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Dogaru CB, Duță C, Muscurel C, Stoian I. "Alphabet" Selenoproteins: Implications in Pathology. Int J Mol Sci 2023; 24:15344. [PMID: 37895024 PMCID: PMC10607139 DOI: 10.3390/ijms242015344] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 10/08/2023] [Accepted: 10/16/2023] [Indexed: 10/29/2023] Open
Abstract
Selenoproteins are a group of proteins containing selenium in the form of selenocysteine (Sec, U) as the 21st amino acid coded in the genetic code. Their synthesis depends on dietary selenium uptake and a common set of cofactors. Selenoproteins accomplish diverse roles in the body and cell processes by acting, for example, as antioxidants, modulators of the immune function, and detoxification agents for heavy metals, other xenobiotics, and key compounds in thyroid hormone metabolism. Although the functions of all this protein family are still unknown, several disorders in their structure, activity, or expression have been described by researchers. They concluded that selenium or cofactors deficiency, on the one hand, or the polymorphism in selenoproteins genes and synthesis, on the other hand, are involved in a large variety of pathological conditions, including type 2 diabetes, cardiovascular, muscular, oncological, hepatic, endocrine, immuno-inflammatory, and neurodegenerative diseases. This review focuses on the specific roles of selenoproteins named after letters of the alphabet in medicine, which are less known than the rest, regarding their implications in the pathological processes of several prevalent diseases and disease prevention.
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Affiliation(s)
| | | | - Corina Muscurel
- Department of Biochemistry, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania (I.S.)
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2
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The Role and Mechanism of Essential Selenoproteins for Homeostasis. Antioxidants (Basel) 2022; 11:antiox11050973. [PMID: 35624837 PMCID: PMC9138076 DOI: 10.3390/antiox11050973] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 05/05/2022] [Accepted: 05/10/2022] [Indexed: 12/25/2022] Open
Abstract
Selenium (Se) is one of the essential trace elements that plays a biological role in the body, mainly in the form of selenoproteins. Selenoproteins can be involved in the regulation of oxidative stress, endoplasmic reticulum (ER) stress, antioxidant defense, immune and inflammatory responses and other biological processes, including antioxidant, anti-inflammation, anti-apoptosis, the regulation of immune response and other functions. Over-loading or lack of Se causes certain damage to the body. Se deficiency can reduce the expression and activity of selenoproteins, disrupt the normal physiological function of cells and affect the body in antioxidant, immunity, toxin antagonism, signaling pathways and other aspects, thus causing different degrees of damage to the body. Se intake is mainly in the form of dietary supplements. Due to the important role of Se, people pay increasingly more attention to Se-enriched foods, which also lays a foundation for better research on the mechanism of selenoproteins in the future. In this paper, the synthesis and mechanism of selenoproteins, as well as the role and mechanism of selenoproteins in the regulation of diseases, are reviewed. Meanwhile, the future development of Se-enriched products is prospected, which is of great significance to further understand the role of Se.
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Schomburg L. Selenium Deficiency in COVID-19-A Possible Long-Lasting Toxic Relationship. Nutrients 2022; 14:283. [PMID: 35057464 PMCID: PMC8781157 DOI: 10.3390/nu14020283] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 12/30/2021] [Accepted: 01/04/2022] [Indexed: 12/24/2022] Open
Abstract
In the last two years, there has been a surge in the number of publications on the trace element selenium (Se) and selenocysteine-containing selenoproteins in human health, largely due to the pandemic and the multiple roles that this micronutrient and Se-dependent selenoproteins play in various aspects of the disease [...].
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Affiliation(s)
- Lutz Schomburg
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, 10115 Berlin, Germany
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Muhammad AI, Dalia AM, Loh TC, Akit H, Samsudin AA. Effect of organic and inorganic dietary selenium supplementation on gene expression in oviduct tissues and Selenoproteins gene expression in Lohman Brown-classic laying hens. BMC Vet Res 2021; 17:281. [PMID: 34419016 PMCID: PMC8380377 DOI: 10.1186/s12917-021-02964-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/01/2021] [Indexed: 11/13/2022] Open
Abstract
Background The oviduct of a hen provides a conducive environment for egg formation, which needs a large amount of mineral elements from the blood via trans-epithelial permeability. Eggshell is the calcified layer on the outside of an egg that provides protection and is critical for egg quality. However, little is known about the genes or proteins involved in eggshell formation, and their relationship to dietary microminerals. We hypothesized that dietary selenium supplementation in chickens will influence genes involved in eggshell biomineralization, and improve laying hen antioxidant capacity. The objective of this research was to investigate how organic and inorganic dietary selenium supplementation affected mRNA expression of shell gland genes involved in eggshell biomineralization, and selenoproteins gene expression in Lohman Brown-Classic laying hens. Results Shell gland (Uterus) and liver tissue samples were collected from hens during the active growth phase of calcification (15–20 h post-ovulation) for RT-PCR analysis. In the oviduct (shell gland and magnum) and liver of laying hens, the relative expression of functional eggshell and hepatic selenoproteins genes was investigated. Results of qPCR confirmed the higher (p < 0.05) mRNA expression of OC-17 and OC-116 in shell gland of organic Se hen compared to inorganic and basal diet treatments. Similarly, dietary Se treatments affected the mRNA expression of OCX-32 and OCX-36 in the shell gland of laying hens. In the magnum, mRNA expression of OC-17 was significantly (p < 0.05) higher in hens fed-bacterial organic, while OC-116 mRNA expression was down-regulated in dietary Se supplemented groups compared to non-Se supplemented hens. Moreover, when compared to sodium selenite, only ADS18 bacterial Se showed significantly (p < 0.05) higher mRNA levels in GPX1, GPX4, DIO1, DIO2 and SELW1, while Se-yeast showed significantly (p < 0.05) higher mRNA levels in TXNRD1 than the non-Se group. Conclusions Dietary Se supplementation especially that from a bacterial organic source, improved shell gland and hepatic selenoproteins gene expression in laying hens, indicating that it could be used as a viable alternative source of Se in laying hens. The findings could suggest that organic Se upregulation of shell gland genes and hepatic selenoproteins in laying hens is efficient.
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Affiliation(s)
- A I Muhammad
- Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.,Department of Animal Science, Faculty of Agriculture, Federal University Dutse, P.M.B. 7156, Dutse, Jigawa State, Nigeria
| | - A M Dalia
- Department of Animal Nutrition, Faculty of Animal Production, University of Khartoum, P.O. Box 321, Khartoum, Sudan
| | - T C Loh
- Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - H Akit
- Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - A A Samsudin
- Department of Animal Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
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Chellan B, Zhao L, Landeche M, Carmean CM, Dumitrescu AM, Sargis RM. Selenocysteine insertion sequence binding protein 2 (Sbp2) in the sex-specific regulation of selenoprotein gene expression in mouse pancreatic islets. Sci Rep 2020; 10:18568. [PMID: 33122797 PMCID: PMC7596060 DOI: 10.1038/s41598-020-75595-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/09/2020] [Indexed: 12/16/2022] Open
Abstract
Selenoproteins are a group of selenocysteine-containing proteins with major roles in cellular antioxidant defense and thyroid hormone metabolism. Selenoprotein expression is determined by hierarchical mechanisms that result in tissue-specific levels. Current data inadequately explain the abundance of various selenoproteins under normal and pathological conditions, including in pancreatic β-cells. Selenocysteine insertion sequence binding protein 2 (SBP2) is a critical protein in selenoprotein translation that also plays an essential role in stabilizing selenoprotein transcripts by antagonizing nonsense-mediated decay (NMD). Importantly, dysfunctional SBP2 is associated with endocrine disorders in humans. Here we describe the impact of induced Sbp2 deficiency in pancreatic β-cells on selenoprotein transcript profiles in the pancreatic islets of C57BL/6J mice. Sex differences were noted in control mice, in which female islets showed 5 selenoproteins decreased and one increased versus male islets. Induced Sbp2 deficiency in pancreatic β-cells altered expression of only 3 selenoprotein transcripts in male islets, whereas 14 transcripts were reduced in female islets. In all cases, decreased transcription was observed in genes known to be regulated by NMD. The differential impact of Sbp2 deletion on selenoprotein transcription between sexes suggests sex-specific hierarchical mechanisms of selenoprotein expression that may influence islet biology and consequentially metabolic disease risk.
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Affiliation(s)
- B Chellan
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott, Suite E625; M/C 640, Chicago, IL, 60612, USA
| | - L Zhao
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott, Suite E625; M/C 640, Chicago, IL, 60612, USA
| | - M Landeche
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott, Suite E625; M/C 640, Chicago, IL, 60612, USA
| | - C M Carmean
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott, Suite E625; M/C 640, Chicago, IL, 60612, USA
| | - A M Dumitrescu
- Section of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Chicago, Chicago, IL, USA
| | - R M Sargis
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott, Suite E625; M/C 640, Chicago, IL, 60612, USA.
- ChicAgo Center for Health and EnvironmenT (CACHET), Chicago, IL, USA.
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Qian S, Xie L, Li G, Zheng S, Li N. Radiosensitization effect of selenocystine on HeLa cells
in vitro. PRECISION RADIATION ONCOLOGY 2020. [DOI: 10.1002/pro6.1085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Shen Qian
- Department of Respiratory and Critical Care Medicinethe First Medical CenterChinese PLA General Hospital Beijing China
- The Third Department of Pulmonary DiseaseThe Third People's Hospital of Shenzhen Shenzhen China
| | - Li‐xin Xie
- Department of Respiratory and Critical Care Medicinethe First Medical CenterChinese PLA General Hospital Beijing China
| | - Guo‐bao Li
- The Third Department of Pulmonary DiseaseThe Third People's Hospital of Shenzhen Shenzhen China
| | - Sha‐sha Zheng
- The Third Department of Pulmonary DiseaseThe Third People's Hospital of Shenzhen Shenzhen China
| | - Na Li
- Department of Respiratory and Critical Care Medicinethe First Medical CenterChinese PLA General Hospital Beijing China
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Seelig J, Heller RA, Hackler J, Haubruck P, Moghaddam A, Biglari B, Schomburg L. Selenium and copper status - potential signposts for neurological remission after traumatic spinal cord injury. J Trace Elem Med Biol 2020; 57:126415. [PMID: 31685353 DOI: 10.1016/j.jtemb.2019.126415] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 08/23/2019] [Accepted: 10/05/2019] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Traumatic Spinal Cord Injury (TSCI) is a severe incident resulting in loss of motor and sensory function caused by complex pathological mechanisms including massive oxidative stress and extensive inflammatory processes. The essential trace elements selenium (Se) and copper (Cu) play crucial roles as part of the antioxidant defense. HYPOTHESIS Remission after TSCI is associated with characteristic dynamics of early changes in serum Cu and Se status. STUDY DESIGN Single-center prospective observational study. PATIENTS AND METHODS Serum samples from TSCI patients were analyzed (n = 52); 21 recovered and showed a positive abbreviated injury score (AIS) conversion within 3 months (G1), whereas 21 had no remission (G0). Ten subjects with vertebral fractures without neurological impairment served as control (C). Different time points (at admission, and after 4, 9, 12, and 24 h) were analyzed for total serum Se and Cu concentrations by total reflection X-ray fluorescence, and for Selenoprotein P (SELENOP) and Ceruloplasmin (CP) by sandwich ELISA. RESULTS At admission, CP and SELENOP concentrations were higher in the remission group (G1) than in the non-remission group (G0). Within 24 h, there were marginal changes in Se, SELENOP, Cu and CP concentrations in the groups of controls (C) and G0. In contrast, these parameters decreased significantly in G1. Binary logistic regression analysis including Cu and Se levels at admission in combination with Se and CP levels after 24 h allowed a prediction for potential remission, with an area under the curve (AUC) of 87.7% (CI: 75.1%-100.0%). CONCLUSION These data indicate a strong association between temporal changes of the Se and Cu status and the clinical outcome after TSCI. The dynamics observed may reflect an ongoing redistribution of the trace elements in favor of a better anti-inflammatory response and a more successful neurological regeneration.
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Affiliation(s)
- Julian Seelig
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Raban Arved Heller
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany; Heidelberg Trauma Research Group, Department of Trauma and Reconstructive Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany
| | - Julian Hackler
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Patrick Haubruck
- Heidelberg Trauma Research Group, Department of Trauma and Reconstructive Surgery, Center for Orthopedics, Trauma Surgery and Spinal Cord Injury, Heidelberg University Hospital, Heidelberg, Germany; Raymond Purves Bone and Joint Research Laboratories, Kolling Institute of Medical Research, Institute of Bone and Joint Research, University of Sydney, St Leonards, New South Wales, 2065, Australia
| | - Arash Moghaddam
- Aschaffenburg Trauma and Orthopedic Research Group, Center for Orthopedics, Trauma Surgery and Sports Medicine, Hospital Aschaffenburg-Alzenau, Aschaffenburg, Germany
| | - Bahram Biglari
- BG Trauma Center Ludwigshafen, Department of Paraplegiology, Ludwigshafen, Germany
| | - Lutz Schomburg
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Augustenburger Platz 1, 13353 Berlin, Germany.
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8
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Genetic Disorders Associated with Metal Metabolism. Cells 2019; 8:cells8121598. [PMID: 31835360 PMCID: PMC6952812 DOI: 10.3390/cells8121598] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 12/12/2022] Open
Abstract
Genetic disorders associated with metal metabolism form a large group of disorders and mostly result from defects in the proteins/enzymes involved in nutrient metabolism and energy production. These defects can affect different metabolic pathways and cause mild to severe disorders related to metal metabolism. Some disorders have moderate to severe clinical consequences. In severe cases, these elements accumulate in different tissues and organs, particularly the brain. As they are toxic and interfere with normal biological functions, the severity of the disorder increases. However, the human body requires a very small amount of these elements, and a deficiency of or increase in these elements can cause different genetic disorders to occur. Some of the metals discussed in the present review are copper, iron, manganese, zinc, and selenium. These elements may play a key role in the pathology and physiology of the nervous system.
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Ziyaee F, Shorafa E, Dastsooz H, Habibzadeh P, Nemati H, Saeed A, Silawi M, Farazi Fard MA, Faghihi MA, Dastgheib SA. A novel mutation in SEPN1 causing rigid spine muscular dystrophy 1: a Case report. BMC MEDICAL GENETICS 2019; 20:13. [PMID: 30642275 PMCID: PMC6332642 DOI: 10.1186/s12881-018-0743-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/26/2018] [Indexed: 12/19/2022]
Abstract
Background Muscular dystrophies are a clinically and genetically heterogeneous group of disorders characterized by variable degrees of progressive muscle degeneration and weakness. There is a wide variability in the age of onset, symptoms and rate of progression in subtypes of these disorders. Herein, we present the results of our study conducted to identify the pathogenic genetic variation involved in our patient affected by rigid spine muscular dystrophy. Case presentation A 14-year-old boy, product of a first-cousin marriage, was enrolled in our study with failure to thrive, fatigue, muscular dystrophy, generalized muscular atrophy, kyphoscoliosis, and flexion contracture of the knees and elbows. Whole-exome sequencing (WES) was carried out on the DNA of the patient to investigate all coding regions and uncovered a novel, homozygous missense mutation in SEPN1 gene (c. 1379 C > T, p.Ser460Phe). This mutation has not been reported before in different public variant databases and also our database (BayanGene), so it is classified as a variation of unknown significance (VUS). Subsequently, it was confirmed that the novel variation was homozygous in our patient and heterozygous in his parents. Different bioinformatics tools showed the damaging effects of the variant on protein. Multiple sequence alignment using BLASTP on ExPASy and WebLogo, revealed the conservation of the mutated residue. Conclusion We reported a novel homozygous mutation in SEPN1 gene that expands our understanding of rigid spine muscular dystrophy. Although bioinformatics analyses of results were in favor of the pathogenicity of the mutation, functional studies are needed to establish the pathogenicity of the variant.
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Affiliation(s)
- Fateme Ziyaee
- Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Eslam Shorafa
- Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hassan Dastsooz
- Italian Institute for Genomic Medicine (IIGM), University of Turin, Turin, Italy.,Persian BayanGene Research and Training Center, Dr. Faghihi's Medical Genetic Center, Shiraz, Iran
| | - Parham Habibzadeh
- Persian BayanGene Research and Training Center, Dr. Faghihi's Medical Genetic Center, Shiraz, Iran.,Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hamid Nemati
- Shiraz Neuroscience Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amir Saeed
- Department of Pediatrics, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Silawi
- Persian BayanGene Research and Training Center, Dr. Faghihi's Medical Genetic Center, Shiraz, Iran
| | - Mohammad Ali Farazi Fard
- Persian BayanGene Research and Training Center, Dr. Faghihi's Medical Genetic Center, Shiraz, Iran
| | - Mohammad Ali Faghihi
- Persian BayanGene Research and Training Center, Dr. Faghihi's Medical Genetic Center, Shiraz, Iran.,Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, Miami, USA
| | - Seyed Alireza Dastgheib
- Persian BayanGene Research and Training Center, Dr. Faghihi's Medical Genetic Center, Shiraz, Iran. .,Department of Genetic, Shiraz University of Medical Sciences, Shiraz, Iran.
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Filippini T, Michalke B, Mandrioli J, Tsatsakis AM, Weuve J, Vinceti M. Selenium Neurotoxicity and Amyotrophic Lateral Sclerosis: An Epidemiologic Perspective. ACTA ACUST UNITED AC 2018. [DOI: 10.1007/978-3-319-95390-8_12] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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On elongation factor eEFSec, its role and mechanism during selenium incorporation into nascent selenoproteins. Biochim Biophys Acta Gen Subj 2018; 1862:2463-2472. [PMID: 29555379 DOI: 10.1016/j.bbagen.2018.03.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 02/28/2018] [Accepted: 03/12/2018] [Indexed: 02/02/2023]
Abstract
BACKGROUND Selenium, an essential dietary micronutrient, is incorporated into proteins as the amino acid selenocysteine (Sec) in response to in-frame UGA codons. Complex machinery ensures accurate recoding of Sec codons in higher organisms. A specialized elongation factor eEFSec is central to the process. SCOPE OF REVIEW Selenoprotein synthesis relies on selenocysteinyl-tRNASec (Sec-tRNASec), selenocysteine inserting sequence (SECIS) and other selenoprotein mRNA elements, an in-trans SECIS binding protein 2 (SBP2) protein factor, and eEFSec. The exact mechanisms of discrete steps of the Sec UGA recoding are not well understood. However, recent studies on mammalian model systems have revealed the first insights into these mechanisms. Herein, we summarize the current knowledge about the structure and role of mammalian eEFSec. MAJOR CONCLUSIONS eEFSec folds into a chalice-like structure resembling that of the archaeal and bacterial orthologues SelB and the initiation protein factor IF2/eIF5B. The three N-terminal domains harbor major functional sites and adopt an EF-Tu-like fold. The C-terminal domain 4 binds to Sec-tRNASec and SBP2, senses distinct binding domains, and modulates the GTPase activity. Remarkably, GTP hydrolysis does not induce a canonical conformational change in eEFSec, but instead promotes a slight ratchet of domains 1 and 2 and a lever-like movement of domain 4, which may be critical for the release of Sec-tRNASec on the ribosome. GENERAL SIGNIFICANCE Based on current findings, a non-canonical mechanism for elongation of selenoprotein synthesis at the Sec UGA codon is proposed. Although incomplete, our understanding of this fundamental biological process is significantly improved, and it is being harnessed for biomedical and synthetic biology initiatives. This article is part of a Special Issue entitled "Selenium research" in celebration of 200 years of selenium discovery, edited by Dr. Elias Arnér and Dr. Regina Brigelius-Flohe.
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Abstract
Trace elements are chemical elements needed in minute amounts for normal physiology. Some of the physiologically relevant trace elements include iodine, copper, iron, manganese, zinc, selenium, cobalt and molybdenum. Of these, some are metals, and in particular, transition metals. The different electron shells of an atom carry different energy levels, with those closest to the nucleus being lowest in energy. The number of electrons in the outermost shell determines the reactivity of such an atom. The electron shells are divided in sub-shells, and in particular the third shell has s, p and d sub-shells. Transition metals are strictly defined as elements whose atom has an incomplete d sub-shell. This incomplete d sub-shell makes them prone to chemical reactions, particularly redox reactions. Transition metals of biologic importance include copper, iron, manganese, cobalt and molybdenum. Zinc is not a transition metal, since it has a complete d sub-shell. Selenium, on the other hand, is strictly speaking a nonmetal, although given its chemical properties between those of metals and nonmetals, it is sometimes considered a metalloid. In this review, we summarize the current knowledge on the inborn errors of metal and metalloid metabolism.
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Affiliation(s)
- Carlos R. Ferreira
- Division of Genetics and Metabolism, Children’s National Health System, Washington, DC, USA
- Department of Pediatrics, George Washington University School of Medicine and Health Sciences, Washington, DC, USA
- Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
| | - William A. Gahl
- Section on Human Biochemical Genetics, Medical Genetics Branch, National Human Genome Research Institute, NIH, Bethesda, MD, USA
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Aminoglycoside-driven biosynthesis of selenium-deficient Selenoprotein P. Sci Rep 2017; 7:4391. [PMID: 28663583 PMCID: PMC5491492 DOI: 10.1038/s41598-017-04586-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 05/17/2017] [Indexed: 12/17/2022] Open
Abstract
Selenoprotein biosynthesis relies on the co-translational insertion of selenocysteine in response to UGA codons. Aminoglycoside antibiotics interfere with ribosomal function and may cause codon misreading. We hypothesized that biosynthesis of the selenium (Se) transporter selenoprotein P (SELENOP) is particularly sensitive to antibiotics due to its ten in frame UGA codons. As liver regulates Se metabolism, we tested the aminoglycosides G418 and gentamicin in hepatoma cell lines (HepG2, Hep3B and Hepa1-6) and in experimental mice. In vitro, SELENOP levels increased strongly in response to G418, whereas expression of the glutathione peroxidases GPX1 and GPX2 was marginally affected. Se content of G418-induced SELENOP was dependent on Se availability, and was completely suppressed by G418 under Se-poor conditions. Selenocysteine residues were replaced mainly by cysteine, tryptophan and arginine in a codon-specific manner. Interestingly, in young healthy mice, antibiotic treatment failed to affect Selenop biosynthesis to a detectable degree. These findings suggest that the interfering activity of aminoglycosides on selenoprotein biosynthesis can be severe, but depend on the Se status, and other parameters likely including age and general health. Focused analyses with aminoglycoside-treated patients are needed next to evaluate a possible interference of selenoprotein biosynthesis by the antibiotics and elucidate potential side effects.
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Abstract
Infectious diseases impair Se metabolism, and low Se status is associated with mortality risk in adults with critical disease. The Se status of neonates is poorly characterised, and a potential impact of connatal infection is unknown. We hypothesised that an infection negatively affects the Se status of neonates. We conducted an observational case-control study at three intensive care units at the Charité-Universitätsmedizin Berlin, Germany. Plasma samples were collected from forty-four neonates. On the basis of clinical signs for bacterial infection and concentrations of IL-6 or C-reactive protein, neonates were classified into control (n 23) and infected (n 21) groups. Plasma Se and selenoprotein P (SePP) concentrations were determined by X-ray fluorescence and ELISA, respectively, at day of birth (day 1) and 48 h later (day 3). Se and SePP showed a positive correlation in both groups of neonates. Se concentrations indicative of Se deficit in adults (500 ng/l). During antibiotic therapy, SePP increased significantly from day 1 (1·03 (sd 0·10) mg/l) to day 3 (1·34 (sd 0·10) mg/l), indicative of improved hepatic Se metabolism. We conclude that both Se and SePP are suitable biomarkers for assessing Se status in neonates and for identifying subjects at risk of deficiency.
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Mondal S, Raja K, Schweizer U, Mugesh G. Chemie und Biologie der Schilddrüsenhormon-Biosynthese und -Wirkung. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201601116] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Santanu Mondal
- Department of Inorganic and Physical Chemistry; Indian Institute of Science; Bangalore Indien
| | - Karuppusamy Raja
- Department of Inorganic and Physical Chemistry; Indian Institute of Science; Bangalore Indien
| | - Ulrich Schweizer
- Rheinische Friedrich-Wilhelms-Universität Bonn; Institut für Biochemie und Molekularbiologie; Nussallee 11 53115 Bonn Deutschland
| | - Govindasamy Mugesh
- Department of Inorganic and Physical Chemistry; Indian Institute of Science; Bangalore Indien
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Mondal S, Raja K, Schweizer U, Mugesh G. Chemistry and Biology in the Biosynthesis and Action of Thyroid Hormones. Angew Chem Int Ed Engl 2016; 55:7606-30. [DOI: 10.1002/anie.201601116] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Santanu Mondal
- Department of Inorganic and Physical Chemistry; Indian Institute of Science; Bangalore India
| | - Karuppusamy Raja
- Department of Inorganic and Physical Chemistry; Indian Institute of Science; Bangalore India
| | - Ulrich Schweizer
- Rheinische Friedrich-Wilhelms-Universität Bonn; Institut für Biochemie und Molekularbiologie; Nussallee 11 53115 Bonn Germany
| | - Govindasamy Mugesh
- Department of Inorganic and Physical Chemistry; Indian Institute of Science; Bangalore India
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17
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Abstract
PURPOSE OF REVIEW This article provides an update on the role of the essential trace element selenium and its interaction with the other trace elements iodine and iron that together contribute to adequate thyroid hormone status. Synthesis, secretion, metabolism and action of thyroid hormone in target tissues depend on a balanced nutritional availability or supplementation of these elements. Selenium status is altered in benign and malignant thyroid diseases and various selenium compounds have been used to prevent or treat widespread diseases such as goiter, autoimmune thyroid disease or thyroid cancer. RECENT FINDINGS Several studies, most with still too low numbers of cases, indicate that selenium administration in both autoimmune thyroiditis (Hashimoto thyroiditis) and mild Graves' disease improves clinical scores and well-being of patients and reduces thyroperoxidase antibody titers. However, published results are still conflicting depending on basal selenium status, dose, time and form of selenium used for intervention. Evidence for sex-specific selenium action, lack of beneficial effects in pregnancy and contribution of genetic polymorphisms (selenoprotein S) has been presented. SUMMARY Adequate nutritional supply of selenium that saturates expression of circulating selenoprotein P, together with optimal iodine and iron intake, is required for a healthy and functional thyroid during development, adolescence, adulthood and aging.
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Affiliation(s)
- Josef Köhrle
- Institute of Experimental Endocrinology, Charité University Medicine Berlin, Berlin, Germany
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18
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Nazıroğlu M, Çelik Ö, Uğuz AC, Bütün A. Protective effects of riboflavin and selenium on brain microsomal Ca2+-ATPase and oxidative damage caused by glyceryl trinitrate in a rat headache model. Biol Trace Elem Res 2015; 164:72-9. [PMID: 25492827 DOI: 10.1007/s12011-014-0199-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 12/01/2014] [Indexed: 01/19/2023]
Abstract
Migraine headaches are considered to be associated with increased mitochondrial energy metabolism. Mitochondrial oxidative stress is also important in migraine headache pathophysiology although riboflavin and selenium (Se) induced a modulator role on mitochondrial oxidative stress in the brain. The current study aimed to determine the effects of Se with/without riboflavin on the microsomal membrane Ca(2+)-ATPase (MMCA), lipid peroxidation, antioxidant, and electroencephalography (EEG) values in glyceryl trinitrate (GTN)-induced brain injury rats. Thirty-two rats were randomly divided into four groups. The first group was used as the control, and the second group was the GTN group. Se and Se plus oral riboflavin were administered to rats constituting the third and fourth groups for 10 days prior to GTN administration. The second, third, and fourth groups received GTN to induce headache. Ten hours after the administration of GTN, the EEG records and brain cortex samples were obtained for all groups. Brain cortex microsomes were obtained from the brain samples. The brain and microsomal lipid peroxidation levels were higher in the GTN group compared to the control group, whereas they were decreased by selenium and selenium + riboflavin treatments. Vitamin A, vitamin C, vitamin E, and reduced glutathione (GSH) concentrations of the brain and MMCA, GSH and glutathione peroxidase values of microsomes were decreased by the GTN administration, although the values and β-carotene concentrations were increased by Se and Se + riboflavin treatments. There was no significant change in EEG records of the four groups. In conclusion, Se with/without riboflavin administration protected against GTN-induced brain oxidative toxicity by inhibiting free radicals and the modulation of MMCA activity and supporting the antioxidant redox system.
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Affiliation(s)
- Mustafa Nazıroğlu
- Department of Biophysics, Faculty of Medicine, Suleyman Demirel University, Isparta, Turkey,
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19
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Pitts MW, Byrns CN, Ogawa-Wong AN, Kremer P, Berry MJ. Selenoproteins in nervous system development and function. Biol Trace Elem Res 2014; 161:231-45. [PMID: 24974905 PMCID: PMC4222985 DOI: 10.1007/s12011-014-0060-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 06/23/2014] [Indexed: 01/03/2023]
Abstract
Selenoproteins are a distinct class of proteins that are characterized by the co-translational incorporation of selenium (Se) in the form of the 21st amino acid selenocysteine. Selenoproteins provide a key defense against oxidative stress, as many of these proteins participate in oxidation-reduction reactions neutralizing reactive oxygen species, where selenocysteine residues act as catalytic sites. Many selenoproteins are highly expressed in the brain, and mouse knockout studies have determined that several are required for normal brain development. In parallel with these laboratory studies, recent reports of rare human cases with mutations in genes involved in selenoprotein biosynthesis have described individuals with an assortment of neurological problems that mirror those detailed in knockout mice. These deficits include impairments in cognition and motor function, seizures, hearing loss, and altered thyroid metabolism. Additionally, due to the fact that oxidative stress is a key feature of neurodegenerative disease, there is considerable interest in the therapeutic potential of selenium supplementation for human neurological disorders. Studies performed in cell culture and rodent models have demonstrated that selenium administration attenuates oxidative stress, prevents neurodegeneration, and counters cell signaling mechanisms known to be dysregulated in certain disease states. However, there is currently no definitive evidence in support of selenium supplementation to prevent and/or treat common neurological conditions in the general population. It appears likely that, in humans, supplementation with selenium may only benefit certain subpopulations, such as those that are either selenium-deficient or possess genetic variants that affect selenium metabolism.
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Affiliation(s)
- Matthew W Pitts
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo St, Honolulu, HI, 96813, USA,
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20
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Seeher S, Atassi T, Mahdi Y, Carlson BA, Braun D, Wirth EK, Klein MO, Reix N, Miniard AC, Schomburg L, Hatfield DL, Driscoll DM, Schweizer U. Secisbp2 is essential for embryonic development and enhances selenoprotein expression. Antioxid Redox Signal 2014; 21:835-49. [PMID: 24274065 PMCID: PMC4116110 DOI: 10.1089/ars.2013.5358] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
AIMS The selenocysteine insertion sequence (SECIS)-binding protein 2 (Secisbp2) binds to SECIS elements located in the 3'-untranslated region of eukaryotic selenoprotein mRNAs. Selenoproteins contain the rare amino acid selenocysteine (Sec). Mutations in SECISBP2 in humans lead to reduced selenoprotein expression thereby affecting thyroid hormone-dependent growth and differentiation processes. The most severe cases also display myopathy, hearing impairment, male infertility, increased photosensitivity, mental retardation, and ataxia. Mouse models are needed to understand selenoprotein-dependent processes underlying the patients' pleiotropic phenotypes. RESULTS Unlike tRNA[Ser]Sec-deficient embryos, homozygous Secisbp2-deleted embryos implant, but fail before gastrulation. Heterozygous inactivation of Secisbp2 reduced the amount of selenoprotein expressed, but did not affect the thyroid hormone axis or growth. Conditional deletion of Secisbp2 in hepatocytes significantly decreased selenoprotein expression. Unexpectedly, the loss of Secisbp2 reduced the abundance of many, but not all, selenoprotein mRNAs. Transcript-specific and gender-selective effects on selenoprotein mRNA abundance were greater in Secisbp2-deficient hepatocytes than in tRNA[Ser]Sec-deficient cells. Despite the massive reduction of Dio1 and Sepp1 mRNAs, significantly more corresponding protein was detected in primary hepatocytes lacking Secisbp2 than in cells lacking tRNA[Ser]Sec. Regarding selenoprotein expression, compensatory nuclear factor, erythroid-derived, like 2 (Nrf2)-dependent gene expression, or embryonic development, phenotypes were always milder in Secisbp2-deficient than in tRNA[Ser]Sec-deficient mice. INNOVATION We report the first Secisbp2 mutant mouse models. The conditional mutants provide a model for analyzing Secisbp2 function in organs not accessible in patients. CONCLUSION In hepatocyte-specific conditional mouse models, Secisbp2 gene inactivation is less detrimental than tRNA[Ser]Sec inactivation. A role of Secisbp2 in stabilizing selenoprotein mRNAs in vivo was uncovered.
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Affiliation(s)
- Sandra Seeher
- 1 Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin , Berlin, Germany
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21
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Seale LA, Gilman CL, Moorman BP, Berry MJ, Grau EG, Seale AP. Effects of acclimation salinity on the expression of selenoproteins in the tilapia, Oreochromis mossambicus. J Trace Elem Med Biol 2014; 28:284-92. [PMID: 24854764 PMCID: PMC4082732 DOI: 10.1016/j.jtemb.2014.04.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 04/02/2014] [Accepted: 04/15/2014] [Indexed: 01/06/2023]
Abstract
Selenoproteins are ubiquitously expressed, act on a variety of physiological redox-related processes, and are mostly regulated by selenium levels in animals. To date, the expression of most selenoproteins has not been verified in euryhaline fish models. The Mozambique tilapia, Oreochromis mossambicus, a euryhaline cichlid fish, has a high tolerance for changes in salinity and survives in fresh water (FW) and seawater (SW) environments which differ greatly in selenium availability. In the present study, we searched EST databases for cichlid selenoprotein mRNAs and screened for their differential expression in FW and SW-acclimated tilapia. The expression of mRNAs encoding iodothyronine deiodinases 1, 2 and 3 (Dio1, Dio2, Dio3), Fep15, glutathione peroxidase 2, selenoproteins J, K, L, M, P, S, and W, was measured in the brain, eye, gill, kidney, liver, pituitary, muscle, and intraperitoneal white adipose tissue. Gene expression of selenophosphate synthetase 1, Secp43, and selenocysteine lyase, factors involved in selenoprotein synthesis or in selenium metabolism, were also measured. The highest variation in selenoprotein and synthesis factor mRNA expression between FW- and SW-acclimated fish was found in gill and kidney. While the branchial expression of Dio3 was increased upon transferring tilapia from SW to FW, the inverse effect was observed when fish were transferred from FW to SW. Protein content of Dio3 was higher in fish acclimated to FW than in those acclimated to SW. Together, these results outline tissue distribution of selenoproteins in FW and SW-acclimated tilapia, and indicate that at least Dio3 expression is regulated by environmental salinity.
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Affiliation(s)
- Lucia A Seale
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA.
| | - Christy L Gilman
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA
| | - Benjamin P Moorman
- Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, HI 96744, USA
| | - Marla J Berry
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa, Honolulu, HI 96813, USA
| | - E Gordon Grau
- Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, HI 96744, USA
| | - Andre P Seale
- Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, HI 96744, USA
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22
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Dharmasena A. Selenium supplementation in thyroid associated ophthalmopathy: an update. Int J Ophthalmol 2014; 7:365-75. [PMID: 24790886 DOI: 10.3980/j.issn.2222-3959.2014.02.31] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 12/12/2013] [Indexed: 12/18/2022] Open
Abstract
The therapeutic effect of selenium (Se) has already been proven in thyroid disease and thyroid associated ophthalmopathy (TAO). In spite of clear scientific proof of its benefits in TAO, there appears to be no clear agreement among the clinicians regarding its optimum dose, duration of the treatment, efficacy and safety to date. In this review, the author summarises the findings of 135 English language articles published on this subject over the past four decades from 1973 to 2013. The regulation and metabolism of thyroid hormones require a steady supply of Se and recent studies have revealed several possible mechanisms by which Se improves the severity of thyroid disease and TAO. These mechanisms include 1) inhibitory effect of HLA-DR molecule expression on thyrocytes; 2) profound reductions of thyroid stimulating hormone (TSH) receptor antibodies (TSHR-Ab) and TPO antibodies (TPO-Ab); 3) prevention of dysregulation of cell-mediated immunity and B cell function; 4) neutralising reactive oxygen species (ROS) and inhibition of redox control processes required for the activation, differentiation and action of lymphocytes, macrophages, neutrophils, natural killer cells involved in both acute and chronic orbital inflammation in TAO; 5) inhibition of expression of pro-inflammatory cytokines and 6) inhibition of prostaglandin and leukotriene synthesis. An increased oxidative stress has been observed in both acute and chronic phases of thyroid disease with raised tissue concentrations of ROS. The benefits of Se supplementation in individuals with TAO appear to be proportionate to the degree of systemic activity of the thyroid disease. The maximal benefit of Se supplementation is therefore seen in the subjects who are hyperthyroid. Restoration of euthyroidism is one of the main goals in the management of TAO and when anti-thyroid drugs are combined with Se, the patients with Graves' disease (GD) and autoimmune thyroiditis (AIT) achieved euthyroidism faster than those treated with anti-thyroid drugs alone. Se status of normal adult humans can vary widely and Se supplementation may confer benefit only if serum Se levels are insufficient. The author recommends that serum Se levels of patients with TAO to be assessed prior to and during Se supplementation at regular intervals to avoid potential iatrogenic chronic Se overdose.
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Affiliation(s)
- Aruna Dharmasena
- Department of Oculoplastics, Lacrimal and Orbital Surgery, Manchester Royal Eye Hospital, Oxford Road, Manchester M13 9WH, UK
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23
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Abstract
Oxygen derived free radicals, generated by a number of cellular reactions, include superoxide anion, hydrogen peroxide and hydroxyl radicals. They exert their cytotoxic effects mainly via peroxidation of the cell membrane resulting in the loss of membrane integrity. The essential trace element, selenium exerts complex effects on the endocrine systems, partly due to its antioxidant capacity. Well-characterized selenoproteins include iodothyronine deiodinases, glutathione peroxidases and thioredoxin reductases involved in thyroid hormone metabolism and protection from oxidative damage. The value of selenium supplementation in autoimmune thyroid disorders has been investigated and most studies confirmed the beneficial effect of selenium supplementation in Hashimoto's and Graves's diseases. Recently, selenium proved to be effective in mild inflammatory orbitopathy. There are a number of reports about the effect of selenium in diabetes mellitus, but the data are controversial as both insulin-like and diabetes-inducing effects of selenium have been described. Selenium was successfully used in both female and male infertility of autoimmune origin.
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Affiliation(s)
- Csaba Balázs
- Budai Endokrin Központ Budapest Ostrom u. 16. 1015
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24
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Hurst R, Collings R, Harvey LJ, King M, Hooper L, Bouwman J, Gurinovic M, Fairweather-Tait SJ. EURRECA-Estimating selenium requirements for deriving dietary reference values. Crit Rev Food Sci Nutr 2014; 53:1077-96. [PMID: 23952089 DOI: 10.1080/10408398.2012.742861] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Current reference values for selenium, an essential micronutrient, are based on the intake of selenium that is required to achieve maximal glutathione peroxidase activity in plasma or erythrocytes. In order to assess the evidence of relevance to setting dietary reference values for selenium, the EURRECA Network of Excellence focused on systematic searches, review, and evaluation of (i) selenium status biomarkers and evidence for relationships between intake and status biomarkers, (ii) selenium and health (including the effect of intake and/or status biomarkers on cancer risk, immune function, HIV, cognition, and fertility), (iii) bioavailability of selenium from the diet, and (iv) impact of genotype/single nucleotide polymorphisms on status or health outcomes associated with selenium. The main research outputs for selenium and future research priorities are discussed further in this review.
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Affiliation(s)
- Rachel Hurst
- Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, NR4 7TJ, UK
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25
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Byrns CN, Pitts MW, Gilman CA, Hashimoto AC, Berry MJ. Mice lacking selenoprotein P and selenocysteine lyase exhibit severe neurological dysfunction, neurodegeneration, and audiogenic seizures. J Biol Chem 2014; 289:9662-74. [PMID: 24519931 DOI: 10.1074/jbc.m113.540682] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Selenoproteins are a unique family of proteins, characterized by the co-translational incorporation of selenium as selenocysteine, which play key roles in antioxidant defense. Among selenoproteins, selenoprotein P (Sepp1) is particularly distinctive due to the fact that it contains multiple selenocysteine residues and has been postulated to act in selenium transport. Within the brain, Sepp1 delivers selenium to neurons by binding to the ApoER2 receptor. Upon feeding a selenium-deficient diet, mice lacking ApoER2 or Sepp1 develop severe neurological dysfunction and exhibit widespread brainstem neurodegeneration, indicating an important role for ApoER2-mediated Sepp1 uptake in normal brain function. Selenocysteine lyase (Scly) is an enzyme that plays an important role in selenium homeostasis, in that it catalyzes the decomposition of selenocysteine and allows selenium to be recycled for additional selenoprotein synthesis. We previously reported that constitutive deletion of Scly results in neurological deficits only when mice are challenged with a low selenium diet. To gain insight into the relationship between Sepp1 and Scly in selenium metabolism, we created novel transgenic mice constitutively lacking both genes (Scly(-/-)Sepp1(-/-)) and characterized the neurobehavioral phenotype. We report that deletion of Scly in conjunction with Sepp1 further aggravates the phenotype of Sepp1(-/-) mice, as these mice needed supraphysiological selenium supplementation to survive, and surviving mice exhibited impaired motor coordination, audiogenic seizures, and brainstem neurodegeneration. These findings provide the first in vivo evidence that Scly and Sepp1 work cooperatively to maintain selenoprotein function in the mammalian brain.
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Affiliation(s)
- China N Byrns
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
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26
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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: 147] [Impact Index Per Article: 13.4] [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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27
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Abstract
PURPOSE OF REVIEW To provide information on the role of the essential trace element selenium, which enables appropriate thyroid hormone synthesis, secretion, and metabolism, and to discuss supplementation with various selenium compounds, which prevent thyroid diseases such as goiter and exert beneficial effects in thyroid autoimmune diseases. RECENT FINDINGS Selenium administration in both autoimmune thyroiditis (M. Hashimoto) and mild Graves' disease improves clinical scores and well-being of patients and reduces autoimmune antibody titres in several prospective, placebo-controlled supplementation studies. SUMMARY Adequate nutritional supply of selenium, together with the two other essential trace elements iodine and iron, is required for a healthy thyroid during development and adolescence, as well as in the adult and aging populations.
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Affiliation(s)
- Josef Köhrle
- Institute of Experimental Endocrinology, Charité University Medicine Berlin, Germany.
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28
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Yürekli VA, Nazıroğlu M. Selenium and topiramate attenuates blood oxidative toxicity in patients with epilepsy: a clinical pilot study. Biol Trace Elem Res 2013; 152:180-6. [PMID: 23389846 DOI: 10.1007/s12011-013-9616-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Accepted: 01/21/2013] [Indexed: 11/28/2022]
Abstract
It is well known that oxidative stress plays an important role in the etiology of epilepsy. We investigated effects of selenium (Se) and topiramate (TPM) combination supplementation on antioxidant and oxidant values in control and patients with epilepsy and refractory epilepsy. For the aim, we used control (n = 19), epilepsy + TPM (n = 19), epilepsy + TPM + Se (n = 15) groups. We also used control (n = 15), refractory epilepsy (n = 15), and refractory epilepsy + Se (n = 8) groups. TPM (0.2 mg/daily) and Se, as sodium selenite (twice daily with 0.1 mg doses), were orally supplemented to the patients for 45 days. Erythrocyte lipid peroxidation levels were higher in refractory epilepsy groups than in control although its level and seizure numbers were decreased in TPM and TPM + Se supplemented groups of the patients. The erythrocyte reduced glutathione (GSH), glutathione peroxidase (GSH-Px), plasma total antioxidant status (TAS), and vitamin E concentration in refractory epilepsy group were lower than in control. However, the erythrocyte and plasma TAS, erythrocyte GSH and GSH-Px, and plasma vitamins A and C values were increased either by Se or Se + TPM in epilepsy and refractory epilepsy groups. There were no effects of TPM and Se on plasma β-carotene values in the groups. In conclusion, TPM and selenium caused protective effects on the epilepsy and refractory epilepsy-induced oxidative injury by inhibiting free radical production and supporting antioxidant redox system.
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Affiliation(s)
- Vedat Ali Yürekli
- Department of Neurology, Medical Faculty, Suleyman Demirel University, Isparta, Turkey
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29
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30
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Meyer HA, Endermann T, Stephan C, Stoedter M, Behrends T, Wolff I, Jung K, Schomburg L. Selenoprotein P status correlates to cancer-specific mortality in renal cancer patients. PLoS One 2012; 7:e46644. [PMID: 23056383 PMCID: PMC3467258 DOI: 10.1371/journal.pone.0046644] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 09/03/2012] [Indexed: 12/21/2022] Open
Abstract
Selenium (Se) is an essential trace element for selenoprotein biosynthesis. Selenoproteins have been implicated in cancer risk and tumor development. Selenoprotein P (SePP) serves as the major Se transport protein in blood and as reliable biomarker of Se status in marginally supplied individuals. Among the different malignancies, renal cancer is characterized by a high mortality rate. In this study, we aimed to analyze the Se status in renal cell cancer (RCC) patients and whether it correlates to cancer-specific mortality. To this end, serum samples of RCC patients (n = 41) and controls (n = 21) were retrospectively analyzed. Serum Se and SePP concentrations were measured by X-ray fluorescence and an immunoassay, respectively. Clinical and survival data were compared to serum Se and SePP concentrations as markers of Se status by receiver operating characteristic (ROC) curve and Kaplan-Meier and Cox regression analyses. In our patients, higher tumor grade and tumor stage at diagnosis correlated to lower SePP and Se concentrations. Kaplan-Meier analyses indicated that low Se status at diagnosis (SePP<2.4 mg/l, bottom tertile of patient group) was associated with a poor 5-year survival rate of 20% only. We conclude that SePP and Se concentrations are of prognostic value in RCC and may serve as additional diagnostic biomarkers identifying a Se deficit in kidney cancer patients potentially affecting therapy regimen. As poor Se status was indicative of high mortality odds, we speculate that an adjuvant Se supplementation of Se-deficient RCC patients might be beneficial in order to stabilize their selenoprotein expression hopefully prolonging their survival. However, this assumption needs to be rigorously tested in prospective clinical trials.
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Affiliation(s)
- Hellmuth A. Meyer
- Institute of Physiology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Tobias Endermann
- Institute for Experimental Endocrinology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Carsten Stephan
- Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute for Urologic Research, Berlin, Germany
| | - Mette Stoedter
- Institute for Experimental Endocrinology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas Behrends
- Institute for Experimental Endocrinology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Ingmar Wolff
- Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Klaus Jung
- Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute for Urologic Research, Berlin, Germany
| | - Lutz Schomburg
- Institute for Experimental Endocrinology, Charité - Universitätsmedizin Berlin, Berlin, Germany
- * E-mail:
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31
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Mostafa-Gharehbaghi M, Mostafa-Gharabaghi P, Ghanbari F, Abdolmohammad-Zadeh H, Sadeghi GH, Jouyban A. Determination of selenium in serum samples of preterm newborn infants with bronchopulmonary dysplasia using a validated hydride generation system. Biol Trace Elem Res 2012; 147:1-7. [PMID: 22144015 DOI: 10.1007/s12011-011-9270-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 11/09/2011] [Indexed: 10/15/2022]
Abstract
Bronchopulmonary dysplasia (BPD), also known as chronic lung disease, is one of the most challenging complications in premature newborn infants. Selenium plays a role in antioxidant system by protecting cell membranes and neutralizing the deleterious effects of free radicals. The aim of this study was to determine the relationship between selenium concentration and incidence of bronchopulmonary dysplasia using a validated analytical method. Umbilical cord blood and blood samples 30 days after the birth were collected from 38 preterm newborn infants with gestation age of 32 weeks or less, and the separated serums were kept at -70°C until analysis time. Selenium concentration of serum was determined using an atomic absorption spectrophotometer. The method was validated on the basis of standard validation techniques. The analytical method was linear in the range of 1 to 500 μg/L with the limit of detection of 0.4 μg/L. Samples were collected from 38 infants whose gestation age was 32 weeks or less. The blood samples were collected from the umbilical cord blood at birth in 19 cases. In 25 cases, blood samples were collected 1 month after birth. Of the 15 patients diagnosed with BPD, 10 were boys (p = 0.02). The mean serum selenium concentration was not different at birth between patients with and without BPD, but it was significantly lower at 30 days after birth in patients with BPD (38.5 ± 14.1vs. 45.4 ± 18.7 μg/L, p = 0.02). Preterm newborn infants with BPD had lower serum selenium concentrations 1 month after birth.
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Affiliation(s)
- Manizheh Mostafa-Gharehbaghi
- Women's Reproductive Health Research Center, Department of Pediatrics, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran.
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Understanding selenoprotein function and regulation through the use of rodent models. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1633-42. [PMID: 22440326 DOI: 10.1016/j.bbamcr.2012.02.018] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/27/2012] [Accepted: 02/29/2012] [Indexed: 01/18/2023]
Abstract
Selenium (Se) is an essential micronutrient. Its biological functions are associated with selenoproteins, which contain this trace element in the form of the 21st amino acid, selenocysteine. Genetic defects in selenocysteine insertion into proteins are associated with severe health issues. The consequences of selenoprotein deficiency are more variable, with several selenoproteins being essential, and several showing no clear phenotypes. Much of these functional studies benefited from the use of rodent models and diets employing variable levels of Se. This review summarizes the data obtained with these models, focusing on mouse models with targeted expression of individual selenoproteins and removal of individual, subsets or all selenoproteins in a systemic or organ-specific manner. This article is part of a Special Issue entitled: Cell Biology of Metals.
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Berr C, Arnaud J, Akbaraly TN. Selenium and cognitive impairment: a brief-review based on results from the EVA study. Biofactors 2012; 38:139-44. [PMID: 22419540 DOI: 10.1002/biof.1003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Accepted: 01/10/2012] [Indexed: 11/09/2022]
Abstract
Preventing cognitive impairment and dementia in the elderly is a major public health challenge for our century and all hypotheses should be explored. Selenium (Se) is one of the factors that may affect the risk of cognitive decline. Its importance in the health and aging process has been documented. Because of the potential of selenoproteins to protect against oxidative stress, Se raises significant expectations for the prevention of chronic diseases including cancer, cardiovascular disease, and type 2 diabetes conditions commonly associated with oxidative stress. Thus, the relationships between Se and cognitive impairment or dementia can be examined through vascular risk factors for dementia, with particular interest in diabetes and dyslipidemia. In addition, in cases of Se deficiency, the brain is the organ that remains Se replete the longest suggesting that Se plays an important role in brain functions. This article presents results obtained in the frame of a longitudinal study on Se and cognitive impairment. They are consistent with the hypothesis that low Se status is a risk factor for cognitive decline even after taking into account vascular risk factors. The concomitant evolution between plasma Se decrease over a 9-year period and cognitive decline suggested that optimal Se status is potentially important to maintain neuropsychological functions in aging people. However, as our understanding of Se biology is incomplete, epidemiological studies are needed to define the groups of population that could benefit from Se supplementation.
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Gammelgaard B, Stürup S, Christensen MV. Human urinary excretion and metabolism of (82)Se-enriched selenite and selenate determined by LC-ICP-MS. Metallomics 2012; 4:149-55. [PMID: 22258472 DOI: 10.1039/c2mt00163b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Urinary excretion of selenium after ingestion of isotope labeled selenite and selenate was studied in seven healthy volunteers, 4 men and 3 women (age 28-50 years). An aqueous solution containing 330 μL (82)Se-selenate (corresponding to 74.3 μg (82)Se) was given orally and urine samples were subsequently collected during the following 24 hours. The scheme was repeated four weeks later with a 280 μL (82)Se-selenite solution (corresponding to 74.4 μg (82)Se). The amount of total Se in the urine samples was determined by inductively coupled mass spectrometry. The mean total urinary excretion of (82)Se following (82)Se-selenate administration was 33.7% (range 15.6-42.5%) while the mean total excretion of (82)Se after (82)Se-selenite administration was 3.2% (range 2.8-3.9%) of the ingested amount. LC-ICPMS analysis of the urine samples showed that the majority of the selenium excreted after selenate ingestion was unchanged selenate for 6 of the individuals while one individual had metabolized a fraction (approx. 20%) of the selenate to selenosugar. Ingestion of 10 times larger doses of selenite in two individuals resulted in 13-23% excretion primarily excreted as selenosugar. These results show that the human metabolic pathways of selenite and selenate are different and indicate that not all selenate, although well absorbed, may be available for the beneficial health effects.
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Affiliation(s)
- Bente Gammelgaard
- Department of Pharmaceutics and Analytical Chemistry, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
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Abstract
The trace element selenium is an essential micronutrient that is required for the biosynthesis of selenocysteine-containing selenoproteins. Most of the known selenoproteins are expressed in the thyroid gland, including some with still unknown functions. Among the well-characterized selenoproteins are the iodothyronine deiodinases, glutathione peroxidases and thioredoxin reductases, enzymes involved in thyroid hormone metabolism, regulation of redox state and protection from oxidative damage. Selenium content in selenium-sensitive tissues such as the liver, kidney or muscle and expression of nonessential selenoproteins, such as the glutathione peroxidases GPx1 and GPx3, is controlled by nutritional supply. The thyroid gland is, however, largely independent from dietary selenium intake and thyroid selenoproteins are preferentially expressed. As a consequence, no explicit effects on thyroid hormone profiles are observed in healthy individuals undergoing selenium supplementation. However, low selenium status correlates with risk of goiter and multiple nodules in European women. Some clinical studies have demonstrated that selenium-deficient patients with autoimmune thyroid disease benefit from selenium supplementation, although the data are conflicting and many parameters must still be defined. The baseline selenium status of an individual could constitute the most important parameter modifying the outcome of selenium supplementation, which might primarily disrupt self-amplifying cycles of the endocrine-immune system interface rectifying the interaction of lymphocytes with thyroid autoantigens. Selenium deficiency is likely to constitute a risk factor for a feedforward derangement of the immune system-thyroid interaction, while selenium supplementation appears to dampen the self-amplifying nature of this derailed interaction.
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Affiliation(s)
- Lutz Schomburg
- Institute for Experimental Endocrinology, Charité-University Medicine Berlin, Südring 10, CVK, 13353 Berlin, Germany.
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