The effects of dietary selenium on selenocysteine incorporation and selenoprotein expression
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE46038 | GEO | 2013/09/17
SECONDARY ACCESSION(S): PRJNA197001
REPOSITORIES: GEO
Similar Datasets
Project description:The goal of this study was to determine the effects of dietary selenium levels on translational control of selenoprotein synthesis in mouse liver. Wild type mice and mice expressing a mutant Sec-tRNA gene (TrspA37G) were fed diets supplemented with 0, 0.1, or 2 ppm selenium for 6 weeks. Livers were harvested and ribosome and mRNA profiles were generated by deep-sequencing using the Illumina HiSeq 2000.
2013-09-17 | E-GEOD-46038 | biostudies-arrayexpress
Project description:In this study, juvenile rainbow trout were exposed four dietary doses of organic selenium (7.1, 10.7 19.5 and 31.8 mg/kg Selenium) over 60 days. The RNA was exctracted from liver tissue and used for further gene expression analysis.
2015-06-30 | GSE67599 | GEO
Project description:Comparative analysis of gene expression in bone marrow-derived macrophages (BMDM) from trsp knockout mice (Trspfl/fl-LysM-Cre+/-) and Control (Trspfl/fl-LysM-Cre-/-) mice. Selenium, a micronutrient whose deficiency in the diet causes immune dysfunction and inflammatory disorders, exerts its physiological effects partly in the form of selenium-containing proteins (selenoproteins). Incorporation of selenium into the amino acid selenocysteine (Sec), and subsequently into selenoproteins, is mediated by Sec tRNA[Ser]Sec. To identify macrophage-specific selenoprotein function, we generated mice with the Sec tRNA[Ser]Sec gene specifically deleted in myeloid cells. These mutant mice were devoid of the selenoproteome in macrophages, yet exhibited largely normal inflammatory responses. However, selenoprotein deficiency led to aberrant expression of extracellular matrix-related genes, and diminished migration of macrophages in a protein gel matrix. Therefore, selenium status may affect immune defense and tissue homeostasis through its effect on selenoprotein expression and the trafficking of tissue macrophages.
2009-12-22 | GSE15610 | GEO
Project description:In this study, juvenile rainbow trout were exposed four dietary doses of organic selenium (7.1, 10.7 19.5 and 31.8 mg/kg Selenium) over 60 days. The RNA was exctracted from liver tissue and used for further gene expression analysis. There were 39 samples analyzed (8) control liver tissues (8) 7.1 mg/kg Se dosed fish liver tissues (7) 10.7 mg/kg Se dosed fish liver tissues (8) 19.5 mg/kg Se dosed fish liver tissues (9) 31.8 mg/kg Se dosed fish liver tissues. There was a total of 39 microarrays processed.
2015-06-30 | E-GEOD-67599 | biostudies-arrayexpress
Project description:Comparative analysis of gene expression in bone marrow-derived macrophages (BMDM) from trsp knockout mice (Trspfl/fl-LysM-Cre+/-) and Control (Trspfl/fl-LysM-Cre-/-) mice. Selenium, a micronutrient whose deficiency in the diet causes immune dysfunction and inflammatory disorders, exerts its physiological effects partly in the form of selenium-containing proteins (selenoproteins). Incorporation of selenium into the amino acid selenocysteine (Sec), and subsequently into selenoproteins, is mediated by Sec tRNA[Ser]Sec. To identify macrophage-specific selenoprotein function, we generated mice with the Sec tRNA[Ser]Sec gene specifically deleted in myeloid cells. These mutant mice were devoid of the selenoproteome in macrophages, yet exhibited largely normal inflammatory responses. However, selenoprotein deficiency led to aberrant expression of extracellular matrix-related genes, and diminished migration of macrophages in a protein gel matrix. Therefore, selenium status may affect immune defense and tissue homeostasis through its effect on selenoprotein expression and the trafficking of tissue macrophages. We have generated mice in which we have selectively removed the selenocysteine tRNA gene (trsp) in macrophages under the control of LysM-Cre promoter. Microarray analysis was performed on RNA samples taken from bone marrow-derived macrophages in knockout and control mice. 1. Control unstimulated 2. Knockout unstimulated 3. Control lipopolysaccharide (LPS) stimulated (4h) 4. Knockout LPS stimulated (4h). Three replicates for each condition. Thus, a total of 12 samples.
2009-12-21 | E-GEOD-15610 | biostudies-arrayexpress
Project description:Selenoproteins are an essential and unique group of proteins in which selenocysteine (Sec) is incorporated in response to a stop codon (UGA). Reprograming of UGA for Sec insertion in eukaryotes requires a cis-acting stem-loop structure in the 3' untranslated region of selenoprotein mRNA and several trans-acting factors. Together these factors are sufficient for Sec incorporation in vitro, but the process is highly inefficient. An additional challenge is the synthesis of selenoprotein P (SELENOP), which uniquely contains multiple UGA codons. Full-length SELENOP expression requires processive Sec incorporation, the mechanism for which is not understood. In this study, we identify core coding region sequence determinants within the SELENOP mRNA that govern SELENOP synthesis. Using 75Se labeling in cells, we determined that the N-terminal coding sequence (upstream of the second UGA) and C-terminal coding sequence context are two independent determinants for efficient synthesis of full-length SELENOP. In addition, the distance between the first UGA and the consensus signal peptide is also critical for efficiency.
| S-EPMC6289641 | biostudies-literature
Project description:We tested the hypothesis that the behavioral response to selenium (Se) follows a hormetic dose response pattern, manifested through the functions of selenoproteins within the brain. We measured anxiety-related behaviors in zebrafish (Danio rerio) at deficient, control and supplemented levels of dietary Se, and measured the transcriptional response of selenoprotein genes important for neuroprotection. We also used a microarray approach to assess the transcriptomic response of the midbrain to Se. The behavioral response to Se was characterized by hormesis, and the direction, magnitude, and shape of the hormetic responses were dependent on both sex and zebrafish population. Transcription of selenoproteins within the midbrain also responded to Se in a similar hormetic dose-dependent manner, with sex and population influencing the trajectory of the responses. The hormetic behavioral response to Se may therefore be manifested through selenoproteins in the brain, but the influence is not direct.
2014-05-01 | GSE52484 | GEO
Project description:Expression of selenoproteins requires the co-translational incorporation of selenocysteine (Sec) in response to an in-frame UGA codon. The machinery of UGA/Sec re-coding is complex and many factors affect the hierarchy of expression among selenoproteins, including modification of tRNA[Ser]Sec. Its hyper-modification in the anticodon stem loop is influenced by selenium bioavailability, and a mutation in adenosine 37 (A37) that abrogates isopentenylation, has a profound effect on selenoprotein expression in mice. Patients with mutations in tRNA-isopentenyl-transferase (TRIT1) show a severe neurological disorder and hence we wondered whether mutations in TRIT1 negatively affected the expression of selenoproteins. Fibroblasts from a patient carrying a pathogenic R323Q mutation in TRIT1 in homozygosity did not show decreased selenoprotein expression, although recombinant TRIT1R323Q had significantly reduced activity in vitro towards anticodon stem-loop substrates. We thus engineered mice conditionally deficient in Trit1 in hepatocytes and neurons. Selenoprotein expression as assessed by western blotting, 75Se metabolic labeling, and ribosomal profiling was not decreased despite the general reduction of N6-isopentenyl-adenosine in tRNAs. We show that 5-methylcarboxymethylation and 2’O-methylation of U34 occur independently of isopentenylation of A37 in tRNA[Ser]Sec. Reanalyzing previously published ribosomal profiling datasets, we demonstrate that (i) failure of 5-carboxymethylation at U34 is associated with reduced expression of GPX1, but not GPX4, and that (ii) FTSJ1 is not the elusive U34-2’O-methyltransferase involved in the methylation of tRNA[Ser]Sec.
2021-11-17 | GSE183923 | GEO
Project description:Selenoproteins are a unique group of proteins that contain selenium in the form of selenocysteine (Sec) co-translationally inserted in response to a UGA codon with the help of cis- and trans-acting factors. Mammalian selenoproteins contain single Sec residues, with the exception of selenoprotein P (SelP) that has 7-15 Sec residues depending on species. Assessing an individual's selenium status is important under various pathological conditions, which requires a reliable selenium biomarker. Due to a key role in organismal selenium homeostasis, high Sec content, regulation by dietary selenium, and availability of robust assays in human plasma, SelP has emerged as a major biomarker of selenium status. Here, we found that Cys is present in various Sec positions in human SelP. Treatment of cells expressing SelP with thiophosphate, an analog of the selenium donor for Sec synthesis, led to a nearly complete replacement of Sec with Cys, whereas supplementation of cells with selenium supported Sec insertion. SelP isolated directly from human plasma had up to 8% Cys inserted in place of Sec, depending on the Sec position. These findings suggest that a change in selenium status may be reflected in both SelP concentration and its Sec content, and that availability of the SelP-derived selenium for selenoprotein synthesis may be overestimated under conditions of low selenium status due to replacement of Sec with Cys.
| S-EPMC4599804 | biostudies-literature
Project description:Protein and mRNA levels for several selenoproteins, such as glutathione peroxidase-1 (Gpx1), are down-regulated dramatically by selenium (Se) deficiency. Selenoprotein levels in rats increase sigmoidally with increasing dietary Se and reach defined plateaus at the Se requirement, making them sensitive biomarkers for Se deficiency, but not high for Se status. Biomarkers for high Se status are needed as super-nutritional Se intakes are associated with beneficial and adverse health outcomes, but conventional biomarkers are not especially useful above the Se requirement. To characterize Se regulation of the transcriptome, we conducted 3 microarray experiments in weanling mice and rats fed Se-deficient diets supplemented with levels of Se up to 5 µg Se/g diet.
2011-01-19 | GSE23895 | GEO