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Boakye PA, Rancic V, Whitlock KH, Simmons D, Longo FM, Ballanyi K, Smith PA. Receptor dependence of BDNF actions in superficial dorsal horn: relation to central sensitization and actions of macrophage colony stimulating factor 1. J Neurophysiol 2019; 121:2308-2322. [PMID: 30995156 DOI: 10.1152/jn.00839.2018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Peripheral nerve injury elicits an enduring increase in the excitability of the spinal dorsal horn. This change, which contributes to the development of neuropathic pain, is a consequence of release and prolonged exposure of dorsal horn neurons to various neurotrophins and cytokines. We have shown in rats that nerve injury increases excitatory synaptic drive to excitatory neurons but decreases drive to inhibitory neurons. Both effects, which contribute to an increase in dorsal horn excitability, appear to be mediated by microglia-derived BDNF. We have used multiphoton Ca2+ imaging and whole cell recording of spontaneous excitatory postsynaptic currents in defined-medium organotypic cultures of GAD67-GFP+ mice spinal cord to determine the receptor dependence of these opposing actions of BDNF. In mice, as in rats, BDNF enhances excitatory transmission onto excitatory neurons. This is mediated via presynaptic TrkB and p75 neurotrophin receptors and exclusively by postsynaptic TrkB. By contrast with findings from rats, in mice BDNF does not decrease excitation of inhibitory neurons. The cytokine macrophage colony-stimulating factor 1 (CSF-1) has also been implicated in the onset of neuropathic pain. Nerve injury provokes its de novo synthesis in primary afferents, its release in spinal cord, and activation of microglia. We now show that CSF-1 increases excitatory drive to excitatory neurons via a BDNF-dependent mechanism and decreases excitatory drive to inhibitory neurons via BDNF-independent processes. Our findings complete missing steps in the cascade of events whereby peripheral nerve injury instigates increased dorsal horn excitability in the context of central sensitization and the onset of neuropathic pain. NEW & NOTEWORTHY Nerve injury provokes synthesis of macrophage colony-stimulating factor 1 (CSF-1) in primary afferents and its release in the dorsal horn. We show that CSF-1 increases excitatory drive to excitatory dorsal horn neurons via BDNF activation of postsynaptic TrkB and presynaptic TrkB and p75 neurotrophin receptors. CSF-1 decreases excitatory drive to inhibitory neurons via a BDNF-independent processes. This completes missing steps in understanding how peripheral injury instigates central sensitization and the onset of neuropathic pain.
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Affiliation(s)
- Paul A Boakye
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada
| | - Vladimir Rancic
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada.,Department of Physiology, University of Alberta , Edmonton , Canada
| | - Kerri H Whitlock
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada
| | - Danielle Simmons
- Department of Neurology and Neurological Sciences, Stanford University , Stanford, California
| | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University , Stanford, California
| | - Klaus Ballanyi
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada.,Department of Physiology, University of Alberta , Edmonton , Canada
| | - Peter A Smith
- Neuroscience and Mental Health Institute, University of Alberta , Edmonton , Canada.,Department of Pharmacology, University of Alberta , Edmonton , Canada
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Meeker R, Williams K. Dynamic nature of the p75 neurotrophin receptor in response to injury and disease. J Neuroimmune Pharmacol 2014; 9:615-28. [PMID: 25239528 DOI: 10.1007/s11481-014-9566-9] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 09/03/2014] [Indexed: 12/23/2022]
Abstract
Neurotrophins and their respective tropomyosin related kinase (Trk) receptors (TrkA, TrkB, and TrkC) and the p75 neurotrophin receptor (p75(NTR)) play a fundamental role in the development and maintenance of the nervous system making them important targets for treatment of neurodegenerative diseases. Whereas Trk receptors are directly activated by specific neurotrophins, the p75(NTR) is a multifunctional receptor that exerts its effects via heterodimeric interactions with TrkA, TrkB, TrkC, sortilin or the Nogo receptor to regulate a wide array of cellular functions. By partnering with different receptors the p75(NTR) regulates binding of mature versus pro-neurotrophins and activation of different signaling pathways with outcomes ranging from growth and survival to cell death. While the developmental downregulation of the p75(NTR) has raised questions regarding its role in the mature nervous system, recent data have revealed widespread expression of low levels, a role in synaptic plasticity and adult neurogenesis and upregulation in response to injury or disease. Studies are needed to better understand these processes, particularly in the damaged nervous system, but will be complicated by expression of p75(NTR) on immune cells including macrophages and microglia that are intimately involved in disease and repair processes. Recent approaches that regulate p75(NTR) function with small non-peptide ligands have demonstrated potent neuroprotection in models of injury and neurodegenerative diseases that highlight the importance of the p75(NTR) as a therapeutic target. Future studies hold the promise of revealing a wealth of information on the multifaceted actions of the p75(NTR) that will inform the design of new neurotrophin-based therapies.
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Affiliation(s)
- Rick Meeker
- Department of Neurology, University of North Carolina, CB #7025 6109F Neuroscience Research Building, 115 Mason Farm Road, Chapel Hill, NC, 27599, USA,
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Niklison-Chirou MV, Steinert JR, Agostini M, Knight RA, Dinsdale D, Cattaneo A, Mak TW, Melino G. TAp73 knockout mice show morphological and functional nervous system defects associated with loss of p75 neurotrophin receptor. Proc Natl Acad Sci U S A 2013; 110:18952-7. [PMID: 24190996 PMCID: PMC3839698 DOI: 10.1073/pnas.1221172110] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Total and N-terminal isoform selective p73 knockout mice show a variety of central nervous system defects. Here we show that TAp73 is a transcriptional activator of p75 neurotrophin receptor (p75(NTR)) and that p75(NTR) mRNA and protein levels are strongly reduced in the central and peripheral nervous systems of p73 knockout mice. In parallel, primary cortical neurons from p73 knockout mice showed a reduction in neurite outgrowth and in nerve growth factor-mediated neuronal differentiation, together with reduced miniature excitatory postsynaptic current frequencies and behavioral defects. p73 null mice also have impairments in the peripheral nervous system with reduced thermal sensitivity, axon number, and myelin thickness. At least some of these morphological and functional impairments in p73 null cells can be rescued by p75(NTR) re-expression. Together, these data demonstrate that loss of p75(NTR) contributes to the neurological phenotype of p73 knockout mice.
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Affiliation(s)
| | - Joern R. Steinert
- Toxicology Unit, Medical Research Council, Leicester LE1 9HN, United Kingdom
| | | | - Richard A. Knight
- Toxicology Unit, Medical Research Council, Leicester LE1 9HN, United Kingdom
| | - David Dinsdale
- Toxicology Unit, Medical Research Council, Leicester LE1 9HN, United Kingdom
| | - Antonio Cattaneo
- European Brain Research Institute–Rita Levi-Montalcini, 64 Rome, Italy
| | - Tak W. Mak
- The Campbell Family Institute for Breast Cancer Research, Princess Margaret Hospital, Toronto, ON, Canada M5G 2C1; and
| | - Gerry Melino
- Toxicology Unit, Medical Research Council, Leicester LE1 9HN, United Kingdom
- Biochemistry Laboratory, Istituto Dermopatico dell’Immacolata–Istituto di Ricovero e Cura a Carattere Scientifico and University of Rome Tor Vergata, 00133 Rome, Italy
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Petrie CN, Smithson LJ, Crotty AM, Michalski B, Fahnestock M, Kawaja MD. Overexpression of nerve growth factor by murine smooth muscle cells: Role of the p75 neurotrophin receptor on sympathetic and sensory sprouting. J Comp Neurol 2013; 521:2621-43. [DOI: 10.1002/cne.23302] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Revised: 11/06/2012] [Accepted: 01/03/2013] [Indexed: 01/06/2023]
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5
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Pettigrew DB, Li YQ, Kuntz C, Crutcher KA. Global expression of NGF promotes sympathetic axonal growth in CNS white matter but does not alter its parallel orientation. Exp Neurol 2007; 203:95-109. [PMID: 16989811 PMCID: PMC2638215 DOI: 10.1016/j.expneurol.2006.07.026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 07/18/2006] [Accepted: 07/26/2006] [Indexed: 11/30/2022]
Abstract
Axonal regeneration is normally limited after injuries to CNS white matter. Infusion of neurotrophins has been successful in promoting regenerative growth through injured white matter but this growth generally fails to extend beyond the infusion site. These observations are consistent with a chemotropic effect of these factors on axonal growth and support the prevailing view that neurotrophin-induced axonal regeneration requires the use of gradients, i.e., gradually increasing neurotrophin levels along the target fiber tract. To examine the potential of global overexpression of neurotrophins to promote, and/or modify the orientation of, regenerative axonal growth within white matter, we grafted nerve growth factor (NGF) responsive neurons into the corpus callosum of transgenic mice overexpressing NGF throughout the CNS under control of the promoter for glial fibrillary acidic protein. One week later, glial fibrillary acidic protein and chondroitin sulfate proteoglycan immunoreactivity increased within injured white matter around the grafts. NGF levels were significantly higher in the brains of transgenic compared with non-transgenic mice and further elevated within injury sites compared with the homotypic region of the non-injured side. Although there was minimal outgrowth from neurons grafted into non-transgenic mice, extensive parallel axonal regeneration had occurred within the corpus callosum up to 1.5 mm beyond the astrogliotic scar (the site of maximum NGF expression) in transgenic mice. These results demonstrate that global overexpression of neurotrophins does not override the constraints limiting regenerative growth to parallel orientations and suggest that such factors need not be presented as positive gradients to promote axonal regeneration within white matter.
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MESH Headings
- Animals
- Astrocytes/cytology
- Astrocytes/physiology
- Axotomy
- Brain Injuries/metabolism
- Brain Injuries/physiopathology
- Brain Injuries/therapy
- Brain Injury, Chronic/metabolism
- Brain Injury, Chronic/physiopathology
- Brain Injury, Chronic/therapy
- Central Nervous System/cytology
- Central Nervous System/metabolism
- Chondroitin Sulfate Proteoglycans/metabolism
- Cicatrix/physiopathology
- Cicatrix/prevention & control
- Glial Fibrillary Acidic Protein/genetics
- Glial Fibrillary Acidic Protein/metabolism
- Graft Survival/physiology
- Growth Cones/metabolism
- Growth Cones/ultrastructure
- Mice
- Mice, Transgenic
- Nerve Fibers, Myelinated/metabolism
- Nerve Fibers, Myelinated/ultrastructure
- Nerve Growth Factor/genetics
- Nerve Growth Factor/metabolism
- Nerve Regeneration/physiology
- Promoter Regions, Genetic/genetics
- Superior Cervical Ganglion/cytology
- Superior Cervical Ganglion/metabolism
- Superior Cervical Ganglion/transplantation
- Sympathetic Fibers, Postganglionic/cytology
- Sympathetic Fibers, Postganglionic/metabolism
- Sympathetic Fibers, Postganglionic/transplantation
- Tissue Transplantation
- Up-Regulation/physiology
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Affiliation(s)
- David B. Pettigrew
- Department of Neurosurgery, The Neuroscience Institute, University of Cincinnati College of Medicine, ML 0515, Cincinnati, OH 45267-0515, USA
| | - Ya-Qin Li
- Department of Neurosurgery, The Neuroscience Institute, University of Cincinnati College of Medicine, ML 0515, Cincinnati, OH 45267-0515, USA
| | - Charles Kuntz
- Department of Neurosurgery, The Neuroscience Institute, University of Cincinnati College of Medicine, ML 0515, Cincinnati, OH 45267-0515, USA
| | - Keith A. Crutcher
- Department of Neurosurgery, The Neuroscience Institute, University of Cincinnati College of Medicine, ML 0515, Cincinnati, OH 45267-0515, USA
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Zhu Y, Antony J, Liu S, Martinez JA, Giuliani F, Zochodne D, Power C. CD8+ lymphocyte-mediated injury of dorsal root ganglion neurons during lentivirus infection: CD154-dependent cell contact neurotoxicity. J Neurosci 2006; 26:3396-403. [PMID: 16571746 PMCID: PMC6673847 DOI: 10.1523/jneurosci.4767-05.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neuronal damage in dorsal root ganglia (DRGs) with accompanying axonal injury is a key feature of human immunodeficiency virus (HIV)-related distal sensory polyneuropathy (DSP). In a model of HIV-related DSP, we observed numerous CD3+ T lymphocytes (p < 0.05) in DRGs from feline immunodeficiency virus (FIV)-infected animals, which also exhibited low CD4+ and high CD8+ lymphocyte levels in blood accompanied by a selective loss of small-diameter sural nerve axons (p < 0.05). FIV-infected lymphocytes cocultured with syngeneic DRGs caused neuronal damage, indicated by neurite retraction, neuronal soma atrophy, and loss (p < 0.05). In contrast, supernatants from FIV-infected or uninfected lymphocytes were minimally neurotoxic, despite high FIV virion levels. Among lymphocyte subsets cocultured with DRG cultures, CD8+ T cells from both FIV-infected and uninfected lymphocytes selectively caused DRG neuronal injury (p < 0.05). FIV-infected CD8+ T cells showed markedly increased CD154 expression (p < 0.05), whereas neurons were the predominant cells expressing CD40 in DRGs. Blocking CD154 on activated CD8+ T cells protected DRG neurons (p < 0.05). These findings indicated that CD8+ T cells were principal effectors of DRG neuronal injury after FIV infection through a CD40-CD154 interaction in a cell contact-dependent manner.
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Zhu Y, Jones G, Tsutsui S, Opii W, Liu S, Silva C, Butterfield DA, Power C. Lentivirus infection causes neuroinflammation and neuronal injury in dorsal root ganglia: pathogenic effects of STAT-1 and inducible nitric oxide synthase. THE JOURNAL OF IMMUNOLOGY 2005; 175:1118-26. [PMID: 16002713 DOI: 10.4049/jimmunol.175.2.1118] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Distal sensory polyneuropathy (DSP) is currently the most common neurological complication of HIV infection in the developed world and is characterized by sensory neuronal injury accompanied by inflammation, which is clinically manifested as disabling pain and gait instability. We previously showed that feline immunodeficiency virus (FIV) infection of cats caused DSP together with immunosuppression in cats, similar to that observed in HIV-infected humans. In this study, we investigated the pathogenic mechanisms underlying the development of FIV-induced DSP using feline dorsal root ganglia (DRG) cultures, consisting of neurons, Schwann cells, and macrophages. FIV-infected cultures exhibited viral Ags (p24 and envelope) in macrophages accompanied by neuronal injury, indicated by neurite retraction, neuronal loss and decreased soma size, compared with mock-infected (control) cultures. FIV infection up-regulated inducible NO synthase (iNOS), STAT-1, and TNF-alpha mRNA levels in DRG cultures. Increased STAT-1 and iNOS mRNA levels were also observed in DRGs from FIV-infected animals relative to mock-infected controls. Similarly, immunolabeling studies of DRGs from FIV-infected animals showed that macrophages were the principal sources of STAT-1 and iNOS protein production. The iNOS inhibitor aminoguanidine reduced nitrotyrosine and protein carbonyl levels, together with preventing neuronal injury in FIV-infected DRG cultures. The present studies indicate that FIV infection of DRGs directly contributes to axonal and neuronal injury through a mechanism involving macrophage immune activation, which is mediated by STAT-1 and iNOS activation.
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Affiliation(s)
- Yu Zhu
- Department of Clinical Neuroscience, University of Calgary, Calgary, Alberta, Canada
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8
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Ruiz G, Baños JE. The effect of endoneurial nerve growth factor on calcitonin gene-related peptide expression in primary sensory neurons. Brain Res 2005; 1042:44-52. [PMID: 15823252 DOI: 10.1016/j.brainres.2005.02.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 01/31/2005] [Accepted: 02/04/2005] [Indexed: 10/25/2022]
Abstract
Recent findings indicate that calcitonin gene-related peptide (CGRP) is involved in neuropathic pain, this peptide being up-regulated in a small population of large- and medium-sized primary sensory neurons after peripheral nerve injury. In adult animals, the expression of CGRP is regulated by nerve growth factor (NGF). After nerve injury, NGF is up-regulated at the injury site for several weeks, and this up-regulation contributes to the onset of neuropathic pain. Using immunohistochemistry, we investigated the time course of the effect of an endoneurial injection of NGF on the expression of CGRP in primary sensory neurons. NGF increased the percentage of medium- to large-sized DRG neuron profiles expressing CGRP, did not modify the percentage of small-sized neurons expressing CGRP, and increased CGRP expression in the laminae III and IV of the dorsal horn. The effects of NGF were evident as soon as 1 day after endoneurial injection, and lasted for 5 days. Ten days after the injection of NGF, the patterns of CGRP expression in the DRG were normal, whereas a slight decrease in CGRP content was observed in the dorsal horn. The injection of vehicle did not produce any change on CGRP expression in primary sensory neurons. These results suggest that endoneurial NGF is responsible for the increase in CGRP expression in some large-sized neurons and their central processes observed after nerve injury in animal models of neuropathic pain. Our findings contribute to the understanding of the role of NGF in neuropathic pain.
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Affiliation(s)
- Guido Ruiz
- Institute of Pharmacy, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
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9
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Hannila SS, Kawaja MD. Nerve growth factor-mediated collateral sprouting of central sensory axons into deafferentated regions of the dorsal horn is enhanced in the absence of the p75 neurotrophin receptor. J Comp Neurol 2005; 486:331-43. [PMID: 15846783 DOI: 10.1002/cne.20537] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
This study examined the growth capacity of nerve growth factor (NGF)-responsive dorsal root ganglion (DRG) central processes using mice of the following genotypes: wildtype, p75 neurotrophin receptor (p75NTR) exon III null mutant, NGF transgenic, and NGF transgenic with p75NTR exon III null mutation (NGF/p75(-/-)). In wildtype and p75NTR exon III null mutant mice calcitonin gene-related peptide (CGRP) immunoreactivity in the dorsal horn is dramatically reduced at both 3 and 28 days after rhizotomy. NGF transgenic and NGF/p75(-/-) mice also display reduced CGRP immunoreactivity 3 days after rhizotomy, but by postsurgical day 28 significant increases in the density of CGRP-positive axons are observed in the injured dorsal horns of these mice. Interestingly, NGF/p75(-/-) mice displayed significantly more new axonal growth when compared to NGF transgenic mice expressing full-length p75NTR. Immunohistochemical and ultrastructural analyses revealed that this axonal growth is not the result of regeneration but rather injury-induced sprouting by intact DRG central processes into the lesion site. This collateral growth is restricted to deafferentated areas of the dorsal horn, and we therefore propose that this is an example of compensatory sprouting by NGF-sensitive axons in the spinal cord, a response that is enhanced in the absence of NGF binding to p75NTR.
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MESH Headings
- Animals
- Axons/drug effects
- Axons/physiology
- Axons/ultrastructure
- Blotting, Western/methods
- Calcitonin Gene-Related Peptide/metabolism
- Cell Count/methods
- Cell Growth Processes/drug effects
- Cell Growth Processes/physiology
- Exons
- Functional Laterality
- GAP-43 Protein/metabolism
- Ganglia, Spinal/cytology
- Immunohistochemistry/methods
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Mice, Transgenic
- Microscopy, Electron, Transmission/methods
- Nerve Growth Factor/physiology
- Nerve Regeneration/drug effects
- Nerve Regeneration/physiology
- Neurons, Afferent/drug effects
- Neurons, Afferent/physiology
- Neurons, Afferent/ultrastructure
- Receptor, Nerve Growth Factor
- Receptors, Nerve Growth Factor/deficiency
- Rhizotomy/methods
- Spinal Cord/metabolism
- Time Factors
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Affiliation(s)
- Sari S Hannila
- Department of Anatomy and Cell Biology, Queen's University, Kingston, Ontario, Canada
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Scott ALM, Borisoff JF, Ramer MS. Deafferentation and neurotrophin-mediated intraspinal sprouting: a central role for the p75 neurotrophin receptor. Eur J Neurosci 2005; 21:81-92. [PMID: 15654845 DOI: 10.1111/j.1460-9568.2004.03838.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Axonal plasticity in the adult spinal cord is governed by intrinsic neuronal growth potential and by extracellular cues. The p75 receptor (p75(NTR)) binds growth-promoting neurotrophins (NTs) as well as the common receptor for growth-inhibiting myelin-derived proteins (the Nogo receptor) and so is well situated to gauge the balance of positive and negative influences on axonal plasticity. Using transgenic mice lacking the extracellular NT-binding domain of p75(NTR) (p75-/- mice), we have examined the influence of p75(NTR) on changes in the density of primary afferent (calcitonin gene-related peptide-expressing) and descending monoaminergic (serotonin- and tyrosine hydroxylase-expressing) projections to the dorsal horn after dorsal rhizotomy, with and without concomitant application of exogenous nerve growth factor and NT-3. We found that, in intact p75-/- mice, the axon density of all populations was equal to or less than that in wild-type mice but that rhizotomy-induced intraspinal sprouting was significantly augmented. Monoaminergic axon sprouting was enhanced in both nerve growth factor- and NT-3-treated p75-/- mice compared with similarly treated wild-type mice. Primary afferent sprouting was particularly robust in NT-3-treated p75-/- mice. These in vivo results illustrate the interactions of p75(NTR) with NTs, with their respective tropomyosin-related kinase receptors and with inhibitory myelin-derived molecules. Our findings illustrate the pivotal role of p75(NTR) in spinal axonal plasticity and identify it as a potential therapeutic target for spinal cord injury.
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Affiliation(s)
- Angela L M Scott
- ICORD (International Collaboration on Repair Discoveries), The University of British Columbia, 6270 University Boulevard, Vancouver, BC, Canada, V6T 1Z4
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