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Ahluwalia M, Mcmichael H, Kumar M, Espinosa MP, Bosomtwi A, Lu Y, Khodadadi H, Jarrahi A, Khan MB, Hess DC, Rahimi SY, Vender JR, Vale FL, Braun M, Baban B, Dhandapani KM, Vaibhav K. Altered endocannabinoid metabolism compromises the brain-CSF barrier and exacerbates chronic deficits after traumatic brain injury in mice. Exp Neurol 2023; 361:114320. [PMID: 36627040 PMCID: PMC9904276 DOI: 10.1016/j.expneurol.2023.114320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 12/07/2022] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
Endocannabinoids [2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine (AEA)], endogenously produced arachidonate-based lipids, are anti-inflammatory physiological ligands for two known cannabinoid receptors, CB1 and CB2, yet the molecular and cellular mechanisms underlying their effects after brain injury are poorly defined. In the present study, we hypothesize that traumatic brain injury (TBI)-induced loss of endocannabinoids exaggerates neurovascular injury, compromises brain-cerebrospinal fluid (CSF) barriers (BCB) and causes behavioral dysfunction. Preliminary analysis in human CSF and plasma indicates changes in endocannabinoid levels. This encouraged us to investigate the levels of endocannabinoid-metabolizing enzymes in a mouse model of controlled cortical impact (CCI). Reductions in endocannabinoid (2-AG and AEA) levels in plasma were supported by higher expression of their respective metabolizing enzymes, monoacylglycerol lipase (MAGL), fatty acid amide hydrolase (FAAH), and cyclooxygenase 2 (Cox-2) in the post-TBI mouse brain. Following increased metabolism of endocannabinoids post-TBI, we observed increased expression of CB2, non-cannabinoid receptor Transient receptor potential vanilloid-1 (TRPV1), aquaporin 4 (AQP4), ionized calcium binding adaptor molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), and acute reduction in cerebral blood flow (CBF). The BCB and pericontusional cortex showed altered endocannabinoid expressions and reduction in ventricular volume. Finally, loss of motor functions and induced anxiety behaviors were observed in these TBI mice. Taken together, our findings suggest endocannabinoids and their metabolizing enzymes play an important role in the brain and BCB integrity and highlight the need for more extensive studies on these mechanisms.
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Affiliation(s)
- Meenakshi Ahluwalia
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Hannah Mcmichael
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Manish Kumar
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Mario P Espinosa
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Asamoah Bosomtwi
- Georgia Cancer Center, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Yujiao Lu
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Hesam Khodadadi
- Department of Oral Biology and Diagnostic Sciences, Center for Excellence in Research, Scholarship and Innovation, Dental College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Abbas Jarrahi
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Mohammad Badruzzaman Khan
- Department of Neurology, Neuroscience Center of Excellence, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - David C Hess
- Department of Neurology, Neuroscience Center of Excellence, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Scott Y Rahimi
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - John R Vender
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Fernando L Vale
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Molly Braun
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America; Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, United States of America; VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), VA Puget Sound Health Care System, Seattle, WA, United States of America
| | - Babak Baban
- Department of Oral Biology and Diagnostic Sciences, Center for Excellence in Research, Scholarship and Innovation, Dental College of Georgia, Augusta University, Augusta, GA, United States of America; Department of Neurology, Neuroscience Center of Excellence, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Krishnan M Dhandapani
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America
| | - Kumar Vaibhav
- Department of Neurosurgery, Medical College of Georgia, Augusta University, Augusta, GA, United States of America; Department of Oral Biology and Diagnostic Sciences, Center for Excellence in Research, Scholarship and Innovation, Dental College of Georgia, Augusta University, Augusta, GA, United States of America.
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Scheff SW, Ansari MA. Natural Compounds as a Therapeutic Intervention following Traumatic Brain Injury: The Role of Phytochemicals. J Neurotrauma 2016; 34:1491-1510. [PMID: 27846772 DOI: 10.1089/neu.2016.4718] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
There has been a tremendous focus on the discovery and development of neuroprotective agents that might have clinical relevance following traumatic brain injury (TBI). This type of brain injury is very complex and is divided into two major components. The first component, a primary injury, occurs at the time of impact and is the result of the mechanical insult itself. This primary injury is thought to be irreversible and resistant to most treatments. A second component or secondary brain injury, is defined as cellular damage that is not immediately obvious after trauma, but that develops after a delay of minutes, hours, or even days. This injury appears to be amenable to treatment. Because of the complexity of the secondary injury, any type of therapeutic intervention needs to be multi-faceted and have the ability to simultaneously modulate different cellular changes. Because of diverse pharmaceutical interactions, combinations of different drugs do not work well in concert and result in adverse physiological conditions. Research has begun to investigate the possibility of using natural compounds as a therapeutic intervention following TBI. These compounds normally have very low toxicity and have reduced interactions with other pharmaceuticals. In addition, many natural compounds have the potential to target numerous different components of the secondary injury. Here, we review 33 different plant-derived natural compounds, phytochemicals, which have been investigated in experimental animal models of TBI. Some of these phytochemicals appear to have potential as possible therapeutic interventions to offset key components of the secondary injury cascade. However, not all studies have used the same scientific rigor, and one should be cautious in the interpretation of studies using naturally occurring phytochemical in TBI research.
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Affiliation(s)
- Stephen W Scheff
- Sanders-Brown Center on Aging, University of Kentucky , Lexington, Kentucky
| | - Mubeen A Ansari
- Sanders-Brown Center on Aging, University of Kentucky , Lexington, Kentucky
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Wang H, Zhang YP, Cai J, Shields LBE, Tuchek CA, Shi R, Li J, Shields CB, Xu XM. A Compact Blast-Induced Traumatic Brain Injury Model in Mice. J Neuropathol Exp Neurol 2016; 75:183-96. [PMID: 26802177 DOI: 10.1093/jnen/nlv019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Blast-induced traumatic brain injury (bTBI) is a common injury on the battlefield and often results in permanent cognitive and neurological abnormalities. We report a novel compact device that creates graded bTBI in mice. The injury severity can be controlled by precise pressures that mimic Friedlander shockwave curves. The mouse head was stabilized with a head fixator, and the body was protected with a metal shield; shockwave durations were 3 to 4 milliseconds. Reflective shockwave peak readings at the position of the mouse head were 12 6 2.6 psi, 50 6 20.3 psi, and 100 6 33.1 psi at 100, 200, and 250 psi predetermined driver chamber pressures, respectively. The bTBIs of 250 psi caused 80% mortality, which decreased to 27% with the metal shield. Brain and lung damage depended on the shockwave duration and amplitude. Cognitive deficits were assessed using the Morris water maze, Y-maze, and open-field tests. Pathological changes in the brain included disruption of the blood-brain barrier, multifocal neuronal and axonal degeneration, and reactive gliosis assessed by Evans Blue dye extravasation, silver and Fluoro-Jade B staining, and glial fibrillary acidic protein immunohistochemistry, respectively. Behavioral and pathological changes were injury severity-dependent. This mouse bTBI model may be useful for investigating injury mechanisms and therapeutic strategies associated with bTBI.
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Mendes Arent A, de Souza LF, Walz R, Dafre AL. Perspectives on molecular biomarkers of oxidative stress and antioxidant strategies in traumatic brain injury. BIOMED RESEARCH INTERNATIONAL 2014; 2014:723060. [PMID: 24689052 PMCID: PMC3943200 DOI: 10.1155/2014/723060] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 12/04/2013] [Accepted: 12/09/2013] [Indexed: 11/23/2022]
Abstract
Traumatic brain injury (TBI) is frequently associated with abnormal blood-brain barrier function, resulting in the release of factors that can be used as molecular biomarkers of TBI, among them GFAP, UCH-L1, S100B, and NSE. Although many experimental studies have been conducted, clinical consolidation of these biomarkers is still needed to increase the predictive power and reduce the poor outcome of TBI. Interestingly, several of these TBI biomarkers are oxidatively modified to carbonyl groups, indicating that markers of oxidative stress could be of predictive value for the selection of therapeutic strategies. Some drugs such as corticosteroids and progesterone have already been investigated in TBI neuroprotection but failed to demonstrate clinical applicability in advanced phases of the studies. Dietary antioxidants, such as curcumin, resveratrol, and sulforaphane, have been shown to attenuate TBI-induced damage in preclinical studies. These dietary antioxidants can increase antioxidant defenses via transcriptional activation of NRF2 and are also known as carbonyl scavengers, two potential mechanisms for neuroprotection. This paper reviews the relevance of redox biology in TBI, highlighting perspectives for future studies.
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Affiliation(s)
- André Mendes Arent
- Department of Biochemistry, Federal University of Santa Catarina, Biological Sciences Centre, 88040-900 Florianópolis, SC, Brazil
- Faculty of Medicine, University of South Santa Catarina (Unisul), 88137-270 Palhoça, SC, Brazil
- Neurosurgery Service, São José Regional Hospital (HRSJ-HMG), 88103-901 São José, SC, Brazil
| | - Luiz Felipe de Souza
- Department of Biochemistry, Federal University of Santa Catarina, Biological Sciences Centre, 88040-900 Florianópolis, SC, Brazil
| | - Roger Walz
- Applied Neurosciences Centre (CeNAp) and Department of Medical Clinics, University Hospital, Federal University of Santa Catarina, 88040-900 Florianópolis, SC, Brazil
| | - Alcir Luiz Dafre
- Department of Biochemistry, Federal University of Santa Catarina, Biological Sciences Centre, 88040-900 Florianópolis, SC, Brazil
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Całkosiński I, Rosińczuk-Tonderys J, Bazan J, Dzierzba K, Całkosińska M, Majda J, Dobrzyński M, Bronowicka-Szydełko A. The influence of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on hematological parameters during experimentally induced pleuritis in rats. Inflammation 2013; 36:387-404. [PMID: 23100032 PMCID: PMC3591537 DOI: 10.1007/s10753-012-9558-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Proper functioning of homeostatic mechanisms is characteristic for every healthy organism and enables adapting to environmental changes. These complicated systematic reactions can neutralize the harmful stress factors leading to various inflammatory reactions. The aim of this study was to determine dynamic changes in the inflammatory reaction after single 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) administration of 5 μg/kg body weight into rats with experimentally induced pleuritis. These changes were observed by monitoring the hematological blood parameters during inflammation. The obtained results proved that dioxins contribute to various changes in the character of the inflammatory response. TCDD administration before pleuritis initiation caused an increase of lymphocytes and significant decrease of the number of neutrophils during inflammation. The current study proved that administration of low TCDD dose (seven times lower than used in other studies) can cause thymus, spleen, or lymphatic gland atrophy. This finding indicates the toxic influence of small TCDD dose especially on the immune system.
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Affiliation(s)
- Ireneusz Całkosiński
- Department of Nervous System Diseases, The Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
| | - Joanna Rosińczuk-Tonderys
- Department of Nervous System Diseases, The Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
| | - Justyna Bazan
- Department of Nervous System Diseases, The Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
| | - Katarzyna Dzierzba
- Department of Medical Biochemistry, Wroclaw Medical University, Chalubinskiego 10, 50-368 Wroclaw, Poland
| | - Monika Całkosińska
- Outpatient Clinic Medcom in Wojkowice, Wojkowice 28B, 55-020 Zurawina, Poland
| | - Jacek Majda
- Department of Diagnostics Laboratory, 4th Military Academic Hospital in Wroclaw, Weigla 5, 53-114 Wroclaw, Poland
| | - Maciej Dobrzyński
- Department of Conservative Dentistry and Pedodontics, Wroclaw Medical University, Krakowska 26, 50-425 Wroclaw, Poland
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Que ZL, Zhou WJ, Chang J, Liu XH, Yu JM, Sun X. Neuroprotective effects of mercaptoethylleonurine and mercaptoethylguanidine analogs on hydrogen peroxide-induced apoptosis in human neuronal SH-SY5Y cells. Bioorg Med Chem Lett 2013; 23:1793-6. [DOI: 10.1016/j.bmcl.2013.01.038] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 12/30/2012] [Accepted: 01/12/2013] [Indexed: 11/29/2022]
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Cederberg D, Siesjö P. What has inflammation to do with traumatic brain injury? Childs Nerv Syst 2010; 26:221-6. [PMID: 19940996 DOI: 10.1007/s00381-009-1029-x] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Indexed: 02/06/2023]
Abstract
INTRODUCTION Inflammation is an stereotypical response to tissue damage and has been extensively documented in experimental and clinical traumatic brain injury (TBI), including children. DISCUSSION The initiation and orchestration of inflammation in TBI, as in other tissues, is complex and multifactorial encompassing pro- and anti-inflammatory cytokines, chemokines, adhesion molecules, complement factors, reactive oxygen and nitrogen species, and other undefined factors. It is evident that inflammation can have both beneficial and detrimental effects in TBI, but the mechanisms underlying this dichotomy are mostly unknown. Modification of the inflammatory response may be neuroprotective. Monitoring inflammation is now possible with techniques such as microdialysis; however, the prognostic value of measuring inflammatory mediators in TBI is still unclear with conflicting reports. Except for corticosteroids, no anti-inflammatory agents have been tested in TBI, and the negative results with these may have been flawed by their multiple side effects. Clinical trials with anti-inflammatory agents that target multiple or central and downstream pathways are warranted in adult and pediatric TBI. This review examines the mechanisms of inflammation after TBI, monitoring, and possible routes of intervention.
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Affiliation(s)
- David Cederberg
- Department of Neurosurgery, Lund University Hospital, 221 85 Lund, Sweden
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The acute and chronic phases of chronic relapsing experimental autoimmune encephalomyelitis (CR EAE) are ameliorated by the peroxynitrite decomposition catalyst, 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinatoiron (III) chloride, (FeTPPS). Eur J Pharmacol 2008; 601:88-93. [PMID: 18977216 DOI: 10.1016/j.ejphar.2008.10.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Revised: 09/28/2008] [Accepted: 10/13/2008] [Indexed: 11/23/2022]
Abstract
There is increasing evidence that the oxidative radical, peroxynitrite (ONOO(-)), is involved in the pathogenesis of inflammatory diseases including multiple sclerosis and the animal counterpart, experimental autoimmune encephalomyelitis (EAE). Compounds that impede the actions of ONOO(-) have proved useful in the control of EAE. In particular, catalytic isomerisation of ONOO(-) to inactive nitrate, through the use of metalloporphyrins, curtails the cellular response to inflammatory stimuli and halts the progression of neuroinflammation during EAE. The present study examined the pharmacological effects of the metalloporphyrin and ONOO(-) decomposition catalyst 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrinatoiron(III)chloride (FeTPPS) on the acute and relapse phases of chronic relapsing (CR) EAE. Administration of FeTPPS to CR EAE-inoculated Biozzi mice commenced either therapeutically and immediately prior to the emergence of acute or relapse symptoms, or prophylactically, from the onset of remission of acute neurological signs. Drug therapy reduced acute and relapse symptoms but, and in contrast to the former phase, was of limited benefit in preventing histological changes during the latter stage of disease. In contrast, prophylactic FeTPPS was effective in limiting CNS pathology and neurological deficits. The findings confirm the inhibitory effects of FeTPPS on acute stage EAE. Moreover, the study extends previous observations by verifying compound efficacy on relapsing disease. Use of metalloporphyrins, such as FeTPPS, again highlights the important role played by ONOO(-) in the development of inflammatory diseases such as EAE.
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Li YN, Wu YL, Jia ZH, Qi JS. Interaction between COX-2 and iNOS aggravates vascular lesion and antagonistic effect of ginsenoside. JOURNAL OF ETHNOPHARMACOLOGY 2008; 119:305-311. [PMID: 18694814 DOI: 10.1016/j.jep.2008.07.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2007] [Revised: 07/05/2008] [Accepted: 07/15/2008] [Indexed: 05/26/2023]
Abstract
AIM OF THE STUDY Ginseng, the root of Panax ginseng C.A.Meyer (Araliaceae), is one of the most widely used Chinese herbs with hypotensive and cardiotonic actions for thousands of years, but the underlying mechanisms have not been well determined. Ginsenoside, the effective components of ginseng, has anti-inflammatory and anti-oxidative effects. Cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are key enzymes in inflammation and oxidative stress, respectively, which have close interaction, aggravating their damaging effects. This study investigated whether COX-2 interacted with iNOS in vascular endothelial lesion and the protective effect of ginsenoside. MATERIALS AND METHODS SD male rats were fed with high l-methionine (3%, w/w) to induce vascular endothelial lesion, and the rats in ginsenoside group were fed ginsenoside solution (0.8 mg kg(-1)d(-1)). The mRNA expression and protein contents of COX-2 and iNOS were detected by RT-PCR and Western blotting, respectively. The interaction between COX-2 and iNOS was analyzed by co-immunoprecipitation and laser confocal microscopy. The content of NT, a specific marker of peroxynitrite, was evaluated by Western blotting. The morphological changes of vascular endothelium were observed. RESULTS Compared with control group, the transcription and protein levels of both COX-2 and iNOS increased obviously and their interaction enhanced significantly in model group, in accord with the increased NT content and the pathological alterations of aorta. In ginsenoside group, all these alterations were attenuated significantly (P < 0.01 or P < 0.05). CONCLUSIONS It is proved that there exists interaction between COX-2 and iNOS, aggravating endothelial lesion through peroxynitrite and ginsenoside might antagonize their interaction, playing a protective role.
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Affiliation(s)
- Yan-Ning Li
- Department of Biochemistry, Hebei Medical University, Shijiazhuang City 050017, Hebei, PR China
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Szabó C, Ischiropoulos H, Radi R. Peroxynitrite: biochemistry, pathophysiology and development of therapeutics. Nat Rev Drug Discov 2007; 6:662-80. [PMID: 17667957 DOI: 10.1038/nrd2222] [Citation(s) in RCA: 1605] [Impact Index Per Article: 94.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Peroxynitrite--the product of the diffusion-controlled reaction of nitric oxide with superoxide radical--is a short-lived oxidant species that is a potent inducer of cell death. Conditions in which the reaction products of peroxynitrite have been detected and in which pharmacological inhibition of its formation or its decomposition have been shown to be of benefit include vascular diseases, ischaemia-reperfusion injury, circulatory shock, inflammation, pain and neurodegeneration. In this Review, we first discuss the biochemistry and pathophysiology of peroxynitrite and then focus on pharmacological strategies to attenuate the toxic effects of peroxynitrite. These include its catalytic reduction to nitrite and its isomerization to nitrate by metalloporphyrins, which have led to potential candidates for drug development for cardiovascular, inflammatory and neurodegenerative diseases.
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Affiliation(s)
- Csaba Szabó
- Department of Surgery, University of Medicine and Dentistry of New Jersey, 185 South Orange Avenue, University Heights, Newark, New Jersey 07103-2714, USA.
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Hickey RW, Adelson PD, Johnnides MJ, Davis DS, Yu Z, Rose ME, Chang YF, Graham SH. Cyclooxygenase-2 activity following traumatic brain injury in the developing rat. Pediatr Res 2007; 62:271-6. [PMID: 17622965 DOI: 10.1203/pdr.0b013e3180db2902] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Cyclooxygenase (COX) is the rate-limiting enzyme in the production of prostaglandins. COX-2, the predominant COX isoform in brain, is induced by synaptic activity. COX-2-generated prostaglandins are important regulators for a range of activities under physiologic conditions. However, under pathologic conditions, COX-2 activity can produce reactive oxygen species and toxic prostaglandin metabolites that can exacerbate brain injury. In this study, we examine the developmental production of COX-2 and test the ability of a COX-2 inhibitor, SC58125, to attenuate traumatic brain injury in developing rats. We show that constitutive COX-2 concentration is low (0.5-fold adult concentration) during the first postnatal week and then increases to 3-fold of adult levels between days 14-60. Controlled cortical impact (CCI) at postnatal day (PND) 17, but not PND 7, caused an additional 3-fold increase in COX-2 content and was associated with an increase in the COX-2 product PGE2. Treatment with the COX-2 inhibitor SC58125 in PND17 rats exposed to CCI attenuated the rise in PGE2 but did not attenuate lesion volume or improve performance in the Morris water maze.
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Affiliation(s)
- Robert W Hickey
- Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA.
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Abstract
The discovery that mammalian cells have the ability to synthesize the free radical nitric oxide (NO) has stimulated an extraordinary impetus for scientific research in all the fields of biology and medicine. Since its early description as an endothelial-derived relaxing factor, NO has emerged as a fundamental signaling device regulating virtually every critical cellular function, as well as a potent mediator of cellular damage in a wide range of conditions. Recent evidence indicates that most of the cytotoxicity attributed to NO is rather due to peroxynitrite, produced from the diffusion-controlled reaction between NO and another free radical, the superoxide anion. Peroxynitrite interacts with lipids, DNA, and proteins via direct oxidative reactions or via indirect, radical-mediated mechanisms. These reactions trigger cellular responses ranging from subtle modulations of cell signaling to overwhelming oxidative injury, committing cells to necrosis or apoptosis. In vivo, peroxynitrite generation represents a crucial pathogenic mechanism in conditions such as stroke, myocardial infarction, chronic heart failure, diabetes, circulatory shock, chronic inflammatory diseases, cancer, and neurodegenerative disorders. Hence, novel pharmacological strategies aimed at removing peroxynitrite might represent powerful therapeutic tools in the future. Evidence supporting these novel roles of NO and peroxynitrite is presented in detail in this review.
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Affiliation(s)
- Pál Pacher
- Section on Oxidative Stress Tissue Injury, Laboratory of Physiologic Studies, National Institutes of Health, National Institute of Alcohol Abuse and Alcoholism, Bethesda, Maryland, USA.
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