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TNF and its receptors in the CNS: The essential, the desirable and the deleterious effects. Neuroscience 2015; 302:2-22. [DOI: 10.1016/j.neuroscience.2015.06.038] [Citation(s) in RCA: 290] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 06/17/2015] [Accepted: 06/19/2015] [Indexed: 12/15/2022]
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Clark IA, Vissel B. Amyloid β: one of three danger-associated molecules that are secondary inducers of the proinflammatory cytokines that mediate Alzheimer's disease. Br J Pharmacol 2015; 172:3714-27. [PMID: 25939581 PMCID: PMC4523330 DOI: 10.1111/bph.13181] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 03/31/2015] [Accepted: 04/14/2015] [Indexed: 12/11/2022] Open
Abstract
This review concerns how the primary inflammation preceding the generation of certain key damage-associated molecular patterns (DAMPs) arises in Alzheimer's disease (AD). In doing so, it places soluble amyloid β (Aβ), a protein hitherto considered as a primary initiator of AD, in a novel perspective. We note here that increased soluble Aβ is one of the proinflammatory cytokine-induced DAMPs recognized by at least one of the toll-like receptors on and in various cell types. Moreover, Aβ is best regarded as belonging to a class of DAMPs, as do the S100 proteins and HMBG1, that further exacerbate production of these same proinflammatory cytokines, which are already enhanced, and induces them further. Moreover, variation in levels of other DAMPs of this same class in AD may explain why normal elderly patients can exhibit high Aβ plaque levels, and why removing Aβ or its plaque does not retard disease progression. It may also explain why mouse transgenic models, having been designed to generate high Aβ, can be treated successfully by this approach.
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Affiliation(s)
- I A Clark
- Biomedical Sciences and Biochemistry, Research School of Biology, Australian National UniversityCanberra, ACT, Australia
| | - B Vissel
- Neurodegeneration Research Group, Garvan InstituteSydney, NSW, Australia
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103
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A Neurologist's Guide to TNF Biology and to the Principles behind the Therapeutic Removal of Excess TNF in Disease. Neural Plast 2015. [PMID: 26221543 PMCID: PMC4510439 DOI: 10.1155/2015/358263] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Tumor necrosis factor (TNF) is an ancient and widespread cytokine required in small amounts for much physiological function. Higher concentrations are central to innate immunity, but if unchecked this cytokine orchestrates much chronic and acute disease, both infectious and noninfectious. While being a major proinflammatory cytokine, it also controls homeostasis and plasticity in physiological circumstances. For the last decade or so these principles have been shown to apply to the central nervous system as well as the rest of the body. Nevertheless, whereas this approach has been a major success in treating noncerebral disease, its investigation and potential widespread adoption in chronic neurological conditions has inexplicably stalled since the first open trial almost a decade ago. While neuroscience is closely involved with this approach, clinical neurology appears to be reticent in engaging with what it offers patients. Unfortunately, the basic biology of TNF and its relevance to disease is largely outside the traditions of neurology. The purpose of this review is to facilitate lowering communication barriers between the traditional anatomically based medical specialties through recognition of shared disease mechanisms and thus advance the prospects of a large group of patients with neurodegenerative conditions for whom at present little can be done.
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104
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Christensen A, Pike CJ. Menopause, obesity and inflammation: interactive risk factors for Alzheimer's disease. Front Aging Neurosci 2015. [PMID: 26217222 PMCID: PMC4493396 DOI: 10.3389/fnagi.2015.00130] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder, the development of which is regulated by several environmental and genetic risk factors. Two factors theorized to contribute to the initiation and/or progression of AD pathogenesis are age-related increases in inflammation and obesity. These factors may be particularly problematic in women. The onset of menopause in mid-life elevates the vulnerability of women to AD, an increased risk that is likely associated with the depletion of estrogens. Menopause is also linked with an abundance of additional changes, including increased central adiposity and inflammation. Here, we review the current literature to explore the interactions between obesity, inflammation, menopause and AD.
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Affiliation(s)
- Amy Christensen
- Davis School of Gerontology, University of Southern California Los Angeles, CA, USA
| | - Christian J Pike
- Davis School of Gerontology, University of Southern California Los Angeles, CA, USA
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105
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Dorostkar MM, Zou C, Blazquez-Llorca L, Herms J. Analyzing dendritic spine pathology in Alzheimer's disease: problems and opportunities. Acta Neuropathol 2015; 130:1-19. [PMID: 26063233 PMCID: PMC4469300 DOI: 10.1007/s00401-015-1449-5] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 06/02/2015] [Accepted: 06/02/2015] [Indexed: 12/22/2022]
Abstract
Synaptic failure is an immediate cause of cognitive decline and memory dysfunction in Alzheimer’s disease. Dendritic spines are specialized structures on neuronal processes, on which excitatory synaptic contacts take place and the loss of dendritic spines directly correlates with the loss of synaptic function. Dendritic spines are readily accessible for both in vitro and in vivo experiments and have, therefore, been studied in great detail in Alzheimer’s disease mouse models. To date, a large number of different mechanisms have been proposed to cause dendritic spine dysfunction and loss in Alzheimer’s disease. For instance, amyloid beta fibrils, diffusible oligomers or the intracellular accumulation of amyloid beta have been found to alter the function and structure of dendritic spines by distinct mechanisms. Furthermore, tau hyperphosphorylation and microglia activation, which are thought to be consequences of amyloidosis in Alzheimer’s disease, may also contribute to spine loss. Lastly, genetic and therapeutic interventions employed to model the disease and elucidate its pathogenetic mechanisms in experimental animals may cause alterations of dendritic spines on their own. However, to date none of these mechanisms have been translated into successful therapeutic approaches for the human disease. Here, we critically review the most intensely studied mechanisms of spine loss in Alzheimer’s disease as well as the possible pitfalls inherent in the animal models of such a complex neurodegenerative disorder.
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Affiliation(s)
- Mario M. Dorostkar
- />Ludwig-Maximilians University Munich, Center for Neuropathology and Prion Research, Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Chengyu Zou
- />Ludwig-Maximilians University Munich, Center for Neuropathology and Prion Research, Feodor-Lynen-Str. 23, 81377 Munich, Germany
- />Graduate School of Systemic Neuroscience, Ludwig-Maximilians-University Munich, Munich, Germany
- />German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Lidia Blazquez-Llorca
- />Ludwig-Maximilians University Munich, Center for Neuropathology and Prion Research, Feodor-Lynen-Str. 23, 81377 Munich, Germany
- />German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Str. 23, 81377 Munich, Germany
| | - Jochen Herms
- />German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Str. 23, 81377 Munich, Germany
- />Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
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106
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Falgairolle M, O’Donovan MJ. Pharmacological Investigation of Fluoro-Gold Entry into Spinal Neurons. PLoS One 2015; 10:e0131430. [PMID: 26102354 PMCID: PMC4477947 DOI: 10.1371/journal.pone.0131430] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 06/02/2015] [Indexed: 12/28/2022] Open
Abstract
The fluorescent tracer Fluoro-Gold has been widely used to label neurons retrogradely. Here we show that Fluoro-Gold can also enter neurons through AMPA receptor endocytosis. We found that a 30 minute application of Fluoro-Gold to the isolated spinal cord labeled neurons under control conditions and in the presence of glutamatergic agonists including NMDA and AMPA. The labeling was abolished or greatly reduced by glutamatergic antagonists and the endocytic inhibitors Dynasore and dynamin inhibitory peptide. Whole cell recordings from spinal neurons exposed to extracellular AMPA revealed large inward currents that spontaneously decayed in the presence of the agonist but were maintained when a dynamin inhibitory peptide was included in the electrode. These findings suggest that Fluoro-Gold enters spinal neurons through AMPA-mediated receptor internalization. Drugs used to induce locomotor-like activity in the spinal cord also increased and decreased Fluoro-Gold labeling in a drug and lamina specific manner, indicating that AMPAR endocytosis is altered in the presence of the locomotor cocktail. Our findings suggest that endocytosis of Fluoro-Gold could potentially complicate the interpretation of experiments in which the tracer is used to label neurons retrogradely. Moreover, they also demonstrate that many drugs, including the locomotor cocktail, can modulate the number and/or the composition of AMPA receptors on spinal neurons and thereby affect network excitability.
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Affiliation(s)
- Melanie Falgairolle
- Section on Developmental Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Michael J. O’Donovan
- Section on Developmental Neurobiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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107
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Challenor M, O'Hare Doig R, Fuller P, Giacci M, Bartlett C, Wale CH, Cozens GS, Hool L, Dunlop S, Swaminathan Iyer K, Rodger J, Fitzgerald M. Prolonged glutamate excitotoxicity increases GluR1 immunoreactivity but decreases mRNA of GluR1 and associated regulatory proteins in dissociated rat retinae in vitro. Biochimie 2015; 112:160-71. [DOI: 10.1016/j.biochi.2015.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 03/06/2015] [Indexed: 12/15/2022]
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Mietto BS, Mostacada K, Martinez AMB. Neurotrauma and inflammation: CNS and PNS responses. Mediators Inflamm 2015; 2015:251204. [PMID: 25918475 PMCID: PMC4397002 DOI: 10.1155/2015/251204] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 02/24/2015] [Accepted: 03/09/2015] [Indexed: 01/09/2023] Open
Abstract
Traumatic injury to the central nervous system (CNS) or the peripheral nervous system (PNS) triggers a cascade of events which culminate in a robust inflammatory reaction. The role played by inflammation in the course of degeneration and regeneration is not completely elucidated. While, in peripheral nerves, the inflammatory response is assumed to be essential for normal progression of Wallerian degeneration and regeneration, CNS trauma inflammation is often associated with poor recovery. In this review, we discuss key mechanisms that trigger the inflammatory reaction after nervous system trauma, emphasizing how inflammations in both CNS and PNS differ from each other, in terms of magnitude, cell types involved, and effector molecules. Knowledge of the precise mechanisms that elicit and maintain inflammation after CNS and PNS tissue trauma and their effect on axon degeneration and regeneration is crucial for the identification of possible pharmacological drugs that can positively affect the tissue regenerative capacity.
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Affiliation(s)
- Bruno Siqueira Mietto
- Laboratório de Neurodegeneração e Reparo, Departamento de Patologia, Faculdade de Medicina, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, 21941-550 Rio de Janeiro, RJ, Brazil
| | - Klauss Mostacada
- Laboratório de Neurodegeneração e Reparo, Departamento de Patologia, Faculdade de Medicina, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, 21941-550 Rio de Janeiro, RJ, Brazil
| | - Ana Maria Blanco Martinez
- Laboratório de Neurodegeneração e Reparo, Departamento de Patologia, Faculdade de Medicina, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, 21941-550 Rio de Janeiro, RJ, Brazil
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109
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Noble M, Mayer-Pröschel M, Li Z, Dong T, Cui W, Pröschel C, Ambeskovic I, Dietrich J, Han R, Yang YM, Folts C, Stripay J, Chen HY, Stevens BM. Redox biology in normal cells and cancer: restoring function of the redox/Fyn/c-Cbl pathway in cancer cells offers new approaches to cancer treatment. Free Radic Biol Med 2015; 79:300-23. [PMID: 25481740 PMCID: PMC10173888 DOI: 10.1016/j.freeradbiomed.2014.10.860] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 12/12/2022]
Abstract
This review discusses a unique discovery path starting with novel findings on redox regulation of precursor cell and signaling pathway function and identification of a new mechanism by which relatively small changes in redox status can control entire signaling networks that regulate self-renewal, differentiation, and survival. The pathway central to this work, the redox/Fyn/c-Cbl (RFC) pathway, converts small increases in oxidative status to pan-activation of the c-Cbl ubiquitin ligase, which controls multiple receptors and other proteins of central importance in precursor cell and cancer cell function. Integration of work on the RFC pathway with attempts to understand how treatment with systemic chemotherapy causes neurological problems led to the discovery that glioblastomas (GBMs) and basal-like breast cancers (BLBCs) inhibit c-Cbl function through altered utilization of the cytoskeletal regulators Cool-1/βpix and Cdc42, respectively. Inhibition of these proteins to restore normal c-Cbl function suppresses cancer cell division, increases sensitivity to chemotherapy, disrupts tumor-initiating cell (TIC) activity in GBMs and BLBCs, controls multiple critical TIC regulators, and also allows targeting of non-TICs. Moreover, these manipulations do not increase chemosensitivity or suppress division of nontransformed cells. Restoration of normal c-Cbl function also allows more effective harnessing of estrogen receptor-α (ERα)-independent activities of tamoxifen to activate the RFC pathway and target ERα-negative cancer cells. Our work thus provides a discovery strategy that reveals mechanisms and therapeutic targets that cannot be deduced by standard genetics analyses, which fail to reveal the metabolic information, isoform shifts, protein activation, protein complexes, and protein degradation critical to our discoveries.
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Affiliation(s)
- Mark Noble
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Margot Mayer-Pröschel
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Zaibo Li
- Department of Pathology, Ohio State University Wexner Medical Center, 410W 10th Avenue, E403 Doan Hall, Columbus, OH 43210-1240, USA.
| | - Tiefei Dong
- University of Michigan Tech Transfer, 1600 Huron Pkwy, 2nd Floor, Building 520, Ann Arbor, MI 48109-2590, USA.
| | - Wanchang Cui
- Department of Radiation Oncology, University of Maryland School of Medicine,10 South Pine Street, MSTF Room 600, Baltimore, MD 21201, USA.
| | - Christoph Pröschel
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Ibro Ambeskovic
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Joerg Dietrich
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Yawkey 9E, Boston, MA 02114, USA.
| | - Ruolan Han
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Yin Miranda Yang
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Christopher Folts
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Jennifer Stripay
- Department of Biomedical Genetics and University of Rochester Stem Cell and Regenerative Medicine Institute, University of Rochester Medical Center, Rochester, NY 14642, USA.
| | - Hsing-Yu Chen
- Harvard Medical School, Department of Cell Biology 240 Longwood Avenue Building C1, Room 513B Boston, MA 02115, USA.
| | - Brett M Stevens
- University of Colorado School of Medicine, Division of Hematology, 12700 E. 19th Avenue, Campus Box F754-AMCA, Aurora, CO 80045, USA.
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110
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Parihar VK, Allen BD, Tran KK, Chmielewski NN, Craver BM, Martirosian V, Morganti JM, Rosi S, Vlkolinsky R, Acharya MM, Nelson GA, Allen AR, Limoli CL. Targeted overexpression of mitochondrial catalase prevents radiation-induced cognitive dysfunction. Antioxid Redox Signal 2015; 22:78-91. [PMID: 24949841 PMCID: PMC4270160 DOI: 10.1089/ars.2014.5929] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS Radiation-induced disruption of mitochondrial function can elevate oxidative stress and contribute to the metabolic perturbations believed to compromise the functionality of the central nervous system. To clarify the role of mitochondrial oxidative stress in mediating the adverse effects of radiation in the brain, we analyzed transgenic (mitochondrial catalase [MCAT]) mice that overexpress human catalase localized to the mitochondria. RESULTS Compared with wild-type (WT) controls, overexpression of the MCAT transgene significantly decreased cognitive dysfunction after proton irradiation. Significant improvements in behavioral performance found on novel object recognition and object recognition in place tasks were associated with a preservation of neuronal morphology. While the architecture of hippocampal CA1 neurons was significantly compromised in irradiated WT mice, the same neurons in MCAT mice did not exhibit extensive and significant radiation-induced reductions in dendritic complexity. Irradiated neurons from MCAT mice maintained dendritic branching and length compared with WT mice. Protected neuronal morphology in irradiated MCAT mice was also associated with a stabilization of radiation-induced variations in long-term potentiation. Stabilized synaptic activity in MCAT mice coincided with an altered composition of the synaptic AMPA receptor subunits GluR1/2. INNOVATION Our findings provide the first evidence that neurocognitive sequelae associated with radiation exposure can be reduced by overexpression of MCAT, operating through a mechanism involving the preservation of neuronal morphology. CONCLUSION Our article documents the neuroprotective properties of reducing mitochondrial reactive oxygen species through the targeted overexpression of catalase and how this ameliorates the adverse effects of proton irradiation in the brain.
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Affiliation(s)
- Vipan K. Parihar
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Barrett D. Allen
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Katherine K. Tran
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Nicole N. Chmielewski
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Brianna M. Craver
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Vahan Martirosian
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Josh M. Morganti
- Departments of Physical Therapy Rehabilitation Science and Neurological Surgery, University of California, San Francisco, San Francisco, California
| | - Susanna Rosi
- Departments of Physical Therapy Rehabilitation Science and Neurological Surgery, University of California, San Francisco, San Francisco, California
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, California
| | - Roman Vlkolinsky
- Departments of Radiation Medicine and Basic Sciences, Loma Linda University, Loma Linda, California
| | - Munjal M. Acharya
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
| | - Gregory A. Nelson
- Departments of Radiation Medicine and Basic Sciences, Loma Linda University, Loma Linda, California
| | - Antiño R. Allen
- Division of Radiation Health, University of Arkansas Medical School, Little Rock, Arkansas
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California, Irvine, Irvine, California
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111
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Liu D, Huang Y, Jia C, Li Y, Liang F, Fu Q. Administration of antagomir-223 inhibits apoptosis, promotes angiogenesis and functional recovery in rats with spinal cord injury. Cell Mol Neurobiol 2014; 35:483-91. [PMID: 25416533 DOI: 10.1007/s10571-014-0142-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 11/18/2014] [Indexed: 12/18/2022]
Abstract
MicroRNAs (miRNAs) are recently described as a class of short non-coding RNAs, which play important roles in post-transcriptional gene regulation and involved in many physiological and pathological processes. MicroRNA-223 (miR-223) has been showed highly elevated in the injured spinal cord. However, the potential role and underlying mechanisms of miR-223 in spinal cord injury (SCI) were incompletely understood. In the present study, we observed the persistent high levels of miR-223 in the injured spinal cord at different time points (1, 3, 7, and 14 days) after SCI. Besides, inhibiting miR-223 by intrathecally injection with antagomir-223 significantly improved recovery in hindlimb motor function and attenuated cell apoptosis in spinal cord-injured rats. Additionally, antagomir-223 treatment markedly decreased the pro-apoptotic protein levels, including Bax and cleaved caspase-3, up-regulated the anti-apoptotic Bcl-2 protein level, as well as the expression of GluR2. Moreover, inhibition of miR-223 promoted angiogenesis, as evidenced by the increased CD31 expression and microvascular density. Taken together, our results indicate that inhibition of miR-223 with antagomir-223 exerts protective role in functional recovery, angiogenesis, and anti-apoptosis during SCI. Thereby, miR-223 may be a promising target of therapy for SCI.
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Affiliation(s)
- Da Liu
- Department of Orthopaedic Surgery, Shengjing Hospital of China Medical University, 36 Sanhao Street, Shenyang, 110004, People's Republic of China,
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112
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Vezzani A, Viviani B. Neuromodulatory properties of inflammatory cytokines and their impact on neuronal excitability. Neuropharmacology 2014; 96:70-82. [PMID: 25445483 DOI: 10.1016/j.neuropharm.2014.10.027] [Citation(s) in RCA: 423] [Impact Index Per Article: 42.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 10/24/2014] [Accepted: 10/29/2014] [Indexed: 01/01/2023]
Abstract
Increasing evidence underlines that prototypical inflammatory cytokines (IL-1β, TNF-α and IL-6) either synthesized in the central (CNS) or peripheral nervous system (PNS) by resident cells, or imported by immune blood cells, are involved in several pathophysiological functions, including an unexpected impact on synaptic transmission and neuronal excitability. This review describes these unconventional neuromodulatory properties of cytokines, that are distinct from their classical action as effector molecules of the immune system. In addition to the role of cytokines in brain physiology, we report evidence that dysregulation of their biosynthesis and cellular release, or alterations in receptor-mediated intracellular pathways in target cells, leads to neuronal cell dysfunction and modifications in neuronal network excitability. As a consequence, targeting of these cytokines, and related signalling molecules, is considered a novel option for the development of therapies in various CNS or PNS disorders associated with an inflammatory component. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
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Affiliation(s)
- Annamaria Vezzani
- IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Department of Neuroscience, Milano, Italy.
| | - Barbara Viviani
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milano, Italy.
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113
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Intra-amygdala microinjection of TNF-α impairs the auditory fear conditioning of rats via glutamate toxicity. Neurosci Res 2014; 91:34-40. [PMID: 25448547 DOI: 10.1016/j.neures.2014.10.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 09/30/2014] [Accepted: 10/11/2014] [Indexed: 11/23/2022]
Abstract
During an inflammatory or infectious process, innate immune cells produce large amount of pro-inflammatory cytokines that act on the brain to cause cognitive dysfunctions. Tumor necrosis factor alpha (TNF-α) is one of the main pro-inflammatory cytokines. Thus, it is important to study how the excessive TNF-α affects the cognitive functions of central nervous system and possible antagonists to its effects. In the present study, we conducted behavioral experiments of rats to determine whether murine TNF-α administered directly into the brain would elicit behavioral effects related to learning and memory impairments. Rats subjected to single-dose intra-amygdala TNF-α infusion showed a significant delay in the acquisition and extinction of auditory fear conditioning. Accordingly, the glutamate level of the tissue samples from amygdala was elevated after the TNF-α treatment. Furthermore, pharmacological blockade of NMDAR before the TNF-α treatment reversed the TNF-α induced impairments in fear learning. Our findings suggest that TNF-α can impair the learning and memory functions through glutamate-NMDAR neurotoxicity, and present the possibility to develop therapeutic modalities directing at glutamate transmission for the treatment of neuro-inflammative dysfunctions.
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114
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Santerre JL, Rogow JA, Kolitz EB, Pal R, Landin JD, Gigante ED, Werner DF. Ethanol dose-dependently elicits opposing regulatory effects on hippocampal AMPA receptor GluA2 subunits through a zeta inhibitory peptide-sensitive kinase in adolescent and adult Sprague-Dawley rats. Neuroscience 2014; 280:50-9. [PMID: 25218807 PMCID: PMC4482479 DOI: 10.1016/j.neuroscience.2014.09.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 09/02/2014] [Accepted: 09/02/2014] [Indexed: 10/24/2022]
Abstract
AMPA receptor GluA2 subunits are strongly implicated in cognition, and prior work suggests that these subunits may be regulated by atypical protein kinase C (aPKC) isoforms. The present study assessed whether hippocampal and cortical AMPA receptor GluA2 subunit regulation may be an underlying factor in known age-related differences to cognitive-impairing doses of ethanol, and if aPKC isoforms modulate such responses. Hippocampal AMPA receptor GluA2 subunit, protein kinase Mζ (PKMζ), and PKCι/λ expression were elevated during adolescence compared to adults. 1 h following a low-dose (1.0-g/kg) ethanol exposure, hippocampal AMPA receptor GluA2 subunit serine 880 phosphorylation was decreased in adolescents, but was increased in adults. Age-dependent changes in GluA2 subunit phosphorylation were paralleled by alterations in aPKC isoforms, and zeta inhibitory peptide (ZIP) administration prevented ethanol-induced increases in both in adults. Ethanol-induced changes in GluA2 subunit phosphorylation were associated with delayed regulation in synaptosomal GluA2 subunit expression 24 h later. A higher ethanol dose (3.5-g/kg) failed to elicit changes in most measures in the hippocampus at either age. Similar to the hippocampus, analysis of cerebral cortical tissue also revealed age-related declines. However, no demonstrable effects were found following a low-dose ethanol exposure at either age. High-dose ethanol exposure reduced adolescent GluA2 subunit phosphorylation and aPKC isoform expression that were again accompanied by delayed reductions in synaptosomal GluA2 subunit expression. Together, these results suggest that GluA2-containing AMPA receptor modulation by aPKC isoforms is age-, region- and dose-dependently regulated, and may potentially be involved in developmentally regulated ethanol-induced cognitive impairment and other ethanol behaviors.
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Affiliation(s)
- J L Santerre
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA
| | - J A Rogow
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA
| | - E B Kolitz
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA
| | - R Pal
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA
| | - J D Landin
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA
| | - E D Gigante
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA
| | - D F Werner
- Department of Psychology, Center for Development and Behavioral Neuroscience, Binghamton University - State University of New York, Binghamton, NY 13902, USA.
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Nielson JL, Haefeli J, Salegio EA, Liu AW, Guandique CF, Stück ED, Hawbecker S, Moseanko R, Strand SC, Zdunowski S, Brock JH, Roy RR, Rosenzweig ES, Nout-Lomas YS, Courtine G, Havton LA, Steward O, Reggie Edgerton V, Tuszynski MH, Beattie MS, Bresnahan JC, Ferguson AR. Leveraging biomedical informatics for assessing plasticity and repair in primate spinal cord injury. Brain Res 2014; 1619:124-38. [PMID: 25451131 DOI: 10.1016/j.brainres.2014.10.048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 10/22/2014] [Accepted: 10/23/2014] [Indexed: 11/18/2022]
Abstract
Recent preclinical advances highlight the therapeutic potential of treatments aimed at boosting regeneration and plasticity of spinal circuitry damaged by spinal cord injury (SCI). With several promising candidates being considered for translation into clinical trials, the SCI community has called for a non-human primate model as a crucial validation step to test efficacy and validity of these therapies prior to human testing. The present paper reviews the previous and ongoing efforts of the California Spinal Cord Consortium (CSCC), a multidisciplinary team of experts from 5 University of California medical and research centers, to develop this crucial translational SCI model. We focus on the growing volumes of high resolution data collected by the CSCC, and our efforts to develop a biomedical informatics framework aimed at leveraging multidimensional data to monitor plasticity and repair targeting recovery of hand and arm function. Although the main focus of many researchers is the restoration of voluntary motor control, we also describe our ongoing efforts to add assessments of sensory function, including pain, vital signs during surgery, and recovery of bladder and bowel function. By pooling our multidimensional data resources and building a unified database infrastructure for this clinically relevant translational model of SCI, we are now in a unique position to test promising therapeutic strategies' efficacy on the entire syndrome of SCI. We review analyses highlighting the intersection between motor, sensory, autonomic and pathological contributions to the overall restoration of function. This article is part of a Special Issue entitled SI: Spinal cord injury.
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Affiliation(s)
- Jessica L Nielson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Jenny Haefeli
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Ernesto A Salegio
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Aiwen W Liu
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Cristian F Guandique
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Ellen D Stück
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Stephanie Hawbecker
- California National Primate Research Center (CNPRC), University of California, Davis, CA (UCD), United States
| | - Rod Moseanko
- California National Primate Research Center (CNPRC), University of California, Davis, CA (UCD), United States
| | - Sarah C Strand
- California National Primate Research Center (CNPRC), University of California, Davis, CA (UCD), United States
| | - Sharon Zdunowski
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (UCLA), United States
| | - John H Brock
- Center for Neural Repair, Department of Neurosciences, University of California, San Diego, La Jolla, CA (UCSD), United States
| | - Roland R Roy
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (UCLA), United States
| | - Ephron S Rosenzweig
- Center for Neural Repair, Department of Neurosciences, University of California, San Diego, La Jolla, CA (UCSD), United States
| | - Yvette S Nout-Lomas
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, United States
| | - Gregoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, Swiss Federal Institute of Technology (EPFL), United States
| | - Leif A Havton
- Reeve-Irvine Research Center (RIRC), University of California, Irvine, CA (UCI), United States; Departments of Anesthesiology & Perioperative Care, Neurology, and Anatomy & Neurobiology, University of California, Irvine, CA, United States
| | - Oswald Steward
- Reeve-Irvine Research Center (RIRC), University of California, Irvine, CA (UCI), United States; Departments of Anatomy & Neurobiology, Neurobiology & Behavior, and Neurosurgery, University of California, Irvine, CA, United States
| | - V Reggie Edgerton
- Department of Integrative Biology and Physiology, University of California, Los Angeles, CA (UCLA), United States
| | - Mark H Tuszynski
- Departments of Anesthesiology & Perioperative Care, Neurology, and Anatomy & Neurobiology, University of California, Irvine, CA, United States; Veterans Administration Medical Center, La Jolla, CA, United States
| | - Michael S Beattie
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Jacqueline C Bresnahan
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States
| | - Adam R Ferguson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, San Francisco, CA (UCSF), United States.
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Targeting TNF: a therapeutic strategy for Alzheimer's disease. Drug Discov Today 2014; 19:1822-1827. [DOI: 10.1016/j.drudis.2014.06.029] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 06/19/2014] [Accepted: 06/26/2014] [Indexed: 12/17/2022]
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Mecollari V, Nieuwenhuis B, Verhaagen J. A perspective on the role of class III semaphorin signaling in central nervous system trauma. Front Cell Neurosci 2014; 8:328. [PMID: 25386118 PMCID: PMC4209881 DOI: 10.3389/fncel.2014.00328] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 09/29/2014] [Indexed: 01/07/2023] Open
Abstract
Traumatic injury of the central nervous system (CNS) has severe impact on the patients’ quality of life and initiates many molecular and cellular changes at the site of insult. Traumatic CNS injury results in direct damage of the axons of CNS neurons, loss of myelin sheaths, destruction of the surrounding vascular architecture and initiation of an immune response. Class III semaphorins (SEMA3s) are present in the neural scar and influence a wide range of molecules and cell types in and surrounding the injured tissue. SEMA3s and their receptors, neuropilins (NRPs) and plexins (PLXNs) were initially studied because of their involvement in repulsive axon guidance. To date, SEMA3 signaling is recognized to be of crucial importance for re-vascularization, the immune response and remyelination. The purpose of this review is to summarize and discuss how SEMA3s modulate these processes that are all crucial components of the tissue response to injury. Most of the functions for SEMA3s are achieved through their binding partners NRPs, which are also co-receptors for a variety of other molecules implicated in the above processes. The most notable ligands are members of the vascular endothelial growth factor (VEGF) family and the transforming growth factor family. Therefore, a second aim is to highlight the overlapping or competing signaling pathways that are mediated through NRPs in the same processes. In conclusion, we show that the role of SEMA3s goes beyond inhibiting axonal regeneration, since they are also critical modulators of re-vascularization, the immune response and re-myelination.
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Affiliation(s)
- Vasil Mecollari
- Laboratory for Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience Amsterdam, Netherlands
| | - Bart Nieuwenhuis
- Laboratory for Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience Amsterdam, Netherlands
| | - Joost Verhaagen
- Laboratory for Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience Amsterdam, Netherlands ; Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University Amsterdam Amsterdam, Netherlands
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118
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Novrup HG, Bracchi-Ricard V, Ellman DG, Ricard J, Jain A, Runko E, Lyck L, Yli-Karjanmaa M, Szymkowski DE, Pearse DD, Lambertsen KL, Bethea JR. Central but not systemic administration of XPro1595 is therapeutic following moderate spinal cord injury in mice. J Neuroinflammation 2014; 11:159. [PMID: 25204558 PMCID: PMC4176557 DOI: 10.1186/s12974-014-0159-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 08/23/2014] [Indexed: 12/27/2022] Open
Abstract
Background Glial cell activation and overproduction of inflammatory mediators in the central nervous system (CNS) have been implicated in acute traumatic injuries to the CNS, including spinal cord injury (SCI). Elevated levels of the proinflammatory cytokine tumor necrosis factor (TNF), which exists in both a soluble (sol) and a transmembrane (tm) form, have been found in the lesioned cord early after injury. The contribution of solTNF versus tmTNF to the development of the lesion is, however, still unclear. Methods We tested the effect of systemically or centrally blocking solTNF alone, using XPro1595, versus using the drug etanercept to block both solTNF and tmTNF compared to a placebo vehicle following moderate SCI in mice. Functional outcomes were evaluated using the Basso Mouse Scale, rung walk test, and thermal hyperalgesia analysis. The inflammatory response in the lesioned cord was investigated using immunohistochemistry and western blotting analyses. Results We found that peripheral administration of anti-TNF therapies had no discernable effect on locomotor performances after SCI. In contrast, central administration of XPro1595 resulted in improved locomotor function, decreased anxiety-related behavior, and reduced damage to the lesioned spinal cord, whereas central administration of etanercept had no therapeutic effects. Improvements in XPro1595-treated mice were accompanied by increases in Toll-like receptor 4 and TNF receptor 2 (TNFR2) protein levels and changes in Iba1 protein expression in microglia/macrophages 7 and 28 days after SCI. Conclusions These studies suggest that, by selectively blocking solTNF, XPro1595 is neuroprotective when applied directly to the lesioned cord. This protection may be mediated via alteration of the inflammatory environment without suppression of the neuroprotective effects of tmTNF signaling through TNFR2.
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Affiliation(s)
- Hans G Novrup
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, J.B. Winsloewsvej 21 St, 5000, Odense C, Denmark.
| | - Valerie Bracchi-Ricard
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA.
| | - Ditte G Ellman
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, J.B. Winsloewsvej 21 St, 5000, Odense C, Denmark.
| | - Jerome Ricard
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA.
| | - Anjana Jain
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA. .,Department of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA, 01609-2280, USA.
| | - Erik Runko
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA.
| | - Lise Lyck
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, J.B. Winsloewsvej 21 St, 5000, Odense C, Denmark. .,Coloplast A/S, Holtedam 1, 3050, Humlebæk, Denmark, Denmark.
| | - Minna Yli-Karjanmaa
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, J.B. Winsloewsvej 21 St, 5000, Odense C, Denmark.
| | | | - Damien D Pearse
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA.
| | - Kate L Lambertsen
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA. .,Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, J.B. Winsloewsvej 21 St, 5000, Odense C, Denmark.
| | - John R Bethea
- Department of Neurological Surgery, The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Ter R-48, Miami, FL, 33136, USA. .,Department of Biology, Drexel University, 3245 Chestnut St., PISB 123, Philadelphia, PA, 19104, USA.
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119
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Garraway SM, Woller SA, Huie JR, Hartman JJ, Hook MA, Miranda RC, Huang YJ, Ferguson AR, Grau JW. Peripheral noxious stimulation reduces withdrawal threshold to mechanical stimuli after spinal cord injury: role of tumor necrosis factor alpha and apoptosis. Pain 2014; 155:2344-59. [PMID: 25180012 DOI: 10.1016/j.pain.2014.08.034] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 08/12/2014] [Accepted: 08/26/2014] [Indexed: 01/23/2023]
Abstract
We previously showed that peripheral noxious input after spinal cord injury (SCI) inhibits beneficial spinal plasticity and impairs recovery of locomotor and bladder functions. These observations suggest that noxious input may similarly affect the development and maintenance of chronic neuropathic pain, an important consequence of SCI. In adult rats with a moderate contusion SCI, we investigated the effect of noxious tail stimulation, administered 1 day after SCI on mechanical withdrawal responses to von Frey stimuli from 1 to 28 days after treatment. In addition, because the proinflammatory cytokine tumor necrosis factor alpha (TNFα) is implicated in numerous injury-induced processes including pain hypersensitivity, we assessed the temporal and spatial expression of TNFα, TNF receptors, and several downstream signaling targets after stimulation. Our results showed that unlike sham surgery or SCI only, nociceptive stimulation after SCI induced mechanical sensitivity by 24h. These behavioral changes were accompanied by increased expression of TNFα. Cellular assessments of downstream targets of TNFα revealed that nociceptive stimulation increased the expression of caspase 8 and the active subunit (12 kDa) of caspase 3, indicative of active apoptosis at a time point consistent with the onset of mechanical allodynia. In addition, immunohistochemical analysis revealed distinct morphological signs of apoptosis in neurons and microglia at 24h after stimulation. Interestingly, expression of the inflammatory mediator NFκB was unaltered by nociceptive stimulation. These results suggest that noxious input caudal to the level of SCI can increase the onset and expression of behavioral responses indicative of pain, potentially involving TNFα signaling.
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Affiliation(s)
- Sandra M Garraway
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA.
| | - Sarah A Woller
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - J Russell Huie
- Department of Neurological Surgery, Brain and Spinal Injury Center (BASIC), University of California, San Francisco, 1001 Potrero Ave, Bldg 1, Room 101, San Francisco, CA 94110, USA
| | - John J Hartman
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - Michelle A Hook
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - Rajesh C Miranda
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, College of Medicine, Medical Research and Education Bldg, 8447 State Highway 47, Bryan, TX 77807-3260, USA
| | - Yung-Jen Huang
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
| | - Adam R Ferguson
- Department of Neurological Surgery, Brain and Spinal Injury Center (BASIC), University of California, San Francisco, 1001 Potrero Ave, Bldg 1, Room 101, San Francisco, CA 94110, USA
| | - James W Grau
- Department of Psychology, Texas A&M University, College Station, TX 77843, USA
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120
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Early administration of tumor necrosis factor-alpha antagonist promotes survival of transplanted neural stem cells and axon myelination after spinal cord injury in rats. Brain Res 2014; 1575:87-100. [DOI: 10.1016/j.brainres.2014.05.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 04/30/2014] [Accepted: 05/23/2014] [Indexed: 12/19/2022]
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121
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Irvine KA, Ferguson AR, Mitchell KD, Beattie SB, Lin A, Stuck ED, Huie JR, Nielson JL, Talbott JF, Inoue T, Beattie MS, Bresnahan JC. The Irvine, Beatties, and Bresnahan (IBB) Forelimb Recovery Scale: An Assessment of Reliability and Validity. Front Neurol 2014; 5:116. [PMID: 25071704 PMCID: PMC4083223 DOI: 10.3389/fneur.2014.00116] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 06/20/2014] [Indexed: 12/24/2022] Open
Abstract
The IBB scale is a recently developed forelimb scale for the assessment of fine control of the forelimb and digits after cervical spinal cord injury [SCI; (1)]. The present paper describes the assessment of inter-rater reliability and face, concurrent and construct validity of this scale following SCI. It demonstrates that the IBB is a reliable and valid scale that is sensitive to severity of SCI and to recovery over time. In addition, the IBB correlates with other outcome measures and is highly predictive of biological measures of tissue pathology. Multivariate analysis using principal component analysis (PCA) demonstrates that the IBB is highly predictive of the syndromic outcome after SCI (2), and is among the best predictors of bio-behavioral function, based on strong construct validity. Altogether, the data suggest that the IBB, especially in concert with other measures, is a reliable and valid tool for assessing neurological deficits in fine motor control of the distal forelimb, and represents a powerful addition to multivariate outcome batteries aimed at documenting recovery of function after cervical SCI in rats.
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Affiliation(s)
- Karen-Amanda Irvine
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Adam R. Ferguson
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Kathleen D. Mitchell
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Stephanie B. Beattie
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Amity Lin
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Ellen D. Stuck
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - J. Russell Huie
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Jessica L. Nielson
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Jason F. Talbott
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Tomoo Inoue
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Michael S. Beattie
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - Jacqueline C. Bresnahan
- Brain and Spinal Cord Injury Center, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
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Abstract
Elevation of inflammatory cytokines in the striatum precedes symptoms in a number of motor dysfunctions, but it is unclear whether this is part of the disease process or an adaptive response to the pathology. In pyramidal cells, TNFα drives the insertion of AMPA-type glutamate receptors into synapses, and contributes to the homeostatic regulation of circuit activity in the developing neocortex. Here we demonstrate that in the mouse dorsolateral striatum, TNFα drives the internalization of AMPARs and reduces corticostriatal synaptic strength, dephosphorylates DARPP-32 and GluA1, and results in a preferential removal of Ca(2+)-permeable AMPARs. Striatal TNFα signaling appears to be adaptive in nature, as TNFα is upregulated in response to the prolonged blockade of D2 dopamine receptors and is necessary to reduce the expression of extrapyramidal symptoms induced by chronic haloperidol treatment. These data indicate that TNFα is a regulator of glutamatergic synaptic strength in the adult striatum in a manner distinct from its regulation of synapses on pyramidal cells and mediates an adaptive response during pathological conditions.
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123
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O'Hare Doig RL, Bartlett CA, Maghzal GJ, Lam M, Archer M, Stocker R, Fitzgerald M. Reactive species and oxidative stress in optic nerve vulnerable to secondary degeneration. Exp Neurol 2014; 261:136-46. [PMID: 24931225 DOI: 10.1016/j.expneurol.2014.06.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/24/2014] [Accepted: 06/05/2014] [Indexed: 12/20/2022]
Abstract
Secondary degeneration contributes substantially to structural and functional deficits following traumatic injury to the CNS. While it has been proposed that oxidative stress is a feature of secondary degeneration, contributing reactive species and resultant oxidized products have not been clearly identified in vivo. The study is designed to identify contributors to, and consequences of, oxidative stress in a white matter tract vulnerable to secondary degeneration. Partial dorsal transection of the optic nerve (ON) was used to model secondary degeneration in ventral nerve unaffected by the primary injury. Reactive species were assessed using fluorescent labelling and liquid chromatography/tandem mass spectroscopy (LC/MS/MS). Antioxidant enzymes and oxidized products were semi-quantified immunohistochemically. Mitophagy was assessed by electron microscopy. Fluorescent indicators of reactive oxygen and/or nitrogen species increased at 1, 3 and 7days after injury, in ventral ON. LC/MS/MS confirmed increases in reactive species linked to infiltrating microglia/macrophages in dorsal ON. Similarly, immunoreactivity for glutathione peroxidase and haem oxygenase-1 increased in ventral ON at 3 and 7days after injury, respectively. Despite increased antioxidant immunoreactivity, DNA oxidation was evident from 1day, lipid oxidation at 3days, and protein nitration at 7days after injury. Nitrosative and oxidative damage was particularly evident in CC1-positive oligodendrocytes, at times after injury at which structural abnormalities of the Node of Ranvier/paranode complex have been reported. The incidence of mitochondrial autophagic profiles was also significantly increased from 3days. Despite modest increases in antioxidant enzymes, increased reactive species are accompanied by oxidative and nitrosative damage to DNA, lipid and protein, associated with increasing abnormal mitochondria, which together may contribute to the deficits of secondary degeneration.
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Affiliation(s)
- Ryan L O'Hare Doig
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Carole A Bartlett
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Ghassan J Maghzal
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia; University of New South Wales, NSW, Australia
| | - Magdalena Lam
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Michael Archer
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - Roland Stocker
- Vascular Biology Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia; University of New South Wales, NSW, Australia
| | - Melinda Fitzgerald
- Experimental and Regenerative Neurosciences, School of Animal Biology, The University of Western Australia, Crawley, Western Australia, Australia.
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Yin HZ, Yu S, Hsu CI, Liu J, Acab A, Wu R, Tao A, Chiang BJ, Weiss JH. Intrathecal infusion of BMAA induces selective motor neuron damage and astrogliosis in the ventral horn of the spinal cord. Exp Neurol 2014; 261:1-9. [PMID: 24918341 DOI: 10.1016/j.expneurol.2014.06.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/16/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022]
Abstract
The neurotoxin beta-N-methylamino-l-alanine (BMAA) was first identified as a "toxin of interest" in regard to the amyotrophic lateral sclerosis-Parkinsonism Dementia Complex of Guam (ALS/PDC); studies in recent years highlighting widespread environmental sources of BMAA exposure and providing new clues to toxic mechanisms have suggested possible relevance to sporadic ALS as well. However, despite clear evidence of uptake into tissues and a range of toxic effects in cells and animals, an animal model in which BMAA induces a neurodegenerative picture resembling ALS is lacking, possibly in part reflecting limited understanding of critical factors pertaining to its absorption, biodistribution and metabolism. To bypass some of these issues and ensure delivery to a key site of disease pathology, we examined effects of prolonged (30day) intrathecal infusion in wild type (WT) rats, and rats harboring the familial ALS associated G93A SOD1 mutation, over an age range (80±2 to 110±2days) during which the G93A rats are developing disease pathology yet remain asymptomatic. The BMAA exposures induced changes that in many ways resemble those seen in the G93A rats, with degenerative changes in ventral horn motor neurons (MNs) with relatively little dorsal horn pathology, marked ventral horn astrogliosis and increased 3-nitrotyrosine labeling in and surrounding MNs, a loss of labeling for the astrocytic glutamate transporter, GLT-1, surrounding MNs, and mild accumulation and aggregation of TDP-43 in the cytosol of some injured and degenerating MNs. Thus, prolonged intrathecal infusion of BMAA can reproduce a picture in spinal cord incorporating many of the pathological hallmarks of diverse forms of human ALS, including substantial restriction of overt pathological changes to the ventral horn, consistent with the possibility that environmental BMAA exposure could be a risk factor and/or contributor to some human disease.
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Affiliation(s)
- Hong Z Yin
- Department of Neurology, University of CA, Irvine, USA
| | - Stephen Yu
- Department of Neurology, University of CA, Irvine, USA
| | - Cheng-I Hsu
- Department of Neurology, University of CA, Irvine, USA
| | - Joe Liu
- Department of Neurology, University of CA, Irvine, USA
| | - Allan Acab
- Department of Neurology, University of CA, Irvine, USA
| | - Richard Wu
- Department of Neurology, University of CA, Irvine, USA
| | - Anna Tao
- Department of Neurology, University of CA, Irvine, USA
| | | | - John H Weiss
- Department of Neurology, University of CA, Irvine, USA; Department of Anatomy & Neurobiology, University of CA, Irvine, USA.
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Leinders M, Koehrn FJ, Bartok B, Boyle DL, Shubayev V, Kalcheva I, Yu NK, Park J, Kaang BK, Hefferan MP, Firestein GS, Sorkin LS. Differential distribution of PI3K isoforms in spinal cord and dorsal root ganglia: potential roles in acute inflammatory pain. Pain 2014; 155:1150-1160. [PMID: 24631588 PMCID: PMC4128246 DOI: 10.1016/j.pain.2014.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 03/03/2014] [Accepted: 03/05/2014] [Indexed: 11/30/2022]
Abstract
PI3-kinases (PI3Ks) participate in nociception within spinal cord, dorsal root ganglion (DRG), and peripheral nerves. To extend our knowledge, we immunohistochemically stained for each of the 4 class I PI3K isoforms along with several cell-specific markers within the lumbar spinal cord, DRG, and sciatic nerve of naive rats. Intrathecal and intraplantar isoform specific antagonists were given as pretreatments before intraplantar carrageenan; pain behavior was then assessed over time. The α-isoform was localized to central terminals of primary afferent fibers in spinal cord laminae IIi to IV as well as to neurons in ventral horn and DRG. The PI3Kβ isoform was the only class I isoform seen in dorsal horn neurons; it was also observed in DRG, Schwann cells, and axonal paranodes. The δ-isoform was found in spinal cord white matter oligodendrocytes and radial astrocytes, and the γ-isoform was seen in a subpopulation of IB4-positive DRG neurons. No isoform co-localized with microglial markers or satellite cells in naive tissue. Only the PI3Kβ antagonist, but none of the other antagonists, had anti-allodynic effects when administered intrathecally; coincident with reduced pain behavior, this agent completely blocked paw carrageenan-induced dorsal horn 2-amino-3-(3-hydroxy-5-methyl-isoxazol-4-yl) propanoic acid (AMPA) receptor trafficking to plasma membranes. Intraplantar administration of the γ-antagonist prominently reduced pain behavior. These data suggest that each isoform displays specificity with regard to neuronal type as well as to specific tissues. Furthermore, each PI3K isoform has a unique role in development of nociception and tissue inflammation.
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Affiliation(s)
- Mathias Leinders
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Fred J. Koehrn
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Beatrix Bartok
- Deprtment of Medicine, Division of Rheumatology, University of California, San Diego, La Jolla, CA
| | - David L. Boyle
- Deprtment of Medicine, Division of Rheumatology, University of California, San Diego, La Jolla, CA
| | - Veronica Shubayev
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
- San Diego VA Healthcare System, La Jolla, CA
| | - Iveta Kalcheva
- Deprtment of Medicine, Division of Rheumatology, University of California, San Diego, La Jolla, CA
| | - Nam-Kyung Yu
- Department of Biological Sciences and Brain and Cognitive Sciences, Seoul National University, Seoul 151-747, Korea
| | - Jihye Park
- Department of Biological Sciences and Brain and Cognitive Sciences, Seoul National University, Seoul 151-747, Korea
| | - Bong-Kiun Kaang
- Department of Biological Sciences and Brain and Cognitive Sciences, Seoul National University, Seoul 151-747, Korea
| | | | - Gary S. Firestein
- Deprtment of Medicine, Division of Rheumatology, University of California, San Diego, La Jolla, CA
| | - Linda S. Sorkin
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA 92093, USA
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126
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Tumor necrosis factor alpha: a link between neuroinflammation and excitotoxicity. Mediators Inflamm 2014; 2014:861231. [PMID: 24966471 PMCID: PMC4055424 DOI: 10.1155/2014/861231] [Citation(s) in RCA: 453] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Accepted: 05/07/2014] [Indexed: 02/08/2023] Open
Abstract
Tumor necrosis factor alpha (TNF-α) is a proinflammatory cytokine that exerts both homeostatic and pathophysiological roles in the central nervous system. In pathological conditions, microglia release large amounts of TNF-α; this de novo production of TNF-α is an important component of the so-called neuroinflammatory response that is associated with several neurological disorders. In addition, TNF-α can potentiate glutamate-mediated cytotoxicity by two complementary mechanisms: indirectly, by inhibiting glutamate transport on astrocytes, and directly, by rapidly triggering the surface expression of Ca+2 permeable-AMPA receptors and NMDA receptors, while decreasing inhibitory GABAA receptors on neurons. Thus, the net effect of TNF-α is to alter the balance of excitation and inhibition resulting in a higher synaptic excitatory/inhibitory ratio. This review summarizes the current knowledge of the cellular and molecular mechanisms by which TNF-α links the neuroinflammatory and excitotoxic processes that occur in several neurodegenerative diseases, but with a special emphasis on amyotrophic lateral sclerosis (ALS). As microglial activation and upregulation of TNF-α expression is a common feature of several CNS diseases, as well as chronic opioid exposure and neuropathic pain, modulating TNF-α signaling may represent a valuable target for intervention.
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127
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Viviani B, Boraso M, Marchetti N, Marinovich M. Perspectives on neuroinflammation and excitotoxicity: a neurotoxic conspiracy? Neurotoxicology 2014; 43:10-20. [PMID: 24662010 DOI: 10.1016/j.neuro.2014.03.004] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 03/11/2014] [Accepted: 03/11/2014] [Indexed: 12/16/2022]
Abstract
Emerging evidences underline the ability of several environmental contaminants to induce an inflammatory response within the central nervous system, named neuroinflammation. This can occur as a consequence of a direct action of the neurotoxicant to the CNS and/or as a response secondary to the activation of the peripheral inflammatory response. In both cases, neuroinflammation is driven by the release of several soluble factors among which pro-inflammatory cytokines. IL-1β and TNF-α have been extensively studied for their effects within the CNS and emerged for their role in the modulation of the neuronal response, which allow the immune response to integrate with specific neuronal functions, as neurotransmission and synaptic plasticity. In particular, it has been evidenced a potential detrimental link between these cytokines and the glutamatergic system that seems to be part of increased brain excitability and excitotoxicity occurring in different pathological conditions. Aim of this mini-review will be to present experimental evidence on the way IL-1β and TNF-α impact neurons, focusing on the glutamatergic signalling, to provide a perspective on novel pathways possibly involved in environmental contaminants neurotoxicity.
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Affiliation(s)
- Barbara Viviani
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy.
| | - Mariaserena Boraso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Natalia Marchetti
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Marina Marinovich
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
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128
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Tobinick E. Perispinal etanercept: a new therapeutic paradigm in neurology. Expert Rev Neurother 2014; 10:985-1002. [DOI: 10.1586/ern.10.52] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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129
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Ji RR, Berta T, Nedergaard M. Glia and pain: is chronic pain a gliopathy? Pain 2013; 154 Suppl 1:S10-S28. [PMID: 23792284 PMCID: PMC3858488 DOI: 10.1016/j.pain.2013.06.022] [Citation(s) in RCA: 815] [Impact Index Per Article: 74.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 05/23/2013] [Accepted: 06/12/2013] [Indexed: 12/22/2022]
Abstract
Activation of glial cells and neuro-glial interactions are emerging as key mechanisms underlying chronic pain. Accumulating evidence has implicated 3 types of glial cells in the development and maintenance of chronic pain: microglia and astrocytes of the central nervous system (CNS), and satellite glial cells of the dorsal root and trigeminal ganglia. Painful syndromes are associated with different glial activation states: (1) glial reaction (ie, upregulation of glial markers such as IBA1 and glial fibrillary acidic protein (GFAP) and/or morphological changes, including hypertrophy, proliferation, and modifications of glial networks); (2) phosphorylation of mitogen-activated protein kinase signaling pathways; (3) upregulation of adenosine triphosphate and chemokine receptors and hemichannels and downregulation of glutamate transporters; and (4) synthesis and release of glial mediators (eg, cytokines, chemokines, growth factors, and proteases) to the extracellular space. Although widely detected in chronic pain resulting from nerve trauma, inflammation, cancer, and chemotherapy in rodents, and more recently, human immunodeficiency virus-associated neuropathy in human beings, glial reaction (activation state 1) is not thought to mediate pain sensitivity directly. Instead, activation states 2 to 4 have been demonstrated to enhance pain sensitivity via a number of synergistic neuro-glial interactions. Glial mediators have been shown to powerfully modulate excitatory and inhibitory synaptic transmission at presynaptic, postsynaptic, and extrasynaptic sites. Glial activation also occurs in acute pain conditions, and acute opioid treatment activates peripheral glia to mask opioid analgesia. Thus, chronic pain could be a result of "gliopathy," that is, dysregulation of glial functions in the central and peripheral nervous system. In this review, we provide an update on recent advances and discuss remaining questions.
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Affiliation(s)
- Ru-Rong Ji
- Department of Anesthesiology and Neurobiology, Duke University Medical Center, Durham, NC, USA
| | - Temugin Berta
- Department of Anesthesiology and Neurobiology, Duke University Medical Center, Durham, NC, USA
| | - Maiken Nedergaard
- Division of Glial Disease and Therapeutics, Center for Translational Neuromedicine, University of Rochester, Rochester, NY, USA
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130
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Xu D, Miller SD, Koh S. Immune mechanisms in epileptogenesis. Front Cell Neurosci 2013; 7:195. [PMID: 24265605 PMCID: PMC3821015 DOI: 10.3389/fncel.2013.00195] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 10/08/2013] [Indexed: 01/03/2023] Open
Abstract
Epilepsy is a chronic brain disorder that affects 1% of the human population worldwide. Immune responses are implicated in seizure induction and the development of epilepsy. Pre-clinical and clinical evidence have accumulated to suggest a positive feedback cycle between brain inflammation and epileptogenesis. Prolonged or recurrent seizures and brain injuries lead to upregulation of proinflammatory cytokines and activated immune responses to further increase seizure susceptibility, promote neuronal excitability, and induce blood-brain barrier breakdown. This review focuses on the potential role of innate and adaptive immune responses in the pathogenesis of epilepsy. Both human studies and animal models that help delineate the contributions of brain inflammation in epileptogenesis will be discussed. We highlight the critical role of brain-resident immune mediators and emphasize the contribution of brain-infiltrating peripheral leukocytes. Additionally, we propose possible immune mechanisms that underlie epileptogenesis. Several proinflammatory pathways are discussed, including the interleukin-1 receptor/toll-like receptor signaling cascade, the pathways activated by damage-associated molecular patterns, and the cyclooxygenase-2/prostaglandin pathway. Finally, development of better therapies that target the key constituents and processes identified in these mechanisms are considered, for instance, engineering antagonizing agents that effectively block these pathways in an antigen-specific manner.
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Affiliation(s)
- Dan Xu
- Department of Microbiology-Immunology and Interdepartmental Immunobiology, Feinberg School of Medicine, Northwestern UniversityChicago IL, USA
- Department of Pediatrics, Division of Neurobiology, Children’s Research Center, Lurie Children’s Hospital of ChicagoChicago IL, USA
| | - Stephen D. Miller
- Department of Microbiology-Immunology and Interdepartmental Immunobiology, Feinberg School of Medicine, Northwestern UniversityChicago IL, USA
| | - Sookyong Koh
- Department of Pediatrics, Division of Neurobiology, Children’s Research Center, Lurie Children’s Hospital of ChicagoChicago IL, USA
- Department of Pediatrics, Feinberg School of Medicine, Northwestern UniversityChicago IL, USA
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131
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Differential control of thrombospondin over synaptic glycine and AMPA receptors in spinal cord neurons. J Neurosci 2013; 33:11432-9. [PMID: 23843515 DOI: 10.1523/jneurosci.5247-12.2013] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Thrombospondin-1 (TSP-1) is a large extracellular matrix protein secreted by astrocytes during development and inflammation. In the developing CNS, TSP-1 is involved in neuronal migration and adhesion, neurite outgrowth, and synaptogenesis. We investigated the effects of TSP-1 on neurons with mature synapses using immunocytochemistry, single-particle tracking, surface biotinylation, and calcium imaging. We show that in cultured rat spinal cord neurons TSP-1 decreased neuronal excitability by reducing the accumulation of excitatory AMPA receptors (AMPARs) and increasing that of inhibitory glycine receptors (GlyRs) in synapses. The effects of TSP-1 on GlyRs were dependent on the activation of excitatory receptors. These changes were abolished by blocking β1-integrins and mimicked by blocking β3-integrins. In the presence of TSP-1, AMPARs were less stabilized at synapses, increasing their lateral diffusion and endocytosis. Interestingly, TSP-1 counteracted the increased neuronal excitability and neuronal death induced by TNFα. These results suggest a role of TSP-1 in controlling the balance between excitation and inhibition which could help the recovery of normal synaptic activity after injury responses.
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132
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Poon VY, Choi S, Park M. Growth factors in synaptic function. Front Synaptic Neurosci 2013; 5:6. [PMID: 24065916 PMCID: PMC3776238 DOI: 10.3389/fnsyn.2013.00006] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 08/29/2013] [Indexed: 12/15/2022] Open
Abstract
Synapses are increasingly recognized as key structures that malfunction in disorders like schizophrenia, mental retardation, and neurodegenerative diseases. The importance and complexity of the synapse has fuelled research into the molecular mechanisms underlying synaptogenesis, synaptic transmission, and plasticity. In this regard, neurotrophic factors such as netrin, Wnt, transforming growth factor-β (TGF-β), tumor necrosis factor-α (TNF-α), and others have gained prominence for their ability to regulate synaptic function. Several of these factors were first implicated in neuroprotection, neuronal growth, and axon guidance. However, their roles in synaptic development and function have become increasingly clear, and the downstream signaling pathways employed by these factors have begun to be elucidated. In this review, we will address the role of these factors and their downstream effectors in synaptic function in vivo and in cultured neurons.
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Affiliation(s)
- Vivian Y Poon
- Neuroscience and Behavioral Disorders Program, Duke-NUS Graduate Medical School Singapore, Singapore
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133
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Reactive oxygen species contribute to neuropathic pain and locomotor dysfunction via activation of CamKII in remote segments following spinal cord contusion injury in rats. Pain 2013; 154:1699-1708. [DOI: 10.1016/j.pain.2013.05.018] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 05/06/2013] [Accepted: 05/09/2013] [Indexed: 01/09/2023]
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134
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Broytman O, Baertsch NA, Baker-Herman TL. Spinal TNF is necessary for inactivity-induced phrenic motor facilitation. J Physiol 2013; 591:5585-98. [PMID: 23878370 DOI: 10.1113/jphysiol.2013.256644] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A prolonged reduction in central neural respiratory activity elicits a form of plasticity known as inactivity-induced phrenic motor facilitation (iPMF), a 'rebound' increase in phrenic burst amplitude apparent once respiratory neural activity is restored. iPMF requires atypical protein kinase C (aPKC) activity within spinal segments containing the phrenic motor nucleus to stabilize an early transient increase in phrenic burst amplitude and to form long-lasting iPMF following reduced respiratory neural activity. Upstream signal(s) leading to spinal aPKC activation are unknown. We tested the hypothesis that spinal tumour necrosis factor-α (TNFα) is necessary for iPMF via an aPKC-dependent mechanism. Anaesthetized, ventilated rats were exposed to a 30 min neural apnoea; upon resumption of respiratory neural activity, a prolonged increase in phrenic burst amplitude (42 ± 9% baseline; P < 0.05) was apparent, indicating long-lasting iPMF. Pretreatment with recombinant human soluble TNF receptor 1 (sTNFR1) in the intrathecal space at the level of the phrenic motor nucleus prior to neural apnoea blocked long-lasting iPMF (2 ± 8% baseline; P > 0.05). Intrathecal TNFα without neural apnoea was sufficient to elicit long-lasting phrenic motor facilitation (pMF; 62 ± 7% baseline; P < 0.05). Similar to iPMF, TNFα-induced pMF required spinal aPKC activity, as intrathecal delivery of a ζ-pseudosubstrate inhibitory peptide (PKCζ-PS) 35 min following intrathecal TNFα arrested TNFα-induced pMF (28 ± 8% baseline; P < 0.05). These data demonstrate that: (1) spinal TNFα is necessary for iPMF; and (2) spinal TNFα is sufficient to elicit pMF via a similar aPKC-dependent mechanism. These data are consistent with the hypothesis that reduced respiratory neural activity elicits iPMF via a TNFα-dependent increase in spinal aPKC activity.
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Affiliation(s)
- Oleg Broytman
- T. Baker-Herman: Department of Comparative Biosciences, University of Wisconsin, 2015 Linden Drive, Madison, WI, USA.
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135
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Kopach O, Viatchenko-Karpinski V, Atianjoh FE, Belan P, Tao YX, Voitenko N. PKCα is required for inflammation-induced trafficking of extrasynaptic AMPA receptors in tonically firing lamina II dorsal horn neurons during the maintenance of persistent inflammatory pain. THE JOURNAL OF PAIN 2013; 14:182-92. [PMID: 23374940 DOI: 10.1016/j.jpain.2012.10.015] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 08/29/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
Abstract
UNLABELLED Persistent inflammation promotes internalization of synaptic GluR2-containing, Ca(2+)-impermeable AMPA receptors (AMPARs) and insertion of GluR1-containing, Ca(2+)-permeable AMPARs at extrasynaptic sites in dorsal horn neurons. Previously we have shown that internalization of synaptic GluR2-containing AMPARs requires activation of spinal cord protein kinase C alpha (PKCα), but molecular mechanisms that underlie altered trafficking of extrasynaptic AMPARs are unclear. Here, using antisense (AS) oligodeoxynucleotides (ODN) that specifically knock down PKCα, we found that a decrease in dorsal horn PKCα expression prevents complete Freund's adjuvant (CFA)-induced increase in functional expression of extrasynaptic Ca(2+)-permeable AMPARs in substantia gelatinosa (SG) neurons of the rat spinal cord. Augmented AMPA-induced currents and associated [Ca(2+)](i) transients were abolished, and the current rectification 1 day post-CFA was reversed. These changes were observed specifically in SG neurons characterized by intrinsic tonic firing properties, but not in those that exhibited strong adaptation. Finally, dorsal horn PKCα knockdown produced an antinociceptive effect on CFA-induced thermal and mechanical hypersensitivity during the maintenance period of inflammatory pain, indicating a role for PKCα in persistent inflammatory pain maintenance. Our results indicate that inflammation-induced trafficking of extrasynaptic Ca(2+)-permeable AMPARs in tonically firing SG neurons depends on PKCα, and that this PKCα-dependent trafficking may contribute to persistent inflammatory pain maintenance. PERSPECTIVE This study shows that PKCα knockdown blocks inflammation-induced upregulation of extrasynaptic Ca(2+)-permeable AMPARs in dorsal horn neurons and produces an antinociceptive effect during the maintenance period of inflammatory pain. These findings have potential implications for use of PKCα gene-silencing therapy to prevent and/or treat persistent inflammatory pain.
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Affiliation(s)
- Olga Kopach
- State Key Laboratory of Molecular and Cellular Biology, Bogomoletz Institute of Physiology, Kiev, Ukraine
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136
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Strey KA, Baertsch NA, Baker-Herman TL. Inactivity-induced respiratory plasticity: protecting the drive to breathe in disorders that reduce respiratory neural activity. Respir Physiol Neurobiol 2013; 189:384-94. [PMID: 23816599 DOI: 10.1016/j.resp.2013.06.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 06/04/2013] [Accepted: 06/24/2013] [Indexed: 12/25/2022]
Abstract
Multiple forms of plasticity are activated following reduced respiratory neural activity. For example, in ventilated rats, a central neural apnea elicits a rebound increase in phrenic and hypoglossal burst amplitude upon resumption of respiratory neural activity, forms of plasticity called inactivity-induced phrenic and hypoglossal motor facilitation (iPMF and iHMF), respectively. Here, we provide a conceptual framework for plasticity following reduced respiratory neural activity to guide future investigations. We review mechanisms giving rise to iPMF and iHMF, present new data suggesting that inactivity-induced plasticity is observed in inspiratory intercostals (iIMF) and point out gaps in our knowledge. We then survey conditions relevant to human health characterized by reduced respiratory neural activity and discuss evidence that inactivity-induced plasticity is elicited during these conditions. Understanding the physiological impact and circumstances in which inactivity-induced respiratory plasticity is elicited may yield novel insights into the treatment of disorders characterized by reductions in respiratory neural activity.
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Affiliation(s)
- K A Strey
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706, USA.
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137
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Pribiag H, Stellwagen D. Neuroimmune regulation of homeostatic synaptic plasticity. Neuropharmacology 2013; 78:13-22. [PMID: 23774138 DOI: 10.1016/j.neuropharm.2013.06.008] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 05/28/2013] [Accepted: 06/02/2013] [Indexed: 01/08/2023]
Abstract
Homeostatic synaptic plasticity refers to a set of negative-feedback mechanisms that are used by neurons to maintain activity within a functional range. While it is becoming increasingly clear that homeostatic regulation of synapse function is a key principle in the nervous system, the molecular details of this regulation are only beginning to be uncovered. Recent evidence implicates molecules classically associated with the peripheral immune system in the modulation of homeostatic synaptic plasticity. In particular, the pro-inflammatory cytokine TNFα, class I major histocompatibility complex, and neuronal pentraxin 2 are essential in the regulation of the compensatory synaptic response that occurs in response to prolonged neuronal inactivity. This review will present and discuss current evidence implicating neuroimmune molecules in the homeostatic regulation of synapse function. This article is part of the Special Issue entitled 'Homeostatic Synaptic Plasticity'.
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Affiliation(s)
- Horia Pribiag
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Center, Montreal General Hospital, L7-132, 1650 Cedar Av, Montreal, QC H3G 1A4, Canada
| | - David Stellwagen
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Center, Montreal General Hospital, L7-132, 1650 Cedar Av, Montreal, QC H3G 1A4, Canada.
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138
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Dong Y, Gu Y, Huan Y, Wang Y, Liu Y, Liu M, Ding F, Gu X, Wang Y. HMGB1 protein does not mediate the inflammatory response in spontaneous spinal cord regeneration: a hint for CNS regeneration. J Biol Chem 2013; 288:18204-18. [PMID: 23649623 DOI: 10.1074/jbc.m113.463810] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Uncontrolled, excessive inflammation contributes to the secondary tissue damage of traumatic spinal cord, and HMGB1 is highlighted for initiation of a vicious self-propagating inflammatory circle by release from necrotic cells or immune cells. Several regenerative-competent vertebrates have evolved to circumvent the second damages during the spontaneous spinal cord regeneration with an unknown HMGB1 regulatory mechanism. By genomic surveys, we have revealed that two paralogs of HMGB1 are broadly retained from fish in the phylogeny. However, their spatial-temporal expression and effects, as shown in lowest amniote gecko, were tightly controlled in order that limited inflammation was produced in spontaneous regeneration. Two paralogs from gecko HMGB1 (gHMGB1) yielded distinct injury and infectious responses, with gHMGB1b significantly up-regulated in the injured cord. The intracellular gHMGB1b induced less release of inflammatory cytokines than gHMGB1a in macrophages, and the effects could be shifted by exchanging one amino acid in the inflammatory domain. Both intracellular proteins were able to mediate neuronal programmed apoptosis, which has been indicated to produce negligible inflammatory responses. In vivo studies demonstrated that the extracellular proteins could not trigger a cascade of the inflammatory cytokines in the injured spinal cord. Signal transduction analysis found that gHMGB1 proteins could not bind with cell surface receptors TLR2 and TLR4 to activate inflammatory signaling pathway. However, they were able to interact with the receptor for advanced glycation end products to potentiate oligodendrocyte migration by activation of both NFκB and Rac1/Cdc42 signaling. Our results reveal that HMGB1 does not mediate the inflammatory response in spontaneous spinal cord regeneration, but it promotes CNS regeneration.
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Affiliation(s)
- Yingying Dong
- Key Laboratory of Neuroregeneration, Nantong University, Nantong 226007, China
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139
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Kopach O, Voitenko N. Extrasynaptic AMPA receptors in the dorsal horn: Evidence and functional significance. Brain Res Bull 2013. [DOI: 10.1016/j.brainresbull.2012.11.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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140
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Ferguson AR, Irvine KA, Gensel JC, Nielson JL, Lin A, Ly J, Segal MR, Ratan RR, Bresnahan JC, Beattie MS. Derivation of multivariate syndromic outcome metrics for consistent testing across multiple models of cervical spinal cord injury in rats. PLoS One 2013; 8:e59712. [PMID: 23544088 PMCID: PMC3609747 DOI: 10.1371/journal.pone.0059712] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Accepted: 02/17/2013] [Indexed: 12/13/2022] Open
Abstract
Spinal cord injury (SCI) and other neurological disorders involve complex biological and functional changes. Well-characterized preclinical models provide a powerful tool for understanding mechanisms of disease; however managing information produced by experimental models represents a significant challenge for translating findings across research projects and presents a substantial hurdle for translation of novel therapies to humans. In the present work we demonstrate a novel ‘syndromic’ information-processing approach for capitalizing on heterogeneous data from diverse preclinical models of SCI to discover translational outcomes for therapeutic testing. We first built a large, detailed repository of preclinical outcome data from 10 years of basic research on cervical SCI in rats, and then applied multivariate pattern detection techniques to extract features that are conserved across different injury models. We then applied this translational knowledge to derive a data-driven multivariate metric that provides a common ‘ruler’ for comparisons of outcomes across different types of injury (NYU/MASCIS weight drop injuries, Infinite Horizons (IH) injuries, and hemisection injuries). The findings revealed that each individual endpoint provides a different view of the SCI syndrome, and that considering any single outcome measure in isolation provides a misleading, incomplete view of the SCI syndrome. This limitation was overcome by taking a novel multivariate integrative approach for leveraging complex data from preclinical models of neurological disease to identify therapies that target multiple outcomes. We suggest that applying this syndromic approach provides a roadmap for translating therapies for SCI and other complex neurological diseases.
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Affiliation(s)
- Adam R. Ferguson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (ARF); (MSB)
| | - Karen-Amanda Irvine
- Department of Comparative Medicine, Stanford University, Palo Alto, California, United States of America
| | - John C. Gensel
- Department of Physiology, Spinal Cord and Brain Injury Research Center (SCoBIRC), University of Kentucky, Lexington, Kentucky, United States of America
| | - Jessica L. Nielson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Amity Lin
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Johnathan Ly
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Mark R. Segal
- Center for Bioinformatics and Molecular Biostatistics, Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, California, United States of America
| | - Rajiv R. Ratan
- Burke-Cornell Medical Research Institute, Department of Neurology and Neuroscience, Weill Medical College of Cornell University, White Plains, New York, United States of America
| | - Jacqueline C. Bresnahan
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
| | - Michael S. Beattie
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (ARF); (MSB)
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141
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Blaylock RL. Immunoexcitatory mechanisms in glioma proliferation, invasion and occasional metastasis. Surg Neurol Int 2013; 4:15. [PMID: 23493580 PMCID: PMC3589840 DOI: 10.4103/2152-7806.106577] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 07/12/2012] [Indexed: 02/07/2023] Open
Abstract
There is increasing evidence of an interaction between inflammatory cytokines and glutamate receptors among a number of neurological diseases including traumatic brain injuries, neurodegenerative diseases and central nervous system (CNS) infections. A number of recent studies have now suggested a strong relation between inflammatory mechanisms and excitatory cascades and these may play a role in glioma invasiveness and proliferation. Chronic inflammation appears to be a major initiating mechanism in most human cancers, involving cell-signaling pathways, which are responsible for cell cycling, cancer cell migration, invasion, tumor aggressiveness, and angiogenesis. It is less well appreciated that glutamate receptors also play a significant role in both proliferation and especially glioma invasion. There is some evidence that sustained elevations in glutamate may play a role in initiating certain cancers and new studies demonstrate an interaction between inflammation and glutamate receptors that may enhance tumor invasion and metastasis by affecting a number of cell-signaling mechanisms. These mechanisms are discussed in this paper as well as novel treatment options for reducing immune-glutamate promotion of cancer growth and invasion.
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Affiliation(s)
- Russell L Blaylock
- Theoretical Neurosciences LLC, Visiting Professor of Biology, Department of Biology, Belhaven University, Jackson, MS 39157, USA
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142
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David BT, Ratnayake A, Amarante MA, Reddy NP, Dong W, Sampath S, Heary RF, Elkabes S. A toll-like receptor 9 antagonist reduces pain hypersensitivity and the inflammatory response in spinal cord injury. Neurobiol Dis 2013; 54:194-205. [PMID: 23313320 DOI: 10.1016/j.nbd.2012.12.012] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 11/11/2012] [Accepted: 12/28/2012] [Indexed: 12/20/2022] Open
Abstract
Toll-like receptors (TLRs) are mediators of the innate immune response to exogenous pathogens. They have also been implicated in sterile inflammation associated with systemic injury and non-infectious diseases via binding of endogenous ligands, possibly released by damaged cells. Emerging evidence indicates that some TLRs play a role in nervous system injury and especially in injury-elicited pain and sterile inflammation. However, no information is available about the contribution of TLR9, a member of the TLR family, to traumatic spinal cord injury (SCI). Moreover, the therapeutic potential of TLR9 ligands in the functional outcomes of SCI, including pain, has not been explored. We report, for the first time, that the intrathecal administration of a TLR9 antagonist, cytidine-phosphate-guanosine oligodeoxynucleotide 2088 (CpG ODN 2088), to mice sustaining a severe contusion SCI, diminishes injury-induced heat hypersensitivity. Investigations on the potential mechanisms underlying the reduction in pain sensitivity indicated an attenuation of the inflammatory reaction manifested by a decrease in the number of CD11b-, CD45- and CD3-immunoreactive cells and a reduction in tumor necrosis factor-α (TNF-α) expression at the epicenter. Conversely, intrathecal delivery of a TLR9 agonist, CpG ODN 1826, increased inflammatory cell numbers and TNF-α expression in the epicenter. The CpG ODN 2088 treatment did not appear to induce systemic adverse effects as shown by spleen histology and serum cytokine levels. We propose that CpG ODN 2088 dampens injury-induced heat hypersensitivity by suppressing the inflammatory response and TNF-α expression. This investigation defines a previously unreported therapeutic role for CpG ODN 2088 in SCI-induced pain.
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Affiliation(s)
- Brian T David
- Department of Neurological Surgery, New Jersey Medical School, Newark, NJ 07103, USA
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143
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De Pittà M, Volman V, Berry H, Parpura V, Volterra A, Ben-Jacob E. Computational quest for understanding the role of astrocyte signaling in synaptic transmission and plasticity. Front Comput Neurosci 2012; 6:98. [PMID: 23267326 PMCID: PMC3528083 DOI: 10.3389/fncom.2012.00098] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 12/06/2012] [Indexed: 01/08/2023] Open
Abstract
The complexity of the signaling network that underlies astrocyte-synapse interactions may seem discouraging when tackled from a theoretical perspective. Computational modeling is challenged by the fact that many details remain hitherto unknown and conventional approaches to describe synaptic function are unsuitable to explain experimental observations when astrocytic signaling is taken into account. Supported by experimental evidence is the possibility that astrocytes perform genuine information processing by means of their calcium signaling and are players in the physiological setting of the basal tone of synaptic transmission. Here we consider the plausibility of this scenario from a theoretical perspective, focusing on the modulation of synaptic release probability by the astrocyte and its implications on synaptic plasticity. The analysis of the signaling pathways underlying such modulation refines our notion of tripartite synapse and has profound implications on our understanding of brain function.
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Affiliation(s)
- Maurizio De Pittà
- School of Physics and Astronomy, Tel Aviv University Ramat Aviv, Israel
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144
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Ferguson AR, Huie JR, Crown ED, Baumbauer KM, Hook MA, Garraway SM, Lee KH, Hoy KC, Grau JW. Maladaptive spinal plasticity opposes spinal learning and recovery in spinal cord injury. Front Physiol 2012; 3:399. [PMID: 23087647 PMCID: PMC3468083 DOI: 10.3389/fphys.2012.00399] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/20/2012] [Indexed: 01/23/2023] Open
Abstract
Synaptic plasticity within the spinal cord has great potential to facilitate recovery of function after spinal cord injury (SCI). Spinal plasticity can be induced in an activity-dependent manner even without input from the brain after complete SCI. A mechanistic basis for these effects is provided by research demonstrating that spinal synapses have many of the same plasticity mechanisms that are known to underlie learning and memory in the brain. In addition, the lumbar spinal cord can sustain several forms of learning and memory, including limb-position training. However, not all spinal plasticity promotes recovery of function. Central sensitization of nociceptive (pain) pathways in the spinal cord may emerge in response to various noxious inputs, demonstrating that plasticity within the spinal cord may contribute to maladaptive pain states. In this review we discuss interactions between adaptive and maladaptive forms of activity-dependent plasticity in the spinal cord below the level of SCI. The literature demonstrates that activity-dependent plasticity within the spinal cord must be carefully tuned to promote adaptive spinal training. Prior work from our group has shown that stimulation that is delivered in a limb position-dependent manner or on a fixed interval can induce adaptive plasticity that promotes future spinal cord learning and reduces nociceptive hyper-reactivity. On the other hand, stimulation that is delivered in an unsynchronized fashion, such as randomized electrical stimulation or peripheral skin injuries, can generate maladaptive spinal plasticity that undermines future spinal cord learning, reduces recovery of locomotor function, and promotes nociceptive hyper-reactivity after SCI. We review these basic phenomena, how these findings relate to the broader spinal plasticity literature, discuss the cellular and molecular mechanisms, and finally discuss implications of these and other findings for improved rehabilitative therapies after SCI.
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Affiliation(s)
- Adam R Ferguson
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California San Francisco San Francisco, CA, USA
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145
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Ferguson AR, Huie JR, Crown ED, Grau JW. Central nociceptive sensitization vs. spinal cord training: opposing forms of plasticity that dictate function after complete spinal cord injury. Front Physiol 2012; 3:396. [PMID: 23060820 PMCID: PMC3463829 DOI: 10.3389/fphys.2012.00396] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 09/15/2012] [Indexed: 11/13/2022] Open
Abstract
The spinal cord demonstrates several forms of plasticity that resemble brain-dependent learning and memory. Among the most studied form of spinal plasticity is spinal memory for noxious (nociceptive) stimulation. Numerous papers have described central pain as a spinally-stored memory that enhances future responses to cutaneous stimulation. This phenomenon, known as central sensitization, has broad relevance to a range of pathological conditions. Work from the spinal cord injury (SCI) field indicates that the lumbar spinal cord demonstrates several other forms of plasticity, including formal learning and memory. After complete thoracic SCI, the lumbar spinal cord can be trained by delivering stimulation to the hindleg when the leg is extended. In the presence of this response-contingent stimulation the spinal cord rapidly learns to hold the leg in a flexed position, a centrally mediated effect that meets the formal criteria for instrumental (response-outcome) learning. Instrumental flexion training produces a central change in spinal plasticity that enables future spinal learning on both the ipsilateral and contralateral leg. However, if stimulation is given in a response-independent manner, the spinal cord develops central maladaptive plasticity that undermines future spinal learning on both legs. The present paper tests for interactions between spinal cord training and central nociceptive sensitization after complete spinal cord transection. We found that spinal training alters future central sensitization by intradermal formalin (24 h post-training). Conversely intradermal formalin impaired future spinal learning (24 h post-injection). Because formalin-induced central sensitization has been shown to involve NMDA receptor activation, we tested whether pre-treatment with NMDA would also affect spinal learning in manner similar to formalin. We found intrathecal NMDA impaired learning in a dose-dependent fashion, and that this effect endures for at least 24 h. These data provide strong evidence for an opposing relationship between nociceptive plasticity and use-dependent learning in the spinal cord. The present work has clinical implications given recent findings that adaptive spinal training improves recovery in humans with SCI. Nociception below the SCI may undermine this rehabilitation potential.
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Affiliation(s)
- Adam R Ferguson
- Department of Neurological Surgery, Brain and Spinal Injury Center, University of California San Francisco San Francisco, CA, USA
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146
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Santello M, Volterra A. TNFα in synaptic function: switching gears. Trends Neurosci 2012; 35:638-47. [DOI: 10.1016/j.tins.2012.06.001] [Citation(s) in RCA: 194] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Revised: 05/18/2012] [Accepted: 06/04/2012] [Indexed: 01/17/2023]
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147
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Yin HZ, Hsu CI, Yu S, Rao SD, Sorkin LS, Weiss JH. TNF-α triggers rapid membrane insertion of Ca(2+) permeable AMPA receptors into adult motor neurons and enhances their susceptibility to slow excitotoxic injury. Exp Neurol 2012; 238:93-102. [PMID: 22921461 DOI: 10.1016/j.expneurol.2012.08.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 07/25/2012] [Accepted: 08/03/2012] [Indexed: 01/03/2023]
Abstract
Excitotoxicity (caused by over-activation of glutamate receptors) and inflammation both contribute to motor neuron (MN) damage in amyotrophic lateral sclerosis (ALS) and other diseases of the spinal cord. Microglial and astrocytic activation in these conditions results in release of inflammatory mediators, including the cytokine, tumor necrosis factor-alpha (TNF-α). TNF-α has complex effects on neurons, one of which is to trigger rapid membrane insertion of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) type glutamate receptors, and in some cases, specific insertion of GluA2 lacking, Ca(2+) permeable AMPA receptors (Ca-perm AMPAr). In the present study, we use a histochemical stain based upon kainate stimulated uptake of cobalt ions ("Co(2+) labeling") to provide the first direct demonstration of the presence of substantial numbers of Ca-perm AMPAr in ventral horn MNs of adult rats under basal conditions. We further find that TNF-α exposure causes a rapid increase in the numbers of these receptors, via a phosphatidylinositol 3 kinase (PI3K) and protein kinase A (PKA) dependent mechanism. Finally, to assess the relevance of TNF-α to slow excitotoxic MN injury, we made use of organotypic spinal cord slice cultures. Co(2+) labeling revealed that MNs in these cultures possess Ca-perm AMPAr. Addition of either a low level of TNF-α, or of the glutamate uptake blocker, trans-pyrrolidine-2,4-dicarboxylic acid (PDC) to the cultures for 48 h resulted in little MN injury. However, when combined, TNF-α+PDC caused considerable MN degeneration, which was blocked by the AMPA/kainate receptor blocker, 2,3-Dihydroxy-6-nitro-7-sulfamoylbenzo (F) quinoxaline (NBQX), or the Ca-perm AMPAr selective blocker, 1-naphthyl acetylspermine (NASPM). Thus, these data support the idea that prolonged TNF-α elevation, as may be induced by glial activation, acts in part by increasing the numbers of Ca-perm AMPAr on MNs to enhance injurious excitotoxic effects of deficient astrocytic glutamate transport.
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Affiliation(s)
- Hong Z Yin
- Department of Neurology, University of California, Irvine, CA 92697‐4292, USA
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148
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Kanno H, Ozawa H, Sekiguchi A, Yamaya S, Tateda S, Yahata K, Itoi E. The role of mTOR signaling pathway in spinal cord injury. Cell Cycle 2012; 11:3175-9. [PMID: 22895182 DOI: 10.4161/cc.21262] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) signaling pathway plays an important role in multiple cellular functions, such as cell metabolism, proliferation and survival. Many previous studies have shown that mTOR regulates both neuroprotective and neuroregenerative functions in trauma and various diseases in the central nervous system (CNS). Recently, we reported that inhibition of mTOR using rapamycin reduces neural tissue damage and locomotor impairment after spinal cord injury (SCI) in mice. Our results demonstrated that the administration of rapamycin at four hours after injury significantly increases the activity of autophagy and reduces neuronal loss and cell death in the injured spinal cord. Furthermore, rapamycin-treated mice show significantly better locomotor function in the hindlimbs following SCI than vehicle-treated mice. These findings indicate that the inhibition of mTOR signaling using rapamycin during the acute phase of SCI produces neuroprotective effects and reduces secondary damage at lesion sites. However, the role of mTOR signaling in injured spinal cords has not yet been fully elucidated. Various functions are regulated by mTOR signaling in the CNS, and multiple pathophysiological processes occur following SCI. Here, we discuss several unresolved issues and review the evidence from related articles regarding the role and mechanisms of the mTOR signaling pathway in neuroprotection and neuroregeneration after SCI.
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Affiliation(s)
- Haruo Kanno
- Department of Orthopaedic Surgery, Tohoku University School of Medicine, Sendai, Japan.
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149
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Huie JR, Baumbauer KM, Lee KH, Bresnahan JC, Beattie MS, Ferguson AR, Grau JW. Glial tumor necrosis factor alpha (TNFα) generates metaplastic inhibition of spinal learning. PLoS One 2012; 7:e39751. [PMID: 22745823 PMCID: PMC3379985 DOI: 10.1371/journal.pone.0039751] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 05/28/2012] [Indexed: 12/28/2022] Open
Abstract
Injury-induced overexpression of tumor necrosis factor alpha (TNFα) in the spinal cord can induce chronic neuroinflammation and excitotoxicity that ultimately undermines functional recovery. Here we investigate how TNFα might also act to upset spinal function by modulating spinal plasticity. Using a model of instrumental learning in the injured spinal cord, we have previously shown that peripheral intermittent stimulation can produce a plastic change in spinal plasticity (metaplasticity), resulting in the prolonged inhibition of spinal learning. We hypothesized that spinal metaplasticity may be mediated by TNFα. We found that intermittent stimulation increased protein levels in the spinal cord. Using intrathecal pharmacological manipulations, we showed TNFα to be both necessary and sufficient for the long-term inhibition of a spinal instrumental learning task. These effects were found to be dependent on glial production of TNFα and involved downstream alterations in calcium-permeable AMPA receptors. These findings suggest a crucial role for glial TNFα in undermining spinal learning, and demonstrate the therapeutic potential of inhibiting TNFα activity to rescue and restore adaptive spinal plasticity to the injured spinal cord. TNFα modulation represents a novel therapeutic target for improving rehabilitation after spinal cord injury.
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Affiliation(s)
- J. Russell Huie
- Department of Psychology, Texas A&M University, College Station, Texas, United States of America
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail: (JRH); (ARF)
| | - Kyle M. Baumbauer
- Department of Psychology, Texas A&M University, College Station, Texas, United States of America
| | - Kuan H. Lee
- Department of Psychology, Texas A&M University, College Station, Texas, United States of America
| | - Jacqueline C. Bresnahan
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States of America
| | - Michael S. Beattie
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States of America
| | - Adam R. Ferguson
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail: (JRH); (ARF)
| | - James W. Grau
- Department of Psychology, Texas A&M University, College Station, Texas, United States of America
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150
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Chen S, Yao L, Cunningham TJ. Secreted phospholipase A2 involvement in neurodegeneration: differential testing of prosurvival and anti-inflammatory effects of enzyme inhibition. PLoS One 2012; 7:e39257. [PMID: 22720084 PMCID: PMC3376100 DOI: 10.1371/journal.pone.0039257] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2012] [Accepted: 05/22/2012] [Indexed: 11/20/2022] Open
Abstract
There is increased interest in the contribution of secreted phospholipase A2 (sPLA2) enzymes to neurodegenerative diseases. Systemic treatment with the nonapeptide CHEC-9, a broad spectrum uncompetitive inhibitor of sPLA2, has been shown previously to inhibit neuron death and aspects of the inflammatory response in several models of neurodegeneration. A persistent question in studies of sPLA2 inhibitors, as for several other anti-inflammatory and neuroprotective compounds, is whether the cell protection is direct or due to slowing of the toxic aspects of the inflammatory response. To further explore this issue, we developed assays using SY5Y (neuronal cells) and HL-60 (monocytes) cell lines and examined the effects of sPLA2 inhibition on these homogeneous cell types in vitro. We found that the peptide inhibited sPLA2 enzyme activity in both SY5Y and HL-60 cultures. This inhibition provided direct protection to SY5Y neuronal cells and their processes in response to several forms of stress including exposure to conditioned medium from HL-60 cells. In cultures of HL-60 cells, sPLA2 inhibition had no effect on survival of the cells but attenuated their differentiation into macrophages, with regard to process development, phagocytic ability, and the expression of differentiation marker CD36, as well as the secretion of proinflammatory cytokines TNF-α and IL-6. These results suggest that sPLA2 enzyme activity organizes a cascade of changes comprising both cell degeneration and inflammation, processes that could theoretically operate independently during neurodegenerative conditions. The effectiveness of sPLA2 inhibitor CHEC-9 may be due to its ability to affect both processes in isolation. Testing potential anti-inflammatory/neuroprotective compounds with these human cell lines and their conditioned media may provide a useful screening tool prior to in vivo therapeutic applications.
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Affiliation(s)
- Shuyan Chen
- Department of Anatomy and Neurobiology, College of Medicine, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Lihua Yao
- Department of Anatomy and Neurobiology, College of Medicine, Drexel University, Philadelphia, Pennsylvania, United States of America
| | - Timothy J. Cunningham
- Department of Anatomy and Neurobiology, College of Medicine, Drexel University, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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