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Ghosh M, Tuesta LM, Puentes R, Patel S, Melendez K, El Maarouf A, Rutishauser U, Pearse DD. Extensive cell migration, axon regeneration, and improved function with polysialic acid-modified Schwann cells after spinal cord injury. Glia 2012; 60:979-92. [PMID: 22460918 DOI: 10.1002/glia.22330] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Accepted: 02/28/2012] [Indexed: 01/07/2023]
Abstract
Schwann cell (SC) implantation after spinal cord injury (SCI) promotes axonal regeneration, remyelination repair, and functional recovery. Reparative efficacy, however, may be limited because of the inability of SCs to migrate outward from the lesion-implant site. Altering SC cell surface properties by overexpressing polysialic acid (PSA) has been shown to promote SC migration. In this study, a SCI contusion model was used to evaluate the migration, supraspinal axon growth support, and functional recovery associated with polysialyltransferase (PST)-overexpressing SCs [PST-green fluorescent protein (GFP) SCs] or controls (GFP SCs). Compared with GFP SCs, which remained confined to the injection site at the injury center, PST-GFP SCs migrated across the lesion:host cord interface for distances of up to 4.4 mm within adjacent host tissue. In addition, with PST-GFP SCs, there was extensive serotonergic and corticospinal axon in-growth within the implants that was limited in the GFP SC controls. The enhanced migration of PST-GFP SCs was accompanied by significant growth of these axons caudal to lesion. Animals receiving PST-GFP SCs exhibited improved functional outcome, both in the open-field and on the gridwalk test, beyond the modest improvements provided by GFP SC controls. This study for the first time demonstrates that a lack of migration by SCs may hinder their reparative benefits and that cell surface overexpression of PSA enhances the ability of implanted SCs to associate with and support the growth of corticospinal axons. These results provide further promise that PSA-modified SCs will be a potent reparative approach for SCI. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Mousumi Ghosh
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33101, USA
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Chang IA, Oh MJ, Kim MH, Park SK, Kim BG, Namgung U. Vimentin phosphorylation by Cdc2 in Schwann cell controls axon growth via β1-integrin activation. FASEB J 2012; 26:2401-13. [PMID: 22371530 DOI: 10.1096/fj.11-199018] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Although preconditioning injury on the peripheral nerve induces axonal regenerative capacity in neurons, it is not known whether similar lesion effects occur in glial cells. Here we demonstrate that Schwann cells are activated by peripheral nerve preinjury and primed to mediate axon regeneration. Cdc2, which was induced from Schwann cells after sciatic nerve injury, phosphorylated vimentin almost exclusively in the distal nerve area. Phospho-vimentin-positive Schwann cells showed increased migration activity and were in close contact with process outgrowth of co-cultured neurons. Vimentin phosphorylation by Cdc2 was involved in β1-integrin activation leading to FAK phoshorylation and associated with Erk1/2 activation in Schwann cells. Neurite outgrowth of dorsal root ganglion neurons was increased by co-culture with activated Schwann cells, in which phospho-vimentin signaling was transmitted into β1-integrin activation. Then neurite outgrowth was suppressed by genetic depletion of phospho-vimentin and β1 integrin as well as inhibition of vimentin phosphorylation by Cdc2 inhibitor purvalanol A. The sciatic nerve graft harboring activated Schwann cells into the spinal cord induced Schwann cell migration beyond the graft-host barrier and facilitated regeneration of spinal axons, which was inhibited by purvalanol A pretreatment of the graft. This is the first report to our knowledge demonstrating that activation of phospho-vimentin linked to β1-integrin pathway may mediate transcellular signaling to promote axon growth.
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Affiliation(s)
- In Ae Chang
- Department of Oriental Medicine, Daejeon University, Daejeon 300-716, Republic of Korea
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Abstract
Spinal cord injury (SCI) has multiple consequences, ranging from molecular imbalances to glial scar formation to functional impairments. It is logical to think that a combination of single treatments implemented in the right order and at the right time will be required to repair the spinal cord. However, the single treatments that compose the combination therapy will need to be chosen with caution as many have multiple outcomes that may or may not be synergistic. Single treatments may also elicit unwanted side-effects and/or effects that would decrease the repair potential of other components and/or the entire combination therapy. In this chapter a number of single treatments are discussed with respect to their multiplicity of action. These include strategies to boost growth and survival (such as neurotrophins and cyclic AMP) and strategies to reduce inhibitory factors (such as antimyelin-associated growth inhibitors and digestion of glial scar-associated inhibitors). We also present an overview of combination therapies that have successfully or unsuccessfully been tested in the laboratory using animal models. To effectively design a combination therapy a number of considerations need to be made such as the nature and timing of the treatments and the method for delivery. This chapter discusses these issues as well as considerations related to chronic SCI and the logistics of bringing combination therapies to the clinic.
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Affiliation(s)
- M Oudega
- Departments of Physical Medicine and Rehabilitation, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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Bunge MB, Wood PM. Realizing the maximum potential of Schwann cells to promote recovery from spinal cord injury. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:523-540. [PMID: 23098734 DOI: 10.1016/b978-0-444-52137-8.00032-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Transplantation of Schwann cells (SCs) has been extensively investigated as a therapeutic intervention in rodent models of spinal cord injury (SCI). Here we review both strengths and weaknesses of this approach and discuss additional strategies for maximizing the potential of SCs to repair the injured spinal cord. With no additional treatments, SCs were consistently shown to provide a bridge across the lesion site, supporting the ingrowth of sensory and propriospinal axons, to myelinate axons and to decrease the size of cavities formed after injury. Supraspinal axons did not, however, grow onto the bridge, axons failed to traverse the caudal SC-host cord interface and transplanted SC survival was poor. More recent studies have shown that the potential of SC transplantation as a therapeutic approach can be strongly enhanced by combining additional strategies . For example, combining SC transplantation with elevation of cAMP levels resulted in growth of brainstem axons into the SC graft and caudal to the lesion and in significant improvements in locomotion. Axon growth (and functional improvement) have been increased by strategies to raise neurotrophin levels, either by injection or by genetic modification of the SCs before transplantation. A major problem in maximizing SC potential in injured cord has been in achieving good integration of the transplanted cells with the adjacent cord parenchyma. Several previous studies suggested an ability of SCs to migrate extensively in CNS tissue when astroctyes were absent and to myelinate CNS axons. Furthermore, in some cases involving very limited injury, SCs migrated and integrated well even in the presence of host astrocytes. Consistent with these observations, treatments with an enzyme, chondroitinase, to modify the SC-astrocyte interface surrounding the graft, have shown much promise. Very new studies have shown that SCs derived from SC precursors show a higher ability to survive, integrate well with host tissue and support brainstem axon growth into and beyond the graft, confirming the innate promise of SCs in spinal cord repair. We review one clinical trial already underway in Iran testing SC transplantation in patients with SCI. Finally, we briefly describe a protocol, adaptable to the principles of good manufacturing practice, for generating large numbers of human SCs. Overall, the available evidence suggests that SCs, especially when used in combination with other treatments, offer one of the best hopes we have today of devising an effective treatment for spinal cord repair.
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Affiliation(s)
- Mary Bartlett Bunge
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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56
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Hill CE, Guller Y, Raffa SJ, Hurtado A, Bunge MB. A calpain inhibitor enhances the survival of Schwann cells in vitro and after transplantation into the injured spinal cord. J Neurotrauma 2011; 27:1685-95. [PMID: 20568964 DOI: 10.1089/neu.2010.1272] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Despite the diversity of cells available for transplantation into sites of spinal cord injury (SCI), and the known ability of transplanted cells to integrate into host tissue, functional improvement associated with cellular transplantation has been limited. One factor potentially limiting the efficacy of transplanted cells is poor cell survival. Recently we demonstrated rapid and early death of Schwann cells (SCs) within the first 24 h after transplantation, by both necrosis and apoptosis, which results in fewer than 20% of the cells surviving beyond 1 week. To enhance SC transplant survival, in vitro and in vivo models to rapidly screen compounds for their ability to promote SC survival are needed. The current study utilized in vitro models of apoptosis and necrosis, and based on withdrawal of serum and mitogens and the application of hydrogen peroxide, we screened several inhibitors of apoptosis and necrosis. Of the compounds tested, the calpain inhibitor MDL28170 enhanced SC survival both in vitro in response to oxidative stress induced by application of H2O2, and in vivo following delayed transplantation into the moderately contused spinal cord. The results support the use of calpain inhibitors as a promising new treatment for promoting the survival of transplanted cells. They also suggest that in vitro assays for cell survival may be useful for establishing new compounds that can then be tested in vivo for their ability to promote transplanted SC survival.
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Affiliation(s)
- Caitlin E Hill
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida, USA.
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57
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Muscle recovery after repair of short and long peripheral nerve gaps using fibrin conduits. Neurosci Lett 2011; 500:41-6. [DOI: 10.1016/j.neulet.2011.06.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/18/2011] [Accepted: 06/01/2011] [Indexed: 02/07/2023]
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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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59
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Tse KH, Kingham PJ, Novikov LN, Wiberg M. Adipose tissue and bone marrow-derived stem cells react similarly in an ischaemia-like microenvironment. J Tissue Eng Regen Med 2011; 6:473-85. [PMID: 21751425 DOI: 10.1002/term.452] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2010] [Accepted: 05/23/2011] [Indexed: 12/22/2022]
Abstract
Mesenchymal stem cells (MSCs) from adipose tissue and bone marrow are promising cell sources for autologous cell therapy of nerve injuries, as demonstrated by their intrinsic neurotrophic potential. However, extensive death of transplanted cells limits their full benefits. This study investigated the effects of ischaemia (metabolically induced by sodium azide and 2-deoxyglucose) and serum-derived mitogens on the viability and functional profile of MSCs in vitro. MSCs were more susceptible to combined, rather than individual, blockade of glycolysis and oxidative phosphorylation. Apoptosis and autophagy were involved in ischaemia-induced cell death. Chemical ischaemia alone and serum withdrawal alone induced a similar amount of cell death, with significantly different intracellular ATP maintenance. Combined ischaemia and serum deprivation had additive effects on cell death. Expression of the extracellular matrix (ECM) molecules laminin and fibronectin was attenuated under ischaemia and independent of serum level; however, BDNF and NGF levels remained relatively constant. Strong upregulation of VEGF and to a lesser extent angiopoietin-1 was observed under ischaemia but not in serum withdrawal conditions. Importantly, this study demonstrated similar reactions of MSCs derived from adipose and bone marrow tissue, in ischaemia-like and mitogen-deprived microenvironments in terms of viability, cellular energetics, cell death mechanisms and expression levels of various growth-promoting molecules. Also, the results suggest that ischaemia has a larger impact on the ability of MSCs to survive transplantation than withdrawal of mitogens.
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Affiliation(s)
- Kai-Hei Tse
- Department of Integrative Medical Biology, Section of Anatomy, Umeå University, Sweden
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60
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Kennelly KP, Wallace DM, Holmes TM, Hankey DJ, Grant TS, O'Farrelly C, Keegan DJ. Preparation of pre-confluent retinal cells increases graft viability in vitro and in vivo: a mouse model. PLoS One 2011; 6:e21365. [PMID: 21738643 PMCID: PMC3126823 DOI: 10.1371/journal.pone.0021365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Accepted: 05/30/2011] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Graft failure remains an obstacle to experimental subretinal cell transplantation. A key step is preparing a viable graft, as high levels of necrosis and apoptosis increase the risk of graft failure. Retinal grafts are commonly harvested from cell cultures. We termed the graft preparation procedure "transplant conditions" (TC). We hypothesized that culture conditions influenced graft viability, and investigated whether viability decreased following TC using a mouse retinal pigment epithelial (RPE) cell line, DH01. METHODS Cell viability was assessed by trypan blue exclusion. Levels of apoptosis and necrosis in vitro were determined by flow cytometry for annexin V and propidium iodide and Western blot analysis for the pro- and cleaved forms of caspases 3 and 7. Graft viability in vivo was established by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and cleaved caspase 3 immunolabeling of subretinal allografts. RESULTS Pre-confluent cultures had significantly less nonviable cells than post-confluent cultures (6.6%±0.8% vs. 13.1%±0.9%, p<0.01). Cell viability in either group was not altered significantly following TC. Caspases 3 and 7 were not altered by levels of confluence or following TC. Pre-confluent cultures had low levels of apoptosis/necrosis (5.6%±1.1%) that did not increase following TC (4.8%±0.5%). However, culturing beyond confluence led to progressively increasing levels of apoptosis and necrosis (up to 16.5%±0.9%). Allografts prepared from post-confluent cultures had significantly more TUNEL-positive cells 3 hours post-operatively than grafts of pre-confluent cells (12.7%±3.1% vs. 4.5%±1.4%, p<0.001). Subretinal grafts of post-confluent cells also had significantly higher rates of cleaved caspase 3 than pre-confluent grafts (20.2%±4.3% vs. 7.8%±1.8%, p<0.001). CONCLUSION Pre-confluent cells should be used to maximize graft cell viability.
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Affiliation(s)
- Kevin P Kennelly
- Catherine McAuley Clinical Research Centre, University College Dublin, Dublin, Ireland.
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61
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Guest J, Benavides F, Padgett K, Mendez E, Tovar D. Technical aspects of spinal cord injections for cell transplantation. Clinical and translational considerations. Brain Res Bull 2011; 84:267-79. [DOI: 10.1016/j.brainresbull.2010.11.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2010] [Revised: 09/20/2010] [Accepted: 11/08/2010] [Indexed: 12/13/2022]
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62
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Luo J, Bo X, Wu D, Yeh J, Richardson PM, Zhang Y. Promoting survival, migration, and integration of transplanted Schwann cells by over-expressing polysialic acid. Glia 2010; 59:424-34. [PMID: 21264949 DOI: 10.1002/glia.21111] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Accepted: 10/27/2010] [Indexed: 12/11/2022]
Abstract
The poor survival and migration of transplanted Schwann cells (SCs) are major drawbacks for their clinical application in cell therapy for neurotrauma. To overcome such drawbacks we genetically modified SCs to over-express polysialic acid (PSA) by lentiviral delivery of polysialyltransferase (PST) to study whether over-expression of PSA could enhance their survival, migration, and integration when transplanted into the spinal cord. It was found that more PSA-expressing SCs (PST/SCs) survived than GFP-expressing SCs (GFP/SCs) after transplantation, although cell loss was still quite significant. PSA expression did not enhance the motility of transplanted SCs in uninjured spinal cord. However, in a spinal cord crush injury model PST/SCs transplanted caudal to the lesion showed that increased number of PST/SCs migrated to the injury site compared with that of GFP/SCs. Induced expression of PSA in spinal cord can further facilitate the infiltration of PST/SCs into the lesion site. PST/SCs were also shown to intermingle well with host spinal cells while GFP/SCs formed boundaries with host tissue. This was confirmed by an in vitro confrontation assay showing that more PST/SCs crossed over to astrocyte territory than GFP/SCs. Furthermore, PST/SCs induced much less expression of glial fibrillary acidic protein and chondroitin sulfate proteoglycan in the surrounding tissues than GFP/SCs, indicating that expression of PSA on SCs do not cause significant stress response of astrocytes. These results demonstrate that expression of PSA on SCs significantly changes their biological properties and makes them more feasible for neural repair after neurotrauma.
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Affiliation(s)
- Juan Luo
- Centre for Neuroscience and Trauma, Blizard Institute of Cell and Molecular Science, Barts and the London School of Medicine and Dentistry, Queen Mary, University of London, Whitechapel, London E1 2AT, United Kingdom
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63
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Patel V, Joseph G, Patel A, Patel S, Bustin D, Mawson D, Tuesta LM, Puentes R, Ghosh M, Pearse DD. Suspension matrices for improved Schwann-cell survival after implantation into the injured rat spinal cord. J Neurotrauma 2010; 27:789-801. [PMID: 20144012 DOI: 10.1089/neu.2008.0809] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Trauma to the spinal cord produces endogenously irreversible tissue and functional loss, requiring the application of therapeutic approaches to achieve meaningful restoration. Cellular strategies, in particular Schwann-cell implantation, have shown promise in overcoming many of the obstacles facing successful repair of the injured spinal cord. Here, we show that the implantation of Schwann cells as cell suspensions with in-situ gelling laminin:collagen matrices after spinal-cord contusion significantly enhances long-term cell survival but not proliferation, as well as improves graft vascularization and the degree of axonal in-growth over the standard implantation vehicle, minimal media. The use of a matrix to suspend cells prior to implantation should be an important consideration for achieving improved survival and effectiveness of cellular therapies for future clinical application.
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Affiliation(s)
- Vivek Patel
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, Florida 33101, USA
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64
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Siriphorn A, Chompoopong S, Floyd CL. 17β-estradiol protects Schwann cells against H2O2-induced cytotoxicity and increases transplanted Schwann cell survival in a cervical hemicontusion spinal cord injury model. J Neurochem 2010; 115:864-72. [PMID: 20456002 DOI: 10.1111/j.1471-4159.2010.06770.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Schwann cell (SC) transplantation is a promising repair strategy after spinal cord injury (SCI); however, a large number of SCs do not survive following transplantation. Previous studies have shown that 17β-estradiol (E2) protects several cell types against cytotoxicity. Thus, this study evaluated the protective potential of E2 on SCs in vitro and investigated the effect of E2 on transplanted SC survival in a rat model of SCI. Primary SC cultures were found to robustly express estrogen receptors (ER) and incubation with E2 protected SCs against hydrogen peroxide-induced cell death. This protection was not inhibited by the ER antagonist ICI 182,780, suggesting that genomic signaling is not necessary for protection. In a subsequent experiment, cervical hemicontusion SCI was induced in male rats followed by sustained administration of E2 or placebo. Eight days after SCI, SCs were transplanted into the injury epicenter. E2 treatment significantly increased the number of surviving labeled transplanted SCs evaluated 7 days after transplantation. These data demonstrate that E2 protects SCs against oxidative stress and improves transplanted SC survival, which suggests that E2 administration may be an intervention of choice for enhancing survival of transplanted SCs after SCI.
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Affiliation(s)
- Akkradate Siriphorn
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, Alabama, USA
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65
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Tetzlaff W, Okon EB, Karimi-Abdolrezaee S, Hill CE, Sparling JS, Plemel JR, Plunet WT, Tsai EC, Baptiste D, Smithson LJ, Kawaja MD, Fehlings MG, Kwon BK. A systematic review of cellular transplantation therapies for spinal cord injury. J Neurotrauma 2010; 28:1611-82. [PMID: 20146557 DOI: 10.1089/neu.2009.1177] [Citation(s) in RCA: 400] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Cell transplantation therapies have become a major focus in pre-clinical research as a promising strategy for the treatment of spinal cord injury (SCI). In this article, we systematically review the available pre-clinical literature on the most commonly used cell types in order to assess the body of evidence that may support their translation to human SCI patients. These cell types include Schwann cells, olfactory ensheathing glial cells, embryonic and adult neural stem/progenitor cells, fate-restricted neural/glial precursor cells, and bone-marrow stromal cells. Studies were included for review only if they described the transplantation of the cell substrate into an in-vivo model of traumatic SCI, induced either bluntly or sharply. Using these inclusion criteria, 162 studies were identified and reviewed in detail, emphasizing their behavioral effects (although not limiting the scope of the discussion to behavioral effects alone). Significant differences between cells of the same "type" exist based on the species and age of donor, as well as culture conditions and mode of delivery. Many of these studies used cell transplantations in combination with other strategies. The systematic review makes it very apparent that cells derived from rodent sources have been the most extensively studied, while only 19 studies reported the transplantation of human cells, nine of which utilized bone-marrow stromal cells. Similarly, the vast majority of studies have been conducted in rodent models of injury, and few studies have investigated cell transplantation in larger mammals or primates. With respect to the timing of intervention, nearly all of the studies reviewed were conducted with transplantations occurring subacutely and acutely, while chronic treatments were rare and often failed to yield functional benefits.
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Affiliation(s)
- Wolfram Tetzlaff
- University of British Columbia, ICORD, Vancouver, British Columbia, Canada.
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66
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Tapadia M, Mozaffar T, Gupta R. Compressive neuropathies of the upper extremity: update on pathophysiology, classification, and electrodiagnostic findings. J Hand Surg Am 2010; 35:668-77. [PMID: 20223605 PMCID: PMC4715364 DOI: 10.1016/j.jhsa.2010.01.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Accepted: 01/12/2010] [Indexed: 02/02/2023]
Abstract
Clinical examination and electrodiagnostic studies remain the gold standard for diagnosis of nerve injuries. Diagnosis of chronic nerve compression (CNC) injuries can be difficult in patients with confounding factors such as diabetes. The treatment of nerve entrapment ranges from medical to surgical management, depending on the nerve involved and on the severity and duration of compression. Considerable insights have been made at the molecular level, differentiating between nerve crush injuries and CNC injuries. Although the myelin changes after CNC injury were previously thought to be a mild form of Wallerian degeneration, recent evidence points to a distinct pathophysiology involving Schwann cell mechanosensitivity. Future areas of research include Schwann cell transplantation in the treatment regimen, the correlation between demyelination and the onset of pain, and the role of Schwann cell integrins in transducing the mechanical forces involved in nerve compression injuries to Schwann cells.
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Affiliation(s)
- Minal Tapadia
- Peripheral Nerve Research Laboratory, University of California, Irvine; Irvine, CA
| | - Tahseen Mozaffar
- Department of Neurology, University of California, Irvine; Irvine, CA
- Peripheral Nerve Research Laboratory, University of California, Irvine; Irvine, CA
| | - Ranjan Gupta
- Department of Orthopaedic Surgery, University of California, Irvine; Irvine, CA
- Department of Anatomy and Neurobiology, University of California, Irvine; Irvine, CA
- Department of Biomedical Engineering, University of California, Irvine; Irvine, CA
- Peripheral Nerve Research Laboratory, University of California, Irvine; Irvine, CA
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Chi GF, Kim MR, Kim DW, Jiang MH, Son Y. Schwann cells differentiated from spheroid-forming cells of rat subcutaneous fat tissue myelinate axons in the spinal cord injury. Exp Neurol 2010; 222:304-17. [DOI: 10.1016/j.expneurol.2010.01.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2009] [Revised: 01/07/2010] [Accepted: 01/08/2010] [Indexed: 02/07/2023]
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68
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Ritfeld GJ, Nandoe Tewarie RD, Rahiem ST, Hurtado A, Roos RA, Grotenhuis A, Oudega M. Reducing macrophages to improve bone marrow stromal cell survival in the contused spinal cord. Neuroreport 2010; 21:221-6. [DOI: 10.1097/wnr.0b013e32833677cd] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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69
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Combinatorial strategies with Schwann cell transplantation to improve repair of the injured spinal cord. Neurosci Lett 2009; 456:124-32. [PMID: 19429147 DOI: 10.1016/j.neulet.2008.08.092] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2008] [Revised: 07/29/2008] [Accepted: 08/04/2008] [Indexed: 12/11/2022]
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70
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White RE, Yin FQ, Jakeman LB. TGF-alpha increases astrocyte invasion and promotes axonal growth into the lesion following spinal cord injury in mice. Exp Neurol 2008; 214:10-24. [PMID: 18647603 DOI: 10.1016/j.expneurol.2008.06.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2008] [Revised: 06/02/2008] [Accepted: 06/17/2008] [Indexed: 11/15/2022]
Abstract
Astrocytes respond to environmental cues and play a multifaceted role in the response to trauma in the central nervous system. As the most prevalent contributors to the glial scar, astrocytes are targeted as barriers to regeneration. However, there is also strong evidence that astrocytes are vital for neuroprotection and metabolic support after injury. In addition, consistent with their role during development, astrocytes may be capable of supporting the growth of injured axons. Therefore, we hypothesized that with appropriate stimulation, the reparative functions of endogenous astrocytes could be harnessed to promote axon growth and recovery after spinal cord injury. Transforming growth factor-alpha (TGF-alpha) is a mitogenic growth factor that is active on astrocytes and is poised to contribute to such a strategy. Recombinant TGF-alpha was administered intrathecally to adult C57BL/6 mice for two weeks following a moderate mid-thoracic spinal cord contusion. By three weeks post-injury, TGF-alpha infusion had not affected locomotor recovery, but promoted extensive axon growth and altered the composition of the lesion site. The center of the lesion in the treated mice contained greater numbers of new cells and increased astrocyte invasion. Despite the expression of inhibitory proteoglycans, there was a marked increase in axons expressing neurofilament and GAP-43 immunoreactivity, and the new axons were closely associated with increased laminin expression within and beyond the astrocyte matrix. The results demonstrate that astrocytes are dynamic players in the response to spinal cord injury, and the growth-supportive role of these cells can be enhanced by TGF-alpha infusion.
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Affiliation(s)
- Robin E White
- The Ohio State University, Neuroscience Graduate Studies Program, OH, USA
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Guest JD, Herrera L, Margitich I, Oliveria M, Marcillo A, Casas CE. Xenografts of expanded primate olfactory ensheathing glia support transient behavioral recovery that is independent of serotonergic or corticospinal axonal regeneration in nude rats following spinal cord transection. Exp Neurol 2008; 212:261-74. [PMID: 18511045 DOI: 10.1016/j.expneurol.2008.03.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 02/20/2008] [Accepted: 03/03/2008] [Indexed: 12/17/2022]
Abstract
Transplantation of olfactory ensheathing glial cells (OEG) may improve the outcome from spinal cord injury. Proof-of-principle studies in primates are desirable and the feasibility and efficacy of using in vitro expanded OEG should be tested. An intermediate step between the validation of rodent studies and human clinical trials is to study expanded primate OEG (POEG) xenografts in immunotolerant rodents. In this study the time course to generate purified POEG was evaluated as well as their survival, effect on damaged axons of the corticospinal and serotonergic systems, tissue sparing, and chronic locomotor recovery following transplantation. Fifty-seven nude rats underwent T9/10 spinal cord transection. Thirty-eight rats received POEG, 19 controls were injected with cell medium, and 10 received lentivirally-GFP-transfected POEG. Histological evaluation was conducted at 6 weeks, 8 weeks, 14 weeks and 23-24 weeks. Of these 57 rats, 18 were studied with 5-HT immunostaining, 16 with BDA anterograde CST labeling, and six were used for transmission electron microscopy. In grafted animals, behavioral recovery, sprouting and limited regeneration of 5-HT fibers, and increased numbers of proximal collateral processes but not regeneration of CST fibers was observed. Grafted animals had less cavitation in the spinal cord stumps than controls. Behavioral recovery peaked at three months and then declined. Five POEG-transplanted animals that had shown behavioral recovery underwent retransection and behavioral scores did not change significantly, suggesting that long tract axonal regeneration did not account for the locomotor improvement. At the ultrastructural level presumptive POEG were found to have direct contacts with astrocytes forming the glia limitans, distinct from those formed by Schwann cells. At 6 weeks GFP expression was detected in cells within the lesion site and within nerve roots but did not match the pattern of Hoechst nuclear labeling. At 3.5 months only GFP-positive debris in macrophages could be detected. Transplanted POEG support behavioral recovery via mechanisms that appear to be independent of long tract regeneration.
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Affiliation(s)
- J D Guest
- Department of Neurological Surgery, University of Miami, Miami, FL 33136, USA.
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