Dissertations / Theses on the topic 'EAAT4'
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Hiltscher, Juliane. "Glutamattransporter und genetisch bedingte Ataxien. Mutationssuche im EAAT1- und EAAT4-Gen." Lübeck Zentrale Hochschulbibliothek Lübeck, 2010. http://d-nb.info/1000297667/34.
Hiltscher, Juliane [Verfasser]. "Glutamattransporter und genetisch bedingte Ataxien : Mutationssuche im EAAT1- und EAAT4-Gen / Juliane Hiltscher." Lübeck : Zentrale Hochschulbibliothek Lübeck, 2010. http://d-nb.info/1000297667/34.
Agarwal, Shailesh Ramjilal. "Pharmacological modeling and regulation of excitatory amino acid transporters (EAATS)." CONNECT TO THIS TITLE ONLINE, 2007. http://etd.lib.umt.edu/theses/available/etd-09262007-111510/.
Fromm, Andrea. "Mutationsscreening und alternative Spleißvarianten des Glutamattransporters EAAT2 bei amyotropher Lateralsklerose." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:289-vts-66108.
Felbecker, Ansgar. "Neue 5'-Isoformen des Glutamattransporters EAAT2: RNA-Sequenzen und genomische Organisation." [S.l.] : Universität Ulm , Medizinische Fakultät, 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB10913301.
Köchert, Karl. "Development of a method to assess EAAT1 transcription levels in Alzheimer's disease." Master's thesis, Universität Potsdam, 2007. http://opus.kobv.de/ubp/volltexte/2008/1596/.
Today about 24 Million people worldwide suffer from dementia, Alzheimer’s Disease accounts for approximately 50-60% of all dementia cases. As the prevalence of dementia grows with increasing age Alzheimer’s Disease becomes more and more of an issue for society as the proportion of elderly people increases from year to year. It is well established, that the amino acid glutamate - quantitatively being the most important neurotransmitter in the central nervous system (CNS) - may reach toxic concentrations if not cleared from the synaptic cleft into which it is released during transmittance of action potentials. In Alzheimer’s Disease there is strong evidence for a generally impaired glutamate uptake system which in turn is thought to result in toxic levels of the amino acid with the potential to kill off neurons. The excitatory amino acid transporter 1 (EAAT1) belongs to the family of Na+-dependent glutamate transporter and accounts together with EAAT2 for most of the glutamate uptake in the CNS. In this project a new splice variant of EAAT1, skipping exon 3 was detected in human brain samples and subsequently called EAAT1Δ3, this being the second splice variant found after the recent detection of EAAT1Δ9. A method was developed to quantify the transcript of EAAT1 wt, EAAT1Δ3 and EAAT1Δ9 by means of real-time PCR. Samples were taken from different brain areas of a set of control and AD cases. The areas chosen for examination are affected differently in Alzheimer’s Disease, this was used an internal control for the experiments done in this project as to determine whether any effect observed is specific for AD, i.e. AD affected areas or is generally seen in all areas examined. The results of this project show that EAAT1Δ3 is transcribed in very low copy numbers making up a proportion of 0.15% of EAAT1 wt whereas EAAT1Δ9 is transcribed in a considerably large proportion of EAAT1 wt of 26.6%. It was moreover found that all EAAT1 variants are transcribed at significantly lower rates (P<0.0001) in AD cases, supporting the theory that EAAT1 protein expression is reduced to a point where glutamate uptake normally mediated by this transporter is impaired. This in turn is thought to result in toxic levels glutamate accounting for neuronal loss in the disease. No area-dependent effects were found, suggesting that the reduction of EAAT1 transcription is rather a result of an underlying general mechanism present in AD. Further research will have to be done to assess the degree of EAAT1 expression in AD and whether those future findings match with the result of this project.
Pantazis, Konstantinos. "Enterprise Architecture at the Financial Sector with the EAAT Tool." Thesis, KTH, Industriella informations- och styrsystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-138610.
Seefried, Ulrich [Verfasser]. "Alternatives RNA-Spleißen des Glutamattransporters EAAT2 im ZNS der Maus / Ulrich Seefried." Ulm : Universität Ulm. Medizinische Fakultät, 2001. http://d-nb.info/1015324916/34.
Felbecker, Ansgar [Verfasser]. "Neue 5´-Isoformen des Glutamattransporters EAAT2: RNA-Sequenzen und genomische Organisation / Ansgar Felbecker." Ulm : Universität Ulm. Medizinische Fakultät, 2003. http://d-nb.info/1015438318/34.
Tian, Guilian. "The molecular mechanism of loss of glial glutamate transporter EAAT2 in neurodegenerative disease." The Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=osu1187038549.
Tian, Guilian. "The molecular mechanisms of the loss of glial glutamate transporter EAAT2 in neurodegenerative diseases." Columbus, Ohio : Ohio State University, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1187038549.
Leinenweber, Ariane [Verfasser]. "Regulation of Excitatory Amino Acid Transporter 2 (EAAT2) by Carboxy-terminal Domains / Ariane Leinenweber." Hannover : Bibliothek der Tierärztlichen Hochschule Hannover, 2010. http://d-nb.info/100962427X/34.
Mullen, Gary. "Integrating Equine-Assisted Activities and Therapy (EAAT) into a Higher Learning Institution." ScholarWorks, 2010. https://scholarworks.waldenu.edu/dissertations/845.
Mavencamp, Terri Lynn. "Design, Synthesis and Biological Evaluation of a Family of Excitatory Amino Acid Transporter 3 (EAAT3) Preferring Inhibitors." The University of Montana, 2009. http://etd.lib.umt.edu/theses/available/etd-03212009-152926/.
This work describes the synthesis and initial characterization of the biological activity of a family of EAAT3 preferring inhibitors, L-β-benzyl aspartate (L-β-BA) and L-β-BA derivatives. L-β-BA and derivatives were initially synthesized in an approximate 2:1 ratio of diasteromers (threo:erythro), using base promoted enolate addition. Kinetic analysis of 3H-D-aspartate uptake into C17.2 cells expressing the hEAATs demonstrated that L-threo-β-BA is the more potent diastereomer (Ki values of 9 µM for EAAT1, 10.0 µM for EAAT2 and 0.8 µM for EAAT3), acts competitively, and exhibits a 10-fold preference for EAAT3 compared to EAAT1 and EAAT2. Electrophysiological recordings of EAAT-mediated currents in Xenopus oocytes further identified L-β-BA as a non-substrate inhibitor. Derivatives of L-β-BA were prepared and characterized for the ability to inhibit 3H-D-aspartate uptake into hEAAT1-3 expressing C17.2 cells. Computational modeling and analysis of structure activity data suggest the area the aromatic moiety of L-β-BA derivatives probe is 1) 3-dimentionally confined, 2) more tolerant of substitutions at the 3 and 5 positions than the 4 position, 3) at least partially distinct from the area probed by L-TBOA and 4) more accessible in the EAAT3 protein than EAAT1 and EAAT2. Computational modeling supports the pharmacological data and lends insight into the selectivity observed with L-β-BA derivatives. Docking studies suggest that H-bonding interactions of L-β-BA derivatives with key residues in the binding site position L-β-BA analogues in a unique manner that is better tolerated in the EAAT3 protein than in the EAAT1 and EAAT2 proteins.
Mavencamp, Terri Lynn. "Design, synthesis and biological evaluation of a family of excitatory amino acid transporter 3 (EAAT3) preferring inhibitors." [Missoula, Mont.] : The University of Montana, 2008. http://etd.lib.umt.edu/theses/available/etd-03212009-152926/unrestricted/Mavencamp_umt_0136D_10009.pdf.
Hotzy, Linda Sabrina Jasmin [Verfasser]. "Fluorometric approaches to analyze the structure-function relationship of excitatory amino acid transporters (EAATs) / Linda Sabrina Jasmin Hotzy." Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2013. http://d-nb.info/1032720204/34.
Cao, Jin. "OPERATING SYSTEM SECURITYMODELING : An Experimental Study on the CySeMoL model." Thesis, KTH, Industriella informations- och styrsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176854.
Maguire, Jamie Lynn. "The Impact of Glutamate Signaling on Tumor Progression." Diss., Neuroscience Program, George Washington University, 2004. http://hdl.handle.net/1961/121.
Glutamate is critically important as an excitatory neurotransmitter in the central nervous system. Increasing evidence suggests additional signaling roles for glutamate in cell proliferation and migration in normal and oncogenic states. Recently, glutamate release from glioma cells has been shown to increase tumor growth in vivo. To investigate the mechanism of glutamate enhancement of tumor growth, we investigated the effect of glutamate on tumor cell proliferation, invasion, and glioma-induced cell death. Here we demonstrate that glutamate enhances tumor growth via increasing tumor cell proliferation and inducing excitotoxic death of cells surrounding the solid tumor mass, thereby facilitating tumor expansion. The evidence that glutamate enhances tumor growth suggests that regulating extracellular levels of glutamate may restrict tumor growth. In the normal brain, extracellular glutamate levels are maintained by a family of glutamate transporters. To investigate the therapeutic potential of regulating extracellular glutamate concentrations on tumor growth, we utilized a transgenic mouse model of EAAT2 glutamate transporter overexpression. In this report, we demonstrate that increased glutamate transport limits tumor growth in vivo and provides protection against glioma-associated neuronal cell death. In addition, seizure activity, often associated with the presence of a CNS tumor, is attenuated in transgenic mice overexpressing the glutamate transporter, EAAT2. These findings suggest that glutamate transporters may provide a new therapeutic target for limiting tumor expansion and secondary epileptogenesis.
Advisory Committee: Dr. Margaret Sutherland (Chair), Dr. Steven Patierno (Chair), Dr. Tim Hales, Dr. Vincent Chiappinelli, Dr. Linda Werling, Dr. Frances Noonan
Rabbani, Talvia. "Empirical Testing of the CySeMoL Tool for Cyber Security Assessment – Case Study of Linux Server and MySQL." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187664.
I denna Masteruppsats modelleras ett antal vanliga applikationer på en MySQL- och Linuxplattform med hjälp av Enterprise Architecture Analysis Tool (EAAT) tillsammans med Cybersecurity Modeling Language (CySeMoL). Båda dessa är utvecklade vid avdelningen för industriella informations- och styrsystem (ICS) på KTH. Syftet med denna studie är att validera korrektheten av CySeMoL-verktygets sårbarhetsprediktioner genom att simulera ett antal specifika cyberattacker mot en Linuxplattform. Ett antal vanligt förekommande applikationer på en MySQL-plattform samt två operativsystemstjänster i en Linuxserver modelleras. Penetrationstest utförs därefter för att validera resultaten som simuleras i CySeMoL-verktyget. Studien visar att CySeMols förutsägelser stämmer väl med resultaten av penetrationstesterna.
Mekki, Sofiane. "Synthèse de nouveaux dérivés de l'acide β-hydroxyaspartique β-Substitués : inhibiteurs du transport du glutamate dans le Système Nerveux Central (SNC)." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20079/document.
Our work focused on the development of synthesis of originals β-substituted β-hydroxy aspartates derivatives: Inhibitors of glutamate transport in the central nervous system (CNS).These analogs of aspartate have been characterized by various spectroscopic methods (1H-NMR, 13C-NMR and HRMS) and their enantiomeric purity was confirmed by chiral HPLC analysis and D measurement.This manuscript is organized into three chapters: the first part presents a bibliographical point of the glutamatergic system in CNS, recalling the different receptors and glutamate transporters in this system and their specific agonists and antagonists.Then, we described an overview of the various syntheses of β-substituted aspartates derivatives and their inhibitory activities toward glutamate transporters in CNS.In order, to have a great diversity in the structure of β-substituted β-hydroxy aspartates derivatives and reduce preparation time and the number of synthetic steps, we have developed in the third part of this manuscript two recent and original strategies for prepare β-substituted β-hydroxy aspartates derivatives via asymmetric aminohydroxylation Sharpless, who is considered the key step in this synthesis. Finally, preliminary results of biological tests on optically pure aspartates derivatives showed no toxicity to nerve cells of the rat hippocampus. The study of the inhibitory activity of these derivatives towards transport of glutamate in CNS is currently underway
Sirko, Alexandre. "Enterprise Application Modularity : New Features Related to Visualization and Measurement of Modulatity Within the Enterprise Architecture Analysis Tool (EAAT)." Thesis, KTH, Industriella informations- och styrsystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-141328.
Brothers, Holly M. "Neuroinflammation, Glutamate Regulation and Memory." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1363603410.
Frost, Per. "Utvärdering av den upplevda användbarheten hos CySeMoL och EAAT med hjälp av ramverk för ändamålet och ISO/IEC 25010:2011." Thesis, KTH, Industriella informations- och styrsystem, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-138576.
Dalet, Antoine. "Homéostasie glutamatergique des synapses en calice de l’appareil vestibulaire : implication de plusieurs transporteurs du glutamate de la famille des EAAT." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20115/document.
Glutamate homeostasis in synaptic clefts shape neurotransmission and prevent excitotoxicity. This may be particularly important in the inner ear where there is a continually high rate of neurotransmitter release. In the case of most cochlear and vestibular hair cells, clearance involves the diffusion of glutamate to supporting cells, where it is taken up by EAAT1 (GLAST), a glial glutamate transporter. A similar mechanism is unlikely to work in vestibular type I hair cells because the presence of calyx endings separates supporting cells from the synaptic zone. Based on this arrangement, we postulated that a glutamate transporter must be present in the type I hair cell, the calyx ending, or both. Using whole-cell patch-clamp recordings, we demonstrated that a glutamate-activated anion current blocked by DL-TBOA is expressed in type I hair cells. In situ hybridization and immunohistochemistry revealed that EAAT4 and EAAT5, two glutamate transporters that could support the anion current, are expressed in both type I and type II hair cells. Furthermore, RT-PCR and immunogold investigations confirmed those results and added that although preferentially expressed presynaptically, the transporters may also be present in the postsynaptic calyx membrane. Previously thought to be exclusively expressed in the cerebellum and retina respectively, this thesis work shows that EAAT4 and EAAT5 have a wider distribution. The potential role of these transporters in the glutamatergic homeostasis of the calyx synapse is then discussed
Westerberg, Per. "Enterprise Architecture Analysis : - Astudy of the IT landscape atAstraZeneca." Thesis, KTH, Industriella informations- och styrsystem, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169227.
Sreemantula, Sai Nandini. "Glutamate Transporter 1 in the Central Nervous System: Potential Target for the Treatment of Alcohol Dependence." University of Toledo Health Science Campus / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=mco1333546775.
Roman, Kenny M. "GLT-1 over-expression attenuates visceral nociception by pharmacological and gene therapy approaches." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1332424243.
Rosell, Peter. "Enterprise Architecture Modeling of Core Administrative Systems at KTH : A Modifiability Analysis." Thesis, KTH, Industriella informations- och styrsystem, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99166.
Foster, Joshua B. "Development of Pyridazine-Derivatives for the Treatment of Neurological Disorders." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1545904228813231.
Johansson, Dan. "Empirical test of a tool for cyber security vulnerability assessment." Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-176032.
Denna rapport beskriver en studie vars mål var att verifiera ett modelleringsspråk för datasäkerhet vid namn Predictive, Probabilistic Cyber Security Modelling Language. Detta modelleringsspråk tillsammans med Enterprise Architecture Analysis Tool utgör ett verktyg för datasäkerhetsutvärderingar av systemarkitekturer. För att verifiera exaktheten och mognadsnivån på verktyget så skapades en generisk modell av ett verkligt Supervisory Control And Data Acquisition System-systems arkitektur. Denna modell utvärderades i ett senare skede. Utvärderingsprocessen bestod av ett Turingtest, som är samma metod som användes i en tidigare utvärdering av Predictive, Probabilistic Cyber Security Modelling Languages föregångare Cyber Security Modelling Language. För Turingtestet hölls fem intervjuer med domänexperter inom datasäkerhet. Fyra av dessa fick i uppgift att skapa attackvägar givet ett scenario i den modellerade systemarkitekturen. Attackvägarna som skapades sammanställdes i ett standardiserat formulär för den sista interna företagsexperten inom datasäkerhet att utvärdera. En expertutvärderare fick i uppgift att betygsätta de attackvägar som hade producerats av de fyra experterna och Predictive, Probabilistic Cyber Security Modelling Language. Betygsättningen baserades på hur sannolika de olika attackvägarna uppfattades av den interna experten. Slutsatsen som gjordes var att givet begränsningarna i studien, så producerade Predictive, Probabilistic Cyber Security Modelling Language en datasäkerhetsutvärdering som var likvärdigt sannolik jämfört med de som skapades av mänskliga experter. Resultaten som producerades var också konsistenta med resultaten som producerades av Predictive, Probabilistic Cyber Security Modelling Language föregångare Cyber Security Modelling Language i en tidigare studie. Förslag på kommande studier som skulle komplettera denna studie och stärka resultaten ytterligare introducerades också. Detta examensarbete var ett samarbete mellan ABB Enterprise Software och medlemmarna i teamet bakom Predictive, Probabilistic Cyber Security Modelling Language på ICS på KTH.
Munger, Emily LaRee. "Alteration to Astrocyte Density and Morphology across Mammalia with Specific Attention to Primate Brain Evolution and Aging." Kent State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=kent1594638449298271.
Kim, Seol-Hee. "Acetaminophen Associated Neurotoxicity and its Relevance to Neurodevelopmental Disorders." Scholar Commons, 2017. http://scholarcommons.usf.edu/etd/6717.
Sopjani, Mentor [Verfasser]. "The AMP activated protein kinase in the regulation of sodium coupled transporters (SGLT1, EAAT3 & EAAT4) and eryptosis / von Mentor Sopjani." 2010. http://d-nb.info/100125581X/34.
Melzer, Nico [Verfasser]. "Der Anionenkanal des neuronalen Glutamattransporters EAAT4 / vorgelegt von Nico Melzer." 2006. http://d-nb.info/98360004X/34.
Schniepp, Roman [Verfasser]. "Regulation der exzitatorischen Aminosäure-Transporter EAAT1, EAAT2, EAAT3 und EAAT5 durch die Serum- und Glukokortikoid-abhängige Kinase SGK und die Ubiquitinligase Nedd4-2 / vorgelegt von Roman Schniepp." 2006. http://d-nb.info/98366790X/34.
Weiss, Thorsten [Verfasser]. "Das Expressionsverhalten der glialen Glutamattransporter EAAT1 und EAAT2 sowie von PACAP nach Schädel-Hirntrauma des Menschen / von Thorsten Weiss." 2006. http://d-nb.info/981850995/34.
Yi, Jae-Hyuk. "Les mécanismes excitotoxiques et le rôle de transporteurs de glutamate dans la physiopathologie des traumatismes crâniens = Excitotoxic mechanisms and the role of glutamate transporters in the pathophysiology of traumatic brain injury." Thèse, 2006. http://hdl.handle.net/1866/15364.
Kim, Helena J. "Effects of long-term inhibition of EAAT2 on the excitability of spinal dorsal horn neurons." Master's thesis, 2010. http://hdl.handle.net/10048/1619.
Pannunzio, Marc. "Effets du cuivre (II) sur le transport à haute affinité du glutamate dans des astrocytes en culture : proposition d'un mécanisme physiopathologique de la maladie de Wilson." Thèse, 2003. http://hdl.handle.net/1866/14883.
Fromm, Andrea Heike Lydia [Verfasser]. "Mutationsscreening und alternative Spleivarianten des Glutamattransporters EAAT2 bei amyotropher Lateralsklerose / vorgelegt von Andrea Heike Lydia Fromm." 2008. http://d-nb.info/100069450X/34.
"Design, synthesis and biological evaluation of a family of excitatory amino acid transporter 3 (EAAT3) preferring inhibitors." UNIVERSITY OF MONTANA, 2009. http://pqdtopen.proquest.com/#viewpdf?dispub=3338786.
Chawla, Aarti R. "CaMKII regulation of astrocytic glutamate uptake." Diss., 2016. http://hdl.handle.net/1805/10605.
Glutamate clearance by astrocytes is an essential part of physiological excitatory neurotransmission. Failure to adapt or maintain low levels of glutamate in the central nervous system is associated with multiple acute and chronic neurodegenerative diseases. The primary excitatory amino acid transporters (EAATs) in human astrocytes are EAAT1 and EAAT2 (GLAST and GLT-1 respectively in rodents). While the inhibition of a ubiquitously-expressed serine/threonine protein kinase, the calcium/calmodulindependent kinase (CaMKII) results in diminished glutamate uptake in cultured primary rodent astrocytes, the molecular mechanism underlying this regulation is unknown. In order to delineate this mechanism, we use a heterologous expression model to explore CaMKII regulation of EAAT1 and EAAT2. In transiently transfected HEK293T cells, pharmacological inhibition of CaMKII and overexpression of a dominant-negative version of CaMKII (Asp136Asn) reduces [3H]-glutamate uptake by EAAT1, without altering EAAT2 mediated glutamate uptake. Surprisingly, overexpression of a constitutively active autophosphorylation mutant (Thr287Asp) to increase autonomous CaMKII activity and a mutant incapable of autophosphorylation (Thr287Val) had no effect on either EAAT1 or EAAT2 mediated glutamate uptake. Pulldown of FLAGtagged glutamate transporters suggests CaMKII does not interact with EAAT1 or EAAT2. SPOTS peptide arrays and recombinant GST-fusion proteins of the intracellular N- and C-termini of EAAT1 identified two potential phosphorylation sites at residues Thr26 and Thr37 in the N-terminus. Introducing an Ala (a non-phospho mimetic) but not an Asp (phosphomimetic) at Thr37 diminished EAAT1-mediated glutamate uptake, suggesting that the phosphorylation state of this residue is important for constitutive EAAT1 function. In sum, this is the first report of a glutamate transporter being identified as a direct CaMKII substrate. These findings indicate that CaMKII signaling is a critical driver of homeostatic glutamate uptake by EAAT1. Aberrations in basal CaMKII activity disrupt glutamate uptake, which can perpetuate glutamate-mediated excitotoxicity and result in cellular death.
Ugbode, Christopher I., W. D. Hirst, and Marcus Rattray. "Neuronal influences are necessary to produce mitochondrial co-localization with glutamate transporters in astrocytes." 2014. http://hdl.handle.net/10454/7811.
Abstract Recent evidence suggests that the predominant astrocyte glutamate transporter, GLT-1/ Excitatory Amino Acid Transporter 2 (EAAT2) is associated with mitochondria. We used primary cultures of mouse astrocytes to assess co-localization of GLT-1 with mitochondria, and tested whether the interaction was dependent on neurons, actin polymerization or the kinesin adaptor, TRAK2. Mouse primary astrocytes were transfected with constructs expressing V5-tagged GLT-1, pDsRed1-Mito with and without dominant negative TRAK2. Astrocytes were visualized using confocal microscopy and co-localization was quantified using Volocity software. Image analysis of confocal z-stacks revealed no co-localization between mitochondria and GLT-1 in pure astrocyte cultures. Co-culture of astrocytes with primary mouse cortical neurons revealed more mitochondria in processes and a positive correlation between mitochondria and GLT-1. This co-localization was not further enhanced after neuronal depolarization induced by 1 h treatment with 15 mM K+. In pure astrocytes, a rho kinase inhibitor, Y27632 caused the distribution of mitochondria to astrocyte processes without enhancing GLT-1/mitochondrial co-localization, however, in co-cultures, Y27632 abolished mitochondrial: GLT-1 co-localization. Disrupting potential mitochondrial: kinesin interactions using dominant negative TRAK2 did not alter GLT-1 distribution or GLT-1: mitochondrial co-localization. We conclude that the association between GLT-1 and mitochondria is modest, is driven by synaptic activity and dependent on polymerized actin filaments. Mitochondria have limited co-localization with the glutamate transporter GLT-1 in primary astrocytes in culture. Few mitochondria are in the fine processes where GLT-1 is abundant. It is necessary to culture astrocytes with neurones to drive a significant level of co-localization, but co-localization is not further altered by depolarization, manipulating sodium ion gradients or Na/K ATPase activity.
Ugbode, Christopher I., W. D. Hirst, and Marcus Rattray. "Astrocytes grown in Alvetex® 3 dimensional scaffolds retain a non-reactive phenotype." 2015. http://hdl.handle.net/10454/8062.
Protocols which permit the extraction of primary astrocytes from either embryonic or postnatal mice are well established however astrocytes in culture are different to those in the mature CNS. Three dimensional (3D) cultures, using a variety of scaffolds may enable better phenotypic properties to be developed in culture. We present data from embryonic (E15) and postnatal (P4) murine primary cortical astrocytes grown on coated coverslips or a 3D polystyrene scaffold, Alvetex. Growth of both embryonic and postnatal primary astrocytes in the 3D scaffold changed astrocyte morphology to a mature, protoplasmic phenotype. Embryonic-derived astrocytes in 3D expressed markers of mature astrocytes, namely the glutamate transporter GLT-1 with low levels of the chondroitin sulphate proteoglycans, NG2 and SMC3. Embroynic astrocytes derived in 3D show lower levels of markers of reactive astrocytes, namely GFAP and mRNA levels of LCN2, PTX3, Serpina3n and Cx43. Postnatal-derived astrocytes show few protein changes between 2D and 3D conditions. Our data shows that Alvetex is a suitable scaffold for growth of astrocytes, and with appropriate choice of cells allows the maintenance of astrocytes with the properties of mature cells and a non-reactive phenotype.
BBSRC
Carbone, M., S. Duty, and Marcus Rattray. "Riluzole neuroprotection in a parkinson’s disease model involves suppression of reactive astrocytosis but not GLT-1 regulation." 2012. http://hdl.handle.net/10454/7807.
Background: Riluzole is a neuroprotective drug used in the treatment of motor neurone disease. Recent evidence suggests that riluzole can up-regulate the expression and activity of the astrocyte glutamate transporter, GLT-1. Given that regulation of glutamate transport is predicted to be neuroprotective in Parkinson’s disease, we tested the effect of riluzole in parkinsonian rats which had received a unilateral 6-hydroxydopamine injection into the median forebrain bundle. Results: Rats were treated with intraperitoneal riluzole (4 mg/kg or 8 mg/kg), 1 hour before the lesion then once daily for seven days. Riluzole produced a modest but significant attenuation of dopamine neurone degeneration, assessed by suppression of amphetamine-induced rotations, preservation of tyrosine hydroxylase positive neuronal cell bodies in the substantia nigra pars compacta and attenuation of striatal tyrosine hydroxylase protein loss. Seven days after 6-hydroxydopamine lesion, reactive astrocytosis was observed in the striatum, as determined by increases in expression of glial fibrillary acidic protein, however the glutamate transporter, GLT-1, which is also expressed in astrocytes was not regulated by the lesion. Conclusions: The results confirm that riluzole is a neuroprotective agent in a rodent model of parkinson’s disease. Riluzole administration did not regulate GLT-1 levels but significantly reduced GFAP levels, in the lesioned striatum. Riluzole suppression of reactive astrocytosis is an intriguing finding which might contribute to the neuroprotective effects of this drug.
Peng, Jhan-Jie, and 彭湛傑. "Investigate roles of Drosophila Eaat1-mediated glutamate clearance in the functional integrity of the motor circuit and the formation of the neuromuscular junction." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/02184445433768124130.
國立臺灣大學
生化科學研究所
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Glutamate transmission in CNS is critical for animal behavior. Upon the release of glutamate from synaptic vesicles, it is immediately removed by the surrounding astrocyte. The Excitatory Amino Acid Transporter (Eaat) in astrocyte is majorly responsible for the glutamate clearance in CNS, which ensures the fidelity of neurotransmission and prevents glutamate excitotoxicity. In neurodegenerative diseases, downregulation of Eaat has been repeatedly reported and accumulation of extracellular glutamate due to impaired recycle system accelerates the disease progression. Although how excessive glutamate leads to neuronal death has been widely studied, the influence of glutamate excitotoxicity on neural circuit is still elusive. Here, we use Drosophila larval locomotor circuit to study the role of glia on the glutamate transmission in CNS. From a genetic screen for novel players involved in synaptic formation, we identified a strong hypomorphic Drosophila eaat1 allele which led to strong loss of eaat1, expanded neuromuscular junction, and severe locomotor deficits. The locomotion of Drosophila larva is controlled by the neural circuit called central pattern generator (CPG). Loss of eaat1 resulted in aberrant CPG activity which caused prolonged but less frequent activation of motoneurons. Restoring the expression of eaat1 exclusively in the astrocyte was sufficient to restore the CPG and locomotion defects in eaat1 mutants. Impaired glutamate clearance in loss of eaat1 led to extracellular glutamate accumulation and disrupted the excitatory and inhibitory synaptic signaling in the CPG. Remarkably, reducing the oxidative stress or increasing the excitability of excitatory cholinergic neurons in eaat1 mutants improved both CPG rhythmicity and mobility. Moreover, the irregular CPG firing pattern in loss of eaat1 triggered the ROS/JNK signaling in motorneurons and caused excessive synaptic bouton formation. We demonstrated a non-cell autonomous mechanism to regulate the physiology of motoneurons via Eaat1 in upstream astrocyte.
Winterberg, Markus [Verfasser]. "Der humane Transporter EAAT 3 ist ein Kandidat für die Vermittlung der L-Glutamat-Aufnahme in Plasmodium-falciparum-infizierte Erythrozyten / vorgelegt von Markus Winterberg." 2009. http://d-nb.info/99588112X/34.
Carbone, M., S. Duty, and Marcus Rattray. "Riluzole elevates GLT-1 activity and levels in striatal astrocytes." 2012. http://hdl.handle.net/10454/5907.