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Cumming P, Gallinat J. Invited commentary: mapping the alteration in glutamate with GluCEST MRI in a mouse model of dopamine deficiency: An Editorial Highlight for 'Mapping the alterations in glutamate with GluCEST MRI in a mouse model of dopamine deficiency'. J Neurochem 2016; 139:346-348. [PMID: 27747879 DOI: 10.1111/jnc.13759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 07/21/2016] [Indexed: 11/27/2022]
Abstract
Read the highlighted article 'Mapping the alterations in glutamate with GluCEST MRI in a mouse model of dopamine deficiency' on page 432.
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Affiliation(s)
- Paul Cumming
- School of Psychology and Counselling and IHBI, Queensland University of Technology, and QIMR Berghofer Institute, Brisbane, Australia.
| | - Jürgen Gallinat
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
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102
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Glia plasma membrane transporters: Key players in glutamatergic neurotransmission. Neurochem Int 2016; 98:46-55. [DOI: 10.1016/j.neuint.2016.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/07/2016] [Accepted: 04/06/2016] [Indexed: 12/27/2022]
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Filpa V, Moro E, Protasoni M, Crema F, Frigo G, Giaroni C. Role of glutamatergic neurotransmission in the enteric nervous system and brain-gut axis in health and disease. Neuropharmacology 2016; 111:14-33. [PMID: 27561972 DOI: 10.1016/j.neuropharm.2016.08.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/18/2016] [Accepted: 08/18/2016] [Indexed: 02/07/2023]
Abstract
Several studies have been carried out in the last 30 years in the attempt to clarify the possible role of glutamate as a neurotransmitter/neuromodulator in the gastrointestinal tract. Such effort has provided immunohistochemical, biomolecular and functional data suggesting that the entire glutamatergic neurotransmitter machinery is present in the complex circuitries of the enteric nervous system (ENS), which participates to the local coordination of gastrointestinal functions. Glutamate is also involved in the regulation of the brain-gut axis, a bi-directional connection pathway between the central nervous system (CNS) and the gut. The neurotransmitter contributes to convey information, via afferent fibers, from the gut to the brain, and to send appropriate signals, via efferent fibers, from the brain to control gut secretion and motility. In analogy with the CNS, an increasing number of studies suggest that dysregulation of the enteric glutamatergic neurotransmitter machinery may lead to gastrointestinal dysfunctions. On the whole, this research field has opened the possibility to find new potential targets for development of drugs for the treatment of gastrointestinal diseases. The present review analyzes the more recent literature on enteric glutamatergic neurotransmission both in physiological and pathological conditions, such as gastroesophageal reflux, gastric acid hypersecretory diseases, inflammatory bowel disease, irritable bowel syndrome and intestinal ischemia/reperfusion injury.
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Affiliation(s)
- Viviana Filpa
- Department of Clinical and Experimental Medicine, University of Insubria, via H. Dunant 5, I-21100 Varese, Italy
| | - Elisabetta Moro
- Department of Internal Medicine and Therapeutics, Section of Pharmacology, via Ferrata 9, I-27100 Pavia, Italy
| | - Marina Protasoni
- Department of Surgical and Morphological Sciences, University of Insubria, via F. Guicciardini 9, I-21100 Varese, Italy
| | - Francesca Crema
- Department of Internal Medicine and Therapeutics, Section of Pharmacology, via Ferrata 9, I-27100 Pavia, Italy
| | - Gianmario Frigo
- Department of Internal Medicine and Therapeutics, Section of Pharmacology, via Ferrata 9, I-27100 Pavia, Italy
| | - Cristina Giaroni
- Department of Clinical and Experimental Medicine, University of Insubria, via H. Dunant 5, I-21100 Varese, Italy
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Affiliation(s)
- Kathleen Holton
- Department of Health Studies, Center for Behavioral Neuroscience, American University, 4400 Massachusetts Avenue NW, Gray Hall 119, Washington, DC 20016, USA
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105
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Glutamate signalling: A multifaceted modulator of oligodendrocyte lineage cells in health and disease. Neuropharmacology 2016; 110:574-585. [PMID: 27346208 DOI: 10.1016/j.neuropharm.2016.06.014] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 05/27/2016] [Accepted: 06/16/2016] [Indexed: 01/10/2023]
Abstract
Myelin is essential for the mammalian brain to function efficiently. Whilst many factors have been associated with regulating the differentiation of oligodendroglia and myelination, glutamate signalling might be particularly important for learning-dependent myelination. The majority of myelinated projection neurons are glutamatergic. Oligodendrocyte precursor cells receive glutamatergic synaptic inputs from unmyelinated axons and oligodendrocyte lineage cells express glutamate receptors which enable them to monitor and respond to changes in neuronal activity. Yet, what role glutamate plays for oligodendroglia is not fully understood. Here, we review glutamate signalling and its effects on oligodendrocyte lineage cells, and myelination in health and disease. Furthermore, we discuss whether glutamate signalling between neurons and oligodendroglia might lay the foundation to activity-dependent white matter plasticity. This article is part of the Special Issue entitled 'Oligodendrocytes in Health and Disease'.
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106
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Ding X, Liu R, Li W, Ni H, Liu Y, Wu D, Yang S, Liu J, Xiao B, Liu S. A metabonomic investigation on the biochemical perturbation in post-stroke patients with depressive disorder (PSD). Metab Brain Dis 2016; 31:279-87. [PMID: 26537495 DOI: 10.1007/s11011-015-9748-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 10/11/2015] [Indexed: 10/22/2022]
Abstract
A metabonomics study based on GC/MS and multivariate statistical analysis was performed involving 28 post stroke depressed (PSD) patients, 27 post-stroke non-depressed (PSND) patients and 33 healthy subjects to investigate the biochemical perturbation in their plasma samples. The outcome of this study showed that there was distinctive metabolic profile for PSD patients. Seven sentinel metabolites showed marked perturbations in PSD patients' blood. The introduction of metabonomics approach may provide a novel metabonomic insight about PSD and the sentinel metabolites for classifying PSD.
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Affiliation(s)
- Xinghua Ding
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China
- State Key Laboratory of Medical Genetics and School of Life Science, Central South University, 110 Xiangya Road, Changsha, 410078, China
| | - Ruoxu Liu
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China
- Departmment of Cell Immunology, Institute of Basic Medical Sciences, Beijing, 100850, China
| | - Wenkai Li
- State Key Laboratory of Medical Genetics and School of Life Science, Central South University, 110 Xiangya Road, Changsha, 410078, China
| | - Hengjia Ni
- Key Laboratory of Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, 410000, China
| | - Yong Liu
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China
| | - Dandan Wu
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China
| | - Shuguang Yang
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China.
| | - Jing Liu
- State Key Laboratory of Medical Genetics and School of Life Science, Central South University, 110 Xiangya Road, Changsha, 410078, China.
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, China.
- Department of Neurology, Xiangya Hospital, Central South University, 110 Xiangya Road, Changsha, Hunan, 410078, China.
| | - Shaojun Liu
- State Key Laboratory of Proteomics and Department of Neurobiology, Institute of Basic Medical Sciences, 27 Taiping Road, Beijing, 100850, China.
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Otter S, Lammert E. Exciting Times for Pancreatic Islets: Glutamate Signaling in Endocrine Cells. Trends Endocrinol Metab 2016; 27:177-188. [PMID: 26740469 DOI: 10.1016/j.tem.2015.12.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Revised: 12/11/2015] [Accepted: 12/14/2015] [Indexed: 01/14/2023]
Abstract
Glutamate represents a key excitatory neurotransmitter in the central nervous system, and also modulates the function and viability of endocrine cells in pancreatic islets. In insulin-secreting beta cells, glutamate acts as an intracellular messenger, and its transport into secretory granules promotes glucose- and incretin-stimulated insulin secretion. Mitochondrial degradation of glutamate also contributes to insulin release when glutamate dehydrogenase is allosterically activated. It also signals extracellularly via glutamate receptors (AMPA and NMDA receptors) to modulate glucagon, insulin and somatostatin secretion, and islet cell survival. Its degradation products, GABA and γ-hydroxybutyrate, are released and also influence islet cell behavior. Thus, islet glutamate receptors, such as the NMDA receptors, might serve as possible drug targets to develop new medications for adjunct treatment of diabetes.
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Affiliation(s)
- Silke Otter
- Institute of Metabolic Physiology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; Institute for Beta Cell Biology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research, and German Center for Diabetes Research (DZD e.V.), Düsseldorf, Germany
| | - Eckhard Lammert
- Institute of Metabolic Physiology, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; Institute for Beta Cell Biology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research, and German Center for Diabetes Research (DZD e.V.), Düsseldorf, Germany.
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Abstract
Mammalian glutaminases catalyze the stoichiometric conversion of L-glutamine to L-glutamate and ammonium ions. In brain, glutaminase is considered the prevailing pathway for synthesis of the neurotransmitter pool of glutamate. Besides neurotransmission, the products of glutaminase reaction also fulfill crucial roles in energy and metabolic homeostasis in mammalian brain. In the last years, new functional roles for brain glutaminases are being uncovered by using functional genomic and proteomic approaches. Glutaminases may act as multifunctional proteins able to perform different tasks: the discovery of multiple transcript variants in neurons and glial cells, novel extramitochondrial localizations, and isoform-specific proteininteracting partners strongly support possible moonlighting functions for these proteins. In this chapter, we present a critical account of essential works on brain glutaminase 80 years after its discovery. We will highlight the impact of recent findings and thoughts in the context of the glutamate/glutamine brain homeostasis.
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109
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Chen JT, Chen TG, Chang YC, Chen CY, Chen RM. Roles of NMDARs in maintenance of the mouse cerebrovascular endothelial cell-constructed tight junction barrier. Toxicology 2016; 339:40-50. [DOI: 10.1016/j.tox.2015.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/18/2015] [Accepted: 11/28/2015] [Indexed: 10/22/2022]
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Immunohistochemical evaluation of hippocampal CA1 region astrocytes in 10-day-old rats after monosodium glutamate treatment. Pol J Vet Sci 2015; 18:767-74. [DOI: 10.1515/pjvs-2015-0099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
High concentration of glutamate (Glu) is excitotoxic for nervous system structures. This may lead to glial reactivity ie. increased expression of glial fibrillary acidic protein (GFAP) and S100β protein, and also to hypertrophy and proliferation of cells which are determined by the presence of Ki-67 antigen. The aim of the study was to analyse the immunoreactivity of the GFAP, S100β and Ki-67 proteins in astrocytes of hippocampal CA1 region in young rats after administration of monosodium glutamate (MSG) at two doses: 2 g/kg b.w. (I group) and 4 g/kg b.w. (II group). In rats from I and II group morphologically altered astrocytes with the GFAP expression were observed in the SLM of the hippocampal CA1 region. The cells had eccentrically located nuclei and on the opposite site of the nuclei there were single or double, long and weakly branched processes. Moreover, in the SLM the increase of the number of GFAP and S100β immunopositive astrocytes and nuclei with Ki-67 expression, in contrary to control individuals, was observed. These results suggest the increased expression of the proteins in early reactions or hyperplasia which, together with cell hypertrophy, indicate late reactivity of astroglia in response to glutamate noxious effect.
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111
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Miladinovic T, Nashed MG, Singh G. Overview of Glutamatergic Dysregulation in Central Pathologies. Biomolecules 2015; 5:3112-41. [PMID: 26569330 PMCID: PMC4693272 DOI: 10.3390/biom5043112] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/03/2015] [Accepted: 11/05/2015] [Indexed: 12/27/2022] Open
Abstract
As the major excitatory neurotransmitter in the mammalian central nervous system, glutamate plays a key role in many central pathologies, including gliomas, psychiatric, neurodevelopmental, and neurodegenerative disorders. Post-mortem and serological studies have implicated glutamatergic dysregulation in these pathologies, and pharmacological modulation of glutamate receptors and transporters has provided further validation for the involvement of glutamate. Furthermore, efforts from genetic, in vitro, and animal studies are actively elucidating the specific glutamatergic mechanisms that contribute to the aetiology of central pathologies. However, details regarding specific mechanisms remain sparse and progress in effectively modulating glutamate to alleviate symptoms or inhibit disease states has been relatively slow. In this report, we review what is currently known about glutamate signalling in central pathologies. We also discuss glutamate's mediating role in comorbidities, specifically cancer-induced bone pain and depression.
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Affiliation(s)
- Tanya Miladinovic
- Department of Pathology and Molecular Medicine, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4L8, Canada.
| | - Mina G Nashed
- Department of Pathology and Molecular Medicine, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4L8, Canada.
| | - Gurmit Singh
- Department of Pathology and Molecular Medicine, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4L8, Canada.
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112
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Miyata S. New aspects in fenestrated capillary and tissue dynamics in the sensory circumventricular organs of adult brains. Front Neurosci 2015; 9:390. [PMID: 26578857 PMCID: PMC4621430 DOI: 10.3389/fnins.2015.00390] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 10/05/2015] [Indexed: 12/20/2022] Open
Abstract
The blood-brain barrier (BBB) generally consists of endothelial tight junction barriers that prevent the free entry of blood-derived substances, thereby maintaining the extracellular environment of the brain. However, the circumventricular organs (CVOs), which are located along the midlines of the brain ventricles, lack these endothelial barriers and have fenestrated capillaries; therefore, they have a number of essential functions, including the transduction of information between the blood circulation and brain. Previous studies have demonstrated the extensive contribution of the CVOs to body fluid and thermal homeostasis, energy balance, the chemoreception of blood-derived substances, and neuroinflammation. In this review, recent advances have been discussed in fenestrated capillary characterization and dynamic tissue reconstruction accompanied by angiogenesis and neurogliogenesis in the sensory CVOs of adult brains. The sensory CVOs, including the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO), and area postrema (AP), have size-selective and heterogeneous vascular permeabilities. Astrocyte-/tanycyte-like neural stem cells (NSCs) sense blood- and cerebrospinal fluid-derived information through the transient receptor potential vanilloid 1, a mechanical/osmotic receptor, Toll-like receptor 4, a lipopolysaccharide receptor, and Nax, a Na-sensing Na channel. They also express tight junction proteins and densely and tightly surround mature neurons to protect them from blood-derived neurotoxic substances, indicating that the NSCs of the CVOs perform BBB functions while maintaining the capacity to differentiate into new neurons and glial cells. In addition to neurogliogenesis, the density of fenestrated capillaries is regulated by angiogenesis, which is accompanied by the active proliferation and sprouting of endothelial cells. Vascular endothelial growth factor (VEGF) signaling may be involved in angiogenesis and neurogliogenesis, both of which affect vascular permeability. Thus, recent findings advocate novel concepts for the CVOs, which have the dynamic features of vascular and parenchymal tissues.
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Affiliation(s)
- Seiji Miyata
- Department of Applied Biology, Kyoto Institute of TechnologyKyoto, Japan
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113
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Abstract
Objective: To analyze the mechanism of neuroprotection of insulin and which blood glucose range was benefit for insulin exerting neuroprotective action. Data Sources: The study is based on the data from PubMed. Study Selection: Articles were selected with the search terms “insulin”, “blood glucose”, “neuroprotection”, “brain”, “glycogen”, “cerebral ischemia”, “neuronal necrosis”, “glutamate”, “γ-aminobutyric acid”. Results: Insulin has neuroprotection. The mechanisms include the regulation of neurotransmitter, promoting glycogen synthesis, and inhibition of neuronal necrosis and apoptosis. Insulin could play its role in neuroprotection by avoiding hypoglycemia and hyperglycemia. Conclusions: Intermittent and long-term infusion insulin may be a benefit for patients with ischemic brain damage at blood glucose 6–9 mmol/L.
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Affiliation(s)
| | - Yu Pei
- Department of Endocrinology, Chinese PLA General Hospital, Beijing 100853, China
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114
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Abstract
A constant supply of glucose to the brain is critical for normal cerebral metabolism. The dysglycemia of type 1 diabetes (T1D) can affect activity, survival, and function of neural cells. Clinical studies in T1D have shown impairments in brain morphology and function. The most neurotoxic milieu seems to be young age and/or diabetic ketoacidosis at onset, severe hypoglycemia under the age of 6 years followed by chronic hyperglycemia. Adverse cognitive outcomes seem to be associated with poorer mental health outcomes. It is imperative to improve outcomes by investigating the mechanisms of injury so that neuroprotective strategies independent of glycemia can be identified.
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Affiliation(s)
- Fergus J Cameron
- Department of Endocrinology and Diabetes, Royal Children's Hospital, Murdoch Childrens Research Institute, 50 Flemington Road, Parkville, Melbourne 3052, Australia; Department of Paediatrics, University of Melbourne, Melbourne 3010, Australia.
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115
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Clark-Matott J, Saleem A, Dai Y, Shurubor Y, Ma X, Safdar A, Beal MF, Tarnopolsky M, Simon DK. Metabolomic analysis of exercise effects in the POLG mitochondrial DNA mutator mouse brain. Neurobiol Aging 2015; 36:2972-2983. [PMID: 26294258 DOI: 10.1016/j.neurobiolaging.2015.07.020] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/12/2015] [Accepted: 07/13/2015] [Indexed: 01/09/2023]
Abstract
Mitochondrial DNA (mtDNA) mutator mice express a mutated form of mtDNA polymerase gamma that results an accelerated accumulation of somatic mtDNA mutations in association with a premature aging phenotype. An exploratory metabolomic analysis of cortical metabolites in sedentary and exercised mtDNA mutator mice and wild-type littermate controls at 9-10 months of age was performed. Pathway analysis revealed deficits in the neurotransmitters acetylcholine, glutamate, and aspartate that were ameliorated by exercise. Nicotinamide adenine dinucleotide (NAD) depletion and evidence of increased poly(adenosine diphosphate-ribose) polymerase 1 (PARP1)activity were apparent in sedentary mtDNA mutator mouse cortex, along with deficits in carnitine metabolites and an upregulated antioxidant response that largely normalized with exercise. These data highlight specific pathways that are altered in the brain in association with an accelerated age-related accumulation of somatic mtDNA mutations. These results may have relevance to age-related neurodegenerative diseases associated with mitochondrial dysfunction, such as Alzheimer's disease and Parkinson's disease and provide insights into potential mechanisms of beneficial effects of exercise on brain function.
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Affiliation(s)
- Joanne Clark-Matott
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
| | - Ayesha Saleem
- Department of Pediatrics, McMaster University Medical Center, Hamilton, Ontario, Canada; Department of Medicine, McMaster University Medical Center, Hamilton, Ontario, Canada
| | - Ying Dai
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Yevgeniya Shurubor
- Brain and Mind Institute, Weill Medical College, Cornell University, New York, NY, USA
| | - Xiaoxing Ma
- Department of Pediatrics, McMaster University Medical Center, Hamilton, Ontario, Canada; Department of Medicine, McMaster University Medical Center, Hamilton, Ontario, Canada
| | - Adeel Safdar
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Myron Flint Beal
- Brain and Mind Institute, Weill Medical College, Cornell University, New York, NY, USA
| | - Mark Tarnopolsky
- Department of Pediatrics, McMaster University Medical Center, Hamilton, Ontario, Canada; Department of Medicine, McMaster University Medical Center, Hamilton, Ontario, Canada
| | - David K Simon
- Department of Neurology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
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Zick SM, Zwickey H, Wood L, Foerster B, Khabir T, Wright B, Ichesco E, Sen A, Harris RE. Preliminary differences in peripheral immune markers and brain metabolites between fatigued and non-fatigued breast cancer survivors: a pilot study. Brain Imaging Behav 2015; 8:506-16. [PMID: 24222427 DOI: 10.1007/s11682-013-9270-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Persistent cancer-related fatigue (PCRF) is one of the most troubling side-effects of breast cancer (BC) treatment. One explanatory model for PCRF is sickness behavior, which is a set of adaptive responses including sleepiness and depressed mood in reaction to an inflammatory trigger. Prior research has investigated differences in inflammatory cytokines between fatigued and non-fatigued BC survivors, but no study has examined differences in brain metabolites. Differences in inflammatory markers, and brain metabolites using proton magnetic resonance spectroscopy were evaluated within 16 fatigued and 13 non-fatigued BC survivors. Fatigued BC survivors had significantly higher ratios of two markers derived from brain metabolites; namely (a) creatine, normalized to total creatine (creatine + phosphocreatine (Cr/tCr)) ratio (P = 0.03) and (b) glutamate + glutamine (Glx) to N-acetyl-aspartate (NAA) ratio (P = 0.01) in the posterior insula compared to non-fatigued breast cancer survivor. Further, serum IL-6 was increased in fatigued women compared to non-fatigued women (P = 0.03), Using receiver operator curves (ROC) we determined that the posterior insula Glx/NAA ratio was the best predictor of fatigue with an overall area under the receiver operating characteristic curve (AUROC) of 79%, with a sensitivity of 81% and a specificity of 69%. However, posterior insula Glx/NAA, Cr/tCr and serum IL-6 were not significantly correlated with one another implying the possibility of independent biological mechanisms for PCRF rather than an interrelated mechanism as represented by the sickness behavior model. This study provides novel preliminary evidence of several distinct neurobiological changes in the posterior insula associated with PCRF in BC survivors. Future, longitudinal studies are needed to explore these distinct biological phenomena where changes through time in peripheral immune markers and brain metabolites are examined to determine if they correlate with changes in fatigue.
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Affiliation(s)
- Suzanna Maria Zick
- Department of Family Medicine, University of Michigan, 24 Frank Lloyd Wright Drive, Ann Arbor, MI, 48105, USA,
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Kurihara K. Umami the Fifth Basic Taste: History of Studies on Receptor Mechanisms and Role as a Food Flavor. BIOMED RESEARCH INTERNATIONAL 2015; 2015:189402. [PMID: 26247011 PMCID: PMC4515277 DOI: 10.1155/2015/189402] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/16/2015] [Indexed: 01/05/2023]
Abstract
Three umami substances (glutamate, 5'-inosinate, and 5'-guanylate) were found by Japanese scientists, but umami has not been recognized in Europe and America for a long time. In the late 1900s, umami was internationally recognized as the fifth basic taste based on psychophysical, electrophysiological, and biochemical studies. Three umami receptors (T1R1 + T1R3, mGluR4, and mGluR1) were identified. There is a synergism between glutamate and the 5'-nucleotides. Among the above receptors, only T1R1 + T1R3 receptor exhibits the synergism. In rats, the response to a mixture of glutamate and 5'-inosinate is about 1.7 times larger than that to glutamate alone. In human, the response to the mixture is about 8 times larger than that to glutamate alone. Since glutamate and 5'-inosinate are contained in various foods, we taste umami induced by the synergism in daily eating. Hence umami taste induced by the synergism is a main umami taste in human.
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118
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Song J, Viggiano A, Monda M, De Luca V. Peripheral glutamate levels in schizophrenia: evidence from a meta-analysis. Neuropsychobiology 2015; 70:133-41. [PMID: 25359535 DOI: 10.1159/000364828] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 05/24/2014] [Indexed: 01/13/2023]
Abstract
BACKGROUND Recent research attempting to develop novel medications has turned to glutamatergic signaling pathways to find effective treatments for symptom clusters of schizophrenia. This meta-analysis was undertaken to clarify whether a difference in peripheral glutamate levels exists between patients with schizophrenia and healthy controls. METHODS The electronic databases Ovid MEDLINE, PubMed, and PsycINFO were systematically searched up to April 2013. The search was limited to case-control studies of blood glutamate levels in schizophrenia written in English. The differences in glutamate levels were evaluated by calculating standardized mean differences (SMD). RESULTS We found ten studies that met the inclusion criteria for a total of 320 schizophrenia patients and 294 controls. The meta-analysis showed that peripheral glutamate levels in schizophrenia patients were significantly higher overall than in controls (SMD = 0.635, p = 0.004). However, a significant effect of the method used to measure glutamate concentrations was found (F = 7.36, p = 0.01) where fluorometric assay was associated with effect sizes in the opposite direction. CONCLUSION A higher blood glutamate concentration was found in patients with schizophrenia. However, given the small sample size and methodological differences among studies, this result is not conclusive. More comprehensive research is needed to understand the relationship between glutamate levels in schizophrenia in the blood and the brain.
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Affiliation(s)
- Jiali Song
- Center for Addiction and Mental Health, University of Toronto, Toronto, Ont., Canada
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119
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eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells. PLoS One 2015; 10:e0125389. [PMID: 25962137 PMCID: PMC4427111 DOI: 10.1371/journal.pone.0125389] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Accepted: 03/24/2015] [Indexed: 01/07/2023] Open
Abstract
Objective We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K)/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs). Methods Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR. Results Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs. Conclusions eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.
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van Vliet E, Aronica E, Gorter J. Blood–brain barrier dysfunction, seizures and epilepsy. Semin Cell Dev Biol 2015; 38:26-34. [DOI: 10.1016/j.semcdb.2014.10.003] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 10/21/2014] [Accepted: 10/23/2014] [Indexed: 02/06/2023]
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Blood–Brain Barrier Permeability and Brain Uptake Mechanism of Kainic Acid and Dihydrokainic Acid. Neurochem Res 2014; 40:542-9. [DOI: 10.1007/s11064-014-1499-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 12/02/2014] [Accepted: 12/02/2014] [Indexed: 01/09/2023]
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Chronic widespread pain: increased glutamate and lactate concentrations in the trapezius muscle and plasma. Clin J Pain 2014; 30:409-20. [PMID: 23887335 DOI: 10.1097/ajp.0b013e31829e9d2a] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Chronic widespread pain (CWP), including fibromyalgia syndrome (FM), is associated with prominent negative consequences. CWP has been associated with alterations in the central processing of nociception. Whereas some researchers consider CWP/FM as a central hyperexcitability pain condition, others suggest that the central alterations are maintained by peripheral nociceptive input. Microdialysis can be used in vivo to study muscle alterations in chronic myalgia. AIM : The aim of the study was to investigate the plasma and interstitial concentrations of metabolites and algesics in the trapezius muscle of women with CWP and in pain-free women (CON). MATERIALS AND METHODS Seventeen women with CWP and 24 CON went through a clinical examination and completed a questionnaire; the pressure pain thresholds in the upper and lower extremities were registered. Microdialysis was conducted in the trapezius muscle, and a blood sample was drawn. Muscle blood flow, interstitial muscle concentrations, and plasma concentrations of lactate, pyruvate, glutamate, glucose, and glycerol (not in the plasma) were determined. RESULTS CWP patients had significantly increased interstitial muscle (P=0.02 to 0.001) and plasma (P=0.026 to 0.017) concentrations of lactate and glutamate. No significant differences existed in blood flow between CWP and CON. The interstitial concentrations-but not the plasma levels-of glutamate and lactate correlated significantly with aspects of pain such as pressure pain thresholds of the trapezius (R=0.22) and tibialis anterior (R=0.18) and the mean pain intensity (R=0.10) in CWP but not in CON. CONCLUSIONS The present study supports the suggestion that aspects of pain and central alterations in CWP/FM are influenced by peripheral tissue alterations.
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Glutamate efflux at the blood-brain barrier: cellular mechanisms and potential clinical relevance. Arch Med Res 2014; 45:639-45. [PMID: 25446623 DOI: 10.1016/j.arcmed.2014.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 11/10/2014] [Indexed: 12/29/2022]
Abstract
L-Glutamate is considered the most important excitatory amino acid in the mammalian brain. Strict control of its concentration in the brain interstitial fluid is important to maintain neurotransmission and avoid excitotoxicity. The role of astrocytes in handling L-glutamate transport and metabolism is well known, however endothelial cells may also play an important role through mediating brain-to-blood L-glutamate efflux. Expression of excitatory amino acid transporters has been demonstrated in brain endothelial cells of bovine, human, murine, rat and porcine origin. These can account for high affinity concentrative uptake of L-glutamate from the brain interstitial fluid into the capillary endothelial cells. The mechanisms in between L-glutamate uptake in the endothelial cells and L-glutamate appearing in the blood are still unclear and may involve a luminal transporter for L-glutamate, metabolism of L-glutamate and transport of metabolites or a combination of the two. However, both in vitro and in vivo studies demonstrated blood-to-brain transport of L-glutamate, at least during pathological events. This review summarizes the current knowledge on the brain-to-blood L-glutamate efflux hypothesis including possible mechanisms to account for the transport, in vivo studies on blood glutamate scavenging and potential clinical relevance of the phenomenon.
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van Vliet E, Aronica E, Gorter J. Role of blood–brain barrier in temporal lobe epilepsy and pharmacoresistance. Neuroscience 2014; 277:455-73. [DOI: 10.1016/j.neuroscience.2014.07.030] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 12/14/2022]
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Seyfried TN, Flores R, Poff AM, D'Agostino DP, Mukherjee P. Metabolic therapy: a new paradigm for managing malignant brain cancer. Cancer Lett 2014; 356:289-300. [PMID: 25069036 DOI: 10.1016/j.canlet.2014.07.015] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 07/09/2014] [Accepted: 07/10/2014] [Indexed: 01/18/2023]
Abstract
Little progress has been made in the long-term management of glioblastoma multiforme (GBM), considered among the most lethal of brain cancers. Cytotoxic chemotherapy, steroids, and high-dose radiation are generally used as the standard of care for GBM. These procedures can create a tumor microenvironment rich in glucose and glutamine. Glucose and glutamine are suggested to facilitate tumor progression. Recent evidence suggests that many GBMs are infected with cytomegalovirus, which could further enhance glucose and glutamine metabolism in the tumor cells. Emerging evidence also suggests that neoplastic macrophages/microglia, arising through possible fusion hybridization, can comprise an invasive cell subpopulation within GBM. Glucose and glutamine are major fuels for myeloid cells, as well as for the more rapidly proliferating cancer stem cells. Therapies that increase inflammation and energy metabolites in the GBM microenvironment can enhance tumor progression. In contrast to current GBM therapies, metabolic therapy is designed to target the metabolic malady common to all tumor cells (aerobic fermentation), while enhancing the health and vitality of normal brain cells and the entire body. The calorie restricted ketogenic diet (KD-R) is an anti-angiogenic, anti-inflammatory and pro-apoptotic metabolic therapy that also reduces fermentable fuels in the tumor microenvironment. Metabolic therapy, as an alternative to the standard of care, has the potential to improve outcome for patients with GBM and other malignant brain cancers.
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Affiliation(s)
| | | | - Angela M Poff
- Department of Molecular Pharmacology and Physiology, University of South Florida, 33612 Tampa, FL, USA
| | - Dominic P D'Agostino
- Department of Molecular Pharmacology and Physiology, University of South Florida, 33612 Tampa, FL, USA
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Vendel E, de Lange ECM. Functions of the CB1 and CB 2 receptors in neuroprotection at the level of the blood-brain barrier. Neuromolecular Med 2014; 16:620-42. [PMID: 24929655 DOI: 10.1007/s12017-014-8314-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2014] [Accepted: 05/14/2014] [Indexed: 12/30/2022]
Abstract
The cannabinoid (CB) receptors are the main targets of the cannabinoids, which include plant cannabinoids, endocannabinoids and synthetic cannabinoids. Over the last few years, accumulated evidence has suggested a role of the CB receptors in neuroprotection. The blood-brain barrier (BBB) is an important brain structure that is essential for neuroprotection. A link between the CB receptors and the BBB is thus likely, but this possible connection has only recently gained attention. Cannabinoids and the BBB share the same mechanisms of neuroprotection and both protect against excitotoxicity (CB1), cell death (CB1), inflammation (CB2) and oxidative stress (possibly CB independent)-all processes that also damage the BBB. Several examples of CB-mediated protection of the BBB have been found, such as inhibition of leukocyte influx and induction of amyloid beta efflux across the BBB. Moreover, the CB receptors were shown to improve BBB integrity, particularly by restoring the tightness of the tight junctions. This review demonstrated that both CB receptors are able to restore the BBB and neuroprotection, but much uncertainty about the underlying signaling cascades still exists and further investigation is needed.
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Affiliation(s)
- Esmée Vendel
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333CC, PO Box 9502, 2300 RA, Leiden, The Netherlands
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127
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Sühs KW, Fairless R, Williams SK, Heine K, Cavalié A, Diem R. N-Methyl-d-Aspartate Receptor Blockade Is Neuroprotective in Experimental Autoimmune Optic Neuritis. J Neuropathol Exp Neurol 2014; 73:507-18. [DOI: 10.1097/nen.0000000000000073] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Lecointre M, Hauchecorne M, Chaussivert A, Marret S, Leroux P, Jegou S, Leroux-Nicollet I, Gonzalez BJ, Henry VJ. The efficiency of glutamate uptake differs between neonatal and adult cortical microvascular endothelial cells. J Cereb Blood Flow Metab 2014; 34:764-7. [PMID: 24517976 PMCID: PMC4013767 DOI: 10.1038/jcbfm.2014.30] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 12/27/2013] [Accepted: 01/19/2014] [Indexed: 11/09/2022]
Abstract
Glutamate transporters (excitatory amino-acid transporters (EAATs)) are essential for brain homeostasis. While previous studies indicate that the vascular endothelium contributes to glutamate efflux in the adult brain, little information is available regarding glutamate uptake in the immature brain. The present study shows a differential expression pattern of EAATs between cortical microvessels in adults and newborns. In addition, adult cortical endothelial cells take up glutamate more efficiently than neonatal cells. Our findings indicate age-specific changes in extracellular glutamate regulation by brain endothelial cells, suggesting differences in the efficiency of glutamate efflux during an excitotoxic process that, in turn, may contribute to age-specific brain vulnerability.
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Affiliation(s)
- Maryline Lecointre
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Michelle Hauchecorne
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Armelle Chaussivert
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Stéphane Marret
- 1] ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France [2] Department of Neonatal Pediatrics and Intensive Care, Rouen University Hospital, Rouen, France
| | - Philippe Leroux
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Sylvie Jegou
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Isabelle Leroux-Nicollet
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Bruno J Gonzalez
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
| | - Vincent J Henry
- ERI28 NeoVasc, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Normandy University, Institute for Research and Innovation in Biomedicine, Rouen, France
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129
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Farina D, Alvau MD, Puggioni G, Calia G, Bazzu G, Migheli R, Sechi O, Rocchitta G, Desole MS, Serra PA. Implantable (Bio)sensors as new tools for wireless monitoring of brain neurochemistry in real time. World J Pharmacol 2014; 3:1-17. [DOI: 10.5497/wjp.v3.i1.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 05/01/2014] [Accepted: 05/29/2014] [Indexed: 02/06/2023] Open
Abstract
Implantable electrochemical microsensors are characterized by high sensitivity, while amperometric biosensors are very selective in virtue of the biological detecting element. Each sensor, specific for every neurochemical species, is a miniaturized high-technology device resulting from the combination of several factors: electrode material, shielding polymers, applied electrochemical technique, and in the case of biosensors, biological sensing material, stabilizers, and entrapping chemical nets. In this paper, we summarize the available technology for the in vivo electrochemical monitoring of neurotransmitters (dopamine, norepinephrine, serotonin, acetylcholine, and glutamate), bioenergetic substrates (glucose, lactate, and oxygen), neuromodulators (ascorbic acid and nitric oxide), and exogenous molecules such as ethanol. We also describe the most represented biotelemetric technologies in order to wirelessly transmit the signals of the above-listed neurochemicals. Implantable (Bio)sensors, integrated into miniaturized telemetry systems, represent a new generation of analytical tools that could be used for studying the brain’s physiology and pathophysiology and the effects of different drugs (or toxic chemicals such as ethanol) on neurochemical systems.
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130
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Wang GD, Wang XY, Xia Y, Wood JD. Dietary glutamate: interactions with the enteric nervous system. J Neurogastroenterol Motil 2013; 20:41-53. [PMID: 24466444 PMCID: PMC3895608 DOI: 10.5056/jnm.2014.20.1.41] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Revised: 10/01/2013] [Accepted: 10/03/2013] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND/AIMS Digestion of dietary protein elevates intraluminal concentrations of glutamate in the small intestine, some of which gain access to the enteric nervous system (ENS). Glutamate, in the central nervous system (CNS), is an excitatory neurotransmitter. A dogma that glutamatergic neurophysiology in the ENS recapitulates CNS glutamatergic function persists. We reassessed the premise that glutamatergic signaling in the ENS recapitulates its neurotransmitter role in the CNS. METHODS Pharmacological analysis of actions of receptor agonists and antagonists in concert with immunohistochemical localization of glutamate transporters and receptors was used. Analysis focused on intracellularly-recorded electrical and synaptic behavior of ENS neurons, on stimulation of mucosal secretion by secretomotor neurons in the submucosal plexus and on muscle contractile behavior mediated by musculomotor neurons in the myenteric plexus. RESULTS Immunoreactivity for glutamate was expressed in ENS neurons. ENS neurons expressed immunoreactivity for the EAAC-1 glutamate transporter. Neither L-glutamate nor glutamatergic receptor agonists had excitatory actions on ENS neurons. Metabotropic glutamatergic receptor agonists did not directly stimulate neurogenic mucosal chloride secretion. Neither L-glutamate nor the metabotropic glutamatergic receptor agonist, aminocyclopentane-1,3-dicarboxylic acid (ACPD), changed the mean amplitude of spontaneously occurring contractions in circular or longitudinal strips of intestinal wall from either guinea pig or human small intestinal preparations. CONCLUSIONS Early discoveries, for excitatory glutamatergic neurotransmission in the CNS, inspired enthusiasm that investigation in the ENS would yield discoveries recapitulating the CNS glutamatergic story. We found this not to be the case.
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Affiliation(s)
- Guo-Du Wang
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Xi-Yu Wang
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Yun Xia
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA. ; Department of Anesthesiology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Jackie D Wood
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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131
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Kuntz M, Mysiorek C, Pétrault O, Boucau MC, Aijjou R, Uzbekov R, Bérézowski V. Transient oxygen-glucose deprivation sensitizes brain capillary endothelial cells to rtPA at 4h of reoxygenation. Microvasc Res 2013; 91:44-57. [PMID: 24333620 DOI: 10.1016/j.mvr.2013.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Revised: 11/28/2013] [Accepted: 12/03/2013] [Indexed: 01/11/2023]
Abstract
Thrombolysis treatment of acute ischemic stroke is limited by the pro-edematous and hemorrhagic effects exerted by reperfusion, which disrupts the blood-brain barrier (BBB) capillary endothelium in the infarct core. Most studies of the ischemic BBB overlook the complexity of the penumbral area, where the affected brain cells are still viable following deprivation. Our present objective was to examine in vitro the kinetic impact of reoxygenation on the integrity of ischemic BBB cells after oxygen-glucose deprivation. Through the use of a co-culture of brain capillary endothelial cells and glial cells, we first showed that the transendothelial permeability increase induced by deprivation can occur with both preserved cell viability and interendothelial tight junction network. The subtle and heterogeneous alteration of the tight junctions was observable only through electron microscopy. A complete permeability recovery was then found after reoxygenation, when Vimentin and Actin networks were reordered. However, still sparse ultrastructural alterations of tight junctions suggested an acquired vulnerability. Endothelial cells were then exposed to recombinant tissue-type plasminogen activator (rtPA) to define a temporal profile for the toxic effect of this thrombolytic on transendothelial permeability. Interestingly, the reoxygenated BBB broke down with aggravated tight junction disruption when exposed to rtPA only at 4h after reoxygenation. Moreover, this breakdown was enhanced by 50% when ischemic glial cells were present during the first hours of reoxygenation. Our results suggest that post-stroke reoxygenation enables retrieval of the barrier function of brain capillary endothelium when in a non-necrotic environment, but may sensitize it to rtPA at the 4-hour time point, when both endothelial breakdown mechanisms and glial secretions could be identified and targeted in a therapeutical perspective.
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Affiliation(s)
- Mélanie Kuntz
- Univ Lille Nord de France, UArtois, LBHE, EA 2465, Faculté des Sciences Jean Perrin, rue Jean Souvraz, S.P.18, F-62307 Lens cedex, France; Institut de Médecine Prédictive et de Recherche Thérapeutique, Place de Verdun, F-59045 Lille cedex, France; Institut Fédératif de Recherche 114, Place de Verdun, F-59045 Lille cedex, France.
| | - Caroline Mysiorek
- Univ Lille Nord de France, UArtois, LBHE, EA 2465, Faculté des Sciences Jean Perrin, rue Jean Souvraz, S.P.18, F-62307 Lens cedex, France; Institut de Médecine Prédictive et de Recherche Thérapeutique, Place de Verdun, F-59045 Lille cedex, France; Institut Fédératif de Recherche 114, Place de Verdun, F-59045 Lille cedex, France.
| | - Olivier Pétrault
- Univ Lille Nord de France, UArtois, LBHE, EA 2465, Faculté des Sciences Jean Perrin, rue Jean Souvraz, S.P.18, F-62307 Lens cedex, France; Institut de Médecine Prédictive et de Recherche Thérapeutique, Place de Verdun, F-59045 Lille cedex, France; Institut Fédératif de Recherche 114, Place de Verdun, F-59045 Lille cedex, France.
| | - Marie-Christine Boucau
- Univ Lille Nord de France, UArtois, LBHE, EA 2465, Faculté des Sciences Jean Perrin, rue Jean Souvraz, S.P.18, F-62307 Lens cedex, France; Institut de Médecine Prédictive et de Recherche Thérapeutique, Place de Verdun, F-59045 Lille cedex, France; Institut Fédératif de Recherche 114, Place de Verdun, F-59045 Lille cedex, France.
| | - Rachid Aijjou
- Univ Lille Nord de France, UArtois, LBHE, EA 2465, Faculté des Sciences Jean Perrin, rue Jean Souvraz, S.P.18, F-62307 Lens cedex, France; Institut de Médecine Prédictive et de Recherche Thérapeutique, Place de Verdun, F-59045 Lille cedex, France; Institut Fédératif de Recherche 114, Place de Verdun, F-59045 Lille cedex, France.
| | - Rustem Uzbekov
- Département des Microscopies, Université François Rabelais, F-37100 Tours, France; Faculty of Bioengineering & Bioinformatics, Moscow State University, 119991 Moscow, Russia.
| | - Vincent Bérézowski
- Univ Lille Nord de France, UArtois, LBHE, EA 2465, Faculté des Sciences Jean Perrin, rue Jean Souvraz, S.P.18, F-62307 Lens cedex, France; Institut de Médecine Prédictive et de Recherche Thérapeutique, Place de Verdun, F-59045 Lille cedex, France; Institut Fédératif de Recherche 114, Place de Verdun, F-59045 Lille cedex, France.
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Kunze A, Lengacher S, Dirren E, Aebischer P, Magistretti PJ, Renaud P. Astrocyte-neuron co-culture on microchips based on the model of SOD mutation to mimic ALS. Integr Biol (Camb) 2013; 5:964-75. [PMID: 23695230 DOI: 10.1039/c3ib40022k] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. ALS is believed to be a non-cell autonomous condition, as other cell types, including astrocytes, have been implicated in disease pathogenesis. Hence, to facilitate the development of therapeutics against ALS, it is crucial to better understand the interactions between astrocytes and neural cells. Furthermore, cell culture assays are needed that mimic the complexity of cell to cell communication at the same time as they provide control over the different microenvironmental parameters. Here, we aim to validate a previously developed microfluidic system for an astrocyte-neuron cell culture platform, in which astrocytes have been genetically modified to overexpress either a human wild-type (WT) or a mutated form of the super oxide dismutase enzyme 1 (SOD1). Cortical neural cells were co-cultured with infected astrocytes and studied for up to two weeks. Using our microfluidic device that prevents direct cell to cell contact, we could evaluate neural cell response in the vicinity of astrocytes. We showed that neuronal cell density was reduced by about 45% when neurons were co-cultured with SOD-mutant astrocytes. Moreover, we demonstrated that SOD-WT overexpressing astrocytes reduced oxidative stress on cortical neurons that were in close metabolic contact. In contrast, cortical neurons in metabolic contact with SOD-mutant astrocytes lost their synapsin protein expression after severe glutamate treatment, an indication of the toxicity potentiating effect of the SOD-mutant enzyme.
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Affiliation(s)
- Anja Kunze
- Di Carlo Laboratory, Department of Bioengineering, University of California, Los Angeles (UCLA), California, USA.
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133
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Morita S, Hourai A, Miyata S. Changes in pericytic expression of NG2 and PDGFRB and vascular permeability in the sensory circumventricular organs of adult mouse by osmotic stimulation. Cell Biochem Funct 2013; 32:51-61. [PMID: 23629811 DOI: 10.1002/cbf.2971] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 02/22/2013] [Accepted: 02/25/2013] [Indexed: 01/27/2023]
Abstract
The blood-brain barrier (BBB) is a barrier that prevents free access of blood-derived substances to the brain through the tight junctions and maintains a specialized brain environment. Circumventricular organs (CVOs) lack the typical BBB. The fenestrated vasculature of the sensory CVOs, including the organum vasculosum of the lamina terminalis (OVLT), subfornical organ (SFO) and area postrema (AP), allows parenchyma cells to sense a variety of blood-derived information, including osmotic ones. In the present study, we utilized immunohistochemistry to examine changes in the expression of NG2 and platelet-derived growth factor receptor beta (PDGFRB) in the OVLT, SFO and AP of adult mice during chronic osmotic stimulation. The expression of NG2 and PDGFRB was remarkably prominent in pericytes, although these angiogenesis-associated proteins are highly expressed at pericytes of developing immature vasculature. The chronic salt loading prominently increased the expression of NG2 in the OVLT and SFO and that of PDGFRB in the OVLT, SFO and AP. The vascular permeability of low-molecular-mass tracer fluorescein isothiocyanate was increased significantly by chronic salt loading in the OVLT and SFO but not AP. In conclusion, the present study demonstrates changes in pericyte expression of NG2 and PDGFRB and vascular permeability in the sensory CVOs by chronic osmotic stimulation, indicating active participation of the vascular system in osmotic homeostasis.
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Affiliation(s)
- Shoko Morita
- Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto, Japan; Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, 840 Shijo-cho, Kashihara, Nara, Japan
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Virarkar M, Alappat L, Bradford PG, Awad AB. L-Arginine and Nitric Oxide in CNS Function and Neurodegenerative Diseases. Crit Rev Food Sci Nutr 2013; 53:1157-67. [DOI: 10.1080/10408398.2011.573885] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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135
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NAKAMURA H, KAWAMATA Y, KUWAHARA T, SMRIGA M, SAKAI R. Long-Term Ingestion of Monosodium L-Glutamate Did Not Induce Obesity, Dyslipidemia or Insulin Resistance: A Two-Generation Study in Mice. J Nutr Sci Vitaminol (Tokyo) 2013; 59:129-35. [DOI: 10.3177/jnsv.59.129] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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136
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Rodriguez M, Sabate M, Rodriguez-Sabate C, Morales I. The role of non-synaptic extracellular glutamate. Brain Res Bull 2012; 93:17-26. [PMID: 23149167 DOI: 10.1016/j.brainresbull.2012.09.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 09/07/2012] [Accepted: 09/12/2012] [Indexed: 12/21/2022]
Abstract
Although there are some mechanisms which allow the direct crossing of substances between the cytoplasm of adjacent cells (gap junctions), most substances use the extracellular space to diffuse between brain cells. The present work reviews the behavior and functions of extracellular glutamate (GLU). There are two extracellular pools of glutamate (GLU) in the brain, a synaptic pool whose functions in the excitatory neurotransmission has been widely studied and an extrasynaptic GLU pool although less known nonetheless is gaining attention among a growing number of researchers. Evidence accumulated over the last years shows a number of mechanisms capable of releasing glial GLU to the extracellular medium, thus modulating neurons, microglia and oligodendrocytes, and regulating the immune response, cerebral blood flow, neuronal synchronization and other brain functions. This new scenario is expanding present knowledge regarding the role of GLU in the brain under different physiological and pathological conditions. This article is part of a Special Issue entitled 'Extrasynaptic ionotropic receptors'.
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Affiliation(s)
- Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La Laguna, La Laguna, Tenerife, Canary Islands, Spain.
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Mehta A, Prabhakar M, Kumar P, Deshmukh R, Sharma PL. Excitotoxicity: bridge to various triggers in neurodegenerative disorders. Eur J Pharmacol 2012; 698:6-18. [PMID: 23123057 DOI: 10.1016/j.ejphar.2012.10.032] [Citation(s) in RCA: 456] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 09/26/2012] [Accepted: 10/06/2012] [Indexed: 12/13/2022]
Abstract
Glutamate is one of the most prominent neurotransmitter in the body, present in over 50% of nervous tissue and plays an important role in neuronal excitation. This neuronal excitation is short-lived and is followed by depression. Multiple abnormal triggers such as energy deficiency, oxidative stress, mitochondrial dysfunction, calcium overload, etc can lead to aberration in neuronal excitation process. Such an aberration, serves as a common pool or bridge between abnormal triggers and deleterious signaling processes with which central neurons cannot cope up, leading to death. Excitotoxicity is the pathological process by which nerve cells are damaged and killed by excessive stimulation by neurotransmitters such as glutamate and similar substances. Such excitotoxic neuronal death has been implicated in spinal cord injury, stroke, traumatic brain injury, hearing loss and in neurodegenerative diseases of the central nervous system such as stroke, epilepsy, multiple sclerosis, Alzheimer disease, Amyltropic lateral sclerosis, Parkinson's disease, Huntington disease and alcohol withdrawal. This review mainly emphasizes the triggering events which sustain neuronal excitation, role of calcium, mitochondrial dysfunction, ROS, NO, chloride homeostasis and eicosanoids pathways. Further, a brief introduction about the recent research occurring in the treatment of various neurodegenerative diseases, including a summary of the presumed physiologic mechanisms behind the pharmacology of these disorders.
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Affiliation(s)
- Ankita Mehta
- Neuropharmacology Division, ISF College of Pharmacy, Ferozpur Road, Ghal Kalan, Moga 142 001, Punjab, India
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138
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Julio-Pieper M, O'Connor RM, Dinan TG, Cryan JF. Regulation of the brain-gut axis by group III metabotropic glutamate receptors. Eur J Pharmacol 2012; 698:19-30. [PMID: 23123053 DOI: 10.1016/j.ejphar.2012.10.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 10/11/2012] [Accepted: 10/22/2012] [Indexed: 01/14/2023]
Abstract
L-glutamate is produced by a great variety of peripheral tissues in both health and disease. Like other components of the glutamatergic system, metabotropic glutamate (mGlu) receptors also have a widespread distribution outside the central nervous system (CNS). In particular, group III mGlu receptors have been recently found in human stomach and colon revealing an extraordinary potential for these receptors in the treatment of peripheral disorders, including gastrointestinal dysfunction. The significance of these findings is that pharmacological tools originally designed for mGlu receptors in the CNS may also be directed towards new disease targets in the periphery. Targeting mGlu receptors can also be beneficial in the treatment of disorders involving central components together with gastrointestinal dysfunction, such as irritable bowel syndrome, which can be co-morbid with anxiety and depression. Conversely, the development of more specific therapeutic approaches for mGlu ligands both centrally as in the gut will depend on the elucidation of tissue-specific elements in mGlu receptor signalling.
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Affiliation(s)
- Marcela Julio-Pieper
- Instituto de Química, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Av Universidad 330, Curauma, Valparaíso, Chile.
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139
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Berg RMG, Taudorf S, Bailey DM, Lundby C, Larsen FS, Pedersen BK, Møller K. Effects of lipopolysaccharide infusion on arterial levels and transcerebral exchange kinetics of glutamate and glycine in healthy humans. APMIS 2012; 120:761-6. [PMID: 22882266 DOI: 10.1111/j.1600-0463.2012.02904.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 03/07/2012] [Indexed: 11/29/2022]
Abstract
An imbalance between glutamate and glycine signalling may contribute to sepsis-associated encephalopathy by causing neuronal excitotoxicity. In this study, we therefore investigated the transcerebral exchange kinetics of glutamate and glycine in a human-experimental model of systemic inflammation. Cerebral blood flow (CBF) and arterial to jugular venous concentration differences of glutamate and glycine were determined before and after a 4-h intravenous infusion of Escherichia coli lipopolysaccharide (LPS, total dose of 0.3 ng/kg) in 12 healthy volunteers. The global cerebral net exchange was calculated by multiplying CBF with the arterial to jugular venous differences. LPS induced a systemic inflammatory response with fever, neutrocytosis, and elevated arterial levels of tumour necrosis factor-α. This was associated with a decrease in the arterial levels of both glutamate and glycine; however, their transcerebral exchange kinetics were unaffected. Inflammation-induced alterations of the circulating levels of glutamate and glycine, do not affect the global transcerebral exchange kinetics of these amino acids in healthy humans.
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Affiliation(s)
- Ronan M G Berg
- Centre of Inflammation and Metabolism, Department of Infectious Diseases, University Hospital Rigshospitalet, Copenhagen, Denmark.
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140
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Leibowitz A, Boyko M, Shapira Y, Zlotnik A. Blood glutamate scavenging: insight into neuroprotection. Int J Mol Sci 2012; 13:10041-10066. [PMID: 22949847 PMCID: PMC3431845 DOI: 10.3390/ijms130810041] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/18/2012] [Accepted: 07/30/2012] [Indexed: 11/16/2022] Open
Abstract
Brain insults are characterized by a multitude of complex processes, of which glutamate release plays a major role. Deleterious excess of glutamate in the brain's extracellular fluids stimulates glutamate receptors, which in turn lead to cell swelling, apoptosis, and neuronal death. These exacerbate neurological outcome. Approaches aimed at antagonizing the astrocytic and glial glutamate receptors have failed to demonstrate clinical benefit. Alternatively, eliminating excess glutamate from brain interstitial fluids by making use of the naturally occurring brain-to-blood glutamate efflux has been shown to be effective in various animal studies. This is facilitated by gradient driven transport across brain capillary endothelial glutamate transporters. Blood glutamate scavengers enhance this naturally occurring mechanism by reducing the blood glutamate concentration, thus increasing the rate at which excess glutamate is cleared. Blood glutamate scavenging is achieved by several mechanisms including: catalyzation of the enzymatic process involved in glutamate metabolism, redistribution of glutamate into tissue, and acute stress response. Regardless of the mechanism involved, decreased blood glutamate concentration is associated with improved neurological outcome. This review focuses on the physiological, mechanistic and clinical roles of blood glutamate scavenging, particularly in the context of acute and chronic CNS injury. We discuss the details of brain-to-blood glutamate efflux, auto-regulation mechanisms of blood glutamate, natural and exogenous blood glutamate scavenging systems, and redistribution of glutamate. We then propose different applied methodologies to reduce blood and brain glutamate concentrations and discuss the neuroprotective role of blood glutamate scavenging.
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Affiliation(s)
- Akiva Leibowitz
- Author to whom correspondence should be addressed; E-Mail: ; Tel: +972-8-6400262; Fax: +972-8-6403795
| | | | - Yoram Shapira
- Department of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University, Beer Sheva 84894, Israel; E-Mails: (M.B.); (Y.S.); (A.Z.)
| | - Alexander Zlotnik
- Department of Anesthesiology and Critical Care, Soroka Medical Center, Ben-Gurion University, Beer Sheva 84894, Israel; E-Mails: (M.B.); (Y.S.); (A.Z.)
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141
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Lin Y, Stephenson MC, Xin L, Napolitano A, Morris PG. Investigating the metabolic changes due to visual stimulation using functional proton magnetic resonance spectroscopy at 7 T. J Cereb Blood Flow Metab 2012; 32:1484-95. [PMID: 22434070 PMCID: PMC3421086 DOI: 10.1038/jcbfm.2012.33] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Proton magnetic resonance spectroscopy ((1)H-MRS) has been used to demonstrate metabolic changes in the visual cortex on visual stimulation. Small (2% to 11%) but significant stimulation induced increases in lactate, glutamate, and glutathione were observed along with decreases in aspartate, glutamine, and glycine, using (1)H-MRS at 7 T during single and repeated visual stimulation. In addition, decreases in glucose and increases in γ-aminobutyric acid (GABA) were seen but did not reach significance. Changes in glutamate and aspartate are indicative of increased activity of the malate-aspartate shuttle, which taken together with the opposite changes in glucose and lactate, reflect the expected increase in brain energy metabolism. These results are in agreement with those of Mangia et al. In addition, increases in glutamate and GABA coupled with the decrease in glutamine can be interpreted in terms of increased activity of the neurotransmitter cycles. An entirely new observation is the increase of glutathione during prolonged visual stimuli. The similarity of its time course to that of glutamate suggests that it may be a response to the increased release of glutamate or to the increased production of reactive oxygen species. Together, these observations constitute the most detailed analysis to date of functional changes in human brain metabolites.
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Affiliation(s)
- Yan Lin
- Sir Peter Mansfield Magnetic Resonance Centre, School of Physics and Astronomy, University of Nottingham, Nottingham, UK
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142
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Mangia S, Giove F, Dinuzzo M. Metabolic pathways and activity-dependent modulation of glutamate concentration in the human brain. Neurochem Res 2012; 37:2554-61. [PMID: 22846967 DOI: 10.1007/s11064-012-0848-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/21/2012] [Accepted: 07/14/2012] [Indexed: 12/26/2022]
Abstract
Glutamate is one of the most versatile molecules present in the human brain, involved in protein synthesis, energy production, ammonia detoxification, and transport of reducing equivalents. Aside from these critical metabolic roles, glutamate plays a major part in brain function, being not only the most abundant excitatory neurotransmitter, but also the precursor for γ-aminobutyric acid, the predominant inhibitory neurotransmitter. Regulation of glutamate levels is pivotal for normal brain function, as abnormal extracellular concentration of glutamate can lead to impaired neurotransmission, neurodegeneration and even neuronal death. Understanding how the neuron-astrocyte functional and metabolic interactions modulate glutamate concentration during different activation status and under physiological and pathological conditions is a challenging task, and can only be tentatively estimated from current literature. In this paper, we focus on describing the various metabolic pathways which potentially affect glutamate concentration in the brain, and emphasize which ones are likely to produce the variations in glutamate concentration observed during enhanced neuronal activity in human studies.
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Affiliation(s)
- Silvia Mangia
- Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, 2021 6th St. S.E., Minneapolis, MN, USA.
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143
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Seyfried TN, Marsh J, Shelton LM, Huysentruyt LC, Mukherjee P. Is the restricted ketogenic diet a viable alternative to the standard of care for managing malignant brain cancer? Epilepsy Res 2012; 100:310-26. [DOI: 10.1016/j.eplepsyres.2011.06.017] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 05/31/2011] [Accepted: 06/03/2011] [Indexed: 12/13/2022]
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144
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Visan A, Hayess K, Sittner D, Pohl EE, Riebeling C, Slawik B, Gulich K, Oelgeschläger M, Luch A, Seiler AEM. Neural differentiation of mouse embryonic stem cells as a tool to assess developmental neurotoxicity in vitro. Neurotoxicology 2012; 33:1135-46. [PMID: 22732190 DOI: 10.1016/j.neuro.2012.06.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 06/13/2012] [Accepted: 06/13/2012] [Indexed: 11/26/2022]
Abstract
Mouse embryonic stem cells (mESCs) represent an attractive cellular system for in vitro studies in developmental biology as well as toxicology because of their potential to differentiate into all fetal cell lineages. The present study aims to establish an in vitro system for developmental neurotoxicity testing employing mESCs. We developed a robust and reproducible protocol for fast and efficient differentiation of the mESC line D3 into neural cells, optimized with regard to chemical testing. Morphological examination and immunocytochemical staining confirmed the presence of different neural cell types, including neural progenitors, neurons, astrocytes, oligodendrocytes, and radial glial cells. Neurons derived from D3 cells expressed the synaptic proteins PSD95 and synaptophysin, and the neurotransmitters serotonin and γ-aminobutyric acid. Calcium ion imaging revealed the presence of functionally active glutamate and dopamine receptors. In addition, flow cytometry analysis of the neuron-specific marker protein MAP2 on day 12 after induction of differentiation demonstrated a concentration dependent effect of the neurodevelopmental toxicants methylmercury chloride, chlorpyrifos, and lead acetate on neuronal differentiation. The current study shows that D3 mESCs differentiate efficiently into neural cells involving a neurosphere-like state and that this system is suitable to detect adverse effects of neurodevelopmental toxicants. Therefore, we propose that the protocol for differentiation of mESCs into neural cells described here could constitute one component of an in vitro testing strategy for developmental neurotoxicity.
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Affiliation(s)
- Anke Visan
- ZEBET-Alternative Methods to Animal Experiments, German Federal Institute for Risk Assessment (BfR), 12277 Berlin, Germany
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145
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Davalli AM, Perego C, Folli FB. The potential role of glutamate in the current diabetes epidemic. Acta Diabetol 2012; 49:167-83. [PMID: 22218826 DOI: 10.1007/s00592-011-0364-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 12/19/2011] [Indexed: 12/27/2022]
Abstract
In the present article, we propose the perspective that abnormal glutamate homeostasis might contribute to diabetes pathogenesis. Previous reports and our recent data indicate that chronically high extracellular glutamate levels exert direct and indirect effects that might participate in the progressive loss of β-cells occurring in both T1D and T2D. In addition, abnormal glutamate homeostasis may impact all the three accelerators of the "accelerator hypothesis" and could partially explain the rising frequency of T1D and T2D.
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Affiliation(s)
- Alberto M Davalli
- Diabetes and Endocrinology Unit, Department of Internal Medicine, San Raffaele Scientific Institute, 20132, Milan, Italy.
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146
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Terán Y, Ponce O, Betancourt L, Hernández L, Rada P. Amino acid profile of plasma and cerebrospinal fluid in preeclampsia. Pregnancy Hypertens 2012; 2:416-22. [PMID: 26105613 DOI: 10.1016/j.preghy.2012.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/26/2012] [Accepted: 05/06/2012] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine patterns in amino acids (arginine, GABA, glutamate and glutamine) and the diamine (agmatine) in plasma and cerebrospinal fluid (CSF) of mild and severe preeclampsia compared to control patients, using capillary zone electrophoresis to generate methods for refining diagnosis and prognosis and shed light on the pathophysiological mechanisms of preeclampsia. STUDY DESIGN This is an observational case-control study in pregnant women that attended the emergency ward of the University Hospital, Mérida, Venezuela, during the period April, 2009-April 2010. MAIN OUTCOME MEASURES Molar concentration of amino acids and diamine in plasma and CSF in control, mild and severe preeclampsia patients. RESULTS An increase in glutamate plasma levels was observed in mild preeclampsia and even higher in severe patients, while a biphasic response occurred in the CSF samples with a significant increment in mild preeclampsia patients and a decrease in severe preeclampsia patients. GABA significantly decreased both in plasma and CSF in mild preeclampsia with a tendency to return to normal levels in severe preeclampsia patients. Arginine CSF and plasma levels decreased in mild preeclampsia patients and even more in severe preeclampsia while agmatine significantly increased in plasma levels with no changes in CSF. CONCLUSIONS The results are discussed in terms of molecules that could be used as biomarkers of the severity of the disease and the possible involvement of these substances in the pathophysiology of preeclampsia.
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Affiliation(s)
- Yurbi Terán
- Obstetrics and Gynecology Unit, University of Los Andes Hospital, Mérida, Venezuela
| | - Ormelys Ponce
- Laboratory of Behavioral Physiology, School of Medicine, University of Los Andes, Mérida, Venezuela
| | - Luis Betancourt
- Laboratory of Behavioral Physiology, School of Medicine, University of Los Andes, Mérida, Venezuela
| | - Luis Hernández
- Laboratory of Behavioral Physiology, School of Medicine, University of Los Andes, Mérida, Venezuela
| | - Pedro Rada
- Laboratory of Behavioral Physiology, School of Medicine, University of Los Andes, Mérida, Venezuela.
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147
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Different vascular permeability between the sensory and secretory circumventricular organs of adult mouse brain. Cell Tissue Res 2012; 349:589-603. [PMID: 22584508 DOI: 10.1007/s00441-012-1421-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2011] [Accepted: 03/19/2012] [Indexed: 01/05/2023]
Abstract
The blood-brain barrier (BBB) prevents free access of circulating molecules to the brain and maintains a specialized brain environment to protect the brain from blood-derived bioactive and toxic molecules; however, the circumventricular organs (CVOs) have fenestrated vasculature. The fenestrated vasculature in the sensory CVOs, including the organum vasculosum of lamina terminalis (OVLT), subfornical organ (SFO) and area postrema (AP), allows neurons and astrocytes to sense a variety of plasma molecules and convey their information into other brain regions and the vasculature in the secretory CVOs, including median eminence (ME) and neurohypophysis (NH), permits neuronal terminals to secrete many peptides into the blood stream. The present study showed that vascular permeability of low-molecular-mass tracers such as fluorescein isothiocyanate (FITC) and Evans Blue was higher in the secretory CVOs and kidney as compared with that in the sensory CVOs. On the other hand, vascular permeability of high-molecular-mass tracers such as FITC-labeled bovine serum albumin and Dextran 70,000 was lower in the CVOs as compared with that in the kidney. Prominent vascular permeability of low- and high-molecular-mass tracers was also observed in the arcuate nucleus. These data demonstrate that vascular permeability for low-molecular-mass molecules is higher in the secretory CVOs as compared with that in the sensory CVOs, possibly for large secretion of peptides to the blood stream. Moreover, vascular permeability for high-molecular-mass tracers in the CVOs is smaller than that of the kidney, indicating that the CVOs are not totally without a BBB.
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148
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Beyoğlu D, Smith RL, Idle JR. Dog bites man or man bites dog? The enigma of the amino acid conjugations. Biochem Pharmacol 2012; 83:1331-9. [PMID: 22227274 PMCID: PMC3314100 DOI: 10.1016/j.bcp.2011.12.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 10/14/2022]
Abstract
The proposition posed is that the value of amino acid conjugation to the organism is not, as in the traditional view, to use amino acids for the detoxication of aromatic acids. Rather, the converse is more likely, to use aromatic acids that originate from the diet and gut microbiota to assist in the regulation of body stores of amino acids, such as glycine, glutamate, and, in certain invertebrates, arginine, that are key neurotransmitters in the central nervous system (CNS). As such, the amino acid conjugations are not so much detoxication reactions, rather they are homeostatic and neuroregulatory processes. Experimental data have been culled in support of this hypothesis from a broad range of scientific and clinical literature. Such data include the low detoxication value of amino acid conjugations and the Janus nature of certain amino acids that are both neurotransmitters and apparent conjugating agents. Amino acid scavenging mechanisms in blood deplete brain amino acids. Amino acids glutamate and glycine when trafficked from brain are metabolized to conjugates of aromatic acids in hepatic mitochondria and then irreversibly excreted into urine. This process is used clinically to deplete excess nitrogen in cases of urea cycle enzymopathies through excretion of glycine or glutamine as their aromatic acid conjugates. Untoward effects of high-dose phenylacetic acid surround CNS toxicity. There appears to be a relationship between extent of glycine scavenging by benzoic acid and psychomotor function. Glycine and glutamine scavenging by conjugation with aromatic acids may have important psychosomatic consequences that link diet to health, wellbeing, and disease.
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Affiliation(s)
- Diren Beyoğlu
- Hepatology Research Group, Department of Clinical Research, Faculty of Medicine, University of Bern, Murtenstrasse 35, 3010 Bern, Switzerland
| | - Robert L. Smith
- Department of Surgery & Cancer, Faculty of Medicine, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Jeffrey R. Idle
- Hepatology Research Group, Department of Clinical Research, Faculty of Medicine, University of Bern, Murtenstrasse 35, 3010 Bern, Switzerland
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149
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Kreft M, Bak LK, Waagepetersen HS, Schousboe A. Aspects of astrocyte energy metabolism, amino acid neurotransmitter homoeostasis and metabolic compartmentation. ASN Neuro 2012; 4:e00086. [PMID: 22435484 PMCID: PMC3338196 DOI: 10.1042/an20120007] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2012] [Revised: 03/06/2012] [Accepted: 03/21/2012] [Indexed: 02/08/2023] Open
Abstract
Astrocytes are key players in brain function; they are intimately involved in neuronal signalling processes and their metabolism is tightly coupled to that of neurons. In the present review, we will be concerned with a discussion of aspects of astrocyte metabolism, including energy-generating pathways and amino acid homoeostasis. A discussion of the impact that uptake of neurotransmitter glutamate may have on these pathways is included along with a section on metabolic compartmentation.
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Key Words
- amino acid
- astrocyte
- compartmentation
- energy
- metabolism
- α-kg, α-ketoglutarate
- aat, aspartate aminotransferase
- cfp, cyan fluorescence protein
- dab, diaminobenzidine
- fret, fluorescence resonance energy transfer
- [glc]i, intracellular glucose concentration
- gaba, γ-aminobutyric acid
- gaba-t, gaba aminotransferase
- gdh, glutamate dehydrogenase
- glut, glucose transporter
- gp, glycogen phosphorylase
- gs, glutamine synthetase
- gsk3, gs kinase 3
- pag, phosphate-activated glutaminase
- pi3k, phosphoinositide 3-kinase
- pkc, protein kinase c
- tca, tricarboxylic acid
- yfp, yellow fluorescence protein
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Affiliation(s)
- Marko Kreft
- *LNMCP, Institute of Pathophysiology, Faculty of Medicine and CPAE, Department of Biology, Biotechnical Faculty, University of Ljubljana and Celica Biomedical Center, Slovenia
| | - Lasse K Bak
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Helle S Waagepetersen
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Arne Schousboe
- †Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, 2100, Copenhagen, Denmark
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150
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Helms HC, Madelung R, Waagepetersen HS, Nielsen CU, Brodin B. In vitro evidence for the brain glutamate efflux hypothesis: Brain endothelial cells cocultured with astrocytes display a polarized brain-to-blood transport of glutamate. Glia 2012; 60:882-93. [DOI: 10.1002/glia.22321] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Revised: 02/08/2012] [Accepted: 02/14/2012] [Indexed: 01/17/2023]
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