1
|
Ghosh T, Almeida RG, Zhao C, Mannioui A, Martin E, Fleet A, Chen CZ, Assinck P, Ellams S, Gonzalez GA, Graham SC, Rowitch DH, Stott K, Adams I, Zalc B, Goldman N, Lyons DA, Franklin RJM. A retroviral link to vertebrate myelination through retrotransposon-RNA-mediated control of myelin gene expression. Cell 2024; 187:814-830.e23. [PMID: 38364788 DOI: 10.1016/j.cell.2024.01.011] [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: 12/12/2022] [Revised: 10/12/2023] [Accepted: 01/07/2024] [Indexed: 02/18/2024]
Abstract
Myelin, the insulating sheath that surrounds neuronal axons, is produced by oligodendrocytes in the central nervous system (CNS). This evolutionary innovation, which first appears in jawed vertebrates, enabled rapid transmission of nerve impulses, more complex brains, and greater morphological diversity. Here, we report that RNA-level expression of RNLTR12-int, a retrotransposon of retroviral origin, is essential for myelination. We show that RNLTR12-int-encoded RNA binds to the transcription factor SOX10 to regulate transcription of myelin basic protein (Mbp, the major constituent of myelin) in rodents. RNLTR12-int-like sequences (which we name RetroMyelin) are found in all jawed vertebrates, and we further demonstrate their function in regulating myelination in two different vertebrate classes (zebrafish and frogs). Our study therefore suggests that retroviral endogenization played a prominent role in the emergence of vertebrate myelin.
Collapse
Affiliation(s)
- Tanay Ghosh
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK.
| | - Rafael G Almeida
- Centre for Discovery Brain Sciences, MS society Edinburgh Centre for MS Research, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Chao Zhao
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Abdelkrim Mannioui
- Sorbonne Université, Institut de Biologie Paris-Seine (IBPS), Aquatic Facility, 75005 Paris, France
| | - Elodie Martin
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Alex Fleet
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Civia Z Chen
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Peggy Assinck
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Sophie Ellams
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK
| | - Ginez A Gonzalez
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK
| | - Stephen C Graham
- Division of Virology, Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK
| | - David H Rowitch
- Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Paediatrics, University of Cambridge, Cambridge, UK
| | - Katherine Stott
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK
| | - Ian Adams
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Bernard Zalc
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Nick Goldman
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome, Genome Campus, Hinxton, Cambridge CB10 1SD, UK
| | - David A Lyons
- Centre for Discovery Brain Sciences, MS society Edinburgh Centre for MS Research, University of Edinburgh, Chancellor's Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Robin J M Franklin
- Altos Labs-Cambridge Institute of Science, Cambridge CB21 6GP, UK; Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 0AW, UK; Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AW, UK.
| |
Collapse
|
2
|
Duncan GJ, Assinck P, Stratton JA, Ajami B, Plemel JR. Editorial: Non-neuronal cell heterogeneity in the nervous system during health and disease. Front Cell Neurosci 2022; 16:1047296. [PMID: 36339821 PMCID: PMC9628672 DOI: 10.3389/fncel.2022.1047296] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 10/10/2022] [Indexed: 11/17/2022] Open
Affiliation(s)
- Greg J. Duncan
- Jungers Center for Neurosciences Research, Department of Neurology, Oregon Health and Science University, Portland, OR, United States
| | - Peggy Assinck
- Wellcome Trust - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Jo Anne Stratton
- Neuroimmunology Group, Montreal Neurological Institute and Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
| | - Bahareh Ajami
- Department of Molecular Microbiology and Immunology (MMI) and Behavioral and Systems Neuroscience, Oregon Health and Science University, Portland, OR, United States
| | - Jason R. Plemel
- Department of Medicine, Division of Neurology, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
- *Correspondence: Jason R. Plemel
| |
Collapse
|
3
|
Zirngibl M, Assinck P, Sizov A, Caprariello AV, Plemel JR. Oligodendrocyte death and myelin loss in the cuprizone model: an updated overview of the intrinsic and extrinsic causes of cuprizone demyelination. Mol Neurodegener 2022; 17:34. [PMID: 35526004 PMCID: PMC9077942 DOI: 10.1186/s13024-022-00538-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [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: 10/28/2021] [Accepted: 04/08/2022] [Indexed: 12/15/2022] Open
Abstract
The dietary consumption of cuprizone – a copper chelator – has long been known to induce demyelination of specific brain structures and is widely used as model of multiple sclerosis. Despite the extensive use of cuprizone, the mechanism by which it induces demyelination are still unknown. With this review we provide an updated understanding of this model, by showcasing two distinct yet overlapping modes of action for cuprizone-induced demyelination; 1) damage originating from within the oligodendrocyte, caused by mitochondrial dysfunction or reduced myelin protein synthesis. We term this mode of action ‘intrinsic cell damage’. And 2) damage to the oligodendrocyte exerted by inflammatory molecules, brain resident cells, such as oligodendrocytes, astrocytes, and microglia or peripheral immune cells – neutrophils or T-cells. We term this mode of action ‘extrinsic cellular damage’. Lastly, we summarize recent developments in research on different forms of cell death induced by cuprizone, which could add valuable insights into the mechanisms of cuprizone toxicity. With this review we hope to provide a modern understanding of cuprizone-induced demyelination to understand the causes behind the demyelination in MS.
Collapse
Affiliation(s)
- Martin Zirngibl
- Faculty of Medicine & Dentistry, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Peggy Assinck
- Wellcome Trust- MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK.,Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, UK
| | - Anastasia Sizov
- Faculty of Medicine & Dentistry, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada
| | - Andrew V Caprariello
- Department of Clinical Neurosciences, Hotchkiss Brain Institute, University of Calgary, Cumming School of Medicine, Calgary, Canada
| | - Jason R Plemel
- Faculty of Medicine & Dentistry, Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Canada. .,Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada. .,Department of Medicine, Division of Neurology, University of Alberta, Edmonton, Canada.
| |
Collapse
|
4
|
Swire M, Assinck P, McNaughton PA, Lyons DA, Ffrench-Constant C, Livesey MR. Oligodendrocyte HCN2 Channels Regulate Myelin Sheath Length. J Neurosci 2021; 41:7954-7964. [PMID: 34341156 PMCID: PMC8460148 DOI: 10.1523/jneurosci.2463-20.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [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: 09/21/2020] [Revised: 06/16/2021] [Accepted: 07/06/2021] [Indexed: 11/21/2022] Open
Abstract
Oligodendrocytes generate myelin sheaths vital for the formation, health, and function of the CNS. Myelin sheath length is a key property that determines axonal conduction velocity and is known to be variable across the CNS. Myelin sheath length can be modified by neuronal activity, suggesting that dynamic regulation of sheath length might contribute to the functional plasticity of neural circuits. Although the mechanisms that establish and refine myelin sheath length are important determinants of brain function, our understanding of these remains limited. In recent years, the membranes of myelin sheaths have been increasingly recognized to contain ion channels and transporters that are associated with specific important oligodendrocyte functions, including metabolic support of axons and the regulation of ion homeostasis, but none have been shown to influence sheath architecture. In this study, we determined that hyperpolarization-activated, cyclic nucleotide-gated (HCN) ion channels, typically associated with neuronal and cardiac excitability, regulate myelin sheath length. Using both in vivo and in vitro approaches, we show that oligodendrocytes abundantly express functional, predominantly HCN2 subunit-containing ion channels. These HCN ion channels retain key pharmacological and biophysical features and regulate the resting membrane potential of myelinating oligodendrocytes. Further, reduction of their function via pharmacological blockade or generation of transgenic mice with two independent oligodendrocyte-specific HCN2 knock-out strategies reduced myelin sheath length. We conclude that HCN2 ion channels are key determinants of myelin sheath length in the CNS.SIGNIFICANCE STATEMENT Myelin sheath length is a critical determinant of axonal conduction velocity, but the signaling mechanisms responsible for determining sheath length are poorly understood. Here we find that oligodendrocytes express functional hyperpolarization-activated, cyclic nucleotide-gated 2 (HCN2) ion channels that regulate the length of myelin sheaths formed by oligodendrocytes in myelinating cultures and in the mouse brain and spinal cord. These results suggest that the regulation of HCN2 channel activity is well placed to refine sheath length and conduction along myelinated axons, providing a potential mechanism for alterations in conduction velocity and circuit function in response to axonal signals such as those generated by increased activity.
Collapse
Affiliation(s)
- Matthew Swire
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, United Kingdom
| | - Peggy Assinck
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Peter A McNaughton
- Wolfson Centre for Age-Related Diseases, King's College London, London WC2R 2LS, United Kingdom
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Charles Ffrench-Constant
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Matthew R Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, United Kingdom
| |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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
Collapse
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.
| |
Collapse
|
7
|
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.
Collapse
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
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
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.
| |
Collapse
|
10
|
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.
Collapse
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
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
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
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Xing H, Zhou M, Assinck P, Liu N. Electrical stimulation influences satellite cell differentiation after sciatic nerve crush injury in rats. Muscle Nerve 2015; 51:400-11. [PMID: 24947716 DOI: 10.1002/mus.24322] [Citation(s) in RCA: 21] [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] [Accepted: 06/16/2014] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Electrical stimulation is often used to prevent muscle atrophy and preserve contractile function, but its effects on the satellite cell population after nerve injury are not well understood. In this study we aimed to determine whether satellite cell differentiation is affected by electrical stimulation after nerve crush. METHODS The sciatic nerves of Sprague-Dawley (SD) rats were crushed. Half of the injured rats received daily electrical stimulation of the gastrocnemius muscle, and the others did not. Tests for detecting paired box protein 7 (Pax7), myogenic differentiation antigen (MyoD), embryonic myosin heavy chain (eMyHC), and force production were performed 2, 4, and 6 weeks after injury. RESULTS More Pax7+/MyoD+ nuclei in stimulated muscles were observed than in non-stimulated muscles. eMyHC expression was elevated in stimulated muscles and correlated positively with enhanced force production. CONCLUSIONS Increased satellite cell differentiation is correlated with preserved muscle function in response to electrical stimulation after nerve injury.
Collapse
Affiliation(s)
- Huayi Xing
- Department of Rehabilitation Medicine, Peking University Third Hospital, 49 North Garden Road, Beijing, 100191, PR China
| | | | | | | |
Collapse
|
14
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
15
|
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.
Collapse
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
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
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.
Collapse
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:
| |
Collapse
|
17
|
Hilton BJ, Assinck P, Duncan GJ, Lu D, Lo S, Tetzlaff W. Dorsolateral Funiculus Lesioning of the Mouse Cervical Spinal Cord at C4 but Not at C6 Results in Sustained Forelimb Motor Deficits. J Neurotrauma 2013; 30:1070-83. [DOI: 10.1089/neu.2012.2734] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Brett J. Hilton
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
| | - Peggy Assinck
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
- Graduate Program in Neuroscience, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Greg J. Duncan
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
| | - Daniel Lu
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
| | - Stephanie Lo
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
| | - Wolfram Tetzlaff
- Department of Zoology, The University of British Columbia, Vancouver, British Columbia, Canada
- International Collaboration on Repair Discoveries (ICORD), Blusson Spinal Cord Centre, Vancouver, British Columbia, Canada
- Graduate Program in Neuroscience, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|