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Geng X, Sun T, Li JH, Zhao N, Wang Y, Yu HL. Electroacupuncture in the repair of spinal cord injury: inhibiting the Notch signaling pathway and promoting neural stem cell proliferation. Neural Regen Res 2015; 10:394-403. [PMID: 25878587 PMCID: PMC4396101 DOI: 10.4103/1673-5374.153687] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2015] [Indexed: 12/23/2022] Open
Abstract
Electroacupuncture for the treatment of spinal cord injury has a good clinical curative effect, but the underlying mechanism is unclear. In our experiments, the spinal cord of adult Sprague-Dawley rats was clamped for 60 seconds. Dazhui (GV14) and Mingmen (GV4) acupoints of rats were subjected to electroacupuncture. Enzyme-linked immunosorbent assay revealed that the expression of serum inflammatory factors was apparently downregulated in rat models of spinal cord injury after electroacupuncture. Hematoxylin-eosin staining and immunohistochemistry results demonstrated that electroacupuncture contributed to the proliferation of neural stem cells in rat injured spinal cord, and suppressed their differentiation into astrocytes. Real-time quantitative PCR and western blot assays showed that electroacupuncture inhibited activation of the Notch signaling pathway induced by spinal cord injury. These findings indicate that electroacupuncture repaired the injured spinal cord by suppressing the Notch signaling pathway and promoting the proliferation of endogenous neural stem cells.
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Affiliation(s)
- Xin Geng
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Tao Sun
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Jing-Hui Li
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Ning Zhao
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Yong Wang
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Hua-Lin Yu
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
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Lam CJ, Assinck P, Liu J, Tetzlaff W, Oxland TR. Impact depth and the interaction with impact speed affect the severity of contusion spinal cord injury in rats. J Neurotrauma 2014; 31:1985-97. [PMID: 24945364 DOI: 10.1089/neu.2014.3392] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Spinal cord injury (SCI) biomechanics suggest that the mechanical factors of impact depth and speed affect the severity of contusion injury, but their interaction is not well understood. The primary aim of this work was to examine both the individual and combined effects of impact depth and speed in contusion SCI on the cervical spinal cord. Spinal cord contusions between C5 and C6 were produced in anesthetized rats at impact speeds of 8, 80, or 800 mm/s with displacements of 0.9 or 1.5 mm (n=8/group). After 7 days postinjury, rats were assessed for open-field behavior, euthanized, and spinal cords were harvested. Spinal cord tissue sections were stained for demyelination (myelin-based protein) and tissue sparing (Luxol fast blue). In parallel, a finite element model of rat spinal cord was used to examine the resulting maximum principal strain in the spinal cord during impact. Increasing impact depth from 0.9 to 1.5 mm reduced open-field scores (p<0.01) above 80 mm/s, reduced gray (GM) and white matter (WM) sparing (p<0.01), and increased the amount of demyelination (p<0.01). Increasing impact speed showed similar results at the 1.5-mm impact depth, but not the 0.9-mm impact depth. Linear correlation analysis with finite element analysis strain showed correlations (p<0.001) with nerve fiber damage in the ventral (R(2)=0.86) and lateral (R(2)=0.74) regions of the spinal cord and with WM (R(2)=0.90) and GM (R(2)=0.76) sparing. The results demonstrate that impact depth is more important in determining the severity of SCI and that threshold interactions exist between impact depth and speed.
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Affiliation(s)
- Cameron J Lam
- 1 Orthopedic and Injury Biomechanics Lab, Departments of Mechanical Engineering and Orthopedics, University of British Columbia , Vancouver, British Columbia, Canada
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Laing AC, Brenneman EC, Yung A, liu J, Kozlowski P, Oxland T. The Effects of Age on the Morphometry of the Cervical Spinal Cord and Spinal Column in Adult Rats: An MRI-Based Study. Anat Rec (Hoboken) 2014; 297:1885-95. [PMID: 25044631 DOI: 10.1002/ar.22995] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 05/04/2014] [Accepted: 05/28/2014] [Indexed: 01/15/2023]
Affiliation(s)
- Andrew C. Laing
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology; University of Waterloo, 200 University Ave West; Waterloo Ontario N2L 3G1 Canada
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
| | - Elora C. Brenneman
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology; University of Waterloo, 200 University Ave West; Waterloo Ontario N2L 3G1 Canada
| | - Andrew Yung
- MRI Research Centre, University of British Columbia; 2221 Westbrook Mall Vancouver British Columbia V6T 2B5 Canada
| | - Jie liu
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
| | - Piotr Kozlowski
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
- MRI Research Centre, University of British Columbia; 2221 Westbrook Mall Vancouver British Columbia V6T 2B5 Canada
| | - Thomas Oxland
- International Collaboration on Repair Discoveries (ICORD); University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
- Orthopaedics and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering; University of British Columbia; 818 West 10th Avenue Vancouver British Columbia V5Z 1M9 Canada
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Protective effects of erythropoietin in traumatic spinal cord injury by inducing the Nrf2 signaling pathway activation. J Trauma Acute Care Surg 2014; 76:1228-34. [PMID: 24747453 DOI: 10.1097/ta.0000000000000211] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Erythropoietin has demonstrated neuroprotective effects against traumatic spinal cord injury (SCI), but the underlying mechanisms remain unclear. The signaling pathway of an antioxidant transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2), has been shown to play an important role in protecting SCI-induced secondary spinal cord damage. This study was undertaken to explore the effect of recombinant human erythropoietin (rhEPO) on the activation of Nrf2 signaling pathway and secondary spinal cord damage in rats after SCI. METHODS Adult male Sprague-Dawley rats were subjected to laminectomy at T8-T9 and compression with a vascular clip. Three groups were analyzed: (1) sham group, (2) SCI group, and (3) SCI + rhEPO group (n = 16 per group). In the SCI + rhEPO group, rhEPO was administered at a dose of 5,000 IU/kg at 30 minutes after SCI. Spinal cord samples were extracted at 72 hours after the trauma. RESULTS As a result, we found that the treatment with rhEPO markedly up-regulated the messenger RNA expressions and activities of Nrf2 signaling pathway-related agents, including Nrf2, NAD(P)H:quinone oxidoreductase 1(NQO1), and glutathione S-transferase. The administration of rhEPO also significantly ameliorated the secondary spinal cord damage, as shown by a decreased severity of locomotion deficit, spinal cord edema, and apoptosis. CONCLUSION Post-SCI rhEPO administration induces Nrf2-mediated cytoprotective response in the injured spinal cord, and this may be a mechanism whereby rhEPO improves the outcome following SCI.
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Pajoohesh-Ganji A, Burns MP, Pal-Ghosh S, Tadvalkar G, Hokenbury NG, Stepp MA, Faden AI. Inhibition of amyloid precursor protein secretases reduces recovery after spinal cord injury. Brain Res 2014; 1560:73-82. [PMID: 24630972 DOI: 10.1016/j.brainres.2014.02.049] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 02/24/2014] [Accepted: 02/25/2014] [Indexed: 12/18/2022]
Abstract
Amyloid-β (Aβ) is produced through the enzymatic cleavage of amyloid precursor protein (APP) by β (Bace1) and γ-secretases. The accumulation and aggregation of Aβ as amyloid plaques is the hallmark pathology of Alzheimer׳s disease and has been found in other neurological disorders, such as traumatic brain injury and multiple sclerosis. Although the role of Aβ after injury is not well understood, several studies have reported a negative correlation between Aβ formation and functional outcome. In this study we show that levels of APP, the enzymes cleaving APP (Bace1 and γ-secretase), and Aβ are significantly increased from 1 to 3 days after impact spinal cord injury (SCI) in mice. To determine the role of Aβ after SCI, we reduced or inhibited Aβ in vivo through pharmacological (using DAPT) or genetic (Bace1 knockout mice) approaches. We found that these interventions significantly impaired functional recovery as evaluated by white matter sparing and behavioral testing. These data are consistent with a beneficial role for Aβ after SCI.
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Affiliation(s)
| | - Mark P Burns
- Georgetown University, Washington, DC, United States
| | | | - Gauri Tadvalkar
- The George Washington University, Washington, DC, United States
| | - Nicole G Hokenbury
- The George Washington University, Washington, DC, United States; Georgetown University, Washington, DC, United States; University of Maryland, Baltimore, United States
| | - Mary Ann Stepp
- The George Washington University, Washington, DC, United States
| | - Alan I Faden
- University of Maryland, Baltimore, United States
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Anti-inflammatory effects of curcumin in experimental spinal cord injury in rats. Inflamm Res 2014; 63:381-7. [DOI: 10.1007/s00011-014-0710-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/17/2013] [Accepted: 01/12/2014] [Indexed: 01/19/2023] Open
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Omega-3 fatty acids and traumatic neurological injury: from neuroprotection to neuroplasticity? Trends Neurosci 2014; 37:30-8. [DOI: 10.1016/j.tins.2013.10.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/22/2013] [Accepted: 10/24/2013] [Indexed: 01/21/2023]
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Ward RE, Huang W, Kostusiak M, Pallier PN, Michael-Titus AT, Priestley JV. A characterization of white matter pathology following spinal cord compression injury in the rat. Neuroscience 2013; 260:227-39. [PMID: 24361176 DOI: 10.1016/j.neuroscience.2013.12.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Revised: 12/09/2013] [Accepted: 12/09/2013] [Indexed: 12/25/2022]
Abstract
Our laboratory has previously described the characteristics of neuronal injury in a rat compression model of spinal cord injury (SCI), focussing on the impact of this injury on the gray matter. However, white matter damage is known to play a critical role in functional outcome following injury. Therefore, in the present study, we used immunohistochemistry and electron microscopy to examine the alterations to the white matter that are initiated by compression SCI applied at T12 vertebral level. A significant loss of axonal and dendritic cytoskeletal proteins was observed at the injury epicenter within 1day of injury. This was accompanied by axonal dysfunction, as demonstrated by the accumulation of β-amyloid precursor protein (β-APP), with a peak at 3days post-SCI. A similar, acute loss of cytoskeletal proteins was observed up to 5mm away from the injury epicenter and was particularly evident rostral to the lesion site, whereas β-APP accumulation was prominent in tracts proximal to the injury. Early myelin loss was confirmed by myelin basic protein (MBP) immunostaining and by electron microscopy, which also highlighted the infiltration of inflammatory and red blood cells. However, 6weeks after injury, areas of new Schwann cell and oligodendrocyte myelination were observed. This study demonstrates that substantial white matter damage occurs following compression SCI in the rat. Moreover, the loss of cytoskeletal proteins and accumulation of β-APP up to 5mm away from the lesion site within 1day of injury indicates the rapid manner in which the axonal damage extends in the rostro-caudal axis. This is likely due to both Wallerian degeneration and spread of secondary cell death, with the latter affecting axons both proximal and distal to the injury.
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Affiliation(s)
- R E Ward
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK.
| | - W Huang
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK; The Institute of Medical Sciences, School of Medical Science, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | - M Kostusiak
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - P N Pallier
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - A T Michael-Titus
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
| | - J V Priestley
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT, UK
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Ling X, Bao F, Qian H, Liu D. The temporal and spatial profiles of cell loss following experimental spinal cord injury: effect of antioxidant therapy on cell death and functional recovery. BMC Neurosci 2013; 14:146. [PMID: 24238557 PMCID: PMC3924333 DOI: 10.1186/1471-2202-14-146] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Accepted: 11/12/2013] [Indexed: 01/22/2023] Open
Abstract
Background Traumatic spinal cord injury (SCI)-induced overproduction of endogenous deleterious substances triggers secondary cell death to spread damage beyond the initial injury site. Substantial experimental evidence supports reactive species (RS) as important mediators of secondary cell death after SCI. This study established quantitative temporal and spatial profiles of cell loss, characterized apoptosis, and evaluated the effectiveness of a broad spectrum RS scavenger - Mn (III) tetrakis (4-benzoic acid) porphyrin (MnTBAP) and a combination of MnTBAP plus nitro-L-arginine to prevent cell loss and neurological dysfunction following contusion SCI to the rat spinal cord. Results By counting the number of surviving cells in spinal cord sections removed at 1, 6, 12, 24, 48, 72 h and 1 week post-SCI and at 0 – 4 mm from the epicenter, the temporal and spatial profiles of motoneuron and glia loss were established. Motoneurons continued to disappear over a week and the losses decreased with increasing distance from the epicenter. Significant glia loss peaked at 24 to 48 h post-SCI, but only at sections 0–1.5 mm from the epicenter. Apoptosis of neurons, motoneurons and astrocytes was characterized morphologically by double immuno-staining with cell-specific markers and apoptosis indicators and confirmed by transmission electron microscopy. DNA laddering, ELISA quantitation and caspase-3 activation in the spinal cord tissue indicated more intense DNA fragments and greater caspase-3 activation in the epicenter than at 1 and 2 cm away from the epicenter or the sham-operated sections. Intraperitoneal treatment with MnTBAP + nitro-L-arginine significantly reduced motoneuron and cell loss and apoptosis in the gray and white matter compared with the vehicle-treated group. MnTBAP alone significantly reduced the number of apoptotic cells and improved functional recovery as evaluated by three behavioral tests. Conclusions Our temporal and spatial profiles of cell loss provide data bases for determining the time and location for pharmacological intervention. Our demonstration that apoptosis follows SCI and that MnTBAP alone or MnTBAP + nitro-L-arginine significantly reduces apoptosis correlates SCI-induced apoptosis with RS overproduction. MnTBAP significantly improved functional recovery, which strongly supports the important role of antioxidant therapy in treating SCI and the candidacy of MnTBAP for such treatment.
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Affiliation(s)
- Xiang Ling
- Department of Neurology, University of Texas Medical Branch, 301 University Blvd,, Rt, 0881, Galveston, TX 77555-0881, USA.
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Satkunendrarajah K, Fehlings MG. Do omega-3 polyunsaturated fatty acids ameliorate spinal cord injury? Exp Neurol 2013; 249:104-10. [DOI: 10.1016/j.expneurol.2013.08.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/07/2013] [Accepted: 08/14/2013] [Indexed: 12/13/2022]
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Okon EB, Streijger F, Lee JHT, Anderson LM, Russell AK, Kwon BK. Intraparenchymal Microdialysis after Acute Spinal Cord Injury Reveals Differential Metabolic Responses to Contusive versus Compressive Mechanisms of Injury. J Neurotrauma 2013; 30:1564-76. [DOI: 10.1089/neu.2013.2956] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Elena B. Okon
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Femke Streijger
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Jae H. T. Lee
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa M. Anderson
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Amy K. Russell
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian K. Kwon
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
- Combined Neurosurgical and Orthopaedics Spine Program (CNOSP), Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
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Kolaric KV, Thomson G, Edgar JM, Brown AM. Focal axonal swellings and associated ultrastructural changes attenuate conduction velocity in central nervous system axons: a computer modeling study. Physiol Rep 2013; 1:e00059. [PMID: 24303138 PMCID: PMC3835014 DOI: 10.1002/phy2.59] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/22/2013] [Accepted: 07/25/2013] [Indexed: 12/11/2022] Open
Abstract
The constancy of action potential conduction in the central nervous system (CNS) relies on uniform axon diameter coupled with fidelity of the overlying myelin providing high-resistance, low capacitance insulation. Whereas the effects of demyelination on conduction have been extensively studied/modeled, equivalent studies on the repercussions for conduction of axon swelling, a common early pathological feature of (potentially reversible) axonal injury, are lacking. The recent description of experimentally acquired morphological and electrical properties of small CNS axons and oligodendrocytes prompted us to incorporate these data into a computer model, with the aim of simulating the effects of focal axon swelling on action potential conduction. A single swelling on an otherwise intact axon, as occurs in optic nerve axons of Cnp1 null mice caused a small decrease in conduction velocity. The presence of single swellings on multiple contiguous internodal regions (INR), as likely occurs in advanced disease, caused qualitatively similar results, except the dimensions of the swellings required to produce equivalent attenuation of conduction were significantly decreased. Our simulations of the consequences of metabolic insult to axons, namely, the appearance of multiple swollen regions, accompanied by perturbation of overlying myelin and increased axolemmal permeability, contained within a single INR, revealed that conduction block occurred when the dimensions of the simulated swellings were within the limits of those measured experimentally, suggesting that multiple swellings on a single axon could contribute to axonal dysfunction, and that increased axolemmal permeability is the decisive factor that promotes conduction block.
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Affiliation(s)
- Katarina V Kolaric
- School of Biomedical Sciences, Queens Medical Centre, University of Nottingham Nottingham, NG7 2UH, U.K
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Shields CB, Zhang YP, Shields LBE. Post-traumatic syringomyelia: CSF hydrodynamic changes following spinal cord injury are the driving force in the development of PTSM. HANDBOOK OF CLINICAL NEUROLOGY 2013; 109:355-67. [PMID: 23098724 DOI: 10.1016/b978-0-444-52137-8.00022-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
Post-traumatic syringomyelia (PTSM) is a disorder that occurs infrequently following spinal cord injury (SCI), characterized by progressive neurological deterioration resulting from syrinx expansion originating in proximity to the traumatic epicenter. Several pathogenetic factors are associated with this disorder, however, the precise mechanism of the development of PTSM is controversial. Combined anatomical alterations and molecular changes following trauma to the spinal cord and arachnoid participate in the development of this condition. These factors include narrowing or obstruction of the subarachnoid space (SAS), central canal occlusion, myelomalacia, and alterations in intramedullary water permeability. If a patient sustains a SCI with delayed progressive deterioration in neurological function, in association with the MRI appearance of syringomyelia (SM), the diagnosis of PTSM is straightforward. The treatment of PTSM has not undergone any significant changes recently. The surgical treatment of PTSM consists of reconstructing the SAS or shunting fluid away from the syrinx to other locations. The advantages and disadvantages of each procedure will be discussed. With greater understanding of the mechanisms contributing to the development of SM, including advanced diagnostic methods and further advances in the development of artificial dural and shunting tubing, future therapies of PTSM will be more effective and long-lasting. Incorporation of alterations of AQP4 expression provides an intriguing possibility for future treatment of PTSM.
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Sjovold SG, Mattucci SF, Choo AM, Liu J, Dvorak MF, Kwon BK, Tetzlaff W, Oxland TR. Histological Effects of Residual Compression Sustained for 60 Minutes at Different Depths in a Novel Rat Spinal Cord Injury Contusion Model. J Neurotrauma 2013; 30:1374-84. [DOI: 10.1089/neu.2013.2906] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Affiliation(s)
- Simon G. Sjovold
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Stephen F.E. Mattucci
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anthony M. Choo
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Marcel F. Dvorak
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Spine, Department of Orthopaedics, University of British Columbia, British Columbia, Canada
| | - Brian K. Kwon
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
- Division of Spine, Department of Orthopaedics, University of British Columbia, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas R. Oxland
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
- International Collaboration on Repair Discoveries, University of Pennsylvania, Philadelphia, Pennsylvania
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Yang JH, Suh SW, Modi HN, Ramani ET, Hong JY, Hwang JH, Jung WY. Effects of vertebral column distraction on transcranial electrical stimulation-motor evoked potential and histology of the spinal cord in a porcine model. J Bone Joint Surg Am 2013; 95:835-42, S1-2. [PMID: 23636191 DOI: 10.2106/jbjs.k.00575] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Spinal cord injury can occur following surgical procedures for correction of scoliosis and kyphosis, as these procedures produce lengthening of the vertebral column. The objective of this study was to cause spinal cord injury by vertebral column distraction and evaluate the histological changes in the spinal cord in relationship to the pattern of recovery from the spinal cord injury. METHODS Global osteotomy of all three spinal columns was performed on the ninth thoracic vertebra of sixteen pigs. The osteotomized vertebra was distracted until transcranial electrical stimulation-motor evoked potential (TES-MEP) signals disappeared or decreased by >80% compared with the baseline amplitude; this was defined as spinal cord injury. The distraction distance at which spinal cord injury occurred was measured, the distraction was released, and the TES-MEP recovery pattern was observed. A wake-up test was performed, two days of observations were made, and histological changes were evaluated in relationship to the recovery pattern. RESULTS Spinal cord injury developed at a distraction distance of 20.2 ± 4.7 mm, equivalent to 3.6% of the thoracolumbar spinal length, and the distraction distance was correlated with the thoracolumbar spinal length (r = 0.632, p = 0.009). No animals exhibited complete recovery according to TES-MEP testing, eleven exhibited incomplete recovery, and five exhibited no recovery. During the two days of observation, all eleven animals with incomplete recovery showed positive responses to sensory and motor tests, whereas none of the five animals with no recovery had positive responses. On histological evaluation, three animals that exhibited no recovery all showed complete severance of nerve fibers (axotomy), whereas six animals that exhibited incomplete recovery all showed partial white-matter injury. CONCLUSIONS Parallel distraction of approximately 3.6% of the thoracolumbar length after global osteotomy resulted in spinal cord injury and histological evidence of spinal cord damage. The pattern of recovery from the spinal cord injury after release of the distraction was consistent with the degree of axonal damage. Axotomy was observed in animals that exhibited no recovery on TES-MEP, and only hemorrhagic changes in the white matter were observed in animals that exhibited incomplete recovery.
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Affiliation(s)
- Jae Hyuk Yang
- Scoliosis Research Institute, Department of Orthopedics, Korea University, Guro Hospital, Guro dong 80, Guro-gu, Seoul, South Korea
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Silva NA, Gimble JM, Sousa N, Reis RL, Salgado AJ. Combining adult stem cells and olfactory ensheathing cells: the secretome effect. Stem Cells Dev 2013; 22:1232-40. [PMID: 23316915 DOI: 10.1089/scd.2012.0524] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Adipose-derived adult stem cells (ASCs), bone marrow mesenchymal stem cells (bmMSCs), and human umbilical cord perivascular cells (HUCPVCs) tissue have been widely tested for regenerative applications, such as bone regeneration. Moreover, olfactory ensheathing cells (OECs) show promise in promoting spinal cord injury (SCI) regeneration. Our group recently proposed the use of a hybrid scaffold targeting both vertebral bone repair and SCI regeneration. According to this concept, both MSCs and OECs should be in close contact to be influenced by the factors that are involved in secretion. For this reason, here we studied the effects of the OEC secretome on the metabolic activity and proliferation of ASCs, bmMSCs, and HUCPVCs. The stem cells' secretome effects on metabolic activity and proliferation of the OECs were also considered. In co-cultures of OECs with ASCs, bmMSCs, or HUCPVCs, the metabolic activity/viability, proliferation, and total cell numbers were measured after 2 and 7 days of culture. The results demonstrated that the secretome of OECs has a positive effect on the metabolic activity and proliferation of MSCs from different origins, especially on ASCs. Furthermore, in general, the stem cells' secretome also had a positive effect on the OECs behavior, particularly when ASCs were in co-culture with OECs. These results suggest that the most suitable combination of cells to be used in our hybrid scaffold is the OECs with the ASCs. Finally, this work adds new knowledge to the cell therapy field, bringing new information about paracrine interactions between OECs and distinct mesenchymal stems.
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Affiliation(s)
- Nuno A Silva
- 3B's Research Group-Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Guimarães, Portugal
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Bock P, Spitzbarth I, Haist V, Stein VM, Tipold A, Puff C, Beineke A, Baumgärtner W. Spatio-temporal development of axonopathy in canine intervertebral disc disease as a translational large animal model for nonexperimental spinal cord injury. Brain Pathol 2012; 23:82-99. [PMID: 22805224 DOI: 10.1111/j.1750-3639.2012.00617.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 07/08/2012] [Indexed: 12/15/2022] Open
Abstract
Spinal cord injury (SCI) represents a devastating central nervous system disease that still lacks sufficient therapies. Here, dogs are increasingly recognized as a preclinical animal model for the development of future therapies. The aim of this study was a detailed characterization of axonopathy in canine intervertebral disc disease, which produces a mixed contusive and compressive injury and functions as a spontaneous translational animal model for human SCI. The results revealed an early occurrence of ultrastructurally distinct axonal swelling. Immunohistochemically, enhanced axonal expression of β-amyloid precursor protein, non-phosphorylated neurofilament (n-NF) and growth-associated protein-43 was detected in the epicenter during acute canine SCI. Indicative of a progressive axonopathy, these changes showed a cranial and caudally accentuated spatial progression in the subacute disease phase. In canine spinal cord slice cultures, immunoreactivity of axons was confined to n-NF. Real-time quantitative polymerase chain reaction of naturally traumatized tissue and slice cultures revealed a temporally distinct dysregulation of the matrix metalloproteinases (MMP)-2 and MMP-9 with a dominating expression of the latter. Contrasting to early axonopathy, diminished myelin basic protein immunoreactivity and phagocytosis were delayed. The results present a basis for assessing new therapies in the canine animal model for translational research that might allow partial extrapolation to human SCI.
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Affiliation(s)
- Patricia Bock
- Department of Pathology, University of Veterinary Medicine, Hannover, Germany
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68
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Rongchao S, Shudong Y, Zhiyi Z. Pathological and immunohistochemical study of lethal primary brain stem injuries. Diagn Pathol 2012; 7:54. [PMID: 22613041 PMCID: PMC3407715 DOI: 10.1186/1746-1596-7-54] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 05/21/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Many of the deaths that occur shortly after injury or in hospitals are caused by mild trauma. Slight morphological changes are often found in the brain stems of these patients during autopsy. The purpose of this study is to investigate the histopathological changes involved in primary brain stem injuries (PBSI) and their diagnostic significance. METHODS A total of 65 patients who had died of PBSI and other conditions were randomly selected. They were divided into 2 groups, an injury group (25 cases) and a control group (20 cases). Slides of each patient's midbrain, pons, and medulla oblongata were prepared and stained with HE, argentaffin, and immunohistochemical agents (GFAP, NF, amyloid-β, MBP). Under low power (×100) and NF staining, the diameter of the thickest longitudinal axon was measured at its widest point. Ten such diameters were collected for each part of the brain (midbrain, pons, and medulla oblongata). Data were recorded and analyzed statistically. RESULTS Brain stem contusions, astrocyte activity, edema, and pathological changes in the neurons were visibly different in the injury and control groups (P < 0.05). Characteristic changes occurred in the neural axons, axon diameter varied from axon to axon and even over different segments of one axon, and several pathological phenomena were observed. These included segmental thickening and curving, wave-like processing, disarrangement, and irregular swelling. A few axons ruptured and intumesced into retraction balls. Immunohistochemical MBP staining showed enlargement and curving of spaces between the myelin sheaths and axons in certain areas. The myelin sheaths lining the surfaces of the axons were in some cases incomplete and even exfoliated, and segmentation disappeared. These pathological changes increased in severity over time (P < 0.05). CONCLUSIONS These histopathological changes may prove beneficial to the pathological diagnosis of PBSI during autopsy. The measurement of axon diameters provides a referent quantitative index for the diagnosis of the specific causes of death involved in PBSI. VIRTUAL SLIDES The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1345298818712204.
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Affiliation(s)
- Sun Rongchao
- Department of Pathology, Wuxi People's Hospital Affiliated to Nanjing Medical University, 299 qingyang road, Wuxi, 214023 China.
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Hou T, Wu Y, Wang L, Liu Y, Zeng L, Li M, Long Z, Chen H, Li Y, Wang Z. Cellular Prostheses Fabricated with Motor Neurons Seeded in Self-Assembling Peptide Promotes Partial Functional Recovery After Spinal Cord Injury in Rats. Tissue Eng Part A 2012; 18:974-85. [PMID: 22115283 DOI: 10.1089/ten.tea.2011.0151] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Tianyong Hou
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
- Department of Orthopaedics, Southwest Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Yamin Wu
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Li Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Yuan Liu
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Lin Zeng
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Min Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Zaiyun Long
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Hongsheng Chen
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Yingyu Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
| | - Zhengguo Wang
- State Key Laboratory of Trauma, Burns and Combined Injury, Department of Neurotrauma, Regeneration and Rehabilitation, Research Institute of Surgery, Daping Hospital, Third Military Medical University, Chongqing, P. R. China
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Russell CM, Choo AM, Tetzlaff W, Chung TE, Oxland TR. Maximum principal strain correlates with spinal cord tissue damage in contusion and dislocation injuries in the rat cervical spine. J Neurotrauma 2012; 29:1574-85. [PMID: 22320127 DOI: 10.1089/neu.2011.2225] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The heterogeneity of the primary mechanical mechanism of spinal cord injury (SCI) is not currently used to tailor treatment strategies because the effects of these distinct patterns of acute mechanical damage on long-term neuropathology have not been fully investigated. A computational model of SCI enables the dynamic analysis of mechanical forces and deformations within the spinal cord tissue that would otherwise not be visible from histological tissue sections. We created a dynamic, three-dimensional finite element (FE) model of the rat cervical spine and simulated contusion and dislocation SCI mechanisms. We investigated the relationship between maximum principal strain and tissue damage, and compared primary injury patterns between mechanisms. The model incorporated the spinal cord white and gray matter, the dura mater, cerebrospinal fluid, spinal ligaments, intervertebral discs, a rigid indenter and vertebrae, and failure criteria for ligaments and vertebral endplates. High-speed (∼ 1 m/sec) contusion and dislocation injuries were simulated between vertebral levels C3 and C6 to match previous animal experiments, and average peak maximum principal strains were calculated for several regions at the injury epicenter and at 1-mm intervals from +5 mm rostral to -5 mm caudal to the lesion. Average peak principal strains were compared to tissue damage measured previously in the same regions via axonal permeability to 10-kD fluorescein-dextran. Linear regression of tissue damage against peak maximum principal strain for pooled data within all white matter regions yielded similar and significant (p<0.0001) correlations for both contusion (R(2)=0.86) and dislocation (R(2)=0.52). The model enhances our understanding of the differences in injury patterns between SCI mechanisms, and provides further evidence for the link between principal strain and tissue damage.
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Affiliation(s)
- Colin M Russell
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, University of British Columbia, British Columbia, Canada
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71
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Priestley JV, Michael-Titus AT, Tetzlaff W. Limiting spinal cord injury by pharmacological intervention. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:463-484. [PMID: 23098731 DOI: 10.1016/b978-0-444-52137-8.00029-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The direct primary mechanical trauma to neurons, glia and blood vessels that occurs with spinal cord injury (SCI) is followed by a complex cascade of biochemical and cellular changes which serve to increase the size of the injury site and the extent of cellular and axonal loss. The aim of neuroprotective strategies in SCI is to limit the extent of this secondary cell loss by inhibiting key components of the evolving injury cascade. In this review we will briefly outline the pathophysiological events that occur in SCI, and then review the wide range of neuroprotective agents that have been evaluated in preclinical SCI models. Agents will be considered under the following categories: antioxidants, erythropoietin and derivatives, lipids, riluzole, opioid antagonists, hormones, anti-inflammatory agents, statins, calpain inhibitors, hypothermia, and emerging strategies. Several clinical trials of neuroprotective agents have already taken place and have generally had disappointing results. In attempting to identify promising new treatments, we will therefore highlight agents with (1) low known risks or established clinical use, (2) behavioral data gained in clinically relevant animal models, (3) efficacy when administered after the injury, and (4) robust effects seen in more than one laboratory and/or more than one model of SCI.
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72
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Lutton C, Young YW, Williams R, Meedeniya ACB, Mackay-Sim A, Goss B. Combined VEGF and PDGF treatment reduces secondary degeneration after spinal cord injury. J Neurotrauma 2011; 29:957-70. [PMID: 21568693 DOI: 10.1089/neu.2010.1423] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Trauma to the spinal cord creates an initial physical injury damaging neurons, glia, and blood vessels, which then induces a prolonged inflammatory response, leading to secondary degeneration of spinal cord tissue, and further loss of neurons and glia surrounding the initial site of injury. Angiogenesis is a critical step in tissue repair, but in the injured spinal cord angiogenesis fails; blood vessels formed initially later regress. Stabilizing the angiogenic response is therefore a potential target to improve recovery after spinal cord injury (SCI). Vascular endothelial growth factor (VEGF) can initiate angiogenesis, but cannot sustain blood vessel maturation. Platelet-derived growth factor (PDGF) can promote blood vessel stability and maturation. We therefore investigated a combined application of VEGF and PDGF as treatment for traumatic spinal cord injury, with the aim to reduce secondary degeneration by promotion of angiogenesis. Immediately after hemisection of the spinal cord in the rat we delivered VEGF and PDGF and to the injury site. One and 3 months later the size of the lesion was significantly smaller in the treated group compared to controls, and there was significantly reduced gliosis surrounding the lesion. There was no significant effect of the treatment on blood vessel density, although there was a significant reduction in the numbers of macrophages/microglia surrounding the lesion, and a shift in the distribution of morphological and immunological phenotypes of these inflammatory cells. VEGF and PDGF delivered singly exacerbated secondary degeneration, increasing the size of the lesion cavity. These results demonstrate a novel therapeutic intervention for SCI, and reveal an unanticipated synergy for these growth factors whereby they modulated inflammatory processes and created a microenvironment conducive to axon preservation/sprouting.
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Affiliation(s)
- Cameron Lutton
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.
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73
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Laing AC, Cox R, Tetzlaff W, Oxland T. Effects of advanced age on the morphometry and degenerative state of the cervical spine in a rat model. Anat Rec (Hoboken) 2011; 294:1326-36. [PMID: 21714115 DOI: 10.1002/ar.21436] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 10/31/2010] [Accepted: 03/26/2011] [Indexed: 11/08/2022]
Abstract
Aging causes changes in the geometry of the human cervical spine that may influence the tissue response to applied loads. Rat models are often used to study spinal cord injuries (SCI) and have the potential to enhance our understanding of the effect of age on SCI. The goal of this study was to characterize the morphometry and degenerative state of the cervical spine in Fisher 344 rats, and to determine the influence of age on these variables. Fifteen rats were split into three age groups: young adult (3 months of age), aged (12-18 months) and geriatric (30 months). Following tissue harvest we used a μCT scanner to image the cervical and upper thoracic spine from each specimen. Analysis software was used to measure variables including canal pinch diameter (the most rostral point on the dorsal aspect of a vertebral body to the most caudal aspect of the lamina on the immediately rostral vertebra), vertebral canal depth, width, and area, vertebral body height, depth, width, and area, and intervertebral disc thickness. Orthopaedic surgeons used midsagittal images to rate the degenerative state of the intervertebral discs. For all measures except disc thickness there was a significant increase (mean (SD) = 15.0 (9.7)%) for the aged compared to young specimens (P < 0.05). There were significant differences between the aged and geriatric specimens for only vertebral body depth (P = 0.016) and area (P = 0.020). Intervertebral disc degeneration was significantly greater on the ventral aspect of the spinal column (P < 0.001), with a trend toward increased degeneration in the geriatric specimens (P = 0.069). The results suggest that age-related morphometric differences may need to be accounted for in experimental aging models of SCI in rats.
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Affiliation(s)
- Andrew C Laing
- Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Ontario, Canada.
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74
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Mao L, Wang H, Wang X, Liao H, Zhao X. Transcription factor Nrf2 protects the spinal cord from inflammation produced by spinal cord injury. J Surg Res 2011; 170:e105-15. [PMID: 21764072 DOI: 10.1016/j.jss.2011.05.049] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 05/15/2011] [Accepted: 05/25/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Inflammation plays an important role in the pathogenesis of secondary damage after spinal cord injury (SCI). Previous studies have suggested that nuclear factor-erythroid 2-related factor 2 (Nrf2), a pleiotropic transcription factor, may play a key role in modulating inflammation in a variety of experimental models. This study evaluated the neuroprotective role of Nrf2 in the inflammatory response after SCI in mice. MATERIALS AND METHODS Nrf2-deficient (Nrf2(-/-)) and wild-type (Nrf2(+/+)) mice spinal cord compression injury was induced by the application of vascular clips (force of 10 g) to the dura. Sulforaphane (SFN) was used to activate Nrf2 after SCI. Inflammatory cytokines, NF-κB activity, histologic injury score, dying neurons count in grey matter, water content of impaired spinal cord, and Basso open-field motor score (BMS) were assessed to determine the extent of SCI-mediated damage. RESULTS The results showed that SFN activated Nrf2 in impaired spinal cord tissue, improved hindlimb locomotor function assessed by BMS, reduced inflammatory damage, histologic injury, dying neurons count, and spinal cord edema caused by SCI. Nrf2(-/-) mice demonstrated more severe neurologic deficit and spinal cord edema after SCI and did not benefit from the protective effect of SFN. CONCLUSIONS Taken together, our results suggest that Nrf2 may represent a strategic target for SCI therapies.
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Affiliation(s)
- Lei Mao
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, PR China
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75
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Seifert JL, Bell JE, Elmer BB, Sucato DJ, Romero MI. Characterization of a novel bidirectional distraction spinal cord injury animal model. J Neurosci Methods 2011; 197:97-103. [PMID: 21334381 DOI: 10.1016/j.jneumeth.2011.02.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 01/17/2011] [Accepted: 02/06/2011] [Indexed: 11/26/2022]
Abstract
Scoliosis corrective surgery requires the application of significant multidirectional stress forces, including distraction, for correction of the curved spine deformity and the application of fixation rods. If excessive, spine distraction may result in the development of new neurological deficits, some as severe as permanent paralysis. Current animal models of spinal cord injury, however, are limited to contusion, transection, or unidirectional distraction injuries, which fail to replicate the multidirectional forces that occur during spine corrective surgery. To address such limitation, we designed a novel device that relies on intervertebral grip fixation and linear actuators to induce controllable bidirectional distraction injuries to the spine. The device was tested in three (i.e., 3, 5, and 7 mm) distention paradigms of the rat T9-T11 vertebra, and the resulting injuries were evaluated through electrophysiological, behavioral, and histological analysis. As expected, 3mm bilateral spine distractions showed no neurological deficit. In contrast, those with 5 and 7 mm showed partial and complete paralysis, respectively. The relationship between the severity of the spine distraction and injury to the spinal cord tissue was determined using glial fibrillary acidic protein immunocytochemistry for visualization of reactive astrocytes and labeling of ED1-positive activated macrophages/microglia. Our results demonstrate that this device can produce bidirectional spine distraction injuries with high precision and control and, thus, may be valuable in contributing to the testing of neuroprotective strategies aimed at preventing unintended new neurological damage during corrective spine surgery.
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Affiliation(s)
- J L Seifert
- Regenerative Neurobiology Laboratory, Joint Program of Bioengineering, University of Texas at Arlington, 701 South Nedderman Drive, Arlington, TX 76019, USA
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76
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Mao L, Wang HD, Pan H, Qiao L. Sulphoraphane enhances aquaporin-4 expression and decreases spinal cord oedema following spinal cord injury. Brain Inj 2011; 25:300-6. [PMID: 21280976 DOI: 10.3109/02699052.2010.542432] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND Aquaporin-4 (AQP4) is a water channel protein and it is an important determinant of outcome after brain injury. Sulphoraphane (SFN) increases AQP4 levels with reduction of brain oedema at 3 days post-traumatic brain injury. However, little is known about the effect of SFN on AQP4 expression and oedema after spinal cord injury (SCI). METHODS AND PROCEDURES The present study used a murine SCI model induced by compression injury. AQP4 protein level and mRNA level were detected by Western blot and by RT-PCR at 48 hours after SCI, respectively. In addition, immunohistochemical study was used to show AQP4 expression in the spinal cord segments and water content of the spinal cord segments were measured by wet?:?dry weight ratio. MAIN OUTCOMES AND RESULTS This study shows that AQP4 level was decreased in the injured spinal cord segments at 48 hours following SCI. Post-injury administration of SFN increased AQP4 levels, which was accompanied by a significant reduction in spinal cord segment oedema at 48 hours post-injury. CONCLUSION These findings suggest that the reduction of spinal cord oedema in response to SFN administration could be due, in part, to water clearance by AQP4 from the injured spinal cord segments.
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Affiliation(s)
- Lei Mao
- Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, Nanjing, Jiangsu Province, PR China
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77
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Weishaupt N, Silasi G, Colbourne F, Fouad K. Secondary damage in the spinal cord after motor cortex injury in rats. J Neurotrauma 2010; 27:1387-97. [PMID: 20515316 DOI: 10.1089/neu.2010.1346] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
When neurons within the motor cortex are fatally injured, their axons, many of which project into the spinal cord, undergo wallerian degeneration. Pathological processes occurring downstream of the cortical damage have not been extensively studied. We created a focal forelimb motor cortex injury in rats and found that axons from cell bodies located in the hindlimb motor cortex (spared by the cortical injury) become secondarily damaged in the spinal cord. To assess axonal degeneration in the spinal cord, we quantified silver staining in the corticospinal tract (CST) at 1 week and 4 weeks after the injury. We found a significant increase in silver deposition at the thoracic spinal cord level at 4 weeks compared to 1 week post-injury. At both time points, no degenerating neurons could be found in the hindlimb motor cortex. In a separate experiment, we showed that direct injury of neurons within the hindlimb motor cortex caused marked silver deposition in the thoracic CST at 1 week post-injury, and declined thereafter. Therefore, delayed axonal degeneration in the thoracic spinal cord after a focal forelimb motor cortex injury is indicative of secondary damage at the spinal cord level. Furthermore, immunolabeling of spinal cord sections showed that a local inflammatory response dominated by partially activated Iba-1-positive microglia is mounted in the CST, a viable mechanism to cause the observed secondary degeneration of fibers. In conclusion, we demonstrate that following motor cortex injury, wallerian degeneration of axons in the spinal cord leads to secondary damage, which is likely mediated by inflammatory processes.
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Affiliation(s)
- Nina Weishaupt
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
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78
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Disruption of Nrf2 enhances the upregulation of nuclear factor-kappaB activity, tumor necrosis factor-α, and matrix metalloproteinase-9 after spinal cord injury in mice. Mediators Inflamm 2010; 2010:238321. [PMID: 20862369 PMCID: PMC2938451 DOI: 10.1155/2010/238321] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 07/06/2010] [Accepted: 07/12/2010] [Indexed: 11/18/2022] Open
Abstract
Matrix metalloproteinase-9 (MMP-9) plays an important role in the acute periods of spinal cord injury (SCI), and its expression is related to the inflammation which could cause the disruption of the blood-spinal barrier (BBB). Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key transcription factor that plays a crucial role in cytoprotection against inflammation. The present study investigated the role of Nrf2 in upregulating of nuclear factor kappa B (NF-κB) activity, tumor necrosis factor-α (TNF-α), and MMP-9 after SCI. Wild-type Nrf2 (+/+) and Nrf2-deficient (Nrf (-/-)) mice were subjected to an SCI model induced by the application of vascular clips (force of 10 g) to the dura after a three-level T8-T10 laminectomy. We detected the wet/dry weight ratio of impaired spinal cord tissue, the activation of NF-κB, the mRNA and protein levels of TNF-α and MMP-9, and the enzyme activity of MMP-9. Nrf2 (-/-) mice were demonstrated to have more spinal cord edema, NF-κB activation, TNF-α production, and MMP-9 expression after SCI compared with the wild-type controls. The results suggest that Nrf2 may play an important role in limiting the upregulation of NF-κB activity, TNF-α, and MMP-9 in spinal cord after SCI.
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Wang Y, Ye Z, Hu X, Huang J, Luo Z. Morphological changes of the neural cells after blast injury of spinal cord and neuroprotective effects of sodium beta-aescinate in rabbits. Injury 2010; 41:707-16. [PMID: 20060971 DOI: 10.1016/j.injury.2009.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 11/24/2009] [Accepted: 12/08/2009] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Explosive blast neurotrauma is becoming more and more common not only in the military population but also in civilian life due to the ever-present threat of terrorism and accidents. However, little attention has been offered to the studies associated with blast wave-induced spinal cord injury in the literatures. The purpose of this study is to report a rabbit model of explosive blast injury to the spinal cord, to investigate the histological changes, focusing especially on apoptosis, and to reveal whether beta-aescinate (SA) has the neuroprotective effects against the blast injury. METHODS Adult male New Zealand white rabbits were randomly divided into sham group, experimental group and SA group. All rabbits except the sham group were exposed to the detonation, produced by the blast tube containing 0.7 g cyclotrimethylene trinitramine, with the mean peak overpressure of 50.4 MP focused on the dorsal surface of T9-T10 level. After evaluation of the neurologic function, spinal cord of the rabbits was removed at 8 h, 1, 3, 7, 14 or 30 days and the H&E staining, EM examination, DNA gel electrophoresis and TUNEL were progressively performed. RESULTS The study demonstrated the occurrence of both necrosis and apoptosis at the lesion site. Moreover, the SA therapy could not only improve the neurologic outcomes (P<0.05) but also reduce the loss of motoneuron and TUNEL-positive rate (P<0.05). CONCLUSIONS In the rabbit model of explosive blast injury to the spinal cord, the coexistent apoptotic and necrotic changes in cells was confirmed and the SA had neuroprotective effects to the blast injury of the spinal cord in rabbits. This is the first report in which the histological characteristics and drug treatment of the blast injury to the spinal cord is demonstrated.
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Affiliation(s)
- Yuqing Wang
- Institute of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Xi'an 710033, PR China
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80
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Treadmill running protects spinal cord contusion from secondary degeneration. Brain Res 2010; 1346:266-78. [PMID: 20513364 DOI: 10.1016/j.brainres.2010.05.070] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 05/18/2010] [Accepted: 05/24/2010] [Indexed: 11/22/2022]
Abstract
It is known that physical activity triggers changes in the central nervous system. Adult rats, trained on treadmills for 4 weeks, and a group of sedentary rats was submitted to contuse moderate spinal cord injury. A group of sedentary rats was submitted to a sham operation. The trained group continued running on treadmill after lesion for 4 weeks. Motor behavior evaluated by BBB score was smaller in the sedentary group compared to the trained rats by 7 days after lesion. Computerized activity monitor showed clear-cut differences in spontaneous motor parameters in trained rats only before lesion. After surgery, sedentary rats showed changes in motor parameters but not in later periods of analysis. Animals were euthanized by 28 days after surgery, and their spinal cords were processed for Nissl staining and immunohistochemistry. The number of the remaining neurons and the lesion areal and lesion volume fractions were obtained by stereological method. The number of the remaining neurons did not change after training. Lesion volume and lesion areal fraction per section were smaller in the trained group. Lesion index was more pronounced in the sedentary group. Microdensitometric image analysis demonstrated a microglial reaction, astroglial activation, and glial FGF-2 production more pronounced in the spinal cord of sedentary animals. GAP-43 was higher in caudal levels of contusion in the sedentary group. In conclusion, treadmill running may favor a better functional recovery in the acute period after spinal cord lesion and wound repair processes leading to neuroprotection.
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81
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Yan X, Liu J, Luo Z, Ding Q, Mao X, Yan M, Yang S, Hu X, Huang J, Luo Z. Proteomic profiling of proteins in rat spinal cord induced by contusion injury. Neurochem Int 2010; 56:971-83. [PMID: 20399821 DOI: 10.1016/j.neuint.2010.04.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Revised: 03/28/2010] [Accepted: 04/09/2010] [Indexed: 01/05/2023]
Abstract
It is widely accepted that mechanical injury to spinal cord can cause nervous system dysfunction, which leads to the loss of movement and sensation. However, the exact molecular mechanism is currently unclear. In this study, contused rat spinal cords were collected at 8h, 1 day, 3, and 5 days after injury and the expression patterns of the proteins were monitored and quantified with two-dimensional gel electrophoresis-based proteomics. Fifty-one protein spots showed significant regulation at least at one time point. Of the 39 proteins, identified by mass spectrometry analysis and clustered into three down-regulation profiles and two up-regulation profiles, eight contusion-related proteins have been reported in previous proteomic studies of spinal cord whereas 31 proteins were described for the first time. For example, apoptosis-related protein of heat shock 70 kDa protein 1B increased after contusion, reaching the peak at 1 day; septin 7, a protein involved in cytoskeleton organization, maintained a steady increase for the first 5 days after injury; metabolism-related protein of 3-hydroxy-3-methylglutaryl-Coenzyme A synthase 1 was constantly down-regulated during the whole time course observed; tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, epsilon polypeptide, associated with cell cycle progression, showed a gradual increase after contusion. To our knowledge, this is the first case of detailed and dynamic proteomic snapshots of contusion-induced spinal cord injury. Most of the identified proteins were found for the first time to be differentially expressed after spinal cord contusion, which may help explore the complex molecular cascades underlying the progressive pathologic changes in the contused spinal cord.
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Affiliation(s)
- Xiaodong Yan
- Institute of Orthopaedics, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China
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