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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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Winter AD, Tjahjono E, Beltrán LJ, Johnstone IL, Bulleid NJ, Page AP. Dietary-derived vitamin B12 protects Caenorhabditis elegans from thiol-reducing agents. BMC Biol 2022; 20:228. [PMID: 36209095 PMCID: PMC9548181 DOI: 10.1186/s12915-022-01415-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 09/20/2022] [Indexed: 11/24/2022] Open
Abstract
Background One-carbon metabolism, which includes the folate and methionine cycles, involves the transfer of methyl groups which are then utilised as a part of multiple physiological processes including redox defence. During the methionine cycle, the vitamin B12-dependent enzyme methionine synthetase converts homocysteine to methionine. The enzyme S-adenosylmethionine (SAM) synthetase then uses methionine in the production of the reactive methyl carrier SAM. SAM-binding methyltransferases then utilise SAM as a cofactor to methylate proteins, small molecules, lipids, and nucleic acids. Results We describe a novel SAM methyltransferase, RIPS-1, which was the single gene identified from forward genetic screens in Caenorhabditis elegans looking for resistance to lethal concentrations of the thiol-reducing agent dithiothreitol (DTT). As well as RIPS-1 mutation, we show that in wild-type worms, DTT toxicity can be overcome by modulating vitamin B12 levels, either by using growth media and/or bacterial food that provide higher levels of vitamin B12 or by vitamin B12 supplementation. We show that active methionine synthetase is required for vitamin B12-mediated DTT resistance in wild types but is not required for resistance resulting from RIPS-1 mutation and that susceptibility to DTT is partially suppressed by methionine supplementation. A targeted RNAi modifier screen identified the mitochondrial enzyme methylmalonyl-CoA epimerase as a strong genetic enhancer of DTT resistance in a RIPS-1 mutant. We show that RIPS-1 is expressed in the intestinal and hypodermal tissues of the nematode and that treating with DTT, β-mercaptoethanol, or hydrogen sulfide induces RIPS-1 expression. We demonstrate that RIPS-1 expression is controlled by the hypoxia-inducible factor pathway and that homologues of RIPS-1 are found in a small subset of eukaryotes and bacteria, many of which can adapt to fluctuations in environmental oxygen levels. Conclusions This work highlights the central importance of dietary vitamin B12 in normal metabolic processes in C. elegans, defines a new role for this vitamin in countering reductive stress, and identifies RIPS-1 as a novel methyltransferase in the methionine cycle. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01415-y.
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Affiliation(s)
- Alan D Winter
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK
| | - Elissa Tjahjono
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK
| | - Leonardo J Beltrán
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK
| | - Iain L Johnstone
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Neil J Bulleid
- School of Molecular Biosciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Antony P Page
- School of Biodiversity, One Health and Veterinary Medicine, University of Glasgow, Glasgow, G61 1QH, UK.
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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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Taylor RM, Mendoza KM, Abrahante JE, Reed KM, Sunde RA. The hepatic transcriptome of the turkey poult (Meleagris gallopavo) is minimally altered by high inorganic dietary selenium. PLoS One 2020; 15:e0232160. [PMID: 32379770 PMCID: PMC7205448 DOI: 10.1371/journal.pone.0232160] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/08/2020] [Indexed: 12/18/2022] Open
Abstract
There is interest in supplementing animals and humans with selenium (Se) above Se-adequate levels, but the only good biomarker for toxicity is tissue Se. We targeted liver because turkeys fed 5 μg Se/g have hepatic Se concentrations 6-fold above Se-adequate (0.4 μg Se/g) levels without effects on growth or health. Our objectives were (i) to identify transcript biomarkers for high Se status, which in turn would (ii) suggest proteins and pathways used by animals to adapt to high Se. Turkey poults were fed 0, 0.025, 0.4, 0.75 and 1.0 μg Se/g diet in experiment 1, and fed 0.4, 2.0 and 5.0 μg Se/g in experiment 2, as selenite, and the full liver transcriptome determined by RNA-Seq. The major effect of Se-deficiency was to down-regulate expression of a subset of selenoprotein transcripts, with little significant effect on general transcript expression. In response to high Se intake (2 and 5 μg Se/g) relative to Se-adequate turkeys, there were only a limited number of significant differentially expressed transcripts, all with only relatively small fold-changes. No transcript showed a consistent pattern of altered expression in response to high Se intakes across the 1, 2 and 5 μg Se/g treatments, and there were no associated metabolic pathways and biological functions that were significant and consistently found with high Se supplementation. Gene set enrichment analysis also found no gene sets that were consistently altered by high-Se and supernutritional-Se. A comparison of differentially expressed transcript sets with high Se transcript sets identified in mice provided high Se (~3 μg Se/g) also failed to identify common differentially expressed transcript sets between these two species. Collectively, this study indicates that turkeys do not alter gene expression in the liver as a homeostatic mechanism to adapt to high Se.
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Affiliation(s)
- Rachel M. Taylor
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Kristelle M. Mendoza
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Juan E. Abrahante
- University of Minnesota Informatics Institute, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Kent M. Reed
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, Minnesota, United States of America
| | - Roger A. Sunde
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
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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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Vinceti M, Filippini T, Malagoli C, Violi F, Mandrioli J, Consonni D, Rothman KJ, Wise LA. Amyotrophic lateral sclerosis incidence following exposure to inorganic selenium in drinking water: A long-term follow-up. ENVIRONMENTAL RESEARCH 2019; 179:108742. [PMID: 31629180 DOI: 10.1016/j.envres.2019.108742] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/10/2019] [Accepted: 09/11/2019] [Indexed: 06/10/2023]
Abstract
Some studies have reported an association between overexposure to selenium and risk of amyotrophic lateral sclerosis (ALS), a rare degenerative disease of motor neurons. From 1986 through 2015, we followed a cohort in Northern Italy that had been inadvertently consuming tap water with unusually high concentrations of inorganic hexavalent selenium from 1974 to 1985. We had previously documented an excess incidence of ALS in this cohort during 1986-1994. Here, we report extended follow-up of the cohort for an additional 21 years, encompassing 50,100 person-years of the exposed cohort and 2,233,963 person-years of the unexposed municipal cohort. We identified 7 and 112 incident ALS cases in the exposed and unexposed cohorts, respectively, yielding crude incidence rates of 14 and 5 cases per 100,000 person-years. A Poisson regression analysis, adjusting for age, sex and calendar year, produced an overall incidence rate ratio (IRR) for ALS of 2.8 (95% confidence interval (CI) 1.3, 6), with a substantially stronger IRR in 1986-1994 (8.2, 95% CI 2.7, 24.7) than in 1995-2015 (1.5, 95% CI 0.5, 4.7), and among women (5.1, 95% CI 1.8, 14.3) than men (1.7, 95% CI 0.5, 5.4). Overall, these results indicate an association between high exposure to inorganic selenium, a recognized neurotoxicant, and ALS incidence, with declining rates after cessation of exposure and stronger effects among women.
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Affiliation(s)
- Marco Vinceti
- CREAGEN - Research Center of Environmental, Genetic and Nutritional Epidemiology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia Medical School, Via Campi 287, 41125, Modena, Italy; Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, United States.
| | - Tommaso Filippini
- CREAGEN - Research Center of Environmental, Genetic and Nutritional Epidemiology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia Medical School, Via Campi 287, 41125, Modena, Italy
| | - Carlotta Malagoli
- CREAGEN - Research Center of Environmental, Genetic and Nutritional Epidemiology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia Medical School, Via Campi 287, 41125, Modena, Italy
| | - Federica Violi
- CREAGEN - Research Center of Environmental, Genetic and Nutritional Epidemiology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia Medical School, Via Campi 287, 41125, Modena, Italy
| | - Jessica Mandrioli
- Department of Neurosciences, St. Agostino Estense Hospital, Azienda Ospedaliero Universitaria di Modena, Modena, Italy
| | - Dario Consonni
- Epidemiology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Kenneth J Rothman
- Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, United States
| | - Lauren A Wise
- Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, Boston, MA, United States
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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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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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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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Lazard M, Dauplais M, Blanquet S, Plateau P. Recent advances in the mechanism of selenoamino acids toxicity in eukaryotic cells. Biomol Concepts 2018; 8:93-104. [PMID: 28574376 DOI: 10.1515/bmc-2017-0007] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/03/2017] [Indexed: 12/31/2022] Open
Abstract
Selenium is an essential trace element due to its incorporation into selenoproteins with important biological functions. However, at high doses it is toxic. Selenium toxicity is generally attributed to the induction of oxidative stress. However, it has become apparent that the mode of action of seleno-compounds varies, depending on its chemical form and speciation. Recent studies in various eukaryotic systems, in particular the model organism Saccharomyces cerevisiae, provide new insights on the cytotoxic mechanisms of selenomethionine and selenocysteine. This review first summarizes current knowledge on reactive oxygen species (ROS)-induced genotoxicity of inorganic selenium species. Then, we discuss recent advances on our understanding of the molecular mechanisms of selenocysteine and selenomethionine cytotoxicity. We present evidences indicating that both oxidative stress and ROS-independent mechanisms contribute to selenoamino acids cytotoxicity. These latter mechanisms include disruption of protein homeostasis by selenocysteine misincorporation in proteins and/or reaction of selenols with protein thiols.
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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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Jiang XQ, Cao CY, Li ZY, Li W, Zhang C, Lin J, Li XN, Li JL. Delineating hierarchy of selenotranscriptome expression and their response to selenium status in chicken central nervous system. J Inorg Biochem 2017; 169:13-22. [PMID: 28088013 DOI: 10.1016/j.jinorgbio.2017.01.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/09/2016] [Accepted: 01/03/2017] [Indexed: 12/25/2022]
Abstract
Selenium (Se) incorporated in selenoproteins as selenocysteine and supports various important cellular and organismal functions. We recently reported that chicken brain exhibited high priority for Se supply and retention under conditions of dietary Se deficiency and supernutrition Li et al. (2012) . However, the selenotranscriptome expressions and their response to Se status in chicken central nervous system (CNS) are unclear. To better understand the relationship of Se homeostasis and selenoproteins expression in chicken CNS, 1day-old HyLine White chickens were fed a low Se diet (Se-L, 0.028mg/g) supplemented with 4 levels of dietary Se (0 to 5.0mgSe/kg) as Na2SeO3 for 8weeks. Then chickens were dissected for getting the CNS, which included cerebral cortex, cerebellum, thalamus, bulbus cinereus and marrow. The expressions of selenoproteome which have 24 selenoproteins were detected by the quantitative real-time PCR array. The concept of a selenoprotein hierarchy was developed and the hierarchy of different regions in chicken CNS was existence, especially cerebral cortex and bulbus cinereus. The expression of selenoproteins has a hierarch while changing Se content, and Selenoprotein T (Selt), Selenoprotein K (Selk), Selenoprotein W (Selw), Selenoprotein U (Selu), Glutathione peroxidase 3 (Gpx3), Glutathione peroxidase 4 (Gpx4), Selenoprotein P (Sepp1), Selenoprotein O (Selo), Selenoprotein 15 (Sel15), Selenoprotein N (Seln), Glutathione peroxidase 2 (Gpx2) and Selenoprotein P 2 (Sepp2) take more necessary function in the chicken CNS. Therefore, we hypothesize that hierarchy of regulated the transcriptions of selenoproteome makes an important role of CNS Se metabolism and transport in birds.
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Affiliation(s)
- Xiu-Qing Jiang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Chang-Yu Cao
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Zhao-Yang Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Wei Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Cong Zhang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Jia Lin
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Xue-Nan Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China
| | - Jing-Long Li
- College of Veterinary Medicine, Northeast Agricultural University, Harbin 150030, People's Republic of China.
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Leoni SG, Sastre-Perona A, De la Vieja A, Santisteban P. Selenium Increases Thyroid-Stimulating Hormone-Induced Sodium/Iodide Symporter Expression Through Thioredoxin/Apurinic/Apyrimidinic Endonuclease 1-Dependent Regulation of Paired Box 8 Binding Activity. Antioxid Redox Signal 2016; 24:855-66. [PMID: 26650895 DOI: 10.1089/ars.2014.6228] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
AIMS The sodium-iodide symporter (NIS) mediates the uptake of I(-) by the thyroid follicular cell and is essential for thyroid hormone biosynthesis. Nis expression is stimulated by thyroid-stimulating hormone (TSH) and also requires paired box 8 (Pax8) to bind to its promoter. Pax8 binding activity depends on its redox state by a mechanism involving thioredoxin/thioredoxin reductase-1 (Txn/TxnRd1) reduction of apurinic/apyrimidinic endonuclease 1 (Ape1). In this study, we investigate the role of Se in Nis expression. RESULTS Selenium increases TSH-induced Nis expression and activity in rat thyroid cells. The stimulatory effect of Se occurs at the transcriptional level and is only observed for Nis promoters containing a Pax8 binding site in the Nis upstream enhancer, suggesting that Pax8 is involved in this effect. In fact, Se increases Pax8 expression and its DNA-binding capacity, and in Pax8-silenced rat thyroid cells, Nis is not Se responsive. By inhibiting Ape1 and TxnRd1 functions, we found that both enzymes are crucial for TSH and TSH plus Se stimulation of Pax8 activity and mediate the Nis response to Se treatment. INNOVATION We describe that Se increases Nis expression and activity. We demonstrate that this effect is dependent on the redox functions of Ape1 and Txn/TxnRd1 through control of the DNA binding activity of Pax8. CONCLUSION Nis expression is controlled by Txn/Ape1 through a TSH/Se-dependent mechanism. These findings open a new field of study regarding the regulation of Nis activity in thyroid cells. Antioxid. Redox Signal. 24, 855-866.
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Affiliation(s)
- Suzana G Leoni
- 1 Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid , Madrid, Spain .,2 Instituto de Salud Carlos III, Unidad de Tumores Endocrinos, Unidad Funcional de Investigación en Enfermedades Crónicas (UFIEC) , Majadahonda (Madrid), Spain
| | - Ana Sastre-Perona
- 1 Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid , Madrid, Spain
| | - Antonio De la Vieja
- 2 Instituto de Salud Carlos III, Unidad de Tumores Endocrinos, Unidad Funcional de Investigación en Enfermedades Crónicas (UFIEC) , Majadahonda (Madrid), Spain
| | - Pilar Santisteban
- 1 Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas y Universidad Autónoma de Madrid , Madrid, Spain
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14
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Tejeda-Benitez L, Olivero-Verbel J. Caenorhabditis elegans, a Biological Model for Research in Toxicology. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 237:1-35. [PMID: 26613986 DOI: 10.1007/978-3-319-23573-8_1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Caenorhabditis elegans is a nematode of microscopic size which, due to its biological characteristics, has been used since the 1970s as a model for research in molecular biology, medicine, pharmacology, and toxicology. It was the first animal whose genome was completely sequenced and has played a key role in the understanding of apoptosis and RNA interference. The transparency of its body, short lifespan, ability to self-fertilize and ease of culture are advantages that make it ideal as a model in toxicology. Due to the fact that some of its biochemical pathways are similar to those of humans, it has been employed in research in several fields. C. elegans' use as a biological model in environmental toxicological assessments allows the determination of multiple endpoints. Some of these utilize the effects on the biological functions of the nematode and others use molecular markers. Endpoints such as lethality, growth, reproduction, and locomotion are the most studied, and usually employ the wild type Bristol N2 strain. Other endpoints use reporter genes, such as green fluorescence protein, driven by regulatory sequences from other genes related to different mechanisms of toxicity, such as heat shock, oxidative stress, CYP system, and metallothioneins among others, allowing the study of gene expression in a manner both rapid and easy. These transgenic strains of C. elegans represent a powerful tool to assess toxicity pathways for mixtures and environmental samples, and their numbers are growing in diversity and selectivity. However, other molecular biology techniques, including DNA microarrays and MicroRNAs have been explored to assess the effects of different toxicants and samples. C. elegans has allowed the assessment of neurotoxic effects for heavy metals and pesticides, among those more frequently studied, as the nematode has a very well defined nervous system. More recently, nanoparticles are emergent pollutants whose toxicity can be explored using this nematode. Overall, almost every type of known toxicant has been tested with this animal model. In the near future, the available knowledge on the life cycle of C. elegans should allow more studies on reproduction and transgenerational toxicity for newly developed chemicals and materials, facilitating their introduction in the market. The great diversity of endpoints and possibilities of this animal makes it an easy first-choice for rapid toxicity screening or to detail signaling pathways involved in mechanisms of toxicity.
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Affiliation(s)
- Lesly Tejeda-Benitez
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena, 130014, Colombia.
| | - Jesus Olivero-Verbel
- Environmental and Computational Chemistry Group, School of Pharmaceutical Sciences, Zaragocilla Campus, University of Cartagena, Cartagena, 130014, Colombia.
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15
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Jablonska E, Vinceti M. Selenium and Human Health: Witnessing a Copernican Revolution? JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2015; 33:328-68. [PMID: 26074278 DOI: 10.1080/10590501.2015.1055163] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In humans, selenium was hypothesized to lower the risk of several chronic diseases, mainly due to the antioxidant activity of selenium-containing proteins. Recent epidemiologic and laboratory studies, however, are changing our perception of the biological effects of this nutritionally essential trace element. We reviewed the most recent epidemiologic and biochemical literature on selenium, synthesizing the findings from these studies into a unifying view. Randomized trials have shown that selenium did not protect against cancer and other chronic diseases, but even increased the risk of specific neoplasms such as advanced prostate cancer and skin cancer, in addition to type 2 diabetes. Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations. Furthermore, its upregulation of antioxidant proteins (selenium-dependent and selenium-independent) may be a manifestation of self-induced oxidative stress. In conclusion, toxic effects of selenium species occur at lower concentrations than previously believed. Those effects may include a large range of proteomic changes and adverse health effects in humans. Since the effects of environmental exposure to this element on human health still remain partially unknown, but are potentially serious, the toxicity of selenium exposure should be further investigated and considered as a public health priority.
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Affiliation(s)
- Ewa Jablonska
- a Department of Toxicology and Carcinogenesis , Nofer Institute of Occupational Medicine , Lodz , Poland
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16
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Wu SM, Su Y, Liang RR, Ai XX, Qian J, Wang C, Chen JQ, Yan ZY. Crucial factors in biosynthesis of fluorescent CdSe quantum dots in Saccharomyces cerevisiae. RSC Adv 2015. [DOI: 10.1039/c5ra13011e] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Simple, controllable and repeatable procedures to biosynthesize CdSe in Saccharomyces cerevisiae are systematically demonstrated.
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Affiliation(s)
- Sheng-Mei Wu
- Department of Analytical Chemistry
- China Pharmaceutical University
- Nanjing 210009
- China
- Key Laboratory of Drug Quality Control and Pharmacovigilance
| | - Yilong Su
- Department of Analytical Chemistry
- China Pharmaceutical University
- Nanjing 210009
- China
- Key Laboratory of Drug Quality Control and Pharmacovigilance
| | - Ran-Ran Liang
- Department of Analytical Chemistry
- China Pharmaceutical University
- Nanjing 210009
- China
- Key Laboratory of Drug Quality Control and Pharmacovigilance
| | - Xiao-Xia Ai
- Department of Analytical Chemistry
- China Pharmaceutical University
- Nanjing 210009
- China
- Key Laboratory of Drug Quality Control and Pharmacovigilance
| | - Jing Qian
- Department of Analytical Chemistry
- China Pharmaceutical University
- Nanjing 210009
- China
- Key Laboratory of Drug Quality Control and Pharmacovigilance
| | - Chao Wang
- College of Bioscience and Technology
- China Pharmaceutical University
- 210009 Nanjing
- China
| | - Jian-Qiu Chen
- Department of Environmental Science
- China Pharmaceutical University
- 210009 Nanjing
- China
| | - Zheng-Yu Yan
- Department of Analytical Chemistry
- China Pharmaceutical University
- Nanjing 210009
- China
- Key Laboratory of Drug Quality Control and Pharmacovigilance
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