1
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Manesh SB, Kondiles BR, Wheeler S, Liu J, Zhang L, Chernoff C, Duncan GJ, Ramer MS, Tetzlaff W. Compensatory changes after spinal cord injury in a remyelination deficient mouse model. J Neurochem 2024. [PMID: 39268880 DOI: 10.1111/jnc.16220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 08/22/2024] [Accepted: 08/23/2024] [Indexed: 09/15/2024]
Abstract
The development of therapeutic strategies to reduce impairments following spinal cord injury (SCI) motivates an active area of research, because there are no effective therapies. One strategy is to address injury-induced demyelination of spared axons by promoting endogenous or exogenous remyelination. However, previously, we showed that new myelin was not necessary to regain hindlimb stepping following moderate thoracic spinal cord contusion in 3-month-old mice. The present analysis investigated two potential mechanisms by which animals can re-establish locomotion in the absence of remyelination: compensation through intact white matter and conduction through spared axons. We induced a severe contusion injury to reduce the spared white matter rim in the remyelination deficient model, with no differences in recovery between remyelination deficient animals and injured littermate controls. We investigated the nodal properties of the axons at the lesion and found that in the remyelination deficient model, axons express the Nav1.2 voltage-gated sodium channel, a sub-type not typically expressed at mature nodes of Ranvier. In a moderate contusion injury, conduction velocities through the lesions of remyelination deficient animals were similar to those in animals with the capacity to remyelinate after injury. Detailed gait analysis and kinematics reveal subtle differences between remyelination deficient animals and remyelination competent controls, but no worse deficits. It is possible that upregulation of Nav1.2 channels may contribute to establishing conduction through the lesion. This conduction could contribute to compensation and regained motor function in mouse models of SCI. Such compensatory mechanism may have implications for interpreting efficacy results for remyelinating interventions in mice and the development of therapies for improving recovery following SCI.
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Affiliation(s)
- S B Manesh
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - B R Kondiles
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - S Wheeler
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - J Liu
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - L Zhang
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - C Chernoff
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - G J Duncan
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
| | - M S Ramer
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
| | - W Tetzlaff
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada
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2
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Saraswat Ohri S, Forston MD, Myers SA, Brown BL, Andres KR, Howard RM, Gao Y, Liu Y, Cavener DR, Hetman M, Whittemore SR. Oligodendrocyte-selective deletion of the eIF2α kinase Perk/Eif2ak3 limits functional recovery after spinal cord injury. Glia 2024; 72:1259-1272. [PMID: 38587137 DOI: 10.1002/glia.24525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/13/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024]
Abstract
After spinal cord injury (SCI), re-establishing cellular homeostasis is critical to optimize functional recovery. Central to that response is PERK signaling, which ultimately initiates a pro-apoptotic response if cellular homeostasis cannot be restored. Oligodendrocyte (OL) loss and white matter damage drive functional consequences and determine recovery potential after thoracic contusive SCI. We examined acute (<48 h post-SCI) and chronic (6 weeks post-SCI) effects of conditionally deleting Perk from OLs prior to SCI. While Perk transcript is expressed in many types of cells in the adult spinal cord, its levels are disproportionately high in OL lineage cells. Deletion of OL-Perk prior to SCI resulted in: (1) enhanced acute phosphorylation of eIF2α, a major PERK substrate and the critical mediator of the integrated stress response (ISR), (2) enhanced acute expression of the downstream ISR genes Atf4, Ddit3/Chop, and Tnfrsf10b/Dr5, (3) reduced acute OL lineage-specific Olig2 mRNA, but not neuronal or astrocytic mRNAs, (4) chronically decreased OL content in the spared white matter at the injury epicenter, (5) impaired hindlimb locomotor recovery, and (6) reduced chronic epicenter white matter sparing. Cultured primary OL precursor cells with reduced PERK expression and activated ER stress response showed: (1) unaffected phosphorylation of eIF2α, (2) enhanced ISR gene induction, and (3) increased cytotoxicity. Therefore, OL-Perk deficiency exacerbates ISR signaling and potentiates white matter damage after SCI. The latter effect is likely mediated by increased loss of Perk-/- OLs.
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Affiliation(s)
- Sujata Saraswat Ohri
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Interdisciplinary Program in Translational Neuroscience, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Michael D Forston
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Scott A Myers
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
| | - Brandon L Brown
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
- Department of Interdisciplinary Program in Translational Neuroscience, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Kariena R Andres
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
| | - Russell M Howard
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
| | - Yonglin Gao
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
| | - Yu Liu
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
| | - Douglas R Cavener
- Department of Biology, Penn State University, University Park, Pennsylvania, USA
| | - Michal Hetman
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Interdisciplinary Program in Translational Neuroscience, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Pharmacology & Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA
- M.D./Ph.D. Program, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Scott R Whittemore
- Kentucky Spinal Cord Injury Research Center, Louisville, Kentucky, USA
- Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Interdisciplinary Program in Translational Neuroscience, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Anatomical Sciences & Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
- Department of Pharmacology & Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, USA
- M.D./Ph.D. Program, University of Louisville School of Medicine, Louisville, Kentucky, USA
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3
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Osorio-Londoño D, Morales-Guadarrama A, Olayo-González R, Roldan-Valadez E. Quantitative Magnetic Resonance Identifies Recovery from Spinal Cord Injury after Bioactive Implants. Arch Med Res 2024; 55:103012. [PMID: 38851049 DOI: 10.1016/j.arcmed.2024.103012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/07/2024] [Accepted: 05/22/2024] [Indexed: 06/10/2024]
Affiliation(s)
| | - Axayácatl Morales-Guadarrama
- Medical Imaging and Instrumentation Research National Center, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | | | - Ernesto Roldan-Valadez
- Division of Research, Instituto Nacional de Rehabilitación, Luis Guillermo Ibarra Ibarra, Mexico City, Mexico; I.M. Sechenov First Moscow State Medical University, Sechenov University, Department of Radiology, Moscow, Russia.
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4
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Malloy DC, Côté MP. Multi-session transcutaneous spinal cord stimulation prevents chloride homeostasis imbalance and the development of hyperreflexia after spinal cord injury in rat. Exp Neurol 2024; 376:114754. [PMID: 38493983 DOI: 10.1016/j.expneurol.2024.114754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/28/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.
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Affiliation(s)
- Dillon C Malloy
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
| | - Marie-Pascale Côté
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129, United States of America.
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5
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Aldrich JC, Scheinfeld AR, Lee SE, Dusenbery KJ, Mahach KM, Van de Veire BC, Fonken LK, Gaudet AD. Effects of dim light at night in C57BL/6 J mice on recovery after spinal cord injury. Exp Neurol 2024; 375:114725. [PMID: 38365132 PMCID: PMC10981559 DOI: 10.1016/j.expneurol.2024.114725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 01/09/2024] [Accepted: 02/12/2024] [Indexed: 02/18/2024]
Abstract
Spinal cord injury (SCI) can cause long-lasting locomotor deficits, pain, and mood disorders. Anatomical and functional outcomes are exacerbated by inflammation after SCI, which causes secondary damage. One promising target after SCI is manipulating the circadian system, which optimizes biology and behavior for time of day - including neuroimmune responses and mood-related behaviors. Circadian disruption after SCI is likely worsened by a disruptive hospital environment, which typically includes dim light-at-night (dLAN). Here, we hypothesized that mice subjected to SCI, then placed in dLAN, would exhibit worsened locomotor deficits, pain-like behavior, and anxiety-depressive-like symptoms compared to mice maintained in light days with dark nights (LD). C57BL/6 J mice received sham surgery or moderate T9 contusion SCI, then were placed permanently in LD or dLAN. dLAN after SCI did not worsen locomotor deficits; rather, SCI-dLAN mice showed slight improvement in open-field locomotion at the final timepoint. Although dLAN did not alter SCI-induced heat hyperalgesia, SCI-dLAN mice exhibited an increase in mechanical allodynia at 13 days post-SCI compared to SCI-LD mice. SCI-LD and SCI-dLAN mice had similar outcomes using sucrose preference (depressive-like) and open-field (anxiety-like) tests. At 21 dpo, SCI-dLAN mice had reduced preference for a novel juvenile compared to SCI-LD, implying that dLAN combined with SCI may worsen this mood-related behavior. Finally, lesion size was similar between SCI-LD and SCI-dLAN mice. Therefore, newly placing C57BL/6 J mice in dLAN after SCI had modest effects on locomotor, pain-like, and mood-related behaviors. Future studies should consider whether clinically-relevant circadian disruptors, alone or in combination, could be ameliorated to enhance outcomes after SCI.
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Affiliation(s)
- John C Aldrich
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Ashley R Scheinfeld
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Sydney E Lee
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kalina J Dusenbery
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kathryn M Mahach
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Brigid C Van de Veire
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Laura K Fonken
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin
| | - Andrew D Gaudet
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin, USA; Department of Neurology, Dell Medical School, The University of Texas at Austin.
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6
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Su H, Luo H, Wang Y, Zhao Q, Zhang Q, Zhu Y, Pan L, Liu Y, Yang C, Yin Y, Tan B. Myelin repair of spinal cord injury in adult mice induced by treadmill training upregulated peroxisome proliferator-activated receptor gamma coactivator 1 alpha. Glia 2024; 72:607-624. [PMID: 38031815 DOI: 10.1002/glia.24493] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 11/10/2023] [Accepted: 11/14/2023] [Indexed: 12/01/2023]
Abstract
Growing evidence has proven the efficacy of physical exercise in remyelination and motor function performance after spinal cord injury (SCI). However, the molecular mechanisms of treadmill training on myelin repair and functional recovery after SCI have not yet been fully studied. Here, we explored the effect of treadmill training on upregulating peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC1α)-mediated myelin repair and functional recovery in a mouse model of thoracic T10 contusion injury. A 4-week treadmill training scheme was conducted on mice with SCI. The expression levels of oligodendrogenesis-related protein and PGC1α were detected by immunofluorescence, RNA fluorescence in situ hybridization and western blotting. Transmission electron microscopy (TEM) was used to observe myelin structure. The Basso Mouse Scale (BMS) and CatWalk automated gait analysis system were used for motor function recovery evaluation. Motor evoked potentials (MEPs) were also identified. In addition, adeno-associated virus (AAV)-mediated PGC1α knockdown in OLs was used to further unravel the role of PGC1α in exercise-induced remyelination. We found that treadmill training boosts oligodendrocyte precursor cells (OPCs) proliferation, potentiates oligodendrocytes (OLs) maturation, and increases myelin-related protein and myelin sheath thickness, thus impelling myelin repair and hindlimb functional performance as well as the speed and amplitude of nerve conduction after SCI. Additionally, downregulating PGC1α through AAV attenuated these positive effects of treadmill training. Collectively, our results suggest that treadmill training enhances remyelination and functional recovery by upregulating PGC1α, which should provide a step forward in the understanding of the effects of physical exercise on myelin repair.
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Affiliation(s)
- Hong Su
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Haodong Luo
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yunhang Wang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qin Zhao
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qing Zhang
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Ying Zhu
- State Key Laboratory of Trauma, Burns and Combined Injuries, Department of Special Environment War Wound Prevention and Treatment, Institute of Surgery Research, Army Medical Center of PLA, Chongqing, China
| | - Lu Pan
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuan Liu
- State Key Laboratory of Trauma, Burns and Combined Injuries, Department of Special Environment War Wound Prevention and Treatment, Institute of Surgery Research, Army Medical Center of PLA, Chongqing, China
| | - Ce Yang
- State Key Laboratory of Trauma, Burns and Combined Injuries, Department of Special Environment War Wound Prevention and Treatment, Institute of Surgery Research, Army Medical Center of PLA, Chongqing, China
| | - Ying Yin
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Botao Tan
- Department of Rehabilitation Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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7
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Aldrich JC, Scheinfeld AR, Lee SE, Dusenbery KJ, Mahach KM, Van de Veire BC, Fonken LK, Gaudet AD. Effects of dim light at night in C57BL/6J mice on recovery after spinal cord injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.15.557980. [PMID: 37745393 PMCID: PMC10516041 DOI: 10.1101/2023.09.15.557980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Spinal cord injury (SCI) can cause long-lasting locomotor deficits, pain, and mood disorders. Anatomical and functional outcomes are exacerbated by inflammation after SCI, which causes secondary damage. One promising target after SCI is manipulating the circadian system, which optimizes biology and behavior for time of day - including neuroimmune responses and mood-related behaviors. Circadian disruption after SCI is likely worsened by a disruptive hospital environment, which typically includes dim light-at-night (dLAN). Here, we hypothesized that mice subjected to SCI, then placed in dLAN, would exhibit worsened locomotor deficits, pain-like behavior, and anxiety-depressive-like symptoms compared to mice maintained in light days with dark nights (LD). C57BL/6J mice received sham surgery or moderate T9 contusion SCI, then were placed permanently in LD or dLAN. dLAN after SCI did not worsen locomotor deficits; rather, SCI-dLAN mice showed slight improvement in open-field locomotion at the final timepoint. Although dLAN did not alter SCI-induced heat hyperalgesia, SCI-dLAN mice exhibited an increase in mechanical allodynia at 13 days post-SCI compared to SCI-LD mice. SCI-LD and SCI-dLAN mice had similar outcomes using sucrose preference (depressive-like) and open-field (anxiety-like) tests. At 21 dpo, SCI-dLAN mice had reduced preference for a novel juvenile compared to SCI-LD, implying that dLAN combined with SCI may worsen this mood-related behavior. Finally, lesion size was similar between SCI-LD and SCI-dLAN mice. Therefore, newly placing C57BL/6J mice in dLAN after SCI had modest effects on locomotor, pain-like, and mood-related behaviors. Future studies should consider whether clinically-relevant circadian disruptors, alone or in combination, could be ameliorated to enhance outcomes after SCI.
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Affiliation(s)
- John C Aldrich
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Ashley R Scheinfeld
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Sydney E Lee
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kalina J Dusenbery
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Kathryn M Mahach
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Brigid C Van de Veire
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Laura K Fonken
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin
| | - Andrew D Gaudet
- Department of Psychology, College of Liberal Arts, The University of Texas at Austin
- Department of Neurology, Dell Medical School, The University of Texas at Austin
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8
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Estera LA, Walsh SP, Headen JA, Williamson RE, Kalinski AL. Neuroinflammation: Breaking barriers and bridging gaps. Neurosci Res 2023; 197:9-17. [PMID: 34748905 DOI: 10.1016/j.neures.2021.11.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 11/01/2021] [Indexed: 01/04/2023]
Abstract
Neurons are the cells of the nervous system and are responsible for every thought, movement and perception. Immune cells are the cells of the immune system, constantly protecting from foreign pathogens. Understanding the interaction between the two systems is especially important in disease states such as autoimmune or neurodegenerative disease. Unfortunately, this interaction is typically detrimental to the host. However, recent efforts have focused on how neurons and immune cells interact, either directly or indirectly, following traumatic injury to the nervous system. The outcome of this interaction can be beneficial - leading to successful neural repair, or detrimental - leading to functional deficits, depending on where the injury occurs. This review will discuss our understanding of neuron-immune cell interactions after traumatic injury to both the peripheral and central nervous system.
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Affiliation(s)
- Lora A Estera
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | - Sam P Walsh
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | - Jordan A Headen
- Department of Biology, Ball State University, Muncie, IN 47306, USA
| | | | - Ashley L Kalinski
- Department of Biology, Ball State University, Muncie, IN 47306, USA.
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9
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Malloy DC, Côté MP. Multi-session transcutaneous spinal cord stimulation prevents chloridehomeostasis imbalance and the development of spasticity after spinal cordinjury in rat. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.24.563419. [PMID: 37961233 PMCID: PMC10634766 DOI: 10.1101/2023.10.24.563419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects. Despite its popularity, the neuroplasticity induced by tSCS also remains widely unexplored, particularly due to the lack of suitable animal models to investigate this intervention. Thus, the basis of this work was to use tSCS over multiple sessions (multi-session tSCS) in a rat model to target spasticity after SCI and identify the long-term physiological improvements and anatomical neuroplasticity occurring in the spinal cord. Here, we show that multi-session tSCS in rats with an incomplete (severe T9 contusion) SCI (1) decreases hyperreflexia, (2) increases the low frequency-dependent modulation of the H-reflex, (3) prevents potassium-chloride cotransporter isoform 2 (KCC2) membrane downregulation in lumbar motoneurons, and (4) generally augments motor output, i.e., EMG amplitude in response to single pulses of tSCS, particularly in extensor muscles. Together, this work displays that multi-session tSCS can target and diminish spasticity after SCI as an alternative to pharmacological interventions and begins to highlight the underlying neuroplasticity contributing to its success in improving functional recovery.
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Affiliation(s)
- Dillon C. Malloy
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
| | - Marie-Pascale Côté
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129
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10
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Zuo Y, Ye J, Cai W, Guo B, Chen X, Lin L, Jin S, Zheng H, Fang A, Qian X, Abdelrahman Z, Wang Z, Zhang Z, Chen Z, Yu B, Gu X, Wang X. Controlled delivery of a neurotransmitter-agonist conjugate for functional recovery after severe spinal cord injury. NATURE NANOTECHNOLOGY 2023; 18:1230-1240. [PMID: 37308588 DOI: 10.1038/s41565-023-01416-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 05/04/2023] [Indexed: 06/14/2023]
Abstract
Despite considerable unmet medical needs, effective pharmacological treatments that promote functional recovery after spinal cord injury remain limited. Although multiple pathological events are implicated in spinal cord injuries, the development of a microinvasive pharmacological approach that simultaneously targets the different mechanisms involved in spinal cord injury remains a formidable challenge. Here we report the development of a microinvasive nanodrug delivery system that consists of amphiphilic copolymers responsive to reactive oxygen species and an encapsulated neurotransmitter-conjugated KCC2 agonist. Upon intravenous administration, the nanodrugs enter the injured spinal cord due to a disruption in the blood-spinal cord barrier and disassembly due to damage-triggered reactive oxygen species. The nanodrugs exhibit dual functions in the injured spinal cord: scavenging accumulated reactive oxygen species in the lesion, thereby protecting spared tissues, and facilitating the integration of spared circuits into the host spinal cord through targeted modulation of inhibitory neurons. This microinvasive treatment leads to notable functional recovery in rats with contusive spinal cord injury.
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Affiliation(s)
- Yanming Zuo
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P. R. China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Jingjia Ye
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P. R. China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Wanxiong Cai
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Binjie Guo
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Xiangfeng Chen
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Lingmin Lin
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Shuang Jin
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Hanyu Zheng
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Ao Fang
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Xingran Qian
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Zeinab Abdelrahman
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P. R. China
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Zhiping Wang
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China
| | - Zhipeng Zhang
- School of Chemistry and Molecular Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science & Technology, Shanghai, P. R. China
| | - Zuobin Chen
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P. R. China
| | - Bin Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, P. R. China
| | - Xiaosong Gu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, P. R. China
| | - Xuhua Wang
- Department of Neurobiology and Department of Rehabilitation Medicine, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, P. R. China.
- Liangzhu Laboratory, MOE Frontier Science Center for Brain Science and Brain-machine Integration, State Key Laboratory of Brain-machine Intelligence, Zhejiang University, Hangzhou, China.
- NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University, Hangzhou, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, P. R. China.
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11
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Akalu Y, Frazer AK, Howatson G, Pearce AJ, Siddique U, Rostami M, Tallent J, Kidgell DJ. Identifying the role of the reticulospinal tract for strength and motor recovery: A scoping review of nonhuman and human studies. Physiol Rep 2023; 11:e15765. [PMID: 37474275 PMCID: PMC10359156 DOI: 10.14814/phy2.15765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 06/26/2023] [Indexed: 07/22/2023] Open
Abstract
In addition to the established postural control role of the reticulospinal tract (RST), there has been an increasing interest on its involvement in strength, motor recovery, and other gross motor functions. However, there are no reviews that have systematically assessed the overall motor function of the RST. Therefore, we aimed to determine the role of the RST underpinning motor function and recovery. We performed a literature search using Ovid Medline, Embase, CINAHL Plus, and Scopus to retrieve papers using key words for RST, strength, and motor recovery. Human and animal studies which assessed the role of RST were included. Studies were screened and 32 eligible studies were included for the final analysis. Of these, 21 of them were human studies while the remaining were on monkeys and rats. Seven experimental animal studies and four human studies provided evidence for the involvement of the RST in motor recovery, while two experimental animal studies and eight human studies provided evidence for strength gain. The RST influenced gross motor function in two experimental animal studies and five human studies. Overall, the RST has an important role for motor recovery, gross motor function and at least in part, underpins strength gain. The role of RST for strength gain in healthy people and its involvement in spasticity in a clinical population has been limitedly described. Further studies are required to ascertain the role of the RST's role in enhancing strength and its contribution to the development of spasticity.
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Affiliation(s)
- Yonas Akalu
- Monash Exercise Neuroplasticity Research UnitDepartment of PhysiotherapySchool of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health ScienceMonash UniversityMelbourneVictoriaAustralia
- Department of Human PhysiologySchool of MedicineUniversity of GondarGondarEthiopia
| | - Ashlyn K. Frazer
- Monash Exercise Neuroplasticity Research UnitDepartment of PhysiotherapySchool of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health ScienceMonash UniversityMelbourneVictoriaAustralia
| | - Glyn Howatson
- Department of Sport, Exercise and RehabilitationNorthumbria UniversityNewcastleUK
- Water Research GroupNorth West UniversityPotchefstroomSouth Africa
| | - Alan J. Pearce
- College of Science, Health and EngineeringLa Trobe UniversityMelbourneVictoriaAustralia
| | - Ummatul Siddique
- Monash Exercise Neuroplasticity Research UnitDepartment of PhysiotherapySchool of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health ScienceMonash UniversityMelbourneVictoriaAustralia
| | - Mohamad Rostami
- Monash Exercise Neuroplasticity Research UnitDepartment of PhysiotherapySchool of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health ScienceMonash UniversityMelbourneVictoriaAustralia
| | - Jamie Tallent
- Monash Exercise Neuroplasticity Research UnitDepartment of PhysiotherapySchool of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health ScienceMonash UniversityMelbourneVictoriaAustralia
- School of Sport, Rehabilitation and Exercise SciencesUniversity of EssexColchesterUK
| | - Dawson J. Kidgell
- Monash Exercise Neuroplasticity Research UnitDepartment of PhysiotherapySchool of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health ScienceMonash UniversityMelbourneVictoriaAustralia
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12
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Kim DH, Sim KB. A Novel Acute Discogenic Myelopathy Model Using Merocel ® Sponge: Comparison With Clip Compression Model in Rats. Korean J Neurotrauma 2023; 19:204-217. [PMID: 37431382 PMCID: PMC10329878 DOI: 10.13004/kjnt.2023.19.e28] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 06/02/2023] [Accepted: 06/08/2023] [Indexed: 07/12/2023] Open
Abstract
Objective Animal models of spinal cord injuries (SCIs) use rats to simulate human SCIs. Among the various techniques, clips have been used to reproduce the compression-contusion model. However, the mechanism of injury in discogenic incomplete SCI may differ from that in clip injury; however, a model has yet to be established. Previously, we issued a patent (No. 10-2053770) for a rat SCI model using Merocel®, a water-absorbing self-expanding polymer sponge. The objectives of this study were to compare the locomotor and histopathological changes between the Merocel®-compression model (MC group) and clip compression model (clip group). Methods This study included 4 groups of rats: MC (n=30), MC-sham (n=5), clip (n=30), and clip-sham (n=5). Locomotor function was evaluated in all groups using the Basso, Beattie, and Bresnahan (BBB) scoring system, 4 weeks after injury. Histopathological analyses included morphology, presence of inflammatory cells, microglial activation, and extent of neuronal damage, which were compared among the groups. Results The BBB scores in the MC group were significantly higher than those in the clip group throughout the 4 weeks (p<0.01). Neuropathological changes in the MC group were significantly less severe than those in the clip group. In addition, motor neurons were well preserved in the ventral horn of the MC group but poorly preserved in the ventral horn of the clip group. Conclusion The novel MC group can help elucidate the pathophysiology of acute discogenic incomplete SCIs and may be applied in various SCI therapeutic strategies.
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Affiliation(s)
- Do-Hyung Kim
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Korea
| | - Ki-Bum Sim
- Department of Neurosurgery, College of Medicine, Jeju National University, Jeju, Korea
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13
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Shafqat A, Albalkhi I, Magableh HM, Saleh T, Alkattan K, Yaqinuddin A. Tackling the glial scar in spinal cord regeneration: new discoveries and future directions. Front Cell Neurosci 2023; 17:1180825. [PMID: 37293626 PMCID: PMC10244598 DOI: 10.3389/fncel.2023.1180825] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/08/2023] [Indexed: 06/10/2023] Open
Abstract
Axonal regeneration and functional recovery are poor after spinal cord injury (SCI), typified by the formation of an injury scar. While this scar was traditionally believed to be primarily responsible for axonal regeneration failure, current knowledge takes a more holistic approach that considers the intrinsic growth capacity of axons. Targeting the SCI scar has also not reproducibly yielded nearly the same efficacy in animal models compared to these neuron-directed approaches. These results suggest that the major reason behind central nervous system (CNS) regeneration failure is not the injury scar but a failure to stimulate axon growth adequately. These findings raise questions about whether targeting neuroinflammation and glial scarring still constitute viable translational avenues. We provide a comprehensive review of the dual role of neuroinflammation and scarring after SCI and how future research can produce therapeutic strategies targeting the hurdles to axonal regeneration posed by these processes without compromising neuroprotection.
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14
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Tan S, Faull RLM, Curtis MA. The tracts, cytoarchitecture, and neurochemistry of the spinal cord. Anat Rec (Hoboken) 2023; 306:777-819. [PMID: 36099279 DOI: 10.1002/ar.25079] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/01/2022] [Accepted: 09/11/2022] [Indexed: 11/06/2022]
Abstract
The human spinal cord can be described using a range of nomenclatures with each providing insight into its structure and function. Here we have comprehensively reviewed the key literature detailing the general structure, configuration of tracts, the cytoarchitecture of Rexed's laminae, and the neurochemistry at the spinal segmental level. The purpose of this review is to detail current anatomical understanding of how the spinal cord is structured and to aid researchers in identifying gaps in the literature that need to be studied to improve our knowledge of the spinal cord which in turn will improve the potential of therapeutic intervention for disorders of the spinal cord.
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Affiliation(s)
- Sheryl Tan
- Centre for Brain Research and Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research and Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research and Department of Anatomy and Medical Imaging, University of Auckland, Auckland, New Zealand
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15
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Sydney-Smith JD, Koltchev AM, Moon LDF, Warren PM. Delayed viral vector mediated delivery of neurotrophin-3 improves skilled hindlimb function and stability after thoracic contusion. Exp Neurol 2023; 360:114278. [PMID: 36455639 DOI: 10.1016/j.expneurol.2022.114278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/07/2022] [Accepted: 11/19/2022] [Indexed: 11/30/2022]
Abstract
Intramuscular injection of an Adeno-associated viral vector serotype 1 (AAV1) encoding Neurotrophin-3 (NT3) into hindlimb muscles 24 h after a severe T9 spinal level contusion in rats has been shown to induce lumbar spinal neuroplasticity, partially restore locomotive function and reduce spasms during swimming. Here we investigate whether a targeted delivery of NT3 to lumbar and thoracic motor neurons 48 h following a severe contusive injury aids locomotive recovery in rats. AAV1-NT3 was injected bilaterally into the tibialis anterior, gastrocnemius and rectus abdominus muscles 48-h following trauma, persistently elevating serum levels of the neurotrophin. NT3 modestly improved trunk stability, accuracy of stepping during skilled locomotion, and alternation of the hindlimbs during swimming, but it had no effect on gross locomotor function in the open field. The number of vGlut1+ boutons, likely arising from proprioceptive afferents, on gastrocnemius α-motor neurons was increased after injury but normalised following NT3 treatment, suggestive of a mechanism in which functional benefits may be mediated through proprioceptive feedback. Ex vivo MRI revealed substantial loss of grey and white matter at the lesion epicentre but no effect of delayed NT3 treatment to induce neuroprotection. Lower body spasms and hyperreflexia of an intrinsic paw muscle were not reliably induced in this severe injury model suggesting a more complex anatomical or physiological cause to their induction. We have shown that delayed intramuscular AAV-NT3 treatment can promote recovery in skilled stepping and coordinated swimming, supporting a role for NT3 as a therapeutic strategy for spinal injuries potentially through modulation of somatosensory feedback.
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Affiliation(s)
- Jared D Sydney-Smith
- The Wolfson Centre for Age-Related Diseases, Guy's Campus, King's College London, London Bridge, London SE1 1UL, UK
| | - Alice M Koltchev
- The Wolfson Centre for Age-Related Diseases, Guy's Campus, King's College London, London Bridge, London SE1 1UL, UK
| | - Lawrence D F Moon
- The Wolfson Centre for Age-Related Diseases, Guy's Campus, King's College London, London Bridge, London SE1 1UL, UK
| | - Philippa M Warren
- The Wolfson Centre for Age-Related Diseases, Guy's Campus, King's College London, London Bridge, London SE1 1UL, UK.
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16
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Lee SY, Schmit BD, Kurpad SN, Budde MD. Acute Magnetic Resonance Imaging Predictors of Chronic Motor Function and Tissue Sparing in Rat Cervical Spinal Cord Injury. J Neurotrauma 2022; 39:1727-1740. [PMID: 35708112 PMCID: PMC9734017 DOI: 10.1089/neu.2022.0034] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Predicting functional outcomes from spinal cord injury (SCI) at the acute setting is important for patient management. This work investigated the relationship of early magnetic resonance imaging (MRI) biomarkers in a rat model of cervical contusion SCI with long-term functional outcome and tissue sparing. Forty rats with contusion injury at C5 at either the spinal cord midline (bilateral) or over the lateral cord (unilateral) were examined using in vivo multi-modal quantitative MRI at 1 day post-injury. The extent of T2-weighted hyperintensity reflecting edema was greater in the bilateral model compared with the unilateral injury. Diffusion tensor imaging (DTI) exhibited microscopic damage in similar regions of the cord as reductions in fractional anisotropy (FA) and mean diffusivity (MD), but DTI parameter maps were also confounded by the presence of vasogenic edema that locally increased FA and MD. In comparison, filtered diffusion-weighted imaging (fDWI) more clearly delineated the location of acute axonal damage without effects of vasogenic edema. Pairwise correlation analysis revealed that 28-day motor functional outcomes were most strongly associated with the extent of edema (R = -0.69). Principal component analysis identified close associations of motor functional score with tissue sparing, the extent of edema, lesion area, and injury type (unilateral or bilateral). Among the diffusion MRI parameters, lesion areas measured with fDWI had the strongest association with functional outcome (R = -0.41). Voxelwise correlation analysis identified a locus of white matter damage associated with function in the dorsal white matter, although this was likely driven by variance across the two injury patterns (unilateral and bilateral injury). Nonetheless, correlation with motor function within the damaged region found in the voxelwise analysis outperformed morphological lesion area measurement as a predictor of chronic function. Collectively, this study characterized anatomical and diffusion MRI signatures of acute SCI at cervical spine and their association with chronic functional outcomes and histological results.
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Affiliation(s)
- Seung-Yi Lee
- Neuroscience Doctoral Program, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
- Department of Biophysics Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Brian D. Schmit
- Department of Biomedical Engineering, Marquette University and Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Shekar N. Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Matthew D. Budde
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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17
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Wu Y, Tang Z, Zhang J, Wang Y, Liu S. Restoration of spinal cord injury: From endogenous repairing process to cellular therapy. Front Cell Neurosci 2022; 16:1077441. [PMID: 36523818 PMCID: PMC9744968 DOI: 10.3389/fncel.2022.1077441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 11/08/2022] [Indexed: 09/26/2023] Open
Abstract
Spinal cord injury (SCI) disrupts neurological pathways and impacts sensory, motor, and autonomic nerve function. There is no effective treatment for SCI currently. Numerous endogenous cells, including astrocytes, macrophages/microglia, and oligodendrocyte, are involved in the histological healing process following SCI. By interfering with cells during the SCI repair process, some advancements in the therapy of SCI have been realized. Nevertheless, the endogenous cell types engaged in SCI repair and the current difficulties these cells confront in the therapy of SCI are poorly defined, and the mechanisms underlying them are little understood. In order to better understand SCI and create new therapeutic strategies and enhance the clinical translation of SCI repair, we have comprehensively listed the endogenous cells involved in SCI repair and summarized the six most common mechanisms involved in SCI repair, including limiting the inflammatory response, protecting the spared spinal cord, enhancing myelination, facilitating neovascularization, producing neurotrophic factors, and differentiating into neural/colloidal cell lines.
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Affiliation(s)
| | | | | | | | - Shengwen Liu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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18
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Hofer AS, Scheuber MI, Sartori AM, Good N, Stalder SA, Hammer N, Fricke K, Schalbetter SM, Engmann AK, Weber RZ, Rust R, Schneider MP, Russi N, Favre G, Schwab ME. Stimulation of the cuneiform nucleus enables training and boosts recovery after spinal cord injury. Brain 2022; 145:3681-3697. [PMID: 35583160 PMCID: PMC9586551 DOI: 10.1093/brain/awac184] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/07/2022] [Accepted: 05/04/2022] [Indexed: 11/15/2022] Open
Abstract
Severe spinal cord injuries result in permanent paraparesis in spite of the frequent sparing of small portions of white matter. Spared fibre tracts are often incapable of maintaining and modulating the activity of lower spinal motor centres. Effects of rehabilitative training thus remain limited. Here, we activated spared descending brainstem fibres by electrical deep brain stimulation of the cuneiform nucleus of the mesencephalic locomotor region, the main control centre for locomotion in the brainstem, in adult female Lewis rats. We show that deep brain stimulation of the cuneiform nucleus enhances the weak remaining motor drive in highly paraparetic rats with severe, incomplete spinal cord injuries and enables high-intensity locomotor training. Stimulation of the cuneiform nucleus during rehabilitative aquatraining after subchronic (n = 8 stimulated versus n = 7 unstimulated versus n = 7 untrained rats) and chronic (n = 14 stimulated versus n = 9 unstimulated versus n = 9 untrained rats) spinal cord injury re-established substantial locomotion and improved long-term recovery of motor function. We additionally identified a safety window of stimulation parameters ensuring context-specific locomotor control in intact rats (n = 18) and illustrate the importance of timing of treatment initiation after spinal cord injury (n = 14). This study highlights stimulation of the cuneiform nucleus as a highly promising therapeutic strategy to enhance motor recovery after subchronic and chronic incomplete spinal cord injury with direct clinical applicability.
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Affiliation(s)
- Anna-Sophie Hofer
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Myriam I Scheuber
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Andrea M Sartori
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Nicolas Good
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Stephanie A Stalder
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Nicole Hammer
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Kai Fricke
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Sina M Schalbetter
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Anne K Engmann
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Rebecca Z Weber
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Ruslan Rust
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Marc P Schneider
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Natalie Russi
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Giacomin Favre
- Department of Economics, University of Zurich, 8032 Zurich, Switzerland
| | - Martin E Schwab
- Brain Research Institute, University of Zurich, 8057 Zurich, Switzerland
- Institute for Regenerative Medicine, University of Zurich, 8952 Schlieren, Switzerland
- Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
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19
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Wang Z, Romanski A, Mehra V, Wang Y, Brannigan M, Campbell BC, Petsko GA, Tsoulfas P, Blackmore MG. Brain-wide analysis of the supraspinal connectome reveals anatomical correlates to functional recovery after spinal injury. eLife 2022; 11:76254. [PMID: 35838234 PMCID: PMC9345604 DOI: 10.7554/elife.76254] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 07/12/2022] [Indexed: 11/15/2022] Open
Abstract
The supraspinal connectome is essential for normal behavior and homeostasis and consists of numerous sensory, motor, and autonomic projections from brain to spinal cord. Study of supraspinal control and its restoration after damage has focused mostly on a handful of major populations that carry motor commands, with only limited consideration of dozens more that provide autonomic or crucial motor modulation. Here, we assemble an experimental workflow to rapidly profile the entire supraspinal mesoconnectome in adult mice and disseminate the output in a web-based resource. Optimized viral labeling, 3D imaging, and registration to a mouse digital neuroanatomical atlas assigned tens of thousands of supraspinal neurons to 69 identified regions. We demonstrate the ability of this approach to clarify essential points of topographic mapping between spinal levels, measure population-specific sensitivity to spinal injury, and test the relationships between region-specific neuronal sparing and variability in functional recovery. This work will spur progress by broadening understanding of essential but understudied supraspinal populations.
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Affiliation(s)
- Zimei Wang
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Adam Romanski
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Vatsal Mehra
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Yunfang Wang
- Department of Neurological Surgery, University of Miami, Miami, United States
| | - Matthew Brannigan
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
| | - Benjamin C Campbell
- Helen and Robert Appel Alzheimer's Disease Research Institute, Cornell University, New York, United States
| | - Gregory A Petsko
- Helen and Robert Appel Alzheimer's Disease Research Institute, Cornell University, New York, United States
| | - Pantelis Tsoulfas
- Department of Neurological Surgery, University of Miami, Miami, United States
| | - Murray G Blackmore
- Department of Biomedical Sciences, Marquette University, Milwaukee, United States
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20
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Xing C, Jia Z, Qu H, Liu S, Jiang W, Zhong H, Zhou M, Zhu S, Ning G, Feng S. Correlation Analysis Between Magnetic Resonance Imaging-Based Anatomical Assessment and Behavioral Outcome in a Rat Contusion Model of Chronic Thoracic Spinal Cord Injury. Front Neurosci 2022; 16:838786. [PMID: 35527814 PMCID: PMC9069114 DOI: 10.3389/fnins.2022.838786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 02/23/2022] [Indexed: 11/21/2022] Open
Abstract
Although plenty of evidences from preclinical studies have led to potential treatments for patients with spinal cord injury (SCI), the failure to translate promising preclinical findings into clinical advances has long puzzled researchers. Thus, a more reliable combination of anatomical assessment and behavioral testing is urgently needed to improve the translational worth of preclinical studies. To address this issue, the present study was designed to relate magnetic resonance imaging (MRI)-based anatomical assessment to behavioral outcome in a rat contusion model. Rats underwent contusion with three different heights to simulate various severities of SCI, and their locomotive functions were evaluated by the grid-walking test, Louisville swim scale (LSS), especially catwalk gait analysis system and basic testing, and Basso, Beattie, Bresnahan (BBB) score. The results showed that the lesion area (LA) is a better indicator for damage assessment compared with other parameters in sagittal T2-weighted MRI (T2WI). Although two samples are marked as outliers by the box plot analysis, LA correlated closely with all of the behavioral testing without ceiling effect and floor effect. Moreover, with a moderate severity of SCI in a contusion height of 25 mm, the smaller the LA of the spinal cord measured on sagittal T2WI the better the functional performance, the smaller the cavity region and glial scar, the more spared the myelin, the higher the volatility, and the thicker the bladder wall. We found that LA significantly related with behavior outcomes, which indicated that LA could be a proxy of damage assessment. The combination of sagittal T2WI and four types of behavioral testing can be used as a reliable scheme to evaluate the prognosis for preclinical studies of SCI.
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Affiliation(s)
- Cong Xing
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Zeyu Jia
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Haodong Qu
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Song Liu
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Wang Jiang
- Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | - Hao Zhong
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Mi Zhou
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Shibo Zhu
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Guangzhi Ning
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
| | - Shiqing Feng
- Department of Orthopedics, Tianjin Medical University General Hospital, Tianjin, China.,International Science and Technology Cooperation Base of Spinal Cord Injury, Tianjin, China.,Tianjin Key Laboratory of Spine and Spinal Cord Injury, Tianjin, China
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21
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Novel Therapeutic Effects in Rat Spinal Cord Injuries: Recovery of the Definitive and Early Spinal Cord Injury by the Administration of Pentadecapeptide BPC 157 Therapy. Curr Issues Mol Biol 2022; 44:1901-1927. [PMID: 35678659 PMCID: PMC9164058 DOI: 10.3390/cimb44050130] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/22/2022] [Accepted: 04/24/2022] [Indexed: 12/17/2022] Open
Abstract
Recently, marked therapeutic effects pertaining to the recovery of injured rat spinal cords (1 min compression injury of the sacrocaudal spinal cord (S2-Co1) resulting in tail paralysis) appeared after a single intraperitoneal administration of the stable gastric pentadecapeptide BPC 157 at 10 min post-injury. Besides the demonstrated rapid and sustained recovery (1 year), we showed the particular points of the immediate effect of the BPC 157 therapy that began rapidly after its administration, (i) soon after injury (10 min), or (ii) later (4 days), in the rats with a definitive spinal cord injury. Specifically, in counteracting spinal cord hematoma and swelling, (i) in rats that had undergone acute spinal cord injury, followed by intraperitoneal BPC 157 application at 10 min, we focused on the first 10–30 min post-injury period (assessment of gross, microscopic, and gene expression changes). Taking day 4 post-injury as the definitive injury, (ii) we focused on the immediate effects after the BPC 157 intragastric application over 20 min of the post-therapy period. Comparable long-time recovery was noted in treated rats which had definitive tail paralysis: (iii) the therapy was continuously given per orally in drinking water, beginning at day 4 after injury and lasting one month after injury. BPC 157 rats presented only discrete edema and minimal hemorrhage and increased Nos1, Nos2, and Nos3 values (30 min post-injury, (i)) or only mild hemorrhage, and only discrete vacuolation of tissue (day 4, (ii)). In the day 4–30 post-injury study (iii), BPC 157 rats rapidly presented tail function recovery, and no demyelination process (Luxol fast blue staining).
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22
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Le Ray D, Guayasamin M. How Does the Central Nervous System for Posture and Locomotion Cope With Damage-Induced Neural Asymmetry? Front Syst Neurosci 2022; 16:828532. [PMID: 35308565 PMCID: PMC8927091 DOI: 10.3389/fnsys.2022.828532] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/07/2022] [Indexed: 12/28/2022] Open
Abstract
In most vertebrates, posture and locomotion are achieved by a biomechanical apparatus whose effectors are symmetrically positioned around the main body axis. Logically, motor commands to these effectors are intrinsically adapted to such anatomical symmetry, and the underlying sensory-motor neural networks are correspondingly arranged during central nervous system (CNS) development. However, many developmental and/or life accidents may alter such neural organization and acutely generate asymmetries in motor operation that are often at least partially compensated for over time. First, we briefly present the basic sensory-motor organization of posturo-locomotor networks in vertebrates. Next, we review some aspects of neural plasticity that is implemented in response to unilateral central injury or asymmetrical sensory deprivation in order to substantially restore symmetry in the control of posturo-locomotor functions. Data are finally discussed in the context of CNS structure-function relationship.
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23
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Park CS, Lee JY, Choi HY, Yune TY. Suppression of TRPM7 by carvacrol protects against injured spinal cord by inhibiting blood-spinal cord barrier disruption. J Neurotrauma 2022; 39:735-749. [PMID: 35171694 DOI: 10.1089/neu.2021.0338] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
When the blood-spinal cord barrier (BSCB) is disrupted after a spinal cord injury (SCI), several pathophysiological cascades occur, including inflammation and apoptotic cell death of neurons and oligodendrocytes, resulting in permanent neurological deficits. Transient receptor potential melastatin 7 (TRPM7) is involved in the pathological processes in many neuronal diseases, including traumatic brain injury, amyotrophic lateral sclerosis, parkinsonism dementia, and Alzheimer's disease. Furthermore, carvacrol (CAR), a TRPM7 inhibitor, is known to protect against SCI by reducing oxidative stress and inhibiting the endothelial nitric oxide synthase pathway. However, the functions of TRPM7 in the regulation of BSCB homeostasis after SCI have not been examined. Here, we demonstrated that TRPM7, a calcium-mediated non-selective divalent cation channel, plays a critical role after SCI in rats. Rats were contused at T9 and given CAR (50 mg/kg) via intraperitoneally immediately and 12 hours after SCI, and then given the same dose once a day for 7 days. TRPM7 was found to be up-regulated after SCI in both in vitro and in vivo studies, and it was expressed in blood vessels alongside neurons and oligodendrocytes. Additionally, CAR treatment suppressed BSCB disruption by inhibiting the loss of TJ proteins and preserved TJ integrity. CAR also reduced apoptotic cell death and improved functional recovery after SCI by preventing BSCB disruption caused by blood infiltration and inflammatory responses. Based on these findings, we propose that blocking the TRPM7 channel can inhibit the destruction of the BSCB and it is a potential target in therapeutic drug development for use in SCI.
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Affiliation(s)
- Chan S Park
- Kyung Hee University, 26723, Dongdaemun-gu, Seoul, Korea (the Republic of);
| | - Jee Youn Lee
- Kyung Hee University, 26723, Seoul, Korea (the Republic of);
| | - Hye Y Choi
- Kyung Hee University, 26723, Age-Related and Brain Diseases Research Center, Seoul, Korea (the Republic of);
| | - Tae Y Yune
- Kyung Hee University, 26723, Age-Related and Brain Diseases Research Center, Seoul, Korea (the Republic of);
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24
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Anatomical and behavioral outcomes following a graded hemi-contusive cervical spinal cord injury model in mice. Behav Brain Res 2022; 419:113698. [PMID: 34856301 DOI: 10.1016/j.bbr.2021.113698] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 11/20/2021] [Accepted: 11/26/2021] [Indexed: 12/29/2022]
Abstract
BACKGROUND A graded hemi-contusion spinal cord injury produces complex anatomical deformation of the spinal cord parenchyma. The relationship between lesion severity and behavioral consequences in a novel contusion mouse model remains unknown. PURPOSE We aimed to establish a graded cervical hemi-contusion spinal cord injury model in mice and investigate the correlation between graded anatomical damage to the spinal cord and resulting behavioral impairments. METHODS Thirty-two mice were divided into groups of 1.2 mm, 1.5 mm and sham. The tip of an impactor with a diameter of 1 mm was utilized to compress the left dorsal cord of C5 by 1.2 mm or 1.5 mm at a speed of 300 mm/s. Forelimb motor function was evaluated using rearing, grooming and grip-strength tests before and after the injuries. Histologically the area of white matter sparing, gray matter sparing and lesion area were quantified at 6-week-post-injury. RESULTS Behavioral assessments showed a more severe forelimb functional deficit in 1.5 mm contusion displacements relative to 1.2 mm contusion displacements after injury. The 1.2 mm hemi-contusion mainly caused damage to the dorsal fasciculus, ventral and dorsal horn, while the 1.5 mm hemi-contusion lead to additional damage extending to ventral fasciculus. Sparing of the gray and white matter at the epicenter was 36.8 ± 2.4% and 12.4 ± 2.6% in the 1.2 mm group, and 27.6 ± 4.0% and 4.1 ± 2.2% in the 1.5 mm group, respectively. Furthermore, the lesion area was 20.8 ± 3.0% and 36.0 ± 2.1% in the 1.2 mm and 1.5 mm groups, respectively. There was a significant correlation between the performance in the grooming test and white matter sparing, and between grip-test strength and gray matter sparing. CONCLUSION The present study demonstrates that a hemi-contusion cervical spinal cord injury in mice can be graded by contusion displacement and that there is a correlation between anatomical and behavioral outcomes. This study provides a means for determining the severity of lesions in a contusion mouse model.
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25
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Borrell JA, Krizsan-Agbas D, Nudo RJ, Frost SB. Activity dependent stimulation increases synaptic efficacy in spared pathways in an anesthetized rat model of spinal cord contusion injury. Restor Neurol Neurosci 2022; 40:17-33. [PMID: 35213336 PMCID: PMC9108576 DOI: 10.3233/rnn-211214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Closed-loop neuromodulation systems have received increased attention in recent years as potential therapeutic approaches for treating neurological injury and disease. OBJECTIVE The purpose of this study was to assess the ability of intraspinal microstimulation (ISMS), triggered by action potentials (spikes) recorded in motor cortex, to alter synaptic efficacy in descending motor pathways in an anesthetized rat model of spinal cord injury (SCI). METHODS Experiments were carried out in adult, male, Sprague Dawley rats with a moderate contusion injury at T8. For activity-dependent stimulation (ADS) sessions, a recording microelectrode was used to detect neuronal spikes in motor cortex that triggered ISMS in the spinal cord grey matter. SCI rats were randomly assigned to one of four experimental groups differing by: a) cortical spike-ISMS stimulus delay (10 or 25 ms) and b) number of ISMS pulses (1 or 3). Four weeks after SCI, ADS sessions were conducted in three consecutive 1-hour conditioning bouts for a total of 3 hours. At the end of each conditioning bout, changes in synaptic efficacy were assessed using intracortical microstimulation (ICMS) to examine the number of spikes evoked in spinal cord neurons during 5-minute test bouts. A multichannel microelectrode recording array was used to record cortically-evoked spike activity from multiple layers of the spinal cord. RESULTS The results showed that ADS resulted in an increase in cortically-evoked spikes in spinal cord neurons at specific combinations of spike-ISMS delays and numbers of pulses. Efficacy in descending motor pathways was increased throughout all dorsoventral depths of the hindlimb spinal cord. CONCLUSIONS These results show that after an SCI, ADS can increase synaptic efficacy in spared pathways between motor cortex and spinal cord. This study provides further support for the potential of ADS therapy as an effective method for enhancing descending motor control after SCI.
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Affiliation(s)
- Jordan A. Borrell
- Bioengineering Program, University of Kansas, Lawrence, KS, USA
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, USA
| | - Dora Krizsan-Agbas
- Molecular & Integrative Physiology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Randolph J. Nudo
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, USA
- Department of Rehabilitation Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Shawn B. Frost
- Landon Center on Aging, University of Kansas Medical Center, Kansas City, KS, USA
- Department of Rehabilitation Medicine, University of Kansas Medical Center, Kansas City, KS, USA
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26
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Blackmore M, Batsel E, Tsoulfas P. Widening spinal injury research to consider all supraspinal cell types: Why we must and how we can. Exp Neurol 2021; 346:113862. [PMID: 34520726 PMCID: PMC8805209 DOI: 10.1016/j.expneurol.2021.113862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/19/2021] [Accepted: 09/08/2021] [Indexed: 01/05/2023]
Abstract
The supraspinal connectome consists of dozens of neuronal populations that project axons from the brain to the spinal cord to influence a wide range of motor, autonomic, and sensory functions. The complexity and wide distribution of supraspinal neurons present significant technical challenges, leading most spinal cord injury research to focus on a handful of major pathways such as the corticospinal, rubrospinal, and raphespinal. Much less is known about many additional populations that carry information to modulate or compensate for these main pathways, or which carry pre-autonomic and other information of high value to individuals with spinal injury. A confluence of technical developments, however, now enables a whole-connectome study of spinal cord injury. Improved viral labeling, tissue clearing, and automated registration to 3D atlases can quantify supraspinal neurons throughout the murine brain, offering a practical means to track responses to injury and treatment on an unprecedented scale. Here we discuss the need for expanded connectome-wide analyses in spinal injury research, illustrate the potential by discussing a new web-based resource for brain-wide study of supraspinal neurons, and highlight future prospects for connectome analyses.
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Affiliation(s)
- Murray Blackmore
- Department of Biomedical Sciences, Marquette University, 53201, United States of America.
| | - Elizabeth Batsel
- Department of Biomedical Sciences, Marquette University, 53201, United States of America
| | - Pantelis Tsoulfas
- Department of Neurological Surgery, Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, United States of America
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27
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Fedorova J, Kellerova E, Bimbova K, Pavel J. The Histopathology of Severe Graded Compression in Lower Thoracic Spinal Cord Segment of Rat, Evaluated at Late Post-injury Phase. Cell Mol Neurobiol 2021; 42:173-193. [PMID: 34410553 PMCID: PMC8732890 DOI: 10.1007/s10571-021-01139-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/04/2021] [Indexed: 11/28/2022]
Abstract
Spontaneous recovery of lost motor functions is relative fast in rodent models after inducing a very mild/moderate spinal cord injury (SCI), and this may complicate a reliable evaluation of the effectiveness of potential therapy. Therefore, a severe graded (30 g, 40 g and 50 g) weight-compression SCI at the Th9 spinal segment, involving an acute mechanical impact followed by 15 min of persistent compression, was studied in adult female Wistar rats. Functional parameters, such as spontaneous recovery of motor hind limb and bladder emptying function, and the presence of hematuria were evaluated within 28 days of the post-traumatic period. The disruption of the blood-spinal cord barrier, measured by extravasated Evans Blue dye, was examined 24 h after the SCI, when maximum permeability occurs. At the end of the survival period, the degradation of gray and white matter associated with the formation of cystic cavities, and quantitative changes of glial structural proteins, such as GFAP, and integral components of axonal architecture, such as neurofilaments and myelin basic protein, were evaluated in the lesioned area of the spinal cord. Based on these functional and histological parameters, and taking the animal’s welfare into account, the 40 g weight can be considered as an upper limit for severe traumatic injury in this compression model.
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Affiliation(s)
- Jana Fedorova
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia
| | - Erika Kellerova
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia
| | - Katarina Bimbova
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia
| | - Jaroslav Pavel
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia.
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28
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Ye J, Jin S, Cai W, Chen X, Zheng H, Zhang T, Lu W, Li X, Liang C, Chen Q, Wang Y, Gu X, Yu B, Chen Z, Wang X. Rationally Designed, Self-Assembling, Multifunctional Hydrogel Depot Repairs Severe Spinal Cord Injury. Adv Healthc Mater 2021; 10:e2100242. [PMID: 34029000 DOI: 10.1002/adhm.202100242] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/25/2021] [Indexed: 01/03/2023]
Abstract
Following severe spinal cord injury (SCI), dysregulated neuroinflammation causes neuronal and glial apoptosis, resulting in scar and cystic cavity formation during wound healing and ultimately the formation of an atrophic microenvironment that inhibits nerve regrowth. Because of this complex and dynamic pathophysiology, a systemic solution for scar- and cavity-free wound healing with microenvironment remodeling to promote nerve regrowth has rarely been explored. A one-step solution is proposed through a self-assembling, multifunctional hydrogel depot that punctually releases the anti-inflammatory drug methylprednisolone sodium succinate (MPSS) and growth factors (GFs) locally according to pathophysiology to repair severe SCI. Synergistically releasing the anti-inflammatory drug MPSS and GFs in the hydrogel depot throughout SCI pathophysiology protects spared tissues/axons from secondary injury, promotes scar boundary- and cavity-free wound healing, and results in permissive bridges for remarkable axonal regrowth. Behavioral and electrophysiological studies indicate that remnants of spared axons, not regenerating axons, mediate functional recovery, strongly suggesting that additional interventions are still required to render the rebuilt neuronal circuits functional. These findings pave the way for the development of a systemic solution to treat acute SCI.
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Affiliation(s)
- Jingjia Ye
- Department of Neurobiology and Department of Orthopedics 2nd Affiliated Hospital Zhejiang University School of Medicine Hangzhou Zhejiang Province 310009 P. R.China
- NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain–Machine Integration School of Brain Science and Brain Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Shuang Jin
- NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain–Machine Integration School of Brain Science and Brain Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Wanxiong Cai
- NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain–Machine Integration School of Brain Science and Brain Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Xiangfeng Chen
- Department of Neurobiology and Department of Orthopedics 2nd Affiliated Hospital Zhejiang University School of Medicine Hangzhou Zhejiang Province 310009 P. R.China
- NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain–Machine Integration School of Brain Science and Brain Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Hanyu Zheng
- NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain–Machine Integration School of Brain Science and Brain Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Tianfang Zhang
- Department of Rehabilitation Medicine First Affiliated Hospital College of Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Wujie Lu
- Department of Rehabilitation Medicine First Affiliated Hospital College of Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Xiaojian Li
- Guangdong Provincial Key Laboratory of Brain Connectome and Behavior CAS Key Laboratory of Brain Connectome and Manipulation the Brain Cognition and Brain Disease Institute (BCBCI) Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen‐Hong Kong Institute of Brain Science‐Shenzhen Fundamental Research Institutions Shenzhen Guangdong Province 518055 P. R. China
| | - Chengzhen Liang
- Department of Neurobiology and Department of Orthopedics 2nd Affiliated Hospital Zhejiang University School of Medicine Hangzhou Zhejiang Province 310009 P. R.China
| | - Qixin Chen
- Department of Neurobiology and Department of Orthopedics 2nd Affiliated Hospital Zhejiang University School of Medicine Hangzhou Zhejiang Province 310009 P. R.China
| | - Yaxian Wang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products Nantong University Nantong Jiangsu Province 226001 P. R. China
| | - Xiaosong Gu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products Nantong University Nantong Jiangsu Province 226001 P. R. China
| | - Bin Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products Nantong University Nantong Jiangsu Province 226001 P. R. China
| | - Zuobing Chen
- Department of Rehabilitation Medicine First Affiliated Hospital College of Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
| | - Xuhua Wang
- Department of Neurobiology and Department of Orthopedics 2nd Affiliated Hospital Zhejiang University School of Medicine Hangzhou Zhejiang Province 310009 P. R.China
- NHC and CAMS Key Laboratory of Medical Neurobiology MOE Frontier Science Center for Brain Research and Brain–Machine Integration School of Brain Science and Brain Medicine Zhejiang University Hangzhou Zhejiang Province 310003 P. R. China
- Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu Province 226001 P. R. China
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29
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Rink S, Manthou ME, Arnold J, Grigo M, Dicken P, Abdulla DSY, Bendella H, Nohroudi K, Angelov DN. Motor, sensitive, and vegetative recovery in rats with compressive spinal-cord injury after combined treatment with erythropoietin and whole-body vibration. Restor Neurol Neurosci 2021; 39:85-100. [PMID: 33612500 DOI: 10.3233/rnn-201120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Physical therapy with whole body vibration (WBV) following compressive spinal cord injury (SCI) in rats restores density of perisomatic synapses, improves body weight support and leads to a better bladder function. The purpose of the study was to determine whether the combined treatment with WBV plus erythropoietin (EPO) would further improve motor, sensory and vegetative functions after SCI in rats. METHODS Severe compressive SCI at low thoracic level was followed by a single i.p. injection of 2,5μg (250 IU) human recombinant EPO. Physical therapy with WBV started on 14th day after injury and continued over a 12-week post injury period. Locomotor recovery, sensitivity tests and urinary bladder scores were analysed at 1, 3, 6, 9, and 12 weeks after SCI. The closing morphological measurements included lesion volume and numbers of axons in the preserved perilesional neural tissue bridges (PNTB). RESULTS Assessment of motor performance sensitivity and bladder function revealed no significant effects of EPO when compared to the control treatments. EPO treatment neither reduced the lesion volume, nor increased the number of axons in PNTB. CONCLUSIONS The combination of WBV + EPO exerts no positive effects on hind limbs motor performance and bladder function after compressive SCI in rats.
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Affiliation(s)
- Svenja Rink
- Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Cologne, Germany
| | - Maria Eleni Manthou
- Department of Histology and Embryology, School of Medicine, Faculty of Health Sciences, Aristotle University Thessaloniki, Thessaloniki, Greece
| | - Julia Arnold
- Department of Anatomy I, University of Cologne, Cologne, Germany
| | - Merle Grigo
- Department of Anatomy I, University of Cologne, Cologne, Germany
| | - Paulina Dicken
- Department of Anatomy I, University of Cologne, Cologne, Germany
| | - Diana Saad Yousif Abdulla
- Department I of Internal Medicine, Faculty of Medicine and University Hospital of Cologne, Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf, Network Genomic Medicine, Lung Cancer Group Cologne, University of Cologne, Cologne, Germany
| | - Habib Bendella
- Department of Neurosurgery, University of Witten/Herdecke, Cologne Merheim Medical Center (CMMC), Cologne, Germany
| | - Klaus Nohroudi
- Department of Anatomy I, University of Cologne, Cologne, Germany
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30
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Chemogenetic stimulation of proprioceptors remodels lumbar interneuron excitability and promotes motor recovery after SCI. Mol Ther 2021; 29:2483-2498. [PMID: 33895324 DOI: 10.1016/j.ymthe.2021.04.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 02/05/2021] [Accepted: 04/16/2021] [Indexed: 12/21/2022] Open
Abstract
Motor recovery after severe spinal cord injury (SCI) is limited due to the disruption of direct descending commands. Despite the absence of brain-derived descending inputs, sensory afferents below injury sites remain intact. Among them, proprioception acts as an important sensory source to modulate local spinal circuits and determine motor outputs. Yet, it remains unclear whether enhancing proprioceptive inputs promotes motor recovery after severe SCI. Here, we first established a viral system to selectively target lumbar proprioceptive neurons and then introduced the excitatory Gq-coupled Designer Receptors Exclusively Activated by Designer Drugs (DREADD) virus into proprioceptors to achieve specific activation of lumbar proprioceptive neurons upon CNO administration. We demonstrated that chronic activation of lumbar proprioceptive neurons promoted the recovery of hindlimb stepping ability in a bilateral hemisection SCI mouse model. We further revealed that chemogenetic proprioceptive stimulation led to coordinated activation of proprioception-receptive spinal interneurons and facilitated transmission of supraspinal commands to lumbar motor neurons, without affecting the regrowth of proprioceptive afferents or brain-derived descending axons. Moreover, application of 4-aminopyridine-3-methanol (4-AP-MeOH) that enhances nerve conductance further improved the transmission of supraspinal inputs and motor recovery in proprioception-stimulated mice. Our study demonstrates that proprioception-based combinatorial modality may be a promising strategy to restore the motor function after severe SCI.
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31
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Combination of Defined CatWalk Gait Parameters for Predictive Locomotion Recovery in Experimental Spinal Cord Injury Rat Models. eNeuro 2021; 8:ENEURO.0497-20.2021. [PMID: 33593735 PMCID: PMC7986542 DOI: 10.1523/eneuro.0497-20.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 01/18/2021] [Accepted: 01/24/2021] [Indexed: 12/27/2022] Open
Abstract
In many preclinical spinal cord injury (SCI) studies, assessment of locomotion recovery is key to understanding the effectiveness of the experimental intervention. In such rat SCI studies, the most basic locomotor recovery scoring system is a subjective observation of animals freely roaming in an open field, the Basso Beattie Bresnahan (BBB) score. In comparison, CatWalk is an automated gait analysis system, providing further parameter specifications. Although together the CatWalk parameters encompass gait, studies consistently report single parameters, which differ in significance from other behavioral assessments. Therefore, we believe no single parameter produced by the CatWalk can represent the fully-coordinated motion of gait. Typically, other locomotor assessments, such as the BBB score, combine several locomotor characteristics into a representative score. For this reason, we ranked the most distinctive CatWalk parameters between uninjured and SC injured rats. Subsequently, we combined nine of the topmost parameters into an SCI gait index score based on linear discriminant analysis (LDA). The resulting combination was applied to assess gait recovery in SCI experiments comprising of three thoracic contusions, a thoracic dorsal hemisection, and a cervical dorsal column lesion model. For thoracic lesions, our unbiased machine learning model revealed gait differences in lesion type and severity. In some instances, our LDA was found to be more sensitive in differentiating recovery than the BBB score alone. We believe the newly developed gait parameter combination presented here should be used in CatWalk gait recovery work with preclinical thoracic rat SCI models.
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32
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Rink S, Pavlov S, Wöhler A, Bendella H, Manthou M, Papamitsou T, Dunlop SA, Angelov DN. Numbers of Axons in Spared Neural Tissue Bridges But Not Their Widths or Areas Correlate With Functional Recovery in Spinal Cord-Injured Rats. J Neuropathol Exp Neurol 2021; 79:1203-1217. [PMID: 32594136 DOI: 10.1093/jnen/nlaa050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/11/2020] [Accepted: 05/08/2020] [Indexed: 11/14/2022] Open
Abstract
The relationships between various parameters of tissue damage and subsequent functional recovery after spinal cord injury (SCI) are not well understood. Patients may regain micturition control and walking despite large postinjury medullar cavities. The objective of this study was to establish possible correlations between morphological findings and degree of functional recovery after spinal cord compression at vertebra Th8 in rats. Recovery of motor (Basso, Beattie, Bresnahan, foot-stepping angle, rump-height index, and ladder climbing), sensory (withdrawal latency), and bladder functions was analyzed at 1, 3, 6, 9, and 12 weeks post-SCI. Following perfusion fixation, spinal cord tissue encompassing the injury site was cut in longitudinal frontal sections. Lesion lengths, lesion volumes, and areas of perilesional neural tissue bridges were determined after staining with cresyl violet. The numbers of axons in these bridges were quantified after staining for class III β-tubulin. We found that it was not the area of the spared tissue bridges, which is routinely determined by magnetic resonance imaging (MRI), but the numbers of axons in them that correlated with functional recovery after SCI (Spearman's ρ > 0.8; p < 0.001). We conclude that prognostic statements based only on MRI measurements should be considered with caution.
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Affiliation(s)
- Svenja Rink
- Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Germany
| | - Stoyan Pavlov
- Department of Anatomy, Histology and Embryology, Medical University, Varna, Bulgaria
| | | | - Habib Bendella
- Department of Neurosurgery, University of Witten/Herdecke, Cologne Merheim Medical Center (CMMC), Cologne, Germany
| | - Marilena Manthou
- Department of Histology and Embryology, Aristotle University Thessaloniki, Greece
| | - Theodora Papamitsou
- Department of Histology and Embryology, Aristotle University Thessaloniki, Greece
| | - Sarah A Dunlop
- School of Biological Sciences, The University of Western Australia, Australia
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Ohri SS, Howard RM, Liu Y, Andres KR, Hetman M, Whittemore SR. Oligodendrocyte-specific deletion of Xbp1 exacerbates the endoplasmic reticulum stress response and restricts locomotor recovery after thoracic spinal cord injury. Glia 2021; 69:424-435. [PMID: 32926479 PMCID: PMC8931742 DOI: 10.1002/glia.23907] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Revised: 08/21/2020] [Accepted: 08/23/2020] [Indexed: 12/31/2022]
Abstract
The endoplasmic reticulum stress response (ERSR) is activated in various neurodegenerative diseases and/or after CNS traumatic injuries. The ERSR is comprised of three major arms, PERK, IRE-1, and activating transcription factor-6, with the latter two contributing to the unfolded protein response (UPR). PERK activity overlaps with the integrated stress response (ISR) kinases, PKR, HRI, and GCN2 which all signal through, eukaryotic initiation factor 2α, ATF4, and CHOP. All initially attempt to restore endoplasmic reticulum (ER) homeostasis, but if ER stress is unresolved, ATF4/CHOP-mediated cell death is initiated. Here, we investigate the contribution of the inositol-requiring protein-1α-X-box binding protein-1 (XBP1)-mediated UPR signaling pathway to the pathogenesis of spinal cord injury (SCI). We demonstrate that deletion of Xbp1 caused an exacerbated ATF4/CHOP signaling in cultured mouse oligodendrocyte (OL) progenitor cells and enhanced their sensitivity to ER stress. Similar effects were also observed with the Xbp1 pathway inhibitor toyocamycin. Furthermore, OL lineage-specific loss of Xbp1 resulted in enhanced ISR in mice that underwent moderate contusive SCI at the T9 level. Consistently, post-injury recovery of hindlimb locomotion and white matter sparing were reduced in OL Xbp1-deficient mice, which correlated with chronically decreased relative density of OPCs and OLs at the injury epicenter at 6 weeks post-SCI. We conclude that the IRE1-XBP1-mediated UPR signaling pathway contributes to restoration of ER homeostasis in OLs and is necessary for enhanced white matter sparing and functional recovery post-SCI.
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Affiliation(s)
- Sujata Saraswat Ohri
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Russell M. Howard
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Yu Liu
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Kariena R. Andres
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Michal Hetman
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Pharmacology & Toxicology, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Anatomical Sciences & Neurobiology, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
| | - Scott R. Whittemore
- Kentucky Spinal Cord Injury Research Center, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Neurological Surgery, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Pharmacology & Toxicology, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
- Departments of Anatomical Sciences & Neurobiology, University of Louisville, School of Medicine, 511 S. Floyd St., MDR 616, Louisville, KY 40202, USA
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Fouad K, Popovich PG, Kopp MA, Schwab JM. The neuroanatomical-functional paradox in spinal cord injury. Nat Rev Neurol 2021; 17:53-62. [PMID: 33311711 PMCID: PMC9012488 DOI: 10.1038/s41582-020-00436-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2020] [Indexed: 12/13/2022]
Abstract
Although lesion size is widely considered to be the most reliable predictor of outcome after CNS injury, lesions of comparable size can produce vastly different magnitudes of functional impairment and subsequent recovery. This neuroanatomical-functional paradox is likely to contribute to the many failed attempts to independently replicate findings from animal models of neurotrauma. In humans, the analogous clinical-radiological paradox could explain why individuals with similar injuries can respond differently to rehabilitation. We describe the neuroanatomical-functional paradox in the context of traumatic spinal cord injury (SCI) and discuss the underlying mechanisms of the paradox, including the concepts of lesion-affected and recovery-related networks. We also consider the various secondary complications that further limit the accuracy of outcome prediction in SCI and provide suggestions for how to increase the predictive, translational value of preclinical SCI models.
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Affiliation(s)
- Karim Fouad
- Department of Physical Therapy, Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, AB, Canada
- Institute for Neuroscience and Mental Health, University of Alberta, Edmonton, AB, Canada
| | - Phillip G Popovich
- Belford Center for Spinal Cord Injury, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
- Center for Brain and Spinal Cord Repair, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
- Department of Neuroscience, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
- The Neurological Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
| | - Marcel A Kopp
- Clinical & Experimental Spinal Cord Injury Research, Department of Neurology with Experimental Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Berlin Institute of Health (QUEST-Center for Transforming Biomedical Research), Berlin, Germany
| | - Jan M Schwab
- Belford Center for Spinal Cord Injury, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Center for Brain and Spinal Cord Repair, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Department of Neuroscience, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- The Neurological Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Clinical & Experimental Spinal Cord Injury Research, Department of Neurology with Experimental Neurology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
- Spinal Cord Injury Medicine (Neuroplegiology), Department of Neurology, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
- Department of Physical Medicine and Rehabilitation, The Ohio State University, Wexner Medical Center, Columbus, OH, USA.
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Krupa P, Stepankova K, Kwok JCF, Fawcett JW, Cimermanova V, Jendelova P, Machova Urdzikova L. New Model of Ventral Spinal Cord Lesion Induced by Balloon Compression in Rats. Biomedicines 2020; 8:biomedicines8110477. [PMID: 33167447 PMCID: PMC7694490 DOI: 10.3390/biomedicines8110477] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 02/02/2023] Open
Abstract
Despite the variety of experimental models of spinal cord injury (SCI) currently used, the model of the ventral compression cord injury, which is commonly seen in humans, is very limited. Ventral balloon compression injury reflects the common anatomical mechanism of a human lesion and has the advantage of grading the injury severity by controlling the inflated volume of the balloon. In this study, ventral compression of the SCI was performed by the anterior epidural placement of the balloon of a 2F Fogarty's catheter, via laminectomy, at the level of T10. The balloon was rapidly inflated with 10 or 15 μL of saline and rested in situ for 5 min. The severity of the lesion was assessed by behavioral and immunohistochemical tests. Compression with the volume of 15 μL resulted in severe motor and sensory deficits represented by the complete inability to move across a horizontal ladder, a final Basso, Beattie and Bresnahan (BBB) score of 7.4 and a decreased withdrawal time in the plantar test (11.6 s). Histology and immunohistochemistry revealed a significant loss of white and gray matter with a loss of motoneuron, and an increased size of astrogliosis. An inflation volume of 10 μL resulted in a mild transient deficit. There are no other balloon compression models of ventral spinal cord injury. This study provided and validated a novel, easily replicable model of the ventral compression SCI, introduced by an inflated balloon of Fogarty´s catheter. For a severe incomplete deficit, an inflated volume should be maintained at 15 μL.
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Affiliation(s)
- Petr Krupa
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
- Department of Neurosurgery, Charles University, Medical Faculty and University Hospital Hradec Králové, Sokolska 581, 50005 Hradec Kralove, Czech Republic
| | - Katerina Stepankova
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
- Department of Neuroscience, Charles University, Second Faculty of Medicine, 15006 Prague, Czech Republic
| | - Jessica CF. Kwok
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - James W. Fawcett
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
- John van Geest Centre for Brain Repair, Dept. Clinical Neurosciences, University of Cambridge, Cambridge CB2 0PY, UK
| | - Veronika Cimermanova
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
| | - Pavla Jendelova
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
- Department of Neuroscience, Charles University, Second Faculty of Medicine, 15006 Prague, Czech Republic
- Correspondence: (P.J.); (L.M.U.); Tel.: (+420-2)-4106-2828 (P.J.); (+420-2)-4106-2619 (L.M.U.); Fax: (+420-2)-4106-2706 (P.J. & L.M.U.)
| | - Lucia Machova Urdzikova
- Institute of Experimental Medicine, Czech Academy of Sciences, Vídeňská, 1083 Prague, Czech Republic; (P.K.); (K.S.); (J.C.K.); (J.W.F.); (V.C.)
- Department of Neuroscience, Charles University, Second Faculty of Medicine, 15006 Prague, Czech Republic
- Correspondence: (P.J.); (L.M.U.); Tel.: (+420-2)-4106-2828 (P.J.); (+420-2)-4106-2619 (L.M.U.); Fax: (+420-2)-4106-2706 (P.J. & L.M.U.)
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Fouad K, Ng C, Basso DM. Behavioral testing in animal models of spinal cord injury. Exp Neurol 2020; 333:113410. [PMID: 32735871 PMCID: PMC8325780 DOI: 10.1016/j.expneurol.2020.113410] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/13/2020] [Accepted: 07/17/2020] [Indexed: 01/08/2023]
Abstract
This review is based on a lecture presented at the Craig H. Neilsen Foundation sponsored Spinal Cord Injury Training Program at Ohio State University. We discuss the advantages and challenges of injury models in rodents and theory relation to various behavioral outcome measures. We offer strategies and advice on experimental design, behavioral testing, and on the challenges, one will encounter with animal testing. This review is designed to guide those entering the field of spinal cord injury and/or involved with in vivo animal testing.
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Affiliation(s)
- K Fouad
- University of Alberta, Faculty of Rehabilitation Medicine, Dept of Physical Therapy, 3-48 Corbett Hall, Edmonton T6G 2G4, Canada; University of Alberta, Neuroscience and Mental Health Institute, 2-132 Li Ka Shing, Edmonton T6G 2E1, Canada.
| | - C Ng
- University of Alberta, Neuroscience and Mental Health Institute, 2-132 Li Ka Shing, Edmonton T6G 2E1, Canada
| | - D M Basso
- Ohio State University, College of Medicine, School of Health and Rehabilitation Sciences, 106A Atwell Hall, 453 W. 10th Ave, Columbus, OH 43210, USA
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Murugan M, Zheng J, Wu G, Mogilevsky R, Zheng X, Hu P, Wu J, Wu LJ. The voltage-gated proton channel Hv1 contributes to neuronal injury and motor deficits in a mouse model of spinal cord injury. Mol Brain 2020; 13:143. [PMID: 33081841 PMCID: PMC7574559 DOI: 10.1186/s13041-020-00682-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/06/2020] [Indexed: 01/30/2023] Open
Abstract
Traumatic injury to the spinal cord initiates a series of pathological cellular processes that exacerbate tissue damage at and beyond the original site of injury. This secondary damage includes oxidative stress and inflammatory cascades that can lead to further neuronal loss and motor deficits. Microglial activation is an essential component of these secondary signaling cascades. The voltage-gated proton channel, Hv1, functionally expressed in microglia has been implicated in microglia polarization and oxidative stress in ischemic stroke. Here, we investigate whether Hv1 mediates microglial/macrophage activation and aggravates secondary damage following spinal cord injury (SCI). Following contusion SCI, wild-type (WT) mice showed significant tissue damage, white matter damage and impaired motor recovery. However, mice lacking Hv1 (Hv1−/−) showed significant white matter sparing and improved motor recovery. The improved motor recovery in Hv1−/− mice was associated with decreased interleukin-1β, reactive oxygen/ nitrogen species production and reduced neuronal loss. Further, deficiency of Hv1 directly influenced microglia activation as noted by decrease in microglia numbers, soma size and reduced outward rectifier K+ current density in Hv1−/− mice compared to WT mice at 7 d following SCI. Our results therefore implicate that Hv1 may be a promising potential therapeutic target to alleviate secondary damage following SCI caused by microglia/macrophage activation.
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Affiliation(s)
- Madhuvika Murugan
- Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA
| | - Jiaying Zheng
- Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA.,Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA
| | - Gongxiong Wu
- One Harvard Street Institute of Health, Brookline, MA, 02446, USA
| | - Rochelle Mogilevsky
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA
| | - Xin Zheng
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA
| | - Peiwen Hu
- Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA
| | - Junfang Wu
- Department of Anesthesiology, University of Maryland, Baltimore, MD, 21201, USA.
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, MN, 55905, USA. .,Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ, 08854, USA. .,Department of Neuroscience, Mayo Clinic, Jacksonville, FL, 32224, USA. .,Department of Immunology, Mayo Clinic, Rochester, MN, 55905, USA.
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Slomnicki LP, Myers SA, Saraswat Ohri S, Parsh MV, Andres KR, Chariker JH, Rouchka EC, Whittemore SR, Hetman M. Improved locomotor recovery after contusive spinal cord injury in Bmal1 -/- mice is associated with protection of the blood spinal cord barrier. Sci Rep 2020; 10:14212. [PMID: 32848194 PMCID: PMC7450087 DOI: 10.1038/s41598-020-71131-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/10/2020] [Indexed: 11/09/2022] Open
Abstract
The transcription factor BMAL1/ARNTL is a non-redundant component of the clock pathway that regulates circadian oscillations of gene expression. Loss of BMAL1 perturbs organismal homeostasis and usually exacerbates pathological responses to many types of insults by enhancing oxidative stress and inflammation. Surprisingly, we observed improved locomotor recovery and spinal cord white matter sparing in Bmal1-/- mice after T9 contusive spinal cord injury (SCI). While acute loss of neurons and oligodendrocytes was unaffected, Bmal1 deficiency reduced the chronic loss of oligodendrocytes at the injury epicenter 6 weeks post SCI. At 3 days post-injury (dpi), decreased expression of genes associated with cell proliferation, neuroinflammation and disruption of the blood spinal cord barrier (BSCB) was also observed. Moreover, intraspinal extravasation of fibrinogen and immunoglobulins was decreased acutely at dpi 1 and subacutely at dpi 7. Subacute decrease of hemoglobin deposition was also observed. Finally, subacutely reduced levels of the leukocyte marker CD45 and even greater reduction of the pro-inflammatory macrophage receptor CD36 suggest not only lower numbers of those cells but also their reduced inflammatory potential. These data indicate that Bmal1 deficiency improves SCI outcome, in part by reducing BSCB disruption and hemorrhage decreasing cytotoxic neuroinflammation and attenuating the chronic loss of oligodendrocytes.
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Affiliation(s)
- Lukasz P Slomnicki
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA
| | - Scott A Myers
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA
| | - Sujata Saraswat Ohri
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA.
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA.
- Kentucky Spinal Cord Injury Research Center, University of Louisville, 511 S. Floyd St., MDR616, Louisville, KY, 40292, USA.
| | - Molly V Parsh
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA
| | - Kariena R Andres
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA
| | - Julia H Chariker
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY, 40202, USA
- Kentucky Biomedical Research Infrastructure Network Bioinformatics Core, University of Louisville, Louisville, KY, 40202, USA
| | - Eric C Rouchka
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY, 40202, USA
- Kentucky Biomedical Research Infrastructure Network Bioinformatics Core, University of Louisville, Louisville, KY, 40202, USA
| | - Scott R Whittemore
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY, 40202, USA
| | - Michal Hetman
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY, 40202, USA.
- Department of Neurological Surgery, University of Louisville, Louisville, KY, 40202, USA.
- Department of Pharmacology and Toxicology, University of Louisville, Louisville, KY, 40202, USA.
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY, 40202, USA.
- Kentucky Spinal Cord Injury Research Center, University of Louisville, 511 S. Floyd St., MDR616, Louisville, KY, 40292, USA.
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Braga A, Bandiera S, Verheyen J, Hamel R, Rutigliani C, Edenhofer F, Smith JA, Pluchino S. Combination of In Situ Lcn2 pRNA-RNAi Nanotherapeutics and iNSC Transplantation Ameliorates Experimental SCI in Mice. Mol Ther 2020; 28:2677-2690. [PMID: 32877696 DOI: 10.1016/j.ymthe.2020.08.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/05/2020] [Accepted: 08/02/2020] [Indexed: 01/19/2023] Open
Abstract
Spinal cord injury (SCI) is a debilitating neurological condition characterized by different cellular and molecular mechanisms that interplay in exacerbating the progression of the pathology. No fully restorative therapies are yet available, and it is thus becoming recognized that combinatorial approaches aimed at addressing different aspects of SCI will likely results in greater functional outcomes. Here we employed packaging RNA-mediated RNA interference (pRNA-RNAi) nanotherapeutics to downregulate in situ the expression of lipocalin 2 (Lcn2), a known mediator of neuroinflammation and autocrine mediator of reactive astrogliosis, and to create a more amenable niche for the subsequent transplantation of induced neural stem cells (iNSCs). To our knowledge, this is the first approach that takes advantage of the modular and multifunctional pRNA three-way junction platform in the SCI niche, while also exploiting the therapeutic potential of immune-compatible and feasible iNSC transplants. We show the combination of such treatments in a mouse model of contusion thoracic SCI leads to significant improvement of locomotor function, albeit not better than single pRNA-RNAi treatment, and results in synergistic histopathological effects, such as reduction of glial scar volume, diminished pro-inflammatory response, and promotion of neuronal survival. Our results provide evidence for a novel combinatorial approach for treating SCI.
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Affiliation(s)
- Alice Braga
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK
| | - Sara Bandiera
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK
| | - Jeroen Verheyen
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK
| | - Regan Hamel
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK
| | - Carola Rutigliani
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK
| | - Frank Edenhofer
- Department of Molecular Biology & CMBI, Genomics, Stem Cell Biology & Regenerative Medicine, Leopold-Franzens-University Innsbruck, 6020 Innsbruck, Austria
| | - Jayden Aaron Smith
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK; Cambridge Innovation Technologies Consulting, Ltd., CB4 0WS Cambridge, UK.
| | - Stefano Pluchino
- Department of Clinical Neurosciences and NIHR Biomedical Research Centre, University of Cambridge, CB2 0HA Cambridge, UK.
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Maqueda A, Rodriguez FJ. Efficacy of human HC016 cell transplants on neuroprotection and functional recovery in a rat model of acute spinal cord injury. J Tissue Eng Regen Med 2019; 14:319-333. [PMID: 31821721 DOI: 10.1002/term.2995] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 11/06/2019] [Accepted: 12/06/2019] [Indexed: 12/23/2022]
Abstract
Spinal cord injury (SCI) is a devastating event with huge personal and social costs, for which there is no effective treatment. Cell therapy constitutes a promising therapeutic approach for SCI; however, its clinical potential is seriously limited by their low survival in the hostile conditions encompassing the acute phase of SCI. Human HC016 (hHC016) cells, generated from expanded human adipose mesenchymal stem cells (hAMSCs) and pulsed with a patented protocol with hydrogen peroxide (H2 O2 ), are expected to acquire improved resistance to oxidative environments which appears as a major limiting factor hampering the engrafting success. Our specific aim was to assess whether H2 O2 -pulsed hHC016 cells had an improved survival and thus therapeutic efficacy in a rat contusion model of acute SCI when grafted 48 hr after injury. Functional recovery was evaluated up to 56 days post-injury (dpi) by locomotor (open field test and CatWalk) and sensory (Von Frey and Hargreaves) tests. Besides, histological evaluation of transplanted cell survival and tissue protection/regeneration was also performed. Functional results showed a statistically significant improvement on locomotor recovery outcomes with hHC016 cells. Accordingly, superior cell survival in correlation with long-term neuroprotection, higher axonal regeneration, and reduced astroglial and microglial reactivity was also observed with hHC016 cells. These results demonstrate an enhanced survival capacity of hHC016 cells resulting in improved functional and histological outcomes as compared with hAMSCs, indicating that hHC016 cell transplants may constitute a promising cell therapy for acute SCI.
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Affiliation(s)
- Alfredo Maqueda
- Laboratory of Molecular Neurology, Hospital Nacional de Parapléjicos, Toledo, Spain
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Pukos N, Goodus MT, Sahinkaya FR, McTigue DM. Myelin status and oligodendrocyte lineage cells over time after spinal cord injury: What do we know and what still needs to be unwrapped? Glia 2019; 67:2178-2202. [PMID: 31444938 DOI: 10.1002/glia.23702] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 01/04/2023]
Abstract
Spinal cord injury (SCI) affects over 17,000 individuals in the United States per year, resulting in sudden motor, sensory and autonomic impairments below the level of injury. These deficits may be due at least in part to the loss of oligodendrocytes and demyelination of spared axons as it leads to slowed or blocked conduction through the lesion site. It has long been accepted that progenitor cells form new oligodendrocytes after SCI, resulting in the acute formation of new myelin on demyelinated axons. However, the chronicity of demyelination and the functional significance of remyelination remain contentious. Here we review work examining demyelination and remyelination after SCI as well as the current understanding of oligodendrocyte lineage cell responses to spinal trauma, including the surprisingly long-lasting response of NG2+ oligodendrocyte progenitor cells (OPCs) to proliferate and differentiate into new myelinating oligodendrocytes for months after SCI. OPCs are highly sensitive to microenvironmental changes, and therefore respond to the ever-changing post-SCI milieu, including influx of blood, monocytes and neutrophils; activation of microglia and macrophages; changes in cytokines, chemokines and growth factors such as ciliary neurotrophic factor and fibroblast growth factor-2; glutamate excitotoxicity; and axon degeneration and sprouting. We discuss how these changes relate to spontaneous oligodendrogenesis and remyelination, the evidence for and against demyelination being an important clinical problem and if remyelination contributes to motor recovery.
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Affiliation(s)
- Nicole Pukos
- Neuroscience Graduate Program, Ohio State University, Columbus, Ohio.,Belford Center for Spinal Cord Injury, Ohio State University, Columbus, Ohio
| | - Matthew T Goodus
- Belford Center for Spinal Cord Injury, Ohio State University, Columbus, Ohio.,Department of Neuroscience, Wexner Medical Center, Ohio State University, Columbus, Ohio
| | - Fatma R Sahinkaya
- Neuroscience Graduate Program, Ohio State University, Columbus, Ohio
| | - Dana M McTigue
- Belford Center for Spinal Cord Injury, Ohio State University, Columbus, Ohio.,Department of Neuroscience, Wexner Medical Center, Ohio State University, Columbus, Ohio
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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] [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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Imbalanced Corticospinal and Reticulospinal Contributions to Spasticity in Humans with Spinal Cord Injury. J Neurosci 2019; 39:7872-7881. [PMID: 31413076 DOI: 10.1523/jneurosci.1106-19.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/22/2019] [Accepted: 07/25/2019] [Indexed: 02/04/2023] Open
Abstract
Damage to the corticospinal and reticulospinal tract has been associated with spasticity in humans with upper motor neuron lesions. We hypothesized that these descending motor pathways distinctly contribute to the control of a spastic muscle in humans with incomplete spinal cord injury (SCI). To test this hypothesis, we examined motor-evoked potentials (MEPs) elicited by transcranial magnetic stimulation over the leg representation of the primary motor cortex, maximal voluntary contractions (MVCs), and the StartReact response (shortening in reaction time evoked by a startling stimulus) in the quadriceps femoris muscle in male and females with and without incomplete SCI. A total of 66.7% of the SCI participants showed symptoms of spasticity, whereas the other 33.3% showed no or low levels of spasticity. We found that participants with spasticity had smaller MEPs and MVCs and larger StartReact compared with participants with no or low spasticity and control subjects. These results were consistently present in spastic subjects but not in the other populations. Clinical scores of spasticity were negatively correlated with MEP-max and MVC values and positively correlated with shortening in reaction time. These findings provide evidence for lesser corticospinal and larger reticulospinal influences to spastic muscles in humans with SCI and suggest that these imbalanced contributions are important for motor recovery.SIGNIFICANCE STATEMENT Although spasticity is one of the most common symptoms manifested in humans with spinal cord injury (SCI) to date, its mechanisms of action remain poorly understood. We provide evidence, for the first time, of imbalanced contributions of the corticospinal and reticulospinal tract to control a spastic muscle in humans with chronic incomplete SCI. We found that participants with SCI with spasticity showed small corticospinal responses and maximal voluntary contractions and larger reticulospinal gain compared with participants with no or low spasticity and control subjects. These results were consistently present in spastic subjects but not in the other populations. We showed that imbalanced corticospinal and reticulospinal tract contributions are more pronounced in participants with chronic incomplete SCI with lesser recovery.
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Perovic D, Kolenc D, Bilic V, Somun N, Drmic D, Elabjer E, Buljat G, Seiwerth S, Sikiric P. Stable gastric pentadecapeptide BPC 157 can improve the healing course of spinal cord injury and lead to functional recovery in rats. J Orthop Surg Res 2019; 14:199. [PMID: 31266512 PMCID: PMC6604284 DOI: 10.1186/s13018-019-1242-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 06/18/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND We focused on the therapeutic effects of the stable gastric pentadecapeptide BPC 157 in spinal cord injury using a rat model. BPC 157, of which the LD1 has not been achieved, has been implemented as an anti-ulcer peptide in inflammatory bowel disease trials and recently in a multiple sclerosis trial. In animals, BPC 157 has an anti-inflammatory effect and therapeutic effects in functional recovery and the rescue of somatosensory neurons in the sciatic nerve after transection, upon brain injury after concussive trauma, and in severe encephalopathies. Additionally, BPC 157 affects various molecular pathways. METHODS Therefore, BPC 157 therapy was administered by a one-time intraperitoneal injection (BPC 157 (200 or 2 μg/kg) or 0.9% NaCl (5 ml/kg)) 10 min after injury. The injury procedure involved laminectomy (level L2-L3) and a 60-s compression (neurosurgical piston (60-66 g) of the exposed dural sac of the sacrocaudal spinal cord). Assessments were performed at 1, 4, 7, 15, 30, 90, 180, and 360 days after injury. RESULTS All of the injured rats that received BPC 157 exhibited consistent clinical improvement, increasingly better motor function of the tail, no autotomy, and resolved spasticity by day 15. BPC 157 application largely counteracted changes at the microscopic level, including the formation of vacuoles and the loss of axons in the white matter, the formation of edema and the loss of motoneurons in the gray matter, and a decreased number of large myelinated axons in the rat caudal nerve from day 7. EMG recordings showed a markedly lower motor unit potential in the tail muscle. CONCLUSION Axonal and neuronal necrosis, demyelination, and cyst formation were counteracted. The functional rescue provided by BPC 157 after spinal cord injury implies that BPC 157 therapy can impact all stages of the secondary injury phase.
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Affiliation(s)
- Darko Perovic
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia
| | - Danijela Kolenc
- Department of Pathology, School of Medicine, University of Zagreb, Salata 9, 10000, Zagreb, Croatia
| | - Vide Bilic
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia
| | - Nenad Somun
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia
| | - Domagoj Drmic
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia
| | - Esmat Elabjer
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia
| | - Gojko Buljat
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia
| | - Sven Seiwerth
- Department of Pathology, School of Medicine, University of Zagreb, Salata 9, 10000, Zagreb, Croatia
| | - Predrag Sikiric
- Department of Pharmacology, School of Medicine, University of Zagreb, Salata 11, P.O. Box 916, 10000, Zagreb, Croatia.
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Hwang DH, Park HH, Shin HY, Cui Y, Kim BG. Insulin-like Growth Factor-1 Receptor Dictates Beneficial Effects of Treadmill Training by Regulating Survival and Migration of Neural Stem Cell Grafts in the Injured Spinal Cord. Exp Neurobiol 2018; 27:489-507. [PMID: 30636901 PMCID: PMC6318559 DOI: 10.5607/en.2018.27.6.489] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 02/06/2023] Open
Abstract
Survival and migration of transplanted neural stem cells (NSCs) are prerequisites for therapeutic benefits in spinal cord injury. We have shown that survival of NSC grafts declines after transplantation into the injured spinal cord, and that combining treadmill training (TMT) enhances NSC survival via insulin-like growth factor-1 (IGF-1). Here, we aimed to obtain genetic evidence that IGF-1 signaling in the transplanted NSCs determines the beneficial effects of TMT. We transplanted NSCs heterozygous (+/-) for Igf1r, the gene encoding IGF-1 receptor, into the mouse spinal cord after injury, with or without combining TMT. We analyzed the influence of genotype and TMT on locomotor recovery and survival and migration of NSC grafts. In vitro experiments were performed to examine the potential roles of IGF-1 signaling in the migratory ability of NSCs. Mice receiving +/- NSC grafts showed impaired locomotor recovery compared with those receiving wild-type (+/+) NSCs. Locomotor improvement by TMT was more pronounced with +/+ grafts. Deficiency of one allele of Igf1r significantly reduced survival and migration of the transplanted NSCs. Although TMT did not significantly influence NSC survival, it substantially enhanced the extent of migration for only +/+ NSCs. Cultured neurospheres exhibited dynamic motility with cytoplasmic protrusions, which was regulated by IGF-1 signaling. IGF-1 signaling in transplanted NSCs may be essential in regulating their survival and migration. Furthermore, TMT may promote NSC graft-mediated locomotor recovery via activation of IGF-1 signaling in transplanted NSCs. Dynamic NSC motility via IGF-1 signaling may be the cellular basis for the TMT-induced enhancement of migration.
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Affiliation(s)
- Dong Hoon Hwang
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Korea
| | - Hee Hwan Park
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, Korea
| | - Hae Young Shin
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Korea.,Logos Biosystems, Anyang 14055, Korea
| | - Yuexian Cui
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Neurology, Yanbian University Hospital, Yanji 133000, Jilin, China
| | - Byung Gon Kim
- Department of Brain Science, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Neurology, Ajou University School of Medicine, Suwon 16499, Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon 16499, Korea
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46
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Jure I, De Nicola AF, Labombarda F. Progesterone effects on oligodendrocyte differentiation in injured spinal cord. Brain Res 2018; 1708:36-46. [PMID: 30527678 DOI: 10.1016/j.brainres.2018.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/27/2018] [Accepted: 12/04/2018] [Indexed: 12/31/2022]
Abstract
Spinal cord lesions result in chronic demyelination as a consequence of secondary injury. Although oligodendrocyte precursor cells proliferate the differentiation program fails. Successful differentiation implies progressive decrease of transcriptional inhibitors followed by upregulation of activators. Progesterone emerges as an anti-inflammatory and pro-myelinating agent which improves locomotor outcome after spinal cord injury. In this study, we have demonstrated that spinal cord injury enhanced oligodendrocyte precursor cell number and decreased mRNA expression of transcriptional inhibitors (Id2, Id4, hes5). However, mRNA expression of transcriptional activators (Olig2, Nkx2.2, Sox10 and Mash1) was down-regulated 3 days post injury. Interestingly, a differentiation factor such as progesterone increased transcriptional activator mRNA levels and the density of Olig2- expressing oligodendrocyte precursor cells. The differentiation program is regulated by extracellular signals which modify transcriptional factors and epigenetic players. As TGFβ1 is a known oligodendrocyte differentiation factor which is regulated by progesterone in reproductive tissues, we assessed whether TGFβ1 could mediate progesterone remyelinating actions after the lesion. Notwithstanding that astrocyte, oligodendrocyte precursor and microglial cell density increased after spinal cord injury, the number of these cells which expressed TGFβ1 remained unchanged regarding sham operated rats. However, progesterone treatment increased TGFβ1 mRNA expression and the number of astrocytes and microglial TGFβ1 expressing cells which would indirectly enhance oligodendrocyte differentiation. Therefore, TGFβ1 arises as a potential mediator of progesterone differentiating effects on oligodendrocyte linage.
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Affiliation(s)
- Ignacio Jure
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina
| | - Alejandro F De Nicola
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina; Dept. of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Paraguay 2155 C1121, Buenos Aires, Argentina
| | - Florencia Labombarda
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Vuelta de Obligado 2490, 1428 Buenos Aires, Argentina; Dept. of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Paraguay 2155 C1121, Buenos Aires, Argentina.
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47
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Guest JD, Moore SW, Aimetti AA, Kutikov AB, Santamaria AJ, Hofstetter CP, Ropper AE, Theodore N, Ulich TR, Layer RT. Internal decompression of the acutely contused spinal cord: Differential effects of irrigation only versus biodegradable scaffold implantation. Biomaterials 2018; 185:284-300. [DOI: 10.1016/j.biomaterials.2018.09.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2018] [Revised: 09/04/2018] [Accepted: 09/16/2018] [Indexed: 12/13/2022]
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Testing Pathological Variation of White Matter Tract in Adult Rats after Severe Spinal Cord Injury with MRI. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4068156. [PMID: 30534561 PMCID: PMC6252222 DOI: 10.1155/2018/4068156] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 09/07/2018] [Accepted: 10/15/2018] [Indexed: 01/21/2023]
Abstract
The purpose of this study was to assess the pathological variation in white matter tracts in the adult severe thoracic contusion spinal cord injury (SCI) rat models combined with in vivo magnetic resonance imaging (MRI), as well as the effect of spared white matter (WM) quantity on hindlimb motor function recovery. 7.0T MRI was conducted for all experimental animals before SCI and 1, 3, 7, and 14 days after SCI. The variation in the white matter tract in different regions of the spinal cord after SCI was examined by luxol fast blue (LFB) staining, NF200 immunochemistry, and diffusion tensor imaging (DTI) parameters, including fraction anisotropy, mean diffusivity, axial diffusion, and radial diffusivity. Meanwhile, Basso-Beattie-Bresnahan (BBB) open-field scoring was performed to evaluate the behavior of the paraplegic hind limbs. The quantitative analysis showed that spared white matter measures assessed by LFB and MRI had a close correlation (R2 = 0.8508). The percentage of spared white matter area was closely correlated with BBB score (R2 = 0.8460). After SCI, spared white matter in the spinal cord, especially the ventral column WM, played a critical role in motor function restoration. The results suggest that the first three days provides a key time window for SCI protection and treatment; spared white matter, especially in the ventral column, plays a key role in motor function recovery in rats. Additionally, DTI may be an important noninvasive technique to diagnose acute SCI degree as well as a tool to evaluate functional prognosis. During the transition from nerve protection toward clinical treatment after SCI, in vivo DTI may serve as an emerging noninvasive technique to diagnose acute SCI degree and predict the degree of spontaneous functional recovery after SCI.
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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: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [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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50
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Systemic epothilone D improves hindlimb function after spinal cord contusion injury in rats. Exp Neurol 2018; 306:250-259. [DOI: 10.1016/j.expneurol.2018.01.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 12/23/2017] [Accepted: 01/25/2018] [Indexed: 01/04/2023]
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