1
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Calabrese M, Preziosa P, Scalfari A, Colato E, Marastoni D, Absinta M, Battaglini M, De Stefano N, Di Filippo M, Hametner S, Howell OW, Inglese M, Lassmann H, Martin R, Nicholas R, Reynolds R, Rocca MA, Tamanti A, Vercellino M, Villar LM, Filippi M, Magliozzi R. Determinants and Biomarkers of Progression Independent of Relapses in Multiple Sclerosis. Ann Neurol 2024; 96:1-20. [PMID: 38568026 DOI: 10.1002/ana.26913] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/04/2024] [Accepted: 02/15/2024] [Indexed: 06/20/2024]
Abstract
Clinical, pathological, and imaging evidence in multiple sclerosis (MS) suggests that a smoldering inflammatory activity is present from the earliest stages of the disease and underlies the progression of disability, which proceeds relentlessly and independently of clinical and radiological relapses (PIRA). The complex system of pathological events driving "chronic" worsening is likely linked with the early accumulation of compartmentalized inflammation within the central nervous system as well as insufficient repair phenomena and mitochondrial failure. These mechanisms are partially lesion-independent and differ from those causing clinical relapses and the formation of new focal demyelinating lesions; they lead to neuroaxonal dysfunction and death, myelin loss, glia alterations, and finally, a neuronal network dysfunction outweighing central nervous system (CNS) compensatory mechanisms. This review aims to provide an overview of the state of the art of neuropathological, immunological, and imaging knowledge about the mechanisms underlying the smoldering disease activity, focusing on possible early biomarkers and their translation into clinical practice. ANN NEUROL 2024;96:1-20.
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Affiliation(s)
- Massimiliano Calabrese
- Department of Neurosciences and Biomedicine and Movement, The Multiple Sclerosis Center of University Hospital of Verona, Verona, Italy
| | - Paolo Preziosa
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Antonio Scalfari
- Centre of Neuroscience, Department of Medicine, Imperial College, London, UK
| | - Elisa Colato
- Department of Neurosciences and Biomedicine and Movement, The Multiple Sclerosis Center of University Hospital of Verona, Verona, Italy
| | - Damiano Marastoni
- Department of Neurosciences and Biomedicine and Movement, The Multiple Sclerosis Center of University Hospital of Verona, Verona, Italy
| | - Martina Absinta
- Translational Neuropathology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Battaglini
- Siena Imaging S.r.l., Siena, Italy
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Nicola De Stefano
- Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Massimiliano Di Filippo
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, Perugia, Italy
| | - Simon Hametner
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Owain W Howell
- Institute of Life Sciences, Swansea University Medical School, Swansea, UK
| | - Matilde Inglese
- Dipartimento di neuroscienze, riabilitazione, oftalmologia, genetica e scienze materno-infantili - DINOGMI, University of Genova, Genoa, Italy
| | - Hans Lassmann
- Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Roland Martin
- Institute of Experimental Immunology, University of Zurich, Zurich, Switzerland
- Therapeutic Design Unit, Center for Molecular Medicine, Department of Clinical Neurosciences, Karolinska Institutet, Stockholm, Sweden
- Cellerys AG, Schlieren, Switzerland
| | - Richard Nicholas
- Department of Brain Sciences, Faculty of Medicine, Burlington Danes, Imperial College London, London, UK
| | - Richard Reynolds
- Division of Neuroscience, Department of Brain Sciences, Imperial College London, London, UK
| | - Maria A Rocca
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
| | - Agnese Tamanti
- Department of Neurosciences and Biomedicine and Movement, The Multiple Sclerosis Center of University Hospital of Verona, Verona, Italy
| | - Marco Vercellino
- Multiple Sclerosis Center & Neurologia I U, Department of Neuroscience, University Hospital AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Luisa Maria Villar
- Department of Immunology, Ramon y Cajal University Hospital. IRYCIS. REI, Madrid, Spain
| | - Massimo Filippi
- Neuroimaging Research Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurology Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Vita-Salute San Raffaele University, Milan, Italy
- Neurorehabilitation Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy
- Neurophysiology Service, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Roberta Magliozzi
- Department of Neurosciences and Biomedicine and Movement, The Multiple Sclerosis Center of University Hospital of Verona, Verona, Italy
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Stekic A, Stevic D, Dokmanovic T, Anastasov M, Popovic D, Stanojevic J, Jovanovic MZ, Stevanovic I, Nedeljkovic N, Dragic M. Intrinsic ecto-5'-Nucleotidase/A 1R Coupling may Confer Neuroprotection to the Cerebellum in Experimental Autoimmune Encephalomyelitis. Mol Neurobiol 2024:10.1007/s12035-024-04174-9. [PMID: 38619745 DOI: 10.1007/s12035-024-04174-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 04/10/2024] [Indexed: 04/16/2024]
Abstract
Experimental autoimmune encephalomyelitis (EAE) is widely used animal model of multiple sclerosis (MS). The disease is characterized by demyelination and neurodegeneration triggered by infiltrated autoimmune cells and their interaction with astrocytes and microglia. While neuroinflammation is most common in the spinal cord and brainstem, it is less prevalent in the cerebellum, where it predisposes to rapid disease progression. Because the induction and progression of EAE are tightly regulated by adenosinergic signaling, in the present study we compared the adenosine-producing and -degrading enzymes, ecto-5'-nucleotidase (eN/CD73) and adenosine deaminase (ADA), as well as the expression levels of adenosine receptors A1R and A2AR subtypes in nearby areas around the fourth cerebral ventricle-the pontine tegmentum, the choroid plexus (CP), and the cerebellum. Significant differences in histopathological findings were observed between pontine tegmentum and cerebellum on the same horizontal section level. Reactive astrogliosis and massive infiltration of CD4 + cells and macrophages in CP and pontine tegmentum resulted in local demyelination. In cerebellum, there was no evidence of infiltrates, microgliosis and neuroinflammation at the same sectional level. In addition, Bergman glia showed no signs of reactive gliosis. As for adenosinergic signaling, significant upregulation of eN/CD73 was observed in all areas studied, but in association with different adenosine receptor subtypes. In CP and pons, overexpression of eN/CD73 was coupled with induction of A2AR, whereas in cerebellum, a modest increase in eN/CD73 in resident Bergman glia was accompanied by a strong induction of A1R in the same type of astrocytes. Thus, the presence of specialized astroglia and intrinsic differences in adenosinergic signaling may play a critical role in the differential regional susceptibility to EAE inflammation.
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Affiliation(s)
- Andjela Stekic
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Dejan Stevic
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Tamara Dokmanovic
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Marina Anastasov
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Danica Popovic
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Jelena Stanojevic
- Medical Faculty of Military Medical Academy, University of Defense, 11 000, Belgrade, Serbia
| | | | - Ivana Stevanovic
- Medical Faculty of Military Medical Academy, University of Defense, 11 000, Belgrade, Serbia
| | - Nadezda Nedeljkovic
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia.
| | - Milorad Dragic
- Laboratory for Neurobiology, Faculty of Biology, University of Belgrade, Belgrade, Serbia.
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3
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Li J, Qi H, Chen Y, Zhu X. Epilepsy and demyelination: Towards a bidirectional relationship. Prog Neurobiol 2024; 234:102588. [PMID: 38378072 DOI: 10.1016/j.pneurobio.2024.102588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/13/2024] [Indexed: 02/22/2024]
Abstract
Demyelination stands out as a prominent feature in individuals with specific types of epilepsy. Concurrently, individuals with demyelinating diseases, such as multiple sclerosis (MS) are at a greater risk of developing epilepsy compared to non-MS individuals. These bidirectional connections raise the question of whether both pathological conditions share common pathogenic mechanisms. This review focuses on the reciprocal relationship between epilepsy and demyelination diseases. We commence with an overview of the neurological basis of epilepsy and demyelination diseases, followed by an exploration of how our comprehension of these two disorders has evolved in tandem. Additionally, we discuss the potential pathogenic mechanisms contributing to the interactive relationship between these two diseases. A more nuanced understanding of the interplay between epilepsy and demyelination diseases has the potential to unveiling the molecular intricacies of their pathological relationships, paving the way for innovative directions in future clinical management and treatment strategies for these diseases.
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Affiliation(s)
- Jiayi Li
- Department of Pharmacology, Medical School of Southeast University, Nanjing, China; Clinical Medicine, Medical School of Southeast University, Nanjing, China
| | - Honggang Qi
- Department of Pharmacology, Medical School of Southeast University, Nanjing, China
| | - Yuzhou Chen
- Department of Pharmacology, Medical School of Southeast University, Nanjing, China; Clinical Medicine, Medical School of Southeast University, Nanjing, China
| | - Xinjian Zhu
- Department of Pharmacology, Medical School of Southeast University, Nanjing, China.
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Mancini M, Natoli S, Gardoni F, Di Luca M, Pisani A. Dopamine Transmission Imbalance in Neuroinflammation: Perspectives on Long-Term COVID-19. Int J Mol Sci 2023; 24:ijms24065618. [PMID: 36982693 PMCID: PMC10056044 DOI: 10.3390/ijms24065618] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/09/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Dopamine (DA) is a key neurotransmitter in the basal ganglia, implicated in the control of movement and motivation. Alteration of DA levels is central in Parkinson’s disease (PD), a common neurodegenerative disorder characterized by motor and non-motor manifestations and deposition of alpha-synuclein (α-syn) aggregates. Previous studies have hypothesized a link between PD and viral infections. Indeed, different cases of parkinsonism have been reported following COVID-19. However, whether SARS-CoV-2 may trigger a neurodegenerative process is still a matter of debate. Interestingly, evidence of brain inflammation has been described in postmortem samples of patients infected by SARS-CoV-2, which suggests immune-mediated mechanisms triggering the neurological sequelae. In this review, we discuss the role of proinflammatory molecules such as cytokines, chemokines, and oxygen reactive species in modulating DA homeostasis. Moreover, we review the existing literature on the possible mechanistic interplay between SARS-CoV-2-mediated neuroinflammation and nigrostriatal DAergic impairment, and the cross-talk with aberrant α-syn metabolism.
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Affiliation(s)
- Maria Mancini
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Silvia Natoli
- Department of Clinical Science and Translational Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;
- IRCCS Maugeri Pavia, 27100 Pavia, Italy
| | - Fabrizio Gardoni
- Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, University of Milan, 20133 Milan, Italy; (F.G.); (M.D.L.)
| | - Monica Di Luca
- Department of Pharmacological and Biomolecular Sciences “Rodolfo Paoletti”, University of Milan, 20133 Milan, Italy; (F.G.); (M.D.L.)
| | - Antonio Pisani
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy;
- IRCCS Mondino Foundation, 27100 Pavia, Italy
- Correspondence: ; Tel.: +39-0382-380-247
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5
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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: 6.0] [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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Schroeter CB, Rolfes L, Gothan KSS, Gruchot J, Herrmann AM, Bock S, Fazio L, Henes A, Narayanan V, Pfeuffer S, Nelke C, Räuber S, Huntemann N, Duarte-Silva E, Dobelmann V, Hundehege P, Wiendl H, Raba K, Küry P, Kremer D, Ruck T, Müntefering T, Budde T, Cerina M, Meuth SG. Cladribine treatment improves cortical network functionality in a mouse model of autoimmune encephalomyelitis. J Neuroinflammation 2022; 19:270. [DOI: 10.1186/s12974-022-02588-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 09/07/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Cladribine is a synthetic purine analogue that interferes with DNA synthesis and repair next to disrupting cellular proliferation in actively dividing lymphocytes. The compound is approved for the treatment of multiple sclerosis (MS). Cladribine can cross the blood–brain barrier, suggesting a potential effect on central nervous system (CNS) resident cells. Here, we explored compartment-specific immunosuppressive as well as potential direct neuroprotective effects of oral cladribine treatment in experimental autoimmune encephalomyelitis (EAE) mice.
Methods
In the current study, we compare immune cell frequencies and phenotypes in the periphery and CNS of EAE mice with distinct grey and white matter lesions (combined active and focal EAE) either orally treated with cladribine or vehicle, using flow cytometry. To evaluate potential direct neuroprotective effects, we assessed the integrity of the primary auditory cortex neuronal network by studying neuronal activity and spontaneous synaptic activity with electrophysiological techniques ex vivo.
Results
Oral cladribine treatment significantly attenuated clinical deficits in EAE mice. Ex vivo flow cytometry showed that cladribine administration led to peripheral immune cell depletion in a compartment-specific manner and reduced immune cell infiltration into the CNS. Histological evaluations revealed no significant differences for inflammatory lesion load following cladribine treatment compared to vehicle control. Single cell electrophysiology in acute brain slices was performed and showed an impact of cladribine treatment on intrinsic cellular firing patterns and spontaneous synaptic transmission in neurons of the primary auditory cortex. Here, cladribine administration in vivo partially restored cortical neuronal network function, reducing action potential firing. Both, the effect on immune cells and neuronal activity were transient.
Conclusions
Our results indicate that cladribine exerts a neuroprotective effect after crossing the blood–brain barrier independently of its peripheral immunosuppressant action.
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Stampanoni Bassi M, Iezzi E, Centonze D. Multiple sclerosis: Inflammation, autoimmunity and plasticity. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:457-470. [PMID: 35034754 DOI: 10.1016/b978-0-12-819410-2.00024-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In recent years, experimental studies have clarified that immune system influences the functioning of the central nervous system (CNS) in both physiologic and pathologic conditions. The neuro-immune crosstalk plays a crucial role in neuronal development and may be critically involved in mediating CNS response to neuronal damage. Multiple sclerosis (MS) represents a good model to investigate how the immune system regulates neuronal activity. Accordingly, a growing body of evidence has demonstrated that increased levels of pro-inflammatory mediators may significantly impact synaptic mechanisms, influencing overall neuronal excitability and synaptic plasticity expression. In this chapter, we provide an overview of preclinical data and clinical studies exploring synaptic functioning noninvasively with transcranial magnetic stimulation (TMS) in patients with MS. Moreover, we examine how inflammation-driven synaptic dysfunction could affect synaptic plasticity expression, negatively influencing the MS course. Contrasting CSF inflammation together with pharmacologic enhancement of synaptic plasticity and application of noninvasive brain stimulation, alone or in combination with rehabilitative treatments, could improve the clinical compensation and prevent the accumulating deterioration in MS.
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Affiliation(s)
| | - Ennio Iezzi
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy
| | - Diego Centonze
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy; Laboratory of Synaptic Immunopathology, Department of Systems Medicine, Tor Vergata University, Rome, Italy.
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Bellingacci L, Mancini A, Gaetani L, Tozzi A, Parnetti L, Di Filippo M. Synaptic Dysfunction in Multiple Sclerosis: A Red Thread from Inflammation to Network Disconnection. Int J Mol Sci 2021; 22:ijms22189753. [PMID: 34575917 PMCID: PMC8469646 DOI: 10.3390/ijms22189753] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 12/24/2022] Open
Abstract
Multiple sclerosis (MS) has been clinically considered a chronic inflammatory disease of the white matter; however, in the last decade growing evidence supported an important role of gray matter pathology as a major contributor of MS-related disability and the involvement of synaptic structures assumed a key role in the pathophysiology of the disease. Synaptic contacts are considered central units in the information flow, involved in synaptic transmission and plasticity, critical processes for the shaping and functioning of brain networks. During the course of MS, the immune system and its diffusible mediators interact with synaptic structures leading to changes in their structure and function, influencing brain network dynamics. The purpose of this review is to provide an overview of the existing literature on synaptic involvement during experimental and human MS, in order to understand the mechanisms by which synaptic failure eventually leads to brain networks alterations and contributes to disabling MS symptoms and disease progression.
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Affiliation(s)
- Laura Bellingacci
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Andrea Mancini
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Lorenzo Gaetani
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Alessandro Tozzi
- Section of Physiology and Biochemistry, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy;
| | - Lucilla Parnetti
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
| | - Massimiliano Di Filippo
- Section of Neurology, Department of Medicine and Surgery, University of Perugia, 06132 Perugia, Italy; (L.B.); (A.M.); (L.G.); (L.P.)
- Correspondence: ; Tel.: +39-075-578-3830
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Vercellino M, Marasciulo S, Grifoni S, Vallino-Costassa E, Bosa C, Pasanisi MB, Crociara P, Casalone C, Chiò A, Giordana MT, Corona C, Cavalla P. Acute and chronic synaptic pathology in multiple sclerosis gray matter. Mult Scler 2021; 28:369-382. [PMID: 34124960 DOI: 10.1177/13524585211022174] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To investigate the extent of synaptic loss, and the contribution of gray matter (GM) inflammation and demyelination to synaptic loss, in multiple sclerosis (MS) brain tissue. METHODS This study was performed on two different post-mortem series of MS and control brains, including deep GM and cortical GM. MS brain samples had been specifically selected for the presence of active demyelinating GM lesions. Over 1,000,000 individual synapses were identified and counted using confocal microscopy, and further characterized as glutamatergic/GABAergic. Synaptic counts were also correlated with neuronal/axonal loss. RESULTS Important synaptic loss was observed in active demyelinating GM lesions (-58.9%), while in chronic inactive GM lesions, synaptic density was only mildly reduced compared to adjacent non-lesional gray matter (NLGM) (-12.6%). Synaptic loss equally affected glutamatergic and GABAergic synapses. Diffuse synaptic loss was observed in MS NLGM compared to control GM (-21.2% overall). CONCLUSION This study provides evidence, in MS brain tissue, of acute synaptic damage/loss during active GM inflammatory demyelination and of synaptic reorganization in chronically demyelinated GM, affecting equally glutamatergic and GABAergic synapses. Furthermore, this study provides a strong indication of widespread synaptic loss in MS NLGM also independently from focal GM demyelination.
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Affiliation(s)
- Marco Vercellino
- I Division of Neurology and Multiple Sclerosis Center, Department of Neurosciences and Mental Health, AOU Città della Salute e della Scienza di Torino, Turin, Italy
| | - Stella Marasciulo
- "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | - Silvia Grifoni
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Elena Vallino-Costassa
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Chiara Bosa
- "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | | | - Paola Crociara
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Cristina Casalone
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Adriano Chiò
- I Division of Neurology and Multiple Sclerosis Center, Department of Neurosciences and Mental Health, AOU Città della Salute e della Scienza di Torino, Turin, Italy/"Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy/Neuroscience Institute of Torino (NIT), Turin, Italy
| | - Maria Teresa Giordana
- "Rita Levi Montalcini" Department of Neuroscience, University of Turin, Turin, Italy
| | - Cristiano Corona
- S.S. Neurobiologia Sperimentale, Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Turin, Italy
| | - Paola Cavalla
- I Division of Neurology and Multiple Sclerosis Center, Department of Neurosciences and Mental Health, AOU Città della Salute e della Scienza di Torino, Turin, Italy
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10
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Interleukin-1β Alters Hebbian Synaptic Plasticity in Multiple Sclerosis. Int J Mol Sci 2020; 21:ijms21196982. [PMID: 32977401 PMCID: PMC7584038 DOI: 10.3390/ijms21196982] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/11/2020] [Accepted: 09/21/2020] [Indexed: 12/16/2022] Open
Abstract
In multiple sclerosis (MS), inflammation alters synaptic transmission and plasticity, negatively influencing the disease course. In the present study, we aimed to explore the influence of the proinflammatory cytokine IL-1β on peculiar features of associative Hebbian synaptic plasticity, such as input specificity, using the paired associative stimulation (PAS). In 33 relapsing remitting-MS patients and 15 healthy controls, PAS was performed on the abductor pollicis brevis (APB) muscle. The effects over the motor hot spot of the APB and abductor digiti minimi (ADM) muscles were tested immediately after PAS and 15 and 30 min later. Intracortical excitability was tested with paired-pulse transcranial magnetic stimulation (TMS). The cerebrospinal fluid (CSF) levels of IL-1β were calculated. In MS patients, PAS failed to induce long-term potentiation (LTP)-like effects in the APB muscle and elicited a paradoxical motor-evoked potential (MEP) increase in the ADM. IL-1β levels were negatively correlated with the LTP-like response in the APB muscle. Moreover, IL-1β levels were associated with synaptic hyperexcitability tested with paired-pulse TMS. Synaptic hyperexcitability caused by IL-1β may critically contribute to alter Hebbian plasticity in MS, inducing a loss of topographic specificity.
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11
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Stampanoni Bassi M, Buttari F, Gilio L, De Paolis N, Fresegna D, Centonze D, Iezzi E. Inflammation and Corticospinal Functioning in Multiple Sclerosis: A TMS Perspective. Front Neurol 2020; 11:566. [PMID: 32733354 PMCID: PMC7358546 DOI: 10.3389/fneur.2020.00566] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/19/2020] [Indexed: 12/13/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) has been employed in multiple sclerosis (MS) to assess the integrity of the corticospinal tract and the corpus callosum and to explore some physiological properties of the motor cortex. Specific alterations of TMS measures have been strongly associated to different pathophysiological mechanisms, particularly to demyelination and neuronal loss. Moreover, TMS has contributed to investigate the neurophysiological basis of MS symptoms, particularly those not completely explained by conventional structural damage, such as fatigue. However, variability existing between studies suggests that alternative mechanisms should be involved. Knowledge of MS pathophysiology has been enriched by experimental studies in animal models (i.e., experimental autoimmune encephalomyelitis) demonstrating that inflammation alters synaptic transmission, promoting hyperexcitability and neuronal damage. Accordingly, TMS studies have demonstrated an imbalance between cortical excitation and inhibition in MS. In particular, cerebrospinal fluid concentrations of different proinflammatory and anti-inflammatory molecules have been associated to corticospinal hyperexcitability, highlighting that inflammatory synaptopathy may represent a key pathophysiological mechanism in MS. In this perspective article, we discuss whether corticospinal excitability alterations assessed with TMS in MS patients could be useful to explain the pathophysiological correlates and their relationships with specific MS clinical characteristics and symptoms. Furthermore, we discuss evidence indicating that, in MS patients, inflammatory synaptopathy could be present since the early phases, could specifically characterize relapses, and could progressively increase during the disease course.
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Affiliation(s)
| | - Fabio Buttari
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy
| | - Luana Gilio
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy
| | - Nicla De Paolis
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy
| | - Diego Fresegna
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy
| | - Diego Centonze
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy.,Laboratory of Synaptic Immunopathology, Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Ennio Iezzi
- Unit of Neurology & Neurorehabilitation, IRCCS Neuromed, Pozzilli, Italy
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12
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Bruno A, Dolcetti E, Rizzo FR, Fresegna D, Musella A, Gentile A, De Vito F, Caioli S, Guadalupi L, Bullitta S, Vanni V, Balletta S, Sanna K, Buttari F, Stampanoni Bassi M, Centonze D, Mandolesi G. Inflammation-Associated Synaptic Alterations as Shared Threads in Depression and Multiple Sclerosis. Front Cell Neurosci 2020; 14:169. [PMID: 32655374 PMCID: PMC7324636 DOI: 10.3389/fncel.2020.00169] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 05/19/2020] [Indexed: 12/11/2022] Open
Abstract
In the past years, several theories have been advanced to explain the pathogenesis of Major Depressive Disorder (MDD), a neuropsychiatric disease that causes disability in general population. Several theories have been proposed to define the MDD pathophysiology such as the classic "monoamine-theory" or the "glutamate hypothesis." All these theories have been recently integrated by evidence highlighting inflammation as a pivotal player in developing depressive symptoms. Proinflammatory cytokines have been indeed claimed to contribute to stress-induced mood disturbances and to major depression, indicating a widespread role of classical mediators of inflammation in emotional control. Moreover, during systemic inflammatory diseases, peripherally released cytokines circulate in the blood, reach the brain and cause anxiety, anhedonia, social withdrawal, fatigue, and sleep disturbances. Accordingly, chronic inflammatory disorders, such as the inflammatory autoimmune disease multiple sclerosis (MS), have been associated to higher risk of MDD, in comparison with overall population. Importantly, in both MS patients and in its experimental mouse model, Experimental Autoimmune Encephalomyelitis (EAE), the notion that depressive symptoms are reactive epiphenomenon to the MS pathology has been recently challenged by the evidence of their early manifestation, even before the onset of the disease. Furthermore, in association to such mood disturbance, inflammatory-dependent synaptic dysfunctions in several areas of MS/EAE brain have been observed independently of brain lesions and demyelination. This evidence suggests that a fine interplay between the immune and nervous systems can have a huge impact on several neurological functions, including depressive symptoms, in different pathological conditions. The aim of the present review is to shed light on common traits between MDD and MS, by looking at inflammatory-dependent synaptic alterations associated with depression in both diseases.
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Affiliation(s)
- Antonio Bruno
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Ettore Dolcetti
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Francesca Romana Rizzo
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Diego Fresegna
- Synaptic Immunopathology Lab, IRCCS San Raffaele Pisana, Rome, Italy
| | - Alessandra Musella
- Synaptic Immunopathology Lab, IRCCS San Raffaele Pisana, Rome, Italy
- Department of Human Sciences and Quality of Life Promotion, University of Rome San Raffaele, Rome, Italy
| | | | - Francesca De Vito
- Unit of Neurology, Mediterranean Neurological Institute IRCCS Neuromed, Pozzilli, Italy
| | - Silvia Caioli
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Livia Guadalupi
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Silvia Bullitta
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
- Synaptic Immunopathology Lab, IRCCS San Raffaele Pisana, Rome, Italy
| | - Valentina Vanni
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
- Synaptic Immunopathology Lab, IRCCS San Raffaele Pisana, Rome, Italy
| | - Sara Balletta
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Krizia Sanna
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
| | - Fabio Buttari
- Unit of Neurology, Mediterranean Neurological Institute IRCCS Neuromed, Pozzilli, Italy
| | | | - Diego Centonze
- Synaptic Immunopathology Lab, Department of Systems Medicine, Tor Vergata University of Rome, Rome, Italy
- Unit of Neurology, Mediterranean Neurological Institute IRCCS Neuromed, Pozzilli, Italy
| | - Georgia Mandolesi
- Synaptic Immunopathology Lab, IRCCS San Raffaele Pisana, Rome, Italy
- Department of Human Sciences and Quality of Life Promotion, University of Rome San Raffaele, Rome, Italy
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13
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Central Modulation of Selective Sphingosine-1-Phosphate Receptor 1 Ameliorates Experimental Multiple Sclerosis. Cells 2020; 9:cells9051290. [PMID: 32455907 PMCID: PMC7291065 DOI: 10.3390/cells9051290] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 01/10/2023] Open
Abstract
Future treatments of multiple sclerosis (MS), a chronic autoimmune neurodegenerative disease of the central nervous system (CNS), aim for simultaneous early targeting of peripheral immune function and neuroinflammation. Sphingosine-1-phosphate (S1P) receptor modulators are among the most promising drugs with both “immunological” and “non-immunological” actions. Selective S1P receptor modulators have been recently approved for MS and shown clinical efficacy in its mouse model, the experimental autoimmune encephalomyelitis (EAE). Here, we investigated the anti-inflammatory/neuroprotective effects of ozanimod (RPC1063), a S1P1/5 modulator recently approved in the United States for the treatment of MS, by performing ex vivo studies in EAE brain. Electrophysiological experiments, supported by molecular and immunofluorescence analysis, revealed that ozanimod was able to dampen the EAE glutamatergic synaptic alterations, through attenuation of local inflammatory response driven by activated microglia and infiltrating T cells, the main CNS-cellular players of EAE synaptopathy. Electrophysiological studies with selective S1P1 (AUY954) and S1P5 (A971432) agonists suggested that S1P1 modulation is the main driver of the anti-excitotoxic activity mediated by ozanimod. Accordingly, in vivo intra-cerebroventricular treatment of EAE mice with AUY954 ameliorated clinical disability. Altogether these results strengthened the relevance of S1P1 agonists as immunomodulatory and neuroprotective drugs for MS therapy.
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14
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Lazo-Gomez R, Velázquez GDLLG, Mireles-Jacobo D, Sotomayor-Sobrino MA. Mechanisms of neurobehavioral abnormalities in multiple sclerosis: Contributions from neural and immune components. Clin Neurophysiol Pract 2019; 4:39-46. [PMID: 30911699 PMCID: PMC6416523 DOI: 10.1016/j.cnp.2019.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 12/21/2018] [Accepted: 01/10/2019] [Indexed: 12/14/2022] Open
Abstract
Multiple sclerosis-related neurobehavioral abnormalities are one of the main components of disability in this disease. The same pathological processes that explain demyelination periods and neurodegeneration also allow the comprehension of neurobehavioral abnormalities. Inflammation in the central nervous system caused by cells of the immune system, especially lymphocytes, and by resident cells, such as astrocytes and microglia, directly modulate neurotransmission and synaptic physiology, resulting in behavioral changes (such as sickness behavior) and amplifying the degenerative mechanisms that occur in multiple sclerosis. In addition, neuronal death caused by glutamate-mediated excitotoxicity, alterations in GABAergic, serotonergic, and dopaminergic neurotransmission, and the mechanisms of axon damage are of foremost importance to explain the reduction in brain volume and the associated cognitive decline. Neuroinflammation and neurodegeneration are not isolated phenomena and various instances of interaction between them have been described. This presents attractive targets for the development of therapeutic strategies for this neglected component of multiple sclerosis related disability.
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Affiliation(s)
- Rafael Lazo-Gomez
- Neuroscience franchise, Novartis Pharma México, Calzada de Tlalpan 1779, San Diego Churubusco, 04120 Coyoacán, CDMX, Mexico
| | | | - Diego Mireles-Jacobo
- Neuroscience franchise, Novartis Pharma México, Calzada de Tlalpan 1779, San Diego Churubusco, 04120 Coyoacán, CDMX, Mexico
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15
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AMBRA1 Controls Regulatory T-Cell Differentiation and Homeostasis Upstream of the FOXO3-FOXP3 Axis. Dev Cell 2018; 47:592-607.e6. [DOI: 10.1016/j.devcel.2018.11.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/03/2018] [Accepted: 11/01/2018] [Indexed: 02/07/2023]
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16
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Enhanced GABAergic Tonic Inhibition Reduces Intrinsic Excitability of Hippocampal CA1 Pyramidal Cells in Experimental Autoimmune Encephalomyelitis. Neuroscience 2018; 395:89-100. [PMID: 30447391 DOI: 10.1016/j.neuroscience.2018.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 11/03/2018] [Accepted: 11/05/2018] [Indexed: 11/24/2022]
Abstract
Cognitive impairment (CI), a debilitating and pervasive feature of multiple sclerosis (MS), is correlated with hippocampal atrophy. Findings from postmortem MS hippocampi indicate that expression of genes involved in both excitatory and inhibitory neurotransmission are altered in MS, and although deficits in excitatory neurotransmission have been reported in the MS model experimental autoimmune encephalomyelitis (EAE), the functional consequence of altered inhibitory neurotransmission remains poorly understood. In this study, we used electrophysiological and biochemical techniques to examine inhibitory neurotransmission in the CA1 region of the hippocampus in EAE. We find that tonic, GABAergic inhibition is enhanced in CA1 pyramidal cells from EAE mice. Although plasma membrane expression of the GABA transporter GAT-3 was decreased in the EAE hippocampus, an increased surface expression of α5 subunit-containing GABAA receptors appears to be primarily responsible for the increase in tonic inhibition during EAE. Enhanced tonic inhibition during EAE was associated with decreased CA1 pyramidal cell excitability and inhibition of α5 subunit-containing GABAA receptors with the negative allosteric modulator L-655,708 enhanced pyramidal cell excitability in EAE mice. Together, our results suggest that altered GABAergic neurotransmission may underlie deficits in hippocampus-dependent cognitive function in EAE and MS.
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17
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Musella A, Gentile A, Rizzo FR, De Vito F, Fresegna D, Bullitta S, Vanni V, Guadalupi L, Stampanoni Bassi M, Buttari F, Centonze D, Mandolesi G. Interplay Between Age and Neuroinflammation in Multiple Sclerosis: Effects on Motor and Cognitive Functions. Front Aging Neurosci 2018; 10:238. [PMID: 30135651 PMCID: PMC6092506 DOI: 10.3389/fnagi.2018.00238] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/20/2018] [Indexed: 01/09/2023] Open
Abstract
Aging is one of the main risk factors for the development of many neurodegenerative diseases. Emerging evidence has acknowledged neuroinflammation as potential trigger of the functional changes occurring during normal and pathological aging. Two main determinants have been recognized to cogently contribute to neuroinflammation in the aging brain, i.e., the systemic chronic low-grade inflammation and the decline in the regulation of adaptive and innate immune systems (immunosenescence, ISC). The persistence of the inflammatory status in the brain in turn may cause synaptopathy and synaptic plasticity impairments that underlie both motor and cognitive dysfunctions. Interestingly, such inflammation-dependent synaptic dysfunctions have been recently involved in the pathophysiology of multiple sclerosis (MS). MS is an autoimmune neurodegenerative disease, typically affecting young adults that cause an early and progressive deterioration of both cognitive and motor functions. Of note, recent controlled studies have clearly shown that age at onset modifies prognosis and exerts a significant effect on presenting phenotype, suggesting that aging is a significant factor associated to the clinical course of MS. Moreover, some lines of evidence point to the different impact of age on motor disability and cognitive deficits, being the former most affected than the latter. The precise contribution of aging-related factors to MS neurological disability and the underlying molecular and cellular mechanisms are still unclear. In the present review article, we first emphasize the importance of the neuroinflammatory dependent mechanisms, such as synaptopathy and synaptic plasticity impairments, suggesting their potential exacerbation or acceleration with advancing age in the MS disease. Lastly, we provide an overview of clinical and experimental studies highlighting the different impact of age on motor disability and cognitive decline in MS, raising challenging questions on the putative age-related mechanisms involved.
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Affiliation(s)
- Alessandra Musella
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy.,San Raffaele University of Rome, Rome, Italy
| | - Antonietta Gentile
- Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Unit of Neurology, Istituto Neurologico Mediterraneo (IRCCS Neuromed), Pozzilli, Italy
| | - Francesca Romana Rizzo
- Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Francesca De Vito
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy.,Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Diego Fresegna
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy.,Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Silvia Bullitta
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy.,Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Valentina Vanni
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy.,Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Livia Guadalupi
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy
| | | | - Fabio Buttari
- Unit of Neurology, Istituto Neurologico Mediterraneo (IRCCS Neuromed), Pozzilli, Italy
| | - Diego Centonze
- Laboratory of Synaptic Immunopathology, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Unit of Neurology, Istituto Neurologico Mediterraneo (IRCCS Neuromed), Pozzilli, Italy
| | - Georgia Mandolesi
- Laboratory of Synaptic Immunopathology, IRCCS San Raffaele Pisana, Rome, Italy.,San Raffaele University of Rome, Rome, Italy
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18
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The role of the cerebellum in multiple sclerosis—150 years after Charcot. Neurosci Biobehav Rev 2018; 89:85-98. [DOI: 10.1016/j.neubiorev.2018.02.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 01/02/2018] [Accepted: 02/18/2018] [Indexed: 12/22/2022]
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19
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Nguyen HB, Sui Y, Thai TQ, Ikenaka K, Oda T, Ohno N. Decreased number and increased volume with mitochondrial enlargement of cerebellar synaptic terminals in a mouse model of chronic demyelination. Med Mol Morphol 2018; 51:208-216. [PMID: 29796936 DOI: 10.1007/s00795-018-0193-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 05/15/2018] [Indexed: 01/02/2023]
Abstract
Impaired nerve conduction, axonal degeneration, and synaptic alterations contribute to neurological disabilities in inflammatory demyelinating diseases. Cerebellar dysfunction is associated with demyelinating disorders, but the alterations of axon terminals in cerebellar gray matter during chronic demyelination are still unclear. We analyzed the morphological and ultrastructural changes of climbing fiber terminals in a mouse model of hereditary chronic demyelination. Three-dimensional ultrastructural analyses using serial block-face scanning electron microscopy and immunostaining for synaptic markers were performed in a demyelination mouse model caused by extra copies of myelin gene (PLP4e). At 1 month old, many myelinated axons were observed in PLP4e and wild-type mice, but demyelinated axons and axons with abnormally thin myelin were prominent in PLP4e mice at 5 months old. The density of climbing fiber terminals was significantly reduced in PLP4e mice at 5 months old. Reconstruction of climbing fiber terminals revealed that PLP4e climbing fibers had increased varicosity volume and enlarged mitochondria in the varicosities at 5-month-old mice. These results suggest that chronic demyelination is associated with alterations and loss of climbing fiber terminals in the cerebellar cortex, and that synaptic changes may contribute to cerebellar phenotypes observed in hereditary demyelinating disorders.
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Affiliation(s)
- Huy Bang Nguyen
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Yang Sui
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Truc Quynh Thai
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan
| | - Toshiyuki Oda
- Department of Anatomy and Structural Biology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Chuo, Japan
| | - Nobuhiko Ohno
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan. .,Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
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20
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Guarnieri FC, Bellani S, Yekhlef L, Bergamaschi A, Finardi A, Fesce R, Pozzi D, Monzani E, Fornasiero EF, Matteoli M, Martino G, Furlan R, Taverna S, Muzio L, Valtorta F. Synapsin I deletion reduces neuronal damage and ameliorates clinical progression of experimental autoimmune encephalomyelitis. Brain Behav Immun 2018; 68:197-210. [PMID: 29066310 DOI: 10.1016/j.bbi.2017.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/10/2017] [Accepted: 10/20/2017] [Indexed: 11/20/2022] Open
Abstract
The classical view of multiple sclerosis (MS) pathogenesis states that inflammation-mediated demyelination is responsible for neuronal damage and loss. However, recent findings show that impairment of neuronal functions and demyelination can be independent events, suggesting the coexistence of other pathogenic mechanisms. Due to the inflammatory milieu, subtle alterations in synaptic function occur, which are probably at the basis of the early cognitive decline that often precedes the neurodegenerative phases in MS patients. In particular, it has been reported that inflammation enhances excitatory synaptic transmission while it decreases GABAergic transmission in vitro and ex vivo. This evidence points to the idea that an excitation/inhibition imbalance occurs in the inflamed MS brain, even though the exact molecular mechanisms leading to this synaptic dysfunction are as yet not completely clear. Along this line, we observed that acute treatment of primary hippocampal neurons in culture with pro-inflammatory cytokines leads to an increased phosphorylation of synapsin I (SynI) by ERK1/2 kinase and to an increase in the frequency of spontaneous synaptic vesicle release events, which is prevented by SynI deletion. In vivo, the ablation of SynI expression is protective in terms of disease progression and neuronal damage in the experimental autoimmune encephalomyelitis mouse model of MS. Our results point to a possible key role in MS pathogenesis of the neuronal protein SynI, a regulator of excitation/inhibition balance in neuronal networks.
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Affiliation(s)
- Fabrizia C Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Serena Bellani
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Latefa Yekhlef
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Andrea Bergamaschi
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Annamaria Finardi
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Riccardo Fesce
- Centre of Neuroscience and DISTA, University of Insubria, Via Ravasi 2, 21100 Varese, Italy
| | - Davide Pozzi
- Humanitas Clinical and Research Centre, Via Manzoni 113, 20089 Rozzano, Milan, Italy
| | - Elena Monzani
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Eugenio F Fornasiero
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Michela Matteoli
- Humanitas Clinical and Research Centre, Via Manzoni 113, 20089 Rozzano, Milan, Italy; CNR Institute of Neuroscience, via Vanvitelli 32, 20129 Milan, Italy
| | - Gianvito Martino
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Roberto Furlan
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Stefano Taverna
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Luca Muzio
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy.
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21
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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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22
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Araújo SES, Mendonça HR, Wheeler NA, Campello-Costa P, Jacobs KM, Gomes FCA, Fox MA, Fuss B. Inflammatory demyelination alters subcortical visual circuits. J Neuroinflammation 2017; 14:162. [PMID: 28821276 PMCID: PMC5562979 DOI: 10.1186/s12974-017-0936-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 08/07/2017] [Indexed: 11/13/2022] Open
Abstract
Background Multiple sclerosis (MS) is an inflammatory demyelinating disease classically associated with axonal damage and loss; more recently, however, synaptic changes have been recognized as additional contributing factors. An anatomical area commonly affected in MS is the visual pathway; yet, changes other than those associated with inflammatory demyelination of the optic nerve, i.e., optic neuritis, have not been described in detail. Methods Adult mice were subjected to a diet containing cuprizone to mimic certain aspects of inflammatory demyelination as seen in MS. Demyelination and inflammation were assessed by real-time polymerase chain reaction and immunohistochemistry. Synaptic changes associated with inflammatory demyelination in the dorsal lateral geniculate nucleus (dLGN) were determined by immunohistochemistry, Western blot analysis, and electrophysiological field potential recordings. Results In the cuprizone model, demyelination was observed in retinorecipient regions of the subcortical visual system, in particular the dLGN, where it was found accompanied by microglia activation and astrogliosis. In contrast, anterior parts of the pathway, i.e., the optic nerve and tract, appeared largely unaffected. Under the inflammatory demyelinating conditions, as seen in the dLGN of cuprizone-treated mice, there was an overall decrease in excitatory synaptic inputs from retinal ganglion cells. At the same time, the number of synaptic complexes arising from gamma-aminobutyric acid (GABA)-generating inhibitory neurons was found increased, as were the synapses that contain the N-methyl-d-aspartate receptor (NMDAR) subunit GluN2B and converge onto inhibitory neurons. These synaptic changes were functionally found associated with a shift toward an overall increase in network inhibition. Conclusions Using the cuprizone model of inflammatory demyelination, our data reveal a novel form of synaptic (mal)adaption in the CNS that is characterized by a shift of the excitation/inhibition balance toward inhibitory network activity associated with an increase in GABAergic inhibitory synapses and a possible increase in excitatory input onto inhibitory interneurons. In addition, our data recognize the cuprizone model as a suitable tool in which to assess the effects of inflammatory demyelination on subcortical retinorecipient regions of the visual system, such as the dLGN, in the absence of overt optic neuritis.
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Affiliation(s)
- Sheila Espírito Santo Araújo
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.,Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto de Biologia, Programa de Neurociências, Universidade Federal Fluminense, Niterói, Brazil.,Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Henrique Rocha Mendonça
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.,Instituto de Biologia, Programa de Neurociências, Universidade Federal Fluminense, Niterói, Brazil
| | - Natalie A Wheeler
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Paula Campello-Costa
- Instituto de Biologia, Programa de Neurociências, Universidade Federal Fluminense, Niterói, Brazil
| | - Kimberle M Jacobs
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Flávia C A Gomes
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Michael A Fox
- Developmental and Translational Neurobiology Center, Virginia Tech Carilion Research Institute, Roanoke, VA, USA
| | - Babette Fuss
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Richmond, VA, USA.
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23
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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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Stampanoni Bassi M, Mori F, Buttari F, Marfia GA, Sancesario A, Centonze D, Iezzi E. Neurophysiology of synaptic functioning in multiple sclerosis. Clin Neurophysiol 2017; 128:1148-1157. [DOI: 10.1016/j.clinph.2017.04.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 04/06/2017] [Accepted: 04/08/2017] [Indexed: 01/16/2023]
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Abstract
Multiple sclerosis (MS) commonly affects the cerebellum causing acute and chronic symptoms. Cerebellar signs contribute significantly to clinical disability, and symptoms such as tremor, ataxia, and dysarthria are particularly difficult to treat. Increasing knowledge concerning the pathophysiology of cerebellar disease in MS from human postmortem studies, experimental models, and clinical trials has raised the hope that cerebellar symptoms will be better treated in the future.
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Affiliation(s)
- Alastair Wilkins
- MS and Stem Cell Group, University of Bristol, Learning and Research, Southmead Hospital, Bristol, United Kingdom
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Gentile A, Musella A, Bullitta S, Fresegna D, De Vito F, Fantozzi R, Piras E, Gargano F, Borsellino G, Battistini L, Schubart A, Mandolesi G, Centonze D. Siponimod (BAF312) prevents synaptic neurodegeneration in experimental multiple sclerosis. J Neuroinflammation 2016; 13:207. [PMID: 27566665 PMCID: PMC5002118 DOI: 10.1186/s12974-016-0686-4] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 08/18/2016] [Indexed: 12/31/2022] Open
Abstract
Background Data from multiple sclerosis (MS) and the MS rodent model, experimental autoimmune encephalomyelitis (EAE), highlighted an inflammation-dependent synaptopathy at the basis of the neurodegenerative damage causing irreversible disability in these disorders. This synaptopathy is characterized by an imbalance between glutamatergic and GABAergic transmission and has been proposed to be a potential therapeutic target. Siponimod (BAF312), a selective sphingosine 1-phosphate1,5 receptor modulator, is currently under investigation in a clinical trial in secondary progressive MS patients. We investigated whether siponimod, in addition to its peripheral immune modulation, may exert direct neuroprotective effects in the central nervous system (CNS) of mice with chronic progressive EAE. Methods Minipumps allowing continuous intracerebroventricular (icv) infusion of siponimod for 4 weeks were implanted into C57BL/6 mice subjected to MOG35-55-induced EAE. Electrophysiology, immunohistochemistry, western blot, qPCR experiments, and peripheral lymphocyte counts were performed. In addition, the effect of siponimod on activated microglia was assessed in vitro to confirm the direct effect of the drug on CNS-resident immune cells. Results Siponimod administration (0.45 μg/day) induced a significant beneficial effect on EAE clinical scores with minimal effect on peripheral lymphocyte counts. Siponimod rescued defective GABAergic transmission in the striatum of EAE, without correcting the EAE-induced alterations of glutamatergic transmission. We observed a significant attenuation of astrogliosis and microgliosis together with reduced lymphocyte infiltration in the striatum of EAE mice treated with siponimod. Interestingly, siponimod reduced the release of IL-6 and RANTES from activated microglial cells in vitro, which might explain the reduced lymphocyte infiltration. Furthermore, the loss of parvalbumin-positive (PV+) GABAergic interneurons typical of EAE brains was rescued by siponimod treatment, providing a plausible explanation of the selective effects of this drug on inhibitory synaptic transmission. Conclusions Altogether, our results show that siponimod has neuroprotective effects in the CNS of EAE mice, which are likely independent of its peripheral immune effect, suggesting that this drug could be effective in limiting neurodegenerative pathological processes in MS.
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Affiliation(s)
- Antonietta Gentile
- Laboratory of Neuroimmunology and Synaptic Transmission, IRCCS Fondazione Santa Lucia, Centro Europeo di Ricerca sul Cervello (CERC), 00143, Rome, Italy.,Multiple Sclerosis Research Unit, Department of Systems Medicine, Tor Vergata University, 00133, Rome, Italy
| | - Alessandra Musella
- Laboratory of Neuroimmunology and Synaptic Transmission, IRCCS Fondazione Santa Lucia, Centro Europeo di Ricerca sul Cervello (CERC), 00143, Rome, Italy
| | - Silvia Bullitta
- Laboratory of Neuroimmunology and Synaptic Transmission, IRCCS Fondazione Santa Lucia, Centro Europeo di Ricerca sul Cervello (CERC), 00143, Rome, Italy
| | - Diego Fresegna
- Laboratory of Neuroimmunology and Synaptic Transmission, IRCCS Fondazione Santa Lucia, Centro Europeo di Ricerca sul Cervello (CERC), 00143, Rome, Italy.,Multiple Sclerosis Research Unit, Department of Systems Medicine, Tor Vergata University, 00133, Rome, Italy
| | - Francesca De Vito
- Laboratory of Neuroimmunology and Synaptic Transmission, IRCCS Fondazione Santa Lucia, Centro Europeo di Ricerca sul Cervello (CERC), 00143, Rome, Italy.,Multiple Sclerosis Research Unit, Department of Systems Medicine, Tor Vergata University, 00133, Rome, Italy
| | - Roberta Fantozzi
- Unit of Neurology and Neurorehabilitation, IRCCS Istituto Neurologico Mediterraneo (INM) Neuromed, 86077, Pozzilli, IS, Italy
| | - Eleonora Piras
- Neuroimmunology Unit, IRCCS Fondazione Santa Lucia-CERC, 00143, Rome, Italy
| | - Francesca Gargano
- Neuroimmunology Unit, IRCCS Fondazione Santa Lucia-CERC, 00143, Rome, Italy
| | | | - Luca Battistini
- Neuroimmunology Unit, IRCCS Fondazione Santa Lucia-CERC, 00143, Rome, Italy
| | - Anna Schubart
- Novartis Institutes of Biomedical Research, Basel, Switzerland
| | - Georgia Mandolesi
- Laboratory of Neuroimmunology and Synaptic Transmission, IRCCS Fondazione Santa Lucia, Centro Europeo di Ricerca sul Cervello (CERC), 00143, Rome, Italy.
| | - Diego Centonze
- Multiple Sclerosis Research Unit, Department of Systems Medicine, Tor Vergata University, 00133, Rome, Italy.,Unit of Neurology and Neurorehabilitation, IRCCS Istituto Neurologico Mediterraneo (INM) Neuromed, 86077, Pozzilli, IS, Italy
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Crowley T, Cryan JF, Downer EJ, O'Leary OF. Inhibiting neuroinflammation: The role and therapeutic potential of GABA in neuro-immune interactions. Brain Behav Immun 2016; 54:260-277. [PMID: 26851553 DOI: 10.1016/j.bbi.2016.02.001] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 01/22/2016] [Accepted: 02/02/2016] [Indexed: 12/25/2022] Open
Abstract
The central nervous system, once thought to be a site of immunological privilege, has since been found to harbour immunocompetent cells and to communicate with the peripheral nervous system. In the central nervous system (CNS), glial cells display immunological responses to pathological and physiological stimuli through pro- and anti-inflammatory cytokine and chemokine signalling, antigen presentation and the clearing of cellular debris through phagocytosis. While this neuroinflammatory signalling can act to reduce neuronal damage and comprises a key facet of CNS homeostasis, persistent inflammation or auto-antigen-mediated immunoreactivity can induce a positive feedback cycle of neuroinflammation that ultimately results in necrosis of glia and neurons. Persistent neuroinflammation has been recognised as a major pathological component of virtually all neurodegenerative diseases and has also been a focus of research into the pathology underlying psychiatric disorders. Thus, pharmacological strategies to curb the pathological effects of persistent neuroinflammation are of interest for many disorders of the CNS. Accumulating evidence suggests that GABAergic activities are closely bound to immune processes and signals, and thus the GABAergic neurotransmitter system might represent an important therapeutic target in modulating neuroinflammation. Here, we review evidence that inflammation induces changes in the GABA neurotransmitter system in the CNS and that GABAergic signalling exerts a reciprocal influence over neuroinflammatory processes. Together, the data support the hypothesis that the GABA system is a potential therapeutic target in the modulation of central inflammation.
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Affiliation(s)
- Tadhg Crowley
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland
| | - Eric J Downer
- School of Medicine, Discipline of Physiology, Trinity Biomedical Sciences Institute, Trinity College, Dublin 2, Ireland.
| | - Olivia F O'Leary
- Department of Anatomy and Neuroscience, University College Cork, Ireland; APC Microbiome Institute, University College Cork, Ireland.
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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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Mandolesi G, Gentile A, Musella A, Centonze D. IL-1β dependent cerebellar synaptopathy in a mouse mode of multiple sclerosis. THE CEREBELLUM 2015; 14:19-22. [PMID: 25326653 DOI: 10.1007/s12311-014-0613-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Multiple sclerosis (MS) is considered as an autoimmune inflammatory disease and is one of the main causes of motor disability in young adults. Focal white matter lesions consisting of T lymphocyte and macrophage infiltrates, demyelination, and axonal transection are clear hallmarks of MS disease. However, white matter pathology does not occur exclusively. Clinical and experimental studies have shown gray matter atrophy and lesions occurring in several brain regions, including the cerebellum. Cerebellar-dependent disability is very common in MS patients. Cerebellar deficits are also relatively refractory to symptomatic therapy and progress even under disease-modifying agents. However, the neuropathology underlying cerebellar dysfunction remains largely unknown. We recently demonstrated that the cerebellum is also targeted in experimental autoimmune encephalomyelitis (EAE), the most widely used animal model of MS. Electrophysiological studies, supported by immunofluorescence and biochemical analysis, revealed an imbalance between the spontaneous excitatory and inhibitory synaptic transmission at Purkinje cell synapses. While the frequency of the spontaneous inhibitory postsynaptic currents (sIPSC) during the acute phase of EAE was reduced in correlation with a selective degeneration of basket and stellate neurons, the glutamatergic transmission was enhanced due to a reduced expression and functioning of glutamate aspartate transporter (GLAST)/excitatory amino acid transporter 1 (EAAT1), the most abundant glutamate transporter expressed by Bergmann glia. Of note, we demonstrated that the proinflammatory cytokine interleukin-1β (IL-1β), highly expressed in EAE cerebellum and released by infiltrating lymphocytes, was one of the molecular players directly responsible for such synaptic alterations during the acute phase. Furthermore, other brain regions in EAE mice seem to be affected by a similar inflammatory dependent synaptopathy, suggesting common molecular targets for potential therapeutic strategies. Accordingly, we observed that intracerebroventricular inhibition of IL-1β signaling in EAE mice was able to ameliorate inflammatory reaction, electrophysiological response, and clinical disability, indicating a pivotal role of IL-1β in EAE disease and likely, in MS.
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Affiliation(s)
- Georgia Mandolesi
- Fondazione Santa Lucia IRCSS, Via del Fosso di Fiorano 64, 00146, Rome, Italy,
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Neural Plasticity in Multiple Sclerosis: The Functional and Molecular Background. Neural Plast 2015; 2015:307175. [PMID: 26229689 PMCID: PMC4503575 DOI: 10.1155/2015/307175] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 06/09/2015] [Accepted: 06/21/2015] [Indexed: 01/19/2023] Open
Abstract
Multiple sclerosis is an autoimmune neurodegenerative disorder resulting in motor dysfunction and cognitive decline. The inflammatory and neurodegenerative changes seen in the brains of MS patients lead to progressive disability and increasing brain atrophy. The most common type of MS is characterized by episodes of clinical exacerbations and remissions. This suggests the presence of compensating mechanisms for accumulating damage. Apart from the widely known repair mechanisms like remyelination, another important phenomenon is neuronal plasticity. Initially, neuroplasticity was connected with the developmental stages of life; however, there is now growing evidence confirming that structural and functional reorganization occurs throughout our lifetime. Several functional studies, utilizing such techniques as fMRI, TBS, or MRS, have provided valuable data about the presence of neuronal plasticity in MS patients. CNS ability to compensate for neuronal damage is most evident in RR-MS; however it has been shown that brain plasticity is also preserved in patients with substantial brain damage. Regardless of the numerous studies, the molecular background of neuronal plasticity in MS is still not well understood. Several factors, like IL-1β, BDNF, PDGF, or CB1Rs, have been implicated in functional recovery from the acute phase of MS and are thus considered as potential therapeutic targets.
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Weiss S, Mori F, Rossi S, Centonze D. Disability in multiple sclerosis: When synaptic long-term potentiation fails. Neurosci Biobehav Rev 2014; 43:88-99. [DOI: 10.1016/j.neubiorev.2014.03.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 02/11/2014] [Accepted: 03/31/2014] [Indexed: 12/13/2022]
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Nisticò R, Mori F, Feligioni M, Nicoletti F, Centonze D. Synaptic plasticity in multiple sclerosis and in experimental autoimmune encephalomyelitis. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130162. [PMID: 24298163 DOI: 10.1098/rstb.2013.0162] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Approximately half of all patients with multiple sclerosis (MS) experience cognitive dysfunction, including learning and memory impairment. Recent studies suggest that hippocampal pathology is involved, although the mechanisms underlying these deficits remain poorly understood. Evidence obtained from a mouse model of MS, the experimental autoimmune encephalomyelitis (EAE), suggests that in the hippocampus of EAE mice long-term potentiation (LTP) is favoured over long-term depression in response to repetitive synaptic activation, through a mechanism dependent on enhanced IL-1β released from infiltrating lymphocytes or activated microglia. Facilitated LTP during an immune-mediated attack might underlie functional recovery, but also cognitive deficits and excitotoxic neurodegeneration. Having identified that pro-inflammatory cytokines such as IL-1β can influence synaptic function and integrity in early MS, it is hoped that new treatments targeted towards preventing synaptic pathology can be developed.
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Affiliation(s)
- Robert Nisticò
- Department of Physiology and Pharmacology, Sapienza University of Rome, , 00185 Rome, Italy
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Microglia: an active player in the regulation of synaptic activity. Neural Plast 2013; 2013:627325. [PMID: 24303218 PMCID: PMC3835777 DOI: 10.1155/2013/627325] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2013] [Revised: 09/05/2013] [Accepted: 09/19/2013] [Indexed: 12/18/2022] Open
Abstract
Synaptic plasticity is critical for elaboration and adaptation in the developing and developed brain. It is well established that astrocytes play an important role in the maintenance of what has been dubbed “the tripartite synapse”. Increasing evidence shows that a fourth cell type, microglia, is critical to this maintenance as well. Microglia are the resident macrophages of the central nervous system (CNS). Because of their well-characterized inflammatory functions, research has primarily focused on their innate immune properties. The role of microglia in the maintenance of synapses in development and in homeostasis is not as well defined. A number of significant findings have shed light on the critical role of microglia at the synapse. It is becoming increasingly clear that microglia play a seminal role in proper synaptic development and elimination.
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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: 115] [Impact Index Per Article: 10.5] [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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Ferrini F, De Koninck Y. Microglia control neuronal network excitability via BDNF signalling. Neural Plast 2013; 2013:429815. [PMID: 24089642 PMCID: PMC3780625 DOI: 10.1155/2013/429815] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2013] [Accepted: 07/28/2013] [Indexed: 12/27/2022] Open
Abstract
Microglia-neuron interactions play a crucial role in several neurological disorders characterized by altered neural network excitability, such as epilepsy and neuropathic pain. While a series of potential messengers have been postulated as substrates of the communication between microglia and neurons, including cytokines, purines, prostaglandins, and nitric oxide, the specific links between messengers, microglia, neuronal networks, and diseases have remained elusive. Brain-derived neurotrophic factor (BDNF) released by microglia emerges as an exception in this riddle. Here, we review the current knowledge on the role played by microglial BDNF in controlling neuronal excitability by causing disinhibition. The efforts made by different laboratories during the last decade have collectively provided a robust mechanistic paradigm which elucidates the mechanisms involved in the synthesis and release of BDNF from microglia, the downstream TrkB-mediated signals in neurons, and the biophysical mechanism by which disinhibition occurs, via the downregulation of the K⁺-Cl⁻ cotransporter KCC2, dysrupting Cl⁻ homeostasis, and hence the strength of GABA(A)- and glycine receptor-mediated inhibition. The resulting altered network activity appears to explain several features of the associated pathologies. Targeting the molecular players involved in this canonical signaling pathway may lead to novel therapeutic approach for ameliorating a wide array of neural dysfunctions.
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Affiliation(s)
- Francesco Ferrini
- Department of Veterinary Sciences, University of Turin, Grugliasco, 10095 Turin, Italy
| | - Yves De Koninck
- Institut Universitaire en Santé Mentale de Québec, Québec, QC, Canada G1J 2G3
- Department of Psychiatry and Neuroscience, Université Laval, Québec, QC, Canada G13 7P4
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Musella A, Mandolesi G, Gentile A, Rossi S, Studer V, Motta C, Sepman H, Fresegna D, Haji N, Paolillo A, Matarese G, Centonze D. Cladribine interferes with IL-1β synaptic effects in experimental multiple sclerosis. J Neuroimmunol 2013; 264:8-13. [PMID: 24045165 DOI: 10.1016/j.jneuroim.2013.08.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Revised: 08/16/2013] [Accepted: 08/20/2013] [Indexed: 11/18/2022]
Abstract
Alterations of glutamate-mediated synaptic transmission occur in both multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), the animal model of MS. Here we investigated whether intracerebroventricular (Icv) administration of cladribine has effects on EAE. Icv infusion of cladribine reduced the clinical deficits of EAE mice and reversed EAE-induced enhancement of excitatory postsynaptic current (sEPSC) frequency, a neurophysiological measure of glutamatergic synaptopathy associated with central inflammation. Cladribine failed to interfere with EAE-induced microglial and astroglial activation, but blocked EAE synaptic alterations by interfering with interleukin-1β effects. Cladribine possesses neuroprotective properties in experimental MS that are independent of its peripheral immunosuppressant action.
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Affiliation(s)
- Alessandra Musella
- Fondazione Santa Lucia, Centro Europeo per la Ricerca sul Cervello (CERC), 00143 Rome, Italy; UOC Neurologia, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, 00133 Rome, Italy
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Interleukin-1β promotes long-term potentiation in patients with multiple sclerosis. Neuromolecular Med 2013; 16:38-51. [PMID: 23892937 DOI: 10.1007/s12017-013-8249-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 07/12/2013] [Indexed: 10/26/2022]
Abstract
The immune system shapes synaptic transmission and plasticity in experimental autoimmune encephalomyelitis (EAE), the mouse model of multiple sclerosis (MS). These synaptic adaptations are believed to drive recovery of function after brain lesions, and also learning and memory deficits and excitotoxic neurodegeneration; whether inflammation influences synaptic plasticity in MS patients is less clear. In a cohort of 59 patients with MS, we found that continuous theta-burst transcranial magnetic stimulation did not induce the expected long-term depression (LTD)-like synaptic phenomenon, but caused persisting enhancement of brain cortical excitability. The amplitude of this long-term potentiation (LTP)-like synaptic phenomenon correlated with the concentration of the pro-inflammatory cytokine interleukin-1β (IL-1β) in the cerebrospinal fluid. In MS and EAE, the brain and spinal cord are typically enriched of CD3(+) T lymphocyte infiltrates, which are, along with activated microglia and astroglia, a major cause of inflammation. Here, we found a correlation between the presence of infiltrating T lymphocytes in the hippocampus of EAE mice and synaptic plasticity alterations. We observed that T lymphocytes from EAE, but not from control mice, release IL-1β and promote LTP appearance over LTD, thereby mimicking the facilitated LTP induction observed in the cortex of MS patients. EAE-specific T lymphocytes were able to suppress GABAergic transmission in an IL-1β-dependent manner, providing a possible synaptic mechanism able to lower the threshold of LTP induction in MS brains. Moreover, in vivo blockade of IL-1β signaling resulted in inflammation and synaptopathy recovery in EAE hippocampus. These data provide novel insights into the pathophysiology of MS.
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Zendedel A, Beyer C, Kipp M. Cuprizone-induced demyelination as a tool to study remyelination and axonal protection. J Mol Neurosci 2013; 51:567-72. [PMID: 23666824 DOI: 10.1007/s12031-013-0026-4] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 04/30/2013] [Indexed: 12/22/2022]
Abstract
In the brain of multiple sclerosis (MS) patients, the conduction block of axons due to demyelination and inflammation underlies early neurological symptoms, whereas axonal transection accounts for permanent deficits occurring during later disease stages. The beneficial function of myelin for the protection of the axonal compartment and network stability between neurons has been shown in numerous studies. Thus, rapid and adequate remyelination is an important factor for axonal patronage during neuroinflammatory conditions. In this review article, we discuss frequently used experimental in vivo and in vitro animal models to examine remyelination and repair in MS. The focus of the discussion is the relevance of the toxin model 'cuprizone' to study the pathology of demyelination and the physiology of remyelination. This also includes recent findings in this animal model which implicate that axonal damage is an ongoing process independent of the initiation of endogenous remyelination.
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Affiliation(s)
- Adib Zendedel
- Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany
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Mecha M, Carrillo-Salinas FJ, Mestre L, Feliú A, Guaza C. Viral models of multiple sclerosis: neurodegeneration and demyelination in mice infected with Theiler's virus. Prog Neurobiol 2013; 101-102:46-64. [PMID: 23201558 PMCID: PMC7117056 DOI: 10.1016/j.pneurobio.2012.11.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/30/2012] [Accepted: 11/12/2012] [Indexed: 11/02/2022]
Abstract
Multiple sclerosis (MS) is a complex inflammatory disease of unknown etiology that affects the central nervous system (CNS) white matter, and for which no effective cure exists. Indeed, whether the primary event in MS pathology affects myelin or axons of the CNS remains unclear. Animal models are necessary to identify the immunopathological mechanisms involved in MS and to develop novel therapeutic and reparative approaches. Specifically, viral models of chronic demyelination and axonal damage have been used to study the contribution of viruses in human MS, and they have led to important breakthroughs in our understanding of MS pathology. The Theiler's murine encephalomyelitis virus (TMEV) model is one of the most commonly used MS models, although other viral models are also used, including neurotropic strains of mouse hepatitis virus (MHV) that induce chronic inflammatory demyelination with similar histological features to those observed in MS. This review will discuss the immunopathological mechanisms involved in TMEV-induced demyelinating disease (TMEV-IDD). The TMEV model reproduces a chronic progressive disease due to the persistence of the virus for the entire lifespan in susceptible mice. The evolution and significance of the axonal damage and neuroinflammation, the importance of epitope spread from viral to myelin epitopes, the presence of abortive remyelination and the existence of a brain pathology in addition to the classical spinal cord demyelination, are some of the findings that will be discussed in the context of this TMEV-IDD model. Despite their limitations, viral models remain an important tool to study the etiology of MS, and to understand the clinical and pathological variability associated with this disease.
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Key Words
- ab, antibody
- ag, antigen
- apc, antigen presenting cell
- bbb, blood–brain barrier
- cns, central nervous system
- cox-2, cyclooxygenase-2
- ctl, cytotoxic t lymphocytes
- dpi, days post-infection
- da, daniels strain of theiler's virus
- eae, experimental autoimmune encephalomyelitis
- galc, galactocerebroside
- mbp, myelin basic protein
- mnc, mononuclear cells
- mhc, major histocompatibility complex
- mhv, mouse hepatitis virus
- mog, myelin oligodendrocyte glycoprotein
- ms, multiple sclerosis
- naa, n-acetylaspartate
- no, nitric oxide
- pcr, polymerase chain reaction
- plp, myelin proteolipid protein
- pprs, pattern recognition receptors
- sfv, semliki forest virus
- sv, sindbis virus
- tmev, theiler's murine encephalomyelitis virus
- tmev-idd, theiler's murine encephalomyelitis virus-induced demyelinating disease
- tregs, regulatory t cells
- theiler's virus
- multiple sclerosis
- demyelination
- axonal damage
- neuroinflammation
- spinal cord pathology
- brain pathology
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Affiliation(s)
| | | | | | | | - Carmen Guaza
- Neuroimmunology Group, Functional and System Neurobiology Department, Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda Dr Arce 37, 28002 Madrid, Spain
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Nisticò R, Mango D, Mandolesi G, Piccinin S, Berretta N, Pignatelli M, Feligioni M, Musella A, Gentile A, Mori F, Bernardi G, Nicoletti F, Mercuri NB, Centonze D. Inflammation subverts hippocampal synaptic plasticity in experimental multiple sclerosis. PLoS One 2013; 8:e54666. [PMID: 23355887 PMCID: PMC3552964 DOI: 10.1371/journal.pone.0054666] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 12/17/2012] [Indexed: 12/18/2022] Open
Abstract
Abnormal use-dependent synaptic plasticity is universally accepted as the main physiological correlate of memory deficits in neurodegenerative disorders. It is unclear whether synaptic plasticity deficits take place during neuroinflammatory diseases, such as multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). In EAE mice, we found significant alterations of synaptic plasticity rules in the hippocampus. When compared to control mice, in fact, hippocampal long-term potentiation (LTP) induction was favored over long-term depression (LTD) in EAE, as shown by a significant rightward shift in the frequency–synaptic response function. Notably, LTP induction was also enhanced in hippocampal slices from control mice following interleukin-1β (IL-1β) perfusion, and both EAE and IL-1β inhibited GABAergic spontaneous inhibitory postsynaptic currents (sIPSC) without affecting glutamatergic transmission and AMPA/NMDA ratio. EAE was also associated with selective loss of GABAergic interneurons and with reduced gamma-frequency oscillations in the CA1 region of the hippocampus. Finally, we provided evidence that microglial activation in the EAE hippocampus was associated with IL-1β expression, and hippocampal slices from control mice incubated with activated microglia displayed alterations of GABAergic transmission similar to those seen in EAE brains, through a mechanism dependent on enhanced IL-1β signaling. These data may yield novel insights into the basis of cognitive deficits in EAE and possibly of MS.
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Affiliation(s)
- Robert Nisticò
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Dipartimento di Fisiologia e Farmacologia, Università di Roma "La Sapienza", Rome, Italy
- * E-mail: (RN); (DC)
| | - Dalila Mango
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | | | - Sonia Piccinin
- Dipartimento di Fisiologia e Farmacologia, Università di Roma "La Sapienza", Rome, Italy
- Laboratorio di Farmacologia della Plasticità Sinaptica, EBRI-European Brain Research Institute, Rome, Italy
| | | | - Marco Pignatelli
- Dipartimento di Fisiologia e Farmacologia, Università di Roma "La Sapienza", Rome, Italy
- Laboratorio di Farmacologia della Plasticità Sinaptica, EBRI-European Brain Research Institute, Rome, Italy
| | - Marco Feligioni
- Laboratorio di Farmacologia della Plasticità Sinaptica, EBRI-European Brain Research Institute, Rome, Italy
| | - Alessandra Musella
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | - Antonietta Gentile
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | - Francesco Mori
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | - Giorgio Bernardi
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | - Ferdinando Nicoletti
- Dipartimento di Fisiologia e Farmacologia, Università di Roma "La Sapienza", Rome, Italy
- IRCCS Neuromed, Pozzilli, Italy
| | - Nicola B. Mercuri
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
| | - Diego Centonze
- IRCSS Fondazione Santa Lucia, Rome, Italy
- Clinica Neurologica, Dipartimento di Medicina dei Sistemi, Università Tor Vergata, Rome, Italy
- * E-mail: (RN); (DC)
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TNF-α-mediated anxiety in a mouse model of multiple sclerosis. Exp Neurol 2012; 237:296-303. [PMID: 22836148 DOI: 10.1016/j.expneurol.2012.07.010] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 07/06/2012] [Accepted: 07/18/2012] [Indexed: 12/15/2022]
Abstract
Multiple sclerosis (MS) causes a variety of motor and sensory deficits and it is also associated with mood disturbances. It is unclear if anxiety and depression in MS entirely reflect a subjective reaction to a chronic disease causing motor disability or rather depend on specific effects of neuroinflammation in neuronal circuits. To answer this question, behavioral, electrophysiological, and immunofluorescence experiments were performed in mice with experimental autoimmune encephalomyelitis (EAE), which models MS in mice. First, we observed high anxiety indexes in EAE mice, preceding the appearance of motor defects. Then, we demonstrated that tumor necrosis factor α (TNF-α) has a crucial role in anxiety associated with neuroinflammation. In fact, intracerebroventricular (icv) administration of etanercept, an inhibitor of TNF-α signaling, resulted in anxiolytic-like effects in EAE-mice. Accordingly, icv injection of TNF-α induced per se overt anxious behavior in control mice. Moreover, we propose the striatum as one of the brain regions potentially involved in EAE anxious behavior. We observed that before disease onset EAE striatum presents elevated TNF-α levels and strong activated microglia, early signs of inflammation associated with alterations of striatal excitatory postsynaptic currents (EPSCs). Interestingly, etanercept corrected the synaptic defects of pre-symptomatic EAE mice while icv injection of TNF-α in non-EAE mice altered EPSCs, thus mimicking the synaptic effects of EAE. In conclusion, anxiety characterizes EAE course since the very early phases of the disease. TNF-α released from activated microglia mediates this effect likely through the modulation of striatal excitatory synaptic transmission.
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