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Microglial Dynamics Modulate Vestibular Compensation in a Rodent Model of Vestibulopathy and Condition the Expression of Plasticity Mechanisms in the Deafferented Vestibular Nuclei. Cells 2022; 11:cells11172693. [PMID: 36078101 PMCID: PMC9454928 DOI: 10.3390/cells11172693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 08/17/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022] Open
Abstract
Unilateral vestibular loss (UVL) induces a vestibular syndrome composed of posturo-locomotor, oculomotor, vegetative, and perceptivo-cognitive symptoms. With time, these functional deficits progressively disappear due to a phenomenon called vestibular compensation, known to be supported by the expression in the deafferented vestibular nuclei (VNs) of various adaptative plasticity mechanisms. UVL is known to induce a neuroinflammatory response within the VNs, thought to be caused by the structural alteration of primary vestibular afferents. The acute inflammatory response, expressed in the deafferented VNs was recently proven to be crucial for the expression of the endogenous plasticity supporting functional recovery. Neuroinflammation is supported by reactive microglial cells, known to have various phenotypes with adverse effects on brain tissue. Here, we used markers of pro-inflammatory and anti-inflammatory phenotypes of reactive microglia to study microglial dynamics following a unilateral vestibular neurectomy (UVN) in the adult rat. In addition, to highlight the role of acute inflammation in vestibular compensation and its underlying mechanisms, we enhanced the inflammatory state of the deafferented VNs using systemic injections of lipopolysaccharide (LPS) during the acute phase after a UVN. We observed that the UVN induced the expression of both M1 proinflammatory and M2 anti-inflammatory microglial phenotypes in the deafferented VNs. The acute LPS treatment exacerbated the inflammatory reaction and increased the M1 phenotype while decreasing M2 expression. These effects were associated with impaired postlesional plasticity in the deafferented VNs and exacerbated functional deficits. These results highlight the importance of a homeostatic inflammatory level in the expression of the adaptative plasticity mechanisms underlying vestibular compensation. Understanding the rules that govern neuroinflammation would provide therapeutic leads in neuropathologies associated with these processes.
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El Mahmoudi N, Rastoldo G, Marouane E, Péricat D, Watabe I, Tonetto A, Hautefort C, Chabbert C, Sargolini F, Tighilet B. Breaking a dogma: acute anti-inflammatory treatment alters both post-lesional functional recovery and endogenous adaptive plasticity mechanisms in a rodent model of acute peripheral vestibulopathy. J Neuroinflammation 2021; 18:183. [PMID: 34419105 PMCID: PMC8380392 DOI: 10.1186/s12974-021-02222-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 07/19/2021] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Due to their anti-inflammatory action, corticosteroids are the reference treatment for brain injuries and many inflammatory diseases. However, the benefits of acute corticotherapy are now being questioned, particularly in the case of acute peripheral vestibulopathies (APV), characterized by a vestibular syndrome composed of sustained spinning vertigo, spontaneous ocular nystagmus and oscillopsia, perceptual-cognitive, posturo-locomotor, and vegetative disorders. We assessed the effectiveness of acute corticotherapy, and the functional role of acute inflammation observed after sudden unilateral vestibular loss. METHODS We used the rodent model of unilateral vestibular neurectomy, mimicking the syndrome observed in patients with APV. We treated the animals during the acute phase of the vestibular syndrome, either with placebo or methylprednisolone, an anti-inflammatory corticosteroid. At the cellular level, impacts of methylprednisolone on endogenous plasticity mechanisms were assessed through analysis of cell proliferation and survival, glial reactions, neuron's membrane excitability, and stress marker. At the behavioral level, vestibular and posturo-locomotor functions' recovery were assessed with appropriate qualitative and quantitative evaluations. RESULTS We observed that acute treatment with methylprednisolone significantly decreases glial reactions, cell proliferation and survival. In addition, stress and excitability markers were significantly impacted by the treatment. Besides, vestibular syndrome's intensity was enhanced, and vestibular compensation delayed under acute methylprednisolone treatment. CONCLUSIONS We show here, for the first time, that acute anti-inflammatory treatment alters the expression of the adaptive plasticity mechanisms in the deafferented vestibular nuclei and generates enhanced and prolonged vestibular and postural deficits. These results strongly suggest a beneficial role for acute endogenous neuroinflammation in vestibular compensation. They open the way to a change in dogma for the treatment and therapeutic management of vestibular patients.
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Affiliation(s)
- Nada El Mahmoudi
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Guillaume Rastoldo
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Emna Marouane
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - David Péricat
- Institut de Pharmacologie Et de Biologie Structurale, Université de Toulouse Paul Sabatier-CNRS, Toulouse, France
| | - Isabelle Watabe
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Alain Tonetto
- Centrale Marseille, FSCM (FR 1739), PRATIM, Aix Marseille Université-CNRS, 13397, Marseille, France
| | - Charlotte Hautefort
- Department of Head and Neck Surgery, Lariboisière University Hospital, Paris, France
| | - Christian Chabbert
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- Centre Saint-Charles, Aix-Marseille Université CNRS, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
- GDR Physiopathologie Vestibulaire-Unité GDR2074 CNRS, Marseille, France
| | - Francesca Sargolini
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France
| | - Brahim Tighilet
- Aix-Marseille Université-CNRS, Laboratoire de Neurosciences Cognitives, LNC UMR 7291, Centre Saint Charles, Case C; 3 Place Victor Hugo, 13331, Marseille Cedex 03, France.
- GDR Physiopathologie Vestibulaire-Unité GDR2074 CNRS, Marseille, France.
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Tran AP, Warren PM, Silver J. The Biology of Regeneration Failure and Success After Spinal Cord Injury. Physiol Rev 2018. [PMID: 29513146 DOI: 10.1152/physrev.00017.2017] [Citation(s) in RCA: 479] [Impact Index Per Article: 79.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Since no approved therapies to restore mobility and sensation following spinal cord injury (SCI) currently exist, a better understanding of the cellular and molecular mechanisms following SCI that compromise regeneration or neuroplasticity is needed to develop new strategies to promote axonal regrowth and restore function. Physical trauma to the spinal cord results in vascular disruption that, in turn, causes blood-spinal cord barrier rupture leading to hemorrhage and ischemia, followed by rampant local cell death. As subsequent edema and inflammation occur, neuronal and glial necrosis and apoptosis spread well beyond the initial site of impact, ultimately resolving into a cavity surrounded by glial/fibrotic scarring. The glial scar, which stabilizes the spread of secondary injury, also acts as a chronic, physical, and chemo-entrapping barrier that prevents axonal regeneration. Understanding the formative events in glial scarring helps guide strategies towards the development of potential therapies to enhance axon regeneration and functional recovery at both acute and chronic stages following SCI. This review will also discuss the perineuronal net and how chondroitin sulfate proteoglycans (CSPGs) deposited in both the glial scar and net impede axonal outgrowth at the level of the growth cone. We will end the review with a summary of current CSPG-targeting strategies that help to foster axonal regeneration, neuroplasticity/sprouting, and functional recovery following SCI.
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Affiliation(s)
- Amanda Phuong Tran
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
| | - Philippa Mary Warren
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
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PPAR Regulation of Inflammatory Signaling in CNS Diseases. PPAR Res 2011; 2008:658520. [PMID: 18670616 PMCID: PMC2490815 DOI: 10.1155/2008/658520] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2007] [Revised: 04/22/2008] [Accepted: 05/12/2008] [Indexed: 12/25/2022] Open
Abstract
Central nervous system (CNS) is an immune privileged site, nevertheless inflammation associates with many CNS diseases. Peroxisome proliferator-activated receptors (PPARs) are a family of nuclear hormone receptors that regulate immune and inflammatory responses. Specific ligands for PPARα, γ, and δ isoforms have proven effective in the animal models of multiple sclerosis (MS), Alzheimer's disease, Parkinson's disease, and trauma/stroke, suggesting their use in the treatment of neuroinflammatory diseases. The activation of NF-κB and Jak-Stat signaling pathways and secretion of inflammatory cytokines are critical in the pathogenesis of CNS diseases. Interestingly, PPAR agonists mitigate CNS disease by modulating inflammatory signaling network in immune cells. In this manuscript, we review the current knowledge on how PPARs regulate neuroinflammatory signaling networks in CNS diseases.
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Esposito E, Paterniti I, Mazzon E, Genovese T, Galuppo M, Meli R, Bramanti P, Cuzzocrea S. MK801 attenuates secondary injury in a mouse experimental compression model of spinal cord trauma. BMC Neurosci 2011; 12:31. [PMID: 21492450 PMCID: PMC3094200 DOI: 10.1186/1471-2202-12-31] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 04/14/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glutamergic excitotoxicity has been shown to play a deleterious role in the pathophysiology of spinal cord injury (SCI). The aim of this study was to investigate the neuroprotective effect of dizocilpine maleate, MK801 (2 mg/Kg, 30 min and 6 hours after injury) in a mice model of SCI. The spinal cord trauma was induced by the application of vascular clips to the dura via a four-level T5-T8 laminectomy. RESULTS Spinal cord injury in mice resulted in severe trauma characterized by edema, neutrophil infiltration and apoptosis. In this study we clearly demonstrated that administration of MK801 attenuated all inflammatory parameters. In fact 24 hours after injury, the degree of spinal cord inflammation and tissue injury (evaluated as histological score), infiltration of neutrophils, NF-κB activation, iNOS, cytokines levels (TNF-α and IL-1β), neurotrophin expression were markedly reduced by MK801 treatment. Moreover, in a separate set of experiments, we have demonstrated that MK801 treatment significantly improved the recovery of locomotory function. CONCLUSIONS Blockade of NMDA by MK801 lends support to the potential importance of NMDA antagonists as therapeutic agents in the treatment of acute spinal cord injury.
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Affiliation(s)
- Emanuela Esposito
- Department of Clinical and Experimental Medicine and Pharmacology, School of Medicine, University of Messina, Italy
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Methylprednisolone fails to improve functional and histological outcome following spinal cord injury in rats. Exp Neurol 2009; 220:71-81. [DOI: 10.1016/j.expneurol.2009.07.030] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 07/27/2009] [Accepted: 07/28/2009] [Indexed: 11/22/2022]
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de Rivero Vaccari JP, Marcillo A, Nonner D, Dietrich WD, Keane RW. Neuroprotective effects of bone morphogenetic protein 7 (BMP7) treatment after spinal cord injury. Neurosci Lett 2009; 465:226-9. [PMID: 19765637 DOI: 10.1016/j.neulet.2009.09.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2009] [Revised: 08/31/2009] [Accepted: 09/11/2009] [Indexed: 11/16/2022]
Abstract
Bone morphogenetic protein 7 (BMP7) has been shown to ameliorate reduced dendritic growth induced by glutamate excitotoxicity in neuronal tissue cultures and/or provide an enhancement of functional recovery in central nervous system (CNS) injury. BMP7 expression is modulated by spinal cord injury (SCI), but the molecular mechanisms involved in neuroprotection have not been clearly defined. Here, we show that BMP7 treatment of rats subjected to mild cervical SCI significantly increased the pro-survival mitogen-activated protein kinase-38 (MAPK-38) pathway and levels of N-methyl-D-aspartate receptor 1 (NMDAR-1) resulting in a significant increase in neuronal sparing in the ventral horn of the spinal cord. Moreover, BMP7 was neuroprotective against glutamate-mediated excitotoxicity in cultured cortical neurons. These studies show that BMP7 administration may be used as a therapeutic strategy to reduce the damaging excitotoxic effects following SCI.
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Affiliation(s)
- Juan Pablo de Rivero Vaccari
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, United States
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8
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Akhtar AZ, Pippin JJ, Sandusky CB. Animal studies in spinal cord injury: a systematic review of methylprednisolone. Altern Lab Anim 2009; 37:43-62. [PMID: 19292575 DOI: 10.1177/026119290903700108] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The objective of this study was to examine whether animal studies can reliably be used to determine the usefulness of methylprednisolone (MP) and other treatments for acute spinal cord injury (SCI) in humans. This was achieved by performing a systematic review of animal studies on the effects of MP administration on the functional outcome of acute SCI. Data were extracted from the published articles relating to: outcome; MP dosing regimen; species/strain; number of animals; methodological quality; type of injury induction; use of anaesthesia; functional scale used; and duration of follow-up. Subgroup analyses were performed, based on species or strain, injury method, MP dosing regimen, functional outcome measured, and methodological quality. Sixty-two studies were included, which involved a wide variety of animal species and strains. Overall, beneficial effects of MP administration were obtained in 34% of the studies, no effects in 58%, and mixed results in 8%. The results were inconsistent both among and within species, even when attempts were made to detect any patterns in the results through subgroup analyses. The results of this study demonstrate the barriers to the accurate prediction from animal studies of the effectiveness of MP in the treatment of acute SCI in humans. This underscores the need for the development and implementation of validated testing methods.
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Affiliation(s)
- Aysha Z Akhtar
- Physicians Committee for Responsible Medicine, Washington, DC, USA.
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9
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Christie SD, Comeau B, Myers T, Sadi D, Purdy M, Mendez I. Duration of lipid peroxidation after acute spinal cord injury in rats and the effect of methylprednisolone. Neurosurg Focus 2009; 25:E5. [PMID: 18980479 DOI: 10.3171/foc.2008.25.11.e5] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Oxidative stress leading to lipid peroxidation is a major cause of secondary injury following spinal cord injury (SCI). The objectives of this study were to determine the duration of lipid peroxidation following acute SCI and the efficacy of short-and long-term administration of methylprednisolone on decreasing lipid peroxidation. METHODS A total of 226 female Wistar rats underwent clip-compression induced SCI. In the first part of the study, spinal cords of untreated rats were assayed colorimetrically for malondialdehyde (MDA) to determine lipid peroxidation levels at various time points between 0 and 10 days. In the second part of the study, animals were treated with methylprednisolone for either 24 hours or 7 days. Control animals received equal volumes of normal saline. Treated and control rats were killed at various time points between 0 and 7 days. RESULTS The MDA levels initially peaked 4 hours postinjury. By 12 hours, the MDA levels returned to baseline. A second increase was observed from 24 hours to 5 days. Both peak values differed statistically from the trough values (p < 0.008). The methylprednisolone reduced MDA levels (p < 0.04) within 12 hours of injury. No effect was seen at 24 hours or later. CONCLUSIONS The results of this study indicate that oxidative stress persists for 5 days following SCI in rats, and although methylprednisolone reduces MDA levels within the first 12 hours, it has no effect on the second lipid peroxidation peak.
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Affiliation(s)
- Sean D Christie
- Department of Anatomy and Neurobiology, Dalhousie University, Halifax, Nova Scotia, Canada.
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Greaves CY, Gadala MS, Oxland TR. A three-dimensional finite element model of the cervical spine with spinal cord: an investigation of three injury mechanisms. Ann Biomed Eng 2008; 36:396-405. [PMID: 18228144 DOI: 10.1007/s10439-008-9440-0] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Accepted: 01/10/2008] [Indexed: 10/22/2022]
Abstract
The spinal cord may be injured through various spinal column injury patterns (e.g., burst fracture, fracture dislocation); however, the relationship between column injury pattern and cord damage is not well understood. A three-dimensional finite element model of a human cervical spine and spinal cord segment was developed, verified using published experimental data, and used to investigate differences in cord strain distributions during various column injury patterns. For a transverse contusion injury, as would occur in a burst fracture, a 33% canal occlusion resulted in two peaks of strain between the indentor and opposing vertebral body and intermediate peak strain values. For a distraction injury, relevant to column distortion injuries, a 2.6 mm axial displacement to the cord resulted in more uniform strains throughout the cord and low peak strain values. For a dislocation injury, as would occur in a fracture dislocation, an anterior displacement of C5 corresponding to 30% of the sagittal dimension of the vertebral body resulted in high peak strain values adjacent to the shearing vertebrae and increased strains in the lateral columns compared to contusion. This model includes more anatomical details compared to previous studies and provides a baseline for mechanical comparisons in spinal cord injury.
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Affiliation(s)
- Carolyn Y Greaves
- Division of Orthopaedic Engineering Research, Departments of Mechanical Engineering and Orthopaedics, University of British Columbia, #566-828 West 10th Ave, Vancouver, BC, Canada
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Immunosuppression after traumatic or ischemic CNS damage: it is neuroprotective and illuminates the role of microglial cells. Prog Neurobiol 2007; 84:211-33. [PMID: 18262323 DOI: 10.1016/j.pneurobio.2007.12.001] [Citation(s) in RCA: 125] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 11/15/2007] [Accepted: 12/11/2007] [Indexed: 01/08/2023]
Abstract
Acute traumatic and ischemic events in the central nervous system (CNS) invariably result in activation of microglial cells as local representatives of the immune system. It is still under debate whether activated microglia promote neuronal survival, or whether they exacerbate the original extent of neuronal damage. Protagonists of the view that microglial cells cause secondary damage have proposed that inhibition of microglial activation by immunosuppression is beneficial after acute CNS damage. It is the aim of this review to analyse the effects of immunosuppressants on isolated microglial cells and neurons, and to scrutinize the effects of immunosuppression in different in vivo models of acute CNS trauma or ischemia. It is found that the immunosuppressants cytosine-arabinoside, different steroids, cyclosporin A, FK506, rapamycin, mycophenolate mofetil, and minocycline all have direct inhibitory effects on microglial cells. These effects are mainly exerted by inhibiting microglial proliferation or microglial secretion of neurotoxic substances such as proinflammatory cytokines and nitric oxide. Furthermore, immunosuppression after acute CNS trauma or ischemia results in improved structure preservation and, mostly, in enhanced function. However, all investigated immunosuppressants also have direct effects on neurons, and some immunosuppressants affect other glial cells such as astrocytes. In summary, it is safe to conclude that immunosuppression after acute CNS trauma or ischemia is neuroprotective. Furthermore, circumferential evidence indicates that microglial activation after traumatic or ischemic CNS damage is not beneficial to adjacent neurons in the immediate aftermath of such acute lesions. Further experiments with more specific agents or genetic approaches that specifically inhibit microglial cells are needed in order to fully answer the question of whether microglial activation is "good or bad".
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Onifer SM, Rabchevsky AG, Scheff SW. Rat Models of Traumatic Spinal Cord Injury to Assess Motor Recovery. ILAR J 2007; 48:385-95. [PMID: 17712224 DOI: 10.1093/ilar.48.4.385] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Devastating motor, sensory, and autonomic dysfunctions render long-term personal hardships to the survivors of traumatic spinal cord injury (SCI). The suffering also extends to the survivors' families and friends, who endure emotional, physical, and financial burdens in providing for necessary surgeries, care, and rehabilitation. After the primary mechanical SCI, there is a complex secondary injury cascade that leads to the progressive death of otherwise potentially viable axons and cells and that impairs endogenous recovery processes. Investigations of possible cures and of ways to alleviate the hardships of traumatic SCI include those of interventions that attenuate or overcome the secondary injury cascade, enhance the endogenous repair mechanisms, regenerate axons, replace lost cells, and rehabilitate. These investigations have led to the creation of laboratory animal models of the different types of traumatic human SCI and components of the secondary injury cascade. However, no particular model completely addresses all aspects of traumatic SCI. In this article, we describe adult rat SCI models and the motor, and in some cases sensory and autonomic, deficits that each produces. Importantly, as researchers in this area move toward clinical trials to alleviate the hardships of traumatic SCI, there is a need for standardized small and large animal SCI models as well as quantitative behavioral and electrophysiological assessments of their outcomes so that investigators testing various interventions can directly compare their results and correlate them with the molecular, biochemical, and histological alterations.
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Affiliation(s)
- Stephen M Onifer
- Spinal Cord and Brain Injury Research Center, Biomedical and Biological Sciences Research Building, University of Kentucky, 741 South Limestone Street, Lexington, KY 40536-0509, USA.
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Rolls A, Cahalon L, Bakalash S, Avidan H, Lider O, Schwartz M. A sulfated disaccharide derived from chondroitin sulfate proteoglycan protects against inflammation-associated neurodegeneration. FASEB J 2006; 20:547-9. [PMID: 16396993 DOI: 10.1096/fj.05-4540fje] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Chondroitin sulfate proteoglycan (CSPG), a matrix protein that occurs naturally in the central nervous system (CNS), is considered to be a major inhibitor of axonal regeneration and is known to participate in activation of the inflammatory response. The degradation of CSPG by a specific enzyme, chondroitinase ABC, promotes repair. We postulated that a disaccharidic degradation product of this glycoprotein (CSPG-DS), generated following such degradation, participates in the modulation of the inflammatory responses and can, therefore, promote recovery in immune-induced neuropathologies of the CNS, such as experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune uveitis (EAU). In these pathologies, the dramatic increase in T cells infiltrating the CNS is far in excess of the numbers needed for regular maintenance. Here, we show that CSPG-DS markedly alleviated the clinical symptoms of EAE and protected against the neuronal loss in EAU. The last effect was associated with a reduction in the numbers of infiltrating T cells and marked microglia activation. This is further supported by our in vitro results indicating that CSPG-DS attenuated T cell motility and decreased secretion of the cytokines interferon-gamma and tumor necrosis factor-alpha. Mechanistically, these effects are associated with an increase in SOCS-3 levels and a decrease in NF-kappaB. Our results point to a potential therapeutic modality, in which a compound derived from an endogenous CNS-resident molecule, known for its destructive role in CNS recovery, might be helpful in overcoming inflammation-induced neurodegenerative conditions.
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MESH Headings
- Amino Acid Sequence
- Animals
- Anti-Inflammatory Agents, Non-Steroidal/isolation & purification
- Anti-Inflammatory Agents, Non-Steroidal/pharmacology
- Anti-Inflammatory Agents, Non-Steroidal/therapeutic use
- Apoptosis/drug effects
- Autoimmune Diseases/complications
- Autoimmune Diseases/drug therapy
- Autoimmune Diseases/pathology
- Cell Adhesion
- Cells, Cultured/drug effects
- Cells, Cultured/immunology
- Cells, Cultured/metabolism
- Chemotaxis/drug effects
- Chondroitin Sulfate Proteoglycans/chemistry
- Chondroitin Sulfate Proteoglycans/isolation & purification
- Chondroitin Sulfate Proteoglycans/pharmacology
- Chondroitin Sulfate Proteoglycans/therapeutic use
- Cytokines/metabolism
- Disaccharides/isolation & purification
- Disaccharides/pharmacology
- Disaccharides/therapeutic use
- Drug Evaluation, Preclinical
- Encephalomyelitis, Autoimmune, Experimental/complications
- Encephalomyelitis, Autoimmune, Experimental/drug therapy
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Female
- Humans
- Hypersensitivity, Delayed/drug therapy
- Hypersensitivity, Delayed/prevention & control
- Immunologic Factors/isolation & purification
- Immunologic Factors/pharmacology
- Immunologic Factors/therapeutic use
- Interferon-gamma/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Microglia/drug effects
- Microglia/pathology
- Molecular Sequence Data
- NF-kappa B/metabolism
- Nerve Degeneration/etiology
- Nerve Degeneration/prevention & control
- Rats
- Rats, Inbred Lew
- Retinal Ganglion Cells/drug effects
- Retinal Ganglion Cells/pathology
- Suppressor of Cytokine Signaling 3 Protein
- Suppressor of Cytokine Signaling Proteins/biosynthesis
- Suppressor of Cytokine Signaling Proteins/genetics
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Uveitis/complications
- Uveitis/drug therapy
- Uveitis/pathology
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Affiliation(s)
- Asya Rolls
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel
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López-Vales R, García-Alías G, Forés J, Udina E, Gold BG, Navarro X, Verdú E. FK 506 reduces tissue damage and prevents functional deficit after spinal cord injury in the rat. J Neurosci Res 2005; 81:827-36. [PMID: 16041804 DOI: 10.1002/jnr.20605] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
We examined the efficacy of FK 506 in reducing tissue damage after spinal cord injury in comparison to methylprednisolone (MP) treatment. Rats were subjected to a photochemical injury (T8) and were given a bolus of MP (30 mg/kg), FK 506 (2 mg/kg), or saline. An additional group received an initial bolus of FK 506 (2 mg/kg) followed by daily injections (0.2 mg/kg intraperitoneally). Functional recovery was evaluated using open-field walking, inclined plane tests, motor evoked potentials (MEPs), and the H-reflex response during 14 days postoperation (dpo). Tissue sparing and glial fibrillary acidic protein (GFAP), biotinylated tomato lectin LEC, cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and interleukin 1 beta (IL-1 beta) immunoreactivity were quantified in the injured spinal cord. FK 506-treated animals demonstrated significantly better neurologic outcome, higher MEP amplitudes, and lower H-wave amplitude compared to that of saline-treated rats. In contrast, administration of MP did not result in significant differences with respect to the saline-treated group. Histologic examination revealed that tissue sparing was largest in FK 506-treated compared to saline and MP-treated animals. GFAP and COX-2 reactivity was decreased in animals treated with FK 506 compared to that in animals given MP or saline, whereas IL-1 beta expression was similarly reduced in both FK 506- and MP-treated groups. Microglia/macrophage response was reduced in FK 506 and MP-injected animals at 3 dpo, but only in MP-treated animals at 7 dpo with respect to saline-injected rats. Repeated administrations of FK 506 improved functional and histologic results to a greater degree than did a single bolus of FK 506. The results indicate that FK 506 administration protects the damaged spinal cord and should be considered as potential therapy for treating spinal cord injuries.
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Affiliation(s)
- Rubèn López-Vales
- Group of Neuroplasticity and Regeneration, Institute of Neuroscience and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Bellaterra, Spain
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15
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Ramer LM, Ramer MS, Steeves JD. Setting the stage for functional repair of spinal cord injuries: a cast of thousands. Spinal Cord 2005; 43:134-61. [PMID: 15672094 DOI: 10.1038/sj.sc.3101715] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Here we review mechanisms and molecules that necessitate protection and oppose axonal growth in the injured spinal cord, representing not only a cast of villains but also a company of therapeutic targets, many of which have yet to be fully exploited. We next discuss recent progress in the fields of bridging, overcoming conduction block and rehabilitation after spinal cord injury (SCI), where several treatments in each category have entered the spotlight, and some are being tested clinically. Finally, studies that combine treatments targeting different aspects of SCI are reviewed. Although experiments applying some treatments in combination have been completed, auditions for each part in the much-sought combination therapy are ongoing, and performers must demonstrate robust anatomical regeneration and/or significant return of function in animal models before being considered for a lead role.
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Affiliation(s)
- L M Ramer
- ICORD (International Collaboration on Repair Discoveries), The University of British Columbia, Vancouver, BC, Canada
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16
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Abstract
The spinal cord of the eel, Anguilla, recovers function rapidly after it has been completely transected. At transection, the excitability of central pattern generating circuits in the distal denervated segments increases to such a level that undulatory movements can occur spontaneously. When this elevated neuronal activity was reduced locally, just caudal to the transection, by chronic blockade of the NMDA receptor, the normally rapid behavioural recovery was retarded. The NMDA-treated fish overcame cordotomy more slowly than untreated animals, and axons did not extend as far into the denervated cord as in untreated counterparts, until later stages of recovery. These results suggest that central pattern generating activity may facilitate axonal growth in spinal cord regeneration.
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Affiliation(s)
- Louise M F Doyle
- Department of Zoology, Trinity College, University of Dublin, Dublin 2, Ireland
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17
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Ozawa H, Wu ZJ, Tanaka Y, Kokubun S. Morphologic change and astrocyte response to unilateral spinal cord compression in rabbits. J Neurotrauma 2004; 21:944-55. [PMID: 15307906 DOI: 10.1089/0897715041526159] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In myelopathy, unilateral compression of the spinal cord in cases of disc herniation would be expected to produce Brown-Séquard syndrome. However, a transverse lesion syndrome occurs in most clinical cases. In order to reveal the mechanism by which unilateral compression induces transverse damage to the spinal cord, damage of the gray and white matter in each half of the spinal cord were evaluated quantitatively to determine the density of GFAP-positive astrocytes. The cervical spinal cord in rabbits was unilaterally compressed with a small screw. The area of each half of the damaged cord and the density of GFAP-positive astrocytes of the compressed and contralateral halves were investigated one week after the surgery. No apparent paralysis was observed during the period of observation. As the compression increased, the area of the compressed half of the spinal cord decreased significantly compared to the contralateral half. The densities of GFAP-positive astrocytes in the gray matter and the anterior funiculus increased significantly in the compressed half. There were no significant differences in the densities at the lateral and dorsal funiculi between the compressed and contralateral halves. The tissue damage in the gray matter of the compressed half was markedly higher. No significant difference between the two halves in damage was seen in the lateral funiculus, where in the lateral pyramidal and the dorsal spinocerebellar tracts are found. These findings provide evidence of the mechanistic basis for the spinal cord damage that leads to transverse lesion syndrome in unilateral compression myelopathy.
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Affiliation(s)
- Hiroshi Ozawa
- Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
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18
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Ibarra A, Hauben E, Butovsky O, Schwartz M. The therapeutic window after spinal cord injury can accommodate T cell-based vaccination and methylprednisolone in rats. Eur J Neurosci 2004; 19:2984-90. [PMID: 15182305 DOI: 10.1111/j.0953-816x.2004.03402.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Immune system activity has traditionally been considered harmful for recovery after spinal cord injury (SCI). Recent evidence suggests, however, that immune activity--and specifically autoimmune activity--is evoked by the insult, is beneficial if properly regulated and is amenable to boosting. Thus, for example, vaccination with an altered peptide ligand derived from myelin basic protein reduces the progressive degeneration of neurons that escaped the initial insult, thereby promoting recovery after SCI. As the steroid drug methylprednisolone (MP) is currently the only treatment available for patients with SCI, our purpose in the present study was to examine the mutual compatibility of the two treatments within the post-traumatic therapeutic window. We show, using rats of two different strains, that if MP is injected concomitantly with the therapeutic vaccination, the beneficial effect of the vaccination is diminished. However, if MP is given immediately after the insult and the vaccination 48 h later, MP does not detract from the beneficial effect of the vaccination. These results demonstrate that the therapeutic window after SCI can accommodate immediate administration of MP plus a delayed therapeutic vaccination.
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Affiliation(s)
- Antonio Ibarra
- Department of Neurobiology, The Weizmann Institute of Science, 76100 Rehovot, Israel.
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19
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Nikulina E, Tidwell JL, Dai HN, Bregman BS, Filbin MT. The phosphodiesterase inhibitor rolipram delivered after a spinal cord lesion promotes axonal regeneration and functional recovery. Proc Natl Acad Sci U S A 2004; 101:8786-90. [PMID: 15173585 PMCID: PMC423273 DOI: 10.1073/pnas.0402595101] [Citation(s) in RCA: 255] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2004] [Indexed: 01/24/2023] Open
Abstract
Although there is no spontaneous regeneration of mammalian spinal axons after injury, they can be enticed to grow if cAMP is elevated in the neuronal cell bodies before the spinal axons are cut. Prophylactic injection of cAMP, however, is useless as therapy for spinal injuries. We now show that the phosphodiesterase 4 (PDE4) inhibitor rolipram (which readily crosses the blood-brain barrier) overcomes inhibitors of regeneration in myelin in culture and promotes regeneration in vivo. Two weeks after a hemisection lesion at C3/4, with embryonic spinal tissue implanted immediately at the lesion site, a 10-day delivery of rolipram results in considerable axon regrowth into the transplant and a significant improvement in motor function. Surprisingly, in rolipram-treated animals, there was also an attenuation of reactive gliosis. Hence, because rolipram promotes axon regeneration, attenuates the formation of the glial scar, and significantly enhances functional recovery, and because it is effective when delivered s.c., as well as post-injury, it is a strong candidate as a useful therapy subsequent to spinal cord injury.
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Affiliation(s)
- Elena Nikulina
- Biology Department, Hunter College, City University of New York, New York, NY 10024, USA
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20
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Nesic O, Svrakic NM, Xu GY, McAdoo D, Westlund KN, Hulsebosch CE, Ye Z, Galante A, Soteropoulos P, Tolias P, Young W, Hart RP, Perez-Polo JR. DNA microarray analysis of the contused spinal cord: effect of NMDA receptor inhibition. J Neurosci Res 2002; 68:406-23. [PMID: 11992467 DOI: 10.1002/jnr.10171] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Spinal cord injury (SCI)-induced neurodegeneration leads to irreversible and devastating motor and sensory dysfunction. Post-traumatic outcomes are determined by events occurring during the first 24 hours after SCI. An increase in extracellular glutamate concentration to neurotoxic levels is one of the earliest events after SCI. We used Affymetrix DNA oligonucleotide microarrays (with 1,322 DNA probes) analysis to measure gene expression in order to test the hypothesis that SCI-induced N-methyl-D-aspartate (NMDA) receptor activation triggers significant postinjury transcriptional changes. Here we report that SCI, 1 hour after trauma, induced change in mRNA levels of 165 genes and expression sequence tags (ESTs). SCI affected mRNA levels of those genes that regulate predominantly transcription factors, inflammation, cell survival, and membrane excitability. We also report that NMDA receptor inhibition (with -(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine hydrogen maleate [MK-801]) reversed the effect of SCI on about 50% of the SCI-affected mRNAs. Especially interesting is the finding that NMDA receptor activation participates in the up-regulation of inflammatory factors. Therefore, SCI-induced NMDA receptor activation is one of the dominant, early signals after trauma that leads to changes in mRNA levels of a number of genes relevant to recovery processes. The majority of MK-801 effects on the SCI-induced mRNA changes reported here are novel. Additionally, we found that the MK-801 treatment also changed the mRNA levels of 168 genes and ESTs that had not been affected by SCI alone, and that some of their gene products could have harmful effects on SCI outcome.
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Affiliation(s)
- O Nesic
- Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, Texas 77555-0652, USA.
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