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Liu P, Tang N, Meng C, Yin Y, Qiu X, Tan L, Sun Y, Song C, Liu W, Liao Y, Lin SH, Ding C. SLC1A3 facilitates Newcastle disease virus replication by regulating glutamine catabolism. Virulence 2022; 13:1407-1422. [PMID: 35993169 PMCID: PMC9415643 DOI: 10.1080/21505594.2022.2112821] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
As obligate intracellular parasites, viruses rely completely on host metabolic machinery and hijack host nutrients for viral replication. Newcastle disease virus (NDV) causes acute, highly contagious avian disease and functions as an oncolytic agent. NDV efficiently replicates in both chicken and tumour cells. However, how NDV reprograms host cellular metabolism for its efficient replication is still ill-defined. We previously identified a significantly upregulated glutamate transporter gene, solute carrier family 1 member 3 (SLC1A3), during NDV infection via transcriptome analysis. To investigate the potential role of SLC1A3 during NDV infection, we first confirmed the marked upregulation of SLC1A3 in NDV-infected DF-1 or A549 cells through p53 and NF-κB pathways. Knockdown of SLC1A3 inhibited NDV infection. Western blot analysis further confirmed that glutamine, but not glutamate, asparagine, or aspartate, was required for NDV replication. Metabolic flux data showed that NDV promotes the decomposition of glutamine into the tricarboxylic acid cycle. Importantly, the level of glutamate and glutaminolysis were reduced by SLC1A3 knockdown, indicating that SLC1A3 propelled glutaminolysis for glutamate utilization and NDV replication in host cells. Taken together, our data identify that SLC1A3 serves as an important regulator for glutamine metabolism and is hijacked by NDV for its efficient replication during NDV infection. These results improve our understanding of the interaction between NDV and host cellular metabolism and lay the foundation for further investigation of efficient vaccines.
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Affiliation(s)
- Panrao Liu
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Ning Tang
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China.,College of Animal Science and Technology, Guangxi University, Nanning, P.R. China
| | - Chunchun Meng
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Yuncong Yin
- College of Veterinary Medicine, Yangzhou University, Yangzhou, P.R. China
| | - Xusheng Qiu
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Lei Tan
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Yingjie Sun
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Cuiping Song
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Weiwei Liu
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Ying Liao
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China
| | - Shu-Hai Lin
- State Key Laboratory of Cellular Stress Biology, Innovation Center for Cell Signaling Network, School of Life Sciences, Xiamen University, Xiamen, P.R. China
| | - Chan Ding
- Department of Avian Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Science, Shanghai, P.R. China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, P.R. China
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2
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Cougnoux A, Yerger JC, Fellmeth M, Serra-Vinardell J, Navid F, Wassif CA, Cawley NX, Porter FD. Reduction of glutamate neurotoxicity: A novel therapeutic approach for Niemann-Pick disease, type C1. Mol Genet Metab 2021; 134:330-336. [PMID: 34802899 PMCID: PMC8767495 DOI: 10.1016/j.ymgme.2021.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 10/19/2022]
Abstract
Niemann-Pick disease, type C1 is a progressive, lethal, neurodegenerative disorder due to endolysosomal storage of unesterified cholesterol. Cerebellar ataxia, as a result of progressive loss of cerebellar Purkinje neurons, is a major symptom of Nieman-Pick disease, type C1. Comparing single cell RNAseq data from control (Npc1+/+) and mutant (Npc1-/-) mice, we observed significantly decreased expression of Slc1a3 in Npc1-/- astrocytes. Slc1a3 encodes a glutamate transporter (GLAST, EAAT1) which functions to decrease glutamate concentrations in the post synaptic space after neuronal firing. Glutamate is an excitatory neurotransmitter and elevated extracellular levels of glutamate can be neurotoxic. Impaired EAAT1 function underlies type-6 episodic ataxia, a rare disorder with progressive cerebellar dysfunction, thus suggesting that impaired glutamate uptake in Niemann-Pick disease, type C1 could contribute to disease progression. We now show that decreased expression of Slc1a3 in Npc1-/- mice has functional consequences that include decreased surface protein expression and decreased glutamate uptake by Npc1-/- astrocytes. To test whether glutamate neurotoxicity plays a role in Niemann-Pick disease, type C1 progression, we treated NPC1 deficient mice with ceftriaxone and riluzole. Ceftriaxone is a β-lactam antibiotic that is known to upregulate the expression of Slc1a2, an alternative glial glutamate transporter. Although ceftriaxone increased Slc1a2 expression, we did not observe a treatment effect in NPC1 mutant mice. Riluzole is a glutamate receptor antagonist that inhibits postsynaptic glutamate receptor signaling and reduces the release of glutamate. We found that treatment with riluzole increased median survival in Npc1-/- by 12%. Given that riluzole is an approved drug for the treatment of amyotrophic lateral sclerosis, repurposing of this drug may provide a novel therapeutic approach to decrease disease progression in Niemann-Pick disease type, C1 patients.
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Affiliation(s)
- Antony Cougnoux
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Julia C Yerger
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Mason Fellmeth
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Jenny Serra-Vinardell
- Human Biochemical Genetics Section, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Fatemeh Navid
- Pediatric Translational Research Branch, National Institute of Arthritis and Musculoskeletal and Skin Disease, National Institutes of Health, Bethesda, MD, USA
| | - Christopher A Wassif
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Niamh X Cawley
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Forbes D Porter
- Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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Xu L, Chen J, Jia L, Chen X, Awaleh Moumin F, Cai J. SLC1A3 promotes gastric cancer progression via the PI3K/AKT signalling pathway. J Cell Mol Med 2020; 24:14392-14404. [PMID: 33145952 PMCID: PMC7753768 DOI: 10.1111/jcmm.16060] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Revised: 09/27/2020] [Accepted: 10/19/2020] [Indexed: 12/24/2022] Open
Abstract
Gastric cancer is a major cause of mortality worldwide. The glutamate/aspartate transporter SLC1A3 has been implicated in tumour metabolism and progression, but the roles of SLC1A3 in gastric cancer remain unclear. We used bioinformatics approaches to analyse the expression of SLC1A3 and its role in gastric cancer. The expression levels of SLC1A3 were examined using RT‐qPCR and Western bolting. SLC1A3 overexpressing and knock‐down cell lines were constructed, and the cell viability was evaluated. Glucose consumption, lactate excretion and ATP levels were determined. The roles of SLC1A3 in tumour growth were evaluated using a xenograft tumour growth model. SLC1A3 was found to be overexpressed in gastric cancer, and this overexpression was associated with poor prognosis. In vitro and in vivo assays showed that SLC1A3 affected glucose metabolism and promoted gastric cancer growth. GSEA analysis suggested that SLC1A3 was positively associated with the up‐regulation of the PI3K/AKT pathway. SLC1A3 overexpression activated the PI3K/AKT pathway and up‐regulated GLUT1, HK II and LDHA expression. The PI3K/AKT inhibitor LY294002 prevented SLC1A3‐induced glucose metabolism and cell proliferation. Our findings indicate that SLC1A3 promotes gastric cancer progression via the PI3K/AKT signalling pathway. SLC1A3 is therefore a potential therapeutic target in gastric cancer.
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Affiliation(s)
- Liyi Xu
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jiamin Chen
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Litao Jia
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiao Chen
- Emergency Department, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Faycal Awaleh Moumin
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jianting Cai
- Department of Gastroenterology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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4
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Abstract
The term Episodic Ataxias (EA) was originally used for a few autosomal dominant diseases, characterized by attacks of cerebellar dysfunction of variable duration and frequency, often accompanied by other ictal and interictal signs. The original group subsequently grew to include other very rare EAs, frequently reported in single families, for some of which no responsible gene was found. The clinical spectrum of these diseases has been enormously amplified over time. In addition, episodes of ataxia have been described as phenotypic variants in the context of several different disorders. The whole group is somewhat confused, since a strong evidence linking the mutation to a given phenotype has not always been established. In this review we will collect and examine all instances of ataxia episodes reported so far, emphasizing those for which the pathophysiology and the clinical spectrum is best defined.
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Affiliation(s)
- Paola Giunti
- Laboratory of Neurogenetics, Department of Molecular Neuroscience, UCL Institute of Neurology, London WC2N 5DU, UK
- Correspondence: (P.G.); (M.F.)
| | - Elide Mantuano
- Laboratory of Neurogenetics, Institute of Translational Pharmacology, National Research Council of Italy, 00133 Rome, Italy;
| | - Marina Frontali
- Laboratory of Neurogenetics, Institute of Translational Pharmacology, National Research Council of Italy, 00133 Rome, Italy;
- Correspondence: (P.G.); (M.F.)
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Ghosh M, Ali A, Joshi S, Srivastava AS, Tapadia MG. SLC1A3 C3590T but not BDNF G196A is a predisposition factor for stress as well as depression, in an adolescent eastern Indian population. BMC Med Genet 2020; 21:53. [PMID: 32171272 PMCID: PMC7071583 DOI: 10.1186/s12881-020-0993-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/04/2020] [Indexed: 01/19/2023]
Abstract
Background Adolescence is a distinctive stage of various changes and is noted as peak age for onset of many psychiatric disorders, especially linked to stress and depression. Several genetic variations are being increasingly known to be linked with stress and depression. The polymorphisms in two such genes, the BDNF and SLC1A3, have been reported to be linked with either depression/stress or with suicidal behaviour. These genes have not been validated in Indian population, and therefore there is a need to investigate these genes in Indian population. The present study was undertaken to test whether the known polymorphisms SLC1A3 C3590T, SLC1A3 C869G and BDNF G196A are associated or not with stress or depression in an eastern Indian population. Methods A case-control association study was performed with 108 cases having variable levels of stress and depression and 205 matched controls. Detection of stress and depression was done by using standard instruments as PSS and CES-D, respectively and demographic profile was obtained for each individual on the basis of personal data sheet. Genotyping for the selected polymorphisms was performed by PCR followed by restriction digestion. Results The SNP SLC1A3 C3590T was found to be associated with stress and depression (p = 0.0042, OR = 2.072). Therefore, the T allele increases the risk by more than two folds for stress and depression in the present population. The other allele of SLC1A3, G869C, as well as BDNF G196A were not associated with stress or depression in the population studied. Conclusion SLC1A3 C3590T is a predisposition factor for stress and depression in an eastern Indian population, whereas SLC1A3 G869C and BDNF G196A were not found to be a risk factor. Therefore, presence of T allele of SLC1A3 C3590T, may predict the development of stress and depression in an individual. This may also help in the understanding of pathophysiology of the disease. However, these findings warrant a wider study in Indian populations and would be of significance in understanding the predisposition of stress and depression in this population.
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Affiliation(s)
- Madhumita Ghosh
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
| | - Akhtar Ali
- Centre for Genetic Disorders, Faculty of Science, Banaras Hindu University, Varanasi, 221005, India
| | - Shobhna Joshi
- Department of Psychology, Faculty of Arts, Banaras Hindu University, Varanasi, 221005, India
| | - Adya Shankar Srivastava
- Department of Psychiatry, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005, India
| | - Madhu G Tapadia
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
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Sun J, Nagel R, Zaal EA, Ugalde AP, Han R, Proost N, Song JY, Pataskar A, Burylo A, Fu H, Poelarends GJ, van de Ven M, van Tellingen O, Berkers CR, Agami R. SLC1A3 contributes to L-asparaginase resistance in solid tumors. EMBO J 2019; 38:e102147. [PMID: 31523835 PMCID: PMC6826201 DOI: 10.15252/embj.2019102147] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 12/12/2022] Open
Abstract
L‐asparaginase (ASNase) serves as an effective drug for adolescent acute lymphoblastic leukemia. However, many clinical trials indicated severe ASNase toxicity in patients with solid tumors, with resistant mechanisms not well understood. Here, we took a functional genetic approach and identified SLC1A3 as a novel contributor to ASNase resistance in cancer cells. In combination with ASNase, SLC1A3 inhibition caused cell cycle arrest or apoptosis, and myriads of metabolic vulnerabilities in tricarboxylic acid (TCA) cycle, urea cycle, nucleotides biosynthesis, energy production, redox homeostasis, and lipid biosynthesis. SLC1A3 is an aspartate and glutamate transporter, mainly expressed in brain tissues, but high expression levels were also observed in some tumor types. Here, we demonstrate that ASNase stimulates aspartate and glutamate consumptions, and their refilling through SLC1A3 promotes cancer cell proliferation. Lastly, in vivo experiments indicated that SLC1A3 expression promoted tumor development and metastasis while negating the suppressive effects of ASNase by fueling aspartate, glutamate, and glutamine metabolisms despite of asparagine shortage. Altogether, our findings identify a novel role for SLC1A3 in ASNase resistance and suggest that restrictive aspartate and glutamate uptake might improve ASNase efficacy with solid tumors.
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Affiliation(s)
- Jianhui Sun
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, The Netherlands.,Department of Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Remco Nagel
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Esther A Zaal
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | - Alejandro Piñeiro Ugalde
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Ruiqi Han
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, The Netherlands.,Department of Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Natalie Proost
- Preclinical Intervention Unit and Pharmacology Unit of the Mouse Clinic for Cancer and Ageing (MCCA), The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Ji-Ying Song
- Division of Experimental Animal Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Abhijeet Pataskar
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Artur Burylo
- Division of Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Haigen Fu
- Department of Chemical and Pharmaceutical Biology, University of Groningen, Groningen, The Netherlands
| | - Gerrit J Poelarends
- Department of Chemical and Pharmaceutical Biology, University of Groningen, Groningen, The Netherlands
| | - Marieke van de Ven
- Preclinical Intervention Unit and Pharmacology Unit of the Mouse Clinic for Cancer and Ageing (MCCA), The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Olaf van Tellingen
- Division of Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Celia R Berkers
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands.,Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Reuven Agami
- Division of Oncogenomics, Oncode Institute, The Netherlands Cancer Institute, Amsterdam, The Netherlands.,Department of Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
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7
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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van Amen-Hellebrekers CJ, Jansen S, Pfundt R, Schuurs-Hoeijmakers JH, Koolen DA, Marcelis CL, de Leeuw N, de Vries BB. Duplications of SLC1A3: Associated with ADHD and autism. Eur J Med Genet 2016; 59:373-6. [PMID: 27296938 DOI: 10.1016/j.ejmg.2016.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 06/07/2016] [Accepted: 06/09/2016] [Indexed: 11/21/2022]
Abstract
We report four patients with a similar gain in 5p13.2 encompassing a single gene: SLC1A3. Behavioural problems resembling ADHD and/or autism-like features are observed which is in line with the glial glutamate transporter role of SLC1A3. We consider an association between SLC1A3 and the behavioural problems which can also be considered a contributing factor to behavioural problems in larger duplications overlapping the 5p13 microduplication syndrome region.
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9
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Abousaab A, Warsi J, Elvira B, Lang F. Caveolin-1 Sensitivity of Excitatory Amino Acid Transporters EAAT1, EAAT2, EAAT3, and EAAT4. J Membr Biol 2015; 249:239-49. [PMID: 26690923 DOI: 10.1007/s00232-015-9863-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022]
Abstract
Excitatory amino acid transporters EAAT1 (SLC1A3), EAAT2 (SLC1A2), EAAT3 (SLC1A1), and EAAT4 (SLC1A6) serve to clear L-glutamate from the synaptic cleft and are thus important for the limitation of neuronal excitation. EAAT3 has previously been shown to form complexes with caveolin-1, a major component of caveolae, which participate in the regulation of transport proteins. The present study explored the impact of caveolin-1 on electrogenic transport by excitatory amino acid transporter isoforms EAAT1-4. To this end cRNA encoding EAAT1, EAAT2, EAAT3, or EAAT4 was injected into Xenopus oocytes without or with additional injection of cRNA encoding caveolin-1. The L-glutamate (2 mM)-induced inward current (I Glu) was taken as a measure of glutamate transport. As a result, I Glu was observed in EAAT1-, EAAT2-, EAAT3-, or EAAT4-expressing oocytes but not in water-injected oocytes, and was significantly decreased by coexpression of caveolin-1. Caveolin-1 decreased significantly the maximal transport rate. Treatment of EAATs-expressing oocytes with brefeldin A (5 µM) was followed by a decrease in conductance, which was similar in oocytes expressing EAAT together with caveolin-1 as in oocytes expressing EAAT1-4 alone. Thus, caveolin-1 apparently does not accelerate transporter protein retrieval from the cell membrane. In conclusion, caveolin-1 is a powerful negative regulator of the excitatory glutamate transporters EAAT1, EAAT2, EAAT3, and EAAT4.
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Affiliation(s)
- Abeer Abousaab
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Jamshed Warsi
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Bernat Elvira
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Florian Lang
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany.
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10
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Kipfer S, Strupp M. The Clinical Spectrum of Autosomal-Dominant Episodic Ataxias. Mov Disord Clin Pract 2014; 1:285-290. [PMID: 30713867 DOI: 10.1002/mdc3.12075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 06/16/2014] [Accepted: 06/20/2014] [Indexed: 11/06/2022] Open
Abstract
Autosomal-dominant episodic ataxias (EAs) represent a clinically and genetically heterogeneous group of disorders characterized by recurrent episodes of cerebellar ataxia (CA). Ataxia episodes are usually of short duration and often triggered by specific stimuli. There are currently seven classified subtypes of EA. EA types 1 and 2 have the highest prevalence and are therefore the clinically most relevant. Between attacks, EA 1 is associated with myokymia. In EA 2, often an interictal downbeat nystagmus with other cerebellar ocular dysfunctions is present; patients with EA 2 may display slowly progessive ataxia and vermian atrophy. EA 1 and 2 are both channelopathies, affecting the potassium channel gene, KCNA1, in EA 1 and the PQ calcium channel-encoding gene, CACNA1A, in EA 2. The types EA 3 to 7 are very rare and have to be further elucidated. Here, we review the historical, clinical, and genetic aspects of autosomal-dominant EAs and their current treatment, focusing on EA 1 and 2.
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Affiliation(s)
- Stefan Kipfer
- Department of Neurology Kantonsspital Olten Switzerland
| | - Michael Strupp
- Department of Neurology and German Center for Vertigo and Balance Disorders University Hospital Munich Munich Germany
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