scholarly journals Fetal sex modulates placental microRNA expression, potential microRNA-mRNA interactions, and levels of amino acid transporter expression and substrates: INFAT study subpopulation analysis of n-3 LCPUFA intervention during pregnancy and associations with offspring body composition

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Eva-Maria Sedlmeier ◽  
Dorothy M. Meyer ◽  
Lynne Stecher ◽  
Manuela Sailer ◽  
Hannelore Daniel ◽  
...  
Keyword(s):  
Body Composition ◽  
Amino Acid ◽  
Amino Acid Transporter ◽  
Microrna Expression ◽  
Sexually Dimorphic ◽  
Mrna Levels ◽  
Control Male ◽  
Cord Plasma ◽  
Amino Acid Levels ◽  
Acid Transporter

Abstract Background Previously, we revealed sexually dimorphic mRNA expression and responsiveness to maternal dietary supplementation with n-3 long-chain polyunsaturated fatty acids (LCPUFA) in placentas from a defined INFAT study subpopulation. Here, we extended these analyses and explored the respective placental microRNA expression, putative microRNA-mRNA interactions, and downstream target processes as well as their associations with INFAT offspring body composition. Results We performed explorative placental microRNA profiling, predicted microRNA-mRNA interactions by bioinformatics, validated placental target microRNAs and their putative targets by RT-qPCR and western blotting, and measured amino acid levels in maternal and offspring cord blood plasma and placenta. microRNA, mRNA, protein, and amino acid levels were associated with each other and with offspring body composition from birth to 5 years of age. Forty-six differentially regulated microRNAs were found. Validations identified differential expression for microRNA-99a (miR-99a) and its predicted target genes mTOR, SLC7A5, encoding L-type amino acid transporter 1 (LAT1), and SLC6A6, encoding taurine transporter (TauT), and their prevailing significant sexually dimorphic regulation. Target mRNA levels were mostly higher in placentas from control male than from female offspring, whereas respective n-3 LCPUFA responsive target upregulation was predominantly found in female placentas, explaining the rather balanced expression levels between the sexes present only in the intervention group. LAT1 and TauT substrates tryptophan and taurine, respectively, were significantly altered in both maternal plasma at 32 weeks’ gestation and cord plasma following intervention, but not in the placenta. Several significant associations were observed for miR-99a, mTOR mRNA, SLC7A5 mRNA, and taurine and tryptophan in maternal and cord plasma with offspring body composition at birth, 1 year, 3 and 5 years of age. Conclusions Our data suggest that the analyzed targets may be part of a sexually dimorphic molecular regulatory network in the placenta, possibly modulating gene expression per se and/or counteracting n-3 LCPUFA responsive changes, and thereby stabilizing respective placental and fetal amino acid levels. Our data propose placental miR-99, SLC7A5 mRNA, and taurine and tryptophan levels in maternal and fetal plasma as potentially predictive biomarkers for offspring body composition.

Inducible antisense RNA targeting amino acid transporter ATB0/ASCT2 elicits apoptosis in human hepatoma cells

2004 ◽  
Vol 286 (3) ◽  
pp. G467-G478 ◽  
Author(s):  
Bryan C. Fuchs ◽  
J. Christian Perez ◽  
Julie E. Suetterlin ◽  
Sofia B. Chaudhry ◽  
Barrie P. Bode
Keyword(s):  
Amino Acid ◽  
Antisense Rna ◽  
Amino Acid Transporter ◽  
Hepatoma Cells ◽  
Parp Cleavage ◽  
Rna Expression ◽  
Mrna Levels ◽  
Human Hepatoma ◽  
Human Hepatoma Cells ◽  
Acid Transporter

Amino acid transporter B0/ASC transporter 2 (ATB0/ASCT2) is responsible for most glutamine uptake in human hepatoma cells. Because this transporter is not expressed in normal hepatocytes, we hypothesized that its expression is necessary for growth of human liver cancer cells. To test this hypothesis, Sloan Kettering hepatoma (SK-Hep) cells were stably transfected with an inducible 1.3-kb ATB0/ASCT2 antisense RNA expression plasmid under the transcriptional control of mifepristone, a synthetic steroid. Induced antisense RNA expression in monolayer cultures decreased ATB0/ASCT2 mRNA levels by 73% and glutamine transport rates by 65% compared with controls after 24 h, leading to a 98% decrease in cell number after 48 h. Cellular death was attributable to apoptosis based on cellular blebbing, caspase-3 activation, vital dye and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining, and poly-(ADP-ribose) polymerase (PARP) cleavage. Transporter knockdown also markedly increased activities of caspases-2 and -9, marginally enhanced caspase-8 activity, and dramatically increased ASCT1 mRNA levels, presumably as a futile compensatory response. Apoptosis elicited via transporter silencing was not attributable to the double-stranded RNA-dependent protein kinase R (PKR) pathway. For comparison, glutamine deprivation also caused apoptotic cell death but with slower temporal kinetics, stimulated caspases-2 and -3 but not caspases-8 or -9 activities, and led to considerable PARP cleavage. Thus ASCT2 suppression exerts proapoptotic effects transcending those of glutamine starvation alone. We conclude that ATB0/ASCT2 expression is necessary for SK-Hep cell growth and viability and suggest that it be further explored as a selective target for human hepatocellular carcinoma.

scholarly journals Intestinal IMINO transporter SIT1 is not expressed in human newborns

2018 ◽  
Vol 315 (5) ◽  
pp. G887-G895 ◽  
Author(s):  
C. Meier ◽  
S. M. Camargo ◽  
S. Hunziker ◽  
U. Moehrlen ◽  
S. J. Gros ◽  
...  
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Amniotic Fluid ◽  
Amino Acid Transporter ◽  
Amino Acid Transporters ◽  
Accessory Proteins ◽  
Mrna Levels ◽  
Small Intestinal ◽  
Acid Transporter ◽  
Transporter Expression

The expression of amino acid transporters in small intestine epithelia of human newborns has not been studied yet. It is further not known whether the maturation of imino acid (proline) transport is delayed as in the kidney proximal tubule. The possibility to obtain small intestinal tissue from patients undergoing surgery for jejunal or ileal atresia during their first days after birth was used to address these questions. As control, adult terminal ileum tissue was sampled during routine endoscopies. Gene expression of luminal imino and amino acid transporter SIT1 (SLC6A20) was approximately threefold lower in newborns versus adults. mRNA levels of all other luminal and basolateral amino acid transporters and accessory proteins tested were similar in newborn mucosa compared with adults. At the protein level, the major luminal neutral amino acid transporter B0AT1 (SLC6A19) and its accessory protein angiotensin-converting enzyme 2 were shown by immunofluorescence to be expressed similarly in newborns and in adults. SIT1 protein was not detectable in the small intestine of human newborns, in contrast to adults. The morphology of newborn intestinal mucosa proximal and distal to the obstruction was generally normal, but a decreased proliferation rate was visualized distally of the atresia by lower levels of the mitosis marker Ki-67. The mRNA level of the 13 tested amino acid transporters and accessory proteins was nonetheless similar, suggesting that the intestinal obstruction and interruption of amniotic fluid passage through the small intestinal lumen did not affect amino acid transporter expression. NEW & NOTEWORTHY System IMINO transporter SIT1 is not expressed in the small intestine of human newborns. This new finding resembles the situation in the proximal kidney tubule leading to iminoglycinuria. Lack of amniotic fluid passage in small intestinal atresia does not affect amino acid transporter expression distal to intestinal occlusion.

Increased expression of an amino acid transporter LAT1 in healing of acetic acid-induced chronic gastric ulcer in rats

2001 ◽  
Vol 120 (5) ◽  
pp. A153-A153
Author(s):  
S MIYAMOTO ◽  
K KATO ◽  
Y ISHII ◽  
S ASAI ◽  
T NAGAISHI ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Gastric Ulcer ◽  
Amino Acid ◽  
Amino Acid Transporter ◽  
Chronic Gastric Ulcer ◽  
Acid Transporter

scholarly journals Identification and Characterization of Inhibitors of a Neutral Amino Acid Transporter, SLC6A19, Using Two Functional Cell-Based Assays

2018 ◽  
Vol 24 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Sanjay J. Danthi ◽  
Beirong Liang ◽  
Oanh Smicker ◽  
Benjamin Coupland ◽  
Jill Gregory ◽  
...  
Keyword(s):  
Amino Acid ◽  
High Throughput Screening ◽  
Amino Acid Transporter ◽  
Neutral Amino Acid ◽  
Imaging Plate ◽  
Acid Uptake ◽  
Functional Assays ◽  
Neutral Amino Acid Transporter ◽  
Acid Transporter ◽  
Pharmacologically Active

SLC6A19 (B0AT1) is a neutral amino acid transporter, the loss of function of which results in Hartnup disease. SLC6A19 is also believed to have an important role in amino acid homeostasis, diabetes, and weight control. A small-molecule inhibitor of human SLC6A19 (hSLC6A19) was identified using two functional cell-based assays: a fluorescence imaging plate reader (FLIPR) membrane potential (FMP) assay and a stable isotope-labeled neutral amino acid uptake assay. A diverse collection of 3440 pharmacologically active compounds from the Microsource Spectrum and Tocriscreen collections were tested at 10 µM in both assays using MDCK cells stably expressing hSLC6A19 and its obligatory subunit, TMEM27. Compounds that inhibited SLC6A19 activity in both assays were further confirmed for activity and selectivity and characterized for potency in functional assays against hSLC6A19 and related transporters. A single compound, cinromide, was found to robustly, selectively, and reproducibly inhibit SLC6A19 in all functional assays. Structurally related analogs of cinromide were tested to demonstrate structure–activity relationship (SAR). The assays described here are suitable for carrying out high-throughput screening campaigns to identify modulators of SLC6A19.

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