Surveying selenium speciation from soil to cell—forms and transformations

Gammelgaard, Bente; Jackson, Matthew I.; Gabel-Jensen, Charlotte

doi:10.1007/s00216-010-4212-8

Cited by 68 publications

(60 citation statements)

References 136 publications

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“…While selenized yeast, together with the major compound selenomethionine (SeMet) [7], contains small amounts of various selenoamino acids and peptides, mineral supplements most often contain inorganic selenite or selenate [8]. The various selenium compounds are metabolized via different pathways [9], and the absorption mechanisms of the various selenium compounds may also play an important role for the bioavailability and thus the effect of the different selenium species [10]. A version of some generally accepted selenium pathways is presented in Fig.…”

Section: Introductionmentioning

confidence: 99%

Estimating Intestinal Absorption of Inorganic and Organic Selenium Compounds by in Vitro Flux and Biotransformation Studies in Caco-2 Cells and ICP-MS Detection

Gammelgaard

Rasmussen

Gabel-Jensen

et al. 2011

Biol Trace Elem Res

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The aim of the present work was to compare and estimate absorption and biotransformation of selected selenium compounds by studying their fluxes across Caco-2 cells. Five different selenium compounds, selenomethionine (SeMet), Se-methylselenocysteine (MeSeCys), selenate, selenite, and methylseleninic acid (MeSeA), were applied to Caco-2 cells in a concentration of 10 μM, and fluxes in both directions were studied for 2 h. Fluxes of selenite and MeSeA in the presence of excess reduced glutathione (selenite + GSH and MeSeA + GSH) and flux of MeSeA in the presence of excess cysteine (MeSeA + Cys) were also studied. Selenium absorptive and exsorptive fluxes and accumulation in cell cytosol were analyzed by means of flow injection inductively coupled plasma mass spectrometry (ICP-MS). Absorptive flux of SeMet, MeSeCys, and selenate showed values correlating to complete in vivo absorption, while selenite and MeSeA fluxes correlated to poor in vivo absorption. Speciation analysis of cell lysate and donor and receptor solutions by LC-ICP-MS showed limited transformation of all selenium compounds. Extensive transformation as well as significantly increased absorptive flux was observed when co-administering selenite with glutathione compared to administering selenite alone. These observations are possibly due to formation of selenodiglutathione (GS-Se-SG) which may be absorbed differently than selenite. Concomitant application of GSH or cysteine with MeSeA resulted in extensive transformation of MeSeA, including volatile species, whereas no significant increases in fluxes were observed. In summary, the absorption of selenite selenate and the selenoamino acids is considered complete under physiological conditions, but the absorption mechanisms and metabolism of the compounds are different.

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Section: Introductionmentioning

confidence: 99%

Estimating Intestinal Absorption of Inorganic and Organic Selenium Compounds by in Vitro Flux and Biotransformation Studies in Caco-2 Cells and ICP-MS Detection

Gammelgaard

Rasmussen

Gabel-Jensen

et al. 2011

Biol Trace Elem Res

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“…9 The identification of selenometabolites has come to rely principally on either HPLC-ICP-MS, ESI-MS-MS, 10 or their combination. 6,11 The latter permits unambiguous identification without the need for standards of the authentic selenium species being available, whereas ICP-MS provides for a more sensitive and robust detection, and is currently the technique of choice for the speciation of selenium in biological samples. 10 Intrinsically volatile selenium species have been characterized by GC-MS, 12 and anionic species by ESI.…”

Section: Introductionmentioning

confidence: 99%

Influence of Speciation on the Response from Selenium to UV-Photochemical Vapor Generation

et al. 2012

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“…However, despite many years of research, there is still substantial uncertainty about the metabolism of selenium and potential regulating factors. Absorbed selenium enters complex pathways, with reduction to selenide (4) and subsequent formation of methylated selenium species, including various selenosugars, which are excreted in the urine (5)(6)(7).…”

Section: Introductionmentioning

confidence: 99%

Selenium metabolism to the trimethylselenonium ion (TMSe) varies markedly because of polymorphisms in the indolethylamine N-methyltransferase gene

Kuehnelt

Engström

Skröder

et al. 2015

The American Journal of Clinical Nutrition

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Background: Selenium is an essential element, but its metabolism in humans is not well characterized. A few small studies indicate that the trimethylselenonium ion (TMSe) is a common selenium metabolite in humans.Objective: This study aimed to elucidate the human metabolism of selenium to TMSe. Design: Study individuals constituted subsamples of 2 cohorts: 1) pregnant women (n = 228) and their 5-y-old children (n = 205) in rural Bangladesh with poor selenium status [median urinary selenium (U-Se): 6.4 mg/L in mothers, 14 mg/L in children] and 2) women in the Argentinian Andes (n = 83) with adequate selenium status (median U-Se: 24 mg/L). Total U-Se and blood selenium were measured by inductively coupled plasma mass spectrometry (ICPMS), and urinary concentrations of TMSe were measured by high-performance liquid chromatography/vapor generation/ICPMS. A genomewide association study (GWAS) was performed for 1,629,299 (after filtration) single nucleotide polymorphisms (SNPs) in the Bangladeshi women (n = 72) by using Illumina Omni5M, and results were validated by using real-time polymerase chain reaction. Results: TMSe "producers" were prevalent (approximately onethird) among the Bangladeshi women and their children, in whom TMSe constituted w10-70% of U-Se, whereas "nonproducers" had, on average, 0.59% TMSe. The TMSe-producing women had, on average, 2-mg U-Se/L higher concentrations than did the nonproducers. In contrast, only 3 of the 83 Andean women were TMSe producers (6-15% TMSe in the urine); the average percentage among the nonproducers was 0.35%. Comparison of the percentage of urinary TMSe in mothers and children indicated a strong genetic influence. The GWAS identified 3 SNPs in the indolethylamine Nmethyltransferase gene (INMT) that were strongly associated with percentage of TMSe (P , 0.001, false-discovery rate corrected) in both cohorts. Conclusions: There are remarkable population and individual variations in the formation of TMSe, which could largely be explained by SNPs in INMT. The TMSe-producing women had higher U-Se concentrations than did nonproducers, but further elucidation of the metabolic pathways of selenium is essential for the understanding of its role in human health. The MINIMat trial was registered at isrctn.org as ISRCTN16581394.Am J Clin Nutr 2015;102:1406-15.

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Surveying selenium speciation from soil to cell—forms and transformations

Cited by 68 publications

References 136 publications

Estimating Intestinal Absorption of Inorganic and Organic Selenium Compounds by in Vitro Flux and Biotransformation Studies in Caco-2 Cells and ICP-MS Detection

Estimating Intestinal Absorption of Inorganic and Organic Selenium Compounds by in Vitro Flux and Biotransformation Studies in Caco-2 Cells and ICP-MS Detection

Influence of Speciation on the Response from Selenium to UV-Photochemical Vapor Generation

Selenium metabolism to the trimethylselenonium ion (TMSe) varies markedly because of polymorphisms in the indolethylamine N-methyltransferase gene

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