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Pesquisa : D12.776.157.530.200.500.500 [Categoria DeCS]
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[PMID]:27900521
[Au] Autor:Feral CC; Tissot FS; Tosello L; Fakhry N; Sebag F; Pacak K; Taïeb D
[Ad] Endereço:INSERM U1081, Institute for Research on Cancer and Aging of Nice (IRCAN), Nice, France.
[Ti] Título:F-fluorodihydroxyphenylalanine PET/CT in pheochromocytoma and paraganglioma: relation to genotype and amino acid transport system L.
[So] Source:Eur J Nucl Med Mol Imaging;44(5):812-821, 2017 May.
[Is] ISSN:1619-7089
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:PURPOSE: F-FDOPA is a highly sensitive and specific radiopharmaceutical for pheochromocytoma and paraganglioma (PPGL) imaging. However, F-FDOPA might be falsely negative in these tumors, especially those related to mutations in succinate dehydrogenase genes (SDHx). The aim of the present study was to evaluate the relationship between expression of L-DOPA transporters and F-FDOPA PET imaging results in PPGL. METHODS: From 2007 to 2015, 175 patients with non-metastatic PPGL were evaluated by F-FDOPA PET/CT for initial diagnosis/staging and follow-up. F-FDOPA PET/CT was considered as falsely negative for at least one lesion in 10/126 (8%) patients (two sporadic, six SDHD, two SDHB PPGLs). The mRNA and protein expression levels of CD98hc and LATs were evaluated in samples with different genetic backgrounds and imaging phenotypes. The qRT-PCR and immunohistochemical analyses were performed in 14 and 16 tumor samples, respectively. RESULTS: The SDHx mutated samples exhibited a significant decrease in mRNA expression of LAT3 when compared to sporadic PPGLs (P = 0.042). There was also a statistical trend toward decreased CD98hc (P = 0.147) and LAT4 (P = 0.012) levels in SDHx vs sporadic PPGLs. No difference was observed for LAT1/LAT2 mRNA levels. LAT1 protein was expressed in 15 out of 16 (93.75%) SDHx tumors, regardless of the F-FDOPA positivity. LAT1 and CD98hc were co-expressed in 6/8 F-FDOPA-negative PPGLs. In contrast, in one case with absence of LAT1/CD98hc, F-FDOPA uptake was positive and attributed to LAT4 expression. CONCLUSIONS: We conclude that down-regulation of LAT1/CD98hc cannot explain the imaging phenotype of SDHx-related PPGLs. A reduced activity of LAT1 remains the primary hypothesis possibly due to a modification of intracellular amino acid content which may reduce F-FDOPA uptake.
[Mh] Termos MeSH primário: Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem
Sistema L de Transporte de Aminoácidos/genética
Di-Hidroxifenilalanina/análogos & derivados
Genótipo
Paraganglioma/diagnóstico por imagem
Feocromocitoma/diagnóstico por imagem
Tomografia Computadorizada com Tomografia por Emissão de Pósitrons
[Mh] Termos MeSH secundário: Neoplasias das Glândulas Suprarrenais/genética
Idoso
Reações Falso-Negativas
Feminino
Cadeia Pesada da Proteína-1 Reguladora de Fusão/genética
Regulação Neoplásica da Expressão Gênica
Seres Humanos
Mutação
Paraganglioma/genética
Feocromocitoma/genética
RNA Mensageiro/genética
RNA Mensageiro/metabolismo
Succinato Desidrogenase/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acid Transport System L); 0 (Fusion Regulatory Protein 1, Heavy Chain); 0 (RNA, Messenger); 2C598205QX (fluorodopa F 18); 63-84-3 (Dihydroxyphenylalanine); EC 1.3.99.1 (Succinate Dehydrogenase)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161201
[St] Status:MEDLINE
[do] DOI:10.1007/s00259-016-3586-z


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[PMID]:27465934
[Au] Autor:Ohshima Y; Kaira K; Yamaguchi A; Oriuchi N; Tominaga H; Nagamori S; Kanai Y; Yokobori T; Miyazaki T; Asao T; Tsushima Y; Kuwano H; Ishioka NS
[Ad] Endereço:Department of Radiation-Applied Biology Research, Quantum Beam Science Research Directorate, National Institutes for Quantum and Radiological Science and Technology, Takasaki, Japan. b16gradmmptimp@yahoo.co.jp.
[Ti] Título:Efficacy of system l amino acid transporter 1 inhibition as a therapeutic target in esophageal squamous cell carcinoma.
[So] Source:Cancer Sci;107(10):1499-1505, 2016 Oct.
[Is] ISSN:1349-7006
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:System l amino acid transporter 1 (LAT1) is highly expressed in various types of human cancer, and contributes to cancer growth and survival. Recently, we have shown that LAT1 expression is closely related to the growth and aggressiveness of esophageal cancer, and is an independent marker of poor prognosis. However, it remains unclear whether LAT1 inhibition could suppress esophageal cancer growth. In this study, we investigated the tumor-suppressive effects of the inhibition of LAT1. Both LAT1 and CD98, which covalently associates to LAT1 on the membrane, were expressed in human esophageal cancer cell lines KYSE30 and KYSE150. Quantitative PCR analysis showed that the expression of LAT1 was much higher than other subtypes of LAT. A selective inhibitor of LAT, 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH), suppressed cellular uptake of l- C-leucine and cell proliferation in a dose-dependent manner. It also suppressed phosphorylation of mammalian target of rapamycin, 4E-BP1, and p70S6K protein, and induced cell cycle arrest at G phase. These results suggest that suppression of both mammalian target of rapamycin signaling and cell cycle progression is involved in BCH-induced growth inhibition. In tumor-bearing mice, daily treatment with BCH significantly delayed tumor growth and decreased glucose metabolism, indicating that LAT1 inhibition potentially suppresses esophageal cancer growth in vivo. Thus, our results suggest that LAT1 inhibition could be a promising molecular target for the esophageal cancer therapy.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/antagonistas & inibidores
Antineoplásicos/farmacologia
Carcinoma de Células Escamosas/metabolismo
Neoplasias Esofágicas/metabolismo
[Mh] Termos MeSH secundário: Sistema L de Transporte de Aminoácidos/genética
Sistema L de Transporte de Aminoácidos/metabolismo
Aminoácidos/metabolismo
Animais
Antineoplásicos/administração & dosagem
Transporte Biológico/efeitos dos fármacos
Carcinoma de Células Escamosas/tratamento farmacológico
Carcinoma de Células Escamosas/genética
Carcinoma de Células Escamosas/patologia
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos
Linhagem Celular Tumoral
Proliferação Celular/efeitos dos fármacos
Modelos Animais de Doenças
Neoplasias Esofágicas/tratamento farmacológico
Neoplasias Esofágicas/genética
Neoplasias Esofágicas/patologia
Proteína-1 Reguladora de Fusão/genética
Proteína-1 Reguladora de Fusão/metabolismo
Perfilação da Expressão Gênica
Seres Humanos
Lactato Desidrogenases/metabolismo
Masculino
Camundongos
Terapia de Alvo Molecular
Transdução de Sinais/efeitos dos fármacos
Serina-Treonina Quinases TOR/metabolismo
Transcriptoma
Ensaios Antitumorais Modelo de Xenoenxerto
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acid Transport System L); 0 (Amino Acids); 0 (Antineoplastic Agents); 0 (Fusion Regulatory Protein-1); EC 1.1.- (Lactate Dehydrogenases); EC 2.7.1.1 (TOR Serine-Threonine Kinases)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160729
[St] Status:MEDLINE
[do] DOI:10.1111/cas.13021


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[PMID]:26647387
[Au] Autor:Cheng Q; Beltran VD; Chan SM; Brown JR; Bevington A; Herbert TP
[Ad] Endereço:Research School of BiologyAustralian National University, Acton, Australia.
[Ti] Título:System-L amino acid transporters play a key role in pancreatic ß-cell signalling and function.
[So] Source:J Mol Endocrinol;56(3):175-87, 2016 04.
[Is] ISSN:1479-6813
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The branched-chain amino acids (BCAA) leucine, isoleucine and valine, are essential amino acids that play a critical role in cellular signalling and metabolism. They acutely stimulate insulin secretion and activate the regulatory serine/threonine kinase mammalian target of rapamycin complex 1 (mTORC1), a kinase that promotes increased ß-cell mass and function. The effects of BCAA on cellular function are dependent on their active transport into the mammalian cells via amino acid transporters and thus the expression and activity of these transporters likely influence ß-cell signalling and function. In this report, we show that the System-L transporters are required for BCAA uptake into clonal ß-cell lines and pancreatic islets, and that these are essential for signalling to mTORC1. Further investigation revealed that the System-L amino acid transporter 1 (LAT1) is abundantly expressed in the islets, and that knockdown of LAT1 using siRNA inhibits mTORC1 signalling, leucine-stimulated insulin secretion and islet cell proliferation. In summary, we show that the LAT1 is required for regulating ß-cell signalling and function in islets and thus may be a novel pharmacological/nutritional target for the treatment and prevention of type 2 diabetes.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/metabolismo
Células Secretoras de Insulina/metabolismo
Transdução de Sinais
[Mh] Termos MeSH secundário: Sistema L de Transporte de Aminoácidos/genética
Animais
Linhagem Celular Tumoral
Proliferação Celular
Expressão Gênica
Insulina/metabolismo
Ilhotas Pancreáticas/metabolismo
Transportador 1 de Aminoácidos Neutros Grandes/metabolismo
Leucina/metabolismo
Masculino
Alvo Mecanístico do Complexo 1 de Rapamicina
Complexos Multiproteicos/metabolismo
Ratos
Serina-Treonina Quinases TOR/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Amino Acid Transport System L); 0 (Insulin); 0 (Large Neutral Amino Acid-Transporter 1); 0 (Multiprotein Complexes); EC 2.7.1.1 (TOR Serine-Threonine Kinases); EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 1); GMW67QNF9C (Leucine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151210
[St] Status:MEDLINE
[do] DOI:10.1530/JME-15-0212


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[PMID]:26305885
[Au] Autor:Zevenbergen C; Meima ME; Lima de Souza EC; Peeters RP; Kinne A; Krause G; Visser WE; Visser TJ
[Ad] Endereço:Department of Internal Medicine and Rotterdam Thyroid Center (C.Z., M.E.M., E.C.L.d.S., R.P.P., W.E.V., T.J.V.), Erasmus University Medical Center, 3015 CN, Rotterdam, The Netherlands; and Department of Nuclear Magnetic Resonance-Supported Structural Biology (A.K., G.K.), Leibniz-Institut für Moleku
[Ti] Título:Transport of Iodothyronines by Human L-Type Amino Acid Transporters.
[So] Source:Endocrinology;156(11):4345-55, 2015 Nov.
[Is] ISSN:1945-7170
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Thyroid hormone (TH) transporters facilitate cellular TH influx and efflux, which is paramount for normal physiology. The L-type amino acid transporters LAT1 and LAT2 are known to facilitate TH transport. However, the role of LAT3, LAT4, and LAT5 is still unclear. Therefore, the aim of this study was to further characterize TH transport by LAT1 and LAT2 and to explore possible TH transport by LAT3, LAT4, and LAT5. FLAG-LAT1-5 constructs were transiently expressed in COS1 cells. LAT1 and LAT2 were cotransfected with the CD98 heavy chain. Cellular transport was measured using 10 nM (125)I-labeled T4, T3, rT3, 3,3'-T2, and 10 µM [(125)I]3'-iodotyrosine (MIT) as substrates. Intracellular metabolism of these substrates was determined in cells cotransfected with either of the LATs with type 1 or type 3 deiodinase. LAT1 facilitated cellular uptake of all substrates and LAT2 showed a net uptake of T3, 3,3'-T2, and MIT. Expression of LAT3 or LAT4 did not affect transport of T4 and T3 but resulted in the decreased cellular accumulation of 3,3'-T2 and MIT. LAT5 did not facilitate the transport of any substrate. Cotransfection with LAT3 or LAT4 strongly diminished the cellular accumulation of 3,3'-T2 and MIT by LAT1 and LAT2. These data were confirmed by metabolism studies. LAT1 and LAT2 show distinct preferences for the uptake of the different iodocompounds, whereas LAT3 and LAT4 specifically facilitate the 3,3'-T2 and MIT efflux. Together our findings suggest that different sets of transporters with specific influx or efflux capacities may cooperate to regulate the cellular thyroid state.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/metabolismo
Hormônios Tireóideos/metabolismo
[Mh] Termos MeSH secundário: Animais
Transporte Biológico
Células COS
Cercopithecus aethiops
Seres Humanos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acid Transport System L); 0 (Thyroid Hormones)
[Em] Mês de entrada:1602
[Cu] Atualização por classe:151017
[Lr] Data última revisão:
151017
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:150826
[St] Status:MEDLINE
[do] DOI:10.1210/en.2015-1140


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[PMID]:26125295
[Au] Autor:Zhen H; Nakamura K; Kitaura Y; Kadota Y; Ishikawa T; Kondo Y; Xu M; Shimomura Y
[Ad] Endereço:a Laboratory of Nutritional Biochemistry, Department of Applied Molecular Biosciences , Graduate School of Bioagricultural Sciences, Nagoya University , Nagoya , Japan.
[Ti] Título:Regulation of the plasma amino acid profile by leucine via the system L amino acid transporter.
[So] Source:Biosci Biotechnol Biochem;79(12):2057-62, 2015.
[Is] ISSN:1347-6947
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Plasma concentrations of amino acids reflect the intracellular amino acid pool in mammals. However, the regulatory mechanism requires clarification. In this study, we examined the effect of leucine administration on plasma amino acid profiles in mice with and without the treatment of 2-aminobicyclo-(2,2,1)-heptane-2-carboxylic acid (BCH) or rapamycin as an inhibitor of system L or mammalian target of rapamycin complex 1, respectively. The elevation of plasma leucine concentration after leucine administration was associated with a significant decrease in the plasma concentrations of isoleucine, valine, methionine, phenylalanine, and tyrosine; BCH treatment almost completely blocked the leucine-induced decrease in plasma amino acid concentrations. Rapamycin treatment had much less effects on the actions of leucine than BCH treatment. These results suggest that leucine regulates the plasma concentrations of branched-chain amino acids, methionine, phenylalanine, and tyrosine, and that system L amino acid transporters are involved in the leucine action.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/metabolismo
Aminoácidos/sangue
Leucina/farmacologia
[Mh] Termos MeSH secundário: Sistema L de Transporte de Aminoácidos/antagonistas & inibidores
Aminoácidos Cíclicos/farmacologia
Animais
Relação Dose-Resposta a Droga
Leucina/administração & dosagem
Masculino
Alvo Mecanístico do Complexo 1 de Rapamicina
Camundongos
Complexos Multiproteicos/antagonistas & inibidores
Complexos Multiproteicos/metabolismo
Sirolimo/farmacologia
Serina-Treonina Quinases TOR/antagonistas & inibidores
Serina-Treonina Quinases TOR/metabolismo
Fatores de Tempo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acid Transport System L); 0 (Amino Acids); 0 (Amino Acids, Cyclic); 0 (Multiprotein Complexes); 20448-79-7 (2-aminobicyclo(2,2,1)heptane-2-carboxylic acid); EC 2.7.1.1 (TOR Serine-Threonine Kinases); EC 2.7.11.1 (Mechanistic Target of Rapamycin Complex 1); GMW67QNF9C (Leucine); W36ZG6FT64 (Sirolimus)
[Em] Mês de entrada:1608
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150701
[St] Status:MEDLINE
[do] DOI:10.1080/09168451.2015.1060845


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[PMID]:26050671
[Au] Autor:Gaccioli F; Aye IL; Roos S; Lager S; Ramirez VI; Kanai Y; Powell TL; Jansson T
[Ad] Endereço:Department of Obstetrics and Gynaecology, University of Cambridge, Cambridge, UK. fg327@medschl.cam.ac.uk.
[Ti] Título:Expression and functional characterisation of System L amino acid transporters in the human term placenta.
[So] Source:Reprod Biol Endocrinol;13:57, 2015 Jun 09.
[Is] ISSN:1477-7827
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: System L transporters LAT1 (SLC7A5) and LAT2 (SLC7A8) mediate the uptake of large, neutral amino acids in the human placenta. Many System L substrates are essential amino acids, thus representing crucial nutrients for the growing fetus. Both LAT isoforms are expressed in the human placenta, but the relative contribution of LAT1 and LAT2 to placental System L transport and their subcellular localisation are not well established. Moreover, the influence of maternal body mass index (BMI) on placental System L amino acid transport is poorly understood. Therefore the aims of this study were to determine: i) the relative contribution of the LAT isoforms to System L transport activity in primary human trophoblast (PHT) cells isolated from term placenta; ii) the subcellular localisation of LAT transporters in human placenta; and iii) placental expression and activity of System L transporters in response to maternal overweight/obesity. METHODS: System L mediated leucine uptake was measured in PHT cells after treatment with si-RNA targeting LAT1 and/or LAT2. The localisation of LAT isoforms was studied in isolated microvillous plasma membranes (MVM) and basal membranes (BM) by Western blot analysis. Results were confirmed by immunohistochemistry in sections of human term placenta. Expression and activity System L transporters was measured in isolated MVM from women with varying pre-pregnancy BMI. RESULTS: Both LAT1 and LAT2 isoforms contribute to System L transport activity in primary trophoblast cells from human term placenta. LAT1 and LAT2 transporters are highly expressed in the MVM of the syncytiotrophoblast layer at term. LAT2 is also localised in the basal membrane and in endothelial cells lining the fetal capillaries. Measurements in isolated MVM vesicles indicate that System L transporter expression and activity is not influenced by maternal BMI. CONCLUSIONS: LAT1 and LAT2 are present and functional in the syncytiotrophoblast MVM, whereas LAT2 is also expressed in the BM and in the fetal capillary endothelium. In contrast to placental System A and beta amino acid transporters, MVM System L activity is unaffected by maternal overweight/obesity.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/metabolismo
Sobrepeso/metabolismo
Placenta/metabolismo
Trofoblastos/metabolismo
[Mh] Termos MeSH secundário: Adulto
Sistema L de Transporte de Aminoácidos/genética
Feminino
Seres Humanos
Obesidade/genética
Obesidade/metabolismo
Sobrepeso/genética
Gravidez
Nascimento a Termo/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL
[Nm] Nome de substância:
0 (Amino Acid Transport System L)
[Em] Mês de entrada:1603
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150609
[St] Status:MEDLINE
[do] DOI:10.1186/s12958-015-0054-8


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[PMID]:24901243
[Au] Autor:Kleppa MJ; Erlenwein SV; Darashchonak N; von Kaisenberg CS; von Versen-Höynck F
[Ad] Endereço:Department of Obstetrics and Gynecology, Hannover Medical School, Hannover, Germany.
[Ti] Título:Hypoxia and the anticoagulants dalteparin and acetylsalicylic acid affect human placental amino acid transport.
[So] Source:PLoS One;9(6):e99217, 2014.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Anticoagulants, e.g. low-molecular weight heparins (LMWHs) and acetylsalicylic acid (ASA) are prescribed to women at risk for pregnancy complications that are associated with impaired placentation and placental hypoxia. Beyond their role as anticoagulants these compounds exhibit direct effects on trophoblast but their impact on placental function is unknown. The amino acid transport systems A and L, which preferably transfer essential amino acids, are well-described models to study placental nutrient transport. We aimed to examine the effect of hypoxia, LMWHs and ASA on the activity of the placental amino acid transport systems A and L and associated signalling mechanisms. METHODS: The uptake of C14-MeAIB (system A) or H3-leucin (system L) was investigated after incubation of primary villous fragments isolated from term placentas. Villous tissue was incubated at 2% O2 (hypoxia), 8% O2 and standard culture conditions (21% O2) or at 2% O2 and 21% O2 with dalteparin or ASA. Activation of the JAK/STAT or mTOR signalling pathways was determined by Western analysis of total and phosphorylated STAT3 or Raptor. RESULTS: Hypoxia decreased system A mediated MeAIB uptake and increased system L mediated leucine uptake compared to standard culture conditions (21% O2). This was accompanied by an impairment of STAT3 and a stimulation of Raptor signalling. System L activity increased at 8% O2. Dalteparin treatment reduced system A and system L activity under normoxic conditions and ASA (1 mM) decreased system A and L transporter activity under normoxic and hypoxic conditions. CONCLUSIONS: Our data underline the dependency of placental function on oxygen supply. LMWHs and ASA are not able to reverse the effects of hypoxia on placental amino acid transport. These findings and the uncovering of the signalling mechanisms in more detail will help to understand the impact of LMWHs and ASA on placental function and fetal growth.
[Mh] Termos MeSH primário: Anticoagulantes/farmacologia
Aspirina/farmacologia
Dalteparina/farmacologia
Hipóxia
Placenta/efeitos dos fármacos
Placenta/metabolismo
Transdução de Sinais/efeitos dos fármacos
[Mh] Termos MeSH secundário: Proteínas Adaptadoras de Transdução de Sinal/metabolismo
Sistema A de Transporte de Aminoácidos/metabolismo
Sistema L de Transporte de Aminoácidos/metabolismo
Transporte Biológico/efeitos dos fármacos
Radioisótopos de Carbono/metabolismo
Vilosidades Coriônicas/metabolismo
Feminino
Seres Humanos
Técnicas In Vitro
Fosforilação/efeitos dos fármacos
Gravidez
Proteína Associada Regulatória a mTOR
Fator de Transcrição STAT3/metabolismo
Trítio/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Adaptor Proteins, Signal Transducing); 0 (Amino Acid Transport System A); 0 (Amino Acid Transport System L); 0 (Anticoagulants); 0 (Carbon Radioisotopes); 0 (RPTOR protein, human); 0 (Regulatory-Associated Protein of mTOR); 0 (STAT3 Transcription Factor); 10028-17-8 (Tritium); R16CO5Y76E (Aspirin); S79O08V79F (Dalteparin)
[Em] Mês de entrada:1510
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140606
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0099217


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[PMID]:24886642
[Au] Autor:Aiko Y; Askew DJ; Aramaki S; Myoga M; Tomonaga C; Hachisuga T; Suga R; Kawamoto T; Tsuji M; Shibata E
[Ti] Título:Differential levels of amino acid transporters System L and ASCT2, and the mTOR protein in placenta of preeclampsia and IUGR.
[So] Source:BMC Pregnancy Childbirth;14:181, 2014 May 30.
[Is] ISSN:1471-2393
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Sufficient amino acid transport activity (AAT) is indispensable for appropriate fetal growth. Studies suggest that placental nutrient uptake activity is responsive to both maternal and fetal nutrient demands. We hypothesize that under conditions of limited nutrient availability to the fetus, as often present in preeclampsia, intrauterine growth restriction (IUGR), and insufficient weight-gain during pregnancy, a general adaptive response aimed to increase amino acid transport activity may be observed in the placenta. METHOD: A total of 40 placentas from full-term (n = 10) and pre-term (average gestational period = 34.8 weeks, n = 10) normal pregnancies, IUGR (n = 10), and preeclampsia (n = 10) associated pregnancies were looked at by immunohistochemistry followed by relative qualitative scoring to compare expression levels and localization of System L, ASCT2, and mTOR proteins. RESULT: Microvillous syncytiotrophoblast (ST) in placenta of pregnancies complicated by IUGR or preeclampsia (PE) showed significant increases in the levels of System L amino acid transport proteins 4F2hc and LAT1 compared to both full-term control and pre-term (early gestation control) pregnancies seperately (p < 0.05). Elevated mTOR protein was uniquely higher in IUGR placentas compared to full-term controls (P = 0.0026). Total cellular ASCT2 transporter protein levels were similar in all groups, however, levels of ASCT2 protein localized to the ST microvillous membrane (MVM) were significantly lower in IUGR compared to both full-term and pre-term pregnancies (P = 0.0006, 0.03, respectively). Additionally, ASCT2 and mTOR protein levels were positively associated with maternal pre-pregnancy BMI (P = 0.046, 0.048, respectively). CONCLUSION: There are three important findings based upon the present study. First, in conditions of limited nutrient availability, such as PE or IUGR, there is an overall increase in the level of System L and mTOR protein expression in the ST, suggestive of an adaptive response. Second, a decrease in ASCT2 protein at the ST MVM suggests a post-translational event that may decrease AAT activity in IUGR placentas. Third, a physiological link between transporter expression and pre-pregnancy BMI is suggested based upon a positive association observed with ASCT2 and mTOR expression values.
[Mh] Termos MeSH primário: Adaptação Fisiológica
Retardo do Crescimento Fetal/metabolismo
Placenta/metabolismo
Pré-Eclâmpsia/metabolismo
Nascimento Prematuro/metabolismo
Nascimento a Termo/metabolismo
[Mh] Termos MeSH secundário: Adulto
Sistema ASC de Transporte de Aminoácidos/metabolismo
Sistema L de Transporte de Aminoácidos/metabolismo
Índice de Massa Corporal
Membrana Celular/metabolismo
Feminino
Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo
Seres Humanos
Transportador 1 de Aminoácidos Neutros Grandes/metabolismo
Antígenos de Histocompatibilidade Menor
Gravidez
Serina-Treonina Quinases TOR/metabolismo
Trofoblastos/metabolismo
Ganho de Peso
Adulto Jovem
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Amino Acid Transport System ASC); 0 (Amino Acid Transport System L); 0 (Fusion Regulatory Protein 1, Heavy Chain); 0 (Large Neutral Amino Acid-Transporter 1); 0 (Minor Histocompatibility Antigens); 0 (SLC1A5 protein, human); 0 (SLC3A2 protein, human); EC 2.7.1.1 (MTOR protein, human); EC 2.7.1.1 (TOR Serine-Threonine Kinases)
[Em] Mês de entrada:1502
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140603
[St] Status:MEDLINE
[do] DOI:10.1186/1471-2393-14-181


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[PMID]:24590488
[Au] Autor:Fujita M; Shinozaki K
[Ad] Endereço:Gene Discovery Research Group, RIKEN Center for Sustainable Resource Science, 3-1-1 Koyadai, Tsukuba, Ibaraki, 305-0074 Japan.
[Ti] Título:Identification of polyamine transporters in plants: paraquat transport provides crucial clues.
[So] Source:Plant Cell Physiol;55(5):855-61, 2014 May.
[Is] ISSN:1471-9053
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Polyamine (PA) transport as well as PA biosynthesis, degradation and conjugation plays a vital role in the regulation of intracellular PA levels, which are essential for cell growth. Generally, PA uptake activity is elevated in rapidly proliferating cells. Previous studies showed that PA uptake in plant cells occurred via energy-dependent, protein-mediated transport systems. Numerous lines of evidence suggest that paraquat (PQ), one of the most widely used herbicides, is transported by the PA transport system in diverse organisms including plants. The PA/PQ transport interactions are proposed to be due to specific structural similarities between PA and PQ. The understanding of PA transport mechanisms has progressed in parallel with that of PQ transport, but the molecular identity of the plant PA/PQ transporter has remained an enigma. Recently, independent studies identified the L-type amino acid transporter (LAT) family transmembrane proteins as transporters of both PA and PQ. Arabidopsis LAT family proteins showed different subcellular localization properties, which suggested that these transporters were involved in intracellular PA trafficking and PA uptake across the plasma membrane. The identification of plant PA transporters is an important step in understanding the mechanism of PA homeostasis in plant cells. In this review, we highlight recent advances in the study of PA transport systems that are linked to the understanding of PQ translocation.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/metabolismo
Paraquat/metabolismo
Proteínas de Plantas/metabolismo
Plantas/metabolismo
Poliaminas/metabolismo
[Mh] Termos MeSH secundário: Transporte Biológico
Membrana Celular/metabolismo
Modelos Biológicos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Amino Acid Transport System L); 0 (Plant Proteins); 0 (Polyamines); PLG39H7695 (Paraquat)
[Em] Mês de entrada:1502
[Cu] Atualização por classe:140512
[Lr] Data última revisão:
140512
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140305
[St] Status:MEDLINE
[do] DOI:10.1093/pcp/pcu032


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[PMID]:24492461
[Au] Autor:Yun DW; Lee SA; Park MG; Kim JS; Yu SK; Park MR; Kim SG; Oh JS; Kim CS; Kim HJ; Kim JS; Chun HS; Kanai Y; Endou H; Wempe MF; Kim DK
[Ad] Endereço:Oral Biology Research Institute, Chosun University School of Dentistry, Korea.
[Ti] Título:JPH203, an L-type amino acid transporter 1-selective compound, induces apoptosis of YD-38 human oral cancer cells.
[So] Source:J Pharmacol Sci;124(2):208-17, 2014.
[Is] ISSN:1347-8648
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Compared to most normal cells that express L-type amino acid transporter 2, L-type amino acid transporter 1 is highly expressed in cancer cells and presumed to support their elevated growth and proliferation. This study examined JPH203, a potent and selective L-type amino acid transporter 1 inhibitor, and its ability to suppress YD-38 human oral cancer cell growth. The YD-38 cells express L-type amino acid transporter 1 with its associating protein 4F2 heavy chain, but not L-type amino acid transporter 2. JPH203 and BCH, a non-selective L-type amino acid transporter inhibitor, completely inhibited l-leucine uptake in YD-38 cells. As expected, the intrinsic affinity of JPH203 to inhibit l-leucine uptake was far more efficient than BCH. Likewise, JPH203 and BCH inhibited YD-38 cell growth, with JPH203 being superior to BCH. JPH203 up-regulated the population of apoptotic YD-38 cells through the activation of apoptotic factors, including caspases and PARP. These results suggest that the inhibition of L-type amino acid transporter 1 activity via JPH203, which may act as a potential novel anti-oral-cancer agent, leads to apoptosis by inducing the intracellular depletion of the neutral amino acids essential for cancer cell growth in YD-38 human oral cancer cells.
[Mh] Termos MeSH primário: Sistema L de Transporte de Aminoácidos/antagonistas & inibidores
Antineoplásicos/farmacologia
Apoptose/efeitos dos fármacos
Benzoxazóis/farmacologia
Transportador 1 de Aminoácidos Neutros Grandes/metabolismo
Neoplasias Bucais/genética
Neoplasias Bucais/patologia
Tirosina/análogos & derivados
[Mh] Termos MeSH secundário: Apoptose/genética
Caspases/metabolismo
Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo
Seres Humanos
Leucina/metabolismo
Neoplasias Bucais/metabolismo
Células Tumorais Cultivadas
Tirosina/farmacologia
Regulação para Cima/efeitos dos fármacos
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (2-amino-3-(4-((5-amino-2-phenylbenzo(d)oxazol-7-yl)methoxy)-3,5-dichlorophenyl)propanoic acid); 0 (Amino Acid Transport System L); 0 (Antineoplastic Agents); 0 (Benzoxazoles); 0 (Fusion Regulatory Protein 1, Heavy Chain); 0 (Large Neutral Amino Acid-Transporter 1); 42HK56048U (Tyrosine); EC 3.4.22.- (Caspases); GMW67QNF9C (Leucine)
[Em] Mês de entrada:1410
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140205
[St] Status:MEDLINE



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