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Krieg JL, Leonard AV, Turner RJ, Corrigan F. Identifying the Phenotypes of Diffuse Axonal Injury Following Traumatic Brain Injury. Brain Sci 2023; 13:1607. [PMID: 38002566 PMCID: PMC10670443 DOI: 10.3390/brainsci13111607] [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: 11/01/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023] Open
Abstract
Diffuse axonal injury (DAI) is a significant feature of traumatic brain injury (TBI) across all injury severities and is driven by the primary mechanical insult and secondary biochemical injury phases. Axons comprise an outer cell membrane, the axolemma which is anchored to the cytoskeletal network with spectrin tetramers and actin rings. Neurofilaments act as space-filling structural polymers that surround the central core of microtubules, which facilitate axonal transport. TBI has differential effects on these cytoskeletal components, with axons in the same white matter tract showing a range of different cytoskeletal and axolemma alterations with different patterns of temporal evolution. These require different antibodies for detection in post-mortem tissue. Here, a comprehensive discussion of the evolution of axonal injury within different cytoskeletal elements is provided, alongside the most appropriate methods of detection and their temporal profiles. Accumulation of amyloid precursor protein (APP) as a result of disruption of axonal transport due to microtubule failure remains the most sensitive marker of axonal injury, both acutely and chronically. However, a subset of injured axons demonstrate different pathology, which cannot be detected via APP immunoreactivity, including degradation of spectrin and alterations in neurofilaments. Furthermore, recent work has highlighted the node of Ranvier and the axon initial segment as particularly vulnerable sites to axonal injury, with loss of sodium channels persisting beyond the acute phase post-injury in axons without APP pathology. Given the heterogenous response of axons to TBI, further characterization is required in the chronic phase to understand how axonal injury evolves temporally, which may help inform pharmacological interventions.
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Affiliation(s)
- Justin L Krieg
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Anna V Leonard
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Renée J Turner
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
| | - Frances Corrigan
- Translational Neuropathology Laboratory, School of Biomedicine, Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide 5000, Australia
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Dolma S, Joshi A. The Node of Ranvier as an Interface for Axo-Glial Interactions: Perturbation of Axo-Glial Interactions in Various Neurological Disorders. J Neuroimmune Pharmacol 2023; 18:215-234. [PMID: 37285016 DOI: 10.1007/s11481-023-10072-z] [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: 09/08/2022] [Accepted: 05/19/2023] [Indexed: 06/08/2023]
Abstract
The action potential conduction along the axon is highly dependent on the healthy interactions between the axon and myelin-producing glial cells. Myelin, which facilitates action potential, is the protective insulation around the axon formed by Schwann cells and oligodendrocytes in the peripheral (PNS) and central nervous system (CNS), respectively. Myelin is a continuous structure with intermittent gaps called nodes of Ranvier, which are the sites enriched with ion channels, transmembrane, scaffolding, and cytoskeletal proteins. Decades-long extensive research has identified a comprehensive proteome with strictly regularized localization at the node of Ranvier. Concurrently, axon-glia interactions at the node of Ranvier have gathered significant attention as the pathophysiological targets for various neurodegenerative disorders. Numerous studies have shown the alterations in the axon-glia interactions culminating in neurological diseases. In this review, we have provided an update on the molecular composition of the node of Ranvier. Further, we have discussed in detail the consequences of disruption of axon-glia interactions during the pathogenesis of various CNS and PNS disorders.
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Affiliation(s)
- Sonam Dolma
- Department of Pharmacy, Birla Institute of Technology and Sciences- Pilani, Hyderabad campus, Telangana state, India
| | - Abhijeet Joshi
- Department of Pharmacy, Birla Institute of Technology and Sciences- Pilani, Hyderabad campus, Telangana state, India.
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Santacruz CA, Vincent JL, Duitama J, Bautista E, Imbault V, Bruneau M, Creteur J, Brimioulle S, Communi D, Taccone FS. vCSF Danger-associated Molecular Patterns After Traumatic and Nontraumatic Acute Brain Injury: A Prospective Study. J Neurosurg Anesthesiol 2023:00008506-990000000-00060. [PMID: 37188652 DOI: 10.1097/ana.0000000000000916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 03/14/2023] [Indexed: 05/17/2023]
Abstract
BACKGROUND Danger-associated molecular patterns (DAMPs) may be implicated in the pathophysiological pathways associated with an unfavorable outcome after acute brain injury (ABI). METHODS We collected samples of ventricular cerebrospinal fluid (vCSF) for 5 days in 50 consecutive patients at risk of intracranial hypertension after traumatic and nontraumatic ABI. Differences in vCSF protein expression over time were evaluated using linear models and selected for functional network analysis using the PANTHER and STRING databases. The primary exposure of interest was the type of brain injury (traumatic vs. nontraumatic), and the primary outcome was the vCSF expression of DAMPs. Secondary exposures of interest included the occurrence of intracranial pressure ≥20 or ≥ 30 mm Hg during the 5 days post-ABI, intensive care unit (ICU) mortality, and neurological outcome (assessed using the Glasgow Outcome Score) at 3 months post-ICU discharge. Secondary outcomes included associations of these exposures with the vCSF expression of DAMPs. RESULTS A network of 6 DAMPs (DAMP_trauma; protein-protein interaction [PPI] P=0.04) was differentially expressed in patients with ABI of traumatic origin compared with those with nontraumatic ABI. ABI patients with intracranial pressure ≥30 mm Hg differentially expressed a set of 38 DAMPS (DAMP_ICP30; PPI P< 0.001). Proteins in DAMP_ICP30 are involved in cellular proteolysis, complement pathway activation, and post-translational modifications. There were no relationships between DAMP expression and ICU mortality or unfavorable versus favorable outcomes. CONCLUSIONS Specific patterns of vCSF DAMP expression differentiated between traumatic and nontraumatic types of ABI and were associated with increased episodes of severe intracranial hypertension.
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Affiliation(s)
- Carlos A Santacruz
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
- Department of Intensive and Critical Care Medicine, Santa Fe de Bogotá Foundation
| | - Jean-Louis Vincent
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jorge Duitama
- Systems and Computing Engineering Department, University of los Andes, Bogotá, Colombia
| | - Edwin Bautista
- Department of Intensive and Critical Care Medicine, Santa Fe de Bogotá Foundation
| | - Virginie Imbault
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium
| | - Michael Bruneau
- Department of Neurosurgery, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Jacques Creteur
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Serge Brimioulle
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - David Communi
- Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire, Université Libre de Bruxelles, Brussels, Belgium
| | - Fabio S Taccone
- Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium
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Garrido JJ. Contribution of Axon Initial Segment Structure and Channels to Brain Pathology. Cells 2023; 12:cells12081210. [PMID: 37190119 DOI: 10.3390/cells12081210] [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: 04/01/2023] [Revised: 04/17/2023] [Accepted: 04/20/2023] [Indexed: 05/17/2023] Open
Abstract
Brain channelopathies are a group of neurological disorders that result from genetic mutations affecting ion channels in the brain. Ion channels are specialized proteins that play a crucial role in the electrical activity of nerve cells by controlling the flow of ions such as sodium, potassium, and calcium. When these channels are not functioning properly, they can cause a wide range of neurological symptoms such as seizures, movement disorders, and cognitive impairment. In this context, the axon initial segment (AIS) is the site of action potential initiation in most neurons. This region is characterized by a high density of voltage-gated sodium channels (VGSCs), which are responsible for the rapid depolarization that occurs when the neuron is stimulated. The AIS is also enriched in other ion channels, such as potassium channels, that play a role in shaping the action potential waveform and determining the firing frequency of the neuron. In addition to ion channels, the AIS contains a complex cytoskeletal structure that helps to anchor the channels in place and regulate their function. Therefore, alterations in this complex structure of ion channels, scaffold proteins, and specialized cytoskeleton may also cause brain channelopathies not necessarily associated with ion channel mutations. This review will focus on how the AISs structure, plasticity, and composition alterations may generate changes in action potentials and neuronal dysfunction leading to brain diseases. AIS function alterations may be the consequence of voltage-gated ion channel mutations, but also may be due to ligand-activated channels and receptors and AIS structural and membrane proteins that support the function of voltage-gated ion channels.
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Affiliation(s)
- Juan José Garrido
- Instituto Cajal, CSIC, 28002 Madrid, Spain
- Alzheimer's Disease and Other Degenerative Dementias, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28002 Madrid, Spain
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5
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Song H, McEwan PP, Ameen-Ali KE, Tomasevich A, Kennedy-Dietrich C, Palma A, Arroyo EJ, Dolle JP, Johnson VE, Stewart W, Smith DH. Concussion leads to widespread axonal sodium channel loss and disruption of the node of Ranvier. Acta Neuropathol 2022; 144:967-985. [PMID: 36107227 PMCID: PMC9547928 DOI: 10.1007/s00401-022-02498-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/08/2022] [Accepted: 09/08/2022] [Indexed: 01/26/2023]
Abstract
Despite being a major health concern, little is known about the pathophysiological changes that underly concussion. Nonetheless, emerging evidence suggests that selective damage to white matter axons, or diffuse axonal injury (DAI), disrupts brain network connectivity and function. While voltage-gated sodium channels (NaChs) and their anchoring proteins at the nodes of Ranvier (NOR) on axons are key elements of the brain's network signaling machinery, changes in their integrity have not been studied in context with DAI. Here, we utilized a clinically relevant swine model of concussion that induces evolving axonal pathology, demonstrated by accumulation of amyloid precursor protein (APP) across the white matter. Over a two-week follow-up post-concussion with this model, we found widespread loss of NaCh isoform 1.6 (Nav1.6), progressive increases in NOR length, the appearance of void and heminodes and loss of βIV-spectrin, ankyrin G, and neurofascin 186 or their collective diffusion into the paranode. Notably, these changes were in close proximity, yet distinct from APP-immunoreactive swollen axonal profiles, potentially representing a unique, newfound phenotype of axonal pathology in DAI. Since concussion in humans is non-fatal, the clinical relevance of these findings was determined through examination of post-mortem brain tissue from humans with higher levels of acute traumatic brain injury. Here, a similar loss of Nav1.6 and changes in NOR structures in brain white matter were observed as found in the swine model of concussion. Collectively, this widespread and progressive disruption of NaChs and NOR appears to be a form of sodium channelopathy, which may represent an important substrate underlying brain network dysfunction after concussion.
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Affiliation(s)
- Hailong Song
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Przemyslaw P McEwan
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Kamar E Ameen-Ali
- School of Neuroscience and Psychology, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Alexandra Tomasevich
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | | | - Alexander Palma
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Edgardo J Arroyo
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Jean-Pierre Dolle
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - Victoria E Johnson
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA
| | - William Stewart
- School of Neuroscience and Psychology, University of Glasgow, Glasgow, G12 8QQ, UK
- Department of Neuropathology, Queen Elizabeth University Hospital, Glasgow, G51 4TF, UK
| | - Douglas H Smith
- Department of Neurosurgery, Center for Brain Injury and Repair, University of Pennsylvania, 3320 Smith Walk, 105 Hayden Hall, Philadelphia, PA, 19104, USA.
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Zhao Y, Ma C, Chen C, Li S, Wang Y, Yang T, Stetler RA, Bennett MVL, Dixon CE, Chen J, Shi Y. STAT1 Contributes to Microglial/Macrophage Inflammation and Neurological Dysfunction in a Mouse Model of Traumatic Brain Injury. J Neurosci 2022; 42:7466-7481. [PMID: 35985835 PMCID: PMC9525171 DOI: 10.1523/jneurosci.0682-22.2022] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/29/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022] Open
Abstract
Traumatic brain injury (TBI) triggers a plethora of inflammatory events in the brain that aggravate secondary injury and impede tissue repair. Resident microglia (Mi) and blood-borne infiltrating macrophages (MΦ) are major players of inflammatory responses in the post-TBI brain and possess high functional heterogeneity. However, the plasticity of these cells has yet to be exploited to develop therapies that can mitigate brain inflammation and improve the outcome after TBI. This study investigated the transcription factor STAT1 as a key determinant of proinflammatory Mi/MΦ responses and aimed to develop STAT1 as a novel therapeutic target for TBI using a controlled cortical impact model of TBI on adult male mice. TBI induced robust upregulation of STAT1 in the brain at the subacute injury stage, which occurred primarily in Mi/MΦ. Intraperitoneal administration of fludarabine, a selective STAT1 inhibitor, markedly alleviated proinflammatory Mi/MΦ responses and brain inflammation burden after TBI. Such phenotype-modulating effects of fludarabine on post-TBI Mi/MΦ were reproduced by tamoxifen-induced, selective KO of STAT1 in Mi/MΦ (STAT1 mKO). By propelling Mi/MΦ away from a detrimental proinflammatory phenotype, STAT1 mKO was sufficient to reduce long-term neurologic deficits and brain lesion size after TBI. Importantly, short-term fludarabine treatment after TBI elicited long-lasting improvement of TBI outcomes, but this effect was lost on STAT1 mKO mice. Together, our study provided the first line of evidence that STAT1 causatively determines the proinflammatory phenotype of brain Mi/MΦ after TBI. We also showed promising preclinical data supporting the use of fludarabine as a novel immunomodulating therapy to TBI.SIGNIFICANCE STATEMENT The functional phenotype of microglia and macrophages (Mi/MΦ) critically influences brain inflammation and the outcome after traumatic brain injury (TBI); however, no therapies have been developed to modulate Mi/MΦ functions to treat TBI. Here we report, for the first time, that the transcription factor STAT1 is a key mediator of proinflammatory Mi/MΦ responses in the post-TBI brain, the specific deletion of which ameliorates neuroinflammation and improves long-term functional recovery after TBI. We also show excellent efficacy of a selective STAT1 inhibitor fludarabine against TBI-induced functional deficits and brain injury using a mouse model, presenting STAT1 as a promising therapeutic target for TBI.
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Affiliation(s)
- Yongfang Zhao
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Cheng Ma
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Caixia Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Sicheng Li
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Yangfan Wang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Tuo Yang
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, Pennsylvania 15261
| | - R Anne Stetler
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, Pennsylvania 15261
| | - Michael V L Bennett
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - C Edward Dixon
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, Pennsylvania 15261
- Department of Neurosurgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
| | - Jun Chen
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, Pennsylvania 15261
| | - Yejie Shi
- Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15213
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, Pennsylvania 15261
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Yazla E, Kayadibi H, Cetin I, Aydinoglu U, Karadere ME. Evaluation of Changes in Peripheric Biomarkers Related to Blood Brain Barrier Damage in Patients with Schizophrenia and Their Correlation with Symptoms. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2022; 20:504-513. [PMID: 35879035 PMCID: PMC9329119 DOI: 10.9758/cpn.2022.20.3.504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/06/2021] [Accepted: 06/18/2021] [Indexed: 11/18/2022]
Abstract
Objective The aim of the study was to evaluate the levels of peripheric biomarkers that have been associated with blood brain barrier (BBB) damage in healthy controls and two groups of patients with schizophrenia, those who received typical-atypical antipsychotics and those who received only atypical antipsychotics. Additionally, we sought relationships between these biomarkers and schizophrenia symptoms. Methods This study was conducted with the inclusion of 41 healthy volunteers and 75 patients with schizophrenia. The biomarkers measured to evaluate BBB injury were as follows spectrin breakdown product 145 (SBDP145), spectrin breakdown product 150 (SBDP150), ubiquitin carboxy terminal hydrolase L1 (UCHL1), ubiquitin ligase cullin-3 (cullin), occludin and claudin, which were measured via ELISA. Symptoms of patients with schizophrenia were evaluated with the Scale for the Assessment of Positive Symptoms (SAPS), Scale for the Assessment of Negative Symptoms, the Clinical Global Impression Scale (CGI), and the general assessment of functionality (GAF). Results Compared to controls, SBDP145 (p = 0.022) and cullin (p = 0.046) levels were significantly higher in patients with schizophrenia receiving atypical antipsychotic treatment. SBDP150 levels were lower in the combination treatment group compared to the control group (p = 0.022). Claudin (p = 0.804), occludin (p = 0.058) and UCHL1 (p = 0.715) levels were similar among groups. In recipients of combination treatment, SBDP145 levels were found to be positively correlated with SAPS-total (r = 0.440, p = 0.036) and SAPS-delusions (r = 0.494, p = 0.017) scores. Conclusion The relationships demonstrated in this study indicate that more comprehensive research is needed to understand whether BBB defects contribute to clinical characteristics in patients with schizophrenia.
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Affiliation(s)
- Ece Yazla
- Department of Psychiatry, Hitit University Faculty of Medicine, Corum, Turkey
| | - Huseyin Kayadibi
- Department of Biochemistry, Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey
| | - Ihsan Cetin
- Department of Biochemistry, Hitit University Faculty of Medicine, Corum, Turkey
| | - Unsal Aydinoglu
- Department of Psychiatry, Hitit University Faculty of Medicine, Corum, Turkey
| | - Mehmet Emrah Karadere
- Department of Psychiatry, Istanbul Medeniyet University Faculty of Medicine, Istanbul, Turkey
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Cetin I, Yazla E, Akmese B, Kayadibi H. A Preliminary Study on Investigation of Blood-Brain Barrier Damage Markers in Patients with Alcohol Use Disorder Before and After Therapy. Alcohol Alcohol 2022; 57:722-726. [PMID: 35997171 DOI: 10.1093/alcalc/agac040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/19/2022] [Accepted: 07/26/2022] [Indexed: 11/14/2022] Open
Abstract
AIM The use of alcohol affects the central nervous system and plays important roles in various neurological disorders through neurotoxicity resulting from blood-brain barrier (BBB) permeability. The BBB is regulated by tight junction proteins interacting closely with endothelial cells. This study evaluated the serum levels of proteins and spectrin degradation products associated with BBB damage in patients with alcohol use disorder. METHODS This preliminary case-control study was conducted with 30 healthy volunteers and 26 alcohol use disorder patients. The serum levels of spectrin breakdown product 145 (SBDP145), spectrin breakdown product 150 (SBDP150), ubiquitin carboxy-terminal hydrolase L1 (UCHL1), ubiquitin ligase cullin-3 (ULC), occludin and claudin were measured with enzyme-linked immunosorbent assay. RESULTS There was no significant difference between the levels of SBDP145, SBDP150, UCHL1, ULC, occludin and claudin before and after treatment in patients with alcohol use disorder. SBDP150 levels were significantly lower in patients than controls (P < 0.001). The area under the curve was 0.841 (0.733-0.949) with the 95% confidence interval for SPDP150. CONCLUSION A decrease of the serum SBDP150 levels appears to be associated with alcohol use disorder. Future studies might clarify whether diminished serum SBDP150 levels are associated with BBB damage in patients with alcohol use disorder.
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Affiliation(s)
- Ihsan Cetin
- Faculty of Medicine, Department of Medical Biochemistry, University of Hitit, Corum, Turkey
| | - Ece Yazla
- Faculty of Medicine, Department of Psychiatry, University of Hitit, Corum, Turkey
| | - Bediha Akmese
- Department of Pharmacy Services, Vocational School of Health Services, University of Hitit, Corum, Turkey
| | - Hüseyin Kayadibi
- Faculty of Medicine, Department of Medical Biochemistry, Eskisehir Osmangazi University, Eskisehir, Turkey
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Ozen I, Arkan S, Clausen F, Ruscher K, Marklund N. Diffuse traumatic injury in the mouse disrupts axon-myelin integrity in the cerebellum. J Neurotrauma 2022; 39:411-422. [PMID: 35018831 DOI: 10.1089/neu.2021.0321] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Cerebellar dysfunction following traumatic brain injury (TBI) is commonly suspected based on clinical symptoms, although cerebellar pathology has rarely been investigated. To address the hypothesis that the cerebellar axon-myelin unit is altered by diffuse TBI, we used the central fluid percussion injury (cFPI) model in adult mice to create wide-spread axonal injury by delivering the impact to the forebrain. We specifically focused on changes in myelin components (myelin basic protein (MBP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), nodal/paranodal domains (neurofascin, ankyrin G), and phosphorylated neurofilaments (SMI-31, SMI-312) in the cerebellum, remote from the impact, at 2, 7 and 30-day post-injury. When compared to sham-injured controls, cerebellar MBP and CNPase protein levels were decreased at 2 days post-injury (dpi) that remained reduced up to 30 dpi. Diffuse TBI induced different effects on neuronal (Nfasc 186, Nfasc 140) and glial (Nfasc 155) neurofascin isoforms that play a key role in the assembly of the nodes of Ranvier. Expression of Nfasc 140 in the cerebellum increased at 7 dpi, in contrast to Nfasc 155 levels which were decreased. Although neurofascin binding partner ankyrin G protein levels decreased acutely after cFPI, its expression levels increased at 7 dpi and remained unchanged up to 30 dpi. TBI-induced reduction in neurofilament phosphorylation (SMI-31) observed in the cerebellum was closely associated with decreased levels of the myelin proteins MBP and CNPase. This is the first evidence of temporal and spatial structural changes in the axon-myelin unit in the cerebellum, remote from the location of the impact site in a diffuse TBI model in mice.
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Affiliation(s)
- Ilknur Ozen
- Lund University, 5193, Department of Clinical Sciences, Lund, Sweden;
| | - Sertan Arkan
- Lund University, 5193, Department of Clinical Sciences, Lund, Sweden;
| | - Fredrik Clausen
- Uppsala University, 8097, Neuroscience, Neurosurgery, Uppsala, Sweden;
| | - Karsten Ruscher
- Lund University, 5193, Dept of Clinical Sciences Lund, Lund, Sweden;
| | - Niklas Marklund
- Lund University, 5193, Department of Clinical Sciences Lund, Lund University, Skåne University Hospital, Neurosurgery, Lund, Sweden, Lund, Sweden;
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10
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Bruggeman GF, Haitsma IK, Dirven CMF, Volovici V. Traumatic axonal injury (TAI): definitions, pathophysiology and imaging-a narrative review. Acta Neurochir (Wien) 2021; 163:31-44. [PMID: 33006648 PMCID: PMC7778615 DOI: 10.1007/s00701-020-04594-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/22/2020] [Indexed: 01/01/2023]
Abstract
Introduction Traumatic axonal injury (TAI) is a condition defined as multiple, scattered, small hemorrhagic, and/or non-hemorrhagic lesions, alongside brain swelling, in a more confined white matter distribution on imaging studies, together with impaired axoplasmic transport, axonal swelling, and disconnection after traumatic brain injury (TBI). Ever since its description in the 1980s and the grading system by Adams et al., our understanding of the processes behind this entity has increased. Methods We performed a scoping systematic, narrative review by interrogating Ovid MEDLINE, Embase, and Google Scholar on the pathophysiology, biomarkers, and diagnostic tools of TAI patients until July 2020. Results We underline the misuse of the Adams classification on MRI without proper validation studies, and highlight the hiatus in the scientific literature and areas needing more research. In the past, the theory behind the pathophysiology relied on the inertial force exerted on the brain matter after severe TBI inducing a primary axotomy. This theory has now been partially abandoned in favor of a more refined theory involving biochemical processes such as protein cleavage and DNA breakdown, ultimately leading to an inflammation cascade and cell apoptosis, a process now described as secondary axotomy. Conclusion The difference in TAI definitions makes the comparison of studies that report outcomes, treatments, and prognostic factors a daunting task. An even more difficult task is isolating the outcomes of isolated TAI from the outcomes of severe TBI in general. Targeted bench-to-bedside studies are required in order to uncover further pathways involved in the pathophysiology of TAI and, ideally, new treatments.
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Affiliation(s)
- Gavin F Bruggeman
- Department of Neurosurgery, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Iain K Haitsma
- Department of Neurosurgery, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Clemens M F Dirven
- Department of Neurosurgery, Erasmus MC University Medical Center, Rotterdam, The Netherlands
| | - Victor Volovici
- Department of Neurosurgery, Erasmus MC University Medical Center, Rotterdam, The Netherlands.
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11
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Kövesdi E, Szabó-Meleg E, Abrahám IM. The Role of Estradiol in Traumatic Brain Injury: Mechanism and Treatment Potential. Int J Mol Sci 2020; 22:ijms22010011. [PMID: 33374952 PMCID: PMC7792596 DOI: 10.3390/ijms22010011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 01/02/2023] Open
Abstract
Patients surviving traumatic brain injury (TBI) face numerous neurological and neuropsychological problems significantly affecting their quality of life. Extensive studies over the past decades have investigated pharmacological treatment options in different animal models, targeting various pathological consequences of TBI. Sex and gender are known to influence the outcome of TBI in animal models and in patients, respectively. Apart from its well-known effects on reproduction, 17β-estradiol (E2) has a neuroprotective role in brain injury. Hence, in this review, we focus on the effect of E2 in TBI in humans and animals. First, we discuss the clinical classification and pathomechanism of TBI, the research in animal models, and the neuroprotective role of E2. Based on the results of animal studies and clinical trials, we discuss possible E2 targets from early to late events in the pathomechanism of TBI, including neuroinflammation and possible disturbances of the endocrine system. Finally, the potential relevance of selective estrogenic compounds in the treatment of TBI will be discussed.
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Affiliation(s)
- Erzsébet Kövesdi
- Molecular Neuroendocrinology Research Group, Institute of Physiology, Medical School, Center for Neuroscience, Szentágothai Research Center, University of Pécs, H-7624 Pecs, Hungary;
| | - Edina Szabó-Meleg
- Department of Biophysics, Medical School, University of Pécs, H-7624 Pecs, Hungary;
| | - István M. Abrahám
- Molecular Neuroendocrinology Research Group, Institute of Physiology, Medical School, Center for Neuroscience, Szentágothai Research Center, University of Pécs, H-7624 Pecs, Hungary;
- Correspondence: ; Tel.: +36-72-536-243 or +36-72-536-424
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12
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Keating CE, Cullen DK. Mechanosensation in traumatic brain injury. Neurobiol Dis 2020; 148:105210. [PMID: 33259894 DOI: 10.1016/j.nbd.2020.105210] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/10/2020] [Accepted: 11/24/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is distinct from other neurological disorders because it is induced by a discrete event that applies extreme mechanical forces to the brain. This review describes how the brain senses, integrates, and responds to forces under both normal conditions and during injury. The response to forces is influenced by the unique mechanical properties of brain tissue, which differ by region, cell type, and sub-cellular structure. Elements such as the extracellular matrix, plasma membrane, transmembrane receptors, and cytoskeleton influence its properties. These same components also act as force-sensors, allowing neurons and glia to respond to their physical environment and maintain homeostasis. However, when applied forces become too large, as in TBI, these components may respond in an aberrant manner or structurally fail, resulting in unique pathological sequelae. This so-called "pathological mechanosensation" represents a spectrum of cellular responses, which vary depending on the overall biomechanical parameters of the injury and may be compounded by repetitive injuries. Such aberrant physical responses and/or damage to cells along with the resulting secondary injury cascades can ultimately lead to long-term cellular dysfunction and degeneration, often resulting in persistent deficits. Indeed, pathological mechanosensation not only directly initiates secondary injury cascades, but this post-physical damage environment provides the context in which these cascades unfold. Collectively, these points underscore the need to use experimental models that accurately replicate the biomechanics of TBI in humans. Understanding cellular responses in context with injury biomechanics may uncover therapeutic targets addressing various facets of trauma-specific sequelae.
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Affiliation(s)
- Carolyn E Keating
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA
| | - D Kacy Cullen
- Department of Neurosurgery, Center for Brain Injury and Repair, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA; Center for Neurotrauma, Neurodegeneration, and Restoration, Corporal Michael J. Crescenz VA Medical Center, USA.
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13
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Abstract
PURPOSE OF REVIEW Diffuse or traumatic axonal injury is one of the principal pathologies encountered in traumatic brain injury (TBI) and the resulting axonal loss, disconnection, and brain atrophy contribute significantly to clinical morbidity and disability. The seminal discovery of the slow Wallerian degeneration mice (Wld) in which transected axons do not degenerate but survive and function independently for weeks has transformed concepts on axonal biology and raised hopes that axonopathies may be amenable to specific therapeutic interventions. Here we review mechanisms of axonal degeneration and also describe how these mechanisms may inform biological therapies of traumatic axonopathy in the context of TBI. RECENT FINDINGS In the last decade, SARM1 [sterile a and Toll/interleukin-1 receptor (TIR) motif containing 1] and the DLK (dual leucine zipper bearing kinase) and LZK (leucine zipper kinase) MAPK (mitogen-activated protein kinases) cascade have been established as the key drivers of Wallerian degeneration, a complex program of axonal self-destruction which is activated by a wide range of injurious insults, including insults that may otherwise leave axons structurally robust and potentially salvageable. Detailed studies on animal models and postmortem human brains indicate that this type of partial disruption is the main initial pathology in traumatic axonopathy. At the same time, the molecular dissection of Wallerian degeneration has revealed that the decision that commits axons to degeneration is temporally separated from the time of injury, a window that allows potentially effective pharmacological interventions. SUMMARY Molecular signals initiating and triggering Wallerian degeneration appear to be playing an important role in traumatic axonopathy and recent advances in understanding their nature and significance is opening up new therapeutic opportunities for TBI.
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Protein Degradome of Spinal Cord Injury: Biomarkers and Potential Therapeutic Targets. Mol Neurobiol 2020; 57:2702-2726. [PMID: 32328876 DOI: 10.1007/s12035-020-01916-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022]
Abstract
Degradomics is a proteomics sub-discipline whose goal is to identify and characterize protease-substrate repertoires. With the aim of deciphering and characterizing key signature breakdown products, degradomics emerged to define encryptic biomarker neoproteins specific to certain disease processes. Remarkable improvements in structural and analytical experimental methodologies as evident in research investigating cellular behavior in neuroscience and cancer have allowed the identification of specific degradomes, increasing our knowledge about proteases and their regulators and substrates along with their implications in health and disease. A physiologic balance between protein synthesis and degradation is sought with the activation of proteolytic enzymes such as calpains, caspases, cathepsins, and matrix metalloproteinases. Proteolysis is essential for development, growth, and regeneration; however, inappropriate and uncontrolled activation of the proteolytic system renders the diseased tissue susceptible to further neurotoxic processes. In this article, we aim to review the protease-substrate repertoires as well as emerging therapeutic interventions in spinal cord injury at the degradomic level. Several protease substrates and their breakdown products, essential for the neuronal structural integrity and functional capacity, have been characterized in neurotrauma including cytoskeletal proteins, neuronal extracellular matrix glycoproteins, cell junction proteins, and ion channels. Therefore, targeting exaggerated protease activity provides a potentially effective therapeutic approach in the management of protease-mediated neurotoxicity in reducing the extent of damage secondary to spinal cord injury.
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Montanino A, Saeedimasine M, Villa A, Kleiven S. Localized Axolemma Deformations Suggest Mechanoporation as Axonal Injury Trigger. Front Neurol 2020; 11:25. [PMID: 32082244 PMCID: PMC7005088 DOI: 10.3389/fneur.2020.00025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/09/2020] [Indexed: 12/19/2022] Open
Abstract
Traumatic brain injuries are a leading cause of morbidity and mortality worldwide. With almost 50% of traumatic brain injuries being related to axonal damage, understanding the nature of cellular level impairment is crucial. Experimental observations have so far led to the formulation of conflicting theories regarding the cellular primary injury mechanism. Disruption of the axolemma, or alternatively cytoskeletal damage has been suggested mainly as injury trigger. However, mechanoporation thresholds of generic membranes seem not to overlap with the axonal injury deformation range and microtubules appear too stiff and too weakly connected to undergo mechanical breaking. Here, we aim to shed a light on the mechanism of primary axonal injury, bridging finite element and molecular dynamics simulations. Despite the necessary level of approximation, our models can accurately describe the mechanical behavior of the unmyelinated axon and its membrane. More importantly, they give access to quantities that would be inaccessible with an experimental approach. We show that in a typical injury scenario, the axonal cortex sustains deformations large enough to entail pore formation in the adjoining lipid bilayer. The observed axonal deformation of 10–12% agree well with the thresholds proposed in the literature for axonal injury and, above all, allow us to provide quantitative evidences that do not exclude pore formation in the membrane as a result of trauma. Our findings bring to an increased knowledge of axonal injury mechanism that will have positive implications for the prevention and treatment of brain injuries.
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Affiliation(s)
- Annaclaudia Montanino
- Division of Neuronic Engineering, Royal Institute of Technology (KTH), Stockholm, Sweden
| | - Marzieh Saeedimasine
- Department of Biosciences and Nutrition, Karolinska Institutet (KI), Stockholm, Sweden
| | - Alessandra Villa
- Department of Biosciences and Nutrition, Karolinska Institutet (KI), Stockholm, Sweden
| | - Svein Kleiven
- Division of Neuronic Engineering, Royal Institute of Technology (KTH), Stockholm, Sweden
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16
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Liang Y, Tong F, Zhang L, Zhu L, Li W, Huang W, Zhao S, He G, Zhou Y. iTRAQ-based proteomic analysis discovers potential biomarkers of diffuse axonal injury in rats. Brain Res Bull 2019; 153:289-304. [PMID: 31539556 DOI: 10.1016/j.brainresbull.2019.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 08/19/2019] [Accepted: 09/13/2019] [Indexed: 12/13/2022]
Abstract
Diffuse axonal injury (DAI) is one of the most common and severe pathological consequences of traumatic brain injury (TBI). The molecular mechanism of DAI is highly complicated and still elusive, yet a clear understanding is crucial for the diagnosis, treatment, and prognosis of DAI. In our study, we used rats to establish a DAI model and applied isobaric tags for relative and absolute quantitation (iTRAQ) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis to identify differentially expressed proteins (DEPs) in the corpus callosum. As a result, a total of 514 proteins showed differential expression between the injury groups and the control. Among these DEPs, 14 common DEPs were present at all seven time points postinjury (1, 3, 6, 12, 24, 48, and 72 h). Next, bioinformatic analysis was performed to elucidate the pathogenesis of DAI, which was found to possibly involve calcium ion-regulatory proteins (e.g., calsenilin and ryanodine receptor 2), cytoskeleton organization (e.g., peripherin, NFL, NFM, and NFH), apoptotic processes (e.g., calsenilin and protein kinase C delta type), and inflammatory response proteins (e.g., complement C3 and C-reactive protein). Moreover, peripherin and calsenilin were successfully confirmed by western blotting to be significantly upregulated during DAI, and immunohistochemical (IHC) analysis revealed that their expression increased and could be observed in axons after injury, thus indicating their potential as DAI biomarkers. Our experiments not only provide insight into the molecular mechanisms of axonal injury in rats during DAI but also give clinicians and pathologists important reference data for the diagnosis of DAI. Our findings may expand the list of DAI biomarkers and improve the postmortem diagnostic rate of DAI.
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Affiliation(s)
- Yue Liang
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
| | - Fang Tong
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
| | - Lin Zhang
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
| | - Longlong Zhu
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
| | - Wenhe Li
- Department of Pathology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, PR China.
| | - Weisheng Huang
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
| | - Shuquan Zhao
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
| | - Guanglong He
- Institute of Forensic Science, Ministry of Public Security People's Republic of China, No. 17 Nanli Mulidi, Beijing, 100038, PR China.
| | - Yiwu Zhou
- Department of Forensic Medicine, Huazhong University of Science and Technology, Tongji Medical College, No. 13 Hangkong Road, Hankou, Wuhan, 430030, PR China.
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17
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Liu CH, Rasband MN. Axonal Spectrins: Nanoscale Organization, Functional Domains and Spectrinopathies. Front Cell Neurosci 2019; 13:234. [PMID: 31191255 PMCID: PMC6546920 DOI: 10.3389/fncel.2019.00234] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 05/09/2019] [Indexed: 11/13/2022] Open
Abstract
Spectrin cytoskeletons are found in all metazoan cells, and their physical interactions between actin and ankyrins establish a meshwork that provides cellular structural integrity. With advanced super-resolution microscopy, the intricate spatial organization and associated functional properties of these cytoskeletons can now be analyzed with unprecedented clarity. Long neuronal processes like peripheral sensory and motor axons may be subject to intense mechanical forces including bending, stretching, and torsion. The spectrin-based cytoskeleton is essential to protect axons against these mechanical stresses. Additionally, spectrins are critical for the assembly and maintenance of axonal excitable domains including the axon initial segment and the nodes of Ranvier (NoR). These sites facilitate rapid and efficient action potential initiation and propagation in the nervous system. Recent studies revealed that pathogenic spectrin variants and diseases that protealyze and breakdown spectrins are associated with congenital neurological disorders and nervous system injury. Here, we review recent studies of spectrins in the nervous system and focus on their functions in axonal health and disease.
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Affiliation(s)
- Cheng-Hsin Liu
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, United States
| | - Matthew Neil Rasband
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX, United States.,Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States
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18
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Gölz C, Kirchhoff FP, Westerhorstmann J, Schmidt M, Hirnet T, Rune GM, Bender RA, Schäfer MKE. Sex hormones modulate pathogenic processes in experimental traumatic brain injury. J Neurochem 2019; 150:173-187. [PMID: 30790293 DOI: 10.1111/jnc.14678] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 01/28/2019] [Accepted: 01/29/2019] [Indexed: 12/26/2022]
Abstract
Clinical and animal studies have revealed sex-specific differences in histopathological and neurological outcome after traumatic brain injury (TBI). The impact of perioperative administration of sex steroid inhibitors on TBI is still elusive. Here, we subjected male and female C57Bl/6N mice to the controlled cortical impact (CCI) model of TBI and applied pharmacological inhibitors of steroid hormone synthesis, that is, letrozole (LET, inhibiting estradiol synthesis by aromatase) and finasteride (FIN, inhibiting dihydrotestosterone synthesis by 5α-reductase), respectively, starting 72 h prior CCI, and continuing for a further 48 h after CCI. Initial gene expression analyses showed that androgen (Ar) and estrogen receptors (Esr1) were sex-specifically altered 72 h after CCI. When examining brain lesion size, we found larger lesions in male than in female mice, but did not observe effects of FIN or LET treatment. However, LET treatment exacerbated neurological deficits 24 and 72 h after CCI. On the molecular level, FIN administration reduced calpain-dependent spectrin breakdown products, a proxy of excitotoxicity and disturbed Ca2+ homeostasis, specifically in males, whereas LET increased the reactive astrocyte marker glial fibrillary acid protein specifically in females. Examination of neurotrophins (brain-derived neurotrophic factor, neuronal growth factor, NT-3) and their receptors (p75NTR , TrkA, TrkB, TrkC) revealed CCI-induced down-regulation of TrkB and TrkC protein expression, which was reduced by LET in both sexes. Interestingly, FIN decreased neuronal growth factor mRNA expression and protein levels of its receptor TrkA only in males. Taken together, our data suggest a sex-specific impact on pathogenic processes in the injured brain after TBI. Sex hormones may thus modulate pathogenic processes in experimental TBI.
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Affiliation(s)
- Christina Gölz
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Florian Paul Kirchhoff
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | | | - Matthias Schmidt
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Tobias Hirnet
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Gabriele M Rune
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Roland A Bender
- Institute of Neuroanatomy, University Medical Center, Hamburg, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany.,Focus Program Translational Neurosciences, Mainz, Germany.,Research Center for Immunotherapy (FZI), Mainz, Germany
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Yermakov LM, Hong LA, Drouet DE, Griggs RB, Susuki K. Functional Domains in Myelinated Axons. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1190:65-83. [PMID: 31760639 DOI: 10.1007/978-981-32-9636-7_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Propagation of action potentials along axons is optimized through interactions between neurons and myelinating glial cells. Myelination drives division of the axons into distinct molecular domains including nodes of Ranvier. The high density of voltage-gated sodium channels at nodes generates action potentials allowing for rapid and efficient saltatory nerve conduction. At paranodes flanking both sides of the nodes, myelinating glial cells interact with axons, forming junctions that are essential for node formation and maintenance. Recent studies indicate that the disruption of these specialized axonal domains is involved in the pathophysiology of various neurological diseases. Loss of paranodal axoglial junctions due to genetic mutations or autoimmune attack against the paranodal proteins leads to nerve conduction failure and neurological symptoms. Breakdown of nodal and paranodal proteins by calpains, the calcium-dependent cysteine proteases, may be a common mechanism involved in various nervous system diseases and injuries. This chapter reviews recent progress in neurobiology and pathophysiology of specialized axonal domains along myelinated nerve fibers.
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Affiliation(s)
- Leonid M Yermakov
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Lulu A Hong
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Domenica E Drouet
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Ryan B Griggs
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA
| | - Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, USA.
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20
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The Effects of a Combination of Ion Channel Inhibitors in Female Rats Following Repeated Mild Traumatic Brain Injury. Int J Mol Sci 2018; 19:ijms19113408. [PMID: 30384417 PMCID: PMC6274967 DOI: 10.3390/ijms19113408] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 10/26/2018] [Accepted: 10/27/2018] [Indexed: 01/26/2023] Open
Abstract
Following mild traumatic brain injury (mTBI), the ionic homeostasis of the central nervous system (CNS) becomes imbalanced. Excess Ca2+ influx into cells triggers molecular cascades, which result in detrimental effects. The authors assessed the effects of a combination of ion channel inhibitors (ICI) following repeated mTBI (rmTBI). Adult female rats were subjected to two rmTBI weight-drop injuries 24 h apart, sham procedures (sham), or no procedures (normal). Lomerizine, which inhibits voltage-gated calcium channels, was administered orally twice daily, whereas YM872 and Brilliant Blue G, inhibiting α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and P2X₇ receptors, respectively, were delivered intraperitoneally every 48 h post-injury. Vehicle treatment controls were included for rmTBI, sham, and normal groups. At 11 days following rmTBI, there was a significant increase in the time taken to cross the 3 cm beam, as a sub-analysis of neurological severity score (NSS) assessments, compared with the normal control (p < 0.05), and a significant decrease in learning-associated improvement in rmTBI in Morris water maze (MWM) trials relative to the sham (p < 0.05). ICI-treated rmTBI animals were not different to sham, normal controls, or rmTBI treated with vehicle in all neurological severity score and Morris water maze assessments (p > 0.05). rmTBI resulted in increases in microglial cell density, antioxidant responses (manganese-dependent superoxide dismutase (MnSOD) immunoreactivity), and alterations to node of Ranvier structure. ICI treatment decreased microglial density, MnSOD immunoreactivity, and abnormalities of the node of Ranvier compared with vehicle controls (p < 0.01). The authors' findings demonstrate the beneficial effects of the combinatorial ICI treatment on day 11 post-rmTBI, suggesting an attractive therapeutic strategy against the damage induced by excess Ca2+ following rmTBI.
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21
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Experimental Traumatic Brain Injury Identifies Distinct Early and Late Phase Axonal Conduction Deficits of White Matter Pathophysiology, and Reveals Intervening Recovery. J Neurosci 2018; 38:8723-8736. [PMID: 30143572 PMCID: PMC6181309 DOI: 10.1523/jneurosci.0819-18.2018] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 06/15/2018] [Accepted: 07/10/2018] [Indexed: 01/26/2023] Open
Abstract
Traumatic brain injury (TBI) patients often exhibit slowed information processing speed that can underlie diverse symptoms. Processing speed depends on neural circuit function at synapses, in the soma, and along axons. Long axons in white matter (WM) tracts are particularly vulnerable to TBI. We hypothesized that disrupted axon–myelin interactions that slow or block action potential conduction in WM tracts may contribute to slowed processing speed after TBI. Concussive TBI in male/female mice was used to produce traumatic axonal injury in the corpus callosum (CC), similar to WM pathology in human TBI cases. Compound action potential velocity was slowed along myelinated axons at 3 d after TBI with partial recovery by 2 weeks, suggesting early demyelination followed by remyelination. Ultrastructurally, dispersed demyelinated axons and disorganized myelin attachment to axons at paranodes were apparent within CC regions exhibiting traumatic axonal injury. Action potential conduction is exquisitely sensitive to paranode abnormalities. Molecular identification of paranodes and nodes of Ranvier detected asymmetrical paranode pairs and abnormal heminodes after TBI. Fluorescent labeling of oligodendrocyte progenitors in NG2CreER;mTmG mice showed increased synthesis of new membranes extended along axons to paranodes, indicating remyelination after TBI. At later times after TBI, an overall loss of conducting axons was observed at 6 weeks followed by CC atrophy at 8 weeks. These studies identify a progression of both myelinated axon conduction deficits and axon–myelin pathology in the CC, implicating WM injury in impaired information processing at early and late phases after TBI. Furthermore, the intervening recovery reveals a potential therapeutic window. SIGNIFICANCE STATEMENT Traumatic brain injury (TBI) is a major global health concern. Across the spectrum of TBI severities, impaired information processing can contribute to diverse functional deficits that underlie persistent symptoms. We used experimental TBI to exploit technical advantages in mice while modeling traumatic axonal injury in white matter tracts, which is a key pathological feature of human TBI. A combination of approaches revealed slowed and failed signal conduction along with damage to the structure and molecular composition of myelinated axons in the white matter after TBI. An early regenerative response was not sustained yet reveals a potential time window for intervention. These insights into white matter abnormalities underlying axon conduction deficits can inform strategies to improve treatment options for TBI patients.
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Reorganization of Destabilized Nodes of Ranvier in β IV Spectrin Mutants Uncovers Critical Timelines for Nodal Restoration and Prevention of Motor Paresis. J Neurosci 2018; 38:6267-6282. [PMID: 29907663 DOI: 10.1523/jneurosci.0515-18.2018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/14/2018] [Accepted: 06/05/2018] [Indexed: 11/21/2022] Open
Abstract
Disorganization of nodes of Ranvier is associated with motor and sensory dysfunctions. Mechanisms that allow nodal recovery during pathological processes remain poorly understood. A highly enriched nodal cytoskeletal protein βIV spectrin anchors and stabilizes the nodal complex to actin cytoskeleton. Loss of murine βIV spectrin allows the initial nodal organization, but causes gradual nodal destabilization. Mutations in human βIV spectrin cause auditory neuropathy and impairment in motor coordination. Similar phenotypes are caused by nodal disruption due to demyelination. Here we report on the precise timelines of nodal disorganization and reorganization by following disassembly and reassembly of key nodal proteins in βIV spectrin mice of both sexes before and after βIV spectrin re-expression at specifically chosen developmental time points. We show that the timeline of nodal restoration has different outcomes in the PNS and CNS with respect to nodal reassembly and functional restoration. In the PNS, restoration of nodes occurs within 1 month regardless of the time of βIV spectrin re-expression. In contrast, the CNS nodal reorganization and functional restoration occurs within a critical time window; after that, nodal reorganization diminishes, leading to less efficient motor recovery. We demonstrate that timely restoration of nodes can improve both the functional properties and the ultrastructure of myelinated fibers affected by long-term nodal disorganization. Our studies, which indicate a critical timeline for nodal restoration together with overall motor performance and prolonged life span, further support the idea that nodal restoration is more beneficial if initiated before any axonal damage, which is critically relevant to demyelinating disorders.SIGNIFICANCE STATEMENT Nodes of Ranvier are integral to efficient and rapid signal transmission along myelinated fibers. Various demyelinating disorders are characterized by destabilization of the nodal molecular complex, accompanied by severe reduction in nerve conduction and the onset of motor and sensory dysfunctions. This study is the first to report in vivo reassembly of destabilized nodes with sequential improvement in overall motor performance. Our study reveals that nodal restoration is achievable before any axonal damage, and that long-term nodal destabilization causes irreversible axonal structural changes that prevent functional restoration. Our studies provide significant insights into timely restoration of nodal domains as a potential therapeutic approach in treatment of demyelinating disorders.
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Glial βII Spectrin Contributes to Paranode Formation and Maintenance. J Neurosci 2018; 38:6063-6075. [PMID: 29853631 DOI: 10.1523/jneurosci.3647-17.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/24/2018] [Accepted: 05/14/2018] [Indexed: 12/18/2022] Open
Abstract
Action potential conduction along myelinated axons depends on high densities of voltage-gated Na+ channels at the nodes of Ranvier. Flanking each node, paranodal junctions (paranodes) are formed between axons and Schwann cells in the peripheral nervous system (PNS) or oligodendrocytes in the CNS. Paranodal junctions contribute to both node assembly and maintenance. Despite their importance, the molecular mechanisms responsible for paranode assembly and maintenance remain poorly understood. βII spectrin is expressed in diverse cells and is an essential part of the submembranous cytoskeleton. Here, we show that Schwann cell βII spectrin is highly enriched at paranodes. To elucidate the roles of glial βII spectrin, we generated mutant mice lacking βII spectrin in myelinating glial cells by crossing mice with a floxed allele of Sptbn1 with Cnp-Cre mice, and analyzed both male and female mice. Juvenile (4 weeks) and middle-aged (60 weeks) mutant mice showed reduced grip strength and sciatic nerve conduction slowing, whereas no phenotype was observed between 8 and 24 weeks of age. Consistent with these findings, immunofluorescence microscopy revealed disorganized paranodes in the PNS and CNS of both postnatal day 13 and middle-aged mutant mice, but not in young adult mutant mice. Electron microscopy confirmed partial loss of transverse bands at the paranodal axoglial junction in the middle-aged mutant mice in both the PNS and CNS. These findings demonstrate that a spectrin-based cytoskeleton in myelinating glia contributes to formation and maintenance of paranodal junctions.SIGNIFICANCE STATEMENT Myelinating glia form paranodal axoglial junctions that flank both sides of the nodes of Ranvier. These junctions contribute to node formation and maintenance and are essential for proper nervous system function. We found that a submembranous spectrin cytoskeleton is highly enriched at paranodes in Schwann cells. Ablation of βII spectrin in myelinating glial cells disrupted the paranodal cell adhesion complex in both peripheral and CNSs, resulting in muscle weakness and sciatic nerve conduction slowing in juvenile and middle-aged mice. Our data show that a spectrin-based submembranous cytoskeleton in myelinating glia plays important roles in paranode formation and maintenance.
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Powell MA, Black RT, Smith TL, Reeves TM, Phillips LL. Mild Fluid Percussion Injury Induces Diffuse Axonal Damage and Reactive Synaptic Plasticity in the Mouse Olfactory Bulb. Neuroscience 2018; 371:106-118. [PMID: 29203228 PMCID: PMC5809206 DOI: 10.1016/j.neuroscience.2017.11.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 11/21/2017] [Accepted: 11/27/2017] [Indexed: 12/21/2022]
Abstract
Despite the regenerative capacity of the olfactory bulb (OB), head trauma causes olfactory disturbances in up to 30% of patients. While models of olfactory nerve transection, olfactory receptor neuron (ORN) ablation, or direct OB impact have been used to examine OB recovery, these models are severe and not ideal for study of OB synaptic repair. We posited that a mild fluid percussion brain injury (mFPI), delivered over mid-dorsal cortex, would produce diffuse OB deafferentation without confounding pathology. Wild type FVB/NJ mice were subjected to mFPI and OB probed for ORN axon degeneration and onset of reactive synaptogenesis. OB extracts revealed 3 d postinjury elevation of calpain-cleaved 150-kDa αII-spectrin, an indicator of axon damage, in tandem with reduced olfactory marker protein (OMP), a protein specific to intact ORN axons. Moreover, mFPI also produced a 3-d peak in GFAP+ astrocyte and IBA1+ microglial reactivity, consistent with postinjury inflammation. OB glomeruli showed disorganized ORN axons, presynaptic degeneration, and glial phagocytosis at 3 and 7 d postinjury, all indicative of deafferentation. At 21 d after mFPI, normal synaptic structure re-emerged along with OMP recovery, supporting ORN afferent reinnervation. Robust 21 d postinjury upregulation of GAP-43 was consistent with the time course of ORN axon sprouting and synapse regeneration reported after more severe olfactory insult. Together, these findings define a cycle of synaptic degeneration and recovery at a site remote to non-contusive brain injury. We show that mFPI models diffuse ORN axon damage, useful for the study of time-dependent reactive synaptogenesis in the deafferented OB.
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Affiliation(s)
- Melissa A Powell
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States.
| | - Raiford T Black
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States.
| | - Terry L Smith
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States.
| | - Thomas M Reeves
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States.
| | - Linda L Phillips
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States.
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Stojic A, Bojcevski J, Williams SK, Diem R, Fairless R. Early Nodal and Paranodal Disruption in Autoimmune Optic Neuritis. J Neuropathol Exp Neurol 2018; 77:361-373. [DOI: 10.1093/jnen/nly011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Aleksandar Stojic
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany
| | - Jovana Bojcevski
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany
| | - Sarah K Williams
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany
| | - Ricarda Diem
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany
| | - Richard Fairless
- Department of Neurology, University Clinic Heidelberg, Heidelberg, Germany
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Glushakova OY, Glushakov AO, Borlongan CV, Valadka AB, Hayes RL, Glushakov AV. Role of Caspase-3-Mediated Apoptosis in Chronic Caspase-3-Cleaved Tau Accumulation and Blood–Brain Barrier Damage in the Corpus Callosum after Traumatic Brain Injury in Rats. J Neurotrauma 2018. [DOI: 10.1089/neu.2017.4999] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Olena Y. Glushakova
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, Virginia
| | - Andriy O. Glushakov
- Department of Neurosurgery, University of South Florida College of Medicine, Tampa, Florida
| | - Cesar V. Borlongan
- Department of Neurosurgery, University of South Florida College of Medicine, Tampa, Florida
| | - Alex B. Valadka
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, Virginia
| | - Ronald L. Hayes
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, Virginia
- Banyan Biomarkers, Inc., Alachua, Florida
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Effects of Female Sex Steroids Administration on Pathophysiologic Mechanisms in Traumatic Brain Injury. Transl Stroke Res 2017; 9:393-416. [PMID: 29151229 DOI: 10.1007/s12975-017-0588-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/16/2017] [Accepted: 11/07/2017] [Indexed: 12/19/2022]
Abstract
Secondary brain damage following initial brain damage in traumatic brain injury (TBI) is a major cause of adverse outcomes. There are many gaps in TBI research and a lack of therapy to limit debilitating outcomes in TBI or enhance the neurogenesis, despite pre-clinical and clinical research performed in TBI. Females show harmful outcomes against brain damage including TBI less than males, independent of different TBI occurrence. A significant reduction in secondary brain damage and improvement in neurologic outcome post-TBI has been reported following the use of progesterone and estrogen in many experimental studies. Although useful features of sex steroids including progesterone have been identified in TBI clinical trials I and II, clinical trials III have been unsuccessful. This review article focuses on evidence of secondary injury mechanisms and neuroprotective effects of estrogen and progesterone in TBI. Understanding these mechanisms may enable researchers to achieve greater success in TBI clinical studies. It seems that the design of clinical studies should be revised due to translation loss of animal studies to clinical studies. The heterogeneous and complex nature of TBI, the endogenous levels of sex hormones at the time of taking these hormones, the therapeutic window of the drug, the dosage of the drug, the selection of appropriate targets in evaluation, the determination of responsive population, gender and age based on animal studies should be considered in the design of TBI human studies in future.
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Ghazale H, Ramadan N, Mantash S, Zibara K, El-Sitt S, Darwish H, Chamaa F, Boustany RM, Mondello S, Abou-Kheir W, Soueid J, Kobeissy F. Docosahexaenoic acid (DHA) enhances the therapeutic potential of neonatal neural stem cell transplantation post-Traumatic brain injury. Behav Brain Res 2017; 340:1-13. [PMID: 29126932 DOI: 10.1016/j.bbr.2017.11.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/27/2017] [Accepted: 11/06/2017] [Indexed: 12/25/2022]
Abstract
Traumatic Brain Injury (TBI) is a major cause of death and disability worldwide with 1.5 million people inflicted yearly. Several neurotherapeutic interventions have been proposed including drug administration as well as cellular therapy involving neural stem cells (NSCs). Among the proposed drugs is docosahexaenoic acid (DHA), a polyunsaturated fatty acid, exhibiting neuroprotective properties. In this study, we utilized an innovative intervention of neonatal NSCs transplantation in combination with DHA injections in order to ameliorate brain damage and promote functional recovery in an experimental model of TBI. Thus, NSCs derived from the subventricular zone of neonatal pups were cultured into neurospheres and transplanted in the cortex of an experimentally controlled cortical impact mouse model of TBI. The effect of NSC transplantation was assessed alone and/or in combination with DHA administration. Motor deficits were evaluated using pole climbing and rotarod tests. Using immunohistochemistry, the effect of transplanted NSCs and DHA treatment was used to assess astrocytic (Glial fibrillary acidic protein, GFAP) and microglial (ionized calcium binding adaptor molecule-1, IBA-1) activity. In addition, we quantified neuroblasts (doublecortin; DCX) and dopaminergic neurons (tyrosine hydroxylase; TH) expression levels. Combined NSC transplantation and DHA injections significantly attenuated TBI-induced motor function deficits (pole climbing test), promoted neurogenesis, coupled with an increase in glial reactivity at the cortical site of injury. In addition, the number of tyrosine hydroxylase positive neurons was found to increase markedly in the ventral tegmental area and substantia nigra in the combination therapy group. Immunoblotting analysis indicated that DHA+NSCs treated animals showed decreased levels of 38kDa GFAP-BDP (breakdown product) and 145kDa αII-spectrin SBDP indicative of attenuated calpain/caspase activation. These data demonstrate that prior treatment with DHA may be a desirable strategy to improve the therapeutic efficacy of NSC transplantation in TBI.
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Affiliation(s)
- Hussein Ghazale
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon
| | - Naify Ramadan
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon
| | - Sara Mantash
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon
| | - Kazem Zibara
- ER045, Laboratory of Stem Cells, DSST, Lebanese University, Beirut, Lebanon; Department of Biology, Faculty of Sciences-I, Lebanese University, Beirut, Lebanon
| | - Sally El-Sitt
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon
| | - Hala Darwish
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon
| | - Farah Chamaa
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Rose Mary Boustany
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon; American University of Beirut Medical Center Special Kids Clinic, Neurogenetics Program and Division of Pediatric Neurology, Departments of Pediatrics and Adolescent Medicine, Beirut, Lebanon
| | - Stefania Mondello
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, A.O.U. "Policlinico G. Martino", Via Consolare Valeria, Messina, 98125, Italy
| | - Wassim Abou-Kheir
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.
| | - Jihane Soueid
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon.
| | - Firas Kobeissy
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon, Lebanon; Department of Psychiatry, Center for Neuroproteomics and Biomarkers Research, University of Florida, Gainesville, FL, USA.
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29
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Harpaz D, Eltzov E, Seet RCS, Marks RS, Tok AIY. Point-of-Care-Testing in Acute Stroke Management: An Unmet Need Ripe for Technological Harvest. BIOSENSORS 2017; 7:E30. [PMID: 28771209 PMCID: PMC5618036 DOI: 10.3390/bios7030030] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 12/20/2022]
Abstract
Stroke, the second highest leading cause of death, is caused by an abrupt interruption of blood to the brain. Supply of blood needs to be promptly restored to salvage brain tissues from irreversible neuronal death. Existing assessment of stroke patients is based largely on detailed clinical evaluation that is complemented by neuroimaging methods. However, emerging data point to the potential use of blood-derived biomarkers in aiding clinical decision-making especially in the diagnosis of ischemic stroke, triaging patients for acute reperfusion therapies, and in informing stroke mechanisms and prognosis. The demand for newer techniques to deliver individualized information on-site for incorporation into a time-sensitive work-flow has become greater. In this review, we examine the roles of a portable and easy to use point-of-care-test (POCT) in shortening the time-to-treatment, classifying stroke subtypes and improving patient's outcome. We first examine the conventional stroke management workflow, then highlight situations where a bedside biomarker assessment might aid clinical decision-making. A novel stroke POCT approach is presented, which combines the use of quantitative and multiplex POCT platforms for the detection of specific stroke biomarkers, as well as data-mining tools to drive analytical processes. Further work is needed in the development of POCTs to fulfill an unmet need in acute stroke management.
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Affiliation(s)
- Dorin Harpaz
- Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
- School of Material Science & Engineering, Nanyang Technology University, 50 Nanyang Avenue, Singapore 639798, Singapore.
- Institute for Sports Research (ISR), Nanyang Technology University and Loughborough University, Nanyang Avenue, Singapore 639798, Singapore.
| | - Evgeni Eltzov
- Agriculture Research Organization (ARO), Volcani Centre, Rishon LeTsiyon 15159, Israel.
| | - Raymond C S Seet
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, NUHS Tower Block, 1E Kent Ridge Road, Singapore 119228, Singapore.
| | - Robert S Marks
- Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
- School of Material Science & Engineering, Nanyang Technology University, 50 Nanyang Avenue, Singapore 639798, Singapore.
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
- The Ilse Katz Centre for Meso and Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
| | - Alfred I Y Tok
- School of Material Science & Engineering, Nanyang Technology University, 50 Nanyang Avenue, Singapore 639798, Singapore.
- Institute for Sports Research (ISR), Nanyang Technology University and Loughborough University, Nanyang Avenue, Singapore 639798, Singapore.
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30
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Daneshi Kohan E, Lashkari BS, Sparrey CJ. The effects of paranodal myelin damage on action potential depend on axonal structure. Med Biol Eng Comput 2017; 56:395-411. [PMID: 28770425 DOI: 10.1007/s11517-017-1691-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 07/17/2017] [Indexed: 12/31/2022]
Abstract
Biophysical computational models of axons provide an important tool for quantifying the effects of injury and disease on signal conduction characteristics. Several studies have used generic models to study the average behavior of healthy and injured axons; however, few studies have included the effects of normal structural variation on the simulated axon's response to injury. The effects of variations in physiological characteristics on axonal function were mapped by altering the structure of the nodal, paranodal, and juxtaparanodal regions across reported values in three different caliber axons (1, 2, and 5.7 μm). Myelin detachment and retraction were simulated to quantify the effects of each injury mechanism on signal conduction. Conduction velocity was most affected by axonal fiber diameter (89%), while membrane potential amplitude was most affected by nodal length (86%) in healthy axons. Postinjury axonal functionality was most affected by myelin detachment in the paranodal and juxtaparanodal regions when retraction and detachment were modeled simultaneously. The efficacy of simulated potassium channel blockers on restoring membrane potential and velocity varied with axonal caliber and injury type. The structural characteristics of axons affect their functional response to myelin retraction and detachment and their subsequent response to potassium channel blocker treatment.
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Affiliation(s)
- Ehsan Daneshi Kohan
- Mechatronic Systems Engineering, Simon Fraser University, 250-13450 102 Avenue, Surrey, BC, V3T 0A3, Canada.,International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, 5th floor, 5200, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada
| | - Behnia Shadab Lashkari
- International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, 5th floor, 5200, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada
| | - Carolyn Jennifer Sparrey
- Mechatronic Systems Engineering, Simon Fraser University, 250-13450 102 Avenue, Surrey, BC, V3T 0A3, Canada. .,International Collaboration on Repair Discoveries (ICORD), Faculty of Medicine, University of British Columbia, 5th floor, 5200, 818 West 10th Avenue, Vancouver, BC, V5Z 1M9, Canada.
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31
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Ng LJ, Volman V, Gibbons MM, Phohomsiri P, Cui J, Swenson DJ, Stuhmiller JH. A Mechanistic End-to-End Concussion Model That Translates Head Kinematics to Neurologic Injury. Front Neurol 2017; 8:269. [PMID: 28663736 PMCID: PMC5471336 DOI: 10.3389/fneur.2017.00269] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 05/26/2017] [Indexed: 11/13/2022] Open
Abstract
Past concussion studies have focused on understanding the injury processes occurring on discrete length scales (e.g., tissue-level stresses and strains, cell-level stresses and strains, or injury-induced cellular pathology). A comprehensive approach that connects all length scales and relates measurable macroscopic parameters to neurological outcomes is the first step toward rationally unraveling the complexity of this multi-scale system, for better guidance of future research. This paper describes the development of the first quantitative end-to-end (E2E) multi-scale model that links gross head motion to neurological injury by integrating fundamental elements of tissue and cellular mechanical response with axonal dysfunction. The model quantifies axonal stretch (i.e., tension) injury in the corpus callosum, with axonal functionality parameterized in terms of axonal signaling. An internal injury correlate is obtained by calculating a neurological injury measure (the average reduction in the axonal signal amplitude) over the corpus callosum. By using a neurologically based quantity rather than externally measured head kinematics, the E2E model is able to unify concussion data across a range of exposure conditions and species with greater sensitivity and specificity than correlates based on external measures. In addition, this model quantitatively links injury of the corpus callosum to observed specific neurobehavioral outcomes that reflect clinical measures of mild traumatic brain injury. This comprehensive modeling framework provides a basis for the systematic improvement and expansion of this mechanistic-based understanding, including widening the range of neurological injury estimation, improving concussion risk correlates, guiding the design of protective equipment, and setting safety standards.
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Affiliation(s)
- Laurel J Ng
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Vladislav Volman
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Melissa M Gibbons
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Pi Phohomsiri
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Jianxia Cui
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
| | - Darrell J Swenson
- Cardiac Rhythm and Heart Failure Numerical Modeling, Medtronic, Mounds View, MN, United States
| | - James H Stuhmiller
- Simulation Engineering and Testing, L-3 Applied Technologies, Inc., San Diego, CA, United States
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Glushakova OY, Glushakov AA, Wijesinghe DS, Valadka AB, Hayes RL, Glushakov AV. Prospective clinical biomarkers of caspase-mediated apoptosis associated with neuronal and neurovascular damage following stroke and other severe brain injuries: Implications for chronic neurodegeneration. Brain Circ 2017; 3:87-108. [PMID: 30276309 PMCID: PMC6126261 DOI: 10.4103/bc.bc_27_16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 04/10/2017] [Accepted: 04/17/2017] [Indexed: 12/11/2022] Open
Abstract
Acute brain injuries, including ischemic and hemorrhagic stroke, as well as traumatic brain injury (TBI), are major worldwide health concerns with very limited options for effective diagnosis and treatment. Stroke and TBI pose an increased risk for the development of chronic neurodegenerative diseases, notably chronic traumatic encephalopathy, Alzheimer's disease, and Parkinson's disease. The existence of premorbid neurodegenerative diseases can exacerbate the severity and prognosis of acute brain injuries. Apoptosis involving caspase-3 is one of the most common mechanisms involved in the etiopathology of both acute and chronic neurological and neurodegenerative diseases, suggesting a relationship between these disorders. Over the past two decades, several clinical biomarkers of apoptosis have been identified in cerebrospinal fluid and peripheral blood following ischemic stroke, intracerebral and subarachnoid hemorrhage, and TBI. These biomarkers include selected caspases, notably caspase-3 and its specific cleavage products such as caspase-cleaved cytokeratin-18, caspase-cleaved tau, and a caspase-specific 120 kDa αII-spectrin breakdown product. The levels of these biomarkers might be a valuable tool for the identification of pathological pathways such as apoptosis and inflammation involved in injury progression, assessment of injury severity, and prediction of clinical outcomes. This review focuses on clinical studies involving biomarkers of caspase-3-mediated pathways, following stroke and TBI. The review further examines their prospective diagnostic utility, as well as clinical utility for improved personalized treatment of stroke and TBI patients and the development of prophylactic treatment chronic neurodegenerative disease.
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Affiliation(s)
- Olena Y Glushakova
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, VA, USA
| | - Andriy A Glushakov
- Department of Neurosurgery, University of South Florida College of Medicine, Tampa, FL, USA
| | - Dayanjan S Wijesinghe
- Department of Pharmacotherapy and Outcomes Sciences, Laboratory of Pharmacometabolomics and Companion Diagnostics, Virginia Commonwealth University, Richmond, VA, USA
| | - Alex B Valadka
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, VA, USA
| | - Ronald L Hayes
- Department of Neurosurgery, Virginia Commonwealth University, Richmond, VA, USA
- Banyan Biomarkers, Inc., Alachua, 32615, USA
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Abou-El-Hassan H, Sukhon F, Assaf EJ, Bahmad H, Abou-Abbass H, Jourdi H, Kobeissy FH. Degradomics in Neurotrauma: Profiling Traumatic Brain Injury. Methods Mol Biol 2017; 1598:65-99. [PMID: 28508358 DOI: 10.1007/978-1-4939-6952-4_4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Degradomics has recently emerged as a subdiscipline in the omics era with a focus on characterizing signature breakdown products implicated in various disease processes. Driven by promising experimental findings in cancer, neuroscience, and metabolomic disorders, degradomics has significantly promoted the notion of disease-specific "degradome." A degradome arises from the activation of several proteases that target specific substrates and generate signature protein fragments. Several proteases such as calpains, caspases, cathepsins, and matrix metalloproteinases (MMPs) are involved in the pathogenesis of numerous diseases that disturb the physiologic balance between protein synthesis and protein degradation. While regulated proteolytic activities are needed for development, growth, and regeneration, uncontrolled proteolysis initiated under pathological conditions ultimately culminates into apoptotic and necrotic processes. In this chapter, we aim to review the protease-substrate repertoires in neural injury concentrating on traumatic brain injury. A striking diversity of protease substrates, essential for neuronal and brain structural and functional integrity, namely, encryptic biomarker neoproteins, have been characterized in brain injury. These include cytoskeletal proteins, transcription factors, cell cycle regulatory proteins, synaptic proteins, and cell junction proteins. As these substrates are subject to proteolytic fragmentation, they are ceaselessly exposed to activated proteases. Characterization of these molecules allows for a surge of "possible" therapeutic approaches of intervention at various levels of the proteolytic cascade.
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Affiliation(s)
- Hadi Abou-El-Hassan
- Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
| | - Fares Sukhon
- Faculty of Medicine, Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Edwyn Jeremy Assaf
- Faculty of Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - Hisham Bahmad
- Faculty of Medical, Neuroscience Research Center, Beirut Arab University, Beirut, Lebanon
- Faculty of Medicine, Department of Anatomy, Cell Biology and Physiological Sciences, American University of Beirut, Beirut, Lebanon
| | - Hussein Abou-Abbass
- Faculty of Medical Sciences, Neuroscience Research Center, Lebanese University, Beirut, Lebanon
- Faculty of Medicine, Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon
| | - Hussam Jourdi
- Faculty of Science¸ Department of Biology, University of Balamand, Souk-el-Gharb Campus, Aley, Lebanon
| | - Firas H Kobeissy
- Faculty of Medicine, Department of Biochemistry and Molecular Genetics, American University of Beirut, Beirut, Lebanon.
- Department of Psychiatry, Center for Neuroproteomics and Biomarkers Research, University of Florida, Gainesville, FL, USA.
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Kobeissy FH, Guingab-Cagmat JD, Zhang Z, Moghieb A, Glushakova OY, Mondello S, Boutté AM, Anagli J, Rubenstein R, Bahmad H, Wagner AK, Hayes RL, Wang KKW. Neuroproteomics and Systems Biology Approach to Identify Temporal Biomarker Changes Post Experimental Traumatic Brain Injury in Rats. Front Neurol 2016; 7:198. [PMID: 27920753 PMCID: PMC5118702 DOI: 10.3389/fneur.2016.00198] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 10/28/2016] [Indexed: 01/15/2023] Open
Abstract
Traumatic brain injury (TBI) represents a critical health problem of which diagnosis, management, and treatment remain challenging. TBI is a contributing factor in approximately one-third of all injury-related deaths in the United States. The Centers for Disease Control and Prevention estimate that 1.7 million people suffer a TBI in the United States annually. Efforts continue to focus on elucidating the complex molecular mechanisms underlying TBI pathophysiology and defining sensitive and specific biomarkers that can aid in improving patient management and care. Recently, the area of neuroproteomics–systems biology is proving to be a prominent tool in biomarker discovery for central nervous system injury and other neurological diseases. In this work, we employed the controlled cortical impact (CCI) model of experimental TBI in rat model to assess the temporal–global proteome changes after acute (1 day) and for the first time, subacute (7 days), post-injury time frame using the established cation–anion exchange chromatography-1D SDS gel electrophoresis LC–MS/MS platform for protein separation combined with discrete systems biology analyses to identify temporal biomarker changes related to this rat TBI model. Rather than focusing on any one individual molecular entity, we used in silico systems biology approach to understand the global dynamics that govern proteins that are differentially altered post-injury. In addition, gene ontology analysis of the proteomic data was conducted in order to categorize the proteins by molecular function, biological process, and cellular localization. Results show alterations in several proteins related to inflammatory responses and oxidative stress in both acute (1 day) and subacute (7 days) periods post-TBI. Moreover, results suggest a differential upregulation of neuroprotective proteins at 7 days post-CCI involved in cellular functions such as neurite growth, regeneration, and axonal guidance. Our study is among the first to assess temporal neuroproteome changes in the CCI model. Data presented here unveil potential neural biomarkers and therapeutic targets that could be used for diagnosis, for treatment and, most importantly, for temporal prognostic assessment following brain injury. Of interest, this work relies on in silico bioinformatics approach to draw its conclusion; further work is conducted for functional studies to validate and confirm the omics data obtained.
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Affiliation(s)
- Firas H Kobeissy
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | | | - Zhiqun Zhang
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Ahmed Moghieb
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Olena Y Glushakova
- Department of Neurosurgery, Virginia Commonwealth University School of Medicine , Richmond, VA , USA
| | - Stefania Mondello
- Department of Neurosciences, University of Messina , Messina , Italy
| | - Angela M Boutté
- Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research , Silver Spring, MD , USA
| | - John Anagli
- NeuroTheranostics Inc., Detroit, MI, USA; Henry Ford Health System, Detroit, MI, USA
| | - Richard Rubenstein
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY, USA; Department of Physiology and Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Hisham Bahmad
- Faculty of Medicine, Beirut Arab University, Beirut, Lebanon; Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, Beirut, Lebanon
| | - Amy K Wagner
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ronald L Hayes
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Department of Neurosurgery, Virginia Commonwealth University School of Medicine, Richmond, VA, USA
| | - Kevin K W Wang
- Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Psychiatry, McKnight Brain Institute, University of Florida, Gainesville, FL, USA; Program for Neurotrauma, Neuroproteomics and Biomarkers Research, Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, USA
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Griggs RB, Yermakov LM, Susuki K. Formation and disruption of functional domains in myelinated CNS axons. Neurosci Res 2016; 116:77-87. [PMID: 27717670 DOI: 10.1016/j.neures.2016.09.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 09/19/2016] [Accepted: 09/23/2016] [Indexed: 12/15/2022]
Abstract
Communication in the central nervous system (CNS) occurs through initiation and propagation of action potentials at excitable domains along axons. Action potentials generated at the axon initial segment (AIS) are regenerated at nodes of Ranvier through the process of saltatory conduction. Proper formation and maintenance of the molecular structure at the AIS and nodes are required for sustaining conduction fidelity. In myelinated CNS axons, paranodal junctions between the axolemma and myelinating oligodendrocytes delineate nodes of Ranvier and regulate the distribution and localization of specialized functional elements, such as voltage-gated sodium channels and mitochondria. Disruption of excitable domains and altered distribution of functional elements in CNS axons is associated with demyelinating diseases such as multiple sclerosis, and is likely a mechanism common to other neurological disorders. This review will provide a brief overview of the molecular structure of the AIS and nodes of Ranvier, as well as the distribution of mitochondria in myelinated axons. In addition, this review highlights important structural and functional changes within myelinated CNS axons that are associated with neurological dysfunction.
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Affiliation(s)
- Ryan B Griggs
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Leonid M Yermakov
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States.
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Cui J, Ng LJ, Volman V. Callosal dysfunction explains injury sequelae in a computational network model of axonal injury. J Neurophysiol 2016; 116:2892-2908. [PMID: 27683891 DOI: 10.1152/jn.00603.2016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 09/22/2016] [Indexed: 12/28/2022] Open
Abstract
Mild traumatic brain injury (mTBI) often results in neurobehavioral aberrations such as impaired attention and increased reaction time. Diffusion imaging and postmortem analysis studies suggest that mTBI primarily affects myelinated axons in white matter tracts. In particular, corpus callosum, mediating interhemispheric information exchange, has been shown to be affected in mTBI. Yet little is known about the mechanisms linking the injury of myelinated callosal axons to the neurobehavioral sequelae of mTBI. To address this issue, we devised and studied a large, biologically plausible neuronal network model of cortical tissue. Importantly, the model architecture incorporated intra- and interhemispheric organization, including myelinated callosal axons and distance-dependent axonal conduction delays. In the resting state, the intact model network exhibited several salient features, including alpha-band (8-12 Hz) collective activity with low-frequency irregular spiking of individual neurons. The network model of callosal injury captured several clinical observations, including 1) "slowing down" of the network rhythms, manifested as an increased resting-state theta-to-alpha power ratio, 2) reduced response to attention-like network stimulation, manifested as a reduced spectral power of collective activity, and 3) increased population response time in response to stimulation. Importantly, these changes were positively correlated with injury severity, supporting proposals to use neurobehavioral indices as biomarkers for determining the severity of injury. Our modeling effort helps to understand the role played by the injury of callosal myelinated axons in defining the neurobehavioral sequelae of mTBI.
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Affiliation(s)
- Jianxia Cui
- L-3 Applied Technologies, Inc., San Diego, California
| | - Laurel J Ng
- L-3 Applied Technologies, Inc., San Diego, California
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Reeves TM, Trimmer PA, Colley BS, Phillips LL. Targeting Kv1.3 channels to reduce white matter pathology after traumatic brain injury. Exp Neurol 2016; 283:188-203. [PMID: 27302680 PMCID: PMC4992637 DOI: 10.1016/j.expneurol.2016.06.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/31/2016] [Accepted: 06/10/2016] [Indexed: 02/07/2023]
Abstract
Axonal injury is present in essentially all clinically significant cases of traumatic brain injury (TBI). While no effective treatment has been identified to date, experimental TBI models have shown promising axonal protection using immunosuppressants FK506 and Cyclosporine-A, with treatment benefits attributed to calcineurin inhibition or protection of mitochondrial function. However, growing evidence suggests neuroprotective efficacy of these compounds may also involve direct modulation of ion channels, and in particular Kv1.3. The present study tested whether blockade of Kv1.3 channels, using Clofazimine (CFZ), would alleviate TBI-induced white matter pathology in rodents. Postinjury CFZ administration prevented suppression of compound action potential (CAP) amplitude in the corpus callosum of adult rats following midline fluid percussion TBI, with injury and treatment effects primarily expressed in unmyelinated CAPs. Kv1.3 protein levels in callosal tissue extracts were significantly reduced postinjury, but this loss was prevented by CFZ treatment. In parallel, CFZ also attenuated the injury-induced elevation in pro-inflammatory cytokine IL1-β. The effects of CFZ on glial function were further studied using mixed microglia/astrocyte cell cultures derived from P3-5 mouse corpus callosum. Cultures of callosal glia challenged with lipopolysaccharide exhibited a dramatic increase in IL1-β levels, accompanied by reactive morphological changes in microglia, both of which were attenuated by CFZ treatment. These results support a cell specific role for Kv1.3 signaling in white matter pathology after TBI, and suggest a treatment approach based on the blockade of these channels. This therapeutic strategy may be especially efficacious for normalizing neuro-glial interactions affecting unmyelinated axons after TBI.
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Affiliation(s)
- Thomas M Reeves
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
| | - Patricia A Trimmer
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
| | - Beverly S Colley
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
| | - Linda L Phillips
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University Medical Center, Richmond, VA 23298, United States
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CHEN SHANGYU, SHI QIANKUN, ZHENG SHUYUN, LUO LIANGSHEN, YUAN SHOUTAO, WANG XIANG, CHENG ZIHAO, ZHANG WENHAO. Role of α-II-spectrin breakdown products in the prediction of the severity and clinical outcome of acute traumatic brain injury. Exp Ther Med 2016; 11:2049-2053. [PMID: 27168849 PMCID: PMC4840563 DOI: 10.3892/etm.2016.3153] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 01/18/2016] [Indexed: 12/12/2022] Open
Abstract
αII-spectrin breakdown products are regarded as potential biomarkers for traumatic brain injury (TBI). The aim of the present study was to further evaluate these biomarkers by assessing their clinical utility in predicting the severity of injury and clinical outcome of patients with TBI. Eligible patients with acute TBI (n=17), defined by a Glasgow Coma Scale (GCS) score of ≤8, were enrolled. Ventricular cerebrospinal fluid (CSF) was sampled from each patient at 24, 72 and 120 h following TBI. An immunoblot assay was used to determine the concentrations of SBDPs in the CSF samples. The concentrations of SBDPs combined with the GCS score at 24 h after injury and the Glasgow Outcome Score (GOS) at 30 days after injury were compared and analyzed. The levels of SBDPs in CSF were markedly increased following acute TBI in comparison with those in the control group. In the early period after TBI, the levels of SBDPs were closely associated with GCS score. Comparisons of the SBDP levels with the severity of injury revealed significant differences between patients with the most severe brain injury and patients with severe brain injury in the first 24 h post-injury (P<0.05). The levels and dynamic changes of SBDPs in CSF exhibited a close association with GOS at 30 days after injury. The levels of SBDPs differed significantly between patients grouped according to prognosis (P<0.05). These results suggest that in the early period after TBI, the levels and dynamic changes of SBDPs in CSF can be useful in the prediction of the severity of injury and clinical outcome of patients.
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Affiliation(s)
- SHANGYU CHEN
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - QIANKUN SHI
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - SHUYUN ZHENG
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - LIANGSHEN LUO
- Department of Neurosurgery, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - SHOUTAO YUAN
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - XIANG WANG
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - ZIHAO CHENG
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
| | - WENHAO ZHANG
- Department of Critical Care Medicine, Nanjing First Hospital, Nanjing Medical University, Nanjing, Jiangsu 210006, P.R. China
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39
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Clark KC, Josephson A, Benusa SD, Hartley RK, Baer M, Thummala S, Joslyn M, Sword BA, Elford H, Oh U, Dilsizoglu-Senol A, Lubetzki C, Davenne M, DeVries GH, Dupree JL. Compromised axon initial segment integrity in EAE is preceded by microglial reactivity and contact. Glia 2016; 64:1190-209. [PMID: 27100937 DOI: 10.1002/glia.22991] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 03/30/2016] [Accepted: 03/31/2016] [Indexed: 11/11/2022]
Abstract
Axonal pathology is a key contributor to long-term disability in multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system (CNS), but the mechanisms that underlie axonal pathology in MS remain elusive. Evidence suggests that axonal pathology is a direct consequence of demyelination, as we and others have shown that the node of Ranvier disassembles following loss of myelin. In contrast to the node of Ranvier, we now show that the axon initial segment (AIS), the axonal domain responsible for action potential initiation, remains intact following cuprizone-induced cortical demyelination. Instead, we find that the AIS is disrupted in the neocortex of mice that develop experimental autoimmune encephalomyelitis (EAE) independent of local demyelination. EAE-induced mice demonstrate profound compromise of AIS integrity with a progressive disruption that corresponds to EAE clinical disease severity and duration, in addition to cortical microglial reactivity. Furthermore, treatment with the drug didox results in attenuation of AIS pathology concomitantly with microglial reversion to a less reactive state. Together, our findings suggest that inflammation, but not demyelination, disrupts AIS integrity and that therapeutic intervention may protect and reverse this pathology. GLIA 2016;64:1190-1209.
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Affiliation(s)
- Kareem C Clark
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia.,VCU, Neuroscience Curriculum, Richmond, Virginia
| | - Anna Josephson
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
| | - Savannah D Benusa
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia.,VCU, Neuroscience Curriculum, Richmond, Virginia
| | - Rebecca K Hartley
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
| | - Matthew Baer
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
| | - Suneel Thummala
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia
| | - Martha Joslyn
- Department of Research,, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Brooke A Sword
- Department of Research,, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | | | - Unsong Oh
- Department of Neurology, VCU, Richmond, Virginia
| | - Aysegul Dilsizoglu-Senol
- UPMC/Univ Paris 06 UMR S 1127, Institut Du Cerveau Et De La Moelle Épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, Paris, F-75013, France
| | - Catherine Lubetzki
- UPMC/Univ Paris 06 UMR S 1127, Institut Du Cerveau Et De La Moelle Épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, Paris, F-75013, France.,AP-HP, Hôpital De La Pitié Salpêtrière, Paris, F-75013, France
| | - Marc Davenne
- UPMC/Univ Paris 06 UMR S 1127, Institut Du Cerveau Et De La Moelle Épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Universités, Paris, F-75013, France
| | - George H DeVries
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia.,Department of Research,, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
| | - Jeffrey L Dupree
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, Virginia.,Department of Research,, Hunter Holmes McGuire VA Medical Center, Richmond, Virginia
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Traumatic Axonal Injury: Mechanisms and Translational Opportunities. Trends Neurosci 2016; 39:311-324. [PMID: 27040729 PMCID: PMC5405046 DOI: 10.1016/j.tins.2016.03.002] [Citation(s) in RCA: 188] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 03/06/2016] [Accepted: 03/07/2016] [Indexed: 12/22/2022]
Abstract
Traumatic axonal injury (TAI) is an important pathoanatomical subgroup of traumatic brain injury (TBI) and a major driver of mortality and functional impairment. Experimental models have provided insights into the effects of mechanical deformation on the neuronal cytoskeleton and the subsequent processes that drive axonal injury. There is also increasing recognition that axonal or white matter loss may progress for years post-injury and represent one mechanistic framework for progressive neurodegeneration after TBI. Previous trials of novel therapies have failed to make an impact on clinical outcome, in both TBI in general and TAI in particular. Recent advances in understanding the cellular and molecular mechanisms of injury have the potential to translate into novel therapeutic targets. Multiple therapeutic targets are emerging that offer the potential to reduce secondary brain injury at a cellular level. These include cytoskeletal and membrane stabilisation, control of calcium flux and calpain activation, optimisation of cellular energetics, and modulation of the inflammatory response. Wallerian degeneration, as occurs following an axonal injury, is an active, cell-autonomous death pathway that involves failure of axonal transport to deliver key enzymes involved in NAD biosynthesis. Chronic microglial activation occurs following traumatic brain injury (TBI) and may persist for decades afterwards. This ongoing response has been linked to long-term neurodegeneration, particularly of white matter tracts. Phagoptosis is the process whereby physiologically stressed but otherwise viable neurons are phagocytosed by microglia in response to a range of eat-me signals induced by tissue injury.
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Choi BR, Kim DH, Back DB, Kang CH, Moon WJ, Han JS, Choi DH, Kwon KJ, Shin CY, Kim BR, Lee J, Han SH, Kim HY. Characterization of White Matter Injury in a Rat Model of Chronic Cerebral Hypoperfusion. Stroke 2016; 47:542-7. [DOI: 10.1161/strokeaha.115.011679] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 11/05/2015] [Indexed: 11/16/2022]
Affiliation(s)
- Bo-Ryoung Choi
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Dong-Hee Kim
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Dong Bin Back
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Chung Hwan Kang
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Won-Jin Moon
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Jung-Soo Han
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Dong-Hee Choi
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Kyoung Ja Kwon
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Chan Young Shin
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Bo-Ram Kim
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Jongmin Lee
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Seol-Heui Han
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Hahn Young Kim
- From the Department of Neurology (B.-R.C., D.B.B., K.J.K., S.-H.H., H.Y.K.), Department of Biological Sciences (B.-R.C., D.-H.K., J.-S.H.), Department of Radiology (C.H.K., W.-J.M.), Department of Medicine (D.-H.C.), Department of Pharmacology (C.Y.S.), and Department of Rehabilitation Medicine (B.-R.K., J.L.), Research Institute of Medical Science, Konkuk University School of Medicine, Seoul, Republic of Korea
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Susuki K, Otani Y, Rasband MN. Submembranous cytoskeletons stabilize nodes of Ranvier. Exp Neurol 2016; 283:446-51. [PMID: 26775177 DOI: 10.1016/j.expneurol.2015.11.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/10/2015] [Accepted: 11/23/2015] [Indexed: 01/22/2023]
Abstract
Rapid action potential propagation along myelinated axons requires voltage-gated Na(+) (Nav) channel clustering at nodes of Ranvier. At paranodes flanking nodes, myelinating glial cells interact with axons to form junctions. The regions next to the paranodes called juxtaparanodes are characterized by high concentrations of voltage-gated K(+) channels. Paranodal axoglial junctions function as barriers to restrict the position of these ion channels. These specialized domains along the myelinated nerve fiber are formed by multiple molecular mechanisms including interactions between extracellular matrix, cell adhesion molecules, and cytoskeletal scaffolds. This review highlights recent findings into the roles of submembranous cytoskeletal proteins in the stabilization of molecular complexes at and near nodes. Axonal ankyrin-spectrin complexes stabilize Nav channels at nodes. Axonal protein 4.1B-spectrin complexes contribute to paranode and juxtaparanode organization. Glial ankyrins enriched at paranodes facilitate node formation. Finally, disruption of spectrins or ankyrins by genetic mutations or proteolysis is involved in the pathophysiology of various neurological or psychiatric disorders.
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Affiliation(s)
- Keiichiro Susuki
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States.
| | - Yoshinori Otani
- Department of Neuroscience, Cell Biology, and Physiology, Boonshoft School of Medicine, Wright State University, Dayton, OH, United States
| | - Matthew N Rasband
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, United States.
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Taurine attenuates hippocampal and corpus callosum damage, and enhances neurological recovery after closed head injury in rats. Neuroscience 2015; 291:331-40. [DOI: 10.1016/j.neuroscience.2014.09.073] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 09/02/2014] [Accepted: 09/16/2014] [Indexed: 12/19/2022]
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Traumatic Brain Injury and the Neuronal Microenvironment: A Potential Role for Neuropathological Mechanotransduction. Neuron 2015; 85:1177-92. [DOI: 10.1016/j.neuron.2015.02.041] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Bramlett HM, Dietrich WD. Long-Term Consequences of Traumatic Brain Injury: Current Status of Potential Mechanisms of Injury and Neurological Outcomes. J Neurotrauma 2014; 32:1834-48. [PMID: 25158206 DOI: 10.1089/neu.2014.3352] [Citation(s) in RCA: 290] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Traumatic brain injury (TBI) is a significant clinical problem with few therapeutic interventions successfully translated to the clinic. Increased importance on the progressive, long-term consequences of TBI have been emphasized, both in the experimental and clinical literature. Thus, there is a need for a better understanding of the chronic consequences of TBI, with the ultimate goal of developing novel therapeutic interventions to treat the devastating consequences of brain injury. In models of mild, moderate, and severe TBI, histopathological and behavioral studies have emphasized the progressive nature of the initial traumatic insult and the involvement of multiple pathophysiological mechanisms, including sustained injury cascades leading to prolonged motor and cognitive deficits. Recently, the increased incidence in age-dependent neurodegenerative diseases in this patient population has also been emphasized. Pathomechanisms felt to be active in the acute and long-term consequences of TBI include excitotoxicity, apoptosis, inflammatory events, seizures, demyelination, white matter pathology, as well as decreased neurogenesis. The current article will review many of these pathophysiological mechanisms that may be important targets for limiting the chronic consequences of TBI.
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Affiliation(s)
- Helen M Bramlett
- The Miami Project to Cure Paralysis/Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida
| | - W Dalton Dietrich
- The Miami Project to Cure Paralysis/Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida
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Kobeissy FH, Liu MC, Yang Z, Zhang Z, Zheng W, Glushakova O, Mondello S, Anagli J, Hayes RL, Wang KKW. Degradation of βII-Spectrin Protein by Calpain-2 and Caspase-3 Under Neurotoxic and Traumatic Brain Injury Conditions. Mol Neurobiol 2014; 52:696-709. [PMID: 25270371 DOI: 10.1007/s12035-014-8898-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/10/2014] [Indexed: 12/22/2022]
Abstract
A major consequence of traumatic brain injury (TBI) is the rapid proteolytic degradation of structural cytoskeletal proteins. This process is largely reflected by the interruption of axonal transport as a result of extensive axonal injury leading to neuronal cell injury. Previous work from our group has described the extensive degradation of the axonally enriched cytoskeletal αII-spectrin protein which results in molecular signature breakdown products (BDPs) indicative of injury mechanisms and to specific protease activation both in vitro and in vivo. In the current study, we investigated the integrity of βII-spectrin protein and its proteolytic profile both in primary rat cerebrocortical cell culture under apoptotic, necrotic, and excitotoxic challenge and extended to in vivo rat model of experimental TBI (controlled cortical impact model). Interestingly, our results revealed that the intact 260-kDa βII-spectrin is degraded into major fragments (βII-spectrin breakdown products (βsBDPs)) of 110, 108, 85, and 80 kDa in rat brain (hippocampus and cortex) 48 h post-injury. These βsBDP profiles were further characterized and compared to an in vitro βII-spectrin fragmentation pattern of naive rat cortex lysate digested by calpain-2 and caspase-3. Results revealed that βII-spectrin was degraded into major fragments of 110/85 kDa by calpain-2 activation and 108/80 kDa by caspase-3 activation. These data strongly support the hypothesis that in vivo activation of multiple protease system induces structural protein proteolysis involving βII-spectrin proteolysis via a specific calpain and/or caspase-mediated pathway resulting in a signature, protease-specific βsBDPs that are dependent upon the type of neural injury mechanism. This work extends on previous published work that discusses the interplay spectrin family (αII-spectrin and βII-spectrin) and their susceptibility to protease proteolysis and their implication to neuronal cell death mechanisms.
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Affiliation(s)
- Firas H Kobeissy
- Center for Neuroproteomics and Biomarkers Research, Department of Psychiatry, University of Florida, Gainesville, FL, 32610, USA,
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Volman V, Ng LJ. Primary paranode demyelination modulates slowly developing axonal depolarization in a model of axonal injury. J Comput Neurosci 2014; 37:439-57. [PMID: 24986633 DOI: 10.1007/s10827-014-0515-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 06/18/2014] [Accepted: 06/20/2014] [Indexed: 01/12/2023]
Abstract
Neurological sequelae of mild traumatic brain injury are associated with the damage to white matter myelinated axons. In vitro models of axonal injury suggest that the progression to pathological ruin is initiated by the mechanical damage to tetrodotoxin-sensitive voltage-gated sodium channels that breaches the ion balance through alteration in kinetic properties of these channels. In myelinated axons, sodium channels are concentrated at nodes of Ranvier, making these sites vulnerable to mechanical injury. Nodal damage can also be inflicted by injury-induced partial demyelination of paranode/juxtaparanode compartments that flank the nodes and contain high density of voltage-gated potassium channels. Demyelination-induced potassium deregulation can further aggravate axonal damage; however, the role of paranode/juxtaparanode demyelination in immediate impairment of axonal function, and its contribution to the development of axonal depolarization remain elusive. A biophysically realistic computational model of myelinated axon that incorporates ion exchange mechanisms and nodal/paranodal/juxtaparanodal organization was developed and used to study the impact of injury-induced demyelination on axonal signal transmission. Injured axons showed alterations in signal propagation that were consistent with the experimental findings and with the notion of reduced axonal excitability immediately post trauma. Injury-induced demyelination strongly modulated the rate of axonal depolarization, suggesting that trauma-induced damage to paranode myelin can affect axonal transition to degradation. Results of these studies clarify the contribution of paranode demyelination to immediate post trauma alterations in axonal function and suggest that partial paranode demyelination should be considered as another "injury parameter" that is likely to determine the stability of axonal function.
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Affiliation(s)
- Vladislav Volman
- L-3 Applied Technologies/Simulation, Engineering, & Testing, 10770 Wateridge Circle, Suite 200, San Diego, CA, 92121, USA,
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Citicoline protects brain against closed head injury in rats through suppressing oxidative stress and calpain over-activation. Neurochem Res 2014; 39:1206-18. [PMID: 24691765 DOI: 10.1007/s11064-014-1299-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 03/23/2014] [Accepted: 03/26/2014] [Indexed: 10/25/2022]
Abstract
Citicoline, a natural compound that functions as an intermediate in the biosynthesis of cell membrane phospholipids, is essential for membrane integrity and repair. It has been reported to protect brain against trauma. This study was designed to investigate the protective effects of citicoline on closed head injury (CHI) in rats. Citicoline (250 mg/kg i.v. 30 min and 4 h after CHI) lessened body weight loss, and improved neurological functions significantly at 7 days after CHI. It markedly lowered brain edema and blood-brain barrier permeability, enhanced the activities of superoxide dismutase and the levels of glutathione, reduced the levels of malondialdehyde and lactic acid. Moreover, citicoline suppressed the activities of calpain, and enhanced the levels of calpastatin, myelin basic protein and αII-spectrin in traumatic tissue 24 h after CHI. Also, it attenuated the axonal and myelin sheath damage in corpus callosum and the neuronal cell death in hippocampal CA1 and CA3 subfields 7 days after CHI. These data demonstrate the protection of citicoline against white matter and grey matter damage due to CHI through suppressing oxidative stress and calpain over-activation, providing additional support to the application of citicoline for the treatment of traumatic brain injury.
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Rosenbluth J, Mierzwa A, Shroff S. Molecular architecture of myelinated nerve fibers: leaky paranodal junctions and paranodal dysmyelination. Neuroscientist 2013; 19:629-41. [PMID: 24122820 DOI: 10.1177/1073858413504627] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Myelinated nerve fibers have evolved to optimize signal propagation. Each myelin segment is attached to the axon by the unique paranodal axoglial junction (PNJ), a highly complex structure that serves to define axonal ion channel domains and to direct nodal action currents through adjacent nodes. Surprisingly, this junction does not entirely seal the paranodal myelin sheath to the axon and thus does not entirely isolate the perinodal space from the internodal periaxonal space. Rather the paranode is penetrated by extracellular pathways between the myelin sheath and the axolemma for movement of molecules and the flow of current to and from the internodal axon. This review summarizes past and current studies demonstrating these pathways and considers what functional roles they subserve. In addition, modern genetic engineering methods permit modification of individual PNJ constituents, which provides an opportunity to define their specific functions. One component in particular, the transverse bands, plays a key role in maintaining the structure and function of the PNJ. Loss of transverse bands results not in frank demyelination but rather in subtle dysmyelination, which causes significant functional impairment. The consequences of such subtle defects in the PNJ are considered along with the relevance of these studies to human diseases of myelin.
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Affiliation(s)
- Jack Rosenbluth
- 1Departments of Physiology and Neuroscience, New York University School of Medicine, New York, NY, USA
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Abstract
Dysfunction and/or disruption of nodes of Ranvier are now recognized as key contributors to the pathophysiology of various neurological diseases. One reason is that the excitable nodal axolemma contains a high density of Nav (voltage-gated Na+ channels) that are required for the rapid and efficient saltatory conduction of action potentials. Nodal physiology is disturbed by altered function, localization, and expression of voltage-gated ion channels clustered at nodes and juxtaparanodes, and by disrupted axon–glial interactions at paranodes. This paper reviews recent discoveries in molecular/cellular neuroscience, genetics, immunology, and neurology that highlight the critical roles of nodes of Ranvier in health and disease.
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