Upregulation of amino acid transporter expression induced by l-leucine availability in L6 myotubes is associated with ATF4 signaling through mTORC1-dependent mechanism

Nutrition ◽  
2013 ◽  
Vol 29 (1) ◽  
pp. 284-290 ◽  
Author(s):  
Jun-qiu Luo ◽  
Dai-wen Chen ◽  
Bing Yu
Keyword(s):  
Amino Acid ◽  
Amino Acid Transporter ◽  
L6 Myotubes ◽  
Acid Transporter ◽  
Transporter Expression ◽  
Dependent Mechanism

scholarly journals Prognostic significance of amino-acid transporter expression (LAT1, ASCT2, and xCT) in surgically resected tongue cancer

2014 ◽  
Vol 110 (10) ◽  
pp. 2506-2513 ◽  
Author(s):  
M Toyoda ◽  
K Kaira ◽  
Y Ohshima ◽  
N S Ishioka ◽  
M Shino ◽  
...  
Keyword(s):  
Amino Acid ◽  
Tongue Cancer ◽  
Prognostic Significance ◽  
Amino Acid Transporter ◽  
Acid Transporter ◽  
Transporter Expression

scholarly journals Downregulation of Placental Amino Acid Transporter Expression and mTORC1 Signaling Activity Contributes to Fetal Growth Retardation in Diabetic Rats

2020 ◽  
Vol 21 (5) ◽  
pp. 1849
Author(s):  
Jie Xu ◽  
Jiao Wang ◽  
Yang Cao ◽  
Xiaotong Jia ◽  
Yujia Huang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rat Model ◽  
Amino Acid Transporter ◽  
Amino Acid Transporters ◽  
Amino Acid Transport System ◽  
Intrauterine Growth ◽  
System L ◽  
Acid Transporter ◽  
Transporter Expression

Alterations in placental transport may contribute to abnormal fetal intrauterine growth in pregnancies complicated by diabetes, but it is not clear whether the placental amino acid transport system is altered in diabetic pregnancies. We therefore studied the changes in the expressions of placental amino acid transporters in a rat model of diabetes induced by streptozotocin, and tested the effects of hyperglycemia on trophoblast amino acid transporter in vitro. Our results showed that the expressions for key isoforms of system L amino acid transporters were significantly reduced in the placentas of streptozotocin-induced diabetic pregnant rats, which was associated with the decreased birthweight in the rats. A decreased placental efficiency and decreased placental mammalian target of rapamycin (mTOR) complex 1 (mTORC1) activity were also found in the rat model. In addition, hyperglycemia in vitro could inhibit amino acid transporter expression and mTORC1 activity in human trophoblast. Inhibition of mTORC1 activity led to reduced amino acid transporter expression in placental trophoblast. We concluded that reduced placental mTORC1 activity during pregnancy resulted in decreased placental amino acid transporter expression and, subsequently, contributed to fetal intrauterine growth restriction in pregnancies complicated with diabetes.

THE RENAL DOPAMINERGIC SYSTEM AND AMINO ACID TRANSPORTER EXPRESSION IN AGED WKY AND SHR RATS

2011 ◽  
Vol 29 ◽  
pp. e371
Author(s):  
V. Pinto ◽  
Mj. Pinho ◽  
J. Amaral ◽  
E. Silva ◽  
S. Simão ◽  
...  
Keyword(s):  
Amino Acid ◽  
Dopaminergic System ◽  
Amino Acid Transporter ◽  
Shr Rats ◽  
Acid Transporter ◽  
Transporter Expression

scholarly journals Scaling of midgut perimeter and amino acid transporter expression in Manduca sexta larvae

2013 ◽  
Vol 27 (S1) ◽  
Author(s):  
Christopher M. Gillen ◽  
Haruhiko Itagaki ◽  
Aaron J. Yeoh ◽  
Allison V. Vela‐Mendoza ◽  
Katheryn P. Connell ◽  
...  
Keyword(s):  
Amino Acid ◽  
Manduca Sexta ◽  
Amino Acid Transporter ◽  
Acid Transporter ◽  
Manduca Sexta Larvae ◽  
Transporter Expression

192 AMINO ACID TRANSPORTER EXPRESSION IN BOVINE OVIDUCT EPITHELIAL CELLS

2008 ◽  
Vol 20 (1) ◽  
pp. 175
Author(s):  
S. L. Whitear ◽  
H. J. Leese
Keyword(s):  
Amino Acid ◽  
Epithelial Cells ◽  
Amino Acid Transporter ◽  
Positive Control ◽  
Amino Acid Transporters ◽  
Oviduct Epithelial Cells ◽  
Acid Transporter ◽  
Oviduct Fluid ◽  
Transporter Expression

Oviduct fluid provides the environment for the gametes and early embryo but little is known about the mechanisms underlying its formation. Components of oviduct fluid have been shown to be present at concentrations different from that in blood, indicative of selective transport by the epithelial cells lining the lumen. For example, amino acid concentrations in oviduct fluid differ from those in extracellular fluid and have also been shown to be important to preimplantation embryos in vitro, enhancing development, especially when added at physiological concentrations. However, little is known about amino acid transport systems in the oviduct, and the aim of this work was to search for mRNA transcripts for amino acid transporters in bovine oviduct epithelial cells. Contra- and ipsi-lateral oviducts were removed from abattoir-derived reproductive tracts at specific stages of the reproductive cycle. Oviducts were trimmed of surrounding tissue and fat and slit longitudinally to expose the luminal surface. Bovine oviduct epithelial cells (bOEC) were scraped from the surface using a sterile glass coverslip and washed by centrifugation. mRNA was isolated using Trizol-chloroform extraction and lithium chloride precipitation methods. PCR was used to detect cDNA encoding the amino acid transporters CAT-1, CAT-4, and LAT1. A negative control (water) and a positive control (human placental cDNA) were included in each experiment and β-actin expression was used as a positive control for cDNA library generation. Products were separated by agarose gel electrophoresis. PCR for β-actin resulted in the presence of a positive band in all samples, showing successful extraction of mRNA and generation of cDNA libraries. mRNA for CAT-1 and LAT1 was detected in bOEC from contra- and ipsi-lateral oviducts and from each cycle stage tested. There was, however, no detectable mRNA for CAT-4 in any of the samples. To our knowledge, this is the first report of amino acid transporter expression in the mammalian oviduct. CAT-1 is a ubiquitous sodium-independent uniporter of cationic amino acids that has been localized to the basolateral membrane of epithelial cells. The presence of mRNA for this amino acid transporter in all samples tested is therefore to be expected. LAT1 is a obligatory exchanger which exports glutamine and cystine and imports large uncharged branched-chain amino acids. This transporter may be partly responsible for the high concentration of glutamate in the basal compartment of in vitro cell cultures reported in our previous work (Whitear and Leese 2007 Biennial Meet. Joint Fertil. Soc., York, UK). CAT-4 shares only 40% sequence homology with CAT-1 and its function is unknown. Its expression appears to be restricted to brain, testis, and placenta, and the absence of mRNA for the oviduct was, perhaps, not surprising. Further experiments will investigate expression levels of other amino acid transporters in bOEC and transporter localization using immunohistochemistry. This work was funded by the BBSRC and ANGLE Technology Ltd.

scholarly journals Skeletal muscle amino acid transporter expression is increased in young and older adults following resistance exercise

2011 ◽  
Vol 111 (1) ◽  
pp. 135-142 ◽  
Author(s):  
Micah J. Drummond ◽  
Christopher S. Fry ◽  
Erin L. Glynn ◽  
Kyle L. Timmerman ◽  
Jared M. Dickinson ◽  
...  
Keyword(s):  
Older Adults ◽  
Amino Acid ◽  
Resistance Exercise ◽  
Amino Acid Transporter ◽  
Initiation Factor ◽  
Amino Acid Transporters ◽  
Α Subunit ◽  
Mtorc1 Signaling ◽  
Acid Transporter ◽  
Transporter Expression

Amino acid transporters and mammalian target of rapamycin complex 1 (mTORC1) signaling are important contributors to muscle protein anabolism. Aging is associated with reduced mTORC1 signaling following resistance exercise, but the role of amino acid transporters is unknown. Young ( n = 13; 28 ± 2 yr) and older ( n = 13; 68 ± 2 yr) subjects performed a bout of resistance exercise. Skeletal muscle biopsies ( vastus lateralis) were obtained at basal and 3, 6, and 24 h postexercise and were analyzed for amino acid transporter mRNA and protein expression and regulators of amino acid transporter transcription utilizing real-time PCR and Western blotting. We found that basal amino acid transporter expression was similar in young and older adults ( P > 0.05). Exercise increased L-type amino acid transporter 1/solute-linked carrier (SLC) 7A5, CD98/SLC3A2, sodium-coupled neutral amino acid transporter 2/SLC38A2, proton-assisted amino acid transporter 1/SLC36A1, and cationic amino acid transporter 1/SLC7A1 mRNA expression in both young and older adults ( P < 0.05). L-type amino acid transporter 1 and CD98 protein increased only in younger adults ( P < 0.05). eukaryotic initiation factor 2 α-subunit (S52) increased similarly in young and older adults postexercise ( P < 0.05). Ribosomal protein S6 (S240/244) and activating transcription factor 4 nuclear protein expression tended to be higher in the young, while nuclear signal transducer and activator of transcription 3 (STAT3) (Y705) was higher in the older subjects postexercise ( P < 0.05). These results suggest that the rapid upregulation of amino acid transporter expression following resistance exercise may be regulated differently between the age groups, but involves a combination of mTORC1, activating transcription factor 4, eukaryotic initiation factor 2 α-subunit, and STAT3. We propose an increase in amino acid transporter expression may contribute to enhanced amino acid sensitivity following exercise in young and older adults. In older adults, the increased nuclear STAT3 phosphorylation may be indicative of an exercise-induced stress response, perhaps to export amino acids from muscle cells.

Excitatory amino acid transporter expression by astrocytes is neuroprotective against microglial excitotoxicity

2008 ◽  
Vol 1210 ◽  
pp. 11-19 ◽  
Author(s):  
Jianfeng Liang ◽  
Hideyuki Takeuchi ◽  
Yukiko Doi ◽  
Jun Kawanokuchi ◽  
Yoshifumi Sonobe ◽  
...  
Keyword(s):  
Amino Acid ◽  
Excitatory Amino Acid ◽  
Amino Acid Transporter ◽  
Excitatory Amino Acid Transporter ◽  
Acid Transporter ◽  
Transporter Expression

Adaptive Placental Transport in Nutrient-Restricted Ewes Is Associated with Altered Amino Acid Transporter Expression.

2012 ◽  
Vol 87 (Suppl_1) ◽  
pp. 417-417
Author(s):  
Ashley B. Keith ◽  
Sorin M. Greff ◽  
Kathrin A. Dunlap ◽  
M. Carey Satterfield
Keyword(s):  
Amino Acid ◽  
Amino Acid Transporter ◽  
Placental Transport ◽  
Acid Transporter ◽  
Transporter Expression
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