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Schrenk D, Bignami M, Bodin L, Chipman JK, del Mazo J, Grasl‐Kraupp B, Hogstrand C, (Ron) Hoogenboom L, Leblanc J, Nebbia CS, Nielsen E, Ntzani E, Petersen A, Sand S, Schwerdtle T, Wallace H, Benford D, Fürst P, Hart A, Rose M, Schroeder H, Vrijheid M, Ioannidou S, Nikolič M, Bordajandi LR, Vleminckx C. Update of the risk assessment of polybrominated diphenyl ethers (PBDEs) in food. EFSA J 2024; 22:e8497. [PMID: 38269035 PMCID: PMC10807361 DOI: 10.2903/j.efsa.2024.8497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
The European Commission asked EFSA to update its 2011 risk assessment on polybrominated diphenyl ethers (PBDEs) in food, focusing on 10 congeners: BDE-28, -47, -49, -99, -100, -138, -153, -154, -183 and ‑209. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour and reproductive/developmental effects are the critical effects in rodent studies. For four congeners (BDE-47, -99, -153, -209) the Panel derived Reference Points, i.e. benchmark doses and corresponding lower 95% confidence limits (BMDLs), for endpoint-specific benchmark responses. Since repeated exposure to PBDEs results in accumulation of these chemicals in the body, the Panel estimated the body burden at the BMDL in rodents, and the chronic intake that would lead to the same body burden in humans. For the remaining six congeners no studies were available to identify Reference Points. The Panel concluded that there is scientific basis for inclusion of all 10 congeners in a common assessment group and performed a combined risk assessment. The Panel concluded that the combined margin of exposure (MOET) approach was the most appropriate risk metric and applied a tiered approach to the risk characterisation. Over 84,000 analytical results for the 10 congeners in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary Lower Bound exposure to PBDEs were meat and meat products and fish and seafood. Taking into account the uncertainties affecting the assessment, the Panel concluded that it is likely that current dietary exposure to PBDEs in the European population raises a health concern.
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Xue J, Xiao Q, Zhang M, Li D, Wang X. Toxic Effects and Mechanisms of Polybrominated Diphenyl Ethers. Int J Mol Sci 2023; 24:13487. [PMID: 37686292 PMCID: PMC10487835 DOI: 10.3390/ijms241713487] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 08/25/2023] [Accepted: 08/27/2023] [Indexed: 09/10/2023] Open
Abstract
Polybrominated diphenyl ethers (PBDEs) are a group of flame retardants used in plastics, textiles, polyurethane foam, and other materials. They contain two halogenated aromatic rings bonded by an ester bond and are classified according to the number and position of bromine atoms. Due to their widespread use, PBDEs have been detected in soil, air, water, dust, and animal tissues. Besides, PBDEs have been found in various tissues, including liver, kidney, adipose, brain, breast milk and plasma. The continued accumulation of PBDEs has raised concerns about their potential toxicity, including hepatotoxicity, kidney toxicity, gut toxicity, thyroid toxicity, embryotoxicity, reproductive toxicity, neurotoxicity, and immunotoxicity. Previous studies have suggested that there may be various mechanisms contributing to PBDEs toxicity. The present study aimed to outline PBDEs' toxic effects and mechanisms on different organ systems. Given PBDEs' bioaccumulation and adverse impacts on human health and other living organisms, we summarize PBDEs' effects and potential toxicity mechanisms and tend to broaden the horizons to facilitate the design of new prevention strategies for PBDEs-induced toxicity.
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Affiliation(s)
- Jinsong Xue
- School of Biology, Food and Environment, Hefei University, Hefei 230601, China; (Q.X.); (M.Z.); (D.L.)
| | | | | | | | - Xiaofei Wang
- School of Biology, Food and Environment, Hefei University, Hefei 230601, China; (Q.X.); (M.Z.); (D.L.)
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Melatonin alleviates BDE-209-induced cognitive impairment and hippocampal neuroinflammation by modulating microglia polarization via SIRT1-mediated HMGB1/TLR4/NF-κB pathway. Food Chem Toxicol 2023; 172:113561. [PMID: 36566971 DOI: 10.1016/j.fct.2022.113561] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 12/11/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022]
Abstract
Polybrominated diphenyl ethers (PBDEs) are persistent environmental contaminants with developmental neurotoxicity, the mechanism of which remains obscure. The present study aimed to evaluate cognitive deficits and microglia-originated neuroinflammation in the hippocampus of offspring rats exposed to BDE-209 (30 and 100 mg/kg) during perinatal period. Compared to the control, BDE-209-treated rats showed significant longer escape latency and less platform crossings in tests of Morris water maze. Besides obvious hippocampal neuron damage, increased microglial activation and pro-inflammatory markers (CD86, TNFα, and IL-1β), meanwhile, decreased anti-inflammatory molecules (CD206, IL-10, and Arg1) were induced by BDE-209. Furthermore, we investigated the neuroprotection of melatonin against BDE-209 and whether through sirtuin 1 (SIRT1). Consistent with restored SIRT1 activity, enhanced deacetylation of HMGB1 and inhibited cytoplasmic translocation of HMGB1, reduced expression of proteins involved in TLR4-NF-κB pathway and nuclear transfer of phosphorylated-NF-κB p65, and ultimately suppressed microglial activation and improved spatial memory were observed in 10 mg/kg melatonin-pretreated rats, compared with BDE-209-exposed alone. These results demonstrated that melatonin ameliorated BDE-209-caused cognitive impairment partially through shifting microglia polarization towards anti-inflammatory phenotype in a SIRT1-dependent manner, suggesting a potential mechanism for prevention.
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Shinoda Y, Akiyama M, Toyama T. Potential Association between Methylmercury Neurotoxicity and Inflammation. Biol Pharm Bull 2023; 46:1162-1168. [PMID: 37661394 DOI: 10.1248/bpb.b23-00075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Methylmercury (MeHg) is the causal substrate of Minamata disease and a major environmental toxicant. MeHg is widely distributed, mainly in the ocean, meaning its bioaccumulation in seafood is a considerable problem for human health. MeHg has been intensively investigated and is known to induce inflammatory responses and neurodegeneration. However, the relationship between MeHg-induced inflammatory responses and neurodegeneration is not understood. In the present review, we first describe recent findings showing an association between inflammatory responses and certain MeHg-unrelated neurological diseases caused by neurodegeneration. In addition, cell-specific MeHg-induced inflammatory responses are summarized for the central nervous system including those of microglia, astrocytes, and neurons. We also describe MeHg-induced inflammatory responses in peripheral cells and tissue, such as macrophages and blood. These findings provide a concept of the relationship between MeHg-induced inflammatory responses and neurodegeneration, as well as direction for future research of MeHg-induced neurotoxicity.
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Affiliation(s)
- Yo Shinoda
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Masahiro Akiyama
- Research Center for Drug Discovery, Faculty of Pharmacy and Graduate School of Pharmaceutical Sciences, Keio University
| | - Takashi Toyama
- Laboratory of Molecular Biology and Metabolism, Graduate School of Pharmaceutical Sciences, Tohoku University
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Yan M, Zhu H, Shi Y, Xu K, Chen S, Zou Q, Sun H, Kannan K. Profiling of multiple classes of flame retardants in house dust in China: Pattern analysis and human exposure assessment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:120012. [PMID: 36007786 DOI: 10.1016/j.envpol.2022.120012] [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: 05/26/2022] [Revised: 08/03/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Legacy [e.g., brominated- (BFRs)] and alternative [e.g., organophosphate- (OPFRs) and nitrogenous- (NFRs)] flame retardants have a propensity to migrate out of consumer products, and thus are dispersed in indoor microenvironments. In this study, simultaneous presence of 11 BFRs, 18 OPFRs and 11 NFRs were measured in house dust collected from Tianjin, China. OPFRs were found at the highest concentrations, with a median value of 3200 ng/g, followed by NFRs (2600) and BFRs (1600). Tris(2-butoxyethyl) phosphate (median: 1800 ng/g), melamine (1100), and BDE-209 (870) were the top three most abundant chemicals in the respective groups. Location-specific patterns of flame retardant concentrations were found with 30%, 20% and 10% of samples were predominated by OPFRs, NFRs and BFRs, respectively, and the remaining samples contained by two or more of the chemical groups occurring concurrently. Network and cluster analysis results indicated the existence of multiple sources of flame retardants in the indoor microenvironment. Estimated human daily intakes via indoor dust ingestion were approximately several tens of ng/kg bw/day and were below their respective reference dose values. Our results indicate widespread occurrence of multiple flame retardant families in indoor dust and suggest need for continued monitoring and efforts to reduce exposures through dust ingestion.
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Affiliation(s)
- Mengqi Yan
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Hongkai Zhu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China.
| | - Yumeng Shi
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Ke Xu
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Shucong Chen
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Qiang Zou
- Department of Interventional Therapy, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin, 300060, China
| | - Hongwen Sun
- MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, China
| | - Kurunthachalam Kannan
- Department of Pediatrics and Department of Environmental Medicine, New York University School of Medicine, New York, NY, 10016, USA
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Novo JP, Martins B, Raposo RS, Pereira FC, Oriá RB, Malva JO, Fontes-Ribeiro C. Cellular and Molecular Mechanisms Mediating Methylmercury Neurotoxicity and Neuroinflammation. Int J Mol Sci 2021; 22:ijms22063101. [PMID: 33803585 PMCID: PMC8003103 DOI: 10.3390/ijms22063101] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 03/06/2021] [Accepted: 03/15/2021] [Indexed: 02/06/2023] Open
Abstract
Methylmercury (MeHg) toxicity is a major environmental concern. In the aquatic reservoir, MeHg bioaccumulates along the food chain until it is consumed by riverine populations. There has been much interest in the neurotoxicity of MeHg due to recent environmental disasters. Studies have also addressed the implications of long-term MeHg exposure for humans. The central nervous system is particularly susceptible to the deleterious effects of MeHg, as evidenced by clinical symptoms and histopathological changes in poisoned humans. In vitro and in vivo studies have been crucial in deciphering the molecular mechanisms underlying MeHg-induced neurotoxicity. A collection of cellular and molecular alterations including cytokine release, oxidative stress, mitochondrial dysfunction, Ca2+ and glutamate dyshomeostasis, and cell death mechanisms are important consequences of brain cells exposure to MeHg. The purpose of this review is to organize an overview of the mercury cycle and MeHg poisoning events and to summarize data from cellular, animal, and human studies focusing on MeHg effects in neurons and glial cells. This review proposes an up-to-date compendium that will serve as a starting point for further studies and a consultation reference of published studies.
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Affiliation(s)
- João P. Novo
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
| | - Beatriz Martins
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
| | - Ramon S. Raposo
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
- Experimental Biology Core, University of Fortaleza, Health Sciences, Fortaleza 60110-001, Brazil
| | - Frederico C. Pereira
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
| | - Reinaldo B. Oriá
- Laboratory of Tissue Healing, Ontogeny and Nutrition, Department of Morphology and Institute of Biomedicine, School of Medicine, Federal University of Ceará, Fortaleza 60430-270, Brazil;
| | - João O. Malva
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
- Correspondence: (J.O.M.); (C.F.-R.)
| | - Carlos Fontes-Ribeiro
- Institute for Clinical and Biomedical Research (iCBR), Center for Innovative Biomedicine and Biotechnology (CIBB), and Institute of Pharmacology and Experimental Therapeutics, Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; (J.P.N.); (B.M.); (R.S.R.); (F.C.P.)
- Correspondence: (J.O.M.); (C.F.-R.)
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Berntsen HF, Duale N, Bjørklund CG, Rangel-Huerta OD, Dyrberg K, Hofer T, Rakkestad KE, Østby G, Halsne R, Boge G, Paulsen RE, Myhre O, Ropstad E. Effects of a human-based mixture of persistent organic pollutants on the in vivo exposed cerebellum and cerebellar neuronal cultures exposed in vitro. ENVIRONMENT INTERNATIONAL 2021; 146:106240. [PMID: 33186814 DOI: 10.1016/j.envint.2020.106240] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 09/25/2020] [Accepted: 10/22/2020] [Indexed: 06/11/2023]
Abstract
Exposure to persistent organic pollutants (POPs), encompassing chlorinated (Cl), brominated (Br) and perfluoroalkyl acid (PFAA) compounds is associated with adverse neurobehaviour in humans and animals, and is observed to cause adverse effects in nerve cell cultures. Most studies focus on single POPs, whereas studies on effects of complex mixtures are limited. We examined the effects of a mixture of 29 persistent compounds (Cl + Br + PFAA, named Total mixture), as well as 6 sub-mixtures on in vitro exposed rat cerebellar granule neurons (CGNs). Protein expression studies of cerebella from in vivo exposed mice offspring were also conducted. The selection of chemicals for the POP mixture was based on compounds being prominent in food, breast milk or blood from the Scandinavian human population. The Total mixture and sub-mixtures containing PFAAs caused greater toxicity in rat CGNs than the single or combined Cl/Br sub-mixtures, with significant impact on viability from 500x human blood levels. The potencies for these mixtures based on LC50 values were Br + PFAA mixture > Total mixture > Cl + PFAA mixture > PFAA mixture. These mixtures also accelerated induced lipid peroxidation. Protection by the competitive N-methyl-D-aspartate (NMDA) receptor antagonist 3-((R)-2-Carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) indicated involvement of the NMDA receptor in PFAA and Total mixture-, but not Cl mixture-induced toxicity. Gene-expression studies in rat CGNs using a sub-toxic and marginally toxic concentration ((0.4 nM-5.5 µM) 333x and (1 nM-8.2 µM) 500x human blood levels) of the mixtures, revealed differential expression of genes involved in apoptosis, oxidative stress, neurotransmission and cerebellar development, with more genes affected at the marginally toxic concentration. The two important neurodevelopmental markers Pax6 and Grin2b were downregulated at 500x human blood levels, accompanied by decreases in PAX6 and GluN2B protein levels, in cerebellum of offspring mice from mothers exposed to the Total mixture throughout pregnancy and lactation. In rat CGNs, the glutathione peroxidase gene Prdx6 and the regulatory transmembrane glycoprotein gene Sirpa were highly upregulated at both concentrations. In conclusion, our results support that early-life exposure to mixtures of POPs can cause adverse neurodevelopmental effects.
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Affiliation(s)
- Hanne Friis Berntsen
- Department of Production Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway; National Institute of Occupational Health, P.O. Box 5330 Majorstuen, 0304 Oslo, Norway.
| | - Nur Duale
- Section of Molecular Toxicology, Norwegian Institute of Public Health, N-0403 Oslo, Norway.
| | - Cesilie Granum Bjørklund
- Department of Production Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway.
| | | | - Kine Dyrberg
- Department of Production Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway.
| | - Tim Hofer
- Section of Toxicology and Risk Assessment, Norwegian Institute of Public Health, N-0403, Oslo, Norway.
| | - Kirsten Eline Rakkestad
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1072, Blindern, NO-0316 Oslo, Norway.
| | - Gunn Østby
- Department of Production Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway.
| | - Ruth Halsne
- Department of Production Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway.
| | - Gudrun Boge
- Department of Companion Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway.
| | - Ragnhild Elisabeth Paulsen
- Section for Pharmacology and Pharmaceutical Biosciences, Department of Pharmacy, University of Oslo, P.O. Box 1072, Blindern, NO-0316 Oslo, Norway.
| | - Oddvar Myhre
- Section of Toxicology and Risk Assessment, Norwegian Institute of Public Health, N-0403, Oslo, Norway.
| | - Erik Ropstad
- Department of Production Animal Clinical Sciences, NMBU-School of Veterinary Science, P.O. Box 369 sentrum, N-0102 Oslo, Norway.
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Arambula SE, McCarthy MM. Neuroendocrine-Immune Crosstalk Shapes Sex-Specific Brain Development. Endocrinology 2020; 161:bqaa055. [PMID: 32270188 PMCID: PMC7217281 DOI: 10.1210/endocr/bqaa055] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/06/2020] [Indexed: 12/11/2022]
Abstract
Sex is an essential biological variable that significantly impacts multiple aspects of neural functioning in both the healthy and diseased brain. Sex differences in brain structure and function are organized early in development during the critical period of sexual differentiation. While decades of research establish gonadal hormones as the primary modulators of this process, new research has revealed a critical, and perhaps underappreciated, role of the neuroimmune system in sex-specific brain development. The immune and endocrine systems are tightly intertwined and share processes and effector molecules that influence the nervous system. Thus, a natural question is whether endocrine-immune crosstalk contributes to sexual differentiation of the brain. In this mini-review, we first provide a conceptual framework by classifying the major categories of neural sex differences and review the concept of sexual differentiation of the brain, a process occurring early in development and largely controlled by steroid hormones. Next, we describe developmental sex differences in the neuroimmune system, which may represent targets or mediators of the sexual differentiation process. We then discuss the overwhelming evidence in support of crosstalk between the neuroendocrine and immune systems and highlight recent examples that shape sex differences in the brain. Finally, we review how early life events can perturb sex-specific neurodevelopment via aberrant immune activation.
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Affiliation(s)
- Sheryl E Arambula
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD
| | - Margaret M McCarthy
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD
- Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD
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Abstract
PURPOSE OF REVIEW With the incidence of neurodevelopmental disorders on the rise, it is imperative to identify and understand the mechanisms by which environmental contaminants can impact the developing brain and heighten risk. Here, we report on recent findings regarding novel mechanisms of developmental neurotoxicity and highlight chemicals of concern, beyond traditionally defined neurotoxicants. RECENT FINDINGS The perinatal window represents a critical and extremely vulnerable period of time during which chemical insult can alter the morphological and functional trajectory of the developing brain. Numerous chemical classes have been associated with alterations in neurodevelopment including metals, solvents, pesticides, and, more recently, endocrine-disrupting compounds. Although mechanisms of neurotoxicity have traditionally been identified as pathways leading to neuronal cell death, neuropathology, or severe neural injury, recent research highlights alternative mechanisms that result in more subtle but consequential changes in the brain and behavior. These emerging areas of interest include neuroendocrine and immune disruption, as well as indirect toxicity via actions on other organs such as the gut and placenta. Understanding of the myriad ways in which the developing brain is vulnerable to chemical exposures has grown tremendously over the past decade. Further progress and implementation in risk assessment is critical to reducing risk of neurodevelopmental disorders.
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Al-Omran LS, Harrad S. Within-room and within-home spatial and temporal variability in concentrations of legacy and "novel" brominated flame retardants in indoor dust. CHEMOSPHERE 2018; 193:1105-1112. [PMID: 29874738 DOI: 10.1016/j.chemosphere.2017.11.147] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 06/08/2023]
Abstract
To test the hypothesis that assessments of human exposure to PBDEs and NBFRs (PBEB, EH-TBB, BEH-TEBP, BTBPE and DBDPE) via dust ingestion should take into account spatial and temporal variability in dust contamination; 238 dust samples were collected from nine different rooms within three homes in Birmingham UK. In each room, three different dust samples were taken at monthly intervals for nine months, one sample from elevated surfaces and two samples from two different floor areas. Substantial within-room and within-home spatial variability in BFR concentrations was apparent between two floor areas and between different rooms due to the varying distances of sampled surfaces from potential BFR sources. With the exception of DBDPE, BFR concentrations in elevated surface dust exceeded significantly those in floor dust. Considerable within-room and within-home temporal variability in BFR concentrations was also apparent over a nine month sampling period. This is likely attributable to changes in room contents. Based on observed spatial and temporal variability, exposure estimates based on analysis of a single dust sample taken from one specific floor area at one specific point in time may not be entirely representative of human exposure in that room. Noticeable variability in BFR concentrations was also observed between colder and warmer seasons. In 13 out of 17 floor areas, concentrations of Σ8tri-deca-BDEs were higher in colder seasons, while those of Σ5NBFRs were higher in warmer seasons. Significant negative correlation was observed in two rooms between concentrations of BDE-99, Σ7tri-hepta-BDEs and BEH-TEBP and dust loading (g/m2).
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Affiliation(s)
- Layla Salih Al-Omran
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK; Division of Ecology, College of Science, University of Basrah, Basrah, Iraq.
| | - Stuart Harrad
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
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Chen J, Li X, Li X, Chen D. The environmental pollutant BDE-209 regulates NO/cGMP signaling through activation of NMDA receptors in neurons. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:3397-3407. [PMID: 29151189 DOI: 10.1007/s11356-017-0651-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/31/2017] [Indexed: 06/07/2023]
Abstract
The common flame retardant decabrominated diphenyl ether (BDE-209) is a persistent organic pollutant. Epidemiological studies have revealed that prenatal or postnatal exposure to BDE-209 can result in delayed cognitive development, and BDE-209 has been shown to be toxic to cultured neurons with maturation interference effects. However, its neurotoxic mechanism remains unclear. Nitric oxide/cyclic guanosine monophosphate (NO/cGMP) signaling plays an important role in regulating neuronal maturation. We examined the influence of BDE-209 (100, 200, and 400 nM) on NO production and cGMP levels signaling in rodent neurons in vitro, with or without pretreatment N-methyl-D-aspartate (NMDA) receptor antagonism. We found that nanomolar concentrations of BDE-209 affected levels of the second messengers NO and cGMP, and that these effects could be blocked by NMDA receptor antagonism. Moreover, BDE-209 activation of NMDA receptors inhibited the expression of phosphodiesterases (PDEs), which modulate intracellular cGMP levels, and increased the Bcl-2/Bax ratio, favoring apoptosis induction. Our studies implicate the NMDA-NO/cGMP pathway in the pathogenic mechanism through which BDE-209 induces neurotoxicity.
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Affiliation(s)
- Jingsi Chen
- Department of Fetal Medicine and Prenatal Diagnosis, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510150, China
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
- Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou, People's Republic of China, Guangzhou, 510150, China
- Key Laboratories for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China
| | - Xiuying Li
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
| | - Xiaomei Li
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China
| | - Dunjin Chen
- Obstetrics & Gynecology Institute of Guangzhou, Guangzhou, 510150, China.
- Key Laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou, People's Republic of China, Guangzhou, 510150, China.
- Key Laboratories for Major Obstetric Diseases of Guangdong Province, Guangzhou, 510150, China.
- , No.63, Duobao Road, Guangzhou, 510150, China.
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English K, Chen Y, Toms LM, Jagals P, Ware RS, Mueller JF, Sly PD. Polybrominated diphenyl ether flame retardant concentrations in faeces from young children in Queensland, Australia and associations with environmental and behavioural factors. ENVIRONMENTAL RESEARCH 2017; 158:669-676. [PMID: 28734253 DOI: 10.1016/j.envres.2017.07.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/06/2017] [Accepted: 07/10/2017] [Indexed: 06/07/2023]
Abstract
The aim of our study was to investigate children's exposure to the flame retardants polybrominated diphenyl ethers (PBDEs) by analysing faecal content, a non-invasive matrix, as well as responses to an exposure-assessment questionnaire. A convenience sample of 61 parents with children (aged >3 months to <2 years) completed an online pre-tested questionnaire and provided faecal samples for analysis by high resolution gas chromatography/mass spectrometry. BDE-209 was the dominant congener in faecal samples adjusted to 8.3ng/g dry weight (dw), with >80% samples above the limit of detection (LOD). BDE-47 (0.23ng/g dw) and BDE-153 (0.03ng/g dw) were each detected above the LOD in approximately 60% of samples. Age was associated with BDE-47 (-7%/month) and BDE-153 (-12%/month) concentrations in faeces, but not BDE-209. Other variables associated with PBDE concentrations included features of the home (carpet, pets) and behaviour (hand-to-mouth, removing shoes, using a car sunshade, frequency of walks outdoors). However, given the small sample size of this study additional research is required to confirm these findings. In this study we demonstrated that faeces may be a viable alternative to monitor human exposure to PBDEs, but further validation studies are required.
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Affiliation(s)
- Karin English
- School of Medicine, The University of Queensland, Brisbane, Australia; Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia.
| | - Yiqin Chen
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Leisa-Maree Toms
- School of Public Health and Social Work, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia
| | - Paul Jagals
- Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia
| | - Robert S Ware
- Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia; Menzies Health Institute Queensland, Griffith University, Brisbane, Australia
| | - Jochen F Mueller
- Queensland Alliance for Environmental Health Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Peter D Sly
- School of Medicine, The University of Queensland, Brisbane, Australia; Children's Health and Environment Program, Child Health Research Centre, The University of Queensland, Brisbane, Australia
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Xu M, Huang Y, Li K, Cheng X, Li G, Liu M, Nie Y, Geng S, Zhao S. Developmental exposure of decabromodiphenyl ether impairs subventricular zone neurogenesis and morphology of granule cells in mouse olfactory bulb. Arch Toxicol 2017; 92:529-539. [DOI: 10.1007/s00204-017-2059-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 08/31/2017] [Indexed: 11/29/2022]
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Al-Omran LS, Harrad S. Influence of sampling approach on concentrations of legacy and "novel" brominated flame retardants in indoor dust. CHEMOSPHERE 2017; 178:51-58. [PMID: 28319741 DOI: 10.1016/j.chemosphere.2017.02.096] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 02/17/2017] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
The study investigates the impact of sampling method on the concentrations of PBDEs (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, and BDE-209) and NBFRs (PBEB, EH-TBB, BEH-TEBP, BTBPE and DBDPE) in indoor dust. A total of 36 dust samples were collected from 12 homes in Birmingham, UK (3 samples per home comprising researcher collected dust - both RCD from the living room (RCDL) and bedroom (RCDB), with an additional householder vacuum dust sample - HHVD). BDE-209 was the predominant compound, with average concentrations of 2642, 2336 and 2634 ng/g in RCDL, RCDB and HHVD respectively. The next most abundant BFR was BEH-TEBP, followed by DBDPE, with average concentrations of 306, 339 and 233 ng/g for BEH-TEBP and 155, 91 and 152 ng/g for DBDPE in RCDL, RCDB and HHVD respectively. Average concentrations of Σ6tri-hexa-BDEs were 47, 41, and 24 ng/g in RCDL, RCDB and HHVD respectively. With the exception of Σ6tri-hexa-BDEs, BDE-153, BDE-99 and to some extent BEH-TEBP, no significant differences were found between BFR concentrations in RCD and HHVD. Statistically significant correlations were observed between concentrations of Σ6tri-hexa-BDEs, BEH-TEBP and DBDPE in HHVD and in both RCDL and RCDB. However, comparison of estimates of exposure via dust ingestion based on these two sampling methods revealed that using householder vacuum dust underestimates exposure, particularly for Σ6tri-hexa-BDEs, and to some extent for BEH-TEBP. In contrast, HHVD could be a viable alternative to RCD as a metric of exposure for higher brominated BFRs.
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Affiliation(s)
- Layla Salih Al-Omran
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK; Division of Ecology, College of Science, University of Basrah, Basrah, Iraq.
| | - Stuart Harrad
- School of Geography, Earth, and Environmental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
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Yang T, Xu Z, Liu W, Xu B, Deng Y. Protective effects of Alpha-lipoic acid on MeHg-induced oxidative damage and intracellular Ca2+dyshomeostasis in primary cultured neurons. Free Radic Res 2016; 50:542-56. [DOI: 10.3109/10715762.2016.1152362] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Doxycycline hinders phenylalanine fibril assemblies revealing a potential novel therapeutic approach in phenylketonuria. Sci Rep 2015; 5:15902. [PMID: 26510963 PMCID: PMC4625134 DOI: 10.1038/srep15902] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 10/06/2015] [Indexed: 12/16/2022] Open
Abstract
A new paradigm for the aetiopathology of phenylketonuria suggests the presence of amyloid-like assemblies in the brains of transgenic mouse models and patients with phenylketonuria, possibly shedding light on the selective cognitive deficit associated with this disease. Paralleling the amyloidogenic route that identifies different stages of peptide aggregation, corresponding to different levels of toxicity, we experimentally address for the first time, the physico-chemical properties of phenylalanine aggregates via Small Angle, Wide Angle X-ray Scattering and Atomic Force Microscopy. Results are consistent with the presence of well-structured, aligned fibres generated by milliMolar concentrations of phenylalanine. Moreover, the amyloid-modulating doxycycline agent affects the local structure of phenylalanine aggregates, preventing the formation of well-ordered crystalline structures. Phenylalanine assemblies prove toxic in vitro to immortalized cell lines and primary neuronal cells. Furthermore, these assemblies also cause dendritic sprouting alterations and synaptic protein impairment in neurons. Doxycycline counteracts these toxic effects, suggesting an approach for the development of future innovative non-dietary preventive therapies.
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Yamada S, Kotake Y, Nakano M, Sekino Y, Kanda Y. Tributyltin induces mitochondrial fission through NAD-IDH dependent mitofusin degradation in human embryonic carcinoma cells. Metallomics 2015; 7:1240-6. [PMID: 25909344 DOI: 10.1039/c5mt00033e] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Organotin compounds, such as tributyltin (TBT), are well-known endocrine disruptors. TBT acts at the nanomolar level through genomic pathways via the peroxisome proliferator activated receptor (PPAR)/retinoid X receptor (RXR). We recently reported that TBT inhibits cell growth and the ATP content in the human embryonic carcinoma cell line NT2/D1 via a non-genomic pathway involving NAD(+)-dependent isocitrate dehydrogenase (NAD-IDH), which metabolizes isocitrate to α-ketoglutarate. However, the molecular mechanisms by which NAD-IDH mediates TBT toxicity remain unclear. In the present study, we evaluated the effects of TBT on mitochondrial NAD-IDH and energy production. Staining with MitoTracker revealed that nanomolar TBT levels induced mitochondrial fragmentation. TBT also degraded the mitochondrial fusion proteins, mitofusins 1 and 2. Interestingly, apigenin, an inhibitor of NAD-IDH, mimicked the effects of TBT. Incubation with an α-ketoglutarate analogue partially recovered TBT-induced mitochondrial dysfunction, supporting the involvement of NAD-IDH. Our data suggest that nanomolar TBT levels impair mitochondrial quality control via NAD-IDH in NT2/D1 cells. Thus, mitochondrial function in embryonic cells could be used to assess cytotoxicity associated with metal exposure.
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Affiliation(s)
- Shigeru Yamada
- Division of Pharmacology, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku 158-8501, Japan.
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