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Dill-Macky AS, Lee EN, Wertheim JA, Koss KM. Glia in Tissue Engineering: From Biomaterial Tools to Transplantation. Acta Biomater 2024:S1742-7061(24)00600-7. [PMID: 39396630 DOI: 10.1016/j.actbio.2024.10.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 10/01/2024] [Accepted: 10/10/2024] [Indexed: 10/15/2024]
Abstract
Glia are imperative in nearly every function of the nervous system, including neurotransmission, neuronal repair, development, immunity, and myelination. Recently, the reparative roles of glia in the central and peripheral nervous systems have been elucidated, suggesting a tremendous potential for these cells as novel treatments to central nervous system disorders. Glial cells often behave as 'double-edged swords' in neuroinflammation, ultimately deciding the life or death of resident cells. Compared to glia, neuronal cells have limited mobility, lack the ability to divide and self-renew, and are generally more delicate. Glia have been candidates for therapeutic use in many successful grafting studies, which have been largely focused on restoring myelin with Schwann cells, olfactory ensheathing glia, and oligodendrocytes with support from astrocytes. However, few therapeutics of this class have succeeded past clinical trials. Several tools and materials are being developed to understand and re-engineer these grafting concepts for greater success, such as extra cellular matrix-based scaffolds, bioactive peptides, biomolecular delivery systems, biomolecular discovery for neuroinflammatory mediation, composite microstructures such as artificial channels for cell trafficking, and graft enhanced electrical stimulation. Furthermore, advances in stem cell-derived cortical/cerebral organoid differentiation protocols have allowed for the generation of patient-derived glia comparable to those acquired from tissues requiring highly invasive procedures or are otherwise inaccessible. However, research on bioengineered tools that manipulate glial cells is nowhere near as comprehensive as that for systems of neurons and neural stem cells. This article explores the therapeutic potential of glia in transplantation with an emphasis on novel bioengineered tools for enhancement of their reparative properties. STATEMENT OF SIGNIFICANCE: Neural glia are responsible for a host of developmental, homeostatic, and reparative roles in the central nervous system but are often a major cause of tissue damage and cellular loss in insults and degenerative pathologies. Most glial grafts have employed Schwann cells for remyelination, but other glial with novel biomaterials have been employed, emphasizing their diverse functionality. Promising strategies have emerged, including neuroimmune mediation of glial scar tissues and facilitated migration and differentiation of stem cells for neural replacement. Herein, a comprehensive review of biomaterial tools for glia in transplantation is presented, highlighting Schwann cells, astrocytes, olfactory ensheating glia, oligodendrocytes, microglia, and ependymal cells.
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Affiliation(s)
- A S Dill-Macky
- Department of Surgery, University of Arizona, 1501 N Campbell Ave, Tucson, AZ 85724
| | - E N Lee
- Department of Surgery, University of Arizona, 1501 N Campbell Ave, Tucson, AZ 85724
| | - J A Wertheim
- Department of Surgery, University of Arizona, 1501 N Campbell Ave, Tucson, AZ 85724
| | - K M Koss
- Department of Surgery, University of Arizona, 1501 N Campbell Ave, Tucson, AZ 85724.
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Bochynska D, Sharpe A, Toland B, Demeter EA. Schwannosis in the brain of a neonatal calf. J Vet Diagn Invest 2024:10406387241283161. [PMID: 39359129 DOI: 10.1177/10406387241283161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2024] Open
Abstract
Schwannosis is a rare, non-neoplastic, perivascular proliferation of aberrant Schwann cells within the CNS with simultaneous partial myelination of axons. A single report exists in veterinary medicine of schwannosis in the spinal cord of 3 foals and 1 calf. Here we describe a case of schwannosis in the brain of a 1-d-old Holstein-Friesian calf, submitted for autopsy due to arthrogryposis and premature death, with no other gross abnormalities observed. Histologically, the brain had multifocal, mainly perivascular, spindle-cell proliferations within the white matter of the medulla oblongata and focally within the gray matter of the midbrain. These cells immunolabeled with periaxin, myelin protein zero, SOX10, S100, and equivocally for vimentin, indicating Schwann cell origin. No changes were identified within other organs. Ancillary tests did not support an infectious etiology. Schwannosis should be considered as a differential diagnosis when investigating cases of arthrogryposis in calves with negative ancillary tests for infectious conditions.
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Affiliation(s)
- Diana Bochynska
- Ross University School of Veterinary Medicine, St Kitts and Nevis
| | - Ann Sharpe
- Department of Agriculture, Food and the Marine Central Veterinary Research Laboratory-Backweston Campus, Kilkenny, Ireland
| | - Brian Toland
- Department of Agriculture, Food and the Marine Central Veterinary Research Laboratory-Backweston Campus, Kilkenny, Ireland
| | - Elena Alina Demeter
- Department of Population Medicine and Diagnostic Sciences, Cornell University, College of Veterinary Medicine, Ithaca, NY, USA
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3
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Sardella-Silva G, Mietto BS, Ribeiro-Resende VT. Four Seasons for Schwann Cell Biology, Revisiting Key Periods: Development, Homeostasis, Repair, and Aging. Biomolecules 2021; 11:1887. [PMID: 34944531 PMCID: PMC8699407 DOI: 10.3390/biom11121887] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/08/2021] [Accepted: 12/10/2021] [Indexed: 01/28/2023] Open
Abstract
Like the seasons of the year, all natural things happen in stages, going through adaptations when challenged, and Schwann cells are a great example of that. During maturation, these cells regulate several steps in peripheral nervous system development. The Spring of the cell means the rise and bloom through organized stages defined by time-dependent regulation of factors and microenvironmental influences. Once matured, the Summer of the cell begins: a high energy stage focused on maintaining adult homeostasis. The Schwann cell provides many neuron-glia communications resulting in the maintenance of synapses. In the peripheral nervous system, Schwann cells are pivotal after injuries, balancing degeneration and regeneration, similarly to when Autumn comes. Their ability to acquire a repair phenotype brings the potential to reconnect axons to targets and regain function. Finally, Schwann cells age, not only by growing old, but also by imposed environmental cues, like loss of function induced by pathologies. The Winter of the cell presents as reduced activity, especially regarding their role in repair; this reflects on the regenerative potential of older/less healthy individuals. This review gathers essential information about Schwann cells in different stages, summarizing important participation of this intriguing cell in many functions throughout its lifetime.
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Affiliation(s)
- Gabriela Sardella-Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil;
- Núcleo Multidisciplinar de Pesquisa em Biologia (Numpex-Bio), Campus de Duque de Caxias Geraldo Guerra Cidade, Universidade Federal do Rio de Janeiro, Duque de Caxias 25255-030, RJ, Brazil
| | - Bruno Siqueira Mietto
- Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Juiz de Fora 36036-900, MG, Brazil;
| | - Victor Túlio Ribeiro-Resende
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil;
- Núcleo Multidisciplinar de Pesquisa em Biologia (Numpex-Bio), Campus de Duque de Caxias Geraldo Guerra Cidade, Universidade Federal do Rio de Janeiro, Duque de Caxias 25255-030, RJ, Brazil
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4
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Suter TACS, Jaworski A. Cell migration and axon guidance at the border between central and peripheral nervous system. Science 2020; 365:365/6456/eaaw8231. [PMID: 31467195 DOI: 10.1126/science.aaw8231] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 07/22/2019] [Indexed: 12/13/2022]
Abstract
The central and peripheral nervous system (CNS and PNS, respectively) are composed of distinct neuronal and glial cell types with specialized functional properties. However, a small number of select cells traverse the CNS-PNS boundary and connect these two major subdivisions of the nervous system. This pattern of segregation and selective connectivity is established during embryonic development, when neurons and glia migrate to their destinations and axons project to their targets. Here, we provide an overview of the cellular and molecular mechanisms that control cell migration and axon guidance at the vertebrate CNS-PNS border. We highlight recent advances on how cell bodies and axons are instructed to either cross or respect this boundary, and present open questions concerning the development and plasticity of the CNS-PNS interface.
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Affiliation(s)
- Tracey A C S Suter
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA.,Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | - Alexander Jaworski
- Department of Neuroscience, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA. .,Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
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5
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Garcia-Diaz B, Baron-Van Evercooren A. Schwann cells: Rescuers of central demyelination. Glia 2020; 68:1945-1956. [PMID: 32027054 DOI: 10.1002/glia.23788] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/15/2020] [Accepted: 01/23/2020] [Indexed: 12/31/2022]
Abstract
The presence of peripheral myelinating cells in the central nervous system (CNS) has gained the neurobiologist attention over the years. Despite the confirmed presence of Schwann cells in the CNS in pathological conditions, and the long list of their beneficial effects on central remyelination, the cues that impede or allow Schwann cells to successfully conquer and remyelinate central axons remain partially undiscovered. A better knowledge of these factors stands out as crucial to foresee a rational therapeutic approach for the use of Schwann cells in CNS repair. Here, we review the diverse origins of Schwann cells into the CNS, both peripheral and central, as well as the CNS components that inhibit Schwann survival and migration into the central parenchyma. Namely, we analyze the astrocyte- and the myelin-derived components that restrict Schwann cells into the CNS. Finally, we highlight the unveiled mode of invasion of these peripheral cells through the central environment, using blood vessels as scaffolds to pave their ways toward demyelinated lesions. In short, this review presents the so far uncovered knowledge of this complex CNS-peripheral nervous system (PNS) relationship.
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Affiliation(s)
- Beatriz Garcia-Diaz
- Unidad de Gestión Clínica de Neurociencias, IBIMA, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain.,Institut du Cerveau et de la Moelle Epinière-Groupe Hospitalier Pitié-Salpêtrière, INSERM, U1127, CNRS, Paris, France.,Sorbonne Universités, Université Pierre et Marie Curie Paris 06, Paris, France
| | - Anne Baron-Van Evercooren
- Institut du Cerveau et de la Moelle Epinière-Groupe Hospitalier Pitié-Salpêtrière, INSERM, U1127, CNRS, Paris, France.,Sorbonne Universités, Université Pierre et Marie Curie Paris 06, Paris, France
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6
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Mukhamedshina YO, Gracheva OA, Mukhutdinova DM, Chelyshev YA, Rizvanov AA. Mesenchymal stem cells and the neuronal microenvironment in the area of spinal cord injury. Neural Regen Res 2019; 14:227-237. [PMID: 30531002 PMCID: PMC6301181 DOI: 10.4103/1673-5374.244778] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cell-based technologies are used as a therapeutic strategy in spinal cord injury (SCI). Mesenchymal stem cells (MSCs), which secrete various neurotrophic factors and cytokines, have immunomodulatory, anti-apoptotic and anti-inflammatory effects, modulate reactivity/phenotype of astrocytes and the microglia, thereby promoting neuroregeneration seem to be the most promising. The therapeutic effect of MSCs is due to a paracrine mechanism of their action, therefore the survival of MSCs and their secretory phenotype is of particular importance. Nevertheless, these data are not always reported in efficacy studies of MSC therapy in SCI. Here, we provide a review with summaries of preclinical trials data evaluating the efficacy of MSCs in animal models of SCI. Based on the data collected, we have tried (1) to establish the behavior of MSCs after transplantation in SCI with an evaluation of cell survival, migration potential, distribution in the area of injured and intact tissue and possible differentiation; (2) to determine the effects MSCs on neuronal microenvironment and correlate them with the efficacy of functional recovery in SCI; (3) to ascertain the conditions under which MSCs demonstrate their best survival and greatest efficacy.
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Affiliation(s)
- Yana O Mukhamedshina
- OpenLab Gene and Cell Technologies, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University; Department of Histology, Cytology and Embryology, Kazan State Medical University, Kazan, Russia
| | - Olga A Gracheva
- Department of Therapy and Clinical Diagnostics with radiology Faculty of Veterinary Medicine, Bauman Kazan State Academy of Veterinary Medicine, Kazan, Russia
| | - Dina M Mukhutdinova
- Department of Therapy and Clinical Diagnostics with radiology Faculty of Veterinary Medicine, Bauman Kazan State Academy of Veterinary Medicine, Kazan, Russia
| | - Yurii A Chelyshev
- Department of Histology, Cytology and Embryology, Kazan State Medical University, Kazan, Russia
| | - Albert A Rizvanov
- OpenLab Gene and Cell Technologies, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Russia
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Influence of Genetically Modified Human Umbilical Cord Blood Mononuclear Cells on the Expression of Schwann Cell Molecular Determinants in Spinal Cord Injury. Stem Cells Int 2018. [PMID: 29531538 PMCID: PMC5835253 DOI: 10.1155/2018/4695275] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Spinal cord injury (SCI) unavoidably results in death of not only neurons but also glial cells. In particular, the death of oligodendrocytes leads to impaired nerve impulse conduction in intact axons. However, after SCI, the Schwann cells (SCs) are capable of migrating towards an area of injury and participating in the formation of functional myelin. In addition to SCI, cell-based therapy can influence the migration of SCs and the expression of their molecular determinants. In a number of cases, it can be explained by the ability of implanted cells to secrete neurotrophic factors (NTFs). Genetically modified stem and progenitor cells overexpressing NTFs have recently attracted special attention of researchers and are most promising for the purposes of regenerative medicine. Therefore, we have studied the effect of genetically modified human umbilical cord blood mononuclear cells on the expression of SC molecular determinants in SCI.
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Nardone R, Florea C, Höller Y, Brigo F, Versace V, Lochner P, Golaszewski S, Trinka E. Rodent, large animal and non-human primate models of spinal cord injury. ZOOLOGY 2017; 123:101-114. [PMID: 28720322 DOI: 10.1016/j.zool.2017.06.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 06/02/2017] [Accepted: 06/02/2017] [Indexed: 01/05/2023]
Abstract
In this narrative review we aimed to assess the usefulness of the different animal models in identifying injury mechanisms and developing therapies for humans suffering from spinal cord injury (SCI). Results obtained from rodent studies are useful but, due to the anatomical, molecular and functional differences, confirmation of these findings in large animals or non-human primates may lead to basic discoveries that cannot be made in rodent models and that are more useful for developing treatment strategies in humans. SCI in dogs can be considered as intermediate between rodent models and human clinical trials, but the primate models could help to develop appropriate methods that might be more relevant to humans. Ideally, an animal model should meet the requirements of availability and repeatability as well as reproduce the anatomical features and the clinical pathological changing process of SCI. An animal model that completely simulates SCI in humans does not exist. The different experimental models of SCI have advantages and disadvantages for investigating the different aspects of lesion development, recovery mechanisms and potential therapeutic interventions. The potential advantages of non-human primate models include genetic similarities, similar caliber/length of the spinal cord as well as biological and physiological responses to injury which are more similar to humans. Among the potential disadvantages, high operating costs, infrastructural requirements and ethical concerns should be considered. The translation from experimental repair strategies to clinical applications needs to be investigated in future carefully designed studies.
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Affiliation(s)
- Raffaele Nardone
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria; Department of Neurology, Franz Tappeiner Hospital, Via Rossini 5, I-39012, Merano, Italy; Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria.
| | - Cristina Florea
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria
| | - Yvonne Höller
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria
| | - Francesco Brigo
- Department of Neurology, Franz Tappeiner Hospital, Via Rossini 5, I-39012, Merano, Italy; Department of Neurosciences, Biomedicine and Movement Sciences, Section of Clinical Neurology, University of Verona, Piazzale L.A. Scuro, I-37134 Verona, Italy
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno, Via Santa Margherita 24, I-39049, Italy
| | - Piergiorgio Lochner
- Department of Neurology, Saarland University Medical Center, Kirrberger-Str. 100, D-66421 Homburg, Germany
| | - Stefan Golaszewski
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria; Spinal Cord Injury and Tissue Regeneration Center, Paracelsus Medical University, Ignaz-Harrer-Str. 79, A-5020, Salzburg, Austria
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9
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The Function of FGFR1 Signalling in the Spinal Cord: Therapeutic Approaches Using FGFR1 Ligands after Spinal Cord Injury. Neural Plast 2017; 2017:2740768. [PMID: 28197342 PMCID: PMC5286530 DOI: 10.1155/2017/2740768] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 12/25/2016] [Indexed: 11/24/2022] Open
Abstract
Extensive research is ongoing that concentrates on finding therapies to enhance CNS regeneration after spinal cord injury (SCI) and to cure paralysis. This review sheds light on the role of the FGFR pathway in the injured spinal cord and discusses various therapies that use FGFR activating ligands to promote regeneration after SCI. We discuss studies that use peripheral nerve grafts or Schwann cell grafts in combination with FGF1 or FGF2 supplementation. Most of these studies show evidence that these therapies successfully enhance axon regeneration into the graft. Further they provide evidence for partial recovery of sensory function shown by electrophysiology and motor activity evidenced by behavioural data. We also present one study that indicates that combination with additional, synergistic factors might further drive the system towards functional regeneration. In essence, this review summarises the potential of nerve and cell grafts combined with FGF1/2 supplementation to improve outcome even after severe spinal cord injury.
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10
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Predegenerated Schwann cells--a novel prospect for cell therapy for glaucoma: neuroprotection, neuroregeneration and neuroplasticity. Sci Rep 2016; 6:23187. [PMID: 27034151 PMCID: PMC4817039 DOI: 10.1038/srep23187] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/26/2016] [Indexed: 02/07/2023] Open
Abstract
Glaucoma is an optic neuropathy that leads to irreversible blindness. Because the current therapies are not sufficient to protect against glaucoma-induced visual impairment, new treatment approaches are necessary to prevent disease progression. Cell transplantation techniques are currently considered to be among the most promising opportunities for nervous system damage treatment. The beneficial effects of undifferentiated cells have been investigated in experimental models of glaucoma, however experiments were accompanied by various barriers, which would make putative treatment difficult or even impossible to apply in a clinical setting. The novel therapy proposed in our study creates conditions to eliminate some of the identified barriers described for precursor cells transplantation and allows us to observe direct neuroprotective and pro-regenerative effects in ongoing optic neuropathy without additional modifications to the transplanted cells. We demonstrated that the proposed novel Schwann cell therapy might be promising, effective and easy to apply, and is safer than the alternative cell therapies for the treatment of glaucoma.
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Bartus K, Galino J, James ND, Hernandez-Miranda LR, Dawes JM, Fricker FR, Garratt AN, McMahon SB, Ramer MS, Birchmeier C, Bennett DLH, Bradbury EJ. Neuregulin-1 controls an endogenous repair mechanism after spinal cord injury. Brain 2016; 139:1394-416. [PMID: 26993800 PMCID: PMC5477508 DOI: 10.1093/brain/aww039] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 01/24/2016] [Indexed: 12/16/2022] Open
Abstract
Spontaneous remyelination after spinal cord injury is mediated largely by Schwann cells
of unknown origin. Bartus et al. show that neuregulin-1 promotes
differentiation of spinal cord-resident precursor cells into PNS-like Schwann cells, which
remyelinate central axons and promote functional recovery. Targeting the neuregulin-1
system could enhance endogenous regenerative processes. Following traumatic spinal cord injury, acute demyelination of spinal axons is followed
by a period of spontaneous remyelination. However, this endogenous repair response is
suboptimal and may account for the persistently compromised function of surviving axons.
Spontaneous remyelination is largely mediated by Schwann cells, where demyelinated central
axons, particularly in the dorsal columns, become associated with peripheral myelin. The
molecular control, functional role and origin of these central remyelinating Schwann cells
is currently unknown. The growth factor neuregulin-1 (Nrg1, encoded by
NRG1) is a key signalling factor controlling myelination in the
peripheral nervous system, via signalling through ErbB tyrosine kinase receptors. Here we
examined whether Nrg1 is required for Schwann cell-mediated remyelination of central
dorsal column axons and whether Nrg1 ablation influences the degree of spontaneous
remyelination and functional recovery following spinal cord injury. In contused adult mice
with conditional ablation of Nrg1, we found an absence of Schwann cells within the spinal
cord and profound demyelination of dorsal column axons. There was no compensatory increase
in oligodendrocyte remyelination. Removal of peripheral input to the spinal cord and
proliferation studies demonstrated that the majority of remyelinating Schwann cells
originated within the injured spinal cord. We also examined the role of specific Nrg1
isoforms, using mutant mice in which only the immunoglobulin-containing isoforms of Nrg1
(types I and II) were conditionally ablated, leaving the type III Nrg1 intact. We found
that the immunoglobulin Nrg1 isoforms were dispensable for Schwann cell-mediated
remyelination of central axons after spinal cord injury. When functional effects were
examined, both global Nrg1 and immunoglobulin-specific Nrg1 mutants demonstrated reduced
spontaneous locomotor recovery compared to injured controls, although global Nrg1 mutants
were more impaired in tests requiring co-ordination, balance and proprioception.
Furthermore, electrophysiological assessments revealed severely impaired axonal conduction
in the dorsal columns of global Nrg1 mutants (where Schwann cell-mediated remyelination is
prevented), but not immunoglobulin-specific mutants (where Schwann cell-mediated
remyelination remains intact), providing robust evidence that the profound demyelinating
phenotype observed in the dorsal columns of Nrg1 mutant mice is related to conduction
failure. Our data provide novel mechanistic insight into endogenous regenerative processes
after spinal cord injury, demonstrating that Nrg1 signalling regulates central axon
remyelination and functional repair and drives the trans-differentiation of central
precursor cells into peripheral nervous system-like Schwann cells that remyelinate spinal
axons after injury. Manipulation of the Nrg1 system could therefore be exploited to
enhance spontaneous repair after spinal cord injury and other central nervous system
disorders with a demyelinating pathology.
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Affiliation(s)
- Katalin Bartus
- The Wolfson Centre for Age-Related Diseases, Regeneration Group, King's College London, Guy's Campus, London Bridge, London, UK
| | - Jorge Galino
- Nuffield Department of Clinical Neurosciences, West Wing, John Radcliffe Hospital, Oxford, UK
| | - Nicholas D James
- The Wolfson Centre for Age-Related Diseases, Regeneration Group, King's College London, Guy's Campus, London Bridge, London, UK
| | | | - John M Dawes
- Nuffield Department of Clinical Neurosciences, West Wing, John Radcliffe Hospital, Oxford, UK
| | - Florence R Fricker
- Nuffield Department of Clinical Neurosciences, West Wing, John Radcliffe Hospital, Oxford, UK
| | - Alistair N Garratt
- Max Delbrück Center for Molecular Medicine, Berlin, Germany Charité Universitätsmedizin Berlin, Charitéplatz, Berlin, Germany
| | - Stephen B McMahon
- The Wolfson Centre for Age-Related Diseases, Regeneration Group, King's College London, Guy's Campus, London Bridge, London, UK
| | - Matt S Ramer
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, Canada
| | | | - David L H Bennett
- Nuffield Department of Clinical Neurosciences, West Wing, John Radcliffe Hospital, Oxford, UK
| | - Elizabeth J Bradbury
- The Wolfson Centre for Age-Related Diseases, Regeneration Group, King's College London, Guy's Campus, London Bridge, London, UK
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Mukhamedshina YO, Shaymardanova GF, Garanina ЕЕ, Salafutdinov II, Rizvanov АА, Islamov RR, Chelyshev YA. Adenoviral vector carrying glial cell-derived neurotrophic factor for direct gene therapy in comparison with human umbilical cord blood cell-mediated therapy of spinal cord injury in rat. Spinal Cord 2015; 54:347-59. [PMID: 26415641 DOI: 10.1038/sc.2015.161] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 07/10/2015] [Accepted: 08/12/2015] [Indexed: 12/31/2022]
Abstract
STUDY DESIGN Experimental study. OBJECTIVE To evaluate the treatment of spinal cord injury with glial cell-derived neurotrophic factor (GDNF) delivered using an adenoviral vector (AdV-GDNF group) in comparison with treatment performed using human umbilical cord blood mononuclear cells (UCB-MCs)-transduced with an adenoviral vector carrying the GDNF gene (UCB-MCs+AdV-GDNF group) in rat. SETTING Kazan, Russian Federation. METHODS We examined the efficacy of AdV-GDNF and UCB-MCs+AdV-GDNF therapy by conducting behavioral tests on the animals and morphometric studies on the spinal cord, performing immunofluorescence analyses on glial cells, investigating the survival and migration potential of UCB-MCs, and evaluating the expression of the recombinant GDNF gene. RESULTS At the 30th postoperative day, equal positive locomotor recovery was observed after both direct and cell-based GDNF therapy. However, after UCB-MCs-mediated GDNF therapy, the area of preserved tissue and the number of spared myelinated fibers were higher than those measured after direct GDNF gene therapy. Moreover, we observed distinct changes in the populations of glial cells; expression patterns of the specific markers for astrocytes (GFAP, S100B and AQP4), oligodendrocytes (PDGFαR and Cx47) and Schwann cells (P0) differed in various areas of the spinal cord of rats treated with AdV-GDNF and UCB-MCs+AdV-GDNF. CONCLUSION The differences detected in the AdV-GDNF and UCB-MCs+AdV-GDNF groups could be partially explained by the action of UCB-MCs. We discuss the insufficiency and the advantages of these two methods of GDNF gene delivery into the spinal cord after traumatic injury.
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Affiliation(s)
- Y O Mukhamedshina
- OpenLab Gene and Cell Technologies, Kazan (Volga Region) Federal University, Kazan, Russia
| | - G F Shaymardanova
- Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, Kazan, Russia
| | - Е Е Garanina
- OpenLab Gene and Cell Technologies, Kazan (Volga Region) Federal University, Kazan, Russia
| | - I I Salafutdinov
- OpenLab Gene and Cell Technologies, Kazan (Volga Region) Federal University, Kazan, Russia
| | - А А Rizvanov
- OpenLab Gene and Cell Technologies, Kazan (Volga Region) Federal University, Kazan, Russia
| | - R R Islamov
- Department of Hystology, Kazan State Medical University, Kazan, Russia
| | - Y A Chelyshev
- Department of Hystology, Kazan State Medical University, Kazan, Russia
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Akkouh O, Ng TB, Cheung RCF, Wong JH, Pan W, Ng CCW, Sha O, Shaw PC, Chan WY. Biological activities of ribosome-inactivating proteins and their possible applications as antimicrobial, anticancer, and anti-pest agents and in neuroscience research. Appl Microbiol Biotechnol 2015; 99:9847-63. [PMID: 26394859 DOI: 10.1007/s00253-015-6941-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/10/2015] [Accepted: 08/13/2015] [Indexed: 02/06/2023]
Abstract
Ribosome-inactivating proteins (RIPs) are enzymes which depurinate ribosomal RNA (rRNA), thus impeding the process of translation resulting in inhibition of protein synthesis. They are produced by various organisms including plants, fungi and bacteria. RIPs from plants are linked to plant defense due to their antiviral, antifungal, antibacterial, and insecticidal activities in which they can be applied in agriculture to combat microbial pathogens and pests. Their anticancer, antiviral, embryotoxic, and abortifacient properties may find medicinal applications. Besides, conjugation of RIPs with antibodies or other carriers to form immunotoxins has been found useful to research in neuroscience and anticancer therapy.
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Affiliation(s)
- Ouafae Akkouh
- Department of Biology and Medical Laboratory Research, Faculty of Technology, University of Applied Sciences Leiden, Zernikdreef 11, 2333 CK, Leiden, The Netherlands.
| | - Tzi Bun Ng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Randy Chi Fai Cheung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Jack Ho Wong
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Wenliang Pan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Charlene Cheuk Wing Ng
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Ou Sha
- School of Medicine, Shenzhen University Health Science Centre, Shenzhen University, Shenzhen, China.
| | - Pang Chui Shaw
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
| | - Wai Yee Chan
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
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14
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Alizadeh A, Dyck SM, Karimi-Abdolrezaee S. Myelin damage and repair in pathologic CNS: challenges and prospects. Front Mol Neurosci 2015; 8:35. [PMID: 26283909 PMCID: PMC4515562 DOI: 10.3389/fnmol.2015.00035] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Accepted: 07/06/2015] [Indexed: 12/28/2022] Open
Abstract
Injury to the central nervous system (CNS) results in oligodendrocyte cell death and progressive demyelination. Demyelinated axons undergo considerable physiological changes and molecular reorganizations that collectively result in axonal dysfunction, degeneration and loss of sensory and motor functions. Endogenous adult oligodendrocyte precursor cells and neural stem/progenitor cells contribute to the replacement of oligodendrocytes, however, the extent and quality of endogenous remyelination is suboptimal. Emerging evidence indicates that optimal remyelination is restricted by multiple factors including (i) low levels of factors that promote oligodendrogenesis; (ii) cell death among newly generated oligodendrocytes, (iii) inhibitory factors in the post-injury milieu that impede remyelination, and (iv) deficient expression of key growth factors essential for proper re-construction of a highly organized myelin sheath. Considering these challenges, over the past several years, a number of cell-based strategies have been developed to optimize remyelination therapeutically. Outcomes of these basic and preclinical discoveries are promising and signify the importance of remyelination as a mechanism for improving functions in CNS injuries. In this review, we provide an overview on: (1) the precise organization of myelinated axons and the reciprocal axo-myelin interactions that warrant properly balanced physiological activities within the CNS; (2) underlying cause of demyelination and the structural and functional consequences of demyelination in axons following injury and disease; (3) the endogenous mechanisms of oligodendrocyte replacement; (4) the modulatory role of reactive astrocytes and inflammatory cells in remyelination; and (5) the current status of cell-based therapies for promoting remyelination. Careful elucidation of the cellular and molecular mechanisms of demyelination in the pathologic CNS is a key to better understanding the impact of remyelination for CNS repair.
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Affiliation(s)
- Arsalan Alizadeh
- Regenerative Medicine Program, Department of Physiology and Pathophysiology, Spinal Cord Research Centre, Faculty of Health Sciences, College of Medicine, University of Manitoba, Winnipeg MB, Canada
| | - Scott M Dyck
- Regenerative Medicine Program, Department of Physiology and Pathophysiology, Spinal Cord Research Centre, Faculty of Health Sciences, College of Medicine, University of Manitoba, Winnipeg MB, Canada
| | - Soheila Karimi-Abdolrezaee
- Regenerative Medicine Program, Department of Physiology and Pathophysiology, Spinal Cord Research Centre, Faculty of Health Sciences, College of Medicine, University of Manitoba, Winnipeg MB, Canada
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15
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Marcol W, Ślusarczyk W, Larysz-Brysz M, Francuz T, Jędrzejowska-Szypułka H, Łabuzek K, Lewin-Kowalik J. Grafted Activated Schwann Cells Support Survival of Injured Rat Spinal Cord White Matter. World Neurosurg 2015; 84:511-9. [PMID: 25910924 DOI: 10.1016/j.wneu.2015.04.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 04/10/2015] [Accepted: 04/11/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND OBJECTIVE The influence of cultured Schwann cells on injured spinal cord in rats is examined. METHODS Focal injury of spinal cord white matter at the T10 level was produced using our original non-laminectomy method with a high-pressure air stream. Schwann cells from 7-day predegenerated rat sciatic nerves were cultured, transducted with green fluorescent protein and injected into the cisterna magna (experimental group) 3 times: immediately after spinal cord injury and 3 and 7 days later. Neurons in the brainstem and motor cortex were labeled with FluoroGold (FG) delivered caudally from the injury site a week before the end of the experiment. The functional outcome and morphologic features of neuronal survival were analyzed during a 12-week follow-up. The lesions were visualized and analyzed using magnetic resonance imaging. The maximal distance of expansion of implanted cells in the spinal cord was measured and the number of FG-positive neurons in the brain was counted. RESULTS Rats treated with Schwann cells presented significant improvement of locomotor performance and spinal cord morphology compared with the control group. The distance covered by Schwann cells was 7 mm from the epicenter of the injury. The number of brainstem and motor cortex FG-positive neurons in the experimental group was significantly higher than in the control group. CONCLUSIONS The data show that activated Schwann cells are able to induce the repair of injured spinal cord white matter. The route of application of cells via the cisterna magna seemed to be useful for their delivery in spinal cord injury therapy.
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Affiliation(s)
- Wiesław Marcol
- Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland.
| | - Wojciech Ślusarczyk
- Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Magdalena Larysz-Brysz
- Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Tomasz Francuz
- Department of Biochemistry, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | | | - Krzysztof Łabuzek
- Department of Pharmacology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
| | - Joanna Lewin-Kowalik
- Department of Physiology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland
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16
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Papastefanaki F, Matsas R. From demyelination to remyelination: the road toward therapies for spinal cord injury. Glia 2015; 63:1101-25. [PMID: 25731941 DOI: 10.1002/glia.22809] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/10/2015] [Accepted: 02/11/2015] [Indexed: 12/14/2022]
Abstract
Myelin integrity is crucial for central nervous system (CNS) physiology while its preservation and regeneration after spinal cord injury (SCI) is key to functional restoration. Disturbance of nodal organization acutely after SCI exposes the axon and triggers conduction block in the absence of overt demyelination. Oligodendrocyte (OL) loss and myelin degradation follow as a consequence of secondary damage. Here, we provide an overview of the major biological events and underlying mechanisms leading to OL death and demyelination and discuss strategies to restrain these processes. Another aspect which is critical for SCI repair is the enhancement of endogenously occurring spontaneous remyelination. Recent findings have unveiled the complex roles of innate and adaptive immune responses in remyelination and the immunoregulatory potential of the glial scar. Moreover, the intimate crosstalk between neuronal activity, oligodendrogenesis and myelination emphasizes the contribution of rehabilitation to functional recovery. With a view toward clinical applications, several therapeutic strategies have been devised to target SCI pathology, including genetic manipulation, administration of small therapeutic molecules, immunomodulation, manipulation of the glial scar and cell transplantation. The implementation of new tools such as cellular reprogramming for conversion of one somatic cell type to another or the use of nanotechnology and tissue engineering products provides additional opportunities for SCI repair. Given the complexity of the spinal cord tissue after injury, it is becoming apparent that combinatorial strategies are needed to rescue OLs and myelin at early stages after SCI and support remyelination, paving the way toward clinical translation.
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Affiliation(s)
- Florentia Papastefanaki
- Laboratory of Cellular and Molecular Neurobiology, Hellenic Pasteur Institute, Athens, 11521, Greece
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17
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Gilabert-Oriol R, Weng A, Mallinckrodt BV, Melzig MF, Fuchs H, Thakur M. Immunotoxins constructed with ribosome-inactivating proteins and their enhancers: a lethal cocktail with tumor specific efficacy. Curr Pharm Des 2014; 20:6584-643. [PMID: 25341935 PMCID: PMC4296666 DOI: 10.2174/1381612820666140826153913] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 08/05/2014] [Indexed: 11/30/2022]
Abstract
The term ribosome-inactivating protein (RIP) is used to denominate proteins mostly of plant origin, which have N-glycosidase enzymatic activity leading to a complete destruction of the ribosomal function. The discovery of the RIPs was almost a century ago, but their usage has seen transition only in the last four decades. With the advent of antibody therapy, the RIPs have been a subject of extensive research especially in targeted tumor therapies, which is the primary focus of this review. In the present work we enumerate 250 RIPs, which have been identified so far. An attempt has been made to identify all the RIPs that have been used for the construction of immunotoxins, which are conjugates or fusion proteins of an antibody or ligand with a toxin. The data from 1960 onwards is reviewed in this paper and an extensive list of more than 450 immunotoxins is reported. The clinical reach of tumor-targeted toxins has been identified and detailed in the work as well. While there is a lot of potential that RIPs embrace for targeted tumor therapies, the success in preclinical and clinical evaluations has been limited mainly because of their inability to escape the endo/lysosomal degradation. Various strategies that can increase the efficacy and lower the required dose for targeted toxins have been compiled in this article. It is plausible that with the advancements in platform technologies or improved endosomal escape the usage of tumor targeted RIPs would see the daylight of clinical success.
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Affiliation(s)
| | | | | | | | | | - Mayank Thakur
- Institut fur Laboratoriumsmedizin, Klinische Chemie und Pathobiochemie, Charite - Universitatsmedizin Berlin, Campus Virchow-Klinikum (Forum 4), Augustenburger Platz 1, D-13353 Berlin, Germany.
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18
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Treatment of a relapse-remitting model of multiple sclerosis with opioid growth factor. Brain Res Bull 2013; 98:122-31. [DOI: 10.1016/j.brainresbull.2013.08.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 07/31/2013] [Accepted: 08/03/2013] [Indexed: 12/30/2022]
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19
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Remyelination reporter reveals prolonged refinement of spontaneously regenerated myelin. Proc Natl Acad Sci U S A 2013; 110:4075-80. [PMID: 23431182 DOI: 10.1073/pnas.1210293110] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Neurological diseases and trauma often cause demyelination, resulting in the disruption of axonal function and integrity. Endogenous remyelination promotes recovery, but the process is not well understood because no method exists to definitively distinguish regenerated from preexisting myelin. To date, remyelinated segments have been defined as anything abnormally short and thin, without empirical data to corroborate these morphological assumptions. To definitively identify regenerated myelin, we used a transgenic mouse with an inducible membrane-bound reporter and targeted Cre recombinase expression to a subset of glial progenitor cells after spinal cord injury, yielding remarkably clear visualization of spontaneously regenerated myelin in vivo. Early after injury, the mean length of sheaths regenerated by Schwann cells and oligodendrocytes (OLs) was significantly shorter than control, uninjured myelin, confirming past assumptions. However, OL-regenerated sheaths elongated progressively over 6 mo to approach control values. Moreover, OL-regenerated myelin thickness was not significantly different from control myelin at most time points after injury. Thus, many newly formed OL sheaths were neither thinner nor shorter than control myelin, vitiating accepted dogmas of what constitutes regenerated myelin. We conclude that remyelination, once thought to be static, is dynamic and elongates independently of axonal growth, in contrast to stretch-based mechanisms proposed in development. Further, without clear identification, past assessments have underestimated the extent and quality of regenerated myelin.
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20
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Campbell AM, Zagon IS, McLaughlin PJ. Opioid growth factor arrests the progression of clinical disease and spinal cord pathology in established experimental autoimmune encephalomyelitis. Brain Res 2012; 1472:138-48. [PMID: 22820301 DOI: 10.1016/j.brainres.2012.07.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/18/2012] [Accepted: 07/05/2012] [Indexed: 11/25/2022]
Abstract
An endogenous neuropeptide, opioid growth factor (OGF), chemically termed [Met(5)]-enkephalin, arrested the progression of established disease in a mouse model of multiple sclerosis (MS) called experimental autoimmune encephalomyelitis (EAE). This study treated mice who demonstrated 2 consecutive days of behavioral decline following injections of myelin oligodendrocyte glycoprotein (MOG) with daily injections of OGF (10mg/kg) or saline (0.1ml) for 40 days. Within 6 days of OGF treatment, mice initially demonstrating clinical signs of EAE had significant reductions (45% reduction) in their behavioral scores relative to EAE mice receiving saline. Behavior was attenuated for the entire 40-day period with mice receiving OGF showing only limp tails and wobbly gait in comparison to saline-treated EAE mice who displayed paralysis of one or more limbs. Neuropathological studies revealed that OGF treatment initiated after the appearance of disease reduced the number of activated astrocytes and damaged neurons, decreased demyelination, and inhibited T cell proliferation. These results demonstrate that OGF can halt the progression of established EAE, return aberrant pain sensitivity to normal levels, inhibit proliferation of T cells and astrocytes, and prevent further spinal cord pathology. The data extend our observations that OGF given at the time of disease induction prevented disease onset, reduced the severity of clinical signs of disease, and reversed neurological deficits in a non-toxic manner. Our data substantiate the role of the OGF-OGFr axis in EAE and support the use of OGF as a biotherapy for MS.
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Affiliation(s)
- Anna M Campbell
- Department of Neural & Behavioral Science Penn State University College of Medicine, 500 University Drive, Hershey, PA 17033, United States
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21
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Navarro R, Juhas S, Keshavarzi S, Juhasova J, Motlik J, Johe K, Marsala S, Scadeng M, Lazar P, Tomori Z, Schulteis G, Beattie M, Ciacci JD, Marsala M. Chronic spinal compression model in minipigs: a systematic behavioral, qualitative, and quantitative neuropathological study. J Neurotrauma 2012; 29:499-513. [PMID: 22029501 DOI: 10.1089/neu.2011.2076] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The goal of the present study was to develop a porcine spinal cord injury (SCI) model, and to describe the neurological outcome and characterize the corresponding quantitative and qualitative histological changes at 4-9 months after injury. Adult Gottingen-Minnesota minipigs were anesthetized and placed in a spine immobilization frame. The exposed T12 spinal segment was compressed in a dorso-ventral direction using a 5-mm-diameter circular bar with a progressively increasing peak force (1.5, 2.0, or 2.5 kg) at a velocity of 3 cm/sec. During recovery, motor and sensory function were periodically monitored. After survival, the animals were perfusion fixed and the extent of local SCI was analyzed by (1) post-mortem MRI analysis of dissected spinal cords, (2) qualitative and quantitative analysis of axonal survival at the epicenter of injury, and (3) defining the presence of local inflammatory changes, astrocytosis, and schwannosis. Following 2.5-kg spinal cord compression the animals demonstrated a near complete loss of motor and sensory function with no recovery over the next 4-9 months. Those that underwent spinal cord compression with 2 kg force developed an incomplete injury with progressive partial neurological recovery characterized by a restricted ability to stand and walk. Animals injured with a spinal compression force of 1.5 kg showed near normal ambulation 10 days after injury. In fully paralyzed animals (2.5 kg), MRI analysis demonstrated a loss of spinal white matter integrity and extensive septal cavitations. A significant correlation between the magnitude of loss of small and medium-sized myelinated axons in the ventral funiculus and neurological deficits was identified. These data, demonstrating stable neurological deficits in severely injured animals, similarities of spinal pathology to humans, and relatively good post-injury tolerance of this strain of minipigs to spinal trauma, suggest that this model can successfully be used to study therapeutic interventions targeting both acute and chronic stages of SCI.
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Affiliation(s)
- Roman Navarro
- Neuroregeneration Laboratory, Department of Anesthesiology, University of California, San Diego (UCSD), San Diego, California, USA
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22
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Saberi H, Firouzi M, Habibi Z, Moshayedi P, Aghayan HR, Arjmand B, Hosseini K, Razavi HE, Yekaninejad MS. Safety of intramedullary Schwann cell transplantation for postrehabilitation spinal cord injuries: 2-year follow-up of 33 cases. J Neurosurg Spine 2011; 15:515-25. [PMID: 21800956 DOI: 10.3171/2011.6.spine10917] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Many experimental studies on spinal cord injuries (SCIs) support behavioral improvement after Schwann cell treatment. This study was conducted to evaluate safety issues 2 years after intramedullary Schwann cell transplantation in 33 consecutively selected patients with SCI. METHODS Of 356 patients with SCIs who had completed at least 6 months of a conventional rehabilitation program and who were screened for the study criteria, 33 were enrolled. After giving their informed consent, they volunteered for participation. They underwent sural nerve harvesting and intramedullary injection of a processed Schwann cell solution. Outcome assessments included a general health questionnaire, neurological examination, and functional recordings in terms of American Spinal Injury Association (ASIA) and Functional Independence Measure scoring, which were documented by independent observers. There were 24 patients with thoracic and 9 with cervical injuries. Sixteen patients were categorized in ASIA Grade A, and the 17 remaining participants had ASIA Grade B. RESULTS There were no cases of deep infection, and the follow-up MR imaging studies obtained at 2 years did not reveal any deformity related to the procedure. There was no case of permanent neurological worsening or any infectious or viral complications. No new increment in syrinx size or abnormal tissue and/or tumor formation were observed on contrast-enhanced MR imaging studies performed 2 years after the treatment. CONCLUSIONS Preliminary results, especially in terms of safety, seem to be promising, paving the way for future cell therapy trials.
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Affiliation(s)
- Hooshang Saberi
- Department of Neurosurgery, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran.
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23
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Analysis of Structural and Molecular Events Associated with Adult Rat Optic Chiasm and Nerves Demyelination and Remyelination; Possible Role for 3rd Ventricle Proliferating Cells. Neuromolecular Med 2011; 13:138-50. [DOI: 10.1007/s12017-011-8143-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Accepted: 01/05/2011] [Indexed: 12/31/2022]
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Gulino R, Perciavalle V, Gulisano M. Expression of cell fate determinants and plastic changes after neurotoxic lesion of adult mice spinal cord by cholera toxin-B saporin. Eur J Neurosci 2010; 31:1423-34. [PMID: 20384775 DOI: 10.1111/j.1460-9568.2010.07170.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Recent studies have attempted to repair the damaged spinal cord (SC) by stimulating neurogenesis or neuroplasticity. Sonic hedgehog (Shh), Notch-1 and Numb are involved in the stem cell functioning. Additionally, Notch-1 has a role as modulator of synaptic plasticity. However, little is known about the role of these proteins in the adult SC after removal of motoneurons. In this study, we have injected cholera toxin-B saporin into the gastrocnemius muscle to induce a depletion of motoneurons within the lumbar SC of adult mice, and analysed the expression of choline acetyltransferase (ChAT), Synapsin-I, Shh, Notch-1 and Numb proteins. The functional outcome of the lesion was monitored by grid walk and rotarod tasks. The neurotoxin lesion determined a motoneuron depletion and a transient decrease of ChAT, Synapsin-I, Shh and Numb levels in the lumbar SC. ChAT was associated with Synapsin-I expression and motor performance at 1 week but not 1 month after lesion, suggesting that the recovery of locomotion could depend on synaptic plasticity, at least in an early phase. Shh and Notch-1 were associated with Synapsin-I levels, suggesting a role in modulating synaptic plasticity. Numb expression also appeared reduced after lesion and linked to motor performance. Moreover, unlike other lesion models, we observed glial reaction but no evidence of cell proliferation within the depleted SC. Given the mentioned roles of Shh, Notch-1 and Numb, we believe that an in vivo manipulation of their signalling after lesion could represent a suitable way to improve functional recovery by modulating synaptic plasticity and/or neurogenesis.
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Affiliation(s)
- Rosario Gulino
- Department of Physiological Sciences, University of Catania, Catania, Italy
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25
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Ohara PT, Vit JP, Bhargava A, Romero M, Sundberg C, Charles AC, Jasmin L. Gliopathic pain: when satellite glial cells go bad. Neuroscientist 2010; 15:450-63. [PMID: 19826169 DOI: 10.1177/1073858409336094] [Citation(s) in RCA: 133] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Neurons in sensory ganglia are surrounded by satellite glial cells (SGCs) that perform similar functions to the glia found in the CNS. When primary sensory neurons are injured, the surrounding SGCs undergo characteristic changes. There is good evidence that the SGCs are not just bystanders to the injury but play an active role in the initiation and maintenance of neuronal changes that underlie neuropathic pain. In this article the authors review the literature on the relationship between SGCs and nociception and present evidence that changes in SGC potassium ion buffering capacity and glutamate recycling can lead to neuropathic pain-like behavior in animal models. The role that SGCs play in the immune responses to injury is also considered. We propose the term gliopathic pain to describe those conditions in which central or peripheral glia are thought to be the principal generators of principal pain generators.
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Affiliation(s)
- Peter T Ohara
- Department of Anatomy, University of California, San Francisco, California 95143-0452, USA.
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26
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Functional recovery of chronic paraplegic pigs after autologous transplantation of bone marrow stromal cells. Transplantation 2008; 86:845-53. [PMID: 18813110 DOI: 10.1097/tp.0b013e318186198f] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Bone marrow stromal cells (BMSC) transplantation offers promise in the treatment of chronic paraplegia in rodents. Here, we report the effect of this cell therapy in adult pigs suffering chronic paraplegia. METHODS Three months after spinal cord injury, autologous BMSC in autologous plasma was injected into lesion zone and adjacent subarachnoid space in seven paraplegic pigs. On the contrary, three paraplegic pigs only received autologous plasma. Functional outcome was measured weekly until the end of the follow-up, 3 months later. RESULTS Our present study showed progressive functional recovery in transplanted pigs. At this time, intramedullary posttraumatic cavities were filled by a neoformed tissue containing several axons, together with BMSC that expressed neuronal or glial markers. Furthermore, in the treated animals, electrophysiological studies showed recovery of the previously abolished somatosensory-evoked potentials. CONCLUSIONS These findings confirm previous observations in rodents and support the possible utility of BMSC transplantation in humans suffering chronic paraplegia.
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Abstract
Remyelination is the regenerative process by which demyelinated axons are reinvested with new myelin sheaths. It is associated with functional recovery and maintenance of axonal health. It occurs as a spontaneous regenerative response following demyelination in a range of pathologies including traumatic injury as well as primary demyelinating disease such as multiple sclerosis (MS). Experimental models of demyelination based on the use of toxins, while not attempting to accurately mimic a disease with complex etiology and pathogenesis such as MS, have nevertheless proven extremely useful for studying the biology of remyelination. In this chapter, we review the main toxin models of demyelination, drawing attention to their differences and how they can be used to study different aspects of remyelination. We also describe the optimal use of these models, highlighting potential pitfalls in interpretation, and how remyelination can be unequivocally recognized. Finally, we discuss the role of toxin models alongside viral and immune-mediated models of demyelination.
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28
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Zujovic V, Bachelin C, Baron-Van Evercooren A. Remyelination of the central nervous system: a valuable contribution from the periphery. Neuroscientist 2007; 13:383-91. [PMID: 17644768 DOI: 10.1177/10738584070130041001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The loss of myelin, a major element involved in the saltatory conduction of the electrical impulse of the nervous system, is a major target of current research. Serious long-term disabilities are observed in patients with demyelinating disease of the central nervous system, such as multiple sclerosis. New therapeutic strategies aimed at overcoming myelin damage and axonal loss focus on the repair potential of myelin-forming cells. This review examines the use of peripheral myelin-forming cells, the Schwann cells, to promote myelin repair.
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Affiliation(s)
- Violetta Zujovic
- Institut National de la Santé et de la Recherche Médicale, Université Pierre et Marie Curie, and AP-HP Hôpital Pitié-Salpêtrière, Fédération de Neurologie, Paris, France
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Samadikuchaksaraei A. An overview of tissue engineering approaches for management of spinal cord injuries. J Neuroeng Rehabil 2007; 4:15. [PMID: 17501987 PMCID: PMC1876804 DOI: 10.1186/1743-0003-4-15] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2006] [Accepted: 05/14/2007] [Indexed: 01/09/2023] Open
Abstract
Severe spinal cord injury (SCI) leads to devastating neurological deficits and disabilities, which necessitates spending a great deal of health budget for psychological and healthcare problems of these patients and their relatives. This justifies the cost of research into the new modalities for treatment of spinal cord injuries, even in developing countries. Apart from surgical management and nerve grafting, several other approaches have been adopted for management of this condition including pharmacologic and gene therapy, cell therapy, and use of different cell-free or cell-seeded bioscaffolds. In current paper, the recent developments for therapeutic delivery of stem and non-stem cells to the site of injury, and application of cell-free and cell-seeded natural and synthetic scaffolds have been reviewed.
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Affiliation(s)
- Ali Samadikuchaksaraei
- Department of Biotechnology, Faculty of Allied Medicine and Cellular and Molecular Research Center, Iran University of Medical Sciences, Iran.
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Onifer SM, Rabchevsky AG, Scheff SW. Rat Models of Traumatic Spinal Cord Injury to Assess Motor Recovery. ILAR J 2007; 48:385-95. [PMID: 17712224 DOI: 10.1093/ilar.48.4.385] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Devastating motor, sensory, and autonomic dysfunctions render long-term personal hardships to the survivors of traumatic spinal cord injury (SCI). The suffering also extends to the survivors' families and friends, who endure emotional, physical, and financial burdens in providing for necessary surgeries, care, and rehabilitation. After the primary mechanical SCI, there is a complex secondary injury cascade that leads to the progressive death of otherwise potentially viable axons and cells and that impairs endogenous recovery processes. Investigations of possible cures and of ways to alleviate the hardships of traumatic SCI include those of interventions that attenuate or overcome the secondary injury cascade, enhance the endogenous repair mechanisms, regenerate axons, replace lost cells, and rehabilitate. These investigations have led to the creation of laboratory animal models of the different types of traumatic human SCI and components of the secondary injury cascade. However, no particular model completely addresses all aspects of traumatic SCI. In this article, we describe adult rat SCI models and the motor, and in some cases sensory and autonomic, deficits that each produces. Importantly, as researchers in this area move toward clinical trials to alleviate the hardships of traumatic SCI, there is a need for standardized small and large animal SCI models as well as quantitative behavioral and electrophysiological assessments of their outcomes so that investigators testing various interventions can directly compare their results and correlate them with the molecular, biochemical, and histological alterations.
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Affiliation(s)
- Stephen M Onifer
- Spinal Cord and Brain Injury Research Center, Biomedical and Biological Sciences Research Building, University of Kentucky, 741 South Limestone Street, Lexington, KY 40536-0509, USA.
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31
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Tang CH, Lee JW, Galvez MG, Robillard L, Mole SE, Chapman HA. Murine cathepsin F deficiency causes neuronal lipofuscinosis and late-onset neurological disease. Mol Cell Biol 2006; 26:2309-16. [PMID: 16508006 PMCID: PMC1430281 DOI: 10.1128/mcb.26.6.2309-2316.2006] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cathepsin F (cat F) is a widely expressed lysosomal cysteine protease whose in vivo role is unknown. To address this issue, mice deficient in cat F were generated via homologous recombination. Although cat F-/- mice appeared healthy and reproduced normally, they developed progressive hind leg weakness and decline in motor coordination at 12 to 16 months of age, followed by significant weight loss and death within 6 months. cat F was found to be expressed throughout the central nervous system (CNS). cat F-/- neurons accumulated eosinophilic granules that had features typical of lysosomal lipofuscin by electron microscopy. Large amounts of autofluorescent lipofuscin, characteristic of the neurodegenerative disease neuronal ceroid lipofuscinosis (NCL), accumulated throughout the CNS but not in visceral organs, beginning as early as 6 weeks of age. Pronounced gliosis, an indicator of neuronal stress and neurodegeneration, was also apparent in older cat F-/- mice. cat F is the only cysteine cathepsin whose inactivation alone causes a lysosomal storage defect and progressive neurological features in mice. The late onset suggests that this gene may be a candidate for adult-onset NCL.
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Affiliation(s)
- Chi-Hui Tang
- Department of Medicine, and The Cardiovascular Research Institute, University of California, San Francisco, Box 0111, San Francisco, CA 94143, USA
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32
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Gao L, Macklin W, Gerson J, Miller RH. Intrinsic and extrinsic inhibition of oligodendrocyte development by rat retina. Dev Biol 2006; 290:277-86. [PMID: 16388796 DOI: 10.1016/j.ydbio.2005.11.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 11/02/2005] [Accepted: 11/07/2005] [Indexed: 10/25/2022]
Abstract
Cell patterning in the vertebrate CNS reflects the combination of localized cell induction, migration and differentiation. A striking example of patterning is the myelination of visual system. In many species, retinal ganglion cell axons are myelinated in the optic nerve but are unmyelinated in the retina. Here, we confirm that rat and mouse retina lack oligodendrocytes and their precursors and identify multiple mechanisms that might contribute to their absence. Soluble cues from embryonic retina inhibit the induction of oligodendrocytes from neural stem cells and their differentiation from optic nerve precursors. This inhibition is mediated by retinal-derived BMPs. During development BMPs are expressed in the retina and addition of the BMP antagonist Noggin reversed retinal inhibition of oligodendrocyte development. The lack of retinal oligodendrocytes does not simply reflect expression of BMPs, since no oligodendrocytes or their precursors developed when embryonic retinal cells were grown in the presence of Noggin and/or inductive cues such as Shh and IGF-1. Similarly, injection of Noggin into the postnatal rat eye failed to induce oligodendrocyte differentiation. These data combined with the proposed inhibition of OPC migration by molecules selectively expressed at the nerve retina junction suggest that multiple mechanisms combine to suppress retinal myelination during development.
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Affiliation(s)
- Limin Gao
- Department of Neurosciences, Case School of Medicine, Cleveland, OH 44106, USA
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33
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Boyd JG, Doucette R, Kawaja MD. Defining the role of olfactory ensheathing cells in facilitating axon remyelination following damage to the spinal cord. FASEB J 2005; 19:694-703. [PMID: 15857884 DOI: 10.1096/fj.04-2833rev] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Olfactory ensheathing cells (OECs) are unique cells that are responsible for the successful regeneration of olfactory axons throughout the life of adult mammals. More than a decade of research has shown that implantation of OECs may be a promising therapy for damage to the nervous system, including spinal cord injury. Based on this research, several clinical trials worldwide have been initiated that use autologous transplantation of olfactory tissue containing OECs into the damaged spinal cord of humans. However, research from several laboratories has challenged the widely held belief that OECs are directly responsible for myelinating axons and promoting axon regeneration. The purpose of this review is to provide a working hypothesis that integrates several current ideas regarding the mechanisms of the beneficial effects of OECs. Specifically, OECs promote axon regeneration and functional recovery indirectly by augmenting the endogenous capacity of host Schwann cells to invade the damaged spinal cord. Together with Schwann cells, OECs create a 3-dimensional matrix that provides a permissive microenvironment for successful axon regeneration in the adult mammalian central nervous system.
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Affiliation(s)
- J Gordon Boyd
- Department of Anatomy and Cell Biology, Queen's University, Room 926, Botterell Hall, Kingston, ON, Canada K7L 3N6.
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34
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Blakemore WF. The case for a central nervous system (CNS) origin for the Schwann cells that remyelinate CNS axons following concurrent loss of oligodendrocytes and astrocytes. Neuropathol Appl Neurobiol 2005; 31:1-10. [PMID: 15634226 DOI: 10.1111/j.1365-2990.2005.00637.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In certain experimental and naturally occurring pathological situations in the central nervous system (CNS), demyelinated axons are remyelinated by Schwann cells. It has always been assumed that these Schwann cells are derived from Schwann cells associated with peripheral nerves. However, it has become apparent that CNS precursors can give rise to Schwann cells in vitro and following transplantation into astrocyte-free areas of demyelination in vivo. This paper compares the behaviour of remyelinating Schwann cells following transplantation of peripheral nerve derived Schwann cells over, and into, astrocyte-depleted areas of demyelination to that which follows transplantation of CNS cells and that seen in normally remyelinating ethidium bromide induced demyelinating lesions. It concludes that while the examination of normally remyelinating lesions can not resolve the origin of the remyelinating Schwann cells, the results from transplantation studies provide strong evidence that the Schwann cells that remyelinate CNS axons are most likely generated from CNS precursors. In addition these studies also indicate that the precursors that give rise to these Schwann cells are the same cells that give rise to remyelinating oligodendrocytes.
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Affiliation(s)
- W F Blakemore
- University of Cambridge, Department of Veterinary Medicine, Cambridge CB3 0ES, UK.
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35
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Ramer LM, Ramer MS, Steeves JD. Setting the stage for functional repair of spinal cord injuries: a cast of thousands. Spinal Cord 2005; 43:134-61. [PMID: 15672094 DOI: 10.1038/sj.sc.3101715] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Here we review mechanisms and molecules that necessitate protection and oppose axonal growth in the injured spinal cord, representing not only a cast of villains but also a company of therapeutic targets, many of which have yet to be fully exploited. We next discuss recent progress in the fields of bridging, overcoming conduction block and rehabilitation after spinal cord injury (SCI), where several treatments in each category have entered the spotlight, and some are being tested clinically. Finally, studies that combine treatments targeting different aspects of SCI are reviewed. Although experiments applying some treatments in combination have been completed, auditions for each part in the much-sought combination therapy are ongoing, and performers must demonstrate robust anatomical regeneration and/or significant return of function in animal models before being considered for a lead role.
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Affiliation(s)
- L M Ramer
- ICORD (International Collaboration on Repair Discoveries), The University of British Columbia, Vancouver, BC, Canada
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36
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Grimpe B, Pressman Y, Lupa MD, Horn KP, Bunge MB, Silver J. The role of proteoglycans in Schwann cell/astrocyte interactions and in regeneration failure at PNS/CNS interfaces. Mol Cell Neurosci 2005; 28:18-29. [PMID: 15607938 DOI: 10.1016/j.mcn.2004.06.010] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2004] [Revised: 06/15/2004] [Accepted: 06/15/2004] [Indexed: 11/19/2022] Open
Abstract
In the dorsal root entry zone (DREZ) peripheral sensory axons fail to regenerate past the peripheral nervous system/central nervous system (PNS/CNS) interface. Additionally, in the spinal cord, central fibers that regenerate into Schwann cell (SC) bridges can enter but do not exit at the distal Schwann cell/astrocyte (AC) boundary. At both interfaces where limited mixing of the two cell types occurs, one can observe an up-regulation of inhibitory chondroitin sulfate proteoglycans (CSPGs). We treated confrontation Schwann cell/astrocyte cultures with the following: (1) a deoxyribonucleic acid (DNA) enzyme against the glycosaminoglycan (GAG)-chain-initiating enzyme, xylosyltransferase-1 (XT-1), (2) a control DNA enzyme, and (3) chondroitinase ABC (Ch'ase ABC) to degrade the GAG chains. Both techniques for reducing CSPGs allowed Schwann cells to penetrate deeply into the territory of the astrocytes. After adding sensory neurons to the assay, the axons showed different growth behaviors depending upon the glial cell type that they first encountered during regeneration. Our results help to explain why regeneration fails at PNS/CNS glial boundaries.
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Affiliation(s)
- Barbara Grimpe
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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37
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Abstract
We have conducted a long-term study of spinal cord morphology and motor function recovery in rats that have undergone lumbar spinal demyelination induced by the B-fragment of cholera toxin (CTB)-saporin. We found that, after the initial demyelination and paraplegia, motor function recovered and was stable for up to 9 months, after which there occurred a slow deterioration of motor function accompanied by loss of motoneurons and loss of spinal white matter. A striking morphological feature was the appearance of large spheroids of calcium in the ventral and dorsal horns and occasionally in the white matter. Motor performance deterioration occurred earlier and was more severe in rats that had been exercised on a treadmill, but the same morphological changes occurred in both exercise- and nonexercise-treated animals. Rats given treadmill exercise starting 3 weeks after toxin injection had a mean motor deficit score of 3.0 (i.e., paraplegia) at perfusion, whereas the nontreadmill-treated rats had a mean score of 1.8 (SD 0.38; n = 6; P <.05). These findings suggest that, in addition to the acute effects of the toxin-induced demyelination from which there is recovery of motor function, there are chronic irreversible effects of the toxin, or the initial demyelination, that cause a slow progressive degeneration of the spinal cord. This model might therefore be useful in studying the long-term effects of spinal insult of the type associated with conditions such as postpolio syndrome.
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Affiliation(s)
- Luc Jasmin
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California 94143-0452, USA
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38
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Farhadi HF, Lepage P, Forghani R, Friedman HCH, Orfali W, Jasmin L, Miller W, Hudson TJ, Peterson AC. A combinatorial network of evolutionarily conserved myelin basic protein regulatory sequences confers distinct glial-specific phenotypes. J Neurosci 2003; 23:10214-23. [PMID: 14614079 PMCID: PMC6741010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Abstract
Myelin basic protein (MBP) is required for normal myelin compaction and is implicated in both experimental and human demyelinating diseases. In this study, as an initial step in defining the regulatory network controlling MBP transcription, we located and characterized the function of evolutionarily conserved regulatory sequences. Long-range human-mouse sequence comparison revealed over 1 kb of conserved noncoding MBP 5' flanking sequence distributed into four widely spaced modules ranging from 0.1 to 0.4 kb. We demonstrate first that a controlled strategy of transgenesis provides an effective means to assign and compare qualitative and quantitative in vivo regulatory programs. Using this strategy, single-copy reporter constructs, designed to evaluate the regulatory significance of modular and intermodular sequences, were introduced by homologous recombination into the mouse hprt (hypoxanthine-guanine phosphoribosyltransferase) locus. The proximal modules M1 and M2 confer comparatively low-level oligodendrocyte expression primarily limited to early postnatal development, whereas the upstream M3 confers high-level oligodendrocyte expression extending throughout maturity. Furthermore, constructs devoid of M3 fail to target expression to newly myelinating oligodendrocytes in the mature CNS. Mutation of putative Nkx6.2/Gtx sites within M3, although not eliminating oligodendrocyte targeting, significantly decreases transgene expression levels. High-level and continuous expression is conferred to myelinating or remyelinating Schwann cells by M4. In addition, when isolated from surrounding MBP sequences, M3 confers transient expression to Schwann cells elaborating myelin. These observations define the in vivo regulatory roles played by conserved noncoding MBP sequences and lead to a combinatorial model in which different regulatory modules are engaged during primary myelination, myelin maintenance, and remyelination.
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Affiliation(s)
- Hooman F Farhadi
- Royal Victoria Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec H3A 1A1, Canada
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Abstract
Although only recently applied to the study of nociception, 'molecular neurosurgery', producing highly selective neural lesions using targeted cytotoxins, has proven a valuable tool for analysis of nociceptive systems and promises to yield much more information on the role of specific types of neurons in pain perception and possibly new pain therapies. Neuropeptide-toxin conjugates, particularly, substance P-saporin, have proven useful research tools and may find clinical applications. Targeting non-lethal moieties (enzymes, genes, viruses) also may prove useful for research and therapeutic purposes.
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Affiliation(s)
- Ronald G Wiley
- Department of Neurology, Vanderbilt University, Nashville, TN 37212, USA.
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40
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Corti S, Locatelli F, Donadoni C, Strazzer S, Salani S, Del Bo R, Caccialanza M, Bresolin N, Scarlato G, Comi GP. Neuroectodermal and microglial differentiation of bone marrow cells in the mouse spinal cord and sensory ganglia. J Neurosci Res 2002; 70:721-33. [PMID: 12444594 DOI: 10.1002/jnr.10455] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
There is now evidence that bone marrow (BM) can generate cells expressing neuronal antigens in adult mouse brain. In the present study, we examined the spinal cord and dorsal root ganglia (DRG) of adult mice 3 months after BM cell transplantation from transgenic donor mice expressing the enhanced green fluorescent protein (GFP). To determine whether GFP(+) cells acquire neuroectodermal phenotypes, we tested, by immunocytochemistry followed by confocal analysis, the coexpression of the astrocytic marker glial fibrillary acidic protein (GFAP) and the neuronal markers NeuN, neurofilament (NF), and class III beta-tubulin (TuJ1). Rare GFP(+) cells coexpressing TuJ1, NF, and NeuN were found both in spinal cord and in sensory ganglia. These cells have small dimensions and short cytoplasmic processes, probably reflecting an immature phenotype. Double GFP and GFAP positivity was found only in spinal cord. To determine whether cell fusion with endogenous cells occurred, we investigated the nuclear content of cells coexpressing GFP and neuronal or astrocytic markers, demonstrating that these cells have only one nucleus and a DNA ploidy that it is not different from that of surrounding neurons and astrocytes. Large numbers of GFP(+) cells are also positively stained for F4/80, a microglial-recognizing antibody, and present a characteristic microglial-like morphology both in spinal cord and, with a higher frequency, in sensory ganglia. These data support a potential role for BM-derived stem cells in spinal cord neuroneogenesis. They also confirm that the microglial compartment within the CNS and in DRG undergoes a relatively fast turnover, with the contribution of hematopoietic stem cells. Both these findings might prove useful for the development of treatments for spinal cord neurodegenerative and acquired disorders.
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Affiliation(s)
- S Corti
- Centro Dino Ferrari, Dipartimento di Scienze Neurologiche, Università degli Studi di Milano, IRCCS Ospedale Maggiore Policlinico, Milano, Italy.
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Gilson JM, Blakemore WF. Schwann cell remyelination is not replaced by oligodendrocyte remyelination following ethidium bromide induced demyelination. Neuroreport 2002; 13:1205-8. [PMID: 12151770 DOI: 10.1097/00001756-200207020-00027] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Demyelinated CNS axons can be remyelinated by Schwann cells. A recent study concluded that with time Schwann cell remyelination is replaced by oligodendrocyte remyelination [9]. To examine this, the extent of Schwann cell and oligodendrocyte remyelination at 4, 6.5 and 24 weeks was determined for ethidium bromide lesions made in the spinal cords of rats. Although the extent of oligoden-drocyte remyelination increased with time there was no significant change in the amount of Schwann cell remyelination. This indicates that Schwann cell remyelination is stable and is not replaced by oligodendrocyte remyelination.
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Affiliation(s)
- J M Gilson
- Department of Clinical Veterinary Medicine, University of Cambridge, Madingley Road, UK
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42
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Jasmin L, Ohara PT. Remyelination within the CNS: do schwann cells pave the way for oligodendrocytes? Neuroscientist 2002; 8:198-203. [PMID: 12061499 DOI: 10.1177/1073858402008003005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Schwann cells that have myelinated the CNS can be replaced by myelinating oligodendrocytes. It is unclear, however, why oligodendrocyte remyelination would occur for axons that are already myelinated. The Schwann cells might signal their own replacement by oligodendrocytes, but more probably a third player, the reactive astrocyte, is essential to this phenomenon. We propose that as long as reactive astrocytes do not form fibrous gliosis, they are beneficial to oligodendrocyte remyelination. Unknown is whether reactive astrocytes induce oligodendrocyte progenitor (NG2 immunopositive cells) cells to differentiate, a phenomenon that is absent in multiple sclerosis. So what role do Schwann cells play in CNS remyelination? They appear to serve to protect central axons and might coincidentally prevent reactive astrocytes from laying down scar tissue that impedes oligodendrocyte remyelination.
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Affiliation(s)
- Luc Jasmin
- Department of Neurological Surgery, University of California, San Francisco, 94143-0452, USA
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