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Tohda C. Pharmacological intervention for chronic phase of spinal cord injury. Neural Regen Res 2025; 20:1377-1389. [PMID: 38934397 DOI: 10.4103/nrr.nrr-d-24-00176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024] Open
Abstract
Spinal cord injury is an intractable traumatic injury. The most common hurdles faced during spinal cord injury are failure of axonal regrowth and reconnection to target sites. These also tend to be the most challenging issues in spinal cord injury. As spinal cord injury progresses to the chronic phase, lost motor and sensory functions are not recovered. Several reasons may be attributed to the failure of recovery from chronic spinal cord injury. These include factors that inhibit axonal growth such as activated astrocytes, chondroitin sulfate proteoglycan, myelin-associated proteins, inflammatory microglia, and fibroblasts that accumulate at lesion sites. Skeletal muscle atrophy due to denervation is another chronic and detrimental spinal cord injury-specific condition. Although several intervention strategies based on multiple outlooks have been attempted for treating spinal cord injury, few approaches have been successful. To treat chronic spinal cord injury, neural cells or tissue substitutes may need to be supplied in the cavity area to enable possible axonal growth. Additionally, stimulating axonal growth activity by extrinsic factors is extremely important and essential for maintaining the remaining host neurons and transplanted neurons. This review focuses on pharmacotherapeutic approaches using small compounds and proteins to enable axonal growth in chronic spinal cord injury. This review presents some of these candidates that have shown promising outcomes in basic research ( in vivo animal studies) and clinical trials: AA-NgR(310)ecto-Fc (AXER-204), fasudil, phosphatase and tensin homolog protein antagonist peptide 4, chondroitinase ABC, intracellular sigma peptide, (-)-epigallocatechin gallate, matrine, acteoside, pyrvate kinase M2, diosgenin, granulocyte-colony stimulating factor, and fampridine-sustained release. Although the current situation suggests that drug-based therapies to recover function in chronic spinal cord injury are limited, potential candidates have been identified through basic research, and these candidates may be subjects of clinical studies in the future. Moreover, cocktail therapy comprising drugs with varied underlying mechanisms may be effective in treating the refractory status of chronic spinal cord injury.
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Affiliation(s)
- Chihiro Tohda
- Section of Neuromedical Science, Institute of Natural Medicine, University of Toyama, Toyama, Japan
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2
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Scheuren PS, Kramer JLK. Next-gen spinal cord injury clinical trials: lessons learned and opportunities for future success. EBioMedicine 2024; 109:105381. [PMID: 39383609 DOI: 10.1016/j.ebiom.2024.105381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 09/19/2024] [Accepted: 09/23/2024] [Indexed: 10/11/2024] Open
Abstract
Despite promising basic science discoveries and a surge in clinical trials, the quest for effective treatments that restore neurological function after spinal cord injury lags on. While "failed" in a conventional sense, emerging solutions to longstanding challenges represent promising steps towards a future with effective interventions. In this personal view, we highlight clinical trials implementing new solutions and their impact on the field. Our perspective is that, ultimately, the integration of shared knowledge, adaptive designs, and a deeper understanding of the intricacies of spinal cord injury holds promise of unlocking of major breakthroughs, leading to improved outcomes for people with spinal cord injury.
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Affiliation(s)
- Paulina S Scheuren
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - John L K Kramer
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Department of Anesthesiology, Pharmacology, and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
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3
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Nheu D, Petratos S. How does Nogo-A signalling influence mitochondrial function during multiple sclerosis pathogenesis? Neurosci Biobehav Rev 2024; 163:105767. [PMID: 38885889 DOI: 10.1016/j.neubiorev.2024.105767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/30/2024] [Accepted: 06/08/2024] [Indexed: 06/20/2024]
Abstract
Multiple sclerosis (MS) is a severe neurological disorder that involves inflammation in the brain, spinal cord and optic nerve with key disabling neuropathological outcomes being axonal damage and demyelination. When degeneration of the axo-glial union occurs, a consequence of inflammatory damage to central nervous system (CNS) myelin, dystrophy and death can lead to large membranous structures from dead oligodendrocytes and degenerative myelin deposited in the extracellular milieu. For the first time, this review covers mitochondrial mechanisms that may be operative during MS-related neurodegenerative changes directly activated during accumulating extracellular deposits of myelin associated inhibitory factors (MAIFs), that include the potent inhibitor of neurite outgrowth, Nogo-A. Axonal damage may occur when Nogo-A binds to and signals through its cognate receptor, NgR1, a multimeric complex, to initially stall axonal transport and limit the delivery of important growth-dependent cargo and subcellular organelles such as mitochondria for metabolic efficiency at sites of axo-glial disintegration as a consequence of inflammation. Metabolic efficiency in axons fails during active demyelination and progressive neurodegeneration, preceded by stalled transport of functional mitochondria to fuel axo-glial integrity.
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Affiliation(s)
- Danica Nheu
- Department of Neuroscience, School of Translational Medicine, Monash University, Prahran, VIC 3004, Australia
| | - Steven Petratos
- Department of Neuroscience, School of Translational Medicine, Monash University, Prahran, VIC 3004, Australia.
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Howard EM, Strittmatter SM. Development of neural repair therapy for chronic spinal cord trauma: soluble Nogo receptor decoy from discovery to clinical trial. Curr Opin Neurol 2023; 36:516-522. [PMID: 37865850 PMCID: PMC10841037 DOI: 10.1097/wco.0000000000001205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2023]
Abstract
PURPOSE OF REVIEW After traumatic spinal cord injury (SCI), neurological deficits persist due to the disconnection of surviving neurons. While repair of connectivity may restore function, no medical therapy exists today.This review traces the development of the neural repair-based therapeutic AXER-204 from animal studies to the recent clinical trial for chronic cervical SCI. RECENT FINDINGS Molecular studies reveal a Nogo-66 Receptor 1 (NgR1, RTN4R) pathway inhibiting axon regeneration, sprouting, and plasticity in the adult mammalian central nervous system (CNS). Rodent and nonhuman primate studies demonstrate that the soluble receptor decoy NgR(310)ecto-Fc or AXER-204 promotes neural repair and functional recovery in transection and contusion SCI. Recently, this biological agent completed a first-in-human and randomized clinical trial for chronic cervical SCI. The intervention was safe and well tolerated. Across all participants, upper extremity strength did not improve with treatment. However, posthoc and biomarker analyses suggest that AXER-204 may benefit treatment-naïve patients with incomplete SCI in the chronic stage. SUMMARY NgR1 signaling restricts neurological recovery in animal studies of CNS injury. The recent clinical trial of AXER-204 provides encouraging signals supporting future focused trials of this neural repair therapeutic. Further, AXER-204 studies provide a roadmap for the development of additional and synergistic therapies for chronic SCI.
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Affiliation(s)
- Elisa M. Howard
- Departments of Neuroscience and Neurology, Yale School of Medicine, New Haven, CT, USA
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Tian T, Zhang S, Yang M. Recent progress and challenges in the treatment of spinal cord injury. Protein Cell 2023; 14:635-652. [PMID: 36856750 PMCID: PMC10501188 DOI: 10.1093/procel/pwad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 12/29/2022] [Indexed: 02/12/2023] Open
Abstract
Spinal cord injury (SCI) disrupts the structural and functional connectivity between the higher center and the spinal cord, resulting in severe motor, sensory, and autonomic dysfunction with a variety of complications. The pathophysiology of SCI is complicated and multifaceted, and thus individual treatments acting on a specific aspect or process are inadequate to elicit neuronal regeneration and functional recovery after SCI. Combinatory strategies targeting multiple aspects of SCI pathology have achieved greater beneficial effects than individual therapy alone. Although many problems and challenges remain, the encouraging outcomes that have been achieved in preclinical models offer a promising foothold for the development of novel clinical strategies to treat SCI. In this review, we characterize the mechanisms underlying axon regeneration of adult neurons and summarize recent advances in facilitating functional recovery following SCI at both the acute and chronic stages. In addition, we analyze the current status, remaining problems, and realistic challenges towards clinical translation. Finally, we consider the future of SCI treatment and provide insights into how to narrow the translational gap that currently exists between preclinical studies and clinical practice. Going forward, clinical trials should emphasize multidisciplinary conversation and cooperation to identify optimal combinatorial approaches to maximize therapeutic benefit in humans with SCI.
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Affiliation(s)
- Ting Tian
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Sensen Zhang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China
- Cryo-EM Facility Center, Southern University of Science and Technology, Shenzhen 518055, China
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Maynard G, Kannan R, Liu J, Wang W, Lam TKT, Wang X, Adamson C, Hackett C, Schwab JM, Liu C, Leslie DP, Chen D, Marino R, Zafonte R, Flanders A, Block G, Smith E, Strittmatter SM. Soluble Nogo-Receptor-Fc decoy (AXER-204) in patients with chronic cervical spinal cord injury in the USA: a first-in-human and randomised clinical trial. Lancet Neurol 2023; 22:672-684. [PMID: 37479373 PMCID: PMC10410101 DOI: 10.1016/s1474-4422(23)00215-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/13/2023] [Accepted: 06/02/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND Spinal cord injury (SCI) causes neural disconnection and persistent neurological deficits, so axon sprouting and plasticity might promote recovery. Soluble Nogo-Receptor-Fc decoy (AXER-204) blocks inhibitors of axon growth and promotes recovery of motor function after SCI in animals. This first-in-human and randomised trial sought to determine primarily the safety and pharmacokinetics of AXER-204 in individuals with chronic SCI, and secondarily its effect on recovery. METHODS We conducted a two-part study in adults (aged 18-65 years) with chronic (>1 year) cervical traumatic SCI at six rehabilitation centres in the USA. In part 1, AXER-204 was delivered open label as single intrathecal doses of 3 mg, 30 mg, 90 mg, or 200 mg, with primary outcomes of safety and pharmacokinetics. Part 2 was a randomised, parallel, double-blind comparison of six intrathecal doses of 200 mg AXER-204 over 104 days versus placebo. Participants were randomly allocated (1:1) by investigators using a central electronic system, stratified in blocks of four by American Spinal Injury Association Impairment Scale grade and receipt of AXER-204 in part 1. All investigators and patients were masked to treatment allocation until at least day 169. The part 2 primary objectives were safety and pharmacokinetics, with a key secondary objective to assess change in International Standards for Neurological Classification of SCI (ISNCSCI) Upper Extremity Motor Score (UEMS) at day 169 for all enrolled participants. This trial is registered with ClinicalTrials.gov, NCT03989440, and is completed. FINDINGS We treated 24 participants in part 1 (six per dose; 18 men, six women), and 27 participants in part 2 (13 placebo, 14 AXER-204; 23 men, four women), between June 20, 2019, and June 21, 2022. There were no deaths and no discontinuations from the study due to an adverse event in part 1 and 2. In part 2, treatment-related adverse events were of similar incidence in AXER-204 and placebo groups (ten [71%] vs nine [69%]). Headache was the most common treatment-related adverse event (five [21%] in part 1, 11 [41%] in part 2). In part 1, AXER-204 reached mean maximal CSF concentration 1 day after dosing with 200 mg of 412 000 ng/mL (SD 129 000), exceeding those concentrations that were efficacious in animal studies. In part 2, mean changes from baseline to day 169 in ISNCSCI UEMS were 1·5 (SD 3·3) for AXER-204 and 0·9 (2·3) for placebo (mean difference 0·54, 95% CI -1·48 to 2·55; p=0·59). INTERPRETATION This study delivers the first, to our knowledge, clinical trial of a rationally designed pharmacological treatment intended to promote neural repair in chronic SCI. AXER-204 appeared safe and reached target CSF concentrations; exploratory biomarker results were consistent with target engagement and synaptic stabilisation. Post-hoc subgroup analyses suggest that future trials could investigate efficacy in patients with moderately severe SCI without prior AXER-204 exposure. FUNDING Wings for Life Foundation, National Institute of Neurological Disorders and Stroke, National Center for Advancing Translational Sciences, National Institute on Drug Abuse, and ReNetX Bio.
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Affiliation(s)
| | - Ramakrishnan Kannan
- Departments of Neuroscience and Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Jian Liu
- Departments of Neuroscience and Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Weiwei Wang
- Keck MS and Proteomic Resource, Yale School of Medicine, New Haven, CT, USA
| | - Tu Kiet T Lam
- Keck MS and Proteomic Resource, Yale School of Medicine, New Haven, CT, USA; Department of Molecular Biophysics and Biochemistry, Yale School of Medicine, New Haven, CT, USA
| | - Xingxing Wang
- Departments of Neuroscience and Neurology, Yale School of Medicine, New Haven, CT, USA
| | | | | | - Jan M Schwab
- Belford Center for Spinal Cord Injury and Departments of Neurology and Neuroscience, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
| | - Charles Liu
- USC Neurorestoration Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - David Chen
- Shirley Ryan AbilityLab, Chicago, IL, USA
| | - Ralph Marino
- Department of Rehabilitation Medicine, Thomas Jefferson University, Philadelphia, PA, USA
| | - Ross Zafonte
- Spaulding Rehabilitation Hospital, Massachusetts General Hospital, Brigham and Womens Hospital, Harvard Medical School, Boston, MA, USA
| | - Adam Flanders
- Department of Rehabilitation Medicine, Thomas Jefferson University, Philadelphia, PA, USA
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Rashidbenam Z, Ozturk E, Pagnin M, Theotokis P, Grigoriadis N, Petratos S. How does Nogo receptor influence demyelination and remyelination in the context of multiple sclerosis? Front Cell Neurosci 2023; 17:1197492. [PMID: 37361998 PMCID: PMC10285164 DOI: 10.3389/fncel.2023.1197492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/15/2023] [Indexed: 06/28/2023] Open
Abstract
Multiple sclerosis (MS) can progress with neurodegeneration as a consequence of chronic inflammatory mechanisms that drive neural cell loss and/or neuroaxonal dystrophy in the central nervous system. Immune-mediated mechanisms can accumulate myelin debris in the disease extracellular milieu during chronic-active demyelination that can limit neurorepair/plasticity and experimental evidence suggests that potentiated removal of myelin debris can promote neurorepair in models of MS. The myelin-associated inhibitory factors (MAIFs) are integral contributors to neurodegenerative processes in models of trauma and experimental MS-like disease that can be targeted to promote neurorepair. This review highlights the molecular and cellular mechanisms that drive neurodegeneration as a consequence of chronic-active inflammation and outlines plausible therapeutic approaches to antagonize the MAIFs during the evolution of neuroinflammatory lesions. Moreover, investigative lines for translation of targeted therapies against these myelin inhibitors are defined with an emphasis on the chief MAIF, Nogo-A, that may demonstrate clinical efficacy of neurorepair during progressive MS.
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Affiliation(s)
- Zahra Rashidbenam
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Ezgi Ozturk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Maurice Pagnin
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Paschalis Theotokis
- Laboratory of Experimental Neurology and Neuroimmunology, Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Nikolaos Grigoriadis
- Laboratory of Experimental Neurology and Neuroimmunology, Department of Neurology, AHEPA University Hospital, Thessaloniki, Greece
| | - Steven Petratos
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia
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Sekine Y, Kannan R, Wang X, Strittmatter SM. Rabphilin3A reduces integrin-dependent growth cone signaling to restrict axon regeneration after trauma. Exp Neurol 2022; 353:114070. [PMID: 35398339 PMCID: PMC9555232 DOI: 10.1016/j.expneurol.2022.114070] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/09/2022] [Accepted: 04/04/2022] [Indexed: 01/03/2023]
Abstract
Neural repair after traumatic spinal cord injury depends upon the restoration of neural networks via axonal sprouting and regeneration. Our previous genome wide loss-of-function screen identified Rab GTPases as playing a prominent role in preventing successful axon sprouting and regeneration. Here, we searched for Rab27b interactors and identified Rabphilin3A as an effector within regenerating axons. Growth cone Rabphilin3a colocalized and physically associated with integrins at puncta in the proximal body of the axonal growth cone. In regenerating axons, loss of Rabphilin3a increased integrin enrichment in the growth cone periphery, enhanced focal adhesion kinase activation, increased F-actin-rich filopodial density and stimulated axon extension. Compared to wild type, mice lacking Rabphilin3a exhibited greater regeneration of retinal ganglion cell axons after optic nerve crush as well as greater corticospinal axon regeneration after complete thoracic spinal cord crush injury. After moderate spinal cord contusion injury, there was greater corticospinal regrowth in the absence of Rph3a. Thus, an endogenous Rab27b - Raphilin3a pathway limits integrin action in the growth cone, and deletion of this monomeric GTPase pathway permits reparative axon growth in the injured adult mammalian central nervous system.
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Affiliation(s)
- Yuichi Sekine
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Ramakrishnan Kannan
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Xingxing Wang
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Stephen M Strittmatter
- Cellular Neuroscience, Neurodegeneration, Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA.
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9
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NogoA-expressing astrocytes limit peripheral macrophage infiltration after ischemic brain injury in primates. Nat Commun 2021; 12:6906. [PMID: 34824275 PMCID: PMC8617297 DOI: 10.1038/s41467-021-27245-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 11/05/2021] [Indexed: 11/08/2022] Open
Abstract
Astrocytes play critical roles after brain injury, but their precise function is poorly defined. Utilizing single-nuclei transcriptomics to characterize astrocytes after ischemic stroke in the visual cortex of the marmoset monkey, we observed nearly complete segregation between stroke and control astrocyte clusters. Screening for the top 30 differentially expressed genes that might limit stroke recovery, we discovered that a majority of astrocytes expressed RTN4A/ NogoA, a neurite-outgrowth inhibitory protein previously only associated with oligodendrocytes. NogoA upregulation on reactive astrocytes post-stroke was significant in both the marmoset and human brain, whereas only a marginal change was observed in mice. We determined that NogoA mediated an anti-inflammatory response which likely contributes to limiting the infiltration of peripheral macrophages into the surviving parenchyma.
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10
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The Implication of Reticulons (RTNs) in Neurodegenerative Diseases: From Molecular Mechanisms to Potential Diagnostic and Therapeutic Approaches. Int J Mol Sci 2021; 22:ijms22094630. [PMID: 33924890 PMCID: PMC8125174 DOI: 10.3390/ijms22094630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023] Open
Abstract
Reticulons (RTNs) are crucial regulatory factors in the central nervous system (CNS) as well as immune system and play pleiotropic functions. In CNS, RTNs are transmembrane proteins mediating neuroanatomical plasticity and functional recovery after central nervous system injury or diseases. Moreover, RTNs, particularly RTN4 and RTN3, are involved in neurodegeneration and neuroinflammation processes. The crucial role of RTNs in the development of several neurodegenerative diseases, including Alzheimer's disease (AD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or other neurological conditions such as brain injury or spinal cord injury, has attracted scientific interest. Reticulons, particularly RTN-4A (Nogo-A), could provide both an understanding of early pathogenesis of neurodegenerative disorders and be potential therapeutic targets which may offer effective treatment or inhibit disease progression. This review focuses on the molecular mechanisms and functions of RTNs and their potential usefulness in clinical practice as a diagnostic tool or therapeutic strategy.
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Wang X, Zhou T, Maynard GD, Terse PS, Cafferty WB, Kocsis JD, Strittmatter SM. Nogo receptor decoy promotes recovery and corticospinal growth in non-human primate spinal cord injury. Brain 2020; 143:1697-1713. [PMID: 32375169 PMCID: PMC7850069 DOI: 10.1093/brain/awaa116] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 12/19/2019] [Accepted: 02/23/2020] [Indexed: 12/20/2022] Open
Abstract
After CNS trauma such as spinal cord injury, the ability of surviving neural elements to sprout axons, reorganize neural networks and support recovery of function is severely restricted, contributing to chronic neurological deficits. Among limitations on neural recovery are myelin-associated inhibitors functioning as ligands for neuronal Nogo receptor 1 (NgR1). A soluble decoy (NgR1-Fc, AXER-204) blocks these ligands and provides a means to promote recovery of function in multiple preclinical rodent models of spinal cord injury. However, the safety and efficacy of this reagent in non-human primate spinal cord injury and its toxicological profile have not been described. Here, we provide evidence that chronic intrathecal and intravenous administration of NgR1-Fc to cynomolgus monkey and to rat are without evident toxicity at doses of 20 mg and greater every other day (≥2.0 mg/kg/day), and far greater than the projected human dose. Adult female African green monkeys underwent right C5/6 lateral hemisection with evidence of persistent disuse of the right forelimb during feeding and right hindlimb during locomotion. At 1 month post-injury, the animals were randomized to treatment with vehicle (n = 6) or 0.10-0.17 mg/kg/day of NgR1-Fc (n = 8) delivered via intrathecal lumbar catheter and osmotic minipump for 4 months. One animal was removed from the study because of surgical complications of the catheter, but no treatment-related adverse events were noted in either group. Animal behaviour was evaluated at 6-7 months post-injury, i.e. 1-2 months after treatment cessation. The use of the impaired forelimb during spontaneous feeding and the impaired hindlimb during locomotion were both significantly greater in the treatment group. Tissue collected at 7-12 months post-injury showed no significant differences in lesion size, fibrotic scar, gliosis or neuroinflammation between groups. Serotoninergic raphespinal fibres below the lesion showed no deficit, with equal density on the lesioned and intact side below the level of the injury in both groups. Corticospinal axons traced from biotin-dextran-amine injections in the left motor cortex were equally labelled across groups and reduced caudal to the injury. The NgR1-Fc group tissue exhibited a significant 2-3-fold increased corticospinal axon density in the cervical cord below the level of the injury relative to the vehicle group. The data show that NgR1-Fc does not have preclinical toxicological issues in healthy animals or safety concerns in spinal cord injury animals. Thus, it presents as a potential therapeutic for spinal cord injury with evidence for behavioural improvement and growth of injured pathways in non-human primate spinal cord injury.
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Affiliation(s)
- Xingxing Wang
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Tianna Zhou
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
| | | | - Pramod S Terse
- National Center for Translational Sciences, NIH, Rockville, MD, USA
| | - William B Cafferty
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Jeffery D Kocsis
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Stephen M Strittmatter
- Cellular Neuroscience, Neurodegeneration and Repair Program, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
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12
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Sharma B, Dutt V, Kaur N, Mittal A, Dabur R. Tinospora cordifolia protects from skeletal muscle atrophy by alleviating oxidative stress and inflammation induced by sciatic denervation. JOURNAL OF ETHNOPHARMACOLOGY 2020; 254:112720. [PMID: 32114167 DOI: 10.1016/j.jep.2020.112720] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 12/09/2019] [Accepted: 02/24/2020] [Indexed: 06/10/2023]
Abstract
ETHANOPHARMACOLOGICAL RELEVANCE Tinospora cordifolia (TC) is widely being used as immunomodulatory and re-juvenile drug and well described in Indian Ayurveda system of medicine. Rejuvenation also means the fine tuning of the skeletal muscles. Skeletal muscle related disorder, i.e. atrophy is major problem which arise due to cachexia, sarcopenia and immobilization. However, despite of the great efforts, there is scarcity of FDA approved drugs in the market to treat skeletal muscle atrophy. AIM OF THE STUDY The current study was aimed to explore the in-vitro and in-vivo efficacy and mechanism of TC in myogenic differentiation and skeletal muscle atrophy to establish the possibility of its usage to counteract skeletal muscle atrophy. MATERIALS AND METHODS C2C12 cell lines were used to determine myogenic potential and anti-atrophic effects of T. cordifolia water extract (TCE). Its in-vitro efficacy was re-validated in vivo by supplementation of TCE at a dose of 200 mg/kg/p.o. for 30 days in denervated mice model of skeletal muscle atrophy. Effects of TCE administration on levels of oxidative stress, inflammatory markers and proteolysis were determined. RESULTS TCE supplementation displayed increased lymphocyte proliferation and induced myogenic differentiation of C2C12 myoblasts by significantly increasing myocytes length and thickness, in comparison to control (p < 0.05). TCE supplementation decreased oxidative stress and inflammatory response by significantly modulating activities of catalase, glutathione peroxidase, lipid peroxidase, superoxide dismutase and β-glucuronidase (p < 0.05). It increased MF-20c expression and ameliorated degradation of muscle protein by down-regulating MuRF-1 and calpain activity. CONCLUSION TCE supplementation promotes myogenic differentiation in C2C12 cell lines and prevents denervation induced skeletal muscle atrophy by antagonizing the proteolytic systems (calpain and UPS) and maintaining the oxidative defense mechanism of the cell. Hence, TCE can be used as a protective agent against muscle atrophy.
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Affiliation(s)
- Bhawana Sharma
- Clinical Biochemistry Research Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, 124001, India
| | - Vikas Dutt
- Skeletal Muscle Lab, Department of Biochemistry, University College, Kurukshetra University, Kurukshetra, Haryana, 136119, India
| | - Nirmaljeet Kaur
- Skeletal Muscle Lab, Department of Biochemistry, University College, Kurukshetra University, Kurukshetra, Haryana, 136119, India
| | - Ashwani Mittal
- Skeletal Muscle Lab, Department of Biochemistry, University College, Kurukshetra University, Kurukshetra, Haryana, 136119, India
| | - Rajesh Dabur
- Clinical Biochemistry Research Laboratory, Department of Biochemistry, Maharshi Dayanand University, Rohtak, Haryana, 124001, India.
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Sartori AM, Hofer AS, Schwab ME. Recovery after spinal cord injury is enhanced by anti-Nogo-A antibody therapy — from animal models to clinical trials. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2019.11.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Hutson TH, Di Giovanni S. The translational landscape in spinal cord injury: focus on neuroplasticity and regeneration. Nat Rev Neurol 2019; 15:732-745. [DOI: 10.1038/s41582-019-0280-3] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/22/2022]
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15
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Fawcett JW. The Struggle to Make CNS Axons Regenerate: Why Has It Been so Difficult? Neurochem Res 2019; 45:144-158. [PMID: 31388931 PMCID: PMC6942574 DOI: 10.1007/s11064-019-02844-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/09/2019] [Accepted: 07/19/2019] [Indexed: 12/12/2022]
Abstract
Axon regeneration in the CNS is inhibited by many extrinsic and intrinsic factors. Because these act in parallel, no single intervention has been sufficient to enable full regeneration of damaged axons in the adult mammalian CNS. In the external environment, NogoA and CSPGs are strongly inhibitory to the regeneration of adult axons. CNS neurons lose intrinsic regenerative ability as they mature: embryonic but not mature neurons can grow axons for long distances when transplanted into the adult CNS, and regeneration fails with maturity in in vitro axotomy models. The causes of this loss of regeneration include partitioning of neurons into axonal and dendritic fields with many growth-related molecules directed specifically to dendrites and excluded from axons, changes in axonal signalling due to changes in expression and localization of receptors and their ligands, changes in local translation of proteins in axons, and changes in cytoskeletal dynamics after injury. Also with neuronal maturation come epigenetic changes in neurons, with many of the transcription factor binding sites that drive axon growth-related genes becoming inaccessible. The overall aim for successful regeneration is to ensure that the right molecules are expressed after axotomy and to arrange for them to be transported to the right place in the neuron, including the damaged axon tip.
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Affiliation(s)
- James W Fawcett
- John Van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge, CB2 0PY, UK.
- Centre of Reconstructive Neuroscience, Institute for Experimental Medicine ASCR, Prague, Czech Republic.
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16
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Plexina2 and CRMP2 Signaling Complex Is Activated by Nogo-A-Liganded Ngr1 to Restrict Corticospinal Axon Sprouting after Trauma. J Neurosci 2019; 39:3204-3216. [PMID: 30804090 DOI: 10.1523/jneurosci.2996-18.2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 01/31/2019] [Accepted: 02/17/2019] [Indexed: 01/01/2023] Open
Abstract
After brain or spinal cord trauma, interaction of Nogo-A with neuronal NgR1 limits regenerative axonal sprouting and functional recovery. Cellular signaling by lipid-anchored NgR1 requires a coreceptor but the relevant partner in vivo is not clear. Here, we examined proteins enriched in NgR1 immunoprecipitates by Nogo-A exposure, identifying CRMP2, a cytosolic protein implicated in axon growth inhibition by Semaphorin/Plexin complexes. The Nogo-A-induced association of NgR1 with CRMP2 requires PlexinA2 as a coreceptor. Non-neuronal cells expressing both NgR1 and PlexinA2, but not either protein alone, contract upon Nogo-A exposure. Inhibition of cortical axon regeneration by Nogo-A depends on a NgR1/PlexinA2 genetic interaction because double-heterozygous NgR1+/-, PlexinA2+/- neurons, but not single-heterozygote neurons, are rescued from Nogo-A inhibition. NgR1 and PlexinA2 also interact genetically in vivo to restrict corticospinal sprouting in mouse cervical spinal cord after unilateral pyramidotomy. Greater post-injury sprouting in NgR1+/-, PlexinA2+/- mice supports enhanced neurological recovery of a mixed female and male double-heterozygous cohort. Thus, a NgR1/PlexinA2/CRMP2 ternary complex limits neural repair after adult mammalian CNS trauma.SIGNIFICANCE STATEMENT Several decades of molecular research have suggested that developmental regulation of axon growth is distinct in most regards from titration of axonal regenerative growth after adult CNS trauma. Among adult CNS pathways, the oligodendrocyte Nogo-A inhibition of growth through NgR1 is thought to have little molecular relationship to axonal guidance mechanisms active embryonically. Here, biochemical analysis of NgR1 function uncovered a physical complex with CRMP cytoplasmic mediators, and this led to appreciation of a role for PlexinA2 in concert with NgR1 after adult trauma. The data extend molecular understanding of neural repair after CNS trauma and link it to developmental processes.
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17
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Smith LM, Kostylev MA, Lee S, Strittmatter SM. Systematic and standardized comparison of reported amyloid-β receptors for sufficiency, affinity, and Alzheimer's disease relevance. J Biol Chem 2019; 294:6042-6053. [PMID: 30787106 DOI: 10.1074/jbc.ra118.006252] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 02/18/2019] [Indexed: 11/06/2022] Open
Abstract
Oligomeric assemblies of amyloid-β (Aβ) peptide (Aβo) in the brains of individuals with Alzheimer's disease (AD) are toxic to neuronal synapses. More than a dozen Aβ receptor candidates have been suggested to be responsible for various aspects of the molecular pathology and memory impairment in mouse models of AD. A lack of consistent experimental design among previous studies of different receptor candidates limits evaluation of the relative roles of these candidates, producing some controversy within the field. Here, using cell-based assays with several Aβ species, including Aβo from AD brains obtained by autopsy, we directly compared the Aβ-binding capacity of multiple receptor candidates while accounting for variation in expression and confirming cell surface expression. In a survey of 15 reported Aβ receptors, only cellular prion protein (PrPC), Nogo receptor 1 (NgR1), and leukocyte immunoglobulin-like receptor subfamily B member 2 (LilrB2) exhibited direct binding to synaptotoxic assemblies of synthetic Aβ. Both PrPC and NgR1 preferentially bound synaptotoxic oligomers rather than nontoxic monomers, and the method of oligomer preparation did not significantly alter our binding results. Hippocampal neurons lacking both NgR1 and LilrB2 exhibited a partial reduction of Aβo binding, but this reduction was lower than in neurons lacking PrPC under the same conditions. Finally, binding studies with soluble Aβo from human AD brains revealed a strong affinity for PrPC, weak affinity for NgR1, and no detectable affinity for LilrB2. These findings clarify the relative contributions of previously reported Aβ receptors under controlled conditions and highlight the prominence of PrPC as an Aβ-binding site.
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Affiliation(s)
- Levi M Smith
- From the Program in Cellular Neuroscience, Neurodegeneration, and Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06536; the Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06536
| | - Mikhail A Kostylev
- From the Program in Cellular Neuroscience, Neurodegeneration, and Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06536
| | - Suho Lee
- From the Program in Cellular Neuroscience, Neurodegeneration, and Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06536
| | - Stephen M Strittmatter
- From the Program in Cellular Neuroscience, Neurodegeneration, and Repair, Departments of Neurology and of Neuroscience, Yale University School of Medicine, New Haven, Connecticut 06536.
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18
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Can We Design a Nogo Receptor-Dependent Cellular Therapy to Target MS? Cells 2018; 8:cells8010001. [PMID: 30577457 PMCID: PMC6357095 DOI: 10.3390/cells8010001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 12/12/2018] [Accepted: 12/18/2018] [Indexed: 12/18/2022] Open
Abstract
The current landscape of therapeutics designed to treat multiple sclerosis (MS) and its pathological sequelae is saturated with drugs that modify disease course and limit relapse rates. While these small molecules and biologicals are producing profound benefits to patients with reductions in annualized relapse rates, the repair or reversal of demyelinated lesions with or without axonal damage, remains the principle unmet need for progressive forms of the disease. Targeting the extracellular pathological milieu and the signaling mechanisms that drive neurodegeneration are potential means to achieve neuroprotection and/or repair in the central nervous system of progressive MS patients. The Nogo-A receptor-dependent signaling mechanism has raised considerable interest in neurological disease paradigms since it can promulgate axonal transport deficits, further demyelination, and extant axonal dystrophy, thereby limiting remyelination. If specific therapeutic regimes could be devised to directly clear the Nogo-A-enriched myelin debris in an expedited manner, it may provide the necessary CNS environment for neurorepair to become a clinical reality. The current review outlines novel means to achieve neurorepair with biologicals that may be directed to sites of active demyelination.
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19
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Gao L, Xu W, Fan S, Li T, Zhao T, Ying G, Zheng J, Li J, Zhang Z, Yan F, Zhu Y, Chen G. MANF attenuates neuronal apoptosis and promotes behavioral recovery via Akt/MDM-2/p53 pathway after traumatic spinal cord injury in rats. Biofactors 2018; 44:369-386. [PMID: 29797541 DOI: 10.1002/biof.1433] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2018] [Revised: 03/31/2018] [Accepted: 04/17/2018] [Indexed: 12/16/2022]
Abstract
The aim of this study was to investigate the potential effect and mechanism of action of MANF in attenuating neuronal apoptosis following t-SCI. A clip compressive model was used to induce a crush injury of the spinal cord in a total of 230 rats. The Basso, Beattie, and Bresnahan (BBB) score, spinal cord water content, and blood spinal cord barrier (BSCB) permeability were evaluated. The expression levels of MANF and its downstream proteins were examined by western blotting. Immunofluorescence staining of MANF, NeuN, GFAP, Iba-1, cleaved caspase-3, and TUNEL staining were also performed. Cells were counted in six randomly selected fields in the gray matter regions of the sections from two spinal cord sites (2 mm rostral and caudal to the epicenter of the injury) per sample. A cell-based mechanical injury model was also conducted using SH-SY5Y cells. Cell apoptosis and viability were assessed by flow cytometry, an MTT assay, and trypan blue staining. Subcellular structures were observed by transmission electron microscopy. MANF was mainly expressed in neurons. The expression levels of MANF, and its downstream target, p-Akt, were gradually increased and after t-SCI. Treatment with MANF increased Bcl-2 and decreased Bax and CC-3 levels; these effects were reversed on treatment with MK2206. The BBB score, spinal cord water content, and BSCB destruction were also ameliorated by MANF treatment. MANF decreases neuronal apoptosis and improves neurological function through Akt/MDM-2/p53 pathway after t-SCI. Therefore, MANF might be a potential treatment for patients with t-SCI.© 2018 BioFactors, 2018.
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Affiliation(s)
- Liansheng Gao
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Weilin Xu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Shuangbo Fan
- Department of Neurosurgery, Ningbo Zhenhai Longsai Hospital, Zhenhai District, Ningbo, Zhejiang, China
| | - Tao Li
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Tengfei Zhao
- Department of Orthopedics, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Guangyu Ying
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jingwei Zheng
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianru Li
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhongyuan Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Feng Yan
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Yongjian Zhu
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Gao Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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20
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Lentiviral vector delivery of short hairpin RNA to NgR1 promotes nerve regeneration and locomotor recovery in injured rat spinal cord. Sci Rep 2018; 8:5447. [PMID: 29615686 PMCID: PMC5882972 DOI: 10.1038/s41598-018-23751-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 03/15/2018] [Indexed: 01/01/2023] Open
Abstract
Nogo receptor 1 (NgR1) is a high-affinity receptor of myelin-associated inhibitors (MAIs), and suppresses neurogenesis. Lentiviral vector are commonly used to alter the expression of targeted genes. However, little is known about the potential function of lentiviral vector harboring NgR1 shRNA (LV-NgR1 shRNA) on neurogenesis in spinal cord injury (SCI). In this study, the rats were randomly divided into three groups: including the LN (LV-NgR1 shRNA injection), LC (LV-control shRNA injection) and Sham (laminectomy only). Eight weeks post-injection of LV, spinal cords were examined by histology for changes in cavity size and by immunohistochemistry for changes in expression of NgR1, cell apoptosis, astrocytes, neurons and myelination. Motor function was assessed using the Basso, Beattie and Bresnahan (BBB) locomotor scale. Animals that received LV-NgR1 shRNA remarkably improved the motor function. These animals also showed an increase in levels of nerve fibers, synapses and myelination, a decrease in levels of lesion cavity and cell apoptosis at 8 weeks post-treatment. These findings give evidence that NgR1 may be a promising target for SCI treatment.
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21
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Sekine Y, Siegel CS, Sekine-Konno T, Cafferty WBJ, Strittmatter SM. The nociceptin receptor inhibits axonal regeneration and recovery from spinal cord injury. Sci Signal 2018; 11:eaao4180. [PMID: 29615517 PMCID: PMC6179440 DOI: 10.1126/scisignal.aao4180] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Axonal growth after traumatic spinal cord injury is limited by endogenous inhibitors, selective blockade of which promotes partial neurological recovery. The partial repair phenotypes suggest that compensatory pathways limit improvement. Gene expression profiles of mice deficient in Ngr1, which encodes a receptor for myelin-associated inhibitors of axonal regeneration such as Nogo, revealed that trauma increased the mRNA expression of ORL1, which encodes the receptor for the opioid-related peptide nociceptin. Endogenous and overexpressed ORL1 coimmunoprecipitated with immature NgR1 protein, and ORL1 enhanced the O-linked glycosylation and surface expression of NgR1 in HEK293T and Neuro2A cells and primary neurons. ORL1 overexpression inhibited cortical neuron axon regeneration independently of NgR1. Furthermore, regeneration was inhibited by an ORL1 agonist and enhanced by the ORL1 antagonist J113397 through a ROCK-dependent mechanism. Mice treated with J113397 after dorsal hemisection of the mid-thoracic spinal cord recovered greater locomotor function and exhibited lumbar raphespinal axon sprouting. These effects were further enhanced by combined Ngr1 deletion and ORL1 inhibition. Thus, ORL1 limits neural repair directly and indirectly by enhancing NgR1 maturation, and ORL1 antagonists enhance recovery from traumatic CNS injuries in wild-type and Ngr1 null mice.
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Affiliation(s)
- Yuichi Sekine
- Cellular Neuroscience, Neurodegeneration and Repair Program, Interdepartmental Neuroscience Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Chad S Siegel
- Cellular Neuroscience, Neurodegeneration and Repair Program, Interdepartmental Neuroscience Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Tomoko Sekine-Konno
- Cellular Neuroscience, Neurodegeneration and Repair Program, Interdepartmental Neuroscience Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - William B J Cafferty
- Cellular Neuroscience, Neurodegeneration and Repair Program, Interdepartmental Neuroscience Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Stephen M Strittmatter
- Cellular Neuroscience, Neurodegeneration and Repair Program, Interdepartmental Neuroscience Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA.
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22
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Hirokawa T, Zou Y, Kurihara Y, Jiang Z, Sakakibara Y, Ito H, Funakoshi K, Kawahara N, Goshima Y, Strittmatter SM, Takei K. Regulation of axonal regeneration by the level of function of the endogenous Nogo receptor antagonist LOTUS. Sci Rep 2017; 7:12119. [PMID: 28935984 PMCID: PMC5608707 DOI: 10.1038/s41598-017-12449-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 09/08/2017] [Indexed: 11/16/2022] Open
Abstract
Axonal regeneration in the adult mammalian central nervous system is limited in part by the non-permissive environment, including axonal growth inhibitors such as the Nogo-A protein. How the functions of these inhibitors can be blocked remains unclear. Here, we examined the role of LOTUS, an endogenous Nogo receptor antagonist, in promoting functional recovery and neural repair after spinal cord injury (SCI), as well as axonal regeneration after optic nerve crush. Wild-type untreated mice show incomplete but substantial intrinsic motor recovery after SCI. The genetic deletion of LOTUS delays and decreases the extent of motor recovery, suggesting that LOTUS is required for spontaneous neural repair. The neuronal overexpression of LOTUS in transgenic mice promotes motor recovery after SCI, and recombinant viral overexpression of LOTUS enhances retinal ganglion cell axonal regeneration after optic nerve crush. Thus, the level of LOTUS function titrates axonal regeneration.
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Affiliation(s)
- Tomoko Hirokawa
- Molecular Medical Bioscience Laboratory, Yokohama City University Graduate School of Medical Life Science, Yokohama, 230-0045, Japan
| | - Yixiao Zou
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Yuji Kurihara
- Molecular Medical Bioscience Laboratory, Yokohama City University Graduate School of Medical Life Science, Yokohama, 230-0045, Japan
| | - Zhaoxin Jiang
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Yusuke Sakakibara
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University Graduate School of Medicine, Yokohama, 246-0004, Japan
| | - Hiromu Ito
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University Graduate School of Medicine, Yokohama, 246-0004, Japan
| | - Kengo Funakoshi
- Department of Neuroanatomy, Yokohama City University Graduate School of Medicine, Yokohama, 246-0004, Japan
| | - Nobutaka Kawahara
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama, 246-0004, Japan.,Advanced Medical Research Center, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Yoshio Goshima
- Department of Molecular Pharmacology and Neurobiology, Yokohama City University Graduate School of Medicine, Yokohama, 246-0004, Japan.,Advanced Medical Research Center, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan
| | - Stephen M Strittmatter
- Cellular Neuroscience, Neurodegeneration and Repair Program, Departments of Neurology and Neuroscience, Yale University School of Medicine, New Haven, CT, 06536, USA
| | - Kohtaro Takei
- Molecular Medical Bioscience Laboratory, Yokohama City University Graduate School of Medical Life Science, Yokohama, 230-0045, Japan. .,Advanced Medical Research Center, Yokohama City University Graduate School of Medicine, Yokohama, 236-0004, Japan.
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23
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Boghdadi AG, Teo L, Bourne JA. The Involvement of the Myelin-Associated Inhibitors and Their Receptors in CNS Plasticity and Injury. Mol Neurobiol 2017; 55:1831-1846. [PMID: 28229330 DOI: 10.1007/s12035-017-0433-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/31/2017] [Indexed: 12/21/2022]
Abstract
The limited capacity for the central nervous system (CNS) to repair itself was first described over 100 years ago by Spanish neuroscientist Ramon Y. Cajal. However, the exact mechanisms underlying this failure in neuronal regeneration remain unclear and, as such, no effective therapeutics yet exist. Numerous studies have attempted to elucidate the biochemical and molecular mechanisms that inhibit neuronal repair with increasing evidence suggesting that several inhibitory factors and repulsive guidance cues active during development actually persist into adulthood and may be contributing to the inhibition of repair. For example, in the injured adult CNS, there are various inhibitory factors that impede the outgrowth of neurites from damaged neurons. One of the most potent of these neurite outgrowth inhibitors is the group of proteins known as the myelin-associated inhibitors (MAIs), present mainly on the membranes of oligodendroglia. Several studies have shown that interfering with these proteins can have positive outcomes in CNS injury models by promoting neurite outgrowth and improving functional recovery. As such, the MAIs, their receptors, and downstream effectors are valid drug targets for the treatment of CNS injury. This review will discuss the current literature on MAIs in the context of CNS development, plasticity, and injury. Molecules that interfere with the MAIs and their receptors as potential candidates for the treatment of CNS injury will additionally be introduced in the context of preclinical and clinical trials.
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Affiliation(s)
- Anthony G Boghdadi
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - Leon Teo
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - James A Bourne
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia.
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24
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Inhibition of Poly-ADP-Ribosylation Fails to Increase Axonal Regeneration or Improve Functional Recovery after Adult Mammalian CNS Injury. eNeuro 2016; 3:eN-NRS-0270-16. [PMID: 28032120 PMCID: PMC5187389 DOI: 10.1523/eneuro.0270-16.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 11/16/2016] [Accepted: 12/07/2016] [Indexed: 11/21/2022] Open
Abstract
After traumatic damage of the brain or spinal cord, many surviving neurons are disconnected, and recovery of function is limited by poor axon regeneration. Recent data have suggested that poly ADP-ribosylation plays a role in limiting axonal regrowth such that inhibition of poly (ADP-ribose) polymerase (PARP) may have therapeutic efficacy for neurological recovery after trauma. Here, we tested systemic administration of the PARP inhibitor, veliparib, and showed effective suppression of PARylation in the mouse CNS. After optic nerve crush injury or dorsal hemisection of the thoracic spinal cord in mice, treatment with veliparib at doses with pharmacodynamic action had no benefit for axonal regeneration or functional recovery. We considered whether PARP gene family specificity might play a role. In vitro mouse cerebral cortex axon regeneration experiments revealed that short hairpin RNA (shRNA)-mediated suppression of PARP1 promoted axonal regeneration, whereas suppression of other PARP isoforms either had no effect or decreased regeneration. Therefore, we examined recovery from neurological trauma in mice lacking PARP1. No increase of axonal regeneration was observed in Parp1–/– mice after optic nerve crush injury or dorsal hemisection of the thoracic spinal cord, and there was no improvement in motor function recovery. Thus, comprehensive in vivo analysis reveals no indication that clinical PARP inhibitors will on their own provide benefit for recovery from CNS trauma.
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25
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Dell'Anno MT, Strittmatter SM. Rewiring the spinal cord: Direct and indirect strategies. Neurosci Lett 2016; 652:25-34. [PMID: 28007647 DOI: 10.1016/j.neulet.2016.12.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 11/15/2016] [Accepted: 12/02/2016] [Indexed: 12/23/2022]
Abstract
Spinal cord injury is currently incurable. Treatment is limited to minimizing secondary complications and maximizing residual function by rehabilitation. Neurologic recovery is prevented by the poor intrinsic regenerative capacity of neurons in the adult central nervous system and by the presence of growth inhibitors in the adult brain and spinal cord. Here we identify three approaches to rewire the spinal cord after injury: axonal regeneration (direct endogenous reconnection), axonal sprouting (indirect endogenous reconnection) and neural stem cell transplantation (indirect exogenous reconnection). Regeneration and sprouting of axonal fibers can be both enhanced through the neutralization of myelin- and extracellular matrix-associated inhibitors described in the first part of this review. Alternatively, in the second part we focus on the formation of a novel circuit through the grafting of neural stem cells in the lesion site. Transplanted neural stem cells differentiate in vivo into neurons and glial cells which form an intermediate station between the rostral and caudal segment of the recipient spinal cord. In particular, here we describe how neural stem cells-derived neurons are endowed with the ability to extend long-distance axons to regain the transmission of motor and sensory information.
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Affiliation(s)
- Maria Teresa Dell'Anno
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Stephen M Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, CT 06536, USA.
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26
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Erasure of fear memories is prevented by Nogo Receptor 1 in adulthood. Mol Psychiatry 2016; 21:1281-9. [PMID: 26619810 PMCID: PMC4887429 DOI: 10.1038/mp.2015.179] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/06/2015] [Accepted: 10/14/2015] [Indexed: 11/12/2022]
Abstract
Critical periods are temporary windows of heightened neural plasticity early in development. For example, fear memories in juvenile rodents are subject to erasure following extinction training, while after closure of this critical period, extinction training only temporarily and weakly suppresses fear memories. Persistence of fear memories is important for survival, but the inability to effectively adapt to the trauma is a characteristic of post-traumatic stress disorder (PTSD). We examined whether Nogo Receptor 1 (NgR1) regulates the plasticity associated with fear extinction. The loss of NgR1 function in adulthood eliminates spontaneous fear recovery and fear renewal, with a restoration of fear reacquisition rate equal to that of naive mice; thus, mimicking the phenotype observed in juvenile rodents. Regional gene disruption demonstrates that NgR1 expression is required in both the basolateral amygdala (BLA) and infralimbic (IL) cortex to prevent fear erasure. NgR1 expression by parvalbumin expressing interneurons is essential for limiting extinction-dependent plasticity. NgR1 gene deletion enhances anatomical changes of inhibitory synapse markers after extinction training. Thus, NgR1 robustly inhibits elimination of fear expression in the adult brain and could serve as a therapeutic target for anxiety disorders, such as PTSD.
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27
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Blocking the Nogo-A Signaling Pathway to Promote Regeneration and Plasticity After Spinal Cord Injury and Stroke. Transl Neurosci 2016. [DOI: 10.1007/978-1-4899-7654-3_20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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28
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Wang X, Lin J, Arzeno A, Choi JY, Boccio J, Frieden E, Bhargava A, Maynard G, Tsai JC, Strittmatter SM. Intravitreal delivery of human NgR-Fc decoy protein regenerates axons after optic nerve crush and protects ganglion cells in glaucoma models. Invest Ophthalmol Vis Sci 2015; 56:1357-66. [PMID: 25655801 DOI: 10.1167/iovs.14-15472] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Glaucoma is a major cause of vision loss due to retinal ganglion cell (RGC) degeneration. Therapeutic intervention controls increased IOP, but neuroprotection is unavailable. NogoReceptor1 (NgR1) limits adult central nervous system (CNS) axonal sprouting and regeneration. We examined NgR1 blocking decoy as a potential therapy by defining the pharmacokinetics of intravitreal NgR(310)-Fc, its promotion of RGC axonal regeneration following nerve crush, and its neuroprotective effect in a microbead glaucoma model. METHODS Human NgR1(310)-Fc was administered intravitreally, and levels were monitored in rat vitreal humor and retina. Axonal regeneration after optic nerve crush was assessed by cholera toxin β anterograde labeling. In a microbead model of glaucoma with increased IOP, the number of surviving and actively transporting RGCs was determined after 4 weeks by retrograde tracing with Fluro-Gold (FG) from the superior colliculus. RESULTS After intravitreal bolus administration, the terminal half-life of NgR1(310)-Fc between 1 and 7 days was approximately 24 hours. Injection of 5 μg protein once per week after optic nerve crush injury significantly increased RGCs with regenerating axons. Microbeads delivered to the anterior chamber increased pressure, and caused 15% reduction in FG-labeled RGCs of control rats, with a 40% reduction in large diameter RGCs. Intravitreal treatment with NgR1(310)-Fc did not reduce IOP, but maintained large diameter RGC density at control levels. CONCLUSIONS Human NgR1(310)-Fc has favorable pharmacokinetics in the vitreal space and rescues large diameter RGC counts from increased IOP. Thus, the NgR1 blocking decoy protein may have efficacy as a disease-modifying therapy for glaucoma.
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Affiliation(s)
- Xingxing Wang
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, Connecticut, United States Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Jun Lin
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Alexander Arzeno
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, Connecticut, United States Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Jin Young Choi
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Juliann Boccio
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Eric Frieden
- Axerion Therapeutics, Branford, Connecticut, United States
| | - Ajay Bhargava
- Shakti BioResearch, Woodbridge, Connecticut, United States
| | - George Maynard
- Axerion Therapeutics, Branford, Connecticut, United States
| | - James C Tsai
- Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, Connecticut, United States
| | - Stephen M Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration & Repair, Yale University School of Medicine, New Haven, Connecticut, United States Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, United States
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29
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Ramer LM, Ramer MS, Bradbury EJ. Restoring function after spinal cord injury: towards clinical translation of experimental strategies. Lancet Neurol 2014; 13:1241-56. [PMID: 25453463 DOI: 10.1016/s1474-4422(14)70144-9] [Citation(s) in RCA: 196] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Spinal cord injury is currently incurable and treatment is limited to minimising secondary complications and maximising residual function by rehabilitation. Improved understanding of the pathophysiology of spinal cord injury and the factors that prevent nerve and tissue repair has fuelled a move towards more ambitious experimental treatments aimed at promoting neuroprotection, axonal regeneration, and neuroplasticity. By necessity, these new options are more invasive. However, in view of recent advances in spinal cord injury research and demand from patients, clinicians, and the scientific community to push promising experimental treatments to the clinic, momentum and optimism exist for the translation of candidate experimental treatments to clinical spinal cord injury. The ability to rescue, reactivate, and rewire spinal systems to restore function after spinal cord injury might soon be within reach.
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Affiliation(s)
- Leanne M Ramer
- King's College London, Regeneration Group, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, UK; International Collaboration On Repair Discoveries, Blusson Spinal Cord Centre, Vancouver General Hospital, Vancouver, BC, Canada
| | - Matt S Ramer
- King's College London, Regeneration Group, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, UK; International Collaboration On Repair Discoveries, Blusson Spinal Cord Centre, Vancouver General Hospital, Vancouver, BC, Canada; Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Elizabeth J Bradbury
- King's College London, Regeneration Group, Wolfson Centre for Age-Related Diseases, Guy's Campus, London, UK.
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