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Novel molecular biomarkers at the blood-brain barrier in ALS. BIOMED RESEARCH INTERNATIONAL 2014; 2014:907545. [PMID: 24949481 PMCID: PMC4037612 DOI: 10.1155/2014/907545] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/04/2014] [Accepted: 04/20/2014] [Indexed: 12/12/2022]
Abstract
Recently neuroinflammation has gained a particular focus as a key mechanism of ALS. Several studies in vivo as well as in vitro have nominated immunoglobulin G (IgG) isolated from ALS patients as an active contributor to disease onset and progression. We have shown that ALS IgG affects astroglial Ca2+ excitability and induces downstream activation of phosphatidylinositol 3-kinase. These studies were hampered by a lack of knowledge of the pathway of entry of immune factors in the CNS. Our MRI data revealed the blood-brain barrier BBB leakage and T cell infiltration into brain parenchyma in ALS G93A rats. Since astrocyte ensheathes blood vessel wall contributing to BBB stability and plays an important role in ALS pathogenesis, we have studied astrocytic membrane proteins water channel aquaporin-4 and the inwardly rectifying potassium channel. In this review, we will summarize data related to BBB disruption with particular emphasis on impaired function of astrocytes in ALS. We will discuss implication of membrane proteins expressed on astrocytic endfeet, aquaporin-4, and inwardly rectifying potassium channel in the pathology of ALS. In addition to ALS-specific IgGs, these membrane proteins are proposed as novel biomarkers of the disease.
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202
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Gallart-Palau X, Tarabal O, Casanovas A, Sábado J, Correa FJ, Hereu M, Piedrafita L, Calderó J, Esquerda JE. Neuregulin-1 is concentrated in the postsynaptic subsurface cistern of C-bouton inputs to α-motoneurons and altered during motoneuron diseases. FASEB J 2014; 28:3618-32. [PMID: 24803543 DOI: 10.1096/fj.13-248583] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
C boutons are large, cholinergic, synaptic terminals that arise from local interneurons and specifically contact spinal α-motoneurons (MNs). C boutons characteristically display a postsynaptic specialization consisting of an endoplasmic reticulum-related subsurface cistern (SSC) of unknown function. In the present work, by using confocal microscopy and ultrastructural immunolabeling, we demonstrate that neuregulin-1 (NRG1) accumulates in the SSC of mouse spinal MNs. We also show that the NRG1 receptors erbB2 and erbB4 are presynaptically localized within C boutons, suggesting that NRG1-based retrograde signaling may occur in this type of synapse. In most of the cranial nuclei, MNs display the same pattern of NRG1 distribution as that observed in spinal cord MNs. Conversely, MNs in oculomotor nuclei, which are spared in amyotrophic lateral sclerosis (ALS), lack both C boutons and SSC-associated NRG1. NRG1 in spinal MNs is developmentally regulated and depends on the maintenance of nerve-muscle interactions, as we show after nerve transection experiments. Changes in NRG1 in C boutons were also investigated in mouse models of MN diseases: i.e., spinal muscular atrophy (SMNΔ7) and ALS (SOD1(G93A)). In both models, a transient increase in NRG1 in C boutons occurs during disease progression. These data increase our understanding of the role of C boutons in MN physiology and pathology.
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Affiliation(s)
- Xavier Gallart-Palau
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Olga Tarabal
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Anna Casanovas
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Javier Sábado
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Francisco J Correa
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Marta Hereu
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Lídia Piedrafita
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Jordi Calderó
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
| | - Josep E Esquerda
- Unitat de Neurobiologia Cellular, Departament de Medicina Experimental, Facultat de Medicina, Institut de Recerca Biomèdica de Lleida (IRBLLEIDA), Universitat de Lleida, Lleida, Catalonia, Spain
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Yang DJ, Wang XL, Ismail A, Ashman CJ, Valori CF, Wang G, Gao S, Higginbottom A, Ince PG, Azzouz M, Xu J, Shaw PJ, Ning K. PTEN regulates AMPA receptor-mediated cell viability in iPS-derived motor neurons. Cell Death Dis 2014; 5:e1096. [PMID: 24577094 PMCID: PMC3944269 DOI: 10.1038/cddis.2014.55] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 01/19/2014] [Accepted: 01/22/2014] [Indexed: 11/09/2022]
Abstract
Excitatory transmission in the brain is commonly mediated by the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors. In amyotrophic lateral sclerosis (ALS), AMPA receptors allow cytotoxic levels of calcium into neurons, contributing to motor neuron injury. We have previously shown that oculomotor neurons resistant to the disease process in ALS show reduced AMPA-mediated inward calcium currents compared with vulnerable spinal motor neurons. We have also shown that PTEN (phosphatase and tensin homolog deleted on chromosome 10) knockdown via siRNA promotes motor neuron survival in models of spinal muscular atrophy (SMA) and ALS. It has been reported that inhibition of PTEN attenuates the death of hippocampal neurons post injury by decreasing the effective translocation of the GluR2 subunit into the membrane. In addition, leptin can regulate AMPA receptor trafficking via PTEN inhibition. Thus, we speculate that manipulation of AMPA receptors by PTEN may represent a potential therapeutic strategy for neuroprotective intervention in ALS and other neurodegenerative disorders. To this end, the first step is to establish a fibroblast-iPS-motor neuron in vitro cell model to study AMPA receptor manipulation. Here we report that iPS-derived motor neurons from human fibroblasts express AMPA receptors. PTEN depletion decreases AMPA receptor expression and AMPA-mediated whole-cell currents, resulting in inhibition of AMPA-induced neuronal death in primary cultured and iPS-derived motor neurons. Taken together, our results imply that PTEN depletion may protect motor neurons by inhibition of excitatory transmission that represents a therapeutic strategy of potential benefit for the amelioration of excitotoxicity in ALS and other neurodegenerative disorders.
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Affiliation(s)
- D-J Yang
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - X-L Wang
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - A Ismail
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - C J Ashman
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - C F Valori
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - G Wang
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - S Gao
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - A Higginbottom
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - P G Ince
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - M Azzouz
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - J Xu
- East Hospital, Tongji University School of Medicine, Shanghai, China
| | - P J Shaw
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
| | - K Ning
- 1] East Hospital, Tongji University School of Medicine, Shanghai, China [2] Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, UK
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204
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Garbuzova-Davis S, Sanberg PR. Blood-CNS Barrier Impairment in ALS patients versus an animal model. Front Cell Neurosci 2014; 8:21. [PMID: 24550780 PMCID: PMC3910123 DOI: 10.3389/fncel.2014.00021] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Accepted: 01/13/2014] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease with a complicated and poorly understood pathogenesis. Recently, alterations in the blood-Central Nervous System barrier (B-CNS-B) have been recognized as a key factor possibly aggravating motor neuron damage. The majority of findings on ALS microvascular pathology have been determined in mutant superoxide dismutase (SOD1) rodent models, identifying barrier damage during disease development which might similarly occur in familial ALS patients carrying the SOD1 mutation. However, our knowledge of B-CNS-B competence in sporadic ALS (SALS) has been limited. We recently showed structural and functional impairment in postmortem gray and white matter microvessels of medulla and spinal cord tissue from SALS patients, suggesting pervasive barrier damage. Although numerous signs of barrier impairment (endothelial cell degeneration, capillary leakage, perivascular edema, downregulation of tight junction proteins, and microhemorrhages) are indicated in both mutant SOD1 animal models of ALS and SALS patients, other pathogenic barrier alterations have as yet only been identified in SALS patients. Pericyte degeneration, perivascular collagen IV expansion, and white matter capillary abnormalities in SALS patients are significant barrier related pathologies yet to be noted in ALS SOD1 animal models. In the current review, these important differences in blood-CNS barrier damage between ALS patients and animal models, which may signify altered barrier transport mechanisms, are discussed. Understanding discrepancies in barrier condition between ALS patients and animal models may be crucial for developing effective therapies.
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Affiliation(s)
- Svitlana Garbuzova-Davis
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, Morsani College of Medicine, University of South FloridaTampa, FL, USA
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South FloridaTampa, FL, USA
- Department of Pathology and Cell Biology, Morsani College of Medicine, University of South FloridaTampa, FL, USA
| | - Paul R. Sanberg
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, Morsani College of Medicine, University of South FloridaTampa, FL, USA
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South FloridaTampa, FL, USA
- Department of Pathology and Cell Biology, Morsani College of Medicine, University of South FloridaTampa, FL, USA
- Department of Psychiatry, Morsani College of Medicine, University of South FloridaTampa, FL, USA
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205
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Thomas CK, Grumbles RM. Age at spinal cord injury determines muscle strength. Front Integr Neurosci 2014; 8:2. [PMID: 24478643 PMCID: PMC3899581 DOI: 10.3389/fnint.2014.00002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 01/06/2014] [Indexed: 11/30/2022] Open
Abstract
As individuals with spinal cord injury (SCI) age they report noticeable deficits in muscle strength, endurance and functional capacity when performing everyday tasks. These changes begin at ~45 years. Here we present a cross-sectional analysis of paralyzed thenar muscle and motor unit contractile properties in two datasets obtained from different subjects who sustained a cervical SCI at different ages (≤46 years) in relation to data from uninjured age-matched individuals. First, completely paralyzed thenar muscles were weaker when C6 SCI occurred at an older age. Muscles were also significantly weaker if the injury was closer to the thenar motor pools (C6 vs. C4). More muscles were strong (>50% uninjured) in those injured at a younger (≤25 years) vs. young age (>25 years), irrespective of SCI level. There was a reduction in motor unit numbers in all muscles tested. In each C6 SCI, only ~30 units survived vs. 144 units in uninjured subjects. Since intact axons only sprout 4-6 fold, the limits for muscle reinnervation have largely been met in these young individuals. Thus, any further reduction in motor unit numbers with time after these injuries will likely result in chronic denervation, and may explain the late-onset muscle weakness routinely described by people with SCI. In a second dataset, paralyzed thenar motor units were more fatigable than uninjured units. This gap widened with age and will reduce functional reserve. Force declines were not due to electromyographic decrements in either group so the site of failure was beyond excitation of the muscle membrane. Together, these results suggest that age at SCI is an important determinant of long-term muscle strength, and fatigability, both of which influence functional capacity.
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Affiliation(s)
- Christine K. Thomas
- The Miami Project to Cure Paralysis, University of Miami Miller School of MedicineMiami, FL, USA
- Department of Neurological Surgery, University of Miami Miller School of MedicineMiami, FL, USA
- Department of Physiology and Biophysics, University of Miami Miller School of MedicineMiami, FL, USA
| | - Robert M. Grumbles
- The Miami Project to Cure Paralysis, University of Miami Miller School of MedicineMiami, FL, USA
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206
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207
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Lladó J, Tolosa L, Olmos G. Cellular and molecular mechanisms involved in the neuroprotective effects of VEGF on motoneurons. Front Cell Neurosci 2013; 7:181. [PMID: 24155688 PMCID: PMC3803143 DOI: 10.3389/fncel.2013.00181] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/30/2013] [Indexed: 01/17/2023] Open
Abstract
Vascular endothelial growth factor (VEGF), originally described as a factor with a regulatory role in vascular growth and development, it is also known for its direct effects on neuronal cells. The discovery in the past decade that transgenic mice expressing reduced levels of VEGF developed late-onset motoneuron pathology, reminiscent of amyotrophic lateral sclerosis (ALS), opened a new field of research on this disease. VEGF has been shown to protect motoneurons from excitotoxic death, which is a relevant mechanism involved in motoneuron degeneration in ALS. Thus, VEGF delays motoneuron degeneration and increases survival in animal models of ALS. VEGF exerts its anti-excitotoxic effects on motoneurons through molecular mechanisms involving the VEGF receptor-2 resulting in the activation of the PI3-K/Akt signaling pathway, upregulation of GluR2 subunit of AMPA receptors, inhibition of p38MAPK, and induction of the anti-apoptotic molecule Bcl-2. In addition, VEGF acts on astrocytes to reduce astroglial activation and to induce the release of growth factors. The potential use of VEGF as a therapeutic tool in ALS is counteracted by its vascular effects and by its short effective time frame. More studies are needed to assess the optimal isoform, route of administration, and time frame for using VEGF in the treatment of ALS.
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Affiliation(s)
- Jerònia Lladó
- Grup de Neurobiologia Celular, Departament de Biologia, Universitat de les Illes Balears Palma de Mallorca, Spain ; Institut Universitari d'Investigacions en Ciències de la Salut (IUNICS), Universitat de les Illes Balears Palma de Mallorca, Spain
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208
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Caioli S, Pieri M, Antonini A, Guglielmotti A, Severini C, Zona C. Monocyte Chemoattractant Protein-1 upregulates GABA-induced current: Evidence of modified GABAA subunit composition in cortical neurons from the G93A mouse model of Amyotrophic Lateral Sclerosis. Neuropharmacology 2013; 73:247-60. [DOI: 10.1016/j.neuropharm.2013.05.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 05/06/2013] [Accepted: 05/27/2013] [Indexed: 02/06/2023]
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209
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Saxena S, Roselli F, Singh K, Leptien K, Julien JP, Gros-Louis F, Caroni P. Neuroprotection through Excitability and mTOR Required in ALS Motoneurons to Delay Disease and Extend Survival. Neuron 2013; 80:80-96. [DOI: 10.1016/j.neuron.2013.07.027] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2013] [Indexed: 12/13/2022]
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210
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Larsson M, Agalave N, Watanabe M, Svensson C. Distribution of transmembrane AMPA receptor regulatory protein (TARP) isoforms in the rat spinal cord. Neuroscience 2013; 248:180-93. [DOI: 10.1016/j.neuroscience.2013.05.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 05/13/2013] [Accepted: 05/31/2013] [Indexed: 02/08/2023]
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211
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Focant MC, Goursaud S, Boucherie C, Dumont AO, Hermans E. PICK1 expression in reactive astrocytes within the spinal cord of amyotrophic lateral sclerosis (ALS) rats. Neuropathol Appl Neurobiol 2013; 39:231-42. [PMID: 22624977 DOI: 10.1111/j.1365-2990.2012.01282.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AIMS The protein interacting with C kinase 1 (PICK1), a PDZ domain-containing protein mainly expressed in the central nervous system, interacts with the glutamate receptor subunit GluR2, with the glutamate transporter GLT-1b and with the enzyme serine racemase. These three proteins appear as key actors in the glutamate-mediated excitotoxicity associated with amyotrophic lateral sclerosis (ALS), in both patients and animal models of the disease. In this study, we examined the expression of PICK1 in the spinal cord of transgenic rats expressing a mutated form of the human superoxide dismutase 1 (hSOD1(G93A) ) during the progression of the disease. METHODS Expression of PICK1 was examined by real-time qPCR at presymptomatic and symptomatic stages as well as at end-stage. The expression of PICK1 in the different cell types of the spinal cord was examined by immunohistochemistry. RESULTS The overall expression of PICK1 is not modified in cervical and lumbar spinal cord of transgenic (hSOD1(G93A) ) rats during the progression of the disease. Nonetheless, immunohistochemical studies of lumbar ventral horns revealed a shift of PICK1 expression from motor neurones in healthy rats to activated astrocytes in end-stage hSOD1(G93A) animals. CONCLUSIONS Considering the documented influence of PICK1 expression on d-serine release and glutamate transport in astrocytes, these findings point to a potential implication of PICK1 in the progression of ALS.
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Affiliation(s)
- M C Focant
- Group of Neuropharmacology, Institute of Neuroscience, Université catholique de Louvain, Brussels, Belgium
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212
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Leal SS, Cardoso I, Valentine JS, Gomes CM. Calcium ions promote superoxide dismutase 1 (SOD1) aggregation into non-fibrillar amyloid: a link to toxic effects of calcium overload in amyotrophic lateral sclerosis (ALS)? J Biol Chem 2013; 288:25219-25228. [PMID: 23861388 DOI: 10.1074/jbc.m113.470740] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Imbalance in metal ion homeostasis is a hallmark in neurodegenerative conditions involving protein deposition, and amyotrophic lateral sclerosis (ALS) is no exception. In particular, Ca(2+) dysregulation has been shown to correlate with superoxide dismutase-1 (SOD1) aggregation in a cellular model of ALS. Here we present evidence that SOD1 aggregation is enhanced and modulated by Ca(2+). We show that at physiological pH, Ca(2+) induces conformational changes that increase SOD1 β-sheet content, as probed by far UV CD and attenuated total reflectance-FTIR, and enhances SOD1 hydrophobicity, as probed by ANS fluorescence emission. Moreover, dynamic light scattering analysis showed that Ca(2+) boosts the onset of SOD1 aggregation. In agreement, Ca(2+) decreases SOD1 critical concentration and nucleation time during aggregation kinetics, as evidenced by thioflavin T fluorescence emission. Attenuated total reflectance FTIR analysis showed that Ca(2+) induced aggregates consisting preferentially of antiparallel β-sheets, thus suggesting a modulation effect on the aggregation pathway. Transmission electron microscopy and analysis with conformational anti-fibril and anti-oligomer antibodies showed that oligomers and amyloidogenic aggregates constitute the prevalent morphology of Ca(2+)-induced aggregates, thus indicating that Ca(2+) diverts SOD1 aggregation from fibrils toward amorphous aggregates. Interestingly, the same heterogeneity of conformations is found in ALS-derived protein inclusions. We thus hypothesize that transient variations and dysregulation of cellular Ca(2+) levels contribute to the formation of SOD1 aggregates in ALS patients. In this scenario, Ca(2+) may be considered as a pathogenic effector in the formation of ALS proteinaceous inclusions.
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Affiliation(s)
- Sónia S Leal
- From the Instituto Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. República 127, 2780-756 Oeiras, Portugal
| | - Isabel Cardoso
- the Molecular Neurobiology Unit, Instituto Biologia Molecular e Celular, 4150-180 Porto, Portugal, and
| | - Joan S Valentine
- the Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095
| | - Cláudio M Gomes
- From the Instituto Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. República 127, 2780-756 Oeiras, Portugal,.
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213
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Dall'Igna OP, Bobermin LD, Souza DO, Quincozes-Santos A. Riluzole increases glutamate uptake by cultured C6 astroglial cells. Int J Dev Neurosci 2013; 31:482-6. [PMID: 23777615 DOI: 10.1016/j.ijdevneu.2013.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 05/24/2013] [Accepted: 06/09/2013] [Indexed: 11/26/2022] Open
Abstract
Riluzole is a drug approved for the treatment of amyotrophic lateral sclerosis (ALS) and may be effective for the treatment of other neurodegenerative and neuropsychiatric disorders. Riluzole exerts diverse actions on the central nervous system, including altering glutamate release and uptake, and therefore act diminishing glutamate extracellular levels, but the underlying mechanism of these actions is still unknown. Here, we demonstrate that riluzole stimulated glutamate uptake and augmented the expression of the glutamate EAAC1 transporter in C6 astroglial cell cultures. The effect of riluzole on glutamate uptake was reduced to below controls when it was co-administered with inhibitors of protein kinase C (PKC; bisindolylmaleimide II), phosphatidylinositol 3-kinase (PI3K; wortmannin) and fibroblast growth factor receptor 1 (FGFR1; PD173074). Riluzole also decreased reactive oxygen species load with no effect on glutathione levels. This study investigates three independent intracellular pathways and the mechanism of action of riluzole on glutamate metabolism.
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Affiliation(s)
- Oscar P Dall'Igna
- Rua Ramiro Barcelos 2600-Anexo, Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, CEP 90035-000, Brazil.
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214
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Anesthetic management of the patient with amyotrophic lateral sclerosis. J Anesth 2013; 27:909-18. [DOI: 10.1007/s00540-013-1644-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 05/13/2013] [Indexed: 12/19/2022]
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215
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Embryonic alteration of motoneuronal morphology induces hyperexcitability in the mouse model of amyotrophic lateral sclerosis. Neurobiol Dis 2013; 54:116-26. [DOI: 10.1016/j.nbd.2013.02.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 01/31/2013] [Accepted: 02/22/2013] [Indexed: 12/12/2022] Open
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216
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Fuchs A, Kutterer S, Mühling T, Duda J, Schütz B, Liss B, Keller BU, Roeper J. Selective mitochondrial Ca2+ uptake deficit in disease endstage vulnerable motoneurons of the SOD1G93A mouse model of amyotrophic lateral sclerosis. J Physiol 2013; 591:2723-45. [PMID: 23401612 PMCID: PMC3678052 DOI: 10.1113/jphysiol.2012.247981] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 02/04/2013] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic lateral sclerosis is a progressive neurodegenerative disease that targets some somatic motoneuron populations, while others, e.g. those of the oculomotor system, are spared. The pathophysiological basis of this pattern of differential vulnerability, which is preserved in a transgenic mouse model of amyotrophic lateral sclerosis (SOD1(G93A)), and the mechanism of neurodegeneration in general are unknown. Hyperexcitability and calcium dysregulation have been proposed by others on the basis of data from juvenile mice that are, however, asymptomatic. No studies have been done with symptomatic mice following disease progression to the disease endstage. Here, we developed a new brainstem slice preparation for whole-cell patch-clamp recordings and single cell fura-2 calcium imaging to study motoneurons in adult wild-type and SOD1(G93A) mice up to disease endstage. We analysed disease-stage-dependent electrophysiological properties and intracellular Ca(2+) handling of vulnerable hypoglossal motoneurons in comparison to resistant oculomotor neurons. Thereby, we identified a transient hyperexcitability in presymptomatic but not in endstage vulnerable motoneurons. Additionally, we revealed a remodelling of intracellular Ca(2+) clearance within vulnerable but not resistant motoneurons at disease endstage characterised by a reduction of uniporter-dependent mitochondrial Ca(2+) uptake and enhanced Ca(2+) extrusion across the plasma membrane. Our study challenged the notion that hyperexcitability is a direct cause of neurodegeneration in SOD1(G93A) mice, but molecularly identified a Ca(2+) clearance deficit in motoneurons and an adaptive Ca(2+) handling strategy that might be targeted by future therapeutic strategies.
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Affiliation(s)
- Andrea Fuchs
- Mammalian Locomotor Laboratory, Department of Neuroscience, Karolinska Institutet, Retzius Väg 8, 17177 Stockholm, Sweden.
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217
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Wang C, Niu L. Mechanism of inhibition of the GluA2 AMPA receptor channel opening by talampanel and its enantiomer: the stereochemistry of the 4-methyl group on the diazepine ring of 2,3-benzodiazepine derivatives. ACS Chem Neurosci 2013; 4:635-44. [PMID: 23402301 DOI: 10.1021/cn3002398] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Stereoselectivity of 2,3-benzodiazepine compounds provides a unique way for the design of stereoisomers as more selective and more potent inhibitors as drug candidates for treatment of the neurological diseases involving excessive activity of AMPA receptors. Here we investigate a pair of enantiomers known as Talampanel and its (+) counterpart about their mechanism of inhibition and selectivity toward four AMPA receptor subunits or GluA1-4. We show that Talampanel is the eutomer with the endismic ratio being 14 for the closed-channel and 10 for the open-channel state of GluA2. Kinetic evidence supports that Talampanel is a noncompetitive inhibitor and it binds to the same site for those 2,3-benzodiazepine compounds with the C-4 methyl group on the diazepine ring. This site, which we term as the "M" site, recognizes preferentially those 2,3-benzodiazepine compounds with the C-4 methyl group being in the R configuration, as in the chemical structure of Talampanel. Given that Talampanel inhibits GluA1 and GluA2, but is virtually ineffective on the GluA3 and GluA4 AMPA receptor subunits, we hypothesize that the "M" site(s) on GluA1 and GluA2 to which Talampanel binds is different from that on GluA3 and GluA4. If the molecular properties of the AMPA receptors and Talampanel are used for selecting an inhibitor as a single drug candidate for controlling the activity of all AMPA receptors in vivo, Talampanel is not ideal. Our results further suggest that addition of longer acyl groups to the N-3 position should produce more potent 2,3-benzodiazepine inhibitors for the "M" site.
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Affiliation(s)
- Congzhou Wang
- Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222,
United States
| | - Li Niu
- Department of Chemistry and Center for Neuroscience Research, University at Albany, SUNY, Albany, New York 12222,
United States
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Wootz H, Fitzsimons-Kantamneni E, Larhammar M, Rotterman TM, Enjin A, Patra K, André E, Van Zundert B, Kullander K, Alvarez FJ. Alterations in the motor neuron-renshaw cell circuit in the Sod1(G93A) mouse model. J Comp Neurol 2013; 521:1449-69. [PMID: 23172249 DOI: 10.1002/cne.23266] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 09/14/2012] [Accepted: 11/06/2012] [Indexed: 12/12/2022]
Abstract
Motor neurons become hyperexcitable during progression of amyotrophic lateral sclerosis (ALS). This abnormal firing behavior has been explained by changes in their membrane properties, but more recently it has been suggested that changes in premotor circuits may also contribute to this abnormal activity. The specific circuits that may be altered during development of ALS have not been investigated. Here we examined the Renshaw cell recurrent circuit that exerts inhibitory feedback control on motor neuron firing. Using two markers for Renshaw cells (calbindin and cholinergic nicotinic receptor subunit alpha2 [Chrna2]), two general markers for motor neurons (NeuN and vesicular acethylcholine transporter [VAChT]), and two markers for fast motor neurons (Chondrolectin and calcitonin-related polypeptide alpha [Calca]), we analyzed the survival and connectivity of these cells during disease progression in the Sod1(G93A) mouse model. Most calbindin-immunoreactive (IR) Renshaw cells survive to end stage but downregulate postsynaptic Chrna2 in presymptomatic animals. In motor neurons, some markers are downregulated early (NeuN, VAChT, Chondrolectin) and others at end stage (Calca). Early downregulation of presynaptic VAChT and Chrna2 was correlated with disconnection from Renshaw cells as well as major structural abnormalities of motor axon synapses inside the spinal cord. Renshaw cell synapses on motor neurons underwent more complex changes, including transitional sprouting preferentially over remaining NeuN-IR motor neurons. We conclude that the loss of presynaptic motor axon input on Renshaw cells occurs at early stages of ALS and disconnects the recurrent inhibitory circuit, presumably resulting in diminished control of motor neuron firing. J. Comp. Neurol. 521:1449-1469, 2013. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Hanna Wootz
- Department of Neuroscience, Uppsala University, 75124 Uppsala, Sweden
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219
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Parone PA, Da Cruz S, Han JS, McAlonis-Downes M, Vetto AP, Lee SK, Tseng E, Cleveland DW. Enhancing mitochondrial calcium buffering capacity reduces aggregation of misfolded SOD1 and motor neuron cell death without extending survival in mouse models of inherited amyotrophic lateral sclerosis. J Neurosci 2013; 33:4657-71. [PMID: 23486940 PMCID: PMC3711648 DOI: 10.1523/jneurosci.1119-12.2013] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 12/18/2012] [Accepted: 12/20/2012] [Indexed: 11/21/2022] Open
Abstract
Mitochondria have been proposed as targets for toxicity in amyotrophic lateral sclerosis (ALS), a progressive, fatal adult-onset neurodegenerative disorder characterized by the selective loss of motor neurons. A decrease in the capacity of spinal cord mitochondria to buffer calcium (Ca(2+)) has been observed in mice expressing ALS-linked mutants of SOD1 that develop motor neuron disease with many of the key pathological hallmarks seen in ALS patients. In mice expressing three different ALS-causing SOD1 mutants, we now test the contribution of the loss of mitochondrial Ca(2+)-buffering capacity to disease mechanism(s) by eliminating ubiquitous expression of cyclophilin D, a critical regulator of Ca(2+)-mediated opening of the mitochondrial permeability transition pore that determines mitochondrial Ca(2+) content. A chronic increase in mitochondrial buffering of Ca(2+) in the absence of cyclophilin D was maintained throughout disease course and was associated with improved mitochondrial ATP synthesis, reduced mitochondrial swelling, and retention of normal morphology. This was accompanied by an attenuation of glial activation, reduction in levels of misfolded SOD1 aggregates in the spinal cord, and a significant suppression of motor neuron death throughout disease. Despite this, muscle denervation, motor axon degeneration, and disease progression and survival were unaffected, thereby eliminating mutant SOD1-mediated loss of mitochondrial Ca(2+) buffering capacity, altered mitochondrial morphology, motor neuron death, and misfolded SOD1 aggregates, as primary contributors to disease mechanism for fatal paralysis in these models of familial ALS.
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Affiliation(s)
- Philippe A. Parone
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Sandrine Da Cruz
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Joo Seok Han
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Melissa McAlonis-Downes
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Anne P. Vetto
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Sandra K. Lee
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Eva Tseng
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
| | - Don W. Cleveland
- Ludwig Institute for Cancer Research and Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093
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220
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Nagara Y, Tateishi T, Yamasaki R, Hayashi S, Kawamura M, Kikuchi H, Iinuma KM, Tanaka M, Iwaki T, Matsushita T, Ohyagi Y, Kira JI. Impaired cytoplasmic-nuclear transport of hypoxia-inducible factor-1α in amyotrophic lateral sclerosis. Brain Pathol 2013; 23:534-46. [PMID: 23368766 DOI: 10.1111/bpa.12040] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 01/25/2013] [Indexed: 12/14/2022] Open
Abstract
We investigated the mechanisms underlying abnormal vascular endothelial growth factor (VEGF) production in amyotrophic lateral sclerosis (ALS). We immunohistochemically studied VEGF, its receptors VEGFR1 and 2, and hypoxia-inducible factor-1α (HIF-1α) in autopsied ALS spinal cords. We also chronologically assessed the expression of HIF-1α, karyopherin β1, karyopherin β-cargo protein complex inhibitors and nuclear pore complex proteins in G93A mutant superoxide dismutase 1 (mSOD1) transgenic mice at presymptomatic, symptomatic and end stages. In ALS patients, compared with controls, HIF-1α immunoreactivity in the cytoplasm of anterior horn cells (AHCs) was significantly increased, while immunoreactivities for VEGF and VEGFRs were significantly decreased. Similar changes in HIF-1α and VEGF levels were observed in mSOD1 transgenic mice. HIF-1α co-localized with karyopherin β1 in the cytoplasm of AHCs and karyopherin β1 co-localized with nucleoporin 62 (Nup62) on the nuclear envelope. From the presymptomatic stage of mSOD1 transgenic mice, karyopherin β1 immunoreactivity in AHC nuclei significantly decreased and morphological irregularities of the Nup62-immunostained nuclear envelope became more pronounced with disease progression. Thus, in AHCs from mSOD1 transgenic mice, transport of cytoplasmic HIF-1α to the nuclear envelope and into the nucleus is impaired from the presymptomatic stage, suggesting that impaired cytoplasmic-nuclear transport of HIF-1α through the nuclear pore might precede motor neuron degeneration.
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Affiliation(s)
- Yuko Nagara
- Department of Neurology, Kyushu University, Fukuoka 812-8582, Japan
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221
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Potenza RL, Armida M, Ferrante A, Pèzzola A, Matteucci A, Puopolo M, Popoli P. Effects of chronic caffeine intake in a mouse model of amyotrophic lateral sclerosis. J Neurosci Res 2013; 91:585-92. [PMID: 23361938 DOI: 10.1002/jnr.23185] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 10/29/2012] [Accepted: 11/01/2012] [Indexed: 01/26/2023]
Abstract
Caffeine is a nonselective adenosine receptor antagonist; chronic consumption has proved protective toward neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. The present study was designed to determine whether caffeine intake affected survival and/or motor performance in a transgenic model of amyotrophic lateral sclerosis (ALS). SOD1(G93A) mice received caffeine through drinking water from 70 days of age until death. Body weight, motor performance and survival were evaluated. Furthermore, the expression of adenosine A(2A) receptors (A(2A) Rs), glial glutamate transporter (GLT1), and glial fibrillar acidic protein (GFAP) were evaluated by Western blotting. The results showed that caffeine intake significantly shortened the survival of SOD1(G93A) mice (log rank test, P = 0.01) and induced a nonsignificant advancing of disease onset. The expression of A(2A) R, GLT1, and GFAP was altered in the spinal cords of ALS mice, but caffeine did not influence their expression in either wild-type or SOD1(G93) mice. These data indicate that adenosine receptors may play an important role in ALS.
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Affiliation(s)
- Rosa Luisa Potenza
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, Rome, Italy.
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222
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Staats KA, Bogaert E, Hersmus N, Jaspers T, Luyten T, Bultynck G, Parys JB, Hisatsune C, Mikoshiba K, Van Damme P, Robberecht W, Van Den Bosch L. Neuronal overexpression of IP3 receptor 2 is detrimental in mutant SOD1 mice. Biochem Biophys Res Commun 2012; 429:210-3. [DOI: 10.1016/j.bbrc.2012.10.094] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Accepted: 10/11/2012] [Indexed: 12/13/2022]
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223
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Herrando-Grabulosa M, Casas C, Aguilera J. The C-terminal domain of tetanus toxin protects motoneurons against acute excitotoxic damage on spinal cord organotypic cultures. J Neurochem 2012; 124:36-44. [PMID: 23106494 DOI: 10.1111/jnc.12062] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 10/03/2012] [Accepted: 10/03/2012] [Indexed: 11/30/2022]
Abstract
The C-terminal domain of tetanus toxin (Hc-TeTx) has been suggested to act as a neuroprotective agent by activating signaling pathways related to neurotrophins and also to exert anti-apoptotic effects. Here, we show the beneficial properties of the recombinant protein Hc-TeTx to protect spinal motoneurons against excitotoxic damage. In vitro spinal cord organotypic cultures were used to assess acute glutamate excitotoxic damage. Our results indicate that Hc-TeTx treatment improves motoneuron survival within a short therapeutical window (the first 2 h post-injury). Within this interval, we found that p44/p42 MAP kinase (ERK1/2) and glycogen synthase kinase-3 (GSK3β) signaling pathways play a crucial role in the neuroprotective effect. Moreover, we demonstrated that Hc-TeTx treatment initiate autophagy which is ERK1/2- and GSK3β-dependent. These findings suggest a possible therapeutical tool to improve motoneuron survival immediately after excitotoxic insults or during the secondary injury phase that occurs after spinal cord trauma.
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Affiliation(s)
- Mireia Herrando-Grabulosa
- Departament de Bioquímica i Biologia Molecular, Institut de Neurociències and CIBERNED, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain
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224
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Over-expression of N-type calcium channels in cortical neurons from a mouse model of Amyotrophic Lateral Sclerosis. Exp Neurol 2012; 247:349-58. [PMID: 23142186 DOI: 10.1016/j.expneurol.2012.11.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 10/24/2012] [Accepted: 11/02/2012] [Indexed: 12/13/2022]
Abstract
Voltage-gated Ca(2+) channels (VGCCs) mediate calcium entry into neuronal cells in response to membrane depolarisation and play an essential role in a variety of physiological processes. In Amyotrophic Lateral Sclerosis (ALS), a fatal neurodegenerative disease caused by motor neuron degeneration in the brain and spinal cord, intracellular calcium dysregulation has been shown, while no studies have been carried out on VGCCs. Here we show that the subtype N-type Ca(2+) channels are over expressed in G93A cultured cortical neurons and in motor cortex of G93A mice compared to Controls. In fact, by western blotting, immunocytochemical and electrophysiological experiments, we observe higher membrane expression of N-type Ca(2+) channels in G93A neurons compared to Controls. G93A cortical neurons filled with calcium-sensitive dye Fura-2, show a net calcium entry during membrane depolarization that is significantly higher compared to Control. Analysis of neuronal vitality following the exposure of neurons to a high K(+) concentration (25 mM, 5h), shows a significant reduction of G93A cellular survival compared to Controls. N-type channels are involved in the G93A higher mortality because ω-conotoxin GVIA (1 μM), which selectively blocks these channels, is able to abolish the higher G93A mortality when added to the external medium. These data provide robust evidence for an excess of N-type Ca(2+) expression in G93A cortical neurons which induces a higher mortality following membrane depolarization. These results may be central to the understanding of pathogenic pathways in ALS and provide novel molecular targets for the design of rational therapies for the ALS disorder.
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225
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Mancuso R, Oliván S, Rando A, Casas C, Osta R, Navarro X. Sigma-1R agonist improves motor function and motoneuron survival in ALS mice. Neurotherapeutics 2012; 9:814-26. [PMID: 22935988 PMCID: PMC3480575 DOI: 10.1007/s13311-012-0140-y] [Citation(s) in RCA: 128] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis is a neurodegenerative disorder characterized by progressive weakness, muscle atrophy, and paralysis due to the loss of upper and lower motoneurons (MNs). Sigma-1 receptor (sigma-1R) activation promotes neuroprotection after ischemic and traumatic injuries to the central nervous system. We recently reported that sigma-1R agonist (PRE-084) improves the survival of MNs after root avulsion injury in rats. Moreover, a mutation of the sigma-1R leading to frontotemporal lobar degeneration/amyotrophic lateral sclerosis (ALS) was recently described in human patients. In the present study, we analyzed the potential therapeutic effect of the sigma-1R agonist (PRE-084) in the SOD1(G93A) mouse model of ALS. Mice were daily administered with PRE-084 (0.25 mg/kg) from 8 to 16 weeks of age. Functional outcome was assessed by electrophysiological tests and computerized analysis of locomotion. Histological, immunohistochemical analyses and Western blot of the spinal cord were performed. PRE-084 administration from 8 weeks of age improved the function of MNs, which was manifested by maintenance of the amplitude of muscle action potentials and locomotor behavior, and preserved neuromuscular connections and MNs in the spinal cord. Moreover, it extended survival in both female and male mice by more than 15 %. Delayed administration of PRE-084 from 12 weeks of age also significantly improved functional outcome and preservation of the MNs. There was an induction of protein kinase C-specific phosphorylation of the NR1 subunit of the N-methyl-D-aspartate (NMDA) receptor in SOD1(G93A) animals, and a reduction of the microglial reactivity compared with untreated mice. PRE-084 exerts a dual therapeutic contribution, modulating NMDA Ca(2+) influx to protect MNs, and the microglial reactivity to ameliorate the MN environment. In conclusion, sigma-1R agonists, such as PRE-084, may be promising candidates for a therapeutical strategy of ALS.
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Affiliation(s)
- Renzo Mancuso
- Group of Neuroplasticity and Regeneration, Institute of Neurosciences and Department of Cell Biology, Physiology, and Immunology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, 08193 Spain
| | - Sara Oliván
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragon Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, 50013 Spain
| | - Amaya Rando
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragon Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, 50013 Spain
| | - Caty Casas
- Group of Neuroplasticity and Regeneration, Institute of Neurosciences and Department of Cell Biology, Physiology, and Immunology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, 08193 Spain
| | - Rosario Osta
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragon Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, 50013 Spain
| | - Xavier Navarro
- Group of Neuroplasticity and Regeneration, Institute of Neurosciences and Department of Cell Biology, Physiology, and Immunology, Universitat Autònoma de Barcelona, Bellaterra, 08193 Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, 08193 Spain
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226
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In silico docking reveals possible Riluzole binding sites on Nav1.6 sodium channel: implications for amyotrophic lateral sclerosis therapy. J Theor Biol 2012; 315:53-63. [PMID: 22995823 DOI: 10.1016/j.jtbi.2012.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 08/31/2012] [Accepted: 09/06/2012] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a common neurodegenerative disorder characterized mainly by a progressive loss of motor neurons. Glutamate excitotoxicity is likely the main cause of neuronal death, and Riluzole interferes with glutamate-mediated transmission. Thus, in such independent pathway, these effects may be partly due to inactivation of voltage-dependent sodium channels. Here we predict the structural model of the interaction and report the possible binding sites of Riluzole on Nav1.6 channel. The docked complexes were subjected to minimization and we further investigated the key interacting residues, binding free energies, pairing bridge determination, folding pattern, hydrogen bounding formation, hydrophobic contacts and flexibilities. Our results demonstrate that Riluzole interacts with the Nav1.6 channel, more specifically in the key residues TYR 1787, LEU 1843 and GLN 1799, suggesting possible cellular implications driven by these amino acids on Riluzole-Nav1.6 interaction, which may serve as an important output for a more specific and experimental drug design therapy against ALS.
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227
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Lin CLG, Kong Q, Cuny GD, Glicksman MA. Glutamate transporter EAAT2: a new target for the treatment of neurodegenerative diseases. Future Med Chem 2012; 4:1689-700. [PMID: 22924507 PMCID: PMC3580837 DOI: 10.4155/fmc.12.122] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Glutamate is the primary excitatory amino acid neurotransmitter in the CNS. The concentration of glutamate in the synaptic cleft is tightly controlled by interplay between glutamate release and glutamate clearance. Abnormal glutamate release and/or dysfunction of glutamate clearance can cause overstimulation of glutamate receptors and result in neuronal injury known as excitotoxicity. The glial glutamate transporter EAAT2 plays a major role in glutamate clearance. Dysfunction or reduced expression of EAAT2 has been documented in many neurodegenerative diseases. In addition, many studies in animal models of disease indicate that increased EAAT2 expression provides neuronal protection. Here, we summarize these studies and suggest that EAAT2 is a potential target for the prevention of excitotoxicity. EAAT2 can be upregulated by transcriptional or translational activation. We discuss current progress in the search for EAAT2 activators, which is a promising direction for the treatment of neurodegenerative diseases.
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228
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Thellung S, Gatta E, Pellistri F, Corsaro A, Villa V, Vassalli M, Robello M, Florio T. Excitotoxicity through NMDA receptors mediates cerebellar granule neuron apoptosis induced by prion protein 90-231 fragment. Neurotox Res 2012; 23:301-14. [PMID: 22855343 DOI: 10.1007/s12640-012-9340-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 07/13/2012] [Accepted: 07/18/2012] [Indexed: 10/28/2022]
Abstract
Prion diseases recognize, as a unique molecular trait, the misfolding of CNS-enriched prion protein (PrP(C)) into an aberrant isoform (PrP(Sc)). In this work, we characterize the in vitro toxicity of amino-terminally truncated recombinant PrP fragment (amino acids 90-231, PrP90-231), on rat cerebellar granule neurons (CGN), focusing on glutamatergic receptor activation and Ca(2+) homeostasis impairment. This recombinant fragment assumes a toxic conformation (PrP90-231(TOX)) after controlled thermal denaturation (1 h at 53 °C) acquiring structural characteristics identified in PrP(Sc) (enrichment in β-structures, increased hydrophobicity, partial resistance to proteinase K, and aggregation in amyloid fibrils). By annexin-V binding assay, and evaluation of the percentage of fragmented and condensed nuclei, we show that treatment with PrP90-231(TOX), used in pre-fibrillar aggregation state, induces CGN apoptosis. This effect was associated with a delayed, but sustained elevation of [Ca(2+)]i. Both CGN apoptosis and [Ca(2+)]i increase were not observed using PrP90-231 in PrP(C)-like conformation. PrP90-231(TOX) effects were significantly reduced in the presence of ionotropic glutamate receptor antagonists. In particular, CGN apoptosis and [Ca(2+)]i increase were largely reduced, although not fully abolished, by pre-treatment with the NMDA antagonists APV and memantine, while the AMPA antagonist CNQX produced a lower, although still significant, effect. In conclusion, we report that CGN apoptosis induced by PrP90-231(TOX) correlates with a sustained elevation of [Ca(2+)]i mediated by the activation of NMDA and AMPA receptors.
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Affiliation(s)
- Stefano Thellung
- Department of Internal Medicine, Section of Pharmacology and Centre of Excellence for Biomedical Research (CEBR) School of Medicine, University of Genova, Viale Benedetto XV, 2, 16132, Genoa, Italy
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229
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Dantrolene is neuroprotective in vitro, but does not affect survival in SOD1(G⁹³A) mice. Neuroscience 2012; 220:26-31. [PMID: 22750242 DOI: 10.1016/j.neuroscience.2012.06.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 05/18/2012] [Accepted: 06/20/2012] [Indexed: 12/12/2022]
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a devastating progressive neurodegenerative disease. One of the proposed disease mechanisms is excitotoxicity, in which excessive cytosolic calcium causes neuronal death. Although most calcium may originate from the extracellular space through activation of calcium-permeable AMPA receptors, we investigated in this study the contribution of endoplasmic reticulum calcium release by blocking the ryanodine receptor (RyR) using dantrolene. In vitro, dantrolene provides a significant protection to motor neurons exposed to a brief excitotoxic insult. However, daily administration of dantrolene to mice overexpressing superoxide dismutase 1 glycine to alanine at position 93 (SOD1(G93A)) does affect neither survival nor the number of motor neurons and ubiquitin aggregates indicating that calcium release through RyRs does not contribute to the selective motor neuron death in this animal model for ALS.
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230
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Tarasiuk J, Kułakowska A, Drozdowski W, Kornhuber J, Lewczuk P. CSF markers in amyotrophic lateral sclerosis. J Neural Transm (Vienna) 2012; 119:747-57. [DOI: 10.1007/s00702-012-0806-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 04/16/2012] [Indexed: 11/29/2022]
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231
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Rodrigues MCO, Voltarelli JC, Sanberg PR, Borlongan CV, Garbuzova-Davis S. Immunological Aspects in Amyotrophic Lateral Sclerosis. Transl Stroke Res 2012; 3:331-40. [DOI: 10.1007/s12975-012-0177-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 04/07/2012] [Accepted: 04/11/2012] [Indexed: 12/11/2022]
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232
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Two-step activation of FOXO3 by AMPK generates a coherent feed-forward loop determining excitotoxic cell fate. Cell Death Differ 2012. [PMID: 22539004 DOI: 10.1038/cdd.2012.49.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Cerebral ischemia and excitotoxic injury induce transient or permanent bioenergetic failure, and may result in neuronal apoptosis or necrosis. We have previously shown that ATP depletion and activation of AMP-activated protein kinase (AMPK) during excitotoxic injury induces neuronal apoptosis by transcription of the pro-apoptotic BH3-only protein, Bim. AMPK, however, also exerts pro-survival functions in neurons. The molecular switches that determine these differential outcomes are not well understood. Using an approach combining biochemistry, single-cell imaging and computational modeling, we here demonstrate that excitotoxic injury activated the bim promoter in a FOXO3-dependent manner. The activation of AMPK reduced AKT activation, and led to dephosphorylation and nuclear translocation of FOXO3. Subsequent mutation studies indicated that bim gene activation during excitotoxic injury required direct FOXO3 phosphorylation by AMPK in the nucleus as a second activation step. Inhibition of this phosphorylation prevented Bim expression and protected neurons against excitotoxic and oxygen/glucose deprivation-induced injury. Systems analysis and computational modeling revealed that these two activation steps defined a coherent feed-forward loop; a network motif capable of filtering any effects of short-term AMPK activation on bim gene induction. This may prevent unwanted AMPK-mediated Bim expression and apoptosis during transient or physiological bioenergetic stress.
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233
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Two-step activation of FOXO3 by AMPK generates a coherent feed-forward loop determining excitotoxic cell fate. Cell Death Differ 2012; 19:1677-88. [PMID: 22539004 DOI: 10.1038/cdd.2012.49] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cerebral ischemia and excitotoxic injury induce transient or permanent bioenergetic failure, and may result in neuronal apoptosis or necrosis. We have previously shown that ATP depletion and activation of AMP-activated protein kinase (AMPK) during excitotoxic injury induces neuronal apoptosis by transcription of the pro-apoptotic BH3-only protein, Bim. AMPK, however, also exerts pro-survival functions in neurons. The molecular switches that determine these differential outcomes are not well understood. Using an approach combining biochemistry, single-cell imaging and computational modeling, we here demonstrate that excitotoxic injury activated the bim promoter in a FOXO3-dependent manner. The activation of AMPK reduced AKT activation, and led to dephosphorylation and nuclear translocation of FOXO3. Subsequent mutation studies indicated that bim gene activation during excitotoxic injury required direct FOXO3 phosphorylation by AMPK in the nucleus as a second activation step. Inhibition of this phosphorylation prevented Bim expression and protected neurons against excitotoxic and oxygen/glucose deprivation-induced injury. Systems analysis and computational modeling revealed that these two activation steps defined a coherent feed-forward loop; a network motif capable of filtering any effects of short-term AMPK activation on bim gene induction. This may prevent unwanted AMPK-mediated Bim expression and apoptosis during transient or physiological bioenergetic stress.
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234
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Wallis N, Zagami CJ, Beart PM, O'Shea RD. Combined excitotoxic-oxidative stress and the concept of non-cell autonomous pathology of ALS: insights into motoneuron axonopathy and astrogliosis. Neurochem Int 2012; 61:523-30. [PMID: 22421531 DOI: 10.1016/j.neuint.2012.02.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/09/2012] [Accepted: 02/22/2012] [Indexed: 12/14/2022]
Abstract
Non-cell autonomous pathology is widely accepted to determine the demise of motoneurons (MNs) in amyotrophic lateral sclerosis (ALS) with astrocytes, GFAP and glutamate transport suggested to play roles in reactive astrogliosis. Previously we described actions of excitotoxicity and oxidative stress to produce differential injury of motoneurons and astrocytes, respectively, and our goal here was to define patterns of MN injury and astrogliosis during a combined excitotoxic-oxidative injury since such a paradigm more closely models disease pathology. Using an in vitro neuronal-glial culture of embryonic mouse spinal cord, we demonstrate that glutamate transport activity was maintained or increased initially, despite a loss of cellular viability, induced by exposure to combinations of excitotoxic [(S)-5-fluorowillardiine (FW)] and oxidative [3-morpholinosydnonimine (SIN-1)] insults over 48 h. Under these conditions, injury was slow in time course and apoptotic-like as shown by the patterns of annexin V and propidium iodide (PI) labelling. Immunocytochemistry for SMI-32 revealed that injury produced time- and insult-dependent reductions in the size of MN arbours, axonal dieback and appreciable neuritic blebbing. These changes were preceded by early hypertrophy of GFAP-positive astrocytes, and followed by more delayed stellation and eventual gliotoxicity. Alterations to EAAT2 immunolabelling were similar to those found for GFAP being initially maintained and then eventually reduced at 48 h. Image analysis of immunocytochemical data confirmed the differential time-dependent changes found with SMI-32, GFAP and EAAT2. Axonopathy and blebbing of MNs was frequently associated with areas of low GFAP immunoreactivity. The exact profile of changes to MNs and astrocytes was context-dependent and sensitive to subtle changes in the mix of excitotoxic-oxidative insults. Overall our findings are consistent with the concepts that the nature, extent and time-course of astrogliosis are insult-dependent, and that discrete pro-survival and destructive components of astrogliosis are likely to determine the precise profile of MN injury in non-cell autonomous pathology of ALS.
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Affiliation(s)
- Nicole Wallis
- Molecular Neuropharmacology, Florey Neuroscience Institutes, Parkville, Australia
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235
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Van Den Bosch L. Endoplasmic reticulum stress plays an important role in amyotrophic lateral sclerosis (Commentary on Prell et al.). Eur J Neurosci 2012; 35:651. [DOI: 10.1111/j.1460-9568.2012.08063.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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236
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Lee S, Kim Y, Li E, Park S. Ghrelin protects spinal cord motoneurons against chronic glutamate excitotoxicity by inhibiting microglial activation. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2012; 16:43-8. [PMID: 22416219 PMCID: PMC3298825 DOI: 10.4196/kjpp.2012.16.1.43] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 01/01/2012] [Accepted: 01/08/2012] [Indexed: 11/17/2022]
Abstract
Glutamate excitotoxicity is emerging as a contributor to degeneration of spinal cord motoneurons in amyotrophic lateral sclerosis (ALS). Recently, we have reported that ghrelin protects motoneurons against chronic glutamate excitotoxicity through the activation of extracellular signal-regulated kinase 1/2 and phosphatidylinositol-3-kinase/Akt/glycogen synthase kinase-3β pathways. Previous studies suggest that activated microglia actively participate in the pathogenesis of ALS motoneuron degeneration. However, it is still unknown whether ghrelin exerts its protective effect on motoneurons via inhibition of microglial activation. In this study, we investigate organotypic spinal cord cultures (OSCCs) exposed to threohydroxyaspartate (THA), as a model of excitotoxic motoneuron degeneration, to determine if ghrelin prevents microglial activation. Exposure of OSCCs to THA for 3 weeks produced typical motoneuron death, and treatment of ghrelin significantly attenuated THA-induced motoneuron loss, as previously reported. Ghrelin prevented THA-induced microglial activation in the spinal cord and the expression of pro-inflammatory cytokines tumor necrosis factor-α and interleukin-1β. Our data indicate that ghrelin may act as a survival factor for motoneurons by functioning as a microglia-deactivating factor and suggest that ghrelin may have therapeutic potential for the treatment of ALS and other neurodegenerative disorders where inflammatory responses play a critical role.
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Affiliation(s)
- Sungyoub Lee
- Department of Pharmacology and Medical Research Center for Bioreaction to ROS and Biomedical Science Institute, School of Medicine, Kyung Hee University, Seoul 130-701, Korea
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Bogaert E, Goris A, Van Damme P, Geelen V, Lemmens R, van Es MA, van den Berg LH, Sleegers K, Verpoorten N, Timmerman V, De Jonghe P, Van Broeckhoven C, Traynor BJ, Landers JE, Brown RH, Glass JD, Al-Chalabi A, Shaw CE, Birve A, Andersen PM, Slowik A, Tomik B, Melki J, Robberecht W, Van Den Bosch L. Polymorphisms in the GluR2 gene are not associated with amyotrophic lateral sclerosis. Neurobiol Aging 2012; 33:418-20. [PMID: 20409611 PMCID: PMC2949683 DOI: 10.1016/j.neurobiolaging.2010.03.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 02/12/2010] [Accepted: 03/11/2010] [Indexed: 02/07/2023]
Abstract
Excitotoxicity is thought to play a pathogenic role in amyotrophic lateral sclerosis (ALS). Excitotoxic motor neuron death is mediated through the Ca(2+)-permeable α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type of glutamate receptors and Ca(2+) permeability is determined by the GluR2 subunit. We investigated whether polymorphisms or mutations in the GluR2 gene (GRIA2) predispose patients to ALS. Upon sequencing 24 patients and 24 controls no nonsynonymous coding variants were observed but 24 polymorphisms were identified, 9 of which were novel. In a screening set of 310 Belgian ALS cases and 794 healthy controls and a replication set of 3157 cases and 5397 controls from 6 additional populations no association with susceptibility, age at onset, or disease duration was observed. We conclude that polymorphisms in the GluR2 gene (GRIA2) are not a major contributory factor in the pathogenesis of ALS.
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Affiliation(s)
- Elke Bogaert
- Laboratory for Neurobiology, Experimental Neurology, University of Leuven, Leuven, Belgium
- Vesalius Research Center, VIB, Leuven, Belgium
| | - An Goris
- Laboratory for Neuroimmunology, section for Experimental Neurology, University of Leuven, Leuven, Belgium
| | - Philip Van Damme
- Laboratory for Neurobiology, Experimental Neurology, University of Leuven, Leuven, Belgium
- Vesalius Research Center, VIB, Leuven, Belgium
| | - Veerle Geelen
- Laboratory for Neurobiology, Experimental Neurology, University of Leuven, Leuven, Belgium
- Vesalius Research Center, VIB, Leuven, Belgium
| | - Robin Lemmens
- Laboratory for Neurobiology, Experimental Neurology, University of Leuven, Leuven, Belgium
- Vesalius Research Center, VIB, Leuven, Belgium
| | - Michael A. van Es
- Dept of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Leonard H. van den Berg
- Dept of Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Kristel Sleegers
- Neurodegenerative Brain Diseases Group, Dept of Molecular Genetics, VIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
| | - Nathalie Verpoorten
- Peripheral Neuropathy Group, Dept of Molecular Genetics, VIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
| | - Vincent Timmerman
- Peripheral Neuropathy Group, Dept of Molecular Genetics, VIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
| | - Peter De Jonghe
- Neurogenetics Group, Dept of Molecular Genetics, VIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
- Division of Neurology, University Hospital of Antwerp, Antwerpen, Belgium
| | - Christine Van Broeckhoven
- Neurodegenerative Brain Diseases Group, Dept of Molecular Genetics, VIB, Antwerpen, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
| | - Bryan J. Traynor
- Neuromuscular Diseases Research Group, Laboratory of Neurogenetics, NIA, Bethesda, Maryland, USA
| | - John E. Landers
- Cecil B Day Laboratory for Neuromuscular Research, University of Massachusetts Medical School, Worcester, MA, USA 01655
| | - Robert H. Brown
- Cecil B Day Laboratory for Neuromuscular Research, University of Massachusetts Medical School, Worcester, MA, USA 01655
| | | | - Ammar Al-Chalabi
- MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, Department of Clinical Neuroscience, London, UK
| | - Christopher E. Shaw
- MRC Centre for Neurodegeneration Research, King's College London, Institute of Psychiatry, Department of Clinical Neuroscience, London, UK
| | - Anna Birve
- Institute of Clinical Neuroscience, Umeå University, Umeå, Sweden
| | | | | | - Barbara Tomik
- Dept of Neurology, Jagiellonian University, Krakow, Poland
| | - Judith Melki
- Inserm U-788 and University of Paris 11, Le Kremlin-Bicêtre, France
| | - Wim Robberecht
- Laboratory for Neurobiology, Experimental Neurology, University of Leuven, Leuven, Belgium
- Vesalius Research Center, VIB, Leuven, Belgium
- Dept of Neurology, University Hospital Leuven, University of Leuven, Leuven, Belgium
| | - Ludo Van Den Bosch
- Laboratory for Neurobiology, Experimental Neurology, University of Leuven, Leuven, Belgium
- Vesalius Research Center, VIB, Leuven, Belgium
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238
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Schuster JE, Fu R, Siddique T, Heckman CJ. Effect of prolonged riluzole exposure on cultured motoneurons in a mouse model of ALS. J Neurophysiol 2012; 107:484-92. [PMID: 22013234 PMCID: PMC3349692 DOI: 10.1152/jn.00714.2011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Accepted: 10/13/2011] [Indexed: 11/22/2022] Open
Abstract
Riluzole is the only FDA-approved drug to treat amyotrophic lateral sclerosis, but its long-term effects on motoneurons are unknown. Therefore, we treated primary mouse spinal cord cultures with 2 μM riluzole for 4-9 days and then used whole cell patch clamp to record the passive and active properties of both wild-type and SOD1(G93A) motoneurons. At this concentration, riluzole blocks >50% of the sodium component of a persistent inward current that plays a major role in determining motoneuron excitability. Prolonged riluzole treatment significantly decreased the amplitude of the persistent inward current. This effect was specific for SOD1(G93A) motoneurons, where the amplitude decreased by 55.4%. In addition, prolonged treatment hyperpolarized the resting membrane potential as well as the voltage onset and voltage maximum of the persistent inward current (∼2-3 mV in each case). These effects appeared to offset one another and resulted in no change in the firing properties. In a subset of cells, acute reapplication of 2 μM riluzole during the recording decreased repetitive firing and the persistent inward current, which is consistent with the normal effects of riluzole. The downregulation of the persistent inward current in response to prolonged riluzole administration is in contrast to the strong upregulation of this same current after descending neuromodulatory drive to the cord is lost following spinal injury. This dichotomy suggests that decreased activation of G protein-coupled pathways can induce upregulation in the persistent inward current but that direct channel block is ineffective.
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Affiliation(s)
| | - R. Fu
- Davee Department of Neurology and Clinical Neurosciences
| | - T. Siddique
- Davee Department of Neurology and Clinical Neurosciences
| | - C. J. Heckman
- Department of Physiology
- Department of Physical Medicine and Rehabilitation, and
- Department of Physical Therapy and Human Movement Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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239
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Rodrigues MCO, Hernandez-Ontiveros DG, Louis MK, Willing AE, Borlongan CV, Sanberg PR, Voltarelli JC, Garbuzova-Davis S. Neurovascular aspects of amyotrophic lateral sclerosis. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2012; 102:91-106. [PMID: 22748827 DOI: 10.1016/b978-0-12-386986-9.00004-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease with a complicated and poorly understood pathogenesis. Strong evidence indicates impairment of all neurovascular unit components including the blood-brain and blood-spinal cord barriers (BBB/BSCB) in both patients and animal models. The present review provides an updated analysis of the microvascular pathology and impaired BBB/BSCB in ALS. Based on experimental and clinical ALS studies, the roles of cellular components, cell interactions, tight junctions, transport systems, cytokines, matrix metalloproteinases, and free radicals in the BBB/BSCB disruption are discussed. The impact of BBB/BSCB damage in ALS pathogenesis is a novel research topic, and this review will reveal some aspects of microvascular pathology involved in the disease and hopefully engender new therapeutic approaches.
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Affiliation(s)
- Maria Carolina O Rodrigues
- Center of Excellence for Aging & Brain Repair, University of South Florida, Morsani College of Medicine, Tampa, Florida, USA
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240
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D-amino acid oxidase controls motoneuron degeneration through D-serine. Proc Natl Acad Sci U S A 2011; 109:627-32. [PMID: 22203986 DOI: 10.1073/pnas.1114639109] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder involving an extensive loss of motoneurons. Aberrant excitability of motoneurons has been implicated in the pathogenesis of selective motoneuronal death in ALS. D-serine, an endogenous coagonist of N-methyl-D-aspartate receptors, exacerbates motoneuronal death and is increased both in patients with sporadic/familial ALS and in a G93A-SOD1 mouse model of ALS (mSOD1 mouse). More recently, a unique mutation in the D-amino acid oxidase (DAO) gene, encoding a D-serine degrading enzyme, was reported to be associated with classical familial ALS. However, whether DAO affects the motoneuronal phenotype and D-serine increase in ALS remains uncertain. Here, we show that genetic inactivation of DAO in mice reduces the number and size of lower motoneurons with axonal degeneration, and that suppressed DAO activity in reactive astrocytes in the reticulospinal tract, one of the major inputs to the lower motoneurons, predominantly contributes to the D-serine increase in the mSOD1 mouse. The DAO inactivity resulted from expressional down-regulation, which was reversed by inhibitors of a glutamate receptor and MEK, but not by those of inflammatory stimuli. Our findings provide evidence that DAO has a pivotal role in motoneuron degeneration through D-serine regulation and that inactivity of DAO is a common feature between the mSOD1 ALS mouse model and the mutant DAO-associated familial ALS. The therapeutic benefit of reducing D-serine or controlling DAO activity in ALS should be tested in future studies.
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241
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Neurotoxic injury pathways in differentiated mouse motor neuron-neuroblastoma hybrid (NSC-34D) cells in vitro--limited effect of riluzole on thapsigargin, but not staurosporine, hydrogen peroxide and homocysteine neurotoxicity. Toxicol Appl Pharmacol 2011; 258:208-15. [PMID: 22108590 DOI: 10.1016/j.taap.2011.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 10/28/2011] [Accepted: 10/30/2011] [Indexed: 12/11/2022]
Abstract
The neuroblastoma-spinal motor neuron fusion cell line, NSC-34, in its differentiated form, NSC-34D, permits examining the effects of riluzole, a proven treatment for amyotrophic lateral sclerosis (ALS) on cell death induction by staurosporine (STS), thapsigargin (Thaps), hydrogen peroxide (H(2)O(2)) and homocysteine (HCy). These neurotoxins, applied exogenously, have mechanisms of action related to the various proposed molecular pathogenetic pathways in ALS and are differentiated from endogenous cell death that is associated with cytoplasmic aggregate formation in motor neurons. Nuclear morphology, caspase-3/7 activation and high content imaging were used to assess toxicity of these neurotoxins with and without co-treatment with riluzole, a benzothiazole compound with multiple pharmacological actions. STS was the most potent neurotoxin at killing NSC-34D cells with a toxic concentration at which 50% of maximal cell death is achieved (TC(50)=0.01μM), followed by Thaps (TC(50)=0.9μM) and H(2)O(2) (TC(50)=15μM) with HCy requiring higher concentrations to kill at the same level (TC(50)=2200μM). Riluzole provided neurorescue with a 20% absolute reduction (47.6% relative reduction) in apoptotic cell death against Thaps-induced NSC-34D cell (p≤0.05), but had no effect on STS-, H(2)O(2)- and HCy-induced NSC-34D cell death. This effect of riluzole on Thaps induction of cell death was independent of caspase-3/7 activation. Riluzole mitigated a toxin that can cause intracellular calcium dysregulation associated with endoplasmic reticulum (ER) stress but not toxins associated with other cell death mechanisms.
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242
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Mitra P, Brownstone RM. An in vitro spinal cord slice preparation for recording from lumbar motoneurons of the adult mouse. J Neurophysiol 2011; 107:728-41. [PMID: 22031766 DOI: 10.1152/jn.00558.2011] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The development of central nervous system slice preparations for electrophysiological studies has led to an explosion of knowledge of neuronal properties in health and disease. Studies of spinal motoneurons in these preparations, however, have been largely limited to the early postnatal period, as adult motoneurons are vulnerable to the insults sustained by the preparation. We therefore sought to develop an adult spinal cord slice preparation that permits recording from lumbar motoneurons. To accomplish this, we empirically optimized the composition of solutions used during preparation in order to limit energy failure, reduce harmful ionic fluxes, mitigate oxidative stress, and prevent excitotoxic cell death. In addition to other additives, this involved the use of ethyl pyruvate, which serves as an effective nutrient and antioxidant. We also optimized and incorporated a host of previously published modifications used for other in vitro preparations, such as the use of polyethylene glycol. We provide an in-depth description of the preparation protocol and discuss the rationale underlying each modification. By using this protocol, we obtained stable whole cell patch-clamp recordings from identified fluorescent protein-labeled motoneurons in adult slices; here, we describe the firing properties of these adult motoneurons. We propose that this preparation will allow further studies of how motoneurons integrate activity to produce adult motor behaviors and how pathological processes such as amyotrophic lateral sclerosis affect these neurons.
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Affiliation(s)
- Pratip Mitra
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada
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243
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Gonzalez LE, Kotler ML, Vattino LG, Conti E, Reisin RC, Mulatz KJ, Snutch TP, Uchitel OD. Amyotrophic lateral sclerosis-immunoglobulins selectively interact with neuromuscular junctions expressing P/Q-type calcium channels. J Neurochem 2011; 119:826-38. [PMID: 21883225 DOI: 10.1111/j.1471-4159.2011.07462.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by a gradual loss of motoneurons. The majority of ALS cases are associated with a sporadic form whose etiology is unknown. Several pieces of evidence favor autoimmunity as a potential contributor to sporadic ALS pathology. To gain understanding concerning possible antigens interacting with IgGs from sporadic ALS patients (ALS-IgGs), we studied immunoreactivity against neuromuscular junction (NMJ), spinal cord and cerebellum of mice with and without the Ca(V) 2.1 pore-forming subunit of the P/Q-type voltage-gated calcium (Ca(2+)) channel. ALS-IgGs showed a strong reactivity against NMJs of wild-type diaphragms. ALS-IgGs also increased muscle miniature end-plate potential frequency, suggesting a functional role for ALS-IgGs on synaptic signaling. In support, in mice lacking the Ca(V) 2.1 subunit ALS-IgGs showed significantly reduced NMJ immunoreactivity and did not alter spontaneous acetylcholine release. This difference in reactivity was absent when comparing N-type Ca(2+) channel wild-type or null mice. These results are particularly relevant because motoneurons are known to be early pathogenic targets in ALS. Our findings add further evidence supporting autoimmunity as one of the possible mechanisms contributing to ALS pathology. They also suggest that serum autoantibodies in a subset of ALS patients would interact with NMJ proteins down-regulated when P/Q-type channels are absent.
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Affiliation(s)
- Laura E Gonzalez
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, IFIBYNE-CONICET, UBA, Argentina
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244
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Caioli S, Curcio L, Pieri M, Antonini A, Marolda R, Severini C, Zona C. Substance P receptor activation induces downregulation of the AMPA receptor functionality in cortical neurons from a genetic model of Amyotrophic Lateral Sclerosis. Neurobiol Dis 2011; 44:92-101. [DOI: 10.1016/j.nbd.2011.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 06/01/2011] [Accepted: 06/16/2011] [Indexed: 12/13/2022] Open
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AMPA receptor regulation at the mRNA and protein level in rat primary cortical cultures. PLoS One 2011; 6:e25350. [PMID: 21966506 PMCID: PMC3178644 DOI: 10.1371/journal.pone.0025350] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 09/01/2011] [Indexed: 11/19/2022] Open
Abstract
Ionotropic glutamate α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors are the major mediators of fast synaptic neurotransmission. In this work, we used primary cortical cultures from rats as a model system to study AMPA receptor regulation during in vitro cell maturation and after synaptic activity modifications. The levels of AMPA receptor mRNA and protein, along with the alternative splicing and RNA editing of the AMPA receptor subunit (GluR1-4) mRNAs, were analyzed in immature (DIV5) and mature (DIV26) rat neuronal cultures. We observed an increase in the expression of all four AMPA receptor subunits during in vitro neuronal maturation. This finding might be due to the formation of new synapses between neurons during the development of a complex neuronal network. We also analyzed the effects of stimulation (KCl and glutamate) and inhibition (APV/TTX) on rat mature neuronal cultures (DIV26): stimulation with KCl led to an overall down-regulation of GluR1 and GluR3 AMPA receptor subunits and an up-regulation of the GluR2 subunit. Similarly, glutamate treatment induced a significant down-regulation of GluR1 together with an up-regulation of GluR2. In contrast, the chronic blockade of neuronal activity that resulted from APV/TTX treatment up-regulated GluR1 and GluR3 with a parallel down-regulation of GluR2 and GluR4. RNA editing at the R/G site increased during neuronal cell maturation for all AMPA receptors (from 8–39% at DIV5 to 28–67% at DIV26). Unexpectedly, all the treatments tested induced a marked reduction (ranging from −9% to −52%) of R/G editing levels in mature neurons, primarily for the mRNA flip variant. In summary, we showed that cultured rat cortical neurons are able to vary the stoichiometric ratios of the AMPA receptor subunits and to control post-transcriptional processes to adapt fast synaptic transmission under different environmental conditions.
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246
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Spinal inhibitory interneuron pathology follows motor neuron degeneration independent of glial mutant superoxide dismutase 1 expression in SOD1-ALS mice. J Neuropathol Exp Neurol 2011; 70:662-77. [PMID: 21760539 DOI: 10.1097/nen.0b013e31822581ac] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Motor neuron degeneration and skeletal muscle denervation are hallmarks of amyotrophic lateral sclerosis (ALS), but other neuron populations and glial cells are also involved in ALS pathogenesis. We examined changes in inhibitory interneurons in spinal cords of the ALS model low-copy Gurney G93A-SOD1 (G1del) mice and found reduced expression of markers of glycinergic and GABAergic neurons, that is, glycine transporter 2 (GlyT2) and glutamic acid decarboxylase (GAD65/67), specifically in the ventral horns of clinically affected mice. There was also loss of GlyT2 and GAD67 messenger RNA-labeled neurons in the intermediate zone. Ubiquitinated inclusions appeared in interneurons before 20 weeks of age, that is, after their development in motor neurons but before the onset of clinical signs and major motor neuron degeneration, which starts from 25 weeks of age. Because mutant superoxide dismutase 1 (SOD1) in glia might contribute to the pathogenesis, we also examined neuron-specific G93A-SOD1 mice; they also had loss of inhibitory interneuron markers in ventral horns and ubiquitinated interneuron inclusions. These data suggest that, in mutant SOD1-associated ALS, pathological changes may spread from motor neurons to interneuronsin a relatively early phase of the disease, independent of the presence of mutant SOD1 in glia. The degeneration of spinal inhibitory interneurons may in turn facilitate degeneration of motor neurons and contribute to disease progression.
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247
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Markedly reduced axonal potassium channel expression in human sporadic amyotrophic lateral sclerosis: an immunohistochemical study. Exp Neurol 2011; 232:149-53. [PMID: 21906595 DOI: 10.1016/j.expneurol.2011.08.015] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 07/27/2011] [Accepted: 08/18/2011] [Indexed: 12/12/2022]
Abstract
Fasciculations are characteristic features of amyotrophic lateral sclerosis (ALS), suggesting abnormally increased excitability of motor axons. Previous nerve excitability studies have shown reduced axonal potassium currents in ALS patients that may contribute to the hyperexcitability and thereby generation of fasciculations. To clarify changes in axonal ion channel expression in motor axons of ALS, we performed immunohistochemistry of potassium and sodium channels in the C7 and L5 ventral/dorsal roots obtained from five autopsy cases of sporadic ALS. Compared to controls, the immunoreactivity of potassium channels (Kv1.2) was markedly reduced in the ventral roots, but normal in the dorsal roots of all the ALS patients. Nodal sodium channel expression was not significantly different in ALS patients and control subjects. Our results show prominently reduced expression of axonal potassium channels, and provide the neuropathological and biological basis for decreased accommodative potassium currents in motor axons of ALS patients. The axonal hyperexcitability would lead to generation of fasciculations, and possibly enhances motor neuron death in ALS.
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Zaitsev AV, Kim KK, Fedorova IM, Dorofeeva NA, Magazanik LG, Tikhonov DB. Specific mechanism of use-dependent channel block of calcium-permeable AMPA receptors provides activity-dependent inhibition of glutamatergic neurotransmission. J Physiol 2011; 589:1587-601. [PMID: 21486838 DOI: 10.1113/jphysiol.2011.204362] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
This study examined the blocking action of the selective channel blocker of calcium-permeable (CP) AMPA receptors, N1-(1-phenylcyclohexyl)pentane-1,5-diaminium bromide (IEM-1925), on excitatory postsynaptic currents in rat neostriatal and cortical neurons and in fly neuromuscular junctions. In both preparations, the blocking of CP-AMPA receptor currents increased along with the stimulation frequency. The continuous presence of kainate, which activates AMPA receptors, in the external solution also caused an enhanced blocking effect. Likewise, decrease of the synaptic release by lowering calcium concentration resulted in significant reduction of the blocking action. The activity dependence of the block is explained using the guarded receptor model. The drug molecule can only bind if the channel is open. After the channel has closed, the drug molecule remains trapped inside. However, the trapped molecule slowly egresses from closed channels to the cytoplasm. The total block effect is determined by the equilibrium between accumulation of the drug in the open channels and relief from the closed channels. Therefore, the conditions that favour the open state result in enhanced inhibition. This significant finding reveals a new way to modulate CP-AMPAR-mediated transmission using a physiologically relevant approach. Moreover, it allows the involvement of CP-AMPARs in the physiological and pathological processes – such as high-frequency synaptic activity or increase of the steady-state glutamate concentration – to be examined.
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Affiliation(s)
- A V Zaitsev
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, 44, Toreza Prospect, Saint-Petersburg, 194223 Russia.
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249
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Autoimmunity in amyotrophic lateral sclerosis: past and present. Neurol Res Int 2011; 2011:497080. [PMID: 21826267 PMCID: PMC3150148 DOI: 10.1155/2011/497080] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Accepted: 05/03/2011] [Indexed: 12/12/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting particularly motor neurons for which no cure or effective treatment is available. Although the cause of ALS remains unknown, accumulative evidence suggests an autoimmune mechanism of pathogenesis. In this paper, we will summarize the current research related to autoimmunity in the sporadic form of ALS and discuss the potential underlying pathogenic mechanisms and perspectives. Presented data supports the view that humoral immune responses against motor nerve terminals can initiate a series of physiological changes leading to alteration of calcium homeostasis. In turn, loss of calcium homeostasis may induce neuronal death through apoptotic signaling pathways. Additional approaches identifying specific molecular features of this hypothesis are required, which will hopefully allow us to develop techniques of early diagnosis and effective therapies.
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Chang G, Guo Y, Jia Y, Duan W, Li B, Yu J, Li C. Protective effect of combination of sulforaphane and riluzole on glutamate-mediated excitotoxicity. Biol Pharm Bull 2011; 33:1477-83. [PMID: 20823560 DOI: 10.1248/bpb.33.1477] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Threohydroxyaspartate (THA) causes glutamate excitotoxicity in motor neurons in organotypic culture of rat spinal cord. Some drugs, including sulforaphane (SF) and riluzole, can protect motor neuron against excitotoxicity. It has been demonstrated that SF is a potent inducer of Phase II enzymes, while riluzole is a classic anti-glutamate agent. The objective of the current study is to investigate whether the combination of SF and riluzole is superior to either one used alone. In our study, the combination of SF with riluzole not only stimulates the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), reduced nicotinamide adenine dinucleotide phosphate (NADPH): quinone oxidoreductase 1 (NQO1) and heme oxygenase 1 (HO-1), but also reduces the extracellular accumulation of glutamate. When used at optimal doses, SF (10 microM) and riluzole (5 microM), either alone or in combination, all exert significant and similar neuroprotection, as measured by the number of motor neuron, medium malondialdehyde (MDA) level and lactate dehydrogenase (LDH) level. When used at low doses, the combination is better than each agent used alone. In conclusion, these results suggest the potential utility of combination use of SF and riluzole for protection of motor neuron against excitotoxicity.
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Affiliation(s)
- Geng Chang
- Department of Neurology, The Second Hospital of Hebei Medical University, Hebei, China
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