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Barretto TA, Tetzlaff W, Illes J. Ethics and accountability for clinical trials. Spinal Cord 2024; 62:192-194. [PMID: 38499760 PMCID: PMC11003861 DOI: 10.1038/s41393-024-00980-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/27/2024] [Accepted: 03/07/2024] [Indexed: 03/20/2024]
Abstract
In May 2023, a disclaimer posted on ClinicalTrials.gov dismisses accountability for the accuracy of registered information. For spinal cord injury, inconsistencies in intervention classification, phase designation, and lack of study protocols and results threaten the integrity of the database and put users at risk. An investment in what the resource should be rather than what it is not will give it the authority commensurate with the requirements for its regulatory use and informed decision-making for prospective trial participants.
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Affiliation(s)
- Tanya A Barretto
- Neuroethics Canada, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Judy Illes
- Neuroethics Canada, Division of Neurology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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2
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Mattucci S, Speidel J, Liu J, Tetzlaff W, Oxland TR. Temporal Progression of Acute Spinal Cord Injury Mechanisms in a Rat Model: Contusion, Dislocation, and Distraction. J Neurotrauma 2021; 38:2103-2121. [PMID: 33820470 DOI: 10.1089/neu.2020.7255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Traumatic spinal cord injuries (SCIs) occur due to different spinal column injury patterns, including burst fracture, dislocation, and flexion-distraction. Pre-clinical studies modeling different SCI mechanisms have shown distinct histological differences between these injuries both acutely (3 h and less) and chronically (8 weeks), but there remains a temporal gap. Different rates of injury progression at specific regions of the spinal cord may provide insight into the pathologies that are initiated by specific SCI mechanisms. Therefore, the objective of this study was to evaluate the temporal progression of injury at specific tracts within the white matter, for time-points of 3 h, 24 h, and 7 days, for three distinct SCI mechanisms. In this study, 96 male Sprague Dawley rats underwent one of three SCI mechanisms: contusion, dislocation, or distraction. Animals were sacrificed at one of three times post-injury: 3 h, 24 h, or 7 days. Histological analysis using eriochrome cyanide and immunostaining for MBP, SMI-312, neurofilament-H (NF-H), and β-III tubulin were used to characterize white matter sparing and axon and myelinated axon counts. The regions analyzed were the gracile fasciculus, cuneate fasciculus, dorsal corticospinal tract, and ventrolateral white matter. Contusion, dislocation, and distraction SCIs demonstrated distinct damage patterns that progressed differently over time. Myelinated axon counts were significantly reduced after dislocation and contusion injuries in most locations and time-points analyzed (compared with sham). This indicates early myelin damage often within 3 h. Myelinated axon counts after distraction dropped early and did not demonstrate any significant progression over the next 7 days. Important differences in white matter degeneration were identified between injury types, with distraction injuries showing the least variability across time-points These findings and the observation that white matter injury occurs early, and in many cases, without much dynamic change, highlight the importance of injury type in SCI research-both clinically and pre-clinically.
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Affiliation(s)
- Stephen Mattucci
- Department of Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jason Speidel
- Department of Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas R Oxland
- Department of Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
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3
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Moulson AJ, Squair JW, Franklin RJM, Tetzlaff W, Assinck P. Diversity of Reactive Astrogliosis in CNS Pathology: Heterogeneity or Plasticity? Front Cell Neurosci 2021; 15:703810. [PMID: 34381334 PMCID: PMC8349991 DOI: 10.3389/fncel.2021.703810] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/02/2021] [Indexed: 01/02/2023] Open
Abstract
Astrocytes are essential for the development and homeostatic maintenance of the central nervous system (CNS). They are also critical players in the CNS injury response during which they undergo a process referred to as "reactive astrogliosis." Diversity in astrocyte morphology and gene expression, as revealed by transcriptional analysis, is well-recognized and has been reported in several CNS pathologies, including ischemic stroke, CNS demyelination, and traumatic injury. This diversity appears unique to the specific pathology, with significant variance across temporal, topographical, age, and sex-specific variables. Despite this, there is limited functional data corroborating this diversity. Furthermore, as reactive astrocytes display significant environmental-dependent plasticity and fate-mapping data on astrocyte subsets in the adult CNS is limited, it remains unclear whether this diversity represents heterogeneity or plasticity. As astrocytes are important for neuronal survival and CNS function post-injury, establishing to what extent this diversity reflects distinct established heterogeneous astrocyte subpopulations vs. environmentally dependent plasticity within established astrocyte subsets will be critical for guiding therapeutic development. To that end, we review the current state of knowledge on astrocyte diversity in the context of three representative CNS pathologies: ischemic stroke, demyelination, and traumatic injury, with the goal of identifying key limitations in our current knowledge and suggesting future areas of research needed to address them. We suggest that the majority of identified astrocyte diversity in CNS pathologies to date represents plasticity in response to dynamically changing post-injury environments as opposed to heterogeneity, an important consideration for the understanding of disease pathogenesis and the development of therapeutic interventions.
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Affiliation(s)
- Aaron J. Moulson
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
| | - Jordan W. Squair
- Department of Clinical Neuroscience, Faculty of Life Sciences, Center for Neuroprosthetics and Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), NeuroRestore, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Robin J. M. Franklin
- Wellcome Trust - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Peggy Assinck
- Wellcome Trust - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, United Kingdom
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4
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Yarar-Fisher C, Li J, Womack ED, Alharbi A, Seira O, Kolehmainen KL, Plunet WT, Alaeiilkhchi N, Tetzlaff W. Ketogenic regimens for acute neurotraumatic events. Curr Opin Biotechnol 2021; 70:68-74. [PMID: 33445134 DOI: 10.1016/j.copbio.2020.12.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/14/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022]
Abstract
Dietary modification would be the most translatable, cost-efficient, and, likely, the safest approach available that can reduce the reliance on pharmaceutical treatments for treating acute or chronic neurological disorders. A wide variety of evidence suggests that the ketogenic diet (KD) could have beneficial effects in acute traumatic events, such as spinal cord injury and traumatic brain injury. Review of existing human and animal studies revealed that KD can improve motor neuro-recovery, gray matter sparing, pain thresholds, and neuroinflammation and decrease depression. Although the exact mechanism by which the KD provides neuroprotection is not fully understood, its effects on cellular energetics, mitochondria function and inflammation are likely to have a role.
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Affiliation(s)
- Ceren Yarar-Fisher
- Department of Physical Medicine and Rehabilitation, School of Medicine, The University of Alabama at Birmingham, USA.
| | - Jia Li
- Department of Physical Medicine and Rehabilitation, School of Medicine, The University of Alabama at Birmingham, USA
| | - Erika D Womack
- Department of Physical Medicine and Rehabilitation, School of Medicine, The University of Alabama at Birmingham, USA
| | - Amal Alharbi
- Department of Physical Medicine and Rehabilitation, School of Medicine, The University of Alabama at Birmingham, USA; Graduate Program in School of Health Professions, The University of Alabama at Birmingham, 1716 9th Avenue South Birmingham, AL 35294, USA
| | - Oscar Seira
- International Collaboration on Repair Discoveries, University of British Columbia, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada; Department of Zoology, University of British Columbia, 4200 - 6270 University Blvd, Vancouver, BC V6T 1Z4, Canada
| | - Kathleen L Kolehmainen
- International Collaboration on Repair Discoveries, University of British Columbia, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada; Graduate Program in Biochemistry and Molecular Biology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada
| | - Ward T Plunet
- International Collaboration on Repair Discoveries, University of British Columbia, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada
| | - Nima Alaeiilkhchi
- International Collaboration on Repair Discoveries, University of British Columbia, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada; Graduate Program in Neuroscience, University of British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada
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Assinck P, Sparling JS, Dworski S, Duncan GJ, Wu DL, Liu J, Kwon BK, Biernaskie J, Miller FD, Tetzlaff W. Transplantation of Skin Precursor-Derived Schwann Cells Yields Better Locomotor Outcomes and Reduces Bladder Pathology in Rats with Chronic Spinal Cord Injury. Stem Cell Reports 2020; 15:140-155. [PMID: 32559459 PMCID: PMC7363874 DOI: 10.1016/j.stemcr.2020.05.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/20/2022] Open
Abstract
Cell transplantation for spinal cord injury (SCI) has largely been studied in sub-acute settings within 1–2 weeks of injury. In contrast, here we transplanted skin-derived precursors differentiated into Schwann cells (SKP-SCs) into the contused rat spinal cord 8 weeks post-injury (wpi). Twenty-one weeks later (29 wpi), SKP-SCs were found to have survived transplantation, integrated with host tissue, and mitigated the formation of a dense glial scar. Furthermore, transplanted SKP-SCs filled much of the lesion sites and greatly enhanced the presence of endogenous SCs, which myelinated thousands of sprouting/spared host axons in and around the injury site. In addition, SKP-SC transplantation improved locomotor outcomes and decreased pathological thickening of bladder wall. To date, functional improvements have very rarely been observed with cell transplantation beyond the sub-acute stage of injury. Hence, these findings indicate that skin-derived SCs are a promising candidate cell type for the treatment of chronic SCI. SKP-SCs injected 8 weeks after SCI survive long-term and integrate with host tissue SKP-SC transplants boosted the presence of endogenous SCs in the chronic SCI site Treated spinal cords showed enhanced growth and SC myelination of axons Treated rats displayed better locomotor outcomes with reduced bladder pathologies
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Affiliation(s)
- Peggy Assinck
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada
| | - Joseph S Sparling
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Graduate Program in Neuroscience, University of British Columbia, Vancouver, BC, Canada; Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Shaalee Dworski
- Neuroscience and Mental Health Program, Hospital for Sick Children, Toronto, ON, Canada
| | - Greg J Duncan
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Di L Wu
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Department of Orthopaedics, University of British Columbia, Vancouver, BC, Canada
| | - Jeff Biernaskie
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada; Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada; Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Freda D Miller
- Neuroscience and Mental Health Program, Hospital for Sick Children, Toronto, ON, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada; Department of Zoology, University of British Columbia, Vancouver, BC, Canada; Department of Surgery, University of British Columbia, Vancouver, BC, Canada.
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6
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Liu J, Li R, Huang Z, Huang Z, Li Y, Wu X, Lin J, Jiang H, Cheng Y, Kong G, Wu X, Liu Q, Liu Y, Yang Z, Li R, Chen J, Fu J, Ramer MS, Kwon BK, Liu J, Kramer JLK, Tetzlaff W, Hu Y, Zhu Q. A Cervical Spinal Cord Hemi-Contusion Injury Model Based on Displacement Control in Non-Human Primates (Macaca fascicularis). J Neurotrauma 2020; 37:1669-1686. [PMID: 32174266 DOI: 10.1089/neu.2019.6822] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Non-human primate (NHP) spinal cord injury (SCI) models can be informative in the evaluation of treatments that show promise in rodent models prior to translation to humans. In the present study, we aimed to establish a cervical spinal hemi-contusion model with controlled displacement and evaluate the abnormalities in behavior, electrophysiology, histology, and magnetic resonance imaging. Twelve adult NHPs were divided into an SCI group (n = 8, 24 and 48 weeks) and a control group (n = 4). An impactor (Φ = 4 mm) was driven to compress the left C5 cord at 800 mm/sec. The contusion displacement and peak force was 4.08 ± 0.17 mm and 19.8 ± 4.6 N. The behavioral assessment showed a consistent dysfunction below the wrist and spontaneous recovery of limb function after injury. Lesion length and lesion area at the epicenter based on T2 hyperintensity were 5.68 ± 0.47 mm and 5.99 ± 0.24 mm2 at 24 weeks post-injury (wpi), and 5.29 ± 0.17 mm and 5.95 ± 0.24 mm2 at 48 wpi. The spared spinal cord area immuno-positive for glial fibrillary acidic protein was significantly reduced, while the staining intensity increased at 24 wpi and 48 wpi, compared with the sham group. Ipsilateral somatosensory and motor evoked potentials were dynamic, increasing in latency and decreasing in amplitude compared with pre-operative values or the contralateral values, and correlated to varying degrees with behavioral outcomes. A shift in size-frequency distribution of sensory neurons of the dorsal root ganglia (DRG) was consistent with a loss of large-diameter cells. The present study demonstrated that the NHP SCI model resulted in consistent unilateral limb dysfunction and potential plasticity in the face of loss of spinal cord and DRG tissue.
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Affiliation(s)
- Junhao Liu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Rong Li
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zucheng Huang
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhiping Huang
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yuefeng Li
- Guangdong Landau Biotechnology Co. Ltd., Guangzhou, China
| | - Xiaoliang Wu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Junyu Lin
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Hui Jiang
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yongquan Cheng
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ganggang Kong
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiuhua Wu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Qi Liu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yapu Liu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhou Yang
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ruoyao Li
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jianting Chen
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Joey Fu
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matt S Ramer
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, University of British Columbia, Vancouver, British Columbia, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, University of British Columbia, Vancouver, British Columbia, Canada
| | - John L K Kramer
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yong Hu
- Department of Orthopedics and Traumatology, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong, China
| | - Qingan Zhu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
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Rawji KS, Young AMH, Ghosh T, Michaels NJ, Mirzaei R, Kappen J, Kolehmainen KL, Alaeiilkhchi N, Lozinski B, Mishra MK, Pu A, Tang W, Zein S, Kaushik DK, Keough MB, Plemel JR, Calvert F, Knights AJ, Gaffney DJ, Tetzlaff W, Franklin RJM, Yong VW. Niacin-mediated rejuvenation of macrophage/microglia enhances remyelination of the aging central nervous system. Acta Neuropathol 2020; 139:893-909. [PMID: 32030468 PMCID: PMC7181452 DOI: 10.1007/s00401-020-02129-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/19/2020] [Accepted: 01/23/2020] [Indexed: 12/17/2022]
Abstract
Remyelination following CNS demyelination restores rapid signal propagation and protects axons; however, its efficiency declines with increasing age. Both intrinsic changes in the oligodendrocyte progenitor cell population and extrinsic factors in the lesion microenvironment of older subjects contribute to this decline. Microglia and monocyte-derived macrophages are critical for successful remyelination, releasing growth factors and clearing inhibitory myelin debris. Several studies have implicated delayed recruitment of macrophages/microglia into lesions as a key contributor to the decline in remyelination observed in older subjects. Here we show that the decreased expression of the scavenger receptor CD36 of aging mouse microglia and human microglia in culture underlies their reduced phagocytic activity. Overexpression of CD36 in cultured microglia rescues the deficit in phagocytosis of myelin debris. By screening for clinically approved agents that stimulate macrophages/microglia, we have found that niacin (vitamin B3) upregulates CD36 expression and enhances myelin phagocytosis by microglia in culture. This increase in myelin phagocytosis is mediated through the niacin receptor (hydroxycarboxylic acid receptor 2). Genetic fate mapping and multiphoton live imaging show that systemic treatment of 9-12-month-old demyelinated mice with therapeutically relevant doses of niacin promotes myelin debris clearance in lesions by both peripherally derived macrophages and microglia. This is accompanied by enhancement of oligodendrocyte progenitor cell numbers and by improved remyelination in the treated mice. Niacin represents a safe and translationally amenable regenerative therapy for chronic demyelinating diseases such as multiple sclerosis.
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Affiliation(s)
- Khalil S Rawji
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Adam M H Young
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Tanay Ghosh
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Nathan J Michaels
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Reza Mirzaei
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Janson Kappen
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | | | | | - Brian Lozinski
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Manoj K Mishra
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Annie Pu
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Weiwen Tang
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Salma Zein
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | - Deepak K Kaushik
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada
| | | | | | - Fiona Calvert
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
| | | | | | | | - Robin J M Franklin
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - V Wee Yong
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive, Calgary, AB, T2N 4N1, Canada.
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8
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Seira O, Wang W, Lee S, Roskams J, Tetzlaff W. HDAC inhibition leads to age-dependent opposite regenerative effect upon PTEN deletion in rubrospinal axons after SCI. Neurobiol Aging 2020; 90:99-109. [PMID: 32171589 DOI: 10.1016/j.neurobiolaging.2020.02.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/05/2020] [Accepted: 02/09/2020] [Indexed: 01/26/2023]
Abstract
Epigenetic changes associated with aging have been linked to functional and cognitive deficits in the adult CNS. Histone acetylation is involved in the control of the transcription of plasticity and regeneration-associated genes. The intrinsic axon growth capacity in the CNS is negatively regulated by phosphatase and tensin homolog (Pten). Inhibition of Pten is an effective method to stimulate axon growth following an injury to the optic nerve, corticospinal tract (CST), and rubrospinal tract (RST). Our laboratory has previously demonstrated that the deletion of Pten in aged animals diminishes the regenerative capacity in rubrospinal neurons. We hypothesize that changes in the chromatin structure might contribute to this age-associated decline. Here, we assessed whether Trichostatin A (TSA), a histone deacetylases (HDACs) inhibitor, reverses the decline in regeneration in aged Ptenf/f mice. We demonstrate that HDAC inhibition induces changes in the expression of GAP43 in both young and aged Ptenf/f mice. The regenerative capacity of the RST did not improve significantly in young mice, neither their motor function on the horizontal ladder or cylinder test after TSA treatment for 7 days. Interestingly, TSA treatment in the aged mice worsened their motor function deficits, suggesting that the systemic treatment with TSA might have an overall adverse effect on motor recovery after SCI in aged animals.
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Affiliation(s)
- Oscar Seira
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada; Department of Zoology, University of British Columbia (UBC), Vancouver, British Columbia, Canada.
| | - Wenchun Wang
- Department of Rehabilitation, Chengdu Military General Hospital, Chengdu, Sichuan, China
| | - Sharon Lee
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Jane Roskams
- Life Sciences Centre and Center for Brain Health, University of British Columbia (UBC), Vancouver, British Columbia, Canada; Neurosurgery University of Washington, Seattle, WA, USA
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada; Department of Zoology, University of British Columbia (UBC), Vancouver, British Columbia, Canada; Department of Surgery, University of British Columbia (UBC), Vancouver, British Columbia, Canada
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9
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Fouad K, Bixby JL, Callahan A, Grethe JS, Jakeman LB, Lemmon VP, Magnuson DS, Martone ME, Nielson JL, Schwab JM, Taylor-Burds C, Tetzlaff W, Torres-Espin A, Ferguson AR. FAIR SCI Ahead: The Evolution of the Open Data Commons for Pre-Clinical Spinal Cord Injury Research. J Neurotrauma 2020; 37:831-838. [PMID: 31608767 PMCID: PMC7071068 DOI: 10.1089/neu.2019.6674] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Over the last 5 years, multiple stakeholders in the field of spinal cord injury (SCI) research have initiated efforts to promote publications standards and enable sharing of experimental data. In 2016, the National Institutes of Health/National Institute of Neurological Disorders and Stroke hosted representatives from the SCI community to streamline these efforts and discuss the future of data sharing in the field according to the FAIR (Findable, Accessible, Interoperable and Reusable) data stewardship principles. As a next step, a multi-stakeholder group hosted a 2017 symposium in Washington, DC entitled "FAIR SCI Ahead: the Evolution of the Open Data Commons for Spinal Cord Injury research." The goal of this meeting was to receive feedback from the community regarding infrastructure, policies, and organization of a community-governed Open Data Commons (ODC) for pre-clinical SCI research. Here, we summarize the policy outcomes of this meeting and report on progress implementing these policies in the form of a digital ecosystem: the Open Data Commons for Spinal Cord Injury (ODC-SCI.org). ODC-SCI enables data management, harmonization, and controlled sharing of data in a manner consistent with the well-established norms of scholarly publication. Specifically, ODC-SCI is organized around virtual "laboratories" with the ability to share data within each of three distinct data-sharing spaces: within the laboratory, across verified laboratories, or publicly under a creative commons license (CC-BY 4.0) with a digital object identifier that enables data citation. The ODC-SCI implements FAIR data sharing and enables pooled data-driven discovery while crediting the generators of valuable SCI data.
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Affiliation(s)
- Karim Fouad
- Address correspondence to: Karim Fouad, PhD, Faculty of Rehabilitation Medicine and Institute for Neuroscience and Mental Health, University of Alberta, 3-87 Corbett Hall, Edmonton, Alberta T6E 2G4, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | - Adam R. Ferguson
- Adam R. Ferguson, PhD, Department of Neurological Surgery, Brain and Spinal Injury Center, University of California San Francisco, 1001 Potrero Avenue [4M39], San Francisco, CA 94110
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10
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Speidel J, Mattucci S, Liu J, Kwon BK, Tetzlaff W, Oxland TR. Effect of Velocity and Duration of Residual Compression in a Rat Dislocation Spinal Cord Injury Model. J Neurotrauma 2020; 37:1140-1148. [PMID: 31950856 DOI: 10.1089/neu.2019.6747] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Early decompression of the traumatically injured and persistently compressed spinal cord is intuitively beneficial for neurological outcome. Despite considerable pre-clinical evidence of a neurological benefit to early decompression, the effect of early surgical decompression in clinical spinal cord injury (SCI) remains less clear. The discrepancy between pre-clinical and clinical results may be due to differences between the biomechanical variables used in pre-clinical animal models and the biomechanical conditions occurring in clinical injuries. These pre-clinical variables include region of spinal cord, velocity of impact, and injury mechanism. In this study, the effect of velocity and duration of residual compression on injury severity were evaluated using a novel, rodent model of cervical dislocation SCI. Fifty-two male Sprague-Dawley rats were included in five groups: two timings of decompression (24 min, 240 min), two velocities (10 mm/sec, 500 mm/sec), and a sham group. All injuries involved a 1.45-mm dorsal dislocation of the C6 vertebra relative to C5 with subsequent residual compression of 0.8 mm. Animals were evaluated for motor function using the Martinez open field, grip strength, and grooming tests for 6 weeks post-injury. Immunohistochemistry and histology following sacrifice were conducted with counts for NeuN- and choline acetyltransferase (ChAT)-positive neurons, and length of cavitation. Behavioral testing and histological analysis revealed that injuries induced by the high velocity were consistently more severe than those induced by the low velocity, with behavioral correlations ranging between 0.46 and 0.58 (p < 0.05). Longer duration of residual compression did not produce significantly more severe injuries as measured by functional tests and histology. These findings demonstrate that the velocity of the initial traumatic impact may be a more important factor than duration of residual compression in determining SCI severity in a dislocation model of SCI.
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Affiliation(s)
- Jason Speidel
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.,Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Stephen Mattucci
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.,Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- 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.,Department of Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.,Departments of Zoology and Surgery, University of British Columbia, Vancouver, British Columbia, Canada
| | - Thomas R Oxland
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada.,Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada
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11
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Tan BT, Jiang H, Moulson AJ, Wu XL, Wang WC, Liu J, Plunet WT, Tetzlaff W. Neuroprotective effects of a ketogenic diet in combination with exogenous ketone salts following acute spinal cord injury. Neural Regen Res 2020; 15:1912-1919. [PMID: 32246640 PMCID: PMC7513973 DOI: 10.4103/1673-5374.280327] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
We have previously shown that induction of ketosis by ketogenic diet (KD) conveyed neuroprotection following spinal cord injury in rodent models, however, clinical translation may be limited by the slow raise of ketone levels when applying KD in the acute post-injury period. Thus we investigated the use of exogenous ketone supplementation (ketone sodium, KS) combined with ketogenic diet as a means rapidly inducing a metabolic state of ketosis following spinal cord injury in adult rats. In uninjured rats, ketone levels increased more rapidly than those in rats with KD alone and peaked at higher levels than we previously demonstrated for the KD in models of spinal cord injury. However, ketone levels in KD + KS treated rats with SCI did not exceed the previously observed levels in rats treated with KD alone. We still demonstrated neuroprotective effects of KD + KS treatment that extend our previous neuroprotective observations with KD only. The results showed increased neuronal and axonal sparing in the dorsal corticospinal tract. Also, better performance of forelimb motor abilities were observed on the Montoya staircase (for testing food pellets reaching) at 4 and 6 weeks post-injury and rearing in a cylinder (for testing forelimb usage) at 6 and 8 weeks post-injury. Taken together, the findings of this study add to the growing body of work demonstrating the potential benefits of inducing ketosis following neurotrauma. Ketone salt combined with a ketogenic diet gavage in rats with acute spinal cord injury can rapidly increase ketone body levels in the blood and promote motor function recovery. This study was approved by the Animal Care Committee of the University of British Columbia (protocol No. A14-350) on August 31, 2015.
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Affiliation(s)
- Bo-Tao Tan
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China; International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Hui Jiang
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada; Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Aaron J Moulson
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center; Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Xiao-Liang Wu
- Department of Spinal Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - Wen-Chun Wang
- Department of Rehabilitation Medicine, The General Hospital of Western Theater Command PLA, Chengdu, Sichuan Province, China
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center; Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ward T Plunet
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center; Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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12
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Duncan GJ, Manesh SB, Hilton BJ, Assinck P, Plemel JR, Tetzlaff W. The fate and function of oligodendrocyte progenitor cells after traumatic spinal cord injury. Glia 2019; 68:227-245. [PMID: 31433109 DOI: 10.1002/glia.23706] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 07/24/2019] [Accepted: 08/01/2019] [Indexed: 12/27/2022]
Abstract
Oligodendrocyte progenitor cells (OPCs) are the most proliferative and dispersed population of progenitor cells in the adult central nervous system, which allows these cells to rapidly respond to damage. Oligodendrocytes and myelin are lost after traumatic spinal cord injury (SCI), compromising efficient conduction and, potentially, the long-term health of axons. In response, OPCs proliferate and then differentiate into new oligodendrocytes and Schwann cells to remyelinate axons. This culminates in highly efficient remyelination following experimental SCI in which nearly all intact demyelinated axons are remyelinated in rodent models. However, myelin regeneration comprises only one role of OPCs following SCI. OPCs contribute to scar formation after SCI and restrict the regeneration of injured axons. Moreover, OPCs alter their gene expression following demyelination, express cytokines and perpetuate the immune response. Here, we review the functional contribution of myelin regeneration and other recently uncovered roles of OPCs and their progeny to repair following SCI.
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Affiliation(s)
- Greg J Duncan
- Department of Neurology, Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, Oregon
| | - Sohrab B Manesh
- Graduate Program in Neuroscience, International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada
| | - Brett J Hilton
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Bonn, Germany
| | - Peggy Assinck
- MRC Centre for Regenerative Medicine, University of Edinburgh, Edinburgh, UK
| | - Jason R Plemel
- Department of Medicine, Division of Neurology, Neuroscience and Mental Health Institute, University of Alberta, Calgary, Alberta, Canada
| | - Wolfram Tetzlaff
- Graduate Program in Neuroscience, International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), Vancouver, British Columbia, Canada.,Departments of Zoology and Surgery, University of British Columbia, Vancouver, British Columbia, Canada
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13
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Mattucci S, Speidel J, Liu J, Ramer MS, Kwon BK, Tetzlaff W, Oxland TR. Development of a traumatic cervical dislocation spinal cord injury model with residual compression in the rat. J Neurosci Methods 2019; 322:58-70. [PMID: 30951755 DOI: 10.1016/j.jneumeth.2019.03.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 03/12/2019] [Accepted: 03/15/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Preclinical spinal cord injury models do not represent the wide range of biomechanical factors seen in human injuries, such as spinal level, injury mechanism, velocity of spinal cord impact, and residual compression. These factors may be responsible for differences observed between experimental and clinical study results, especially related to the controversial issue of timing of surgical decompression. NEW METHOD Somatosensory Evoked Potentials were used to: a) characterize residual compression depths in a dislocation model, and b) evaluate the physiological effect of whether or not the spinal cord was decompressed following the initial injury, prior to the application of residual compression. Modifications to vertebral clamps and the development of a novel surgical frame allowed us to conduct surgical and injury procedures in a controlled manner without the risk of additional damage to the spinal cord. Behavioural outcomes were evaluated following varying dislocation displacements, in addition to the survivability of 4 h of residual compression following a traumatic injury. RESULTS Residual compression immediately following the initial dislocation demonstrated significantly different electrophysiological response compared to when the residual compression was delayed. COMPARISON WITH EXISTING METHOD There are currently no other residual compression models that utilize a dislocation injury mechanism. Many residual compression studies have demonstrated the effectiveness of early decompression, however the compression of the spinal cord is often not representative of clinical traumatic injuries. Preclinical studies typically model residual compression using a sustained force through quasi-static application, when human injuries often occur at high velocities, followed by a sustained displacement occlusion of the spinal canal. CONCLUSIONS This study has validated several novel procedural approaches and injury parameters, and provided critical details to implement in the development of a traumatic cervical dislocation SCI model with residual compression.
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Affiliation(s)
- Stephen Mattucci
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Jason Speidel
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Matt S Ramer
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
| | - Thomas R Oxland
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
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14
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Erskine E, Tetzlaff W, Plunet W, Salterio N, Smaila B, Kramer J, Ramer M. Following unilateral spinal contusion pregabalin has an at‐time effect on pruritus and a protective effect on mechanosensory nociception, but does not improve ipsilateral motor outcomes with early administration in rats. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.450.4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Erin Erskine
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
- Department of Cell and Developmental BiologyUniversity of British ColumbiaVancouverBCCanada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
- Department of ZoologyUniversity of British ColumbiaVancouverBCCanada
| | - Ward Plunet
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
| | - Nicholas Salterio
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
| | - Brittney Smaila
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
- Department of ZoologyUniversity of British ColumbiaVancouverBCCanada
| | - John Kramer
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
- School of KinesiologyUniversity of British ColumbiaVancouverBCCanada
| | - Matthew Ramer
- International Collaboration on Repair Discovery (ICORD)University of British ColumbiaVancouverBCCanada
- Department of ZoologyUniversity of British ColumbiaVancouverBCCanada
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15
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Mattucci S, Speidel J, Liu J, Kwon BK, Tetzlaff W, Oxland TR. Basic biomechanics of spinal cord injury - How injuries happen in people and how animal models have informed our understanding. Clin Biomech (Bristol, Avon) 2019; 64:58-68. [PMID: 29685426 DOI: 10.1016/j.clinbiomech.2018.03.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 02/05/2018] [Accepted: 03/24/2018] [Indexed: 02/07/2023]
Abstract
The wide variability, or heterogeneity, in human spinal cord injury is due partially to biomechanical factors. This review summarizes our current knowledge surrounding the patterns of human spinal column injury and the biomechanical factors affecting injury. The biomechanics of human spinal injury is studied most frequently with human cadaveric models and the features of the two most common injury patterns, burst fracture and fracture dislocation, are outlined. The biology of spinal cord injury is typically studied with animal models and the effects of the most relevant biomechanical factors - injury mechanism, injury velocity, and residual compression, are described. Tissue damage patterns and behavioural outcomes following dislocation or distraction injury mechanisms differ from the more commonly used contusion mechanism. The velocity of injury affects spinal cord damage, principally in the white matter. Ongoing, or residual compression after the initial impact does affect spinal cord damage, but few models exist that replicate the clinical scenario. Future research should focus on the effects of these biomechanical factors in different preclinical animal models as recent data suggests that treatment outcomes may vary between models.
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Affiliation(s)
- Stephen Mattucci
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC V6T 1Z4, Canada
| | - Jason Speidel
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC V6T 1Z4, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Department of Orthopaedics, University of British Columbia, 910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Departments of Zoology and Surgery, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada
| | - Thomas R Oxland
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada; Department of Mechanical Engineering, University of British Columbia, 6250 Applied Science Lane, Vancouver, BC V6T 1Z4, Canada; Department of Orthopaedics, University of British Columbia, 910 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada.
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16
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Squair JW, Ruiz I, Phillips AA, Zheng MM, Sarafis ZK, Sachdeva R, Gopaul R, Liu J, Tetzlaff W, West CR, Krassioukov AV. Minocycline Reduces the Severity of Autonomic Dysreflexia after Experimental Spinal Cord Injury. J Neurotrauma 2018; 35:2861-2871. [DOI: 10.1089/neu.2018.5703] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Affiliation(s)
- Jordan W. Squair
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- MD/PhD Training Program, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ian Ruiz
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aaron A. Phillips
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mei M.Z. Zheng
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zoe K. Sarafis
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rahul Sachdeva
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rayshad Gopaul
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Zoology, Faculty of Science, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Christopher R. West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrei V. Krassioukov
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
- GF Strong Rehabilitation Centre, Vancouver Health Authority, Vancouver, British Columbia, Canada
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17
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Lucas E, Whyte T, Liu J, Russell C, Tetzlaff W, Cripton PA. High-Speed Fluoroscopy to Measure Dynamic Spinal Cord Deformation in an In Vivo Rat Model. J Neurotrauma 2018; 35:2572-2580. [PMID: 29786472 DOI: 10.1089/neu.2017.5478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Although spinal cord deformation is thought to be a predictor of injury severity, few researchers have investigated dynamic cord deformation, in vivo, during impact. This is needed to establish correlations among impact parameters, internal cord deformation, and histological and functional outcomes. Relying on surface deformations alone may not sufficiently represent spinal cord deformation. The objective of this study was to develop a high-speed fluoroscopic method of tracking the surface and internal cord deformations of rat spinal cord during experimental cord injury. Two radio-opaque beads were injected into the cord at C5/6 in the dorsal and ventral white matter. Four additional beads were glued to the surface of the cord. Dynamic bead displacement was tracked during a dorsal impact (130 mm/sec, 1 mm depth) by high-speed radiographic imaging at 3000 FPS, laterally. The internal spinal cord beads displaced significantly more than the surface beads in the ventral direction (1.1-1.9 times) and more than most surface beads in the cranial direction (1.2-1.5 times). The dorsal beads (internal and surface) displaced more than the ventral beads during all impacts. The bead displacement pattern implies that the spinal cord undergoes complex internal and surface deformations during impact. Residual displacement of the internal beads was significantly greater than that of the surface beads in the cranial-caudal direction but not the dorsoventral direction. Finite element simulation confirmed that the additional bead mass likely had little effect on the internal cord deformations. These results support the merit of this technique for measuring in vivo spinal cord deformation.
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Affiliation(s)
- Erin Lucas
- 1 Orthopaedic Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and the School of Biomedical Engineering, The University of British Columbia , Vancouver, British Columbia, Canada .,2 International Collaboration on Repair Discoveries (ICORD), The University of British Columbia , Vancouver, British Columbia, Canada
| | - Thomas Whyte
- 1 Orthopaedic Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and the School of Biomedical Engineering, The University of British Columbia , Vancouver, British Columbia, Canada .,2 International Collaboration on Repair Discoveries (ICORD), The University of British Columbia , Vancouver, British Columbia, Canada
| | - Jie Liu
- 2 International Collaboration on Repair Discoveries (ICORD), The University of British Columbia , Vancouver, British Columbia, Canada
| | - Colin Russell
- 1 Orthopaedic Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and the School of Biomedical Engineering, The University of British Columbia , Vancouver, British Columbia, Canada .,2 International Collaboration on Repair Discoveries (ICORD), The University of British Columbia , Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- 2 International Collaboration on Repair Discoveries (ICORD), The University of British Columbia , Vancouver, British Columbia, Canada
| | - Peter Alec Cripton
- 1 Orthopaedic Injury Biomechanics Group, Departments of Mechanical Engineering and Orthopaedics and the School of Biomedical Engineering, The University of British Columbia , Vancouver, British Columbia, Canada .,2 International Collaboration on Repair Discoveries (ICORD), The University of British Columbia , Vancouver, British Columbia, Canada
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18
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Yung A, Mattucci S, Bohnet B, Liu J, Fournier C, Tetzlaff W, Kozlowski P, Oxland T. Diffusion tensor imaging shows mechanism-specific differences in injury pattern and progression in rat models of acute spinal cord injury. Neuroimage 2018; 186:43-55. [PMID: 30409758 DOI: 10.1016/j.neuroimage.2018.10.067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 10/19/2018] [Accepted: 10/25/2018] [Indexed: 10/28/2022] Open
Abstract
We investigate the ability of diffusion tensor imaging (DTI) to distinguish between three experimental rat models of spinal cord injury mechanism - contusion, dislocation, and distraction. Ex vivo DTI scans were performed on cord specimens that were preserved at different time points of the acute injury (3 hr, 24 hr, and 7 days post-injury) across all three injury mechanisms. White matter was classified as abnormal if their DTI metric was substantially different from regional values measured from a set of uninjured controls, thus allowing generation of binary "white matter damage maps" which categorizes each pixel in the DTI image as "normal" or "damaged". Damage classification was most robust using thresholds in the longitudinal diffusivity, which supports previous studies that show that longitudinal diffusivity is the most robust DTI metric in depicting damage in SCI. Furthermore, the spatial damage patterns from all subjects in the same group were consolidated into a "damage occurrence ratio map", which illustrates an average damage shape that characterizes the injury mechanism. Our analysis has yielded a dataset which highlights the differences in injury pattern due to the initial mode of mechanical injury. For example, contusion produced an initial injury that emanated radially outward from the central canal, with subsequent damage along the caudal corticospinal tract and rostral gracile fasciculus; dislocation injuries showed a high level of involvement in the lateral and ventral white matter which became less apparent by 7 days post-injury, and distraction injuries were found to be less focal and more distributed rostrocaudally. This work represents a first step in adopting the use of the primary injury mechanism as a clinical prognostic factor in SCI, which may help to inform the trialing of existing neuroprotective treatment candidates, the development of new therapies as well as personalize the management of SCI for the individual patient.
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Affiliation(s)
- Andrew Yung
- University of British Columbia MRI Research Centre, 2221, Wesbrook Mall, M10 Purdy Pavilion, Vancouver, BC V6T 2B5, Canada.
| | | | - Barry Bohnet
- University of British Columbia MRI Research Centre, 2221, Wesbrook Mall, M10 Purdy Pavilion, Vancouver, BC V6T 2B5, Canada.
| | - Jie Liu
- ICORD, 818 W. 10th Ave., Vancouver, BC V5Z 1M9, Canada.
| | | | | | - Piotr Kozlowski
- University of British Columbia MRI Research Centre, 2221, Wesbrook Mall, M10 Purdy Pavilion, Vancouver, BC V6T 2B5, Canada; ICORD, 818 W. 10th Ave., Vancouver, BC V5Z 1M9, Canada.
| | - Thomas Oxland
- ICORD, 818 W. 10th Ave., Vancouver, BC V5Z 1M9, Canada.
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19
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Stratton JA, Assinck P, Sinha S, Kumar R, Moulson A, Patrick N, Raharjo E, Chan JA, Midha R, Tetzlaff W, Biernaskie J. Factors Within the Endoneurial Microenvironment Act to Suppress Tumorigenesis of MPNST. Front Cell Neurosci 2018; 12:356. [PMID: 30364248 PMCID: PMC6193112 DOI: 10.3389/fncel.2018.00356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/21/2018] [Indexed: 12/13/2022] Open
Abstract
Background: Deciphering avenues to adequately control malignancies in the peripheral nerve will reduce the need for current, largely-ineffective, standards of care which includes the use of invasive, nerve-damaging, resection surgery. By avoiding the need for en bloc resection surgery, the likelihood of retained function or efficient nerve regeneration following the control of tumor growth is greater, which has several implications for long-term health and well-being of cancer survivors. Nerve tumors can arise as malignant peripheral nerve sheath tumors (MPNST) that result in a highly-aggressive form of soft tissue sarcoma. Although the precise cause of MPNST remains unknown, studies suggest that dysregulation of Schwann cells, mediated by the microenvironment, plays a key role in tumor progression. This study aimed to further characterize the role of local microenvironment on tumor progression, with an emphasis on identifying factors within tumor suppressive environments that have potential for therapeutic application. Methods: We created GFP-tagged adult induced tumorigenic Schwann cell lines (iSCs) and transplanted them into various in vivo microenvironments. We used immunohistochemistry to document the response of iSCs and performed proteomics analysis to identify local factors that might modulate divergent iSC behaviors. Results: Following transplant into the skin, spinal cord or epineurial compartment of the nerve, iSCs formed tumors closely resembling MPNST. In contrast, transplantation into the endoneurial compartment of the nerve significantly suppressed iSC proliferation. Proteomics analysis revealed a battery of factors enriched within the endoneurial compartment, of which one growth factor of interest, ciliary neurotrophic factor (CNTF) was capable of preventing iSCs proliferation in vitro. Conclusions: This dataset describes a novel approach for identifying biologically relevant therapeutic targets, such as CNTF, and highlights the complex relationship that tumor cells have with their local microenvironment. This study has significant implications for the development of future therapeutic strategies to fight MPNSTs, and, consequently, improve peripheral nerve regeneration and nerve function.
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Affiliation(s)
- Jo Anne Stratton
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
| | - Peggy Assinck
- Department of International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, BC, Canada.,Graduate Program in Neuroscience, The University of British Columbia, Vancouver, BC, Canada
| | - Sarthak Sinha
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Ranjan Kumar
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Aaron Moulson
- Department of International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, BC, Canada
| | - Natalya Patrick
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Eko Raharjo
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Jennifer A Chan
- Arnie Charbonneau Cancer Institute, University of Calgary, Calgary, AB, Canada.,Department of Pathology and Laboratory Medicine, University of Calgary, Calgary, AB, Canada
| | - Rajiv Midha
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Wolfram Tetzlaff
- Department of International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, BC, Canada
| | - Jeff Biernaskie
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.,Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB, Canada
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20
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Squair JW, Tigchelaar S, Moon KM, Liu J, Tetzlaff W, Kwon BK, Krassioukov AV, West CR, Foster LJ, Skinnider MA. Integrated systems analysis reveals conserved gene networks underlying response to spinal cord injury. eLife 2018; 7:39188. [PMID: 30277459 PMCID: PMC6173583 DOI: 10.7554/elife.39188] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/24/2018] [Indexed: 12/20/2022] Open
Abstract
Spinal cord injury (SCI) is a devastating neurological condition for which there are currently no effective treatment options to restore function. A major obstacle to the development of new therapies is our fragmentary understanding of the coordinated pathophysiological processes triggered by damage to the human spinal cord. Here, we describe a systems biology approach to integrate decades of small-scale experiments with unbiased, genome-wide gene expression from the human spinal cord, revealing a gene regulatory network signature of the pathophysiological response to SCI. Our integrative analyses converge on an evolutionarily conserved gene subnetwork enriched for genes associated with the response to SCI by small-scale experiments, and whose expression is upregulated in a severity-dependent manner following injury and downregulated in functional recovery. We validate the severity-dependent upregulation of this subnetwork in rodents in primary transcriptomic and proteomic studies. Our analysis provides systems-level view of the coordinated molecular processes activated in response to SCI.
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Affiliation(s)
- Jordan W Squair
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Seth Tigchelaar
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Kyung-Mee Moon
- Centre for High-Throughput Biology, University of British Columbia, Vancouver, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada
| | - Brian K Kwon
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,Department of Orthopaedics, University of British Columbia, Vancouver, Canada
| | - Andrei V Krassioukov
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,GF Strong Rehabilitation Centre, Vancouver Health Authority, Vancouver, Canada.,Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, Canada
| | - Christopher R West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, Canada.,School of Kinesiology, University of British Columbia, Vancouver, Canada
| | - Leonard J Foster
- Centre for High-Throughput Biology, University of British Columbia, Vancouver, Canada.,Department of Biochemistry and Molecular Biology and Michael Smith Laboratories, University of British Columbia, Vancouver, Canada
| | - Michael A Skinnider
- Centre for High-Throughput Biology, University of British Columbia, Vancouver, Canada
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21
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Duncan GJ, Manesh SB, Hilton BJ, Assinck P, Liu J, Moulson A, Plemel JR, Tetzlaff W. Locomotor recovery following contusive spinal cord injury does not require oligodendrocyte remyelination. Nat Commun 2018; 9:3066. [PMID: 30076300 PMCID: PMC6076268 DOI: 10.1038/s41467-018-05473-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 06/28/2018] [Indexed: 12/16/2022] Open
Abstract
Remyelination occurs after spinal cord injury (SCI) but its functional relevance is unclear. We assessed the necessity of myelin regulatory factor (Myrf) in remyelination after contusive SCI by deleting the gene from platelet-derived growth factor receptor alpha positive (PDGFRα-positive) oligodendrocyte progenitor cells (OPCs) in mice prior to SCI. While OPC proliferation and density are not altered by Myrf inducible knockout after SCI, the accumulation of new oligodendrocytes is largely prevented. This greatly inhibits myelin regeneration, resulting in a 44% reduction in myelinated axons at the lesion epicenter. However, spontaneous locomotor recovery after SCI is not altered by remyelination failure. In controls with functional MYRF, locomotor recovery precedes the onset of most oligodendrocyte myelin regeneration. Collectively, these data demonstrate that MYRF expression in PDGFRα-positive cell derived oligodendrocytes is indispensable for myelin regeneration following contusive SCI but that oligodendrocyte remyelination is not required for spontaneous recovery of stepping.
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Affiliation(s)
- Greg J Duncan
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, 4200-6270 University Blvd, Vancouver, V6T 1Z4, BC, Canada
| | - Sohrab B Manesh
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada
- Graduate Program in Neuroscience, University of British Columbia, 3402-2215 Wesbrook Mall, Vancouver, V6T 1Z3, BC, Canada
| | - Brett J Hilton
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, 4200-6270 University Blvd, Vancouver, V6T 1Z4, BC, Canada
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Sigmund-Freud-Straße 27, 53127, Bonn, Germany
| | - Peggy Assinck
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada
- Graduate Program in Neuroscience, University of British Columbia, 3402-2215 Wesbrook Mall, Vancouver, V6T 1Z3, BC, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada
| | - Aaron Moulson
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, 4200-6270 University Blvd, Vancouver, V6T 1Z4, BC, Canada
| | - Jason R Plemel
- The Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, 3330 Hospital Drive NW, T2N 4N1, Calgary, AB, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia (UBC), 818 West 10th Avenue, V5Z 1M9, Vancouver, BC, Canada.
- Department of Zoology, University of British Columbia, 4200-6270 University Blvd, Vancouver, V6T 1Z4, BC, Canada.
- Department of Surgery, University of British Columbia, 2775 Laurel Street, Vancouver, V5Z 1M9, BC, Canada.
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22
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May Z, Fuehrmann T, Shoichet MS, Tetzlaff W, Biernaskie J, Fouad K. Reply to Comment on 'Adult skin-derived precursor Schwann cell grafts form growths in the injured spinal cord of Fischer rats'. ACTA ACUST UNITED AC 2018. [PMID: 29532786 DOI: 10.1088/1748-605x/aab629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Zacnicte May
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB T6G 2E1, Canada
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23
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Mattucci S, Liu J, Fijal P, Tetzlaff W, Oxland TR. Repeatability of a Dislocation Spinal Cord Injury Model in a Rat-A High-Speed Biomechanical Analysis. J Biomech Eng 2018; 139:2644121. [PMID: 28696485 DOI: 10.1115/1.4037224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Indexed: 12/27/2022]
Abstract
Dislocation is the most common, and severe, spinal cord injury (SCI) mechanism in humans, yet there are few preclinical models. While dislocation in the rat model has been shown to produce unique outcomes, like other closed column models it exhibits higher outcome variability. Refinement of the dislocation model will enhance the testing of neuroprotective strategies, further biomechanical understanding, and guide therapeutic decisions. The overall objective of this study is to improve biomechanical repeatability of a dislocation SCI model in the rat, through the following specific aims: (i) design new injury clamps that pivot and self-align to the vertebrae; (ii) measure intervertebral kinematics during injury using the existing and redesigned clamps; and (iii) compare relative motion at the vertebrae-clamp interface to determine which clamps provide the most rigid connection. Novel clamps that pivot and self-align were developed based on the quantitative rat vertebral anatomy. A dislocation injury was produced in 34 rats at C4/C5 using either the existing or redesigned clamps, and a high-speed X-ray device recorded the kinematics. Relative motion between the caudal clamp and C5 was significantly greater in the existing clamps compared to the redesigned clamps in dorsoventral translation and sagittal rotation. This study demonstrates that relative motions can be of magnitudes that likely affect injury outcomes. We recommend such biomechanical analyses be applied to other SCI models when repeatability is an issue. For this dislocation model, the results show the importance of using clamps that pivot and self-align to the vertebrae.
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Affiliation(s)
- Stephen Mattucci
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada e-mail:
| | - Jie Liu
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada e-mail:
| | - Paul Fijal
- Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada e-mail:
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada e-mail:
| | - Thomas R Oxland
- Professor and Director Orthopaedic and Injury Biomechanics Group, Departments of Orthopaedics and Mechanical Engineering, International Collaboration on Repair Discoveries, University of British Columbia, 818 West 10th Avenue, Vancouver, BC V5Z 1M9, Canada e-mail:
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24
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25
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May Z, Kumar R, Fuehrmann T, Tam R, Vulic K, Forero J, Lucas Osma A, Fenrich K, Assinck P, Lee MJ, Moulson A, Shoichet MS, Tetzlaff W, Biernaskie J, Fouad K. Adult skin-derived precursor Schwann cell grafts form growths in the injured spinal cord of Fischer rats. ACTA ACUST UNITED AC 2018; 13:034101. [PMID: 29068322 DOI: 10.1088/1748-605x/aa95f8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In this study, GFP+ skin-derived precursor Schwann cells (SKP-SCs) from adult rats were grafted into the injured spinal cord of immunosuppressed rats. Our goal was to improve grafted cell survival in the injured spinal cord, which is typically low. Cells were grafted in hyaluronan-methylcellulose hydrogel (HAMC) or hyaluronan-methylcellulose modified with laminin- and fibronectin-derived peptide sequences (eHAMC). The criteria for selection of hyaluronan was for its shear-thinning properties, making the hydrogel easy to inject, methylcellulose for its inverse thermal gelation, helping to keep grafted cells in situ, and fibronectin and laminin to improve cell attachment and, thus, prevent cell death due to dissociation from substrate molecules (i.e., anoikis). Post-mortem examination revealed large masses of GFP+ SKP-SCs in the spinal cords of rats that received cells in HAMC (5 out of n = 8) and eHAMC (6 out of n = 8). Cell transplantation in eHAMC caused significantly greater spinal lesions compared to lesion and eHAMC only control groups. A parallel study showed similar masses in the contused spinal cord of rats after transplantation of adult GFP+ SKP-SCs without a hydrogel or immunosuppression. These findings suggest that adult GFP+ SKP-SCs, cultured/transplanted under the conditions described here, have a capacity for uncontrolled proliferation. Growth-formation in pre-clinical research has also been documented after transplantation of: human induced pluripotent stem cell-derived neural stem cells (Itakura et al 2015 PLoS One 10 e0116413), embryonic stem cells and embryonic stem cell-derived neurons (Brederlau et al 2006 Stem Cells 24 1433-40; Dressel et al 2008 PLoS One 3 e2622), bone marrow derived mesenchymal stem cells (Jeong et al 2011 Circ. Res. 108 1340-47) and rat nerve-derived SCs following in vitro expansion for >11 passages (Funk et al 2007 Eur. J. Cell Biol. 86 207-19; Langford et al 1988 J. Neurocytology 17 521-9; Morrissey et al 1991 J. Neurosci. 11 2433-42). It is of upmost importance to define the precise culture/transplantation parameters for maintenance of normal cell function and safe and effective use of cell therapy.
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Affiliation(s)
- Zacnicte May
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, T6G 2E1, Canada
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26
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Squair JW, Liu J, Tetzlaff W, Krassioukov AV, West CR. Spinal cord injury-induced cardiomyocyte atrophy and impaired cardiac function are severity dependent. Exp Physiol 2018; 103:179-189. [PMID: 29235182 DOI: 10.1113/ep086549] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 11/13/2017] [Indexed: 12/30/2022]
Abstract
NEW FINDINGS What is the central question of this study? How does the severity of spinal cord injury affect left ventricular mechanics, function and the underlying cardiomyocyte morphology? What is the main finding and its importance? Here, we show that severe, but not moderate, spinal cord injury causes cardiomyocyte atrophy, altered left ventricular mechanics and impaired cardiac function. The principal aim of the present study was to assess how the severity of spinal cord injury (SCI) affects left ventricular (LV) mechanics, function and underlying cardiomyocyte morphology. Here, we used different severities of T3 spinal cord contusions (MODERATE, 200 kdyn contusion; SEVERE, 400 kdyn contusion; SHAM) and combined standard echocardiography with speckle tracking analyses to investigate in vivo cardiac function and deformation (contractility) after experimental SCI in the Wistar rat. In addition, we investigated changes in the intrinsic structure of cardiac myocytes ex vivo. We demonstrate that SEVERE SCI induces a characteristic decline in LV chamber size and a reduction in in vivo LV deformation (i.e. radial strain) throughout the entire systolic portion of the cardiac cycle [25.6 ± 3.0 versus 44.5 ± 8.1% (Pre-injury); P = 0.0029]. SEVERE SCI also caused structural changes in cardiomyocytes, including decreased length [115.6 ± 7.63 versus 125.8 ± 6.75 μm (SHAM); P = 0.0458], decreased width [7.78 ± 0.71 versus 10.78 ± 1.08 μm (SHAM); P = 0.0015] and an increase in the length/width ratio [14.88 ± 0.66 versus 11.74 ± 0.89 (SHAM); P = 0.0018], which was significantly correlated with LV flow-generating capacity after SCI (i.e. stroke volume, R2 = 0.659; P = 0.0013). Rats with MODERATE SCI exhibited no changes in any metric versus SHAM. This is the first study to demonstrate that the severity of SCI determines the course of changes in the intrinsic structure of cardiomyocytes, which are directly related to contractile function of the LV.
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Affiliation(s)
- Jordan W Squair
- International Collaboration of Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,MD/PhD Training Program, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Jie Liu
- International Collaboration of Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada
| | - Wolfram Tetzlaff
- International Collaboration of Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Zoology, Faculty of Science, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Andrei V Krassioukov
- International Collaboration of Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, BC, Canada.,GF Strong Rehabilitation Centre, Vancouver Health Authority, University of British Columbia, Vancouver, BC, Canada
| | - Christopher R West
- International Collaboration of Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.,School of Kinesiology, University of British Columbia, Vancouver, BC, Canada
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27
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Hirschler V, Martín M, Oestreicher K, Molinari C, Tetzlaff W, Botta E, Boero L, Brites F. Activity of the antioxidant enzyme paraoxonase in Argentinean children living at high altitude. Redox Rep 2017; 23:35-40. [PMID: 28853330 PMCID: PMC6748698 DOI: 10.1080/13510002.2017.1370783] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background: Children living at high altitude in San Antonio de los
Cobres (SAC), Argentina, were shown to have lower high-density lipoprotein
cholesterol (HDL-C) levels than Buenos Aires (BA) children. HDL antioxidant
capacity is mainly attributed to paraoxonase1 (PON1). Objective: To compare PON1 activity in indigenous SAC vs. BA
children. Methods: A cross-sectional study compared 158 SAC vs. 97 BA children
(6–16 years). Anthropometric data and lipoprotein profile were measured.
PON1 was evaluated employing paraoxon (PON) and phenylacetate (ARE)
activity. Results: The prevalence of overweight/obesity was lower in SAC than
in BA children (18.3 vs. 30.9%). Triglycerides (1.34 vs.
0.90 mmol/l), apo B (0.84 vs.0.72 g/l), apo A-I
(1.33 vs. 1.27 g/l), and ARE activity (100
vs. 90 µmol/ml/min) were higher, while HDL-C
(1.16 vs. 1.32 mmol/l) and PON activity (170 vs.
203 nmol/ml/min) were lower in SAC than in BA. Separate multiple linear
regression analyses showed that SAC children had significantly higher
triglyceride (Beta −0.38), apo B (Beta −0.34), and ARE (Beta
−0.36) plus lower HDL-C (Beta 0.33) and PON (Beta 0.25) compared with BA;
adjusted for age, gender, and BMI. Conclusion: SAC showed an unfavorable lipoprotein profile, lower PON
and higher ARE activities compared with BA children, suggesting the presence of
altered HDL metabolism and antioxidant capacity.
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Affiliation(s)
- V Hirschler
- a University of Buenos Aires , Buenos Aires , Argentina
| | - M Martín
- b Laboratory of Lipids and Atherosclerosis, Department of Clinical Biochemistry, School of Pharmacy and Biochemistry , University of Buenos Aires-CONICET , Buenos Aires , Argentina
| | - K Oestreicher
- a University of Buenos Aires , Buenos Aires , Argentina
| | - C Molinari
- a University of Buenos Aires , Buenos Aires , Argentina
| | - W Tetzlaff
- b Laboratory of Lipids and Atherosclerosis, Department of Clinical Biochemistry, School of Pharmacy and Biochemistry , University of Buenos Aires-CONICET , Buenos Aires , Argentina
| | - E Botta
- b Laboratory of Lipids and Atherosclerosis, Department of Clinical Biochemistry, School of Pharmacy and Biochemistry , University of Buenos Aires-CONICET , Buenos Aires , Argentina
| | - L Boero
- b Laboratory of Lipids and Atherosclerosis, Department of Clinical Biochemistry, School of Pharmacy and Biochemistry , University of Buenos Aires-CONICET , Buenos Aires , Argentina
| | - F Brites
- b Laboratory of Lipids and Atherosclerosis, Department of Clinical Biochemistry, School of Pharmacy and Biochemistry , University of Buenos Aires-CONICET , Buenos Aires , Argentina
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28
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Hilton BJ, Moulson AJ, Tetzlaff W. Neuroprotection and secondary damage following spinal cord injury: concepts and methods. Neurosci Lett 2017; 652:3-10. [DOI: 10.1016/j.neulet.2016.12.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/28/2016] [Accepted: 12/02/2016] [Indexed: 01/29/2023]
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29
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Chen HSM, Holmes N, Liu J, Tetzlaff W, Kozlowski P. Validating myelin water imaging with transmission electron microscopy in a rat spinal cord injury model. Neuroimage 2017; 153:122-130. [PMID: 28377211 DOI: 10.1016/j.neuroimage.2017.03.065] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/23/2017] [Accepted: 03/28/2017] [Indexed: 10/19/2022] Open
Abstract
Myelin content is an important marker for neuropathology and MRI generated myelin water fraction (MWF) has been shown to correlate well with myelin content. However, because MWF is based on the amount of signal from myelin water, that is, the water trapped between the myelin lipid bilayers, the reading may depend heavily on myelin morphology. This is of special concern when there is a mix of intact myelin and myelin debris, as in the case of injury. To investigate what MWF measures in the presence of debris, we compared MWF to transmission electron microscopy (TEM) derived myelin fraction that measures the amount of compact appearing myelin. A rat spinal cord injury model was used with time points at normal (normal myelin), 3 weeks post-injury (myelin debris), and 8 weeks post-injury (myelin debris, partially cleared). The myelin period between normal and 3 or 8 weeks post-injury cords did not differ significantly, suggesting that as long as the bilayer structure is intact, myelin debris has the same water content as intact myelin. The MWF also correlated strongly with the TEM-derived myelin fraction, suggesting that MWF measures the amount of compact appearing myelin in both intact myelin and myelin debris. From the TEM images, it appears that as myelin degenerates, it tends to form large watery spaces within the myelin sheaths that are not classified as myelin water. The results presented in this study improve our understanding and allows for better interpretation of MWF in the presence of myelin debris.
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Affiliation(s)
- Henry Szu-Meng Chen
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada; University of British Columbia MRI Research Centre, Vancouver, Canada.
| | - Nathan Holmes
- International Collaboration on Repair Discoveries (ICORD), Vancouver, Canada; Department of Zoology, University of British Columbia, Vancouver, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), Vancouver, Canada.
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), Vancouver, Canada; Department of Zoology, University of British Columbia, Vancouver, Canada.
| | - Piotr Kozlowski
- University of British Columbia MRI Research Centre, Vancouver, Canada; International Collaboration on Repair Discoveries (ICORD), Vancouver, Canada; Department of Radiology, University of British Columbia, Vancouver, Canada.
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30
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Squair JW, West CR, Popok D, Assinck P, Liu J, Tetzlaff W, Krassioukov AV. High Thoracic Contusion Model for the Investigation of Cardiovascular Function after Spinal Cord Injury. J Neurotrauma 2017; 34:671-684. [DOI: 10.1089/neu.2016.4518] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Jordan W. Squair
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
- MD/PhD Training Program, University of British Columbia, Vancouver, British Columbia, Canada
| | - Christopher R. West
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - David Popok
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Peggy Assinck
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
- Graduate Program in Neuroscience, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
- Department of Zoology, Faculty of Science, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrei V. Krassioukov
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
- GF Strong Rehabilitation Centre, Vancouver Health Authority, Vancouver, British Columbia, Canada
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Abstract
Several studies have shown that minocycline, a semisynthetic, second-generation tetracycline derivative, is neuroprotective in animal models of central nervous system trauma and several neurodegenerative diseases. Common to all these reports are the beneficial effects of minocycline in reducing neural inflammation and preventing cell death. Here, the authors review the proposed mechanisms of action of minocycline and suggest that minocycline may inhibit several aspects of the inflammatory response and prevent cell death through the inhibition of the p38 mitogen-activated protein kinase pathway, an important regulator of immune cell function and cell death.
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Affiliation(s)
- David P Stirling
- ICORD (International Collaboration On Repair Discoveries), University of British Columbia, Vancouver, BC, Canada
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32
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Tharmarajah G, Ouellet E, Seira O, Liu J, Thomas A, Leaver T, Wild A, Li Y, Wang YT, Tetzlaff W, Hansen C, Cullis P, Taylor JR, Ramsay E. 614. Microfluidic Manufacture of RNA-Lipid Nanoparticles Leads to Highly Efficient Delivery of Potent Nucleic Acid Therapeutics for Controlling Gene Expression. Mol Ther 2016. [DOI: 10.1016/s1525-0016(16)33422-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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33
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Bhatnagar T, Liu J, Yung A, Cripton P, Kozlowski P, Tetzlaff W, Oxland T. Relating Histopathology and Mechanical Strain in Experimental Contusion Spinal Cord Injury in a Rat Model. J Neurotrauma 2016; 33:1685-95. [PMID: 26729511 PMCID: PMC5035832 DOI: 10.1089/neu.2015.4200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
During traumatic spinal cord injury (SCI), the spinal cord is subject to external displacements that result in damage of neural tissues. These displacements produce complex internal deformations, or strains, of the spinal cord parenchyma. The aim of this study is to determine a relationship between these internal strains during SCI and primary damage to spinal cord gray matter (GM) in an in vivo rat contusion model. Using magnetic resonance imaging and novel image registration methods, we measured three-dimensional (3D) mechanical strain in in vivo rat cervical spinal cord (n = 12) during an imposed contusion injury. We then assessed expression of the neuronal transcription factor, neuronal nuclei (NeuN), in ventral horns of GM (at the epicenter of injury as well as at intervals cranially and caudally), immediately post-injury. We found that minimum principal strain was most strongly correlated with loss of NeuN stain across all animals (R2 = 0.19), but varied in strength between individual animals (R2 = 0.06–0.52). Craniocaudal distribution of anatomical damage was similar to measured strain distribution. A Monte Carlo simulation was used to assess strain field error, and minimum principal strain (which ranged from 8% to 36% in GM ventral horns) exhibited a standard deviation of 2.6% attributed to the simulated error. This study is the first to measure 3D deformation of the spinal cord and relate it to patterns of ensuing tissue damage in an in vivo model. It provides a platform on which to build future studies addressing the tolerance of spinal cord tissue to mechanical deformation.
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Affiliation(s)
- Tim Bhatnagar
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada .,2 Department of Mechanical Engineering, University of British Columbia , Vancouver, British Columbia, Canada
| | - Jie Liu
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada
| | - Andrew Yung
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada .,3 UBC MRI Research Center, University of British Columbia , Vancouver, British Columbia, Canada
| | - Peter Cripton
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada .,2 Department of Mechanical Engineering, University of British Columbia , Vancouver, British Columbia, Canada
| | - Piotr Kozlowski
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada .,3 UBC MRI Research Center, University of British Columbia , Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada .,4 Department of Zoology, University of British Columbia , Vancouver, British Columbia, Canada
| | - Thomas Oxland
- 1 International Collaboration On Repair Discoveries (ICORD), University of British Columbia, Vancouver , British Columbia, Canada .,2 Department of Mechanical Engineering, University of British Columbia , Vancouver, British Columbia, Canada .,5 Department of Orthopedics, University of British Columbia , Vancouver, British Columbia, Canada
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Chen K, Liu J, Assinck P, Bhatnagar T, Streijger F, Zhu Q, Dvorak MF, Kwon BK, Tetzlaff W, Oxland TR. Differential Histopathological and Behavioral Outcomes Eight Weeks after Rat Spinal Cord Injury by Contusion, Dislocation, and Distraction Mechanisms. J Neurotrauma 2016; 33:1667-84. [PMID: 26671448 PMCID: PMC5035937 DOI: 10.1089/neu.2015.4218] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The objective of this study was to compare the long-term histological and behavioral outcomes after spinal cord injury (SCI) induced by one of three distinct biomechanical mechanisms: dislocation, contusion, and distraction. Thirty male Sprague-Dawley rats were randomized to incur a traumatic cervical SCI by one of these three clinically relevant mechanisms. The injured cervical spines were surgically stabilized, and motor function was assessed for the following 8 weeks. The spinal cords were then harvested for histologic analysis. Quantification of white matter sparing using Luxol fast blue staining revealed that dislocation injury caused the greatest overall loss of white matter, both laterally and along the rostrocaudal axis of the injured cord. Distraction caused enlarged extracellular spaces and structural alteration in the white matter but spared the most myelinated axons overall. Contusion caused the most severe loss of myelinated axons in the dorsal white matter. Immunohistochemistry for the neuronal marker NeuN combined with Fluoro Nissl revealed that the dislocation mechanism resulted in the greatest neuronal cell losses in both the ventral and dorsal horns. After the distraction injury mechanism, animals displayed no recovery of grip strength over time, in contrast to the animals subjected to contusion or dislocation injuries. After the dislocation injury mechanism, animals displayed no improvement in the grooming test, in contrast to the animals subjected to contusion or distraction injuries. These data indicate that different SCI mechanisms result in distinct patterns of histopathology and behavioral recovery. Understanding this heterogeneity may be important for the future development of therapeutic interventions that target specific neuropathology after SCI.
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Affiliation(s)
- Kinon Chen
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,4 Department of Orthopaedics, University of British Columbia , Vancouver, British Columbia, Canada .,6 School of Biological Science and Medical Engineering, Beihang University , Haidian, Beijing, China
| | - Jie Liu
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Peggy Assinck
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,2 Graduate Program in Neuroscience, University of British Columbia , Vancouver, British Columbia, Canada
| | - Tim Bhatnagar
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,3 Department of Mechanical Engineering, University of British Columbia , Vancouver, British Columbia, Canada
| | - Femke Streijger
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada
| | - Qingan Zhu
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,4 Department of Orthopaedics, University of British Columbia , Vancouver, British Columbia, Canada
| | - Marcel F Dvorak
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,4 Department of Orthopaedics, University of British Columbia , Vancouver, British Columbia, Canada
| | - Brian K Kwon
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,4 Department of Orthopaedics, University of British Columbia , Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,5 Department of Zoology and Surgery, University of British Columbia , Vancouver, British Columbia, Canada
| | - Thomas R Oxland
- 1 International Collaboration on Repair Discoveries (ICORD), University of British Columbia , Vancouver, British Columbia, Canada .,3 Department of Mechanical Engineering, University of British Columbia , Vancouver, British Columbia, Canada .,4 Department of Orthopaedics, University of British Columbia , Vancouver, British Columbia, Canada
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35
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Geoffroy CG, Hilton BJ, Tetzlaff W, Zheng B. Evidence for an Age-Dependent Decline in Axon Regeneration in the Adult Mammalian Central Nervous System. Cell Rep 2016; 15:238-46. [PMID: 27050519 DOI: 10.1016/j.celrep.2016.03.028] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 01/28/2016] [Accepted: 03/07/2016] [Indexed: 10/22/2022] Open
Abstract
How aging impacts axon regeneration after CNS injury is not known. We assessed the impact of age on axon regeneration induced by Pten deletion in corticospinal and rubrospinal neurons, two neuronal populations with distinct innate regenerative abilities. As in young mice, Pten deletion in older mice remains effective in preventing axotomy-induced decline in neuron-intrinsic growth state, as assessed by mTOR activity, neuronal soma size, and axonal growth proximal to a spinal cord injury. However, axonal regeneration distal to injury is greatly diminished, accompanied by increased expression of astroglial and inflammatory markers at the injury site. Thus, the mammalian CNS undergoes an age-dependent decline in axon regeneration, as revealed when neuron-intrinsic growth state is elevated. These results have important implications for developing strategies to promote axonal repair after CNS injuries or diseases, which increasingly affect middle-aged to aging populations.
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Affiliation(s)
- Cédric G Geoffroy
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0691, USA
| | - Brett J Hilton
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Zoology, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada; Department of Surgery, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada.
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California, San Diego, La Jolla, CA 92093-0691, USA.
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36
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Zhang S, Kojic L, Tsang M, Grewal P, Liu J, Namjoshi D, Wellington CL, Tetzlaff W, Cynader MS, Jia W. Distinct roles for metalloproteinases during traumatic brain injury. Neurochem Int 2016; 96:46-55. [PMID: 26939762 DOI: 10.1016/j.neuint.2016.02.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 02/16/2016] [Accepted: 02/25/2016] [Indexed: 12/22/2022]
Abstract
BACKGROUND Significant protease activations have been reported after traumatic brain injury (TBI). These proteases are responsible for cleavage of transmembrane proteins in neurons, glial, and endothelial cells and this results in the release of their extracellular domains (ectodomains). METHODS Two TBI models were employed here, representing both closed head injury (CHI) and open head injury (OHI). In situ zymography, immunohistochemistry, bright field and confocal microscopy, quantification of immunopositive cells and statistical analysis were applied. RESULTS We found, using in situ zymography, that gelatinase activity of matrix metalloproteinases (MMP)-2 and MMP-9 was upregulated in cortex of both injury models. Using immunohistochemistry for several MPPs (Matrix metalloproteinases) and ADAMs (disintegrin and metalloproteinases), including MMP-2, -9, ADAM-10, -17, distinct patterns of induction were observed in the two TBI models. In closed head injury, an early increase in protein expression of MMP-2, -9 and ADAM-17 was found as early as 10 min post injury in cortex and peaked at 1 h for all 4 proteases examined. In contrast, after OHI the maximal expression was observed locally neighboring the impact site, at a later time-point, as long as 24 h after the injury for MMP-2 and MMP-9. Confocal microscopy revealed colocalization of the 4 proteases with the neuronal marker NeuN in CHI, but only MMP2 colocalized with NeuN in OHI. CONCLUSIONS The findings may lead to a trauma-induced therapeutic strategy triggered soon after a primary insult to improve survival and to reduce brain damage following TBI.
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Affiliation(s)
- Si Zhang
- Brain Research Center, University of British Columbia, Vancouver, BC, Canada.
| | - Luba Kojic
- Brain Research Center, University of British Columbia, Vancouver, BC, Canada.
| | - Michelle Tsang
- Brain Research Center, University of British Columbia, Vancouver, BC, Canada.
| | - Parampal Grewal
- Brain Research Center, University of British Columbia, Vancouver, BC, Canada.
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.
| | - Dhananjay Namjoshi
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - Cheryl L Wellington
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, BC, Canada.
| | - Max S Cynader
- Brain Research Center, University of British Columbia, Vancouver, BC, Canada.
| | - William Jia
- Brain Research Center, University of British Columbia, Vancouver, BC, Canada.
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37
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Gordon T, Tetzlaff W. Regeneration-associated genes decline in chronically injured rat sciatic motoneurons. Eur J Neurosci 2015; 42:2783-91. [DOI: 10.1111/ejn.13070] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 02/02/2023]
Affiliation(s)
- Tessa Gordon
- Neuroscience and Mental Health Institute; Faculty of Medicine and Dentistry; University of Alberta; Edmonton AB T6G 2S2 Canada
- Department of Surgery; Division of Plastic Reconstructive Surgery; 5549A The Hospital for Sick Children; 555 University Avenue Toronto ON M5G 1X8 Canada
| | - Wolfram Tetzlaff
- ICORD (International Collaboration on Repair Discoveries); Blusson Spinal Cord Centre; 818 W. 10th Avenue Vancouver BC V5Z 1M9 Canada
- Departments of Zoology and Surgery; University of British Columbia; Vancouver BC Canada
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38
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Bhatnagar T, Liu J, Yung A, Cripton P, Kozlowski P, Tetzlaff W, Oxland T. Quantifying the internal deformation of the rodent spinal cord during acute spinal cord injury – the validation of a method. Comput Methods Biomech Biomed Engin 2015; 19:386-95. [DOI: 10.1080/10255842.2015.1032944] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kwon BK, Streijger F, Hill CE, Anderson AJ, Bacon M, Beattie MS, Blesch A, Bradbury EJ, Brown A, Bresnahan JC, Case CC, Colburn RW, David S, Fawcett JW, Ferguson AR, Fischer I, Floyd CL, Gensel JC, Houle JD, Jakeman LB, Jeffery ND, Jones LAT, Kleitman N, Kocsis J, Lu P, Magnuson DSK, Marsala M, Moore SW, Mothe AJ, Oudega M, Plant GW, Rabchevsky AS, Schwab JM, Silver J, Steward O, Xu XM, Guest JD, Tetzlaff W. Large animal and primate models of spinal cord injury for the testing of novel therapies. Exp Neurol 2015; 269:154-68. [PMID: 25902036 DOI: 10.1016/j.expneurol.2015.04.008] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 04/08/2015] [Accepted: 04/13/2015] [Indexed: 12/28/2022]
Abstract
Large animal and primate models of spinal cord injury (SCI) are being increasingly utilized for the testing of novel therapies. While these represent intermediary animal species between rodents and humans and offer the opportunity to pose unique research questions prior to clinical trials, the role that such large animal and primate models should play in the translational pipeline is unclear. In this initiative we engaged members of the SCI research community in a questionnaire and round-table focus group discussion around the use of such models. Forty-one SCI researchers from academia, industry, and granting agencies were asked to complete a questionnaire about their opinion regarding the use of large animal and primate models in the context of testing novel therapeutics. The questions centered around how large animal and primate models of SCI would be best utilized in the spectrum of preclinical testing, and how much testing in rodent models was warranted before employing these models. Further questions were posed at a focus group meeting attended by the respondents. The group generally felt that large animal and primate models of SCI serve a potentially useful role in the translational pipeline for novel therapies, and that the rational use of these models would depend on the type of therapy and specific research question being addressed. While testing within these models should not be mandatory, the detection of beneficial effects using these models lends additional support for translating a therapy to humans. These models provides an opportunity to evaluate and refine surgical procedures prior to use in humans, and safety and bio-distribution in a spinal cord more similar in size and anatomy to that of humans. Our results reveal that while many feel that these models are valuable in the testing of novel therapies, important questions remain unanswered about how they should be used and how data derived from them should be interpreted.
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Affiliation(s)
- Brian K Kwon
- University of British Columbia, ICORD, Room 6196, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC V5Z 1 M9, Canada.
| | - Femke Streijger
- University of British Columbia, ICORD, Room 6196, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC V5Z 1 M9, Canada.
| | - Caitlin E Hill
- Burke Medical Research Institute/Weill Cornell Medical College, 785 Mamaroneck Ave., White Plains, NY 10605, USA.
| | | | - Mark Bacon
- International Spinal Research Trust, International Spinal Research Trust, Bramley Business Centre, Station Road, Bramley, Guildford, Surrey GU5 0AZ, UK.
| | - Michael S Beattie
- University of California at San Francisco, 1001 Potrero Ave., Bldg 1 Rm 101, San Francisco, CA 94110, USA.
| | - Armin Blesch
- Heidelberg University Hospital, Spinal Cord Injury Center, Germany.
| | - Elizabeth J Bradbury
- King's College London, The Wolfson Centre for Age-Related Diseases, Wolfson Wing, Hodgkin Building, Guy's Campus, London Bridge, London SE1 1UL, UK.
| | - Arthur Brown
- University of Western Ontario, Robarts Research Institute, University of Western Ontario, Department of Anatomy and Cell Biology, 1151 Richmond Street, North, N6A 5B7, Canada.
| | - Jacqueline C Bresnahan
- University of California at San Francisco, 1001 Potrero Ave., Bldg 1 Rm 101, San Francisco, CA 94110, USA.
| | - Casey C Case
- Asterias Biotherapeutics, 230 Constitution Drive, Menlo Park, CA 94025, USA.
| | - Raymond W Colburn
- Acorda Therapeutics, Acorda Therapeutics, Inc., 420 Saw Mill River Road, Ardsley, NY 10502, USA.
| | - Samuel David
- Centre for Research in Neuroscience, Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
| | - James W Fawcett
- University of Cambridge, John van Geest Centre for Brain Repair, Robinson Way, Cambridge CB2 0PY, UK.
| | - Adam R Ferguson
- University of California, San Francisco (UCSF), Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, USA.
| | - Itzhak Fischer
- Drexel University College of Medicine, Dept. of Neurobiology and Anatomy, 2900 Queen Lane, Philadelphia, PA 19129, USA.
| | - Candace L Floyd
- University of Alabama at Birmingham, 529C Spain Rehabilitation Center, 1717 6th Avenue South, Birmingham, AL 35249, USA.
| | - John C Gensel
- University of Kentucky, Spinal Cord and Brain Injury Research Center, B463 Biomedical & Biological Sciences Research Building (BBSRB), 741 S. Limestone, Lexington, KY 40536, USA.
| | - John D Houle
- Drexel University College of Medicine, Spinal Cord Research Center, Philadelphia, PA 19129, USA.
| | - Lyn B Jakeman
- National Institutes of Health/NINDS, 6001 Executive Blvd. North, Bethesda, MD 20852, USA.
| | - Nick D Jeffery
- Iowa State University, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
| | | | - Naomi Kleitman
- Craig H. Neilsen Foundation, 16830 Ventura Blvd. Suite 352, Encino, CA 91436, USA.
| | - Jeffery Kocsis
- Yale University and VA CT Healthcare System, Neuroscience Center (127A), VA CT Healthcare Center, 950 Campbell Ave., West Haven, CT 06516, USA.
| | - Paul Lu
- VA-San Diego Healthcare System, University of California at San Diego, BMF2, Room 2126, 9500 Gilman Dr., La Jolla, CA 92093-0626, USA.
| | - David S K Magnuson
- University of Louisville School of Medicine, 511 S. Floyd St., MDR Rm 616, USA.
| | - Martin Marsala
- University of California, San Diego, Department of Anesthesiology SCRM, Room 4009, 2880 Torrey Pines Scenic Dr., La Jolla, CA 92037, USA.
| | - Simon W Moore
- InVivo Therapeutics Corporation, One Kendall Square, Suite B14402, Cambridge, MA 02139, USA.
| | - Andrea J Mothe
- Toronto Western Research Institute, Krembil Discovery Tower, 60 Leonard Ave. , 7KD-406, Toronto ON M5T 2S8, Canada.
| | - Martin Oudega
- University of Miami Miller School of Medicine, LPLC, 1095 NW 14 Terrace, Miami, FL 33136, USA.
| | - Giles W Plant
- Stanford University, Lorry I. Lokey Stem Cell Research Building, Stanford University, 265 Campus Drive, Stanford, CA 94305, USA.
| | | | | | - Jerry Silver
- Case Western Reserve University, Dept. of Neurosciences, School of Medicine, 2109 Adelbert Rd., Cleveland, OH 44106, USA.
| | - Oswald Steward
- University of California Irvine, Reeve-Irvine Research Center, Department of Anatomy & Neurobiology, University of California Irvine School of Medicine, Irvine, CA 92697, USA.
| | - Xiao-Ming Xu
- Indiana University School of Medicine, 320 W. 15th St., Indianapolis, IN 46202, USA.
| | | | - Wolfram Tetzlaff
- University of British Columbia, ICORD, Room 6196, Blusson Spinal Cord Centre, 818 West 10th Avenue, Vancouver, BC V5Z 1 M9, Canada.
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Gordon T, You S, Cassar SL, Tetzlaff W. Reduced expression of regeneration associated genes in chronically axotomized facial motoneurons. Exp Neurol 2014; 264:26-32. [PMID: 25446720 DOI: 10.1016/j.expneurol.2014.10.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 09/15/2014] [Accepted: 10/29/2014] [Indexed: 12/24/2022]
Abstract
Chronically axotomized motoneurons progressively fail to regenerate their axons. Since axonal regeneration is associated with the increased expression of tubulin, actin and GAP-43, we examined whether the regenerative failure is due to failure of chronically axotomized motoneurons to express and sustain the expression of these regeneration associated genes (RAGs). Chronically axotomized facial motoneurons were subjected to a second axotomy to mimic the clinical surgical procedure of refreshing the proximal nerve stump prior to nerve repair. Expression of α1-tubulin, actin and GAP-43 was analyzed in axotomized motoneurons using in situ hybridization followed by autoradiography and silver grain quantification. The expression of these RAGs by acutely axotomized motoneurons declined over several months. The chronically injured motoneurons responded to a refreshment axotomy with a re-increase in RAG expression. However, this response to a refreshment axotomy of chronically injured facial motoneurons was less than that seen in acutely axotomized facial motoneurons. These data demonstrate that the neuronal RAG expression can be induced by injury-related signals and does not require acute deprivation of target derived factors. The transient expression is consistent with a transient inflammatory response to the injury. We conclude that transient RAG expression in chronically axotomized motoneurons and the weak response of the chronically axotomized motoneurons to a refreshment axotomy provides a plausible explanation for the progressive decline in regenerative capacity of chronically axotomized motoneurons.
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Affiliation(s)
- T Gordon
- Department of Neuroscience, University of Alberta, Edmonton, AB T6G 2S2, Canada; ICORD (International Collaboration on Repair Discoveries), Canada; Department Zoology, University of British Columbia, Vancouver, V5Z 1M9, BC, Canada; Department Surgery, University of British Columbia, Vancouver, BC, Canada.
| | - S You
- Department of Neuroscience, University of Alberta, Edmonton, AB T6G 2S2, Canada; ICORD (International Collaboration on Repair Discoveries), Canada; Department Zoology, University of British Columbia, Vancouver, V5Z 1M9, BC, Canada; Department Surgery, University of British Columbia, Vancouver, BC, Canada
| | - S L Cassar
- Department of Neuroscience, University of Alberta, Edmonton, AB T6G 2S2, Canada; ICORD (International Collaboration on Repair Discoveries), Canada; Department Zoology, University of British Columbia, Vancouver, V5Z 1M9, BC, Canada; Department Surgery, University of British Columbia, Vancouver, BC, Canada
| | - W Tetzlaff
- Department of Neuroscience, University of Alberta, Edmonton, AB T6G 2S2, Canada; ICORD (International Collaboration on Repair Discoveries), Canada; Department Zoology, University of British Columbia, Vancouver, V5Z 1M9, BC, Canada; Department Surgery, University of British Columbia, Vancouver, BC, Canada.
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41
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Plemel JR, Keough MB, Duncan GJ, Sparling JS, Yong VW, Stys PK, Tetzlaff W. Remyelination after spinal cord injury: Is it a target for repair? Prog Neurobiol 2014; 117:54-72. [DOI: 10.1016/j.pneurobio.2014.02.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 02/15/2014] [Accepted: 02/20/2014] [Indexed: 12/12/2022]
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Streijger F, Lee JHT, Duncan GJ, Ng MTL, Assinck P, Bhatnagar T, Plunet WT, Tetzlaff W, Kwon BK. Combinatorial treatment of acute spinal cord injury with ghrelin, ibuprofen, C16, and ketogenic diet does not result in improved histologic or functional outcome. J Neurosci Res 2014; 92:870-83. [PMID: 24658967 DOI: 10.1002/jnr.23372] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 11/28/2013] [Accepted: 01/20/2014] [Indexed: 11/09/2022]
Abstract
Because of the complex, multifaceted nature of spinal cord injury (SCI), it is widely believed that a combination of approaches will be superior to individual treatments. Therefore, we employed a rat model of cervical SCI to evaluate the combination of four noninvasive treatments that individually have been reported to be effective for acute SCI during clinically relevant therapeutic time windows. These treatments included ghrelin, ibuprofen, C16, and ketogenic diet (KD). These were selected not only because of their previously reported efficacy in SCI models but also for their potentially different mechanisms of action. The administration of ghrelin, ibuprofen, C16, and KD several hours to days postinjury was based on previous observations by others that each treatment had profound effects on the pathophysiology and functional outcome following SCI. Here we showed that, with the exception of a modest improvement in performance on the Montoya staircase test at 8-10 weeks postinjury, the combinatorial treatment with ghrelin, ibuprofen, C16, and KD did not result in any significant improvements in the rearing test, grooming test, or horizontal ladder. Histologic analysis of the spinal cords did not reveal any significant differences in tissue sparing between treatment and control groups. Although single approaches of ghrelin, ibuprofen, C16, and KD have been reported to be beneficial after SCI, our results show that the combination of the four interventions did not confer significant functional or histological improvements in a cervical model of SCI. Possible interactions among the treatments may have negated their beneficial effects, emphasizing the challenges that have to be addressed when considering combinatorial drug therapies for SCI.
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Affiliation(s)
- F Streijger
- International Collaboration on Repair Discoveries (ICORD), University of British Columbia, Vancouver, British Columbia, Canada; Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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Anenberg E, Arstikaitis P, Niitsu Y, Harrison TC, Boyd JD, Hilton BJ, Tetzlaff W, Murphy TH. Ministrokes in channelrhodopsin-2 transgenic mice reveal widespread deficits in motor output despite maintenance of cortical neuronal excitability. J Neurosci 2014; 34:1094-104. [PMID: 24453302 PMCID: PMC6705317 DOI: 10.1523/jneurosci.1442-13.2014] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 11/28/2013] [Accepted: 12/04/2013] [Indexed: 11/21/2022] Open
Abstract
We evaluated the effects of ministrokes targeted to individual pial arterioles on motor function in Thy-1 line 18 channelrhodopsin-2 (ChR2) transgenic mice within the first hours after ischemia. Using optogenetics, we directly assessed both the excitability and motor output of cortical neurons in a manner independent of behavioral state or training. Occlusion of individual arterioles within the motor cortex led to a ministroke that was verified using laser speckle contrast imaging. Surprisingly, ministrokes targeted to a relatively small region of the forelimb motor map, with an ischemic core of 0.07 ± 0.03 mm(2), impaired motor responses evoked from points across widespread areas of motor cortex even 1.5 mm away. Contrasting averaged ChR2-evoked electroencephalographic, spinal (ChR2 evoked potential), and electromyographic responses revealed a mismatch between measures of cortical excitability and motor output within 60 min after stroke. This mismatch suggests that apparently excitable cortical neurons (even >1 mm into peri-infarct areas, away from the infarct core) were impaired in their capacity to generate spinal potentials leading to even more severe deficits in motor output at muscles. We suggest that ischemia, targeted to a subset of motor cortex, leads to relatively small reductions in excitability within motor cortex, and cumulative depression of both descending spinal circuits and motor output in response to the activation of widespread cortical territories even outside of the area directly affected by the ischemia.
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Affiliation(s)
| | | | | | | | | | - Brett J. Hilton
- Department of Zoology, and
- International Collaboration on Repair Discoveries, University of British Columbia at Vancouver, Vancouver, British Columbia V6T 1Z3, Canada
| | - Wolfram Tetzlaff
- Department of Zoology, and
- International Collaboration on Repair Discoveries, University of British Columbia at Vancouver, Vancouver, British Columbia V6T 1Z3, Canada
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Kozlowski P, Rosicka P, Liu J, Yung AC, Tetzlaff W. In vivo longitudinal Myelin Water Imaging in rat spinal cord following dorsal column transection injury. Magn Reson Imaging 2013; 32:250-8. [PMID: 24462106 DOI: 10.1016/j.mri.2013.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 10/15/2013] [Accepted: 12/01/2013] [Indexed: 11/29/2022]
Abstract
Longitudinal Myelin Water Imaging was carried out in vivo to characterize white matter damage following dorsal column transection (DC Tx) injury at the lumbar level L1 of rat spinal cords. A transmit-receive implantable coil system was used to acquire multiple spin-echo (MSE) quantitative T2 data from the lumbar spinal cords of 16 rats at one week pre-injury as well as 3 and 8weeks post-injury (117 microns in-plane resolution and 1.5mm slice thickness). In addition, ex vivo MSE and DTI data were acquired from cords fixed and excised at 3 or 8weeks post injury using a solenoid coil. The MSE data were used to generate Myelin Water Fractions (MWFs) as a surrogate measure of myelin content, while DTI data were acquired to study damage to the axons. Myelin damage was assessed histologically with Eriochrome cyanine (EC) and Myelin Basic Protein in degenerated myelin (dgen-MBP) staining, and axonal damage was assessed by neurofilament-H in combination with neuron specific beta-III-tubulin (NF/Tub) staining. These MRI and histological measures of injury were studied in the dorsal column at 5mm cranial and 5mm caudal to injury epicenter. MWF increased significantly at 3weeks post-injury at both the cranial and caudal sites, relative to baseline. The values on the cranial side of injury returned to baseline at 8weeks post-injury but remained elevated on the caudal side. This trend was found in both in vivo and ex vivo data. This MWF increase was likely due to the presence of myelin debris, which were cleared by 8 weeks on the cranial, but not the caudal, side. Both EC and dgen-MBP stains displayed similar trends. MWF showed significant correlation with EC staining (R=0.63, p=0.005 in vivo and R=0.74, p=0.0001 ex vivo). MWF also correlated strongly with the dgen-MBP stain, but only on the cranial side (R=0.64, p=0.05 in vivo; R=0.63, p=0.038 ex vivo). This study demonstrates that longitudinal MWI in vivo can accurately characterize white matter damage in DC Tx model of injury in the rat spinal cord.
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Affiliation(s)
- Piotr Kozlowski
- Univeristy of British Columbia, Departments of Radiology and Urologic Sciences, Vancouver British Columbia, Canada; UBC MRI Research Centre, Vancouver, British Columbia, Canada; ICORD, International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada.
| | - Paulina Rosicka
- Institute of Nuclear Physics, Department of Magnetic Resonance Imaging, Krakow, Poland; UBC MRI Research Centre, Vancouver, British Columbia, Canada
| | - Jie Liu
- ICORD, International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada
| | - Andrew C Yung
- UBC MRI Research Centre, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- University of British Columbia, Departments of Zoology and Surgery, Vancouver, British Columbia, Canada; ICORD, International Collaboration on Repair Discoveries, Vancouver, British Columbia, Canada
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Streijger F, Beernink TMJ, Lee JHT, Bhatnagar T, Park S, Kwon BK, Tetzlaff W. Characterization of a cervical spinal cord hemicontusion injury in mice using the infinite horizon impactor. J Neurotrauma 2013; 30:869-83. [PMID: 23360150 DOI: 10.1089/neu.2012.2405] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The majority of clinical spinal cord injuries (SCIs) are contusive and occur at the cervical level of the spinal cord. Most scientists and clinicians agree that the preclinical evaluation of novel candidate treatments should include testing in a cervical SCI contusion model. Because mice are increasingly used because of the availability of genetically engineered lines, we characterized a novel cervical hemicontusion injury in mice using the Infinite Horizon Spinal Cord Impactor (Precisions Systems & Instrumentation, Lexington, KY). In the current study, C57BL/6 mice received a hemicontusion injury of 75 kilodynes with or without dwell time in an attempt to elicit a sustained moderate-to-severe motor deficit. Hemicontusion injuries without dwell time resulted in sustained deficits of the affected forepaw, as revealed by a 3-fold decrease in usage during rearing, a ∼50% reduction in grooming scores, and retrieval of significantly fewer pellets on the Montoya staircase test. Only minor transient deficits were observed in grasping force. CatWalk analysis revealed reduced paw-print size and swing speed of the affected forelimb. Added dwell time of 15 or 30 sec significantly worsened behavioral outcome, and mice demonstrated minimal ability of grasping, paw usage, and overground locomotion. Besides worsening of behavioral deficits, added dwell time also reduced residual white and gray matter at the epicenter and rostral-caudal to the injury, including on the contralateral side of the spinal cord. Taken together, we developed and characterized a new hemicontusion SCI model in mice that produces sufficient and sustained impairments in gross and skilled forelimb function and produced primarily unilateral functional deficits.
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Affiliation(s)
- Femke Streijger
- International Collaboration on Repair Discoveries-ICORD, Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
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Streijger F, Plunet WT, Lee JHT, Liu J, Lam CK, Park S, Hilton BJ, Fransen BL, Matheson KAJ, Assinck P, Kwon BK, Tetzlaff W. Ketogenic diet improves forelimb motor function after spinal cord injury in rodents. PLoS One 2013; 8:e78765. [PMID: 24223849 PMCID: PMC3817084 DOI: 10.1371/journal.pone.0078765] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Accepted: 09/16/2013] [Indexed: 11/29/2022] Open
Abstract
High fat, low carbohydrate ketogenic diets (KD) are validated non-pharmacological treatments for some forms of drug-resistant epilepsy. Ketones reduce neuronal excitation and promote neuroprotection. Here, we investigated the efficacy of KD as a treatment for acute cervical spinal cord injury (SCI) in rats. Starting 4 hours following C5 hemi-contusion injury animals were fed either a standard carbohydrate based diet or a KD formulation with lipid to carbohydrate plus protein ratio of 3:1. The forelimb functional recovery was evaluated for 14 weeks, followed by quantitative histopathology. Post-injury 3:1 KD treatment resulted in increased usage and range of motion of the affected forepaw. Furthermore, KD improved pellet retrieval with recovery of wrist and digit movements. Importantly, after returning to a standard diet after 12 weeks of KD treatment, the improved forelimb function remained stable. Histologically, the spinal cords of KD treated animals displayed smaller lesion areas and more grey matter sparing. In addition, KD treatment increased the number of glucose transporter-1 positive blood vessels in the lesion penumbra and monocarboxylate transporter-1 (MCT1) expression. Pharmacological inhibition of MCTs with 4-CIN (α-cyano-4-hydroxycinnamate) prevented the KD-induced neuroprotection after SCI, In conclusion, post-injury KD effectively promotes functional recovery and is neuroprotective after cervical SCI. These beneficial effects require the function of monocarboxylate transporters responsible for ketone uptake and link the observed neuroprotection directly to the function of ketones, which are known to exert neuroprotection by multiple mechanisms. Our data suggest that current clinical nutritional guidelines, which include relatively high carbohydrate contents, should be revisited.
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Affiliation(s)
- Femke Streijger
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Ward T. Plunet
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Jae H. T. Lee
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Jie Liu
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Clarrie K. Lam
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Soeyun Park
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Brett J. Hilton
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Bas L. Fransen
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Keely A. J. Matheson
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Peggy Assinck
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
| | - Brian K. Kwon
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
- Combined Neurosurgical and Orthopaedic Spine Program, Department of Orthopaedics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Center, Vancouver, British Columbia, Canada
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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Kwon BK, Soril LJ, Bacon M, Beattie MS, Blesch A, Bresnahan JC, Bunge MB, Dunlop SA, Fehlings MG, Ferguson AR, Hill CE, Karimi-Abdolrezaee S, Lu P, McDonald JW, Müller HW, Oudega M, Rosenzweig ES, Reier PJ, Silver J, Sykova E, Xu XM, Guest JD, Tetzlaff W. Corrigendum to “Demonstrating efficacy in preclinical studies of cellular therapies for spinal cord injury — How much is enough?” [Exp. Neurol. 248 (2013) 30–44]. Exp Neurol 2013. [DOI: 10.1016/j.expneurol.2013.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Plemel JR, Manesh SB, Sparling JS, Tetzlaff W. Myelin inhibits oligodendroglial maturation and regulates oligodendrocytic transcription factor expression. Glia 2013; 61:1471-87. [PMID: 23839973 DOI: 10.1002/glia.22535] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 04/20/2013] [Accepted: 04/26/2013] [Indexed: 12/12/2022]
Abstract
Myelin loss is a hallmark of multiple sclerosis (MS) and promoting central nervous system myelin repair has become a major therapeutic target. Despite the presence of oligodendrocytes precursors cells (OPCs) in chronic lesions of MS, remyelination often fails. The mechanism underlying this failure of remyelination remains unknown, but it is hypothesized that environmental cues act to inhibit the maturation/differentiation of oligodendroglia, preventing remyelination. The rate of CNS remyelination is correlated to the speed of phagocytosis of myelin debris, which is present following demyelination and trauma. Thus, myelin debris could inhibit CNS remyelination. Here, we demonstrate that OPCs cultured on myelin were robustly inhibited in their maturation, as characterized by the decreased expression of immature and mature oligodendrocytes markers, the impaired production of myelin gene products, as well as their stalled morphological complexity relative to OPCs cultured on a control substrate. OPCs in contact with myelin stopped proliferating and decreased the expression of OPC markers to a comparable degree as cells grown on a control substrate. The expression of two transcription factors known to prevent OPC differentiation and maturation were increased in cells that were in contact with myelin: inhibitor of differentiation family (ID) members 2 and 4. Overexpression of ID2 and ID4 in OPCs was previously reported to decrease the percentage of cells expressing mature oligodendrocyte markers. However, knockdown of ID2 and/or ID4 in OPCs did not increase oligodendroglial maturation on or off of myelin, suggesting that contact with myelin regulates additional regulatory elements.
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Affiliation(s)
- Jason R Plemel
- ICORD (International Collaboration on Repair Discoveries), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
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