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Grijalva-Otero I, Doncel-Pérez E. Traumatic Human Spinal Cord Injury: Are Single Treatments Enough to Solve the Problem? Arch Med Res 2024; 55:102935. [PMID: 38157747 DOI: 10.1016/j.arcmed.2023.102935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/17/2023] [Accepted: 12/11/2023] [Indexed: 01/03/2024]
Abstract
Traumatic spinal cord injury (SCI) results in partial or complete motor deficits, such as paraplegia, tetraplegia, and sphincter control, as well as sensory disturbances and autonomic dysregulation such as arterial hypotension, lack of sweating, and alterations in skin lability. All this has a strong psychological impact on the affected person and his/her family, as well as costs to healthcare institutions with an economic burden in the short, medium, and long terms. Despite at least forty years of experimental animal studies and several clinical trials with different therapeutic strategies, effective therapy is not universally accepted. Most of the published works on acute and chronic injury use a single treatment, such as medication, trophic factor, transplant of a cell type, and so on, to block some secondary injury mechanisms or promote some mechanisms of structural/functional restoration. However, despite significant results in experimental models, the outcome is a moderate improvement in muscle strength, sensation, or eventually in sphincter control, which has been considered non-significant in human clinical trials. Here we present a brief compilation of successful individual treatments that have been applied to secondary mechanisms of action. These studies show limited neuroprotective or neurorestorative approaches in animal models and clinical trials. Thus, the few benefits achieved so far represent a rationale to further explore other strategies that seek better structural and functional restoration of the injured spinal cord.
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Affiliation(s)
- Israel Grijalva-Otero
- Medical Research Unit for Neurological Diseases, Unidad Médica de Alta Especialidad, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City, Mexico.
| | - Ernesto Doncel-Pérez
- Neural Regeneration Group, Hospital Nacional de Parapléjicos de Toledo, Servicios de Salud de Castilla-La Mancha, Toledo, Spain
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2
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Chen C, Khanthiyong B, Thaweetee-Sukjai B, Charoenlappanit S, Roytrakul S, Thanoi S, Reynolds GP, Nudmamud-Thanoi S. Proteomic association with age-dependent sex differences in Wisconsin Card Sorting Test performance in healthy Thai subjects. Sci Rep 2023; 13:20238. [PMID: 37981639 PMCID: PMC10658079 DOI: 10.1038/s41598-023-46750-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 11/04/2023] [Indexed: 11/21/2023] Open
Abstract
Sex differences in cognitive function exist, but they are not stable and undergo dynamic change during the lifespan. However, our understanding of how sex-related neural information transmission evolves with age is still in its infancy. This study utilized the Wisconsin Card Sorting Test (WCST) and the label-free proteomics method with bioinformatic analysis to investigate the molecular mechanisms underlying age-related sex differences in cognitive performance in 199 healthy Thai subjects (aged 20-70 years), as well as explore the sex-dependent protein complexes for predicting cognitive aging. The results showed that males outperformed females in two of the five WCST sub-scores: %Corrects and %Errors. Sex differences in these scores were related to aging, becoming noticeable in those over 60. At the molecular level, differently expressed individual proteins and protein complexes between both sexes are associated with the potential N-methyl-D-aspartate type glutamate receptor (NMDAR)-mediated excitotoxicity, with the NMDAR complex being enriched exclusively in elderly female samples. These findings provided a preliminary indication that healthy Thai females might be more susceptible to such neurotoxicity, as evidenced by their cognitive performance. NMDAR protein complex enrichment in serum could be proposed as a potential indication for predicting cognitive aging in healthy Thai females.
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Affiliation(s)
- Chen Chen
- Medical Science Graduate Program, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | | | | | - Sawanya Charoenlappanit
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Sittiruk Roytrakul
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand
| | - Samur Thanoi
- School of Medical Sciences, University of Phayao, Phayao, Thailand.
| | - Gavin P Reynolds
- Biomolecular Sciences Research Centre, Sheffield Hallam University, Sheffield, UK
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand
| | - Sutisa Nudmamud-Thanoi
- Centre of Excellence in Medical Biotechnology, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand.
- Department of Anatomy, Faculty of Medical Science, Naresuan University, Phitsanulok, Thailand.
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3
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Kaur J, Mojumdar A. A mechanistic overview of spinal cord injury, oxidative DNA damage repair and neuroprotective therapies. Int J Neurosci 2023; 133:307-321. [PMID: 33789065 DOI: 10.1080/00207454.2021.1912040] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Despite substantial development in medical treatment strategies scientists are struggling to find a cure against spinal cord injury (SCI) which causes long term disability and paralysis. The prime rationale behind it is the enlargement of primary lesion due to an initial trauma to the spinal cord which spreads to the neighbouring spinal tissues It begins from the time of traumatic event happened and extends to hours and even days. It further causes series of biological and functional alterations such as inflammation, excitotoxicity and ischemia, and promotes secondary lesion to the cord which worsens the life of individuals affected by SCI. Oxidative DNA damage is a stern consequence of oxidative stress linked with secondary injury causes oxidative base alterations and strand breaks, which provokes cell death in neurons. It is implausible to stop primary damage however it is credible to halt the secondary lesion and improve the quality of the patient's life to some extent. Therefore it is crucial to understand the hidden perspectives of cell and molecular biology affecting the pathophysiology of SCI. Thus the focus of the review is to connect the missing links and shed light on the oxidative DNA damages and the functional repair mechanisms, as a consequence of the injury in neurons. The review will also probe the significance of neuroprotective strategies in the present scenario. HIGHLIGHTSSpinal cord injury, a pernicious condition, causes excitotoxicity and ischemia, ultimately leading to cell death.Oxidative DNA damage is a consequence of oxidative stress linked with secondary injury, provoking cell death in neurons.Base excision repair (BER) is one of the major repair pathways that plays a crucial role in repairing oxidative DNA damages.Neuroprotective therapies curbing SCI and boosting BER include the usage of pharmacological drugs and other approaches.
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Affiliation(s)
- Jaspreet Kaur
- Department of Neuroscience, University of Copenhagen, Copenhagen N, Denmark
| | - Aditya Mojumdar
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
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4
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Sabet MF, Barman S, Beller M, Meuth SG, Melzer N, Aktas O, Goebels N, Prozorovski T. Myelinating Co-Culture as a Model to Study Anti-NMDAR Neurotoxicity. Int J Mol Sci 2022; 24:ijms24010248. [PMID: 36613687 PMCID: PMC9820503 DOI: 10.3390/ijms24010248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/06/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Anti-NMDA receptor (NMDAR) encephalitis is frequently associated with demyelinating disorders (e.g., multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein-associated disease (MOGAD)) with regard to clinical presentation, neuropathological and cerebrospinal fluid findings. Indeed, autoantibodies (AABs) against the GluN1 (NR1) subunit of the NMDAR diminish glutamatergic transmission in both neurons and oligodendrocytes, leading to a state of NMDAR hypofunction. Considering the vital role of oligodendroglial NMDAR signaling in neuron-glia communication and, in particular, in tightly regulated trophic support to neurons, the influence of GluN1 targeting on the physiology of myelinated axon may be of importance. We applied a myelinating spinal cord cell culture model that contains all major CNS cell types, to evaluate the effects of a patient-derived GluN1-specific monoclonal antibody (SSM5) on neuronal and myelin integrity. A non-brain reactive (12D7) antibody was used as the corresponding isotype control. We show that in cultures at the late stage of myelination, prolonged treatment with SSM5, but not 12D7, leads to neuronal damage. This is characterized by neurite blebbing and fragmentation, and a reduction in the number of myelinated axons. However, this significant toxic effect of SSM5 was not observed in earlier cultures at the beginning of myelination. Anti-GluN1 AABs induce neurodegenerative changes and associated myelin loss in myelinated spinal cord cultures. These findings may point to the higher vulnerability of myelinated neurons towards interference in glutamatergic communication, and may refer to the disturbance of the NMDAR-mediated oligodendrocyte metabolic supply. Our work contributes to the understanding of the emerging association of NMDAR encephalitis with demyelinating disorders.
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Affiliation(s)
- Mercedeh Farhat Sabet
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Sumanta Barman
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Mathias Beller
- Institut für Mathematische Modellierung Biologischer Systeme, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Sven G. Meuth
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Nico Melzer
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Orhan Aktas
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Norbert Goebels
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
- Correspondence: (N.G.); (T.P.); Tel.: +49-211-81-04594 (N.G.); +49-211-81-05146 (T.P.)
| | - Tim Prozorovski
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
- Correspondence: (N.G.); (T.P.); Tel.: +49-211-81-04594 (N.G.); +49-211-81-05146 (T.P.)
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5
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Zhang JK, Sun P, Jayasekera D, Greenberg JK, Javeed S, Dibble CF, Blum J, Song C, Song SK, Ray WZ. Utility of Diffusion Basis Spectrum Imaging in Quantifying Baseline Disease Severity and Prognosis of Cervical Spondylotic Myelopathy. Spine (Phila Pa 1976) 2022; 47:1687-1693. [PMID: 35969006 PMCID: PMC9712150 DOI: 10.1097/brs.0000000000004456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 07/20/2022] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Prospective cohort study. OBJECTIVE The aim was to assess the association between diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) measures and cervical spondylotic myelopathy (CSM) clinical assessments at baseline and two-year follow-up. SUMMARY OF BACKGROUND DATA Despite advancements in diffusion-weighted imaging, few studies have examined associations between diffusion magnetic resonance imaging (MRI) markers and CSM-specific clinical domains at baseline and long-term follow-up. MATERIALS AND METHODS A single-center prospective cohort study enrolled 50 CSM patients who underwent surgical decompression and 20 controls from 2018 to 2020. At initial evaluation, all patients underwent diffusion-weighted MRI acquisition, followed by DTI and DBSI analyses. Diffusion-weighted MRI metrics assessed white matter integrity by fractional anisotropy, axial diffusivity, radial diffusivity, and fiber fraction. To improve estimations of intra-axonal anisotropic diffusion, DBSI measures intra-/extra-axonal fraction and intra-axonal axial diffusivity. DBSI also evaluates extra-axonal isotropic diffusion by restricted and nonrestricted fraction. Clinical assessments were performed at baseline and two-year follow-up and included the modified Japanese Orthopedic Association (mJOA); 36-Item Short Form Survey physical component summary (SF-36 PCS); SF-36 mental component summary; neck disability index; myelopathy disability index; and disability of the arm, shoulder, and hand. Pearson correlation coefficients were computed to compare associations between DTI/DBSI and clinical measures. A False Discovery Rate correction was applied for multiple comparisons testing. RESULTS At baseline presentation, of 36 correlations analyzed between DTI metrics and CSM clinical measures, only DTI fractional anisotropy showed a positive correlation with SF-36 PCS ( r =0.36, P =0.02). In comparison, there were 30/81 (37%) significant correlations among DBSI and clinical measures. Increased DBSI axial diffusivity, intra-axonal axial diffusivity, intra-axonal fraction, restricted fraction, and extra-axonal anisotropic fraction were associated with worse clinical presentation (decreased mJOA; SF-36 PCS/mental component summary; and increased neck disability index; myelopathy disability index; disability of the arm, shoulder, and hand). At latest follow-up, increased preoperative DBSI intra-axonal axial diffusivity and extra-axonal anisotropic fraction were significantly correlated with improved mJOA. CONCLUSIONS This findings demonstrate that DBSI measures may reflect baseline disease burden and long-term prognosis of CSM as compared with DTI. With further validation, DBSI may serve as a noninvasive biomarker following decompressive surgery. LEVEL OF EVIDENCE 3.
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Affiliation(s)
- Justin K. Zhang
- Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, Missouri, 63110, USA
| | - Peng Sun
- Department of Imaging Physics, UT MD Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Dinal Jayasekera
- Department of Biomedical Engineering, Washington University in St. Louis McKelvey School of Engineering, Saint Louis, Missouri, 63130, USA
| | - Jacob K. Greenberg
- Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, Missouri, 63110, USA
| | - Saad Javeed
- Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, Missouri, 63110, USA
| | - Christopher F. Dibble
- Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, Missouri, 63110, USA
| | - Jacob Blum
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Chunyu Song
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Sheng-Kwei Song
- Department of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Wilson Z. Ray
- Department of Neurological Surgery, Washington University School of Medicine, Saint Louis, Missouri, 63110, USA
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6
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Zinc Concentration Dynamics Indicate Neurological Impairment Odds after Traumatic Spinal Cord Injury. Antioxidants (Basel) 2020; 9:antiox9050421. [PMID: 32414139 PMCID: PMC7278606 DOI: 10.3390/antiox9050421] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/24/2022] Open
Abstract
Traumatic Spinal Cord Injury (TSCI) is debilitating and often results in a loss of motor and sensory function caused by an interwoven set of pathological processes. Oxidative stress and inflammatory processes are amongst the critical factors in the secondary injury phase after TSCI. The essential trace element Zinc (Zn) plays a crucial role during this phase as part of the antioxidant defense system. The study aims to determine dynamic patterns in serum Zn concentration in patients with TSCI and test for a correlation with neurological impairment. A total of 42 patients with TSCI were enrolled in this clinical observational study. Serum samples were collected at five different points in time after injury (at admission, and after 4 h, 9 h, 12 h, 24 h, and 3 days). The analysis of the serum Zn concentrations was conducted by total reflection X-ray fluorescence (TXRF). The patients were divided into two groups—a study group S (n = 33) with neurological impairment, including patients with remission (G1, n = 18) and no remission (G0, n = 15) according to a positive AIS (American Spinal Injury Association (ASIA) Impairment Scale) conversion within 3 months after the trauma; and a control group C (n = 9), consisting of subjects with vertebral fractures without neurological impairment. The patient data and serum concentrations were examined and compared by non-parametric test methods to the neurological outcome. The median Zn concentrations in group S dropped within the first 9 h after injury (964 µg/L at admission versus 570 µg/L at 9 h, p < 0.001). This decline was stronger than in control subjects (median of 751 µg/L versus 729 µg/L, p = 0.023). A binary logistic regression analysis including the difference in serum Zn concentration from admission to 9 h after injury yielded an area under the curve (AUC) of 82.2% (CI: 64.0–100.0%) with respect to persistent neurological impairment. Early Zn concentration dynamics differed in relation to the outcome and may constitute a helpful diagnostic indicator for patients with spinal cord trauma. The fast changes in serum Zn concentrations allow an assessment of neurological impairment risk on the first day after trauma. This finding supports strategies for improving patient care by avoiding strong deficits via adjuvant nutritive measures, e.g., in unresponsive patients after trauma.
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7
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Degenerative cervical myelopathy - update and future directions. Nat Rev Neurol 2020; 16:108-124. [PMID: 31974455 DOI: 10.1038/s41582-019-0303-0] [Citation(s) in RCA: 222] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2019] [Indexed: 11/09/2022]
Abstract
Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults worldwide. DCM encompasses various acquired (age-related) and congenital pathologies related to degeneration of the cervical spinal column, including hypertrophy and/or calcification of the ligaments, intervertebral discs and osseous tissues. These pathologies narrow the spinal canal, leading to chronic spinal cord compression and disability. Owing to the ageing population, rates of DCM are increasing. Expeditious diagnosis and treatment of DCM are needed to avoid permanent disability. Over the past 10 years, advances in basic science and in translational and clinical research have improved our understanding of the pathophysiology of DCM and helped delineate evidence-based practices for diagnosis and treatment. Surgical decompression is recommended for moderate and severe DCM; the best strategy for mild myelopathy remains unclear. Next-generation quantitative microstructural MRI and neurophysiological recordings promise to enable quantification of spinal cord tissue damage and help predict clinical outcomes. Here, we provide a comprehensive, evidence-based review of DCM, including its definition, epidemiology, pathophysiology, clinical presentation, diagnosis and differential diagnosis, and non-operative and operative management. With this Review, we aim to equip physicians across broad disciplines with the knowledge necessary to make a timely diagnosis of DCM, recognize the clinical features that influence management and identify when urgent surgical intervention is warranted.
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8
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Zhang Y, Hou G, Ji W, Rao F, Zhou R, Gao S, Mao L, Zhou F. Persistent oppression and simple decompression both exacerbate spinal cord ascorbate levels. Int J Med Sci 2020; 17:1167-1176. [PMID: 32547312 PMCID: PMC7294922 DOI: 10.7150/ijms.41289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 05/08/2020] [Indexed: 12/01/2022] Open
Abstract
Background: Surgical decompression after acute spinal cord injury has become the consensus of orthopaedic surgeons. However, the choice of surgical decompression time window after acute spinal cord injury has been one of the most controversial topics in orthopaedics. Objective: We apply an online electrochemical system (OECS) for continuously monitoring the ascorbate of the rats' spinal cord to determine the extent to which ascorbate levels were influenced by contusion or sustained compression. Methods: Adult Sprague-Dawley rats (n=10) were instrumented for ascorbate concentration recording and received T11 drop spinal cord injury (SCI). The Group A (n=5) were treated with immediately decompression after SCI. The Group B (n=5) were contused and oppressed until 1 h after the injury to decompress. Results: The ascorbate level of spinal cord increased immediately by contusion injury and reached to 1.62 μmol/L ± 0.61 μmol/L (217.30% ± 95.09% of the basal level) at the time point of 60 min after the injury. Compared with the Group A, the ascorbate level in Group B increased more significantly at 1 h after the injury, reaching to 3.76 μmol/L ± 1.75 μmol/L (430.25% ± 101.30% of the basal level). Meanwhile, we also found that the decompression after 1 hour of continuous compression will cause delayed peaks of ascorbate reaching to 5.71 μmol/L ± 2.69 μmol/L (627.73% ± 188.11% of the basal level). Conclusion: Our study provides first-hand direct experimental evidence indicating ascorbate is directly involved in secondary spinal cord injury and exhibits the dynamic time course of microenvironment changes after continuous compression injury of the spinal cord.
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Affiliation(s)
- Yawen Zhang
- Department of Orthopaedics, Peking University Third Hospital, Beijing, China.,Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, The Chinese Academy of Sciences (CAS), Beijing, China
| | - Guojin Hou
- Department of Orthopaedics, Peking University Third Hospital, Beijing, China
| | - Wenliang Ji
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, The Chinese Academy of Sciences (CAS), Beijing, China
| | - Feng Rao
- Trauma Medicine Centre, Peking University People's Hospital, Beijing, China
| | - Rubing Zhou
- Department of Orthopaedics, Peking University Third Hospital, Beijing, China
| | - Shan Gao
- Department of Orthopaedics, Peking University Third Hospital, Beijing, China
| | - Lanqun Mao
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, The Chinese Academy of Sciences (CAS), Beijing, China
| | - Fang Zhou
- Department of Orthopaedics, Peking University Third Hospital, Beijing, China
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9
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Degenerative cervical myelopathy: Recent updates and future directions. J Clin Orthop Trauma 2020; 11:822-829. [PMID: 32879568 PMCID: PMC7452218 DOI: 10.1016/j.jcot.2020.07.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/07/2020] [Accepted: 07/15/2020] [Indexed: 02/06/2023] Open
Abstract
Advances in patient selection, surgical techniques, and postoperative care have facilitated spine surgeons to manage complex spine cases with shorter operative times, reduced hospital stay and improved outcomes. We focus this article on a few areas which have shown maximum developments in management of degenerative cervical myelopathy and also throw a glimpse into the future ahead. Imaging modalities, surgical decision making, robotics and neuro-navigation, minimally invasive spinal surgery, motion preservation, use of biologics are few of them. Through this review article, we hope to provide the readers with an insight into the present state of art in cervical myelopathy and what the future has in store for us.
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10
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Wilson JRF, Badhiwala JH, Moghaddamjou A, Martin AR, Fehlings MG. Degenerative Cervical Myelopathy; A Review of the Latest Advances and Future Directions in Management. Neurospine 2019; 16:494-505. [PMID: 31476852 PMCID: PMC6790745 DOI: 10.14245/ns.1938314.157] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 01/23/2023] Open
Abstract
The assessment, diagnosis, operative and nonoperative management of degenerative cervical myelopathy (DCM) have evolved rapidly over the last 20 years. A clearer understanding of the pathobiology of DCM has led to attempts to develop objective measurements of the severity of myelopathy, including technology such as multiparametric magnetic resonance imaging, biomarkers, and ancillary clinical testing. New pharmacological treatments have the potential to alter the course of surgical outcomes, and greater innovation in surgical techniques have made surgery safer, more effective and less invasive. Future developments for the treatment of DCM will seek to improve the diagnostic accuracy of imaging, improve the objectivity of clinical assessment, and increase the use of surgical technology to ensure the best outcome is achieved for each individual patient.
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Affiliation(s)
- Jamie R F Wilson
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Jetan H Badhiwala
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Ali Moghaddamjou
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Allan R Martin
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Michael G Fehlings
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
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11
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Mazzone GL, Nistri A. Modulation of extrasynaptic GABAergic receptor activity influences glutamate release and neuronal survival following excitotoxic damage to mouse spinal cord neurons. Neurochem Int 2019; 128:175-185. [PMID: 31051211 DOI: 10.1016/j.neuint.2019.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 04/08/2019] [Accepted: 04/30/2019] [Indexed: 12/14/2022]
Abstract
Excitotoxic levels of released glutamate trigger a cascade of deleterious cellular events leading to delayed neuronal death. This phenomenon implies extensive dysregulation in the balance between network excitation and inhibition. Our hypothesis was that enhancing network inhibition should prevent excitotoxicity and provide neuroprotection. To test this notion, we used mouse organotypic spinal slice cultures and explored if excitotoxicity caused by the potent glutamate analogue kainate was blocked by pharmacological increase in GABAA receptor activity. To this end we monitored (with a biosensor) real-time glutamate release following 1 h kainate application and quantified neuronal survival 24 h later. Glutamate release evoked by kainate was strongly decreased by the allosteric GABAA modulator midazolam (10 nM) or the GABA agonist THIP (10 μM), leading to neuroprotection. On the contrary, much higher glutamate release was induced by the GABA antagonist bicuculline (20 μM) that inhibits synaptic and extrasynaptic GABAA receptors. Gabazine (20 μM), an antagonist of synaptic GABAA receptors, had no effect on glutamate release or neuroprotection. No effect was observed with the glycine antagonist strychnine or the glycine agonist L-alanine. These findings indicate that enhancement of GABA receptor activity was an effective tool to counteract excitotoxic death in spinal networks. In view of the potent activity by THIP, preferentially acting on extrasynaptic GABAA receptors, the present data imply a significant role for extrasynaptic GABAA receptors in sparing spinal cord neurons from injury.
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Affiliation(s)
- Graciela L Mazzone
- Instituto de Investigaciones en Medicina Traslacional (IIMT), CONICET-Universidad Austral, Derqui-Pilar, Buenos Aires, Argentina.
| | - Andrea Nistri
- Neuroscience Dept., International School for Advanced Studies (SISSA), Trieste, Italy
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12
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Alizadeh A, Dyck SM, Karimi-Abdolrezaee S. Traumatic Spinal Cord Injury: An Overview of Pathophysiology, Models and Acute Injury Mechanisms. Front Neurol 2019; 10:282. [PMID: 30967837 PMCID: PMC6439316 DOI: 10.3389/fneur.2019.00282] [Citation(s) in RCA: 586] [Impact Index Per Article: 117.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 03/05/2019] [Indexed: 12/11/2022] Open
Abstract
Traumatic spinal cord injury (SCI) is a life changing neurological condition with substantial socioeconomic implications for patients and their care-givers. Recent advances in medical management of SCI has significantly improved diagnosis, stabilization, survival rate and well-being of SCI patients. However, there has been small progress on treatment options for improving the neurological outcomes of SCI patients. This incremental success mainly reflects the complexity of SCI pathophysiology and the diverse biochemical and physiological changes that occur in the injured spinal cord. Therefore, in the past few decades, considerable efforts have been made by SCI researchers to elucidate the pathophysiology of SCI and unravel the underlying cellular and molecular mechanisms of tissue degeneration and repair in the injured spinal cord. To this end, a number of preclinical animal and injury models have been developed to more closely recapitulate the primary and secondary injury processes of SCI. In this review, we will provide a comprehensive overview of the recent advances in our understanding of the pathophysiology of SCI. We will also discuss the neurological outcomes of human SCI and the available experimental model systems that have been employed to identify SCI mechanisms and develop therapeutic strategies for this condition.
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Affiliation(s)
- Arsalan Alizadeh
- Regenerative Medicine Program, Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Spinal Cord Research Center, University of Manitoba, Winnipeg, MB, Canada
| | - Scott Matthew Dyck
- Regenerative Medicine Program, Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Spinal Cord Research Center, University of Manitoba, Winnipeg, MB, Canada
| | - Soheila Karimi-Abdolrezaee
- Regenerative Medicine Program, Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Spinal Cord Research Center, University of Manitoba, Winnipeg, MB, Canada
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Lee BJ, Jun HO, Kim JH, Kim JH. Astrocytic cystine/glutamate antiporter is a key regulator of erythropoietin expression in the ischemic retina. FASEB J 2019; 33:6045-6054. [PMID: 30742774 DOI: 10.1096/fj.201802144r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Ischemic retinopathies and optic neuropathies are important causes of vision loss. The neuroprotective effect of erythropoietin (EPO) in ischemic neuronal injury and the expression of EPO and its receptor in retinal tissue have been well documented. However, the exact regulatory mechanism of EPO expression in retinal ischemia still remains to be elucidated. In this study, we investigated the role of cystine/glutamate antiporter (system xc-) in the regulation of astrocytic EPO expression by using both in vitro and in vivo models. Under hypoxia, the expression of astrocytic system xc- is up-regulated both in vitro and in vivo. Inhibition of system xc- resulted in depletion of intracellular glutathione (GSH) and decrement of GSH disulfide ratios in human brain astrocytes (HBAs). In HBAs, hypoxia-induced stabilization of hypoxia-inducible factor (Hif)-2α is nearly completely abolished by inhibition of system xc-. Hypoxia-induced up-regulation of astrocytic EPO expression is suppressed by both pharmacological inhibition and siRNA-mediated knockdown of system xc-. In contrast, basal EPO expression under normoxia is not affected by system xc- modulation. In summary, under hypoxia, increased system xc- acts as the major source of intracellular GSH, which helps in stabilizing Hif-2α and subsequent up-regulation of EPO in astrocytes.-Lee, B. J., Jun, H. O., Kim, J. H., Kim, J. H. Astrocytic cystine/glutamate antiporter is a key regulator of erythropoietin expression in the ischemic retina.
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Affiliation(s)
- Byung Joo Lee
- Fight Against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul National University, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
| | - Hyoung Oh Jun
- Fight Against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul National University, Seoul, South Korea
| | - Jin Hyoung Kim
- Fight Against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul National University, Seoul, South Korea
| | - Jeong Hun Kim
- Fight Against Angiogenesis-Related Blindness (FARB) Laboratory, Clinical Research Institute, Seoul National University Hospital, Seoul National University, Seoul, South Korea.,Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea.,Department of Ophthalmology, Seoul National University College of Medicine, Seoul National University, Seoul, South Korea
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14
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The role of timing in the treatment of spinal cord injury. Biomed Pharmacother 2017; 92:128-139. [DOI: 10.1016/j.biopha.2017.05.048] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 05/07/2017] [Accepted: 05/09/2017] [Indexed: 12/23/2022] Open
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Hill Lucas J, Emery DG, Rosenberg LJ. REVIEW ■ : Physical Injury of Neurons: Important Roles for Sodium and Chloride Ions. Neuroscientist 2016. [DOI: 10.1177/107385849700300208] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
There is growing evidence that ions other than Ca2+ play important roles in the deterioration of neuronal elements in both gray and white matter after physical injury. This review features information gathered with a tissue culture model of dendrite transection regarding the contributions of Na+ and CI- to ultrastructural damage and neuronal death. This information and the results of other in vitro investigations of physical and ischemic/excitotoxic injuries indicate that elevation of internal Na+ is an early event that may contribute significantly to neuronal injury through effects on Na+-driven transport mechanisms. Proposed deleterious consequences include cytoplasmic acidification, reduced mitochondrial energy production, and elevation of intracellular Ca2+ and extracellular excitatory amino acids to toxic levels. Prevention of Na+ entry into neurons after injury has been found to limit ultrastructural damage, prevent death, and preserve electrophysiological function. Although the role of CI- in neuronal injury is less well defined, there is also evidence that elevation of intracellular CI- contributes to structural damage, particularly to the smooth endoplasmic reticulum. In terventions that limit Na+- and CI--mediated damage to injured neurons may have utility in neurosurgery and as acute phase treatments for nervous system trauma and other pathological states. NEURO SCIENTIST 3:89-101, 1997
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Affiliation(s)
- Jen Hill Lucas
- Department of Physiology The Ohio State University Columbus,
Ohio
| | - Dennis G. Emery
- Department of Zoology and Genetics lowa State University
Ames, Iowa
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Battaglia G, Riozzi B, Bucci D, Di Menna L, Molinaro G, Pallottino S, Nicoletti F, Bruno V. Activation of mGlu3 metabotropic glutamate receptors enhances GDNF and GLT-1 formation in the spinal cord and rescues motor neurons in the SOD-1 mouse model of amyotrophic lateral sclerosis. Neurobiol Dis 2015; 74:126-36. [DOI: 10.1016/j.nbd.2014.11.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/29/2014] [Accepted: 11/19/2014] [Indexed: 11/28/2022] Open
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17
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Cytokine signaling by grafted neuroectodermal stem cells rescues motoneurons destined to die. Exp Neurol 2014; 261:180-9. [DOI: 10.1016/j.expneurol.2014.05.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 05/23/2014] [Accepted: 05/28/2014] [Indexed: 12/16/2022]
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Clinical evaluation of a neuroprotective drug in patients with cervical spondylotic myelopathy undergoing surgical treatment: design and rationale for the CSM-Protect trial. Spine (Phila Pa 1976) 2013; 38:S68-75. [PMID: 23962993 DOI: 10.1097/brs.0b013e3182a7e9b0] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Descriptive article and narrative review. OBJECTIVE To explain the rationale and design of the cervical spondylotic myelopathy (CSM)-Protect clinical trial that aims to elucidate the efficacy and safety of riluzole in the context of CSM. SUMMARY OF BACKGROUND DATA CSM is the most common cause of spinal cord-related dysfunction internationally. Although surgery is effective in preventing the progression of impairment, and in some cases improving functional outcomes, many patients continue to exhibit significant disability in the postoperative setting. Evidence from preclinical studies suggests that glutamate-related excitotoxicity may contribute to the pathology of CSM and that administration of the sodium and glutamate-blocking medication riluzole, when combined with spinal cord decompression, may mitigate this effect and improve neurobehavioral outcomes. Although riluzole is FDA approved and has been shown to be safe and effective in the context of amyotrophic lateral sclerosis, its efficacy and safety in the context of CSM remain unknown. METHODS Descriptive article with narrative review of the literature. RESULTS In addition to providing pertinent preclinical background on the topic, this descriptive article and narrative review discusses the design and current status of an ongoing phase III randomized controlled trial evaluating the efficacy and safety of riluzole, combined with surgical decompression, in the treatment of CSM. CONCLUSION On the basis of current projections, we estimate that the interim analysis for this study will take place in the spring of 2014, at which time an adaptive sample size adjustment may take place.
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Ates O, Cayli SR, Gurses I, Karabulut AB, Yucel N, Kocak A, Cakir CO, Yologlu S. Do sodium channel blockers have neuroprotective effect after onset of ischemic insult? Neurol Res 2013; 29:317-23. [PMID: 17509233 DOI: 10.1179/016164107x159225] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Cerebral ischemia causes a series of pathophysiologic events that may result in cerebral infarct. Some neurons are more vulnerable to ischemia, particularly pyramidal neurons in the hippocampal CA1 region. Pharmacologic intervention for treatment of cerebral ischemia aims to counteract secondary neurotoxic events or to interrupt the progression of this process. In the present study, we compare the neuroprotective effects of sodium channel blockers (mexiletine, riluzole and phenytoin) and investigate whether they have neuroprotective effect when given after ischemic insult. METHODS A transient global cerebral ischemia model was performed in this study by clipping bilateral common carotid arteries during 45 minutes. Riluzole (8 mg/kg), mexiletine (80 mg/kg) and phenytoin (200 mg/kg) were injected into the rats intraperitoneally 30 minutes before or after reperfusion. Lipid peroxidation levels and cerebral water contents were evaluated 24 hours after ischemia. Histopathologic assessment of hippocampal region was determined 7 days after ischemia. RESULTS Riluzole, mexiletine and phenytoin treatment after global ischemia significantly decreased water content of the ischemic brain (p<0.05 for each). No significant difference was observed in cerebral edema among the drug treatment groups (p>0.05). When pre-treatment and post-treatment groups were compared with each other, only riluzole pre-treatment group revealed better result for cerebral edema (p<0.05). Pre-treatment with these drugs revealed significantly better results for the malonyldialdehyde (MDA) level and the number of survival neuron on the hippocampal region than the post-treatment groups. CONCLUSION It is demonstrated that riluzole, mexiletine and phenytoin are potent neuroprotective agents in the rat model of transient global cerebral ischemia, but they are more effective when given before onset of the ischemia.
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Affiliation(s)
- Ozkan Ates
- Department of Neurosurgery, School of Medicine, Inonu University, Malatya, Turkey.
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20
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Yoon H, Radulovic M, Wu J, Blaber SI, Blaber M, Fehlings MG, Scarisbrick IA. Kallikrein 6 signals through PAR1 and PAR2 to promote neuron injury and exacerbate glutamate neurotoxicity. J Neurochem 2013; 127:283-98. [PMID: 23647384 DOI: 10.1111/jnc.12293] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 04/18/2013] [Accepted: 04/29/2013] [Indexed: 01/19/2023]
Abstract
CNS trauma generates a proteolytic imbalance contributing to secondary injury, including axonopathy and neuron degeneration. Kallikrein 6 (Klk6) is a serine protease implicated in neurodegeneration, and here we investigate the role of protease-activated receptors 1 (PAR1) and PAR2 in mediating these effects. First, we demonstrate Klk6 and the prototypical activator of PAR1, thrombin, as well as PAR1 and PAR2, are each elevated in murine experimental traumatic spinal cord injury (SCI) at acute or subacute time points. Recombinant Klk6 triggered extracellular signal-regulated kinase (ERK1/2) signaling in cerebellar granule neurons and in the NSC34 spinal cord motoneuron cell line, in a phosphoinositide 3-kinae and MEK-dependent fashion. Importantly, lipopeptide inhibitors of PAR1 or PAR2, and PAR1 genetic deletion, each reduced Klk6-ERK1/2 activation. In addition, Klk6 and thrombin promoted degeneration of cerebellar neurons and exacerbated glutamate neurotoxicity. Moreover, genetic deletion of PAR1 blocked thrombin-mediated cerebellar neurotoxicity and reduced the neurotoxic effects of Klk6. Klk6 also increased glutamate-mediated Bim signaling, poly-ADP-ribose polymerase cleavage and lactate dehydrogenase release in NSC34 motoneurons and these effects were blocked by PAR1 and PAR2 lipopeptide inhibitors. Taken together, these data point to a novel Klk6-signaling axis in CNS neurons that is mediated by PAR1 and PAR2 and is positioned to contribute to neurodegeneration.
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Affiliation(s)
- Hyesook Yoon
- Neurobiology of Disease Program, Mayo Medical and Graduate School, Rochester, Minnesota, USA; Department of Physical Medicine and Rehabilitation, Mayo Medical and Graduate School, Rochester, Minnesota, USA
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Fehlings MG, Wilson JR, Frankowski RF, Toups EG, Aarabi B, Harrop JS, Shaffrey CI, Harkema SJ, Guest JD, Tator CH, Burau KD, Johnson MW, Grossman RG. Riluzole for the treatment of acute traumatic spinal cord injury: rationale for and design of the NACTN Phase I clinical trial. J Neurosurg Spine 2013; 17:151-6. [PMID: 22985381 DOI: 10.3171/2012.4.aospine1259] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In the immediate period after traumatic spinal cord injury (SCI) a variety of secondary injury mechanisms combine to gradually expand the initial lesion size, potentially leading to diminished neurological outcomes at long-term follow-up. Riluzole, a benzothiazole drug, which has neuroprotective properties based on sodium channel blockade and mitigation of glutamatergic toxicity, is currently an approved drug that attenuates the extent of neuronal degeneration in patients with amyotrophic lateral sclerosis. Moreover, several preclinical SCI studies have associated riluzole administration with improved functional outcomes and increased neural tissue preservation. Based on these findings, riluzole has attracted considerable interest as a potential neuroprotective drug for the treatment of SCI. Currently, a Phase I trial evaluating the safety and pharmacokinetic profile of riluzole in human SCI patients is being conducted by the North American Clinical Trials Network (NACTN) for Treatment of Spinal Cord Injury. The current review summarizes the existing preclinical and clinical literature on riluzole, provides a detailed description of the Phase I trial, and suggests potential opportunities for future investigation. Clinical trial registration no.: NCT00876889.
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Affiliation(s)
- Michael G Fehlings
- Department of Surgery, Division of Neurosurgery and Spinal Program, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada.
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Wilson JR, Fehlings MG. Riluzole for acute traumatic spinal cord injury: a promising neuroprotective treatment strategy. World Neurosurg 2013; 81:825-9. [PMID: 23295632 DOI: 10.1016/j.wneu.2013.01.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 01/02/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND Over the years, understanding of the specific secondary injury mechanisms that follow traumatic spinal cord injury (SCI) has improved. These pathologic mechanisms collectively serve to increase the extent of neural tissue injury, reducing prospects for neurologic recovery. An enhanced understanding of the pathobiology of SCI has permitted investigation of therapies targeting specific elements of this pathologic cascade. It is now known that the continuous posttraumatic activation of neuronal voltage-gated sodium ion channels leads to increased rates of cell death through the development of cellular swelling, acidosis, and glutaminergic excitotoxicity. The objective herein is to provide an update regarding the current status of the potential neuroprotective drug riluzole in the treatment of traumatic SCI. METHODS Narrative review and summary paper. RESULTS Riluzole is a sodium channel-blocking benzothiazole anticonvulsant drug that is approved by the U.S. Food and Drug Administration for the treatment of amyotrophic lateral sclerosis and has shown efficacy in preclinical models of SCI in reducing the extent of sodium and glutamate mediated secondary injury. This drug is currently under early stages of clinical investigation in SCI and shows promise as an acute neuroprotective therapy in this context. CONCLUSION This article reviews the biologic rationale, existing preclinical evidence, and emerging clinical data for riluzole in the treatment of traumatic SCI.
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Affiliation(s)
- Jefferson R Wilson
- Department of Surgery, Division of Neurosurgery and Spinal Program, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada
| | - Michael G Fehlings
- Department of Surgery, Division of Neurosurgery and Spinal Program, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada.
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23
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Borgens RB, Liu-Snyder P. Understanding secondary injury. QUARTERLY REVIEW OF BIOLOGY 2012; 87:89-127. [PMID: 22696939 DOI: 10.1086/665457] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Secondary injury is a term applied to the destructive and self-propagating biological changes in cells and tissues that lead to their dysfunction or death over hours to weeks after the initial insult (the "primary injury"). In most contexts, the initial injury is usually mechanical. The more destructive phase of secondary injury is, however, more responsible for cell death and functional deficits. This subject is described and reviewed differently in the literature. To biomedical researchers, systemic and tissue-level changes such as hemorrhage, edema, and ischemia usually define this subject. To cell and molecular biologists, "secondary injury" refers to a series of predominately molecular events and an increasingly restricted set of aberrant biochemical pathways and products. These biochemical and ionic changes are seen to lead to death of the initially compromised cells and "healthy" cells nearby through necrosis or apoptosis. This latter process is called "bystander damage." These viewpoints have largely dominated the recent literature, especially in studies of the central nervous system (CNS), often without attempts to place the molecular events in the context of progressive systemic and tissue-level changes. Here we provide a more comprehensive and inclusive discussion of this topic.
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Affiliation(s)
- Richard Ben Borgens
- Center for Paralysis Research, School of Veterinary Medicine, Department of Biomedical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
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24
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Ionov ID, Roslavtseva LA. Coadministration of bicuculline and NMDA induces paraplegia in the rat. Brain Res 2012; 1451:27-33. [PMID: 22445063 DOI: 10.1016/j.brainres.2012.03.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 02/27/2012] [Accepted: 03/05/2012] [Indexed: 11/28/2022]
Abstract
Motor neurons (MNs) of an adult rat are normally insensitive to the neurotoxic action of NMDA. Meanwhile, the experiments in non-motor neurons showed that sensitivity to NMDA can be increased by bicuculline, an antagonist at GABA(A) receptors. The aim of the present work was to examine whether bicuculline would produce such an effect in the adult MNs. In adult Wistar rats, intrathecal injection of bicuculline and NMDA individually failed to affect motor activity of the extremities. In contrast, bicuculline-NMDA combination dose-dependently impaired hindlimb functions. At the 9th day after injections of the combination, a paraplegia with persistent bilateral spastic extension developed in all animals. Light microscopic assessment showed that the development of the motor deficit is associated with pathological changes in spinal motor neurons (swelling, accumulation of the Nissl substance near nucleus, hyperchromatosis, shrinkage, and chromatolysis), mainly in the lumbar ventral horns. Additionally, distinct abnormalities were observed in the white matter of the lumbar cords. The bicuculline-NMDA combination induced a loss of spinal cord MNs while sparing the dorsal horn neurons. The effects of the combination were reversed by muscimol, a GABA(A) agonist. Thus, an inhibition of GABA(A)ergic processes can induce NMDA sensitivity in adult MNs. The present data may provide new insights into the mechanism of motor disorders in amyotrophic lateral sclerosis and other states wherein the combination of glutamatergic overstimulation and GABA(A)ergic understimulation takes place.
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Affiliation(s)
- Ilya D Ionov
- Centre on Theoretical Problems in Physical and Chemical Pharmacology, Russian Academy of Sciences, Moscow, Russia.
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25
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The role of embryonic motoneuron transplants to restore the lost motor function of the injured spinal cord. Ann Anat 2011; 193:362-70. [PMID: 21600746 DOI: 10.1016/j.aanat.2011.04.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 03/28/2011] [Accepted: 04/06/2011] [Indexed: 12/26/2022]
Abstract
Spinal cord injury or disease result in the loss of critical numbers of spinal motoneurons and consequentially, in severe functional impairment. The most successful way to replace missing motoneurons is the use of embryonic postmitotic motoneuron grafts. This method may also at least partially restore integrity of the injured spinal cord. It has been shown that grafted motoneurons survive, differentiate and integrate into the host cord and many of them are able to reinnervate the denervated muscles. If grafted motoneurons are provided with a conduit (e.g. reimplanted ventral root) the grafted cells are able to extend their axons along the entire length of the peripheral nerves and reach the hind or forelimb muscles and to restore limb locomotion patterns. Grafted motoneurons show excellent survival in motoneuron-depleted adult host cords, but the developing spinal cord appears to provide an unfavourable environment for these motoneurons as they do not survive in immature cords. The long term survival and maturation of the grafted neurons depend on the availability of a nerve conduit and one or more target muscles, independently of whether these are ectopic nerve-muscle implants or limb muscles in their original site. Thus, grafted and host motoneurons induce functional recovery in the denervated limb muscles when their axons can grow into an avulsed and reimplanted ventral root and then reach the limb muscles. Following segmental loss of motoneurons induced by partial spinal cord injury, motoneuron-enriched embryonic grafts can be placed into the gap-like hemisection cavity in the cervical spinal cord. Such transplants induce the regeneration of great numbers of host motoneurons possibly by the bridging effect of the grafts. In this case, the regenerating host motoneurons reinnervate their original target muscles while the small graft plays a minimal role in the reinnervation of muscles. These results suggest that reconstruction of the injured spinal cord using an embryonic motoneuron-enriched spinal cord graft is a feasible way to achieve improvement after severe functional motor deficits of the spinal cord.
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26
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Liu WM, Wu JY, Li FC, Chen QX. Ion channel blockers and spinal cord injury. J Neurosci Res 2011; 89:791-801. [PMID: 21394757 DOI: 10.1002/jnr.22602] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 12/11/2010] [Accepted: 12/19/2010] [Indexed: 12/23/2022]
Abstract
The activation of a delayed secondary cascade of unsatisfactory cellular and molecular responses after a primary mechanical insult to the spinal cord causes the progressive degeneration of this structure. Disturbance of ionic homeostasis is part of the secondary injury process and plays an integral role in the early stage of spinal cord injury (SCI). The secondary pathology of SCI is complex and involves disturbance of the homeostasis of K(+) , Na(+) , and Ca(2+) . The effect of ion channel blockers on chronic SCI has also been proved. In this Mini-Review, we provide a comprehensive summary of the effects of ion channel blockers on the natural responses after SCI. Combination therapy is based on the roles of ions and disturbance of their homeostasis in SCI. The effects of ion channel blockers suggest that they have potential in the treatment of SCI, although the complexity of their effects shows that further knowledge is needed before they can be applied clinically.
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Affiliation(s)
- Wang-Mi Liu
- Department of Orthopedic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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27
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Sanjoinine A isolated from Semen Zizyphi Spinosi protects against kainic acid-induced convulsions. Arch Pharm Res 2010; 32:1515-23. [PMID: 20091264 DOI: 10.1007/s12272-009-2103-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 08/05/2009] [Accepted: 08/11/2009] [Indexed: 10/20/2022]
Abstract
These experiments were performed to know whether sanjoinine A, a component of the alkaloid fraction of Semen Zizyphi Spinosi, acts as an anti-convulsive agent in the kainic acid (KA)-induced experimental convulsion model and whether these effects are mediated by decreased intracellular calcium. Oral administration of sanjoinine A (4 and 8 mg/kg) increased the survival rate and latency of convulsion onset, and decreased the seizure scores and the weight loss induced by intraperitoneal (i.p.) injection of KA (50 mg/kg) in mice. In addition, sanjoinine A protected against neuronal damage and apoptosis in the hippocampus after KA administration, as analyzed by using immunohistochemistry and TUNEL assay. Sanjoinine A also significantly blocked seizure-form electroencephalogram alterations induced by KA. Moreover, in cultured rat neuronal cells, sanjoinine A inhibited KA-induced cell death, as measured by propidium iodide detection. Sanjoinine A also increased intracellular chloride and inhibited the elevation of intracellular calcium induced by KA. Sanjoinine A, therefore protects against KA-induced convulsions by increasing intracellular chloride and reducing intracellular calcium levels.
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28
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Long-term homeostasis of extracellular glutamate in the rat cerebral cortex across sleep and waking states. J Neurosci 2009; 29:620-9. [PMID: 19158289 DOI: 10.1523/jneurosci.5486-08.2009] [Citation(s) in RCA: 196] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neuronal firing patterns, neuromodulators, and cerebral metabolism change across sleep-waking states, and the synaptic release of glutamate is critically involved in these processes. Extrasynaptic glutamate can also affect neural function and may be neurotoxic, but whether and how extracellular glutamate is regulated across sleep-waking states is unclear. To assess the effect of behavioral state on extracellular glutamate at high temporal resolution, we recorded glutamate concentration in prefrontal and motor cortex using fixed-potential amperometry in freely behaving rats. Simultaneously, we recorded local field potentials (LFPs) and electroencephalograms (EEGs) from contralateral cortex. We observed dynamic, progressive changes in the concentration of glutamate that switched direction as a function of behavioral state. Specifically, the concentration of glutamate increased progressively during waking (0.329 +/- 0.06%/min) and rapid eye movement (REM) sleep (0.349 +/- 0.13%/min). This increase was opposed by a progressive decrease during non-REM (NREM) sleep (0.338 +/- 0.06%/min). During a 3 h sleep deprivation period, glutamate concentrations initially exhibited the progressive rise observed during spontaneous waking. As sleep pressure increased, glutamate concentrations ceased to increase and began decreasing despite continuous waking. During NREM sleep, the rate of decrease in glutamate was positively correlated with sleep intensity, as indexed by LFP slow-wave activity. The rate of decrease doubled during recovery sleep after sleep deprivation. Thus, the progressive increase in cortical extrasynaptic glutamate during EEG-activated states is counteracted by a decrease during NREM sleep that is modulated by sleep pressure. These results provide evidence for a long-term homeostasis of extracellular glutamate across sleep-waking states.
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Gupta R, Deshpande SB. 3-Nitropropionic acid-induced depression of spinal reflexes involves mechanisms different from ischemia-induced depression. Brain Res Bull 2008; 77:382-7. [DOI: 10.1016/j.brainresbull.2008.09.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
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Fogal B, Hewett SJ. Interleukin-1beta: a bridge between inflammation and excitotoxicity? J Neurochem 2008; 106:1-23. [PMID: 18315560 DOI: 10.1111/j.1471-4159.2008.05315.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Interleukin-1 (IL-1) is a proinflammatory cytokine released by many cell types that acts in both an autocrine and/or paracrine fashion. While IL-1 is best described as an important mediator of the peripheral immune response during infection and inflammation, increasing evidence implicates IL-1 signaling in the pathogenesis of several neurological disorders. The biochemical pathway(s) by which this cytokine contributes to brain injury remain(s) largely unidentified. Herein, we review the evidence that demonstrates the contribution of IL-1beta to the pathogenesis of both acute and chronic neurological disorders. Further, we highlight data that leads us to propose IL-1beta as the missing mechanistic link between a potential beneficial inflammatory response and detrimental glutamate excitotoxicity.
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Affiliation(s)
- Birgit Fogal
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA
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31
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Marsh DR, Holmes KD, Dekaban GA, Weaver LC. Distribution of an NMDA receptor:GFP fusion protein in sensory neurons is altered by a C-terminal construct. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.2001.00182.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Adenosine modulates excitatory synaptic transmission and suppresses neuronal death induced by ischaemia in rat spinal motoneurones. Pflugers Arch 2008; 457:441-51. [PMID: 18584206 DOI: 10.1007/s00424-008-0542-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Accepted: 06/04/2008] [Indexed: 10/21/2022]
Abstract
Although adenosine is an important neuromodulator, its role in modulating motor functions at the level of the spinal cord is poorly understood. In the present study, we investigated the effects of adenosine on excitatory synaptic transmission and neuronal death induced by experimental ischaemia by using whole-cell patch-clamp recordings from lamina IX neurones in spinal cord slices. Adenosine significantly decreased the frequency of miniature excitatory postsynaptic currents (mEPSCs) in almost all neurones examined that could be mimicked by an A(1) receptor agonist, N (6)-cyclopentyladenosine (CPA), and inhibited by an A(1) receptor antagonist, 8-cyclopentyl-1, 3-dipropylxanthine (DPCPX). Interestingly, adenosine increased mEPSC frequency in the presence of DPCPX in a subpopulation of neurones. In these neurones, an A(2A) receptor agonist, 2-[4-(2-carbonylethyl)-phenethylamino]-5'-N-ethylcarboxamidoadenosine (CGS21680), increased mEPSC frequency. Adenosine also induced an outward current that was blocked by the addition of Cs(+) and tetraethylammonium into the patch-pipette solution and inhibited in the presence of Ba(2+). The adenosine-induced outward current was mimicked by CPA, but not CGS21680, and inhibited by DPCPX. Moreover, superfusing with ischaemia simulating medium (ISM) generated an agonal inward current in all of the neurones tested. The latencies of the inward currents induced by ISM were significantly prolonged by adenosine or CPA, but not by CGS21680. These results suggest that adenosine receptors are functionally expressed in both the pre- and postsynaptic sites of lamina IX neurones and that their activation may exert multiple effects on motor function. Moreover, this study has provided a cellular basis for an involvement of A(1) receptors in the neuroprotective actions of adenosine.
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Survey of ALS-associated factors potentially promoting Ca2+ overload of motor neurons. ACTA ACUST UNITED AC 2008; 8:260-5. [PMID: 17917848 DOI: 10.1080/17482960701523124] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The deleterious consequences of Ca(2+) overload are thought to be a probable cause of motoneuronal death in ALS, although the overloading mechanism is currently unclear. In this paper some ALS-linked factors are analysed with regard to their influence on Ca(2+ )influx into neurons. Intensive cortex activity can render motor neurons susceptible to stimulation of calcium-permeable glutamate NMDA-receptors; increase in CSF concentrations of glutamate, glycine, and norepinephrine supposedly can intensify these receptors' activity. Elevated CSF levels of GABA and reduced levels of serotonin can promote Ca(2+ )influx through glutamate AMPA-receptors and voltage-gated channels of L-, N-, and P-type. Additionally, brain ischaemia can contribute to Ca(2+ )overload of motor neurons. Thus, ALS is characterized by the unique combination of factors potentially able to promote the overload of motor neurons with calcium.
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Thibault O, Gant JC, Landfield PW. Expansion of the calcium hypothesis of brain aging and Alzheimer's disease: minding the store. Aging Cell 2007; 6:307-17. [PMID: 17465978 PMCID: PMC1974776 DOI: 10.1111/j.1474-9726.2007.00295.x] [Citation(s) in RCA: 287] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Evidence accumulated over more than two decades has implicated Ca2+ dysregulation in brain aging and Alzheimer's disease (AD), giving rise to the Ca2+ hypothesis of brain aging and dementia. Electrophysiological, imaging, and behavioral studies in hippocampal or cortical neurons of rodents and rabbits have revealed aging-related increases in the slow afterhyperpolarization, Ca2+ spikes and currents, Ca2+ transients, and L-type voltage-gated Ca2+ channel (L-VGCC) activity. Several of these changes have been associated with age-related deficits in learning or memory. Consequently, one version of the Ca2+ hypothesis has been that increased L-VGCC activity drives many of the other Ca2+-related biomarkers of hippocampal aging. In addition, other studies have reported aging- or AD model-related alterations in Ca2+ release from ryanodine receptors (RyR) on intracellular stores. The Ca2+-sensitive RyR channels amplify plasmalemmal Ca2+ influx by the mechanism of Ca2+-induced Ca2+ release (CICR). Considerable evidence indicates that a preferred functional link is present between L-VGCCs and RyRs which operate in series in heart and some brain cells. Here, we review studies implicating RyRs in altered Ca2+ regulation in cell toxicity, aging, and AD. A recent study from our laboratory showed that increased CICR plays a necessary role in the emergence of Ca2+-related biomarkers of aging. Consequently, we propose an expanded L-VGCC/Ca2+ hypothesis, in which aging/pathological changes occur in both L-type Ca2+ channels and RyRs, and interact to abnormally amplify Ca2+ transients. In turn, the increased transients result in dysregulation of multiple Ca2+-dependent processes and, through somewhat different pathways, in accelerated functional decline during aging and AD.
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Affiliation(s)
- Olivier Thibault
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, University of Kentucky Medical Center, Lexington, KY 40536, USA
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Hewett SJ, Bell SC, Hewett JA. Contributions of cyclooxygenase-2 to neuroplasticity and neuropathology of the central nervous system. Pharmacol Ther 2006; 112:335-57. [PMID: 16750270 DOI: 10.1016/j.pharmthera.2005.04.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 04/19/2005] [Indexed: 01/08/2023]
Abstract
Cyclooxygenase (COX) enzymes, or prostaglandin-endoperoxide synthases (PTGS), are heme-containing bis-oxygenases that catalyze the first committed reaction in metabolism of arachidonic acid (AA) to the potent lipid mediators, prostanoids and thromboxanes. Two isozymes of COX enzymes (COX-1 and COX-2) have been identified to date. This review will focus specifically on the neurobiological and neuropathological consequences of AA metabolism via the COX-2 pathway and discuss the potential therapeutic benefit of COX-2 inhibition in the setting of neurological disease. However, given the controversy surrounding the use of COX-2 selective inhibitors with respect to cardiovascular health, it will be important to move beyond COX to identify which down-stream effectors are responsible for the deleterious and/or potentially protective effects of COX-2 activation in the setting of neurological disease. Important advances toward this goal are highlighted herein. Identification of unique effectors in AA metabolism could direct the development of new therapeutics holding significant promise for the prevention and treatment of neurological disorders.
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Affiliation(s)
- Sandra J Hewett
- Department of Neuroscience MC3401, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA.
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Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease which results from selective loss of upper and lower motor neurons. Mouse models of ALS, such as one carrying the G93A mutant of the human Cu-Zn superoxide dismutase gene[SOD1(G93A)], develop motor neuron pathology and clinical symptoms similar to those observed in ALS patients. There is compelling evidence that both direct and indirect glutamate toxicity contribute to the pathogenesis of motor neuron degeneration. However, the therapeutic effect of various glutamate receptor antagonists has not been clearly demonstrated. Memantine is a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist. It has been shown to protect neurons against NMDA- or glutamate-induced toxicity in vitro and in animal models of neurodegenerative diseases. In the current study, we have examined the therapeutic efficacy of memantine in an ALS mouse model carrying a high copy number of SOD1(G93A). Memantine treatment significantly delayed the disease progression and increased the life span of SOD1(G93A) mice, from 121.4 +/- 5.5 to 129.7 +/- 4.5 days (P = 0.032). Furthermore, NMDA receptor subunits were reliably detected in the spinal cord of SOD1(G93A) mice and their expression levels were similar to those in the wild-type littermate control. Therefore, the neuroprotective effect of memantine in SOD1(G93A) mice is most probably due to the inhibition of spinal cord NMDA receptors. In view of the long-term usage of memantine for dementia patients, with excellent tolerance and safety, these data suggest that memantine may be used in ALS patients alone or in combination with other therapies to prolong survival.
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Affiliation(s)
- Rengang Wang
- Center for Neuroscience and Ageing, The Burnham Institute, La Jolla, California 92037, USA
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Perrella J, Bhavnani BR. Protection of cortical cells by equine estrogens against glutamate-induced excitotoxicity is mediated through a calcium independent mechanism. BMC Neurosci 2005; 6:34. [PMID: 15882473 PMCID: PMC1142325 DOI: 10.1186/1471-2202-6-34] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Accepted: 05/10/2005] [Indexed: 12/20/2022] Open
Abstract
Background High concentrations of glutamate can accumulate in the brain and may be involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease. This form of neurotoxicity involves changes in the regulation of cellular calcium (Ca2+) and generation of free radicals such as peroxynitrite (ONOO-). Estrogen may protect against glutamate-induced cell death by reducing the excitotoxic Ca2+ influx associated with glutamate excitotoxicity. In this study, the inhibition of N-methyl-D-aspartate (NMDA) receptor and nitric oxide synthase (NOS) along with the effect of 17β-estradiol (17β-E2) and a more potent antioxidant Δ8, 17β-estradiol (Δ8, 17β-E2) on cell viability and intracellular Ca2+ ([Ca2+]i), following treatment of rat cortical cells with glutamate, was investigated. Results Primary rat cortical cells were cultured for 7–12 days in Neurobasal medium containing B27 supplements. Addition of glutamate (200 μM) decreased cell viability to 51.3 ± 0.7% compared to control. Treatment with the noncompetitive NMDAR antagonist, MK-801, and the NOS inhibitor, L-NAME, completely prevented cell death. Pretreatment (24 hrs) with 17β-E2 and Δ8, 17β-E2 (0.01 to 10 μM) significantly reduced cell death. 17β-E2 was more potent than Δ8, 17β-E2. Glutamate caused a rapid 2.5 fold increase in [Ca2+]i. Treatment with 0.001 to 10 μM MK-801 reduced the initial Ca2+ influx by 14–41% and increased cell viability significantly. Pretreatment with 17β-E2 and Δ8, 17β-E2 had no effect on Ca2+ influx but protected the cortical cells against glutamate-induced cell death. Conclusion Glutamate-induced cell death in cortical cultures can occur through NMDAR and NOS-linked mechanisms by increasing nitric oxide and ONOO-. Equine estrogens: 17β-E2 and Δ8, 17β-E2, significantly protected cortical cells against glutamate-induced excitotoxicity by a mechanism that appears to be independent of Ca2+ influx. To our knowledge, this is a first such observation. Whether the decrease in NOS related products such as ONOO-, is a mechanism by which estrogens protect against glutamate toxicity, remains to be investigated. Estrogen replacement therapy in healthy and young postmenopausal women may protect against neurodegenerative diseases by these mechanisms.
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Affiliation(s)
- Joel Perrella
- Department of Obstetrics and Gynecology, University of Toronto, Toronto, Canada
- Department of Obstetrics and Gynecology, St. Michael's Hospital, Toronto, Canada
| | - Bhagu R Bhavnani
- Department of Obstetrics and Gynecology, University of Toronto, Toronto, Canada
- Institute of Medical Sciences, University of Toronto, Toronto, Canada
- Department of Obstetrics and Gynecology, St. Michael's Hospital, Toronto, Canada
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Lee HJ, Ban JY, Koh SB, Seong NS, Song KS, Bae KW, Seong YH. Polygalae radix extract protects cultured rat granule cells against damage induced by NMDA. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2005; 32:599-610. [PMID: 15481649 DOI: 10.1142/s0192415x04002235] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Polygalae Radix (PR) from Polygala tenuifolia (Polygalaceae) is traditionally used in China and Korea, as this herb has a sedative, anti-inflammatory and antibacterial agent. To extend our understanding of the pharmacological actions of PR in the CNS on the basis of its CNS inhibitory effect, the present study examined whether PR has the neuroprotective action against N-methyl-D-aspartate (NMDA)-induced cell death in primarily cultured rat cerebellar granule neurons. PR, over a concentration range of 0.05 to 5 microg/ml, inhibited NMDA (1 mM)-induced neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. PR (0.5 microg/ml) inhibited glutamate release into medium induced by NMDA (1 mM), which was measured by HPLC. Pre-treatment of PR (0.5 microg/ml) inhibited NMDA (1 mM)-induced elevation of intracellular Ca2+ concentration ([Ca2+]i), which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that PR prevents NMDA-induced neuronal cell damage in vitro.
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Affiliation(s)
- Hyun Joo Lee
- College of Veterinary Medicine and Research Institute of Veterinary Medicine Chungbuk National University, Cheongju, Chungbuk, 361-763, Korea
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Dinse A, Föhr KJ, Georgieff M, Beyer C, Bulling A, Weigt HU. Xenon reduces glutamate-, AMPA-, and kainate-induced membrane currents in cortical neurones. Br J Anaesth 2005; 94:479-85. [PMID: 15695547 DOI: 10.1093/bja/aei080] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The anaesthetic, analgesic, and neuroprotective effects of xenon (Xe) are believed to be mediated by a block of the NMDA (N-methyl-D-aspartate) receptor channel. Interestingly, the clinical profile of the noble gas differs markedly from that of specific NMDA receptor antagonists. The aim of this study was, therefore, to investigate whether Xe might be less specific, also inhibiting the two other subtypes of glutamate receptor channels, such as the alpha-amino-3-hydroxy-5-methyl-4-isoxazolole propionate (AMPA) and kainate receptors. METHODS The study was performed on voltage-clamped cortical neurones from embryonic mice and SH-SY5Y cells expressing GluR6 kainate receptors. Drugs were applied by a multi-barreled fast perfusion system. RESULTS Xe, dissolved at approximately 3.45 mM in aqueous solution, diminished the peak and even more the plateau of AMPA and glutamate induced currents. At the control EC(50) value for AMPA (29 microM) these reductions were by about 40 and 56% and at 3 mM glutamate the reductions were by 45 and 66%, respectively. Currents activated at the control EC(50) value for kainate (57 microM) were inhibited by 42%. Likewise, Xe showed an inhibitory effect on kainate-induced membrane currents of SH-SY5Y cells transfected with the GluR6 subunit of the kainate receptor. Xe reduced kainate-induced currents by between 35 and 60%, depending on the kainate concentration. CONCLUSIONS Xe blocks not only NMDA receptors, but also AMPA and kainate receptors in cortical neurones as well as GluR6-type receptors expressed in SH-SY5Y cells. Thus, Xe seems to be rather non-specific as a channel blocker and this may contribute to the analgesic and anaesthetic potency of Xe.
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Affiliation(s)
- A Dinse
- Clinic for Anesthesiology, Ulm, Germany
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Matsumoto M, Sasaki T, Nagashima H, Ahn ES, Young W, Kodama N. Effects of N-methyl-d-aspartate, glutamate, and glycine on the dorsal column axons of neonatal rat spinal cord: in vitro study. Neurol Med Chir (Tokyo) 2005; 45:73-80, discussion 81. [PMID: 15722604 DOI: 10.2176/nmc.45.73] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effects of N-methyl-D-aspartate (NMDA), glutamate, and glycine on the developmental axons of the neonatal rat spinal cord were investigated. Isolated dorsal column preparations from postnatal day (PN) 0 to 14 Long-Evans hooded rats (n = 119) were used in vitro. Compound action potentials (CAPs) were recorded from the cuneate and gracile fasciculi with a glass micropipette electrode. NMDA (100 microM) significantly increased CAP amplitude in PN 0-6 cords by 21.5 +/- 9.2% (mean +/- standard error of the mean, p < 0.001, n = 8) and in PN 7-14 cords by 6.7 +/- 6.6% (p < 0.001, n = 10). NMDA (10 microM) significantly increased the CAP amplitude by 6.3 +/- 2.9% in PN 0-6 cords (p < 0.01, n = 10). The increase of CAP amplitude induced by NMDA (100 microM) in PN 0-6 cords was significantly greater than that in PN 7-14 cords (p < 0.005). Glutamate (100 microM) significantly increased the CAP amplitude by 8.8 +/- 8.1% in PN 0-6 cords (p < 0.001, n = 29) and 6.7 +/- 7.5% in PN 7-14 cords (p < 0.01, n = 14), and glutamate (10 microM) significantly increased by 6.3 +/- 2.9% in PN 0-6 cords (p < 0.01, n = 21). The amplitudes induced by glutamate (100 microM or 10 microM) did not significantly differ between PN 0-6 and PN 7-14 cords. Application of glycine (100 microM) did not significantly alter CAP amplitudes induced by NMDA (100 microM or 10 microM) and glutamate (100 microM or 10 microM). D(-)-2-amino-5-phosphonopentanoic acid (NMDA receptor antagonist) blocked the effects of NMDA and glutamate. These results suggest that NMDA receptor is present on afferent dorsal column axons and may modulate axonal excitability, especially during the 1st week after birth.
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Affiliation(s)
- Masato Matsumoto
- W.M. Keck Center for Collaborate Neuroscience, Rutgers-The State University of New Jersey, Piscataway, NJ, USA.
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Metzger F, Klapproth N, Kulik A, Sendtner M, Ballanyi K. Optical assessment of motoneuron function in a “twenty-four-hour” acute spinal cord slice model from fetal rats. J Neurosci Methods 2005; 141:309-20. [PMID: 15661313 DOI: 10.1016/j.jneumeth.2004.07.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2003] [Revised: 06/02/2004] [Accepted: 07/13/2004] [Indexed: 10/26/2022]
Abstract
In acute slice preparations of most brain regions, neuronal functions are preserved for only few hours. Since the effects of growth factors or neurotoxic agents are often manifested beyond this time scale, corresponding studies are typically performed on cultured cells. However, cell cultures are generated and maintained under vastly different conditions that can grossly alter neuronal properties. For example, glutamate application to motoneuronal cultures has been reported to modulate neurite formation in some studies while in others it has been reported to kill cells. Here, we have examined whether acute spinal cord slices from rat fetuses can be used within a time window of 24 h for assessment of long-term effects of neuromodulators. In these slices, we have studied the action of glutamate on lumbar motoneurons loaded with fura-2 and rhodamine-123 to monitor intracellular Ca2+ ([Ca2+]i) and mitochondrial potential (Deltapsi), respectively. Further, loading with fura-2 or propidium iodide allowed for morphological assessment of cell viability and death, respectively. Pulses (15 s) or 1 h application of glutamate (300 microM) evoked a moderate (approximately 500 nM) [Ca2+]i rise, but no change of Deltapsi. Even after 24 h, no glutamate-induced cell death was observed and glutamate pulse-evoked [Ca2+]i transients were comparable to controls. The data demonstrate that glutamate does not deregulate [Ca2+]i homeostasis in fetal motoneurons in situ. We propose that acute spinal cord slices from perinatal rodents are a robust model that allows for analysis of neuronal properties and cell viability within a time window of at least 24 h.
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Affiliation(s)
- Friedrich Metzger
- Klinische Forschergruppe Neuroregeneration, Neurologische Klinik, Universität Würzburg, Josef-Schneider-Strasse 11, D-97080 Würzburg, Germany
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Naguro I, Adachi-Akahane S, Ichijo H. Calcium signalingvia voltage-dependent L-type Ca2+ channels. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/sita.200400035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Spalloni A, Pascucci T, Albo F, Ferrari F, Puglisi-Allegra S, Zona C, Bernardi G, Longone P. Altered vulnerability to kainate excitotoxicity of transgenic-Cu/Zn SOD1 neurones. Neuroreport 2004; 15:2477-80. [PMID: 15538178 DOI: 10.1097/00001756-200411150-00009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The neurotoxicity of the AMPA/kainate receptor agonist kainate was investigated in motor and cortical neurones from mice over-expressing the wild-type and G93A mutant form of Cu/Zn superoxide dismutase (SOD1) human gene, a mouse model of familial amyotrophic lateral sclerosis. G93A mutant motor neurones were more vulnerable and wild-type SOD1 motor neurones were more resistant to kainate toxicity than were controls. Voltage-gated Na channels blockage prevented G93A mutant SOD1 motor neurone death. Cortical cultures exhibited fewer differences in their vulnerability to kainate toxicity. These results demonstrate that SOD1 over-expression selectively affects the sensitivity to kainate excitotoxicity of motor neurones but not neocortical neurones, and that wild-type SOD1 expression increases the resistance to excitotoxicity of motor neurones.
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Affiliation(s)
- Alida Spalloni
- IRCCS Fondazione Santa Lucia Via Ardeatina 306 00179 Rome, Italy
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Park JH, Lee HJ, Koh SB, Ban JY, Seong YH. Protection of NMDA-induced neuronal cell damage by methanol extract of zizyphi spinosi semen in cultured rat cerebellar granule cells. JOURNAL OF ETHNOPHARMACOLOGY 2004; 95:39-45. [PMID: 15374605 DOI: 10.1016/j.jep.2004.06.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2003] [Revised: 04/24/2004] [Accepted: 06/08/2004] [Indexed: 05/24/2023]
Abstract
Zizypus is one of the herbs widely used in Korea and China due to the CNS calming effect. The present study aims to investigate the effect of the methanol extract of Zizyphi Spinosi Semen (ZSS), the seeds of Zizyphus jujuba Mill var. spinosa, on N-methyl-D-aspartate (NMDA)-induced neurotoxicity in cultured rat cerebellar granule neuron. ZSS, over a concentration range of 0.05-5 microg/ml, inhibited NMDA (1 mM)-induced neuronal cell death, which was measured by a trypan blue exclusion test and a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) assay. ZSS (0.5 microg/ml) inhibited glutamate release into medium induced by NMDA (1mM), which was measured by HPLC. Pretreatment of ZSS (0.5 microg/ml) inhibited NMDA (1mM)-induced elevation of cytosolic calcium concentration ([Ca(2+)](c)), which was measured by a fluorescent dye, Fura 2-AM, and generation of reactive oxygen species (ROS). These results suggest that ZSS prevents NMDA-induced neuronal cell damage in vitro.
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Affiliation(s)
- Jeong Hee Park
- College of Veterinary Medicine and Research Institute of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk 361-763, South Korea
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De Witte P. Imbalance between neuroexcitatory and neuroinhibitory amino acids causes craving for ethanol. Addict Behav 2004; 29:1325-39. [PMID: 15345268 DOI: 10.1016/j.addbeh.2004.06.020] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Long-term exposure to ethanol leads to an imbalance in different excitatory and inhibitory amino acids. When ethanol consumption is reduced or completely stopped, these imbalances in different amino acids and neurotransmitters are behaviorally expressed in the form of ethanol withdrawal. Glutamate, a major excitatory amino acid, and GABA, a major inhibitory amino acid, are responsible, at least partly, for ethanol withdrawal symptoms. The hypofunction of GABAA receptors and enhanced function of NMDA receptors are suggested to be responsible for the increase in the behavioral susceptibility during ethanol withdrawal. This imbalance between receptors may be exacerbated by repeated withdrawal. Because multiple and repeated periods of chronic ethanol consumption and withdrawal often occur in alcohol abusers, animal studies on the neurochemical changes in different amino acids following chronic ethanol treatment (CET) that is interrupted by repeated ethanol withdrawal episodes may be of clinical relevance for the development of treatment strategies. Brain glutamate increases during the first cycle of ethanol withdrawal, and this increase is much higher during the third cycle of ethanol withdrawal. The elevated glutamate released in the hippocampus during the first cycle of ethanol withdrawal episode was exacerbated in subsequent withdrawal episodes. Acamprosate, a drug used during human alcohol detoxification, is able to completely block the glutamate increase observed during the first as well as the third withdrawal of ethanol. In ethanol-naïve rats, there was no change in the glutamate microdialysate content after an acute ethanol injection. However, when repeated ethanol injections were cued with a vinegar stimulus that had previously been associated with the same ethanol injection, a significant increase in glutamate microdialysate content was assayed. Furthermore, when the cue was omitted, the ethanol injection induced no changes in glutamate microdialysate content in rats that had been previously ethanol conditioned. By comparison, a saline injection had no effect on extracellular glutamate concentration in rats naïve for ethanol as well as in rats daily administered with repeated ethanol injections that were not paired with the cue. It appears probable that these conditioned responses by extracellular glutamate concentrations may participate in the environmental cue-induced conditioned cravings for ethanol that are thought to be related to the high frequency of relapse in detoxified alcoholics.
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Affiliation(s)
- Philippe De Witte
- UCL-Biologie du Comportement, Place Croix du Sud, 1-bte 10-B 1348 Louvain-la-Neuve, Belgium.
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Jha A, Deshpande SB. Aglycemia and ischemia depress spinal synaptic transmission via inhibitory systems involving NMDA receptors. Eur J Pharmacol 2004; 481:189-96. [PMID: 14642785 DOI: 10.1016/j.ejphar.2003.09.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The effects of in vitro aglycemia (glucose-free) and ischemia (glucose-free and O(2)-free) were examined on the dorsal root-evoked ventral root spinal monosynaptic and polysynaptic reflexes in neonatal rat spinal cords. Aglycemia and ischemia depressed the reflexes in a time-dependent manner and abolished them by 35 min. The depression by ischemia began immediately while that by aglycemia began after 15 min. The NMDA receptor antagonist, DL-2-amino-5-phosphonovaleric acid (APV), blocked the depression induced by aglycemia completely and that by ischemia partially. Strychnine (glycine(A) receptor antagonist) or bicuculline (GABA(A) receptor antagonist) blocked the aglycemia-induced depression of the reflexes. In the case of ischemia, strychnine but not bicuculline, blocked the depression partially. The results indicate that aglycemia and ischemia depress the synaptic transmission involving NMDA receptors. Aglycemia involves both gamma-aminobutyric acid-ergic and glycinergic inhibitory transmission while ischemia involves other additional mechanisms.
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Affiliation(s)
- Archana Jha
- Department of Physiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India
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Park E, Velumian AA, Fehlings MG. The Role of Excitotoxicity in Secondary Mechanisms of Spinal Cord Injury: A Review with an Emphasis on the Implications for White Matter Degeneration. J Neurotrauma 2004; 21:754-74. [PMID: 15253803 DOI: 10.1089/0897715041269641] [Citation(s) in RCA: 396] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Following an initial impact after spinal cord injury (SCI), there is a cascade of downstream events termed 'secondary injury', which culminate in progressive degenerative events in the spinal cord. These secondary injury mechanisms include, but are not limited to, ischemia, inflammation, free radical-induced cell death, glutamate excitotoxicity, cytoskeletal degradation and induction of extrinsic and intrinsic apoptotic pathways. There is emerging evidence that glutamate excitotoxicity plays a key role not only in neuronal cell death but also in delayed posttraumatic spinal cord white matter degeneration. Importantly however, the differences in cellular composition and expression of specific types of glutamate receptors in grey versus white matter require a compartmentalized approach to understand the mechanisms of secondary injury after SCI. This review examines mechanisms of secondary white matter injury with particular emphasis on glutamate excitotoxicity and the potential link of this mechanism to apoptosis. Recent studies have provided new insights into the mechanisms of glutamate release and its potential targets, as well as the downstream pathways associated with glutamate receptor activation in specific types of cells. Evidence from molecular and functional expression of glutamatergic AMPA receptors in white matter glia (and possibly axons), the protective effects of AMPA/kainate antagonists in posttraumatic white matter axonal function, and the vulnerability of oligodendrocytes to excitotoxic cell death suggest that glutamate excitotoxicity is associated with oligodendrocyte apoptosis. The latter mechanism appears key to glutamatergic white matter degeneration after SCI and may represent an attractive therapeutic target.
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Affiliation(s)
- Eugene Park
- Division of Neurosurgery and Institute of Medical Science, University of Toronto, and Division of Cell and Molecular Biology, Toronto Western Research Institute, Toronto Western Hospital, University Health Network, Ontario, Canada
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Usul H, Cakir E, Cobanoglu U, Alver A, Peksoylu B, Topbas M, Baykal S. The effects of tyrphostine Ag 556 on experimental spinal cord ischemia reperfusion injury. ACTA ACUST UNITED AC 2004; 61:45-54; discussion 54. [PMID: 14706378 DOI: 10.1016/s0090-3019(03)00539-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
BACKGROUND To investigate the effects of Tyrphostin Ag 556 on spinal cord ischemia reperfusion injury. METHODS The inhibition of tyrosine kinase may represent a novel approach in the treatment of spinal cord ischemia reperfusion injury. Recently, a family of tyrosine kinase inhibitors, the tyrphostins, has been successfully used in models of endotoxemia, peritonitis, and hypovolemic shock. MATERIALS AND METHODS Twenty-four Wistar rats were used in the study. Rats were divided into 4 groups of 6 animals. The groups were named as sham operated group, injury group, vehicle group, and treatment group. Clamping of the abdominal aorta was performed for 45 minutes with all of the groups except sham-operated group. All of the rats were sacrificed 24 hours after the operation for biochemical and ultrastructural studies. RESULTS Tyrphostin Ag 556 treatment was found effective on experimental spinal cord ischemia reperfusion injury. The Malondialdehyde (MDA) values of the treatment group were statistically significant lower then the other reperfusion injury groups. The histologic examination showed better cellular structure in the treatment group than the other reperfusion injury groups. The neurologic scores of the treatment group also improved after treatment. CONCLUSIONS Tyrphostin Ag 556 alters spinal cord ischemia reperfusion injury by inhibiting protein kinases. Further investigations will be required to determine the long-term effects of this drug.
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Affiliation(s)
- Haydar Usul
- Departments of Neurosurgery, Trabzon, Turkey
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Nottingham SA, Springer JE. Temporal and spatial distribution of activated caspase-3 after subdural kainic acid infusions in rat spinal cord. J Comp Neurol 2003; 464:463-71. [PMID: 12900917 DOI: 10.1002/cne.10806] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The molecular events initiating apoptosis following traumatic spinal cord injury (SCI) remain poorly understood. Soon after injury, the spinal cord is exposed to numerous secondary insults, including elevated levels of glutamate, that contribute to cell dysfunction and death. In the present study, we attempted to mimic the actions of glutamate by subdural infusion of the selective glutamate receptor agonist, kainic acid, into the uninjured rat spinal cord. Immunohistochemical colocalization studies revealed that activated caspase-3 was present in ventral horn motor neurons at 24 hours, but not 4 hours or 96 hours, following kainic acid treatment. However, at no time point examined was there evidence of significant neuronal loss. Kainic acid resulted in caspase-3 activation in several glial cell populations at all time points examined, with the most pronounced effect occurring at 24 hours following infusion. In particular, caspase-3 activation was observed in a significant number of oligodendroglia in the dorsal and ventral funiculi, and there was a pronounced loss of oligodendroglia at 96 hours following treatment. The results of these experiments indicate a role for glutamate as a mediator of oligodendroglial apoptosis in traumatic SCI. In addition, understanding the apoptotic signaling events activated by glutamate will be important for developing therapies targeting this cell death process.
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Affiliation(s)
- Stephanie A Nottingham
- Department of Anatomy and Neurobiology, Spinal Cord and Brain Injury Research Center, University of Kentucky Medical Center, Lexington, Kentucky 40536-0084, USA
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