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Rigo YR, Benvenutti R, Portela LV, Strogulski NR. Neurogenic potential of NG2 in neurotrauma: a systematic review. Neural Regen Res 2024; 19:2673-2683. [PMID: 38595286 PMCID: PMC11168526 DOI: 10.4103/nrr.nrr-d-23-01031] [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: 06/21/2023] [Revised: 12/20/2023] [Accepted: 02/07/2024] [Indexed: 04/11/2024] Open
Abstract
Regenerative approaches towards neuronal loss following traumatic brain or spinal cord injury have long been considered a dogma in neuroscience and remain a cutting-edge area of research. This is reflected in a large disparity between the number of studies investigating primary and secondary injury as therapeutic targets in spinal cord and traumatic brain injuries. Significant advances in biotechnology may have the potential to reshape the current state-of-the-art and bring focus to primary injury neurotrauma research. Recent studies using neural-glial factor/antigen 2 (NG2) cells indicate that they may differentiate into neurons even in the developed brain. As these cells show great potential to play a regenerative role, studies have been conducted to test various manipulations in neurotrauma models aimed at eliciting a neurogenic response from them. In the present study, we systematically reviewed the experimental protocols and findings described in the scientific literature, which were peer-reviewed original research articles (1) describing preclinical experimental studies, (2) investigating NG2 cells, (3) associated with neurogenesis and neurotrauma, and (4) in vitro and/or in vivo, available in PubMed/MEDLINE, Web of Science or SCOPUS, from 1998 to 2022. Here, we have reviewed a total of 1504 papers, and summarized findings that ultimately suggest that NG2 cells possess an inducible neurogenic potential in animal models and in vitro. We also discriminate findings of NG2 neurogenesis promoted by different pharmacological and genetic approaches over functional and biochemical outcomes of traumatic brain injury and spinal cord injury models, and provide mounting evidence for the potential benefits of manipulated NG2 cell ex vivo transplantation in primary injury treatment. These findings indicate the feasibility of NG2 cell neurogenesis strategies and add new players in the development of therapeutic alternatives for neurotrauma.
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Affiliation(s)
- Yuri R. Rigo
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Radharani Benvenutti
- School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland
| | - Luis V. Portela
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Nathan R. Strogulski
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, University of Dublin, Dublin, Ireland
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Patil N, Korenfeld O, Scalf RN, Lavoie N, Huntemer-Silveira A, Han G, Swenson R, Parr AM. Electrical stimulation affects the differentiation of transplanted regionally specific human spinal neural progenitor cells (sNPCs) after chronic spinal cord injury. Stem Cell Res Ther 2023; 14:378. [PMID: 38124191 PMCID: PMC10734202 DOI: 10.1186/s13287-023-03597-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023] Open
Abstract
BACKGROUND There are currently no effective clinical therapies to ameliorate the loss of function that occurs after spinal cord injury. Electrical stimulation of the rat spinal cord through the rat tail has previously been described by our laboratory. We propose combinatorial treatment with human induced pluripotent stem cell-derived spinal neural progenitor cells (sNPCs) along with tail nerve electrical stimulation (TANES). The purpose of this study was to examine the influence of TANES on the differentiation of sNPCs with the hypothesis that the addition of TANES would affect incorporation of sNPCs into the injured spinal cord, which is our ultimate goal. METHODS Chronically injured athymic nude rats were allocated to one of three treatment groups: injury only, sNPC only, or sNPC + TANES. Rats were sacrificed at 16 weeks post-transplantation, and tissue was processed and analyzed utilizing standard histological and tissue clearing techniques. Functional testing was performed. All quantitative data were presented as mean ± standard error of the mean. Statistics were conducted using GraphPad Prism. RESULTS We found that sNPCs were multi-potent and retained the ability to differentiate into mainly neurons or oligodendrocytes after this transplantation paradigm. The addition of TANES resulted in more transplanted cells differentiating into oligodendrocytes compared with no TANES treatment, and more myelin was found. TANES not only promoted significantly higher numbers of sNPCs migrating away from the site of injection but also influenced long-distance axonal/dendritic projections especially in the rostral direction. Further, we observed localization of synaptophysin on SC121-positive cells, suggesting integration with host or surrounding neurons, and this finding was enhanced when TANES was applied. Also, rats that were transplanted with sNPCs in combination with TANES resulted in an increase in serotonergic fibers in the lumbar region. This suggests that TANES contributes to integration of sNPCs, as well as activity-dependent oligodendrocyte and myelin remodeling of the chronically injured spinal cord. CONCLUSIONS Together, the data suggest that the added electrical stimulation promoted cellular integration and influenced the fate of human induced pluripotent stem cell-derived sNPCs transplanted into the injured spinal cord.
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Affiliation(s)
- Nandadevi Patil
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Olivia Korenfeld
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Rachel N Scalf
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Nicolas Lavoie
- Massachusetts Institute of Technology, 77 Massachusetts Ave, Cambridge, MA, 02139, USA
| | - Anne Huntemer-Silveira
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Guebum Han
- Department of Mechanical Engineering, College of Science and Engineering, University of Minnesota, 1100 Mechanical Engineering Building, 111 Church St. SE, Minneapolis, MN, 55455, USA
| | - Riley Swenson
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, 2-214 MTRF, 2001 6th St. SE, Minneapolis, MN, 55455, USA
| | - Ann M Parr
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, MMC 96, 420 Delaware St. SE, Minneapolis, MN, 55455, USA.
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Patil N, Walsh P, Carrabre K, Holmberg EG, Lavoie N, Dutton JR, Parr AM. Regionally Specific Human Pre-Oligodendrocyte Progenitor Cells Produce Both Oligodendrocytes and Neurons after Transplantation in a Chronically Injured Spinal Cord Rat Model after Glial Scar Ablation. J Neurotrauma 2021; 38:777-788. [PMID: 33107383 DOI: 10.1089/neu.2020.7009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chronic spinal cord injury (SCI) is a devastating medical condition. In the acute phase after injury, there is cell loss resulting in chronic axonal damage and loss of sensory and motor function including loss of oligodendrocytes that results in demyelination of axons and further dysfunction. In the chronic phase, the inhibitory environment within the lesion including the glial scar can arrest axonal growth and regeneration and can also potentially affect transplanted cells. We hypothesized that glial scar ablation (GSA) along with cell transplantation may be required as a combinatorial therapy to achieve functional recovery, and therefore we proposed to examine the survival and fate of human induced pluripotent stem cell (iPSC) derived pre-oligodendrocyte progenitor cells (pre-OPCs) transplanted in a model of chronic SCI, whether this was affected by GSA, and whether this combination of treatments would result in functional recovery. In this study, chronically injured athymic nude (ATN) rats were allocated to one of three treatment groups: GSA only, pre-OPCs only, or GSA+pre-OPCs. We found that human iPSC derived pre-OPCs were multi-potent and retained the ability to differentiate into mainly oligodendrocytes or neurons when transplanted into the chronically injured spinal cords of rats. Twelve weeks after cell transplantation, we observed that more of the transplanted cells differentiated into oligodendrocytes when the glial scar was ablated compared with no GSA. Further, we also observed that a higher percentage of transplanted cells differentiated into V2a interneurons and motor neurons in the pre-OPCs only group when compared with GSA+pre-OPCs. This suggests that the local environment created by ablation of the glial scar may have a significant effect on the fate of cells transplanted into the injury site.
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Affiliation(s)
- Nandadevi Patil
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Patrick Walsh
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Kailey Carrabre
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Eric G Holmberg
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Nicolas Lavoie
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - James R Dutton
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
| | - Ann M Parr
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, USA
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Patil N, Truong V, Holmberg MH, Lavoie NS, McCoy MR, Dutton JR, Holmberg EG, Parr AM. Safety and Efficacy of Rose Bengal Derivatives for Glial Scar Ablation in Chronic Spinal Cord Injury. J Neurotrauma 2018; 35:1745-1754. [PMID: 29373946 PMCID: PMC6033306 DOI: 10.1089/neu.2017.5398] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
There are no effective therapies available currently to ameliorate loss of function for patients with spinal cord injuries (SCIs). In addition, proposed treatments that demonstrated functional recovery in animal models of acute SCI have failed almost invariably when applied to chronic injury models. Glial scar formation in chronic injury is a likely contributor to limitation on regeneration. We have removed existing scar tissue in chronically contused rat spinal cord using a rose Bengal-based photo ablation approach. In this study, we compared two chemically modified rose bengal derivatives to unmodified rose bengal, both confirming and expanding on our previously published report. Rats were treated with unmodified rose bengal (RB1) or rose bengal modified with hydrocarbon (RB2) or polyethylene glycol (RB3), to determine the effects on scar components and spared tissue post-treatment. Our results showed that RB1 was more efficacious than RB2, while still maintaining minimal collateral effects on spared tissue. RB3 was not taken up by the cells, likely because of its size, and therefore had no effect. Treatment with RB1 also resulted in an increase in serotonin eight days post-treatment in chronically injured spinal cords. Thus, we suggest that unmodified rose Bengal is a potent candidate agent for the development of a therapeutic strategy for scar ablation in chronic SCI.
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Affiliation(s)
- Nandadevi Patil
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | - Vincent Truong
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | - Mackenzie H. Holmberg
- Department of Chemistry, University of Alaska Anchorage, Anchorage, Alaska
- University of Washington School of Medicine, Seattle, Washington
| | - Nicolas S. Lavoie
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | - Mark R. McCoy
- Department of Chemistry, University of Alaska Anchorage, Anchorage, Alaska
| | - James R. Dutton
- Department of Genetics, Cell Biology and Development, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
| | - Eric G. Holmberg
- Department of Chemistry, University of Alaska Anchorage, Anchorage, Alaska
| | - Ann M. Parr
- Department of Neurosurgery, Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota
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Abstract
Cold exposure and a variety of types of mild stress increase pain in patients with painful disorders such as fibromyalgia syndrome. Acutely, stress induces thermogenesis by increasing sympathetic activation of beta-3 (β3) adrenergic receptors in brown adipose tissue. Chronic stress leads to the hypertrophy of brown adipose, a phenomenon termed adaptive thermogenesis. Based on the innervation of skeletal muscle by collaterals of nerves projecting to brown adipose, we theorized an association between brown adipose tissue activity and musculoskeletal hyperalgesia and tested this hypothesis in mice. Exposure to a cold swim or injection of BRL37344 (β3 adrenergic agonist) each enhanced musculoskeletal hyperalgesia, as indicated by morphine-sensitive decreases in grip force responses, whereas SR59230A (β3 adrenergic antagonist) attenuated swim-induced hyperalgesia. Chemical ablation of interscapular brown adipose, using Rose Bengal, attenuated the development of hyperalgesia in response to either swim stress or BRL37344. In addition, elimination of the gene expressing uncoupling protein-1 (UCP1), the enzyme responsible for thermogenesis, prevented musculoskeletal hyperalgesia in response to either a swim or BRL37344, as documented in UCP1-knockout (UCP1-KO) mice compared with wild-type controls. Together, these data provide a convergence of evidence suggesting that activation of brown adipose contributes to stress-induced musculoskeletal hyperalgesia.
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DePaul MA, Lin CY, Silver J, Lee YS. Combinatory repair strategy to promote axon regeneration and functional recovery after chronic spinal cord injury. Sci Rep 2017; 7:9018. [PMID: 28827771 PMCID: PMC5567101 DOI: 10.1038/s41598-017-09432-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 07/26/2017] [Indexed: 01/08/2023] Open
Abstract
Eight weeks post contusive spinal cord injury, we built a peripheral nerve graft bridge (PNG) through the cystic cavity and treated the graft/host interface with acidic fibroblast growth factor (aFGF) and chondroitinase ABC (ChABC). This combinatorial strategy remarkably enhanced integration between host astrocytes and graft Schwann cells, allowing for robust growth, especially of catecholaminergic axons, through the graft and back into the distal spinal cord. In the absence of aFGF+ChABC fewer catecholaminergic axons entered the graft, no axons exited, and Schwann cells and astrocytes failed to integrate. In sharp contrast with the acutely bridge-repaired cord, in the chronically repaired cord only low levels of serotonergic axons regenerated into the graft, with no evidence of re-entry back into the spinal cord. The failure of axons to regenerate was strongly correlated with a dramatic increase of SOCS3 expression. While regeneration was more limited overall than at acute stages, our combinatorial strategy in the chronically injured animals prevented a decline in locomotor behavior and bladder physiology outcomes associated with an invasive repair strategy. These results indicate that PNG+aFGF+ChABC treatment of the chronically contused spinal cord can provide a permissive substrate for the regeneration of certain neuronal populations that retain a growth potential over time, and lead to functional improvements.
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Affiliation(s)
- Marc A DePaul
- Case Western Reserve Univ., Dept. of Neurosciences, 10900 Euclid Ave., SOM E654, Cleveland, OH, 44106, USA
| | - Ching-Yi Lin
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, 44195, USA
| | - Jerry Silver
- Case Western Reserve Univ., Dept. of Neurosciences, 10900 Euclid Ave., SOM E654, Cleveland, OH, 44106, USA
| | - Yu-Shang Lee
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, 44195, USA.
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Rodríguez-Barrera R, Flores-Romero A, Fernández-Presas AM, García-Vences E, Silva-García R, Konigsberg M, Blancas-Espinoza L, Buzoianu-Anguiano V, Soria-Zavala K, Suárez-Meade P, Ibarra A. Immunization with neural derived peptides plus scar removal induces a permissive microenvironment, and improves locomotor recovery after chronic spinal cord injury. BMC Neurosci 2017; 18:7. [PMID: 28056790 PMCID: PMC5217189 DOI: 10.1186/s12868-016-0331-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 12/27/2016] [Indexed: 11/17/2022] Open
Abstract
Background Immunization with neural derived peptides (INDP) as well as scar removal—separately—have shown to induce morphological and functional improvement after spinal cord injury (SCI). In the present study, we compared the effect of INDP alone versus INDP with scar removal on motor recovery, regeneration-associated and cytokine gene expression, and axonal regeneration after chronic SCI. Scar removal was conducted through a single incision with a double-bladed scalpel along the stump, and scar renewal was halted by adding α,α′-dipyridyl. Results During the chronic injury stage, two experiments were undertaken. The first experiment was aimed at testing the therapeutic effect of INDP combined with scar removal. Sixty days after therapeutic intervention, the expression of genes encoding for TNFα, IFNγ, IL4, TGFβ, BDNF, IGF1, and GAP43 was evaluated at the site of injury. Tyrosine hydroxylase and 5-hydroxytryptamine positive fibers were also studied. Locomotor evaluations showed a significant recovery in the group treated with scar removal + INDP. Moreover; this group presented a significant increase in IL4, TGFβ, BDNF, IGF1, and GAP43 expression, but a decrease of TNFα and IFNγ. Also, the spinal cord of animals receiving both treatments presented a significant increase of serotonergic and catecholaminergic fibers as compared to other the groups. The second experiment compared the results of the combined approach versus INDP alone. Rats receiving INDP likewise showed improved motor recovery, although on a lesser scale than those who received the combined treatment. An increase in inflammation and regeneration-associated gene expression, as well as in the percentage of serotonergic and catecholaminergic fibers was observed in INDP-treated rats to a lesser degree than those in the combined therapy group. Conclusions These findings suggest that INDP, both alone and in combination with scar removal, could modify the non-permissive microenvironment prevailing at the chronic phase of SCI, providing the opportunity of improving motor recovery.
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Affiliation(s)
- Roxana Rodríguez-Barrera
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Facultad de Ciencias de la Salud, Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Centro de Investigación del Proyecto CAMINA A.C., Ciudad de México, Mexico.,Posgrado en Biología Experimental, UAMI, Ciudad de México, Mexico
| | - Adrián Flores-Romero
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Facultad de Ciencias de la Salud, Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Centro de Investigación del Proyecto CAMINA A.C., Ciudad de México, Mexico
| | | | - Elisa García-Vences
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Facultad de Ciencias de la Salud, Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Centro de Investigación del Proyecto CAMINA A.C., Ciudad de México, Mexico
| | | | - Mina Konigsberg
- Lab. Bioenergética y Envejecimiento Celular, UAMI, Ciudad de México, Mexico
| | - Liliana Blancas-Espinoza
- Centro de Investigación del Proyecto CAMINA A.C., Ciudad de México, Mexico.,Hospital de Pediatría CMN Siglo XXI, Ciudad de México, Mexico
| | | | - Karla Soria-Zavala
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Facultad de Ciencias de la Salud, Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Centro de Investigación del Proyecto CAMINA A.C., Ciudad de México, Mexico
| | - Paola Suárez-Meade
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico.,Facultad de Ciencias de la Salud, Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico
| | - Antonio Ibarra
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico. .,Facultad de Ciencias de la Salud, Universidad Anáhuac México Campus Norte, Huixquilucan, Estado de México, Mexico. .,Centro de Investigación del Proyecto CAMINA A.C., Ciudad de México, Mexico.
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Zhang SX, Huang F, Gates M, Holmberg EG. Role of endogenous Schwann cells in tissue repair after spinal cord injury. Neural Regen Res 2014; 8:177-85. [PMID: 25206489 PMCID: PMC4107512 DOI: 10.3969/j.issn.1673-5374.2013.02.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 12/25/2012] [Indexed: 01/09/2023] Open
Abstract
Schwann cells are glial cells of peripheral nervous system, responsible for axonal myelination and ensheathing, as well as tissue repair following a peripheral nervous system injury. They are one of several cell types that are widely studied and most commonly used for cell transplantation to treat spinal cord injury, due to their intrinsic characteristics including the ability to secrete a variety of neurotrophic factors. This mini review summarizes the recent findings of endogenous Schwann cells after spinal cord injury and discusses their role in tissue repair and axonal regeneration. After spinal cord injury, numerous endogenous Schwann cells migrate into the lesion site from the nerve roots, involving in the construction of newly formed repaired tissue and axonal myelination. These invading Schwann cells also can move a long distance away from the injury site both rostrally and caudally. In addition, Schwann cells can be induced to migrate by minimal insults (such as scar ablation) within the spinal cord and integrate with astrocytes under certain circumstances. More importantly, the host Schwann cells can be induced to migrate into spinal cord by transplantation of different cell types, such as exogenous Schwann cells, olfactory ensheathing cells, and bone marrow-derived stromal stem cells. Migration of endogenous Schwann cells following spinal cord injury is a common natural phenomenon found both in animal and human, and the myelination by Schwann cells has been examined effective in signal conduction electrophysiologically. Therefore, if the inherent properties of endogenous Schwann cells could be developed and utilized, it would offer a new avenue for the restoration of injured spinal cord.
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Affiliation(s)
- Shu-Xin Zhang
- Spinal Cord Society Research Center, Fort Collins, CO 80526, USA
| | - Fengfa Huang
- Spinal Cord Society Research Center, Fort Collins, CO 80526, USA
| | - Mary Gates
- Spinal Cord Society Research Center, Fort Collins, CO 80526, USA
| | - Eric G Holmberg
- Spinal Cord Society Research Center, Fort Collins, CO 80526, USA ; Department of Chemistry University of Alaska, Anchorage, AK 99508, USA
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Scar-modulating treatments for central nervous system injury. Neurosci Bull 2014; 30:967-984. [PMID: 24957881 DOI: 10.1007/s12264-013-1456-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 04/09/2014] [Indexed: 02/04/2023] Open
Abstract
Traumatic injury to the adult mammalian central nervous system (CNS) leads to complex cellular responses. Among them, the scar tissue formed is generally recognized as a major obstacle to CNS repair, both by the production of inhibitory molecules and by the physical impedance of axon regrowth. Therefore, scar-modulating treatments have become a leading therapeutic intervention for CNS injury. To date, a variety of biological and pharmaceutical treatments, targeting scar modulation, have been tested in animal models of CNS injury, and a few are likely to enter clinical trials. In this review, we summarize current knowledge of the scar-modulating treatments according to their specific aims: (1) inhibition of glial and fibrotic scar formation, and (2) blockade of the production of scar-associated inhibitory molecules. The removal of existing scar tissue is also discussed as a treatment of choice. It is believed that only a combinatorial strategy is likely to help eliminate the detrimental effects of scar tissue on CNS repair.
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10
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Yuan YM, He C. The glial scar in spinal cord injury and repair. Neurosci Bull 2013; 29:421-35. [PMID: 23861090 DOI: 10.1007/s12264-013-1358-3] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 05/03/2013] [Indexed: 12/21/2022] Open
Abstract
Glial scarring following severe tissue damage and inflammation after spinal cord injury (SCI) is due to an extreme, uncontrolled form of reactive astrogliosis that typically occurs around the injury site. The scarring process includes the misalignment of activated astrocytes and the deposition of inhibitory chondroitin sulfate proteoglycans. Here, we first discuss recent developments in the molecular and cellular features of glial scar formation, with special focus on the potential cellular origin of scar-forming cells and the molecular mechanisms underlying glial scar formation after SCI. Second, we discuss the role of glial scar formation in the regulation of axonal regeneration and the cascades of neuro-inflammation. Last, we summarize the physical and pharmacological approaches targeting the modulation of glial scarring to better understand the role of glial scar formation in the repair of SCI.
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Affiliation(s)
- Yi-Min Yuan
- Institute of Neuroscience and Key Laboratory of Molecular Neurobiology of Ministry of Education, Neuroscience Research Center of Changzheng Hospital, Second Military Medical University, Shanghai 200433, China
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11
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Tail nerve electrical stimulation combined with scar ablation and neural transplantation promotes locomotor recovery in rats with chronically contused spinal cord. Brain Res 2012; 1456:22-35. [DOI: 10.1016/j.brainres.2012.03.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 03/20/2012] [Accepted: 03/21/2012] [Indexed: 01/28/2023]
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Leal-Filho MB. Spinal cord injury: From inflammation to glial scar. Surg Neurol Int 2011; 2:112. [PMID: 21886885 PMCID: PMC3162797 DOI: 10.4103/2152-7806.83732] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Accepted: 07/25/2011] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Glial scar (GS) is the most important inhibitor factor to neuroregeneration after spinal cord injury (SCI) and behaves as a tertiary lesion. The present review of the literature searched for representative studies concerning GS and therapeutic strategies to neuroregeneration. METHODS The author used the PubMed database and Google scholar to search articles published in the last 20 years. Key words used were SCI, spinal cord (SC) inflammation, GS, and SCI treatment. RESULTS Both inflammation and GS are considered important events after SCI. Despite the fact that firstly they seem to cause benefit, in the end they cause more harm than good to neuroregeneration. Each stage has its own aspects under the influence of the immune system causing inflammation, from the primary to secondary lesion and from those to GS (tertiary lesion). CONCLUSION Future studies should stress the key points where and when GS presents itself as an inhibitory factor to neuroregeneration. Considering GS as an important event after SCI, the author defends GS as being a tertiary lesion. Current strategies are presented with emphasis on stem cells and drug therapy. A better understanding will permit the development of a therapeutic basis in the treatment of the SCI patients considering each stage of the lesion, with emphasis on GS and neuroregeneration.
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Zhang SX, Huang F, Gates M, Holmberg EG. Scar ablation combined with LP/OEC transplantation promotes anatomical recovery and P0-positive myelination in chronically contused spinal cord of rats. Brain Res 2011; 1399:1-14. [DOI: 10.1016/j.brainres.2011.05.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 04/30/2011] [Accepted: 05/02/2011] [Indexed: 01/27/2023]
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Hu R, Zhou J, Luo C, Lin J, Wang X, Li X, Bian X, Li Y, Wan Q, Yu Y, Feng H. Glial scar and neuroregeneration: histological, functional, and magnetic resonance imaging analysis in chronic spinal cord injury. J Neurosurg Spine 2010; 13:169-80. [DOI: 10.3171/2010.3.spine09190] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Object
A glial scar is thought to be responsible for halting neuroregeneration following spinal cord injury (SCI). However, little quantitative evidence has been provided to show the relationship of a glial scar and axonal regrowth after injury.
Methods
In this study performed in rats and dogs, a traumatic SCI model was made using a weight-drop injury device, and tissue sections were stained with H & E for immunohistochemical analysis. The function and behavior of model animals were tested using electrophysiological recording and the Basso-Beattie-Bresnahan Locomotor Rating Scale, respectively. The cavity in the spinal cord after SCI in dogs was observed using MR imaging.
Results
The morphological results showed that the formation of an astroglial scar was defined at 4 weeks after SCI. While regenerative axons reached the vicinity of the lesion site, the glial scar blocked the extension of regrown axons. In agreement with these findings, the electrophysiological, behavioral, and in vivo MR imaging tests showed that functional recovery reached a plateau at 4 weeks after SCI. The thickness of the glial scars in the injured rat spinal cords was also measured. The mean thickness of the glial scar rostral and caudal to the lesion cavity was 107.00 ± 20.12 μm; laterally it was 69.92 ± 15.12 μm.
Conclusions
These results provide comprehensive evidence indicating that the formation of a glial scar inhibits axonal regeneration at 4 weeks after SCI. This study reveals a critical time window of postinjury recovery and a detailed spatial orientation of glial scar, which would provide an important basis for the development of therapeutic strategy for glial scar ablation.
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Affiliation(s)
- Rong Hu
- 1Department of Neurosurgery and
| | | | | | | | | | - Xiaoguang Li
- 2Beijing Center for Neural Regeneration and Repairing, Capital University of Medical Sciences, Beijing
| | - Xiuwu Bian
- 3Institute of Pathology, Southwest Hospital, Third Military Medical University, Chongqing
| | - Yunqing Li
- 4Department of Anatomy, Faculty of Basic Medicine, Fourth Military Medical University, Xi'an, China; and
| | - Qi Wan
- 5Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada
| | - Yanbing Yu
- 6Beijing Sino-Japan Friendship Hospital, Beijing
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