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Zeng ML, Xu W. A Narrative Review of the Published Pre-Clinical Evaluations: Multiple Effects of Arachidonic Acid, its Metabolic Enzymes and Metabolites in Epilepsy. Mol Neurobiol 2024:10.1007/s12035-024-04274-6. [PMID: 38842673 DOI: 10.1007/s12035-024-04274-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 05/29/2024] [Indexed: 06/07/2024]
Abstract
Arachidonic acid (AA), an important polyunsaturated fatty acid in the brain, is hydrolyzed by a direct action of phospholipase A2 (PLA2) or through the combined action of phospholipase C and diacylglycerol lipase, and released into the cytoplasm. Various derivatives of AA can be synthesized mainly through the cyclooxygenase (COX), lipoxygenase (LOX) and cytochrome P450 (P450) enzyme pathways. AA and its metabolic enzymes and metabolites play important roles in a variety of neurophysiological activities. The abnormal metabolites and their catalytic enzymes in the AA cascade are related to the pathogenesis of various central nervous system (CNS) diseases, including epilepsy. Here, we systematically reviewed literatures in PubMed about the latest randomized controlled trials, animal studies and clinical studies concerning the known features of AA, its metabolic enzymes and metabolites, and their roles in epilepsy. The exclusion criteria include non-original studies and articles not in English.
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Affiliation(s)
- Meng-Liu Zeng
- Medical Science Research Center, Zhongnan Hospital of Wuhan University, Wuhan, 430071, China.
| | - Wei Xu
- Department of Pancreatic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
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2
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Zhang M, Rottschäfer V, C M de Lange E. The potential impact of CYP and UGT drug-metabolizing enzymes on brain target site drug exposure. Drug Metab Rev 2024; 56:1-30. [PMID: 38126313 DOI: 10.1080/03602532.2023.2297154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023]
Abstract
Drug metabolism is one of the critical determinants of drug disposition throughout the body. While traditionally associated with the liver, recent research has unveiled the presence and functional significance of drug-metabolizing enzymes (DMEs) within the brain. Specifically, cytochrome P-450 enzymes (CYPs) and UDP-glucuronosyltransferases (UGTs) enzymes have emerged as key players in drug biotransformation within the central nervous system (CNS). This comprehensive review explores the cellular and subcellular distribution of CYPs and UGTs within the CNS, emphasizing regional expression and contrasting profiles between the liver and brain, humans and rats. Moreover, we discuss the impact of species and sex differences on CYPs and UGTs within the CNS. This review also provides an overview of methodologies for identifying and quantifying enzyme activities in the brain. Additionally, we present factors influencing CYPs and UGTs activities in the brain, including genetic polymorphisms, physiological variables, pathophysiological conditions, and environmental factors. Examples of CYP- and UGT-mediated drug metabolism within the brain are presented at the end, illustrating the pivotal role of these enzymes in drug therapy and potential toxicity. In conclusion, this review enhances our understanding of drug metabolism's significance in the brain, with a specific focus on CYPs and UGTs. Insights into the expression, activity, and influential factors of these enzymes within the CNS have crucial implications for drug development, the design of safe drug treatment strategies, and the comprehension of drug actions within the CNS. To that end, CNS pharmacokinetic (PK) models can be improved to further advance drug development and personalized therapy.
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Affiliation(s)
- Mengxu Zhang
- Division of Systems Pharmacology and Pharmacy, Predictive Pharmacology Group, Leiden Academic Centre of Drug Research, Leiden University, Leiden, The Netherlands
| | - Vivi Rottschäfer
- Mathematical Institute, Leiden University, Leiden, The Netherlands
- Korteweg-de Vries Institute for Mathematics, University of Amsterdam, Amsterdam, The Netherlands
| | - Elizabeth C M de Lange
- Division of Systems Pharmacology and Pharmacy, Predictive Pharmacology Group, Leiden Academic Centre of Drug Research, Leiden University, Leiden, The Netherlands
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3
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Glaser ST, Jayanetti K, Oubraim S, Hillowe A, Frank E, Jong J, Wang L, Wang H, Ojima I, Haj-Dahmane S, Kaczocha M. Fatty acid binding proteins are novel modulators of synaptic epoxyeicosatrienoic acid signaling in the brain. Sci Rep 2023; 13:15234. [PMID: 37709856 PMCID: PMC10502087 DOI: 10.1038/s41598-023-42504-4] [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: 02/13/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023] Open
Abstract
Fatty acid binding proteins (FABPs) govern intracellular lipid transport to cytosolic organelles and nuclear receptors. More recently, FABP5 has emerged as a key regulator of synaptic endocannabinoid signaling, suggesting that FABPs may broadly regulate the signaling of neuroactive lipids in the brain. Herein, we demonstrate that brain-expressed FABPs (FABP3, FABP5, and FABP7) interact with epoxyeicosatrienoic acids (EETs) and the peroxisome proliferator-activated receptor gamma agonist 15-deoxy-Δ12,14-Prostaglandin J2 (15d-PGJ2). Among these lipids, EETs displayed highest affinities for FABP3 and FABP5, and 11,12-EET was identified as the preferred FABP ligand. Similarly, 15d-PGJ2 interacted with FABP3 and FABP5 while binding to FABP7 was markedly lower. Molecular modeling revealed unique binding interactions of the ligands within the FABP binding pockets and highlighted major contributions of van der Waals clashes and acyl chain solvent exposure in dictating FABP affinity and specificity. Functional studies demonstrated that endogenous EETs gate the strength of CA1 hippocampal glutamate synapses and that this function was impaired following FABP inhibition. As such, the present study reveals that FABPs control EET-mediated synaptic gating, thereby expanding the functional roles of this protein family in regulating neuronal lipid signaling.
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Affiliation(s)
- Sherrye T Glaser
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
- Department of Biological Sciences, Kingsborough Community College, Brooklyn, NY, USA
| | - Kalani Jayanetti
- Department of Chemistry, Stony Brook University, Stony Brook, NY, USA
| | - Saida Oubraim
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA
| | - Andrew Hillowe
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Elena Frank
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Jason Jong
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Liqun Wang
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA
| | - Hehe Wang
- Department of Chemistry, Stony Brook University, Stony Brook, NY, USA
| | - Iwao Ojima
- Department of Chemistry, Stony Brook University, Stony Brook, NY, USA
- Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY, USA
| | - Samir Haj-Dahmane
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
| | - Martin Kaczocha
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA.
- Institute of Chemical Biology and Drug Discovery, Stony Brook University, Stony Brook, NY, USA.
- Stony Brook University Pain and Analgesia Research Center (SPARC), Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, USA.
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4
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Ohashi SN, DeLong JH, Kozberg MG, Mazur-Hart DJ, van Veluw SJ, Alkayed NJ, Sansing LH. Role of Inflammatory Processes in Hemorrhagic Stroke. Stroke 2023; 54:605-619. [PMID: 36601948 DOI: 10.1161/strokeaha.122.037155] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Hemorrhagic stroke is the deadliest form of stroke and includes the subtypes of intracerebral hemorrhage and subarachnoid hemorrhage. A common cause of hemorrhagic stroke in older individuals is cerebral amyloid angiopathy. Intracerebral hemorrhage and subarachnoid hemorrhage both lead to the rapid collection of blood in the central nervous system and generate inflammatory immune responses that involve both brain resident and infiltrating immune cells. These responses are complex and can contribute to both tissue recovery and tissue injury. Despite the interconnectedness of these major subtypes of hemorrhagic stroke, few reviews have discussed them collectively. The present review provides an update on inflammatory processes that occur in response to intracerebral hemorrhage and subarachnoid hemorrhage, and the role of inflammation in the pathophysiology of cerebral amyloid angiopathy-related hemorrhage. The goal is to highlight inflammatory processes that underlie disease pathology and recovery. We aim to discuss recent advances in our understanding of these conditions and identify gaps in knowledge with the potential to develop effective therapeutic strategies.
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Affiliation(s)
- Sarah N Ohashi
- Department of Neurology (S.N.O., J.H.D., L.H.S.), Yale School of Medicine, New Haven, CT
- Department of Immunobiology (S.N.O., J.H.D., L.H.S.), Yale School of Medicine, New Haven, CT
| | - Jonathan H DeLong
- Department of Neurology (S.N.O., J.H.D., L.H.S.), Yale School of Medicine, New Haven, CT
- Department of Immunobiology (S.N.O., J.H.D., L.H.S.), Yale School of Medicine, New Haven, CT
| | - Mariel G Kozberg
- J. Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital/ Harvard Medical School, Boston (M.G.K., S.J.v.V.)
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Charlestown (M.G.K., S.J.v.V.)
| | - David J Mazur-Hart
- Department of Neurological Surgery (D.J.M.-H.), Oregon Health and Science University (OHSU), Portland
| | - Susanne J van Veluw
- J. Philip Kistler Stroke Research Center, Department of Neurology, Massachusetts General Hospital/ Harvard Medical School, Boston (M.G.K., S.J.v.V.)
- MassGeneral Institute for Neurodegenerative Disease, Department of Neurology, Massachusetts General Hospital, Charlestown (M.G.K., S.J.v.V.)
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine and Knight Cardiovascular Institute (N.J.A.), Oregon Health and Science University (OHSU), Portland
| | - Lauren H Sansing
- Department of Neurology (S.N.O., J.H.D., L.H.S.), Yale School of Medicine, New Haven, CT
- Department of Immunobiology (S.N.O., J.H.D., L.H.S.), Yale School of Medicine, New Haven, CT
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5
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Astrocytes amplify neurovascular coupling to sustained activation of neocortex in awake mice. Nat Commun 2022; 13:7872. [PMID: 36550102 PMCID: PMC9780254 DOI: 10.1038/s41467-022-35383-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Functional hyperemia occurs when enhanced neuronal activity signals to increase local cerebral blood flow (CBF) to satisfy regional energy demand. Ca2+ elevation in astrocytes can drive arteriole dilation to increase CBF, yet affirmative evidence for the necessity of astrocytes in functional hyperemia in vivo is lacking. In awake mice, we discovered that functional hyperemia is bimodal with a distinct early and late component whereby arteriole dilation progresses as sensory stimulation is sustained. Clamping astrocyte Ca2+ signaling in vivo by expressing a plasma membrane Ca2+ ATPase (CalEx) reduces sustained but not brief sensory-evoked arteriole dilation. Elevating astrocyte free Ca2+ using chemogenetics selectively augments sustained hyperemia. Antagonizing NMDA-receptors or epoxyeicosatrienoic acid production reduces only the late component of functional hyperemia, leaving brief increases in CBF to sensory stimulation intact. We propose that a fundamental role of astrocyte Ca2+ is to amplify functional hyperemia when neuronal activation is prolonged.
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6
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Nippert AR, Chiang PP, Del Franco AP, Newman EA. Astrocyte regulation of cerebral blood flow during hypoglycemia. J Cereb Blood Flow Metab 2022; 42:1534-1546. [PMID: 35296178 PMCID: PMC9274859 DOI: 10.1177/0271678x221089091] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 02/07/2022] [Accepted: 02/28/2022] [Indexed: 12/13/2022]
Abstract
Hypoglycemia triggers increases in cerebral blood flow (CBF), augmenting glucose supply to the brain. We have tested whether astrocytes, which can regulate vessel tone, contribute to this CBF increase. We hypothesized that hypoglycemia-induced adenosine signaling acts to increase astrocyte Ca2+ activity, which then causes the release of prostaglandins (PGs) and epoxyeicosatrienoic acids (EETs), leading to the dilation of brain arterioles and blood flow increases. We used an awake mouse model to investigate the effects of insulin-induced hypoglycemia on arterioles and astrocytes in the somatosensory cortex. During insulin-induced hypoglycemia, penetrating arterioles dilated and astrocyte Ca2+ signaling increased when blood glucose dropped below a threshold of ∼50 mg/dL. Application of the A2A adenosine receptor antagonist ZM-241385 eliminated hypoglycemia-evoked astrocyte Ca2+ increases and reduced arteriole dilations by 44% (p < 0.05). SC-560 and miconazole, which block the production of the astrocyte vasodilators PGs and EETs respectively, reduced arteriole dilations in response to hypoglycemia by 89% (p < 0.001) and 76% (p < 0.001). Hypoglycemia-induced arteriole dilations were decreased by 65% (p < 0.001) in IP3R2 knockout mice, which have reduced astrocyte Ca2+ signaling compared to wild-type. These results support the hypothesis that astrocytes contribute to hypoglycemia-induced increases in CBF by releasing vasodilators in a Ca2+-dependent manner.
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Affiliation(s)
- Amy R Nippert
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Pei-Pei Chiang
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | | | - Eric A Newman
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
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7
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Lansdell TA, Chambers LC, Dorrance AM. Endothelial Cells and the Cerebral Circulation. Compr Physiol 2022; 12:3449-3508. [PMID: 35766836 DOI: 10.1002/cphy.c210015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.
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Affiliation(s)
- Theresa A Lansdell
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
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8
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Skoug C, Holm C, Duarte JMN. Hormone-sensitive lipase is localized at synapses and is necessary for normal memory functioning in mice. J Lipid Res 2022; 63:100195. [PMID: 35300984 PMCID: PMC9026619 DOI: 10.1016/j.jlr.2022.100195] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 02/21/2022] [Accepted: 03/03/2022] [Indexed: 10/31/2022] Open
Abstract
Hormone-sensitive lipase (HSL) is mainly present in adipose tissue where it hydrolyses diacylglycerol. Although expression of HSL has also been reported in the brain, its presence in different cellular compartments is uncertain, and its role in regulating brain lipid metabolism remains hitherto unexplored. We hypothesized HSL might play a role in regulating the availability of bioactive lipids necessary for neuronal function, and therefore investigated whether dampening HSL activity could lead to brain dysfunction. In mice, we found HSL protein and enzymatic activity throughout the brain, both localized within neurons and enriched in synapses. HSL-null mice were then analyzed using a battery of behavioral tests. Relative to wild-type littermates, HSL-null mice showed impaired short- and long-term memory, yet preserved exploratory behaviurs. Molecular analysis of the cortex and hippocampus showed increased expression of genes involved in glucose utilization in the hippocampus, but not cortex, of HSL-null mice compared to controls. Furthermore, lipidomics analyses indicated an impact of HSL deletion on the profile of bioactive lipids, including a decrease in endocannabinoids and eicosanoids that are known to modulate neuronal activity, cerebral blood flow, and inflammation processes. Accordingly, mild increases in the expression of pro-inflammatory cytokines in HSL mice compared to littermates were suggestive of low-grade inflammation. We conclude that HSL has a homeostatic role in maintaining pools of lipids required for normal brain function. It remains to be tested, however, whether the recruitment of HSL for the synthesis of these lipids occurs during increased neuronal activity, or whether HSL participates in neuroinflammatory responses.
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Affiliation(s)
- Cecilia Skoug
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Sweden; Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Sweden
| | - Cecilia Holm
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Sweden
| | - João M N Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Sweden; Wallenberg Centre for Molecular Medicine, Faculty of Medicine, Lund University, Sweden.
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9
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Hamsanathan S, Gurkar AU. Lipids as Regulators of Cellular Senescence. Front Physiol 2022; 13:796850. [PMID: 35370799 PMCID: PMC8965560 DOI: 10.3389/fphys.2022.796850] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 01/03/2022] [Indexed: 12/11/2022] Open
Abstract
Lipids are key macromolecules that perform a multitude of biological functions ranging from maintaining structural integrity of membranes, energy storage, to signaling molecules. Unsurprisingly, variations in lipid composition and its levels can influence the functional and physiological state of the cell and its milieu. Cellular senescence is a permanent state of cell cycle arrest and is a hallmark of the aging process, as well as several age-related pathologies. Senescent cells are often characterized by alterations in morphology, metabolism, chromatin remodeling and exhibit a complex pro-inflammatory secretome (SASP). Recent studies have shown that the regulation of specific lipid species play a critical role in senescence. Indeed, some lipid species even contribute to the low-grade inflammation associated with SASP. Many protein regulators of senescence have been well characterized and are associated with lipid metabolism. However, the link between critical regulators of cellular senescence and senescence-associated lipid changes is yet to be elucidated. Here we systematically review the current knowledge on lipid metabolism and dynamics of cellular lipid content during senescence. We focus on the roles of major players of senescence in regulating lipid metabolism. Finally, we explore the future prospects of lipid research in senescence and its potential to be targeted as senotherapeutics.
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Affiliation(s)
- Shruthi Hamsanathan
- Aging Institute of UPMC, The University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
| | - Aditi U. Gurkar
- Aging Institute of UPMC, The University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Division of Geriatric Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, United States
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Healthcare System, Pittsburgh, PA, United States
- *Correspondence: Aditi U. Gurkar,
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10
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Puebla M, Tapia PJ, Espinoza H. Key Role of Astrocytes in Postnatal Brain and Retinal Angiogenesis. Int J Mol Sci 2022; 23:ijms23052646. [PMID: 35269788 PMCID: PMC8910249 DOI: 10.3390/ijms23052646] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/21/2022] [Accepted: 02/23/2022] [Indexed: 01/27/2023] Open
Abstract
Angiogenesis is a key process in various physiological and pathological conditions in the nervous system and in the retina during postnatal life. Although an increasing number of studies have addressed the role of endothelial cells in this event, the astrocytes contribution in angiogenesis has received less attention. This review is focused on the role of astrocytes as a scaffold and in the stabilization of the new blood vessels, through different molecules release, which can modulate the angiogenesis process in the brain and in the retina. Further, differences in the astrocytes phenotype are addressed in glioblastoma, one of the most devastating types of brain cancer, in order to provide potential targets involved in the cross signaling between endothelial cells, astrocytes and glioma cells, that mediate tumor progression and pathological angiogenesis. Given the relevance of astrocytes in angiogenesis in physiological and pathological conditions, future studies are required to better understand the interrelation between endothelial and astrocyte signaling pathways during this process.
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Affiliation(s)
- Mariela Puebla
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina-Clínica Alemana, Universidad del Desarrollo, Av. Plaza 680, Las Condes, Santiago 7550000, Chile;
| | - Pablo J. Tapia
- Centro de Biología Celular y Biomedicina (CEBICEM), Facultad de Medicina y Ciencia, Universidad San Sebastián, Av. Lota 2465, Providencia, Santiago 7500000, Chile;
- Facultad de Medicina Veterinaria y Agronomía, Universidad de las Américas, Av. República 71, Santiago 8320000, Chile
| | - Hilda Espinoza
- Facultad de Ciencias de la Salud, Universidad del Alba, Av. Ejército Libertador 171, Santiago 8320000, Chile
- Correspondence:
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11
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Martini RP, Siler D, Cetas J, Alkayed NJ, Allen E, Treggiari MM. A Double-Blind, Randomized, Placebo-Controlled Trial of Soluble Epoxide Hydrolase Inhibition in Patients with Aneurysmal Subarachnoid Hemorrhage. Neurocrit Care 2021; 36:905-915. [PMID: 34873674 DOI: 10.1007/s12028-021-01398-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 11/08/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND Epoxyeicosatrienoates (EETs) are endogenous regulators of neuroinflammation and cerebral blood flow. Their metabolism to dihydroxyeicosatrienoates (DHETs) is catalyzed by soluble epoxide hydrolase (sEH). After subarachnoid hemorrhage (SAH), EETs' pathway amplification may be a therapeutic target for the prevention of delayed cerebral ischemia (DCI). We conducted a double-blind, placebo-controlled, phase Ib randomized trial of GSK2256294, a pharmacologic inhibitor of sEH, to evaluate the safety profile and to assess biomarkers of neurovascular inflammation in patients with aneurysmal SAH. METHODS Patients were randomly assigned to receive 10 mg of GSK2256294 or a placebo treatment once daily for 10 days, beginning within 72 hours after aneurysm rupture. The primary study end point was safety. Secondary end points included serum and cerebrospinal fluid (CSF) EETs-to-DHETs ratio, cytokine levels, and serum endothelial injury biomarkers, measured at day 7 and day 10 after SAH. Tertiary end points included neurologic status, disposition, length of stay, incidence of DCI, and mortality; these were assessed at hospital discharge and at 90 days. RESULTS Ten patients received GSK2256294 and nine patients received a placebo. There were no adverse events related to the study drug. GSK2256294 administration resulted in a significant increase in the EET/DHET ratio at day 7 and day 10 in serum, but not in the CSF. There was a trend for decreased CSF inflammatory cytokines following GSK2256294 administration, but this did not reach statistical significance. CONCLUSIONS GSK2256294 administration was safe and well tolerated in critically ill patients with SAH, producing an increase in serum EETs and the EET-to-DHET ratio. Our findings support future studies in a larger population to evaluate the role of sEH inhibition in the prevention of DCI after SAH and other forms of brain injury and inflammatory conditions. CLINICAL TRIAL REGISTRATION ClinicalTrials.gov: NCT03318783.
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Affiliation(s)
- Ross P Martini
- Oregon Anesthesiology Group, Portland, OR, USA.,Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA
| | - Dominic Siler
- Department of Neurosurgery, Oregon Health and Science University, Portland, OR, USA
| | - Justin Cetas
- Department of Neurosurgery, Oregon Health and Science University, Portland, OR, USA
| | - Nabil J Alkayed
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA.,Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Elyse Allen
- Department of Anesthesiology and Perioperative Medicine, Oregon Health and Science University, Portland, OR, USA.,Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
| | - Miriam M Treggiari
- Department of Anesthesiology, Yale University School of Medicine, 333 Cedar Street, TMP3, New Haven, CT, 06510, USA.
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12
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Abstract
The cerebral microcirculation undergoes dynamic changes in parallel with the development of neurons, glia, and their energy metabolism throughout gestation and postnatally. Cerebral blood flow (CBF), oxygen consumption, and glucose consumption are as low as 20% of adult levels in humans born prematurely but eventually exceed adult levels at ages 3 to 11 years, which coincide with the period of continued brain growth, synapse formation, synapse pruning, and myelination. Neurovascular coupling to sensory activation is present but attenuated at birth. By 2 postnatal months, the increase in CBF often is disproportionately smaller than the increase in oxygen consumption, in contrast to the relative hyperemia seen in adults. Vascular smooth muscle myogenic tone increases in parallel with developmental increases in arterial pressure. CBF autoregulatory response to increased arterial pressure is intact at birth but has a more limited range with arterial hypotension. Hypoxia-induced vasodilation in preterm fetal sheep with low oxygen consumption does not sustain cerebral oxygen transport, but the response becomes better developed for sustaining oxygen transport by term. Nitric oxide tonically inhibits vasomotor tone, and glutamate receptor activation can evoke its release in lambs and piglets. In piglets, astrocyte-derived carbon monoxide plays a central role in vasodilation evoked by glutamate, ADP, and seizures, and prostanoids play a large role in endothelial-dependent and hypercapnic vasodilation. Overall, homeostatic mechanisms of CBF regulation in response to arterial pressure, neuronal activity, carbon dioxide, and oxygenation are present at birth but continue to develop postnatally as neurovascular signaling pathways are dynamically altered and integrated. © 2021 American Physiological Society. Compr Physiol 11:1-62, 2021.
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13
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Zhang W, Davis CM, Zeppenfeld DM, Golgotiu K, Wang MX, Haveliwala M, Hong D, Li Y, Wang RK, Iliff JJ, Alkayed NJ. Role of endothelium-pericyte signaling in capillary blood flow response to neuronal activity. J Cereb Blood Flow Metab 2021; 41:1873-1885. [PMID: 33853406 PMCID: PMC8327110 DOI: 10.1177/0271678x211007957] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Local blood flow in the brain is tightly coupled to metabolic demands, a phenomenon termed functional hyperemia. Both capillaries and arterioles contribute to the hyperemic response to neuronal activity via different mechanisms and timescales. The nature and specific signaling involved in the hyperemic response of capillaries versus arterioles, and their temporal relationship are not fully defined. We determined the time-dependent changes in capillary flux and diameter versus arteriolar velocity and flow following whisker stimulation using optical microangiography (OMAG) and two-photon microscopy. We further characterized depth-resolved responses of individual capillaries versus capillary networks. We hypothesized that capillaries respond first to neuronal activation, and that they exhibit a coordinated response mediated via endothelial-derived epoxyeicosatrienoates (EETs) acting on pericytes. To visualize peri-capillary pericytes, we used Tie2-GFP/NG2-DsRed mice, and to determine the role of endothelial-derived EETs, we compared cerebrovascular responses to whisker stimulation between wild-type mice and mice with lower endothelial EETs (Tie2-hsEH). We found that capillaries respond immediately to neuronal activation in an orchestrated network-level manner, a response attenuated in Tie2-hsEH and inhibited by blocking EETs action on pericytes. These results demonstrate that capillaries are first responders during functional hyperemia, and that they exhibit a network-level response mediated via endothelial-derived EETs' action on peri-capillary pericytes.
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Affiliation(s)
- Wenri Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Douglas M Zeppenfeld
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Kirsti Golgotiu
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Marie X Wang
- Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care Center, Seattle, WA, USA.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Mariya Haveliwala
- Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care Center, Seattle, WA, USA.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Daniel Hong
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Yuandong Li
- Department of Bioengineering, University of Washington School of Medicine, Seattle, WA, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington School of Medicine, Seattle, WA, USA
| | - Jeffrey J Iliff
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA.,Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care Center, Seattle, WA, USA.,Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA.,Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
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14
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Aksenov DP. Normal Development of Local Neurovascular Interactions and the Diagnostic Value of Resting State Functional MRI in Neurovascular Deficiency Based on the Example of Neonatal Anesthesia Exposure. Front Neurol 2021; 12:664706. [PMID: 33995262 PMCID: PMC8116565 DOI: 10.3389/fneur.2021.664706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 04/08/2021] [Indexed: 01/25/2023] Open
Affiliation(s)
- Daniil P Aksenov
- Department of Radiology, NorthShore University HealthSystem, Evanston, IL, United States.,Department of Anesthesiology, NorthShore University HealthSystem, Evanston, IL, United States
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15
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Matin N, Fisher C, Lansdell TA, Hammock BD, Yang J, Jackson WF, Dorrance AM. Soluble epoxide hydrolase inhibition improves cognitive function and parenchymal artery dilation in a hypertensive model of chronic cerebral hypoperfusion. Microcirculation 2020; 28:e12653. [PMID: 32767848 DOI: 10.1111/micc.12653] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/30/2020] [Accepted: 07/30/2020] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Parenchymal arterioles (PAs) regulate perfusion of the cerebral microcirculation, and impaired PA endothelium-dependent dilation occurs in dementia models mimicking chronic cerebral hypoperfusion (CCH). Epoxyeicosatrienoic acids (EETs) are vasodilators; their actions are potentiated by soluble epoxide hydrolase (sEH) inhibition. We hypothesized that chronic sEH inhibition with trifluoromethoxyphenyl-3 (1-propionylpiperidin-4-yl) urea (TPPU) would prevent cognitive dysfunction and improve PA dilation in a hypertensive CCH model. METHODS Bilateral carotid artery stenosis (BCAS) was used to induce CCH in twenty-week-old male stroke-prone spontaneously hypertensive rats (SHSRP) that were treated with vehicle or TPPU for 8 weeks. Cognitive function was assessed by novel object recognition. PA dilation and structure were assessed by pressure myography, and mRNA expression in brain tissue was assessed by qRT-PCR. RESULTS TPPU did not enhance resting cerebral perfusion, but prevented CCH-induced memory deficits. TPPU improved PA endothelium-dependent dilation but reduced the sensitivity of PAs to a nitric oxide donor. TPPU treatment had no effect on PA structure or biomechanical properties. TPPU treatment increased brain mRNA expression of brain derived neurotrophic factor, doublecortin, tumor necrosis factor-alpha, sEH, and superoxide dismutase 3, CONCLUSIONS: These data suggest that sEH inhibitors may be viable treatments for cognitive impairments associated with hypertension and CCH.
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Affiliation(s)
- Nusrat Matin
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Courtney Fisher
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Theresa A Lansdell
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Bruce D Hammock
- Department of Entomology &, University of California Comprehensive Cancer Center, Davis, CA, USA
| | - Jun Yang
- Department of Entomology &, University of California Comprehensive Cancer Center, Davis, CA, USA
| | - William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
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16
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Montecillo-Aguado M, Tirado-Rodriguez B, Tong Z, Vega OM, Morales-Martínez M, Abkenari S, Pedraza-Chaverri J, Huerta-Yepez S. Importance of the Role of ω-3 and ω-6 Polyunsaturated Fatty Acids in the Progression of Brain Cancer. Brain Sci 2020; 10:E381. [PMID: 32560280 PMCID: PMC7349634 DOI: 10.3390/brainsci10060381] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 05/28/2020] [Accepted: 06/09/2020] [Indexed: 12/21/2022] Open
Abstract
Brain cancer is one of the most malignant types of cancer in both children and adults. Brain cancer patients tend to have a poor prognosis and a high rate of mortality. Additionally, 20-40% of all other types of cancer can develop brain metastasis. Numerous pieces of evidence suggest that omega-3-polyunsaturated fatty acids (ω-PUFAs) could potentially be used in the prevention and therapy of several types of cancer. PUFAs and oxylipins are fundamental in preserving physiological events in the nervous system; it is, therefore, necessary to maintain a certain ratio of ω-3 to ω-6 for normal nervous system function. Alterations in PUFAs signaling are involved in the development of various pathologies of the nervous system, including cancer. It is well established that an omega-6-polyunsaturated fatty acid (ω-6 PUFA)-rich diet has a pro-tumoral effect, whereas the consumption of an ω-3 rich diet has an anti-tumoral effect. This review aims to offer a better understanding of brain cancer and PUFAs and to discuss the role and impact of PUFAs on the development of different types of brain cancer. Considering the difficulty of antitumor drugs in crossing the blood-brain barrier, the therapeutic role of ω-3/ω-6 PUFAs against brain cancer would be a good alternative to consider. We highlight our current understanding of the role of PUFAs and its metabolites (oxylipins) in different brain tumors, proliferation, apoptosis, invasion, angiogenesis, and immunosuppression by focusing on recent research in vitro and in vivo.
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Affiliation(s)
- Mayra Montecillo-Aguado
- Programa de Doctorado en Ciencias Biomédicas, Facultad de Medicina, Universidad Nacional Autónoma de Mexico (UNAM), Mexico City 04510, Mexico;
- Hospital Infantil de Mexico, Federico Gomez, Unidad de Investigacion en Enfermedades Oncologicas, Mexico City 06720, Mexico; (B.T.-R.); (M.M.-M.)
| | - Belen Tirado-Rodriguez
- Hospital Infantil de Mexico, Federico Gomez, Unidad de Investigacion en Enfermedades Oncologicas, Mexico City 06720, Mexico; (B.T.-R.); (M.M.-M.)
| | - Zhen Tong
- Molecular Toxicology Interdepartmental Program and Environmental Health Sciences, University of California, Los Angeles, CA 90095, USA;
- Department of Pathology & Laboratory Medicine, University of California, Los Angeles, CA 90095, USA; (O.M.V.); (S.A.)
| | - Owen M. Vega
- Department of Pathology & Laboratory Medicine, University of California, Los Angeles, CA 90095, USA; (O.M.V.); (S.A.)
| | - Mario Morales-Martínez
- Hospital Infantil de Mexico, Federico Gomez, Unidad de Investigacion en Enfermedades Oncologicas, Mexico City 06720, Mexico; (B.T.-R.); (M.M.-M.)
| | - Shaheen Abkenari
- Department of Pathology & Laboratory Medicine, University of California, Los Angeles, CA 90095, USA; (O.M.V.); (S.A.)
| | - José Pedraza-Chaverri
- Departamento de Biología, Facultad de Química, Universidad Nacional Autonoma de Mexico (UNAM), Mexico City 04510, Mexico;
| | - Sara Huerta-Yepez
- Hospital Infantil de Mexico, Federico Gomez, Unidad de Investigacion en Enfermedades Oncologicas, Mexico City 06720, Mexico; (B.T.-R.); (M.M.-M.)
- Department of Pathology & Laboratory Medicine, University of California, Los Angeles, CA 90095, USA; (O.M.V.); (S.A.)
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17
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Sakuta H, Lin CH, Yamada M, Kita Y, Tokuoka SM, Shimizu T, Noda M. Nax-positive glial cells in the organum vasculosum laminae terminalis produce epoxyeicosatrienoic acids to induce water intake in response to increases in [Na+] in body fluids. Neurosci Res 2020; 154:45-51. [DOI: 10.1016/j.neures.2019.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/24/2019] [Accepted: 05/27/2019] [Indexed: 01/06/2023]
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18
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Staricha K, Meyers N, Garvin J, Liu Q, Rarick K, Harder D, Cohen S. Effect of high glucose condition on glucose metabolism in primary astrocytes. Brain Res 2020; 1732:146702. [PMID: 32032612 DOI: 10.1016/j.brainres.2020.146702] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 01/29/2020] [Accepted: 02/03/2020] [Indexed: 12/23/2022]
Abstract
In the brain, glucose enters astrocytes through glucose transporter (GLUT1) and either enters glycolysis or the glycogen shunt. Astrocytes meet the energy needs of neurons by building up and breaking down their glycogen supply. High glucose exposure causes astrocyte dysregulation, but its effects on glucose metabolism are relatively unknown. We hypothesized that high glucose conditioning induces a glycogenic state in the astrocyte, resulting in an inefficient mobilization of substrates when challenged with glucose deprivation. Using neonatal rat astrocytes, we used normal glucose (NG, 5.5 mM) vs. high glucose (HG, 25 mM) feeding media and measured cell membrane GLUT1 expression, glucose analog uptake, glycogen content, and cellular bioenergetics. This study demonstrates that HG conditioning causes increased glucose analog uptake (p < 0.05) without affecting GLUT1 membrane expression when compared to NG conditioned astrocytes. Increased glucose uptake in HG astrocytes is associated with higher baseline glycogen content compared to NG exposed astrocytes (p < 0.05). When challenged with glucose deprivation, HG astrocytes break down more than double the amount of glycogen molecules compared to NG astrocytes, although they break down a similar percentage of the starting glycogen stores (NG = 62%, HG = 55%). Additionally, HG conditioning negatively impacts astrocyte maximal respiration and glycolytic reserve capacity assessed by the Seahorse mitochondrial stress test and glycolytic stress test, respectively (p < 0.05). These results suggest that HG conditioning shifts astrocytes towards glycogen storage at baseline. Despite increased glycogen storage, HG astrocytes demonstrate decreased metabolic efficiency and capacity putting them at higher risk during extended periods of glucose deprivation.
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Affiliation(s)
- Kelly Staricha
- Department of Pediatrics, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States
| | - Nicholas Meyers
- Department of Pediatrics, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States
| | - Jodi Garvin
- Department of Pediatrics, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States
| | - Qiuli Liu
- Department of Pediatrics, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States
| | - Kevin Rarick
- Department of Pediatrics, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States
| | - David Harder
- Department of Physiology, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States
| | - Susan Cohen
- Department of Pediatrics, Medical College of Wisconsin, 8701 W Watertown Plank Rd, Wauwatosa, WI 53226, United States.
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19
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van Raalte DH, Bjornstad P, Persson F, Powell DR, de Cassia Castro R, Wang PS, Liu M, Heerspink HJL, Cherney D. The Impact of Sotagliflozin on Renal Function, Albuminuria, Blood Pressure, and Hematocrit in Adults With Type 1 Diabetes. Diabetes Care 2019; 42:1921-1929. [PMID: 31371432 PMCID: PMC6905482 DOI: 10.2337/dc19-0937] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 07/02/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE In people with type 2 diabetes, sodium-glucose cotransporter 2 inhibitors (SGLT2i) reduce cardiovascular risk and progression of diabetic kidney disease. Our aim was to determine whether sotagliflozin (SOTA), a dual SGLT1i and SGLT2i, had favorable effects on clinical biomarkers suggestive of kidney protection in adults with type 1 diabetes. RESEARCH DESIGN AND METHODS In this 52-week pooled analysis, 1,575 adults enrolled in the inTandem1 and inTandem2 trials were randomized to SOTA 200 mg, 400 mg, or placebo in addition to optimized insulin therapy. Changes in cardiorenal biomarkers were assessed. RESULTS At 52 weeks, in response to SOTA 200 and 400 mg, the placebo-corrected least squares mean change from baseline in estimated glomerular filtration rate was -2.0 mL/min/1.73 m2 (P = 0.010) and -0.5 mL/min/1.73 m2 (P = 0.52), respectively. Systolic blood pressure difference was -2.9 and -3.6 mmHg (P < 0.0001 for both); diastolic blood pressure changed by -1.4 (P = 0.0033) and -1.6 mmHg (P = 0.0008). In participants with baseline urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g, UACR decreased by 23.7% (P = 0.054) and 18.3% (P = 0.18) for SOTA 200 and SOTA 400 mg, respectively, versus placebo. Increases in serum albumin and hematocrit and reductions in uric acid were observed throughout 52 weeks with both SOTA doses. CONCLUSIONS SOTA was associated with short- and long-term renal hemodynamic changes, which were similar to those seen with SGLT2i in type 2 diabetes. Further investigation around cardiorenal effects of SOTA in people with type 1 diabetes is justified.
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Affiliation(s)
- Daniël H van Raalte
- Diabetes Center, Internal Medicine, Amsterdam UMC, Location VUmc, Amsterdam, the Netherlands
| | - Petter Bjornstad
- Division of Nephrology, Department of Medicine, and Section of Endocrinology, Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO
| | | | | | | | | | | | - Hiddo J L Heerspink
- The George Institute for Global Health, Sydney, Australia.,Department of Clinical Pharmacy and Pharmacology, University of Groningen, Groningen, the Netherlands
| | - David Cherney
- Division of Nephrology, University of Toronto, Toronto, Canada
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20
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Glutamate affects the CYP1B1- and CYP2U1-mediated hydroxylation of arachidonic acid metabolism via astrocytic mGlu5 receptor. Int J Biochem Cell Biol 2019; 110:111-121. [DOI: 10.1016/j.biocel.2019.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 01/27/2019] [Accepted: 03/01/2019] [Indexed: 01/10/2023]
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21
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Ferdouse A, Leng S, Winter T, Aukema HM. The Brain Oxylipin Profile Is Resistant to Modulation by Dietary n-6 and n-3 Polyunsaturated Fatty Acids in Male and Female Rats. Lipids 2019; 54:67-80. [DOI: 10.1002/lipd.12122] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 12/17/2018] [Accepted: 12/18/2018] [Indexed: 01/03/2023]
Affiliation(s)
- Afroza Ferdouse
- Department of Food and Human Nutritional Sciences; 190 Dysart Road, University of Manitoba Winnipeg; Canada R3T 2N2
- Canadian Centre for Agri-Food Research in Health and Medicine; 351 Tache Ave, Winnipeg Canada R2H 2A6
| | - Shan Leng
- Department of Food and Human Nutritional Sciences; 190 Dysart Road, University of Manitoba Winnipeg; Canada R3T 2N2
- Canadian Centre for Agri-Food Research in Health and Medicine; 351 Tache Ave, Winnipeg Canada R2H 2A6
| | - Tanja Winter
- Department of Food and Human Nutritional Sciences; 190 Dysart Road, University of Manitoba Winnipeg; Canada R3T 2N2
- Canadian Centre for Agri-Food Research in Health and Medicine; 351 Tache Ave, Winnipeg Canada R2H 2A6
| | - Harold M. Aukema
- Department of Food and Human Nutritional Sciences; 190 Dysart Road, University of Manitoba Winnipeg; Canada R3T 2N2
- Canadian Centre for Agri-Food Research in Health and Medicine; 351 Tache Ave, Winnipeg Canada R2H 2A6
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22
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Lakkappa N, Krishnamurthy PT, M D P, Hammock BD, Hwang SH. Soluble epoxide hydrolase inhibitor, APAU, protects dopaminergic neurons against rotenone induced neurotoxicity: Implications for Parkinson's disease. Neurotoxicology 2019; 70:135-145. [PMID: 30472438 PMCID: PMC6873230 DOI: 10.1016/j.neuro.2018.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 11/12/2018] [Accepted: 11/13/2018] [Indexed: 01/20/2023]
Abstract
Epoxyeicosatrienoic acids (EETs), metabolites of arachidonic acid, play a crucial role in cytoprotection by attenuating oxidative stress, inflammation and apoptosis. EETs are rapidly metabolised in vivo by the soluble epoxide hydrolase (sEH). Increasing the half life of EETs by inhibiting the sEH enzyme is a novel strategy for neuroprotection. In the present study, sEH inhibitors APAU was screened in silico and further evaluated for their antiparkinson activity against rotenone (ROT) induced neurodegeneration in N27 dopaminergic cell line and Drosophila melanogaster model of Parkinson disease (PD). In the in vitro study cell viability (MTT and LDH release assay), oxidative stress parameters (total intracellular ROS, hydroperoxides, protein oxidation, lipid peroxidation, superoxide dismutase, catalase, glutathione peroxidise, glutathione reductase, glutathione, total antioxidant status, mitochondrial complex-1activity and mitochondrial membrane potential), inflammatory markers (IL-6, COX-1 and COX-2), and apoptotic markers (JNK, phospho-JNK, c-jun, phospho-c-jun, pro and active caspase-3) were assessed to study the neuroprotective effects. In vivo activity of APAU was assessed in Drosophila melanogaster by measuring survival rate, negative geotaxis, oxidative stress parameters (total intracellular ROS, hydroperoxides, glutathione levels) were measured. Dopamine and its metabolites were estimated by LC-MS/MS analysis. In the in silico study the molecule, APAU showed good binding interaction at the active site of sEH (PDB: 1VJ5). In the in vitro study, APAU significantly attenuated ROT induced changes in oxidative, pro-inflammatory and apoptotic parameters. In the in vivo study, APAU significantly attenuates ROT induced changes in survival rate, negative geotaxis, oxidative stress, dopamine and its metabolites levels (p < 0.05). Our study, therefore, concludes that the molecule APAU, has significant neuroprotection benefits against rotenone induced Parkinsonism.
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Affiliation(s)
- Navya Lakkappa
- Department of Pharmacology, JSS College of Pharmacy, Ooty, India
| | | | - Pandareesh M D
- Department of Neurochemistry, National Institute of Mental Health & Neuro Sciences, Bangalore, India
| | - Bruce D Hammock
- Department of Entomology and Nematology, and Comprehensive Cancer Research Center, University of California, Davis, United States
| | - Sung Hee Hwang
- Department of Entomology and Nematology, and Comprehensive Cancer Research Center, University of California, Davis, United States
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23
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Liu X, Davis CM, Alkayed NJ. P450 Eicosanoids and Reactive Oxygen Species Interplay in Brain Injury and Neuroprotection. Antioxid Redox Signal 2018; 28:987-1007. [PMID: 28298143 PMCID: PMC5849284 DOI: 10.1089/ars.2017.7056] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Significance: Eicosanoids are endogenous lipid mediators that play important roles in brain function and disease. Acute brain injury such as that which occurs in stroke and traumatic brain injury increases the formation of eicosanoids, which, in turn, exacerbate or diminish injury. In chronic neurodegenerative diseases such as Alzheimer's disease and vascular dementia (VD), eicosanoid synthetic and metabolizing enzymes are altered, disrupting the balance between neuroprotective and neurotoxic eicosanoids. Recent Advances: Human and experimental studies have established the opposing roles of hydroxy- and epoxyeicosanoids and their potential utility as diagnostic biomarkers and therapeutic targets in neural injury. Critical Issues: A gap in knowledge remains in understanding the cellular and molecular mechanisms underlying the neurovascular actions of specific eicosanoids, such as specific isomers of epoxyeicosatrienoic (EETs) and hydroxyeicosatetraenoic acids (HETEs). Future Directions: EETs and HETEs exert their actions on brain cells by targeting multiple mechanisms, which include surface G-protein coupled receptors. The identification of high-affinity receptors for EETs and HETEs and their cellular localization in the brain will be a breakthrough in our understanding of these eicosanoids as mediators of cell-cell communications and contributors to brain development, function, and disease. Antioxid. Redox Signal. 28, 987-1007.
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Affiliation(s)
- Xuehong Liu
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon
| | - Catherine M Davis
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon.,Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon
| | - Nabil J Alkayed
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon.,Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, Oregon
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24
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Tu R, Armstrong J, Lee KSS, Hammock BD, Sapirstein A, Koehler RC. Soluble epoxide hydrolase inhibition decreases reperfusion injury after focal cerebral ischemia. Sci Rep 2018; 8:5279. [PMID: 29588470 PMCID: PMC5869703 DOI: 10.1038/s41598-018-23504-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/13/2018] [Indexed: 01/01/2023] Open
Abstract
Epoxyeicosatrienoic acids (EETs) are produced by cytochrome P450 epoxygenases from arachidonic acid, and their rapid metabolism is mainly through soluble epoxide hydrolase (sEH). EETs exert vasodilatory, anti-inflammatory, anti-apoptotic, and pro-angiogenic effects. Administration of sEH inhibitors before or at the onset of stroke is protective, but the effects of post-treatment at reperfusion, when inflammation is augmented, has not been as well studied. We tested the hypothesis that 1-Trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl)urea (TPPU), a potent and highly selective sEH inhibitor, suppresses inflammation and protects the brain when administered at reperfusion. Vehicle or 1 mg/kg TPPU was administered at reperfusion after 90 minutes of focal ischemia and again 24 hours later. Protein expression and activity of sEH increased after reperfusion and activity was decreased by TPPU administration. TPPU decreased infarct volume by 50%, reduced neurologic deficits and improved performance on sensorimotor tasks. Furthermore, TPPU significantly lowered the mRNA expression of interleukin-1beta by 3.5-fold and tumor necrosis factor-alpha by 2.2-fold, increased transforming growth factor-beta mRNA by 1.8-fold, and augmented immunostaining of vascular endothelial growth factor in peri-infarct cortex. Thus, inhibition of sEH at reperfusion significantly reduces infarction and improves sensorimotor function, possibly by suppressing early proinflammatory cytokines and promoting reparative cytokines and growth factors.
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Affiliation(s)
- Ranran Tu
- Department of Neurology, Second Xiangya Hospital, Central South University, Changsha, China.,Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Jillian Armstrong
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Kin Sing Stephen Lee
- Department of Entomology and Nematology and UCD Comprehensive Cancer Center, University of California, Davis, CA, USA
| | - Bruce D Hammock
- Department of Entomology and Nematology and UCD Comprehensive Cancer Center, University of California, Davis, CA, USA
| | - Adam Sapirstein
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Raymond C Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, MD, USA.
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25
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Harder DR, Rarick KR, Gebremedhin D, Cohen SS. Regulation of Cerebral Blood Flow: Response to Cytochrome P450 Lipid Metabolites. Compr Physiol 2018; 8:801-821. [PMID: 29687906 DOI: 10.1002/cphy.c170025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
There have been numerous reviews related to the cerebral circulation. Most of these reviews are similar in many ways. In the present review, we thought it important to provide an overview of function with specific attention to details of cerebral arterial control related to brain homeostasis, maintenance of neuronal energy demands, and a unique perspective related to the role of astrocytes. A coming review in this series will discuss cerebral vascular development and unique properties of the neonatal circulation and developing brain, thus, many aspects of development are missing here. Similarly, a review of the response of the brain and cerebral circulation to heat stress has recently appeared in this series (8). By trying to make this review unique, some obvious topics were not discussed in lieu of others, which are from recent and provocative research such as endothelium-derived hyperpolarizing factor, circadian regulation of proteins effecting cerebral blood flow, and unique properties of the neurovascular unit. © 2018 American Physiological Society. Compr Physiol 8:801-821, 2018.
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Affiliation(s)
- David R Harder
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.,Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin, USA
| | - Kevin R Rarick
- Department of Pediatrics, Division of Critical Care, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Debebe Gebremedhin
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Susan S Cohen
- Department of Pediatrics, Division of Neonatology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Wagner KM, McReynolds CB, Schmidt WK, Hammock BD. Soluble epoxide hydrolase as a therapeutic target for pain, inflammatory and neurodegenerative diseases. Pharmacol Ther 2017; 180:62-76. [PMID: 28642117 PMCID: PMC5677555 DOI: 10.1016/j.pharmthera.2017.06.006] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Eicosanoids are biologically active lipid signaling molecules derived from polyunsaturated fatty acids. Many of the actions of eicosanoid metabolites formed by cyclooxygenase and lipoxygenase enzymes have been characterized, however, the epoxy-fatty acids (EpFAs) formed by cytochrome P450 enzymes are newly described by comparison. The EpFA metabolites modulate a diverse set of physiologic functions that include inflammation and nociception among others. Regulation of EpFAs occurs primarily via release, biosynthesis and enzymatic transformation by the soluble epoxide hydrolase (sEH). Targeting sEH with small molecule inhibitors has enabled observation of the biological activity of the EpFAs in vivo in animal models, greatly contributing to the overall understanding of their role in the inflammatory response. Their role in modulating inflammation has been demonstrated in disease models including cardiovascular pathology and inflammatory pain, but extends to neuroinflammation and neuroinflammatory disease. Moreover, while EpFAs demonstrate activity against inflammatory pain, interestingly, this action extends to blocking chronic neuropathic pain as well. This review outlines the role of modulating sEH and the biological action of EpFAs in models of pain and inflammatory diseases.
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Affiliation(s)
- Karen M Wagner
- Department of Entomology and Nematology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Cindy B McReynolds
- Department of Entomology and Nematology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | | | - Bruce D Hammock
- Department of Entomology and Nematology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States.
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Abstract
Cytochrome P450 eicosanoids play important roles in brain function and disease through their complementary actions on cell-cell communications within the neurovascular unit (NVU) and mechanisms of brain injury. Epoxy- and hydroxyeicosanoids, respectively formed by cytochrome P450 epoxygenases and ω-hydroxylases, play opposing roles in cerebrovascular function and in pathological processes underlying neural injury, including ischemia, neuroinflammation and oxidative injury. P450 eicosanoids also contribute to cerebrovascular disease risk factors, including hypertension and diabetes. We summarize studies investigating the roles P450 eicosanoids in cerebrovascular physiology and disease to highlight the existing balance between these important lipid signaling molecules, as well as their roles in maintaining neurovascular homeostasis and in acute and chronic neurovascular and neurodegenerative disorders.
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Affiliation(s)
- Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR 97239, United States; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, United States
| | - Xuehong Liu
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, United States
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR 97239, United States; The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR 97239, United States.
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Nippert AR, Biesecker KR, Newman EA. Mechanisms Mediating Functional Hyperemia in the Brain. Neuroscientist 2017; 24:73-83. [PMID: 28403673 DOI: 10.1177/1073858417703033] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuronal activity within the brain evokes local increases in blood flow, a response termed functional hyperemia. This response ensures that active neurons receive sufficient oxygen and nutrients to maintain tissue function and health. In this review, we discuss the functions of functional hyperemia, the types of vessels that generate the response, and the signaling mechanisms that mediate neurovascular coupling, the communication between neurons and blood vessels. Neurovascular coupling signaling is mediated primarily by the vasoactive metabolites of arachidonic acid (AA), by nitric oxide, and by K+. While much is known about these pathways, many contentious issues remain. We highlight two controversies, the role of glial cell Ca2+ signaling in mediating neurovascular coupling and the importance of capillaries in generating functional hyperemia. We propose signaling pathways that resolve these controversies. In this scheme, capillary dilations are generated by Ca2+ increases in astrocyte endfeet, leading to production of AA metabolites. In contrast, arteriole dilations are generated by Ca2+ increases in neurons, resulting in production of nitric oxide and AA metabolites. Arachidonic acid from neurons also diffuses into astrocyte endfeet where it is converted into additional vasoactive metabolites. While this scheme resolves several discrepancies in the field, many unresolved challenges remain and are discussed in the final section of the review.
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Affiliation(s)
- Amy R Nippert
- 1 Department of Neuroscience, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Kyle R Biesecker
- 1 Department of Neuroscience, University of Minnesota-Twin Cities, Minneapolis, MN, USA
| | - Eric A Newman
- 1 Department of Neuroscience, University of Minnesota-Twin Cities, Minneapolis, MN, USA
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Mishra A, Reynolds JP, Chen Y, Gourine AV, Rusakov DA, Attwell D. Astrocytes mediate neurovascular signaling to capillary pericytes but not to arterioles. Nat Neurosci 2016; 19:1619-1627. [PMID: 27775719 PMCID: PMC5131849 DOI: 10.1038/nn.4428] [Citation(s) in RCA: 365] [Impact Index Per Article: 45.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 09/20/2016] [Indexed: 12/11/2022]
Abstract
Active neurons increase their energy supply by dilating nearby arterioles and capillaries. This neurovascular coupling underlies blood oxygen level-dependent functional imaging signals, but its mechanism is controversial. Canonically, neurons release glutamate to activate metabotropic glutamate receptor 5 (mGluR5) on astrocytes, evoking Ca2+ release from internal stores, activating phospholipase A2 and generating vasodilatory arachidonic acid derivatives. However, adult astrocytes lack mGluR5, and knockout of the inositol 1,4,5-trisphosphate receptors that release Ca2+ from stores does not affect neurovascular coupling. We now show that buffering astrocyte Ca2+ inhibits neuronally evoked capillary dilation, that astrocyte [Ca2+]i is raised not by release from stores but by entry through ATP-gated channels, and that Ca2+ generates arachidonic acid via phospholipase D2 and diacylglycerol lipase rather than phospholipase A2. In contrast, dilation of arterioles depends on NMDA receptor activation and Ca2+-dependent NO generation by interneurons. These results reveal that different signaling cascades regulate cerebral blood flow at the capillary and arteriole levels.
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Affiliation(s)
- Anusha Mishra
- Department of Neuroscience, Physiology &Pharmacology, University College London, London, UK
| | | | - Yang Chen
- Department of Neuroscience, Physiology &Pharmacology, University College London, London, UK
| | - Alexander V Gourine
- Department of Neuroscience, Physiology &Pharmacology, University College London, London, UK
| | | | - David Attwell
- Department of Neuroscience, Physiology &Pharmacology, University College London, London, UK
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Mishra A. Binaural blood flow control by astrocytes: listening to synapses and the vasculature. J Physiol 2016; 595:1885-1902. [PMID: 27619153 DOI: 10.1113/jp270979] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 07/15/2016] [Indexed: 12/28/2022] Open
Abstract
Astrocytes are the most common glial cells in the brain with fine processes and endfeet that intimately contact both neuronal synapses and the cerebral vasculature. They play an important role in mediating neurovascular coupling (NVC) via several astrocytic Ca2+ -dependent signalling pathways such as K+ release through BK channels, and the production and release of arachidonic acid metabolites. They are also involved in maintaining the resting tone of the cerebral vessels by releasing ATP and COX-1 derivatives. Evidence also supports a role for astrocytes in maintaining blood pressure-dependent change in cerebrovascular tone, and perhaps also in blood vessel-to-neuron signalling as posited by the 'hemo-neural hypothesis'. Thus, astrocytes are emerging as new stars in preserving the intricate balance between the high energy demand of active neurons and the supply of oxygen and nutrients from the blood by maintaining both resting blood flow and activity-evoked changes therein. Following neuropathology, astrocytes become reactive and many of their key signalling mechanisms are altered, including those involved in NVC. Furthermore, as they can respond to changes in vascular pressure, cardiovascular diseases might exert previously unknown effects on the central nervous system by altering astrocyte function. This review discusses the role of astrocytes in neurovascular signalling in both physiology and pathology, and the impact of these findings on understanding BOLD-fMRI signals.
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Affiliation(s)
- Anusha Mishra
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
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31
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Sakuta H, Nishihara E, Hiyama TY, Lin CH, Noda M. Nax signaling evoked by an increase in [Na+] in CSF induces water intake via EET-mediated TRPV4 activation. Am J Physiol Regul Integr Comp Physiol 2016; 311:R299-306. [DOI: 10.1152/ajpregu.00352.2015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 05/27/2016] [Indexed: 11/22/2022]
Abstract
Water-intake behavior is under the control of brain systems that sense body fluid conditions at sensory circumventricular organs (sCVOs); however, the underlying mechanisms have not yet been elucidated in detail. Nax is a sodium (Na+) level sensor in the brain, and the transient receptor potential vanilloid (TRPV) channels TRPV1 and TRPV4 have been proposed to function as osmosensors. We herein investigated voluntary water intake immediately induced after an intracerebroventricular administration of a hypertonic NaCl solution in TRPV1-, TRPV4-, Na x-, and their double-gene knockout (KO) mice. The induction of water intake by TRPV1-KO mice was normal, whereas intake by TRPV4-KO and Na x-KO mice was significantly less than that by WT mice. Water intake by Na x /TRPV4-double KO mice was similar to that by the respective single KO mice. When TRPV4 activity was blocked with a specific antagonist HC-067047, water intake by WT mice was significantly reduced, whereas intake by TRPV4-KO and Na x-KO mice was not. Similar results were obtained with the administration of miconazole, which inhibits the biosynthesis of epoxyeicosatrienoic acids (EETs), endogenous agonists for TRPV4, from arachidonic acid (AA). Intracerebroventricular injection of hypertonic NaCl with AA or 5,6-EET restored water intake by Na x-KO mice to the wild-type level but not that by TRPV4-KO mice. These results suggest that the Na+ signal generated in Nax-positive glial cells leads to the activation of TRPV4-positive neurons in sCVOs to stimulate water intake by using EETs as gliotransmitters. Intracerebroventricular injection of equiosmolar hypertonic sorbitol solution induced small but significant water intake equally in all the genotypes, suggesting the presence of an unknown osmosensor in the brain.
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Affiliation(s)
- Hiraki Sakuta
- Division of Molecular Neurobiology, National Institute for Basic Biology, and
- School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
| | - Eri Nishihara
- Division of Molecular Neurobiology, National Institute for Basic Biology, and
| | - Takeshi Y. Hiyama
- Division of Molecular Neurobiology, National Institute for Basic Biology, and
- School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
| | - Chia-Hao Lin
- Division of Molecular Neurobiology, National Institute for Basic Biology, and
| | - Masaharu Noda
- Division of Molecular Neurobiology, National Institute for Basic Biology, and
- School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Okazaki, Aichi, Japan
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Ghosh C, Hossain M, Solanki J, Dadas A, Marchi N, Janigro D. Pathophysiological implications of neurovascular P450 in brain disorders. Drug Discov Today 2016; 21:1609-1619. [PMID: 27312874 DOI: 10.1016/j.drudis.2016.06.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 04/14/2016] [Accepted: 06/06/2016] [Indexed: 01/12/2023]
Abstract
Over the past decades, the significance of cytochrome P450 (CYP) enzymes has expanded beyond their role as peripheral drug metabolizers in the liver and gut. CYP enzymes are also functionally active at the neurovascular interface. CYP expression is modulated by disease states, impacting cellular functions, detoxification, and reactivity to toxic stimuli and brain drug biotransformation. Unveiling the physiological and molecular complexity of brain P450 enzymes will improve our understanding of the mechanisms underlying brain drug availability, pharmacological efficacy, and neurotoxic adverse effects from pharmacotherapy targeting brain disorders.
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Affiliation(s)
- Chaitali Ghosh
- Cerebrovascular Research, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.
| | - Mohammed Hossain
- Cerebrovascular Research, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA; Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA
| | | | - Aaron Dadas
- The Ohio State University, Columbus, OH, USA
| | - Nicola Marchi
- Cerebrovascular Mechanisms of Brain Disorders, Department of Neuroscience, Institute of Functional Genomics (CNRS/INSERM), Montpellier, France
| | - Damir Janigro
- Flocel Inc. and Case Western Reserve University, Cleveland, OH, USA
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Fan F, Ge Y, Lv W, Elliott MR, Muroya Y, Hirata T, Booz GW, Roman RJ. Molecular mechanisms and cell signaling of 20-hydroxyeicosatetraenoic acid in vascular pathophysiology. Front Biosci (Landmark Ed) 2016; 21:1427-63. [PMID: 27100515 DOI: 10.2741/4465] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cytochrome P450s enzymes catalyze the metabolism of arachidonic acid to epoxyeicosatrienoic acids (EETs), dihydroxyeicosatetraenoic acid and hydroxyeicosatetraeonic acid (HETEs). 20-HETE is a vasoconstrictor that depolarizes vascular smooth muscle cells by blocking K+ channels. EETs serve as endothelial derived hyperpolarizing factors. Inhibition of the formation of 20-HETE impairs the myogenic response and autoregulation of renal and cerebral blood flow. Changes in the formation of EETs and 20-HETE have been reported in hypertension and drugs that target these pathways alter blood pressure in animal models. Sequence variants in CYP4A11 and CYP4F2 that produce 20-HETE, UDP-glucuronosyl transferase involved in the biotransformation of 20-HETE and soluble epoxide hydrolase that inactivates EETs are associated with hypertension in human studies. 20-HETE contributes to the regulation of vascular hypertrophy, restenosis, angiogenesis and inflammation. It also promotes endothelial dysfunction and contributes to cerebral vasospasm and ischemia-reperfusion injury in the brain, kidney and heart. This review will focus on the role of 20-HETE in vascular dysfunction, inflammation, ischemic and hemorrhagic stroke and cardiac and renal ischemia reperfusion injury.
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Affiliation(s)
- Fan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216
| | - Ying Ge
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216
| | - Wenshan Lv
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216 and Department of Endocrinology and Metabolism, the Affiliated Hospital of Qingdao University, Qingdao, China
| | - Matthew R Elliott
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216
| | - Yoshikazu Muroya
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216 and Department of General Medicine and Rehabilitation, Tohoku Medical and Pharmaceutical University School of Medicine, Sendai, Japan
| | - Takashi Hirata
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216 and Taisho Pharmaceutical Co., Ltd., Saitama, Japan
| | - George W Booz
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216,
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Filosa JA, Morrison HW, Iddings JA, Du W, Kim KJ. Beyond neurovascular coupling, role of astrocytes in the regulation of vascular tone. Neuroscience 2016; 323:96-109. [PMID: 25843438 PMCID: PMC4592693 DOI: 10.1016/j.neuroscience.2015.03.064] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 03/24/2015] [Accepted: 03/27/2015] [Indexed: 12/22/2022]
Abstract
The brain possesses two intricate mechanisms that fulfill its continuous metabolic needs: cerebral autoregulation, which ensures constant cerebral blood flow over a wide range of arterial pressures and functional hyperemia, which ensures rapid delivery of oxygen and glucose to active neurons. Over the past decade, a number of important studies have identified astrocytes as key intermediaries in neurovascular coupling (NVC), the mechanism by which active neurons signal blood vessels to change their diameter. Activity-dependent increases in astrocytic Ca(2+) activity are thought to contribute to the release of vasoactive substances that facilitate arteriole vasodilation. A number of vasoactive signals have been identified and their role on vessel caliber assessed both in vitro and in vivo. In this review, we discuss mechanisms implicating astrocytes in NVC-mediated vascular responses, limitations encountered as a result of the challenges in maintaining all the constituents of the neurovascular unit intact and deliberate current controversial findings disputing a main role for astrocytes in NVC. Finally, we briefly discuss the potential role of pericytes and microglia in NVC-mediated processes.
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Affiliation(s)
- J A Filosa
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States.
| | - H W Morrison
- University of Arizona, 1305 N. Martin Avenue, P.O. Box 210203, Tucson, AZ 85721, United States
| | - J A Iddings
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
| | - W Du
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
| | - K J Kim
- Georgia Regents University, 1120 15th Street, Augusta, GA 30912, United States
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Gebremedhin D, Zhang DX, Carver KA, Rau N, Rarick KR, Roman RJ, Harder DR. Expression of CYP 4A ω-hydroxylase and formation of 20-hydroxyeicosatetreanoic acid (20-HETE) in cultured rat brain astrocytes. Prostaglandins Other Lipid Mediat 2016; 124:16-26. [PMID: 27174801 DOI: 10.1016/j.prostaglandins.2016.04.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 04/19/2016] [Accepted: 04/27/2016] [Indexed: 02/07/2023]
Abstract
Astrocytes secrete vasodilator and vasoconstrictor factors via end feet processes, altering blood flow to meet neuronal metabolic demand. Compared to what is known about the ability of astrocytes to release factors that dilate local cerebral vasculature, very little is known regarding the source and identity of astrocyte derived constricting factors. The present study investigated if astrocytes express CYP 4A ω-hydroxylase and metabolize arachidonic acid (AA) to 20-hydroxyeicotetraenoic acid (20-HETE) that regulates KCa channel activity in astrocytes and cerebral arterial myocyte contractility. Here we report that cultured astrocytes express CYP 4A2/3 ω-hydroxylase mRNA and CYP 4A protein and produce 20-HETE and the CYP epoxygenase metabolites epoxyeicosatrienoic acids (EETs) when incubated with AA. The production of 20-HETE and EETs was enhanced following stimulation of metabotropic glutamate receptors (mGluR) on the astrocytes. Exogenous application of 20-HETE attenuated, whereas inhibition of 20-HETE production with HET-0016 increased the open state probabilities (NPo) of 71pS and 161pS KCa single-channel currents recorded from astrocytes. Exposure of isolated cerebral arterial myocytes to conditioned media from cultured astrocytes caused shortening of the length of freshly isolated cerebral arterial myocytes that was not evident following inhibition of astrocyte 20-HETE synthesis and action. These findings suggest that astrocytes not only release vasodilator EETs in response to mGluR stimulation but also synthetize and release the cerebral arterial myocyte constrictor 20-HETE that also functions as an endogenous inhibitor of the activity of two types of KCa channel currents found in astrocytes.
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Affiliation(s)
- Debebe Gebremedhin
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - David X Zhang
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Koryn A Carver
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Nicole Rau
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Kevin R Rarick
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States
| | - Richard J Roman
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, United States
| | - David R Harder
- Department of Physiology, Milwaukee, WI 53226, United States; Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, WI 53226, United States; Clement Zablocki VA Medical Center, Milwaukee, WI 53226, United States.
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Longden TA, Hill-Eubanks DC, Nelson MT. Ion channel networks in the control of cerebral blood flow. J Cereb Blood Flow Metab 2016; 36:492-512. [PMID: 26661232 PMCID: PMC4794103 DOI: 10.1177/0271678x15616138] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/17/2015] [Accepted: 10/14/2015] [Indexed: 12/26/2022]
Abstract
One hundred and twenty five years ago, Roy and Sherrington made the seminal observation that neuronal stimulation evokes an increase in cerebral blood flow.(1) Since this discovery, researchers have attempted to uncover how the cells of the neurovascular unit-neurons, astrocytes, vascular smooth muscle cells, vascular endothelial cells and pericytes-coordinate their activity to control this phenomenon. Recent work has revealed that ionic fluxes through a diverse array of ion channel species allow the cells of the neurovascular unit to engage in multicellular signaling processes that dictate local hemodynamics.In this review we center our discussion on two major themes: (1) the roles of ion channels in the dynamic modulation of parenchymal arteriole smooth muscle membrane potential, which is central to the control of arteriolar diameter and therefore must be harnessed to permit changes in downstream cerebral blood flow, and (2) the striking similarities in the ion channel complements employed in astrocytic endfeet and endothelial cells, enabling dual control of smooth muscle from either side of the blood-brain barrier. We conclude with a discussion of the emerging roles of pericyte and capillary endothelial cell ion channels in neurovascular coupling, which will provide fertile ground for future breakthroughs in the field.
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Affiliation(s)
- Thomas A Longden
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | | | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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Jia J, Davis CM, Zhang W, Edin ML, Jouihan S, Jia T, Bradbury JA, Graves JP, DeGraff LM, Lee CR, Ronnekleiv O, Wang R, Xu Y, Zeldin DC, Alkayed NJ. Sex- and isoform-specific mechanism of neuroprotection by transgenic expression of P450 epoxygenase in vascular endothelium. Exp Neurol 2016; 279:75-85. [PMID: 26902473 DOI: 10.1016/j.expneurol.2016.02.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 02/07/2016] [Accepted: 02/15/2016] [Indexed: 10/22/2022]
Abstract
OBJECTIVE Cytochrome P450 epoxygenases (CYP) metabolize arachidonic acid to epoxyeicosatrienoic acids (EETs), which exhibit vasodilatory, anti-inflammatory and neuroprotective actions in experimental cerebral ischemia. We evaluated the effect of endothelial-specific CYP overexpression on cerebral blood flow, inflammatory cytokine expression and tissue infarction after focal cerebral ischemia in transgenic mice. APPROACH AND RESULTS Male and female wild-type and transgenic mice overexpressing either human CYP2J2 or CYP2C8 epoxygenases in vascular endothelium under control of the Tie2 promoter (Tie2-CYP2J2 and Tie2-CYP2C8) were subjected to 60-min middle cerebral artery occlusion (MCAO). Microvascular cortical perfusion was monitored during vascular occlusion and reperfusion using laser-Doppler flowmetry and optical imaging. Infarct size and inflammatory cytokines were measured at 24h of reperfusion by TTC and real-time quantitative PCR, respectively. Infarct size was significantly reduced in both Tie2-CYP2J2 and Tie2-CYP2C8 transgenic male mice compared to corresponding WT male mice (n=10 per group, p<0.05). Tie2-CYP2J2, but not Tie2-CYP2C8 male mice maintained higher blood flow during MCAO; however, both Tie2-CYP2J2 and Tie2-CYP2C8 had lower inflammatory cytokine expression after ischemia compared to corresponding WT males (n=10 per group for CBF and n=3 for cytokines, p<0.05). In females, a reduction in infarct was observed in the caudate-putamen, but not in the cortex or hemisphere as a whole and no differences were observed in blood flow between female transgenic and WT mice (n=10 per group). CONCLUSIONS Overexpression of CYP epoxygenases in vascular endothelial cells protects against experimental cerebral ischemia in male mice. The mechanism of protection is in part linked to enhanced blood flow and suppression of inflammation, and is both sex- and CYP isoform-specific.
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Affiliation(s)
- Jia Jia
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, PR China
| | - Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
| | - Wenri Zhang
- Department of Anesthesiology & Perioperative Medicine, The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
| | - Matthew L Edin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Sari Jouihan
- Department of Anesthesiology & Perioperative Medicine, The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
| | - Taiping Jia
- Department of Physiology and Pharmacology, Oregon Health and Science University, USA
| | - J Alyce Bradbury
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Joan P Graves
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Laura M DeGraff
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Craig R Lee
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Oline Ronnekleiv
- Department of Physiology and Pharmacology, Oregon Health and Science University, USA
| | - Ruikang Wang
- Department of Biomedical Engineering, University of Washington, Seattle, WA, USA
| | - Yun Xu
- Department of Neurology, University of Nanjing School of Medicine, Nanjing, PR China
| | - Darryl C Zeldin
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA.
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Marowsky A, Haenel K, Bockamp E, Heck R, Rutishauser S, Mule N, Kindler D, Rudin M, Arand M. Genetic enhancement of microsomal epoxide hydrolase improves metabolic detoxification but impairs cerebral blood flow regulation. Arch Toxicol 2016; 90:3017-3027. [PMID: 26838043 PMCID: PMC5104800 DOI: 10.1007/s00204-016-1666-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 01/06/2016] [Indexed: 01/05/2023]
Abstract
Microsomal epoxide hydrolase (mEH) is a detoxifying enzyme for xenobiotic compounds. Enzymatic activity of mEH can be greatly increased by a point mutation, leading to an E404D amino acid exchange in its catalytic triad. Surprisingly, this variant is not found in any vertebrate species, despite the obvious advantage of accelerated detoxification. We hypothesized that this evolutionary avoidance is due to the fact that the mEH plays a dualistic role in detoxification and control of endogenous vascular signaling molecules. To test this, we generated mEH E404D mice and assessed them for detoxification capacity and vascular dynamics. In liver microsomes from these mice, turnover of the xenobiotic compound phenanthrene-9,10-oxide was four times faster compared to WT liver microsomes, confirming accelerated detoxification. mEH E404D animals also showed faster metabolization of a specific class of endogenous eicosanoids, arachidonic acid-derived epoxyeicosatrienoic acids (EETs) to dihydroxyeicosatrienoic acids (DHETs). Significantly higher DHETs/EETs ratios were found in mEH E404D liver, urine, plasma, brain and cerebral endothelial cells compared to WT controls, suggesting a broad impact of the mEH mutant on endogenous EETs metabolism. Because EETs are strong vasodilators in cerebral vasculature, hemodynamics were assessed in mEH E404D and WT cerebral cortex and hippocampus using cerebral blood volume (CBV)-based functional magnetic resonance imaging (fMRI). Basal CBV0 levels were similar between mEH E404D and control mice in both brain areas. But vascular reactivity and vasodilation in response to the vasodilatory drug acetazolamide were reduced in mEH E404D forebrain compared to WT controls by factor 3 and 2.6, respectively. These results demonstrate a critical role for mEH E404D in vasodynamics and suggest that deregulation of endogenous signaling pathways is the undesirable gain of function associated with the E404D variant.
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Affiliation(s)
- Anne Marowsky
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Karen Haenel
- Institute of Complex Systems (ICS-6), Research Center Julich, Wilhelm-Johnen-Straße, 52425, Julich, Germany
| | - Ernesto Bockamp
- Institute of Translational Immunology, University of Mainz, Obere Zahlbacherstrasse 63, 55131, Mainz, Germany
| | - Rosario Heck
- Institute of Translational Immunology, University of Mainz, Obere Zahlbacherstrasse 63, 55131, Mainz, Germany
| | - Sibylle Rutishauser
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Nandkishor Mule
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Diana Kindler
- Institute for Biomedical Engineering, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093, Zurich, Switzerland
| | - Markus Rudin
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.,Institute for Biomedical Engineering, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093, Zurich, Switzerland
| | - Michael Arand
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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Huang H, Al-Shabrawey M, Wang MH. Cyclooxygenase- and cytochrome P450-derived eicosanoids in stroke. Prostaglandins Other Lipid Mediat 2015; 122:45-53. [PMID: 26747234 DOI: 10.1016/j.prostaglandins.2015.12.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/22/2015] [Accepted: 12/24/2015] [Indexed: 12/28/2022]
Abstract
Arachidonic acid (AA) is metabolized by cyclooxygenase (COX) and cytochrome P450 (CYP) enzymes into eicosanoids, which are involved in cardiovascular diseases and stroke. Evidence has demonstrated the important functions of these eicosanoids in regulating cerebral vascular tone, cerebral blood flow, and autoregulation of cerebral circulation. Although COX-2 inhibitors have been suggested as potential treatments for stroke, adverse events, including an increased risk of stroke, occur following long-term use of coxibs. It is important to note that prolonged treatment with rofecoxib increased circulating levels of 20-hydroxyeicosatetraenoic acid (20-HETE), and 20-HETE blockade is a possible strategy to prevent coxib-induced stroke events. It appears that 20-HETE has detrimental effects in the brain, and that its blockade exerts cerebroprotection against ischemic stroke and subarachnoid hemorrhage (SAH). There is clear evidence that activation of EP2 and EP4 receptors exerts cerebroprotection against ischemic stroke. Several elegant studies have contributed to defining the importance of stabilizing the levels of epoxyeicosatrienoic acids (EETs), by inhibiting or deleting soluble epoxide hydrolase (sEH), in stroke research. These reports support the notion that sEH blockade is cerebroprotective against ischemic stroke and SAH. Here, we summarize recent findings implicating these eicosanoid pathways in cerebral vascular function and stroke. We also discuss the development of animal models with targeted gene deletion and specific enzymatic inhibitors in each pathway to identify potential targets for the treatment of ischemic stroke and SAH.
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Affiliation(s)
- Hui Huang
- Guangdong Province Key Laboratory of Arrhythmia and Electrophysiology, Guangzhou, China; Department of Cardiology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, China
| | - Mohamed Al-Shabrawey
- Department of Oral Biology/Anatomy, College of Dental Medicine, Georgia Regents University, Augusta, GA 30912, United states
| | - Mong-Heng Wang
- Department of Physiology, Georgia Regents University, Augusta, GA 30912, United states.
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Rosenegger DG, Gordon GR. A slow or modulatory role of astrocytes in neurovascular coupling. Microcirculation 2015; 22:197-203. [PMID: 25556627 DOI: 10.1111/micc.12184] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/16/2014] [Indexed: 11/30/2022]
Abstract
Astrocytes are thought to play an important role in NVC, a process that allows the brain to locally control blood flow in response to changes in activity. However, there is an ongoing debate as to when, and under what conditions astrocyte activity is required. In the following review we set forth the hypotheses that astrocytes: (i) act to modulate but not initiate functional hyperemia and (ii) help set the basal tone state of the brain microvasculature by the tonic release of vaso-active messengers. Through these actions astrocytes could help match metabolic demand with supply over a spectrum of activity timescales.
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Affiliation(s)
- David George Rosenegger
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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COX-2-Derived Prostaglandin E2 Produced by Pyramidal Neurons Contributes to Neurovascular Coupling in the Rodent Cerebral Cortex. J Neurosci 2015; 35:11791-810. [PMID: 26311764 DOI: 10.1523/jneurosci.0651-15.2015] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Vasodilatory prostaglandins play a key role in neurovascular coupling (NVC), the tight link between neuronal activity and local cerebral blood flow, but their precise identity, cellular origin and the receptors involved remain unclear. Here we show in rats that NMDA-induced vasodilation and hemodynamic responses evoked by whisker stimulation involve cyclooxygenase-2 (COX-2) activity and activation of the prostaglandin E2 (PgE2) receptors EP2 and EP4. Using liquid chromatography-electrospray ionization-tandem mass spectrometry, we demonstrate that PgE2 is released by NMDA in cortical slices. The characterization of PgE2 producing cells by immunohistochemistry and single-cell reverse transcriptase-PCR revealed that pyramidal cells and not astrocytes are the main cell type equipped for PgE2 synthesis, one third expressing COX-2 systematically associated with a PgE2 synthase. Consistent with their central role in NVC, in vivo optogenetic stimulation of pyramidal cells evoked COX-2-dependent hyperemic responses in mice. These observations identify PgE2 as the main prostaglandin mediating sensory-evoked NVC, pyramidal cells as their principal source and vasodilatory EP2 and EP4 receptors as their targets. SIGNIFICANCE STATEMENT Brain function critically depends on a permanent spatiotemporal match between neuronal activity and blood supply, known as NVC. In the cerebral cortex, prostaglandins are major contributors to NVC. However, their biochemical identity remains elusive and their cellular origins are still under debate. Although astrocytes can induce vasodilations through the release of prostaglandins, the recruitment of this pathway during sensory stimulation is questioned. Using multidisciplinary approaches from single-cell reverse transcriptase-PCR, mass spectrometry, to ex vivo and in vivo pharmacology and optogenetics, we provide compelling evidence identifying PgE2 as the main prostaglandin in NVC, pyramidal neurons as their main cellular source and the vasodilatory EP2 and EP4 receptors as their main targets. These original findings will certainly change the current view of NVC.
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Liu Y, Wan Y, Fang Y, Yao E, Xu S, Ning Q, Zhang G, Wang W, Huang X, Xie M. Epoxyeicosanoid Signaling Provides Multi-target Protective Effects on Neurovascular Unit in Rats After Focal Ischemia. J Mol Neurosci 2015; 58:254-65. [DOI: 10.1007/s12031-015-0670-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 10/20/2015] [Indexed: 01/01/2023]
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COX-2-Derived Prostaglandin E2 Produced by Pyramidal Neurons Contributes to Neurovascular Coupling in the Rodent Cerebral Cortex. J Neurosci 2015. [PMID: 26311764 DOI: 10.1523/jneurosci.0651‐15.2015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Vasodilatory prostaglandins play a key role in neurovascular coupling (NVC), the tight link between neuronal activity and local cerebral blood flow, but their precise identity, cellular origin and the receptors involved remain unclear. Here we show in rats that NMDA-induced vasodilation and hemodynamic responses evoked by whisker stimulation involve cyclooxygenase-2 (COX-2) activity and activation of the prostaglandin E2 (PgE2) receptors EP2 and EP4. Using liquid chromatography-electrospray ionization-tandem mass spectrometry, we demonstrate that PgE2 is released by NMDA in cortical slices. The characterization of PgE2 producing cells by immunohistochemistry and single-cell reverse transcriptase-PCR revealed that pyramidal cells and not astrocytes are the main cell type equipped for PgE2 synthesis, one third expressing COX-2 systematically associated with a PgE2 synthase. Consistent with their central role in NVC, in vivo optogenetic stimulation of pyramidal cells evoked COX-2-dependent hyperemic responses in mice. These observations identify PgE2 as the main prostaglandin mediating sensory-evoked NVC, pyramidal cells as their principal source and vasodilatory EP2 and EP4 receptors as their targets. SIGNIFICANCE STATEMENT Brain function critically depends on a permanent spatiotemporal match between neuronal activity and blood supply, known as NVC. In the cerebral cortex, prostaglandins are major contributors to NVC. However, their biochemical identity remains elusive and their cellular origins are still under debate. Although astrocytes can induce vasodilations through the release of prostaglandins, the recruitment of this pathway during sensory stimulation is questioned. Using multidisciplinary approaches from single-cell reverse transcriptase-PCR, mass spectrometry, to ex vivo and in vivo pharmacology and optogenetics, we provide compelling evidence identifying PgE2 as the main prostaglandin in NVC, pyramidal neurons as their main cellular source and the vasodilatory EP2 and EP4 receptors as their main targets. These original findings will certainly change the current view of NVC.
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Lacoste B, Gu C. Control of cerebrovascular patterning by neural activity during postnatal development. Mech Dev 2015; 138 Pt 1:43-9. [PMID: 26116138 DOI: 10.1016/j.mod.2015.06.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 05/26/2015] [Accepted: 06/16/2015] [Indexed: 01/08/2023]
Abstract
The brain represents only a small portion of the body mass and yet consumes almost a quarter of the available energy, and has a limited ability to store energy. The brain is therefore highly dependent on oxygen and nutrient supply from the blood circulation, which makes it vulnerable to vascular pathologies. Key vascular determinants will ensure proper brain maturation and function: the establishment of vascular networks, the formation of the blood-brain barrier, and the regulation of blood flow. Recent evidence suggests that the phenomenon of neurovascular coupling, during which increased neural activity normally leads to increased blood flow, is not functional until few weeks after birth, implying that the developing brain must rely on alternative mechanisms to adequately couple blood supply to increasing energy demands. This review will focus on these alternative mechanisms, which have been partly elucidated recently via the demonstration that neural activity influences the maturation of cerebrovascular networks. We also propose possible mechanisms underlying activity-induced vascular plasticity.
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Affiliation(s)
- Baptiste Lacoste
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
| | - Chenghua Gu
- Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA.
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Liu X, Gebremedhin D, Harder DR, Koehler RC. Contribution of epoxyeicosatrienoic acids to the cerebral blood flow response to hypoxemia. J Appl Physiol (1985) 2015; 119:1202-9. [PMID: 25792716 DOI: 10.1152/japplphysiol.01043.2014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 03/17/2015] [Indexed: 02/01/2023] Open
Abstract
Adenosine A2A receptors and ATP-activated K(+) (KATP) channels contribute to part of the cerebral vasodilatory response to systemic hypoxia, but other mediators are likely involved. Epoxyeicosatrienoic acids (EETs) are cerebral vasodilators and are released from astrocytes exposed to hypoxia. Moreover, stimulation of metabotropic glutamate receptors (mGluR) produces vasodilation by an EET-dependent mechanism. Here, we tested the hypothesis that EET signaling and mGluR activation contribute to hypoxic vasodilation. Laser-Doppler flow was measured over cerebral cortex of anesthetized rats subjected to stepwise reductions in arterial oxygen saturation to 50-70%. Hypoxic reactivity was calculated as the slope of the change in laser-Doppler flow vs. the reciprocal of arterial oxygen content. Hypoxic reactivity significantly decreased from 9.2 ± 1.9 (±95% confidence interval) in controls with vehicle treatment to 2.6 ± 1.4 with the EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid, to 3.0 ± 1.5 with the EET synthesis inhibitor MS-PPOH, to 1.9 ± 2.3 with the combined mGluR subtype 1 and 5 antagonists 2-methyl-6-(phenylethynyl)pyridine and LY367385, to 5.6 ± 1.2 with the KATP channel inhibitor glibenclamide, and to 5.8 ± 2.3 with the A2A receptor antagonist SCH58261. However, reactivity was not significantly altered by the A2B receptor antagonist MRS1754 (6.7 ± 1.8; P = 0.28 Dunnett's test) or by the 20-hydroxyeicosatetraenoic acid synthesis inhibitor HET0016 (7.5 ± 2.3; P = 0.6). These data indicate that, in addition to the known contributions of A2A receptors and KATP channels to the increase in cerebral blood flow during hypoxia, EETs and mGluRs make a major contribution, possibly by mGluR stimulation and hypoxia-induced release of EETs. In contrast, A2B receptors do not make a major contribution, and 20-hydroxyeicosatetraenoic acid does not significantly limit hypoxic vasodilation.
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Affiliation(s)
- Xiaoguang Liu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Debebe Gebremedhin
- Department of Physiology and the Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - David R Harder
- Department of Physiology and the Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and Clement J. Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin
| | - Raymond C Koehler
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland;
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Soluble epoxide hydrolase activity regulates inflammatory responses and seizure generation in two mouse models of temporal lobe epilepsy. Brain Behav Immun 2015; 43:118-29. [PMID: 25135858 DOI: 10.1016/j.bbi.2014.07.016] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 07/15/2014] [Accepted: 07/28/2014] [Indexed: 12/31/2022] Open
Abstract
Neuroinflammation is known to be involved in epileptogenesis with unclear mechanisms. Inhibition of soluble epoxide hydrolase (sEH) seems to offer anti-inflammatory protection to ischemic brain injury in rodents. Thus, it is hypothesized that sEH inhibition might also affect the neuroinflammatory responses caused by epileptic seizures. In the present study, we investigated the involvement of sEH in neuroinflammation, seizure generation and subsequent epileptogenesis using two mouse models of temporal lobe epilepsy. Experimental epileptic seizures were induced by either pilocarpine or electrical amygdala kindling in both wild-type (WT) C57BL/6 mice and sEH knockout (sEH KO) mice. The sEH expression in the hippocampus was detected by immunohistochemistry and Western blot analysis. The effects of the sEH hydrolase inhibitors, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) and N-[1-(1-oxopropyl)-4-piperidinyl]-N'-[4-(trifluoromethoxy) phenyl)-urea (TPPU), and of the genetic deletion of sEH on seizure-induced neuroinflammatory responses and the development of epilepsy were evaluated. In the hippocampus of WT mice, sEH was mainly expressed in astrocytes (GFAP(+)), neurons (NeuN(+)) and scattered microglia (Iba-1(+)) in the regions of CA1, CA3 and dentate gyrus. Expression of sEH was significantly increased on day 7, 14, 21 and 28 after pilocarpine-induced status epilepticus (SE). Administration with sEH inhibitors attenuated the SE-induced up-regulation of interleukin-1β (IL-1β) and interleukin-6 (IL-6), the degradation of EETs, as well as IκB phosphorylation. Following treatment with AUDA, the frequency and duration of spontaneous motor seizures in the pilocarpine-SE mice were decreased and the seizure-induction threshold of the fully kindled mice was increased. Up-regulation of hippocampal IL-1β and IL-6 was found in both WT and sEH KO mice after successful induction of SE. Notably, sEH KO mice were more susceptible to seizures than WT mice. Seizure related neuroinflammation and ictogenesis were attenuated by pharmacological inhibition of sEH enzymatic activity but not by sEH genetic deletion. Therefore, sEH may play an important role in the generation of epilepsy. Furthermore, the effectiveness of AUDA in terms of anti-inflammatory and anti-ictogenesis properties suggests that it may have clinical therapeutic implication for epilepsy in the future, particularly when treating temporal lobe epilepsy.
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Wagner K, Vito S, Inceoglu B, Hammock BD. The role of long chain fatty acids and their epoxide metabolites in nociceptive signaling. Prostaglandins Other Lipid Mediat 2014; 113-115:2-12. [PMID: 25240260 PMCID: PMC4254344 DOI: 10.1016/j.prostaglandins.2014.09.001] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/27/2014] [Accepted: 09/03/2014] [Indexed: 12/15/2022]
Abstract
Lipid derived mediators contribute to inflammation and the sensing of pain. The contributions of omega-6 derived prostanoids in enhancing inflammation and pain sensation are well known. Less well explored are the opposing anti-inflammatory and analgesic effects of the omega-6 derived epoxyeicosatrienoic acids. Far less has been described about the epoxidized metabolites derived from omega-3 long chain fatty acids. The epoxide metabolites are turned over rapidly with enzymatic hydrolysis by the soluble epoxide hydrolase being the major elimination pathway. Despite this, the overall understanding of the role of lipid mediators in the pathology of chronic pain is growing. Here, we review the role of long chain fatty acids and their metabolites in alleviating both acute and chronic pain conditions. We focus specifically on the epoxidized metabolites of omega-6 and omega-3 long chain fatty acids as well as a novel strategy to modulate their activity in vivo.
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Affiliation(s)
- Karen Wagner
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Steve Vito
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Bora Inceoglu
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States
| | - Bruce D Hammock
- Department of Entomology and UC Davis Comprehensive Cancer Center, University of California Davis, Davis, CA 95616, United States.
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Carver KA, Lourim D, Tryba AK, Harder DR. Rhythmic expression of cytochrome P450 epoxygenases CYP4x1 and CYP2c11 in the rat brain and vasculature. Am J Physiol Cell Physiol 2014; 307:C989-98. [PMID: 25055826 DOI: 10.1152/ajpcell.00401.2013] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Mammals have circadian variation in blood pressure, heart rate, vascular tone, thrombotic tendency, and cerebral blood flow (CBF). These changes may be in part orchestrated by circadian variation in clock gene expression within cells comprising the vasculature that modulate blood flow (e.g., fibroblasts, cerebral vascular smooth muscle cells, astrocytes, and endothelial cells). However, the downstream mechanisms that underlie circadian changes in blood flow are unknown. Cytochrome P450 epoxygenases (Cyp4x1 and Cyp2c11) are expressed in the brain and vasculature and metabolize arachidonic acid (AA) to form epoxyeicosatrienoic acids (EETs). EETs are released from astrocytes, neurons, and vascular endothelial cells and act as potent vasodilators, increasing blood flow. EETs released in response to increases in neural activity evoke a corresponding increase in blood flow known as the functional hyperemic response. We examine the hypothesis that Cyp2c11 and Cyp4x1 expression and EETs production vary in a circadian manner in the rat brain and cerebral vasculature. RT-PCR revealed circadian/diurnal expression of clock and clock-controlled genes as well as Cyp4x1 and Cyp2c11, within the rat hippocampus, middle cerebral artery, inferior vena cava, hippocampal astrocytes and rat brain microvascular endothelial cells. Astrocyte and endothelial cell culture experiments revealed rhythmic variation in Cyp4x1 and Cyp2c11 gene and protein expression with a 12-h period and parallel rhythmic production of EETs. Our data suggest there is circadian regulation of Cyp4x1 and Cyp2c11 gene expression. Such rhythmic EETs production may contribute to circadian changes in blood flow and alter risk of adverse cardiovascular events throughout the day.
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Affiliation(s)
- Koryn A Carver
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - David Lourim
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Andrew K Tryba
- Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin
| | - David R Harder
- Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Physiology, Medical College of Wisconsin, Milwaukee, Wisconsin; and Clement J. Zablocki VA Medical Center, Milwaukee, Wisconsin
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Chen S, Feng H, Sherchan P, Klebe D, Zhao G, Sun X, Zhang J, Tang J, Zhang JH. Controversies and evolving new mechanisms in subarachnoid hemorrhage. Prog Neurobiol 2014; 115:64-91. [PMID: 24076160 PMCID: PMC3961493 DOI: 10.1016/j.pneurobio.2013.09.002] [Citation(s) in RCA: 270] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 09/07/2013] [Accepted: 09/12/2013] [Indexed: 12/13/2022]
Abstract
Despite decades of study, subarachnoid hemorrhage (SAH) continues to be a serious and significant health problem in the United States and worldwide. The mechanisms contributing to brain injury after SAH remain unclear. Traditionally, most in vivo research has heavily emphasized the basic mechanisms of SAH over the pathophysiological or morphological changes of delayed cerebral vasospasm after SAH. Unfortunately, the results of clinical trials based on this premise have mostly been disappointing, implicating some other pathophysiological factors, independent of vasospasm, as contributors to poor clinical outcomes. Delayed cerebral vasospasm is no longer the only culprit. In this review, we summarize recent data from both experimental and clinical studies of SAH and discuss the vast array of physiological dysfunctions following SAH that ultimately lead to cell death. Based on the progress in neurobiological understanding of SAH, the terms "early brain injury" and "delayed brain injury" are used according to the temporal progression of SAH-induced brain injury. Additionally, a new concept of the vasculo-neuronal-glia triad model for SAH study is highlighted and presents the challenges and opportunities of this model for future SAH applications.
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Affiliation(s)
- Sheng Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China; Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Prativa Sherchan
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Damon Klebe
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shanxi, China
| | - Xiaochuan Sun
- Department of Neurosurgery, First Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jiping Tang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA
| | - John H Zhang
- Department of Physiology & Pharmacology, Loma Linda University, Loma Linda, CA, USA; Department of Neurosurgery, Loma Linda University, Loma Linda, CA, USA.
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Involvement of TRPV4 channels in Aβ40-induced hippocampal cell death and astrocytic Ca2+ signalling. Neurotoxicology 2014; 41:64-72. [DOI: 10.1016/j.neuro.2014.01.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/09/2014] [Accepted: 01/12/2014] [Indexed: 11/18/2022]
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