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Bierla K, Szpunar J, Lobinski R, Sunde RA. Effect of graded levels of selenium supplementation as selenite on expression of selenosugars, selenocysteine, and other selenometabolites in rat liver. Metallomics 2023; 15:mfad066. [PMID: 37898555 DOI: 10.1093/mtomcs/mfad066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/27/2023] [Indexed: 10/30/2023]
Abstract
Using high pressure liquid chromatography (HPLC) coupled with selenium-specific inductively coupled plasma mass spectrometry (ICP-MS) and molecule specific (Orbitrap MS/MS) detection, we previously found that far more selenium (Se) is present as selenosugar (seleno-N-acetyl galactosamine) in Se-adequate turkey liver than is present as selenocysteine (Sec) in true selenoproteins, and that selenosugars account for half of the Se in high-Se turkey liver. To expand these observations to mammals, we studied Se metabolism in rats fed graded levels of selenite from 0 to 5 μg Se/g for 4 wk. In Se-adequate (0.24 μg Se/g) rats, 43% of liver Se was present as Sec, 32% was present as selenosugars, and 22% as inorganic Se bound to protein. In liver of rats fed 5 μg Se/g as selenite, the quantity of Sec remained at the Se-adequate plateau (11% of total Se), 22% was present as low molecular weight (LMW) selenosugars with substantial additional selenosugars linked to protein, but 64% was present as inorganic Se bound to protein. No selenomethionine was found at any level of selenite supplementation. Below the Se requirement, Se is preferentially incorporated into Sec-selenoproteins. Above the dietary Se requirement, selenosugars become by far the major LMW water soluble Se species in liver, and levels of selenosugar-decorated proteins are far higher than Sec-selenoproteins, making these selenosugar-decorated proteins the major Se-containing protein species in liver with high Se supplementation. This accumulation of selenosugars linked to cysteines on proteins or the build-up of inorganic Se bound to protein may underlie Se toxicity at the molecular level.
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Affiliation(s)
- Katarzyna Bierla
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, Helioparc, 64053 Pau, France
| | - Joanna Szpunar
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, Helioparc, 64053 Pau, France
| | - Ryszard Lobinski
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, Helioparc, 64053 Pau, France
- Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, ul. Noakowskiego 3, 00-664 Warsaw, Poland
| | - Roger A Sunde
- Department of Nutritional Sciences, University of Wisconsin, Madison, WI 53706, USA
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2
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Banerjee M, Chakravarty D, Kalwani P, Ballal A. Voyage of selenium from environment to life: Beneficial or toxic? J Biochem Mol Toxicol 2022; 36:e23195. [PMID: 35976011 DOI: 10.1002/jbt.23195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 06/22/2022] [Accepted: 07/21/2022] [Indexed: 11/08/2022]
Abstract
Selenium (Se), a naturally occurring metalloid, is an essential micronutrient for life as it is incorporated as selenocysteine in proteins. Although beneficial at low doses, Se is hazardous at high concentrations and poses a serious threat to various ecosystems. Due to this contrasting 'dual' nature, Se has garnered the attention of researchers wishing to unravel its puzzling properties. In this review, we describe the impact of selenium's journey from environment to diverse biological systems, with an emphasis on its chemical advantage. We describe the uneven distribution of Se and how this affects the bioavailability of this element, which, in turn, profoundly affects the habitat of a region. Once taken up, the subsequent incorporation of Se into proteins as selenocysteine and its antioxidant functions are detailed here. The causes of improved protein function due to the incorporation of redox-active Se atom (instead of S) are examined. Subsequently, the reasons for the deleterious effects of Se, which depend on its chemical form (organo-selenium or the inorganic forms) in different organisms are elaborated. Although Se is vital for the function of many antioxidant enzymes, how the pro-oxidant nature of Se can be potentially exploited in different therapies is highlighted. Furthermore, we succinctly explain how the presence of Se in biological systems offsets the toxic effects of heavy metal mercury. Finally, the different avenues of research that are fundamental to expand our understanding of selenium biology are suggested.
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Affiliation(s)
- Manisha Banerjee
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Dhiman Chakravarty
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Prakash Kalwani
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
| | - Anand Ballal
- Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai, India.,Homi Bhabha National Institute, Mumbai, India
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3
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Lei XG, Combs GF, Sunde RA, Caton JS, Arthington JD, Vatamaniuk MZ. Dietary Selenium Across Species. Annu Rev Nutr 2022; 42:337-375. [PMID: 35679623 DOI: 10.1146/annurev-nutr-062320-121834] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This review traces the discoveries that led to the recognition of selenium (Se) as an essential nutrient and discusses Se-responsive diseases in animals and humans in the context of current understanding of the molecular mechanisms of their pathogeneses. The article includes a comprehensive analysis of dietary sources, nutritional utilization, metabolic functions, and dietary requirements of Se across various species. We also compare the function and regulation of selenogenomes and selenoproteomes among rodents, food animals, and humans. The review addresses the metabolic impacts of high dietary Se intakes in different species and recent revelations of Se-metabolites, means of increasing Se status, and the recycling of Se in food systems and ecosystems. Finally, research needs are identified for supporting basic science and practical applications of dietary Se in food, nutrition, and health across species. Expected final online publication date for the Annual Review of Nutrition, Volume 42 is August 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Xin Gen Lei
- Department of Animal Science, Cornell University, Ithaca, New York, USA;
| | - Gerald F Combs
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, Massachusetts, USA
| | - Roger A Sunde
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Joel S Caton
- Department of Animal Science, North Dakota State University, Fargo, North Dakota, USA
| | - John D Arthington
- Department of Animal Sciences, University of Florida, Gainesville, Florida, USA
| | - Marko Z Vatamaniuk
- Department of Animal Science, Cornell University, Ithaca, New York, USA;
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4
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Ibrahim SE, Alzawqari MH, Eid YZ, Zommara M, Hassan AM, Dawood MAO. Comparing the Influences of Selenium Nanospheres, Sodium Selenite, and Biological Selenium on the Growth Performance, Blood Biochemistry, and Antioxidative Capacity of Growing Turkey Pullets. Biol Trace Elem Res 2022; 200:2915-2922. [PMID: 34420135 DOI: 10.1007/s12011-021-02894-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 08/17/2021] [Indexed: 10/20/2022]
Abstract
Supplementation of selenium in poultry feed is required in an optimum dose and form for optimizing the growth performance and health status. Selenium nanospheres are suggested as an efficient and alternative to the conventional organic or inorganic forms. The study evaluated the effects of selenium (Se) nanospheres (SeNPs) as an alternative to organic Se (Sel-Plex®) or inorganic Se (sodium selenite, Se(IV Se(IV)) on the growth performance, carcass traits, blood biochemistry, and antioxidative capacity in turkey pullets. A total of 160 1-day-old Bronze turkey poults chicks were divided into four groups with 40 pullets each. The birds were fed on four types of diets as fellow: control (basal diet, 0.01 Se mg/kg), SeNPs (0.43 Se mg/kg), organic Se Sel-Plex® (0.41 Se mg/kg), and inorganic Se(IV) (0.42 Se mg/kg) for 8 weeks. No changes were seen in the body weight gain in growing turkey pullet, but chicks fed with Sel-Plex® form recorded the lowest feed intake (p < 0.05) compared to other treatments. Dietary SeNPs and Se(IV) selenium sources improved the feed conversion ratio compared to other treatments. All Se forms fed on turkey pullets showed higher carcass percentage weight and liver Se content than the control group. However, the gizzard percentage weight in the SeNPs group was lower than in the other treatments (p < 0.05). Birds fed SeNPs, and Sel-Plex® forms supplemental diets had a lower cholesterol concentration (p < 0.05) than the control and Se(IV). While high-density lipoprotein (HDL) concentration was increased in SeNPs and Se(IV) groups, and total protein concentration was higher in the Se(IV) group. Furthermore, dietary SeNPs reduced (p < 0.05) the low-density lipoprotein (LDL), total lipids, triglycerides, alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine, uric acid, urea, and malondialdehyde plasma concentrations and increased the glutathione peroxidase activity (GPx) and total antioxidative capacity (TAC). In conclusion, the results confirmed that feeding turkey pullets on SeNPs form with the 0.4 Se mg/kg of feed enhanced feed efficiency, growth performance, carcass traits, plasma lipids concentration, and antioxidative capacity.
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Affiliation(s)
- Samya E Ibrahim
- Animal Production Research Institute, Agriculture Research Center, Giza, Egypt
| | - Mohammed H Alzawqari
- Department of Poultry Production, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt
- Department of Animal Production, Faculty of Agriculture and Food Sciences, Ibb University, 70270, Ibb, Yemen
| | - Yahya Z Eid
- Department of Poultry Production, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt.
| | - Mohsen Zommara
- Department of Dairy Science, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, 33516, Egypt
| | - Aziza M Hassan
- Department of Biotechnology, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
| | - Mahmoud A O Dawood
- Department of Animal Production, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, 33512, Egypt.
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5
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Pecoraro BM, Leal DF, Frias-De-Diego A, Browning M, Odle J, Crisci E. The health benefits of selenium in food animals: a review. J Anim Sci Biotechnol 2022; 13:58. [PMID: 35550013 PMCID: PMC9101896 DOI: 10.1186/s40104-022-00706-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 03/07/2022] [Indexed: 12/01/2022] Open
Abstract
Selenium is an essential trace mineral important for the maintenance of homeostasis in animals and humans. It evinces a strong antioxidant, anti-inflammatory and potential antimicrobial capacity. Selenium biological function is primarily achieved by its presence in selenoproteins as a form of selenocysteine. Selenium deficiency may result in an array of health disorders, affecting many organs and systems; to prevent this, dietary supplementation, mainly in the forms of organic (i.e., selenomethionine and selenocysteine) inorganic (i.e., selenate and selenite) sources is used. In pigs as well as other food animals, dietary selenium supplementation has been used for improving growth performance, immune function, and meat quality. A substantial body of knowledge demonstrates that dietary selenium supplementation is positively associated with overall animal health especially due to its immunomodulatory activity and protection from oxidative damage. Selenium also possesses potential antiviral activity and this is achieved by protecting immune cells against oxidative damage and decreasing viral replication. In this review we endeavor to combine established and novel knowledge on the beneficial effects of dietary selenium supplementation, its antioxidant and immunomodulatory actions, and the putative antimicrobial effect thereof. Furthermore, our review demonstrates the gaps in knowledge pertaining to the use of selenium as an antiviral, underscoring the need for further in vivo and in vitro studies, particularly in pigs.
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Affiliation(s)
- Brittany M Pecoraro
- College of Veterinary Medicine, Department of Population Health and Pathobiology, North Carolina State University, Raleigh, North Carolina, USA
| | - Diego F Leal
- College of Veterinary Medicine, Department of Population Health and Pathobiology, North Carolina State University, Raleigh, North Carolina, USA
| | - Alba Frias-De-Diego
- College of Veterinary Medicine, Department of Population Health and Pathobiology, North Carolina State University, Raleigh, North Carolina, USA
| | - Matthew Browning
- College of Veterinary Medicine, Department of Population Health and Pathobiology, North Carolina State University, Raleigh, North Carolina, USA
| | - Jack Odle
- Laboratory of Developmental Nutrition, Department of Animal Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Elisa Crisci
- College of Veterinary Medicine, Department of Population Health and Pathobiology, North Carolina State University, Raleigh, North Carolina, USA.
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6
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Michalczuk M, Batorska M, Sikorska U, Bień D, Urban J, Capecka K, Konieczka P. Selenium and the health status, production results, and product quality in poultry. Anim Sci J 2021; 92:e13662. [PMID: 34786781 DOI: 10.1111/asj.13662] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/27/2021] [Accepted: 10/07/2021] [Indexed: 01/11/2023]
Abstract
A Selenium (Se) is an element belonging to the nonmetallic group. It was first discovered in 1817 by J.J. Berzelius. Until the 1950s, it was considered to be toxic to animals. However, with increasing research conducted on laboratory animals, it is now clear that Se is necessary for the proper functioning of both plants and animals. Recent studies indicate that Se is necessary for the proper functioning of metabolic pathways in animals. It was evidenced that Se is a component of about 100 proteins involved in the immune system, antioxidant homeostasis, or release of an inflammatory mediator. Therefore, it is of key interest to find the appropriate dosage for the supplementation of Se in the diet of farm animals and thereby eliminate physiological disorders in the body associated with Se imbalance. In this study, we present a literature review on the importance and appropriate dosage of Se in the diet of poultry concerning their health status, production results, and the quality of animal-origin products.
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Affiliation(s)
- Monika Michalczuk
- Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Martyna Batorska
- Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Urszula Sikorska
- Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Damian Bień
- Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Jakub Urban
- Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Katarzyna Capecka
- Department of Animal Breeding, Institute of Animal Sciences, Warsaw University of Life Sciences, Warsaw, Poland
| | - Paweł Konieczka
- Department of Poultry Science, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
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7
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Li T, Zhang J, Wang PJ, Zhang ZW, Huang JQ. Selenoproteins Protect Against Avian Liver Necrosis by Metabolizing Peroxides and Regulating Receptor Interacting Serine Threonine Kinase 1/Receptor Interacting Serine Threonine Kinase 3/Mixed Lineage Kinase Domain-Like and Mitogen-Activated Protein Kinase Signaling. Front Physiol 2021; 12:696256. [PMID: 34456747 PMCID: PMC8397447 DOI: 10.3389/fphys.2021.696256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 07/12/2021] [Indexed: 12/17/2022] Open
Abstract
Liver necroptosis of chicks is induced by selenium (Se)/vitamin E (VE) deficiencies and may be associated with oxidative cell damage. To reveal the underlying mechanisms of liver necrosis, a pool of the corn-soy basal diet (10 μg Se/kg; no VE added), a basal diet plus all-rac-α-tocopheryl acetate (50 mg/kg), Se (sodium selenite at 0.3 mg/kg), or both of these nutrients were provided to day-old broiler chicks (n = 40/group) for 6 weeks. High incidences of liver necrosis (30%) of chicks were induced by -SE-VE, starting at day 16. The Se concentration in liver and glutathione peroxidase (GPX) activity were decreased (P < 0.05) by dietary Se deficiency. Meanwhile, Se deficiency elevated malondialdehyde content and decreased superoxide dismutase (SOD) activity in the liver at weeks 2 and 4. Chicks fed with the two Se-deficient diets showed lower (P < 0.05) hepatic mRNA expression of Gpx1, Gpx3, Gpx4, Selenof, Selenoh, Selenok, Selenom, Selenon, Selenoo, Selenop, Selenot, Selenou, Selenow, and Dio1 than those fed with the two Se-supplemented diets. Dietary Se deficiency had elevated (P < 0.05) the expression of SELENOP, but decreased the downregulation (P < 0.05) of GPX1, GPX4, SELENON, and SELENOW in the liver of chicks at two time points. Meanwhile, dietary Se deficiency upregulated (P < 0.05) the abundance of hepatic proteins of p38 mitogen-activated protein kinase, phospho-p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, phospho-c-Jun N-terminal kinase, extracellular signal-regulated kinase, phospho-mitogen-activated protein kinase, receptor-interacting serine-threonine kinase 1 (RIPK1), receptor-interacting serine-threonine kinase 3 (RIPK3), and mixed lineage kinase domain-like (MLKL) at two time points. In conclusion, our data confirmed the differential regulation of dietary Se deficiency on several key selenoproteins, the RIPK1/RIPK3/MLKL, and mitogen-activated protein kinase signaling pathway in chicks and identified new molecular clues for understanding the etiology of nutritional liver necrosis.
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Affiliation(s)
- Tong Li
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Nutrition and Health, China Agricultural University, Beijing, China
| | - Jing Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Nutrition and Health, China Agricultural University, Beijing, China.,Administrative Engineering College, Xu Zhou University of Technology, Xuzhou, China
| | - Peng-Jie Wang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Nutrition and Health, China Agricultural University, Beijing, China.,Key Laboratory of Precision Nutrition and Food Quality, Ministry of Education, Department of Nutrition and Health, China Agricultural University, Beijing, China
| | - Zi-Wei Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Nutrition and Health, China Agricultural University, Beijing, China.,College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Jia-Qiang Huang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Nutrition and Health, China Agricultural University, Beijing, China.,Key Laboratory of Precision Nutrition and Food Quality, Ministry of Education, Department of Nutrition and Health, China Agricultural University, Beijing, China
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8
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Katarzyna B, Taylor RM, Szpunar J, Lobinski R, Sunde RA. Identification and determination of selenocysteine, selenosugar, and other selenometabolites in turkey liver. Metallomics 2021; 12:758-766. [PMID: 32211715 DOI: 10.1039/d0mt00040j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Liver and other tissues accumulate selenium (Se) when animals are supplemented with high dietary Se as inorganic Se. To further study selenometabolites in Se-deficient, Se-adequate, and high-Se liver, turkey poults were fed 0, 0.4, and 5 μg Se g-1 diet as Na2SeO3 (Se(iv)) in a Se-deficient (0.005 μg Se g-1) diet for 28 days, and the effects of Se status determined using HPLC-ICP-MS and HPLC-ESI-MS/MS. No selenomethionine (SeMet) was detected in liver in turkeys fed either this true Se-deficient diet or supplemented with inorganic Se, showing that turkeys cannot synthesize SeMet de novo from inorganic Se. Selenocysteine (Sec) was also below the level of detection in Se-deficient liver, as expected in animals with negligible selenoprotein levels. Sec content in high Se liver only doubled as compared to Se-adequate liver, indicating that the 6-fold increase in liver Se was not due to increases in selenoproteins. What increased dramatically in high Se liver were low molecular weight (MW) selenometabolites: glutathione-, cysteine- and methyl-conjugates of the selenosugar, seleno-N-acetyl galactosamine (SeGalNac). Substantial Se in Se-adequate liver was present as selenosugars decorating general proteins via mixed-disulfide bonds. In high-Se liver, these "selenosugar-decorated" proteins comprised ∼50% of the Se in the water-soluble fraction, in addition to low MW selenometabolites. In summary, more Se is present as the selenosugar moiety in Se-adequate liver, mostly decorating general proteins, than is present as Sec in selenoproteins. With high Se supplementation, increased selenosugar formation occurs, further increasing selenosugar-decorated proteins, but also increasing selenosugar linked to low MW thiols.
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Affiliation(s)
- Bierla Katarzyna
- Universite de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM UMR 5254, Hélioparc, 64053 Pau, France
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9
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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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10
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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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