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Zytner P, Kutschbach A, Gong W, Ohse VA, Taudte L, Kipp AP, Klotz LO, Priebs J, Steinbrenner H. Selenium-Enriched E. coli Bacteria Mitigate the Age-Associated Degeneration of Cholinergic Neurons in C. elegans. Antioxidants (Basel) 2024; 13:492. [PMID: 38671939 PMCID: PMC11047679 DOI: 10.3390/antiox13040492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 04/28/2024] Open
Abstract
Selenium (Se) is an essential trace element for humans and animals, but high-dose supplementation with Se compounds, most notably selenite, may exert cytotoxic and other adverse effects. On the other hand, bacteria, including Escherichia coli (E. coli), are capable of reducing selenite to red elemental Se that may serve as a safer Se source. Here, we examined how a diet of Se-enriched E. coli bacteria affected vital parameters and age-associated neurodegeneration in the model organism Caenorhabditis elegans (C. elegans). The growth of E. coli OP50 for 48 h in medium supplemented with 1 mM sodium selenite resulted in reddening of the bacterial culture, accompanied by Se accumulation in the bacteria. Compared to nematodes supplied with the standard E. coli OP50 diet, the worms fed on Se-enriched bacteria were smaller and slimmer, even though their food intake was not diminished. Nevertheless, given the choice, the nematodes preferred the standard diet. The fecundity of the worms was not affected by the Se-enriched bacteria, even though the production of progeny was somewhat delayed. The levels of the Se-binding protein SEMO-1, which serves as a Se buffer in C. elegans, were elevated in the group fed on Se-enriched bacteria. The occurrence of knots and ruptures within the axons of cholinergic neurons was lowered in aged nematodes provided with Se-enriched bacteria. In conclusion, C. elegans fed on Se-enriched E. coli showed less age-associated neurodegeneration, as compared to nematodes supplied with the standard diet.
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Affiliation(s)
- Palina Zytner
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
| | - Anne Kutschbach
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
| | - Weiye Gong
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
| | - Verena Alexia Ohse
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
| | - Laura Taudte
- Institute of Nutritional Sciences, Department of Nutritional Physiology, Friedrich Schiller University Jena, D-07743 Jena, Germany; (L.T.); (A.P.K.)
| | - Anna Patricia Kipp
- Institute of Nutritional Sciences, Department of Nutritional Physiology, Friedrich Schiller University Jena, D-07743 Jena, Germany; (L.T.); (A.P.K.)
| | - Lars-Oliver Klotz
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
| | - Josephine Priebs
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
| | - Holger Steinbrenner
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich Schiller University Jena, D-07743 Jena, Germany; (P.Z.); (A.K.); (W.G.); (V.A.O.); (L.-O.K.)
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2
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Sunde RA. Gene Set Enrichment Analysis of Selenium-Deficient and High-Selenium Rat Liver Transcript Expression and Comparison With Turkey Liver Expression. J Nutr 2021; 151:772-784. [PMID: 33245116 DOI: 10.1093/jn/nxaa333] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 09/14/2020] [Accepted: 10/05/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Better biomarkers of selenium (Se) status and a better understanding of toxic Se biochemistry are needed to set safe dietary upper limits. In previous studies, differential expression (DE) of individual liver transcripts in rats and turkeys failed to identify a single transcript that was consistently and significantly (q < 0.05) altered by high Se. OBJECTIVES To evaluate the effect of Se status on rat liver transcript expression data at the level of gene sets, and to compare transcript expression in rats with that in turkeys to identify common regulated transcripts. METHODS Gene set enrichment analysis (GSEA) was conducted on liver from weanling rats fed an Se-deficient basal diet (0.005 μg Se/g) supplemented with 0, 0.24 (Se-adequate), 2, or 5 μg Se/g diet as selenite for 28 d. In addition, transcript expression was compared with liver expression in turkeys fed 0, 0.4, 2, or 5 μg Se/g diet as selenite. RESULTS Se deficiency significantly downregulated the rat selenoprotein gene set but also upregulated gene sets for a variety of pathways, processes, and disease states. GSEA of 2 compared with 0.24 μg Se/g found no significantly up- or downregulated gene sets, showing that 2 μg Se/g is not particularly toxic to the rat. GSEA analysis of 5 compared with 0.24 μg Se/g transcripts, however, found 27 significantly upregulated gene sets for a wide variety of conditions. Cross-species GSEA comparison of transcript expression, however, identified no common gene sets significantly and consistently regulated by high Se in rats and turkeys. In addition, comparison of individual marginally significant (unadjusted P < 0.05) DE transcripts between rats and turkeys also failed to find common transcripts. CONCLUSIONS The dramatic increase in significant liver transcript DE and GSEA gene sets in rats fed 5 compared with 2 μg Se/g clearly appears to be a biomarker for Se toxicity, albeit not Se-specific. These analyses, however, failed to identify specific transcripts or pathways, biological states, or processes that were directly linked with high Se status, strongly indicating that adaptation to high Se lies outside transcriptional regulation.
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Affiliation(s)
- Roger A Sunde
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI, USA
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3
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Köhnlein K, Urban N, Steinbrenner H, Guerrero-Gómez D, Miranda-Vizuete A, Kaether C, Klotz LO. Selenite-induced Expression of a Caenorhabditis elegans Pro-aging Factor and Ortholog of Human Selenium-binding Protein 1. ACTA ACUST UNITED AC 2020. [DOI: 10.2174/2665978601666200212105825] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Background:
The essential trace element and micronutrient selenium exerts most of its
biological actions through incorporation into selenoproteins as selenocysteine. Two further types of
Se-containing proteins exist, including those that have selenomethionine incorporated instead of
methionine, and the group of selenium-binding proteins. We previously described an ortholog of
selenium-binding protein 1 (SELENBP1) in the nematode Caenorhabditis elegans, Y37A1B.5, and
demonstrated that it confers resistance to toxic selenite concentrations while impairing general
stress resistance and life expectancy of C. elegans.
Objective:
We tested for the effect of selenite on Y37A1B.5 expression, and we analyzed whether
Y37A1B.5 also shows a lifespan-modulating effect when the nematodes are deficient in the
selenoenzyme thioredoxin reductase-1 (TRXR-1).
Methods:
C. elegans expressing a translational reporter construct encoding GFP-tagged Y37A1B.5
under the control of the Y37A1B.5 promoter were exposed to selenite, followed by fluorescence
microscopic analysis of GFP levels. Lifespan analyses and RNA interference experiments were
performed in trxr-1-deficient worms.
Results:
We here demonstrate that selenite at toxic concentrations stimulates the expression of the
translational Y37A1B.5 reporter. The lifespan-extending effect of Y37A1B.5 deficiency was
preserved upon the deletion of the only selenoprotein in C. elegans, TRXR-1.
Conclusion:
These data suggest that (1) Y37A1B.5 may serve as a selenite-responsive buffer
against high environmental selenium concentrations and that (2) lifespan extension elicited by
Y37A1B.5 knockdown does not require functional TRXR-1.
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Affiliation(s)
- Karl Köhnlein
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Nadine Urban
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Holger Steinbrenner
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - David Guerrero-Gómez
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Antonio Miranda-Vizuete
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | | | - Lars-Oliver Klotz
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
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Romanelli-Credrez L, Doitsidou M, Alkema MJ, Salinas G. HIF-1 Has a Central Role in Caenorhabditis elegans Organismal Response to Selenium. Front Genet 2020; 11:63. [PMID: 32161616 PMCID: PMC7052493 DOI: 10.3389/fgene.2020.00063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/17/2020] [Indexed: 11/13/2022] Open
Abstract
Selenium is a trace element for most organisms; its deficiency and excess are detrimental. Selenium beneficial effects are mainly due to the role of the 21st genetically encoded amino acid selenocysteine (Sec). Selenium also exerts Sec-independent beneficial effects. Its harmful effects are thought to be mainly due to non-specific incorporation in protein synthesis. Yet the selenium response in animals is poorly understood. In Caenorhabditis elegans, Sec is genetically incorporated into a single selenoprotein. Similar to mammals, a 20-fold excess of the optimal selenium requirement is harmful. Sodium selenite (Na2SeO3) excess causes development retardation, impaired growth, and neurodegeneration of motor neurons. To study the organismal response to selenium we performed a genetic screen for C. elegans mutants that are resistant to selenite. We isolated non-sense and missense egl-9/EGLN mutants that confer robust resistance to selenium. In contrast, hif-1/HIF null mutant was highly sensitive to selenium, establishing a role for this transcription factor in the selenium response. We showed that EGL-9 regulates HIF-1 activity through VHL-1, and identified CYSL-1 as a key sensor that transduces the selenium signal. Finally, we showed that the key enzymes involved in sulfide and sulfite stress (sulfide quinone oxidoreductase and sulfite oxidase) are not required for selenium resistance. In contrast, knockout strains in the persulfide dioxygenase ETHE-1 and the sulfurtransferase MPST-7 affect the organismal response to selenium. In sum, our results identified a transcriptional pathway as well as enzymes possibly involved in the organismal selenium response.
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Affiliation(s)
- Laura Romanelli-Credrez
- Laboratorio de Biología de Gusanos. Unidad Mixta, Departamento de Biociencias, Facultad de Química, Universidad de la República-Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Maria Doitsidou
- Centre for Discovery Brain Sciences (CDBS), University of Edinburgh, Edinburgh, United Kingdom
| | - Mark J Alkema
- Neurobiology Department, University of Massachusetts Medical School, Worcester, MA, United States
| | - Gustavo Salinas
- Laboratorio de Biología de Gusanos. Unidad Mixta, Departamento de Biociencias, Facultad de Química, Universidad de la República-Institut Pasteur de Montevideo, Montevideo, Uruguay
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5
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Köhnlein K, Urban N, Guerrero-Gómez D, Steinbrenner H, Urbánek P, Priebs J, Koch P, Kaether C, Miranda-Vizuete A, Klotz LO. A Caenorhabditis elegans ortholog of human selenium-binding protein 1 is a pro-aging factor protecting against selenite toxicity. Redox Biol 2019; 28:101323. [PMID: 31557719 PMCID: PMC6812014 DOI: 10.1016/j.redox.2019.101323] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/30/2019] [Accepted: 09/07/2019] [Indexed: 12/21/2022] Open
Abstract
Human selenium-binding protein 1 (SELENBP1) was originally identified as a protein binding selenium, most likely as selenite. SELENBP1 is associated with cellular redox and thiol homeostasis in several respects, including its established role as a methanethiol oxidase that is involved in degradation of methanethiol, a methionine catabolite, generating hydrogen sulfide (H2S) and hydrogen peroxide (H2O2). As both H2S and reactive oxygen species (such as H2O2) are major regulators of Caenorhabditis elegans lifespan and stress resistance, we hypothesized that a SELENBP1 ortholog in C. elegans would likely be involved in regulating these aspects. Here we characterize Y37A1B.5, a putative selenium-binding protein 1 ortholog in C. elegans with 52% primary structure identity to human SELENBP1. While conferring resistance to toxic concentrations of selenite, Y37A1B.5 also attenuates resistance to oxidative stress and lowers C. elegans lifespan: knockdown of Y37A1B.5 using RNA interference resulted in an approx. 10% increase of C. elegans lifespan and an enhanced resistance against the redox cycler paraquat, as well as enhanced motility. Analyses of transgenic reporter strains suggest hypodermal expression and cytoplasmic localization of Y37A1B.5, whose expression decreases with worm age. We identify the transcriptional coregulator MDT-15 and transcription factor EGL-27 as regulators of Y37A1B.5 levels and show that the lifespan extending effect elicited by downregulation of Y37A1B.5 is independent of known MDT-15 interacting factors, such as DAF-16 and NHR-49. In summary, Y37A1B.5 is an ortholog of SELENBP1 that shortens C. elegans lifespan and lowers resistance against oxidative stress, while allowing for a better survival under toxic selenite concentrations.
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Affiliation(s)
- Karl Köhnlein
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany; Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
| | - Nadine Urban
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - David Guerrero-Gómez
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Holger Steinbrenner
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Pavel Urbánek
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Josephine Priebs
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Philipp Koch
- Leibniz Institute on Aging - Fritz Lipmann Institute, Jena, Germany
| | | | - Antonio Miranda-Vizuete
- Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Lars-Oliver Klotz
- Institute of Nutritional Sciences, Nutrigenomics Section, Friedrich-Schiller-Universität Jena, Jena, Germany.
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Romero I, de Francisco P, Gutiérrez JC, Martín-González A. Selenium cytotoxicity in Tetrahymena thermophila: New clues about its biological effects and cellular resistance mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 671:850-865. [PMID: 30947056 DOI: 10.1016/j.scitotenv.2019.03.115] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
Selenium is an essential micronutrient but at high concentrations can produce severe cytotoxicity and genomic damage. We have evaluated the cytotoxicity, ultrastructural and mitochondrial alterations of the two main selenium inorganic species; selenite and selenate, in the eukaryotic microorganism Tetrahymena thermophila. In this ciliate, selenite is more toxic than selenate. Their LC50 values were calculated as 27.65 μM for Se(IV) and 56.88 mM for Se(VI). Significant levels of peroxides/hydroperoxides are induced under low-moderate selenite or selenate concentrations. Se(VI) exposures induce an immediate mitochondrial membrane depolarization. Selenium treated cells show an intense vacuolization and some of them present numerous discrete and small electrondense particles, probably selenium deposits. Mitochondrial fusion, an intense swelling in peripheral mitochondria and mitophagy are detected in selenium treated cells, especially in those exposed to Se (IV). qRT-PCR analysis of diverse genes, encoding relevant antioxidant enzymes or other proteins, like metallothioneins, involved in an environmental general stress response, have shown that they may be crucial against Se(IV) and/or Se (VI) cytotoxicity.
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Affiliation(s)
- Ivan Romero
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain
| | - Patricia de Francisco
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain
| | - Juan Carlos Gutiérrez
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain
| | - Ana Martín-González
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain..
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7
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Ferguson GD, Bridge WJ. The glutathione system and the related thiol network in Caenorhabditis elegans. Redox Biol 2019. [DOI: 10.1110.1016/j.redox.2019.101171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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8
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Rohn I, Raschke S, Aschner M, Tuck S, Kuehnelt D, Kipp A, Schwerdtle T, Bornhorst J. Treatment of Caenorhabditis elegans with Small Selenium Species Enhances Antioxidant Defense Systems. Mol Nutr Food Res 2019; 63:e1801304. [PMID: 30815971 PMCID: PMC6499701 DOI: 10.1002/mnfr.201801304] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/28/2019] [Indexed: 01/10/2023]
Abstract
SCOPE Small selenium (Se) species play a key role in Se metabolism and act as dietary sources of the essential trace element. However, they are redox-active and trigger pro- and antioxidant responses. As health outcomes are strongly species-dependent, species-specific characteristics of Se compounds are tested in vivo. METHODS AND RESULTS In the model organism Caenorhabditis elegans (C. elegans), immediate and sustained effects of selenite, selenomethionine (SeMet), and Se-methylselenocysteine (MeSeCys) are studied regarding their bioavailability, incorporation into proteins, as well as modulation of the cellular redox status. While all tested Se compounds are bioavailable, only SeMet persistently accumulates and is non-specifically incorporated into proteins. However, the protection toward chemically-induced formation of reactive species is independent of the applied Se compound. Increased thioredoxin reductase (TXNRD) activity and changes in mRNA expression levels of antioxidant proteins indicate the activation of cellular defense mechanisms. However, in txnrd-1 deletion mutants, no protective effects of the Se species are observed anymore, which is also reflected by differential gene expression data. CONCLUSION Se species protect against chemically-induced reactive species formation. The identified immediate and sustained systemic effects of Se species give rise to speculations on possible benefits facing subsequent periods of inadequate Se intake.
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Affiliation(s)
- Isabelle Rohn
- Institute of Nutritional Science, University of Potsdam, 14558, Nuthetal, Germany
| | - Stefanie Raschke
- Institute of Nutritional Science, University of Potsdam, 14558, Nuthetal, Germany
| | | | - Simon Tuck
- Umeå Centre for Molecular Medicine, Umeå University, 90187, Umeå, Sweden
| | - Doris Kuehnelt
- Institute of Chemistry, Analytical Chemistry, NAWI Graz, University of Graz, 8010, Graz, Austria
| | - Anna Kipp
- Institute of Nutrition, Friedrich Schiller University Jena, 07743, Jena, Germany
- TraceAge - DFG Research Unit FOR 2558, Berlin-Potsdam-Jena, Germany
| | - Tanja Schwerdtle
- Institute of Nutritional Science, University of Potsdam, 14558, Nuthetal, Germany
- TraceAge - DFG Research Unit FOR 2558, Berlin-Potsdam-Jena, Germany
| | - Julia Bornhorst
- Institute of Nutritional Science, University of Potsdam, 14558, Nuthetal, Germany
- TraceAge - DFG Research Unit FOR 2558, Berlin-Potsdam-Jena, Germany
- Faculty of Mathematics and Natural Sciences, University of Wuppertal, 42119, Wuppertal, Germany
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9
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Rohn I, Marschall TA, Kroepfl N, Jensen KB, Aschner M, Tuck S, Kuehnelt D, Schwerdtle T, Bornhorst J. Selenium species-dependent toxicity, bioavailability and metabolic transformations in Caenorhabditis elegans. Metallomics 2019; 10:818-827. [PMID: 29770420 DOI: 10.1039/c8mt00066b] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The essential micronutrient selenium (Se) is required for various systemic functions, but its beneficial range is narrow and overexposure may result in adverse health effects. Additionally, the chemical form of the ingested selenium contributes crucially to its health effects. While small Se species play a major role in Se metabolism, their toxicological effects, bioavailability and metabolic transformations following elevated uptake are poorly understood. Utilizing the tractable invertebrate Caenorhabditis elegans allowed for an alternative approach to study species-specific characteristics of organic and inorganic Se forms in vivo, revealing remarkable species-dependent differences in the toxicity and bioavailability of selenite, selenomethionine (SeMet) and Se-methylselenocysteine (MeSeCys). An inverse relationship was found between toxicity and bioavailability of the Se species, with the organic species displaying a higher bioavailability than the inorganic form, yet being less toxic. Quantitative Se speciation analysis with HPLC/mass spectrometry revealed a partial metabolism of SeMet and MeSeCys. In SeMet exposed worms, identified metabolites were Se-adenosylselenomethionine (AdoSeMet) and Se-adenosylselenohomocysteine (AdoSeHcy), while worms exposed to MeSeCys produced Se-methylselenoglutathione (MeSeGSH) and γ-glutamyl-MeSeCys (γ-Glu-MeSeCys). Moreover, the possible role of the sole selenoprotein in the nematode, thioredoxin reductase-1 (TrxR-1), was studied comparing wildtype and trxr-1 deletion mutants. Although a lower basal Se level was detected in trxr-1 mutants, Se toxicity and bioavailability following acute exposure was indistinguishable from wildtype worms. Altogether, the current study demonstrates the suitability of C. elegans as a model for Se species dependent toxicity and metabolism, while further research is needed to elucidate TrxR-1 function in the nematode.
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Affiliation(s)
- Isabelle Rohn
- Department of Food Chemistry, Institute of Nutritional Science, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.
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10
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Ferguson GD, Bridge WJ. The glutathione system and the related thiol network in Caenorhabditis elegans. Redox Biol 2019; 24:101171. [PMID: 30901603 PMCID: PMC6429583 DOI: 10.1016/j.redox.2019.101171] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 03/07/2019] [Accepted: 03/13/2019] [Indexed: 01/09/2023] Open
Abstract
Advances in the field of redox biology have contributed to the understanding of the complexity of the thiol-based system in mediating signal transduction. The redox environment is the overall spatiotemporal balance of oxidation-reduction systems within the integrated compartments of the cell, tissues and whole organisms. The ratio of the reduced to disulfide glutathione redox couple (GSH:GSSG) is a key indicator of the redox environment and its associated cellular health. The reaction mechanisms of glutathione-dependent and related thiol-based enzymes play a fundamental role in the function of GSH as a redox regulator. Glutathione homeostasis is maintained by the balance of GSH synthesis (de novo and salvage pathways) and its utilization through its detoxification, thiol signalling, and antioxidant defence functions via GSH-dependent enzymes and free radical scavenging. As such, GSH acts in concert with the entire redox network to maintain reducing conditions in the cell. Caenorhabditis elegans offers a simple model to facilitate further understanding at the multicellular level of the physiological functions of GSH and the GSH-dependent redox network. This review discusses the C. elegans studies that have investigated glutathione and related systems of the redox network including; orthologs to the protein-encoding genes of GSH synthesis; glutathione peroxidases; glutathione-S-transferases; and the glutaredoxin, thioredoxin and peroxiredoxin systems.
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Affiliation(s)
- Gavin Douglas Ferguson
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia
| | - Wallace John Bridge
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, NSW, 2052, Australia.
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11
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Josende ME, Nunes SM, Müller L, Ferreira-Cravo M, Monserrat JM, Ventura-Lima J. Circular Estimate Method (CEM) - a Simple Method to Estimate Caenorhabditis elegans Culture Densities in Liquid Medium. Biol Proced Online 2019; 21:1. [PMID: 30675134 PMCID: PMC6334471 DOI: 10.1186/s12575-018-0089-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 12/28/2018] [Indexed: 11/10/2022] Open
Abstract
Background Nematodes are used in many different fields of science, including environmental and biomedical research. Counting and/or estimating nematode numbers is required during research. Although being one of the most common procedures, this apparently simple task is a time-consuming process, prone to errors and concerns regarding procedure, reliability, and accuracy. When an estimate is necessary, there is a traditional manual counting procedure that in this study it will be called as "drop method" (DM). This popular method that extrapolates an animal count from a small drop of fluid shows a high coefficient of variation. To solve this problem, the present study used the free-living nematode Caenorhabditis elegans to develop a new estimation procedure that was based on a relationship between area and volume of a larger sample. Results The new method showed a low coefficient of variation and a close relationship between estimated and real counts of the total number of nematodes in large C. elegans suspensions. Reactive oxygen concentration was measured as an example of method application and to allow comparison between methods. Conclusion The proposed method is accurate, facile and reproducible, requiring simple, inexpensive materials that make it an excellent alternative to the DM manual counting procedure. Although the DM is faster, its estimates are not as accurate or as precise as those of the new proposed method.
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Affiliation(s)
- Marcelo Estrella Josende
- 1Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Av. Itália km 8, Rio Grande, RS 96203-900 Brazil.,Programa de Pós-Graduação em Ciências Fisiológicas (PPGCF) - FURG, Rio Grande, Brazil
| | - Silvana Manske Nunes
- 1Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Av. Itália km 8, Rio Grande, RS 96203-900 Brazil.,Programa de Pós-Graduação em Ciências Fisiológicas (PPGCF) - FURG, Rio Grande, Brazil
| | - Larissa Müller
- 1Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Av. Itália km 8, Rio Grande, RS 96203-900 Brazil.,Programa de Pós-Graduação em Ciências Fisiológicas (PPGCF) - FURG, Rio Grande, Brazil
| | - Marlize Ferreira-Cravo
- 1Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Av. Itália km 8, Rio Grande, RS 96203-900 Brazil
| | - José Marìa Monserrat
- 1Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Av. Itália km 8, Rio Grande, RS 96203-900 Brazil.,Programa de Pós-Graduação em Ciências Fisiológicas (PPGCF) - FURG, Rio Grande, Brazil
| | - Juliane Ventura-Lima
- 1Instituto de Ciências Biológicas (ICB), Universidade Federal do Rio Grande - FURG, Av. Itália km 8, Rio Grande, RS 96203-900 Brazil.,Programa de Pós-Graduação em Ciências Fisiológicas (PPGCF) - FURG, Rio Grande, Brazil
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12
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Constantinescu-Aruxandei D, Frîncu RM, Capră L, Oancea F. Selenium Analysis and Speciation in Dietary Supplements Based on Next-Generation Selenium Ingredients. Nutrients 2018; 10:E1466. [PMID: 30304813 PMCID: PMC6213372 DOI: 10.3390/nu10101466] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 10/02/2018] [Accepted: 10/03/2018] [Indexed: 12/27/2022] Open
Abstract
Selenium is essential for humans and the deficit of Se requires supplementation. In addition to traditional forms such as Se salts, amino acids, or selenium-enriched yeast supplements, next-generation selenium supplements, with lower risk for excess supplementation, are emerging. These are based on selenium forms with lower toxicity, higher bioavailability, and controlled release, such as zerovalent selenium nanoparticles (SeNPs) and selenized polysaccharides (SPs). This article aims to focus on the existing analytical systems for the next-generation Se dietary supplement, providing, at the same time, an overview of the analytical methods available for the traditional forms. The next-generation dietary supplements are evaluated in comparison with the conventional/traditional ones, as well as the analysis and speciation methods that are suitable to reveal which Se forms and species are present in a dietary supplement. Knowledge gaps and further research potential in this field are highlighted. The review indicates that the methods of analysis of next-generation selenium supplements should include a step related to chemical species separation. Such a step would allow a proper characterization of the selenium forms/species, including molecular mass/dimension, and substantiates the marketing claims related to the main advantages of these new selenium ingredients.
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Affiliation(s)
- Diana Constantinescu-Aruxandei
- National Research & Development Institute for Chemistry and Petrochemistry ICECHIM, 202 Splaiul Independentei, 060021 Bucharest, Romania.
| | - Rodica Mihaela Frîncu
- INCDCP-ICECHIM Calarasi Subsidiary, 7A Nicolae Titulescu St., 915300 Lehliu Gara, Romania.
| | - Luiza Capră
- National Research & Development Institute for Chemistry and Petrochemistry ICECHIM, 202 Splaiul Independentei, 060021 Bucharest, Romania.
| | - Florin Oancea
- National Research & Development Institute for Chemistry and Petrochemistry ICECHIM, 202 Splaiul Independentei, 060021 Bucharest, Romania.
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13
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McDermott JR, Geng X, Jiang L, Gálvez-Peralta M, Chen F, Nebert DW, Liu Z. Zinc- and bicarbonate-dependent ZIP8 transporter mediates selenite uptake. Oncotarget 2018; 7:35327-40. [PMID: 27166256 PMCID: PMC5085232 DOI: 10.18632/oncotarget.9205] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 04/11/2016] [Indexed: 12/26/2022] Open
Abstract
Selenite (HSeO3−) is a monovalent anion of the essential trace element and micronutrient selenium (Se). In therapeutic concentrations, HSeO3− has been studied for treating certain cancers, serious inflammatory disorders, and septic shock. Little is known, however, about HSeO3− uptake into mammalian cells; until now, no mammalian HSeO3− uptake transporter has been identified. The ubiquitous mammalian ZIP8 divalent cation transporter (encoded by the SLC39A8 gene) is bicarbonate-dependent, moving endogenous substrates (Zn2+, Mn2+, Fe2+ or Co2+) and nonessential metals such as Cd2+ into the cell. Herein we studied HSeO3− uptake in: human and mouse cell cultures, shRNA-knockdown experiments, Xenopus oocytes, wild-type mice and two transgenic mouse lines having genetically altered ZIP8 expression, and mouse erythrocytes ex vivo. In mammalian cell culture, excess Zn2+ levels and/or ZIP8 over-expression can be associated with diminished viability in selenite-treated cells. Intraperitoneal HSeO3− causes the largest ZIP8-dependent increases in intracellular Se content in liver, followed by kidney, heart, lung and spleen. In every model system studied, HSeO3− uptake is tightly associated with ZIP8 protein levels and sufficient Zn2+ and HCO3− concentrations, suggesting that the ZIP8-mediated electroneutral complex transported contains three ions: Zn2+/(HCO3−)(HSeO3−). Transporters having three different ions in their transport complex are not without precedent. Although there might be other HSeO3− influx transporters as yet undiscovered, data herein suggest that mammalian ZIP8 plays a major role in HSeO3− uptake.
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Affiliation(s)
- Joseph R McDermott
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Xiangrong Geng
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Lan Jiang
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
| | - Marina Gálvez-Peralta
- Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA
| | - Fei Chen
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, Wayne State University, Detroit, MI 48201, USA
| | - Daniel W Nebert
- Department of Environmental Health and Center for Environmental Genetics, University of Cincinnati Medical Center, Cincinnati, OH 45267, USA
| | - Zijuan Liu
- Department of Biological Sciences, Oakland University, Rochester, MI 48309, USA
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14
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Yim SH, Tobe R, Turanov AA, Carlson BA. Radioactive 75Se Labeling and Detection of Selenoproteins. Methods Mol Biol 2018; 1661:177-192. [PMID: 28917045 DOI: 10.1007/978-1-4939-7258-6_13] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The trace element selenium (Se) is incorporated into proteins as the amino acid selenocysteine (Sec), which is cotranslationally inserted into specific proteins in response to a UGA codon. Proteins containing Sec at these specific positions are called selenoproteins. Most selenoproteins function as oxidoreductases, while some serve other important functions. There are 25 known selenoprotein genes in humans and 24 in mice. The use of Sec allows selenoproteins to be detected by a convenient method involving metabolic labeling with 75Se. Labeling of cells and whole animals are used for the examination of selenoprotein expression profiles and the investigation of selenoprotein functions. In mammals, nonspecific 75Se insertion is very low, and sensitivity and specificity of selenoprotein detection approaches that of Western blotting. This method allows for the examination of selenoprotein expression and Se metabolism in model and non-model organisms. Herein, we describe experimental protocols for analyzing selenoproteins by metabolic labeling with 75Se both in vitro and in vivo. As an example, the procedure for metabolic labeling of HEK293T human embryonic kidney cells is described in detail. This approach remains a method of choice for the detection of selenoproteins in diverse settings.
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Affiliation(s)
- Sun Hee Yim
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Ryuta Tobe
- College of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Anton A Turanov
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Bradley A Carlson
- Molecular Biology of Selenium Section, Mouse Cancer Genetics Program, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
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15
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Vinceti M, Chiari A, Eichmüller M, Rothman KJ, Filippini T, Malagoli C, Weuve J, Tondelli M, Zamboni G, Nichelli PF, Michalke B. A selenium species in cerebrospinal fluid predicts conversion to Alzheimer's dementia in persons with mild cognitive impairment. ALZHEIMERS RESEARCH & THERAPY 2017; 9:100. [PMID: 29258624 PMCID: PMC5735937 DOI: 10.1186/s13195-017-0323-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 11/20/2017] [Indexed: 12/13/2022]
Abstract
Background Little is known about factors influencing progression from mild cognitive impairment to Alzheimer’s dementia. A potential role of environmental chemicals and specifically of selenium, a trace element of nutritional and toxicological relevance, has been suggested. Epidemiologic studies of selenium are lacking, however, with the exception of a recent randomized trial based on an organic selenium form. Methods We determined concentrations of selenium species in cerebrospinal fluid sampled at diagnosis in 56 participants with mild cognitive impairment of nonvascular origin. We then investigated the relation of these concentrations to subsequent conversion from mild cognitive impairment to Alzheimer’s dementia. Results Twenty-one out of the 56 subjects developed Alzheimer’s dementia during a median follow-up of 42 months; four subjects developed frontotemporal dementia and two patients Lewy body dementia. In a Cox proportional hazards model adjusting for age, sex, duration of sample storage, and education, an inorganic selenium form, selenate, showed a strong association with Alzheimer’s dementia risk, with an adjusted hazard ratio of 3.1 (95% confidence interval 1.0–9.5) in subjects having a cerebrospinal fluid content above the median level, compared with those with lower concentration. The hazard ratio of Alzheimer’s dementia showed little departure from unity for all other inorganic and organic selenium species. These associations were similar in analyses that measured exposure on a continuous scale, and also after excluding individuals who converted to Alzheimer’s dementia at the beginning of the follow-up. Conclusions These results indicate that higher amounts of a potentially toxic inorganic selenium form in cerebrospinal fluid may predict conversion from mild cognitive impairment to Alzheimer’s dementia. Electronic supplementary material The online version of this article (doi:10.1186/s13195-017-0323-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Marco Vinceti
- CREAGEN-Environmental, Genetic, and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy. .,Center for Neurosciences and Neurotechnology, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy. .,Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, 02118, USA.
| | - Annalisa Chiari
- Center for Neurosciences and Neurotechnology, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy.,Department of Neurosciences, Azienda Ospedaliero-Universitaria di Modena, via del Pozzo 71, Modena, Italy
| | - Marcel Eichmüller
- Helmholtz Zentrum München GmbH-German Research Center for Environmental Health GmbH, Research Unit Analytical BioGeoChemistry, 1 Ingolstaedter Landstrasse, Neuherberg, 85764, Germany
| | - Kenneth J Rothman
- Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, 02118, USA.,Research Triangle Institute, Research Triangle Park, 3040 E Cornwallis Road, Durham, NC, 27709, USA
| | - Tommaso Filippini
- CREAGEN-Environmental, Genetic, and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy
| | - Carlotta Malagoli
- CREAGEN-Environmental, Genetic, and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy
| | - Jennifer Weuve
- Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, 02118, USA
| | - Manuela Tondelli
- Center for Neurosciences and Neurotechnology, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy.,Department of Neurosciences, Azienda Ospedaliero-Universitaria di Modena, via del Pozzo 71, Modena, Italy
| | - Giovanna Zamboni
- Center for Neurosciences and Neurotechnology, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy
| | - Paolo F Nichelli
- Center for Neurosciences and Neurotechnology, Department of Biomedical, Metabolic, and Neural Sciences, University of Modena and Reggio Emilia, 287 Via Campi, Modena, 41125, Italy.,Department of Neurosciences, Azienda Ospedaliero-Universitaria di Modena, via del Pozzo 71, Modena, Italy
| | - Bernhard Michalke
- Helmholtz Zentrum München GmbH-German Research Center for Environmental Health GmbH, Research Unit Analytical BioGeoChemistry, 1 Ingolstaedter Landstrasse, Neuherberg, 85764, Germany
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16
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Selenium requirements based on muscle and kidney selenoprotein enzyme activity and transcript expression in the turkey poult (Meleagris gallopavo). PLoS One 2017; 12:e0189001. [PMID: 29190764 PMCID: PMC5708738 DOI: 10.1371/journal.pone.0189001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/16/2017] [Indexed: 11/19/2022] Open
Abstract
The current NRC selenium (Se) requirement for turkeys is 0.2 μg Se/g diet. We previously fed turkey poults a Se-deficient diet (0.005 μg Se/g) supplemented with 10 graded levels of Se (0, 0.025, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.75, 1.0 μg Se/g as Na2SeO3, 5/treatment) for 4 wk, and found that the minimum dietary Se requirement was 0.3 μg Se/g based on selenoprotein enzyme activity in blood, liver, gizzard and pancreas. Because the turkey is primarily a production animal, we expanded this analysis to kidney, heart, breast and thigh. Se concentrations in Se-deficient poults were 5.0, 9.8, 33, and 15% of levels in poults fed 0.4 μg Se/g in liver, kidney, thigh and breast, respectively. Increasing Se supplementation resulted in hyperbolic response curves for all tissues; breakpoint analysis indicated minimum Se requirements of 0.34-0.36 μg Se/g based on tissue Se levels in liver, kidney and thigh. Similarly, GPX1 activity in muscle tissues and kidney responded hyperbolically to increasing dietary Se, reaching well-defined plateaus with breakpoints at 0.30-0.36 μg Se/g. Minimum Se requirements based on GPX4 activity were 0.30-0.32 μg Se/g for breast and thigh. Selenoprotein transcript expression decreased significantly in Se deficiency for only 2, 3, 5, and 6 mRNA in breast, thigh, heart, and kidney, respectively, out of 24 known avian selenoproteins. Se response curves for regulated selenoprotein transcripts were hyperbolic, and reached well-defined plateaus with breakpoints in a narrow range of 0.08-0.19 μg Se/g. No selenoprotein transcript was altered by supernutritional Se. In summary, these results clearly indicate that the NRC dietary Se requirement should be raised to 0.4 μg Se/g, at least for poults, to meet the nutritional needs of the young turkey. The Se response curve plateaus further show that limits for turkey supplementation with selenite could safely be raised to 0.5 μg Se/g diet.
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17
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Salgueiro WG, Goldani BS, Peres TV, Miranda-Vizuete A, Aschner M, da Rocha JBT, Alves D, Ávila DS. Insights into the differential toxicological and antioxidant effects of 4-phenylchalcogenil-7-chloroquinolines in Caenorhabditis elegans. Free Radic Biol Med 2017; 110:133-141. [PMID: 28571752 DOI: 10.1016/j.freeradbiomed.2017.05.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 05/18/2017] [Accepted: 05/24/2017] [Indexed: 01/01/2023]
Abstract
Organic selenium and tellurium compounds are known for their broad-spectrum effects in a variety of experimental disease models. However, these compounds commonly display high toxicity and the molecular mechanisms underlying these deleterious effects have yet to be elucidated. Thus, the need for an animal model that is inexpensive, amenable to high-throughput analyses, and feasible for molecular studies is highly desirable to improve organochalcogen pharmacological and toxicological characterization. Herein, we use Caenorhabdtis elegans (C. elegans) as a model for the assessment of pharmacological and toxicological parameters following exposure to two 4-phenylchalcogenil-7-chloroquinolines derivatives (PSQ for selenium and PTQ for tellurium-containing compounds). While non-lethal concentrations (NLC) of PTQ and PSQ attenuated paraquat-induced effects on survival, lifespan and oxidative stress parameters, lethal concentrations (LC) of PTQ and PSQ alone are able to impair these parameters in C. elegans. We also demonstrate that DAF-16/FOXO and SKN-1/Nrf2 transcription factors underlie the mechanism of action of these compounds, as their targets sod-3, gst-4 and gcs-1 were modulated following exposures in a daf-16- and skn-1-dependent manner. Finally, in accordance with a disturbed thiol metabolism in both LC and NLC, we found higher sensitivity of trxr-1 worm mutants (lacking the selenoprotein thioredoxin reductase 1) when exposed to PSQ. Finally, our study suggests new targets for the investigation of organochalcogen pharmacological effects, reinforcing the use of C. elegans as a powerful platform for preclinical approaches.
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Affiliation(s)
- Willian G Salgueiro
- Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCE),Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970 Uruguaiana, RS, Brazil
| | - Bruna S Goldani
- Laboratório de Síntese Orgânica Limpa - LASOL - CCQFA - Universidade Federal de Pelotas - UFPel, CEP 96010-900 Pelotas, RS, Brazil
| | - Tanara V Peres
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Antonio Miranda-Vizuete
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - João Batista Teixeira da Rocha
- Departamento de Bioquímica e Biologia Molecular, CCNE, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil
| | - Diego Alves
- Laboratório de Síntese Orgânica Limpa - LASOL - CCQFA - Universidade Federal de Pelotas - UFPel, CEP 96010-900 Pelotas, RS, Brazil
| | - Daiana S Ávila
- Grupo de Pesquisa em Bioquímica e Toxicologia em Caenorhabditis elegans (GBToxCE),Universidade Federal do Pampa - UNIPAMPA, CEP 97500-970 Uruguaiana, RS, Brazil.
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18
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Wyatt LH, Diringer SE, Rogers LA, Hsu-Kim H, Pan WK, Meyer JN. Antagonistic Growth Effects of Mercury and Selenium in Caenorhabditis elegans Are Chemical-Species-Dependent and Do Not Depend on Internal Hg/Se Ratios. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:3256-64. [PMID: 26938845 PMCID: PMC4964607 DOI: 10.1021/acs.est.5b06044] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The relationship between mercury (Hg) and selenium (Se) toxicity is complex, with coexposure reported to reduce, increase, and have no effect on toxicity. Different interactions may be related to chemical compound, but this has not been systematically examined. Our goal was to assess the interactive effects between the two elements on growth in the nematode Caenorhabditis elegans, focusing on inorganic and organic Hg (HgCl2 and MeHgCl) and Se (selenomethionine, sodium selenite, and sodium selenate) compounds. We utilized aqueous Hg/Se dosing molar ratios that were either above, below, or equal to 1 and measured the internal nematode total Hg and Se concentrations for the highest concentrations of each Se compound. Observed interactions were complicated, differed between Se and Hg compounds, and included greater-than-additive, additive, and less-than-additive growth impacts. Biologically significant interactions were only observed when the dosing Se solution concentration was 100-25,000 times greater than the dosing Hg concentration. Mitigation of growth impacts was not predictable on the basis of internal Hg/Se molar ratio; improved growth was observed at some internal Hg/Se molar ratios both above and below 1. These findings suggest that future assessments of the Hg and Se relationship should incorporate chemical compound into the evaluation.
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Affiliation(s)
- Lauren H. Wyatt
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
| | - Sarah E. Diringer
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Laura A. Rogers
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - Heileen Hsu-Kim
- Department of Civil and Environmental Engineering, Duke University, Durham, North Carolina 27708, United States
| | - William K. Pan
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- Global Health Institute, Duke University, Durham, North Carolina 27708, United States
| | - Joel N. Meyer
- Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States
- Corresponding Author. Phone: 919-613-8109;
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19
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Solovyev ND. Importance of selenium and selenoprotein for brain function: From antioxidant protection to neuronal signalling. J Inorg Biochem 2015; 153:1-12. [PMID: 26398431 DOI: 10.1016/j.jinorgbio.2015.09.003] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 09/03/2015] [Accepted: 09/09/2015] [Indexed: 12/21/2022]
Abstract
Multiple biological functions of selenium manifest themselves mainly via 25 selenoproteins that have selenocysteine at their active centre. Selenium is vital for the brain and seems to participate in the pathology of disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and epilepsy. Since selenium was shown to be involved in diverse functions of the central nervous system, such as motor performance, coordination, memory and cognition, a possible role of selenium and selenoproteins in brain signalling pathways may be assumed. The aim of the present review is to analyse possible relations between selenium and neurotransmission. Selenoproteins seem to be of special importance in the development and functioning of GABAergic (GABA, γ-aminobutyric acid) parvalbumin positive interneurons of the cerebral cortex and hippocampus. Dopamine pathway might be also selenium dependent as selenium shows neuroprotection in the nigrostriatal pathway and also exerts toxicity towards dopaminergic neurons under higher concentrations. Recent findings also point to acetylcholine neurotransmission involvement. The role of selenium and selenoproteins in neurotransmission might not only be limited to their antioxidant properties but also to inflammation, influencing protein phosphorylation and ion channels, alteration of calcium homeostasis and brain cholesterol metabolism. Moreover, a direct signalling function was proposed for selenoprotein P through interaction with post-synaptic apoliprotein E receptors 2 (ApoER2).
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Affiliation(s)
- Nikolay D Solovyev
- Institute of Chemistry, St. Petersburg State University, St. Petersburg 198504, Russian Federation.
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20
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Li WH, Ju YR, Liao CM, Liao VHC. Assessment of selenium toxicity on the life cycle of Caenorhabditis elegans. ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:1245-1253. [PMID: 24906985 DOI: 10.1007/s10646-014-1267-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/22/2014] [Indexed: 06/03/2023]
Abstract
Selenium (Se) is a growing problem of global concern. Se can cause adverse effects on reproductive systems, which have been linked to declines in animal populations. The soil nematode Caenorhabditis elegans (C. elegans) is a ubiquitous soil organism that is increasingly utilized as a model organism in aquatic and soil toxicology. In the present study, the experimental data for individual body length, survival rate, brood size, and hatching rate were used to evaluate the possible effects of selenite [Se(IV)] on C. elegans. A stage-classified matrix model was applied to the experimental data to provide information on the population dynamics of C. elegans and to assess the Se(IV)-affected asymptotic population growth rate. Estimates of the survival probability showed significant decreases in survival at all stages when C. elegans was exposed to Se(IV). The growth probability of C. elegans in the L1 stage showed the most significant decline, from 0.11 h(-1) (for the control) to 0.04 h(-1) [for exposure to 3 mM Se(IV)]. These results showed that Se(IV) has a profound impact on C. elegans population dynamics. The asymptotic population growth rate (λ) was found to range from 1.00 to 0.64 h(-1) for increasing Se(IV) concentrations, implying a potential risk of population decrease for C. elegans exposure to a Se(IV)-contaminated environment. Our study shows how a mechanistic view based on the Se(IV) effects on the soil nematode C. elegans can promote a life cycle toxicity assessment. An important implication of this analysis is that mathematical models can be used to produce a population stage structure, to give clarity to the analysis of the key population-level endpoint (the asymptotic population growth rate) of population dynamics, and to evaluate the influences for the response of other species to environmental Se. These models sequentially provide candidate environmental criteria for the evaluation of the population impact of Se.
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Affiliation(s)
- Wen-Hsuan Li
- Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1 Roosevelt Road, Sec. 4, Taipei, 106, Taiwan
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21
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Deep-sea water containing selenium provides intestinal protection against duodenal ulcers through the upregulation of Bcl-2 and thioredoxin reductase 1. PLoS One 2014; 9:e96006. [PMID: 24984066 PMCID: PMC4077573 DOI: 10.1371/journal.pone.0096006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 04/02/2014] [Indexed: 02/06/2023] Open
Abstract
Deep-sea water (DSW), which is rich in micronutrients and minerals and with antioxidant and anti-inflammatory qualities, may be developed as marine drugs to provide intestinal protection against duodenal ulcers. We determined several characteristics in the modified DSW. We explored duodenal pressure, oxygenation, microvascular blood flow, and changes in pH and oxidative redox potential (ORP) values within the stomach and duodenum in response to tap water (TW, hardness: 2.48 ppm), DSW600 (hardness: 600 ppm), and DSW1200 (hardness: 1200 ppm) in Wistar rats and analyzed oxidative stress and apoptosis gene expressions by cDNA and RNA microarrays in the duodenal epithelium. We compared the effects of drinking DSW, MgCl2, and selenium water on duodenal ulcers using pathologic scoring, immunohistochemical analysis, and Western blotting. Our results showed DSW has a higher pH value, lower ORP value, higher scavenging H2O2 and HOCl activity, higher Mg2+ concentrations, and micronutrients selenium compared with TW samples. Water infusion significantly increased intestinal pressure, O2 levels, and microvascular blood flow in DSW and TW groups. Microarray showed DSW600, DSW1200, selenium water upregulated antioxidant and anti-apoptotic genes and downregulated pro-apoptotic gene expression compared with the TW group. Drinking DSW600, DSW1200, and selenium water but not Mg2+ water significantly enhanced Bcl-2 and thioredoxin reductase 1 expression. Bax/Bcl-2/caspase 3/poly-(ADP-ribose)-polymerase signaling was activated during the pathogenesis of duodenal ulceration. DSW drinking reduced ulcer area as well as apoptotic signaling in acetic acid-induced duodenal ulcers. DSW, which contains selenium, provides intestinal protection against duodenal ulcers through the upregulation of Bcl-2 and thioredoxin reductase 1.
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Boehler CJ, Raines AM, Sunde RA. Toxic-selenium and low-selenium transcriptomes in Caenorhabditis elegans: toxic selenium up-regulates oxidoreductase and down-regulates cuticle-associated genes. PLoS One 2014; 9:e101408. [PMID: 24971995 PMCID: PMC4074201 DOI: 10.1371/journal.pone.0101408] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 06/05/2014] [Indexed: 01/29/2023] Open
Abstract
Selenium (Se) is an element that in trace quantities is both essential in mammals but also toxic to bacteria, yeast, plants and animals, including C. elegans. Our previous studies showed that selenite was four times as toxic as selenate to C. elegans, but that deletion of thioredoxin reductase did not modulate Se toxicity. To characterize Se regulation of the full transcriptome, we conducted a microarray study in C. elegans cultured in axenic media supplemented with 0, 0.05, 0.1, 0.2, and 0.4 mM Se as selenite. C. elegans cultured in 0.2 and 0.4 mM Se displayed a significant delay in growth as compared to 0, 0.05, or 0.1 mM Se, indicating Se-induced toxicity, so worms were staged to mid-L4 larval stage for these studies. Relative to 0.1 mM Se treatment, culturing C. elegans at these Se concentrations resulted in 1.9, 9.7, 5.5, and 2.3%, respectively, of the transcriptome being altered by at least 2-fold. This toxicity altered the expression of 295 overlapping transcripts, which when filtered against gene sets for sulfur and cadmium toxicity, identified a dataset of 182 toxic-Se specific genes that were significantly enriched in functions related to oxidoreductase activity, and significantly depleted in genes related to structural components of collagen and the cuticle. Worms cultured in low Se (0 mM Se) exhibited no signs of deficiency, but low Se was accompanied by a transcriptional response of 59 genes changed ≥2-fold when compared to all other Se concentrations, perhaps due to decreases in Se-dependent TRXR-1 activity. Overall, these results suggest that Se toxicity in C. elegans causes an increase in ROS and stress responses, marked by increased expression of oxidoreductases and reduced expression of cuticle-associated genes, which together underlie the impaired growth observed in these studies.
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Affiliation(s)
- Christopher J. Boehler
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Anna M. Raines
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Roger A. Sunde
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
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Estevez AO, Morgan KL, Szewczyk NJ, Gems D, Estevez M. The neurodegenerative effects of selenium are inhibited by FOXO and PINK1/PTEN regulation of insulin/insulin-like growth factor signaling in Caenorhabditis elegans. Neurotoxicology 2014; 41:28-43. [PMID: 24406377 PMCID: PMC3979119 DOI: 10.1016/j.neuro.2013.12.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/23/2013] [Accepted: 12/27/2013] [Indexed: 12/12/2022]
Abstract
Insulin/insulin-like signaling reduction alters selenium-induced neurodegeneration. Selenium induces nuclear translocation of DAF-16/FOXO3a. DAF-16 overexpression decreases GABAergic and cholinergic motor neuron degeneration. Loss of DAF-18/PTEN increases sensitivity to selenium-induced movement deficits. Glutathione requires DAF-18/PINK-1 to improve selenium-induced movement deficits.
Exposures to high levels of environmental selenium have been associated with motor neuron disease in both animals and humans and high levels of selenite have been identified in the cerebrospinal fluid of patients with amyotrophic lateral sclerosis (ALS). We have shown previously that exposures to high levels of sodium selenite in the environment of Caenorhabditis elegans adult animals can induce neurodegeneration and cell loss resulting in motor deficits and death and that this is at least partially caused by a reduction in cholinergic signaling across the neuromuscular junction. Here we provide evidence that reduction in insulin/insulin-like (IIS) signaling alters response to high dose levels of environmental selenium which in turn can regulate the IIS pathway. Most specifically we show that nuclear localization and thus activation of the DAF-16/forkhead box transcription factor occurs in response to selenium exposure although this was not observed in motor neurons of the ventral cord. Yet, tissue specific expression and generalized overexpression of DAF-16 can partially rescue the neurodegenerative and behavioral deficits observed with high dose selenium exposures in not only the cholinergic, but also the GABAergic motor neurons. In addition, two modifiers of IIS signaling, PTEN (phosphatase and tensin homolog, deleted on chromosome 10) and PINK1 (PTEN-induced putative kinase 1) are required for the cellular antioxidant reduced glutathione to mitigate the selenium-induced movement deficits. Studies have suggested that environmental exposures can lead to ALS or other neurological diseases and this model of selenium-induced neurodegeneration developed in a genetically tractable organism provides a tool for examining the combined roles of genetics and environment in the neuro-pathologic disease process.
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Affiliation(s)
- Annette O Estevez
- Department of Neurology, University of Arizona College of Medicine, Tucson, AZ 85724, USA.
| | - Kathleen L Morgan
- Veterans Affairs Pittsburgh Healthcare System, Research and Development (151U), University Drive C, Pittsburgh, PA 15240, USA.
| | - Nathaniel J Szewczyk
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | - David Gems
- Institute of Healthy Ageing, and Department of Genetics, Evolution, and Environment, University College London, The Darwin Building, Gower Street, London WC1E 6BT, UK.
| | - Miguel Estevez
- Department of Neurology, University of Arizona College of Medicine, Tucson, AZ 85724, USA; Veterans Affairs Pittsburgh Healthcare System, Research and Development (151U), University Drive C, Pittsburgh, PA 15240, USA.
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Vinceti M, Mandrioli J, Borella P, Michalke B, Tsatsakis A, Finkelstein Y. Selenium neurotoxicity in humans: bridging laboratory and epidemiologic studies. Toxicol Lett 2013; 230:295-303. [PMID: 24269718 DOI: 10.1016/j.toxlet.2013.11.016] [Citation(s) in RCA: 144] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Revised: 11/06/2013] [Accepted: 11/14/2013] [Indexed: 12/14/2022]
Abstract
Selenium is a metalloid of considerable interest in the human from both a toxicological and a nutritional perspective, with a very narrow safe range of intake. Acute selenium intoxication is followed by adverse effects on the nervous system with special clinical relevance, while the neurotoxicity of long-term overexposure is less characterized and recognized. We aimed to address this issue from a public health perspective, focusing on both laboratory studies and the few epidemiologic human studies available, with emphasis on their methodological strengths and limitations. The frequently overlooked differences in toxicity and biological activity of selenium compounds are also outlined. In addition to lethargy, dizziness, motor weakness and paresthesias, an excess risk of amyotrophic lateral sclerosis is the effect on the nervous system which has been more consistently associated with chronic low-level selenium overexposure, particularly to its inorganic compounds. Additional research efforts are needed to better elucidate the neurotoxic effects exerted by selenium overexposure.
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Affiliation(s)
- Marco Vinceti
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy; Trace Element Institute for Unesco Satellite Center, Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy.
| | - Jessica Mandrioli
- Department of Neuroscience, University of Modena and Reggio Emilia and Local Health Unit of Modena, Modena, Italy
| | - Paola Borella
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy; Trace Element Institute for Unesco Satellite Center, Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Modena, Italy
| | - Bernhard Michalke
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München - German Research Center for Environmental Health GmbH, Munich, Germany
| | - Aristidis Tsatsakis
- Department of Forensic Sciences and Toxicology, University of Crete, Heraklion, Greece
| | - Yoram Finkelstein
- Neurology and Toxicology Service and Unit, Shaare Zedek Medical Center, Jerusalem, Israel
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