgrave
- Centre for Neuroscience, University of Alberta, Edmonton, AB, Canada
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Grygorowicz T, Struzyńska L, Sulkowski G, Chalimoniuk M, Sulejczak D. Temporal expression of P2X7 purinergic receptor during the course of experimental autoimmune encephalomyelitis. Neurochem Int 2010; 57:823-9. [PMID: 20817062 DOI: 10.1016/j.neuint.2010.08.021] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 08/24/2010] [Accepted: 08/25/2010] [Indexed: 10/19/2022]
Abstract
Purinergic P2X(7) receptors are nucleotide-gated ion channels widely distributed in brain. Strong evidence suggests that they are involved in cross-talk between glial and neuronal cells. These receptors activated under pathological conditions may participate in regulation of inflammatory response and cell death. In this study we show the expression of P2X(7) protein and mRNA during the course of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), in different stages of the disease (4, 6, 8, 10 post-immunization). The enhanced expression of the receptor at the level of both mRNA and protein was observed in the peak of neurological symptoms and was connected mostly with neurons. However, early overexpression of receptor protein was observed also in an asymptomatic phase of EAE and was tightly related to astrocytic pool of cells. This suggests the early involvement of this kind of receptor into pathological mechanisms leading for symptoms characteristic for EAE.
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Affiliation(s)
- Tomasz Grygorowicz
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
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Groebe A, Clarner T, Baumgartner W, Dang J, Beyer C, Kipp M. Cuprizone treatment induces distinct demyelination, astrocytosis, and microglia cell invasion or proliferation in the mouse cerebellum. THE CEREBELLUM 2009; 8:163-74. [PMID: 19259754 DOI: 10.1007/s12311-009-0099-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2008] [Accepted: 02/11/2009] [Indexed: 10/21/2022]
Abstract
Demyelination of the cerebellum is a well-known phenomenon in human multiple sclerosis (MS). Concordantly, patients with MS frequently developed symptoms deriving from cerebellar lesions, i.e., dysmetria leading to hand dexterity impairment. Important advances in MS research have been made as a direct or indirect consequence of the establishment of adequate animal models. In this study, we used the cuprizone mouse model to investigate cerebellar demyelination in young adult male mice. The myelin status was analyzed by immunohistochemistry for proteolipoprotein and electron microscopy. The expression and presence of oligodendrocyte, astroglial, and microglia markers were supplementary studied. Cuprizone intoxication induced an almost complete demyelination of cerebellar nuclei. Cerebellar cortex regions were not (cortical gray matter) or only marginally (cortical white matter) affected. In addition, the affected areas displayed hypertrophic and hyperplastic astrocytosis accompanied by microglia or macrophage invasion. We conclude that cuprizone-induced demyelination pictures cerebellar deep gray matter involvement but not cerebellar cortex pathology as described for human MS. Behavioral changes after cuprizone described for this animal model may not only result from effects on commissural fiber tracts but also can arise from cerebellar demyelination.
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Affiliation(s)
- Angela Groebe
- Faculty of Medicine, Institute of Neuroanatomy, RWTH Aachen University, 52074 Aachen, Germany
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