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Mohamed W, Kumar J, Alghamdi BS, Soliman AH, Toshihide Y. Neurodegeneration and inflammation crosstalk: Therapeutic targets and perspectives. IBRO Neurosci Rep 2023; 14:95-110. [PMID: 37388502 PMCID: PMC10300452 DOI: 10.1016/j.ibneur.2022.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/19/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Glia, which was formerly considered to exist just to connect neurons, now plays a key function in a wide range of physiological events, including formation of memory, learning, neuroplasticity, synaptic plasticity, energy consumption, and homeostasis of ions. Glial cells regulate the brain's immune responses and confers nutritional and structural aid to neurons, making them an important player in a broad range of neurological disorders. Alzheimer's, ALS, Parkinson's, frontotemporal dementia (FTD), and epilepsy are a few of the neurodegenerative diseases that have been linked to microglia and astroglia cells, in particular. Synapse growth is aided by glial cell activity, and this activity has an effect on neuronal signalling. Each glial malfunction in diverse neurodegenerative diseases is distinct, and we will discuss its significance in the progression of the illness, as well as its potential for future treatment.
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Affiliation(s)
- Wael Mohamed
- Department of Basic Medical Sciences, Kulliyyah of Medicine, International Islamic University Malaysia (IIUM), Kuantan, Malaysia
- Clinical Pharmacology Department, Menoufia Medical School, Menoufia University, Menoufia, Egypt
| | - Jaya Kumar
- Department of Physiology, Faculty of Medicine, UKM Medical Centre (UKMMC), Kuala Lumpur, Malaysia
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2
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Geng X, Zou Y, Li S, Qi R, Jing C, Ding X, Li J, Yu H. Electroacupuncture promotes the recovery of rats with spinal cord injury by suppressing the Notch signaling pathway via the H19/EZH2 axis. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:844. [PMID: 34164478 PMCID: PMC8184438 DOI: 10.21037/atm-21-1526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background Spinal cord injury (SCI) is a life-changing event with an extremely poor prognosis. In our preliminary studies, electroacupuncture (EA) was found to promote the repair of SCI, which was closely related to the Notch signaling pathway. Therefore, in the present study, we hypothesized that EA protects against SCI by inhibiting the Notch signaling pathway and sought to investigate the underlying molecular mechanisms. Methods Rat and cell models of SCI were established. The expression of long non-coding RNA H19 was measured by real-time quantitative polymerase chain reaction. The expression levels of EZH2, Notch1, Notch3, Notch4, Hes1, and PS1 protein were measured by western blot. Cell apoptosis and viability were analyzed using flow cytometry and Cell Counting Kit-8 assays, respectively. The expressions of glial fibrillary acidic protein (GFAP) and nestin were detected by immunofluorescence staining. Results The expressions of H19, EZH2, and GFAP were significantly increased after SCI but were inhibited by EA; in contrast, nestin expression was significantly decreased by SCI but was restored by EA. Moreover, oxygen-glucose deprivation (OGD) treatment elevated the expression of H19, EZH2, and Notch-related factors as well as apoptosis in PC-12 cells, while suppressing cell viability. Suppressing H19 alleviated the effects of OGD on cell viability and apoptosis, and inhibited the expression of EZH2 and Notch-related factors expression; these effects were reversed by EZH2 overexpression. Finally, EA promoted the recovery of SCI rats and neural stem cell (NSC) proliferation by inhibiting the Notch signaling pathway, which was reversed by H19 overexpression. Conclusions Our results demonstrated that EA promotes the recovery of SCI rats and increases the proliferation and differentiation of NSCs by suppressing the Notch signaling pathway via modulating the H19/EZH2 axis.
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Affiliation(s)
- Xin Geng
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Yanghong Zou
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Shipeng Li
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Renli Qi
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Cong Jing
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiangqian Ding
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Jinghui Li
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Hualin Yu
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, China
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3
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Wang W, Li J, Zhang Z, Ma H, Li Q, Yang H, Li M, Liu L. Genome-wide analysis of acute traumatic spinal cord injury-related RNA expression profiles and uncovering of a regulatory axis in spinal fibrotic scars. Cell Prolif 2020; 54:e12951. [PMID: 33150698 PMCID: PMC7791181 DOI: 10.1111/cpr.12951] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/08/2020] [Accepted: 10/20/2020] [Indexed: 02/05/2023] Open
Abstract
Objectives Long non‐coding RNAs (lncRNAs) are critical for posttranscriptional and transcriptional regulation in eukaryotic cells. However, data on lncRNA expression in the lesion epicentres of spinal tissues after acute traumatic spinal cord injury (ATSCI) are scarce. We aimed to identify lncRNA expression profiles in such centres and predict latent regulatory networks. Materials and methods High‐throughput RNA‐sequencing was used to profile the expression and regulatory patterns of lncRNAs, microRNAs and messenger RNAs (mRNAs) in an ATSCI C57BL/6 mouse model. Chromosome distributions, open reading frames (ORFs), transcript abundances, exon numbers and lengths were compared between lncRNAs and mRNAs. Gene ontology, KEGG pathways and binding networks were analysed. The findings were validated by qRT‐PCRs and luciferase assays. Results Intronic lncRNAs were the most common differentially expressed lncRNA. Most lncRNAs had <6 exons, and lncRNAs had shorter lengths and lesser ORFs than mRNAs. MiR‐21a‐5p had the most significant differential expression and bound to the differentially expressed lncRNA ENSMUST00000195880. The microRNAs and lncRNAs with significant differential expression were screened, and a lncRNA/miRNA/mRNA interaction network was predicted, constructed and verified. Conclusions The regulatory actions of this network may play a role in the pathophysiology of ATSCI. Our findings may lead to better understanding of potential ncRNA biomarkers and confer better therapeutic strategies for ATSCIs.
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Affiliation(s)
- Wenzhao Wang
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Jun Li
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Zhengdong Zhang
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Huixu Ma
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Qin Li
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Hai Yang
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Mingxin Li
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
| | - Lei Liu
- Department of Orthopedics, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, China
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4
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Goulding DS, Vogel RC, Gensel JC, Morganti JM, Stromberg AJ, Miller BA. Acute brain inflammation, white matter oxidative stress, and myelin deficiency in a model of neonatal intraventricular hemorrhage. J Neurosurg Pediatr 2020; 26:613-623. [PMID: 32858507 DOI: 10.3171/2020.5.peds20124] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 05/18/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Neonatal intraventricular hemorrhage (IVH) leads to posthemorrhagic hydrocephalus (PHH), brain injury, and long-term disability. Current therapy for IVH is based on treating PHH but does not address the underlying brain injury. In order to develop pharmacological treatment for IVH, there must be a better understanding of the underlying pathology of this disease. This study was designed to determine the time course of the acute inflammation and oxidative stress that may underlie the progressive pathology of IVH. The authors sought to understand the temporal relationships among inflammation, oxidative stress, and white matter pathology in a rat model of IVH. METHODS A rat model of IVH consisting of hemoglobin injection into the lateral ventricle was used. Tissue was analyzed via biochemical and histological methods to map the spatiotemporal distribution of innate immune activation and oxidative stress. White matter was quantified using both immunohistochemistry and Western blot for myelin basic protein (MBP) in the corpus callosum. RESULTS IVH led to acute induction of inflammatory cytokines, followed by oxidative stress. Oxidative stress was concentrated in white matter, adjacent to the lateral ventricles. Animals with IVH initially gained weight at a lower rate than control animals and had larger ventricles and less MBP than control animals. CONCLUSIONS Experimental IVH induces global inflammation throughout the brain and oxidative stress concentrated in the white matter. Both of these phenomena occur early after IVH. This has implications for human neonates with immature white matter that is exquisitely sensitive to inflammation and oxidative stress. Antiinflammatory or antioxidant therapy for IVH may need to be initiated early in order to protect developing white matter.
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Affiliation(s)
- Danielle S Goulding
- 1Departments of Neurosurgery.,2Spinal Cord and Brain Injury Research Center, University of Kentucky; and
| | - R Caleb Vogel
- 1Departments of Neurosurgery.,2Spinal Cord and Brain Injury Research Center, University of Kentucky; and
| | - John C Gensel
- 2Spinal Cord and Brain Injury Research Center, University of Kentucky; and.,3Physiology
| | - Josh M Morganti
- 2Spinal Cord and Brain Injury Research Center, University of Kentucky; and.,4Neuroscience, and.,5Sanders-Brown Center on Aging, University of Kentucky, Lexington, Kentucky
| | | | - Brandon A Miller
- 1Departments of Neurosurgery.,2Spinal Cord and Brain Injury Research Center, University of Kentucky; and.,4Neuroscience, and
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Pukos N, McTigue DM. Delayed short-term tamoxifen treatment does not promote remyelination or neuron sparing after spinal cord injury. PLoS One 2020; 15:e0235232. [PMID: 32735618 PMCID: PMC7394399 DOI: 10.1371/journal.pone.0235232] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/10/2020] [Indexed: 12/18/2022] Open
Abstract
The tamoxifen-dependent Cre/lox system in transgenic mice has become an important research tool across all scientific disciplines for manipulating gene expression in specific cell types. In these mouse models, Cre-recombination is not induced until tamoxifen is administered, which allows researchers to have temporal control of genetic modifications. Interestingly, tamoxifen has been identified as a potential therapy for spinal cord injury (SCI) and traumatic brain injury patients due to its neuroprotective properties. It is also reparative in that it stimulates oligodendrocyte differentiation and remyelination after toxin-induced demyelination. However, it is unknown whether tamoxifen is neuroprotective and neuroreparative when administration is delayed after SCI. To properly interpret data from transgenic mice in which tamoxifen treatment is delayed after SCI, it is necessary to identify the effects of tamoxifen alone on anatomical and functional recovery. In this study, female and male mice received a moderate mid-thoracic spinal cord contusion. Mice were then gavaged with corn oil or a high dose of tamoxifen from 19-22 days post-injury, and sacrificed 42 days post-injury. All mice underwent behavioral testing for the duration of the study, which revealed that tamoxifen treatment did not impact hindlimb motor recovery. Similarly, histological analyses revealed that tamoxifen had no effect on white matter sparing, total axon number, axon sprouting, glial reactivity, cell proliferation, oligodendrocyte number, or myelination, but tamoxifen did decrease the number of neurons in the dorsal and ventral horn. Semi-thin sections confirmed that axon demyelination and remyelination were unaffected by tamoxifen. Sex-specific responses to tamoxifen were also assessed, and there were no significant differences between female and male mice. These data suggest that delayed tamoxifen administration after SCI does not change functional recovery or improve tissue sparing in female or male mice.
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Affiliation(s)
- Nicole Pukos
- Neuroscience Graduate Program, The Ohio State University, Columbus, OH, United States of America
- Belford Center for Spinal Cord Injury, The Ohio State University, Columbus, OH, United States of America
| | - Dana M. McTigue
- Belford Center for Spinal Cord Injury, The Ohio State University, Columbus, OH, United States of America
- Department of Neuroscience, Wexner Medical Center, Ohio State University, Columbus, OH, United States of America
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6
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Goulding DS, Vogel RC, Pandya CD, Shula C, Gensel JC, Mangano FT, Goto J, Miller BA. Neonatal hydrocephalus leads to white matter neuroinflammation and injury in the corpus callosum of Ccdc39 hydrocephalic mice. J Neurosurg Pediatr 2020; 25:476-483. [PMID: 32032950 PMCID: PMC7415550 DOI: 10.3171/2019.12.peds19625] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/05/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The authors sought to determine if hydrocephalus caused a proinflammatory state within white matter as is seen in many other forms of neonatal brain injury. Common causes of hydrocephalus (such as trauma, infection, and hemorrhage) are inflammatory insults themselves and therefore confound understanding of how hydrocephalus itself affects neuroinflammation. Recently, a novel animal model of hydrocephalus due to a genetic mutation in the Ccdc39 gene has been developed in mice. In this model, ciliary dysfunction leads to early-onset ventriculomegaly, astrogliosis, and reduced myelination. Because this model of hydrocephalus is not caused by an antecedent proinflammatory insult, it was utilized to study the effect of hydrocephalus on inflammation within the white matter of the corpus callosum. METHODS A Meso Scale Discovery assay was used to measure levels of proinflammatory cytokines in whole brain from animals with and without hydrocephalus. Immunohistochemistry was used to measure macrophage activation and NG2 expression within the white matter of the corpus callosum in animals with and without hydrocephalus. RESULTS In this model of hydrocephalus, levels of cytokines throughout the brain revealed a more robust increase in classic proinflammatory cytokines (interleukin [IL]-1β, CXCL1) than in immunomodulatory cytokines (IL-10). Increased numbers of macrophages were found within the corpus callosum. These macrophages were polarized toward a proinflammatory phenotype as assessed by higher levels of CD86, a marker of proinflammatory macrophages, compared to CD206, a marker for antiinflammatory macrophages. There was extensive structural damage to the corpus callosum of animals with hydrocephalus, and an increase in NG2-positive cells. CONCLUSIONS Hydrocephalus without an antecedent proinflammatory insult induces inflammation and tissue injury in white matter. Future studies with this model will be useful to better understand the effects of hydrocephalus on neuroinflammation and progenitor cell development. Antiinflammatory therapy for diseases that cause hydrocephalus may be a powerful strategy to reduce tissue damage.
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Affiliation(s)
- Danielle S. Goulding
- Department of Neurosurgery, University of Kentucky,
Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of
Kentucky, Lexington, Kentucky
| | - R. Caleb Vogel
- Department of Neurosurgery, University of Kentucky,
Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of
Kentucky, Lexington, Kentucky
| | - Chirayu D. Pandya
- Department of Neurosurgery, University of Kentucky,
Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of
Kentucky, Lexington, Kentucky
| | - Crystal Shula
- Division of Pediatric Neurosurgery, Cincinnati
Children’s Hospital Medical Center, Cincinnati, Ohio
| | - John C. Gensel
- Spinal Cord and Brain Injury Research Center, University of
Kentucky, Lexington, Kentucky
- Department of Physiology, University of Kentucky,
Lexington, Kentucky
| | - Francesco T. Mangano
- Division of Pediatric Neurosurgery, Cincinnati
Children’s Hospital Medical Center, Cincinnati, Ohio
| | - June Goto
- Division of Pediatric Neurosurgery, Cincinnati
Children’s Hospital Medical Center, Cincinnati, Ohio
| | - Brandon A. Miller
- Department of Neurosurgery, University of Kentucky,
Lexington, Kentucky
- Spinal Cord and Brain Injury Research Center, University of
Kentucky, Lexington, Kentucky
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7
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Orem BC, Partain SB, Stirling DP. Inhibiting store-operated calcium entry attenuates white matter secondary degeneration following SCI. Neurobiol Dis 2019; 136:104718. [PMID: 31846736 DOI: 10.1016/j.nbd.2019.104718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 11/22/2019] [Accepted: 12/13/2019] [Indexed: 01/11/2023] Open
Abstract
Axonal degeneration plays a key role in the pathogenesis of numerous neurological disorders including spinal cord injury. After the irreversible destruction of the white matter elements during the primary (mechanical) injury, spared axons and their supporting glial cells begin to breakdown causing an expansion of the lesion site. Here we mechanistically link external sources of calcium entry through axoplasmic reticulum calcium store depletion that contributes to secondary axonal degeneration through a process called store-operated calcium entry. There is increasing evidence suggesting that store-operated calcium entry impairment is responsible for numerous disorders. Nevertheless, its role following spinal cord injury remains poorly understood. We hypothesize that store-operated calcium entry mediates secondary white matter degeneration after spinal cord injury. We used our previously published model of laser-induced spinal cord injury to focally transect mid cervical dorsal column axons from live 6-8-week-old heterozygous CNPaseGFP/+: Thy1YFP+ double transgenic murine spinal cord preparations (five treated, eight controls) and documented the dynamic changes in axons over time using two-photon excitation microscopy. We report that 1 hour delayed treatment with YM-58483, a potent inhibitor of store-operated calcium entry, significantly decreased intra-axonal calcium accumulation, axonal dieback both proximal and distal to the lesion site, reduced secondary axonal "bystander" damage acutely after injury, and promoted greater oligodendrocyte survival compared to controls. We also targeted store-operated calcium entry following a clinically relevant contusion spinal cord injury model in vivo. Adult, 6-8-week-old Advillin-Cre: Ai9 mice were subjected to a mild 30 kdyn contusion and imaged to observe secondary axonal degeneration in live animals. We found that delayed treatment with YM-58483 increased axonal survival and reduced axonal spheroid formation compared to controls (n = 5 mice per group). These findings suggest that blocking store-operated calcium entry acutely is neuroprotective and introduces a novel target to prevent pathological calcium entry following spinal cord injury using a clinically relevant model.
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Affiliation(s)
- Ben C Orem
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40202, USA
| | - Steven B Partain
- Department of Bioengineering, University of Louisville, Louisville, KY 40202, USA
| | - David P Stirling
- Kentucky Spinal Cord Injury Research Center, University of Louisville, Louisville, KY 40202, USA; Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40202, USA; Department of Neurological Surgery, University of Louisville, Louisville, KY 40202, USA; Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202, USA.
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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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9
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Ho MS, Verkhratsky A, Duan S, Parpura V. Editorial: Glia in Health and Disease. Front Mol Neurosci 2019; 12:63. [PMID: 30949026 PMCID: PMC6436194 DOI: 10.3389/fnmol.2019.00063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 02/25/2019] [Indexed: 12/11/2022] Open
Affiliation(s)
- Margaret S Ho
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Shumin Duan
- Department of Neurobiology, School of Medicine, Zhejiang University, Hangzhou, China
| | - Vladimir Parpura
- Department of Neurobiology, The University of Alabama at Birmingham, Birmingham, AL, United States
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10
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Dyck S, Kataria H, Akbari-Kelachayeh K, Silver J, Karimi-Abdolrezaee S. LAR and PTPσ receptors are negative regulators of oligodendrogenesis and oligodendrocyte integrity in spinal cord injury. Glia 2018; 67:125-145. [PMID: 30394599 DOI: 10.1002/glia.23533] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 09/18/2018] [Accepted: 09/19/2018] [Indexed: 12/26/2022]
Abstract
Following spinal cord injury (SCI), the population of mature oligodendrocytes undergoes substantial cell death; promoting their preservation and replacement is a viable strategy for preserving axonal integrity and white matter repair in the injured spinal cord. Dramatic upregulation of matrix chondroitin sulfate proteoglycans (CSPGs) is shown to pose an obstacle to endogenous repair processes, and targeting CSPGs improves functional recovery after SCI. However, the cellular and molecular mechanisms underlying the inhibitory effects of CSPGs remain largely undefined. Modulation of CSPGs specific signaling receptors, leukocyte common antigen-related (LAR), and protein tyrosine phosphatase-sigma (PTPσ) allows us to uncover the role and mechanisms of CSPGs in regulating oligodendrocytes in SCI. Here, utilizing specific functionally blocking peptides in a clinically relevant model of contusive/compressive SCI in the rat, we demonstrate that inhibition of PTPσ and LAR receptors promotes oligodendrogenesis by endogenous precursor cells, attenuates caspase 3-mediated cell death in mature oligodendrocytes, and preserves myelin. In parallel in vitro systems, we have unraveled that CSPGs directly induce apoptosis in populations of neural precursor cells and oligodendrocyte progenitor cells and limit their ability for oligodendrocyte differentiation, maturation, and myelination. These negative effects of CSPGs are mediated through the activation of both LAR and PTPσ receptors and the downstream Rho/ROCK pathway. Thus, we have identified a novel inhibitory role for PTPσ and LAR in regulating oligodendrocyte differentiation and apoptosis in the injured adult spinal cord and a new feasible therapeutic strategy for optimizing endogenous cell replacement following SCI.
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Affiliation(s)
- Scott Dyck
- Department of Physiology and Pathophysiology, The Regenerative Medicine Program, The Spinal Cord Research Center, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Hardeep Kataria
- Department of Physiology and Pathophysiology, The Regenerative Medicine Program, The Spinal Cord Research Center, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Khashayar Akbari-Kelachayeh
- Department of Physiology and Pathophysiology, The Regenerative Medicine Program, The Spinal Cord Research Center, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jerry Silver
- Department of Neuroscience, Case Western Reserve University School of Medicine, Cleveland, Ohio
| | - Soheila Karimi-Abdolrezaee
- Department of Physiology and Pathophysiology, The Regenerative Medicine Program, The Spinal Cord Research Center, University of Manitoba, Winnipeg, Manitoba, Canada.,Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
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11
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Tran AP, Warren PM, Silver J. The Biology of Regeneration Failure and Success After Spinal Cord Injury. Physiol Rev 2018. [PMID: 29513146 DOI: 10.1152/physrev.00017.2017] [Citation(s) in RCA: 479] [Impact Index Per Article: 79.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Since no approved therapies to restore mobility and sensation following spinal cord injury (SCI) currently exist, a better understanding of the cellular and molecular mechanisms following SCI that compromise regeneration or neuroplasticity is needed to develop new strategies to promote axonal regrowth and restore function. Physical trauma to the spinal cord results in vascular disruption that, in turn, causes blood-spinal cord barrier rupture leading to hemorrhage and ischemia, followed by rampant local cell death. As subsequent edema and inflammation occur, neuronal and glial necrosis and apoptosis spread well beyond the initial site of impact, ultimately resolving into a cavity surrounded by glial/fibrotic scarring. The glial scar, which stabilizes the spread of secondary injury, also acts as a chronic, physical, and chemo-entrapping barrier that prevents axonal regeneration. Understanding the formative events in glial scarring helps guide strategies towards the development of potential therapies to enhance axon regeneration and functional recovery at both acute and chronic stages following SCI. This review will also discuss the perineuronal net and how chondroitin sulfate proteoglycans (CSPGs) deposited in both the glial scar and net impede axonal outgrowth at the level of the growth cone. We will end the review with a summary of current CSPG-targeting strategies that help to foster axonal regeneration, neuroplasticity/sprouting, and functional recovery following SCI.
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Affiliation(s)
- Amanda Phuong Tran
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
| | - Philippa Mary Warren
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
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12
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Liu M, Xu P, Guan Z, Qian X, Dockery P, Fitzgerald U, O'Brien T, Shen S. Ulk4 deficiency leads to hypomyelination in mice. Glia 2017; 66:175-190. [PMID: 29034508 DOI: 10.1002/glia.23236] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 09/07/2017] [Accepted: 09/11/2017] [Indexed: 12/14/2022]
Abstract
Brain nerve fibers are insulated by myelin which is produced by oligodendrocytes. Defects in myelination are increasingly recognized as a common pathology underlying neuropsychiatric and neurodevelopmental disorders, which are associated with deletions of the Unc-51-like kinase 4 (ULK4) gene. Key transcription factors have been identified for oligodendrogenesis, but little is known about their associated regulators. Here we report that Ulk4 acts as a key regulator of myelination. Myelination is reduced by half in the Ulk4tm1a/tm1a hypomorph brain, whereas expression of axonal marker genes Tubb3, Nefh, Nefl and Nefm remains unaltered. Transcriptome analyses reveal that 8 (Gfap, Mbp, Mobp, Plp1, Slc1a2, Ttr, Cnp, Scd2) of the 10 most significantly altered genes in the Ulk4tm1a/tm1a brain are myelination-related. Ulk4 is co-expressed in Olig2+ (pan-oligodendrocyte marker) and CC1+ (mature myelinated oligodendrocyte marker) cells during postnatal development. Major oligodendrogeneic transcription factors, including Olig2, Olig1, Myrf, Sox10, Sox8, Sox6, Sox17, Nkx2-2, Nkx6-2 and Carhsp1, are significantly downregulated in the mutants. mRNA transcripts enriched in oligodendrocyte progenitor cells (OPCs), the newly formed oligodendrocytes (NFOs) and myelinating oligodendrocytes (MOs), are significantly attenuated. Expression of stage-specific oligodendrocyte factors including Cspg4, Sox17, Nfasc, Enpp6, Sirt2, Cnp, Plp1, Mbp, Ugt8, Mag and Mog are markedly decreased. Indirect effects of axon caliber and neuroinflammation may also contribute to the hypomyelination, as Ulk4 mutants display smaller axons and increased neuroinflammation. This is the first evidence demonstrating that ULK4 is a crucial regulator of myelination, and ULK4 may therefore become a novel therapeutic target for hypomyelination diseases.
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Affiliation(s)
- Min Liu
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Ping Xu
- State Key Laboratory of Proteomics, National Center for Protein Sciences, Beijing Proteome Research Center, National Engineering Research Center for Protein Drugs, Beijing Institute of Radiation Medicine, Beijing, 102206, China
| | - Zhenlong Guan
- Department of Physiology, College of Life Science, Hebei Normal University, Shijiazhuang, China
| | - Xiaohong Qian
- State Key Laboratory of Proteomics, National Center for Protein Sciences, Beijing Proteome Research Center, National Engineering Research Center for Protein Drugs, Beijing Institute of Radiation Medicine, Beijing, 102206, China
| | - Peter Dockery
- Anatomy, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Una Fitzgerald
- National Centre for Biomedical Engineering Science, Galway Neuroscience Centre, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Timothy O'Brien
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
| | - Sanbing Shen
- Regenerative Medicine Institute, School of Medicine, National University of Ireland (NUI) Galway, Galway, Ireland
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13
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Chang KT, Lin YL, Lin CT, Hong CJ, Tsai MJ, Huang WC, Shih YH, Lee YY, Cheng H, Huang MC. Leptin is essential for microglial activation and neuropathic pain after preganglionic cervical root avulsion. Life Sci 2017; 187:31-41. [PMID: 28822786 DOI: 10.1016/j.lfs.2017.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 08/02/2017] [Accepted: 08/14/2017] [Indexed: 12/13/2022]
Abstract
AIMS Preganglionic cervical root avulsion (PCRA) affects both the peripheral and central nervous systems and is often associated with neuropathic pain. Unlike peripheral nerve injuries (PNI), central lesions caused by disruption of cervical roots from the spinal cord following PCRA contribute to the generation of neuropathic pain. Leptin is involved in the development of neuropathic pain after PNI by affecting neurons. However, whether leptin is involved in microglial activation leading to neuropathic pain after PCRA is unknown. MAIN METHODS Preganglionic avulsion of the left 6th-8th cervical roots was performed in C57B/6J mice and leptin-deficient mice. A leptin antagonist or leptin was administered to C57B/6J mice and leptin-deficient mice after injury, respectively. The expression pattern of spinal and supraspinal microglia was examined by immunofluorescent staining. Von Frey filaments were used to test pain sensitivity. KEY FINDINGS Leptin is essential for the development of neuropathic pain after PCRA. Allodynia was absent in the leptin-deficient mice and the mice administered the leptin antagonist. We also found that leptin deficiency or the administration of its antagonist inhibited the development of microgliosis in the dorsal horn and brainstem. Furthermore, increase in the expression of CD86 and iNOS, and Wallerian degeneration were noted in the spinal cord. The administration of exogenous leptin to leptin-deficient mice reversed these effects. SIGNIFICANCE We concluded that leptin is involved in the proliferation and activation of microglia, which in turn enhances the development of neuropathic pain. Blocking the effects of leptin might be a target for the treatment of neuropathic pain after PCRA.
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Affiliation(s)
- Kai-Ting Chang
- Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Lo Lin
- Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Chi-Te Lin
- Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Nursing, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Chen-Jei Hong
- Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - May-Jywan Tsai
- Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Wen-Cheng Huang
- Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Pediatric Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yang-Hsin Shih
- Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Yen Lee
- Division of Pediatric Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Henrich Cheng
- Institute of Pharmacology, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Center for Neural Regeneration, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Department of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Ming-Chao Huang
- Neural Regeneration Laboratory, Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Division of Pediatric Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan; Basic Medical Education Center, Central Taiwan University of Science and Technology, Taichung, Taiwan; School of Medicine, Taipei Medical University, Taipei, Taiwan.
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14
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Boghdadi AG, Teo L, Bourne JA. The Involvement of the Myelin-Associated Inhibitors and Their Receptors in CNS Plasticity and Injury. Mol Neurobiol 2017; 55:1831-1846. [PMID: 28229330 DOI: 10.1007/s12035-017-0433-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/31/2017] [Indexed: 12/21/2022]
Abstract
The limited capacity for the central nervous system (CNS) to repair itself was first described over 100 years ago by Spanish neuroscientist Ramon Y. Cajal. However, the exact mechanisms underlying this failure in neuronal regeneration remain unclear and, as such, no effective therapeutics yet exist. Numerous studies have attempted to elucidate the biochemical and molecular mechanisms that inhibit neuronal repair with increasing evidence suggesting that several inhibitory factors and repulsive guidance cues active during development actually persist into adulthood and may be contributing to the inhibition of repair. For example, in the injured adult CNS, there are various inhibitory factors that impede the outgrowth of neurites from damaged neurons. One of the most potent of these neurite outgrowth inhibitors is the group of proteins known as the myelin-associated inhibitors (MAIs), present mainly on the membranes of oligodendroglia. Several studies have shown that interfering with these proteins can have positive outcomes in CNS injury models by promoting neurite outgrowth and improving functional recovery. As such, the MAIs, their receptors, and downstream effectors are valid drug targets for the treatment of CNS injury. This review will discuss the current literature on MAIs in the context of CNS development, plasticity, and injury. Molecules that interfere with the MAIs and their receptors as potential candidates for the treatment of CNS injury will additionally be introduced in the context of preclinical and clinical trials.
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Affiliation(s)
- Anthony G Boghdadi
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - Leon Teo
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - James A Bourne
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia.
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15
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Flygt J, Gumucio A, Ingelsson M, Skoglund K, Holm J, Alafuzoff I, Marklund N. Human Traumatic Brain Injury Results in Oligodendrocyte Death and Increases the Number of Oligodendrocyte Progenitor Cells. J Neuropathol Exp Neurol 2016; 75:503-15. [PMID: 27105664 DOI: 10.1093/jnen/nlw025] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 02/28/2016] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocyte (OL) death may contribute to white matter pathology, a common cause of network dysfunction and persistent cognitive problems in patients with traumatic brain injury (TBI). Oligodendrocyte progenitor cells (OPCs) persist throughout the adult CNS and may replace dead OLs. OL death and OPCs were analyzed by immunohistochemistry of human brain tissue samples, surgically removed due to life-threatening contusions and/or focal brain swelling at 60.6 ± 75 hours (range 4-192 hours) postinjury in 10 severe TBI patients (age 51.7 ± 18.5 years). Control brain tissue was obtained postmortem from 5 age-matched patients without CNS disorders. TUNEL and CC1 co-labeling was used to analyze apoptotic OLs, which were increased in injured brain tissue (p < 0.05), without correlation with time from injury until surgery. The OPC markers Olig2, A2B5, NG2, and PDGFR-α were used. In contrast to the number of single-labeled Olig2, A2B5, NG2, and PDGFR-α-positive cells, numbers of Olig2 and A2B5 co-labeled cells were increased in TBI samples (p < 0.05); this was inversely correlated with time from injury to surgery (r = -0.8, p < 0.05). These results indicate that severe focal human TBI results in OL death and increases in OPCs postinjury, which may influence white matter function following TBI.
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Affiliation(s)
- Johanna Flygt
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Astrid Gumucio
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Martin Ingelsson
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Karin Skoglund
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Jonatan Holm
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Irina Alafuzoff
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden
| | - Niklas Marklund
- From the Department of Neuroscience, Neurosurgery (JF, KS, JH, NM), and Department of Public Health and Caring Sciences, Geriatrics (AG, MI), and Department of Immunology, Genetics and Pathology (IA), Uppsala University, Uppsala, Sweden.
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16
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Delbary-Gossart S, Lee S, Baroni M, Lamarche I, Arnone M, Canolle B, Lin A, Sacramento J, Salegio EA, Castel MN, Delesque-Touchard N, Alam A, Laboudie P, Ferzaz B, Savi P, Herbert JM, Manley GT, Ferguson AR, Bresnahan JC, Bono F, Beattie MS. A novel inhibitor of p75-neurotrophin receptor improves functional outcomes in two models of traumatic brain injury. Brain 2016; 139:1762-82. [PMID: 27084575 PMCID: PMC4892754 DOI: 10.1093/brain/aww074] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/20/2016] [Indexed: 11/14/2022] Open
Abstract
The p75 neurotrophin receptor is important in multiple physiological actions including neuronal survival and neurite outgrowth during development, and after central nervous system injury. We have discovered a novel piperazine-derived compound, EVT901, which interferes with p75 neurotrophin receptor oligomerization through direct interaction with the first cysteine-rich domain of the extracellular region. Using ligand binding assays with cysteine-rich domains-fused p75 neurotrophin receptor, we confirmed that EVT901 interferes with oligomerization of full-length p75 neurotrophin receptor in a dose-dependent manner. Here we report that EVT901 reduces binding of pro-nerve growth factor to p75 neurotrophin receptor, blocks pro-nerve growth factor induced apoptosis in cells expressing p75 neurotrophin receptor, and enhances neurite outgrowth in vitro. Furthermore, we demonstrate that EVT901 abrogates p75 neurotrophin receptor signalling by other ligands, such as prion peptide and amyloid-β. To test the efficacy of EVT901 in vivo, we evaluated the outcome in two models of traumatic brain injury. We generated controlled cortical impacts in adult rats. Using unbiased stereological analysis, we found that EVT901 delivered intravenously daily for 1 week after injury, reduced lesion size, protected cortical neurons and oligodendrocytes, and had a positive effect on neurological function. After lateral fluid percussion injury in adult rats, oral treatment with EVT901 reduced neuronal death in the hippocampus and thalamus, reduced long-term cognitive deficits, and reduced the occurrence of post-traumatic seizure activity. Together, these studies provide a new reagent for altering p75 neurotrophin receptor actions after injury and suggest that EVT901 may be useful in treatment of central nervous system trauma and other neurological disorders where p75 neurotrophin receptor signalling is affected.
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Affiliation(s)
| | - Sangmi Lee
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Marco Baroni
- 3 Sanofi Research, Exploratory Unit, Via Gaetano Sbodio 2, 20134 Milano, Italy
| | - Isabelle Lamarche
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Michele Arnone
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Benoit Canolle
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Amity Lin
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Jeffrey Sacramento
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Ernesto A Salegio
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Marie-Noelle Castel
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | | | - Antoine Alam
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Patricia Laboudie
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Badia Ferzaz
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Pierre Savi
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Jean-Marc Herbert
- 4 From Sanofi Research, Early to Candidate, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Geoffrey T Manley
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Adam R Ferguson
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Jacqueline C Bresnahan
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
| | - Françoise Bono
- 1 Evotec, 195 route d'Espagne, 31036 Toulouse cedex, France
| | - Michael S Beattie
- 2 Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, 1001 Potrero Ave, San Francisco, CA 94110, USA
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17
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Luo Y, Hu Q, Zhang Q, Hong S, Tang X, Cheng L, Jiang L. Alterations in hippocampal myelin and oligodendrocyte precursor cells during epileptogenesis. Brain Res 2015; 1627:154-64. [PMID: 26433043 DOI: 10.1016/j.brainres.2015.09.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Revised: 09/21/2015] [Accepted: 09/22/2015] [Indexed: 12/19/2022]
Abstract
Recent reports have described damage to myelinated fibers in the central nervous system (CNS) in patients with temporal lobe epilepsy (TLE) and animal models. However, only limited data are available on the dynamic changes that occur in myelinated fibers, oligodendrocytes (which are myelin-forming cells), and oligodendrocyte precursor cells (OPCs), which are a reservoir of new oligodendrocytes, in the hippocampus throughout epileptogenesis. The current study was designed to examine this issue using a rat model of lithium-pilocarpine-induced epilepsy. Electroencephalography (EEG), immunofluorescence, and Western blot analysis showed that the loss of myelin and oligodendrocytes in the rat hippocampus began during the acute stage of epileptogenesis, and the severity of this loss increased throughout epileptogenesis. Accompanying this loss of myelin and oligodendrocytes, OPCs in the rat hippocampus became activated and their populations increased during several phases of epileptogenesis (the acute, latent and chronic phases). The transcription factors olig1 and olig2, which play crucial roles in regulating OPC proliferation, differentiation and remyelination, were up-regulated during the early phases (the acute and latent phases) followed by a sharp decline in their expression during the chronic and late chronic phases. This study is the first to confirm the loss of myelin and oligodendrocytes during lithium-pilocarpine-induced epileptogenesis accompanied by a transient increase in the number of OPCs. Prevention of the loss of myelin and oligodendrocytes may provide a novel treatment strategy for epilepsy.
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Affiliation(s)
- Yuanyuan Luo
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China
| | - Qiao Hu
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China
| | - Qian Zhang
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China
| | - Siqi Hong
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Department of Neurology, Children's Hospital of Chongqing Medical University, 136# Zhongshan 2 Road, Chongqing 400014, PR China
| | - Xiaoju Tang
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China
| | - Li Cheng
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China
| | - Li Jiang
- Lab of Pediatric Neurology, Ministry of Education, Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, PR China; Department of Neurology, Children's Hospital of Chongqing Medical University, 136# Zhongshan 2 Road, Chongqing 400014, PR China.
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18
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Geng X, Sun T, Li JH, Zhao N, Wang Y, Yu HL. Electroacupuncture in the repair of spinal cord injury: inhibiting the Notch signaling pathway and promoting neural stem cell proliferation. Neural Regen Res 2015; 10:394-403. [PMID: 25878587 PMCID: PMC4396101 DOI: 10.4103/1673-5374.153687] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2015] [Indexed: 12/23/2022] Open
Abstract
Electroacupuncture for the treatment of spinal cord injury has a good clinical curative effect, but the underlying mechanism is unclear. In our experiments, the spinal cord of adult Sprague-Dawley rats was clamped for 60 seconds. Dazhui (GV14) and Mingmen (GV4) acupoints of rats were subjected to electroacupuncture. Enzyme-linked immunosorbent assay revealed that the expression of serum inflammatory factors was apparently downregulated in rat models of spinal cord injury after electroacupuncture. Hematoxylin-eosin staining and immunohistochemistry results demonstrated that electroacupuncture contributed to the proliferation of neural stem cells in rat injured spinal cord, and suppressed their differentiation into astrocytes. Real-time quantitative PCR and western blot assays showed that electroacupuncture inhibited activation of the Notch signaling pathway induced by spinal cord injury. These findings indicate that electroacupuncture repaired the injured spinal cord by suppressing the Notch signaling pathway and promoting the proliferation of endogenous neural stem cells.
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Affiliation(s)
- Xin Geng
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Tao Sun
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Jing-Hui Li
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Ning Zhao
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Yong Wang
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
| | - Hua-Lin Yu
- Second Department of Neurosurgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan Province, China
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19
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Lee JY, Kang SR, Yune TY. Fluoxetine prevents oligodendrocyte cell death by inhibiting microglia activation after spinal cord injury. J Neurotrauma 2015; 32:633-44. [PMID: 25366938 DOI: 10.1089/neu.2014.3527] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Oligodendrocyte cell death and axon demyelination after spinal cord injury (SCI) are known to be important secondary injuries contributing to permanent neurological disability. Thus, blocking oligodendrocyte cell death should be considered for therapeutic intervention after SCI. Here, we demonstrated that fluoxetine, an antidepressant drug, alleviates oligodendrocyte cell death by inhibiting microglia activation after SCI. After injury at the T9 level with a Precision Systems and Instrumentation (Lexington, KY) device, fluoxetine (10 mg/kg, intraperitoneal) was administered once a day for the indicated time points. Immunostaining with CD11b (OX-42) antibody and quantification analysis showed that microglia activation was significantly inhibited by fluoxetine at 5 days after injury. Fluoxetine also significantly inhibited activation of p38 mitogen-activated protein kinase (p38-MAPK) and expression of pro-nerve growth factor (pro-NGF), which is known to mediate oligodendrocyte cell death through the p75 neurotrophin receptor after SCI. In addition, fluoxetine attenuated activation of Ras homolog gene family member A and decreased the level of phosphorylated c-Jun and, ultimately, alleviated caspase-3 activation and significantly reduced cell death of oligodendrocytes at 5 days after SCI. Further, the decrease of myelin basic protein, myelin loss, and axon loss in white matter was also significantly blocked by fluoxetine, as compared to vehicle control. These results suggest that fluoxetine inhibits oligodendrocyte cell death by inhibiting microglia activation and p38-MAPK activation, followed by pro-NGF production after SCI, and provide a potential usage of fluoxetine for a therapeutic agent after acute SCI in humans.
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Affiliation(s)
- Jee Y Lee
- 1 Age-Related and Brain Diseases Research Center, Kyung Hee University , Seoul, Korea
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20
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Wu H, Hu M, Yuan D, Wu H, Wang Y, Wang J, Li T, Qian C, Yu H. Electroacupuncture promotes the proliferation of endogenous neural stem cells and oligodendrocytes in the injured spinal cord of adult rats. Neural Regen Res 2015; 7:1138-44. [PMID: 25722706 PMCID: PMC4340030 DOI: 10.3969/j.issn.1673-5374.2012.15.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Accepted: 04/23/2012] [Indexed: 11/24/2022] Open
Abstract
A contusive model of spinal cord injury at spinal segment T8-9 was established in rats. Huantiao (GB30) and Huatuojiaji (Ex-B05) were punctured with needles, and endogenous neural stem cells were labeled with 5-bromo-2’-deoxyuridine (BrdU) and NG2. Double immunofluorescence staining showed that electroacupuncture markedly increased the numbers of BrdU+/NG2+ cells at spinal cord tissue 15 mm away from the injury center in the rostral and caudal directions. The results suggest that electroacupuncture promotes the proliferation of endogenous neural stem cells and oligodendrocytes in rats with spinal cord injury.
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Affiliation(s)
- Haiying Wu
- Department of Emergency and Intensive Care Unit, First Affiliated Hospital, Kunming Medical College, Kunming 650032, Yunnan Province, China
| | - Min Hu
- Kunming University, Kunming 650118, Yunnan Province, China
| | - Dekai Yuan
- Kunming University, Kunming 650118, Yunnan Province, China
| | - Haiying Wu
- Department of Otolaryngology, Second Affiliated Hospital, Kunming Medical College, Kunming 650101, Yunnan Province, China
| | - Yunhui Wang
- Department of Emergency and Intensive Care Unit, First Affiliated Hospital, Kunming Medical College, Kunming 650032, Yunnan Province, China
| | - Jing Wang
- Department of Emergency and Intensive Care Unit, First Affiliated Hospital, Kunming Medical College, Kunming 650032, Yunnan Province, China
| | - Tao Li
- Department of Emergency and Intensive Care Unit, First Affiliated Hospital, Kunming Medical College, Kunming 650032, Yunnan Province, China
| | - Chuanyun Qian
- Department of Emergency and Intensive Care Unit, First Affiliated Hospital, Kunming Medical College, Kunming 650032, Yunnan Province, China
| | - Hualin Yu
- Department of Minimally Invasive Neurosurgery, First Affiliated Hospital, Kunming Medical College, Kunming 650032, Yunnan Province, China
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21
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Plemel JR, Keough MB, Duncan GJ, Sparling JS, Yong VW, Stys PK, Tetzlaff W. Remyelination after spinal cord injury: Is it a target for repair? Prog Neurobiol 2014; 117:54-72. [DOI: 10.1016/j.pneurobio.2014.02.006] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Revised: 02/15/2014] [Accepted: 02/20/2014] [Indexed: 12/12/2022]
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22
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Burda JE, Sofroniew MV. Reactive gliosis and the multicellular response to CNS damage and disease. Neuron 2014; 81:229-48. [PMID: 24462092 DOI: 10.1016/j.neuron.2013.12.034] [Citation(s) in RCA: 949] [Impact Index Per Article: 94.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2013] [Indexed: 02/07/2023]
Abstract
The CNS is prone to heterogeneous insults of diverse etiologies that elicit multifaceted responses. Acute and focal injuries trigger wound repair with tissue replacement. Diffuse and chronic diseases provoke gradually escalating tissue changes. The responses to CNS insults involve complex interactions among cells of numerous lineages and functions, including CNS intrinsic neural cells, CNS intrinsic nonneural cells, and CNS extrinsic cells that enter from the circulation. The contributions of diverse nonneuronal cell types to outcome after acute injury, or to the progression of chronic disease, are of increasing interest as the push toward understanding and ameliorating CNS afflictions accelerates. In some cases, considerable information is available, in others, comparatively little, as examined and reviewed here.
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Affiliation(s)
- Joshua E Burda
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095-1763, USA
| | - Michael V Sofroniew
- Department of Neurobiology and Brain Research Institute, University of California Los Angeles, Los Angeles, CA 90095-1763, USA.
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23
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Sahinkaya FR, Milich LM, McTigue DM. Changes in NG2 cells and oligodendrocytes in a new model of intraspinal hemorrhage. Exp Neurol 2014; 255:113-26. [PMID: 24631375 DOI: 10.1016/j.expneurol.2014.02.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 02/18/2014] [Accepted: 02/22/2014] [Indexed: 02/04/2023]
Abstract
Spinal cord injury (SCI) evokes rapid deleterious and reparative glial reactions. Understanding the triggers for these responses is necessary for designing strategies to maximize repair. This study examined lesion formation and glial responses to vascular disruption and hemorrhage, a prominent feature of acute SCI. The specific role of hemorrhage is difficult to evaluate in trauma-induced lesions, because mechanical injury initiates many downstream responses. To isolate vascular disruption from trauma-induced effects, we created a novel and reproducible model of collagenase-induced intraspinal hemorrhage (ISH) and compared glial reactions between unilateral ISH and a hemi-contusion injury. Similar to contusion injuries, ISH lesions caused loss of myelin and axons and became filled with iron-laden macrophages. We hypothesized that intraspinal hemorrhage would also initiate reparative cellular responses including NG2+ oligodendrocyte progenitor cell (OPC) proliferation and oligodendrocyte genesis. Indeed, ISH induced OPC proliferation within 1d post-injury (dpi), which continued throughout the first week and resulted in a sustained elevation of NG2+ OPCs. ISH also caused oligodendrocyte loss within 4h that was sustained through 3d post-ISH. However, oligodendrogenesis, as determined by bromo-deoxyuridine (BrdU) positive oligodendrocytes, restored oligodendrocyte numbers by 7dpi, revealing that proliferating OPCs differentiated into new oligodendrocytes after ISH. The signaling molecules pERK1/2 and pSTAT3 were robustly increased acutely after ISH, with pSTAT3 being expressed in a portion of OPCs, suggesting that activators of this signaling cascade may initiate OPC responses. Aside from subtle differences in timing of OPC responses, changes in ISH tissue closely mimicked those in hemi-contusion tissue. These results are important for elucidating the contribution of hemorrhage to lesion formation and endogenous cell-mediated repair, and will provide the foundation for future studies geared toward identifying the role of specific blood components on injury and repair mechanisms. This understanding may provide new clinical targets for SCI and other devastating conditions such as intracerebral hemorrhage.
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Affiliation(s)
- F Rezan Sahinkaya
- Department of Neuroscience, Ohio State University, Columbus, OH 43210, USA; Neuroscience Graduate Studies Program, Ohio State University, Columbus, OH 43210, USA; Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, OH 43210, USA
| | - Lindsay M Milich
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, OH 43210, USA
| | - Dana M McTigue
- Department of Neuroscience, Ohio State University, Columbus, OH 43210, USA; Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, OH 43210, USA.
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24
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Flygt J, Djupsjö A, Lenne F, Marklund N. Myelin loss and oligodendrocyte pathology in white matter tracts following traumatic brain injury in the rat. Eur J Neurosci 2013; 38:2153-65. [PMID: 23458840 DOI: 10.1111/ejn.12179] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 01/29/2013] [Accepted: 02/05/2013] [Indexed: 12/11/2022]
Abstract
Axonal injury is an important contributor to the behavioral deficits observed following traumatic brain injury (TBI). Additionally, loss of myelin and/or oligodendrocytes can negatively influence signal transduction and axon integrity. Apoptotic oligodendrocytes, changes in the oligodendrocyte progenitor cell (OPC) population and loss of myelin were evaluated at 2, 7 and 21 days following TBI. We used the central fluid percussion injury model (n = 18 and three controls) and the lateral fluid percussion injury model (n = 15 and three controls). The external capsule, fimbriae and corpus callosum were analysed. With Luxol Fast Blue and RIP staining, myelin loss was observed in both models, in all evaluated regions and at all post-injury time points, as compared with sham-injured controls (P ≤ 0.05). Accumulation of β-amyloid precursor protein was observed in white matter tracts in both models in areas with preserved and reduced myelin staining. White matter microglial/macrophage activation, evaluated by isolectin B4 immunostaining, was marked at the early time points. In contrast, the glial scar, evaluated by glial fibrillary acidic protein staining, showed its highest intensity 21 days post-injury in both models. The number of apoptotic oligodendrocytes, detected by CC1/caspase-3 co-labeling, was increased in both models in all evaluated regions. Finally, the numbers of OPCs, evaluated with the markers Tcf4 and Olig2, were increased from day 2 (Olig2) or day 7 (Tcf4) post-injury (P ≤ 0.05). Our results indicate that TBI induces oligodendrocyte apoptosis and widespread myelin loss, followed by a concomitant increase in the number of OPCs. Prevention of myelin loss and oligodendrocyte death may represent novel therapeutic targets for TBI.
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Affiliation(s)
- J Flygt
- Department of Neurosurgery, Uppsala University Hospital, Uppsala SE-751 85, Sweden
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25
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Piltti KM, Salazar DL, Uchida N, Cummings BJ, Anderson AJ. Safety of epicenter versus intact parenchyma as a transplantation site for human neural stem cells for spinal cord injury therapy. Stem Cells Transl Med 2013; 2:204-16. [PMID: 23413374 DOI: 10.5966/sctm.2012-0110] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Neural stem cell transplantation may have the potential to yield repair and recovery of function in central nervous system injury and disease, including spinal cord injury (SCI). Multiple pathological processes are initiated at the epicenter of a traumatic spinal cord injury; these are generally thought to make the epicenter a particularly hostile microenvironment. Conversely, the injury epicenter is an appealing potential site of therapeutic human central nervous system-derived neural stem cell (hCNS-SCns) transplantation because of both its surgical accessibility and the avoidance of spared spinal cord tissue. In this study, we compared hCNS-SCns transplantation into the SCI epicenter (EPI) versus intact rostral/caudal (R/C) parenchyma in contusion-injured athymic nude rats, and assessed the cell survival, differentiation, and migration. Regardless of transplantation site, hCNS-SCns survived and proliferated; however, the total number of hCNS-SCns quantified in the R/C transplant animals was twice that in the EPI animals, demonstrating increased overall engraftment. Migration and fate profile were unaffected by transplantation site. However, although transplantation site did not alter the proportion of human astrocytes, EPI transplantation shifted the localization of these cells and exhibited a correlation with calcitonin gene-related peptide fiber sprouting. Critically, no changes in mechanical allodynia or thermal hyperalgesia were observed. Taken together, these data suggest that the intact parenchyma may be a more favorable transplantation site than the injury epicenter in the subacute period post-SCI.
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Affiliation(s)
- Katja M Piltti
- Sue and Bill Gross Stem Cell Research Center, Uiversity of California, Irvine, CA, USA
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26
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Mohammadi E, Ghaedi K, Esmailie A, Rahgozar S. Gene expression profiling of liver X receptor α and Bcl-2-associated X protein in experimental transection spinal cord-injured rats. J Spinal Cord Med 2013; 36:66-71. [PMID: 23433337 PMCID: PMC3555109 DOI: 10.1179/2045772312y.0000000032] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Study of molecular responses to central nervous system injury would be helpful for controlling the harmful pathways post-injury and triggering the useful pathways required for the treatment of injury. OBJECTIVE To investigate the expression level of liver X receptor α (LXRα) which has anti-inflammatory effects and pro-apoptotic Bcl-2-associated X protein (Bax) upon spinal cord injury (SCI). DESIGN To induce SCI, transection was carried out at T9 level of male Wister rats. Approximately 8 mm of rostral, caudal, and epicenter tissues of injured sites in treated rats were chosen for quantitative real-time polymerase chain reaction at the 6, 24, and 72 hours, and 7 and 10 days post-surgery. RESULTS Our results showed a complicated temporal and spatial pattern of alteration in LXRα and Bax mRNA expression levels after SCI. LXRα expression level followed a homologues pattern (additive and subtractive wave) with a difference in time at three areas of studied. Rostral, caudal, and epicenter expression patterns of Bax were dissimilar in these areas. Gradual increase in the expression of Bax without any decrease at the rostral area was observed, presumably indicating the active transcription process of this gene, regardless of its protein situation. CONCLUSION A time lapse significant change in Bax expression level was observed only in the epicenter of injury, emphasizing that apoptotic responses are limited to this area. Furthermore, an increase in LXRα transcription level was observed first in rostral area and then extended to epicentral and caudal areas, implying that inflammation responses extended from rostral to caudal areas.
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Affiliation(s)
| | - Kamran Ghaedi
- Correspondence to: Kamran Ghaedi (Ph.D.), Biology Department, School of Sciences, University of Isfahan, Hezar jerib Ave., Azadi Sq., Postal Code 73441-81746 Isfahan, Iran. Tel No.: +98-311-7932479; Fax No.: +98-311-7932456.
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27
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Huang JK, Ferrari CC, Monteiro de Castro G, Lafont D, Zhao C, Zaratin P, Pouly S, Greco B, Franklin RJM. Accelerated axonal loss following acute CNS demyelination in mice lacking protein tyrosine phosphatase receptor type Z. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1518-23. [PMID: 22940073 DOI: 10.1016/j.ajpath.2012.07.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2012] [Revised: 05/14/2012] [Accepted: 07/03/2012] [Indexed: 12/17/2022]
Abstract
Protein tyrosine phosphatase receptor type Z (Ptprz) is widely expressed in the mammalian central nervous system and has been suggested to regulate oligodendrocyte survival and differentiation. We investigated the role of Ptprz in oligodendrocyte remyelination after acute, toxin-induced demyelination in Ptprz null mice. We found neither obvious impairment in the recruitment of oligodendrocyte precursor cells, astrocytes, or reactive microglia/macrophage to lesions nor a failure for oligodendrocyte precursor cells to differentiate and remyelinate axons at the lesions. However, we observed an unexpected increase in the number of dystrophic axons by 3 days after demyelination, followed by prominent Wallerian degeneration by 21 days in the Ptprz-deficient mice. Moreover, quantitative gait analysis revealed a deficit of locomotor behavior in the mutant mice, suggesting increased vulnerability to axonal injury. We propose that Ptprz is necessary to maintain central nervous system axonal integrity in a demyelinating environment and may be an important target of axonal protection in inflammatory demyelinating diseases, such as multiple sclerosis and periventricular leukomalacia.
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Affiliation(s)
- Jeffrey K Huang
- Wellcome Trust and MRC Cambridge Stem Cell Institute, University of Cambridge, United Kingdom
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28
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Abstract
AbstractCentral nervous system (CNS) injuries affect all levels of society indiscriminately, resulting in functional and behavioral deficits with devastating impacts on life expectancies, physical and emotional wellbeing. Considerable literature exists describing the pathophysiology of CNS injuries as well as the cellular and molecular factors that inhibit regrowth and regeneration of damaged connections. Based on these data, numerous therapeutic strategies targeting the various factors of repair inhibition have been proposed and on-going assessment has demonstrated some promising results in the laboratory environ. However, several of these treatment strategies have subsequently been taken into clinical trials but demonstrated little to no improvement in patient outcomes. As a result, options for clinical interventions following CNS injuries remain limited and effective restorative treatment strategies do not as yet exist. This review discusses some of the current animal models, with focus on nonhuman primates, which are currently being modeled in the laboratory for the study of CNS injuries. Last, we review the current understanding of the mechanisms underlying repair/regrowth inhibition and the current trends in experimental treatment strategies that are being assessed for potential translation to clinical applications.
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Ferguson AR, Stück ED, Nielson JL. Syndromics: a bioinformatics approach for neurotrauma research. Transl Stroke Res 2011; 2:438-54. [PMID: 22207883 PMCID: PMC3236294 DOI: 10.1007/s12975-011-0121-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 10/14/2011] [Accepted: 10/18/2011] [Indexed: 12/25/2022]
Abstract
Substantial scientific progress has been made in the past 50 years in delineating many of the biological mechanisms involved in the primary and secondary injuries following trauma to the spinal cord and brain. These advances have highlighted numerous potential therapeutic approaches that may help restore function after injury. Despite these advances, bench-to-bedside translation has remained elusive. Translational testing of novel therapies requires standardized measures of function for comparison across different laboratories, paradigms, and species. Although numerous functional assessments have been developed in animal models, it remains unclear how to best integrate this information to describe the complete translational "syndrome" produced by neurotrauma. The present paper describes a multivariate statistical framework for integrating diverse neurotrauma data and reviews the few papers to date that have taken an information-intensive approach for basic neurotrauma research. We argue that these papers can be described as the seminal works of a new field that we call "syndromics", which aim to apply informatics tools to disease models to characterize the full set of mechanistic inter-relationships from multi-scale data. In the future, centralized databases of raw neurotrauma data will enable better syndromic approaches and aid future translational research, leading to more efficient testing regimens and more clinically relevant findings.
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Affiliation(s)
- Adam R. Ferguson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, 1001 Potrero Avenue, Building 1, Room 101, San Francisco, CA 94110 USA
| | - Ellen D. Stück
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, 1001 Potrero Avenue, Building 1, Room 101, San Francisco, CA 94110 USA
| | - Jessica L. Nielson
- Brain and Spinal Injury Center (BASIC), Department of Neurological Surgery, University of California, 1001 Potrero Avenue, Building 1, Room 101, San Francisco, CA 94110 USA
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30
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Veiga S, Ly J, Chan PH, Bresnahan JC, Beattie MS. SOD1 overexpression improves features of the oligodendrocyte precursor response in vitro. Neurosci Lett 2011; 503:10-4. [PMID: 21843597 DOI: 10.1016/j.neulet.2011.07.053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 07/28/2011] [Accepted: 07/31/2011] [Indexed: 12/19/2022]
Abstract
Spinal cord injury (SCI) produces a significant loss of oligodendrocytes (OL) and demyelination. The oligodendrocyte precursor cells (OPCs) response includes a group of cellular changes in OPCs that are directed to replenish OL loss from the injury. However, this adaptive response is hampered and OPCs eventually die or fail to differentiate to mature and functional OL. In this study, we wanted to evaluate if overexpression of human superoxide dismutase 1 (hSOD1) in OPCs from the SOD1 transgenic rat could improve some of the features of the OPC response in vitro. We found that hSOD1 overexpression increases the proliferation of OPCs and accelerates their differentiation to mature OL in vitro. Furthermore, hSOD1 overexpression reduces oxidative stress-mediated death in OPCs. These results suggest hSOD1 as a therapeutic target to increase OPC response success and potentially, OL replacement and remyelination after SCI.
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Affiliation(s)
- S Veiga
- Brain and Spinal Injury Center, Department of Neurological Surgery, University of California, San Francisco, United States
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31
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Abstract
Oligodendrocytes (OLs) are particularly susceptible to the toxicity of the acute lesion environment after spinal cord injury (SCI). They undergo both necrosis and apoptosis acutely, with apoptosis continuing at chronic time points. Loss of OLs causes demyelination and impairs axon function and survival. In parallel, a rapid and protracted OL progenitor cell proliferative response occurs, especially at the lesion borders. Proliferating and migrating OL progenitor cells differentiate into myelinating OLs, which remyelinate demyelinated axons starting at 2 weeks post-injury. The progression of OL lineage cells into mature OLs in the adult after injury recapitulates development to some degree, owing to the plethora of factors within the injury milieu. Although robust, this endogenous oligogenic response is insufficient against OL loss and demyelination. First, in this review we analyze the major spatial-temporal mechanisms of OL loss, replacement, and myelination, with the purpose of highlighting potential areas of intervention after SCI. We then discuss studies on OL protection and replacement. Growth factors have been used both to boost the endogenous progenitor response, and in conjunction with progenitor transplantation to facilitate survival and OL fate. Considerable progress has been made with embryonic stem cell-derived cells and adult neural progenitor cells. For therapies targeting oligogenesis to be successful, endogenous responses and the effects of the acute and chronic lesion environment on OL lineage cells must be understood in detail, and in relation, the optimal therapeutic window for such strategies must also be determined.
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Affiliation(s)
- Akshata Almad
- Neuroscience Graduate Studies Program, Ohio State University, Columbus, Ohio 43210 USA
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, Ohio 43210 USA
| | - F. Rezan Sahinkaya
- Neuroscience Graduate Studies Program, Ohio State University, Columbus, Ohio 43210 USA
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, Ohio 43210 USA
| | - Dana M. McTigue
- Center for Brain and Spinal Cord Repair, Ohio State University, Columbus, Ohio 43210 USA
- Department of Neuroscience, Ohio State University, 788 Biomedical Research Tower, 460 W. 12th Ave, Columbus, Ohio 43210 USA
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