1
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Wei H, Frey AM, Jasanoff A. Molecular fMRI of neurochemical signaling. J Neurosci Methods 2021; 364:109372. [PMID: 34597714 DOI: 10.1016/j.jneumeth.2021.109372] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/23/2021] [Accepted: 09/25/2021] [Indexed: 12/12/2022]
Abstract
Magnetic resonance imaging (MRI) is the most widely applied technique for brain-wide measurement of neural function in humans and animals. In conventional functional MRI (fMRI), brain signaling is detected indirectly, via localized activity-dependent changes in regional blood flow, oxygenation, and volume, to which MRI contrast can be readily sensitized. Although such hemodynamic fMRI methods are powerful tools for analysis of brain activity, they lack specificity for the many molecules and cell types that play functionally distinct roles in neural processing. A suite of techniques collectively known to as "molecular fMRI," addresses this limitation by permitting MRI-based detection of specific molecular processes in deep brain tissue. This review discusses how molecular fMRI is coming to be used in the study of neurochemical dynamics that mediate intercellular communication in the brain. Neurochemical molecular fMRI is a potentially powerful approach for mechanistic analysis of brain-wide function, but the techniques are still in early stages of development. Here we provide an overview of the major advances and results that have been achieved to date, as well as directions for further development.
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Affiliation(s)
- He Wei
- Department of Biological Engineering, Massachusetts Institute of Technology, United States
| | - Abigail M Frey
- Department of Chemical Engineering, Massachusetts Institute of Technology, United States
| | - Alan Jasanoff
- Department of Biological Engineering, Massachusetts Institute of Technology, United States; Department of Brain & Cognitive Sciences, Massachusetts Institute of Technology, United States; Department of Nuclear Science & Engineering, Massachusetts Institute of Technology, United States.
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2
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Ma Q, Feng L, Wang T, Li Y, Li Z, Zhao B, Qin X, Li Q, Wu S, Sun H, Yuan J, Chu L, Wu J, Gu Y, Pang P, Chen Z, Fan D. 2020 expert consensus statement on neuro-protection after cardiac arrest in China. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:175. [PMID: 33569477 PMCID: PMC7867902 DOI: 10.21037/atm-20-7853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Qingbian Ma
- Emergency Department, Peking University Third Hospital, Beijing, China
| | - Liqun Feng
- Neurology Department, Anzhen Hospital, Capital Medical University, Beijing, China
| | - Tao Wang
- Neurosurgery Department, Peking University Third Hospital, Beijing, China
| | - Yongqiu Li
- Neurology Department, Tangshan Gongren Hospital, Tangshan, China
| | - Zhenzhong Li
- Neurology Department, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Bin Zhao
- Emergency Department, Beijing Jishuitan Hospital, Beijing, China
| | - Xiuchuan Qin
- Emergency Department, Anzhen Hospital, Capital Medical University, Beijing, China
| | - Qingxi Li
- Neurosurgery Department, Dandong Central Hospital, Dandong, China
| | - Shizheng Wu
- Neurology Department, Qinghai Provincial People's Hospital, Xining, China
| | - Hongbin Sun
- Neurology Department, Sichuan Provincial People's Hospital, Chengdu, China
| | - Jun Yuan
- Neurology Department, Inner Mongolia People's Hospital, Hohhot, China
| | - Lan Chu
- Neurology Department, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Jian Wu
- Neurology Department, Beijing Tsinghua Changgung Hospital, Beijing, China
| | - Yuxiang Gu
- Neurosurgery Department, Fudan University Huashan Hospital, Shanghai, China
| | - Peter Pang
- Accident and Emergency Department, Yan Chai Hospital, Hong Kong, China
| | - Zhi Chen
- Beijing Emergency Medical Center, Beijing, China
| | - Dongsheng Fan
- Neurology Department, Peking University Third Hospital, Beijing, China
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3
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Abrahamson EE, Poloyac SM, Dixon CE, Dekosky ST, Ikonomovic MD. Acute and chronic effects of single dose memantine after controlled cortical impact injury in adult rats. Restor Neurol Neurosci 2020; 37:245-263. [PMID: 31177251 DOI: 10.3233/rnn-190909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND Altered glutamatergic neurotransmission after traumatic brain injury (TBI) contributes to excitotoxic cell damage and death. Prevention or suppression of such changes is a desirable goal for treatment of TBI. Memantine (3,5-dimethyl-1-adamantanamine), an uncompetitive NMDA receptor antagonist with voltage-dependent open channel blocking kinetics, was reported to be neuroprotective in preclinical models of excitotoxicity, brain ischemia, and in TBI when administered prophylactically, immediately, or within minutes after injury. METHODS The current study examined effects of memantine administered by single intraperitoneal injection to adult male rats at a more clinically relevant delay of one hour after moderate-severe controlled cortical impact (CCI) injury or sham surgery. Histopathology was assessed on days 1, 7, 21, and 90, vestibulomotor function (beam balance and beam walk) was assessed on days 1-5 and 71-75, and spatial memory (Morris water maze test, MWM) was assessed on days 14-21 and 83-90 after CCI injury or sham surgery. RESULTS When administered at 10 mg/kg, but not 2.5 or 5 mg/kg, memantine preserved cortical tissue and reduced neuronal degeneration 1 day after injury, and attenuated loss of synaptophysin immunoreactivity in the hippocampus 7 days after injury. No effects of 10 mg/kg memantine were observed on histopathology at 21 and 90 days after CCI injury or sham surgery, or on vestibulomotor function and spatial memory acquisition assessed during any of the testing periods. However, 10 mg/kg memantine resulted in trends for improved search strategy in the MWM memory retention probe trial. CONCLUSIONS Administration of memantine at a clinically-relevant delay after moderate-severe CCI injury has beneficial effects on acute outcomes, while more significant improvement on subacute and chronic outcomes may require repeated drug administration or its combination with another therapy.
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Affiliation(s)
- Eric E Abrahamson
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, University of Pittsburgh, Pittsburgh PA, USA.,Department of Neurology, University of Pittsburgh, Pittsburgh PA, USA
| | - Samuel M Poloyac
- Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh PA, USA
| | - C Edward Dixon
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, University of Pittsburgh, Pittsburgh PA, USA.,Department of Neurosurgery, University of Pittsburgh, Pittsburgh PA, USA
| | - Steven T Dekosky
- Department of Neurology and McKnight Brain Institute, University of Florida, Gainesville, FL, USA
| | - Milos D Ikonomovic
- Geriatric Research Education and Clinical Center, VA Pittsburgh Healthcare System, University of Pittsburgh, Pittsburgh PA, USA.,Department of Neurology, University of Pittsburgh, Pittsburgh PA, USA.,Department of Psychiatry, University of Pittsburgh, Pittsburgh PA, USA
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4
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Glotfelty EJ, Delgado TE, Tovar-y-Romo LB, Luo Y, Hoffer BJ, Olson L, Karlsson TE, Mattson MP, Harvey BK, Tweedie D, Li Y, Greig NH. Incretin Mimetics as Rational Candidates for the Treatment of Traumatic Brain Injury. ACS Pharmacol Transl Sci 2019; 2:66-91. [PMID: 31396586 PMCID: PMC6687335 DOI: 10.1021/acsptsci.9b00003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Indexed: 12/17/2022]
Abstract
Traumatic brain injury (TBI) is becoming an increasing public health issue. With an annually estimated 1.7 million TBIs in the United States (U.S) and nearly 70 million worldwide, the injury, isolated or compounded with others, is a major cause of short- and long-term disability and mortality. This, along with no specific treatment, has made exploration of TBI therapies a priority of the health system. Age and sex differences create a spectrum of vulnerability to TBI, with highest prevalence among younger and older populations. Increased public interest in the long-term effects and prevention of TBI have recently reached peaks, with media attention bringing heightened awareness to sport and war related head injuries. Along with short-term issues, TBI can increase the likelihood for development of long-term neurodegenerative disorders. A growing body of literature supports the use of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and glucagon (Gcg) receptor (R) agonists, along with unimolecular combinations of these therapies, for their potent neurotrophic/neuroprotective activities across a variety of cellular and animal models of chronic neurodegenerative diseases (Alzheimer's and Parkinson's diseases) and acute cerebrovascular disorders (stroke). Mild or moderate TBI shares many of the hallmarks of these conditions; recent work provides evidence that use of these compounds is an effective strategy for its treatment. Safety and efficacy of many incretin-based therapies (GLP-1 and GIP) have been demonstrated in humans for the treatment of type 2 diabetes mellitus (T2DM), making these compounds ideal for rapid evaluation in clinical trials of mild and moderate TBI.
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Affiliation(s)
- Elliot J. Glotfelty
- Translational
Gerontology Branch, and Laboratory of Neurosciences, Intramural
Research Program, National Institute on
Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
- Department
of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Thomas E. Delgado
- Translational
Gerontology Branch, and Laboratory of Neurosciences, Intramural
Research Program, National Institute on
Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Luis B. Tovar-y-Romo
- Division
of Neuroscience, Institute of Cellular Physiology, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Yu Luo
- Department
of Molecular Genetics, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Barry J. Hoffer
- Department
of Neurosurgery, Case Western Reserve University
School of Medicine, Cleveland, Ohio 44106, United States
| | - Lars Olson
- Department
of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | | | - Mark P. Mattson
- Translational
Gerontology Branch, and Laboratory of Neurosciences, Intramural
Research Program, National Institute on
Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Brandon K. Harvey
- Molecular
Mechanisms of Cellular Stress and Inflammation Unit, Integrative Neuroscience
Department, National Institute on Drug Abuse,
National Institutes of Health, Baltimore, Maryland 21224, United States
| | - David Tweedie
- Translational
Gerontology Branch, and Laboratory of Neurosciences, Intramural
Research Program, National Institute on
Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Yazhou Li
- Translational
Gerontology Branch, and Laboratory of Neurosciences, Intramural
Research Program, National Institute on
Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
| | - Nigel H. Greig
- Translational
Gerontology Branch, and Laboratory of Neurosciences, Intramural
Research Program, National Institute on
Aging, National Institutes of Health, Baltimore, Maryland 21224, United States
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5
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Zhou Z, Austin GL, Young LEA, Johnson LA, Sun R. Mitochondrial Metabolism in Major Neurological Diseases. Cells 2018; 7:E229. [PMID: 30477120 PMCID: PMC6316877 DOI: 10.3390/cells7120229] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 11/19/2018] [Accepted: 11/21/2018] [Indexed: 01/18/2023] Open
Abstract
Mitochondria are bilayer sub-cellular organelles that are an integral part of normal cellular physiology. They are responsible for producing the majority of a cell's ATP, thus supplying energy for a variety of key cellular processes, especially in the brain. Although energy production is a key aspect of mitochondrial metabolism, its role extends far beyond energy production to cell signaling and epigenetic regulation⁻functions that contribute to cellular proliferation, differentiation, apoptosis, migration, and autophagy. Recent research on neurological disorders suggest a major metabolic component in disease pathophysiology, and mitochondria have been shown to be in the center of metabolic dysregulation and possibly disease manifestation. This review will discuss the basic functions of mitochondria and how alterations in mitochondrial activity lead to neurological disease progression.
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Affiliation(s)
- Zhengqiu Zhou
- Molecular & Cellular Biochemistry Department, University of Kentucky, Lexington, KY 40536, USA.
| | - Grant L Austin
- Molecular & Cellular Biochemistry Department, University of Kentucky, Lexington, KY 40536, USA.
| | - Lyndsay E A Young
- Molecular & Cellular Biochemistry Department, University of Kentucky, Lexington, KY 40536, USA.
| | - Lance A Johnson
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA.
| | - Ramon Sun
- Molecular & Cellular Biochemistry Department, University of Kentucky, Lexington, KY 40536, USA.
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6
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Liu M, Bachstetter AD, Cass WA, Lifshitz J, Bing G. Pioglitazone Attenuates Neuroinflammation and Promotes Dopaminergic Neuronal Survival in the Nigrostriatal System of Rats after Diffuse Brain Injury. J Neurotrauma 2016; 34:414-422. [PMID: 27142118 DOI: 10.1089/neu.2015.4361] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Increasing evidence suggests that traumatic brain injury (TBI) may raise the risk of developing late-onset Parkinson's disease (PD). Recently, the peroxisome proliferation-activated receptor gamma (PPARγ) agonist pioglitazone has been demonstrated to be neuroprotective in animal models of neurodegeneration. The present study investigates the vulnerability of the nigrostriatal system after TBI, and intervention with pioglitazone treatment. Adult male Sprague-Dawley rats were subjected to sham or moderate midline fluid percussion brain injury (mFPI), followed by an intraperitoneal injection of 10 mg/kg pioglitazone or vehicle beginning 30 min after the injury and subsequently every 24 h for 5 days. Following injury, pro-inflammatory cytokines and chemokine were acutely increased in the striatum and substantia nigra within 6 h. Dopaminergic axonal damage and microglial activation were revealed using immunohistochemistry in the medial forebrain bundle at 1 day post-injury. Microglial activation identified by Iba1 and OX-6 immunostaining was persistently increased in the substantia nigra pars compacta 7 to 28 days post-injury. Further, brain injury induced significant dopaminergic neuronal loss, which was quantified by tyrosine hydroxylase immunostaining and retrograde fluorescent tracer fluorogold labeling in the nigra at 28 days. Loss of neurons was accompanied by increased extracellular dopamine (DA) turnover in the striatum, indicating enhanced dopaminergic activity in functional compensation after nigrostriatal damage. Strikingly, pioglitazone treatment greatly attenuated microglial activation and improved dopaminergic neuronal survival in the nigrostriatal system, which may promote locomotor recovery. These results suggest that interventions that attenuate secondary inflammation could be a feasible therapeutic treatment to improve outcome after TBI.
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Affiliation(s)
- Mei Liu
- 1 Department of Anatomy and Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Adam D Bachstetter
- 2 Sanders-Brown Center on Aging, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Wayne A Cass
- 1 Department of Anatomy and Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
| | - Jonathan Lifshitz
- 3 BARROW Neurological Institute at Phoenix Children's Hospital; Department of Child Health, University of Arizona College of Medicine, Phoenix, Arizona; Phoenix Veteran Affairs Healthcare System, Phoenix, Arizona; Interdisciplinary Graduate Program in Neuroscience, Arizona State University , Tempe, Arizona
| | - Guoying Bing
- 1 Department of Anatomy and Neurobiology, University of Kentucky College of Medicine , Lexington, Kentucky
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7
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Yonutas HM, Vekaria HJ, Sullivan PG. Mitochondrial specific therapeutic targets following brain injury. Brain Res 2016; 1640:77-93. [PMID: 26872596 DOI: 10.1016/j.brainres.2016.02.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 01/29/2016] [Accepted: 02/02/2016] [Indexed: 02/03/2023]
Abstract
Traumatic brain injury is a complicated disease to treat due to the complex multi-factorial secondary injury cascade that is initiated following the initial impact. This secondary injury cascade causes nonmechanical tissue damage, which is where therapeutic interventions may be efficacious for intervention. One therapeutic target that has shown much promise following brain injury are mitochondria. Mitochondria are complex organelles found within the cell. At a superficial level, mitochondria are known to produce the energy substrate used within the cell called ATP. However, their importance to overall cellular homeostasis is even larger than their production of ATP. These organelles are necessary for calcium cycling, ROS production and play a role in the initiation of cell death pathways. When mitochondria become dysfunctional, they can become dysregulated leading to a loss of cellular homeostasis and eventual cell death. Within this review there will be a deep discussion into mitochondrial bioenergetics followed by a brief discussion into traumatic brain injury and how mitochondria play an integral role in the neuropathological sequelae following an injury. The review will conclude with a discussion pertaining to the therapeutic approaches currently being studied to ameliorate mitochondrial dysfunction following brain injury. This article is part of a Special Issue entitled SI:Brain injury and recovery.
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Affiliation(s)
- H M Yonutas
- University of Kentucky, 741 South Limestone Street, BBSRB 475, 30536 Lexington, United States
| | - H J Vekaria
- University of Kentucky, 741 South Limestone Street, BBSRB 475, 30536 Lexington, United States
| | - P G Sullivan
- University of Kentucky, 741 South Limestone Street, BBSRB 475, 30536 Lexington, United States.
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8
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Nikolaeva I, Crowell B, Valenziano J, Meaney D, D'Arcangelo G. Beneficial Effects of Early mTORC1 Inhibition after Traumatic Brain Injury. J Neurotrauma 2015; 33:183-93. [PMID: 26122481 DOI: 10.1089/neu.2015.3899] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) signaling pathway mediates many aspects of cell growth and regeneration and is upregulated after moderate to severe traumatic brain injury (TBI). The significance of this increased signaling event for recovery of brain function is presently unclear. We analyzed the time course and cell specificity of mTORC1 signal activation in the mouse hippocampus after moderate controlled cortical impact (CCI) and identified an early neuronal peak of activity that occurs within a few hours after injury. We suppressed this peak activity by a single injection of the mTORC1 inhibitor rapamycin 1 h after CCI and showed that this acute treatment significantly diminishes the extent of neuronal death, astrogliosis, and cognitive impairment 1-3 days after injury. Our findings suggest that the early neuronal peak of mTORC1 activity after TBI is deleterious to brain function, and that acute, early intervention with mTORC1 inhibitors after injury may represent an effective form of treatment to improve recovery in human patients.
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Affiliation(s)
- Ina Nikolaeva
- 1 Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey.,2 Graduate Program in Molecular Bioscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey
| | - Beth Crowell
- 1 Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey
| | - Julia Valenziano
- 3 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - David Meaney
- 3 Department of Bioengineering, University of Pennsylvania , Philadelphia, Pennsylvania
| | - Gabriella D'Arcangelo
- 1 Department of Cell Biology and Neuroscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey.,2 Graduate Program in Molecular Bioscience, Rutgers, the State University of New Jersey , Piscataway, New Jersey
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9
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Foster KA, Recker MJ, Lee PS, Bell MJ, Tyler-Kabara EC. Factors associated with hemispheric hypodensity after subdural hematoma following abusive head trauma in children. J Neurotrauma 2014; 31:1625-31. [PMID: 24693985 DOI: 10.1089/neu.2014.3372] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abusive head trauma (AHT) is a unique form of pediatric TBI with increased mortality and neurologic sequelae. Hemispheric hypodensity (HH) in association with subdural blood after AHT has been described. Though risk factors for HH are not understood, we hypothesized that risk factors could be identified. We retrospectively enrolled children under 5 years with TBI secondary to AHT (child advocacy diagnosis) who had undergone initial and interval brain imaging. Records were interrogated for prearrival and in-hospital physiologic and radiographic findings. HH was determined by a blinded observer. Twenty-four children were enrolled and 13 developed HH. HH was not significantly associated with age, initial Glascow Coma Scale, or mortality. Pediatric Intensity Level of Therapy (PILOT) scores (p=0.01) and daily maximal intracranial pressure (ICPmax; p=0.037) were higher in HH. Hypoxia, hypotension, cardiopulmonary arrest, need for blood transfusion, and daily blood glucoses tended to be greater in HH. Whereas all children with HH had acute subdural hematoma (SBH), many children without HH also had subdural blood; the presence of skull fracture was more likely in the children who did not develop HH (p=0.04), but no other intracranial radiographic pattern of injury was associated with HH. Surgical intervention did not appear to protect against development of HH. A variety of insults associated with ischemia, including intracranial hypertension, ICP-directed therapies, hypoxia, hypotension, and cardiac arrest, occurred in the children who developed HH. Given the morbidity and mortality of this condition, larger studies to identify mechanisms leading to the development of HH and mitigating clinical approaches are warranted.
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Affiliation(s)
- Kimberly A Foster
- 1 Department of Neurological Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
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10
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Boyko M, Gruenbaum SE, Gruenbaum BF, Shapira Y, Zlotnik A. Brain to blood glutamate scavenging as a novel therapeutic modality: a review. J Neural Transm (Vienna) 2014; 121:971-9. [PMID: 24623040 DOI: 10.1007/s00702-014-1181-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 02/11/2014] [Indexed: 12/27/2022]
Abstract
It is well known that abnormally elevated glutamate levels in the brain are associated with secondary brain injury following acute and chronic brain insults. As such, a tight regulation of brain glutamate concentrations is of utmost importance in preventing the neurodegenerative effects of excess glutamate. There has been much effort in recent years to better understand the mechanisms by which glutamate is reduced in the brain to non-toxic concentrations, and in how to safely accelerate these mechanisms. Blood glutamate scavengers such as oxaloacetate, pyruvate, glutamate-oxaloacetate transaminase, and glutamate-pyruvate transaminase have been shown to reduce blood glutamate concentrations, thereby increasing the driving force of the brain to blood glutamate efflux and subsequently reducing brain glutamate levels. In the past decade, blood glutamate scavengers have gained increasing international interest, and its uses have been applied to a wide range of experimental contexts in animal models of traumatic brain injury, ischemic stroke, subarachnoid hemorrhage, epilepsy, migraine, and malignant gliomas. Although glutamate scavengers have not yet been used in humans, there is increasing evidence that their use may provide effective and exciting new therapeutic modalities. Here, we review the laboratory evidence for the use of blood glutamate scavengers. Other experimental neuroprotective treatments thought to scavenge blood glutamate, including estrogen and progesterone, beta-adrenergic activation, hypothermia, insulin and glucagon, and hemodialysis and peritoneal dialysis are also discussed. The evidence reviewed here will hopefully pave the way for future clinical trials.
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Affiliation(s)
- Matthew Boyko
- Department of Anesthesiology and Critical Care, Faculty of Health Sciences, Soroka Medical Center Ben Gurion University of the Negev, Beer Sheba, Israel
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11
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Papa L, Robinson G, Oli M, Pineda J, Demery J, Brophy G, Robicsek SA, Gabrielli A, Robertson CS, Wang KK, Hayes RL. Use of biomarkers for diagnosis and management of traumatic brain injury patients. ACTA ACUST UNITED AC 2013; 2:937-45. [PMID: 23495867 DOI: 10.1517/17530059.2.8.937] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Advances in the understanding of human biochemistry and physiology have provided insight into new pathways by which we can understand traumatic brain injury (TBI). Increased sophistication of laboratory techniques and developments in the field of proteomics has led to the discovery and rapid detection of new biomarkers not previously available. OBJECTIVE To review recent advances in biomarker research for traumatic brain injury, describe the features of the ideal biomarker and to explore the potential role of these biomarkers in improving clinical management of brain injured patients. METHODS Through a literature review of recent research on TBI biomarkers and through experience with TBI research, important elements of biomarker development are described together with potential applications to patient care. CONCLUSIONS TBI biomarkers could have a significant impact on patient care by assisting in the diagnosis, risk stratification and management of TBI. Biomarkers could provide major opportunities for the conduct of clinical research, including confirmation of injury mechanism(s) and drug target identification. Continuing studies by the authors' group are now being conducted to elucidate more fully the relationships between new biomarkers and severity of injury and clinical outcomes in all severities of TBI patients.
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Affiliation(s)
- Linda Papa
- Director of Academic Clinical Research Orlando Regional Medical Center, Department of Emergency Medicine, 86 W. Underwood (S-200), Orlando, FL 32806, USA +1 407 237 6329 ; +1 407 649 3083 ;
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12
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Alessandri B, Schwandt E, Kamada Y, Nagata M, Heimann A, Kempski O. The neuroprotective effect of lactate is not due to improved glutamate uptake after controlled cortical impact in rats. J Neurotrauma 2012; 29:2181-91. [PMID: 22888957 DOI: 10.1089/neu.2011.2067] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
For many years lactate was considered to be a waste product of glycolysis. Data are accumulating that suggest that lactate is an important energy substrate for neurons during activation. In severe traumatic brain injury (TBI) glutamate release and ischemic cerebral blood flow (CBF) are major factors for a mismatch between energy demand and supply and for neuronal cell death. Although ATP and behavior could be improved by lactate treatment after TBI, no histological correlate nor any linkage to better astrocytic glutamate uptake or CBF as possible mechanisms have been described. We subjected male rats to a controlled cortical impact (CCI; 5 m/sec, 2.5 mm). To study the effects of lactate treatment on lesion volume, glutamate release, and CBF, animals were infused with either NaCl or 100 mM lactate for up to 3 h. The role of endogenous lactate was investigated by inhibiting transport with α-cyano-4-hydroxy-cinnamic acid (4-CIN; 90 mg/kg). Lactate treatment 15 min post-CCI reduced lesion volume from 21.1±2.8 mm³ to 12.1±1.9 mm³ at day 2 after CCI. Contusion produced a significant three- to fourfold increase of glutamate in microdialysates, but there was no significant difference between treatments that began 30 min before CCI. In this experiment lesion volume was significantly reduced by lactate at day 7 post-CCI (23.7±4 to 9.3±1-2 mm³). CBF increased immediately after CCI and dropped thereafter below baseline in all animals. Lactate infusion 15 min post-CCI elevated CBF for 20 min in 7 of 10 animals, whereas 7 of 8 NaCl-treated animals showed a further CBF decline. Neuroprotection was achieved by lactate treatment following contusion injury, whereas blocking of endogenous lactate transport exerted no adverse effects. Neuroprotection was not achieved by improved glutamate uptake into astrocytes, but was supported by augmented CBF following CCI. Due to its neuroprotective property, lactate might be a beneficial pharmacological treatment for TBI patients.
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Affiliation(s)
- Beat Alessandri
- Institute for Neurosurgical Pathophysiology, University Medical Center of the Johannes Gutenberg-University of Mainz, Mainz, Germany.
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13
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Leibowitz A, Boyko M, Shapira Y, Zlotnik A. Blood glutamate scavenging: insight into neuroprotection. Int J Mol Sci 2012; 13:10041-10066. [PMID: 22949847 PMCID: PMC3431845 DOI: 10.3390/ijms130810041] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/18/2012] [Accepted: 07/30/2012] [Indexed: 11/16/2022] Open
Abstract
Brain insults are characterized by a multitude of complex processes, of which glutamate release plays a major role. Deleterious excess of glutamate in the brain's extracellular fluids stimulates glutamate receptors, which in turn lead to cell swelling, apoptosis, and neuronal death. These exacerbate neurological outcome. Approaches aimed at antagonizing the astrocytic and glial glutamate receptors have failed to demonstrate clinical benefit. Alternatively, eliminating excess glutamate from brain interstitial fluids by making use of the naturally occurring brain-to-blood glutamate efflux has been shown to be effective in various animal studies. This is facilitated by gradient driven transport across brain capillary endothelial glutamate transporters. Blood glutamate scavengers enhance this naturally occurring mechanism by reducing the blood glutamate concentration, thus increasing the rate at which excess glutamate is cleared. Blood glutamate scavenging is achieved by several mechanisms including: catalyzation of the enzymatic process involved in glutamate metabolism, redistribution of glutamate into tissue, and acute stress response. Regardless of the mechanism involved, decreased blood glutamate concentration is associated with improved neurological outcome. This review focuses on the physiological, mechanistic and clinical roles of blood glutamate scavenging, particularly in the context of acute and chronic CNS injury. We discuss the details of brain-to-blood glutamate efflux, auto-regulation mechanisms of blood glutamate, natural and exogenous blood glutamate scavenging systems, and redistribution of glutamate. We then propose different applied methodologies to reduce blood and brain glutamate concentrations and discuss the neuroprotective role of blood glutamate scavenging.
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Affiliation(s)
- Akiva Leibowitz
- Author to whom correspondence should be addressed; E-Mail: ; Tel: +972-8-6400262; Fax: +972-8-6403795
| | | | - Yoram Shapira
- Department of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University, Beer Sheva 84894, Israel; E-Mails: (M.B.); (Y.S.); (A.Z.)
| | - Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University, Beer Sheva 84894, Israel; E-Mails: (M.B.); (Y.S.); (A.Z.)
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Hinzman JM, Thomas TC, Quintero JE, Gerhardt GA, Lifshitz J. Disruptions in the regulation of extracellular glutamate by neurons and glia in the rat striatum two days after diffuse brain injury. J Neurotrauma 2012; 29:1197-208. [PMID: 22233432 DOI: 10.1089/neu.2011.2261] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Disrupted regulation of extracellular glutamate in the central nervous system contributes to and can exacerbate the acute pathophysiology of traumatic brain injury (TBI). Previously, we reported increased extracellular glutamate in the striatum of anesthetized rats 2 days after diffuse brain injury. To determine the mechanism(s) responsible for increased extracellular glutamate, we used enzyme-based microelectrode arrays (MEAs) coupled with specific pharmacological agents targeted at in vivo neuronal and glial regulation of extracellular glutamate. After TBI, extracellular glutamate was significantly increased in the striatum by (∼90%) averaging 4.1±0.6 μM compared with sham 2.2±0.4 μM. Calcium-dependent neuronal glutamate release, investigated by local application of an N-type calcium channel blocker, was no longer a significant source of extracellular glutamate after TBI, compared with sham. In brain-injured animals, inhibition of glutamate uptake with local application of an excitatory amino acid transporter inhibitor produced significantly greater increase in glutamate spillover (∼ 65%) from the synapses compared with sham. Furthermore, glutamate clearance measured by locally applying glutamate into the extracellular space revealed significant reductions in glutamate clearance parameters in brain-injured animals compared with sham. Taken together, these data indicate that disruptions in calcium-mediated glutamate release and glial regulation of extracellular glutamate contribute to increased extracellular glutamate in the striatum 2 days after diffuse brain injury. Overall, these data suggest that therapeutic strategies used to regulate glutamate release and uptake may improve excitatory circuit function and, possibly, outcomes following TBI.
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Affiliation(s)
- Jason M Hinzman
- Department of Anatomy and Neurobiology, University of Kentucky Chandler Medical Center, Lexington, Kentucky 40536-0509, USA
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15
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Zlotnik A, Leibowitz A, Gurevich B, Ohayon S, Boyko M, Klein M, Knyazer B, Shapira Y, Teichberg VI. Effect of estrogens on blood glutamate levels in relation to neurological outcome after TBI in male rats. Intensive Care Med 2011; 38:137-44. [PMID: 22124768 DOI: 10.1007/s00134-011-2401-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 11/02/2011] [Indexed: 10/15/2022]
Abstract
PURPOSE Estrogen has been shown to possess neuroprotective properties both in vitro and in vivo. Traumatic brain injury (TBI) in ovulating females results in favorable neurological outcomes when compared to males with similar insults. The brain-to-blood glutamate gradient removes excess glutamate from brain extracellular fluids (ECF). Enhancing this gradient leads to improved neurological outcomes following TBI. In this study we investigate the effect of female gonadal steroids on blood glutamate levels and neurological outcomes. METHODS Forty male Sprague-Dawley rats were assigned to one of five groups: (1) sham, (2) Premarin treatment, (3) TBI, (4) TBI + Premarin treatment, and (5) TBI + Premarin pretreatment. TBI was induced, and estrogen and glutamate levels were determined at 0, 60, 120, 135, and 150 min. Neurological recovery was evaluated using the Neurological Severity Score (NSS) at 1 h and reassessed at 24 h post TBI. RESULTS Premarin treatment groups demonstrated a decline in blood glutamate levels by 60 min. This decline was found to be more pronounced in the TBI + Premarin group, which maintained the decline throughout the experiment. At 120 min, the difference between groups was most pronounced (TBI + Premarin 99 ± 36 μM/l vs. control 200 ± 46 μM/l, p < 0.01). Neurological recovery was significantly better in the Premarin treatment group (NSS at 24 h 6 ± 1 vs. control 11 ± 1). CONCLUSIONS Premarin injected into male rats significantly decreases blood glutamate levels in rats suffering TBI. This decrease is associated with improved neurological outcomes, thus implicating the role of estrogen in neuroprotection.
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Affiliation(s)
- Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer Sheva, Israel
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O'Connor WT, Smyth A, Gilchrist MD. Animal models of traumatic brain injury: A critical evaluation. Pharmacol Ther 2011; 130:106-13. [DOI: 10.1016/j.pharmthera.2011.01.001] [Citation(s) in RCA: 123] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Accepted: 11/17/2010] [Indexed: 11/28/2022]
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17
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Zlotnik A, Gurevich B, Artru AA, Gruenbaum SE, Dubilet M, Leibowitz A, Shaked G, Ohayon S, Shapira Y, Teichberg VI. The effect of hyperthermia on blood glutamate levels. Anesth Analg 2010; 111:1497-504. [PMID: 21048094 DOI: 10.1213/ane.0b013e3181fc0112] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Glutamate neurotoxicity is determined by the balance between glutamate release within the brain and efflux of excess glutamate from the brain. Brain-to-blood efflux of glutamate is increased by decreasing the concentration of glutamate in blood. Little is known about the effect of hyperthermia on blood glutamate concentrations, and the effectiveness of blood glutamate-decreasing mechanisms in these conditions. Although hyperthermia is hypothesized to decrease blood glutamate concentrations by activation of stress mechanisms, blunting the stress response by blocking β-adrenergic receptors should prevent this decrease. Furthermore, during hyperthermia there should be a concurrent process of leakage of glutamate from muscle tissue into blood, resulting in a contradictory increase of blood glutamate concentrations. In this study we investigated the effects of hyperthermia on blood glutamate levels and studied the effects of the β-adrenergic receptor antagonist propranolol on stress-induced changes in glutamate levels. We then studied the effectiveness of the blood glutamate scavenger oxaloacetate on hyperthermia-induced increases of glutamate levels. MATERIALS AND METHODS Twenty-four rats were randomly divided into 3 groups. Rats' body temperatures were increased (by 1°C every 40 minutes) from 37°C to 42°C. The first group received 1 mL per 100 g of isotonic saline (control). The second group received 1 mL per 100 g of 1M oxaloacetate when the temperature reached 39°C. The third group received 10 mg/kg of propranolol before initiation of the warming. RESULTS Warming the rats from 37°C to 39°C decreased the blood glutamate levels in the control group (P < 0.01) and oxaloacetate treatment group (P < 0.0001), whereas further increases in temperature from 40°C to 42°C increased the blood glutamate levels (P < 0.01 and P < 0.0001, respectively). Pretreatment with propranolol prevented the decrease in blood glutamate concentrations seen in mild hyperthermia and did not affect the increase in blood glutamate levels seen at temperatures of 41°C and 42°C (P < 0.005). DISCUSSION The results of this study demonstrated that hyperthermia leads to decreases in glutamate levels in the blood, presumably by activation of the sympathetic nervous system. Oxaloacetate, previously reported to reduce blood glutamate levels at 37°C, was ineffective at temperatures over 40°C. Propranolol pretreatment blunted the initial decrease in blood glutamate, and thereafter had no effect when compared with control and treatment groups. Understanding the mechanisms underlying glutamate regulation in the blood during states of hyperthermia and stress has important clinical implications in treating neurodegenerative conditions.
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Affiliation(s)
- Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka University Medical Center, Ben Gurion University, Beer Sheva, Israel
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18
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Klin Y, Zlotnik A, Boyko M, Ohayon S, Shapira Y, Teichberg VI. Distribution of radiolabeled l-glutamate and d-aspartate from blood into peripheral tissues in naive rats: significance for brain neuroprotection. Biochem Biophys Res Commun 2010; 399:694-8. [PMID: 20691657 DOI: 10.1016/j.bbrc.2010.07.144] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Accepted: 07/30/2010] [Indexed: 11/17/2022]
Abstract
Excess l-glutamate (glutamate) levels in brain interstitial and cerebrospinal fluids (ISF and CSF, respectively) are the hallmark of several neurodegenerative conditions such as stroke, traumatic brain injury or amyotrophic lateral sclerosis. Its removal could prevent the glutamate excitotoxicity that causes long-lasting neurological deficits. As in previous studies, we have established the role of blood glutamate levels in brain neuroprotection, we have now investigated the contribution of the peripheral organs to the homeostasis of glutamate in blood. We have administered naive rats with intravenous injections of either l-[1-(14)C] Glutamic acid (l-[1-(14)C] Glu), l-[G-(3)H] Glutamic acid (l-[G-(3)H] Glu) or d-[2,3-(3)H] Aspartic acid (d-[2,3-(3)H] Asp), a non-metabolized analog of glutamate, and have followed their distribution into peripheral organs. We have observed that the decay of the radioactivity associated with l-[1-(14)C] Glu and l-[G-(3)H] Glu was faster than that associated with glutamate non-metabolized analog, d-[2,3-(3)H] Asp. l-[1-(14)C] Glu was subjected in blood to a rapid decarboxylation with the loss of (14)CO(2). The three major sequestrating organs, serving as depots for the eliminated glutamate and/or its metabolites were skeletal muscle, liver and gut, contributing together 92% or 87% of total l-[U-(14)C] Glu or d-[2,3-(3)H] Asp radioactivity capture. l-[U-(14)C] Glu and d-[2,3-(3)H] Asp showed a different organ sequestration pattern. We conclude that glutamate is rapidly eliminated from the blood into peripheral tissues, mainly in non-metabolized form. The liver plays a central role in glutamate metabolism and serves as an origin for glutamate metabolites that redistribute into skeletal muscle and gut. The findings of this study suggest now that pharmacological manipulations that reduce the liver glutamate release rate or cause a boosting of the skeletal muscle glutamate pumping rate are likely to cause brain neuroprotection.
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Affiliation(s)
- Yael Klin
- Department of Neurobiology, The Weizmann Institute of Science, Rehovot 76100, Israel
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19
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Regulation of blood L-glutamate levels by stress as a possible brain defense mechanism. Exp Neurol 2010; 224:465-71. [DOI: 10.1016/j.expneurol.2010.05.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2010] [Revised: 05/02/2010] [Accepted: 05/12/2010] [Indexed: 11/21/2022]
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20
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Traumatic brain injury reduces soluble extracellular amyloid-β in mice: a methodologically novel combined microdialysis-controlled cortical impact study. Neurobiol Dis 2010; 40:555-64. [PMID: 20682338 DOI: 10.1016/j.nbd.2010.06.018] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2010] [Revised: 06/22/2010] [Accepted: 06/26/2010] [Indexed: 12/21/2022] Open
Abstract
Acute amyloid-β peptide (Aβ) deposition has been observed in young traumatic brain injury (TBI) patients, leading to the hypothesis that elevated extracellular Aβ levels could underlie the increased risk of dementia following TBI. However, a recent microdialysis-based study in human brain injury patients found that extracellular Aβ dynamics correlate with changes in neurological status. Because neurological status is generally diminished following injury, this correlation suggested the alternative hypothesis that soluble extracellular Aβ levels may instead be reduced after TBI relative to baseline. We have developed a methodologically novel mouse model that combines experimental controlled cortical impact TBI with intracerebral microdialysis. In this model, we found that Aβ levels in microdialysates were immediately decreased by 25-50% in the ipsilateral hippocampus following TBI. This result was found in PDAPP, Tg2576, and Tg2576-ApoE2 transgenic mice producing human Aβ plus wild-type animals. Changes were not due to altered probe function, edema, changes in APP levels, or Aβ deposition. Similar decreases in Aβ were observed in phosphate buffered saline-soluble tissue extracts. Hippocampal electroencephalographic activity was also decreased up to 40% following TBI, and correlated with reduced microdialysate Aβ levels. These results support the alternative hypothesis that post-injury extracellular soluble Aβ levels are acutely decreased relative to baseline. Reduced neuronal activity may contribute, though the underlying mechanisms have not been definitively determined. Further work will be needed to assess the dynamics of insoluble and oligomeric Aβ after TBI.
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Bell JD, Park E, Ai J, Baker AJ. PICK1-mediated GluR2 endocytosis contributes to cellular injury after neuronal trauma. Cell Death Differ 2009; 16:1665-80. [DOI: 10.1038/cdd.2009.106] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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22
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The Neuroprotective Effects of Oxaloacetate in Closed Head Injury in Rats is Mediated by its Blood Glutamate Scavenging Activity. J Neurosurg Anesthesiol 2009; 21:235-41. [DOI: 10.1097/ana.0b013e3181a2bf0b] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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23
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Alessandri B, Gugliotta M, Levasseur JE, Bullock MR. Lactate and glucose as energy substrates and their role in traumatic brain injury and therapy. FUTURE NEUROLOGY 2009. [DOI: 10.2217/14796708.4.2.209] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Traumatic brain injury is a leading cause of disability and mortality worldwide, but no new pharmacological treatments are clinically available. A key pathophysiological development in the understanding of traumatic brain injury is the energy crisis derived from decreased cerebral blood flow, increased energy demand and mitochondrial dysfunction. Although still controversial, new findings suggest that brain cells try to cope in these conditions by metabolizing lactate as an energy substrate ‘on-demand’ in lieu of glucose. Experimental and clinical data suggest that lactate, at least when exogenously administered, is transported from astrocytes to neurons for neuronal utilization, essentially bypassing the slow, catabolizing glycolysis process to quickly and efficiently produce ATP. Treatment strategies using systemically applied lactate have proved to be protective in various experimental traumatic brain injury studies. However, lactate has the potential to elevate oxygen consumption to high levels and, therefore, could potentially impose a danger for tissue-at-risk with low cerebral blood flow. The present review outlines the experimental basis of lactate in energy metabolism under physiological and pathophysiological conditions and presents arguments for lactate as a new therapeutical tool in human head injury.
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Affiliation(s)
- Beat Alessandri
- Johannes Gutenberg University, Institute for Neurosurgical Pathophysiology, Langenbeckstrasse 1, D-55131 Mainz, Germany
| | - Marinella Gugliotta
- Department of Neurosurgery, University Hospital of Lausanne (CHUV), Lausanne, Switzerland
| | - Joseph E Levasseur
- Department of Neurosurgery, VCU Medical Center, PO Box 980631, Richmond, VA 23298, USA
| | - M Ross Bullock
- Department of Neurosurgery, University of Miami Miller School of Medicine, Lois Pope LIFE Center, Room 3–20, 1095 NW 14th Terrace, Miami, FL 33136, USA
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24
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Teichberg V, Cohen-Kashi-Malina K, Cooper I, Zlotnik A. Homeostasis of glutamate in brain fluids: An accelerated brain-to-blood efflux of excess glutamate is produced by blood glutamate scavenging and offers protection from neuropathologies. Neuroscience 2009; 158:301-8. [DOI: 10.1016/j.neuroscience.2008.02.075] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2007] [Revised: 02/26/2008] [Accepted: 02/29/2008] [Indexed: 10/22/2022]
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25
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The Contribution of the Blood Glutamate Scavenging Activity of Pyruvate to its Neuroprotective Properties in a Rat Model of Closed Head Injury. Neurochem Res 2007; 33:1044-50. [DOI: 10.1007/s11064-007-9548-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Accepted: 11/08/2007] [Indexed: 10/22/2022]
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26
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Cheng JP, Aslam HA, Hoffman AN, Zafonte RD, Kline AE. The neurobehavioral benefit conferred by a single systemic administration of 8-OH-DPAT after brain trauma is confined to a narrow therapeutic window. Neurosci Lett 2007; 416:165-8. [PMID: 17321680 PMCID: PMC1876743 DOI: 10.1016/j.neulet.2007.02.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 02/01/2007] [Accepted: 02/01/2007] [Indexed: 11/15/2022]
Abstract
The 5-HT(1A) receptor agonist 8-OH-DPAT (0.5mg/kg) enhances behavioral recovery when administered 15min after experimental traumatic brain injury (TBI). To determine if benefits are still attainable at clinically relevant times, treatment was delayed 1 and 2h post-TBI and motor/cognitive performance was compared to early (i.e., 15min) administration. No differences were observed among the vehicle and 8-OH-DPAT groups treated at 1 and 2h, but all three were significantly impaired versus early 8-OH-DPAT. The data suggest that an early and narrow critical period exists for the behavioral recovery afforded by a single 8-OH-DPAT treatment paradigm. The critical window corresponds to the well documented TBI-induced glutamate increase, suggesting that 8-OH-DPAT may be conferring neuroprotection by attenuating this acute deleterious surge.
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Affiliation(s)
- Jeffrey P Cheng
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15260, USA
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27
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Zlotnik A, Gurevich B, Tkachov S, Maoz I, Shapira Y, Teichberg VI. Brain neuroprotection by scavenging blood glutamate. Exp Neurol 2007; 203:213-20. [PMID: 17014847 DOI: 10.1016/j.expneurol.2006.08.021] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2006] [Revised: 08/02/2006] [Accepted: 08/04/2006] [Indexed: 10/24/2022]
Abstract
Excess glutamate in brain fluids characterizes acute brain insults such as traumatic brain injury and stroke. Its removal could prevent the glutamate excitotoxicity that causes long-lasting neurological deficits. As blood glutamate scavenging has been demonstrated to increase the efflux of excess glutamate from brain into blood, we tested the prediction that oxaloacetate-mediated blood glutamate scavenging causes neuroprotection in a pathological situation such as closed head injury (CHI), in which there is a well established deleterious increase of glutamate in brain fluids. We observed highly significant improvements of the neurological status of rats submitted to CHI following an intravenous treatment with 1 mmol oxaloacetate/100 g rat weight which decreases blood glutamate levels by 40%. No detectable therapeutic effect was obtained when rats were treated IV with 1 mmol oxaloacetate together with 1 mmol glutamate/100 g rat. The treatment with 0.005 mmol/100 g rat oxaloacetate was no more effective than saline but when it was combined with the intravenous administration of 0.14 nmol/100 g of recombinant glutamate-oxaloacetate transaminase, recovery was almost complete. Oxaloacetate provided neuroprotection when administered before CHI or at 60 min post CHI but not at 120 min post CHI. Since neurological recovery from CHI was highly correlated with the decrease of blood glutamate levels (r=0.89, P=0.001), we conclude that blood glutamate scavenging affords brain neuroprotection Blood glutamate scavenging may open now new therapeutic options.
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Affiliation(s)
- Alexander Zlotnik
- Division of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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28
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Kline AE, Wagner AK, Westergom BP, Malena RR, Zafonte RD, Olsen AS, Sozda CN, Luthra P, Panda M, Cheng JP, Aslam HA. Acute treatment with the 5-HT(1A) receptor agonist 8-OH-DPAT and chronic environmental enrichment confer neurobehavioral benefit after experimental brain trauma. Behav Brain Res 2006; 177:186-94. [PMID: 17166603 PMCID: PMC1850378 DOI: 10.1016/j.bbr.2006.11.036] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2006] [Revised: 11/13/2006] [Accepted: 11/21/2006] [Indexed: 11/24/2022]
Abstract
Acute treatment with the 5-HT(1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) or chronic environmental enrichment (EE) hasten behavioral recovery after experimental traumatic brain injury (TBI). The aim of this study was to determine if combining these interventions would confer additional benefit. Anesthetized adult male rats received either a cortical impact or sham injury followed 15min later by a single intraperitoneal injection of 8-OH-DPAT (0.5mg/kg) or saline vehicle (1.0mL/kg) and then randomly assigned to either enriched or standard (STD) housing. Behavioral assessments were conducted utilizing established motor and cognitive tests on post-injury days 1-5 and 14-18, respectively. Hippocampal CA(1)/CA(3) neurons were quantified at 3 weeks. Both 8-OH-DPAT and EE attenuated CA(3) cell loss. 8-OH-DPAT enhanced spatial learning in a Morris water maze (MWM) as revealed by differences between the TBI+8-OH-DPAT+STD and TBI+VEHICLE+STD groups (P=0.0014). EE improved motor function as demonstrated by reduced time to traverse an elevated narrow beam in both the TBI+8-OH-DPAT+EE and TBI+VEHICLE+EE groups versus the TBI+VEHICLE+STD group (P=0.0007 and 0.0016, respectively). EE also facilitated MWM learning as evidenced by both the TBI+8-OH-DPAT+EE and TBI+VEHICLE+EE groups locating the escape platform quicker than the TBI+VEHICLE+STD group (P's<0.0001). MWM differences were also observed between the TBI+8-OH-DPAT+EE and TBI+8-OH-DPAT+STD groups (P=0.0004) suggesting that EE enhanced the effect of 8-OH-DPAT. However, there was no difference between the TBI+8-OH-DPAT+EE and TBI+VEHICLE+EE groups. These data replicate previous results from our laboratory showing that both a single systemic administration of 8-OH-DPAT and EE improve recovery after TBI and extend those findings by elucidating that the combination of treatments in this particular paradigm did not confer additional benefit. One explanation for the lack of an additive effect is that EE is a very effective treatment and thus there is very little room for 8-OH-DPAT to confer additional statistically significant improvement.
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Affiliation(s)
- Anthony E Kline
- Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, PA 15213, United States.
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29
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Pettus EH, Wright DW, Stein DG, Hoffman SW. Progesterone treatment inhibits the inflammatory agents that accompany traumatic brain injury. Brain Res 2005; 1049:112-9. [PMID: 15932748 DOI: 10.1016/j.brainres.2005.05.004] [Citation(s) in RCA: 185] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Revised: 05/03/2005] [Accepted: 05/03/2005] [Indexed: 02/08/2023]
Abstract
Progesterone given after traumatic brain injury (TBI) has been shown to reduce the initial cytotoxic surge of inflammatory factors. We used Western blot techniques to analyze how progesterone might affect three inflammation-related factors common to TBI: complement factor C3 (C3), glial fibrillary acidic protein (GFAP), and nuclear factor kappa beta (NFkappaB). One hour after bilateral injury to the medial frontal cortex, adult male rats were given injections of progesterone (16 mg/kg) for 2 days. Brains were harvested 48 h post-TBI, proteins were extracted from samples, each of which contained tissue from both the contused and peri-contused areas, then measured by Western blot densitometry. Complete C3, GFAP, and NFkappaB p65 were increased in all injured animals. However, in animals given progesterone post-TBI, NFkappaB p65 and the inflammatory metabolites of C3 (9 kDa and 75 kDa) were decreased in comparison to vehicle-treated animals. Measures of NFkappaB p50 showed no change after injury or progesterone treatment, and progesterone did not alter the expression of GFAP. The therapeutic benefit of post-TBI progesterone administration may be due to its salutary effect on inflammatory proteins known to increase immune cell invasion and cerebral edema.
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Affiliation(s)
- Edward H Pettus
- Department of Cell Biology, Emory University, Atlanta, GA 30322, USA
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Dash PK, Moore AN, Moody MR, Treadwell R, Felix JL, Clifton GL. Post-Trauma Administration of Caffeine Plus Ethanol Reduces Contusion Volume and Improves Working Memory in Rats. J Neurotrauma 2004; 21:1573-83. [PMID: 15684650 DOI: 10.1089/neu.2004.21.1573] [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: 11/13/2022] Open
Abstract
It has been demonstrated that ethanol exerts dose-dependent effects, both beneficial and detrimental, on the outcome of traumatic brain injury (TBI). Recently, it has been reported that co-administration of caffeine (10 mg/kg) and a low amount of alcohol (0.65 g/kg; caffeinol) reduces cortical infarct volume up to 80%, and improves motor coordination, following a rodent model of reversible common carotid/middle cerebral artery occlusion. However, the protective effects of caffeinol following other CNS insults, nor its influence on cognitive function, have been examined. Using a controlled cortical impact model of brain injury, the effect of caffeinol administration on TBI-associated motor and cognitive deficits was assessed. When given 15 min following injury, caffeinol reduced cortical tissue loss and improved working memory. However, no influence on motor skills, Morris water maze performance or associative learning and memory was observed. Delayed administration (6 h post-injury) of caffeinol containing a dose of ethanol (1 g/kg) previously demonstrated to improve motor performance eliminated the working memory benefit and cortical protection. These results indicate that early administration of caffeinol may be beneficial in lessening some of the deficits and cortical tissue loss associated with brain trauma.
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Affiliation(s)
- Pramod K Dash
- Vivian L. Smith Center for Neurologic Research, Department of Neurobiology and Anatomy, University of Texas Medical School, Houston, Texas 77225, USA.
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