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Shrimpton HK, Ptacek CJ, Blowes DW. Selenite Stable Isotope Fractionation during Abiotic Reduction by Sodium Sulfide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39012316 DOI: 10.1021/acs.est.4c03607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/17/2024]
Abstract
Reduction of Se(IV) by sulfur reducing bacteria (SRB) can remove Se from groundwater either by direct respiration or the production of H2S(g) and subsequent abiotic reduction. This study examined abiotic Se(IV) reduction by H2S(g) to determine the associated Se isotope fractionation. The extent of fractionation was compared to the results with studies of Se(IV) reduction in systems containing microorganisms to assess whether these processes could be distinguished. A solution containing Na2S was added in increasing concentrations to solutions containing Se(IV) as SeO32- to reduce and precipitate Se. Precipitates with three distinct colors were observed. Powder X-ray diffraction (PXRD) results yielded three distinct spectra for each of the three colors of precipitate, which corresponded to SenS8-n (orange) or Se(0) (red) and S(0) (yellow). The δ82Se values of the residual dissolved Se increased as the aqueous Se concentration decreased. The S/Se in solution affected the isotopic fractionation, with an 82ε of 10.1 ± 0.6‰ observed for solutions with S/Se < 1.7, and of 7.9 ± 0.3‰ for solutions with S/Se > 1.7.
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Affiliation(s)
- Heather K Shrimpton
- University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1, Canada
| | - Carol J Ptacek
- University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1, Canada
| | - David W Blowes
- University of Waterloo, 200 University Ave West, Waterloo, Ontario N2L 3G1, Canada
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2
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Green D, Bluhm K, Brinkmann M, Raes K, Lane T, Liber K, Janz DM, Hecker M. Cross-species apical microinjected selenomethionine toxicity in embryo-larval fishes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:169338. [PMID: 38104801 DOI: 10.1016/j.scitotenv.2023.169338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/10/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Selenium (Se) is an essential micronutrient that becomes toxic when exposures minimally exceed those that are physiologically required. Studies on Se contaminated aquatic environments have identified that embryo-larval fishes are at particular risk of Se toxicity, primarily due to maternal Se transfer to developing eggs during oogenesis. This study emulated these exposures in embryo-larval fathead minnow (FHM), rainbow trout (RBT), white sucker (WSu), and white sturgeon (WSt) using embryonic selenomethionine (SeMet) microinjections. Adverse Se-outcomes observed across these species included spinal and edematous deformities, total individuals deformed, and reduced survival. Spinal deformity was the most sensitive sublethal endpoint and developed at the lowest concentrations in WSt (10 % effects concentration (EC10) = 12.42 μg (total) Se/g dry weight (d.w.)) followed by WSu (EC10 = 14.49 μg Se/g d.w.) and FHM (EC10 = 18.10 μg Se/g d.w.). High mortality was observed in RBT, but SeMet influences were confounded by the species' innate sensitivity to the microinjections themselves. 5 % hazardous concentrations derived across exposure type data subsets were ∼49 % higher when derived from within-species maternal transfer exclusive data as opposed to all, or within-species microinjection exclusive, data. These results support the current exclusion of SeMet microinjections during regulatory guideline derivation and their inclusion when studying mechanistic Se toxicity across phylogenetically distant fishes.
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Affiliation(s)
- Derek Green
- Toxicology Graduate Program, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Kerstin Bluhm
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Markus Brinkmann
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, 117 Science Place, Saskatoon, SK S7N 5C8, Canada
| | - Katherine Raes
- Toxicology Graduate Program, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Taylor Lane
- Toxicology Graduate Program, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada
| | - Karsten Liber
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, 117 Science Place, Saskatoon, SK S7N 5C8, Canada
| | - David M Janz
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, 117 Science Place, Saskatoon, SK S7N 5C8, Canada.
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3
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Urbano T, Filippini T, Wise LA, Sucato S, Polledri E, Malavolti M, Fustinoni S, Michalke B, Vinceti M. Selenium exposure and urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine: Major effects of chemical species and sex. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:161584. [PMID: 36702271 DOI: 10.1016/j.scitotenv.2023.161584] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/09/2023] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
Selenium is an element present in trace amounts and different chemical forms. It may exert both beneficial and adverse effects on cellular redox status and on the generation of reactive oxygen species. 8-oxo-7,8-dihydro-2'deoxyguanosine (8-oxodG) is an oxidized derivative of deoxyguanosine, and a sensitive biomarker of oxidative stress and genotoxicity. The present study assessed the extent to which selenium status was associated with urinary 8-oxodG concentrations in a Northern Italian population. We recruited healthy, non-smoking blood donors living in the Reggio Emilia province during 2017-2019. We measured urinary 8-oxodG concentrations and used restricted cubic spline regression analyses to investigate the association between selenium status (estimated using food frequency questionnaires, urinary concentrations, and serum concentrations of selenium and selenium species) and 8-oxodG/g creatinine. Among 137 participants aged 30-60 years, median urinary selenium and 8-oxodG concentrations were 22.02 μg/L and 3.21 μg/g creatinine, respectively. Serum samples and selenium speciation analyses were available for 104 participants. Median total serum selenium levels and dietary intake were 116.5 μg/L and 78.7 μg/day, respectively. In spline regression analysis, there was little association between dietary, serum, or urinary selenium with 8-oxodG concentrations. In sex-specific analyses, urinary selenium showed a positive association with the endpoint among males. For single selenium species, we observed positive associations with urinary 8-oxodG for serum organic selenium species, and negative associations for inorganic selenium forms. In the most adjusted analysis, urinary 8-oxodG concentrations showed a strong positive association with selenomethione-bound selenium (Se-Met) and a negative association with inorganic tetravalent selenium, selenite. In sex-specific analyses, these associations were considerably stronger in males than in females. Overall, study findings indicate that selenium species exhibited very different patterns of associations with the biomarker of oxidative stress, and that these associations also depended on sex. Background exposure to Se-Met appears to be strongly and positively associated with oxidative stress.
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Affiliation(s)
- Teresa Urbano
- CREAGEN - Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Tommaso Filippini
- CREAGEN - Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; School of Public Health, University of California Berkeley, Berkeley, CA, USA
| | - Lauren A Wise
- Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA
| | - Sabrina Sucato
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Elisa Polledri
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Marcella Malavolti
- CREAGEN - Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Silvia Fustinoni
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy; IRCCS Ca' Granda Foundation Maggiore Policlinico Hospital, Milan, Italy
| | - Bernhard Michalke
- Research Unit Analytical BioGeoChemistry, German Research Center for Environmental Health, Helmholtz Center Munich, Neuherberg, Germany
| | - Marco Vinceti
- CREAGEN - Environmental, Genetic and Nutritional Epidemiology Research Center, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy; Department of Epidemiology, Boston University School of Public Health, Boston, MA, USA.
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4
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Brandt JE, Roberts JJ, Stricker CA, Rogers HA, Nease P, Schmidt TS. Temporal Influences on Selenium Partitioning, Trophic Transfer, and Exposure in a Major U.S. River. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3645-3656. [PMID: 33617249 DOI: 10.1021/acs.est.0c06582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Hydrologic and irrigation regimes mediate the timing of selenium (Se) mobilization to rivers, but the extent to which patterns in Se uptake and trophic transfer through recipient food webs reflect the temporal variation in Se delivery is unknown. We investigated Se mobilization, partitioning, and trophic transfer along approximately 60 river miles of the selenium-impaired segment of the Lower Gunnison River (Colorado, USA) during six sampling trips between June 2015 and October 2016. We found temporal patterns in Se partitioning and trophic transfer to be independent of those in dissolved Se concentrations and that the recipient food web sustained elevated Se concentrations from earlier periods of high Se mobilization. Using an ecosystem-scale Se accumulation model tailored to the Lower Gunnison River, we predicted that the endangered Razorback Sucker (Xyrauchen texanus) and Colorado Pikeminnow (Ptychocheilus lucius) achieve whole-body Se concentrations exceeding aquatic life protection criteria during periods of high runoff and irrigation activity (April-August) that coincide with susceptible phases of reproduction and early-life development. The results of this study challenge assumptions about Se trophodynamics in fast-flowing waters and introduce important considerations for the management of Se risks for biota in river ecosystems.
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Affiliation(s)
- Jessica E Brandt
- Department of Natural Resources and the Environment & Center for Environmental Sciences and Engineering, University of Connecticut, Storrs, Connecticut 06269, United States
- Under Contract to the U.S. Geological Survey, Columbia Environmental Research Center, Columbia, Missouri 65201, United States
| | - James J Roberts
- U.S. Geological Survey, Great Lakes Science Center, Ann Arbor, Michigan 48105, United States
| | - Craig A Stricker
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado 80526, United States
| | - Holly A Rogers
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado 80526, United States
| | - Patricia Nease
- U.S. Geological Survey, Fort Collins Science Center, Fort Collins, Colorado 80526, United States
| | - Travis S Schmidt
- U.S. Geological Survey, Wyoming-Montana Water Science Center, Helena, Montana 59601, United States
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5
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Lane T, Green D, Bluhm K, Raes K, Janz DM, Liber K, Hecker M. In ovo exposure of fathead minnow (Pimephales promelas) to selenomethionine via maternal transfer and embryo microinjection: A comparative study. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2019; 216:105299. [PMID: 31593906 DOI: 10.1016/j.aquatox.2019.105299] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 09/11/2019] [Accepted: 09/12/2019] [Indexed: 06/10/2023]
Abstract
Selenium (Se) is an essential trace element of concern that is known to contaminate aquatic ecosystems as a consequence of releases from anthropogenic activities. Selenium is of particular toxicological concern for egg-laying vertebrates as they bioaccumulate Se through the diet and deposit excess Se to embryo-offspring via maternal transfer, a process which has been shown to result in significant teratogenic effects. The purpose of the present study was to determine and compare the in ovo effects of Se exposure on early development of a laboratory model fish species native to North American freshwater systems, the fathead minnow (Pimephales promelas), through two different exposure routes, maternal transfer and microinjection. For maternal transfer studies, fathead minnow breeding groups (3 females: 2 males) were exposed to diets containing Se-background levels (1.21 μg Se/g food, dry mass [dm]) or environmentally relevant concentrations of selenomethionine (SeMet; 3.88, 8.75 and 26.5 μg Se/g food dm) and bred for 28 days. Embryos were collected at different time points throughout the study to measure Se concentrations and to assess teratogenicity in embryos. While exposure to dietary Se did not negatively affect fecundity among treatment groups, the lowest treatment group (3.88 μg Se/g food dm) produced on average the most embryos per day, per female. The maternal transfer of excess Se occurred rapidly upon onset of exposure, reaching steady-state after approximately 14 days, and embryo Se concentrations increased in a dose-dependent manner. The greatest concentrations of maternally transferred Se significantly increased the total proportion of deformed embryo-larval fathead minnows but did not impact hatchability or survival. In a second study, fathead minnow embryos were injected with SeMet at concentrations of 0.00 (vehicle control), 9.73, 13.5 and 18.9 μg Se/g embryo dm. Microinjection of SeMet did not affect hatchability but significantly increased the proportion of deformed embryo-larval fish in a dose-dependent manner. There was a greater proportion of deformed fathead minnows at embryo Se concentrations of 18.9 μg Se/g embryo dm when exposed via microinjection versus maternal transfer at concentrations of 28.4 μg Se/g embryo dm. However, the findings suggest that both exposure routes induced analogous developmental toxicities in early life stage fish at Se concentrations between 9.73 and 13.5 μg Se/g embryo dm. Overall, this study demonstrated that microinjection has utility for studying the effects of Se in embryo-larval fish and is a promising method for the study of early life stage Se exposure in egg-laying vertebrates.
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Affiliation(s)
- Taylor Lane
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada.
| | - Derek Green
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada.
| | - Kerstin Bluhm
- School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C8, Canada.
| | - Katherine Raes
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada.
| | - David M Janz
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B4, Canada.
| | - Karsten Liber
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C8, Canada.
| | - Markus Hecker
- Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 5C8, Canada.
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6
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Kim JJ, Pham PH, Hamilton ME, Lee LEJ, Bols NC. Effect of selenomethionine on cell viability and heat shock protein 70 levels in rainbow trout intestinal epithelial cells at hypo-, normo-, and hyper-thermic temperatures. J Therm Biol 2018; 76:107-114. [PMID: 30143285 DOI: 10.1016/j.jtherbio.2018.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/07/2018] [Accepted: 07/21/2018] [Indexed: 10/28/2022]
Abstract
As global warming and environmental pollution modify aquatic environments, the thermal biology of fish could be affected by interactions between temperature and pollutants, such as selenium (Se). Therefore, selenomethionine (SeMet) was studied for effects on cell viability and on heat shock protein 70 (HSP70) levels in the rainbow trout intestinal epithelial cell, RTgutGC, at hypothermic (4 °C), normothermic (14 and 18 °C) and hyperthermic (26 °C) temperatures. RTgutGC cultures remained viable for at least a week at all temperatures, although energy metabolism as measured with Alamar Blue (resazurin) was appreciably diminished at 4 °C. Over a 7-day incubation, HSP 70 levels in cultures remained steady at 4 °C, declined at 18 °C, and increased slightly at 26 °C. When 125 μM SeMet was present, cultures remained viable and HSP70 levels were neither increased nor decreased relative to control cultures, regardless of the temperature. With 500 and 1000 μM SeMet, cell viability was profoundly impaired after 7 days in cultures at 14, 18 and 26 °C but was unchanged at 4 °C. Overall the results suggest that only hypothermia modulated the response of rainbow trout cells to SeMet.
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Affiliation(s)
- John J Kim
- Department of Biology, University of Waterloo, Waterloo, Canada N2L 3G1
| | - Phuc H Pham
- Department of Biology, University of Waterloo, Waterloo, Canada N2L 3G1
| | - Mark E Hamilton
- Department of Biology, University of Waterloo, Waterloo, Canada N2L 3G1
| | - Lucy E J Lee
- Faculty of Science, University of the Fraser Valley, Abbotsford, Canada BC V2S 7M8
| | - Niels C Bols
- Department of Biology, University of Waterloo, Waterloo, Canada N2L 3G1.
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7
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Chernick M, Ware M, Albright E, Kwok KWH, Dong W, Zheng N, Hinton DE. Parental dietary seleno-L-methionine exposure and resultant offspring developmental toxicity. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 170:187-198. [PMID: 26655662 PMCID: PMC4698014 DOI: 10.1016/j.aquatox.2015.11.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 11/02/2015] [Accepted: 11/03/2015] [Indexed: 05/15/2023]
Abstract
Selenium (Se) leaches into water from agricultural soils and from storage sites for coal fly ash. Se toxicity causes population and community level effects in fishes and birds. We used the laboratory aquarium model fish, Japanese medaka (Oryzias latipes), an asynchronous breeder, to determine aspects of uptake in adults and resultant developmental toxicity in their offspring. The superior imaging properties of the model enabled detailed descriptions of phenotypic alterations not commonly reported in the existing Se literature. Adult males and females in treatment groups were exposed, separately and together, to a dry diet spiked with 0, 12.5, 25, or 50 μg/g (dry weight) seleno-L-methionine (SeMet) for 6 days, and their embryo progeny collected for 5 days, maintained under controlled conditions and observed daily for hatchability, mortality and/or developmental toxicity. Sites of alteration included: craniofacial, pericardium and abdomen (Pc/Ab), notochord, gall bladder, spleen, blood, and swim bladder. Next, adult tissue Se concentrations (liver, skeletal muscle, ovary and testis) were determined and compared in treatment groups of bred and unbred individuals. No significant difference was found across treatment groups at the various SeMet concentrations; and, subsequent analysis compared exposed vs. control in each of the treatment groups at 10 dpf. Increased embryo mortality was observed in all treatment groups, compared to controls, and embryos had a decreased hatching rate when both parents were exposed. Exposure resulted in significantly more total altered phenotypes than controls. When altered phenotypes following exposure of both parents were higher than maternal only exposure, a male role was suggested. The comparisons between treatment groups revealed that particular types of phenotypic change may be driven by the sex of the exposed parent. Additionally, breeding reduced Se concentrations in some adult tissues, specifically the liver of exposed females and skeletal muscle of exposed males. Detailed phenotypic analysis of progeny from SeMet exposed parents should inform investigations of later life stages in an effort to determine consequences of early life exposure.
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Affiliation(s)
- Melissa Chernick
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Megan Ware
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Elizabeth Albright
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Kevin W H Kwok
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Wu Dong
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA
| | - Na Zheng
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA; Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, Jilin 130012, China
| | - David E Hinton
- Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
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Vinceti M, Grill P, Malagoli C, Filippini T, Storani S, Malavolti M, Michalke B. Selenium speciation in human serum and its implications for epidemiologic research: a cross-sectional study. J Trace Elem Med Biol 2015; 31:1-10. [PMID: 26004885 DOI: 10.1016/j.jtemb.2015.02.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 02/10/2015] [Accepted: 02/13/2015] [Indexed: 12/27/2022]
Abstract
Observational studies addressing the relation between selenium and human health, particularly cancer risk, yielded inconsistent results, while most recent randomized trials showed a fairly consistent pattern suggesting null or adverse effects of the metalloid. One of the most plausible explanations for such inconsistencies is inadequate exposure assessment in observational studies, commonly carried out by measuring total Se content without taking into account the specific exposure to the individual chemical forms of the metalloid, whose toxic and nutritional properties may vary greatly. Data on the distribution of these species in human blood and their correlation with overall selenium levels are very limited. The concentrations of organic and inorganic selenium species were analyzed in serum of fifty subjects sampled from the general population of the municipality of Modena, northern Italy, aged from 35 to 70 years. Samples were collected during a 30-month period, and determinations of selenium species were carried out using high pressure liquid chromatography coupled with inductively coupled plasma dynamic reaction cell mass spectrometry. The majority of selenium was found to be present as organic species, but the inorganic forms showed higher levels than expected. These species showed limited correlations with age, sex and body mass index, while the organic forms increased in subjects consuming selenium-containing dietary supplements and decreased in smokers. The length of the sample storage period strongly influenced the distribution of selenium compounds, with a clear tendency towards higher inorganic and lower organic selenium levels over time. In multivariate analysis adjusting for potential confounders, total serum selenium correlated with human serum albumin-bound selenium and, in males, with two organic species of the metalloid (selenocysteine and glutathione peroxidase-bound selenium), while little association existed with the other organic forms and the inorganic ones. These findings highlight the potential for exposure misclassification of observational epidemiologic investigations based on overall selenium content in blood and possibly other tissues, and the critical role of the storage conditions for speciation analysis.
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Affiliation(s)
- Marco Vinceti
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Reggio Emilia, Italy.
| | - Peter Grill
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München - German Research Center for Environmental Health GmbH, Munich, Germany
| | - Carlotta Malagoli
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Tommaso Filippini
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Simone Storani
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Marcella Malavolti
- Environmental, Genetic and Nutritional Epidemiology Research Center (CREAGEN), Department of Diagnostic, Clinical and Public Health Medicine, University of Modena and Reggio Emilia, Reggio Emilia, Italy
| | - Bernhard Michalke
- Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München - German Research Center for Environmental Health GmbH, Munich, Germany
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9
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Jablonska E, Vinceti M. Selenium and Human Health: Witnessing a Copernican Revolution? JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2015; 33:328-68. [PMID: 26074278 DOI: 10.1080/10590501.2015.1055163] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In humans, selenium was hypothesized to lower the risk of several chronic diseases, mainly due to the antioxidant activity of selenium-containing proteins. Recent epidemiologic and laboratory studies, however, are changing our perception of the biological effects of this nutritionally essential trace element. We reviewed the most recent epidemiologic and biochemical literature on selenium, synthesizing the findings from these studies into a unifying view. Randomized trials have shown that selenium did not protect against cancer and other chronic diseases, but even increased the risk of specific neoplasms such as advanced prostate cancer and skin cancer, in addition to type 2 diabetes. Biochemical studies indicate that selenium may exert a broad pattern of toxic effects at unexpectedly low concentrations. Furthermore, its upregulation of antioxidant proteins (selenium-dependent and selenium-independent) may be a manifestation of self-induced oxidative stress. In conclusion, toxic effects of selenium species occur at lower concentrations than previously believed. Those effects may include a large range of proteomic changes and adverse health effects in humans. Since the effects of environmental exposure to this element on human health still remain partially unknown, but are potentially serious, the toxicity of selenium exposure should be further investigated and considered as a public health priority.
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Affiliation(s)
- Ewa Jablonska
- a Department of Toxicology and Carcinogenesis , Nofer Institute of Occupational Medicine , Lodz , Poland
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