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Cell transplantation to repair the injured spinal cord. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 166:79-158. [PMID: 36424097 PMCID: PMC10008620 DOI: 10.1016/bs.irn.2022.09.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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2
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Sever-Bahcekapili M, Yilmaz C, Demirel A, Kilinc MC, Dogan I, Caglar YS, Guler MO, Tekinay AB. Neuroactive Peptide Nanofibers for Regeneration of Spinal Cord after Injury. Macromol Biosci 2020; 21:e2000234. [PMID: 33043585 DOI: 10.1002/mabi.202000234] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 09/23/2020] [Indexed: 12/27/2022]
Abstract
The highly complex nature of spinal cord injuries (SCIs) requires design of novel biomaterials that can stimulate cellular regeneration and functional recovery. Promising SCI treatments use biomaterial scaffolds, which provide bioactive cues to the cells in order to trigger neural regeneration in the spinal cord. In this work, the use of peptide nanofibers is demonstrated, presenting protein binding and cellular adhesion epitopes in a rat model of SCI. The self-assembling peptide molecules are designed to form nanofibers, which display heparan sulfate mimetic and laminin mimetic epitopes to the cells in the spinal cord. These neuroactive nanofibers are found to support adhesion and viability of dorsal root ganglion neurons as well as neurite outgrowth in vitro and enhance tissue integrity after 6 weeks of injury in vivo. Treatment with the peptide nanofiber scaffolds also show significant behavioral improvement. These results demonstrate that it is possible to facilitate regeneration especially in the white matter of the spinal cord, which is usually damaged during the accidents using bioactive 3D nanostructures displaying high densities of laminin and heparan sulfate-mimetic epitopes on their surfaces.
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Affiliation(s)
- Melike Sever-Bahcekapili
- Institute of Materials Science and NanotechnologyNational Nanotechnology Research Center (UNAM), Bilkent University, Ankara, 06800, Turkey
| | - Canelif Yilmaz
- Neuroscience Graduate Program, Bilkent University, Ankara, 06800, Turkey
| | - Altan Demirel
- Department of Neurosurgery, Aksaray State Hospital, Aksaray, 68200, Turkey
| | - Mustafa Cemil Kilinc
- Faculty of Medicine, Department of Neurosurgery, Ankara University, Ankara, 06100, Turkey
| | - Ihsan Dogan
- Faculty of Medicine, Department of Neurosurgery, Ankara University, Ankara, 06100, Turkey
| | - Yusuf Sukru Caglar
- Faculty of Medicine, Department of Neurosurgery, Ankara University, Ankara, 06100, Turkey
| | - Mustafa O Guler
- The Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL, 60637, USA
| | - Ayse B Tekinay
- Institute of Materials Science and NanotechnologyNational Nanotechnology Research Center (UNAM), Bilkent University, Ankara, 06800, Turkey.,The Pritzker School of Molecular Engineering, The University of Chicago, Chicago, IL, 60637, USA.,Eryigit Research and Development Center, Ankara, 06380, Turkey
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3
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Adler AF, Björklund A, Parmar M. Transsynaptic tracing and its emerging use to assess graft-reconstructed neural circuits. Stem Cells 2020; 38:716-726. [PMID: 32101353 DOI: 10.1002/stem.3166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/20/2020] [Accepted: 02/19/2020] [Indexed: 12/16/2022]
Abstract
Fetal neural progenitor grafts have been evaluated in preclinical animal models of spinal cord injury and Parkinson's disease for decades, but the initial reliance on primary tissue as a cell source limited the scale of their clinical translatability. With the development of robust methods to differentiate human pluripotent stem cells to specific neural subtypes, cell replacement therapy holds renewed promise to treat a variety of neurodegenerative diseases and injuries at scale. As these cell sources are evaluated in preclinical models, new transsynaptic tracing methods are making it possible to study the connectivity between host and graft neurons with greater speed and detail than was previously possible. To date, these studies have revealed that widespread, long-lasting, and anatomically appropriate synaptic contacts are established between host and graft neurons, as well as new aspects of host-graft connectivity which may be relevant to clinical cell replacement therapy. It is not yet clear, however, whether the synaptic connectivity between graft and host neurons is as cell-type specific as it is in the endogenous nervous system, or whether that connectivity is responsible for the functional efficacy of cell replacement therapy. Here, we review evidence suggesting that the new contacts established between host and graft neurons may indeed be cell-type specific, and how transsynaptic tracing can be used in the future to further elucidate the mechanisms of graft-mediated functional recovery in spinal cord injury and Parkinson's disease.
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Affiliation(s)
- Andrew F Adler
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden.,Lund Stem Cell Center, Lund University, Lund, Sweden
| | - Anders Björklund
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden
| | - Malin Parmar
- Developmental and Regenerative Neurobiology, Department of Experimental Medical Science, Wallenberg Neuroscience Center, Lund University, Lund, Sweden.,Lund Stem Cell Center, Lund University, Lund, Sweden
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4
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Grafting Embryonic Raphe Neurons Reestablishes Serotonergic Regulation of Sympathetic Activity to Improve Cardiovascular Function after Spinal Cord Injury. J Neurosci 2020; 40:1248-1264. [PMID: 31896670 DOI: 10.1523/jneurosci.1654-19.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/17/2019] [Accepted: 12/18/2019] [Indexed: 12/16/2022] Open
Abstract
Cardiovascular dysfunction often occurs after high-level spinal cord injury. Disrupting supraspinal vasomotor pathways affects basal hemodynamics and contributes to the development of autonomic dysreflexia (AD). Transplantation of early-stage neurons to the injured cord may reconstruct the descending projections to enhance cardiovascular performance. To determine the specific role of reestablishing serotonergic regulation of hemodynamics, we implanted serotonergic (5-HT+) neuron-enriched embryonic raphe nucleus-derived neural stem cells/progenitors (RN-NSCs) into a complete spinal cord transection lesion site in adult female rats. Grafting embryonic spinal cord-derived NSCs or injury alone served as 2 controls. Ten weeks after injury/grafting, histological analysis revealed well-survived grafts and partial integration with host tissues in the lesion site. Numerous graft-derived serotonergic axons topographically projected to the caudal autonomic regions. Neuronal tracing showed that host supraspinal vasomotor pathways regenerated into the graft, and 5-HT+ neurons within graft and host brainstem neurons were transsynaptically labeled by injecting pseudorabies virus (PRV-614) into the kidney, indicating reconnected serotonergic circuits regulating autonomic activity. Using an implanted telemeter to record cardiovascular parameters, grafting RN-NSCs restored resting mean arterial pressure to normal levels and remarkably alleviated naturally occurring and colorectal distension-induced AD. Subsequent pharmacological blockade of 5-HT2A receptors with ketanserin in RN-NSC-grafted rats reduced resting mean arterial pressure and increased heart rate in all but 2 controls. Furthermore, spinal cord retransection below RN-NSC grafts partially eliminated the recovery in AD. Collectively, these data indicate that RN-NSCs grafted into a spinal cord injury site relay supraspinal control of serotonergic regulation for sympathetic activity to improve cardiovascular function.SIGNIFICANCE STATEMENT Disruption of supraspinal vasomotor pathways results in cardiovascular dysfunction following high-level spinal cord injury. To reestablish the descending regulation of autonomic function, we transplanted serotonergic neuron enriched embryonic raphe nucleus-derived neural stem cells/progenitors into the lesion site of completely transected rat spinal cord. Consequently, grafted raphe nucleus-derived neural stem cells/progenitors acted as a neuronal relay to reconnect supraspinal center and spinal sympathetic neurons below the injury. The reconstituted serotonergic regulation of sympathetic activity led to the improvement of hemodynamic parameters and mitigated autonomic dysreflexia. Based on morphological and physiological results, this study validates the effectiveness of transplanting early-stage serotonergic neurons into the spinal cord for cardiovascular functional recovery after spinal cord injury.
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Vishwakarma SK, Bardia A, Lakkireddy C, Paspala SAB, Khan AA. Bioengineering Human Neurological Constructs Using Decellularized Meningeal Scaffolds for Application in Spinal Cord Injury. Front Bioeng Biotechnol 2018; 6:150. [PMID: 30443545 PMCID: PMC6221909 DOI: 10.3389/fbioe.2018.00150] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/02/2018] [Indexed: 12/25/2022] Open
Abstract
Spinal cord injury (SCI) is one of the most devastating conditions echoes with inflammation, enhanced fibrosis and larger axonal gaps due to destruction of neurological cells which has caused continuous increasing mortality rate of SCI patients due to absence of suitable treatment modalities. The restoration of structural and functional aspect of damaged neurological tissues at the lesion site in spinal cord has been challenging. Recent developments have showed tremendous potential of neural stem cell-based strategies to form a neuronal relay circuit across the injury gap which facilitates some levels of improvement in SCI condition. However, to provide better therapeutic responses, critical mass of grafted cells must survive for long-term and differentiate into neuronal cells with well-developed axonal networks. Hence, development of tissue specific biological neuronal constructs is highly desirable to provide mechanical and biological support for long-term survival and function of neurological cells within natural biological niche. In this study, we report development of a tissue specific neuronal constructs by culturing human neural precursor cells on decellularized meningeal scaffolds to provide suitable biological neuronal construct which can be used to support mechanical, structural and functional aspect of damaged spinal cord tissues. This particular tissue specific biological construct is immunologically tolerable and provides precisely orchestral three-dimensional platform to choreograph the long-distance axonal guidance and more organized neuronal cell growth. It passes sufficient mechanical and biological properties enriched with several crucial neurotrophins required for long-term survival and function of neurological cells which is required to form proper axonal bridge to regenerate the damaged axonal connectomes at lesion-site in SCI.
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Affiliation(s)
- Sandeep Kumar Vishwakarma
- Central Laboratory for Stem Cell Research and Translational Medicine, CLRD, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, India
- Dr. Habeebullah Life Sciences, Hyderabad, India
| | - Avinash Bardia
- Central Laboratory for Stem Cell Research and Translational Medicine, CLRD, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, India
- Dr. Habeebullah Life Sciences, Hyderabad, India
| | - Chandrakala Lakkireddy
- Central Laboratory for Stem Cell Research and Translational Medicine, CLRD, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, India
- Dr. Habeebullah Life Sciences, Hyderabad, India
| | - Syed Ameer Basha Paspala
- Central Laboratory for Stem Cell Research and Translational Medicine, CLRD, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, India
- Dr. Habeebullah Life Sciences, Hyderabad, India
| | - Aleem Ahmed Khan
- Central Laboratory for Stem Cell Research and Translational Medicine, CLRD, Deccan College of Medical Sciences, Kanchanbagh, Hyderabad, India
- Dr. Habeebullah Life Sciences, Hyderabad, India
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Spruance VM, Zholudeva LV, Hormigo KM, Randelman ML, Bezdudnaya T, Marchenko V, Lane MA. Integration of Transplanted Neural Precursors with the Injured Cervical Spinal Cord. J Neurotrauma 2018; 35:1781-1799. [PMID: 29295654 PMCID: PMC6033309 DOI: 10.1089/neu.2017.5451] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cervical spinal cord injuries (SCI) result in devastating functional consequences, including respiratory dysfunction. This is largely attributed to the disruption of phrenic pathways, which control the diaphragm. Recent work has identified spinal interneurons as possible contributors to respiratory neuroplasticity. The present work investigated whether transplantation of developing spinal cord tissue, inherently rich in interneuronal progenitors, could provide a population of new neurons and growth-permissive substrate to facilitate plasticity and formation of novel relay circuits to restore input to the partially denervated phrenic motor circuit. One week after a lateralized, C3/4 contusion injury, adult Sprague-Dawley rats received allografts of dissociated, developing spinal cord tissue (from rats at gestational days 13-14). Neuroanatomical tracing and terminal electrophysiology was performed on the graft recipients 1 month later. Experiments using pseudorabies virus (a retrograde, transynaptic tracer) revealed connections from donor neurons onto host phrenic circuitry and from host, cervical interneurons onto donor neurons. Anatomical characterization of donor neurons revealed phenotypic heterogeneity, though donor-host connectivity appeared selective. Despite the consistent presence of cholinergic interneurons within donor tissue, transneuronal tracing revealed minimal connectivity with host phrenic circuitry. Phrenic nerve recordings revealed changes in burst amplitude after application of a glutamatergic, but not serotonergic antagonist to the transplant, suggesting a degree of functional connectivity between donor neurons and host phrenic circuitry that is regulated by glutamatergic input. Importantly, however, anatomical and functional results were variable across animals, and future studies will explore ways to refine donor cell populations and entrain consistent connectivity.
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Affiliation(s)
- Victoria M Spruance
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Lyandysha V Zholudeva
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Kristiina M Hormigo
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Margo L Randelman
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Tatiana Bezdudnaya
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Vitaliy Marchenko
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Michael A Lane
- Department of Neurobiology and Anatomy, Spinal Cord Research Center, Drexel University College of Medicine , Philadelphia, Pennsylvania
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Rosenzweig ES, Brock JH, Lu P, Kumamaru H, Salegio EA, Kadoya K, Weber JL, Liang JJ, Moseanko R, Hawbecker S, Huie JR, Havton LA, Nout-Lomas YS, Ferguson AR, Beattie MS, Bresnahan JC, Tuszynski MH. Restorative effects of human neural stem cell grafts on the primate spinal cord. Nat Med 2018; 24:484-490. [PMID: 29480894 DOI: 10.1038/nm.4502] [Citation(s) in RCA: 209] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 01/26/2018] [Indexed: 12/14/2022]
Abstract
We grafted human spinal cord-derived neural progenitor cells (NPCs) into sites of cervical spinal cord injury in rhesus monkeys (Macaca mulatta). Under three-drug immunosuppression, grafts survived at least 9 months postinjury and expressed both neuronal and glial markers. Monkey axons regenerated into grafts and formed synapses. Hundreds of thousands of human axons extended out from grafts through monkey white matter and synapsed in distal gray matter. Grafts gradually matured over 9 months and improved forelimb function beginning several months after grafting. These findings in a 'preclinical trial' support translation of NPC graft therapy to humans with the objective of reconstituting both a neuronal and glial milieu in the site of spinal cord injury.
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Affiliation(s)
- Ephron S Rosenzweig
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - John H Brock
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA.,Veterans Administration Medical Center, La Jolla, California, USA
| | - Paul Lu
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA.,Veterans Administration Medical Center, La Jolla, California, USA
| | - Hiromi Kumamaru
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Ernesto A Salegio
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - Ken Kadoya
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA.,Department of Orthopaedic Surgery, Hokkaido University, Sapporo, Japan
| | - Janet L Weber
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Justine J Liang
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA
| | - Rod Moseanko
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - Stephanie Hawbecker
- California National Primate Research Center, University of California, Davis, Davis, California, USA
| | - J Russell Huie
- Department of Neurosurgery, University of California, San Francisco, San Francisco, California, USA
| | - Leif A Havton
- Department of Neurology, University of California, Los Angeles, Los Angeles, California, USA
| | - Yvette S Nout-Lomas
- College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USA
| | - Adam R Ferguson
- Department of Neurosurgery, University of California, San Francisco, San Francisco, California, USA.,Veterans Administration Medical Center, San Francisco, California, USA
| | - Michael S Beattie
- Department of Neurosurgery, University of California, San Francisco, San Francisco, California, USA
| | - Jacqueline C Bresnahan
- Department of Neurosurgery, University of California, San Francisco, San Francisco, California, USA
| | - Mark H Tuszynski
- Department of Neurosciences, University of California, San Diego, La Jolla, California, USA.,Veterans Administration Medical Center, La Jolla, California, USA
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8
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Giovanini MA, Reier PJ, Eskin TA, Anderson DK. Map2 Expression in the Developing Human Fetal Spinal Cord and following Xenotransplantation. Cell Transplant 2017; 6:339-46. [PMID: 9171166 DOI: 10.1177/096368979700600316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Human fetal spinal cord (FSC) tissue was obtained from elective abortions at 6-14 wk gestational age (GA). The specimens were then either immediately processed for immunohistochemical analysis or xenotransplantation. In the latter case, donor tissue was prepared as a dissociated cell suspension and then introduced either sub-pially or intraspinally into contusion lesions of the adult rat midthoracic spinal cord. The xenografts were subsequently examined by conventional histological and immunohistochemical methods at 2-3 mo postgrafting. Immunostaining showed that MAP2 was expressed heavily in cells residing in the mantle layer of the human fetal spinal cord in situ as early as 6 wk GA. Subpial and intraparenchymal xenografts also were intensely immunoreactive for MAP2, but no staining of surrounding host neural tissue was detected. We conclude that the differential expression of MAP2 can be used to distinguish human graft tissue from the surrounding rat spinal cord in this xenograft paradigm. Under appropriate staining conditions, MAP2 can thus serve to facilitate analyses of host-graft integration, donor cell migration, and neuritic outgrowth.
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Affiliation(s)
- M A Giovanini
- Department of Neurological Surgery, Gainesville Veterans Affairs Medical Center, University of Florida College of Medicine, 32610, USA
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Blits B, Boer GJ, Verhaagen J. Pharmacological, Cell, and Gene Therapy Strategies to Promote Spinal Cord Regeneration. Cell Transplant 2017. [DOI: 10.3727/000000002783985521] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
In this review, recent studies using pharmacological treatment, cell transplantation, and gene therapy to promote regeneration of the injured spinal cord in animal models will be summarized. Pharmacological and cell transplantation treatments generally revealed some degree of effect on the regeneration of the injured ascending and descending tracts, but further improvements to achieve a more significant functional recovery are necessary. The use of gene therapy to promote repair of the injured nervous system is a relatively new concept. It is based on the development of methods for delivering therapeutic genes to neurons, glia cells, or nonneural cells. Direct in vivo gene transfer or gene transfer in combination with (neuro)transplantation (ex vivo gene transfer) appeared powerful strategies to promote neuronal survival and axonal regrowth following traumatic injury to the central nervous system. Recent advances in understanding the cellular and molecular mechanisms that govern neuronal survival and neurite outgrowth have enabled the design of experiments aimed at viral vector-mediated transfer of genes encoding neurotrophic factors, growth-associated proteins, cell adhesion molecules, and antiapoptotic genes. Central to the success of these approaches was the development of efficient, nontoxic vectors for gene delivery and the acquirement of the appropriate (genetically modified) cells for neurotransplantation. Direct gene transfer in the nervous system was first achieved with herpes viral and E1-deleted adenoviral vectors. Both vector systems are problematic in that these vectors elicit immunogenic and cytotoxic responses. Adeno-associated viral vectors and lentiviral vectors constitute improved gene delivery systems and are beginning to be applied in neuroregeneration research of the spinal cord. Ex vivo approaches were initially based on the implantation of genetically modified fibroblasts. More recently, transduced Schwann cells, genetically modified pieces of peripheral nerve, and olfactory ensheathing glia have been used as implants into the injured spinal cord.
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Affiliation(s)
- Bas Blits
- Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research, Meibergdreef 33, 1105 AZ Amsterdam-ZO, The Netherlands
| | - Gerard J. Boer
- Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research, Meibergdreef 33, 1105 AZ Amsterdam-ZO, The Netherlands
| | - Joost Verhaagen
- Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research, Meibergdreef 33, 1105 AZ Amsterdam-ZO, The Netherlands
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Onifer SM, Cannon AB, Whittemore SR. Altered Differentiation of Cns Neural Progenitor Cells after Transplantation into the Injured Adult Rat Spinal Cord. Cell Transplant 2017; 6:327-38. [PMID: 9171165 DOI: 10.1177/096368979700600315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Denervation of CNS neurons and peripheral organs is a consequence of traumatic SCI. Intraspinal transplantation of embryonic CNS neurons is a potential strategy for reinnervating these targets. Neural progenitor cell lines are being investigated as alternates to embryonic CNS neurons. RN33B is an immortalized neural progenitor cell line derived from embryonic rat raphé nuclei following infection with a retrovirus encoding the temperature-sensitive mutant of SV40 large T-antigen. Transplantation studies have shown that local epigenetic signals in intact or partially neuron-depleted adult rat hippocampal formation or striatum direct RN33B cell differentiation to complex multipolar morphologies resembling endogenous neurons. After transplantation into neuron-depleted regions of the hippocampal formation or striatum, RN33B cells were relatively undifferentiated or differentiated with bipolar morphologies. The present study examines RN33B cell differentiation after transplantation into normal spinal cord and under different lesion conditions. Adult rats underwent either unilateral lesion of lumbar spinal neurons by intraspinal injection of kainic acid or complete transection at the T10 spinal segment. Neonatal rats underwent either unilateral lesion of lumbar motoneurons by sciatic nerve crush or complete transection at the T10 segment. At 2 or 6-7 wk postinjury, lacZ-labeled RN33B cells were transplanted into the lumbar enlargement of injured and age-matched normal rats. At 2 wk posttransplantation, bipolar and some multipolar RN33B cells were found throughout normal rat gray matter. In contrast, only bipolar RN33B cells were seen in gray matter of kainic acid lesioned, sciatic nerve crush, or transection rats. These observations suggest that RN33B cell multipolar morphological differentiation in normal adult spinal cord is mediated by direct cell-cell interaction through surface molecules on endogenous neurons and may be suppressed by molecules released after SCI. They also indicate that the fate of immortalized neural progenitor cell lines in injured CNS must be stringently characterized.
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Affiliation(s)
- S M Onifer
- The Miami Project to Cure Paralysis, University of Miami School of Medicine, FL 33136, USA
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11
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Abstract
Research over the past decade has demonstrated that, under some circumstances, structural reorganization of the CNS, including the spinal cord, can occur after injury, raising hopes that spinal cord repair associated with functional recovery, although a daunting goal, may not be an unreachable one. This brief review dis cusses recent approaches to this problem: use of neurotrophins and the rerouting of axons within the transected spinal cord from white matter to gray matter through nerve grafts, and the transplantation of exogenous myelin-forming glial cells to spinal cord tracts in which myelin has been lost. Results available to date indicate that, in models mimicking some aspects of human spinal cord injury, these approaches may yield anatomical repair that is associated with partial restoration of physiological and behavioral func tion. Many important questions remain unanswered. Nevertheless, although the clinical goal of repairing spinal cords in humans is a very challenging one, results in animal models suggest that spinal cord repair is a realistic objective and provide a glimpse of what is likely to be a period of rapid progress. NEURO SCIENTIST 3:263-269, 1997
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Affiliation(s)
- Stephen G. Waxman
- Department of Neurology Yale University School of Medicine
New Haven, Connecticut PVAlEPVA Center for Neuroscience Veterans Administration
Medical Center West Haven, Connecticut
| | - Jeffery D. Kocsis
- Department of Neurology Yale University School of Medicine
New Haven, Connecticut PVAlEPVA Center for Neuroscience Veterans Administration
Medical Center West Haven, Connecticut
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12
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Abstract
Spinal cord injury (SCI) often represents a condition of permanent neurologic deficit. It has been possible to understand and delineate the mechanisms contributing to loss of function following primary injury. The clinicians might hope to improve the outcome in SCI injury by designing treatment strategies that could target these secondary mechanisms of response to injury. However, the approaches like molecular targeting of the neurons or surgical interventions have yielded very limited success till date. In recent times, a great thrust is put on to the cellular transplantation mode of treatment strategies to combat SCI problems so as to gain maximum functional recovery. In this review, we discuss about the various cellular transplantation strategies that could be employed in the treatment of SCI. The success of such cellular approaches involving Schwann cells, olfactory ensheathing cells, peripheral nerve, embryonic CNS tissue and activated macrophage has been supported by a number of reports and has been detailed here. Many of these cell transplantation strategies have reached the clinical trial stages. Also, the evolving field of stem cell therapy has made it possible to contemplate the role of both embryonic stem cells and induced pluripotent stem cells to stimulate the differentiation of neurons when transplanted in SCI models. Moreover, the roles of tissue engineering techniques and synthetic biomaterials have also been explained with their beneficial and deleterious effects. Many of these cell-based therapeutic approaches have been able to cause only a little change in recovery and a combinatorial approach involving more than one strategy are now being tried out to successfully treat SCI and improve functional recovery.
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13
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Hou S. Relay strategies combined with axon regeneration: a promising approach to restore spinal cord injury. Neural Regen Res 2014; 9:1177-9. [PMID: 25206778 PMCID: PMC4146293 DOI: 10.4103/1673-5374.135322] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/23/2014] [Indexed: 12/19/2022] Open
Affiliation(s)
- Shaoping Hou
- Spinal Cord Research Center, Department of Neurobiology & Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
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14
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Burnside ER, Bradbury EJ. Review: Manipulating the extracellular matrix and its role in brain and spinal cord plasticity and repair. Neuropathol Appl Neurobiol 2014; 40:26-59. [DOI: 10.1111/nan.12114] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 12/20/2013] [Indexed: 12/17/2022]
Affiliation(s)
- E. R. Burnside
- King's College London; Regeneration Group; The Wolfson Centre for Age-Related Diseases; Guy's Campus; London UK
| | - E. J. Bradbury
- King's College London; Regeneration Group; The Wolfson Centre for Age-Related Diseases; Guy's Campus; London UK
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15
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In vivo (31)P NMR spectroscopy assessment of skeletal muscle bioenergetics after spinal cord contusion in rats. Eur J Appl Physiol 2014; 114:847-58. [PMID: 24399112 DOI: 10.1007/s00421-013-2810-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 11/29/2013] [Indexed: 10/25/2022]
Abstract
PURPOSE Muscle paralysis after spinal cord injury leads to muscle atrophy, enhanced muscle fatigue, and increased energy demands for functional activities. Phosphorus magnetic resonance spectroscopy ((31)P-MRS) offers a unique non-invasive alternative of measuring energy metabolism in skeletal muscle and is especially suitable for longitudinal investigations. We determined the impact of spinal cord contusion on in vivo muscle bioenergetics of the rat hind limb muscle using (31)P-MRS. METHODS A moderate spinal cord contusion injury (cSCI) was induced at the T8-T10 thoracic spinal segments. (31)P-MRS measurements were performed weekly in the rat hind limb muscles for 3 weeks. Spectra were acquired in a Bruker 11 T/470 MHz spectrometer using a 31P surface coil. The sciatic nerve was electrically stimulated by subcutaneous needle electrodes. Spectra were acquired at rest (5 min), during stimulation (6 min), and recovery (20 min). Phosphocreatine (PCr) depletion rates and the pseudo first-order rate constant for PCr recovery (k PCr) were determined. The maximal rate of PCr resynthesis, the in vivo maximum oxidative capacity (V max) and oxidative adenosine triphosphate (ATP) synthesis rate (Q max) were subsequently calculated. RESULTS One week after cSCI, there was a decline in the resting total creatine of the paralyzed muscle. There was a significant reduction (~24 %) in k PCr measures of the paralyzed muscle, maximum in vivo mitochondrial capacity (V max) and the maximum oxidative ATP synthesis rate (Q max) at 1 week post-cSCI. During exercise, the PCr depletion rates in the paralyzed muscle one week after injury were rapid and to a greater extent than in a healthy muscle. CONCLUSIONS Using in vivo MRS assessments, we reveal an acute oxidative metabolic defect in the paralyzed hind limb muscle. These altered muscle bioenergetics might contribute to the host of motor dysfunctions seen after cSCI.
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Nakano N, Nakai Y, Seo TB, Homma T, Yamada Y, Ohta M, Suzuki Y, Nakatani T, Fukushima M, Hayashibe M, Ide C. Effects of bone marrow stromal cell transplantation through CSF on the subacute and chronic spinal cord injury in rats. PLoS One 2013; 8:e73494. [PMID: 24039961 PMCID: PMC3770680 DOI: 10.1371/journal.pone.0073494] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 07/30/2013] [Indexed: 12/18/2022] Open
Abstract
It has been demonstrated that the infusion of bone marrow stromal cells (BMSCs) through the cerebrospinal fluid (CSF) has beneficial effects on acute spinal cord injury (SCI) in rats. The present study examined whether BMSC infusion into the CSF is effective for subacute (1- and 2-week post-injury), and/or chronic (4-week post-injury) SCI in rats. The spinal cord was contused by dropping a weight at the thoracic 8-9 levels. BMSCs cultured from GFP-transgenic rats of the same strain were injected three times (once weekly) into the CSF through the fourth ventricle, beginning at 1, 2 and 4 weeks post-injury. At 4 weeks after initial injection, the average BBB score for locomotor assessment increased from 1.0–3.5 points before injection to 9.0-10.9 points in the BMSC-injection subgroups, while, in the PBS (vehicle)-injection subgroups, it increased only from 0.5–4.0 points before injection to 3.0-5.1 points. Numerous axons associated with Schwann cells extended longitudinally through the connective tissue matrices in the astrocyte-devoid lesion without being blocked at either the rostral or the caudal borders in the BMSC-injection subgroups. A small number of BMSCs were found to survive within the spinal cord lesion in SCI of the 1-week post-injury at 2 days of injection, but none at 7 days. No BMSCs were found in the spinal cord lesion at 2 days or at 7 days in the SCI of the 2-week and the 4-week post-injury groups. In an in vitro experiment, BMSC-injected CSF promoted the survival and the neurite extension of cultured neurons more effectively than did the PBS-injected CSF. These results indicate that BMSCs had beneficial effects on locomotor improvement as well as on axonal regeneration in both subacute and chronic SCI rats, and the results also suggest that BMSCs might function as neurotrophic sources via the CSF.
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Affiliation(s)
- Norihiko Nakano
- Institute of Regeneration and Rehabilitation, Aino University School of Nursing and Rehabilitation, Osaka, Japan
| | - Yoshiyasu Nakai
- Institute of Regeneration and Rehabilitation, Aino University School of Nursing and Rehabilitation, Osaka, Japan
| | - Tae-Beom Seo
- Institute of Regeneration and Rehabilitation, Aino University School of Nursing and Rehabilitation, Osaka, Japan
| | - Tamami Homma
- Institute of Regeneration and Rehabilitation, Aino University School of Nursing and Rehabilitation, Osaka, Japan
| | - Yoshihiro Yamada
- Department of Physical Therapy, Aino University School of Nursing and Rehabilitation, Osaka, Japan
| | - Masayoshi Ohta
- Department of Plastic and Reconstructive Surgery, Tazuke Medical Research Institute, Kitano Hospital, Osaka, Japan
| | - Yoshihisa Suzuki
- Department of Plastic and Reconstructive Surgery, Tazuke Medical Research Institute, Kitano Hospital, Osaka, Japan
| | - Toshio Nakatani
- Emergency and Critical Care Center, Kansai Medical University, Osaka, Japan
| | - Masanori Fukushima
- Translational Research Informatics Center, Foundation for Biomedical Research and Innovation, Kobe, Japan
| | - Miki Hayashibe
- Department of Occupational Therapy, Aino University School of Nursing and Rehabilitation, Osaka, Japan
| | - Chizuka Ide
- Institute of Regeneration and Rehabilitation, Aino University School of Nursing and Rehabilitation, Osaka, Japan
- Department of Occupational Therapy, Aino University School of Nursing and Rehabilitation, Osaka, Japan
- * E-mail:
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Bose PK, Hou J, Parmer R, Reier PJ, Thompson FJ. Altered patterns of reflex excitability, balance, and locomotion following spinal cord injury and locomotor training. Front Physiol 2012; 3:258. [PMID: 22934014 PMCID: PMC3429034 DOI: 10.3389/fphys.2012.00258] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 06/20/2012] [Indexed: 11/13/2022] Open
Abstract
Spasticity is an important problem that complicates daily living in many individuals with spinal cord injury (SCI). While previous studies in human and animals revealed significant improvements in locomotor ability with treadmill locomotor training, it is not known to what extent locomotor training influences spasticity. In addition, it would be of considerable practical interest to know how the more ergonomically feasible cycle training compares with treadmill training as therapy to manage SCI-induced spasticity and to improve locomotor function. Thus the main objective of our present studies was to evaluate the influence of different types of locomotor training on measures of limb spasticity, gait, and reflex components that contribute to locomotion. For these studies, 30 animals received midthoracic SCI using the standard Multicenter Animal Spinal cord Injury Studies (MASCIS) protocol (10 g 2.5 cm weight drop). They were divided randomly into three equal groups: control (contused untrained), contused treadmill trained, and contused cycle trained. Treadmill and cycle training were started on post-injury day 8. Velocity-dependent ankle torque was tested across a wide range of velocities (612-49°/s) to permit quantitation of tonic (low velocity) and dynamic (high velocity) contributions to lower limb spasticity. By post-injury weeks 4 and 6, the untrained group revealed significant velocity-dependent ankle extensor spasticity, compared to pre-surgical control values. At these post-injury time points, spasticity was not observed in either of the two training groups. Instead, a significantly milder form of velocity-dependent spasticity was detected at postcontusion weeks 8-12 in both treadmill and bicycle training groups at the four fastest ankle rotation velocities (350-612°/s). Locomotor training using treadmill or bicycle also produced significant increase in the rate of recovery of limb placement measures (limb axis, base of support, and open field locomotor ability) and reflex rate-depression, a quantitative assessment of neurophysiological processes that regulate segmental reflex excitability, compared with those of untrained injured controls. Light microscopic qualitative studies of spared tissue revealed better preservation of myelin, axons, and collagen morphology in both locomotor trained animals. Both locomotor trained groups revealed decreased lesion volume (rostro-caudal extension) and more spared tissue at the lesion site. These improvements were accompanied by marked upregulation of BDNF, GABA/GABA(b), and monoamines (e.g., norepinephrine and serotonin) which might account for these improved functions. These data are the first to indicate that the therapeutic efficacy of ergonomically practical cycle training is equal to that of the more labor-intensive treadmill training in reducing spasticity and improving locomotion following SCI in an animal model.
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Affiliation(s)
- Prodip K Bose
- Brain Rehabilitation Research Center, North Florida/South Georgia VA Medical Center Gainesville, FL, USA
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Miranda TAB, Vicente JMY, Marcon RM, Cristante AF, Morya E, Valle ACD. Time-related effects of general functional training in spinal cord-injured rats. Clinics (Sao Paulo) 2012; 67:799-804. [PMID: 22892926 PMCID: PMC3400172 DOI: 10.6061/clinics/2012(07)16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 03/09/2012] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES This prospective, randomized, experimental study with rats aimed to investigate the influence of general treatment strategies on the motor recovery of Wistar rats with moderate contusive spinal cord injury. METHODS A total of 51 Wistar rats were randomized into five groups: control, maze, ramp, runway, and sham (laminectomy only). The rats underwent spinal cord injury at the T9-T10 levels using the NYU-Impactor. Each group was trained for 12 minutes twice a week for two weeks before and five weeks after the spinal cord injury, except for the control group. Functional motor recovery was assessed with the Basso, Beattie, and Bresnahan Scale on the first postoperative day and then once a week for five weeks. The animals were euthanized, and the spinal cords were collected for histological analysis. RESULTS Ramp and maze groups showed an earlier and greater functional improvement effect than the control and runway groups. However, over time, unexpectedly, all of the groups showed similar effects as the control group, with spontaneous recovery. There were no histological differences in the injured area between the trained and control groups. CONCLUSION Short-term benefits can be associated with a specific training regime; however, the same training was ineffective at maintaining superior long-term recovery. These results might support new considerations before hospital discharge of patients with spinal cord injuries.
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Hejčl A, Jendelová P, Syková E. Experimental reconstruction of the injured spinal cord. Adv Tech Stand Neurosurg 2011:65-95. [PMID: 21997741 DOI: 10.1007/978-3-7091-0673-0_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Injury to the spinal cord, with its pathological sequelae, results in a permanent neurological deficit. With currently available tools at hand, there is very little that clinicians can do to treat such a condition with the view of helping patients with spinal cord injury (SCI). On the other hand, in the last 20 years experimental research has brought new insights into the pathophysiology of spinal cord injury; we can divide the time course into 3 phases: primary injury (the time of traumatic impact and the period immediately afterwards), the secondary phase (cell death, inflammation, ischemia), and the chronic phase (scarring, demyelination, cyst formation). Increased knowledge about the pathophysiology of SCI can stimulate the development of new therapeutic modalities and approaches, which may be feasible in the future in clinical practice. Some of the most promising experimental therapies include: neurotrophic factors, enzymes and antibodies against inhibitory molecules (such as Nogo), activated macrophages, stem cells and bridging scaffolds. Their common goal is to reconstitute the damaged tissue in order to recover the lost function. In the current review, we focus on some of the recent developments in experimental SCI research.
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Affiliation(s)
- A Hejčl
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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20
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Usvald D, Vodicka P, Hlucilova J, Prochazka R, Motlik J, Kuchorova K, Johe K, Marsala S, Scadeng M, Kakinohana O, Navarro R, Santa M, Hefferan MP, Yaksh TL, Marsala M. Analysis of Dosing Regimen and Reproducibility of Intraspinal Grafting of Human Spinal Stem Cells in Immunosuppressed Minipigs. Cell Transplant 2010; 19:1103-22. [DOI: 10.3727/096368910x503406] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In recent studies using a rat aortic balloon occlusion model, we have demonstrated that spinal grafting of rat or human neuronal precursors or human postmitotic hNT neurons leads to progressive amelioration of spasticity and rigidity and corresponding improvement in ambulatory function. In the present study, we characterized the optimal dosing regimen and safety profile of human spinal stem cells (HSSC) when grafted into the lumbar spinal cord segments of naive immunosuppressed minipigs. Gottingen-Minnesota minipigs (18–23 kg) were anesthetized with halothane, mounted into a spine-immobilization apparatus, and received five bilateral injections of HSSC delivered in 2, 4, 6, 8, or 10 μl of media targeted into L2-L5 central gray matter (lamina VII). The total number of delivered cells ranged between 2,500 and 100,000 per injection. Animals were immunosuppressed with Prograf® for the duration of study. After cell grafting, ambulatory function was monitored daily using a Tarlov's score. Sensory functions were assessed by mechanically evoked skin twitch test. Animals survived for 6–7 weeks. Three days before sacrifice animals received daily injections of bromodeoxyuridine (100 mg/kg; IV) and were then transcardially perfused with 4% paraformaldehyde. Th12-L6 spinal column was then dissected; the spinal cord was removed and scanned with MRI. Lumbar transverse spinal cord sections were then cut and stained with a combination of human-specific (hNUMA, hMOC, hNSE, hSYN) or nonspecific (DCX, MAP2, GABA, CHAT) antibodies. The total number of surviving cells was estimated using stereological quantification. During the first 12–24 h after cell grafting, a modest motor weakness was observed in three of eight animals but was no longer present at 4 days to 7 weeks. No sensory dysfunction was seen at any time point. Postmortem MRI scans revealed the presence of the individual grafts in the targeted spinal cord areas. Histological examination of spinal cord sections revealed the presence of hNUMA-immunoreactive grafted cells distributed between the base of the dorsal horn and the ventral horn. In all grafts intense hMOC, DCX, and hSYN immunoreactivity in grafted cells was seen. In addition, a rich axodendritic network of DCX-positive processes was identified extending 300–700 μm from the grafts. On average, 45% of hNUMA-positive neurons were GABA immunoreactive. Stereological analysis of hNUMA-positive cells showed an average of 2.5- to 3-fold increase in number of surviving cells compared with the number of injected cells. Analysis of spinal structural morphology showed that in animals injected with more than 50,000 cells/injection or volumes of injectate higher than 6 μl/injection there was tissue expansion and disruption of the local axodendritic network. Based on these data the safe total number of injected cells and volume of injectate were determined to be 30,000 cells delivered in ≤6 μl of media. These data demonstrate that highly reproducible delivery of a potential cell therapeutic candidate into spinal parenchyma can be achieved across a wide range of cell doses by direct intraspinal injections. The resulting grafts uniformly showed robust cell survival and progressive neuronal maturation.
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Affiliation(s)
- Dusan Usvald
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Libechov, Czech Republic
| | - Peter Vodicka
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Libechov, Czech Republic
| | - Jana Hlucilova
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Libechov, Czech Republic
| | - Radek Prochazka
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Libechov, Czech Republic
| | - Jan Motlik
- Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Libechov, Czech Republic
| | - Karolina Kuchorova
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
- Institute of Neurobiology, Slovak Academy of Sciences, Kosice, Slovakia
| | - Karl Johe
- Neuralstem, Inc., Rockville, MD, USA
| | - Silvia Marsala
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Miriam Scadeng
- UCSD Center for Functional MRI, University of California, San Diego, La Jolla, CA, USA
| | - Osamu Kakinohana
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Roman Navarro
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Marian Santa
- Faculty of Health, Department of Emergency Medicine, University of Presov, Presov, Slovakia
| | - Michael P. Hefferan
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Tony L. Yaksh
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
| | - Martin Marsala
- Anesthesiology Research Laboratory, University of California, San Diego, La Jolla, CA, USA
- Institute of Neurobiology, Slovak Academy of Sciences, Kosice, Slovakia
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Abstract
Stem cell therapy is a potential treatment for spinal cord injury (SCI), and a variety of different stem cell types have been evaluated in animal models and humans with SCI. No consensus exists regarding the type of stem cell, if any, that will prove to be effective therapeutically. Most data suggest that no single therapy will be sufficient to overcome all the biological complications caused by SCI. Rationales for therapeutic use of stem cells for SCI include replacement of damaged neurons and glial cells, secretion of trophic factors, regulation of gliosis and scar formation, prevention of cyst formation, and enhancement of axon elongation. Most therapeutic approaches that use stem cells involve implantation of these cells into the spinal cord. The attendant risks of stem cell therapy for SCI--including tumor formation, or abnormal circuit formation leading to dysfunction--must be weighed against the potential benefits of this approach. This Review will examine the biological effects of SCI, the opportunities for stem cell treatment, and the types of stem cells that might be used therapeutically. The limited information available on the possible benefits of stem cell therapy to humans will also be discussed.
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Affiliation(s)
- Vibhu Sahni
- MGH-HMS Center for Nervous System Repair, Harvard Medical School, 50 Blossom Street, Boston, MA 02114, USA
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22
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Smith GM, Onifer SM. Construction of pathways to promote axon growth within the adult central nervous system. Brain Res Bull 2010; 84:300-5. [PMID: 20554000 DOI: 10.1016/j.brainresbull.2010.05.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2010] [Revised: 05/25/2010] [Accepted: 05/31/2010] [Indexed: 12/12/2022]
Abstract
Inducing significant axon growth or regeneration after spinal cord injury has been difficult, primarily due to the poor growth supportive environment and low intrinsic growth ability of neurons within the CNS. Neurotrophins alone have been shown to readily induce regeneration of sensory axons after dorsal root lesions, however if neurotrophin gradients are expressed within the spinal cord these axons fail to terminate within appropriate target regions. Under such conditions, addition of a "stop" signal reduces growth into deeper dorsal laminae to support more specific targeting. Such neurotrophin gradients alone lose their effectiveness when lesions are within the spinal cord, requiring a combined treatment regime. Construction of pathways using combined treatments support good regeneration when they increase the intrinsic growth properties of neurons, provide a bridge across the lesion site, and supply a growth supportive substrate to induce axon growth out of the bridge and back into the host. Neurotrophin gradients distal to the bridge greatly enhance axon outgrowth. In disorders where neuronal circuits are lost, construction of preformed growth supportive pathways sustain long distance axon growth from a neuronal transplant to distal target locations.
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Affiliation(s)
- George M Smith
- Department of Physiology, Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, 40536, USA.
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23
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Knafo S, Choi D. Clinical studies in spinal cord injury: moving towards successful trials. Br J Neurosurg 2008; 22:3-12. [PMID: 18224516 DOI: 10.1080/02688690701593595] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Spinal cord injury is a devastating condition for which there is still no cure. Many new therapies have emerged in the past few decades that have attempted to improve the outcome after injury, with varying levels of supporting experimental and clinical data. Most studies have been preliminary and have lacked control groups, but positive results can often be embraced by clinicians and patients who are faced without an alternative, despite the poor design and bias of many studies. This article is a review of clinical studies in spinal cord injury and discusses guidelines for future clinical trial design.
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Affiliation(s)
- S Knafo
- Institute of Neurology, University College London, London, UK
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Louro J, Pearse DD. Stem and progenitor cell therapies: recent progress for spinal cord injury repair. Neurol Res 2008; 30:5-16. [PMID: 18387258 DOI: 10.1179/174313208x284070] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Mechanical trauma to the spinal cord is often accompanied by irreversible tissue damage, limited endogenous repair and permanent loss of motor, sensory and autonomic function. The implantation of exogenous cells or the stimulation of endogenous cells, to repopulate and replace or to provide a conducive environment for repair, offers a promising therapeutic direction for overcoming the multitude of obstacles facing successful recovery from spinal cord injury. Although relatively new to the scene of cell based therapies for reparative medicine, stem cells and their progenitors have been labeled as the 'cell of the future' for revolutionizing the treatment of CNS injury and neurodegenerative disorders. The following review examines the different types of stem cells and their progenitors, their utility in experimental models of spinal cord injury and explores the outstanding issues that still need to be addressed before they move towards clinical implementation.
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Affiliation(s)
- J Louro
- The Miami Project to Cure Paralysis, University of Miami School of Medicine, Miami, FL 33136, USA
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25
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Guo J, Su H, Zeng Y, Liang YX, Wong WM, Ellis-Behnke RG, So KF, Wu W. Reknitting the injured spinal cord by self-assembling peptide nanofiber scaffold. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2007; 3:311-21. [PMID: 17964861 DOI: 10.1016/j.nano.2007.09.003] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Revised: 09/16/2007] [Accepted: 09/20/2007] [Indexed: 01/09/2023]
Abstract
In traumatic spinal cord injury, loss of neurological function is due to the inability of damaged axons to regenerate across large, cystic cavities. It has recently been demonstrated that a self-assembled nanofiber scaffold (SAPNS) could repair the injured optical pathway and restore visual function. To demonstrate the possibility of using it to repair spinal cord injury, transplanted neural progenitor cells and Schwann cells were isolated from green fluorescent protein-transgenic rats, cultured within SAPNS, and then transplanted into the transected dorsal column of spinal cord of rats. Here we report the use of SAPNS to bridge the injured spinal cord of rats, demonstrating robust migration of host cells, growth of blood vessels, and axons into the scaffolds, indicating that SAPNS provides a true three-dimensional environment for the migration of living cells.
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Affiliation(s)
- Jiasong Guo
- Department of Anatomy, The University of Hong Kong Li Ka Shing Faculty of Medicine, Pokfulam, Hong Kong SAR, China
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Cizkova D, Kakinohana O, Kucharova K, Marsala S, Johe K, Hazel T, Hefferan MP, Marsala M. Functional recovery in rats with ischemic paraplegia after spinal grafting of human spinal stem cells. Neuroscience 2007; 147:546-60. [PMID: 17524565 PMCID: PMC3417127 DOI: 10.1016/j.neuroscience.2007.02.065] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2006] [Revised: 02/19/2007] [Accepted: 02/20/2007] [Indexed: 12/15/2022]
Abstract
Transient spinal cord ischemia in humans can lead to the development of permanent paraplegia with prominent spasticity and rigidity. Histopathological analyses of spinal cords in animals with ischemic spastic paraplegia show a selective loss of small inhibitory interneurons in previously ischemic segments but with a continuing presence of ventral alpha-motoneurons and descending cortico-spinal and rubro-spinal projections. The aim of the present study was to examine the effect of human spinal stem cells (hSSCs) implanted spinally in rats with fully developed ischemic paraplegia on the recovery of motor function and corresponding changes in motor evoked potentials. In addition the optimal time frame for cell grafting after ischemia and the optimal dosing of grafted cells were also studied. Spinal cord ischemia was induced for 10 min using aortic occlusion and systemic hypotension. In the functional recovery study, hSSCs (10,000-30,000 cells/0.5 mul/injection) were grafted into spinal central gray matter of L2-L5 segments at 21 days after ischemia. Animals were immunosuppressed with Prograf (1 mg/kg or 3 mg/kg) for the duration of the study. After cell grafting the recovery of motor function was assessed periodically using the Basso, Beattie and Bresnahan (BBB) scoring system and correlated with the recovery of motor evoked potentials. At predetermined times after grafting (2-12 weeks), animals were perfusion-fixed and the survival, and maturation of implanted cells were analyzed using antibodies recognizing human-specific antigens: nuclear protein (hNUMA), neural cell adhesion molecule (hMOC), neuron-specific enolase (hNSE) and synapthophysin (hSYN) as well as the non-human specific antibodies TUJ1, GFAP, GABA, GAD65 and GLYT2. After cell grafting a time-dependent improvement in motor function and suppression of spasticity and rigidity was seen and this improvement correlated with the recovery of motor evoked potentials. Immunohistochemical analysis of grafted lumbar segments at 8 and 12 weeks after grafting revealed intense hNSE immunoreactivity, an extensive axo-dendritic outgrowth as well as rostrocaudal and dorsoventral migration of implanted hNUMA-positive cells. An intense hSYN immunoreactivity was identified within the grafts and in the vicinity of persisting alpha-motoneurons. On average, 64% of hSYN terminals were GAD65 immunoreactive which corresponded to GABA immunoreactivity identified in 40-45% of hNUMA-positive grafted cells. The most robust survival of grafted cells was seen when cells were grafted 21 days after ischemia. As defined by cell survival and laminar distribution, the optimal dose of injected cells was 10,000-30,000 cells per injection. These data indicate that spinal grafting of hSSCs can represent an effective therapy for patients with spinal ischemic paraplegia.
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Affiliation(s)
- Dasa Cizkova
- Institute of Neurobiology, Centrum of Excellence, Slovak Academy of Science, Kosice, Soltesovej 4, Slovakia
- Anesthesiology Research, University of California, San Diego, La Jolla, CA 92093
| | - Osamu Kakinohana
- Anesthesiology Research, University of California, San Diego, La Jolla, CA 92093
| | - Karolina Kucharova
- Institute of Neurobiology, Centrum of Excellence, Slovak Academy of Science, Kosice, Soltesovej 4, Slovakia
- Anesthesiology Research, University of California, San Diego, La Jolla, CA 92093
| | - Silvia Marsala
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093
| | - Karl Johe
- Neuralstem, Inc., Rockville, MD 20850
| | | | - Michael P. Hefferan
- Anesthesiology Research, University of California, San Diego, La Jolla, CA 92093
| | - Martin Marsala
- Anesthesiology Research, University of California, San Diego, La Jolla, CA 92093
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Dinh P, Bhatia N, Rasouli A, Suryadevara S, Cahill K, Gupta R. Transplantation of preconditioned Schwann cells following hemisection spinal cord injury. Spine (Phila Pa 1976) 2007; 32:943-9. [PMID: 17450067 DOI: 10.1097/01.brs.0000261408.61303.77] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Chronically compressed sciatic nerve segments were transplanted to hemisected spinal cord injured rats. Histologic evaluation and behavior functional outcomes were tested after 6 weeks following surgery. OBJECTIVE To evaluate the outcome of preconditioned peripheral nerves as a permissive environment in axonal regeneration of the injured spinal cord. SUMMARY OF BACKGROUND DATA Schwann cells have been used to facilitate a permissive environment for the injured spinal cord to regenerate. Previous experiments have shown compressive mechanical stress to be important in stimulating the regenerative behavior of Schwann cells. Transplantation of highly permissive Schwann cell-enriched peripheral nerve grafts may enhance regeneration in spinal cord injury. METHODS Adult Sprague-Dawley rats (n = 24) were used to create a hemisection injury of the spinal cord. At 1-week postinjury creation, the spinal cords were reexposed for all animals. Peripheral nerve grafts were obtained from rat sciatic nerve, either untreated or subjected to mechanical compression for 2 weeks with nonconstrictive tubing. Transplantation of grafts was performed after a resection of the glial scar. Functional outcome was measured using the Basso, Beattie, Bresnahan Locomotor Rating Score and footprint analysis. Tract tracing of descending and ascending spinal cord tracts was performed at 6 weeks after surgery for histologic evaluation of axonal regeneration. RESULTS Preconditioned transplants had significantly higher Basso, Beattie, Bresnahan Scores versus hemisection alone in the late postoperative period (P < 0.05). They also had significantly less foot exorotation and base of support when compared to nonconditioned transplants. Histologic analysis showed increased regeneration at lesional sites for preconditioned transplants versus control group (P < 0.05). CONCLUSIONS Functional recovery after hemisection injury improved significantly in the late postoperative period with transplantation of preconditioned peripheral nerve. Preconditioned grafts also exhibit sustained axonal regeneration at and past the lesional site in histologic analysis. Further investigation with later time points is warranted.
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Affiliation(s)
- Paul Dinh
- University of California, Irvine, CA, USA
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Abstract
Spinal cord injury (SCI) can lead to paraplegia or quadriplegia. Although there are no fully restorative treatments for SCI, various rehabilitative, cellular and molecular therapies have been tested in animal models. Many of these have reached, or are approaching, clinical trials. Here, we review these potential therapies, with an emphasis on the need for reproducible evidence of safety and efficacy. Individual therapies are unlikely to provide a panacea. Rather, we predict that combinations of strategies will lead to improvements in outcome after SCI. Basic scientific research should provide a rational basis for tailoring specific combinations of clinical therapies to different types of SCI.
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Affiliation(s)
- Sandrine Thuret
- Centre for the Cellular Basis of Behaviour, Institute of Psychiatry, King's College London, P.O. Box 39, 1-2 WW Ground, Denmark Hill, London SE5 8AF, UK
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Houle JD, Tom VJ, Mayes D, Wagoner G, Phillips N, Silver J. Combining an autologous peripheral nervous system "bridge" and matrix modification by chondroitinase allows robust, functional regeneration beyond a hemisection lesion of the adult rat spinal cord. J Neurosci 2006; 26:7405-15. [PMID: 16837588 PMCID: PMC6674179 DOI: 10.1523/jneurosci.1166-06.2006] [Citation(s) in RCA: 261] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Chondroitinase-ABC (ChABC) was applied to a cervical level 5 (C5) dorsal quadrant aspiration cavity of the adult rat spinal cord to degrade the local accumulation of inhibitory chondroitin sulfate proteoglycans. The intent was to enhance the extension of regenerated axons from the distal end of a peripheral nerve (PN) graft back into the C5 spinal cord, having bypassed a hemisection lesion at C3. ChABC-treated rats showed (1) gradual improvement in the range of forelimb swing during locomotion, with some animals progressing to the point of raising their forelimb above the nose, (2) an enhanced ability to use the forelimb in a cylinder test, and (3) improvements in balance and weight bearing on a horizontal rope. Transection of the PN graft, which cuts through regenerated axons, greatly diminished these functional improvements. Axonal regrowth from the PN graft correlated well with the behavioral assessments. Thus, many more axons extended for much longer distances into the cord after ChABC treatment and bridge insertion compared with the control groups, in which axons regenerated into the PN graft but growth back into the spinal cord was extremely limited. These results demonstrate, for the first time, that modulation of extracellular matrix components after spinal cord injury promotes significant axonal regeneration beyond the distal end of a PN bridge back into the spinal cord and that regenerating axons can mediate the return of useful function of the affected limb.
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Affiliation(s)
- John D Houle
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA.
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Abstract
The implantation of exogenous cells or tissues has been a popular and successful strategy to overcome physical discontinuity and support axon growth in experimental models of spinal cord injury (SCI). Cellular therapies exhibit a multifarious potential for SCI restoration, providing not only a supportive substrate upon which axons can traverse the injury site, but also reducing progressive tissue damage and scarring, facilitating remyelination repair, and acting as a source for replacing and re-establishing lost neural tissue and its circuitry. The past two decades of research into cell therapies for SCI repair have seen the progressive evolution from whole tissue strategies, such as peripheral nerve grafts, to the use of specific, purified cell types from a diverse range of sources and, recently, to the employment of stem or neural precursor cell populations that have the potential to form a full complement of neural cell types. Although the progression of cell therapies from laboratory to clinical implementation has been slow, human SCI safety and efficacy trials involving several cell types within the US appear to be close at hand.
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Affiliation(s)
- Damien D Pearse
- University of Miami Miller School of Medicine, The Miami Project to Cure Paralysis, Department of Neurological Surgery, Lois Pope Life Center, 1095 NW 14th Terrace (R-48), Miami, FL 33136, USA.
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Guest J, Herrera LP, Qian T. Rapid recovery of segmental neurological function in a tetraplegic patient following transplantation of fetal olfactory bulb-derived cells. Spinal Cord 2006; 44:135-42. [PMID: 16151453 DOI: 10.1038/sj.sc.3101820] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
STUDY DESIGN Case report. OBJECTIVE Report rapid neurological changes in a complete tetraplegic following a cell injection procedure. SETTING Beijing, China. METHODS ASIA/IMSOP neurological scale. Immunostaining of cell cultures. Cellular transplantation to effect functional restoration following spinal cord injury (SCI) has been hypothesized to cause improvements through axonal regeneration, increased plasticity, or axonal remyelination. Several human trials are in preliminary phases. We report a rapid improvement in motor and sensory functions in the segment adjacent to the level of complete SCI within days following cellular transplantation of cultured fetal olfactory bulb-derived cells. The patient was an 18-year-old C3 ASIA A complete tetraplegic 18 months post-injury who had been neurologically stable for more than 6 months. RESULTS Within 48 h of cell transplantation, the patient improved one ASIA motor grade in the left elbow flexors and began to show right wrist extensor function. Descent of the sensory level occurred within 4 days and then the rate of change slowed. He is now a C5 motor and C4 sensory complete tetraplegic. Cellular cultures prepared in the same facility showed viable human cells that labeled for nestin and GFAP. CONCLUSION We hypothesize that improved transmission in intact fibers subserving the zone of partial preservation accounts for these early improvements. We emphasize the need for further independent analysis of the outcomes of this and other preliminary cell transplant studies.
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Affiliation(s)
- J Guest
- The Department of Neurological Surgery, University of Miami, Lois Pope LIFE Center, Miami, FL 33136, USA
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Hendriks WTJ, Eggers R, Ruitenberg MJ, Blits B, Hamers FPT, Verhaagen J, Boer GJ. Profound Differences in Spontaneous Long-Term Functional Recovery after Defined Spinal Tract Lesions in the Rat. J Neurotrauma 2006; 23:18-35. [PMID: 16430370 DOI: 10.1089/neu.2006.23.18] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The purpose of this study was to compare spontaneous functional recovery after different spinal motor tract lesions in the rat spinal cord using three methods of analysis, the BBB, the rope test, and the CatWalk. We transected the dorsal corticospinal tract (CSTx) or the rubrospinal tract (RSTx) or the complete dorsal half of the spinal cord (Hx) at thoracic level T8. Functional recovery was monitored for 31 weeks. We found no recovery of consistent inter limb coordination in any experimental group over time using the BBB locomotor rating scale. Quantitative CatWalk analysis revealed significant differences between experimental groups for inter limb coordination (RI). RSTx and Hx animals showed a significant decrease in the RI, and only in the RSTx group did the RI improve from 6 weeks post-lesion onward. Significant differences between experimental groups in step sequence patterns and base of support were also observed. In the rope test all experimental groups had significantly higher error percentages compared to control animals. Tracing of the CST revealed enhanced collateral formation rostral to the lesion in the CSTx group, not in other groups. The results presented here show that locomotor function in all, but CSTx groups gradually improved over time. This is important for studies that employ pharmacological, cell-, and/or gene therapy- based interventions to improve axonal regeneration and functional recovery after spinal cord injury.
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Affiliation(s)
- William T J Hendriks
- Department of Neuroregeneration, Netherlands Institute for Brain Research, Amsterdam, The Netherlands
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33
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Abstract
There are currently no fully restorative therapies for human spinal cord injury (SCI). Here,we briefly review the different types of human SCI pathology as well as the most commonly used rodent and nonhuman primate models of SCI that are used to simulate these pathologies and to test potential therapies. We then discuss various high profile (sometimes controversial) experimental strategies that have reported CNS axon regeneration and functional recovery of limb movement using these animal models of SCI. We particularly focus upon strategies that have been tested both in rodents and in nonhuman primates, and highlight those which are currently transitioning to clinical tests or trials in humans. Finally we discuss ways in which animal studies might be improved and what the future may hold for physical therapists involved in rehabilitation of humans with SCI.
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Affiliation(s)
- Lawrence Moon
- The Miami Project to Cure Paralysis, Miami, FL, USA.
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Abstract
Clinicians and scientists in the field of spinal cord injury research and medicine are poised to begin translating promising new experimental findings into treatments for people. Advances in experimental regeneration research have led to several transplantation strategies that promote axonal regrowth and partial functional recovery in animal models of injury. In this review, we summarize current knowledge regarding various invasive experimental treatments that have been or are now being applied clinically. Various questions about the timeliness, safety, and benefits of the procedures are under discussion within the spinal cord injury (SCI) research community. We also describe guidelines for carrying out optimal clinical trials and efforts to establish specific international guidelines to translate preclinical treatment strategies into clinical trials in SCI. The clinical trial process and the role that clinical professionals have in advising individuals regarding participation in experimental procedures also is discussed.
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Affiliation(s)
- Maria J Amador
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA.
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Dai X, Noga BR, Douglas JR, Jordan LM. Localization of spinal neurons activated during locomotion using the c-fos immunohistochemical method. J Neurophysiol 2005; 93:3442-52. [PMID: 15634712 DOI: 10.1152/jn.00578.2004] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The c-fos immunohistochemical method of activity-dependent labeling was used to localize locomotor-activated neurons in the adult cat spinal cord. In decerebrate cats, treadmill locomotion was evoked by electrical stimulation of the mesencephalic locomotor region (MLR). Spontaneous or MLR-evoked fictive locomotion was produced in decerebrate animals paralyzed with a neuromuscular blocking agent. After bouts of locomotion during a 7- to 9-h time period, the animals were perfused and the L3-S1 spinal cord segments removed for immunohistochemistry. Control animals were subjected to the same surgical procedures but no locomotor task. Labeled cells were concentrated in Rexed's laminae III and IV of the dorsal horn and laminae VII, VIII, and X of the intermediate zone/ventral horn after treadmill locomotion. Cells in laminae VII, VIII, and X were labeled after fictive locomotion, but labeling in the dorsal horn was much reduced. In control animals, c-fos labeling was a small fraction of that observed in the locomotor animals. The results suggest that labeled cells in laminae VII, VIII, and X are premotor interneurons involved in the production of locomotion, whereas the laminae III and IV cells are those activated during locomotion due to afferent feedback from the moving limb. c-fos-labeled cells were most numerous in the L5-L7 segments, consistent with the distribution of locomotor activated neurons detected through the use of MLR-evoked field potentials.
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Affiliation(s)
- X Dai
- Dept. of Physiology, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba R3E 0W3, Canada
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36
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Feng SQ, Kong XH, Guo SF, Wang P, Li L, Zhong JH, Zhou XF. Treatment of spinal cord injury with co-grafts of genetically modified Schwann cells and fetal spinal cord cell suspension in the rat. Neurotox Res 2005; 7:169-77. [PMID: 15639807 DOI: 10.1007/bf03033785] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Fetal spinal cord cells, Schwann cells and neurotrophins all have the capacity to promote repair of injured spinal cord in animal models. To explore the possibility of using these approaches to treat clinical patients, we have examined whether a combination of these protocols produces functional and anatomical improvement. The spinal cords of adult rats (n=16) were injured with a modified New York University (NYU) device (10 gram.5cm). One week after injury, the injured cords were injected with Dulbecco-modified Eagles Medium (DMEM, control group), or fetal spinal cord cell suspension (FSCS) plus nerve growth factor (NGF) gene-modified Schwann cells (SC) and brain-derived neurotrophic factor (BDNF) gene-modified SC (treatment group). The rats were subjected to BBB (Basso, Beattie, Bresnahan, Exp. Neurol. 139:244, 1996) behavioral tests. Anterograde tracing of corticospinal tract was performed before sacrifice 3 months after the treatment. The results showed that the combination treatment elicited a robust growth of corticospinal axons within and beyond the injury site. A dramatic functional recovery in the treatment group was observed compared with the control group. We conclude that the combination of FSCS with genetically modified Schwann cells over-expressing NGF and BDNF was an effective protocol for the treatment of severe spinal cord injury.
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Affiliation(s)
- Shi-Qing Feng
- Department of Orthopaedic, Tianjin Medical University Hospital, Tianjin, 300052, P.R. China
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37
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Abstract
Basic science advances in spinal cord injury and regeneration research have led to a variety of novel experimental therapeutics designed to promote functionally effective axonal regrowth and sprouting. Among these interventions are cell-based approaches involving transplantation of neural and non-neural tissue elements that have potential for restoring damaged neural pathways or reconstructing intraspinal synaptic circuitries by either regeneration or neuronal/glial replacement. Notably, some of these strategies (e.g., grafts of peripheral nerve tissue, olfactory ensheathing glia, activated macrophages, marrow stromal cells, myelin-forming oligodendrocyte precursors or stem cells, and fetal spinal cord tissue) have already been translated to the clinical arena, whereas others have imminent likelihood of bench-to-bedside application. Although this progress has generated considerable enthusiasm about treating what once was thought to be a totally incurable condition, there are many issues to be considered relative to treatment safety and efficacy. The following review reflects on different experimental applications of intraspinal transplantation with consideration of the underlying pathological, pathophysiological, functional, and neuroplastic responses to spinal trauma that such treatments may target along with related issues of procedural and biological safety. The discussion then moves to an overview of ongoing and completed clinical trials to date. The pros and cons of these endeavors are considered, as well as what has been learned from them. Attention is primarily directed at preclinical animal modeling and the importance of patterning clinical trials, as much as possible, according to laboratory experiences.
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Affiliation(s)
- Paul J Reier
- College of Medicine and McKnight Brain Institute, University of Florida, Gainesville, Florida 32610, USA.
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38
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Cellular transplantation strategies for spinal cord injury and translational neurobiology. Neurotherapeutics 2004. [DOI: 10.1007/bf03206629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Gris P, Murphy S, Jacob JE, Atkinson I, Brown A. Differential gene expression profiles in embryonic, adult-injured and adult-uninjured rat spinal cords. Mol Cell Neurosci 2003; 24:555-67. [PMID: 14664807 DOI: 10.1016/s1044-7431(03)00211-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
To identify genes that render the adult-injured spinal cord nonpermissive and the embryonic spinal cord permissive to regeneration, we used subtraction hybridization and suppression PCR to generate subtractive cDNA populations representing (1) genes expressed in the embryonic but not in the adult-injured or uninjured spinal cords, (2) genes expressed in the adult-injured but not in the embryonic or adult-uninjured spinal cords, and (3) genes expressed in the embryonic and adult-injured spinal cords but not in the adult-uninjured spinal cord. Between 85 and 98% of the cDNAs identified are differentially represented in each population. Genes in each cDNA population were identified by microarray hybridization. Genes involved in inflammation, apoptosis, and neuroprotection were overrepresented in injured spinal cord cDNA, whereas genes involved in cell signaling and differentiation were overrepresented in the embryonic cDNA. This gene expression profiling suggests new hypotheses regarding the genes involved in inhibition and promotion of spinal cord regeneration.
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Affiliation(s)
- P Gris
- Stem Cell and Regenerative Medicine and BioTherapeutics Research Groups, The Robarts Research Institute and The Graduate Program in Neuroscience, The University of Western Ontario, London, Ontario, Canada
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40
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Nakamura M, Houghtling RA, MacArthur L, Bayer BM, Bregman BS. Differences in cytokine gene expression profile between acute and secondary injury in adult rat spinal cord. Exp Neurol 2003; 184:313-25. [PMID: 14637102 DOI: 10.1016/s0014-4886(03)00361-3] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It is likely that the environment within the injured spinal cord influences the capacity of fetal spinal cord transplants to support axonal growth. We have recently demonstrated that fetal spinal cord transplants and neurotrophin administration support axonal regeneration after spinal cord transection, and that the distance and amount of axonal growth is greater when these treatments are delayed by several weeks after injury. In this study, we sought to determine whether differences in inflammatory mediators exist between the acutely injured spinal cord and the spinal cord after a second injury and re-section, which could provide a more favorable environment for the axonal re-growth. The results of this study show a more rapid induction of transforming growth factor (TGF) beta1 mRNA expression in the re-injured spinal cord than the acutely injured spinal cord and an attenuation of proinflammatory cytokine mRNA expression. Furthermore, there was a rapid recruitment of activated microglia/macrophages in the degenerating white matter rostral and caudal to the injury but fewer within the lesion site itself. These findings suggest that the augmentation of TGFbeta-1 gene expression and the attenuation of pro-inflammatory cytokine gene expression combined with an altered distribution of activated microglia/macrophages in the re-injured spinal cord might create a more favorable milieu for transplants and axonal regrowth as compared to the acutely injured spinal cord.
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Affiliation(s)
- Masaya Nakamura
- Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Road, NW, Washington, DC 20007, USA.
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41
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Abstract
Advances in medical and rehabilitative care now allow the 10-12,000 individuals who suffer spinal cord injuries each year in the United States to lead productive lives of nearly normal life expectancy, so that the numbers of those with chronic injuries will approximate 300,000 at the end of the next decade. This signals an urgent need for new treatments that will improve repair and recovery after longstanding injuries. In the present report we consider the characteristics of the chronically injured spinal cord that make it an even more challenging setting in which to elicit regeneration than the acutely injured spinal cord and review the treatments that have been designed to enhance axon growth. When applied in the first 2 weeks after experimental spinal cord injury, transplants, usually in combination with supplementary neurotrophic factors, and possibly modifications of the inhibitory central nervous system environment, have produced limited long-distance axon regeneration and behavioral recovery. When applied to injuries older than 4 weeks, the same treatments have almost invariably failed to overcome the obstacles posed by the neurons' diminished capacity for regeneration and by the increasing hostility to growth of the terrain at and beyond the injury site. Novel treatments that have stimulated regeneration after acute injuries have not yet been applied to chronic injuries. A therapeutic strategy that combines rehabilitation training and pharmacological modulation of neurotransmitters appears to be a particularly promising approach to increasing recovery after longstanding injury. Identifying patients with no hope of useful recovery in the early days after injury will allow these treatments to be administered as early as possible.
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Affiliation(s)
- John D Houle
- Department of Anatomy and Neurobiology, University of Arkansas for Medical Science, Little Rock, AR 72205, USA.
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42
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Lu D, Mahmood A, Chopp M. Biologic Transplantation and Neurotrophin-Induced Neuroplasticity After Traumatic Brain Injury. J Head Trauma Rehabil 2003; 18:357-76. [PMID: 16222130 DOI: 10.1097/00001199-200307000-00006] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE In this review, we analyze progress in the treatment of traumatic brain injury with neurotrophins, growth factors and cell and tissue neurotransplantation. The primary objective of these therapies is to reduce neurologic deficits associated with the trauma by inducing neuroplasticity. These therapies are restorative and not necessarily neuroprotective. MAIN OUTCOME MEASURES An extensive literature on administration of neurotrophics factors and cell and tissue cerebral transplantation is reviewed. The effects of these therapeutic approaches on brain biochemical, molecular, cellular, and tissue responses are summarized. CONCLUSION The cumulative data indicate that cell therapy shows substantial promise in the treatment of neural injury.
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Affiliation(s)
- Dunyue Lu
- Department of Neurosurgery, Henry Ford Health System, Henry Ford Hospital, 2799 West Grand Boulevard, Detroit, MI 48202, USA
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43
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Abstract
Inflammation has been widely perceived as participating in the etiology of acute and chronic neurodegenerative conditions. Accordingly, in the context of traumatic injuries or chronic neurodegenerative diseases in the central nervous system (CNS), activated microglia have been viewed as detrimental and attempts have been made to treat both conditions by antiinflammatory therapy. Recent studies have suggested that microglia act as stand- by cells in the service of both the immune and the nervous systems. In the healthy CNS these cells are quiescent, but in the event of injury to axons or cell bodies they exercise their neural function by buffering harmful self-compounds and clearing debris from the damaged site, and their immune function by providing immune-related requirements for recovery. Proper regulation of the inflammatory (autoimmune) response to injury will arrest degeneration and promote regrowth, whereas inappropriate regulation will lead to ongoing degeneration. Regulation is achieved by the operation of a T cell-mediated response directed to abundant self-antigens residing in the damaged site. Since this immune-dependent mechanism was found to protect against glutamate toxicity (a major factor in neurodegenerative disorders), boosting of this response might constitute the basis for development of a therapeutic vaccination against neurodegenerative diseases, all of which exhibit similar pathways and patterns of progression.
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Affiliation(s)
- Michal Schwartz
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot, Israel.
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44
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Palaoğlu S. Restorative neurosurgery. ACTA NEUROCHIRURGICA. SUPPLEMENT 2003; 83:93-9. [PMID: 12442627 DOI: 10.1007/978-3-7091-6743-4_15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Restorative neurosurgery currently is the frontier of neuroscientists for the restoration of lost neuronal function especially in neurodegenerative diseases and ischemic and traumatic central nervous system (CNS) disorders. The striking developments in molecular neurobiology and bio-technology are progressively offering new opportunities for a better quality of life to patients suffering from loss of neuronal function. Besides all new and challenging medical therapeutic interventions, great emphasis is also given to transplantation for neuronal restoration as well.
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Affiliation(s)
- S Palaoğlu
- Neurosurgery Department, Hacettepe University, School of Medicine, Ankara, Turkey
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45
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Abstract
Most human spinal cord injuries involve contusions of the spinal cord. Many investigators have long used weight-drop contusion animal models to study the pathophysiology and genetic responses of spinal cord injury. All spinal cord injury therapies tested to date in clinical trial were validated in such models. In recent years, the trend has been towards use of rats for spinal cord injury studies. The MASCIS Impactor is a well-standardized rat spinal cord contusion model that produces very consistent graded spinal cord damage that linearly predicts 24-h lesion volumes, 6-week white matter sparing, and locomotor recovery in rats. All aspects of the model, including anesthesia for male and female rats, age rather than body weight criteria, and arterial blood gases were empirically selected to enhance the consistency of injury.
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Affiliation(s)
- Wise Young
- W.M. Keck Center for Collaborative Neuroscience, Rutgers State University of New Jersey, 604 Allison Rd., Piscataway, NJ 08854-8082, USA.
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46
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de Barros Filho TEP, de Oliveira RP, Tsanaclis AM, de Barros EMKP, Cristante AF, Palma RM, dos Santos CV, Marcon RM. An experimental model for the transplantation of fetal central nervous system cells to the injured spinal cord in rats. REVISTA DO HOSPITAL DAS CLINICAS 2002; 57:257-64. [PMID: 12612757 DOI: 10.1590/s0041-87812002000600003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
INTRODUCTION Traumatic spinal cord injury is one of the most disabling conditions occurring in man and thus stimulates a strong interest in its histopathological, biochemical, and functional changes, primarily as we search for preventive and therapeutic methods. PURPOSE To develop an experimental model for transplantation of cells from the fetal rat central nervous system to the site of an injured spinal cord of an adult rat in which the transplanted cells survive and become integrated. This experimental model will facilitate investigations of factors that promote regeneration and functional recovery after spinal cord trauma. MATERIAL AND METHODS Fifteen adult Wistar rats underwent laminectomy, and an spinal cord lesion was made with microdissection. Fetal spinal cord tissue was then transplanted to the site of the injury. The rats were monitored over a 48-hour period, and then their vertebral column was completely removed for histological analysis. RESULTS In 60% of transplanted rats, the fetal tissue at the injured site remained viable in the site of the lesion.
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47
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Murray M, Kim D, Liu Y, Tobias C, Tessler A, Fischer I. Transplantation of genetically modified cells contributes to repair and recovery from spinal injury. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 2002; 40:292-300. [PMID: 12589927 DOI: 10.1016/s0165-0173(02)00211-4] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The effects of transplantation of fibroblasts genetically modified to produce brain derived neurotrophin factor (Fb/BDNF) on rescue of axotomized neurons, axonal growth and recovery of function was tested in a lateral funiculus lesion model in adult rats. Operated control animals included those in which the lesion was filled with gelfoam implant (Hx) and those in which the cavity was filled with unmodified fibroblasts (Fb). Both Fb/BDNF and Fb transplants survived and filled the lesion site. Unoperated control groups showed a marked retrograde death of Red nucleus neurons contralateral to the lesion; Fb/BDNF recipients showed a significant rescue effect. Anterograde and retrograde labeling studies indicated no regeneration of rubrospinal axons into the lesion/transplant in operated control animals, but regeneration into, around, and through the transplant into the host was seen in the Fb/BDNF recipients. All animals showed deficits on the more challenging behavioral tests but the Fb/BDNF recipients showed fewer deficits, particularly in tests of spontaneous vertical exploration, horizontal rope crossing and a sensory test (patch removal). The improved function on these tests in the Fb/BDNF recipients was abolished by a second lateral funiculus lesion rostral to the transport site. These results indicate that delivery of neurotrophic factors by grafting genetically modified cells can improve repair and function after spinal injury.
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Affiliation(s)
- Marion Murray
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, PA 19129, USA.
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48
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Bose P, Parmer R, Thompson FJ. Velocity-dependent ankle torque in rats after contusion injury of the midthoracic spinal cord: time course. J Neurotrauma 2002; 19:1231-49. [PMID: 12427331 DOI: 10.1089/08977150260338029] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Progressive neurophysiological changes in the excitability of the pathways that subserved ankle extensor stretch reflexes were observed following midthoracic contusion. The purpose of the present study was to determine the nature and time course of velocity-dependent changes in the excitability of the ankle stretch reflex following T(8) contusion injury. These studies were conducted in adult Sprague-Dawley rats using a 10-g 2.5-cm weight drop onto the exposed thoracic spinal cord (using an NYU injury device and a MASCIS protocol). Velocity-dependent ankle torques and triceps surae EMGs were measured in awake animals over a broad range of rotation velocities (49-612 deg/sec) using instrumentation and protocol previously reported. EMGs and ankle torques were measured before and at weekly intervals following injury. Statistical tests of the data included within group repeated measures ANOVA and between group one-way ANOVA comparisons with time-matched control animals. An alternating pattern of significant increase followed by significant decrease in velocity-dependent ankle torque was observed during the first postinjury month. An increase of 33% in the peak torque and 24% in peak EMG magnitude at 612 deg/sec was observed in the first week. EMG burst amplitudes, that were timed-locked to the dynamic phase of the rotation, were observed to increase and decrease in a manner, which indicated that the changes in torque included stretch-evoked active contractions of the ankle extensors. During the second and third postinjury months, consistent 24-40% increases in the peak torques and 17-107% increases in the EMG magnitudes at the highest velocity were observed. No significant increases in torques were observed in the slowest rotation velocity in these periods.
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Affiliation(s)
- Prodip Bose
- Department of Neuroscience, University of Florida McKnight Brain Institute, University of Florida Health Sciences Center, Gainesville 32610, USA
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Kwon BK, Liu J, Oschipok L, Tetzlaff W. Reaxotomy of chronically injured rubrospinal neurons results in only modest cell loss. Exp Neurol 2002; 177:332-7. [PMID: 12429236 DOI: 10.1006/exnr.2002.7983] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Among the most promising therapeutic strategies to facilitate axonal regeneration after spinal cord injury is the transplantation of various cellular substrates into the injury site. With the establishment of a glial scar and cyst at the injury site over time, the implantation of such cells in the chronic injury setting may require some resection of these nonpermissive elements, which could concomitantly reinjure already severed axons. This study evaluates the response of chronically injured rubrospinal neurons to such a second axotomy. Our findings indicate that the second axotomy does not lead to an accelerated loss of rubrospinal neurons, which represents an important finding for those who evaluate axonal regeneration of this motor system in chronic transplantation studies.
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Affiliation(s)
- Brian K Kwon
- Collaboration on Repair Discoveries, University of British Columbia, Room 2469 Biosciences Building, 6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada
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Wang DC, Bose P, Parmer R, Thompson FJ. Chronic intrathecal baclofen treatment and withdrawal: I. Changes in ankle torque and hind limb posture in normal rats. J Neurotrauma 2002; 19:875-86. [PMID: 12184857 DOI: 10.1089/08977150260190465] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
This study evaluated reflex excitability and locomotor changes during chronic intrathecal infusion of the GABAb agonist baclofen (ITB) and its withdrawal, in the rat. We observed sustained velocity dependent decreases in ankle torque during four weeks of ITB treatment. These changes were correlated with a significant reduction of the EMG burst magnitude time locked to the dynamic phase of ankle dorsiflexion during the first ITB treatment week. However, a considerable recovery of EMG magnitude was observed during the third and fourth weeks of treatment. During baclofen withdrawal, significantly increased velocity dependent ankle torque was observed for 4 weeks. These increases in ankle torque were correlated with increased magnitudes of EMG time locked to the dynamic phase of ankle rotation. Measures of hind limb axis and base of support were obtained using analysis of footprints on a treadmill during ITB treatment and withdrawal periods. During ITB treatment and for up to 7 weeks of withdrawal, hindlimb axis and base of support were significantly altered compared with vehicle controls. These studies were performed to provide a foundation for evaluation of treatment and withdrawal in the setting of experimental chronic contusion spinal cord injury.
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Affiliation(s)
- David C Wang
- Department of Neuroscience, Evelyn F. and William L. McKnight Brain Institute, University of Florida, Gainesville, Florida 32610-0244, USA
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