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Naderi M, Puar P, Zonouzi-Marand M, Chivers DP, Niyogi S, Kwong RWM. A comprehensive review on the neuropathophysiology of selenium. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 767:144329. [PMID: 33445002 DOI: 10.1016/j.scitotenv.2020.144329] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 12/05/2020] [Accepted: 12/05/2020] [Indexed: 05/25/2023]
Abstract
As an essential micronutrient, selenium (Se) exerts its biological function as a catalytic entity in a variety of enzymes. From a toxicological perspective, however, Se can become extremely toxic at concentrations slightly above its nutritional levels. Over the last few decades, there has been a growing level of concern worldwide regarding the adverse effects of both inorganic and organic Se compounds on a broad spectrum of neurological functions. A wealth of evidence has shown that exposure to excess Se may compromise the normal functioning of various key proteins, neurotransmitter systems (the glutamatergic, dopaminergic, serotonergic, and cholinergic systems), and signaling molecules involved in the control and regulation of cognitive, behavioral, and neuroendocrine functions. Elevated Se exposure has also been suspected to be a risk factor for the development of several neurodegenerative and neuropsychiatric diseases. Nonetheless, despite the various deleterious effects of excess Se on the central nervous system (CNS), Se neurotoxicity and negative behavioral outcomes are still disregarded at the expense of its beneficial health effects. This review focuses on the current state of knowledge regarding the neurobehavioral effects of Se and discusses its potential mode of action on different aspects of the central and peripheral nervous systems. This review also provides a brief history of Se discovery and uses, its physicochemical properties, biological roles in the CNS, environmental occurrence, and toxicity. We also review potential links between exposure to different forms of Se compounds and aberrant neurobehavioral functions in humans and animals, and identify key knowledge gaps and hypotheses for future research.
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Affiliation(s)
- Mohammad Naderi
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Pankaj Puar
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada
| | | | - Douglas P Chivers
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada
| | - Som Niyogi
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK S7N 5E2, Canada; Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
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2
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Graves SD, Liber K, Palace V, Hecker M, Doig LE, Janz DM. Effects of selenium on benthic macroinvertebrates and fathead minnow (Pimephales promelas) in a boreal lake ecosystem. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 182:109354. [PMID: 31272025 DOI: 10.1016/j.ecoenv.2019.06.037] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 06/09/2023]
Abstract
Selenium (Se) is a contaminant of concern in many aquatic ecosystems due to its narrow range between essentiality and toxicity in oviparous (yolk-bearing) vertebrates. The objective of the present study was to determine the effects of Se, experimentally added to in situ limnocorrals as selenite, on invertebrate communities and fathead minnow (Pimephales promelas) at environmentally realistic Se concentrations. Nine limnocorrals were deployed in a mesotrophic lake at the International Institute for Sustainable Development - Experimental Lakes Area in Ontario, Canada in May 2017. From June 1 to August 17, 2017, selenite was added to six enclosures to attain mean measured aqueous Se concentrations of 1.0 ± 0.10 or 8.9 ± 2.7 μg/L Se (in triplicate) and three limnocorrals were untreated controls (background mean aqueous Se = 0.12 ± 0.03 μg/L). Benthic macroinvertebrates were collected throughout and at the end of the exposure period using artificial substrates to determine density, dry biomass, diversity, and taxa richness at the family level. Reproductively mature female fathead minnows (added on d 33 of the study) were collected throughout and at the end of the exposure period. After 77 d, Chironomidae and Gammaridae densities and biomass were significantly lower in the 8.9 μg/L Se treatment relative to the 1.0 μg/L Se treatment and the control. Invertebrate diversity (measured as Shannon's and Simpson's indices) significantly declined in the 1.0 μg/L and 8.9 μg/L Se treatments relative to the control (0.12 μg/L Se group). Fulton's condition factor for fathead minnow was significantly less in the 8.9 μg/L treatment compared to 0.12 and 1.0 μg/L Se experimental groups. The results of this study indicated that exposure to relatively low aqueous selenite concentrations can negatively affect invertebrate density and biomass, as well as fish condition. More research is necessary to characterize the risk of selenite exposure to aquatic invertebrates under realistic field conditions, and future risk assessments may need to consider reduced food availability as a factor that may impair the health of higher trophic level organisms in areas with elevated selenite.
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Affiliation(s)
- Stephanie D Graves
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
| | - Karsten Liber
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Vince Palace
- International Institute for Sustainable Development - Experimental Lakes Area, Winnipeg, Manitoba, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Lorne E Doig
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - David M Janz
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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3
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Romero I, de Francisco P, Gutiérrez JC, Martín-González A. Selenium cytotoxicity in Tetrahymena thermophila: New clues about its biological effects and cellular resistance mechanisms. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 671:850-865. [PMID: 30947056 DOI: 10.1016/j.scitotenv.2019.03.115] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 03/07/2019] [Accepted: 03/08/2019] [Indexed: 06/09/2023]
Abstract
Selenium is an essential micronutrient but at high concentrations can produce severe cytotoxicity and genomic damage. We have evaluated the cytotoxicity, ultrastructural and mitochondrial alterations of the two main selenium inorganic species; selenite and selenate, in the eukaryotic microorganism Tetrahymena thermophila. In this ciliate, selenite is more toxic than selenate. Their LC50 values were calculated as 27.65 μM for Se(IV) and 56.88 mM for Se(VI). Significant levels of peroxides/hydroperoxides are induced under low-moderate selenite or selenate concentrations. Se(VI) exposures induce an immediate mitochondrial membrane depolarization. Selenium treated cells show an intense vacuolization and some of them present numerous discrete and small electrondense particles, probably selenium deposits. Mitochondrial fusion, an intense swelling in peripheral mitochondria and mitophagy are detected in selenium treated cells, especially in those exposed to Se (IV). qRT-PCR analysis of diverse genes, encoding relevant antioxidant enzymes or other proteins, like metallothioneins, involved in an environmental general stress response, have shown that they may be crucial against Se(IV) and/or Se (VI) cytotoxicity.
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Affiliation(s)
- Ivan Romero
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain
| | - Patricia de Francisco
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain
| | - Juan Carlos Gutiérrez
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain
| | - Ana Martín-González
- Dpto. Genética, Fisiología y Microbiología, Facultad de Biología, C/. José Antonio Novais, 12, Universidad Complutense (UCM), 28040 Madrid, Spain..
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Honkanen AP, Ollikkala S, Ahopelto T, Kallio AJ, Blomberg M, Huotari S. Johann-type laboratory-scale x-ray absorption spectrometer with versatile detection modes. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2019; 90:033107. [PMID: 30927829 DOI: 10.1063/1.5084049] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 03/01/2019] [Indexed: 06/09/2023]
Abstract
We present a low-cost laboratory X-ray absorption spectrometer that uses a conventional X-ray tube source and bent Johann-type crystal monochromators. The instrument is designed for X-ray absorption spectroscopy studies in the 4-20 keV range which covers most K edges of 3d transition metals and L edges of 5d transition metals and actinides. The energy resolution is typically in the range of 1-5 eV at 10 keV depending on the crystal analyser and the Bragg angle. Measurements can be performed in transmission, fluorescence, and imaging modes. Due to its simple and modular design, the spectrometer can be modified to accommodate additional equipment and complex sample environments required for in situ studies. A showcase of various applications is presented.
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Affiliation(s)
- Ari-Pekka Honkanen
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Sami Ollikkala
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Taru Ahopelto
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Antti-Jussi Kallio
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Merja Blomberg
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Simo Huotari
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
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Tobe R, Mihara H. Delivery of selenium to selenophosphate synthetase for selenoprotein biosynthesis. Biochim Biophys Acta Gen Subj 2018; 1862:2433-2440. [PMID: 29859962 DOI: 10.1016/j.bbagen.2018.05.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 05/28/2018] [Accepted: 05/29/2018] [Indexed: 11/16/2022]
Abstract
BACKGROUND Selenophosphate, the key selenium donor for the synthesis of selenoprotein and selenium-modified tRNA, is produced by selenophosphate synthetase (SPS) from ATP, selenide, and H2O. Although free selenide can be used as the in vitro selenium substrate for selenophosphate synthesis, the precise physiological system that donates in vivo selenium substrate to SPS has not yet been characterized completely. SCOPE OF REVIEW In this review, we discuss selenium metabolism with respect to the delivery of selenium to SPS in selenoprotein biosynthesis. MAJOR CONCLUSIONS Glutathione, selenocysteine lyase, cysteine desulfurase, and selenium-binding proteins are the candidates of selenium delivery system to SPS. The thioredoxin system is also implicated in the selenium delivery to SPS in Escherichia coli. GENERAL SIGNIFICANCE Selenium delivered via a protein-bound selenopersulfide intermediate emerges as a central element not only in achieving specific selenoprotein biosynthesis but also in preventing the occurrence of toxic free selenide in the cell. This article is part of a Special Issue entitled "Selenium research in biochemistry and biophysics - 200 year anniversary".
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Affiliation(s)
- Ryuta Tobe
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hisaaki Mihara
- Department of Biotechnology, College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
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Saibu Y, Jamwal A, Feng R, Peak D, Niyogi S. Distribution and speciation of zinc in the gills of rainbow trout (Oncorhynchus mykiss) during acute waterborne zinc exposure: Interactions with cadmium or copper. Comp Biochem Physiol C Toxicol Pharmacol 2018; 206-207:23-31. [PMID: 29501824 DOI: 10.1016/j.cbpc.2018.02.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/21/2018] [Accepted: 02/25/2018] [Indexed: 11/18/2022]
Abstract
We utilized micro X-ray fluorescence imaging (μ-XFI) and micro X-ray absorption near-edge spectroscopy (μ-XANES), which are both synchrotron-based techniques to investigate Zn distribution profile, its co-localization patterns with Ca, S, and Fe and speciation in the gills of rainbow trout (RBT). Fish (~100 g) were exposed to acutely toxic levels of waterborne Zn alone and in combination with waterborne Cd or Cu for 24 h (each at 1 × 96 h LC50). Gill sections were prepared and analyzed at the VESPERS beamline of the Canadian Light Source. The primary lamellae of the fish gill were found to be the primary area of Zn accumulation. These regions also correspond to the zones of mitochondria rich cells localization in fish gills, supporting the putative roles of these cells in metal uptake. Zn was also found to predominantly co-localize with Ca and S, but not with Fe, indicating the roles of Ca and S in intracellular Zn handling. Zn distribution in the gill was markedly reduced during co-exposure to Cd, but not to Cu, suggesting a competitive interaction between Zn and Cd for uptake. The speciation of Zn in the gill was dominated by Zn-phosphate, Zn-histidine and Zn-cysteine species; however, the interactions of Zn with Cd or Cu resulted in the loss of Zn-cysteine. Overall, our findings provide important novel insights into the interactions of Zn, Cd and Cu in the fish gill, which may ultimately help to explain the mechanisms underlying the acute toxicity of these metals in binary mixture to fish.
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Affiliation(s)
- Yusuf Saibu
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada.
| | - Ankur Jamwal
- Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, Canada
| | - Renfei Feng
- Canadian Light Source Incorporated, 44 Innovation Blvd, Saskatoon, SK, Canada
| | - Derek Peak
- Department of Soil Science, University of Saskatchewan, 114 Science Place, Saskatoon, SK, Canada
| | - Som Niyogi
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, Canada; Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, SK, Canada
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Lazard M, Dauplais M, Blanquet S, Plateau P. Recent advances in the mechanism of selenoamino acids toxicity in eukaryotic cells. Biomol Concepts 2018; 8:93-104. [PMID: 28574376 DOI: 10.1515/bmc-2017-0007] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 05/03/2017] [Indexed: 12/31/2022] Open
Abstract
Selenium is an essential trace element due to its incorporation into selenoproteins with important biological functions. However, at high doses it is toxic. Selenium toxicity is generally attributed to the induction of oxidative stress. However, it has become apparent that the mode of action of seleno-compounds varies, depending on its chemical form and speciation. Recent studies in various eukaryotic systems, in particular the model organism Saccharomyces cerevisiae, provide new insights on the cytotoxic mechanisms of selenomethionine and selenocysteine. This review first summarizes current knowledge on reactive oxygen species (ROS)-induced genotoxicity of inorganic selenium species. Then, we discuss recent advances on our understanding of the molecular mechanisms of selenocysteine and selenomethionine cytotoxicity. We present evidences indicating that both oxidative stress and ROS-independent mechanisms contribute to selenoamino acids cytotoxicity. These latter mechanisms include disruption of protein homeostasis by selenocysteine misincorporation in proteins and/or reaction of selenols with protein thiols.
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Naderi M, Salahinejad A, Jamwal A, Chivers DP, Niyogi S. Chronic Dietary Selenomethionine Exposure Induces Oxidative Stress, Dopaminergic Dysfunction, and Cognitive Impairment in Adult Zebrafish (Danio rerio). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:12879-12888. [PMID: 28981273 DOI: 10.1021/acs.est.7b03937] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The present study was designed to investigate the effects of chronic dietary exposure to selenium (Se) on zebrafish cognition and also to elucidate possible mechanism(s) by which Se exerts its neurotoxicity. To this end, adult zebrafish were exposed to different concentrations of dietary l-selenomethionine (control, 2.3, 9.7, 32.5, or 57.7 μg Se/g dry weight) for 30 days. Cognitive performance of fish was tested using a latent learning paradigm in a complex maze. In addition, we also evaluated oxidative stress biomarkers and the expression of genes involved in dopaminergic neurotransmission in the zebrafish brain. Fish treated with higher dietary Se doses (32.5 and 57.5 μg Se/g) exhibited impaired performance in the latent learning task. The impaired learning was associated with the induction of oxidative stress and altered mRNA expression of dopamine receptors, tyrosine hydroxylase, and dopamine transporter genes in the zebrafish brain. Collectively, our results illustrate that cognitive impairment in zebrafish could be associated with Se-induced oxidative stress and altered dopaminergic neurotransmission in the brain.
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Affiliation(s)
- Mohammad Naderi
- Department of Biology, University of Saskatchewan , 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Arash Salahinejad
- Department of Biology, University of Saskatchewan , 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Ankur Jamwal
- Department of Biology, University of Saskatchewan , 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Douglas P Chivers
- Department of Biology, University of Saskatchewan , 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Som Niyogi
- Department of Biology, University of Saskatchewan , 112 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
- Toxicology Centre, University of Saskatchewan , 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada
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9
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Bloch SR, Kim JJ, Pham PH, Hodson PV, Lee LEJ, Bols NC. Responses of an American eel brain endothelial-like cell line to selenium deprivation and to selenite, selenate, and selenomethionine additions in different exposure media. In Vitro Cell Dev Biol Anim 2017; 53:940-953. [PMID: 28940125 DOI: 10.1007/s11626-017-0196-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/09/2017] [Indexed: 01/08/2023]
Abstract
The effect of selenium deprivation and addition on the American eel brain endothelial cell line (eelB) was studied in three exposure media: complete growth medium (L15/FBS), serum-free medium (L15), and minimal medium (L15/ex). L15/ex contains only galactose and pyruvate and allowed the deprivation of selenium on cells to be studied. In L15/ex, without any obvious source of selenium, eelB cells survived for at least 7 d, formed capillary-like structures (CLS) on Matrigel, and migrated to heal wounds. Three selenium compounds were added to cultures: selenite, selenate, and selenomethionine (SeMet). Adding selenite or selenate to eelB cell cultures for 24 h caused dose-dependent declines in cell viability, regardless of the exposure media. Although varying with exposure media and viability end point, selenite was approximately 70-fold more cytotoxic than selenate. By contrast, 24 h exposures to either DL- or L-SeMet in the three media caused little or no cytotoxicity. However for 7 d exposures in L15/ex, DL- and L-SeMet were very cytotoxic, even at the lowest tested concentration of 31 μM. By contrast in L15 and L15/FBS, cytotoxicity was only observed with 500 and 1000 μM L-SeMet. In L15/FBS, eelB continued to migrate and form CLS in the presence of SeMet but at 500 μM, cell migration appeared stimulated. As judged from a colony-forming assay over 14 d in L15/FBS, 500 and 1000 μM DL- and L-SeMet inhibited cell proliferation. Overall, the responses of eel cells to selenium depended on the selenium form, concentration, and exposure media, with responses to SeMet being most dependent on exposure media.
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Affiliation(s)
- Sophia R Bloch
- Department of Biology, University of Waterloo, Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - John J Kim
- Department of Biology, University of Waterloo, Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Phuc H Pham
- Department of Biology, University of Waterloo, Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Peter V Hodson
- Department of Biology and School of Environmental Studies, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Lucy E J Lee
- Faculty of Science, University of the Fraser Valley, Abbotsford, BC, V2S 7M8, Canada
| | - Niels C Bols
- Department of Biology, University of Waterloo, Waterloo, Waterloo, ON, N2L 3G1, Canada.
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10
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Jamwal A, Niyogi S. Dose and chemical species-specific effects of selenium against arsenite toxicity in cultured hepatocytes of rainbow trout (Oncorhynchus mykiss). Metallomics 2017; 9:744-756. [DOI: 10.1039/c7mt00006e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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11
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Langford-Smith A, Tilakaratna V, Lythgoe PR, Clark SJ, Bishop PN, Day AJ. Age and Smoking Related Changes in Metal Ion Levels in Human Lens: Implications for Cataract Formation. PLoS One 2016; 11:e0147576. [PMID: 26794210 PMCID: PMC4721641 DOI: 10.1371/journal.pone.0147576] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/05/2016] [Indexed: 12/13/2022] Open
Abstract
Age-related cataract formation is the primary cause of blindness worldwide and although treatable by surgical removal of the lens the majority of sufferers have neither the finances nor access to the medical facilities required. Therefore, a better understanding of the pathogenesis of cataract may identify new therapeutic targets to prevent or slow its progression. Cataract incidence is strongly correlated with age and cigarette smoking, factors that are often associated with accumulation of metal ions in other tissues. Therefore this study evaluated the age-related changes in 14 metal ions in 32 post mortem human lenses without known cataract from donors of 11 to 82 years of age by inductively coupled plasma mass spectrometry; smoking-related changes in 10 smokers verses 14 non-smokers were also analysed. A significant age-related increase in selenium and decrease in copper ions was observed for the first time in the lens tissue, where cadmium ion levels were also increased as has been seen previously. Aluminium and vanadium ions were found to be increased in smokers compared to non-smokers (an analysis that has only been carried out before in lenses with cataract). These changes in metal ions, i.e. that occur as a consequence of normal ageing and of smoking, could contribute to cataract formation via induction of oxidative stress pathways, modulation of extracellular matrix structure/function and cellular toxicity. Thus, this study has identified novel changes in metal ions in human lens that could potentially drive the pathology of cataract formation.
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Affiliation(s)
- Alex Langford-Smith
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Viranga Tilakaratna
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Paul R Lythgoe
- School of Earth, Atmospheric and Environmental Sciences and Williamson Research Centre for Molecular Environmental Science, University of Manchester, Manchester, United Kingdom
| | - Simon J Clark
- Centre for Ophthalmology and Vision Sciences, Institute of Human Development, University of Manchester, Manchester, United Kingdom.,Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom
| | - Paul N Bishop
- Centre for Ophthalmology and Vision Sciences, Institute of Human Development, University of Manchester, Manchester, United Kingdom.,Centre for Advanced Discovery and Experimental Therapeutics, University of Manchester and Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, United Kingdom.,Manchester Royal Eye Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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12
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Jamwal A, Naderi M, Niyogi S. An in vitro examination of selenium–cadmium antagonism using primary cultures of rainbow trout (Oncorhynchus mykiss) hepatocytes. Metallomics 2016; 8:218-27. [DOI: 10.1039/c5mt00232j] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Se has antagonistic effects on Cd-induced cytotoxicityviaboth enzymatic and non-enzymatic antioxidative mechanisms and the effects are strictly dose dependent. Confocal fluorescent images of isolated rainbow trout hepatocytes exposed to 100 µM Cd, alone or in combination with low (25 µM) or high (250 µM) concentration of Se, show reduced ROS generation with low concentration of Se.
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Affiliation(s)
- Ankur Jamwal
- Department of Biology
- University of Saskatchewan
- Saskatoon, Canada
| | - Mohammad Naderi
- Department of Biology
- University of Saskatchewan
- Saskatoon, Canada
| | - Som Niyogi
- Department of Biology
- University of Saskatchewan
- Saskatoon, Canada
- Toxicology Centre
- University of Saskatchewan
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13
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Oh SM, Lee E, Adpakpang K, Patil SB, Park MJ, Lim YS, Lee KH, Kim JY, Hwang SJ. Evolution of the chemical bonding nature and electrode activity of indium selenide upon the composite formation with graphene nanosheets. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.04.121] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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14
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Misra S, Boylan M, Selvam A, Spallholz JE, Björnstedt M. Redox-active selenium compounds--from toxicity and cell death to cancer treatment. Nutrients 2015; 7:3536-56. [PMID: 25984742 PMCID: PMC4446766 DOI: 10.3390/nu7053536] [Citation(s) in RCA: 200] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 04/24/2015] [Accepted: 05/05/2015] [Indexed: 11/29/2022] Open
Abstract
Selenium is generally known as an antioxidant due to its presence in selenoproteins as selenocysteine, but it is also toxic. The toxic effects of selenium are, however, strictly concentration and chemical species dependent. One class of selenium compounds is a potent inhibitor of cell growth with remarkable tumor specificity. These redox active compounds are pro-oxidative and highly cytotoxic to tumor cells and are promising candidates to be used in chemotherapy against cancer. Herein we elaborate upon the major forms of dietary selenium compounds, their metabolic pathways, and their antioxidant and pro-oxidant potentials with emphasis on cytotoxic mechanisms. Relative cytotoxicity of inorganic selenite and organic selenocystine compounds to different cancer cells are presented as evidence to our perspective. Furthermore, new novel classes of selenium compounds specifically designed to target tumor cells are presented and the potential of selenium in modern oncology is extensively discussed.
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Affiliation(s)
- Sougat Misra
- Division of Pathology F46, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm 141 86, Sweden.
| | - Mallory Boylan
- Department of Nutritional Sciences, College of Human Sciences, Texas Tech University, P.O. Box 41270, Lubbock, TX 79409-1270, USA.
| | - Arun Selvam
- Division of Pathology F46, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm 141 86, Sweden.
| | - Julian E Spallholz
- Department of Nutritional Sciences, College of Human Sciences, Texas Tech University, P.O. Box 41270, Lubbock, TX 79409-1270, USA.
| | - Mikael Björnstedt
- Division of Pathology F46, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm 141 86, Sweden.
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Lazard M, Dauplais M, Blanquet S, Plateau P. Trans-sulfuration Pathway Seleno-amino Acids Are Mediators of Selenomethionine Toxicity in Saccharomyces cerevisiae. J Biol Chem 2015; 290:10741-50. [PMID: 25745108 DOI: 10.1074/jbc.m115.640375] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 12/29/2022] Open
Abstract
Toxicity of selenomethionine, an organic derivative of selenium widely used as supplement in human diets, was studied in the model organism Saccharomyces cerevisiae. Several DNA repair-deficient strains hypersensitive to selenide displayed wild-type growth rate properties in the presence of selenomethionine indicating that selenide and selenomethionine exert their toxicity via distinct mechanisms. Cytotoxicity of selenomethionine decreased when the extracellular concentration of methionine or S-adenosylmethionine was increased. This protection resulted from competition between the S- and Se-compounds along the downstream metabolic pathways inside the cell. By comparing the sensitivity to selenomethionine of mutants impaired in the sulfur amino acid pathway, we excluded a toxic effect of Se-adenosylmethionine, Se-adenosylhomocysteine, or of any compound in the methionine salvage pathway. Instead, we found that selenomethionine toxicity is mediated by the trans-sulfuration pathway amino acids selenohomocysteine and/or selenocysteine. Involvement of superoxide radicals in selenomethionine toxicity in vivo is suggested by the hypersensitivity of a Δsod1 mutant strain, increased resistance afforded by the superoxide scavenger manganese, and inactivation of aconitase. In parallel, we showed that, in vitro, the complete oxidation of the selenol function of selenocysteine or selenohomocysteine by dioxygen is achieved within a few minutes at neutral pH and produces superoxide radicals. These results establish a link between superoxide production and trans-sulfuration pathway seleno-amino acids and emphasize the importance of the selenol function in the mechanism of organic selenium toxicity.
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Affiliation(s)
- Myriam Lazard
- From the Ecole Polytechnique, Laboratoire de Biochimie, CNRS, 91128 Palaiseau Cedex, France
| | - Marc Dauplais
- From the Ecole Polytechnique, Laboratoire de Biochimie, CNRS, 91128 Palaiseau Cedex, France
| | - Sylvain Blanquet
- From the Ecole Polytechnique, Laboratoire de Biochimie, CNRS, 91128 Palaiseau Cedex, France
| | - Pierre Plateau
- From the Ecole Polytechnique, Laboratoire de Biochimie, CNRS, 91128 Palaiseau Cedex, France
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16
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Bao P, Chen Z, Tai RZ, Shen HM, Martin FL, Zhu YG. Selenite-induced toxicity in cancer cells is mediated by metabolic generation of endogenous selenium nanoparticles. J Proteome Res 2015; 14:1127-36. [PMID: 25567070 DOI: 10.1021/pr501086e] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Selenite has been a touted cancer chemopreventative agent but generates conflicting outcomes. Multiple mechanisms of selenite cytotoxicity in cancer cells are thought to be induced by metabolites of selenite. We observed that intracellular metabolism of selenite generates endogenous selenium nanoparticles (SeNPs) in cancer cells. Critical proteins that bind with high affinity to elemental selenium during SeNPs self-assembly were identified through proteomics analysis; these include glycolytic enzymes, insoluble tubulin, and heat shock proteins 90 (HSP90). Sequestration of glycolytic enzymes by SeNPs dramatically inhibits ATP generation, which leads to functional and structural disruption of mitochondria. Transcriptome sequencing showed tremendous down-regulation of mitochondrial respiratory NADH dehydrogenase (complex I), cytochrome c oxidase (complex IV), and ATP synthase (complex V) in response to glycolysis-dependent mitochondrial dysfunction. Sequestration of insoluble tubulin led to microtubule depolymerization, altering microtubule dynamics. HSP90 sequestration led to degradation of its downstream effectors via autophagy, ultimately resulting in a cell-signaling switch to apoptosis. Additionally, the surface effects of SeNPs generated oxidative stress, thus contributing to selenite cytotoxicity. Herein, we reveal that the multiple mechanisms of selenite-induced cytotoxicity are caused by endogenous protein-assisted self-assembly of SeNPs and suggest that endogenous SeNPs could potentially be the primary cause of selenite-induced cytotoxicity.
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Affiliation(s)
- Peng Bao
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , 18 Shuangqing Road, Haidian District, Beijing 100085, P.R. China
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17
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Selenium status affects selenoprotein expression, reproduction, and F₁ generation locomotor activity in zebrafish (Danio rerio). Br J Nutr 2014; 111:1918-31. [PMID: 24666596 DOI: 10.1017/s000711451300439x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Se is an essential trace element, and is incorporated into selenoproteins which play important roles in human health. Mammalian selenoprotein-coding genes are often present as paralogues in teleost fish, and it is unclear whether the expression patterns or functions of these fish paralogues reflect their mammalian orthologues. Using the model species zebrafish (Danio rerio; ZF), we aimed to assess how dietary Se affects key parameters in Se metabolism and utilisation including glutathione peroxidase (GPX) activity, the mRNA expression of key Se-dependent proteins (gpx1a, gpx1b, sepp1a and sepp1b), oxidative status, reproductive success and F1 generation locomotor activity. From 27 d until 254 d post-fertilisation, ZF were fed diets with graded levels of Se ranging from deficient ( < 0·10 mg/kg) to toxic (30 mg/kg). The mRNA expression of gpx1a and gpx1b and GPX activity responded in a similar manner to changes in Se status. GPX activity and mRNA levels were lowest when dietary Se levels (0·3 mg/kg) resulted in the maximum growth of ZF, and a proposed bimodal mechanism in response to Se status below and above this dietary Se level was identified. The expression of the sepp1 paralogues differed, with only sepp1a responding to Se status. High dietary Se supplementation (30 mg/kg) decreased reproductive success, while the offspring of ZF fed above 0·3 mg Se/kg diet had lower locomotor activity than the other groups. Overall, the novel finding of low selenoprotein expression and activity coinciding with maximum body growth suggests that even small Se-induced variations in redox status may influence cellular growth rates.
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18
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Gräfe M, Donner E, Collins RN, Lombi E. Speciation of metal(loid)s in environmental samples by X-ray absorption spectroscopy: a critical review. Anal Chim Acta 2014; 822:1-22. [PMID: 24725743 DOI: 10.1016/j.aca.2014.02.044] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Revised: 02/12/2014] [Accepted: 02/27/2014] [Indexed: 10/25/2022]
Abstract
Element specificity is one of the key factors underlying the widespread use and acceptance of X-ray absorption spectroscopy (XAS) as a research tool in the environmental and geo-sciences. Independent of physical state (solid, liquid, gas), XAS analyses of metal(loid)s in complex environmental matrices over the past two decades have provided important information about speciation at environmentally relevant interfaces (e.g. solid-liquid) as well as in different media: plant tissues, rhizosphere, soils, sediments, ores, mineral process tailings, etc. Limited sample preparation requirements, the concomitant ability to preserve original physical and chemical states, and independence from crystallinity add to the advantages of using XAS in environmental investigations. Interpretations of XAS data are founded on sound physical and statistical models that can be applied to spectra of reference materials and mixed phases, respectively. For spectra collected directly from environmental matrices, abstract factor analysis and linear combination fitting provide the means to ascertain chemical, bonding, and crystalline states, and to extract quantitative information about their distribution within the data set. Through advances in optics, detectors, and data processing, X-ray fluorescence microprobes capable of focusing X-rays to micro- and nano-meter size have become competitive research venues for resolving the complexity of environmental samples at their inherent scale. The application of μ-XANES imaging, a new combinatorial approach of X-ray fluorescence spectrometry and XANES spectroscopy at the micron scale, is one of the latest technological advances allowing for lateral resolution of chemical states over wide areas due to vastly improved data processing and detector technology.
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Affiliation(s)
- Markus Gräfe
- Division of Process Science and Engineering, Commonwealth Scientific Industrial Research Organisation, Australian Minerals Research Centre, 7 Conlon Street, Waterford, WA 6152, Australia.
| | - Erica Donner
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes, SA 5095, Australia; CRC-CARE, P.O. Box 486, Salisbury, SA 5106, Australia
| | - Richard N Collins
- UNSW Water Research Centre, School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Enzo Lombi
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Building X, Mawson Lakes, SA 5095, Australia
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19
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Pacini N, Elia AC, Abete MC, Dörr AJM, Brizio P, Gasco L, Righetti M, Prearo M. Antioxidant response versus selenium accumulation in the liver and kidney of the Siberian sturgeon (Acipenser baeri). CHEMOSPHERE 2013; 93:2405-2412. [PMID: 24034889 DOI: 10.1016/j.chemosphere.2013.08.042] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/18/2013] [Accepted: 08/10/2013] [Indexed: 06/02/2023]
Abstract
The aim of this study was to examine the effects of selenium on concentrations of metabolites and enzyme activities acting as antioxidant markers in liver and kidney of Siberian sturgeon Acipenser baeri. Sturgeons were fed selenium cysteine for 30 and 60 d at 1.25, 5, 20mg Sekg(-1). Selenium level in the control feed was 0.32 mg kg(-1). Se concentration was measured in liver, kidney and muscle of every specimen. Sturgeon accumulated Se in tissues with a clear dose-response relationship and the highest Se concentration was recorded in liver. This outcome is lined up with the findings obtained on the antioxidant markers evaluated in both tissues, and in which a dose-response for several biomarkers was recorded in liver. The superoxide dismutase activity in Se-treated fish was generally induced, while catalase activity was lower in liver or unaltered in kidney. The concentrations of glutathione S-transferase, glutathione reductase and total glutathione responded differently for both tissues and were induced in a different way at both endpoints. No changes of glyoxalase I activity were noted for both Se-treated tissues, while for glyoxalase II enzyme in liver a dose-related pattern was found showing a reversible effect (decreased and increased counteractive response) only in the 5 mg kg(-1) group. Moreover, the highest Se concentrations did not cause marked changes in malondialdehyde levels of liver and kidney. The enhancement of glutathione peroxidase activity in Se-treated sturgeon might have prevented the lipid peroxidation in both tissues, providing to the Siberian sturgeon a great defense ability versus the prooxidant effect of selenium.
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Affiliation(s)
- Nicole Pacini
- Department of Cellular and Environmental Biology, University of Perugia, 06123 Perugia, Italy
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20
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Weekley CM, Aitken JB, Finney L, Vogt S, Witting PK, Harris HH. Selenium metabolism in cancer cells: the combined application of XAS and XFM techniques to the problem of selenium speciation in biological systems. Nutrients 2013; 5:1734-56. [PMID: 23698165 PMCID: PMC3708347 DOI: 10.3390/nu5051734] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Revised: 05/02/2013] [Accepted: 05/06/2013] [Indexed: 01/23/2023] Open
Abstract
Determining the speciation of selenium in vivo is crucial to understanding the biological activity of this essential element, which is a popular dietary supplement due to its anti-cancer properties. Hyphenated techniques that combine separation and detection methods are traditionally and effectively used in selenium speciation analysis, but require extensive sample preparation that may affect speciation. Synchrotron-based X-ray absorption and fluorescence techniques offer an alternative approach to selenium speciation analysis that requires minimal sample preparation. We present a brief summary of some key HPLC-ICP-MS and ESI-MS/MS studies of the speciation of selenium in cells and rat tissues. We review the results of a top-down approach to selenium speciation in human lung cancer cells that aims to link the speciation and distribution of selenium to its biological activity using a combination of X-ray absorption spectroscopy (XAS) and X-ray fluorescence microscopy (XFM). The results of this approach highlight the distinct fates of selenomethionine, methylselenocysteine and selenite in terms of their speciation and distribution within cells: organic selenium metabolites were widely distributed throughout the cells, whereas inorganic selenium metabolites were compartmentalized and associated with copper. New data from the XFM mapping of electrophoretically-separated cell lysates show the distribution of selenium in the proteins of selenomethionine-treated cells. Future applications of this top-down approach are discussed.
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Affiliation(s)
- Claire M. Weekley
- School of Chemistry and Physics, The University of Adelaide, Adelaide, SA 5005, Australia; E-Mail:
| | - Jade B. Aitken
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia; E-Mail:
| | - Lydia Finney
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA; E-Mails: (L.F.); (S.V.)
- Biosciences Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Stefan Vogt
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA; E-Mails: (L.F.); (S.V.)
| | - Paul K. Witting
- The Discipline of Pathology, Sydney Medical School, The University of Sydney, Sydney, NSW 2006, Australia; E-Mail:
| | - Hugh H. Harris
- School of Chemistry and Physics, The University of Adelaide, Adelaide, SA 5005, Australia; E-Mail:
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +61-08-8313-5060; Fax: +61-08-8313-4358
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21
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Pacitti D, Wang T, Page MM, Martin SAM, Sweetman J, Feldmann J, Secombes CJ. Characterization of cytosolic glutathione peroxidase and phospholipid-hydroperoxide glutathione peroxidase genes in rainbow trout (Oncorhynchus mykiss) and their modulation by in vitro selenium exposure. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 130-131:97-111. [PMID: 23384997 DOI: 10.1016/j.aquatox.2012.12.020] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2012] [Revised: 12/19/2012] [Accepted: 12/20/2012] [Indexed: 06/01/2023]
Abstract
Selenium (Se) is an oligonutrient with both essential biological functions and recognized harmful effects. As the selenocysteine (SeCys) amino acid, selenium is integrated in several Se-containing proteins (selenoproteins), many of which are fundamental for cell homeostasis. Nevertheless, selenium may exert toxic effects at levels marginally above those required, mainly through the generation of reactive oxygen species (ROS). The selenium chemical speciation can strongly affect the bioavailability of this metal and its impact on metabolism, dictating the levels that can be beneficial or detrimental towards an organism. Glutathione peroxidase (GPxs) is the largest and the most studied selenoprotein family. Cytosolic glutathione peroxidase (cGPx, GPx1) and phospholipid hydroperoxide glutathione peroxidase (PHGPx, GPx4) are widely distributed throughout tissues, and play a pivotal role in regulating the oxidative status in the cell. In this study we have cloned GPx1 and GPx4 genes in rainbow trout (Oncorhynchus mykiss). The constitutive mRNA expression of these GPx genes was examined in 18 trout tissues and their responsiveness to Se availability was analysed using a rainbow trout liver cell line (RTL). An inorganic (sodium selenite, Na2SeO3) and organic (selenocysteine, Cys-Se-Se-Cys) selenocompound have been used as Se sources. GPx1 activity was also tested to verify the impact of transcript changes on the enzymatic function of these molecules. To understand if the results obtained from the transcript expression analysis were due to Se bioavailability or generation of ROS, the cytoxicity of the two selenocompounds was tested by measuring the impact of Se on cell membrane integrity. Lastly, Se availability was quantified by mass spectrophotometry to determine the amount of Se in the cell culture media, the Se background due to the foetal calf serum supplement and the contribution from the two selenocompounds used in the treatments. Three isoforms of genes for both GPx1 (GPx1a, 1b1 and 1b2) and GPx4 (GPx4a1, a2 and b) have been identified. The discovery of a third gene encoding for GPx1 and GPx4 hints that salmonids may have the biggest selenoproteome amongst all vertebrates. Transcripts of GPx4 genes were more highly expressed in most tissues examined in vivo (except blood, head kidney and spleen), whereas those of the GPx1 genes were more responsive to selenium exposure in vitro, especially to the organic form. Interestingly, GPx1a was the most sensitive to selenium availability in non stressful conditions, whereas GPx1b1 and GPx1b2 were highly induced by exposure to selenium levels that had some toxic effects on the cells. Although the different concentrations tested of the two selenocompounds modulate GPx1 transcript expression to various degrees, no significant change of GPx1 enzymatic activity was detectable. Our results lead us to conclude that trout GPx1 transcripts expression level may represent a sensitive biomarker for selenium intake, helping to evaluate if selenium concentration and chemical speciation impact on cell homeostasis.
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Affiliation(s)
- D Pacitti
- Scottish Fish Immunology Research Centre, Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
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22
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Németh A, García Reyes JF, Kosáry J, Dernovics M. The relationship of selenium tolerance and speciation in Lecythidaceae species. Metallomics 2013; 5:1663-73. [DOI: 10.1039/c3mt00140g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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George GN, Pickering IJ, Pushie MJ, Nienaber K, Hackett MJ, Ascone I, Hedman B, Hodgson KO, Aitken JB, Levina A, Glover C, Lay PA. X-ray-induced photo-chemistry and X-ray absorption spectroscopy of biological samples. JOURNAL OF SYNCHROTRON RADIATION 2012; 19:875-86. [PMID: 23093745 PMCID: PMC3480274 DOI: 10.1107/s090904951203943x] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2012] [Accepted: 09/16/2012] [Indexed: 05/03/2023]
Abstract
As synchrotron light sources and optics deliver greater photon flux on samples, X-ray-induced photo-chemistry is increasingly encountered in X-ray absorption spectroscopy (XAS) experiments. The resulting problems are particularly pronounced for biological XAS experiments. This is because biological samples are very often quite dilute and therefore require signal averaging to achieve adequate signal-to-noise ratios, with correspondingly greater exposures to the X-ray beam. This paper reviews the origins of photo-reduction and photo-oxidation, the impact that they can have on active site structure, and the methods that can be used to provide relief from X-ray-induced photo-chemical artifacts.
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Affiliation(s)
- Graham N. George
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Ingrid J. Pickering
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - M. Jake Pushie
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Kurt Nienaber
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Mark J. Hackett
- Department of Geological Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N 5E2
| | - Isabella Ascone
- ENSCP Chimie ParisTech, LCF, CNRS, UMR 7223, 75005 Paris, France
| | - Britt Hedman
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Keith O. Hodgson
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Jade B. Aitken
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
- Australian Synchrotron, Clayton, VIC 3168, Australia
- Institute of Materials Structure Science, KEK, Tsukuba, Ibaraki 305-0801, Japan
| | - Aviva Levina
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | | | - Peter A. Lay
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
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24
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Misra S, Kwong RWM, Niyogi S. Transport of selenium across the plasma membrane of primary hepatocytes and enterocytes of rainbow trout. ACTA ACUST UNITED AC 2012; 215:1491-501. [PMID: 22496285 DOI: 10.1242/jeb.062307] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Transport of essential solutes across biological membranes is one of the fundamental characteristics of living cells. Although selenium is an essential micronutrient, little is known about the cellular mechanisms of chemical species-specific selenium transport in fish. We report here the kinetic and pharmacological transport characteristics of selenite and its thiol (glutathione and l-cysteine) derivatives in primary cultures of hepatocytes and isolated enterocytes of rainbow trout. Findings from the current study suggest an apparent low-affinity linear transport system for selenite in both cell types. However, we recorded high-affinity Hill kinetics (K(d)=3.61±0.28 μmol l(-1)) in enterocytes exposed to selenite in the presence of glutathione. The uptake of selenite in the presence of thiols was severalfold higher than uptake of selenite alone (at equimolar concentration) in both hepatocytes and enterocytes. Cellular accumulation of selenium was found to be energy independent. Interestingly, we observed a decrease in selenite transport with increasing pH, whereas selenite uptake increased with increasing pH in the presence glutathione in both cell types. The cellular uptake of selenite demonstrated a pronounced competitive interaction with a structurally similar compound, sulfite. The uptake of selenite as well as its thiol derivatives was found to be sensitive to the anion transport blocker DIDS, irrespective of the cell type. Inorganic mercury (Hg(2+)) elicited an inhibition of selenite transport in both cell types, but augmented the transport of reduced forms of selenite in hepatocytes. Based on the substrate choice and comparable pharmacological properties, we advocate that multiple anion transport systems are probably involved in the cellular transport of selenite in fish.
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Affiliation(s)
- Sougat Misra
- Department of Biology, 112 Science Place, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5E2
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25
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Misra S, Peak D, Chen N, Hamilton C, Niyogi S. Tissue-specific accumulation and speciation of selenium in rainbow trout (Oncorhynchus mykiss) exposed to elevated dietary selenomethionine. Comp Biochem Physiol C Toxicol Pharmacol 2012; 155:560-5. [PMID: 22261037 DOI: 10.1016/j.cbpc.2012.01.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Revised: 12/25/2011] [Accepted: 01/05/2012] [Indexed: 11/28/2022]
Abstract
The toxicity of selenium in fish is influenced by its chemical speciation and the exposure route. In the natural environment, selenium exposure to fish occurs primarily in the form of selenomethionine in diet. Thus, the main objective of this study was to examine the tissue-specific selenium burden and speciation in fish exposed to elevated dietary selenomethionine. Rainbow trout (Oncorhynchus mykiss) were treated with dietary selenomethionine (40 μg g(-1) dry mass) for 2 weeks, and at the end of the exposure different tissue samples were collected to assess the tissue-specific distribution and speciation of selenium. We used synchrotron-based X-ray absorption near edge spectroscopy (XANES) to determine the selenium speciation profile. Selenomethionine, selenocysteine and selenocystine were found to be the predominant form of selenium in all of the tissues; however their relative proportion varied across different tissues. In general, the organs primarily involved in selenium handling in fish (e.g., liver, kidney) accumulated a higher percentage of selenocystine. We also found that dietary selenomethionine exposure resulted into a marked increase in selenium burden of all major tissues in fish including the brain. Collectively, our findings provide new insights into the tissue-specific distribution and speciation of selenium in fish exposed to selenomethionine via diet.
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Affiliation(s)
- Sougat Misra
- Department of Biology, 112 Science Place, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N 5E2
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26
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Induction of oxidative stress by selenomethionine in isolated hepatocytes of rainbow trout (Oncorhynchus mykiss). Toxicol In Vitro 2012; 26:621-9. [PMID: 22342462 DOI: 10.1016/j.tiv.2012.02.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2011] [Revised: 01/10/2012] [Accepted: 02/04/2012] [Indexed: 11/23/2022]
Abstract
Fish are exposed to environmental selenium predominantly in the form of dietary selenomethionine (SeMet). The present study was designed to investigate the role of oxidative stress in the toxicity of SeMet using isolated hepatocytes of rainbow trout (Oncorhynchus mykiss) as the model experimental system. Cells were exposed to an increasing range of SeMet (0-1000 μM) over 24h, and the time-dependent effects on cell viability, response of enzymatic antioxidants, thiol redox, intracellular calcium balance and caspase-mediated apoptosis were evaluated. SeMet was found to be toxic only at the highest exposure dose (1000 μM), with ∼15% decrease in cell viability. Although modest increases in the activities of antioxidant enzymes were recorded following SeMet exposure, the ratio of reduced to oxidized glutathione decreased in a dose-dependent manner, suggesting a gradual progression towards an oxidative intracellular environment. The peroxidation of membrane lipids also increased with increasing SeMet exposure dose. In addition, a rapid increase in intracellular calcium level and the activation of caspase 3/7 enzymes were recorded at the highest exposure dose, indicating that SeMet at a high exposure dose causes cell death probably via apoptosis. Overall, our study demonstrated that oxidative stress plays a key role in the cytotoxicity of SeMet in fish.
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27
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Yoshida S, Haratake M, Fuchigami T, Nakayama M. Characterization of Selenium Species in Extract from Niboshi (a Processed Japanese Anchovy). Chem Pharm Bull (Tokyo) 2012; 60:348-53. [DOI: 10.1248/cpb.60.348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Sakura Yoshida
- Graduate School of Biomedical Sciences, Nagasaki University
| | | | | | - Morio Nakayama
- Graduate School of Biomedical Sciences, Nagasaki University
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28
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Weekley CM, Aitken JB, Vogt S, Finney LA, Paterson DJ, de Jonge MD, Howard DL, Witting PK, Musgrave IF, Harris HH. Metabolism of selenite in human lung cancer cells: X-ray absorption and fluorescence studies. J Am Chem Soc 2011; 133:18272-9. [PMID: 21957893 PMCID: PMC3237720 DOI: 10.1021/ja206203c] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Selenite is an inorganic form of selenium that has a cytotoxic effect against several human cancer cell lines: one or more selenite metabolites are considered to be responsible for its toxicity. X-ray absorption spectroscopy was used to monitor Se speciation in A549 human lung cancer cells incubated with selenite over 72 h. As anticipated, selenodiglutathione and elemental Se both comprised a large proportion of Se in the cells between 4 and 72 h after treatment, which is in accordance with the reductive metabolism of selenite in the presence of glutathione and glutathione reductase/NADPH system. Selenocystine was also present in the cells but was only detected as a significant component between 24 and 48 h concomitant with a decrease in the proportion of selenocysteine and the viability of the cells. The change in speciation from the selenol, selenocysteine, to the diselenide, selenocystine, is indicative of a change in the redox status of the cells to a more oxidizing environment, likely brought about by metabolites of selenite. X-ray fluorescence microscopy of single cells treated with selenite for 24 h revealed a punctate distribution of Se in the cytoplasm. The accumulation of Se was associated with a greater than 2-fold increase in Cu, which was colocalized with Se. Selenium K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy revealed Se-Se and Se-S bonding, but not Se-Cu bonding, despite the spatial association of Se and Cu. Microprobe X-ray absorption near-edge structure spectroscopy (μ-XANES) showed that the highly localized Se species was mostly elemental Se.
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Affiliation(s)
- Claire M. Weekley
- School of Chemistry and Physics, The University of Adelaide, SA 5005, Australia
| | - Jade B. Aitken
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Stefan Vogt
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Lydia A. Finney
- X-ray Science Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | | | | | | | - Paul K. Witting
- The Discipline of Pathology, Sydney Medical School, The University of Sydney, NSW 2006, Australia
| | - Ian F. Musgrave
- School of Medical Sciences, The University of Adelaide, SA 5005, Australia
| | - Hugh H. Harris
- School of Chemistry and Physics, The University of Adelaide, SA 5005, Australia
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George GN, MacDonald TC, Korbas M, Singh SP, Myers GJ, Watson GE, O'Donoghue JL, Pickering IJ. The chemical forms of mercury and selenium in whale skeletal muscle. Metallomics 2011; 3:1232-7. [PMID: 21935544 DOI: 10.1039/c1mt00077b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Human exposure to potentially neurotoxic methylmercury species is a public-health concern for many populations worldwide. Both fish and whale are known to contain varying amounts of methylmercury species. However studies of populations that consume large quantities of fish or whale have provided no clear consensus as to the extent of the risk. The toxicological profile of an element depends strongly on its chemical form. We have used X-ray absorption spectroscopy to investigate the comparative chemical forms of mercury and selenium in fish and whale skeletal muscle. The predominant chemical form of mercury in whale is found to closely resemble that found in fish. In the samples of skeletal muscle studied, no involvement of selenium in coordination of mercury is indicated in either whale or fish, with no significant inorganic HgSe or HgS type phases being detected. The selenium speciation in fish and whale shows that similar chemical types are present in each, but in significantly different proportions. Our results suggest that for equal amounts of Hg in skeletal muscle, the direct detrimental effects arising from the mercury content from consuming skeletal muscle from whale and fish should be similar if the effects of interactions with other components in the meat are not considered.
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Affiliation(s)
- Graham N George
- Department of Geological Sciences, University of Saskatchewan, 114 Science Place, Saskatoon, SK S7N 5E2, Canada.
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Phibbs J, Wiramanaden CIE, Hauck D, Pickering IJ, Liber K, Janz DM. Selenium uptake and speciation in wild and caged fish downstream of a metal mining and milling discharge. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2011; 74:1139-1150. [PMID: 21419485 DOI: 10.1016/j.ecoenv.2011.02.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2011] [Revised: 02/18/2011] [Accepted: 02/21/2011] [Indexed: 05/30/2023]
Abstract
The aim of this research was to evaluate the dominance of the feeding pathway with respect to selenium (Se) uptake and speciation in fish inhabiting the receiving waters downstream of a uranium processing mill in northern Saskatchewan, Canada. The experimental design included analysis of Se in the predominant fish species located in the study area, a caging validation study using wild, naïve (i.e., collected from a reference lake) lake chub (Couesius plumbeus) and spottail shiner (Notropis hudsonius), and a 21-day feeding cage study using wild naïve lake chub. Three exposure lakes located downstream of the uranium mill and one reference lake situated in an adjacent watershed were studied to investigate a gradient of Se exposure. Lake chub were identified as more suitable candidates for caging due to higher survival and condition factor at the completion of the 21-day trial. Analytical results indicated that lake chub caged in the exposure lakes had significantly greater whole-body Se concentrations after 21 days compared to fish caged in the reference lake. Selenium speciation results (obtained using X-ray absorption spectroscopy) from wild and caged lake chub indicated that organic Se modeled as selenomethionine was the dominant form of Se found in both wild and caged lake chub from the exposure lakes, and that selenomethionine (R-Se-R) acts as a marker of bioavailable Se exposure.
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Affiliation(s)
- James Phibbs
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
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31
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Lombi E, Hettiarachchi GM, Scheckel KG. Advanced in situ spectroscopic techniques and their applications in environmental biogeochemistry: introduction to the special section. JOURNAL OF ENVIRONMENTAL QUALITY 2011; 40:659-666. [PMID: 21546653 DOI: 10.2134/jeq2010.0542] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Understanding the molecular-scale complexities and interplay of chemical and biological processes of contaminants at solid, liquid, and gas interfaces is a fundamental and crucial element to enhance our understanding of anthropogenic environmental impacts. The ability to describe the complexity of environmental biogeochemical reaction mechanisms relies on our analytical ability through the application and developmemnt of advanced spectroscopic techniques. Accompanying this introductory article are nine papers that either review advanced in situ spectroscopic methods or present original research utilizing these techniques. This collection of articles summarizes the challenges facing environmental biogeochemistry, highlights the recent advances and scientific gaps, and provides an outlook into future research that may benefit from the use of in situ spectroscopic approaches. The use of synchrotron-based techniques and other methods are discussed in detail, as is the importance to integrate multiple analytical approaches to confirm results of complementary procedures or to fill data gaps. We also argue that future direction in research will be driven, in addition to recent analytical developments, by emerging factors such as the need for risk assessment of new materials (i.e., nanotechnologies) and the realization that biogeochemical processes need to be investigated in situ under environmentally relevant conditions.
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Affiliation(s)
- Enzo Lombi
- Centre for Environmental Risk Assessment and Remediation, University of South Australia Building X, Mawson Lakes Campus, South Australia, Australia.
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Species-specific sensitivity to selenium-induced impairment of cortisol secretion in adrenocortical cells of rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis). Toxicol Appl Pharmacol 2011; 253:137-44. [PMID: 21466817 DOI: 10.1016/j.taap.2011.03.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Revised: 03/25/2011] [Accepted: 03/27/2011] [Indexed: 11/22/2022]
Abstract
Species differences in physiological and biochemical attributes exist even among closely related species and may underlie species-specific sensitivity to toxicants. Rainbow trout (RT) are more sensitive than brook trout (BT) to the teratogenic effects of selenium (Se), but it is not known whether all tissues exhibit this pattern of vulnerability. In this study, primary cultures of RT and BT adrenocortical cells were exposed to selenite (Na(2)SO(3)) and selenomethionine (Se-Met) to compare cell viability and ACTH-stimulated cortisol secretion in the two fish species. Cortisol, the primary stress hormone in fish, facilitates maintenance of homeostasis when fish are exposed to stressors, including toxicants. Cell viability was not affected by Se, but selenite impaired cortisol secretion, while Se-Met did not (RT and BT EC(50)>2000mg/L). RT cells were more sensitive (EC(50)=8.7mg/L) to selenite than BT cells (EC(50)=90.4mg/L). To identify the targets where Se disrupts cortisol synthesis, selenite-impaired RT and BT cells were stimulated with ACTH, dbcAMP, OH-cholesterol, and pregnenolone. Selenite acted at different steps in the cortisol biosynthesis pathway in RT and BT cells, confirming a species-specific toxicity mechanism. To test the hypothesis that oxidative stress mediates Se-induced toxicity, selenite-impaired RT cells were exposed to NAC, BSO and antioxidants (DETCA, ATA, Vit A, and Vit E). Inhibition of SOD by DETCA enhanced selenite-induced cortisol impairment, indicating that oxidative stress plays a role in Se toxicity; however, modifying GSH content of the cells did not have an effect. The results of this study, with two closely related salmonids, provided additional evidence for species-specific differences in sensitivity to Se which should be considered when setting thresholds and water quality guidelines.
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Yoshida S, Haratake M, Fuchigami T, Nakayama M. Selenium in Seafood Materials. ACTA ACUST UNITED AC 2011. [DOI: 10.1248/jhs.57.215] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Sakura Yoshida
- Graduate School of Biomedical Sciences, Nagasaki University
| | | | | | - Morio Nakayama
- Graduate School of Biomedical Sciences, Nagasaki University
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