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Chari D, Basit R, Wiseman J, Chowdhury F. Simulating traumatic brain injury in vitro: developing high throughput models to test biomaterial based therapies. Neural Regen Res 2023; 18:289-292. [PMID: 35900405 PMCID: PMC9396524 DOI: 10.4103/1673-5374.346465] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Traumatic brain injuries are serious clinical incidents associated with some of the poorest outcomes in neurological practice. Coupled with the limited regenerative capacity of the brain, this has significant implications for patients, carers, and healthcare systems, and the requirement for life-long care in some cases. Clinical treatment currently focuses on limiting the initial neural damage with long-term care/support from multidisciplinary teams. Therapies targeting neuroprotection and neural regeneration are not currently available but are the focus of intensive research. Biomaterial-based interventions are gaining popularity for a range of applications including biomolecule and drug delivery, and to function as cellular scaffolds. Experimental investigations into the development of such novel therapeutics for traumatic brain injury will be critically underpinned by the availability of appropriate high throughput, facile, ethically viable, and pathomimetic biological model systems. This represents a significant challenge for researchers given the pathological complexity of traumatic brain injury. Specifically, there is a concerted post-injury response mounted by multiple neural cell types which includes microglial activation and astroglial scarring with the expression of a range of growth inhibitory molecules and cytokines in the lesion environment. Here, we review common models used for the study of traumatic brain injury (ranging from live animal models to in vitro systems), focusing on penetrating traumatic brain injury models. We discuss their relative advantages and drawbacks for the developmental testing of biomaterial-based therapies.
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2
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Slice Culture Modeling of CNS Viral Infection. Methods Mol Biol 2021. [PMID: 34033080 DOI: 10.1007/978-1-0716-1437-2_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
The complexity of the central nervous system (CNS) is not recapitulated in cell culture models. Thin slicing and subsequent culture of CNS tissue has become a valued means to study neuronal and glial biology within the context of the physiologically relevant tissue milieu. Modern membrane-interface slice culturing methodology allows for straightforward access to both CNS tissue and feeding medium, enabling experimental manipulations and analyses that would otherwise be impossible in vivo. CNS slices can be successfully maintained in culture for up to several weeks for investigation of evolving pathology and long-term intervention in models of chronic neurologic disease.Herein, membrane-interface slice culture models for studying viral encephalitis and myelitis are detailed, with emphasis on the use of these models for investigation of pathogenesis and evaluation of novel treatment strategies. We describe techniques to (1) generate brain and spinal cord slices from rodent donors, (2) virally infect slices, (3) monitor viral replication, (4) assess virally induced injury/apoptosis, (5) characterize "CNS-specific" cytokine production, and, (6) treat slices with cytokines/pharmaceuticals. Although our focus is on CNS viral infection, we anticipate that the described methods can be adapted to address a wide range of investigations within the fields of neuropathology, neuroimmunology, and neuropharmacology.
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Nguyen T, Al-Juboori MH, Walerstein J, Xiong W, Jin X. Impaired Glutamate Receptor Function Underlies Early Activity Loss of Ipsilesional Motor Cortex after Closed-Head Mild Traumatic Brain Injury. J Neurotrauma 2021; 38:2018-2029. [PMID: 33238833 DOI: 10.1089/neu.2020.7225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Although mild traumatic brain injury (mTBI) accounts for the majority of TBI patients, the effects and cellular and molecular mechanisms of mTBI on cortical neural circuits are still not well understood. Given the transient and non-specific functional deficits after mTBI, it is important to understand whether mTBI causes functional deficits of the brain and the underlying mechanism, particularly during the early stage after injury. Here, we used in vivo optogenetic motor mapping to determine longitudinal changes in cortical motor map and in vitro calcium imaging to study how changes in cortical excitability and calcium signals may contribute to the motor deficits in a closed-head mTBI model. In channelrhodopsin 2 (ChR2)-expressing transgenic mice, we recorded electromyograms (EMGs) from bicep muscles induced by scanning blue laser on the motor cortex. There were significant decreases in the size and response amplitude of motor maps of the injured cortex at 2 h post-mTBI, but an increase in motor map size of the contralateral cortex in 12 h post-mTBI, both of which recovered to baseline level in 24 h. Calcium imaging of cortical slices prepared from green fluorescent calmodulin proteins-expressing transgenic mice showed a lower amplitude, but longer duration, of calcium transients of the injured cortex in 2 h post-mTBI. Blockade of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid or N-methyl-d-aspartate receptors resulted in smaller amplitude of calcium transients, suggesting impaired function of both receptor types. Imaging of calcium transients evoked by glutamate uncaging revealed reduced response amplitudes and longer duration in 2, 12, and 24 h after mTBI. Higher percentages of neurons of the injured cortex had a longer latency period after uncaging than that of the uninjured neurons. The results suggest that impaired glutamate neurotransmission contributes to functional deficits of the motor cortex in vivo, which supports enhancing glutamate neurotransmission as a potential therapeutic approach for the treatment of mTBI.
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Affiliation(s)
- Tyler Nguyen
- Indiana Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute and Department of Anatomy, Cell Biology, and Physiology, Stark Neuroscience Research Institute and Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA.,Medical Neuroscience Program, Stark Neuroscience Research Institute, Stark Neuroscience Research Institute and Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Mohammed Haider Al-Juboori
- Indiana Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute and Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Jakub Walerstein
- Indiana Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute and Department of Anatomy, Cell Biology, and Physiology, Stark Neuroscience Research Institute and Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Wenhui Xiong
- Indiana Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute and Department of Anatomy, Cell Biology, and Physiology, Stark Neuroscience Research Institute and Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Xiaoming Jin
- Indiana Spinal Cord and Brain Injury Research Group, Stark Neuroscience Research Institute and Department of Anatomy, Cell Biology, and Physiology, Stark Neuroscience Research Institute and Department of Neurological Surgery, Indiana University School of Medicine, Indianapolis, Indiana, USA
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Rosas-Hernandez H, Burks SM, Cuevas E, Ali SF. Stretch-Induced Deformation as a Model to Study Dopaminergic Dysfunction in Traumatic Brain Injury. Neurochem Res 2019; 44:2546-2555. [DOI: 10.1007/s11064-019-02872-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 01/08/2023]
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Chierto E, Simon A, Castoldi F, Meffre D, Cristinziano G, Sapone F, Carrete A, Borderie D, Etienne F, Rannou F, Morrison B, Massaad C, Jafarian-Tehrani M. Mechanical Stretch of High Magnitude Provokes Axonal Injury, Elongation of Paranodal Junctions, and Signaling Alterations in Oligodendrocytes. Mol Neurobiol 2019; 56:4231-4248. [PMID: 30298339 PMCID: PMC6505516 DOI: 10.1007/s12035-018-1372-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 09/27/2018] [Indexed: 12/13/2022]
Abstract
Increasing findings suggest that demyelination may play an important role in the pathophysiology of brain injury, but the exact mechanisms underlying such damage are not well known. Mechanical tensile strain of brain tissue occurs during traumatic brain injury. Several studies have investigated the cellular and molecular events following a static tensile strain of physiological magnitude on individual cells such as oligodendrocytes. However, the pathobiological impact of high-magnitude mechanical strain on oligodendrocytes and myelinated fibers remains under investigated. In this study, we reported that an applied mechanical tensile strain of 30% on mouse organotypic culture of cerebellar slices induced axonal injury and elongation of paranodal junctions, two hallmarks of brain trauma. It was also able to activate MAPK-ERK1/2 signaling, a stretch-induced responsive pathway. The same tensile strain applied to mouse oligodendrocytes in primary culture induced a profound damage to cell morphology, partial cell loss, and a decrease of myelin protein expression. The lower tensile strain of 20% also caused cell loss and the remaining oligodendrocytes appeared retracted with decreased myelin protein expression. Finally, high-magnitude tensile strain applied to 158N oligodendroglial cells altered myelin protein expression, dampened MAPK-ERK1/2 and MAPK-p38 signaling, and enhanced the production of reactive oxygen species. The latter was accompanied by increased protein oxidation and an alteration of anti-oxidant defense that was strain magnitude-dependent. In conclusion, mechanical stretch of high magnitude provokes axonal injury with significant alterations in oligodendrocyte biology that could initiate demyelination.
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Affiliation(s)
- Elena Chierto
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Anne Simon
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Francesca Castoldi
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Delphine Meffre
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Giulia Cristinziano
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Francesca Sapone
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Alex Carrete
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Didier Borderie
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
- Service de Diagnostic Biologique Automatisé, Hôpitaux Universitaires Paris Centre - Groupe Hospitalier Cochin (AP-HP), 27 rue du faubourg saint Jacques, 75679, Paris Cedex 14, France
| | - François Etienne
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
- Plateforme de mécanobiologie, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, 45 rue des Saints-Pères, 75006, Paris, France
| | - François Rannou
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
- Plateforme de mécanobiologie, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, Université Paris Descartes, 45 rue des Saints-Pères, 75006, Paris, France
- Service de Rééducation et de Réadaptation de l'Appareil Locomoteur et des Pathologies du Rachis, Hôpitaux Universitaires Paris Centre - Groupe Hospitalier Cochin (AP-HP), 27 rue du faubourg saint Jacques, 75679, Paris Cedex 14, France
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, 1210 Amsterdam Ave, 351 Engineering Terrace, MC8904, New York, NY, 10027, USA
| | - Charbel Massaad
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France
| | - Mehrnaz Jafarian-Tehrani
- INSERM UMR-S 1124, Université Paris Descartes, Sorbonne Paris Cité, Faculté des Sciences Fondamentales et Biomédicales, 45 rue des Saints-Pères, 75006, Paris, France.
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6
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Post A, Dawson L, Hoshizaki TB, Gilchrist MD, Cusimano MD. The influence of impact source on variables associated with strain for impacts in ice hockey. Comput Methods Biomech Biomed Engin 2019; 22:713-726. [DOI: 10.1080/10255842.2019.1588255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Andrew Post
- St. Michael’s Hospital, University of Toronto, Toronto, Ontario, Canada
- Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | - Lauren Dawson
- Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Michael D. Gilchrist
- School of Mechanical & Materials Engineering, University College Dublin, Dublin, Ireland
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7
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The Role of MicroRNA in Traumatic Brain Injury. Neuroscience 2017; 367:189-199. [DOI: 10.1016/j.neuroscience.2017.10.046] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/26/2017] [Accepted: 10/30/2017] [Indexed: 12/13/2022]
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Abstract
Traumatic Brain Injury (TBI) remains a significant cause of mortality and morbidity, affecting individuals of all age groups. Much remains to be learned about its complex pathophysiology, with a view to designing effective neuroprotective strategies to protect sublethally injured brain tissue that would otherwise die in secondary injury processes. Experimental in vivo models offer the potential to study TBI in the laboratory, however, treatments that were neuroprotective in animals have, thus far, largely failed to translate in human clinical studies. In vitro models of neurotrauma can be used to study specific pathophysiological cascades — individually and without confounding factors — and to test potential neuroprotective strategies. These in vitro models include transection, compression, barotrauma, acceleration, hydrodynamic, chemical injury and cell-stretch methodologies. Various cell culture systems can also be utilised, including brain-on-a-chip, immortalised cell lines, primary cultures, acute preparations and organotypic cultures. Potential positive outcomes of the increased use of in vitro platforms to study TBI would be the refinement of in vivo experiments, as well as enhanced translation of the results into clinically meaningful neuroprotective strategies for the future. In addition, the replacement of in vivo experiments by suitable in vitro studies would lead to a welcome reduction in the numbers of animal procedures in this ethically-challenging field.
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Affiliation(s)
- Ashwin Kumaria
- Department of Neurosurgery, Queen's Medical Centre, Nottingham NG7 2UH, UK
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Hakimizadeh E, Shamsizadeh A, Roohbakhsh A, Arababadi MK, Hajizadeh MR, Shariati M, Rahmani MR, Allahtavakoli M. Inhibition of transient receptor potential vanilloid-1 confers neuroprotection, reduces tumor necrosis factor-alpha, and increases IL-10 in a rat stroke model. Fundam Clin Pharmacol 2017; 31:420-428. [PMID: 28199737 DOI: 10.1111/fcp.12279] [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: 11/07/2016] [Revised: 01/15/2017] [Accepted: 02/10/2017] [Indexed: 12/30/2022]
Abstract
Stroke is a major cause of mortality and long-term disability in adults. Transient receptor potential vanilloid-1 (TRPV1) plays a crucial role in neuroinflammation. In this study, the effects of TRPV1 agonist (capsaicin) and antagonist (AMG9810) on cerebral ischemia were investigated. Forty male Wistar rats were assigned to the following experimental groups: sham, vehicle) ischemic), AMG9810 (selective TRPV1 antagonist, 0.5 mg/kg; 3 h after stroke), and capsaicin (1 mg/kg; 3 h after stroke). Stroke was induced by permanent middle cerebral artery occlusion and neurological deficits were evaluated 1, 3, and 7 days after stroke. Then, infarct volume, brain edema, body temperature, mRNA expression of TRPV1, and serum concentrations of tumor necrosis factor-alpha (TNF-α) and IL-10 were measured. Compared to the vehicle group, AMG9810 significantly decreased the infarct volume (P < 0.01). Latency for the removal of sticky labels from the forepaw and the hanging time were significantly decreased and increased, respectively, following administration of AMG9810 (P < 0.01 and P < 0.001 vs. vehicle) 3 and 7 days after stroke. Compared to the sham group, the mRNA expression of TRPV1 was significantly increased in vehicle group (P < 0.01). Administration of AMG9810 significantly increased the anti-inflammatory cytokine IL-10 and decreased the inflammatory cytokine TNF-α (P < 0.05). Moreover, our results indicate that AMG9810 might a promising candidate for the hypothermic treatment of stroke. The findings also suggest a key role for AMG9810 in reducing inflammation after stroke and imply that TRPV1 could be a potential target for the treatment of ischemic stroke.
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Affiliation(s)
- Elham Hakimizadeh
- Physiology-Pharmacology Research Center, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
| | - Ali Shamsizadeh
- Department of Physiology and Pharmacology, School of Medicine, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
| | - Ali Roohbakhsh
- Pharmaceutical Research Center, University street, Mashhad University of Medical Sciences, Mashhad, 1394491388, Iran
| | - Mohammad Kazemi Arababadi
- Department of Laboratory Sciences, Faculty of Paramedicine, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
| | - Mohammad R Hajizadeh
- Department of Biochemistry, Molecular Medicine Research Center, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
| | - Mehdi Shariati
- Department of Anatomy, School of Medicine, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
| | - Mohammad R Rahmani
- Department of Physiology and Pharmacology, School of Medicine, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
| | - Mohammad Allahtavakoli
- Department of Physiology and Pharmacology, School of Medicine, Emam Ali Boulevard, Rafsanjan University of Medical Sciences, Rafsanjan, 7717933777, Iran
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Miller AP, Shah AS, Aperi BV, Kurpad SN, Stemper BD, Glavaski-Joksimovic A. Acute death of astrocytes in blast-exposed rat organotypic hippocampal slice cultures. PLoS One 2017; 12:e0173167. [PMID: 28264063 PMCID: PMC5338800 DOI: 10.1371/journal.pone.0173167] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 02/16/2017] [Indexed: 01/06/2023] Open
Abstract
Blast traumatic brain injury (bTBI) affects civilians, soldiers, and veterans worldwide and presents significant health concerns. The mechanisms of neurodegeneration following bTBI remain elusive and current therapies are largely ineffective. It is important to better characterize blast-evoked cellular changes and underlying mechanisms in order to develop more effective therapies. In the present study, our group utilized rat organotypic hippocampal slice cultures (OHCs) as an in vitro system to model bTBI. OHCs were exposed to either 138 ± 22 kPa (low) or 273 ± 23 kPa (high) overpressures using an open-ended helium-driven shock tube, or were assigned to sham control group. At 2 hours (h) following injury, we have characterized the astrocytic response to a blast overpressure. Immunostaining against the astrocytic marker glial fibrillary acidic protein (GFAP) revealed acute shearing and morphological changes in astrocytes, including clasmatodendrosis. Moreover, overlap of GFAP immunostaining and propidium iodide (PI) indicated astrocytic death. Quantification of the number of dead astrocytes per counting area in the hippocampal cornu Ammonis 1 region (CA1), demonstrated a significant increase in dead astrocytes in the low- and high-blast, compared to sham control OHCs. However only a small number of GFAP-expressing astrocytes were co-labeled with the apoptotic marker Annexin V, suggesting necrosis as the primary type of cell death in the acute phase following blast exposure. Moreover, western blot analyses revealed calpain mediated breakdown of GFAP. The dextran exclusion additionally indicated membrane disruption as a potential mechanism of acute astrocytic death. Furthermore, although blast exposure did not evoke significant changes in glutamate transporter 1 (GLT-1) expression, loss of GLT-1-expressing astrocytes suggests dysregulation of glutamate uptake following injury. Our data illustrate the profound effect of blast overpressure on astrocytes in OHCs at 2 h following injury and suggest increased calpain activity and membrane disruption as potential underlying mechanisms.
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Affiliation(s)
- Anna P. Miller
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Alok S. Shah
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Brandy V. Aperi
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Shekar N. Kurpad
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Brian D. Stemper
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
| | - Aleksandra Glavaski-Joksimovic
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin, United States of America
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Anthonymuthu TS, Kenny EM, Bayır H. Therapies targeting lipid peroxidation in traumatic brain injury. Brain Res 2016; 1640:57-76. [PMID: 26872597 PMCID: PMC4870119 DOI: 10.1016/j.brainres.2016.02.006] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 02/06/2023]
Abstract
Lipid peroxidation can be broadly defined as the process of inserting a hydroperoxy group into a lipid. Polyunsaturated fatty acids present in the phospholipids are often the targets for peroxidation. Phospholipids are indispensable for normal structure of membranes. The other important function of phospholipids stems from their role as a source of lipid mediators - oxygenated free fatty acids that are derived from lipid peroxidation. In the CNS, excessive accumulation of either oxidized phospholipids or oxygenated free fatty acids may be associated with damage occurring during acute brain injury and subsequent inflammatory responses. There is a growing body of evidence that lipid peroxidation occurs after severe traumatic brain injury in humans and correlates with the injury severity and mortality. Identification of the products and sources of lipid peroxidation and its enzymatic or non-enzymatic nature is essential for the design of mechanism-based therapies. Recent progress in mass spectrometry-based lipidomics/oxidative lipidomics offers remarkable opportunities for quantitative characterization of lipid peroxidation products, providing guidance for targeted development of specific therapeutic modalities. In this review, we critically evaluate previous attempts to use non-specific antioxidants as neuroprotectors and emphasize new approaches based on recent breakthroughs in understanding of enzymatic mechanisms of lipid peroxidation associated with specific death pathways, particularly apoptosis. We also emphasize the role of different phospholipases (calcium-dependent and -independent) in hydrolysis of peroxidized phospholipids and generation of pro- and anti-inflammatory lipid mediators. This article is part of a Special Issue entitled SI:Brain injury and recovery.
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Affiliation(s)
- Tamil Selvan Anthonymuthu
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Elizabeth Megan Kenny
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Hülya Bayır
- Department of Critical Care Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Environmental and Occupational Health, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Center for Free Radical and Antioxidant Health, University of Pittsburgh, Pittsburgh, PA 15219, USA; Safar Center for Resuscitation Research, University of Pittsburgh, Pittsburgh, PA 15260, USA; Childrens׳s Hospital of Pittsburgh of UPMC, University of Pittsburgh, Pittsburgh, PA 15224, USA.
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12
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Lamprecht MR, Elkin BS, Kesavabhotla K, Crary JF, Hammers JL, Huh JW, Raghupathi R, Morrison B. Strong Correlation of Genome-Wide Expression after Traumatic Brain Injury In Vitro and In Vivo Implicates a Role for SORLA. J Neurotrauma 2016; 34:97-108. [PMID: 26919808 DOI: 10.1089/neu.2015.4306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The utility of in vitro models of traumatic brain injury (TBI) depends on their ability to recapitulate the in vivo TBI cascade. In this study, we used a genome-wide approach to compare changes in gene expression at several time points post-injury in both an in vitro model and an in vivo model of TBI. We found a total of 2073 differentially expressed genes in our in vitro model and 877 differentially expressed genes in our in vivo model when compared to noninjured controls. We found a strong correlation in gene expression changes between the two models (r = 0.69), providing confidence that the in vitro model represented at least part of the in vivo injury cascade. From these data, we searched for genes with significant changes in expression over time (analysis of covariance) and identified sorting protein-related receptor with A-type repeats (SORLA). SORLA directs amyloid precursor protein to the recycling pathway by direct binding and away from amyloid-beta producing enzymes. Mutations of SORLA have been linked to Alzheimer's disease (AD). We confirmed downregulation of SORLA expression in organotypic hippocampal slice cultures by immunohistochemistry and Western blotting and present preliminary data from human tissue that is consistent with these experimental results. Together, these data suggest that the in vitro model of TBI used in this study strongly recapitulates the in vivo TBI pathobiology and is well suited for future mechanistic or therapeutic studies. The data also suggest the possible involvement of SORLA in the post-traumatic cascade linking TBI to AD.
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Affiliation(s)
- Michael R Lamprecht
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - Benjamin S Elkin
- 1 Department of Biomedical Engineering, Columbia University , New York, New York.,2 MEA Forensic Engineers & Scientists , Mississauga, Ontario, Canada
| | - Kartik Kesavabhotla
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
| | - John F Crary
- 3 Department of Pathology, Fishberg Department of Neuroscience, Friedman Brain Institute , and the Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jennifer L Hammers
- 4 Office of Chief Medical Examiner , City of New York, New York, New York
| | - Jimmy W Huh
- 5 Department of Anesthesia and Critical Care, Children's Hospital of Philadelphia , Philadelphia, Pennsylvania
| | - Ramesh Raghupathi
- 6 Department of Neurobiology and Anatomy, Drexel University College of Medicine , Philadelphia, Pennsylvania
| | - Barclay Morrison
- 1 Department of Biomedical Engineering, Columbia University , New York, New York
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13
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Post A, Blaine Hoshizaki T. Rotational Acceleration, Brain Tissue Strain, and the Relationship to Concussion. J Biomech Eng 2015; 137:1926227. [DOI: 10.1115/1.4028983] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Indexed: 11/08/2022]
Abstract
The mechanisms of concussion have been investigated by many researchers using a variety of methods. However, there remains much debate over the relationships between head kinematics from an impact and concussion. This review presents the links between research conducted in different disciplines to better understand the relationship between linear and rotational acceleration and brain strains that have been postulated as the root cause of concussion. These concepts are important when assigning performance variables for helmet development, car design, and protective innovation research.
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Affiliation(s)
- Andrew Post
- School of Human Kinetics, Faculty of Health Science, University of Ottawa, 200 Lees, Room A106, Ottawa, ON K1S 5S9, Canada e-mail:
| | - T. Blaine Hoshizaki
- School of Human Kinetics, Faculty of Health Science, University of Ottawa, 200 Lees, Room A106, Ottawa, ON K1S 5S9, Canada
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Hopkins AM, DeSimone E, Chwalek K, Kaplan DL. 3D in vitro modeling of the central nervous system. Prog Neurobiol 2015; 125:1-25. [PMID: 25461688 PMCID: PMC4324093 DOI: 10.1016/j.pneurobio.2014.11.003] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2014] [Revised: 10/12/2014] [Accepted: 11/15/2014] [Indexed: 12/15/2022]
Abstract
There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here.
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Affiliation(s)
- Amy M Hopkins
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA
| | - Elise DeSimone
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA
| | - Karolina Chwalek
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, Science & Technology Center, 4 Colby Street, Medford, MA 02155, USA.
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Tuttolomondo A, Pecoraro R, Pinto A. Studies of selective TNF inhibitors in the treatment of brain injury from stroke and trauma: a review of the evidence to date. DRUG DESIGN DEVELOPMENT AND THERAPY 2014; 8:2221-38. [PMID: 25422582 PMCID: PMC4232043 DOI: 10.2147/dddt.s67655] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The brain is very actively involved in immune-inflammatory processes, and the response to several trigger factors such as trauma, hemorrhage, or ischemia causes the release of active inflammatory substances such as cytokines, which are the basis of second-level damage. During brain ischemia and after brain trauma, the intrinsic inflammatory mechanisms of the brain, as well as those of the blood, are mediated by leukocytes that communicate with each other through cytokines. A neuroinflammatory cascade has been reported to be activated after a traumatic brain injury (TBI) and this cascade is due to the release of pro- and anti-inflammatory cytokines and chemokines. Microglia are the first sources of this inflammatory cascade in the brain setting. Also in an ischemic stroke setting, an important mediator of this inflammatory reaction is tumor necrosis factor (TNF)-α, which seems to be involved in every phase of stroke-related neuronal damage such as inflammatory and prothrombotic events. TNF-α has been shown to have an important role within the central nervous system; its properties include activation of microglia and astrocytes, influence on blood–brain barrier permeability, and influences on glutamatergic transmission and synaptic plasticity. TNF-α increases the amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor density on the cell surface and simultaneously decreases expression of γ-aminobutyric acid receptor cells, and these effects are related to a direct neurotoxic effect. Several endogenous mechanisms regulate TNF-α activity during inflammatory responses. Endogenous inhibitors of TNF include prostaglandins, cyclic adenosine monophosphate, and glucocorticoids. Etanercept, a biologic TNF antagonist, has a reported effect of decreasing microglia activation in experimental models, and it has been used therapeutically in animal models of ischemic and traumatic neuronal damage. In some studies using animal models, researchers have reported a limitation of TBI-induced cerebral ischemia due to etanercept action, amelioration of brain contusion signs, as well as motor and cognitive dysfunction. On this basis, it appears that etanercept may improve outcomes of TBI by penetrating into the cerebrospinal fluid in rats, although further studies in humans are needed to confirm these interesting and suggestive experimental findings.
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Affiliation(s)
- Antonino Tuttolomondo
- Biomedical Department of Internal and Specialistic Medicine, University of Palermo, Palermo, Italy
| | - Rosaria Pecoraro
- Biomedical Department of Internal and Specialistic Medicine, University of Palermo, Palermo, Italy
| | - Antonio Pinto
- Biomedical Department of Internal and Specialistic Medicine, University of Palermo, Palermo, Italy
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Pharmacologic modulation of cerebral metabolic derangement and excitotoxicity in a porcine model of traumatic brain injury and hemorrhagic shock. Surgery 2013; 154:234-43. [PMID: 23889951 DOI: 10.1016/j.surg.2013.04.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2013] [Accepted: 04/03/2013] [Indexed: 01/28/2023]
Abstract
BACKGROUND Cerebral metabolic derangement and excitotoxicity play critical roles in the evolution of traumatic brain injury (TBI). We have shown previously that treatment with large doses of valproic acid (VPA) decreases the size of brain lesion. The goal of this experiment was to determine whether this effect was owing to metabolic modulation. METHODS Yorkshire swine (n = 9) underwent a protocol of computer-controlled TBI and 40% hemorrhage and were resuscitated randomly with either fresh frozen plasma equal to the volume of shed blood (FFP; n = 4) or VPA (300 mg/kg) and FFP (FFP+VPA; n = 5). Hemodynamics, brain oxygenation, and blood glucose were monitored continuously for 6 hours after resuscitation. Cerebral microdialysis was used to measure glucose, lactate, pyruvate, glutamate, and glycerol levels at baseline, 1 and 2 hours post-shock, post-resuscitation (PR), and at 2, 4, and 6 hours PR. Brain samples from the injured side were then separated into mitochondrial and cytosolic fractions, and activity of pyruvate dehydrogenase complex (PDH) was measured using a dipstick assay kit. RESULTS At baseline, there was no difference in brain lactate, pyruvate, glycerol, and glutamate concentrations between the groups. At all time points, there were no differences between the groups in brain oxygenation, cerebral perfusion pressure, or blood and brain glucose concentrations. After VPA infusion (PR time point), however, there was sustained decrease in lactate (0.91 ± 0.47 vs 2.54 ± 0.59 mmol/L; P < .01) and pyruvate (12.80 ± 4.89 vs 46.25 ± 9.22; P < .001) concentrations compared with the FFP alone group, implying superior glucose utilization for ATP production. There was also a decrease in concentrations of glutamate (6.64 ± 3.68 vs 42.25 ± 27.07 mmol/L; P = .02) and glycerol (19.20 ± 6.76 vs 69.75 ± 30.07 mmol/L; P = .01), in the FFP+VPA group, signifying lesser degree of excitotoxicity and brain damage, respectively. Brain PDH activity was greater in the mitochondrial fractions (5,984 ± 504 adjusted volume intensity [INT] × mm(2) vs 4,332 ± 1,055 INT × mm(2); P = .04) and lower in cytosolic fractions in the FFP+VPA group (1,597 ± 1,395 vs 4,026 ± 1,067 INT × mm(2); P = .03), indicating better mitochondrial membrane function and enhanced mitochondrial PDH retention. CONCLUSION VPA treatment attenuates perturbation of post-traumatic cerebral metabolism by mitigating mitochondrial dysfunction, and decreases glutamate-mediated excitotoxic damage. These properties could explain its effectiveness in decreasing lesion size and post-traumatic cerebral edema.
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Koo HM, Lee SM, Kim MH. Spontaneous Wheel Running Exercise Induces Brain Recovery via Neurotrophin-3 Expression Following Experimental Traumatic Brain Injury in Rats. J Phys Ther Sci 2013; 25:1103-7. [PMID: 24259924 PMCID: PMC3818758 DOI: 10.1589/jpts.25.1103] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 04/19/2013] [Indexed: 11/24/2022] Open
Abstract
[Purpose] The aim of the present study was to investigate the expression of
neurotrophin-3 (NT-3) after applying spontaneous wheel running exercises (SWR) after
experimental traumatic brain injury (TBI). [Subjects and Methods] Thirty male
Sprague-Dawley rats were divided into 3 groups; 20 rats were subjected to controlled
cortical impact for TBI, and then, animals were randomly collected from the SWR group and
subjected to wheel running exercise for 3 weeks. Ten rats were not subjected to any injury
or running exercise to compare with the effect of TBI and SWR. Immunohistochemistry,
Western blotting, skilled ladder rung walking test, and 2,3,5-triphenyltetrazolium
chloride staining analysis for the evaluation of NT-3 expression were used to assess brain
damage and recovery. [Results] The TBI-induced decrease in NT-3 expression was recovered
by wheel running exercise. Moreover, decreased ischemic volume and progressive
neurobehavioral outcome were observed in the SWR group. [Conclusion] Spontaneous running
exercise promotes brain recovery and motor function through an increase in expression of
NT-3.
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Affiliation(s)
- Hyun Mo Koo
- Department of Physical Therapy, College of Science, Kyungsung University
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Abstract
The complexity of the central nervous system (CNS) is not recapitulated in cell culture models. Thin slicing and subsequent culture of CNS tissue has become a valued means to study neuronal and glial biology within the context of the physiologically relevant tissue milieu. Modern membrane-interface slice culturing methodology allows straightforward access to both CNS tissue and feeding medium, enabling experimental manipulations and analyses that would otherwise be impossible in vivo. CNS slices can be successfully maintained in culture for up to several weeks for investigation of evolving pathology and long-term intervention in models of chronic neurologic disease.Herein, membrane-interface slice culture models for studying viral encephalitis and myelitis are detailed, with emphasis on the use of these models for investigation of pathogenesis and evaluation of novel treatment strategies. We describe techniques to (1) generate brain and spinal cord slices from rodent donors, (2) virally infect slices, (3) assess virally induced injury/apoptosis, (4) characterize "CNS-specific" cytokine production, and (5) treat slices with cytokines/pharmaceuticals. Although our focus is on CNS viral infection, we anticipate that the described methods can be adapted to address a wide range of investigations within the fields of neuropathology, neuroimmunology, and neuropharmacology.
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Abstract
In vitro models of traumatic brain injury (TBI) are helping elucidate the pathobiological mechanisms responsible for dysfunction and delayed cell death after mechanical stimulation of the brain. Researchers have identified compounds that have the potential to break the chain of molecular events set in motion by traumatic injury. Ultimately, the utility of in vitro models in identifying novel therapeutics will be determined by how closely the in vitro cascades recapitulate the sequence of cellular events that play out in vivo after TBI. Herein, the major in vitro models are reviewed, and a discussion of the physical injury mechanisms and culture preparations is employed. A comparison between the efficacy of compounds tested in vitro and in vivo is presented as a critical evaluation of the fidelity of in vitro models to the complex pathobiology that is TBI. We conclude that in vitro models were greater than 88% predictive of in vivo results.
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Affiliation(s)
- Barclay Morrison
- Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA.
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Zinc neurotoxicity to hippocampal neurons in vitro induces ubiquitin conjugation that requires p38 activation. Brain Res 2012; 1438:1-7. [DOI: 10.1016/j.brainres.2011.12.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/15/2011] [Accepted: 12/14/2011] [Indexed: 11/21/2022]
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Avila MA, Sell SL, Hawkins BE, Hellmich HL, Boone DR, Crookshanks JM, Prough DS, DeWitt DS. Cerebrovascular connexin expression: effects of traumatic brain injury. J Neurotrauma 2011; 28:1803-11. [PMID: 21895483 PMCID: PMC3172862 DOI: 10.1089/neu.2011.1900] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) results in dysfunction of the cerebrovasculature. Gap junctions coordinate vasomotor responses and evidence suggests that they are involved in cerebrovascular dysfunction after TBI. Gap junctions are comprised of connexin proteins (Cxs), of which Cx37, Cx40, Cx43, and Cx45 are expressed in vascular tissue. This study tests the hypothesis that TBI alters Cx mRNA and protein expression in cerebral vascular smooth muscle and endothelial cells. Anesthetized (1.5% isoflurane) male Sprague-Dawley rats received sham or fluid-percussion TBI. Two, 6, and 24 h after, cerebral arteries were harvested, fresh-frozen for RNA isolation, or homogenized for Western blot analysis. Cerebral vascular endothelial and smooth muscle cells were selected from frozen sections using laser capture microdissection. RNA was quantified by ribonuclease protection assay. The mRNA for all four Cx genes showed greater expression in the smooth muscle layer compared to the endothelial layer. Smooth muscle Cx43 mRNA expression was reduced 2 h and endothelial Cx45 mRNA expression was reduced 24 h after injury. Western blot analysis revealed that Cx40 protein expression increased, while Cx45 protein expression decreased 24 h after injury. These studies revealed significant changes in the mRNA and protein expression of specific vascular Cxs after TBI. This is the first demonstration of cell type-related differential expression of Cx mRNA in cerebral arteries, and is a first step in evaluating the effects of TBI on gap junction communication in the cerebrovasculature.
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Affiliation(s)
| | | | - Bridget E. Hawkins
- Charles Allen Laboratories, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas
| | - Helen L. Hellmich
- Charles Allen Laboratories, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas
| | - Debbie R. Boone
- Charles Allen Laboratories, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas
| | - Jeanna M. Crookshanks
- Charles Allen Laboratories, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas
| | - Donald S. Prough
- Charles Allen Laboratories, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas
| | - Douglas S. DeWitt
- Charles Allen Laboratories, Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas
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Abstract
The rising awareness of the long-term health problems associated with concussions re-emphasizes the need for understanding the mechanical etiology of concussions. This article reviews past studies defining the common mechanisms for mild traumatic brain injury and summarizes efforts to convert the external input to the head (force, acceleration, and velocity) into estimates of motions and deformations of the brain that occur during mild traumatic brain injury. Studies of how these mechanical conditions contribute to the cellular mechanisms of damage in mild traumatic brain injury are reviewed. Finally, future directions for improving understanding concussion biomechanics are discussed.
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Morrison B, Cullen DK, LaPlaca M. In Vitro Models for Biomechanical Studies of Neural Tissues. NEURAL TISSUE BIOMECHANICS 2011. [DOI: 10.1007/8415_2011_79] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Fahlenkamp AV, Coburn M, Czaplik M, Ryang YM, Kipp M, Rossaint R, Beyer C. Expression analysis of the early chemokine response 4 h after in vitro traumatic brain injury. Inflamm Res 2010; 60:379-87. [PMID: 21104293 DOI: 10.1007/s00011-010-0281-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 10/15/2010] [Accepted: 11/02/2010] [Indexed: 10/18/2022] Open
Abstract
OBJECTIVE AND DESIGN The importance of cytokine- and chemokine-mediated neuroinflammation in the progress of brain injury is becoming increasingly evident. We investigated the early local cytokine and chemokine expression and the development of tissue injury after moderate mechanical hippocampus trauma. MATERIAL OR SUBJECTS Mouse organotypic hippocampal slice cultures. TREATMENT Drop-weight trauma in the CA1 region of the hippocampus. METHODS Staining of necrotic tissue, PCR array and evaluation, real-time PCR, statistical analysis with a two-tailed, independent t test. RESULTS At 12 and 24 h after trauma, the tissue injury spread from the primary mechanical lesion to the entire hippocampal formation. A pronounced up-regulation of distinct chemokine transcripts was found 4 h after in vitro traumatic brain injury which preceded the development of the secondary injury. CONCLUSIONS The enhanced expression of inflammatory genes might contribute to the development of the secondary trauma and could pinpoint future neuroinflammatory and neuroprotective targets for research and treatment.
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Affiliation(s)
- Astrid V Fahlenkamp
- Department of Anesthesiology, University Hospital Aachen, RWTH Aachen, Pauwelsstr. 30, 52074, Aachen, Germany
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Loetscher PD, Rossaint J, Rossaint R, Weis J, Fries M, Fahlenkamp A, Ryang YM, Grottke O, Coburn M. Argon: neuroprotection in in vitro models of cerebral ischemia and traumatic brain injury. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:R206. [PMID: 20017934 PMCID: PMC2811924 DOI: 10.1186/cc8214] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 11/23/2009] [Accepted: 12/17/2009] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Recently, it has been shown in several experimental settings that the noble gases xenon and helium have neuroprotective properties. In this study we tested the hypothesis that the noble gas argon has a neuroprotective potential as well. Since traumatic brain injury and stroke are widespread and generate an enormous economic and social burden, we investigated the possible neuroprotective effect in in vitro models of traumatic brain injury and cerebral ischemia. METHODS Organotypic hippocampal slice cultures from mice pups were subjected to either oxygen-glucose deprivation or to a focal mechanical trauma and subsequently treated with three different concentrations (25, 50 and 74%) of argon immediately after trauma or with a two-or-three-hour delay. After 72 hours of incubation tissue injury assessment was performed using propidium iodide, a staining agent that becomes fluorescent when it diffuses into damaged cells via disintegrated cell membranes. RESULTS We could show argon's neuroprotective effects at different concentrations when applied directly after oxygen-glucose deprivation or trauma. Even three hours after application, argon was still neuroprotective. CONCLUSIONS Argon showed a neuroprotective effect in both in vitro models of oxygen-glucose deprivation and traumatic brain injury. Our promising results justify further in vivo animal research.
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Affiliation(s)
- Philip D Loetscher
- Department of Anesthesiology, University Hospital of the RWTH Aachen, Aachen, Germany.
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Chen YC, Smith DH, Meaney DF. In-vitro approaches for studying blast-induced traumatic brain injury. J Neurotrauma 2009; 26:861-76. [PMID: 19397424 DOI: 10.1089/neu.2008.0645] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Traumatic brain injury caused by explosive or blast events is currently divided into four phases: primary, secondary, tertiary, and quaternary blast injury. These phases of blast-induced traumatic brain injury (bTBI) are biomechanically distinct, and can be modeled in both in-vivo and in-vitro systems. The purpose of this review is to consider the mechanical phases of bTBI, how these phases are reproduced with in-vitro models, and to review findings from these models to assess how each phase of bTBI can be examined in more detail. Highlighted are some important gaps in the literature that may be addressed in the future to better identify the exact contributing mechanisms for bTBI. These in-vitro models, viewed in combination with in-vivo models and clinical studies, can be used to assess both the mechanisms and possible treatments for this type of trauma.
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Affiliation(s)
- Yung Chia Chen
- Departments of Bioengineering, University of Pennsylvania, 210 S. 33rd Street, Philadelphia, PA 19104, USA
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Rossaint J, Rossaint R, Weis J, Fries M, Rex S, Coburn M. Propofol: neuroprotection in an in vitro model of traumatic brain injury. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2009; 13:R61. [PMID: 19397790 PMCID: PMC2689510 DOI: 10.1186/cc7795] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 03/18/2009] [Accepted: 04/27/2009] [Indexed: 02/01/2023]
Abstract
Introduction The anaesthetic agent propofol (2,6-diisopropylphenol) has been shown to be an effective neuroprotective agent in different in vitro models of brain injury induced by oxygen and glucose deprivation. We examined its neuroprotective properties in an in vitro model of traumatic brain injury. Methods In this controlled laboratory study organotypic hippocampal brain-slice cultures were gained from six- to eight-day-old mice pups. After 14 days in culture, hippocampal brain slices were subjected to a focal mechanical trauma and subsequently treated with different molar concentrations of propofol under both normo- and hypothermic conditions. After 72 hours of incubation, tissue injury assessment was performed using propidium iodide (PI), a staining agent that becomes fluorescent only when it enters damaged cells via perforated cell membranes. Inside the cell, PI forms a fluorescent complex with nuclear DNA. Results A dose-dependent reduction of both total and secondary tissue injury could be observed in the presence of propofol under both normo- and hypothermic conditions. This effect was further amplified when the slices were incubated at 32°C after trauma. Conclusions When used in combination, the dose-dependent neuroprotective effect of propofol is additive to the neuroprotective effect of hypothermia in an in vitro model of traumatic brain injury.
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Affiliation(s)
- Jan Rossaint
- Department of Anesthesiology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany
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Ahmad M, Rose ME, Vagni V, Griffith RP, Dixon CE, Kochanek PM, Hickey RW, Graham SH. Genetic disruption of cyclooxygenase-2 does not improve histological or behavioral outcome after traumatic brain injury in mice. J Neurosci Res 2009; 86:3605-12. [PMID: 18711748 DOI: 10.1002/jnr.21809] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Increasing evidence suggests a role for cyclooxygenase-2 (COX-2) in traumatic brain injury (TBI). In the present study, the role of COX-2 in TBI was investigated using COX-2 gene-disrupted (COX-2 null) mice and wild-type (WT) controls that were subjected to the controlled cortical impact (CCI) model of TBI. There was increased expression of COX-2 in ipsilateral hippocampus in WT mice subjected to CCI. CCI resulted in a significant increase in prostaglandin E(2) concentrations in WT compared with COX-2 null hippocampi. There was a significant increase in TUNEL staining of CA1 neurons 24 hr after CCI in WT, but not in COX-2 null mice, compared with sham-operated controls, which is consistent with a protective role for COX-2 in the early phase of injury after TBI. However, there was no difference in lesion volume 21 days after CCI in COX-2 null and WT mice. COX-2 gene disruption did not alter Morris water maze performance. Taken together, these results suggest only a minor role for COX-2 activity in determining outcome after TBI in mouse.
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Affiliation(s)
- Muzamil Ahmad
- Geriatric Research Educational and Clinical Center, VA Pittsburgh Healthcare System, Pittsburgh, PA 15206, USA
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Harry GJ, Kraft AD. Neuroinflammation and microglia: considerations and approaches for neurotoxicity assessment. Expert Opin Drug Metab Toxicol 2008; 4:1265-77. [PMID: 18798697 PMCID: PMC2658618 DOI: 10.1517/17425255.4.10.1265] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The impact of an inflammatory response, as well as interactions between the immune and nervous systems, are rapidly assuming major roles in neurodegenerative disease and injury. However, it is now appreciated that the exact nature of such responses can differ with each type of insult and interaction. More recently, neuroinflammation and the associated cellular response of microglia are being considered for their contribution to neurotoxicity of environmental agents; yet, so far, the inclusion of inflammatory end points into neurotoxicity assessment have relied primarily on relatively limited measures or driven by in vitro models of neurotoxicity. OBJECTIVE To present background information on relevant biological considerations of neuroinflammation and the microglia response demonstrating the complex integrative nature of these biological processes and raising concern with regards to translation of effects demonstrated in vitro to the in vivo situation. Specific points are addressed that would influence the design and interpretation of neuroinflammation with regards to neurotoxicology assessment. CONCLUSION There is a complex and dynamic response in the brain to regulate inflammatory processes and maintain a normal homeostatic level. The classification of such responses as beneficial or detrimental is an oversimplification. Neuroinflammation should be considered as a balanced network of processes in which subtle modifications can shift the cells toward disparate outcomes. The tendency to overinterpret data obtained in an isolated culture system should be discouraged. Rather, the use of cross-disciplinary approaches to evaluate several end points should be incorporated into the assessment of inflammatory contributions to the neurotoxicity of environmental exposures.
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Affiliation(s)
- Gaylia Jean Harry
- National Institute of Environmental Health Sciences, National Institutes of Health, Neurotoxicology Group, Laboratory of Neurobiology, Department of Health and Human Services, Research Triangle Park, NC 27709, USA.
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Deshpande LS, Sun DA, Sombati S, Baranova A, Wilson MS, Attkisson E, Hamm RJ, DeLorenzo RJ. Alterations in neuronal calcium levels are associated with cognitive deficits after traumatic brain injury. Neurosci Lett 2008; 441:115-9. [PMID: 18583041 DOI: 10.1016/j.neulet.2008.05.113] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 05/30/2008] [Accepted: 05/31/2008] [Indexed: 11/17/2022]
Abstract
Traumatic brain injury (TBI) survivors often suffer from a post-traumatic syndrome with deficits in learning and memory. Calcium (Ca(2+)) has been implicated in the pathophysiology of TBI-induced neuronal death. However, the role of long-term changes in neuronal Ca(2+) function in surviving neurons and the potential impact on TBI-induced cognitive impairments are less understood. Here we evaluated neuronal death and basal free intracellular Ca(2+) ([Ca(2+)](i)) in acutely isolated rat CA3 hippocampal neurons using the Ca(2+) indicator, Fura-2, at seven and thirty days after moderate central fluid percussion injury. In moderate TBI, cognitive deficits as evaluated by the Morris Water Maze (MWM), occur after injury but resolve after several weeks. Using MWM paradigm we compared alterations in [Ca(2+)](i) and cognitive deficits. Moderate TBI did not cause significant hippocampal neuronal death. However, basal [Ca(2+)](i) was significantly elevated when measured seven days post-TBI. At the same time, these animals exhibited significant cognitive impairment (F(2,25)=3.43, p<0.05). When measured 30 days post-TBI, both basal [Ca(2+)](i) and cognitive functions had returned to normal. Pretreatment with MK-801 blocked this elevation in [Ca(2+)](i) and also prevented MWM deficits. These studies provide evidence for a link between elevated [Ca(2+)](i) and altered cognition. Since no significant neuronal death was observed, the alterations in Ca(2+) homeostasis in the traumatized, but surviving neurons may play a role in the pathophysiology of cognitive deficits that manifest in the acute setting after TBI and represent a novel target for therapeutic intervention following TBI.
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Sun DA, Deshpande LS, Sombati S, Baranova A, Wilson MS, Hamm RJ, DeLorenzo RJ. Traumatic brain injury causes a long-lasting calcium (Ca2+)-plateau of elevated intracellular Ca levels and altered Ca2+ homeostatic mechanisms in hippocampal neurons surviving brain injury. Eur J Neurosci 2008; 27:1659-72. [PMID: 18371074 DOI: 10.1111/j.1460-9568.2008.06156.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Traumatic brain injury (TBI) survivors often suffer chronically from significant morbidity associated with cognitive deficits, behavioral difficulties and a post-traumatic syndrome and thus it is important to understand the pathophysiology of these long-term plasticity changes after TBI. Calcium (Ca2+) has been implicated in the pathophysiology of TBI-induced neuronal death and other forms of brain injury including stroke and status epilepticus. However, the potential role of long-term changes in neuronal Ca2+ dynamics after TBI has not been evaluated. In the present study, we measured basal free intracellular Ca2+ concentration ([Ca2+](i)) in acutely isolated CA3 hippocampal neurons from Sprague-Dawley rats at 1, 7 and 30 days after moderate central fluid percussion injury. Basal [Ca2+](i) was significantly elevated when measured 1 and 7 days post-TBI without evidence of neuronal death. Basal [Ca2+](i) returned to normal when measured 30 days post-TBI. In contrast, abnormalities in Ca2+ homeostasis were found for as long as 30 days after TBI. Studies evaluating the mechanisms underlying the altered Ca2+ homeostasis in TBI neurons indicated that necrotic or apoptotic cell death and abnormalities in Ca2+ influx and efflux mechanisms could not account for these changes and suggested that long-term changes in Ca2+ buffering or Ca2+ sequestration/release mechanisms underlie these changes in Ca2+ homeostasis after TBI. Further elucidation of the mechanisms of altered Ca2+ homeostasis in traumatized, surviving neurons in TBI may offer novel therapeutic interventions that may contribute to the treatment and relief of some of the morbidity associated with TBI.
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Affiliation(s)
- David A Sun
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Spaethling JM, Geddes-Klein DM, Miller WJ, von Reyn CR, Singh P, Mesfin M, Bernstein SJ, Meaney DF. Linking impact to cellular and molecular sequelae of CNS injury: modeling in vivo complexity with in vitro simplicity. PROGRESS IN BRAIN RESEARCH 2007; 161:27-39. [PMID: 17618968 DOI: 10.1016/s0079-6123(06)61003-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Traumatic brain injury (TBI) represents one of most common disorders to the central nervous system (CNS). Despite significant efforts, though, an effective clinical treatment for TBI is not yet available. The complexity of human TBI is modeled with a broad group of experimental models, with each model matching some aspect of the human condition. In the past 15 years, these in vivo models were complemented with a group of in vitro models, with these in vitro models allowing investigators to more precisely identify the mechanism(s) of TBI, the different intracellular events that occur in acute period following injury, and the possible treatment of this injury in vitro. In this paper, we review the available in vitro models to study TBI, discuss their biomechanical basis for human TBI, and review the findings from these in vitro models. Finally, we synthesize the current knowledge and point out possible future directions for this group of models, especially in the effort toward developing new therapies for the traumatically brain injured patient.
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Affiliation(s)
- Jennifer M Spaethling
- Department of Bioengineering, University of Pennsylvania, 3320 Smith Walk, Philadelphia, PA 19104-6392, USA
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Yao X, Liu J, McCabe JT. Ubiquitin and ubiquitin-conjugated protein expression in the rat cerebral cortex and hippocampus following traumatic brain injury (TBI). Brain Res 2007; 1182:116-22. [PMID: 17936732 DOI: 10.1016/j.brainres.2007.08.076] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Revised: 08/29/2007] [Accepted: 08/30/2007] [Indexed: 01/25/2023]
Abstract
Regulation of protein turnover is essential to the survival of eukaryotic cells. This important cellular process is partly regulated by the ubiquitin-proteasome system through posttranslational modification by the conjugation of ubiquitin chains to proteins targeted for degradation by proteasomes. The present study examined ubiquitin mRNA and protein expression in the CNS of rats that sustained traumatic brain injury (TBI). Quantitative real-time polymerase chain reaction results indicated that mRNA levels of ubA52, ubB and ubC in the ipsilateral cerebral cortex were significantly decreased on Day 1 post-TBI, that ubC mRNA levels also were significantly lower than control on Day 3 post-TBI, but that by Day 7 post-TBI, ubA52, ubB and ubC mRNA levels had all returned to control levels. In the ipsilateral hippocampus, ubA52 mRNA levels were significantly lower on Days 1-7 post-TBI, while ubB and ubC mRNA levels were less only on Day 1 post-TBI. Western blotting found that free ubiquitin protein levels were significantly reduced in both ipsilateral cerebral cortex and hippocampus on Days 1-7 post-TBI, while there was markedly increased ubiquitin-conjugated protein in ipsilateral cerebral cortex on Day 7 and in hippocampus on Days 3-7 post-TBI. Our study suggests that altered ubiquitin system function in the CNS contributes to the pathological outcomes of TBI.
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Affiliation(s)
- Xianglan Yao
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, USA
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Staal JA, Dickson TC, Chung RS, Vickers JC. Cyclosporin-A treatment attenuates delayed cytoskeletal alterations and secondary axotomy following mild axonal stretch injury. Dev Neurobiol 2007; 67:1831-42. [PMID: 17702000 DOI: 10.1002/dneu.20552] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Following central nervous system trauma, diffuse axonal injury and secondary axotomy result from a cascade of cellular alterations including cytoskeletal and mitochondrial disruption. We have examined the link between intracellular changes following mild/moderate axonal stretch injury and secondary axotomy in rat cortical neurons cultured to relative maturity (21 days in vitro). Axon bundles were transiently stretched to a strain level between 103% and 106% using controlled pressurized fluid. Double-immunohistochemical analysis of neurofilaments, neuronal spectrin, alpha-internexin, cytochrome-c, and ubiquitin was conducted at 24-, 48-, 72-, and 96-h postinjury. Stretch injury resulted in delayed cytoskeletal damage, maximal at 48-h postinjury. Accumulation of cytochrome-c and ubiquitin was also evident at 48 h following injury and colocalized to axonal regions of cytoskeletal disruption. Pretreatment of cultures with cyclosporin-A, an inhibitor of calcineurin and the mitochondrial membrane transitional pore, reduced the degree of cytoskeletal damage in stretch-injured axonal bundles. At 48-h postinjury, 20% of untreated cultures demonstrated secondary axotomy, whereas cyclosporin A-treated axon bundles remained intact. By 72-h postinjury, 50% of control preparations and 7% of cyclosporin A-treated axonal bundles had progressed to secondary axotomy, respectively. Statistical analyses demonstrated a significant (p < 0.05) reduction in secondary axotomy between treated and untreated cultures. In summary, these results suggest that cyclosporin-A reduces progressive cytoskeletal damage and secondary axotomy following transient axonal stretch injury in vitro.
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Affiliation(s)
- J A Staal
- NeuroRepair Group, Menzies Research Institute, University of Tasmania, Hobart, Tasmania, Australia
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Yang L, Benardo LS, Valsamis H, Ling DSF. Acute injury to superficial cortex leads to a decrease in synaptic inhibition and increase in excitation in neocortical layer V pyramidal cells. J Neurophysiol 2006; 97:178-87. [PMID: 16987927 DOI: 10.1152/jn.01374.2005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Injury to the superficial layers of cerebral cortex produces alterations in the synaptic responses of local circuits that promote the development of seizures. To further delineate the specific changes in synaptic strength that are induced by this type of cortical injury, whole cell voltage-clamp recordings were used to examine evoked and spontaneous synaptic events from layer V pyramidal cells in coronal slices prepared from surgically traumatized rat neocortices in which the superficial third of the cortex (layers I, II, and part of III) was removed. Slices from intact neocortices were used as controls. Examinations of fast inhibitory postsynaptic currents (IPSCs) indicated that traumatized slices were disinhibited, exhibiting evoked IPSCs (eIPSCs) with lower peak amplitudes. Measurements of spontaneous IPSCs (sIPSCs) revealed no difference in the mean amplitudes of sIPSCs recorded in traumatized versus control slices. However, the mean sIPSC frequency was lower in traumatized slices, indicative of a decrease in GABA release at these inhibitory synapses. Traumatized slices also displayed an increase in synaptic excitation, exhibiting spontaneous EPSCs (sESPCs) with larger peak amplitudes and higher frequencies. Peak-scaled nonstationary fluctuation analysis of sEPSCs and sIPSCs was used to obtain estimates of the unit conductance and number of functional receptor channels. EPSC and IPSC channel numbers and IPSC unit conductance did not differ between traumatized and intact slices. However, the mean unit conductance of EPSCs was higher (+25%) in traumatized slices. These findings suggest that acute injury to the superficial neocortical layers results in a disinhibition of cortical circuits that stems from a decline in GABA release likely due to the loss of superficial inhibitory interneurons and an enhancement of synaptic excitation consequent to an increase in the AMPA receptor unit conductance.
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Affiliation(s)
- Lie Yang
- Dept. of Physiology and Pharmacology, SUNY Downstate Medical Center, 450 Clarkson Ave. Box 29, Brooklyn, NY 11203, USA.
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36
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Wölfer J, Bantel C, Köhling R, Speckmann EJ, Wassmann H, Greiner C. Electrophysiology in ischemic neocortical brain slices: species differences vs. influences of anaesthesia and preparation. Eur J Neurosci 2006; 23:1795-800. [PMID: 16623836 DOI: 10.1111/j.1460-9568.2006.04696.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ischemia models are indispensable for the evaluation of measures to be clinically applied to brain trauma or stroke patients. Slice models provide good control over experimental parameters and allow for comparative examinations of human and animal brain tissue. Experimental tissue, however, may be altered by anaesthesia, preparatory technique, and, in the case of human tissue, by underlying diseases. These influences on tissue behaviour under ischemia were examined electrophysiologically. Native rat tissue slices were prepared either immediately after decapitation (n = 13), during short ether/barbiturate narcosis (n = 18), or after two hours of inhalation anaesthesia (n = 12) imitating clinical narcosis. Tissue from rats in which generalized amygdala-kindled seizures had been triggered by electric stimulation (n = 10) was prepared according to the decapitation protocol, while human tissue (n = 10) was obtained during epilepsy or tumour surgery. Electrophysiological data (latency and amplitude of anoxic depolarization, recovery of evoked potentials) were recorded during ischemia simulation. Neither details of preparation or anaesthesia nor a history of epileptic fits were associated with significant changes of electrophysiological reactions under ischemia. Human tissue showed a significantly higher ability to uphold transmembrane ion gradients under ischemia. The ability of brain tissue to withstand ischemia is obviously species dependent. For the transfer of experimental results into clinical use it is important that interspecies differences alone can bring about a significant change of tissue behaviour.
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Affiliation(s)
- Johannes Wölfer
- Klinik und Poliklinik für Neurochirurgie am Universitätsklinikum Münster, Albert-Schweitzer-Strasse 33, D-48149 Münster, Germany.
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Neeves KB, Lo CT, Foley CP, Saltzman WM, Olbricht WL. Fabrication and characterization of microfluidic probes for convection enhanced drug delivery. J Control Release 2006; 111:252-62. [PMID: 16476500 DOI: 10.1016/j.jconrel.2005.11.018] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2005] [Revised: 11/18/2005] [Accepted: 11/28/2005] [Indexed: 10/25/2022]
Abstract
Convection enhanced drug delivery (CED) is a promising therapeutic method for treating diseases of the brain by enhancing the penetration of drugs. Most controlled release delivery methods rely on diffusion from a source to transport drugs throughout tissue. CED relies on direct infusion of drugs into tissue at a sufficiently high rate so that convective transport of drug is at least as important as diffusive transport. This work describes the fabrication and characterization of microfluidic probes for CED protocols and the role diffusion plays in determining penetration. Microfluidic channels were formed on silicon substrates by employing a sacrificial photoresist layer encased in a parylene structural layer. Flow in the microchannels was characterized by applying constant upstream pressures from 35 to 310 kPa, which resulted in flow rates of 0.5-4.5 microL/min. The devices were used to infuse Evans Blue and albumin in hydrogel brain phantoms. The results of these infusions were compared to a simple convection-diffusion model for infusions into porous media. In vivo infusions of albumin were performed in the gray matter of rats at upstream pressures of 35, 70, and 140 kPa. The microfabricated probes show reduced evidence of backflow along the device-tissue interface when compared with conventional needles used for CED.
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Affiliation(s)
- K B Neeves
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY 14853, USA
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38
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Yang Y, Xie Y, Chai H, Fan M, Liu S, Liu H, Bruce I, Wu W. Microarray analysis of gene expression patterns in adult spinal motoneurons after different types of axonal injuries. Brain Res 2006; 1075:1-12. [PMID: 16460709 DOI: 10.1016/j.brainres.2005.12.060] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 10/05/2005] [Accepted: 12/04/2005] [Indexed: 10/25/2022]
Abstract
Three experimental models of axonal injuries in adult rat spinal motoneurons were established to investigate changes of gene expression in response to such injuries. We took advantage of cDNA microarray analysis to determine the differential expression of genes in injured motoneurons following distal axotomy or root avulsion in the absence or presence of BDNF. The major finding was that, in response to proximal axonal injury (avulsion), expression of genes that are known to facilitate neuronal survival and axonal regeneration (e.g., IGFRII, PI3K, IGFBP-6, GSTs, GalR2) were down-regulated; but following treatment with BDNF they were up-regulated. In addition, the expression of genes known to be involved in apoptosis and DNA damage (e.g., ANX5, TS, ALR) were down-regulated in BDNF-treated animals with avulsion. Furthermore, many functional families of genes previously shown to play roles in the pathophysiology of axonal injury, including SNAP-25A, SV2B, Ras-related ras3a/4b, ERK1/2, 14-3-3 proteins, proteasome proteins, oncogenes, GAP-43, and NMDAR1, were altered after either distal axotomy or avulsion injury. Some of the changes in gene expression, including Lim-2, FRAG1, GlaR2, GSTs, ALR, TS, ANX3/5, and nhe1/2, are first reported here in injured motoneurons. The differential expression of genes identified by the expression arrays was confirmed by gene-specific RT-PCR for eight genes (GAP-43, IGFR II, Lim-2, MIF, NDAP1, TS, PCC3, and FRAG1) and by in situ hybridization for Lim-2. These results suggest that abnormal regulation of particular biochemical pathways may induce motoneuron death after ventral root avulsion in adult animals. This study presents an approach for selecting specific genes and their products that may be involved in motoneuron degeneration following axonal injuries.
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Affiliation(s)
- Yi Yang
- Department of Anatomy, Faculty of Medicine, The University of Hong Kong, 21 Sassoon Road, Hong Kong, China
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39
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Morrison B, Cater HL, Benham CD, Sundstrom LE. An in vitro model of traumatic brain injury utilising two-dimensional stretch of organotypic hippocampal slice cultures. J Neurosci Methods 2006; 150:192-201. [PMID: 16098599 DOI: 10.1016/j.jneumeth.2005.06.014] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Revised: 06/10/2005] [Accepted: 06/20/2005] [Indexed: 11/27/2022]
Abstract
Traumatic brain injury (TBI) is caused by rapid deformation of the brain, resulting in a cascade of pathological events and ultimately neurodegeneration. Understanding how the biomechanics of brain deformation leads to tissue damage remains a considerable challenge. We have developed an in vitro model of TBI utilising organotypic hippocampal slice cultures on deformable silicone membranes, and an injury device, which generates tissue deformation through stretching the silicone substrate. Our injury device controls the biomechanical parameters of the stretch via feedback control, resulting in a reproducible and equi-biaxial deformation stimulus. Organotypic cultures remain well adhered to the membrane during deformation, so that tissue strain is 93 and 86% of the membrane strain in the x- and y-axis, respectively. Cell damage following injury is positively correlated with strain. In conclusion, we have developed a unique in vitro model to study the effects of mechanical stimuli within a complex cellular environment that mimics the in vivo environment. We believe this model could be a powerful tool to study the acute phases of TBI and the induced cell degeneration could provide a good platform for the development of potential therapeutic approaches and may be a useful in vitro alternative to animal models of TBI.
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Affiliation(s)
- Barclay Morrison
- Division of Clinical Neurosciences, University of Southampton, Rm 6207, Biomedical Sciences Building, Boldrewood, Bassett Crescent East, Highfield, Southampton SO16 7PX, UK
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40
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DeRidder MN, Simon MJ, Siman R, Auberson YP, Raghupathi R, Meaney DF. Traumatic mechanical injury to the hippocampus in vitro causes regional caspase-3 and calpain activation that is influenced by NMDA receptor subunit composition. Neurobiol Dis 2005; 22:165-76. [PMID: 16356733 DOI: 10.1016/j.nbd.2005.10.011] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Revised: 10/15/2005] [Accepted: 10/27/2005] [Indexed: 10/25/2022] Open
Abstract
Apoptotic or necrotic cell death in the hippocampus is a major factor underlying the cognitive impairments following traumatic brain injury. In this study, we examined if traumatic mechanical injury would produce regional activation of calpain and caspase-3 in the in vitro hippocampus and studied how the mechanically induced activation of NR2A and NR2B containing N-methyl-d-aspartate receptors (NMDARs) affects the activation of these proteases following mechanical injury. Following a 75% stretch, significant levels of activated caspase-3 and calpain-mediated spectrin breakdown products were evident only in cells within the dentate gyrus, and little co-localization of the markers was identified within individual cells. After 100% stretch, only calpain activation was observed, localized to the CA3 subregion 24 h after stretch. At moderate injury levels, both caspase-3 and calpain activation was attenuated by blocking NR2B containing NMDARs prior to stretch or by blocking all NMDARs prior to stretch injury. Treatment with an NR2A selective NMDAR antagonist had little effect on either activated caspase-3 or Ab38 immunoreactivity following moderate injury but resulted in the appearance of activated caspase-3 in the dentate gyrus following severe mechanical stretch. Together, these studies suggest that the injury induced activation of NR2A containing NMDARs functions as a pro-survival signal, while the activation of NR2B containing NMDARs is a competing, anti-survival, signal following mechanical injury to the hippocampus.
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Affiliation(s)
- Michael N DeRidder
- Department of Bioengineering, University of Pennsylvania, 3320 Smith Walk, Room 105E, Hayden Hall, Philadelphia, PA 19104, USA
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41
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von Gertten C, Morales AF, Holmin S, Mathiesen T, Nordqvist ACS. Genomic responses in rat cerebral cortex after traumatic brain injury. BMC Neurosci 2005; 6:69. [PMID: 16318630 PMCID: PMC1310614 DOI: 10.1186/1471-2202-6-69] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Accepted: 11/30/2005] [Indexed: 11/27/2022] Open
Abstract
Background Traumatic brain injury (TBI) initiates a complex sequence of destructive and neuroprotective cellular responses. The initial mechanical injury is followed by an extended time period of secondary brain damage. Due to the complicated pathological picture a better understanding of the molecular events occurring during this secondary phase of injury is needed. This study was aimed at analysing gene expression patterns following cerebral cortical contusion in rat using high throughput microarray technology with the goal of identifying genes involved in an early and in a more delayed phase of trauma, as genomic responses behind secondary mechanisms likely are time-dependent. Results Among the upregulated genes 1 day post injury, were transcription factors and genes involved in metabolism, e.g. STAT-3, C/EBP-δ and cytochrome p450. At 4 days post injury we observed increased gene expression of inflammatory factors, proteases and their inhibitors, like cathepsins, α-2-macroglobulin and C1q. Notably, genes with biological function clustered to immune response were significantly upregulated 4 days after injury, which was not found following 1 day. Osteopontin and one of its receptors, CD-44, were both upregulated showing a local mRNA- and immunoreactivity pattern in and around the injury site. Fewer genes had decreased expression both 1 and 4 days post injury and included genes implicated in transport, metabolism, signalling, and extra cellular matrix formation, e.g. vitronectin, neuroserpin and angiotensinogen. Conclusion The different patterns of gene expression, with little overlap in genes, 1 and 4 days post injury showed time dependence in genomic responses to trauma. An early induction of factors involved in transcription could lead to the later inflammatory response with strongly upregulated CD-44 and osteopontin expression. An increased knowledge of genes regulating the pathological mechanisms in trauma will help to find future treatment targets. Since trauma is a risk factor for development of neurodegenerative disease, this knowledge may also reduce late negative effects.
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Affiliation(s)
- Christina von Gertten
- Department of Clinical Neuroscience, Karolinska Institutet, Section of Clinical CNS research, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | | | - Staffan Holmin
- Department of Clinical Neuroscience, Karolinska Institutet, Section of Clinical CNS research, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - Tiit Mathiesen
- Department of Clinical Neuroscience, Karolinska Institutet, Section of Clinical CNS research, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
| | - Ann-Christin Sandberg Nordqvist
- Department of Clinical Neuroscience, Karolinska Institutet, Section of Clinical CNS research, Karolinska University Hospital, SE-171 76 Stockholm, Sweden
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Shimamura M, Garcia JM, Prough DS, Dewitt DS, Uchida T, Shah SA, Avila MAA, Hellmich HL. Analysis of long-term gene expression in neurons of the hippocampal subfields following traumatic brain injury in rats. Neuroscience 2005; 131:87-97. [PMID: 15680694 DOI: 10.1016/j.neuroscience.2004.10.041] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2004] [Indexed: 01/19/2023]
Abstract
After experimental traumatic brain injury (TBI), widespread neuronal loss is progressive and continues in selectively vulnerable brain regions, such as the hippocampus, for months to years after the initial insult. To clarify the molecular mechanisms underlying secondary or delayed cell death in hippocampal neurons after TBI, we compared long-term changes in gene expression in the CA1, CA3 and dentate gyrus (DG) subfields of the rat hippocampus at 24 h and 3, 6, and 12 months after TBI with changes in gene expression in sham-operated rats. We used laser capture microdissection to collect several hundred hippocampal neurons from the CA1, CA3, and DG subfields and linearly amplified the nanogram samples of neuronal RNA with T7 RNA polymerase. Subsequent quantitative analysis of gene expression using ribonuclease protection assay revealed that mRNA expression of the anti-apoptotic gene, Bcl-2, and the chaperone heat shock protein 70 was significantly downregulated at 3, 6 (Bcl-2 only), and 12 months after TBI. Interestingly, the expression of the pro-apoptotic genes caspase-3 and caspase-9 was also significantly decreased at 3, 6 (caspase-9 only), and 12 months after TBI, suggesting that long-term neuronal loss after TBI is not mediated by increased expression of pro-apoptotic genes. The expression of two aging-related genes, p21 and integrin beta3 (ITbeta3), transiently increased 24 h after TBI, returned to baseline levels at 3 months and significantly decreased below sham levels at 12 months (ITbeta3 only). Expression of the gene for the antioxidant glutathione peroxidase-1 also significantly increased 6 months after TBI. These results suggest that decreased levels of neuroprotective genes may contribute to long-term neurodegeneration in animals and human patients after TBI. Conversely, long-term increases in antioxidant gene expression after TBI may be an endogenous neuroprotective response that compensates for the decrease in expression of other neuroprotective genes.
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Affiliation(s)
- M Shimamura
- Department of Anesthesiology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-0830, USA
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43
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Bendel O, Langmoen IA, von Euler G. Crush injury induces NMDA-receptor-dependent delayed nerve cell death in rat entorhinal-hippocampal slice cultures. Brain Res 2005; 1025:35-42. [PMID: 15464742 DOI: 10.1016/j.brainres.2004.07.089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2004] [Indexed: 10/26/2022]
Abstract
The aim of the present study was to develop an in vitro model that produces an injury-induced delayed nerve cell death. We used entorhinal-hippocampal slices from 12-day-old rats, which were cultured for 14 days before experiments prior to a crush injury in the middle layers of the entorhinal cortex. Crush injury increased specific propidium iodide (PI) fluorescence at the site of primary injury at day 1. Specific PI fluorescence decreased over the following days, with a slower decrease taking place at days 4-7. At days 4-7, PI fluorescence increased in CA1 and CA3. Treatment with 30 microM MK-801 for 2 h at the time of crush injury prevented the increase in PI fluorescence at days 4-7 at the site of injury, in CA1, and in CA3. Crush injury induced TUNEL-positive cells at the site of injury at days 1 and 5. MK-801 markedly reduced the number of TUNEL-positive cells observed at day 5, but had no effect on the number of TUNEL-positive cells at day 1. The present data indicate that crush injury may induce two types of secondary cell death. The first, early, type of cell death is induced quickly and is maximal at day 1, after which the dead cells are gradually removed. The second, delayed, type of cell death appears at day 4. NMDA receptor antagonism prevents the induction of the delayed cell death but has no effect on the early cell death.
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Affiliation(s)
- Olof Bendel
- Section of Clinical CNS Research, Department of Clinical Neuroscience, Karolinska Institutet, Karolinska University Hospital, Solna, S-14186 Stockholm, Sweden
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Li HH, Lee SM, Cai Y, Sutton RL, Hovda DA. Differential gene expression in hippocampus following experimental brain trauma reveals distinct features of moderate and severe injuries. J Neurotrauma 2004; 21:1141-53. [PMID: 15453985 DOI: 10.1089/neu.2004.21.1141] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Microarray technology was employed to determine the differential pattern of gene expression within the hippocampus as a result of traumatic brain injury (TBI). The validity of the microarray data was confirmed using real-time RT-PCR. Following either moderate or severe lateral fluid percussion injury, rats were studied 0.5, 4, and 24 h after injury. In general, animals exhibited mRNA up or down regulation of approximately 10% of the genes studied. However, it was clear that the pattern of gene expression was influenced by both the severity of injury and the time after injury at which animals were studied. For example, genes encoding molecules for cellular signaling, synaptic plasticity, metabolism, ion channels and transporters were up regulated following severe injury, but down regulated following moderate injury. Furthermore, moderate injury was associated with an increasing number of responsive genes as a function of time post-injury. However, animals sustaining a severe level of injury exhibited decreasing number of responsive genes during the same post-injury period. The different patterns of gene expression between injury severity and across time after the insult suggests that the pathophysiological cascade induced by TBI is accompanied by a molecular response which, like the other aspects of the cellular response for survival, may indicate a "molecular window" that may offer an opportunity for therapeutic interventions involving gene therapy. Our results also suggest that fundamentally different pathophysiological processes or cascades may be induced by different severities of injury.
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Affiliation(s)
- Hong Hua Li
- Division of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7039, USA
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Adembri C, Bechi A, Meli E, Gramigni E, Venturi L, Moroni F, De Gaudio AR, Pellegrini-Giampietro DE. Erythropoietin Attenuates Post-Traumatic Injury in Organotypic Hippocampal Slices. J Neurotrauma 2004; 21:1103-12. [PMID: 15319009 DOI: 10.1089/0897715041651079] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Recent experimental evidence indicates that erythropoietin (Epo), in addition to its hormonal role in regulating red cell production, operates as a neuroprotective agent. So far, the neuroprotective effect of human recombinant Epo (rhEpo) has been mainly demonstrated in models of cerebral ischemia/hypoxia and in selected in vivo studies of traumatic neuronal injury. To further investigate the potential role of this multifunctional trophic factor in post-traumatic cell death, we examined the protective effects of rhEpo in a newly developed model of mechanical trauma in organotypic hippocampal slices. Organotypic rat hippocampal slices were subjected to traumatic injury by allowing a stylus to impact on the CA1 area with an energy of 6 microJ. Hippocampal damage was identified and measured 24 and 48 h later with the fluorescent dye propidium iodide (PI). In untreated slices, the impact induced a significant increase in the mean hippocampal PI fluorescence, co-localized with the area of impact at 24 h (primary post-traumatic injury) and progressively spread to the whole slice between 24 and 48 h (secondary post-traumatic injury). Addition of rhEpo (1-100 UI/mL) or of the NMDA antagonist MK-801 (30 microM) immediately after the traumatic injury reduced hippocampal damage by approximately 30% when observed 24 h later. At 48 h after trauma, the protective effect of rhEpo was greater (by about 47%) and significantly more pronounced than that of MK-801 (28%). Our results suggest that the neuroprotective activity of rhEpo is particularly effective against delayed, secondary post-traumatic damage. This well tolerated agent could provide a therapeutic benefit in pathologies involving post-traumatic neurodegeneration.
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Affiliation(s)
- Chiara Adembri
- Dipartimento di Area Critica Medico Chirurgica, Sezione di Anestesiologia e Terapia Intensiva, Università di Firenze, Firenze, Italy.
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Marciano PG, Brettschneider J, Manduchi E, Davis JE, Eastman S, Raghupathi R, Saatman KE, Speed TP, Stoeckert CJ, Eberwine JH, McIntosh TK. Neuron-specific mRNA complexity responses during hippocampal apoptosis after traumatic brain injury. J Neurosci 2004; 24:2866-76. [PMID: 15044525 PMCID: PMC6729833 DOI: 10.1523/jneurosci.5051-03.2004] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In an effort to understand the complexity of genomic responses within selectively vulnerable regions after experimental brain injury, we examined whether single apoptotic neurons from both the CA3 and dentate differed from those in an uninjured brain. The mRNA from individual active caspase 3(+)/terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling [TUNEL(-)] and active caspase 3(+)/TUNEL(+) pyramidal and granule neurons in brain-injured mice were amplified and compared with those from nonlabeled neurons in uninjured brains. Gene analysis revealed that overall expression of mRNAs increased with activation of caspase 3 and decreased to below uninjured levels with TUNEL reactivity. Cell type specificity of the apoptotic response was observed with both regionally distinct expression of mRNAs and differences in those mRNAs that were maximally regulated. Immunohistochemical analysis for two of the most highly differentially expressed genes (prion and Sos2) demonstrated a correlation between the observed differential gene expression after traumatic brain injury and corresponding protein translation.
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Affiliation(s)
- Paolo G Marciano
- Departments of Neuroscience, Center for Bioinformatics, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Hinkle D, Glanzer J, Sarabi A, Pajunen T, Zielinski J, Belt B, Miyashiro K, McIntosh T, Eberwine J. Single neurons as experimental systems in molecular biology. Prog Neurobiol 2004; 72:129-42. [PMID: 15063529 DOI: 10.1016/j.pneurobio.2004.01.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2003] [Accepted: 01/22/2004] [Indexed: 01/23/2023]
Abstract
The cellular and the inter-connective complexity of the central nervous system (CNS) necessitate's analysis of functioning at both the system and single cell levels. Systems neuroscience has developed procedures that facilitate the analysis of multicellular systems including multielectrode arrays, dye tracings and lesioning assays, and at the single cell level there have been significant strides in assessing the physiology and morphology of individual cells. Until recently little progress had been made in understanding the molecular biology of single neuronal cells. This review will highlight the development of PCR and aRNA procedures for analysis of mRNA abundances in single cells. Also, other procedures for the analysis of protein abundances as well as the association of RNA with proteins will also be summarized. These procedures promise to provide experimental insights that will help unravel the functional mechanisms regulating the cellular components of the CNS.
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Affiliation(s)
- David Hinkle
- Department of Pharmacology, University of Pennsylvania Medical School, 36th and Hamilton Walk, Philadelphia, PA 19104, USA
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MacManus JP, Graber T, Luebbert C, Preston E, Rasquinha I, Smith B, Webster J. Translation-state analysis of gene expression in mouse brain after focal ischemia. J Cereb Blood Flow Metab 2004; 24:657-67. [PMID: 15181373 DOI: 10.1097/01.wcb.0000123141.67811.91] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Confounding any genome-scale analysis of gene expression after cerebral ischemia is massive suppression of protein synthesis. This inefficient translation questions the utility of examining profiles of total transcripts. Our approach to such postischemic gene profiling in the mouse by microarray analysis was to concentrate on those mRNAs bound to polyribosomes. In our proof-of-principle study, polysomally bound and unbound mRNAs were subjected to microarray analysis: of the 1,161 transcripts that we found to increase after ischemia, only 36% were bound to polyribosomes. In addition to the expected increases in heat-shock proteins and metallothioneins, increases in several other bound transcripts involved in the promotion of cell survival or antiinflammatory behavior were noted, such as CD63 (Lamp3), Lcn2 (lipocalin-2), Msn (moesin), and UCP2 (uncoupling protein 2), all of which showed increases in cognate protein by Western blotting. The list of heretofore nonfunctionally annotated transcripts (RIKEN clones/ESTs) that increased appeared to be novel. How some transcripts are selected in ischemic brain for translation into protein, while others are rejected, is not clear. The length of the 5'-UTR in the ischemically induced transcripts that occur in the NCBI RefSeq database did not indicate any general tendency to be more than 200 nt, nor to be longer than the 5'-UTRs of the unbound transcripts. Thus, the presence of a complex 5'-UTR region with internal ribosome entry sites (IRES) or polypyrimidine tracts (TOP) does not appear to be the basis of selection for translation in ischemic brain.
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Affiliation(s)
- John P MacManus
- Experimental Stroke Group, Institute for Biological Sciences, National Research Council, Ottawa, ON, Canada.
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Affiliation(s)
- Margaret M McCarthy
- Department of Physiology and Program in Neuroscience, University of Maryland, Baltimore, Baltimore, MD 21201, USA.
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50
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Morrison B, Cater HL, Wang CCB, Thomas FC, Hung CT, Ateshian GA, Sundstrom LE. A tissue level tolerance criterion for living brain developed with an in vitro model of traumatic mechanical loading. STAPP CAR CRASH JOURNAL 2003; 47:93-105. [PMID: 17096246 DOI: 10.4271/2003-22-0006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Traumatic brain injury (TBI) is caused by brain deformations resulting in the pathophysiological activation of cellular cascades which produce delayed cell damage and death. Understanding the consequences of mechanical injuries on living brain tissue continues to be a significant challenge. We have developed a reproducible tissue culture model of TBI which employs organotypic brain slice cultures to study the relationship between mechanical stimuli and the resultant biological response of living brain tissue. The device allows for the independent control of tissue strain (up to 100%) and strain rate (up to 150 s-1) so that tolerance criteria at the tissue level can be developed for the interpretation of computational simulations. The application of texture correlation image analysis algorithms to high speed video of the dynamic deformation allows for the direct calculation of substrate strain and strain rate which was found to be equi-biaxial and independent of radial position. Precisely controlled, mechanical injuries were applied to organotypic hippocampal slice cultures, and resultant cell death was quantified. Cell death was found to be dependent on both strain magnitude and rate and required several days to develop. An immunohistological examination of injured cultures with antibodies to amyloid precursor protein revealed the presence of traumatic axonal injury, suggesting that the model closely replicates in vivo TBI but with advantages gained in vitro. We anticipate that a combined in vitro approach with optical strain mapping will provide a more detailed understanding of the dependence of brain cell injury and death on strain and strain rate.
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