1
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Holt LM, Nestler EJ. Astrocytic transcriptional and epigenetic mechanisms of drug addiction. J Neural Transm (Vienna) 2024; 131:409-424. [PMID: 37940687 PMCID: PMC11066772 DOI: 10.1007/s00702-023-02716-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 10/24/2023] [Indexed: 11/10/2023]
Abstract
Addiction is a leading cause of disease burden worldwide and remains a challenge in current neuroscience research. Drug-induced lasting changes in gene expression are mediated by transcriptional and epigenetic regulation in the brain and are thought to underlie behavioral adaptations. Emerging evidence implicates astrocytes in regulating drug-seeking behaviors and demonstrates robust transcriptional response to several substances of abuse. This review focuses on the astrocytic transcriptional and epigenetic mechanisms of drug action.
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Affiliation(s)
- Leanne M Holt
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Eric J Nestler
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
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2
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Tsai T, Reinehr S, Deppe L, Strubbe A, Kluge N, Dick HB, Joachim SC. Glaucoma Animal Models beyond Chronic IOP Increase. Int J Mol Sci 2024; 25:906. [PMID: 38255979 PMCID: PMC10815097 DOI: 10.3390/ijms25020906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 01/04/2024] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
Glaucoma is a complex and multifactorial disease defined as the loss of retinal ganglion cells (RGCs) and their axons. Besides an elevated intraocular pressure (IOP), other mechanisms play a pivotal role in glaucoma onset and progression. For example, it is known that excitotoxicity, immunological alterations, ischemia, and oxidative stress contribute to the neurodegeneration in glaucoma disease. To study these effects and to discover novel therapeutic approaches, appropriate animal models are needed. In this review, we focus on various glaucoma animal models beyond an elevated IOP. We introduce genetically modified mice, e.g., the optineurin E50K knock-in or the glutamate aspartate transporter (GLAST)-deficient mouse. Excitotoxicity can be mimicked by injecting the glutamate analogue N-methyl-D-aspartate intravitreally, which leads to rapid RGC degeneration. To explore the contribution of the immune system, the experimental autoimmune glaucoma model can serve as a useful tool. Here, immunization with antigens led to glaucoma-like damage. The ischemic mechanism can be mimicked by inducing a high IOP for a certain amount of time in rodents, followed by reperfusion. Thereby, damage to the retina and the optic nerve occurs rapidly after ischemia/reperfusion. Lastly, we discuss the importance of optic nerve crush models as model systems for normal-tension glaucoma. In summary, various glaucoma models beyond IOP increase can be utilized.
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Affiliation(s)
| | | | | | | | | | | | - Stephanie C. Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892 Bochum, Germany; (T.T.); (S.R.); (L.D.); (N.K.); (H.B.D.)
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3
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Inan S, Meissler JJ, Shekarabi A, Foss J, Wiah S, Eisenstein TK, Rawls SM. Cyanidin prevents MDPV withdrawal-induced anxiety-like effects and dysregulation of cytokine systems in rats. Brain Res 2023; 1806:148310. [PMID: 36871847 PMCID: PMC10190163 DOI: 10.1016/j.brainres.2023.148310] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/21/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023]
Abstract
Psychostimulant exposure and withdrawal cause neuroimmune dysregulation and anxiety that contributes to dependence and relapse. Here, we tested the hypothesis that withdrawal from the synthetic cathinone MDPV (methylenedioxypyrovalerone) produces anxiety-like effects and enhanced levels of mesocorticolimbic cytokines that are inhibited by cyanidin, an anti-inflammatory flavonoid and nonselective blocker of IL-17A signaling. For comparison, we tested effects on glutamate transporter systems that are also dysregulated during psychostimulant free period. Rats injected for 9 d with MDPV (1 mg/kg, IP) or saline were pretreated daily with cyanidin (0.5 mg/kg, IP) or saline, followed by behavioral testing on the elevated zero maze (EZM) 72 h after the last MDPV injection. MDPV withdrawal caused a reduction in time spent on the open arm of the EZM that was prevented by cyanidin. Cyanidin itself did not affect locomotor activity or time spent on the open arm, or cause aversive or rewarding effects in place preference experiments. MDPV withdrawal caused enhancement of cytokine levels (IL-17A, IL-1β, IL-6, TNF=α, IL-10, and CCL2) in the ventral tegmental area, but not amygdala, nucleus accumbens, or prefrontal cortex, that was prevented by cyanidin. During MDPV withdrawal, mRNA levels of glutamate aspartate transporter (GLAST) and glutamate transporter subtype 1 (GLT-1) in the amygdala were also elevated but normalized by cyanidin treatment. These results show that MDPV withdrawal induced anxiety, and brain-region specific dysregulation of cytokine and glutamate systems, that are both prevented by cyanidin, thus identifying cyanidin for further investigation in the context of psychostimulant dependence and relapse.
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Affiliation(s)
- Saadet Inan
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA.
| | - Joseph J Meissler
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Aryan Shekarabi
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Jeffrey Foss
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Sonita Wiah
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Toby K Eisenstein
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
| | - Scott M Rawls
- Center for Substance Abuse Research, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA; Department of Neural Sciences, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, USA
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4
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Temmermand R, Barrett JE, Fontana ACK. Glutamatergic systems in neuropathic pain and emerging non-opioid therapies. Pharmacol Res 2022; 185:106492. [PMID: 36228868 PMCID: PMC10413816 DOI: 10.1016/j.phrs.2022.106492] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/05/2022] [Accepted: 10/06/2022] [Indexed: 01/14/2023]
Abstract
Neuropathic pain, a disease of the somatosensory nervous system, afflicts many individuals and adequate management with current pharmacotherapies remains elusive. The glutamatergic system of neurons, receptors and transporters are intimately involved in pain but, to date, there have been few drugs developed that therapeutically modulate this system. Glutamate transporters, or excitatory amino acid transporters (EAATs), remove excess glutamate around pain transmitting neurons to decrease nociception suggesting that the modulation of glutamate transporters may represent a novel approach to the treatment of pain. This review highlights and summarizes (1) the physiology of the glutamatergic system in neuropathic pain, (2) the preclinical evidence for dysregulation of glutamate transport in animal pain models, and (3) emerging novel therapies that modulate glutamate transporters. Successful drug discovery requires continuous focus on basic and translational methods to fully elucidate the etiologies of this disease to enable the development of targeted therapies. Increasing the efficacy of astrocytic EAATs may serve as a new way to successfully treat those suffering from this devastating disease.
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Affiliation(s)
- Rhea Temmermand
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA
| | - James E Barrett
- Center for Substance Abuse Research, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
| | - Andréia C K Fontana
- Department of Pharmacology and Physiology, Drexel University College of Medicine, Philadelphia, PA 19102, USA.
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5
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Zhang Y, Chu JMT, Wong GTC. Cerebral Glutamate Regulation and Receptor Changes in Perioperative Neuroinflammation and Cognitive Dysfunction. Biomolecules 2022; 12:biom12040597. [PMID: 35454185 PMCID: PMC9029551 DOI: 10.3390/biom12040597] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 04/11/2022] [Accepted: 04/15/2022] [Indexed: 12/23/2022] Open
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system and is intricately linked to learning and memory. Its activity depends on the expression of AMPA and NMDA receptors and excitatory amino transporters on neurons and glial cells. Glutamate transporters prevent the excess accumulation of glutamate in synapses, which can lead to aberrant synaptic signaling, excitotoxicity, or cell death. Neuroinflammation can occur acutely after surgical trauma and contributes to the development of perioperative neurocognitive disorders, which are characterized by impairment in multiple cognitive domains. In this review, we aim to examine how glutamate handling and glutamatergic function are affected by neuroinflammation and their contribution to cognitive impairment. We will first summarize the current data regarding glutamate in neurotransmission, its receptors, and their regulation and trafficking. We will then examine the impact of inflammation on glutamate handling and neurotransmission, focusing on changes in glial cells and the effect of cytokines. Finally, we will discuss these changes in the context of perioperative neuroinflammation and the implications they have for perioperative neurocognitive disorders.
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6
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Rodríguez-Campuzano AG, Hernández-Kelly LC, Ortega A. DNA Methylation-Dependent Gene Expression Regulation of Glutamate Transporters in Cultured Radial Glial Cells. Mol Neurobiol 2022; 59:1912-1924. [PMID: 35032319 DOI: 10.1007/s12035-022-02746-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/11/2022] [Indexed: 11/26/2022]
Abstract
Exposure to xenobiotics has a significant impact in brain physiology that could be liked to an excitotoxic process induced by a massive release of the main excitatory neurotransmitter, L-glutamate. Overstimulation of extra-synaptic glutamate receptors, mainly of the N-methyl-D-aspartate subtype leads to a disturbance of intracellular calcium homeostasis that is critically involved in neuronal death. Hence, glutamate extracellular levels are tightly regulated through its uptake by glial glutamate transporters. It has been observed that glutamate regulates its own removal, both in the short-time frame via a transporter-mediated decrease in the uptake, and in the long-term through the transcriptional control of its gene expression, a process mediated by glutamate receptors that involves the Ca2+/diacylglycerol-dependent protein kinase and the transcription factor Ying Yang 1. Taking into consideration that this transcription factor is a member of the Polycomb complex and thus, part of repressive and activating chromatin remodeling factors, it might direct the interaction of DNA methyltransferases or dioxygenases of methylated cytosines to their target sequences. Here we explored the role of dynamic DNA methylation in the expression and function of glial glutamate transporters. To this end, we used the well-characterized models of primary cultures of chick cerebellar Bergmann glia cells and a human retina-derived Müller glia cell line. A time and dose-dependent increase in global DNA methylation was evident upon glutamate exposure. Under hypomethylation conditions, the glial glutamate transporter protein levels and uptake activity were increased. These results favor the notion that a dynamic DNA methylation program triggered by glutamate in glial cells modulates one of its major functions: glutamate removal.
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Affiliation(s)
- Ada G Rodríguez-Campuzano
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. IPN 2508, Zacatenco Ciudad de México, 07360, México
| | - Luisa C Hernández-Kelly
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. IPN 2508, Zacatenco Ciudad de México, 07360, México
| | - Arturo Ortega
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. IPN 2508, Zacatenco Ciudad de México, 07360, México.
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7
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Rodríguez-Campuzano AG, Ortega A. Glutamate transporters: Critical components of glutamatergic transmission. Neuropharmacology 2021; 192:108602. [PMID: 33991564 DOI: 10.1016/j.neuropharm.2021.108602] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/09/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the vertebrate central nervous system. Once released, it binds to specific membrane receptors and transporters activating a wide variety of signal transduction cascades, as well as its removal from the synaptic cleft in order to avoid its extracellular accumulation and the overstimulation of extra-synaptic receptors that might result in neuronal death through a process known as excitotoxicity. Although neurodegenerative diseases are heterogenous in clinical phenotypes and genetic etiologies, a fundamental mechanism involved in neuronal degeneration is excitotoxicity. Glutamate homeostasis is critical for brain physiology and Glutamate transporters are key players in maintaining low extracellular Glutamate levels. Therefore, the characterization of Glutamate transporters has been an active area of glutamatergic research for the last 40 years. Transporter activity its regulated at different levels: transcriptional and translational control, transporter protein trafficking and membrane mobility, and through extensive post-translational modifications. The elucidation of these mechanisms has emerged as an important piece to shape our current understanding of glutamate actions in the nervous system.
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Affiliation(s)
- Ada G Rodríguez-Campuzano
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México, 07000, Mexico
| | - Arturo Ortega
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México, 07000, Mexico.
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8
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O'Carroll SJ, Cook WH, Young D. AAV Targeting of Glial Cell Types in the Central and Peripheral Nervous System and Relevance to Human Gene Therapy. Front Mol Neurosci 2021; 13:618020. [PMID: 33505247 PMCID: PMC7829478 DOI: 10.3389/fnmol.2020.618020] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/11/2020] [Indexed: 12/12/2022] Open
Abstract
Different glial cell types are found throughout the central (CNS) and peripheral nervous system (PNS), where they have important functions. These cell types are also involved in nervous system pathology, playing roles in neurodegenerative disease and following trauma in the brain and spinal cord (astrocytes, microglia, oligodendrocytes), nerve degeneration and development of pain in peripheral nerves (Schwann cells, satellite cells), retinal diseases (Müller glia) and gut dysbiosis (enteric glia). These cell type have all been proposed as potential targets for treating these conditions. One approach to target these cell types is the use of gene therapy to modify gene expression. Adeno-associated virus (AAV) vectors have been shown to be safe and effective in targeting cells in the nervous system and have been used in a number of clinical trials. To date, a number of studies have tested the use of different AAV serotypes and cell-specific promoters to increase glial cell tropism and expression. However, true glial-cell specific targeting for a particular glial cell type remains elusive. This review provides an overview of research into developing glial specific gene therapy and discusses some of the issues that still need to be addressed to make glial cell gene therapy a clinical reality.
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Affiliation(s)
- Simon J O'Carroll
- Spinal Cord Injury Research Group, Department of Anatomy and Medical Imaging, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - William H Cook
- Molecular Neurotherapeutics Group, Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Deborah Young
- Molecular Neurotherapeutics Group, Department of Pharmacology and Clinical Pharmacology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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9
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Todd AC, Hardingham GE. The Regulation of Astrocytic Glutamate Transporters in Health and Neurodegenerative Diseases. Int J Mol Sci 2020; 21:E9607. [PMID: 33348528 PMCID: PMC7766851 DOI: 10.3390/ijms21249607] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2020] [Revised: 12/04/2020] [Accepted: 12/11/2020] [Indexed: 12/24/2022] Open
Abstract
The astrocytic glutamate transporters excitatory amino acid transporters 1 and 2 (EAAT1 and EAAT2) play a key role in nervous system function to maintain extracellular glutamate levels at low levels. In physiology, this is essential for the rapid uptake of synaptically released glutamate, maintaining the temporal fidelity of synaptic transmission. However, EAAT1/2 hypo-expression or hypo-function are implicated in several disorders, including epilepsy and neurodegenerative diseases, as well as being observed naturally with aging. This not only disrupts synaptic information transmission, but in extremis leads to extracellular glutamate accumulation and excitotoxicity. A key facet of EAAT1/2 expression in astrocytes is a requirement for signals from other brain cell types in order to maintain their expression. Recent evidence has shown a prominent role for contact-dependent neuron-to-astrocyte and/or endothelial cell-to-astrocyte Notch signalling for inducing and maintaining the expression of these astrocytic glutamate transporters. The relevance of this non-cell-autonomous dependence to age- and neurodegenerative disease-associated decline in astrocytic EAAT expression is discussed, plus the implications for disease progression and putative therapeutic strategies.
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Affiliation(s)
- Alison C. Todd
- UK Dementia Research Institute at the University of Edinburgh, Chancellor’s Building, Edinburgh Medical School, Edinburgh EH16 4SB, UK;
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
| | - Giles E. Hardingham
- UK Dementia Research Institute at the University of Edinburgh, Chancellor’s Building, Edinburgh Medical School, Edinburgh EH16 4SB, UK;
- Centre for Discovery Brain Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK
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10
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Bozic I, Savic D, Lavrnja I. Astrocyte phenotypes: Emphasis on potential markers in neuroinflammation. Histol Histopathol 2020; 36:267-290. [PMID: 33226087 DOI: 10.14670/hh-18-284] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes, the most abundant glial cells in the central nervous system (CNS), have numerous integral roles in all CNS functions. They are essential for synaptic transmission and support neurons by providing metabolic substrates, secreting growth factors and regulating extracellular concentrations of ions and neurotransmitters. Astrocytes respond to CNS insults through reactive astrogliosis, in which they go through many functional and molecular changes. In neuroinflammatory conditions reactive astrocytes exert both beneficial and detrimental functions, depending on the context and heterogeneity of astrocytic populations. In this review we profile astrocytic diversity in the context of neuroinflammation; with a specific focus on multiple sclerosis (MS) and its best-described animal model experimental autoimmune encephalomyelitis (EAE). We characterize two main subtypes, protoplasmic and fibrous astrocytes and describe the role of intermediate filaments in the physiology and pathology of these cells. Additionally, we outline a variety of markers that are emerging as important in investigating astrocytic biology in both physiological conditions and neuroinflammation.
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Affiliation(s)
- Iva Bozic
- Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Danijela Savic
- Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia
| | - Irena Lavrnja
- Institute for Biological Research "Sinisa Stankovic", National Institute of Republic of Serbia, University of Belgrade, Belgrade, Serbia.
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11
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Balcar VJ, Zeman T, Janout V, Janoutová J, Lochman J, Šerý O. Single Nucleotide Polymorphism rs11136000 of CLU Gene (Clusterin, ApoJ) and the Risk of Late-Onset Alzheimer's Disease in a Central European Population. Neurochem Res 2020; 46:411-422. [PMID: 33206315 DOI: 10.1007/s11064-020-03176-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 11/03/2020] [Accepted: 11/10/2020] [Indexed: 11/28/2022]
Abstract
Clusterin (CLU; also known as apolipoprotein J, ApoJ) is a protein of inconstant structure known to be involved in diverse processes inside and outside of brain cells. CLU can act as a protein chaperon or protein solubilizer, lipid transporter as well as redox sensor and be anti- or proapoptotic, depending on context. Primary structure of CLU is encoded by CLU gene which contains single nucleotide polymorphisms (SNP's) associated with the risk of late-onset Alzheimer's disease (LOAD). Studying a sample of Czech population and using the case-control association approach we identified C allele of the SNP rs11136000 as conferring a reduced risk of LOAD, more so in females than in males. Additionally, data from two smaller subsets of the population sample suggested a possible association of rs11136000 with diabetes mellitus. In a parallel study, we found no association between rs11136000 and mild cognitive impairment (MCI). Our findings on rs11136000 and LOAD contradict those of some previous studies done elsewhere. We discuss the multiple roles of CLU in a broad range of molecular mechanisms that may contribute to the variability of genetic studies of CLU in various ethnic groups. The above discordance notwithstanding, our conclusions support the association of rs1113600 with the risk of LOAD.
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Affiliation(s)
- Vladimir J Balcar
- Bosch Institute and Discipline of Anatomy and Histology, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia. .,Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.
| | - Tomáš Zeman
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.,Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Vladimír Janout
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic.,Present address: Faculty of Health Sciences, Palacký University Olomouc, Olomouc, Czech Republic
| | - Jana Janoutová
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Ostrava, Czech Republic.,Present address: Faculty of Health Sciences, Palacký University Olomouc, Olomouc, Czech Republic
| | - Jan Lochman
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.,Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Omar Šerý
- Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Veveří 97, 602 00, Brno, Czech Republic.,Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
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12
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Castañeda-Cabral JL, López-Ortega JG, Fajardo-Fregoso BF, Beas-Zárate C, Ureña-Guerrero ME. Glutamate induced neonatal excitotoxicity modifies the expression level of EAAT1 (GLAST) and EAAT2 (GLT-1) proteins in various brain regions of the adult rat. Neurosci Lett 2020; 735:135237. [PMID: 32645399 DOI: 10.1016/j.neulet.2020.135237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2019] [Revised: 07/03/2020] [Accepted: 07/04/2020] [Indexed: 02/08/2023]
Abstract
Glutamate-mediated excitatory synaptic signalling is primarily controlled by excitatory amino acid transporters (EAATs), such as EAAT1 and EAAT2, which are located mostly on astrocytes and, together, uptake more than 95 % of extracellular glutamate. Alterations in the functional expression levels of EAATs can lead to excessive extracellular glutamate accumulation, potentially triggering excitotoxicity and seizures, among other neurological disorders. Excitotoxicity induced in early developmental stages can lead to lasting changes in several neurotransmission systems, including the glutamatergic system, which could make the brain more susceptible to a second insult. In this study, the expression levels of EAAT1 (GLAST) and EAAT2 (GLT-1) proteins were assessed in the cerebral motor cortex (CMC), striatum, hippocampus and entorhinal cortex (EC) of male adult rats following the neonatal excitotoxic process triggered by monosodium glutamate (MSG)-treatment (4 g/kg of body weight at postnatal days 1,3,5 and 7, subcutaneously). Western blot analysis showed that neonatal MSG-treatment decreased EAAT1 expression levels in the CMC, striatum and hippocampus, while EAAT2 levels were increased in the striatum and EC and decreased in the CMC. Immunofluorescence staining confirmed the changes in EAAT1 and EAAT2 expression induced by neonatal MSG-treatment, which were accompanied by an increase in the glial fibrillary acidic protein (GFAP) immunofluorescence signalthat was particularly significant in the hippocampus. Our results show that a neonatal excitotoxic processes can induce lasting changes in the expression levels of EAAT1 and EAAT2 proteins and suggest that although astrogliosis occurs, glutamate uptake could be deficient, particularly in the CMC and hippocampus.
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Affiliation(s)
- José Luis Castañeda-Cabral
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara, Zapopan, Jalisco, Mexico
| | - José Guadalupe López-Ortega
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara, Zapopan, Jalisco, Mexico
| | - Blanca Fabiola Fajardo-Fregoso
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara, Zapopan, Jalisco, Mexico
| | - Carlos Beas-Zárate
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara, Zapopan, Jalisco, Mexico
| | - Mónica E Ureña-Guerrero
- Departamento de Biología Celular y Molecular, Centro Universitario de Ciencias Biológicas y Agropecuarias (CUCBA), Universidad de Guadalajara, Zapopan, Jalisco, Mexico.
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13
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Buckingham SD, Mann HJ, Hearnden OK, Sattelle DB. Turning a Drug Target into a Drug Candidate: A New Paradigm for Neurological Drug Discovery? Bioessays 2020; 42:e2000011. [PMID: 32776366 DOI: 10.1002/bies.202000011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/26/2020] [Indexed: 11/11/2022]
Abstract
The conventional paradigm for developing new treatments for disease mainly involves either the discovery of new drug targets, or finding new, improved drugs for old targets. However, an ion channel found only in invertebrates offers the potential of a completely new paradigm in which an established drug target can be re-engineered to serve as a new candidate therapeutic agent. The L-glutamate-gated chloride channels (GluCls) of invertebrates are absent from vertebrate genomes, offering the opportunity to introduce this exogenous, inhibitory, L-glutamate receptor into vertebrate neuronal circuits either as a tool with which to study neural networks, or a candidate therapy. Epileptic seizures can involve L-glutamate-induced hyper-excitation and toxicity. Variant GluCls, with their inhibitory responses to L-glutamate, when engineered into human neurons, might counter the excitotoxic effects of excess L-glutamate. In reviewing recent studies on model organisms, it appears that this approach might offer a new paradigm for the development of candidate therapeutics for epilepsy.
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Affiliation(s)
- Steven D Buckingham
- School of Biological and Chemical Sciences, Queen Mary University London, Mile End Road, London, E1 4NS, UK.,UCL Respiratory, University College London, 5 University Street, London, WC1E 6JF, UK
| | - Harry-Jack Mann
- UCL Respiratory, University College London, 5 University Street, London, WC1E 6JF, UK
| | - Olivia K Hearnden
- UCL Respiratory, University College London, 5 University Street, London, WC1E 6JF, UK
| | - David B Sattelle
- UCL Respiratory, University College London, 5 University Street, London, WC1E 6JF, UK
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14
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Li W, Gao H, Li W. Effects of Combined Bushen Zhichan Recipe and Levodopa in a Rodent Model of Parkinson Disease: Potential Mechanisms. Med Sci Monit 2020; 26:e922345. [PMID: 32555131 PMCID: PMC7325557 DOI: 10.12659/msm.922345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Parkinson disease is characterized by the loss of neurons in the substantia nigra, and under pathological conditions, glutamate can produce excitotoxic effects on nerve cells. The astrocytic excitatory amino acid transporter (EAAT) 1 can be functionally upregulated and targeted to functional compartments, resulting in reduced excitotoxicity. levodopa is the gold standard for the treatment of Parkinson disease, but prolonged levodopa treatment often leads to the development of abnormal involuntary movements. Numerous studies suggest the potential beneficial effects of traditional Chinese medicine on Parkinson disease. MATERIAL AND METHODS We validated the efficacy of a Bushen Zhichan recipe combined with levodopa in a rodent Parkinson disease model and explored its possible mechanisms. RESULTS Rats in the combined levodopa and Bushen Zhichan recipe group performed significantly better than the control group in the open field and forelimb function experiments. The number of midbrain dopaminergic neurons in rats in the levodopa and Bushen Zhichan recipe group was greater compared to controls. The levodopa and Bushen Zhichan recipe group exhibited decreased glutamate receptors and increased γ-aminobutyric acid receptors in the striatum. At the same time, EAAT1 was increased and EAAT2 was synchronized with the number of glutamate receptors. CONCLUSIONS Our results indicate that levodopa combined with Bushen Zhichan recipe significantly improves behavior and protects dopaminergic neurons in a rodent Parkinson disease model, and suggest that the mechanism involves the decrease of excitatory amino acid toxicity and the increase in the expression of EAAT1.
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Affiliation(s)
- Wenhao Li
- Encephalopathy Department, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China (mainland)
| | - Han Gao
- Encephalopathy Department, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China (mainland)
| | - Wentao Li
- Encephalopathy Department, Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, China (mainland)
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15
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Lee A, Balcar VJ, McCombe P, Pow DV. Human brain neurons express a novel splice variant of excitatory amino acid transporter 5 (hEAAT5v). J Comp Neurol 2020; 528:3134-3142. [PMID: 32173860 DOI: 10.1002/cne.24907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 11/08/2022]
Abstract
Excitatory amino acid transporter 5 (EAAT5) is a protein that is known to be alternately spliced and to be abundantly expressed in the retina by populations of neurons including photoreceptors and bipolar cells. EAAT5 acts as a slow glutamate transporter and also as glutamate-gated chloride channel, the chloride conductance being large enough for EAAT5 to serve functionally as an "inhibitory" glutamate receptor. However, there has been a long-standing view that the classically spliced form of EAAT5 is not abundant or widespread in the brain and so it has not been extensively investigated in the literature. We recently identified a human-specific splicing form of EAAT5 that was not expressed by rodents but was shown to be a functional glutamate transporter. We have examined the expression of this form of EAAT5, hEAAT5v at the mRNA, and protein level in human brain, and show that populations of human cortical pyramidal neurons and cerebellar Purkinje cells show significant expression of hEAAT5v. Accordingly, we infer that EAAT5 may well be a player in modulating neuronal function in the human brain and propose that its localization in both glutamatergic and GABAergic neurons could be compatible with a role in influencing intracellular chloride and thereby neuronal parameters such as membrane potential rather than acting as a presynaptic glutamate transporter.
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Affiliation(s)
- Aven Lee
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Vladimir J Balcar
- Discipline of Anatomy and Histology, School of Medical Sciences and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, New South Wales, Australia.,Laboratory of Neurobiology and Pathological Physiology, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Pamela McCombe
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
| | - David V Pow
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, Queensland, Australia
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16
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Pajarillo E, Rizor A, Lee J, Aschner M, Lee E. The role of astrocytic glutamate transporters GLT-1 and GLAST in neurological disorders: Potential targets for neurotherapeutics. Neuropharmacology 2019; 161:107559. [PMID: 30851309 PMCID: PMC6731169 DOI: 10.1016/j.neuropharm.2019.03.002] [Citation(s) in RCA: 202] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 02/28/2019] [Accepted: 03/02/2019] [Indexed: 12/12/2022]
Abstract
Glutamate is the primary excitatory neurotransmitter in the central nervous system (CNS) which initiates rapid signal transmission in the synapse before its re-uptake into the surrounding glia, specifically astrocytes. The astrocytic glutamate transporters glutamate-aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) and their human homologs excitatory amino acid transporter 1 (EAAT1) and 2 (EAAT2), respectively, are the major transporters which take up synaptic glutamate to maintain optimal extracellular glutamic levels, thus preventing accumulation in the synaptic cleft and ensuing excitotoxicity. Growing evidence has shown that excitotoxicity is associated with various neurological disorders, including amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), Parkinson's disease (PD), manganism, ischemia, schizophrenia, epilepsy, and autism. While the mechanisms of neurological disorders are not well understood, the dysregulation of GLAST/GLT-1 may play a significant role in excitotoxicity and associated neuropathogenesis. The expression and function of GLAST/GLT-1 may be dysregulated at the genetic, epigenetic, transcriptional or translational levels, leading to high levels of extracellular glutamate and excitotoxicity. Consequently, understanding the regulatory mechanisms of GLAST/GLT-1 has been an area of interest in developing therapeutics for the treatment of neurological disorders. Pharmacological agents including β-lactam antibiotics, estrogen/selective estrogen receptor modulators (SERMs), growth factors, histone deacetylase inhibitors (HDACi), and translational activators have shown significant efficacy in enhancing the expression and function of GLAST/GLT-1 and glutamate uptake both in vitro and in vivo. This comprehensive review will discuss the regulatory mechanisms of GLAST/GLT-1, their association with neurological disorders, and the pharmacological agents which mediate their expression and function. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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Affiliation(s)
- Edward Pajarillo
- Department of Pharmaceutical Sciences, College of Pharmacy, Florida A&M University, Tallahassee, FL, 32301, USA
| | - Asha Rizor
- Department of Pharmaceutical Sciences, College of Pharmacy, Florida A&M University, Tallahassee, FL, 32301, USA
| | - Jayden Lee
- Department of Speech, Language & Hearing Sciences, Boston University, Boston, MA, 02215, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Eunsook Lee
- Department of Pharmaceutical Sciences, College of Pharmacy, Florida A&M University, Tallahassee, FL, 32301, USA.
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17
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The solute carrier transporters and the brain: Physiological and pharmacological implications. Asian J Pharm Sci 2019; 15:131-144. [PMID: 32373195 PMCID: PMC7193445 DOI: 10.1016/j.ajps.2019.09.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Revised: 08/17/2019] [Accepted: 09/27/2019] [Indexed: 02/05/2023] Open
Abstract
Solute carriers (SLCs) are the largest family of transmembrane transporters that determine the exchange of various substances, including nutrients, ions, metabolites, and drugs across biological membranes. To date, the presence of about 287 SLC genes have been identified in the brain, among which mutations or the resultant dysfunctions of 71 SLC genes have been reported to be correlated with human brain disorders. Although increasing interest in SLCs have focused on drug development, SLCs are currently still under-explored as drug targets, especially in the brain. We summarize the main substrates and functions of SLCs that are expressed in the brain, with an emphasis on selected SLCs that are important physiologically, pathologically, and pharmacologically in the blood-brain barrier, astrocytes, and neurons. Evidence suggests that a fraction of SLCs are regulated along with the occurrences of brain disorders, among which epilepsy, neurodegenerative diseases, and autism are representative. Given the review of SLCs involved in the onset and procession of brain disorders, we hope these SLCs will be screened as promising drug targets to improve drug delivery to the brain.
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18
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Wang W, Zeng F, Hu Y, Li X. A Mini-Review of the Role of Glutamate Transporter in Drug Addiction. Front Neurol 2019; 10:1123. [PMID: 31695674 PMCID: PMC6817614 DOI: 10.3389/fneur.2019.01123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 10/08/2019] [Indexed: 12/29/2022] Open
Abstract
Goals: The development of new treatment for drug abuse requires identification of targetable molecular mechanisms. The pathology of glutamate neurotransmission system in the brain reward circuit is related to the relapse of multiple drugs. Glutamate transporter regulates glutamate signaling by removing excess glutamate from the synapse. And the mechanisms between glutamate transporter and drug addiction are still unclear. Methods: A systematic review of the literature searched in Pubmed and reporting drug addiction in relation to glutamate transporter. Studies were screened by title, abstract, and full text. Results: This review is to highlight the effects of drug addiction on glutamate transporter and glutamate uptake, and targeting glutamate transporter as an addictive drug addiction treatment. We focus on the roles of glutamate transporter in different brain regions in drug addiction. More importantly, we suggest the functional roles of glutamate transporter may prove beneficial in the treatment of drug addiction. Conclusion: Overall, understanding how glutamate transporter impacts central nervous system may provide a new insight for treatment of drug addiction.
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Affiliation(s)
- Wenjun Wang
- Institute for Cancer Medicine and School of Basic Medical Sciences, Southwest Medical University, Luzhou, China
| | - Fancai Zeng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
| | - Yingying Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
| | - Xiang Li
- Department of Biochemistry and Molecular Biology, School of Basic Medical Science, Southwest Medical University, Luzhou, China
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19
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Erickson EK, Blednov YA, Harris RA, Mayfield RD. Glial gene networks associated with alcohol dependence. Sci Rep 2019; 9:10949. [PMID: 31358844 PMCID: PMC6662804 DOI: 10.1038/s41598-019-47454-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/17/2019] [Indexed: 02/07/2023] Open
Abstract
Chronic alcohol abuse alters the molecular structure and function of brain cells. Recent work suggests adaptations made by glial cells, such as astrocytes and microglia, regulate physiological and behavioral changes associated with addiction. Defining how alcohol dependence alters the transcriptome of different cell types is critical for developing the mechanistic hypotheses necessary for a nuanced understanding of cellular signaling in the alcohol-dependent brain. We performed RNA-sequencing on total homogenate and glial cell populations isolated from mouse prefrontal cortex (PFC) following chronic intermittent ethanol vapor exposure (CIE). Compared with total homogenate, we observed unique and robust gene expression changes in astrocytes and microglia in response to CIE. Gene co-expression network analysis revealed biological pathways and hub genes associated with CIE in astrocytes and microglia that may regulate alcohol-dependent phenotypes. Astrocyte identity and synaptic calcium signaling genes were enriched in alcohol-associated astrocyte networks, while TGF-β signaling and inflammatory response genes were disrupted by CIE treatment in microglia gene networks. Genes related to innate immune signaling, specifically interferon pathways, were consistently up-regulated across CIE-exposed astrocytes, microglia, and total homogenate PFC tissue. This study illuminates the cell-specific effects of chronic alcohol exposure and provides novel molecular targets for studying alcohol dependence.
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Affiliation(s)
- Emma K Erickson
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, 78712-01095, USA.
| | - Yuri A Blednov
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, 78712-01095, USA
| | - R Adron Harris
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, 78712-01095, USA
| | - R Dayne Mayfield
- Waggoner Center for Alcohol and Addiction Research, The University of Texas at Austin, Austin, TX, 78712-01095, USA
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20
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HIV infection and latency induce a unique metabolic signature in human macrophages. Sci Rep 2019; 9:3941. [PMID: 30850623 PMCID: PMC6408492 DOI: 10.1038/s41598-019-39898-5] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 01/29/2019] [Indexed: 12/31/2022] Open
Abstract
Currently, a major barrier to curing HIV infection is the generation of tissue-associated, non-replicating, long-lasting viral reservoirs that are refractory to therapy and can be reactivated upon anti-retroviral therapy interruption. One of these reservoirs are latently HIV-infected macrophages. Here, we show that HIV infection of macrophages results in survival of a small population of infected cells that are metabolically altered and characterized by mitochondrial fusion, lipid accumulation, and reduced mitochondrial ATP production. No changes in glycolysis were detected. Metabolic analysis indicated an essential role of succinate and other TCA metabolites in the tricarboxylic acid (TCA) cycle in mediating lipid accumulation and oxidative phosphorylation (OXPHOS) in the mitochondria. Furthermore, we show that while uninfected and HIV infected macrophages use fatty acids and glucose as primary sources of energy, surviving HIV infected macrophages also use glutamine/glutamate as a major energy source, and blocking these new sources of energy resulted in the killing of latent HIV infected macrophages. Together, our data provide a new understanding of the formation, properties, and potential novel ways to eliminate macrophage viral reservoirs.
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21
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Kashem MA, Sultana N, Pow DV, Balcar VJ. GLAST (GLutamate and ASpartate Transporter) in human prefrontal cortex; interactome in healthy brains and the expression of GLAST in brains of chronic alcoholics. Neurochem Int 2019; 125:111-116. [PMID: 30817938 DOI: 10.1016/j.neuint.2019.02.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/05/2019] [Accepted: 02/16/2019] [Indexed: 01/08/2023]
Abstract
We have analysed post-mortem samples of prefrontal cortex from control and alcoholic human brains by the technique of Western blotting to estimate and compare the expressions of glutamate transporter GLAST (Excitatory Amino Acid Transporter One; EAAT1). Furthermore, using the non-alcoholic prefrontal cortex and custom-made GLAST (EAAT1) antibody we determined GLAST (EAAT1) "interactome" i.e. the set of proteins selectively bound by GLAST (EAAT1). We found that GLAST (EAAT1) was significantly more abundant (about 1.6-fold) in the cortical tissue from alcoholic brains compared to that from non-alcoholic controls. The greatest increase in the level of GLAST (EAAT1) was found in plasma membrane fraction (2.2-fold). Additionally, using the prefrontal cortical tissue from control brains, we identified 38 proteins specifically interacting with GLAST (EAAT1). These can be classified as contributing to the cell structure (6 proteins; 16%), energy and general metabolism (18 proteins; 47%), neurotransmitter metabolism (three proteins; 8%), signalling (6 proteins: 16%), neurotransmitter storage/release at synapses (three proteins; 8%) and calcium buffering (two proteins; 5%). We discuss possible consequences of the increased expression of GLAST (EAAT1) in alcoholic brain tissue and whether or how this could disturb the function of the proteins potentially interacting with GLAST (EAAT1) in vivo. The data represent an extension of our previous proteomic and metabolomic studies of human alcoholism revealing another aspect of the complexity of changes imposed on brain by chronic long-term consumption of ethanol.
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Affiliation(s)
- Mohammed Abul Kashem
- School of Medical Sciences, Bosch Institute, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Nilufa Sultana
- School of Medical Sciences, Bosch Institute, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW, 2006, Australia
| | - David V Pow
- UQ Centre for Clinical Research, The University of Queensland, Herston, Brisbane, QLD, 4029, Australia
| | - Vladimir J Balcar
- School of Medical Sciences, Bosch Institute, Faculty of Health and Medicine, The University of Sydney, Sydney, NSW, 2006, Australia.
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22
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Cyanin Chloride Inhibits Hyperbaric Pressure-Induced Decrease of Intracellular Glutamate-Aspartate Transporter in Rat Retinal Müller Cells. J Ophthalmol 2018; 2018:6128470. [PMID: 30515320 PMCID: PMC6234450 DOI: 10.1155/2018/6128470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/09/2018] [Accepted: 10/02/2018] [Indexed: 11/18/2022] Open
Abstract
Purpose Glaucoma is the leading cause of irreversible blindness throughout the world. The pathogenesis of glaucoma is complex, and neuroprotection is a crucial aspect of therapy. High concentrations of extracellular glutamate are toxic to the optic nerve. The glutamate-aspartate transporter (GLAST) in retinal Müller cells is involved in the development of glaucoma. Anthocyanin has been reported to protect retinal neurons. We hypothesize that cyanin chloride, a type of anthocyanin, can inhibit hyperbaric pressure-induced GLAST decreases in cultured rat retinal Müller cells and may serve as a potential neuroprotective agent in glaucoma treatment. Materials and Methods Sprague Dawley rat Müller cells were cultured in a hyperbaric pressure device at 60 mmHg additional pressure and treated with cyanin chloride (10 μmol/L, 30 μmol/L, or 50 μmol/L) or vehicle for 2 hours. Cell survival rates (SRs) were evaluated by an MTT assay. GLAST mRNA and protein expression were determined by western blot and RT-PCR analyses, respectively. Results Cell SR was significantly decreased in the 60 mmHg additional hyperbaric pressure group compared to the control group (P < 0.01). Cyanin chloride treatment significantly improved SR under 60 mmHg additional pressure (P < 0.01). GLAST mRNA and protein expression levels in Müller cells were significantly reduced in the 60 mmHg hyperbaric pressure group compared to the control group (P < 0.01), but cyanin chloride significantly inhibited hyperbaric pressure-induced decreases in GLAST expression (P < 0.01). Conclusion Our results support our hypothesis and demonstrate that cyanin chloride can protect rat retinal Müller cells from hyperbaric pressure-induced decreases of GLAST.
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23
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Tajan M, Hock AK, Blagih J, Robertson NA, Labuschagne CF, Kruiswijk F, Humpton TJ, Adams PD, Vousden KH. A Role for p53 in the Adaptation to Glutamine Starvation through the Expression of SLC1A3. Cell Metab 2018; 28:721-736.e6. [PMID: 30122553 PMCID: PMC6224545 DOI: 10.1016/j.cmet.2018.07.005] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 05/29/2018] [Accepted: 07/09/2018] [Indexed: 12/24/2022]
Abstract
Numerous mechanisms to support cells under conditions of transient nutrient starvation have been described. Several functions of the tumor-suppressor protein p53 can contribute to the adaptation of cells to metabolic stress and help cancer cell survival under nutrient-limiting conditions. We show here that p53 promotes the expression of SLC1A3, an aspartate/glutamate transporter that allows the utilization of aspartate to support cells in the absence of extracellular glutamine. Under glutamine deprivation, SLC1A3 expression maintains electron transport chain and tricarboxylic acid cycle activity, promoting de novo glutamate, glutamine, and nucleotide synthesis to rescue cell viability. Tumor cells with high levels of SLC1A3 expression are resistant to glutamine starvation, and SLC1A3 depletion retards the growth of these cells in vitro and in vivo, suggesting a therapeutic potential for SLC1A3 inhibition.
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Affiliation(s)
- Mylène Tajan
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Andreas K Hock
- Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, UK
| | - Julianna Blagih
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Neil A Robertson
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1BD, UK
| | | | - Flore Kruiswijk
- Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, UK
| | - Timothy J Humpton
- Cancer Research UK Beatson Institute, Switchback Road, Glasgow G61 1BD, UK
| | - Peter D Adams
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Glasgow G61 1BD, UK; Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Karen H Vousden
- The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK.
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Kashem MA, Sultana N, Balcar VJ. Exposure of Rat Neural Stem Cells to Ethanol Affects Cell Numbers and Alters Expression of 28 Proteins. Neurochem Res 2018; 43:1841-1854. [PMID: 30043189 DOI: 10.1007/s11064-018-2600-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 07/17/2018] [Accepted: 07/20/2018] [Indexed: 11/28/2022]
Abstract
Developing brain cells express many proteins but little is known of how their protein composition responds to chronic exposure to alcohol and/or how such changes might relate to alcohol toxicity. We used cultures derived from embryonic rat brain (previously shown to contain mostly neural stem cells; rat NSC, rNSC), exposed them to ethanol (25-100 mM) for up to 96 h and studied how they reacted. Ethanol (50 and 100 mM) reduced cell numbers indicating either compromised cell proliferation, cytotoxicity or both. Increased lipid peroxidation was consistent with the presence of oxidative stress accompanying alcohol-induced cytotoxicity. Proteomics revealed 28 proteins as altered by ethanol (50 mM for 96 h). Some were constituents of cytoskeleton, others were involved in transcription/translation, signal transduction and oxidative stress. Nucleophosmin (NPM1) and dead-end protein homolog 1 (DND1) were further studied by immunological techniques in cultured neurons and astrocytes (derived from brain tissue at embryonic ages E15 and E20, respectively). In the case of DND1 (but not NPM1) ethanol induced similar pattern of changes in both types of cells. Given the critical role of the protein NPM1 in cell proliferation and differentiation, its reduced expression in the ethanol-exposed rNSC could, in part, explain the lower cells numbers. We conclude that chronic ethanol profoundly alters protein composition of rNSC to the extent that their functioning-including proliferation and survival-would be seriously compromised. Translated to humans, such changes could point the way towards mechanisms underlying the fetal alcohol spectrum disorder and/or alcoholism later in life.
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Affiliation(s)
- Mohammed A Kashem
- Laboratory of Neurochemistry, Bosch Institute and Discipline of Anatomy and Histology, School of Medical Sciences, Sydney Medical School, The University of Sydney, Anderson Stuart Building F13, Sydney, NSW, 2006, Australia
| | - Nilufa Sultana
- Laboratory of Neurochemistry, Bosch Institute and Discipline of Anatomy and Histology, School of Medical Sciences, Sydney Medical School, The University of Sydney, Anderson Stuart Building F13, Sydney, NSW, 2006, Australia
| | - Vladimir J Balcar
- Laboratory of Neurochemistry, Bosch Institute and Discipline of Anatomy and Histology, School of Medical Sciences, Sydney Medical School, The University of Sydney, Anderson Stuart Building F13, Sydney, NSW, 2006, Australia.
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25
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Astrocyte-specific transcriptome responses to chronic ethanol consumption. THE PHARMACOGENOMICS JOURNAL 2018; 18:578-589. [PMID: 29305589 PMCID: PMC6033697 DOI: 10.1038/s41397-017-0012-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/04/2017] [Accepted: 11/06/2017] [Indexed: 01/01/2023]
Abstract
Astrocytes play critical roles in central nervous system (CNS) homeostasis and are implicated in the pathogenesis of neurological and psychiatric conditions, including drug dependence. Little is known about the effects of chronic ethanol consumption on astrocyte gene expression. To address this gap in knowledge, we performed transcriptome-wide RNA sequencing of astrocytes isolated from the prefrontal cortex (PFC) of mice following chronic ethanol consumption. Differential expression analysis revealed ethanol-induced changes unique to astrocytes that were not identified in total homogenate preparations. Astrocyte-specific gene expression revealed calcium-related signaling and regulation of extracellular matrix genes as responses to chronic ethanol use. These findings emphasize the importance of investigating expression changes in specific cellular populations to define molecular consequences of chronic ethanol consumption in mammalian brain.
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26
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Dostal CR, Carson Sulzer M, Kelley KW, Freund GG, M cCusker RH. Glial and tissue-specific regulation of Kynurenine Pathway dioxygenases by acute stress of mice. Neurobiol Stress 2017; 7:1-15. [PMID: 29520368 PMCID: PMC5840960 DOI: 10.1016/j.ynstr.2017.02.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/10/2017] [Accepted: 02/07/2017] [Indexed: 01/11/2023] Open
Abstract
Stressors activate the hypothalamic-pituitary-adrenal (HPA) axis and immune system eliciting changes in cognitive function, mood and anxiety. An important link between stress and altered behavior is stimulation of the Kynurenine Pathway which generates neuroactive and immunomodulatory kynurenines. Tryptophan entry into this pathway is controlled by rate-limiting indoleamine/tryptophan 2,3-dioxygenases (DOs: Ido1, Ido2, Tdo2). Although implicated as mediating changes in behavior, detecting stress-induced DO expression has proven inconsistent. Thus, C57BL/6J mice were used to characterize DO expression in brain-regions, astrocytes and microglia to characterize restraint-stress-induced DO expression. Stress increased kynurenine in brain and plasma, demonstrating increased DO activity. Of three Ido1 transcripts, only Ido1-v1 expression was increased by stress and within astrocytes, not microglia, indicating transcript- and glial-specificity. Stress increased Ido1-v1 only in frontal cortex and hypothalamus, indicating brain-region specificity. Of eight Ido2 transcripts, Ido2-v3 expression was increased by stress, again only within astrocytes. Likewise, stress increased Tdo2-FL expression in astrocytes, not microglia. Interestingly, Ido2 and Tdo2 transcripts were not correspondingly induced in Ido1-knockout (Ido1KO) mice, suggesting that Ido1 is necessary for the central DO response to acute stress. Unlike acute inflammatory models resulting in DO induction within microglia, only astrocyte DO expression was increased by acute restraint-stress, defining their unique role during stress-dependent activation of the Kynurenine Pathway.
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Affiliation(s)
- Carlos R. Dostal
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Medical Scholars Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Megan Carson Sulzer
- School of Molecular and Cellular Biology, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Keith W. Kelley
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Gregory G. Freund
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
| | - Robert H. McCusker
- Neuroscience Program, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Animal Sciences, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
- Department of Pathology, University of Illinois at Urbana-Champaign, 250 Edward R Madigan Laboratory, 1201 W. Gregory Drive, Urbana, IL 61801, USA
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27
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O'Donovan SM, Sullivan CR, McCullumsmith RE. The role of glutamate transporters in the pathophysiology of neuropsychiatric disorders. NPJ SCHIZOPHRENIA 2017; 3:32. [PMID: 28935880 PMCID: PMC5608761 DOI: 10.1038/s41537-017-0037-1] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/24/2017] [Accepted: 09/01/2017] [Indexed: 02/08/2023]
Abstract
Altered glutamate transporter expression is a common feature of many neuropsychiatric conditions, including schizophrenia. Excitatory amino acid transporters (EAATs) are responsible for the reuptake of glutamate, preventing non-physiological spillover from the synapse. Postmortem studies have revealed significant dysregulation of EAAT expression in various brain regions at the cellular and subcellular level. Recent animal studies have also demonstrated a role for glutamate spillover as a mechanism of disease. In this review, we describe current evidence for the role of glutamate transporters in regulating synaptic plasticity and transmission. In neuropsychiatric conditions, EAAT splice variant expression is altered. There are changes in the localization of the transporters and disruption of the metabolic and structural protein network that supports EAAT activity. This results in aberrant neuroplasticity and excitatory signaling, contributing to the symptoms associated with neuropsychiatric disease. Understanding the complex functions of glutamate transporters will clarify the relevance of their role in the pathophysiology of neuropsychiatric disorders.
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Affiliation(s)
- Sinead M O'Donovan
- Department of Psychiatry, University of Cincinnati, Cincinnati, OH, 45221, USA.
| | - Courtney R Sullivan
- Department of Psychiatry, University of Cincinnati, Cincinnati, OH, 45221, USA
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28
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Spencer S, Kalivas PW. Glutamate Transport: A New Bench to Bedside Mechanism for Treating Drug Abuse. Int J Neuropsychopharmacol 2017; 20:797-812. [PMID: 28605494 PMCID: PMC5632313 DOI: 10.1093/ijnp/pyx050] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 06/09/2017] [Indexed: 02/06/2023] Open
Abstract
Drug addiction has often been described as a "hijacking" of the brain circuits involved in learning and memory. Glutamate is the principal excitatory neurotransmitter in the brain, and its contribution to synaptic plasticity and learning processes is well established in animal models. Likewise, over the past 20 years the addiction field has ascribed a critical role for glutamatergic transmission in the development of addiction. Chronic drug use produces enduring neuroadaptations in corticostriatal projections that are believed to contribute to a maladaptive deficit in inhibitory control over behavior. Much of this research focuses on the role played by ionotropic glutamate receptors directly involved in long-term potentiation and depression or metabotropic receptors indirectly modulating synaptic plasticity. Importantly, the balance between glutamate release and clearance tightly regulates the patterned activation of these glutamate receptors, emphasizing an important role for glutamate transporters in maintaining extracellular glutamate levels. Five excitatory amino acid transporters participate in active glutamate reuptake. Recent evidence suggests that these glutamate transporters can be modulated by chronic drug use at a variety of levels. In this review, we synopsize the evidence and mechanisms associated with drug-induced dysregulation of glutamate transport. We then summarize the preclinical and clinical data suggesting that glutamate transporters offer an effective target for the treatment of drug addiction. In particular, we focus on the role that altered glutamate transporters have in causing drug cues and contexts to develop an intrusive quality that guides maladaptive drug seeking behaviors.
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Affiliation(s)
- Sade Spencer
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina.,Correspondence: Sade Spencer, PhD, Medical University of South Carolina, 173 Ashley Avenue, BSB, 403- MSC 510, Charleston, SC 29425 ()
| | - Peter W Kalivas
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina.
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29
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Kashem MA, Lee A, Pow DV, Šerý O, Balcar VJ. Could ethanol-induced alterations in the expression of glutamate transporters in testes contribute to the effect of paternal drinking on the risk of abnormalities in the offspring? Med Hypotheses 2017; 98:57-59. [DOI: 10.1016/j.mehy.2016.11.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Accepted: 11/23/2016] [Indexed: 01/01/2023]
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30
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Warden A, Erickson E, Robinson G, Harris RA, Mayfield RD. The neuroimmune transcriptome and alcohol dependence: potential for targeted therapies. Pharmacogenomics 2016; 17:2081-2096. [PMID: 27918243 DOI: 10.2217/pgs-2016-0062] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Transcriptome profiling enables discovery of gene networks that are altered in alcoholic brains. This technique has revealed involvement of the brain's neuroimmune system in regulating alcohol abuse and dependence, and has provided potential therapeutic targets. In this review, we discuss Toll-like-receptor pathways, hypothesized to be key players in many stages of the alcohol addiction cycle. The growing appreciation of the neuroimmune system's involvement in alcoholism has also led to consideration of crucial roles for glial cells, including astrocytes and microglia, in the brain's response to alcohol abuse. We discuss current knowledge and hypotheses on the roles that specific neuroimmune cell types may play in addiction. Current strategies for repurposing US FDA-approved drugs for the treatment of alcohol use disorders are also discussed.
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Affiliation(s)
- Anna Warden
- The University of Texas at Austin, Waggoner Center for Alcohol & Addiction Research, Austin, TX, USA
| | - Emma Erickson
- The University of Texas at Austin, Waggoner Center for Alcohol & Addiction Research, Austin, TX, USA
| | - Gizelle Robinson
- The University of Texas at Austin, Waggoner Center for Alcohol & Addiction Research, Austin, TX, USA
| | - R Adron Harris
- The University of Texas at Austin, Waggoner Center for Alcohol & Addiction Research, Austin, TX, USA
| | - R Dayne Mayfield
- The University of Texas at Austin, Waggoner Center for Alcohol & Addiction Research, Austin, TX, USA
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31
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Pamies D, Barreras P, Block K, Makri G, Kumar A, Wiersma D, Smirnova L, Zang C, Bressler J, Christian KM, Harris G, Ming GL, Berlinicke CJ, Kyro K, Song H, Pardo CA, Hartung T, Hogberg HT. A human brain microphysiological system derived from induced pluripotent stem cells to study neurological diseases and toxicity. ALTEX-ALTERNATIVES TO ANIMAL EXPERIMENTATION 2016; 34:362-376. [PMID: 27883356 PMCID: PMC6047513 DOI: 10.14573/altex.1609122] [Citation(s) in RCA: 134] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 11/23/2016] [Indexed: 12/30/2022]
Abstract
Human in vitro models of brain neurophysiology are needed to investigate molecular and cellular mechanisms associated with neurological disorders and neurotoxicity. We have developed a reproducible iPSC-derived human 3D brain microphysiological system (BMPS), comprised of differentiated mature neurons and glial cells (astrocytes and oligodendrocytes) that reproduce neuronal-glial interactions and connectivity. BMPS mature over eight weeks and show the critical elements of neuronal function: synaptogenesis and neuron-to-neuron (e.g., spontaneous electric field potentials) and neuronal-glial interactions (e.g., myelination), which mimic the microenvironment of the central nervous system, rarely seen in vitro before. The BMPS shows 40% overall myelination after 8 weeks of differentiation. Myelin was observed by immunohistochemistry and confirmed by confocal microscopy 3D reconstruction and electron microscopy. These findings are of particular relevance since myelin is crucial for proper neuronal function and development. The ability to assess oligodendroglial function and mechanisms associated with myelination in this BMPS model provide an excellent tool for future studies of neurological disorders such as multiple sclerosis and other demyelinating diseases. The BMPS provides a suitable and reliable model to investigate neuron-neuroglia function as well as pathogenic mechanisms in neurotoxicology.
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Affiliation(s)
- David Pamies
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA
| | - Paula Barreras
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Division of Neuroimmunology, Johns Hopkins University, Baltimore, USA
| | - Katharina Block
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA
| | - Georgia Makri
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Institute for Cell Engineering, Johns Hopkins University, Baltimore, USA
| | - Anupama Kumar
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Division of Neuroimmunology, Johns Hopkins University, Baltimore, USA
| | - Daphne Wiersma
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA
| | - Lenna Smirnova
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA
| | - Ce Zang
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Institute for Cell Engineering, Johns Hopkins University, Baltimore, USA
| | - Joseph Bressler
- Hugo Moser Institute at the Kennedy Krieger, Johns Hopkins University, Baltimore, USA
| | - Kimberly M Christian
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Institute for Cell Engineering, Johns Hopkins University, Baltimore, USA
| | - Georgina Harris
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA
| | - Guo-Li Ming
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Institute for Cell Engineering, Johns Hopkins University, Baltimore, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, USA
| | | | - Kelly Kyro
- US Army Edgewood Chemical Biological Center, Aberdeen Proving Ground, USA
| | - Hongjun Song
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Institute for Cell Engineering, Johns Hopkins University, Baltimore, USA.,The Solomon Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, USA
| | - Carlos A Pardo
- Department of Neurology, Johns Hopkins University, Baltimore, USA.,Division of Neuroimmunology, Johns Hopkins University, Baltimore, USA
| | - Thomas Hartung
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA.,University of Konstanz, Konstanz, Germany
| | - Helena T Hogberg
- Center for Alternatives to Animal Testing, Johns Hopkins University, Baltimore, USA
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32
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Lee A, Stevens MG, Anderson AR, Kwan A, Balcar VJ, Pow DV. A novel splice variant of the Excitatory Amino Acid Transporter 5: Cloning, immunolocalization and functional characterization of hEAAT5v in human retina. Neurochem Int 2016; 101:S0197-0186(16)30404-1. [PMID: 27984169 DOI: 10.1016/j.neuint.2016.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 10/24/2016] [Accepted: 10/26/2016] [Indexed: 11/15/2022]
Abstract
Excitatory Amino Acid Transporter 5 (EAAT5) is abundantly expressed by retinal photoreceptors and bipolar cells, where it acts as a slow glutamate transporter and a glutamate-gated chloride channel. The chloride conductance is large enough for EAAT5 to serve as an "inhibitory" glutamate receptor. Our recent work in rodents has shown that EAAT5 is differentially spliced and exists in many variant forms. The chief aim of the present study was to examine whether EAAT5 is also alternately spliced in human retina and, if so, what significance this might have for retinal function in health and disease. Retinal tissues from human donor eyes were used in RT-PCR to amplify the entire coding region of EAAT5. Amplicons of differing sizes were sub-cloned and analysis of sequenced data revealed the identification of wild-type human EAAT5 (hEAAT5) and an abundant alternately spliced form, referred to as hEAAT5v, where the open reading frame is expanded by insertion of an additional exon. hEAAT5v encodes a protein of 619 amino acids and when expressed in COS7 cells, the protein functioned as a glutamate transporter. We raised antibodies that selectively recognized the hEAAT5v protein and have performed immunocytochemistry to demonstrate expression in photoreceptors in human retina. We noted that in retinas afflicted by dry aged-related macular degeneration (AMD), there was a loss of hEAAT5v from the lesioned area and from photoreceptors adjacent to the lesion. We conclude that hEAAT5v protein expression may be perturbed in peri-lesional areas of AMD-afflicted retinas that do not otherwise exhibit evidence of damage. The loss of hEAAT5v could, therefore, represent an early pathological change in the development of AMD and might be involved in its aetiology.
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Affiliation(s)
- A Lee
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD 4029, Australia.
| | - M G Stevens
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD 4029, Australia
| | - A R Anderson
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD 4029, Australia
| | - A Kwan
- Queensland Eye Institute, South Brisbane, QLD 4101, Australia
| | - V J Balcar
- Laboratory of Neurochemistry, School of Medical Sciences (Discipline of Anatomy and Neurochemistry) and Bosch Institute, Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia
| | - D V Pow
- UQ Centre for Clinical Research, The University of Queensland, Brisbane, QLD 4029, Australia; School of Medical Sciences, RMIT University, Melbourne, Australia
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33
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Rae C, Sonnewald U. Astrocytes, Metabolism, Signaling and Brain Drains: Introduction to the Special Issue in Honor of Gerald Dienel. Neurochem Res 2016; 40:2383-5. [PMID: 26613618 DOI: 10.1007/s11064-015-1781-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Caroline Rae
- Neuroscience Research Australian & The University of New South Wales, Randwick, NSW, Australia.
| | - Ursula Sonnewald
- Norwegian University of Science and Technology (NTNU), Trondheim, Norway
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34
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Logica T, Riviere S, Holubiec MI, Castilla R, Barreto GE, Capani F. Metabolic Changes Following Perinatal Asphyxia: Role of Astrocytes and Their Interaction with Neurons. Front Aging Neurosci 2016; 8:116. [PMID: 27445788 PMCID: PMC4921470 DOI: 10.3389/fnagi.2016.00116] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 05/03/2016] [Indexed: 11/13/2022] Open
Abstract
Perinatal Asphyxia (PA) represents an important cause of severe neurological deficits including delayed mental and motor development, epilepsy, major cognitive deficits and blindness. The interaction between neurons, astrocytes and endothelial cells plays a central role coupling energy supply with changes in neuronal activity. Traditionally, experimental research focused on neurons, whereas astrocytes have been more related to the damage mechanisms of PA. Astrocytes carry out a number of functions that are critical to normal nervous system function, including uptake of neurotransmitters, regulation of pH and ion concentrations, and metabolic support for neurons. In this work, we aim to review metabolic neuron-astrocyte interactions with the purpose of encourage further research in this area in the context of PA, which is highly complex and its mechanisms and pathways have not been fully elucidated to this day.
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Affiliation(s)
- Tamara Logica
- Laboratorio de Citoarquitectura y Plasticidad Neuronal, Facultad de Medicina, Instituto de Investigaciones Cardiológicas Prof. Dr. Alberto C. Taquini (ININCA), UBA-CONICET, CABA Buenos Aires, Argentina
| | - Stephanie Riviere
- Laboratorio de Biología Molecular, Facultad de Medicina, Instituto de Investigaciones cardiológicas Prof. Dr. Alberto C. Taquini (ININCA), UBA-CONICET, CABA Buenos Aires, Argentina
| | - Mariana I Holubiec
- Laboratorio de Citoarquitectura y Plasticidad Neuronal, Facultad de Medicina, Instituto de Investigaciones Cardiológicas Prof. Dr. Alberto C. Taquini (ININCA), UBA-CONICET, CABA Buenos Aires, Argentina
| | - Rocío Castilla
- Laboratorio de Biología Molecular, Facultad de Medicina, Instituto de Investigaciones cardiológicas Prof. Dr. Alberto C. Taquini (ININCA), UBA-CONICET, CABA Buenos Aires, Argentina
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana Bogotá Bogotá, Colombia
| | - Francisco Capani
- Laboratorio de Citoarquitectura y Plasticidad Neuronal, Facultad de Medicina, Instituto de Investigaciones Cardiológicas Prof. Dr. Alberto C. Taquini (ININCA), UBA-CONICET, CABABuenos Aires, Argentina; Departamento de Biología, Universidad Argentina JF KennedyBuenos Aires, Argentina; Investigador Asociado, Universidad Autónoma de ChileSantiago, Chile
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35
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Bjørn-Yoshimoto WE, Underhill SM. The importance of the excitatory amino acid transporter 3 (EAAT3). Neurochem Int 2016; 98:4-18. [PMID: 27233497 DOI: 10.1016/j.neuint.2016.05.007] [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: 11/16/2015] [Revised: 05/09/2016] [Accepted: 05/17/2016] [Indexed: 12/21/2022]
Abstract
The neuronal excitatory amino acid transporter 3 (EAAT3) is fairly ubiquitously expressed in the brain, though it does not necessarily maintain the same function everywhere. It is important in maintaining low local concentrations of glutamate, where its predominant post-synaptic localization can buffer nearby glutamate receptors and modulate excitatory neurotransmission and synaptic plasticity. It is also the main neuronal cysteine uptake system acting as the rate-limiting factor for the synthesis of glutathione, a potent antioxidant, in EAAT3 expressing neurons, while on GABAergic neurons, it is important in supplying glutamate as a precursor for GABA synthesis. Several diseases implicate EAAT3, and modulation of this transporter could prove a useful therapeutic approach. Regulation of EAAT3 could be targeted at several points for functional modulation, including the level of transcription, trafficking and direct pharmacological modulation, and indeed, compounds and experimental treatments have been identified that regulate EAAT3 function at different stages, which together with observations of EAAT3 regulation in patients is giving us insight into the endogenous function of this transporter, as well as the consequences of altered function. This review summarizes work done on elucidating the role and regulation of EAAT3.
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Affiliation(s)
- Walden E Bjørn-Yoshimoto
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, 2100 København Ø, Denmark
| | - Suzanne M Underhill
- National Institute of Mental Health, National Institutes of Health, 35 Convent Drive Room 3A: 210 MSC3742, Bethesda, MD 20892-3742, USA.
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36
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Kashem MA, Ahmed S, Sultana N, Ahmed EU, Pickford R, Rae C, Šerý O, McGregor IS, Balcar VJ. Metabolomics of Neurotransmitters and Related Metabolites in Post-Mortem Tissue from the Dorsal and Ventral Striatum of Alcoholic Human Brain. Neurochem Res 2016; 41:385-97. [PMID: 26801172 DOI: 10.1007/s11064-016-1830-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 01/05/2016] [Accepted: 01/05/2016] [Indexed: 12/20/2022]
Abstract
We report on changes in neurotransmitter metabolome and protein expression in the striatum of humans exposed to heavy long-term consumption of alcohol. Extracts from post mortem striatal tissue (dorsal striatum; DS comprising caudate nucleus; CN and putamen; P and ventral striatum; VS constituted by nucleus accumbens; NAc) were analysed by high performance liquid chromatography coupled with tandem mass spectrometry. Proteomics was studied in CN by two-dimensional gel electrophoresis followed by mass-spectrometry. Proteomics identified 25 unique molecules expressed differently by the alcohol-affected tissue. Two were dopamine-related proteins and one a GABA-synthesizing enzyme GAD65. Two proteins that are related to apoptosis and/or neuronal loss (BiD and amyloid-β A4 precursor protein-binding family B member 3) were increased. There were no differences in the levels of dopamine (DA), 3,4-dihydrophenylacetic acid (DOPAC), serotonin (5HT), homovanillic acid (HVA), 5-hydroxyindoleacetic acid (HIAA), histamine, L-glutamate (Glu), γ-aminobutyric acid (GABA), tyrosine (Tyr) and tryptophan (Tryp) between the DS (CN and P) and VS (NAc) in control brains. Choline (Ch) and acetylcholine (Ach) were higher and norepinephrine (NE) lower, in the VS. Alcoholic striata had lower levels of neurotransmitters except for Glu (30 % higher in the alcoholic ventral striatum). Ratios of DOPAC/DA and HIAA/5HT were higher in alcoholic striatum indicating an increase in the DA and 5HT turnover. Glutathione was significantly reduced in all three regions of alcohol-affected striatum. We conclude that neurotransmitter systems in both the DS (CN and P) and the VS (NAc) were significantly influenced by long-term heavy alcohol intake associated with alcoholism.
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Affiliation(s)
- Mohammed Abul Kashem
- Lab of Neurochemistry, Discipline of Anatomy and Histology, Bosch Institute for Biomedical Research and School of Medical Sciences, Sydney Medical School, Anderson Stuart Bldg F13, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Selina Ahmed
- Lab of Psychopharmacology, School of Psychology, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Nilufa Sultana
- Lab of Neurochemistry, Discipline of Anatomy and Histology, Bosch Institute for Biomedical Research and School of Medical Sciences, Sydney Medical School, Anderson Stuart Bldg F13, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Eakhlas U Ahmed
- Lab of Psychopharmacology, School of Psychology, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Russell Pickford
- Bioanalytical Mass Spectrometry Facility, NeuRA, NSW University, Sydney, NSW, 2031, Australia
| | - Caroline Rae
- Neuroscience Research Australia, Randwick, Sydney, NSW, 2031, Australia
- School of Medical Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Omar Šerý
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Iain S McGregor
- Lab of Psychopharmacology, School of Psychology, The University of Sydney, Sydney, NSW, 2006, Australia
| | - Vladimir J Balcar
- Lab of Neurochemistry, Discipline of Anatomy and Histology, Bosch Institute for Biomedical Research and School of Medical Sciences, Sydney Medical School, Anderson Stuart Bldg F13, The University of Sydney, Sydney, NSW, 2006, Australia.
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37
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Šerý O, Hlinecká L, Povová J, Bonczek O, Zeman T, Janout V, Ambroz P, Khan NA, Balcar VJ. Arachidonate 5-lipoxygenase (ALOX5) gene polymorphism is associated with Alzheimer's disease and body mass index. J Neurol Sci 2016; 362:27-32. [PMID: 26944113 DOI: 10.1016/j.jns.2016.01.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 01/11/2016] [Accepted: 01/13/2016] [Indexed: 12/20/2022]
Abstract
Dementias of old age, in particular Alzheimer's disease (AD), pose a growing threat to the longevity and quality of life of individuals as well as whole societies world-wide. The risk factors are both genetic and environmental (life-style) and there is an overlap with similar factors predisposing to cardiovascular diseases (CVD). Using a case-control genetic approach, we have identified a SNP (rs10507391) in ALOX5 gene, previously associated with an increased risk of stroke, as a novel genetic risk factor for AD. ALOX5 gene encodes a 5'-lipoxygenase (5'-LO) activating protein (FLAP), a crucial component of the arachidonic acid/leukotriene inflammatory cascade. A-allele of rs4769874 polymorphism increases the risk of AD 1.41-fold (p<0.0001), while AA genotype does so 1.79-fold (p<0.0001). In addition, GG genotype of rs4769874 polymorphism is associated with a modest increase in body mass index (BMI). We discuss potential biochemical mechanisms linking the SNP to AD and suggest possible preventive pharmacotherapies some of which are based on commonly available natural products. Finally, we set the newly identified AD risk factors into a broader context of similar CVD risk factors to generate a more comprehensive picture of interacting genetics and life-style habits potentially leading to the deteriorating mental health in the old age.
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Affiliation(s)
- Omar Šerý
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic; Institute of Animal Physiology and Genetics, Academy of Sciences, Veveří 97, 602 00 Brno, Czech Republic.
| | - Lýdia Hlinecká
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Jana Povová
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Czech Republic
| | - Ondřej Bonczek
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic; Institute of Animal Physiology and Genetics, Academy of Sciences, Veveří 97, 602 00 Brno, Czech Republic
| | - Tomáš Zeman
- Laboratory of Neurobiology and Molecular Psychiatry, Department of Biochemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Vladimír Janout
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Czech Republic
| | - Petr Ambroz
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Czech Republic
| | - Naim A Khan
- Physiologie de la Nutrition et Toxicologie, UMR U866 INSERM/Université de Bourgogne/Agro-Sup, 6, Boulevard Gabriel, Dijon 21000, France
| | - Vladimir J Balcar
- Discipline Anatomy and Histology and Bosch Institute, School of Medical Sciences, Sydney Medical School, University of Sydney, NSW 2006, Australia
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38
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Cacabelos R, Torrellas C. Epigenetics of Aging and Alzheimer's Disease: Implications for Pharmacogenomics and Drug Response. Int J Mol Sci 2015; 16:30483-543. [PMID: 26703582 PMCID: PMC4691177 DOI: 10.3390/ijms161226236] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/16/2015] [Accepted: 12/08/2015] [Indexed: 02/07/2023] Open
Abstract
Epigenetic variability (DNA methylation/demethylation, histone modifications, microRNA regulation) is common in physiological and pathological conditions. Epigenetic alterations are present in different tissues along the aging process and in neurodegenerative disorders, such as Alzheimer’s disease (AD). Epigenetics affect life span and longevity. AD-related genes exhibit epigenetic changes, indicating that epigenetics might exert a pathogenic role in dementia. Epigenetic modifications are reversible and can potentially be targeted by pharmacological intervention. Epigenetic drugs may be useful for the treatment of major problems of health (e.g., cancer, cardiovascular disorders, brain disorders). The efficacy and safety of these and other medications depend upon the efficiency of the pharmacogenetic process in which different clusters of genes (pathogenic, mechanistic, metabolic, transporter, pleiotropic) are involved. Most of these genes are also under the influence of the epigenetic machinery. The information available on the pharmacoepigenomics of most drugs is very limited; however, growing evidence indicates that epigenetic changes are determinant in the pathogenesis of many medical conditions and in drug response and drug resistance. Consequently, pharmacoepigenetic studies should be incorporated in drug development and personalized treatments.
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Affiliation(s)
- Ramón Cacabelos
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, 15165-Bergondo, Corunna, Spain.
- Chair of Genomic Medicine, Camilo José Cela University, 28692-Madrid, Spain.
| | - Clara Torrellas
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, 15165-Bergondo, Corunna, Spain.
- Chair of Genomic Medicine, Camilo José Cela University, 28692-Madrid, Spain.
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Karki P, Kim C, Smith K, Son DS, Aschner M, Lee E. Transcriptional Regulation of the Astrocytic Excitatory Amino Acid Transporter 1 (EAAT1) via NF-κB and Yin Yang 1 (YY1). J Biol Chem 2015; 290:23725-37. [PMID: 26269591 DOI: 10.1074/jbc.m115.649327] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Indexed: 12/19/2022] Open
Abstract
Astrocytic glutamate transporter excitatory amino acid transporter (EAAT) 1, also known as glutamate aspartate transporter (GLAST) in rodents, is one of two glial glutamate transporters that are responsible for removing excess glutamate from synaptic clefts to prevent excitotoxic neuronal death. Despite its important role in neurophysiological functions, the molecular mechanisms of EAAT1 regulation at the transcriptional level remain to be established. Here, we report that NF-κB is a main positive transcription factor for EAAT1, supported by the following: 1) EAAT1 contains two consensus sites for NF-κB, 2) mutation of NF-κB binding sites decreased EAAT1 promoter activity, and 3) activation of NF-κB increased, whereas inhibition of NF-κB decreased EAAT1 promoter activity and mRNA/protein levels. EGF increased EAAT1 mRNA/protein levels and glutamate uptake via NF-κB. The transcription factor yin yang 1 (YY1) plays a role as a critical negative regulator of EAAT1, supported by the following: 1) the EAAT1 promoter contains multiple consensus sites for YY1, 2) overexpression of YY1 decreased EAAT1 promoter activity and mRNA/protein levels, and 3) knockdown of YY1 increased EAAT1 promoter activity and mRNA/protein levels. Manganese decreased EAAT1 expression via YY1. Epigenetic modifiers histone deacetylases (HDACs) served as co-repressors of YY1 to further decrease EAAT1 promoter activity, whereas inhibition of HDACs reversed manganese-induced decrease of EAAT1 expression. Taken together, our findings suggest that NF-κB is a critical positive regulator of EAAT1, mediating the stimulatory effects of EGF, whereas YY1 is a negative regulator of EAAT1 with HDACs as co-repressors, mediating the inhibitory effects of manganese on EAAT1 regulation.
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Affiliation(s)
- Pratap Karki
- From the Department of Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Clifford Kim
- the Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115, and
| | - Keisha Smith
- From the Department of Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Deok-Soo Son
- From the Department of Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208
| | - Michael Aschner
- the Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Eunsook Lee
- From the Department of Physiology, School of Medicine, Meharry Medical College, Nashville, Tennessee 37208,
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