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Abstract
Multiple sclerosis is a multifactorial disease with heterogeneous pathogenetic mechanisms, which deserve to be studied to evaluate new possible targets for treatments and improve patient management. MR spectroscopy and PET allow assessing in vivo the molecular and metabolic mechanisms underlying the pathogenesis of multiple sclerosis. This article focuses on the relationship between these imaging techniques and the biologic and chemical pathways leading to multiple sclerosis pathology and its clinical features. Future directions of research are also presented.
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Affiliation(s)
- Marcello Moccia
- NMR Research Unit, Queen Square MS Centre, University College London, Institute of Neurology, 10-12 Russell Square, London WC1B 5EH, UK; MS Clinical Care and Research Centre, Department of Neuroscience, Federico II University, Via Sergio Pansini 5, Naples 80131, Italy
| | - Olga Ciccarelli
- NMR Research Unit, Queen Square MS Centre, University College London, Institute of Neurology, 10-12 Russell Square, London WC1B 5EH, UK; NIHR University College London Hospitals, Biomedical Research Centre, Maple House Suite A 1st floor, 149 Tottenham Court Road, London W1T 7DN, UK.
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52
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Kynurenine pathway and white matter microstructure in bipolar disorder. Eur Arch Psychiatry Clin Neurosci 2018; 268:157-168. [PMID: 27619930 DOI: 10.1007/s00406-016-0731-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 09/02/2016] [Indexed: 12/27/2022]
Abstract
Decreased availability of serotonin in the central nervous system has been suggested to be a central factor in the pathogenesis of depression. Activation of indoleamine 2-3 dioxygenase following a pro-inflammatory state could reduce the amount of tryptophan converted to serotonin and increase the production of tryptophan catabolites such as kynurenic acid, an antagonist of ionotropic excitatory aminoacid receptors, whose levels are reduced in bipolar disorder. Abnormalities in white matter (WM) integrity have been widely reported in BD. We then hypothesized that metabolites involved in serotoninergic turnover in BD could influence DTI measures of WM microstructure. Peripheral levels of tryptophan, kynurenine, kynurenic acid, 3-hydroxy-kynurenine, and 5-HIAA were analysed in 22 patients affected by BD and 15 healthy controls. WM microstructure was evaluated using diffusion tensor imaging and tract-based spatial statistics with threshold-free cluster enhancement only in bipolar patients. We observed that kynurenic acid and 5-HIAA were reduced in BD and associated with DTI measures of WM integrity in several association fibres: inferior and superior longitudinal fasciculus, cingulum bundle, corpus callosum, uncus, anterior thalamic radiation and corona radiata. Our results seem to suggest that higher levels of 5-HIAA, a measure of serotonin levels, and higher levels of kynurenic acid, which protects from glutamate excitotoxicity, could exert a protective effect on WM microstructure. Reduced levels of these metabolites in BD thus seem to confirm a crucial role of serotonin turnover in BD pathophysiology.
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Abstract
PURPOSE OF REVIEW Studies of large longitudinal cohorts of patients with multiple sclerosis (MS) have emphasized the prognostic value of conventional MRI markers, at least during early stages. Advanced imaging metrics derived from quantitative MRI and PET provide relevant information about microstructural damage within and outside visible lesions that may be more sensitive to predict long-term disability. Here, we summarize the most recent findings regarding the prognostic value of imaging markers throughout MS stages. RECENT FINDINGS In clinically isolated syndrome, the presence of at least one brain or spinal cord T2 lesion strongly increases the risk of conversion to clinically definite MS (hazard ratio ranging from 5 to 11). Similarly, the occurrence of new white matter lesions is strongly predictive of subsequent relapse rate and response to current disease modifying therapies. Beyond white matter lesions, volumetric changes in the grey matter and normal-appearing tissue damage are more sensitive prognostic markers for physical and cognitive disability, especially in progressive MS. SUMMARY Although white matter lesion number and volume still remains the imaging metric used in daily clinical practice, further development of advanced imaging predictors of long-term disability should allow a better stratification of patients in future clinical trials aimed at promoting repair or neuroprotection.
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54
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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: 19] [Impact Index Per Article: 3.2] [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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Bai W, Zhou YG. Homeostasis of the Intraparenchymal-Blood Glutamate Concentration Gradient: Maintenance, Imbalance, and Regulation. Front Mol Neurosci 2017; 10:400. [PMID: 29259540 PMCID: PMC5723322 DOI: 10.3389/fnmol.2017.00400] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Accepted: 11/20/2017] [Indexed: 12/25/2022] Open
Abstract
It is widely accepted that glutamate is the most important excitatory neurotransmitter in the central nervous system (CNS). However, there is also a large amount of glutamate in the blood. Generally, the concentration gradient of glutamate between intraparenchymal and blood environments is stable. However, this gradient is dramatically disrupted under a variety of pathological conditions, resulting in an amplifying cascade that causes a series of pathological reactions in the CNS and peripheral organs. This eventually seriously worsens a patient’s prognosis. These two “isolated” systems are rarely considered as a whole even though they mutually influence each other. In this review, we summarize what is currently known regarding the maintenance, imbalance and regulatory mechanisms that control the intraparenchymal-blood glutamate concentration gradient, discuss the interrelationships between these systems and further explore their significance in clinical practice.
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Affiliation(s)
- Wei Bai
- Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing, China
| | - Yuan-Guo Zhou
- Molecular Biology Center, State Key Laboratory of Trauma, Burn, and Combined Injury, Research Institute of Surgery and Daping Hospital, Third Military Medical University, Chongqing, China
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56
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Axo-myelinic neurotransmission: a novel mode of cell signalling in the central nervous system. Nat Rev Neurosci 2017; 19:49-58. [PMID: 29118449 DOI: 10.1038/nrn.2017.128] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It is widely recognized that myelination of axons greatly enhances the speed of signal transmission. An exciting new finding is the dynamic communication between axons and their myelin-forming oligodendrocytes, including activity-dependent signalling from axon to myelin. The oligodendrocyte-myelin complex may in turn respond by providing metabolic support or alter subtle myelin properties to modulate action potential propagation. In this Opinion, we discuss what is known regarding the molecular physiology of this novel, synapse-like communication and speculate on potential roles in disease states including multiple sclerosis, schizophrenia and Alzheimer disease. An emerging appreciation of the contribution of white-matter perturbations to neurological dysfunction identifies the axo-myelinic synapse as a potential novel therapeutic target.
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57
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Sormani MP, Pardini M. Assessing Repair in Multiple Sclerosis: Outcomes for Phase II Clinical Trials. Neurotherapeutics 2017; 14:924-933. [PMID: 28695472 PMCID: PMC5722763 DOI: 10.1007/s13311-017-0558-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Multiple Sclerosis (MS) pathology is complex and includes inflammatory processes, neurodegeneration, and demyelination. While multiple drugs have been developed to tackle MS-related inflammation, to date there is scant evidence regarding which therapeutic approach, if any, could be used to reverse demyelination, foster tissue repair, and thus positively impact on chronic disability. Here, we reviewed the current structural and functional markers (magnetic resonance imaging, positron emission tomography, optical coherence tomography, and visual evoked potentials) which could be used in phase II clinical trials of new compounds aimed to foster tissue repair in MS. Magnetic transfer ratio recovery in newly formed lesions currently represents the most widely used biomarker of tissue repair in MS, even if other markers, such as optical coherence tomography and positron emission tomography hold great promise to complement magnetic transfer ratio in tissue repair clinical trials. Future studies are needed to better characterize the different possible biomarkers to study tissue repair in MS, especially regarding their pathological specificity, sensitivity to change, and their relationship with disease activity.
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Affiliation(s)
- Maria Pia Sormani
- Biostatistics Unit, Department of Health Sciences, University of Genoa, Genoa, Italy.
| | - Matteo Pardini
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, and Maternal and Child Health, University of Genoa, Genoa, Italy
- Policlinic San Martino-IST, Genoa, Italy
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58
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Modica CM, Schweser F, Sudyn ML, Bertolino N, Preda M, Polak P, Siebert DM, Krawiecki JC, Sveinsson M, Hagemeier J, Dwyer MG, Pol S, Zivadinov R. Effect of teriflunomide on cortex-basal ganglia-thalamus (CxBGTh) circuit glutamatergic dysregulation in the Theiler's Murine Encephalomyelitis Virus mouse model of multiple sclerosis. PLoS One 2017; 12:e0182729. [PMID: 28796815 PMCID: PMC5552032 DOI: 10.1371/journal.pone.0182729] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Accepted: 07/24/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Pathology of gray matter is associated with development of physical and cognitive disability in patients with multiple sclerosis. In particular, glutamatergic dysregulation in the cortex-basal ganglia-thalamus (CxBGTh) circuit could be associated with decline in these behaviors. OBJECTIVES To investigate the effect of an immunomodulatory therapy (teriflunomide, Aubagio®) on changes of the CxBGTh loop in the Theiler's Murine Encephalomyelitis Virus, (TMEV) mouse model of MS. METHODS Forty-eight (48) mice were infected with TMEV, treated with teriflunomide (24) or control vehicle (24) and followed for 39 weeks. Mice were examined with MRS and volumetric MRI scans (0, 8, 26, and 39 weeks) in the cortex, basal ganglia and thalamus, using a 9.4T scanner, and with behavioral tests (0, 4, 8, 12, 17, 26, and 39 weeks). Within conditions, MRI measures were compared between two time points by paired samples t-test and across multiple time points by repeated measures ANOVA (rmANOVA), and between conditions by independent samples t-test and rmANOVA, respectively. Data were considered as significant at the p<0.01 level and as a trend at p<0.05 level. RESULTS In the thalamus, the teriflunomide arm exhibited trends toward decreased glutamate levels at 8 and 26 weeks compared to the control arm (p = 0.039 and p = 0.026), while the control arm exhibited a trend toward increased glutamate between 0 to 8 weeks (p = 0.045). In the basal ganglia, the teriflunomide arm exhibited a trend toward decreased glutamate earlier than the control arm, from 0 to 8 weeks (p = 0.011), resulting in decreased glutamate compared to the control arm at 8 weeks (p = 0.016). CONCLUSIONS Teriflunomide may reduce possible excitotoxicity in the thalamus and basal ganglia by lowering glutamate levels.
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Affiliation(s)
- Claire M Modica
- Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Ferdinand Schweser
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Translational Imaging Center, Clinical and Translational Science Institute, University at Buffalo, Buffalo, New York, United States of America
| | - Michelle L Sudyn
- Neuroscience Program, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Nicola Bertolino
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Marilena Preda
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Translational Imaging Center, Clinical and Translational Science Institute, University at Buffalo, Buffalo, New York, United States of America
| | - Paul Polak
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Danielle M Siebert
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Exercise Science, School of Public Health and Health Professions, University at Buffalo, Buffalo, New York, United States of America
| | - Jacqueline C Krawiecki
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Department of Geology, University at Buffalo, Buffalo, New York, United States of America
| | - Michele Sveinsson
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Jesper Hagemeier
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Michael G Dwyer
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Suyog Pol
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America
| | - Robert Zivadinov
- Department of Neurology, Buffalo Neuroimaging Analysis Center, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, New York, United States of America.,Translational Imaging Center, Clinical and Translational Science Institute, University at Buffalo, Buffalo, New York, United States of America
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59
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Nantes JC, Proulx S, Zhong J, Holmes SA, Narayanan S, Brown RA, Hoge RD, Koski L. GABA and glutamate levels correlate with MTR and clinical disability: Insights from multiple sclerosis. Neuroimage 2017; 157:705-715. [DOI: 10.1016/j.neuroimage.2017.01.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 01/12/2017] [Accepted: 01/15/2017] [Indexed: 01/04/2023] Open
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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: 85] [Impact Index Per Article: 12.1] [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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61
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Raphael I, Webb J, Gomez-Rivera F, Chase Huizar CA, Gupta R, Arulanandam BP, Wang Y, Haskins WE, Forsthuber TG. Serum Neuroinflammatory Disease-Induced Central Nervous System Proteins Predict Clinical Onset of Experimental Autoimmune Encephalomyelitis. Front Immunol 2017; 8:812. [PMID: 28769926 PMCID: PMC5512177 DOI: 10.3389/fimmu.2017.00812] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/27/2017] [Indexed: 11/24/2022] Open
Abstract
There is an urgent need in multiple sclerosis (MS) patients to develop biomarkers and laboratory tests to improve early diagnosis, predict clinical relapses, and optimize treatment responses. In healthy individuals, the transport of proteins across the blood–brain barrier (BBB) is tightly regulated, whereas, in MS, central nervous system (CNS) inflammation results in damage to neuronal tissues, disruption of BBB integrity, and potential release of neuroinflammatory disease-induced CNS proteins (NDICPs) into CSF and serum. Therefore, changes in serum NDICP abundance could serve as biomarkers of MS. Here, we sought to determine if changes in serum NDICPs are detectable prior to clinical onset of experimental autoimmune encephalomyelitis (EAE) and, therefore, enable prediction of disease onset. Importantly, we show in longitudinal serum specimens from individual mice with EAE that pre-onset expression waves of synapsin-2, glutamine synthetase, enolase-2, and synaptotagmin-1 enable the prediction of clinical disease with high sensitivity and specificity. Moreover, we observed differences in serum NDICPs between active and passive immunization in EAE, suggesting hitherto not appreciated differences for disease induction mechanisms. Our studies provide the first evidence for enabling the prediction of clinical disease using serum NDICPs. The results provide proof-of-concept for the development of high-confidence serum NDICP expression waves and protein biomarker candidates for MS.
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Affiliation(s)
- Itay Raphael
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States.,Division of Rheumatology and Clinical Immunology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Johanna Webb
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Francisco Gomez-Rivera
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Carol A Chase Huizar
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Rishein Gupta
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Bernard P Arulanandam
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Yufeng Wang
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - William E Haskins
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Thomas G Forsthuber
- Department of Biology, University of Texas at San Antonio, San Antonio, TX, United States
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Sadeghnia HR, Jamshidi R, Afshari AR, Mollazadeh H, Forouzanfar F, Rakhshandeh H. Terminalia chebula attenuates quinolinate-induced oxidative PC12 and OLN-93 cell death. Mult Scler Relat Disord 2017; 14:60-67. [DOI: 10.1016/j.msard.2017.03.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 03/04/2017] [Accepted: 03/26/2017] [Indexed: 11/28/2022]
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63
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Klauser AM, Wiebenga OT, Eijlers AJC, Schoonheim MM, Uitdehaag BMJ, Barkhof F, Pouwels PJW, Geurts JJG. Metabolites predict lesion formation and severity in relapsing-remitting multiple sclerosis. Mult Scler 2017; 24:491-500. [DOI: 10.1177/1352458517702534] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background: Multiple sclerosis is characterized by white matter lesions, which are visualized with conventional T2-weighted magnetic resonance imaging (MRI). Little is known about local metabolic processes preceding the appearance and during the pathological development of new lesions. Objective: To identify metabolite changes preceding white matter (WM) lesions and pathological severity of lesions over time. Methods: A total of 59 relapsing-remitting multiple sclerosis (MS) patients were scanned four times, with 6-month intervals. Imaging included short-TE magnetic resonance spectroscopic imaging (MRSI) and diffusion tensor imaging (DTI). Results: A total of 16 new lesions appeared within the MRSI slab in 12 patients. Glutamate increased (+1.0 mM (+19%), p = 0.039) 12 and 6 months before new lesions appeared. In these areas, the increase in creatine and choline 6 months before until lesion appearance was negatively correlated with radial diffusivity (ρ = −0.73, p = 0.002 and ρ = −0.72, p = 0.002). Increase in creatine also correlated with the increase of axial diffusivity in the same period (ρ = −0.53, p = 0.034). When splitting the lesions into “mild” and “severe” based on radial diffusivity, only mild lesions showed an increase in creatine and choline during lesion formation ( p = 0.039 and p = 0.008, respectively). Conclusion: Increased glutamate heralded the appearance of new T2-visible WM lesions. In pathologically “mild” lesions, an increase in creatine and choline was found during lesion formation.
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Affiliation(s)
- Antoine M Klauser
- Department of Anatomy & Neurosciences, VU University Medical Center, Amsterdam, The Netherlands/Department of Radiology and Medical Informatics, University of Geneva, Switzerland
| | - Oliver T Wiebenga
- Department of Anatomy & Neurosciences, VU University Medical Center, Amsterdam, The Netherlands/Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Anand JC Eijlers
- Department of Anatomy & Neurosciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Menno M Schoonheim
- Department of Anatomy & Neurosciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Bernard MJ Uitdehaag
- Department of Neurology, VU University Medical Center, Amsterdam, The Netherlands
| | - Frederik Barkhof
- Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands
| | - Petra JW Pouwels
- Department of Physics and Medical Technology, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands
| | - Jeroen JG Geurts
- Department of Anatomy & Neurosciences, VU University Medical Center, Amsterdam, The Netherlands
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Levite M. Glutamate, T cells and multiple sclerosis. J Neural Transm (Vienna) 2017; 124:775-798. [PMID: 28236206 DOI: 10.1007/s00702-016-1661-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/25/2016] [Indexed: 12/18/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the nervous system, where it induces multiple beneficial and essential effects. Yet, excess glutamate, evident in a kaleidoscope of acute and chronic pathologies, is absolutely catastrophic, since it induces excitotoxicity and massive loss of brain function. Both the beneficial and the detrimental effects of glutamate are mediated by a large family of glutamate receptors (GluRs): the ionotropic glutamate receptors (iGluRs) and the metabotropic glutamate receptors (mGluRs), expressed by most/all cells of the nervous system, and also by many non-neural cells in various peripheral organs and tissues. T cells express on their cell surface several types of functional GluRs, and so do few other immune cells. Furthermore, glutamate by itself activates resting normal human T cells, and induces/elevates key T cell functions, among them: T cell adhesion, chemotactic migration, cytokine secretion, gene expression and more. Glutamate has also potent effects on antigen/mitogen/cytokine-activated T cells. Furthermore, T cells can even produce and release glutamate, and affect other cells and themselves via their own glutamate. Multiple sclerosis (MS) and its animal model Experimental Autoimmune Encephalomyelitis (EAE) are mediated by autoimmune T cells. In MS and EAE, there are excess glutamate levels, and multiple abnormalities in glutamate degrading enzymes, glutamate transporters, glutamate receptors and glutamate signaling. Some GluR antagonists block EAE. Enhancer of mGluR4 protects from EAE via regulatory T cells (Tregs), while mGluR4 deficiency exacerbates EAE. The protective effect of mGluR4 on EAE calls for testing GluR4 enhancers in MS patients. Oral MS therapeutics, namely Fingolimod, dimethyl fumarate and their respective metabolites Fingolimod-phosphate and monomethyl fumarate, can protect neurons against acute glutamatergic excitotoxic damage. Furthermore, Fingolimod reduce glutamate-mediated intracortical excitability in relapsing-remitting MS. Glatiramer acetate -COPAXONE®, an immunomodulator drug for MS, reverses TNF-α-induced alterations of striatal glutamate-mediated excitatory postsynaptic currents in EAE-afflicted mice. With regard to T cells of MS patients: (1) The cell surface expression of a specific GluR: the AMPA GluR3 is elevated in T cells of MS patients during relapse and with active disease, (2) Glutamate and AMPA (a selective agonist for glutamate/AMPA iGluRs) augment chemotactic migration of T cells of MS patients, (3) Glutamate augments proliferation of T cells of MS patients in response to myelin-derived proteins: MBP and MOG, (4) T cells of MS patients respond abnormally to glutamate, (5) Significantly higher proliferation values in response to glutamate were found in MS patients assessed during relapse, and in those with gadolinium (Gd)+ enhancing lesions on MRI. Furthermore, glutamate released from autoreactive T cells induces excitotoxic cell death of neurons. Taken together, the evidences accumulated thus far indicate that abnormal glutamate levels and signaling in the nervous system, direct activation of T cells by glutamate, and glutamate release by T cells, can all contribute to MS. This may be true also to other neurological diseases. It is postulated herein that the detrimental activation of autoimmune T cells by glutamate in MS could lead to: (1) Cytotoxicity in the CNS: T cell-mediated killing of neurons and glia cells, which would subsequently increase the extracellular glutamate levels, and by doing so increase the excitotoxicity mediated by excess glutamate, (2) Release of proinflammatory cytokines, e.g., TNFα and IFNγ that increase neuroinflammation. Finally, if excess glutamate, abnormal neuronal signaling, glutamate-induced activation of T cells, and glutamate release by T cells are indeed all playing a key detrimental role in MS, then optional therapeutic tolls include GluR antagonists, although these may have various side effects. In addition, an especially attractive therapeutic strategy is the novel and entirely different therapeutic approach to minimize excess glutamate and excitotoxicity, titled: 'brain to blood glutamate scavenging', designed to lower excess glutamate levels in the CNS by 'pumping it out' from the brain to the blood. The glutamate scavanging is achieved by lowering glutamate levels in the blood by intravenous injection of the blood enzyme glutamate oxaloacetate transaminase (GOT). The glutamate-scavenging technology, which is still experimental, validated so far for other brain pathologies, but not tested on MS or EAE yet, may be beneficial for MS too, since it could decrease both the deleterious effects of excess glutamate on neural cells, and the activation of autoimmune T cells by glutamate in the brain. The topic of glutamate scavenging, and also its potential benefit for MS, are discussed towards the end of the review, and call for research in this direction.
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Affiliation(s)
- Mia Levite
- Faculty of Medicine, School of Pharmacy, The Hebrew University, Jerusalem, Israel. .,Institute of Gene Therapy, Hadassah Medical Center, 91120, Ein Karem, Jerusalem, Israel.
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Kantorová E, Poláček H, Bittšanský M, Baranovičová E, Hnilicová P, Čierny D, Sivák Š, Nosáľ V, Zeleňák K, Kurča E. Hypothalamic damage in multiple sclerosis correlates with disease activity, disability, depression, and fatigue. Neurol Res 2017; 39:323-330. [DOI: 10.1080/01616412.2016.1275460] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- E. Kantorová
- Clinic of Neurology, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Slovakia
| | - H. Poláček
- Clinic of Nuclear Medicine, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Bratislava, Slovakia
| | - M. Bittšanský
- BioMed Division of Neurosciences, Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Bratislava, Slovakia
| | - E. Baranovičová
- BioMed Division of Neurosciences, Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Bratislava, Slovakia
| | - P. Hnilicová
- BioMed Division of Neurosciences, Biomedical Center Martin, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Bratislava, Slovakia
| | - D. Čierny
- Department of Clinical Biochemistry, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Bratislava, Slovakia
| | - Š. Sivák
- Clinic of Neurology, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Slovakia
| | - V. Nosáľ
- Clinic of Neurology, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Slovakia
| | - K. Zeleňák
- Clinic of Radiodiagnostics, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Bratislava, Slovakia
| | - E. Kurča
- Clinic of Neurology, Jessenius Faculty of Medicine in Martin, Comenius University Bratislava, Slovakia
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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: 41] [Impact Index Per Article: 5.9] [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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Lee P, Adany P, Choi IY. Imaging based magnetic resonance spectroscopy (MRS) localization for quantitative neurochemical analysis and cerebral metabolism studies. Anal Biochem 2017; 529:40-47. [PMID: 28082217 DOI: 10.1016/j.ab.2017.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Revised: 12/10/2016] [Accepted: 01/08/2017] [Indexed: 11/15/2022]
Abstract
Accurate quantitative metabolic imaging of the brain presents significant challenges due to the complexity and heterogeneity of its structures and compositions with distinct compartmentations of brain tissue types (e.g., gray and white matter). The brain is compartmentalized into various regions based on their unique functions and locations. In vivo magnetic resonance spectroscopy (MRS) techniques allow non-invasive measurements of neurochemicals in either single voxel or multiple voxels, yet the spatial resolution and detection sensitivity of MRS are significantly lower compared with MRI. A fundamentally different approach, namely spectral localization by imaging (SLIM) provides a new framework that overcomes major limitations of conventional MRS techniques. Conventional MRS allows only rectangular voxel shapes that do not conform to the shapes of brain structures or lesions, while SLIM allows compartments with arbitrary shapes. However, the restrictive assumption proposed in the original concept of SLIM, i.e., compartmental homogeneity, led to spectral localization errors, which have limited its broad applications. This review focuses on the recent technical frontiers of image-based MRS localization techniques that overcome the limitations of SLIM through the development and implementation of various new strategies, including incorporation of magnetic field inhomogeneity corrections, the use of multiple receiver coils, and prospective optimization of data acquisition.
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Affiliation(s)
- Phil Lee
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
| | - Peter Adany
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - In-Young Choi
- Hoglund Brain Imaging Center, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA; Department of Neurology, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Macrez R, Stys PK, Vivien D, Lipton SA, Docagne F. Mechanisms of glutamate toxicity in multiple sclerosis: biomarker and therapeutic opportunities. Lancet Neurol 2016; 15:1089-102. [PMID: 27571160 DOI: 10.1016/s1474-4422(16)30165-x] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 06/21/2016] [Accepted: 06/27/2016] [Indexed: 12/22/2022]
Abstract
Research advances support the idea that excessive activation of the glutamatergic pathway plays an important part in the pathophysiology of multiple sclerosis. Beyond the well established direct toxic effects on neurons, additional sites of glutamate-induced cell damage have been described, including effects in oligodendrocytes, astrocytes, endothelial cells, and immune cells. Such toxic effects could provide a link between various pathological aspects of multiple sclerosis, such as axonal damage, oligodendrocyte cell death, demyelination, autoimmunity, and blood-brain barrier dysfunction. Understanding of the mechanisms underlying glutamate toxicity in multiple sclerosis could help in the development of new approaches for diagnosis, treatment, and follow-up in patients with this debilitating disease. While several clinical trials of glutamatergic modulators have had disappointing results, our growing understanding suggests that there is reason to remain optimistic about the therapeutic potential of these drugs.
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Affiliation(s)
| | - Peter K Stys
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Denis Vivien
- INSERM U919, University of Caen Normandy, Caen, France
| | - Stuart A Lipton
- Scintillon Institute San Diego, CA, USA; Scripps Research Institute, La Jolla, CA, USA; School of Mecicine, University of California, San Diego, CA, USA
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Peyro Saint Paul L, Creveuil C, Heinzlef O, De Seze J, Vermersch P, Castelnovo G, Cabre P, Debouverie M, Brochet B, Dupuy B, Lebiez P, Sartori É, Clavelou P, Brassat D, Lebrun-Frenay C, Daplaud D, Pelletier J, Coman I, Hautecoeur P, Tourbah A, Defer G. Efficacy and safety profile of memantine in patients with cognitive impairment in multiple sclerosis: A randomized, placebo-controlled study. J Neurol Sci 2016; 363:69-76. [DOI: 10.1016/j.jns.2016.02.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 01/01/2023]
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Larochelle C, Uphaus T, Prat A, Zipp F. Secondary Progression in Multiple Sclerosis: Neuronal Exhaustion or Distinct Pathology? Trends Neurosci 2016; 39:325-339. [PMID: 26987259 DOI: 10.1016/j.tins.2016.02.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 02/03/2016] [Accepted: 02/09/2016] [Indexed: 01/08/2023]
Abstract
Prevention of progression in neurological diseases, particularly in multiple sclerosis (MS) but also in neurodegenerative diseases, remains a significant challenge. MS patients switch from a relapsing-remitting to a progressive disease course, but it is not understood why and how this conversion occurs and why some patients never experience disease progression. Do aging and accumulation of neuronal damage induce progression, or do cognitive symptoms and accelerated grey matter (GM) atrophy point to distinct processes affecting networks? This review weighs accepted dogma against real data on the secondary progressive phase of the disease, highlighting current challenges in this important field and directions towards development of treatment strategies to slow or prevent progression of disability.
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Affiliation(s)
- Catherine Larochelle
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn(2)), University Medical Centre of the Johannes Gutenberg University Mainz, Germany; Neuroimmunology Unit, Department of Neuroscience, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Université de Montréal, Montréal, Canada
| | - Timo Uphaus
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn(2)), University Medical Centre of the Johannes Gutenberg University Mainz, Germany
| | - Alexandre Prat
- Neuroimmunology Unit, Department of Neuroscience, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Université de Montréal, Montréal, Canada
| | - Frauke Zipp
- Department of Neurology, Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine-Main Neuroscience Network (rmn(2)), University Medical Centre of the Johannes Gutenberg University Mainz, Germany.
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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: 20.1] [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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MacMillan EL, Tam R, Zhao Y, Vavasour IM, Li DKB, Oger J, Freedman MS, Kolind SH, Traboulsee AL. Progressive multiple sclerosis exhibits decreasing glutamate and glutamine over two years. Mult Scler 2015; 22:112-6. [DOI: 10.1177/1352458515586086] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 04/11/2015] [Indexed: 11/17/2022]
Abstract
Background: Few biomarkers of progressive multiple sclerosis (MS) are sensitive to change within the two-year time frame of a clinical trial. Objective: To identify biomarkers of MS disease progression with magnetic resonance spectroscopy (MRS) in secondary progressive MS (SPMS). Methods: Forty-seven SPMS subjects were scanned at baseline and annually for two years. Concentrations of N-acetylaspartate, total creatine, total choline, myo-inositol, glutamate, glutamine, and the sum glutamate+glutamine were measured in a single white matter voxel. Results: Glutamate and glutamine were the only metabolites to show an effect with time: with annual declines of (95% confidence interval): glutamate −4.2% (−6.2% to −2.2%, p < 10−4), glutamine −7.3% (−11.8% to −2.9%, p = 0.003), and glutamate+glutamine −5.2% (−7.6% to −2.8%, p < 10−4). Metabolite rates of change were more apparent than changes in clinical scores or brain atrophy measures. Conclusions: The high rates of change of both glutamate and glutamine over two years suggest they are promising new biomarkers of MS disease progression.
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Affiliation(s)
- EL MacMillan
- Division of Neurology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - R Tam
- Department of Radiology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada/UBC MS/MRI Research Group, The University of British Columbia, Vancouver, Canada
| | - Y Zhao
- UBC MS/MRI Research Group, The University of British Columbia, Vancouver, Canada
| | - IM Vavasour
- Department of Radiology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - DKB Li
- Department of Radiology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada/UBC MS/MRI Research Group, The University of British Columbia, Vancouver, Canada
| | - J Oger
- Division of Neurology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - MS Freedman
- Department of Neurology, Faculty of Medicine, The University of Ottawa, Canada
| | - SH Kolind
- Division of Neurology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
| | - AL Traboulsee
- Division of Neurology, Faculty of Medicine, The University of British Columbia, Vancouver, Canada
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Didonna A, Oksenberg JR. Genetic determinants of risk and progression in multiple sclerosis. Clin Chim Acta 2015; 449:16-22. [PMID: 25661088 DOI: 10.1016/j.cca.2015.01.034] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 01/21/2015] [Indexed: 01/07/2023]
Abstract
Multiple sclerosis (MS) is an autoimmune disease that represents a primary cause of neurological disability in the young adult population. Converging evidence supports the importance of genetic determinants for MS etiology. However, with the exception of the major histocompatibility complex, their nature has been elusive for more than 20 years. In the last decade, the advent of large genome-wide association studies has significantly improved our understanding of the disease, leading to the golden era of MS genetic research. To date more than 110 genetic variants have been firmly associated to an increased risk of developing MS. A large part of these variants tag genes involved in the regulation of immune response and several of them are shared with other autoimmune diseases, suggesting a common etiological root for this class of disorders. Despite the impressive body of data obtained in the last years, we are still far from fully decoding MS genetic complexity. For example, we ignore how these genetic factors interact with each other and with the environment. Thus, the biggest challenge for the next era of MS research will consist in identifying and characterizing the molecular mechanisms and the cellular pathways in which these risk variants play a role.
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Affiliation(s)
- Alessandro Didonna
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Jorge R Oksenberg
- Department of Neurology, University of California San Francisco, San Francisco, CA, USA.
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Londoño AC, Mora CA. Nonconventional MRI biomarkers for in vivo monitoring of pathogenesis in multiple sclerosis. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2014; 1:e45. [PMID: 25419539 PMCID: PMC4239827 DOI: 10.1212/nxi.0000000000000045] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 10/03/2014] [Indexed: 02/06/2023]
Abstract
To date, biomarkers based on nonconventional MRI have not been standardized for diagnosis and follow-up of patients with multiple sclerosis (MS). The sequential monitoring of pathogenesis in MS by imaging of the normal appearing brain tissue is an important research tool in understanding the early stages of MS. In this review, we focus on the importance of deciphering the physiopathogenesis of the disease cascade in vivo based on imaging biomarkers that allow a correlation with immunohistochemistry and molecular biology findings in order to provide earlier clinical diagnosis and better individualization of treatment and follow-up in patients with MS. Among the nonconventional imaging techniques available, we remark on the importance of proton magnetic resonance spectroscopy imaging because of its ability to assist in the simultaneous evaluation of different events in the pathogenesis of MS that cannot be determined by conventional MRI. Nonconventional MRI and the use of novel contrast agents are expected to elucidate the process of neuroinflammation and excitotoxicity in vivo that characterizes MS, thus leading to more specific neuroprotective and immunomodulatory therapies and reducing progression toward disability.
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Affiliation(s)
- Ana C Londoño
- Neurological Institute of Colombia-INDEC and Link Diagnostico Digital (A.C.L.), Medellín, Colombia; and Department of Neurology (C.A.M.), Georgetown Multiple Sclerosis Center, MedStar Georgetown University Hospital, Washington, DC
| | - Carlos A Mora
- Neurological Institute of Colombia-INDEC and Link Diagnostico Digital (A.C.L.), Medellín, Colombia; and Department of Neurology (C.A.M.), Georgetown Multiple Sclerosis Center, MedStar Georgetown University Hospital, Washington, DC
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