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Michelangeli F, Mohammed NA, Jones B, Tairu M, Al-Mousa F. Cytotoxicity by endocrine disruptors through effects on ER Ca 2+ transporters, aberrations in Ca 2+ signalling pathways and ER stress. FEBS Open Bio 2024. [PMID: 39138623 DOI: 10.1002/2211-5463.13880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/24/2024] [Accepted: 08/05/2024] [Indexed: 08/15/2024] Open
Abstract
Concerns regarding man-made organic chemicals pervading our ecosystem and having adverse and detrimental effects upon organisms, including man, have now been studied for several decades. Since the 1970s, some environmental pollutants were identified as having endocrine disrupting affects. These endocrine disrupting chemicals (EDC) were initially shown to have estrogenic or anti-estrogenic properties and some were also shown to bind to a variety of hormone receptors. However, since the 1990s it has also been identified that many of these EDC additionally, have the ability of causing abnormal alterations in Ca2+ signalling pathways (also commonly involved in hormone signalling), leading to exaggerated elevations in cytosolic [Ca2+] levels, that is known to cause activation of a number of cell death pathways. The major emphasis of this review is to present a personal perspective of the evidence for some types of EDC, specifically alkylphenols and brominated flame retardants (BFRs), causing direct effects on Ca2+ transporters (mainly the SERCA Ca2+ ATPases), culminating in acute cytotoxicity and cell death. Evidence is also presented to indicate that this Ca2+ATPase inhibition, which leads to abnormally elevated cytosolic [Ca2+], as well as a decreased luminal ER [Ca2+], which triggers the ER stress response, are both involved in acute cytotoxicity.
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Affiliation(s)
- Francesco Michelangeli
- Chester Medical School, University of Chester, UK
- School of Biosciences, University of Birmingham, UK
| | - Noor A Mohammed
- School of Biosciences, University of Birmingham, UK
- Department of Biology, University of Duhok, Iraq
| | - Brogan Jones
- Chester Medical School, University of Chester, UK
| | | | - Fawaz Al-Mousa
- General Directorate of Poison Control Centre, Ministry of Health, Riyadh, Saudi Arabia
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Broniatowski M, Wydro P. Interactions of Brominated Flame Retardants with Membrane Models of Dehalogenating Bacteria: Langmuir Monolayer and Grazing Incidence X-ray Diffraction Studies. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:10600-10614. [PMID: 38721840 PMCID: PMC11112749 DOI: 10.1021/acs.langmuir.4c00518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 04/24/2024] [Accepted: 04/29/2024] [Indexed: 05/22/2024]
Abstract
Brominated flame retardants (BFRs) are small organic molecules containing several bromine substituents added to plastics to limit their flammability. BFRs can constitute up to 30% of the weight of some plastics, which is why they are produced in large quantities. Along with plastic waste and microplastic particles, BFRs end up in the soil and can easily leach causing contamination. As polyhalogenated molecules, multiple BFRs were classified as persistent organic pollutants (POPs), meaning that their biodegradation in the soils is especially challenging. However, some anaerobic bacteria as Dehaloccocoides can dehalogenate BFRs, which is important in the bioremediation of contaminated soils. BFRs are hydrophobic, can accumulate in plasma membranes, and disturb their function. On the other hand, limited membrane accumulation is necessary for BFR dehalogenation. To study the BFR-membrane interaction, we created membrane models of soil dehalogenating bacteria and tested their interactions with seven legacy and novel BFRs most common in soils. Phospholipid Langmuir monolayers with appropriate composition were used as membrane models. These membranes were doped in the selected BFRs, and the incorporation of BFR molecules into the phospholipid matrix and also the effects of BFR presence on membrane physical properties and morphology were studied. It turned out that the seven BFRs differed significantly in their membrane affinity. For some, the incorporation was very limited, and others incorporated effectively and could affect membrane properties, while one of the tested molecules induced the formation of bilayer domains in the membranes. Thus, Langmuir monolayers can be effectively used for pretesting BFR membrane activity.
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Affiliation(s)
- Marcin Broniatowski
- Department
of Environmental Chemistry, Faculty of Chemistry, the Jagiellonian University in Kraków, ul. Gronostajowa 2, Kraków 30-387, Poland
| | - Paweł Wydro
- Department
of Physical Chemistry and Electrochemistry, Faculty of Chemistry, the Jagiellonian University in Kraków, ul. Gronostajowa 2, Kraków 30-387, Poland
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Khani L, Martin L, Pułaski Ł. Cellular and physiological mechanisms of halogenated and organophosphorus flame retardant toxicity. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 897:165272. [PMID: 37406685 DOI: 10.1016/j.scitotenv.2023.165272] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 06/19/2023] [Accepted: 06/30/2023] [Indexed: 07/07/2023]
Abstract
Flame retardants (FRs) are chemical substances used to inhibit the spread of fire in numerous industrial applications, and their abundance in modern manufactured products in the indoor and outdoor environment leads to extensive direct and food chain exposure of humans. Although once considered relatively non-toxic, FRs are demonstrated by recent literature to have disruptive effects on many biological processes, including signaling pathways, genome stability, reproduction, and immune system function. This review provides a summary of research investigating the impact of major groups of FRs, including halogenated and organophosphorus FRs, on animals and humans in vitro and/or in vivo. We put in focus those studies that explained or referenced the modes of FR action at the level of cells, tissues and organs. Since FRs are highly hydrophobic chemicals, their biophysical and biochemical modes of action usually involve lipophilic interactions, e.g. with biological membranes or elements of signaling pathways. We present selected toxicological information about these molecular actions to show how they can lead to damaging membrane integrity, damaging DNA and compromising its repair, changing gene expression, and cell cycle as well as accelerating cell death. Moreover, we indicate how this translates to deleterious bioactivity of FRs at the physiological level, with disruption of hormonal action, dysregulation of metabolism, adverse effects on male and female reproduction as well as alteration of normal pattern of immunity. Concentrating on these subjects, we make clear both the advances in knowledge in recent years and the remaining gaps in our understanding, especially at the mechanistic level.
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Affiliation(s)
- Leila Khani
- Laboratory of Transcriptional Regulation, Institute of Medical Biology PAS, Lodz, Poland; Bio-Med-Chem Doctoral School of the University of Lodz and Lodz Institutes of the Polish Academy of Sciences, Lodz, Poland
| | - Leonardo Martin
- Laboratory of Transcriptional Regulation, Institute of Medical Biology PAS, Lodz, Poland; Department of Biochemistry and Molecular Biology, Federal University of São Paulo, São Paulo, Brazil
| | - Łukasz Pułaski
- Department of Oncobiology and Epigenetics, Faculty of Biology and Environmental Protection, University of Lodz, Lodz, Poland; Laboratory of Transcriptional Regulation, Institute of Medical Biology PAS, Lodz, Poland.
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Photocatalytic Degradation of 4,4'-Isopropylidenebis(2,6-dibromophenol) on Magnetite Catalysts vs. Ozonolysis Method: Process Efficiency and Toxicity Assessment of Disinfection By-Products. Int J Mol Sci 2022; 23:ijms23073438. [PMID: 35408795 PMCID: PMC8999079 DOI: 10.3390/ijms23073438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 03/13/2022] [Accepted: 03/20/2022] [Indexed: 01/27/2023] Open
Abstract
Flame retardants have attracted growing environmental concern. Recently, an increasing number of studies have been conducted worldwide to investigate flame-retardant sources, environmental distribution, living organisms’ exposure, and toxicity. The presented studies include the degradation of 4,4′-isopropylidenebis(2,6-dibromophenol) (TBBPA) by ozonolysis and photocatalysis. In the photocatalytic process, nano- and micro-magnetite (n-Fe3O4 and μ-Fe3O4) are used as a catalyst. Monitoring of TBBPA decay in the photocatalysis and ozonolysis showed photocatalysis to be more effective. Significant removal of TBBPA was achieved within 10 min in photocatalysis (ca. 90%), while for ozonation, a comparable effect was observed within 70 min. To determine the best method of TBBPA degradation concentration on COD and TOC, the removals were examined. The highest oxidation state was obtained for photocatalysis on μ-Fe3O4, whereas for n-Fe3O4 and ozonolysis, the COD/TOC ratio was lower. Acute toxicity results show noticeable differences in the toxicity of TBBPA and its degradation products to Artemia franciscana and Thamnocephalus platyurus. The EC50 values indicate that TBBPA degradation products were toxic to harmful, whereas the TBPPA and post-reaction mixtures were toxic to the invertebrate species tested. The best efficiency in the removal and degradation of TBBPA was in the photocatalysis process on μ-Fe3O4 (reaction system 1). The examined crustaceans can be used as a sensitive test for acute toxicity evaluation.
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Nunes RS, Vila-Viçosa D, Costa PJ. Halogen Bonding: An Underestimated Player in Membrane–Ligand Interactions. J Am Chem Soc 2021; 143:4253-4267. [DOI: 10.1021/jacs.0c12470] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Rafael Santana Nunes
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
- Centro de Química Estrutural, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Diogo Vila-Viçosa
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
| | - Paulo J. Costa
- BioISI - Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisboa, Campo Grande, C8 bdg, 1749-016 Lisboa, Portugal
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Diamandakis D, Zieminska E, Siwiec M, Tokarski K, Salinska E, Lenart J, Hess G, Lazarewicz JW. Tetrabromobisphenol A-induced depolarization of rat cerebellar granule cells: ex vivo and in vitro studies. CHEMOSPHERE 2019; 223:64-73. [PMID: 30769291 DOI: 10.1016/j.chemosphere.2019.02.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/05/2019] [Accepted: 02/07/2019] [Indexed: 06/09/2023]
Abstract
The brominated flame retardant tetrabromobisphenol A (TBBPA) is toxic to cultured brain neurons, and glutamate receptors partially mediate this effect; consequently, the depolarizing effect of TBBPA on neurons is to be expected, but it is yet to be actually demonstrated. The aim of this study was to detect TBBPA-evoked depolarization and identify the underlying mechanisms. The plasma membrane potential of rat cerebellar granule cells (CGC) in cerebellar slices or in primary cultures was measured using whole-cell current clamp recordings, or the fluorescent probe oxonol VI, respectively. The contribution of NMDA and AMPA receptors, voltage-gated sodium channels and intracellular calcium mobilization was tested using their selective antagonists or inhibitors. Direct interactions of TBBPA with NMDARs were tested by measuring the specific binding of radiolabeled NMDAR ligands to isolated rat cortical membrane fraction. TBBPA (25 μM) strongly depolarized CGC in cerebellar slices, and at ≥ 7.5 μM concentration-dependently depolarized primary CGC cultures. Depolarization of the primary CGC by 25 μM TBBPA was partly reduced when MK-801 was applied alone or in combination with either TTX or CNQX, or where bastadin 12 was applied in combination with ryanodine, whereas depolarization was completely prevented when MK-801, CNQX and TTX where combined. TBBPA had no effect on the specific binding of NMDAR radio-ligands to isolated cortical membranes. These results demonstrate the depolarizing effect of TBBPA on CGC, which is mainly mediated by ionotropic glutamate receptors, while voltage-gated sodium channels are also involved. We found no evidence for the direct activation of NMDARs by TBBPA.
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Affiliation(s)
- Dominik Diamandakis
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106, Warsaw, Poland.
| | - Elzbieta Zieminska
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106, Warsaw, Poland.
| | - Marcin Siwiec
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland.
| | - Krzysztof Tokarski
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland.
| | - Elzbieta Salinska
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106, Warsaw, Poland.
| | - Jacek Lenart
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106, Warsaw, Poland.
| | - Grzegorz Hess
- Department of Physiology, Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343, Krakow, Poland.
| | - Jerzy W Lazarewicz
- Department of Neurochemistry, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawinskiego 5, 02-106, Warsaw, Poland.
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7
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NTP Research Report on Biological Activity of Bisphenol A (BPA) Structural Analogues and Functional Alternatives. ACTA ACUST UNITED AC 2017. [DOI: 10.22427/ntp-rr-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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8
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Choi EM, Suh KS, Rhee SY, Oh S, Kim SW, Pak YK, Choe W, Ha J, Chon S. Exposure to tetrabromobisphenol A induces cellular dysfunction in osteoblastic MC3T3-E1 cells. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2017; 52:561-570. [PMID: 28276884 DOI: 10.1080/10934529.2017.1284435] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study was undertaken to investigate the possible involvement of oxidative stress in tetrabromobisphenol A (TBBPA)-induced toxicity in osteoblastic MC3T3-E1 cells. To examine the potential effect of TBBPA on cultured osteoblastic cells, we measured cell viability, apoptosis, reactive oxygen species (ROS), mitochondrial superoxide, and mitochondrial parameters including adenosine triphosphate (ATP) level, cardiolipin content, cytochrome c release, cyclophilin levels, and differentiation markers in osteoblastic MC3T3-E1 cells. TBBPA exposure for 48 h caused the apoptosis and cytotoxicity of MC3T3-E1 cells. TBBPA also induced ROS and mitochondrial superoxide production in a concentration-dependent manner. These results suggest that TBBPA induces osteoblast apoptosis and ROS production, resulting in bone diseases. Moreover, TBBPA induced cardiolipin peroxidation, cytochrome c release, and decreased ATP levels which induced apoptosis or necrosis. TBBPA decreased the differentiation markers, collagen synthesis, alkaline phosphatase activity, and calcium deposition in cells. Additionally, TBBPA decreased cyclophilin A and B releases. Taken together, these data support the notion that TBBPA inhibits osteoblast function and has detrimental effects on osteoblasts through a mechanism involving oxidative stress and mitochondrial dysfunction.
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Affiliation(s)
- Eun Mi Choi
- a Department of Endocrinology & Metabolism , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Kwang Sik Suh
- a Department of Endocrinology & Metabolism , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Sang Youl Rhee
- a Department of Endocrinology & Metabolism , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Seungjoon Oh
- a Department of Endocrinology & Metabolism , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Sung Woon Kim
- a Department of Endocrinology & Metabolism , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Youngmi Kim Pak
- b Department of Physiology , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Wonchae Choe
- c Department of Biochemistry and Molecular Biology (BK21 project) , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Joohun Ha
- c Department of Biochemistry and Molecular Biology (BK21 project) , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
| | - Suk Chon
- a Department of Endocrinology & Metabolism , School of Medicine, Kyung Hee University , Seoul , Republic of Korea
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Honkisz E, Wójtowicz AK. The role of PPARγ in TBBPA-mediated endocrine disrupting effects in human choriocarcinoma JEG-3 cells. Mol Cell Biochem 2015; 409:81-91. [PMID: 26253174 PMCID: PMC4589557 DOI: 10.1007/s11010-015-2514-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 07/04/2015] [Indexed: 11/04/2022]
Abstract
The goal of the present study was to investigate the action of TBBPA on PPARγ protein expression in vitro in human choriocarcinoma-derived placental JEG-3 cells. We also analyzed TBBPA for its action on placental secretion of progesterone and β-hCG, cell viability, and apoptosis. Our results showed that after TBBPA treatment at 10 nM and 10 µM, PPARγ protein expression increased in a time-dependent manner until 48 h and then slightly decreased at 72 h but was still above the control level. This alteration in PPARγ protein expression was accompanied by a decreased β-hCG level. Interestingly, co-treatment with the PPARγ antagonist GW9662 reversed the TBBPA-mediated changes in PPARγ protein expression but, according to β-hCG secretion, potentiated an inhibitory effect of TBBPA. Additionally, in our study, we assessed the ability of TBBPA to increase progesterone levels in JEG-3 cells compared with those of controls. Finally, in the present study, we demonstrated that TBBPA at all of the tested doses significantly increased caspase-3 activity compared with that of the vehicle control. The apoptotic action of TBBPA was also confirmed by Hoechst 33342 staining. These results showed the up-regulation of PPARγ protein expression after TBBPA exposure in human placental cells. Although co-treatment with antagonist of PPARγ reversed the TBBPA-mediated increase in this protein expression and restored it to the control level, it did not reverse the effect on β-hCG secretion. This indicated that the mechanism of TBBPA-induced changes in β-hCG secretion is PPARγ-independent.
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Affiliation(s)
- Ewelina Honkisz
- Department of Animal Biotechnology, University of Agriculture, Rędzina 1B, 30-248, Kraków, Poland
| | - Anna K Wójtowicz
- Department of Animal Biotechnology, University of Agriculture, Rędzina 1B, 30-248, Kraków, Poland.
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10
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Wang YQ, Zhang HM, Cao J. Quest for the binding mode of tetrabromobisphenol A with Calf thymus DNA. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 131:109-113. [PMID: 24830628 DOI: 10.1016/j.saa.2014.04.077] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/06/2014] [Accepted: 04/17/2014] [Indexed: 06/03/2023]
Abstract
The binding interaction of tetrabromobisphenol A with Calf thymus DNA was studied by multi-spectroscopic and molecular modeling methods. The UV-vis study revealed that an obvious interaction between tetrabromobisphenol A and Calf thymus DNA happened. The π-π(∗) transitions and the electron cloud of tetrabromobisphenol A might be changed by entering the groove of Calf thymus DNA. From the fluorescence spectral and thermodynamics studies, it was concluded that the hydrogen bonds and hydrophobic force played a major role in the binding of tetrabromobisphenol A to Calf thymus DNA. The molecular modeling study showed that the possible sites of tetrabromobisphenol A in the groove of DNA. Circular dichroism study also depicted that tetrabromobisphenol A bond to DNA. These above results would further advance our knowledge on the molecular mechanism of the binding interactions of brominated flame-retardants with nucleic acid.
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Affiliation(s)
- Yan-Qing Wang
- Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
| | - Hong-Mei Zhang
- Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China
| | - Jian Cao
- Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China
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Holmstrup M, Bouvrais H, Westh P, Wang C, Slotsbo S, Waagner D, Enggrob K, Ipsen JH. Lipophilic contaminants influence cold tolerance of invertebrates through changes in cell membrane fluidity. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9797-9803. [PMID: 25050459 DOI: 10.1021/es502221g] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Contaminants taken up by living organisms in the environment as a result of anthropogenic contamination can reduce the tolerance of natural stressors, e.g., low temperatures, but the physiological mechanisms behind these interactions of effects are poorly understood. The tolerance to low temperatures of organisms that cannot regulate their body temperature (ectotherms) depends on their ability to increase the fluidity of their cellular membranes at low temperatures. Our study shows that contaminants accumulating in lipids of organisms alter the physical state of their membranes simply by being present. Contaminants of varying chemical structures can alter the membrane fluidity in either direction and correspondingly modulate the cold tolerance of intact animals.
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Affiliation(s)
- Martin Holmstrup
- Department of Bioscience, Aarhus University , Vejlsøvej 25, DK-8600 Silkeborg, Denmark
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12
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Osimitz TG, Dourson ML, Hayes AW, Kacew S. Crystallographic analysis and mimicking of estradiol binding: interpretation and speculation. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:A91. [PMID: 24691106 PMCID: PMC3984215 DOI: 10.1289/ehp.1307987] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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13
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Løkke H, Ragas AMJ, Holmstrup M. Tools and perspectives for assessing chemical mixtures and multiple stressors. Toxicology 2012; 313:73-82. [PMID: 23238274 DOI: 10.1016/j.tox.2012.11.009] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 10/29/2012] [Accepted: 11/24/2012] [Indexed: 01/22/2023]
Abstract
The present paper summarizes the most important insights and findings of the EU NoMiracle project with a focus on (1) risk assessment of chemical mixtures, (2) combinations of chemical and natural stressors, and (3) the receptor-oriented approach in cumulative risk assessment. The project aimed at integration of methods for human and ecological risk assessment. A mechanistically based model, considering uptake and toxicity as a processes in time, has demonstrated considerable potential for predicting mixture effects in ecotoxicology, but requires the measurement of toxicity endpoints at different moments in time. Within a novel framework for risk assessment of chemical mixtures, the importance of environmental factors on toxicokinetic processes is highlighted. A new paradigm for applying personal characteristics that determine individual exposure and sensitivity in human risk assessment is suggested. The results are discussed in the light of recent developments in risk assessment of mixtures and multiple stressors.
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Affiliation(s)
- Hans Løkke
- Aarhus University, Department of Bioscience, Vejlsøvej 25, P.O. Box 314, DK-8600 Silkeborg, Denmark.
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Some commonly used brominated flame retardants cause Ca2+-ATPase inhibition, beta-amyloid peptide release and apoptosis in SH-SY5Y neuronal cells. PLoS One 2012; 7:e33059. [PMID: 22485137 PMCID: PMC3317662 DOI: 10.1371/journal.pone.0033059] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Accepted: 02/06/2012] [Indexed: 11/19/2022] Open
Abstract
Brominated flame retardants (BFRs) are chemicals commonly used to reduce the flammability of consumer products and are considered pollutants since they have become widely dispersed throughout the environment and have also been shown to bio-accumulate within animals and man. This study investigated the cytotoxicity of some of the most commonly used groups of BFRs on SH-SY5Y human neuroblastoma cells. The results showed that of the BFRs tested, hexabromocyclododecane (HBCD), tetrabromobisphenol-A (TBBPA) and decabromodiphenyl ether (DBPE), all are cytotoxic at low micromolar concentrations (LC50 being 2.7±0.7µM, 15±4µM and 28±7µM, respectively). They induced cell death, at least in part, by apoptosis through activation of caspases. They also increased intracellular [Ca2+] levels and reactive-oxygen-species within these neuronal cells. Furthermore, these BFRs also caused rapid depolarization of the mitochondria and cytochrome c release in these neuronal cells. Elevated intracellular [Ca2+] levels appear to occur through a mechanism involving microsomal Ca2+-ATPase inhibition and this maybe responsible for Ca2+-induced mitochondrial dysfunction. In addition, µM levels of these BFRs caused β-amyloid peptide (Aβ-42) processing and release from these cells with a few hours of exposure. These results therefore shows that these pollutants are both neurotoxic and amyloidogenic in-vitro.
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15
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Determination of brominated phenols in water samples by on-line coupled isotachophoresis with capillary zone electrophoresis. J Chromatogr A 2010; 1217:3446-51. [DOI: 10.1016/j.chroma.2010.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 03/03/2010] [Accepted: 03/04/2010] [Indexed: 11/18/2022]
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Legler J. New insights into the endocrine disrupting effects of brominated flame retardants. CHEMOSPHERE 2008; 73:216-22. [PMID: 18667224 DOI: 10.1016/j.chemosphere.2008.04.081] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Revised: 04/27/2008] [Accepted: 04/28/2008] [Indexed: 05/24/2023]
Abstract
The objective of this review is to provide an overview of recent studies demonstrating the endocrine disrupting (ED) effects of brominated flame retardants (BFRs), while highlighting interesting data presented at the recent international BFR workshop in Amsterdam in April, 2007. A review written in 2002 was used as a starting point and about 60 publications published since 2003 were reviewed. New insights into the in vivo effects of BFRs on thyroid hormone, estrogen and androgen pathways in both mammalian and non-mammalian models are provided, and novel (in vitro) findings on the mechanisms underlying ED effects are highlighted. Special attention is also given to reports on neurotoxicological effects at relatively low doses of BFRs, although an endocrine-related mechanism is disputable. Convincing evidence has been published showing that BFRs and importantly, BFR metabolites, have the potential to disrupt endocrine systems at multiple target sites. While some studies suggest a wide margin of safety between effect concentrations in rodent models and levels encountered in humans and the environment, other studies demonstrate that exposure to low doses relevant for humans and wildlife at critical time points in development can result in profound effects on both endocrine pathways and (neuro)development.
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Affiliation(s)
- Juliette Legler
- Institute for Environmental Studies, VU University Amsterdam, De Boelelaan 1087, Amsterdam, The Netherlands.
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Ogunbayo OA, Lai PF, Connolly TJ, Michelangeli F. Tetrabromobisphenol A (TBBPA), induces cell death in TM4 Sertoli cells by modulating Ca2+ transport proteins and causing dysregulation of Ca2+ homeostasis. Toxicol In Vitro 2008; 22:943-52. [DOI: 10.1016/j.tiv.2008.01.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2007] [Revised: 01/18/2008] [Accepted: 01/21/2008] [Indexed: 10/22/2022]
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Ogunbayo O, Michelangeli F. The widely utilized brominated flame retardant tetrabromobisphenol A (TBBPA) is a potent inhibitor of the SERCA Ca2+ pump. Biochem J 2008; 408:407-15. [PMID: 17784851 PMCID: PMC2267361 DOI: 10.1042/bj20070843] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
TBBPA (tetrabromobisphenol A) is currently the most widely used type of BFR (brominated flame retardant) employed to reduce the combustibility of a large variety of electronic and other manufactured products. Recent studies have indicated that BFRs, including TBBPA, are bio-accumulating within animal and humans. BFRs including TBBPA have also been shown to be cytotoxic and potentially endocrine-disrupting to a variety of cells in culture. Furthermore, TBBPA has specifically been shown to cause disruption of Ca2+ homoeostasis within cells, which may be the underlying cause of its cytotoxicity. In this study, we have demonstrated that TBBPA is a potent non-isoform-specific inhibitor of the SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase) (apparent K(i) 0.46-2.3 microM), thus we propose that TBBPA inhibition of SERCA contributes in some degree to Ca2+ signalling disruption. TBBPA binds directly to the SERCA without the need to partition into the phospholipid bilayer. From activity results and Ca2+-induced conformational results, it appears that the major effect of TBBPA is to decrease the SERCA affinity for Ca2+ (increasing the K(d) from approx. 1 microM to 30 microM in the presence of 10 microM TBBPA). Low concentrations of TBBPA can quench the tryptophan fluorescence of the SERCA and this quenching can be reversed by BHQ [2,5-di-(t-butyl)-1,4-hydroquinone] and 4-n-nonylphenol, but not thapsigargin, indicating that TBBPA and BHQ may be binding to similar regions in the SERCA.
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Affiliation(s)
- Oluseye A. Ogunbayo
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
| | - Francesco Michelangeli
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
- To whom correspondence should be addressed (email )
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