1
|
Schweizer U, Wirth EK, Klopstock T, Hölter SM, Becker L, Moskovitz J, Grune T, Fuchs H, Gailus-Durner V, Hrabe de Angelis M, Köhrle J, Schomburg L. Seizures, ataxia and parvalbumin-expressing interneurons respond to selenium supply in Selenop-deficient mice. Redox Biol 2022; 57:102490. [PMID: 36182809 PMCID: PMC9526222 DOI: 10.1016/j.redox.2022.102490] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 09/19/2022] [Accepted: 09/22/2022] [Indexed: 11/20/2022] Open
Abstract
Mice with constitutive disruption of the Selenop gene have been key to delineate the importance of selenoproteins in neurobiology. However, the phenotype of this mouse model is exquisitely dependent on selenium supply and timing of selenium supplementation. Combining biochemical, histological, and behavioral methods, we tested the hypothesis that parvalbumin-expressing interneurons in the primary somatosensory cortex and hippocampus depend on dietary selenium availability in Selenop-/- mice. Selenop-deficient mice kept on adequate selenium diet (0.15 mg/kg, i.e. the recommended dietary allowance, RDA) developed ataxia, tremor, and hyperexcitability between the age of 4-5 weeks. Video-electroencephalography demonstrated epileptic seizures in Selenop-/- mice fed the RDA diet, while Selenop± heterozygous mice behaved normally. Both neurological phenotypes, hyperexcitability/seizures and ataxia/dystonia were successfully prevented by selenium supplementation from birth or transgenic expression of human SELENOP under a hepatocyte-specific promoter. Selenium supplementation with 10 μM selenite in the drinking water on top of the RDA diet increased the activity of glutathione peroxidase in the brains of Selenop-/- mice to control levels. The effects of selenium supplementation on the neurological phenotypes were dose- and time-dependent. Selenium supplementation after weaning was apparently too late to prevent ataxia/dystonia, while selenium withdrawal from rescued Selenop-/- mice eventually resulted in ataxia. We conclude that SELENOP expression is essential for preserving interneuron survival under limiting Se supply, while SELENOP appears dispensable under sufficiently high Se status.
Collapse
Affiliation(s)
- Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Uniklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
| | - Eva K Wirth
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Thomas Klopstock
- Friedrich-Baur-Institute, Department of Neurology, University Hospital, Ludwig Maximilian University of Munich, Ziemssenstraße 1a, 80336, Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sabine M Hölter
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany; Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Lore Becker
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Jackob Moskovitz
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, USA
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558, Nuthetal, Germany; German Center for Cardiovascular Research (DZHK), 10117, Berlin, Germany; Department of Physiological Chemistry, Faculty of Chemistry, University of Vienna, 1090, Vienna, Austria; German Center for Diabetes Research (DZD), Ingolstaedter Landstraße. 1, 85764, Neuherberg, Germany
| | - Helmut Fuchs
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Valerie Gailus-Durner
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Martin Hrabe de Angelis
- Institute of Experimental Genetics, German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany; Experimental Genetics, TUM School of Life Sciences, Technische Universität München, Alte Akademie 8, 85354, Freising, Germany; German Center for Diabetes Research (DZD), Ingolstaedter Landstraße. 1, 85764, Neuherberg, Germany
| | - Josef Köhrle
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Lutz Schomburg
- Institut für Experimentelle Endokrinologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
2
|
Schweizer U, Fabiano M. Selenoproteins in brain development and function. Free Radic Biol Med 2022; 190:105-115. [PMID: 35961466 DOI: 10.1016/j.freeradbiomed.2022.07.022] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/21/2022] [Accepted: 07/26/2022] [Indexed: 01/18/2023]
Abstract
Expression of selenoproteins is widespread in neurons of the central nervous system. There is continuous evidence presented over decades that low levels of selenium or selenoproteins are linked to seizures and epilepsy indicating a failure of the inhibitory system. Many developmental processes in the brain depend on the thyroid hormone T3. T3 levels can be locally increased by the action of iodothyronine deiodinases on the prohormone T4. Since deiodinases are selenoproteins, it is expected that selenoprotein deficiency may affect development of the central nervous system. Studies in genetically modified mice or clinical observations of patients with rare diseases point to a role of selenoproteins in brain development and degeneration. In particular selenoprotein P is central to brain function by virtue of its selenium transport function into and within the brain. We summarize which selenoproteins are essential for the brain, which processes depend on selenoproteins, and what is known about genetic deficiencies of selenoproteins in humans. This review is not intended to cover the potential influence of selenium or selenoproteins on major neurodegenerative disorders in human.
Collapse
Affiliation(s)
- Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 11, 53115, Bonn, Germany.
| | - Marietta Fabiano
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, Nussallee 11, 53115, Bonn, Germany
| |
Collapse
|
3
|
Tsuji PA, Santesmasses D, Lee BJ, Gladyshev VN, Hatfield DL. Historical Roles of Selenium and Selenoproteins in Health and Development: The Good, the Bad and the Ugly. Int J Mol Sci 2021; 23:ijms23010005. [PMID: 35008430 PMCID: PMC8744743 DOI: 10.3390/ijms23010005] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 12/25/2022] Open
Abstract
Selenium is a fascinating element that has a long history, most of which documents it as a deleterious element to health. In more recent years, selenium has been found to be an essential element in the diet of humans, all other mammals, and many other life forms. It has many health benefits that include, for example, roles in preventing heart disease and certain forms of cancer, slowing AIDS progression in HIV patients, supporting male reproduction, inhibiting viral expression, and boosting the immune system, and it also plays essential roles in mammalian development. Elucidating the molecular biology of selenium over the past 40 years generated an entirely new field of science which encompassed the many novel features of selenium. These features were (1) how this element makes its way into protein as the 21st amino acid in the genetic code, selenocysteine (Sec); (2) the vast amount of machinery dedicated to synthesizing Sec uniquely on its tRNA; (3) the incorporation of Sec into protein; and (4) the roles of the resulting Sec-containing proteins (selenoproteins) in health and development. One of the research areas receiving the most attention regarding selenium in health has been its role in cancer prevention, but further research has also exposed the role of this element as a facilitator of various maladies, including cancer.
Collapse
Affiliation(s)
- Petra A. Tsuji
- Department of Biological Sciences, Towson University, 8000 York Rd., Towson, MD 21252, USA
- Correspondence:
| | - Didac Santesmasses
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02215, USA; (D.S.); (V.N.G.)
| | - Byeong J. Lee
- School of Biological Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Korea;
| | - Vadim N. Gladyshev
- Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02215, USA; (D.S.); (V.N.G.)
| | - Dolph L. Hatfield
- Scientist Emeritus, Mouse Cancer Genetics Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA;
| |
Collapse
|
4
|
Fradejas-Villar N, Bohleber S, Zhao W, Reuter U, Kotter A, Helm M, Knoll R, McFarland R, Taylor RW, Mo Y, Miyauchi K, Sakaguchi Y, Suzuki T, Schweizer U. The Effect of tRNA [Ser]Sec Isopentenylation on Selenoprotein Expression. Int J Mol Sci 2021; 22:ijms222111454. [PMID: 34768885 PMCID: PMC8583801 DOI: 10.3390/ijms222111454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 12/22/2022] Open
Abstract
Transfer RNA[Ser]Sec carries multiple post-transcriptional modifications. The A37G mutation in tRNA[Ser]Sec abrogates isopentenylation of base 37 and has a profound effect on selenoprotein expression in mice. Patients with a homozygous pathogenic p.R323Q variant in tRNA-isopentenyl-transferase (TRIT1) show a severe neurological disorder, and hence we wondered whether selenoprotein expression was impaired. Patient fibroblasts with the homozygous p.R323Q variant did not show a general decrease in selenoprotein expression. However, recombinant human TRIT1R323Q had significantly diminished activities towards several tRNA substrates in vitro. We thus engineered mice conditionally deficient in Trit1 in hepatocytes and neurons. Mass-spectrometry revealed that hypermodification of U34 to mcm5Um occurs independently of isopentenylation of A37 in tRNA[Ser]Sec. Western blotting and 75Se metabolic labeling showed only moderate effects on selenoprotein levels and 75Se incorporation. A detailed analysis of Trit1-deficient liver using ribosomal profiling demonstrated that UGA/Sec re-coding was moderately affected in Selenop, Txnrd1, and Sephs2, but not in Gpx1. 2′O-methylation of U34 in tRNA[Ser]Sec depends on FTSJ1, but does not affect UGA/Sec re-coding in selenoprotein translation. Taken together, our results show that a lack of isopentenylation of tRNA[Ser]Sec affects UGA/Sec read-through but differs from a A37G mutation.
Collapse
Affiliation(s)
- Noelia Fradejas-Villar
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany; (N.F.-V.); (S.B.); (W.Z.); (U.R.); (R.K.)
| | - Simon Bohleber
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany; (N.F.-V.); (S.B.); (W.Z.); (U.R.); (R.K.)
| | - Wenchao Zhao
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany; (N.F.-V.); (S.B.); (W.Z.); (U.R.); (R.K.)
| | - Uschi Reuter
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany; (N.F.-V.); (S.B.); (W.Z.); (U.R.); (R.K.)
| | - Annika Kotter
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University of Mainz, Staudingerweg 5, D-55128 Mainz, Germany; (A.K.); (M.H.)
| | - Mark Helm
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg University of Mainz, Staudingerweg 5, D-55128 Mainz, Germany; (A.K.); (M.H.)
| | - Rainer Knoll
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany; (N.F.-V.); (S.B.); (W.Z.); (U.R.); (R.K.)
| | - Robert McFarland
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (R.M.); (R.W.T.)
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Clinical and Translational Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (R.M.); (R.W.T.)
| | - Yufeng Mo
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan; (Y.M.); (K.M.); (Y.S.); (T.S.)
| | - Kenjyo Miyauchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan; (Y.M.); (K.M.); (Y.S.); (T.S.)
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan; (Y.M.); (K.M.); (Y.S.); (T.S.)
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan; (Y.M.); (K.M.); (Y.S.); (T.S.)
| | - Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, D-53115 Bonn, Germany; (N.F.-V.); (S.B.); (W.Z.); (U.R.); (R.K.)
- Correspondence:
| |
Collapse
|
5
|
Schweizer U, Bohleber S, Zhao W, Fradejas-Villar N. The Neurobiology of Selenium: Looking Back and to the Future. Front Neurosci 2021; 15:652099. [PMID: 33732108 PMCID: PMC7959785 DOI: 10.3389/fnins.2021.652099] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/08/2021] [Indexed: 12/18/2022] Open
Abstract
Eighteen years ago, unexpected epileptic seizures in Selenop-knockout mice pointed to a potentially novel, possibly underestimated, and previously difficult to study role of selenium (Se) in the mammalian brain. This mouse model was the key to open the field of molecular mechanisms, i.e., to delineate the roles of selenium and individual selenoproteins in the brain, and answer specific questions like: how does Se enter the brain; which processes and which cell types are dependent on selenoproteins; and, what are the individual roles of selenoproteins in the brain? Many of these questions have been answered and much progress is being made to fill remaining gaps. Mouse and human genetics have together boosted the field tremendously, in addition to traditional biochemistry and cell biology. As always, new questions have become apparent or more pressing with solving older questions. We will briefly summarize what we know about selenoproteins in the human brain, glance over to the mouse as a useful model, and then discuss new questions and directions the field might take in the next 18 years.
Collapse
Affiliation(s)
- Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Medizinische Fakultät, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Simon Bohleber
- Institut für Biochemie und Molekularbiologie, Medizinische Fakultät, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Wenchao Zhao
- Institut für Biochemie und Molekularbiologie, Medizinische Fakultät, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Noelia Fradejas-Villar
- Institut für Biochemie und Molekularbiologie, Medizinische Fakultät, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| |
Collapse
|
6
|
Jung J, Choi I, Ro H, Huh TL, Choe J, Rhee M. march5 Governs the Convergence and Extension Movement for Organization of the Telencephalon and Diencephalon in Zebrafish Embryos. Mol Cells 2020; 43:76-85. [PMID: 31910335 PMCID: PMC6999709 DOI: 10.14348/molcells.2019.0210] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/25/2019] [Accepted: 12/04/2019] [Indexed: 11/27/2022] Open
Abstract
MARCH5 is a RING finger E3 ligase involved in mitochondrial integrity, cellular protein homeostasis, and the regulation of mitochondrial fusion and fission. To determine the function of MARCH5 during development, we assessed transcript expression in zebrafish embryos. We found that march5 transcripts were of maternal origin and evenly distributed at the 1-cell stage, except for the mid-blastula transition, with expression predominantly in the developing central nervous system at later stages of embryogenesis. Overexpression of march5 impaired convergent extension movement during gastrulation, resulting in reduced patterning along the dorsoventral axis and alterations in the ventral cell types. Overexpression and knockdown of march5 disrupted the organization of the developing telencephalon and diencephalon. Lastly, we found that the transcription of march5 was tightly regulated by the transcriptional regulators CHOP, C/EBPα, Staf, Znf143a, and Znf76. These results demonstrate the essential role of March5 in the development of zebrafish embryos.
Collapse
Affiliation(s)
- Jangham Jung
- Department of Life Science, BK21 Plus Program, Graduate School, Chungnam National University, Daejeon 34134,
Korea
| | - Issac Choi
- Department of Life Science, BK21 Plus Program, Graduate School, Chungnam National University, Daejeon 34134,
Korea
| | - Hyunju Ro
- Department of Life Science, BK21 Plus Program, Graduate School, Chungnam National University, Daejeon 34134,
Korea
| | - Tae-Lin Huh
- School of Life Sciences and Biotechnology, College of Natural Sciences, Kyungpook National University, Daegu 41566,
Korea
| | - Joonho Choe
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141,
Korea
| | - Myungchull Rhee
- Department of Life Science, BK21 Plus Program, Graduate School, Chungnam National University, Daejeon 34134,
Korea
| |
Collapse
|
7
|
Selenocysteine β-Lyase: Biochemistry, Regulation and Physiological Role of the Selenocysteine Decomposition Enzyme. Antioxidants (Basel) 2019; 8:antiox8090357. [PMID: 31480609 PMCID: PMC6770646 DOI: 10.3390/antiox8090357] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 08/23/2019] [Accepted: 08/27/2019] [Indexed: 12/19/2022] Open
Abstract
The enzyme selenocysteine β-lyase (SCLY) was first isolated in 1982 from pig livers, followed by its identification in bacteria. SCLY works as a homodimer, utilizing pyridoxal 5'-phosphate as a cofactor, and catalyzing the specific decomposition of the amino acid selenocysteine into alanine and selenide. The enzyme is thought to deliver its selenide as a substrate for selenophosphate synthetases, which will ultimately be reutilized in selenoprotein synthesis. SCLY subcellular localization is unresolved, as it has been observed both in the cytosol and in the nucleus depending on the technical approach used. The highest SCLY expression and activity in mammals is found in the liver and kidneys. Disruption of the Scly gene in mice led to obesity, hyperinsulinemia, glucose intolerance, and hepatic steatosis, with SCLY being suggested as a participant in the regulation of energy metabolism in a sex-dependent manner. With the physiological role of SCLY still not fully understood, this review attempts to discuss the available literature regarding SCLY in animals and provides avenues for possible future investigation.
Collapse
|
8
|
Zhao W, Bohleber S, Schmidt H, Seeher S, Howard MT, Braun D, Arndt S, Reuter U, Wende H, Birchmeier C, Fradejas-Villar N, Schweizer U. Ribosome profiling of selenoproteins in vivo reveals consequences of pathogenic Secisbp2 missense mutations. J Biol Chem 2019; 294:14185-14200. [PMID: 31350336 DOI: 10.1074/jbc.ra119.009369] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/08/2019] [Indexed: 01/31/2023] Open
Abstract
Recoding of UGA codons as selenocysteine (Sec) codons in selenoproteins depends on a selenocysteine insertion sequence (SECIS) in the 3'-UTR of mRNAs of eukaryotic selenoproteins. SECIS-binding protein 2 (SECISBP2) increases the efficiency of this process. Pathogenic mutations in SECISBP2 reduce selenoprotein expression and lead to phenotypes associated with the reduction of deiodinase activities and selenoprotein N expression in humans. Two functions have been ascribed to SECISBP2: binding of SECIS elements in selenoprotein mRNAs and facilitation of co-translational Sec insertion. To separately probe both functions, we established here two mouse models carrying two pathogenic missense mutations in Secisbp2 previously identified in patients. We found that the C696R substitution in the RNA-binding domain abrogates SECIS binding and does not support selenoprotein translation above the level of a complete Secisbp2 null mutation. The R543Q missense substitution located in the selenocysteine insertion domain resulted in residual activity and caused reduced selenoprotein translation, as demonstrated by ribosomal profiling to determine the impact on UGA recoding in individual selenoproteins. We found, however, that the R543Q variant is thermally unstable in vitro and completely degraded in the mouse liver in vivo, while being partially functional in the brain. The moderate impairment of selenoprotein expression in neurons led to astrogliosis and transcriptional induction of genes associated with immune responses. We conclude that differential SECISBP2 protein stability in individual cell types may dictate clinical phenotypes to a much greater extent than molecular interactions involving a mutated amino acid in SECISBP2.
Collapse
Affiliation(s)
- Wenchao Zhao
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Simon Bohleber
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Henrik Schmidt
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Sandra Seeher
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Michael T Howard
- Department of Genetics, University of Utah, Salt Lake City, Utah 84112
| | - Doreen Braun
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Simone Arndt
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Uschi Reuter
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Hagen Wende
- Max Delbrück Center of Molecular Medicine, 13125 Berlin, Germany
| | | | - Noelia Fradejas-Villar
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| |
Collapse
|
9
|
Kudin AP, Baron G, Zsurka G, Hampel KG, Elger CE, Grote A, Weber Y, Lerche H, Thiele H, Nürnberg P, Schulz H, Ruppert AK, Sander T, Cheng Q, Arnér ES, Schomburg L, Seeher S, Fradejas-Villar N, Schweizer U, Kunz WS. Homozygous mutation in TXNRD1 is associated with genetic generalized epilepsy. Free Radic Biol Med 2017; 106:270-277. [PMID: 28232204 DOI: 10.1016/j.freeradbiomed.2017.02.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 02/10/2017] [Accepted: 02/20/2017] [Indexed: 11/16/2022]
Abstract
Increased oxidative stress has been widely implicated in the pathogenesis in various forms of human epilepsy. Here, we report a homozygous mutation in TXNRD1 (thioredoxin reductase 1) in a family with genetic generalized epilepsy. TXNRD1 is an essential selenium-containing enzyme involved in detoxification of reactive oxygen species (ROS) and redox signaling. The TXNRD1 mutation p.Pro190Leu affecting a highly conserved amino acid residue was identified by whole-exome sequencing of blood DNA from the index patient. The detected mutation and its segregation within the family - all siblings of the index patient were homozygous and the parents heterozygous - were confirmed by Sanger sequencing. TXNRD1 activity was determined in subcellular fractions from a skeletal muscle biopsy and skin fibroblasts of the index patient and the expression levels of the mutated protein were assessed by 75Se labeling and Western blot analysis. As result of the mutation, the activity of TXNRD1 was reduced in the patient's fibroblasts and skeletal muscle (to 34±3% and 16±8% of controls, respectively). In fibroblasts, we detected reduced 75Se-labeling of the enzyme (41±3% of controls). An in-depth in vitro kinetic analysis of the recombinant mutated TXNRD1 indicated 30-40% lowered kcat/Se values. Therefore, a reduced activity of the enzyme in the patient's tissue samples is explained by (i) lower enzyme turnover and (ii) reduced abundance of the mutated enzyme as confirmed by Western blotting and 75Se labeling. The mutant fibroblasts were also found to be less resistant to a hydrogen peroxide challenge. Our data agree with a potential role of insufficient ROS detoxification for disease manifestation in genetic generalized epilepsy.
Collapse
Affiliation(s)
- Alexei P Kudin
- Department of Epileptology and Life & Brain Center, University of Bonn, Bonn, Germany.
| | - Gregor Baron
- Department of Epileptology and Life & Brain Center, University of Bonn, Bonn, Germany.
| | - Gábor Zsurka
- Department of Epileptology and Life & Brain Center, University of Bonn, Bonn, Germany.
| | - Kevin G Hampel
- Department of Epileptology and Life & Brain Center, University of Bonn, Bonn, Germany.
| | - Christian E Elger
- Department of Epileptology and Life & Brain Center, University of Bonn, Bonn, Germany.
| | - Alexander Grote
- Department of Neurosurgery, University of Bonn, Bonn, Germany.
| | - Yvonne Weber
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany.
| | - Holger Thiele
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.
| | - Peter Nürnberg
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.
| | - Herbert Schulz
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.
| | | | - Thomas Sander
- Cologne Center for Genomics, University of Cologne, Cologne, Germany.
| | - Qing Cheng
- Division of Biochemistry, Dept. Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Stockholm, Sweden.
| | - Elias Sj Arnér
- Division of Biochemistry, Dept. Medical Biochemistry and Biophysics (MBB), Karolinska Institutet, Stockholm, Sweden.
| | - Lutz Schomburg
- Institute of Experimental Endocrinology, Charité-Universitätsmedizin, Berlin, Germany.
| | - Sandra Seeher
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany.
| | - Noelia Fradejas-Villar
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany.
| | - Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Germany.
| | - Wolfram S Kunz
- Department of Epileptology and Life & Brain Center, University of Bonn, Bonn, Germany.
| |
Collapse
|
10
|
Schweizer U, Bohleber S, Fradejas-Villar N. The modified base isopentenyladenosine and its derivatives in tRNA. RNA Biol 2017; 14:1197-1208. [PMID: 28277934 PMCID: PMC5699536 DOI: 10.1080/15476286.2017.1294309] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Base 37 in tRNA, 3′-adjacent to the anticodon, is occupied by a purine base that is thought to stabilize codon recognition by stacking interactions on the first Watson-Crick base pair. If the first codon position forms an A.U or U.A base pair, the purine is likely further modified in all domains of life. One of the first base modifications found in tRNA is N6-isopentenyl adenosine (i6A) present in a fraction of tRNAs in bacteria and eukaryotes, which can be further modified to 2-methyl-thio-N6-isopentenyladenosine (ms2i6A) in a subset of tRNAs. Homologous tRNA isopentenyl transferase enzymes have been identified in bacteria (MiaA), yeast (Mod5, Tit1), roundworm (GRO-1), and mammals (TRIT1). In eukaryotes, isopentenylation of cytoplasmic and mitochondrial tRNAs is mediated by products of the same gene. Accordingly, a patient with homozygous mutations in TRIT1 has mitochondrial disease. The role of i6A in a subset of tRNAs in gene expression has been linked with translational fidelity, speed of translation, skewed gene expression, and non-sense suppression. This review will not cover the action of i6A as a cytokinin in plants or the potential function of Mod5 as a prion in yeast.
Collapse
Affiliation(s)
- Ulrich Schweizer
- a Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn , Bonn , Germany
| | - Simon Bohleber
- a Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn , Bonn , Germany
| | - Noelia Fradejas-Villar
- a Institut für Biochemie und Molekularbiologie, Rheinische Friedrich-Wilhelms-Universität Bonn , Bonn , Germany
| |
Collapse
|
11
|
Schweizer U, Fradejas‐Villar N. Why 21? The significance of selenoproteins for human health revealed by inborn errors of metabolism. FASEB J 2016; 30:3669-3681. [DOI: 10.1096/fj.201600424] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 07/18/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Ulrich Schweizer
- Institut für Biochemie und MolekularbiologieRheinische Friedrich‐Wilhelms‐Universitfät Bonn Bonn Germany
| | - Noelia Fradejas‐Villar
- Institut für Biochemie und MolekularbiologieRheinische Friedrich‐Wilhelms‐Universitfät Bonn Bonn Germany
| |
Collapse
|
12
|
Lei XG, Zhu JH, Cheng WH, Bao Y, Ho YS, Reddi AR, Holmgren A, Arnér ESJ. Paradoxical Roles of Antioxidant Enzymes: Basic Mechanisms and Health Implications. Physiol Rev 2016; 96:307-64. [PMID: 26681794 DOI: 10.1152/physrev.00010.2014] [Citation(s) in RCA: 247] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate "paradoxical" outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of "antioxidant" nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that "paradoxical" roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways.
Collapse
Affiliation(s)
- Xin Gen Lei
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Jian-Hong Zhu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Wen-Hsing Cheng
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Yongping Bao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Ye-Shih Ho
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Amit R Reddi
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Arne Holmgren
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Elias S J Arnér
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing,China; Department of Animal Science, Cornell University, Ithaca, New York; Department of Preventive Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, China; Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Mississippi State, Mississippi; Department of Nutrition, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom; Institute of Environmental Health Sciences, Wayne State University, Detroit, Michigan; Georgia Institute of Technology, School of Chemistry and Biochemistry, Parker Petit Institute for Bioengineering and Biosciences, Atlanta, Georgia; and Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
| |
Collapse
|
13
|
Solovyev ND. Importance of selenium and selenoprotein for brain function: From antioxidant protection to neuronal signalling. J Inorg Biochem 2015; 153:1-12. [PMID: 26398431 DOI: 10.1016/j.jinorgbio.2015.09.003] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Revised: 09/03/2015] [Accepted: 09/09/2015] [Indexed: 12/21/2022]
Abstract
Multiple biological functions of selenium manifest themselves mainly via 25 selenoproteins that have selenocysteine at their active centre. Selenium is vital for the brain and seems to participate in the pathology of disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and epilepsy. Since selenium was shown to be involved in diverse functions of the central nervous system, such as motor performance, coordination, memory and cognition, a possible role of selenium and selenoproteins in brain signalling pathways may be assumed. The aim of the present review is to analyse possible relations between selenium and neurotransmission. Selenoproteins seem to be of special importance in the development and functioning of GABAergic (GABA, γ-aminobutyric acid) parvalbumin positive interneurons of the cerebral cortex and hippocampus. Dopamine pathway might be also selenium dependent as selenium shows neuroprotection in the nigrostriatal pathway and also exerts toxicity towards dopaminergic neurons under higher concentrations. Recent findings also point to acetylcholine neurotransmission involvement. The role of selenium and selenoproteins in neurotransmission might not only be limited to their antioxidant properties but also to inflammation, influencing protein phosphorylation and ion channels, alteration of calcium homeostasis and brain cholesterol metabolism. Moreover, a direct signalling function was proposed for selenoprotein P through interaction with post-synaptic apoliprotein E receptors 2 (ApoER2).
Collapse
Affiliation(s)
- Nikolay D Solovyev
- Institute of Chemistry, St. Petersburg State University, St. Petersburg 198504, Russian Federation.
| |
Collapse
|
14
|
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.
Collapse
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
| | | | | | | | | |
Collapse
|
15
|
Maciel-Dominguez A, Swan D, Ford D, Hesketh J. Selenium alters miRNA profile in an intestinal cell line: evidence that miR-185 regulates expression of GPX2 and SEPSH2. Mol Nutr Food Res 2013; 57:2195-205. [PMID: 23934683 DOI: 10.1002/mnfr.201300168] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/25/2013] [Accepted: 05/23/2013] [Indexed: 12/30/2022]
Abstract
SCOPE Intake of the essential micronutrient selenium (Se) has health implications. This work addressed whether some effects of Se on gene expression are exerted through microRNAs (miRNA). METHODS AND RESULTS Human colon adenocarcinoma cells (Caco-2) were grown in Se-deficient or Se-adequate medium for 72 h. RNA was extracted and subjected to analysis of 737 miRNA using microarray technology. One hundred and forty-five miRNA were found to be expressed in Caco-2 cells. Twelve miRNA showed altered expression after Se depletion: miR-625, miR-492, miR-373*, miR-22, miR-532-5p, miR-106b, miR-30b, miR-185, miR-203, miR1308, miR-28-5p, miR-10b. These changes were validated by quantitative real-time PCR (RT-qPCR). Transcriptomic analysis showed that Se depletion altered expression of 50 genes including selenoproteins GPX1, SELW, GPX3, SEPN1, SELK, SEPSH2 and GPX4. Pathway analysis identified arachidonic acid metabolism, glutathione metabolism, oxidative stress, positive acute phase response proteins and respiration of mitochondria as Se-sensitive pathways. Bioinformatic analysis identified 13 transcripts as targets for the Se-sensitive miRNA; three were predicted to be recognised by miR-185. Silencing of miR-185 increased GPX2 and SEPSH2 expression. CONCLUSIONS We propose that miR-185 plays a role in up-regulation of GPX2 and SEPHS2 expression. In the case of SEPHS2 this may contribute to maintaining selenoprotein synthesis. The data indicate that micronutrient supply can regulate the cell miRNA expression profile.
Collapse
Affiliation(s)
- Anabel Maciel-Dominguez
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK; Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, UK
| | | | | | | |
Collapse
|
16
|
Pitts MW, Reeves MA, Hashimoto AC, Ogawa A, Kremer P, Seale LA, Berry MJ. Deletion of selenoprotein M leads to obesity without cognitive deficits. J Biol Chem 2013; 288:26121-26134. [PMID: 23880772 DOI: 10.1074/jbc.m113.471235] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Selenium is an essential trace element that is co-translationally incorporated into selenoproteins in the form of the 21st amino acid, selenocysteine. This class of proteins largely functions in oxidation-reduction reactions and is critically involved in maintaining proper redox balance essential to health. Selenoprotein M (SelM) is a thioredoxin-like endoplasmic reticulum-resident protein that is highly expressed in the brain and possesses neuroprotective properties. In this study, we first assessed the regional pattern of SelM expression in the mouse brain to provide insights into the potential functional implications of this protein in physiology and behavior. Next, we generated transgenic mice with a targeted deletion of the SelM gene and subjected them to a battery of neurobehavioral tests to evaluate motor coordination, locomotion, and cognitive function in comparison with wild-type controls. Finally, these mice were tested for several measures of metabolic function and body composition. Our results show that SelM knock-out (KO) mice display no deficits in measures of motor coordination and cognitive function but exhibit increased weight gain, elevated white adipose tissue deposition, and diminished hypothalamic leptin sensitivity. These findings suggest that SelM plays an important role in the regulation of body weight and energy metabolism.
Collapse
Affiliation(s)
- Matthew W Pitts
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813.
| | - Mariclair A Reeves
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
| | - Ann C Hashimoto
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
| | - Ashley Ogawa
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
| | - Penny Kremer
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
| | - Lucia A Seale
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
| | - Marla J Berry
- From the Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii 96813
| |
Collapse
|
17
|
Benner MJ, Settles ML, Murdoch GK, Hardy RW, Robison BD. Sex-specific transcriptional responses of the zebrafish (Danio rerio) brain selenoproteome to acute sodium selenite supplementation. Physiol Genomics 2013; 45:653-66. [PMID: 23737534 DOI: 10.1152/physiolgenomics.00030.2013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The potential benefits of selenium (Se) supplementation are currently under investigation for prevention of certain cancers and treatment of neurological disorders. However, little is known concerning the response of the brain to increased dietary Se under conditions of Se sufficiency, despite the majority of Se supplementation trials occurring in healthy, Se sufficient subjects. We evaluated the transcriptional response of Se-dependent genes, selenoproteins and the genes necessary for their synthesis (the selenoproteome), in the zebrafish (Danio rerio) brain to supplementation with nutritionally relevant levels of dietary Se (sodium selenite) during conditions of assumed Se sufficiency. We first used a microarray approach to analyze the response of the brain selenoproteome to dietary Se supplementation for 14 days and then assessed the immediacy and time-scale transcriptional response of the brain selenoproteome to 1, 7, and 14 days of Se supplementation by quantitative real-time PCR (qRT-PCR). The microarray approach did not indicate large-scale influences of Se on the brain transcriptome as a whole or the selenoproteome specifically; only one nonselenoproteome gene (si:ch73-44m9.2) was significantly differentially expressed. Our qRT-PCR results, however, indicate that increases of dietary Se cause small, but significant transcriptional changes within the brain selenoproteome, even after only 1 day of supplementation. These responses were dynamic over a short period of supplementation in a manner highly dependent on sex and the duration of Se supplementation. In nutritional intervention studies, it may be necessary to utilize methods such as qRT-PCR, which allow larger sample sizes, for detecting subtle transcriptional changes in the brain.
Collapse
Affiliation(s)
- Maia J Benner
- Department of Biological Sciences, University of Idaho, Moscow, Idaho83844-3051, USA
| | | | | | | | | |
Collapse
|
18
|
Kasaikina MV, Turanov AA, Avanesov A, Schweizer U, Seeher S, Bronson RT, Novoselov SN, Carlson BA, Hatfield DL, Gladyshev VN. Contrasting roles of dietary selenium and selenoproteins in chemically induced hepatocarcinogenesis. Carcinogenesis 2013; 34:1089-95. [PMID: 23389288 DOI: 10.1093/carcin/bgt011] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Selenium (Se) has long been known for its cancer prevention properties, but the molecular basis remains unclear. The principal questions in assessing the effect of dietary Se in cancer are whether selenoproteins, small molecule selenocompounds, or both, are involved, and under which conditions and genotypes Se may be protective. In this study, we examined diethylnitrosamine-induced hepatocarcinogenesis in mice lacking a subset of selenoproteins due to expression of a mutant selenocysteine tRNA gene (Trsp (A37G) mice). To uncouple the effects of selenocompounds and selenoproteins, these animals were examined at several levels of dietary Se. Our analysis revealed that tumorigenesis in Trsp (A37G) mice maintained on the adequate Se diet was increased. However, in the control, wild-type mice, both Se deficiency and high Se levels protected against tumorigenesis. We further found that the Se-deficient diet induced severe neurological phenotypes in Trsp A37G mice. Surprisingly, a similar phenotype could be induced in these mice at high dietary Se intake. Overall, our results show a complex role of Se in chemically induced hepatocarcinogenesis, which involves interaction among selenoproteins, selenocompounds and toxins, and depends on genotype and background of the animals.
Collapse
Affiliation(s)
- Marina V Kasaikina
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
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.
Collapse
|
20
|
Abstract
PURPOSE OF REVIEW Inborn errors of metabolism are increasingly recognized as underlying causes in pediatric diseases. Selenium and selenoproteins have only recently been identified as causes of inherited defects. Respective case reports have broadened our understanding of selenoprotein function and their developmental importance. This review presents the characterized defects and tries to attract attention to the spectrum of potential phenotypes. RECENT FINDINGS The characterization of patients with inherited mutations in selenoprotein N has corroborated the physiological importance of selenium for muscle function. Individuals with inherited defects in selenocysteine insertion sequence (SECIS)-binding protein 2 display a syndrome of selenoprotein-related defects including abnormal thyroid hormone metabolism, delayed bone maturation, and other more individual phenotypes. The recent identification of mutations in selenocysteine synthase causing progressive cerebello-cerebral atrophy underlines the central role of selenoproteins in brain development and protection from neurodegeneration. SUMMARY The spectrum of diseases related to inborn defects of selenium utilization, transport, and metabolism is expanding. However, only few examples are already known, resulting from defects in one selenoprotein gene and two genes involved in selenoprotein biosynthesis, respectively. Complex syndromes with impaired muscle function, stunted growth, neurosensory and/or immune defects may point to the involvement of impaired selenium metabolism and selenoprotein function, necessitating specific diagnostic procedures.
Collapse
|
21
|
Kasaikina MV, Fomenko DE, Labunskyy VM, Lachke SA, Qiu W, Moncaster JA, Zhang J, Wojnarowicz MW, Natarajan SK, Malinouski M, Schweizer U, Tsuji PA, Carlson BA, Maas RL, Lou MF, Goldstein LE, Hatfield DL, Gladyshev VN. Roles of the 15-kDa selenoprotein (Sep15) in redox homeostasis and cataract development revealed by the analysis of Sep 15 knockout mice. J Biol Chem 2011; 286:33203-12. [PMID: 21768092 DOI: 10.1074/jbc.m111.259218] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The 15-kDa selenoprotein (Sep15) is a thioredoxin-like, endoplasmic reticulum-resident protein involved in the quality control of glycoprotein folding through its interaction with UDP-glucose:glycoprotein glucosyltransferase. Expression of Sep15 is regulated by dietary selenium and the unfolded protein response, but its specific function is not known. In this study, we developed and characterized Sep15 KO mice by targeted removal of exon 2 of the Sep15 gene coding for the cysteine-rich UDP-glucose:glycoprotein glucosyltransferase-binding domain. These KO mice synthesized a mutant mRNA, but the shortened protein product could be detected neither in tissues nor in Sep15 KO embryonic fibroblasts. Sep15 KO mice were viable and fertile, showed normal brain morphology, and did not activate endoplasmic reticulum stress pathways. However, parameters of oxidative stress were elevated in the livers of these mice. We found that Sep15 mRNA was enriched during lens development. Further phenotypic characterization of Sep15 KO mice revealed a prominent nuclear cataract that developed at an early age. These cataracts did not appear to be associated with severe oxidative stress or glucose dysregulation. We suggest that the cataracts resulted from an improper folding status of lens proteins caused by Sep15 deficiency.
Collapse
Affiliation(s)
- Marina V Kasaikina
- Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Mutation of megalin leads to urinary loss of selenoprotein P and selenium deficiency in serum, liver, kidneys and brain. Biochem J 2010; 431:103-11. [PMID: 20653565 DOI: 10.1042/bj20100779] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Distribution of selenium (Se) within the mammalian body is mediated by SePP (selenoprotein P), an Se-rich glycoprotein secreted by hepatocytes. Genetic and biochemical evidence indicate that the endocytic receptors ApoER2 (apolipoprotein E receptor 2) and megalin mediate tissue-specific SePP uptake. In the present study megalin-mutant mice were fed on diets containing adequate (0.15 p.p.m.) or low (0.08 p.p.m.) Se content and were analysed for tissue and plasma Se levels, cellular GPx (glutathione peroxidase) activities and protein expression patterns. Megalin-mutant mice displayed increased urinary Se loss, which correlated with SePP excretion in their urine. Accordingly, serum Se and SePP levels were significantly reduced in megalin-mutant mice, reaching marginal levels on the low-Se diet. Moreover, kidney Se content and expression of renal selenoproteins were accordingly reduced, as was SePP internalization along the proximal tubule epithelium. Although GPx4 expression was not altered in testis, Se and GPx activity in liver and brain were significantly reduced. When fed on a low-Se diet, megalin-mutant mice developed impaired movement co-ordination, but no astrogliosis. These findings suggest that megalin prevents urinary SePP loss and participates in brain Se/SePP uptake.
Collapse
|
23
|
Conrad M, Schweizer U. Unveiling the molecular mechanisms behind selenium-related diseases through knockout mouse studies. Antioxid Redox Signal 2010; 12:851-65. [PMID: 19803749 DOI: 10.1089/ars.2009.2912] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Selenium (Se), in the form of the 21st amino acid selenocysteine, is an integral part of selenoproteins and essential for mammals. While a large number of health claims for Se has been proposed in a diverse set of diseases, little is known about the precise molecular mechanisms and the physiological roles of selenoproteins. With the recent and rigorous application of reverse genetics in the mouse, great strides have been made to address this on a more molecular level. In this review, we focus on results obtained from the application of mouse molecular genetics in mouse physiology and discuss these insights into the physiological actions of selenoproteins in light of evidence from human genetics.
Collapse
Affiliation(s)
- Marcus Conrad
- Institute of Clinical Molecular Biology and Tumor Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Marchioninistrasse 25, Munich, Germany.
| | | |
Collapse
|
24
|
Selenoproteins and the aging brain. Mech Ageing Dev 2010; 131:253-60. [DOI: 10.1016/j.mad.2010.02.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 01/11/2010] [Accepted: 02/20/2010] [Indexed: 01/18/2023]
|
25
|
Wirth EK, Conrad M, Winterer J, Wozny C, Carlson BA, Roth S, Schmitz D, Bornkamm GW, Coppola V, Tessarollo L, Schomburg L, Köhrle J, Hatfield DL, Schweizer U. Neuronal selenoprotein expression is required for interneuron development and prevents seizures and neurodegeneration. FASEB J 2009; 24:844-52. [PMID: 19890015 DOI: 10.1096/fj.09-143974] [Citation(s) in RCA: 165] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Cerebral selenium (Se) deficiency is associated with neurological phenotypes including seizures and ataxia. We wanted to define whether neurons require selenoprotein expression and which selenoproteins are most important, and explore the possible pathomechanism. Therefore, we abrogated the expression of all selenoproteins in neurons by genetic inactivation of the tRNA[Ser](Sec) gene. Cerebral expression of selenoproteins was significantly diminished in the mutants, and histological analysis revealed progressive neurodegeneration. Developing interneurons failed to specifically express parvalbumin (PV) in the mutants. Electrophysiological recordings, before overt cell death, showed normal excitatory transmission, but revealed spontaneous epileptiform activity consistent with seizures in the mutants. In developing cortical neuron cultures, the number of PV(+) neurons was reduced on combined Se and vitamin E deprivation, while other markers, such as calretinin (CR) and GAD67, remained unaffected. Because of the synergism between Se and vitamin E, we analyzed mice lacking neuronal expression of the Se-dependent enzyme glutathione peroxidase 4 (GPx4). Although the number of CR(+) interneurons remained normal in Gpx4-mutant mice, the number of PV(+) interneurons was reduced. Since these mice similarly exhibit seizures and ataxia, we conclude that GPx4 is a selenoenzyme modulating interneuron function and PV expression. Cerebral SE deficiency may thus act via reduced GPx4 expression.-Wirth, E. K., Conrad, M., Winterer, J., Wozny, C., Carlson, B. A., Roth, S., Schmitz, D., Bornkamm, G. W., Coppola, V., Tessarollo, L., Schomburg, L., Köhrle, J., Hatfield, D. L., Schweizer, U. Neuronal selenoprotein expression is required for interneuron development and prevents seizures and neurodegeneration.
Collapse
Affiliation(s)
- Eva K Wirth
- Institute for Experimental Endocrinology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Carlson BA, Yoo MH, Tsuji PA, Gladyshev VN, Hatfield DL. Mouse models targeting selenocysteine tRNA expression for elucidating the role of selenoproteins in health and development. Molecules 2009; 14:3509-27. [PMID: 19783940 PMCID: PMC3459062 DOI: 10.3390/molecules14093509] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 09/03/2009] [Accepted: 09/07/2009] [Indexed: 01/31/2023] Open
Abstract
Selenium (Se) deficiency has been known for many years to be associated with disease, impaired growth and a variety of other metabolic disorders in mammals. Only recently has the major role that Se-containing proteins, designated selenoproteins, play in many aspects of health and development begun to emerge. Se is incorporated into protein by way of the Se-containing amino acid, selenocysteine (Sec). The synthesis of selenoproteins is dependent on Sec tRNA for insertion of Sec, the 21st amino acid in the genetic code, into protein. We have taken advantage of this dependency to modulate the expression of Sec tRNA that in turn modulates the expression of selenoproteins by generating transgenic, conditional knockout, transgenic/standard knockout and transgenic/conditional knockout mouse models, all of which involve the Sec tRNA gene, to elucidate the intracellular roles of this protein class.
Collapse
Affiliation(s)
- Bradley A. Carlson
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA;E-mails: (M-H.Y.); (P.A.T.); (D.L.H.)
- Author to whom correspondence should be addressed; E-Mail:
| | - Min-Hyuk Yoo
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA;E-mails: (M-H.Y.); (P.A.T.); (D.L.H.)
| | - Petra A. Tsuji
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA;E-mails: (M-H.Y.); (P.A.T.); (D.L.H.)
- Cancer Prevention Fellowship Program, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Nutritional Science Research Group, Division of Cancer Prevention, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vadim N. Gladyshev
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, NE 68588, USA; E-mail: (V.N.G.)
| | - Dolph L. Hatfield
- Molecular Biology of Selenium Section, Laboratory of Cancer Prevention, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA;E-mails: (M-H.Y.); (P.A.T.); (D.L.H.)
| |
Collapse
|
27
|
Reeves MA, Hoffmann PR. The human selenoproteome: recent insights into functions and regulation. Cell Mol Life Sci 2009; 66:2457-78. [PMID: 19399585 PMCID: PMC2866081 DOI: 10.1007/s00018-009-0032-4] [Citation(s) in RCA: 354] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 04/01/2009] [Accepted: 04/03/2009] [Indexed: 12/16/2022]
Abstract
Selenium (Se) is a nutritional trace mineral essential for various aspects of human health that exerts its effects mainly through its incorporation into selenoproteins as the amino acid, selenocysteine. Twenty-five selenoprotein genes have been identified in humans and several selenoproteins are broadly classified as antioxidant enzymes. As progress is made on characterizing the individual members of this protein family, however, it is becoming clear that their properties and functions are quite diverse. This review summarizes recent insights into properties of individual selenoproteins such as tissue distribution, subcellular localization, and regulation of expression. Also discussed are potential roles the different selenoproteins play in human health and disease.
Collapse
Affiliation(s)
- M. A. Reeves
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813 USA
| | - P. R. Hoffmann
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, 651 Ilalo Street, Honolulu, HI 96813 USA
| |
Collapse
|