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de Souza Prestes A, Vargas JLS, Dos Santos MM, Druzian GT, da Rocha JT, Aschner M, Barbosa NV. EtHg is more toxic than MeHg to human peripheral blood mononuclear cells: Involvement of apoptotic, mitochondrial, oxidative and proliferative parameters. Biochim Biophys Acta Gen Subj 2023; 1867:130446. [PMID: 37619690 DOI: 10.1016/j.bbagen.2023.130446] [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] [Received: 04/10/2023] [Revised: 08/15/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023]
Abstract
BACKGROUND Methylmercury (MeHg) and ethylmercury (EtHg) are potent toxicants affecting the environment and human healthy. In this way, the present study aimed to investigate and compare the effects of MeHg and EtHg exposure on human peripheral blood mononuclear cells (PBMCs), which are critical components of the mammalian immune system. METHODS PBMCs were exposed to 2.5 μM MeHg or 2.5 μM EtHg. The number of cells and incubation times varied according to each assay. After exposures, the PBMCs were subjected to different evaluations, including cell viability, morphological aspects, cell cycle phases, indices of apoptosis and necrosis, reactive species (RS) production, and mitochondrial functionality. RESULTS PBMCs exposed to EtHg were characterized by decreased viability and size, increased granularity, RS production, and apoptotic indexes accompanied by an intensification of Sub-G1 and reduction in G0-G1 cell cycle phases. Preceding these effects, we found mitochondrial dysfunctions, namely a reduction in the electron transport system related to mitochondrial complex I. In contrast, PBMCs exposed to MeHg showed only reduced viability. By ICP-MS, we found that PBMCs treated with EtHg accumulated Hg + levels ∼1.8-fold greater than MeHg-exposed cells. CONCLUSIONS AND SIGNIFICANCE Taken together, our findings provide important insights about mercury immunotoxicity, showing that EtHg is more immunotoxic to human PBMCs than MeHg.
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Affiliation(s)
- Alessandro de Souza Prestes
- Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil.
| | - João Luis Souza Vargas
- Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Matheus Mülling Dos Santos
- Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | | | - João Teixeira da Rocha
- Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Nilda Vargas Barbosa
- Department of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil.
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Korotkov SM. Mitochondrial Oxidative Stress Is the General Reason for Apoptosis Induced by Different-Valence Heavy Metals in Cells and Mitochondria. Int J Mol Sci 2023; 24:14459. [PMID: 37833908 PMCID: PMC10572412 DOI: 10.3390/ijms241914459] [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] [Received: 08/09/2023] [Revised: 09/08/2023] [Accepted: 09/15/2023] [Indexed: 10/15/2023] Open
Abstract
This review analyzes the causes and consequences of apoptosis resulting from oxidative stress that occurs in mitochondria and cells exposed to the toxic effects of different-valence heavy metals (Ag+, Tl+, Hg2+, Cd2+, Pb2+, Al3+, Ga3+, In3+, As3+, Sb3+, Cr6+, and U6+). The problems of the relationship between the integration of these toxic metals into molecular mechanisms with the subsequent development of pathophysiological processes and the appearance of diseases caused by the accumulation of these metals in the body are also addressed in this review. Such apoptosis is characterized by a reduction in cell viability, the activation of caspase-3 and caspase-9, the expression of pro-apoptotic genes (Bax and Bcl-2), and the activation of protein kinases (ERK, JNK, p53, and p38) by mitogens. Moreover, the oxidative stress manifests as the mitochondrial permeability transition pore (MPTP) opening, mitochondrial swelling, an increase in the production of reactive oxygen species (ROS) and H2O2, lipid peroxidation, cytochrome c release, a decline in the inner mitochondrial membrane potential (ΔΨmito), a decrease in ATP synthesis, and reduced glutathione and oxygen consumption as well as cytoplasm and matrix calcium overload due to Ca2+ release from the endoplasmic reticulum (ER). The apoptosis and respiratory dysfunction induced by these metals are discussed regarding their interaction with cellular and mitochondrial thiol groups and Fe2+ metabolism disturbance. Similarities and differences in the toxic effects of Tl+ from those of other heavy metals under review are discussed. Similarities may be due to the increase in the cytoplasmic calcium concentration induced by Tl+ and these metals. One difference discussed is the failure to decrease Tl+ toxicity through metallothionein-dependent mechanisms. Another difference could be the decrease in reduced glutathione in the matrix due to the reversible oxidation of Tl+ to Tl3+ near the centers of ROS generation in the respiratory chain. The latter may explain why thallium toxicity to humans turned out to be higher than the toxicity of mercury, lead, cadmium, copper, and zinc.
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Affiliation(s)
- Sergey M Korotkov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, Thorez pr. 44, 194223 St. Petersburg, Russia
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Miao J, Feng S, Dou S, Ma Y, Yang L, Yan L, Yu P, Wu Y, Ye T, Wen B, Lu P, Li S, Guo Y. Association between mercury exposure and lung function in young adults: A prospective cohort study in Shandong, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 878:162759. [PMID: 36907407 DOI: 10.1016/j.scitotenv.2023.162759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 02/02/2023] [Accepted: 03/05/2023] [Indexed: 05/13/2023]
Abstract
BACKGROUND Mercury has been associated with many adverse health outcomes. However, limited studies have explored the association between blood mercury concentrations and lung function. OBJECTIVE To examine the association between blood mercury concentrations and lung function among young adults. METHODS We conducted a prospective cohort study among 1800 college students based on the Chinese Undergraduates Cohort in Shandong, China during August 2019 and September 2020. Lung function indicators including forced vital capacity (FVC, ml), forced expiratory volume in 1 s (FEV1, ml) and peak expiratory flow (PEF, ml) were collected with a spirometers (Chestgraph Jr. HI-101, Chest M.I., Tokyo, Japan). The blood mercury concentration was measured using inductively coupled plasma mass spectrometry. We divided participants into low (≤25 percentiles), intermediate (25-75 percentiles), and high (≥75 percentile) subgroups according to blood mercury concentrations. The multiple linear regression model was used to examine the associations between blood mercury concentrations and lung function changes. Stratification analyses by sex and fish consumption frequency were also conducted. RESULTS The results showed that each 2-fold increase in blood mercury concentrations was significantly associated with -70.75 ml [95 % confidence interval (CI): -122.35, -19.15] change in FVC, -72.68 ml (95%CI: -120.36, -25.00) in FEV1, and -158.06 ml (95%CI: -283.77, -32.35) in PEF. The effect was more pronounced among participants with high blood mercury and male participants. Participants who consumed fish more than once a week more likely to be affected by mercury. CONCLUSION Our study indicated that blood mercury was significantly associated with decreased lung function in young adults. It is necessary to implement corresponding measures to reduce the effect of mercury on the respiratory system, especially for men and people who consumed fish more than once a week.
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Affiliation(s)
- Jiaming Miao
- Binzhou Medical University, Yantai, Shandong, China
| | - Shurong Feng
- Binzhou Medical University, Yantai, Shandong, China
| | - Siqi Dou
- Binzhou Medical University, Yantai, Shandong, China
| | - Yang Ma
- Binzhou Medical University, Yantai, Shandong, China
| | - Liu Yang
- Binzhou Medical University, Yantai, Shandong, China
| | - Lailai Yan
- Department of Laboratorial Science and Technology, School of Public Health, Peking University, Beijing, China
| | - Pei Yu
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Yao Wu
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Tingting Ye
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Bo Wen
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Peng Lu
- Binzhou Medical University, Yantai, Shandong, China.
| | - Shanshan Li
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
| | - Yuming Guo
- Binzhou Medical University, Yantai, Shandong, China; Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
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de Carvalho Machado C, Dinis-Oliveira RJ. Clinical and Forensic Signs Resulting from Exposure to Heavy Metals and Other Chemical Elements of the Periodic Table. J Clin Med 2023; 12:jcm12072591. [PMID: 37048674 PMCID: PMC10095087 DOI: 10.3390/jcm12072591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/19/2023] [Accepted: 03/28/2023] [Indexed: 03/31/2023] Open
Abstract
Several heavy metals and other chemical elements are natural components of the Earth’s crust and their properties and toxicity have been recognized for thousands of years. Moreover, their use in industries presents a major source of environmental and occupational pollution. Therefore, this ubiquity in daily life may result in several potential exposures coming from natural sources (e.g., through food and water contamination), industrial processes, and commercial products, among others. The toxicity of most chemical elements of the periodic table accrues from their highly reactive nature, resulting in the formation of complexes with intracellular compounds that impair cellular pathways, leading to dysfunction, necrosis, and apoptosis. Nervous, gastrointestinal, hematopoietic, renal, and dermatological systems are the main targets. This manuscript aims to collect the clinical and forensic signs related to poisoning from heavy metals, such as thallium, lead, copper, mercury, iron, cadmium, and bismuth, as well as other chemical elements such as arsenic, selenium, and fluorine. Furthermore, their main sources of occupational and environmental exposure are highlighted in this review. The importance of rapid recognition is related to the fact that, through a high degree of suspicion, the clinician could rapidly initiate treatment even before the toxicological results are available, which can make a huge difference in these patients’ outcomes.
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Affiliation(s)
- Carolina de Carvalho Machado
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- Correspondence: (C.d.C.M.); or (R.J.D.-O.); Tel.: +351-224-157-216 (R.J.D.-O.)
| | - Ricardo Jorge Dinis-Oliveira
- Department of Public Health and Forensic Sciences, and Medical Education, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- TOXRUN—Toxicology Research Unit, University Institute of Health Sciences (IUCS), CESPU, 4585-116 Gandra, Portugal
- UCIBIO-REQUIMTE-Applied Molecular Biosciences Unit, Laboratory of Toxicology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, 4050-313 Porto, Portugal
- MTG Research and Development Lab, 4200-604 Porto, Portugal
- Correspondence: (C.d.C.M.); or (R.J.D.-O.); Tel.: +351-224-157-216 (R.J.D.-O.)
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Ahmad S, Tufail N, Parveen N, Mahmood R. Attenuation of Hg(II)-induced cellular and DNA damage in human blood cells by uric acid. Biochem Cell Biol 2021; 100:45-58. [PMID: 34653346 DOI: 10.1139/bcb-2021-0229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mercury (Hg) is a widespread environmental pollutant and toxicant which induces multiple organ damage in humans and animals. Hg toxicity is mediated by the induction of oxidative stress in target cells. We have used uric acid (UA), a potent antioxidant found in biological fluids, to protect human red blood cells (RBC) and lymphocytes against Hg-mediated cell, organelle and genotoxicity. RBC were incubated with HgCl2, an Hg(II) compound, either alone or in presence of UA. Incubation of RBC with only HgCl2 increased production of nitrogen and oxygen radical species, enhanced methemoglobin levels, heme degradation, free ferrous iron, oxidation of proteins and membrane lipids and reduced antioxidant capacity of cells. UA enhanced the antioxidant capacity of RBC and restored metabolic, plasma membrane-bound and antioxidant enzyme activities. Scanning electron microscopy showed that UA prevented HgCl2-mediated morphological changes in RBC. HgCl2 dissipated the mitochondrial membrane potential and increased lysosomal membrane damage in lymphocytes, but UA pre-treatment attenuated these effects. Genotoxicity analysis by comet assay showed that UA protected lymphocyte DNA from HgCl2-induced damage. Importantly, UA itself did not exhibit any deleterious effects in either RBC or lymphocytes. Thus, UA protects human blood cells from Hg(II)-mediated oxidative damage reducing the harmful effects of this extremely toxic metal. We suggest that UA performs a similar protective role in the plasma against heavy metal toxicity.
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Affiliation(s)
- Shahbaz Ahmad
- Aligarh Muslim University Faculty of Life Sciences, 154014, Aligarh, Uttar Pradesh, India;
| | - Neda Tufail
- Aligarh Muslim University Faculty of Life Sciences, 154014, Aligarh, Uttar Pradesh, India;
| | - Nazia Parveen
- Aligarh Muslim University Faculty of Life Sciences, 154014, Aligarh, Uttar Pradesh, India;
| | - Riaz Mahmood
- Aligarh Muslim University, Department of Biochemistry, Department of Biochemistry, Faculty of Life Sciences, AMU, Aligarh, Aligarh, Uttar Pradesh, India, 202002;
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Yuan L, Shi X, Tang BZ, Wang WX. Real-time in vitro monitoring of the subcellular toxicity of inorganic Hg and methylmercury in zebrafish cells. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 236:105859. [PMID: 34004410 DOI: 10.1016/j.aquatox.2021.105859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 04/19/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
Mercury (Hg) is a prominent environmental contaminant and can cause various subcellular effects. Elucidating the different subcellular toxicities of inorganic Hg (Hg2+) and methylmercury (MeHg) is critical for understanding their overall cytotoxicity. In this study, we employed aggregation-induced emission (AIE) probes to investigate the toxicity of Hg at the subcellular level using an aquatic embryonic zebrafish fibroblast cell line ZF4 as a model. The dynamic monitoring of lysosomal pH and the mapping of pH distribution during Hg2+ or MeHg exposure were successfully realized for the first time. We found that both Hg2+ and MeHg decreased the mean lysosomal pH, but with contrasting effects and mechanisms. Hg2+ had a greater impact on lysosomal pH than MeHg at a similar intracellular concentration. In addition, Hg2+ in comparison to MeHg exposure led to an increased number of lysosomes, probably because of their different effects on autophagy. We further showed that MeHg (200 nM) exposure had an inverse effect on mitochondrial respiratory function. A high dose (1000 nM) of Hg2+ increased the amount of intracellular lipid droplets by 13%, indicating that lipid droplets may potentially play a role in Hg2+detoxification. Our study suggested that, compared with other parameters, lysosome pH was most sensitive to Hg2+ and MeHg. Therefore, lysosomal pH can be used as a potential biomarker to assess the cellular toxicity of Hg in vitro.
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Affiliation(s)
- Liuliang Yuan
- Division of Life Science, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong, China; School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China
| | - Xiujuan Shi
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, HKUST, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, HKUST, Clear Water Bay, Kowloon, Hong Kong, China
| | - Wen-Xiong Wang
- School of Energy and Environment and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China; Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen518057, China.
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7
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Effects of foetal and breastfeeding exposure to methylmercury (MeHg) and retinol palmitate (Vitamin A) in rats: Redox parameters and susceptibility to DNA damage in liver. Mutat Res 2020; 858-860:503239. [PMID: 33198929 DOI: 10.1016/j.mrgentox.2020.503239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 08/01/2020] [Accepted: 08/14/2020] [Indexed: 01/01/2023]
Abstract
Methylmercury (MeHg) is known to be a chemical that poses a risk to public health. Exposure to MeHg and vitamin A (VitA) occurs through the ingestion of fish, present in the diet of most pregnant women. The absorption of these elements generates oxidative stress and can generate adaptations for future stressful events. Here, we assessed how exposure to VitA and/or MeHg during the fetal and breastfeeding period modulates the toxicity of MeHg reexposure in adulthood. We focus on redox systems and repairing DNA damage. Male rats (n = 50), were divided into 5 groups. Control received mineral oil; The VitA group received VitA during pregnancy, during breastfeeding and was exposed to MeHg in adulthood; VitA + MeHg received VitA and MeHg during pregnancy and breastfeeding and was exposed to MeHg in adulthood. The single exposure group (SE) was exposed to MeHg only in adulthood; and the MeHg group was pre-exposed to MeHg during pregnancy and breastfeeding and re-exposed to MeHg in adulthood. After treating the animals, we evaluated the redox status and the level of DNA damage in all rats. The results revealed that MeHg significantly decreased the activity of glutathione peroxidase (GPx) and sulfhydryl levels and increased the activity of superoxide dismutase (SOD), glutathione transferase, glutathione and carbonyl in all exposed groups. These results suggest that the second exposure to MeHg directly altered the effects of oxidation and that there were no specific effects associated with exposure during the fetal and breastfeeding periods. In addition, our findings indicate that MDA levels increased in MeHg and SE levels and no differences in MDA levels were observed between the VitA and MeHg + VitA groups. We also observed that animals pretreated exclusively with VitA showed residual damage similar to the control's DNA, while the other groups showed statistically higher levels of damage. In conclusion, low doses of MeHg and VitA during fetal and breastfeeding periods were unable to condition an adaptive response to subsequent exposure to MeHg in adulthood in relation to the observed levels of oxidative damage assessed after exposure.
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8
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Malik C, Ghosh S. Regulation of Single-Channel Conductance of Voltage-Dependent Anion Channel by Mercuric Chloride in a Planar Lipid Bilayer. J Membr Biol 2020; 253:357-371. [PMID: 32748041 DOI: 10.1007/s00232-020-00134-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/24/2020] [Indexed: 11/26/2022]
Abstract
The existence of mercury in various forms, e.g., elemental, organic, and inorganic has been known for decades. In any of these forms, it is poisonous to metabolism. In this, an investigation about the effect of the inorganic form of mercury, i.e., mercuric chloride (HgCl2) to the mitochondrial voltage-dependent anion channel (VDAC), has been done after isolation from the cardiac and brain tissues of Wistar rats. In vitro electrophysiology experiments were performed in Cardiolipin planar lipid bilayer membrane (BLM) to study the change in the conductance, selectivity, and gating charge of VDAC post HgCl2 treatment. A reduction in mean conductance of VDAC from 4.3 ± 0.18 to 1.66 ± 0.11 nS was observed. Further, the Gating charge calculated before (± 3.5) and after HgCl2 treatment (± 2.3) showed significant difference. Later, VDAC's behavior was studied at different concentrations of HgCl2 ranging from 0.1 μM to 1 mM. The Inhibitory concentration (IC50) was calculated from the linear regression plot. The IC50 was found to be 488.1 μM. In the asymmetrical HgCl2 (5:1), a permeability ratio of cation to anion was found to be 4.2. It is interpreted that VDAC functioning is affected due to the application of 4 mM HgCl2 and a reduction in the conductance, gating charge, and permeability of VDAC was detected. The results provide clues to HgCl2-induced toxicity mediated through VDAC in the Cardiolipin BLM.
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Affiliation(s)
- Chetan Malik
- Department of Biophysics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India
| | - Subhendu Ghosh
- Department of Biophysics, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021, India.
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9
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Oliveira LF, Rodrigues LD, Cardillo GM, Nejm MB, Guimarães-Marques M, Reyes-Garcia SZ, Zuqui K, Vassallo DV, Fiorini AC, Scorza CA, Scorza FA. Deleterious effects of chronic mercury exposure on in vitro LTP, memory process, and oxidative stress. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:7559-7569. [PMID: 31885058 DOI: 10.1007/s11356-019-06625-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 09/25/2019] [Indexed: 05/21/2023]
Abstract
Heavy metal contamination in aquatic environments plays an important role in the exposure of humans to these toxicants. Among these pollutants, mercury (Hg) is one main concern due to its high neurotoxicity and environmental persistence. Even in low concentrations, Hg bioaccumulation is a major threat to human health, with higher impact on populations whose diet has fish as chief consumption. Mercury compounds have high affinity for neuronal receptors and proteins, which gives Hg its cumulative feature and have the ability to cross cell membranes and blood-brain barrier to show their neurotoxicity. Intoxication with Hg increases levels of reactive oxygen species (ROS), thus depleting faster the resource of antioxidant proteins. To evaluate Hg-induced hippocampal ROS production, synaptic plasticity, anxiety, and memory, a total of 11 male Wistar rats were exposed to HgCl2 (Hg30 group) to produce a residual concentration of 8 ng/mL at the end of 30 days. Behavioral tests (plus-maze discriminative avoidance task), in vitro electrophysiology, and ROS assays were performed. Western blot assay showed decreased levels of antioxidant proteins GPx and SOD in Hg30 group. Increased ROS production was observed in the CA1 and CA3 regions in the Hg-exposed group. Plus-maze task detected long-term memory impairment in Hg30 group, linked to poorer in vitro long-term potentiation as compared to control group. Hg intoxication also promoted higher anxiety-like behavior in the exposed animals. In conclusion, our data suggests that low doses of HgCl2 resulted in impaired long-term memory and unbalance between decreased antioxidant protein expression and increased ROS production in the hippocampus.
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Affiliation(s)
- Leandro F Oliveira
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
| | - Laís D Rodrigues
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
| | | | - Mariana B Nejm
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
| | | | - Selvin Z Reyes-Garcia
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
- Department of Morphological Science, Faculty of Medical Sciences, National Autonomous University of Honduras, San Pedro Sula, Honduras
| | - Karolini Zuqui
- Department of Physiological Sciences, Federal University of Espírito Santo, Espírito Santo, Brazil
| | - Dalton V Vassallo
- Department of Physiological Sciences, Federal University of Espírito Santo, Espírito Santo, Brazil
| | - Ana C Fiorini
- Department of Department of Speech-Language Pathology, Audiology, UNIFESP/EPM, Brazil and Pontifical Catholic University, São Paulo, Brazil
| | - Carla A Scorza
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil
| | - Fulvio A Scorza
- Department of Neurology and Neurosurgery, UNIFESP/EPM, São Paulo, Brazil.
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Khan MF, Wang H. Environmental Exposures and Autoimmune Diseases: Contribution of Gut Microbiome. Front Immunol 2020; 10:3094. [PMID: 31998327 PMCID: PMC6970196 DOI: 10.3389/fimmu.2019.03094] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
Environmental agents have been gaining more attention in recent years for their role in the pathogenesis of autoimmune diseases (ADs). Increasing evidence has linked environmental exposures, including trichloroethene (TCE), silica, mercury, pristane, pesticides, and smoking to higher risk for ADs. However, potential mechanisms by which these environmental agents contribute to the disease pathogenesis remains largely unknown. Dysbiosis of the gut microbiome is another important environmental factor that has been linked to the onset of different ADs. Altered microbiota composition is associated with impaired intestinal barrier function and dysregulation of mucosal immune system, but it is unclear if gut dysbiosis is a causal factor or an outcome of ADs. In this review article, we first describe the recent epidemiological and mechanistic evidences linking environmental/occupational exposures with various ADs (especially SLE). Secondly, we discuss how changes in the gut microbiome composition (dysbiosis) could contribute to the disease pathogenesis, especially in response to exposure to environmental chemicals.
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Affiliation(s)
- M. Firoze Khan
- Department of Pathology, University of Texas Medical Branch at Galveston, Galveston, TX, United States
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Chen N, Lin M, Liu N, Wang S, Xiao X. Methylmercury-induced testis damage is associated with activation of oxidative stress and germ cell autophagy. J Inorg Biochem 2019; 190:67-74. [DOI: 10.1016/j.jinorgbio.2018.10.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/15/2018] [Accepted: 10/16/2018] [Indexed: 12/22/2022]
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12
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Espitia-Pérez P, Albino SM, da Rosa HT, Silveira AK, Espitia-Pérez L, Brango H, Moraes DP, Hermann PRS, Mingori M, Barreto F, Kunzler A, Gelain DP, Schnorr CE, Moreira JCF. Effects of methylmercury and retinol palmitate co-administration in rats during pregnancy and breastfeeding: Metabolic and redox parameters in dams and their offspring. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2018; 162:603-615. [PMID: 30031321 DOI: 10.1016/j.ecoenv.2018.06.093] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/28/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
Ubiquitous low-dose methylmercury (MeHg) exposure through an increased fish consumption represents a global public health problem, especially among pregnant women. A plethora of micronutrients presented in fish affects MeHg uptake/distribution, but limited data is available. Vitamin A (VitA), another fish micronutrient is used in nutritional supplementation, especially during pregnancy. However, there is no information about the health effects arising from their combined exposure. Therefore, the present study aimed to examine the effects of both MeHg and retinyl palmitate administered on pregnant and lactating rats in metabolic and redox parameters from dams and their offspring. Thirty Wistar female rats were orally supplemented with MeHg (0,5 mg/kg/day) and retinyl palmitate (7500 µg RAE/kg/day) via gavage, either individually or in combination from the gestational day 0 to weaning. For dams (150 days old) and their offspring (31 days old), glycogen accumulation (hepatic and cardiac) and retinoid contents (plasma and liver) were analyzed. Hg deposition in liver tissue was quantified. Redox parameters (liver, kidney, and heart) were evaluated for both animals. Cytogenetic damage was analyzed with micronucleus test. Our results showed no general toxic or metabolic alterations in dams and their offspring by MeHg-VitA co-administration during pregnancy and lactation. However, increased lipoperoxidation in maternal liver and a disrupted pro-oxidant response in the heart of male pups was encountered, with apparently no particular effects in the antioxidant response in female offspring. GST activity in dam kidney was altered leading to possible redox disruption of this tissue with no alterations in offspring. Finally, the genomic damage was exacerbated in both male and female pups. In conclusion, low-dose MeHg exposure and retinyl palmitate supplementation during gestation and lactation produced a potentiated pro-oxidant effect, which was tissue-specific. Although this is a pre-clinical approach, we recommend precaution for pregnant women regarding food consumption, and we encourage more epidemiological studies to assess possible modulations effects of MeHg-VitA co-administration at safe or inadvertently used doses in humans, which may be related to specific pathologies in mothers and their children.
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Affiliation(s)
- Pedro Espitia-Pérez
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
| | - Suelen Marin Albino
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Helen Tais da Rosa
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Alexandre Kleber Silveira
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Lyda Espitia-Pérez
- Facultad de Ciencias de la Salud, Laboratorio de Investigación Biomédica y Biología Molecular, Universidad del Sinú, Calle 38 Carrera 1W, Barrio Juan XXIII, Montería, Córdoba, Colombia
| | - Hugo Brango
- Instituto de Matemática e Estatística, Universidade de São Paulo, São Paulo, Brazil
| | - Diogo Pompéu Moraes
- Instituto de Química, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 9500, CEP 91501-970 Porto Alegre, Rio Grande do Sul, Brazil
| | - Paolla Rissi Silva Hermann
- Instituto de Química, Universidade Federal do Rio Grande do Sul, Avenida Bento Gonçalves 9500, CEP 91501-970 Porto Alegre, Rio Grande do Sul, Brazil
| | - Moara Mingori
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Fabiano Barreto
- Laboratório de Análise de Resíduos de Pesticidas e Medicamentos Veterinários (RPM), Laboratório Nacional Agropecuário RS, Estrada da Ponta Grossa 3036, CEP: 91780-580 Porto Alegre, Rio Grande do Sul, Brazil
| | - Alice Kunzler
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Daniel Pens Gelain
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil
| | - Carlos Eduardo Schnorr
- Departamento de Civil y Ambiental, Programa de Ingeniería Ambiental, Universidad de la Costa, Calle 58 #55- 66, Barranquilla, Atlántico, Colombia
| | - José Cláudio Fonseca Moreira
- Centro de Estudos em Estresse Oxidativo, Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Anexo Depto. Bioquímica, Lab 32, CEP 90035-003 Porto Alegre, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
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Cao J, Xu X, Zhang Y, Zeng Z, Hylkema MN, Huo X. Increased memory T cell populations in Pb-exposed children from an e-waste-recycling area. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 616-617:988-995. [PMID: 29096958 DOI: 10.1016/j.scitotenv.2017.10.220] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Revised: 10/21/2017] [Accepted: 10/21/2017] [Indexed: 02/05/2023]
Abstract
Chronic exposure to heavy metals could affect cell-mediated immunity. The aim of this study was to explore the status of memory T cell development in preschool children from an e-waste recycling area. Blood lead (Pb) levels, peripheral T cell subpopulations, and serum levels of cytokines (IL-2/IL-7/IL-15), relevant to generation and homeostasis of memory T cells were evaluated in preschool children from Guiyu (e-waste-exposed group) and Haojiang (reference group). The correlations between blood Pb levels and percentages of memory T cell subpopulations were also evaluated. Guiyu children had higher blood Pb levels and increased percentages of CD4+ central memory T cells and CD8+ central memory T cells than in the Haojiang group. Moreover, blood Pb levels were positively associated with the percentages of CD4+ central memory T cells. In contrast, Pb exposure contributed marginally in the change of percentages of CD8+ central memory T cells in children. There was no significant difference in the serum cytokine levels between the e-waste-exposed and reference children. Taken together, preschool children from an e-waste recycling area suffer from relatively higher levels of Pb exposure, which might facilitate the development of CD4+ central memory T cells in these children.
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Affiliation(s)
- Junjun Cao
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands; GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands
| | - Xijin Xu
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Cell Biology and Genetics, Shantou University Medical College, Shantou 515041, Guangdong, China.
| | - Yu Zhang
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands; GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands
| | - Zhijun Zeng
- Laboratory of Environmental Medicine and Developmental Toxicology, Shantou University Medical College, Shantou 515041, Guangdong, China; Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands; GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands
| | - Machteld N Hylkema
- Department of Pathology and Medical Biology, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands; GRIAC Research Institute, University of Groningen, University Medical Center Groningen, Groningen 9713, GZ, The Netherlands
| | - Xia Huo
- School of Environment, Guangzhou Key Laboratory of Environmental Exposure and Health, Guangdong Key Laboratory of Environmental Pollution and Health, Jinan University, Guangzhou 510632, Guangdong, China.
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14
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Affiliation(s)
- Seong Su Moon
- Department of Internal Medicine, Dongguk University College of Medicine, Gyeongju, Korea.
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15
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Bridges CC, Zalups RK. The aging kidney and the nephrotoxic effects of mercury. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2017; 20:55-80. [PMID: 28339347 PMCID: PMC6088787 DOI: 10.1080/10937404.2016.1243501] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Owing to advances in modern medicine, life expectancies are lengthening and leading to an increase in the population of older individuals. The aging process leads to significant alterations in many organ systems, with the kidney being particularly susceptible to age-related changes. Within the kidney, aging leads to ultrastructural changes such as glomerular and tubular hypertrophy, glomerulosclerosis, and tubulointerstitial fibrosis, which may compromise renal plasma flow (RPF) and glomerular filtration rate (GFR). These alterations may reduce the functional reserve of the kidneys, making them more susceptible to pathological events when challenged or stressed, such as following exposure to nephrotoxicants. An important and prevalent environmental toxicant that induces nephrotoxic effects is mercury (Hg). Since exposure of normal kidneys to mercuric ions might induce glomerular and tubular injury, aged kidneys, which may not be functioning at full capacity, may be more sensitive to the effects of Hg than normal kidneys. Age-related renal changes and the effects of Hg in the kidney have been characterized separately. However, little is known regarding the influence of nephrotoxicants, such as Hg, on aged kidneys. The purpose of this review was to summarize known findings related to exposure of aged and diseased kidneys to the environmentally relevant nephrotoxicant Hg.
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Affiliation(s)
- Christy C Bridges
- a Mercer University School of Medicine , Division of Basic Medical Sciences , Macon , Georgia , USA
| | - Rudolfs K Zalups
- a Mercer University School of Medicine , Division of Basic Medical Sciences , Macon , Georgia , USA
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16
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Genchi G, Sinicropi MS, Carocci A, Lauria G, Catalano A. Mercury Exposure and Heart Diseases. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14010074. [PMID: 28085104 PMCID: PMC5295325 DOI: 10.3390/ijerph14010074] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 12/13/2016] [Accepted: 12/30/2016] [Indexed: 01/05/2023]
Abstract
Environmental contamination has exposed humans to various metal agents, including mercury. It has been determined that mercury is not only harmful to the health of vulnerable populations such as pregnant women and children, but is also toxic to ordinary adults in various ways. For many years, mercury was used in a wide variety of human activities. Nowadays, the exposure to this metal from both natural and artificial sources is significantly increasing. Recent studies suggest that chronic exposure, even to low concentration levels of mercury, can cause cardiovascular, reproductive, and developmental toxicity, neurotoxicity, nephrotoxicity, immunotoxicity, and carcinogenicity. Possible biological effects of mercury, including the relationship between mercury toxicity and diseases of the cardiovascular system, such as hypertension, coronary heart disease, and myocardial infarction, are being studied. As heart rhythm and function are under autonomic nervous system control, it has been hypothesized that the neurotoxic effects of mercury might also impact cardiac autonomic function. Mercury exposure could have a long-lasting effect on cardiac parasympathetic activity and some evidence has shown that mercury exposure might affect heart rate variability, particularly early exposures in children. The mechanism by which mercury produces toxic effects on the cardiovascular system is not fully elucidated, but this mechanism is believed to involve an increase in oxidative stress. The exposure to mercury increases the production of free radicals, potentially because of the role of mercury in the Fenton reaction and a reduction in the activity of antioxidant enzymes, such as glutathione peroxidase. In this review we report an overview on the toxicity of mercury and focus our attention on the toxic effects on the cardiovascular system.
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Affiliation(s)
- Giuseppe Genchi
- Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, 87036 Arcavacata di Rende (Cosenza), Italy.
| | - Maria Stefania Sinicropi
- Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, 87036 Arcavacata di Rende (Cosenza), Italy.
| | - Alessia Carocci
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro", 70125 Bari, Italy.
| | - Graziantonio Lauria
- Dipartimento di Farmacia e Scienze della Salute e della Nutrizione, Università della Calabria, 87036 Arcavacata di Rende (Cosenza), Italy.
| | - Alessia Catalano
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari "A. Moro", 70125 Bari, Italy.
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Kumagai Y, Abiko Y. Environmental Electrophiles: Protein Adducts, Modulation of Redox Signaling, and Interaction with Persulfides/Polysulfides. Chem Res Toxicol 2016; 30:203-219. [DOI: 10.1021/acs.chemrestox.6b00326] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Yoshito Kumagai
- Environmental Biology Section, Faculty
of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yumi Abiko
- Environmental Biology Section, Faculty
of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
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Saikia J, Narzary B, Roy S, Bordoloi M, Saikia P, Saikia BK. Nanominerals, fullerene aggregates, and hazardous elements in coal and coal combustion-generated aerosols: An environmental and toxicological assessment. CHEMOSPHERE 2016; 164:84-91. [PMID: 27580261 DOI: 10.1016/j.chemosphere.2016.08.086] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2016] [Revised: 08/16/2016] [Accepted: 08/17/2016] [Indexed: 06/06/2023]
Abstract
Studies on coal-derived nanoparticles as well as nano-minerals are important in the context of the human health and the environment. The coal combustion-generated aerosols also affect human health and environmental quality aspects in any coal-fired station. In this study, the feed coals and their combustion-generated aerosols from coal-fired boilers of two tea industry facilities were investigated for the presence of nanoparticles/nano minerals, fullerene aggregates, and potentially hazardous elements (PHEs). The samples were characterized by using X-ray diffraction (XRD), Time-of-flight secondary ion mass spectroscopy (TOF-SIMS), High resolution-transmission electron microscopy/energy dispersive spectroscopy (HR-TEM/EDS) and Ultra Violet-visible spectroscopy (UV-Vis) to know their extent of environmental risks to the human health when present in coals and aerosols. The feed coals contain mainly clay minerals, whilst glass fragments, spinel, quartz, and other minerals occur in lesser quantities. The PM samples contain potentially hazardous elements (PHEs) like As, Pb, Cd and Hg. Enrichment factor of the trace elements in particulate matters (PMs) was calculated to determine their sources. The aerosol samples were also found to contain nanomaterials and ultrafine particles. The fullerene aggregates along with potentially hazardous elements were also detected in the aerosol samples. The cytotoxicity studies on the coal combustion-generated PM samples show their potential risk to the human health. This detailed investigation on the inter-relationship between the feed coals and their aerosol chemistry will be useful for understanding the extent of environmental hazards and related human health risk.
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Affiliation(s)
- Jyotilima Saikia
- Polymer Petroleum and Coal Chemistry Group, Materials Sciences & Technology Division, CSIR-North East Institute of Science and Technology, Jorhat, 785006, India; Academy of Scientific and Innovative Research, CSIR-NEIST Campus, Jorhat, 785006, India
| | - Bardwi Narzary
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science and Technology, Jorhat, 785006, India
| | - Sonali Roy
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science and Technology, Jorhat, 785006, India
| | - Manobjyoti Bordoloi
- Natural Product Chemistry Group, Chemical Sciences & Technology Division, CSIR-North East Institute of Science and Technology, Jorhat, 785006, India
| | - Prasenjit Saikia
- Polymer Petroleum and Coal Chemistry Group, Materials Sciences & Technology Division, CSIR-North East Institute of Science and Technology, Jorhat, 785006, India
| | - Binoy K Saikia
- Polymer Petroleum and Coal Chemistry Group, Materials Sciences & Technology Division, CSIR-North East Institute of Science and Technology, Jorhat, 785006, India; Academy of Scientific and Innovative Research, CSIR-NEIST Campus, Jorhat, 785006, India.
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Reyes ES, Aristizabal Henao JJ, Kornobis KM, Hanning RM, Majowicz SE, Liber K, Stark KD, Low G, Swanson HK, Laird BD. Associations between omega-3 fatty acids, selenium content, and mercury levels in wild-harvested fish from the Dehcho Region, Northwest Territories, Canada. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2016; 80:18-31. [PMID: 27905863 DOI: 10.1080/15287394.2016.1230916] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Accepted: 08/28/2016] [Indexed: 06/06/2023]
Abstract
To better understand the risks and benefits of eating wild-harvested fish from the Northwest Territories, Canada, levels of total mercury (HgT) and selenium (Se) and composition of omega-3 fatty acid (n-3 FA) were measured in muscle tissue of fish harvested from lakes in the Dehcho Region, Northwest Territories, Canada. Average HgT levels ranged from 0.057 mg/kg (cisco) to 0.551 mg/kg (northern pike), while average n-3 FA concentrations ranged from 101 mg/100 g (burbot) to 1,689 mg/100 g (lake trout). In contrast to HgT and n-3 FA, mean Se concentrations were relatively similar among species. Consequently, species such as lake whitefish, cisco, and longnose sucker displayed the highest nutrient levels relative to HgT content. Levels of HgT tended to increase with fish size, while Se and n-3 FA levels were typically not associated with fork length or fish weight. Interestingly, HgT concentration was occasionally inversely related to tissue nutrient content. Significant negative correlations were observed between Hg and n-3 FA for lake trout, northern pike, and walleye. There were also significant negative correlations between Hg and Se noted for lake whitefish, cisco, and northern pike. Samples with the highest nutritional content displayed, on occasion, lower levels of HgT. This study provides valuable information for the design of probabilistic models capable of refining public health messaging related to minimizing Hg risks and maximizing nutrient levels in wild-harvested fish in the Canadian subarctic.
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Affiliation(s)
- Ellen S Reyes
- a School of Public Health and Health Systems, University of Waterloo , Waterloo , Canada
| | | | | | - Rhona M Hanning
- a School of Public Health and Health Systems, University of Waterloo , Waterloo , Canada
| | - Shannon E Majowicz
- a School of Public Health and Health Systems, University of Waterloo , Waterloo , Canada
| | - Karsten Liber
- d Toxicology Centre, University of Saskatchewan , Saskatoon , Saskatchewan , Canada
| | - Ken D Stark
- b Department of Kinesiology , University of Waterloo , Waterloo , Canada
| | - George Low
- e Dehcho Aboriginal Aquatic Resources and Ocean Management , Hay River, Northwest Territories , Canada
| | - Heidi K Swanson
- c Department of Biology , University of Waterloo , Waterloo , Canada
| | - Brian D Laird
- a School of Public Health and Health Systems, University of Waterloo , Waterloo , Canada
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Bellum S, Thuett KA, Grajeda R, Abbott LC. Coordination Deficits Induced in Young Adult Mice Treated with Methylmercury. Int J Toxicol 2016; 26:115-21. [PMID: 17454251 DOI: 10.1080/10915810701225190] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Male and female C57BL/6J mice starting at postnatal (P) day 34 were exposed orally to five divided doses totaling 1.0 or 5.0 mg/kg of methylmercury (MeHg; given as methylmercuric chloride) or sterile deionized water in moistened rodent chow. After a 5-day waiting period, control and MeHg-treated mice were subjected to a standard battery of behavior tests for balance and motor coordination. Latency to falling on the accelerating rota-rod was significantly decreased in 5.0 mg/kg MeHg-exposed mice when compared to control mice. In the open field, horizontal exploration with respect to total distance traveled during the first 5 min on the first test day was significantly reduced in 1.0 mg/kg MeHg-exposed mice when compared to control mice. Rearing activity was not affected by MeHg treatment. In the footprint analysis, angle of foot placement measured in 1.0 mg/kg MeHg-treated mice was significantly greater compared to control mice. Base stance and stride length were unaffected by MeHg treatment. On the vertical pole test, 10 mice from each treatment group fell off the pole during the time the pole was shifted from a horizontal position to a vertical position, whereas none of the control mice fell. These results indicate that short-term, low to moderate doses of MeHg in young adult mice can be detrimental to motor coordination and balance.
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Affiliation(s)
- Sairam Bellum
- Safety Assessment, Merck Research Laboratories, West Point, Pennsylvania, USA
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21
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Methylmercury, an environmental electrophile capable of activation and disruption of the Akt/CREB/Bcl-2 signal transduction pathway in SH-SY5Y cells. Sci Rep 2016; 6:28944. [PMID: 27357941 PMCID: PMC4928048 DOI: 10.1038/srep28944] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/06/2016] [Indexed: 11/24/2022] Open
Abstract
Methylmercury (MeHg) modifies cellular proteins via their thiol groups in a process referred to as “S-mercuration”, potentially resulting in modulation of the cellular signal transduction pathway. We examined whether low-dose MeHg could affect Akt signaling involved in cell survival. Exposure of human neuroblastoma SH-SY5Y cells of up to 2 μM MeHg phosphorylated Akt and its downstream signal molecule CREB, presumably due to inactivation of PTEN through S-mercuration. As a result, the anti-apoptotic protein Bcl-2 was up-regulated by MeHg. The activation of Akt/CREB/Bcl-2 signaling mediated by MeHg was, at least in part, linked to cellular defence because either pretreatment with wortmannin to block PI3K/Akt signaling or knockdown of Bcl-2 enhanced MeHg-mediated cytotoxicity. In contrast, increasing concentrations of MeHg disrupted Akt/CREB/Bcl-2 signaling. This phenomenon was attributed to S-mercuration of CREB through Cys286 rather than Akt. These results suggest that although MeHg is an apoptosis-inducing toxicant, this environmental electrophile is able to activate the cell survival signal transduction pathway at lower concentrations prior to apoptotic cell death.
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Abstract
BACKGROUND Mercury (Hg) has been reported to have adverse effects on the immune system. However, the association between Hg exposure and asthma remains unclear. We hypothesized that blood Hg concentrations are associated with asthma and immune system blood profile changes in school-age children. METHODS Between 2005 and 2010, we evaluated 4,350 Korean children at 7-8 years of age with no previous asthma diagnosis. Follow-up surveys were conducted twice, each 2 years apart, until 11-12 years of age. For every survey, we evaluated asthma through a questionnaire and blood profile. We analyzed the association of Hg concentration with asthma by logistic and Cox regression models and the association with blood profile by generalized additive and linear mixed models. RESULTS Blood Hg concentrations at 7-8 years of age were associated with an increased risk of asthma (odds ratio [OR] = 1.3; 95% confidence interval [CI] = 1.0, 1.6) at ages up to 11-12 years (n = 191). Hg concentration was also associated with wheezing (OR = 1.2; 95% CI = 1.0, 1.3), asthma medication use (OR = 1.4; 95% CI = 0.97, 2.0), and airway hyperresponsiveness (OR = 1.2; 95% CI = 1.0, 1.3). Further adjustment for fish consumption did not change the results appreciably. CONCLUSIONS Low-level Hg exposure was associated with asthma and blood profile changes in school-age children.
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Gribble MO, Karimi R, Feingold BJ, Nyland JF, O'Hara TM, Gladyshev MI, Chen CY. Mercury, selenium and fish oils in marine food webs and implications for human health. JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM. MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM 2016; 96:43-59. [PMID: 26834292 PMCID: PMC4720108 DOI: 10.1017/s0025315415001356] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 07/23/2015] [Indexed: 05/04/2023]
Abstract
Humans who eat fish are exposed to mixtures of healthful nutrients and harmful contaminants that are influenced by environmental and ecological factors. Marine fisheries are composed of a multitude of species with varying life histories, and harvested in oceans, coastal waters and estuaries where environmental and ecological conditions determine fish exposure to both nutrients and contaminants. Many of these nutrients and contaminants are thought to influence similar health outcomes (i.e., neurological, cardiovascular, immunological systems). Therefore, our understanding of the risks and benefits of consuming seafood require balanced assessments of contaminants and nutrients found in fish and shellfish. In this paper, we review some of the reported benefits of fish consumption with a focus on the potential hazards of mercury exposure, and compare the environmental variability of fish oils, selenium and mercury in fish. A major scientific gap identified is that fish tissue concentrations are rarely measured for both contaminants and nutrients across a range of species and geographic regions. Interpreting the implications of seafood for human health will require a better understanding of these multiple exposures, particularly as environmental conditions in the oceans change.
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Affiliation(s)
- Matthew O. Gribble
- Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, CA, USA
| | - Roxanne Karimi
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Beth J. Feingold
- Department of Environmental Health Sciences, University at Albany School of Public Health, State University of New York, Rensselaer, NY, USA
| | - Jennifer F. Nyland
- Department of Pathology, Microbiology and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Todd M. O'Hara
- Department of Veterinary Medicine, College of Natural Science and Mathematics, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Michail I. Gladyshev
- Institute of Biophysics of Siberian Branch of Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, Russia
- Siberian Federal University, Krasnoyarsk, Russia
| | - Celia Y. Chen
- Department of Biological Sciences – Dartmouth College, Hanover, NH, USA
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Afridi HI, Kazi TG, Talpur FN, Kazi A, Arain SS, Arain SA, Brahman KD, Panhwar AH, Khan N, Arain MS, Ali J. Assessment of selenium and mercury in biological samples of normal and night blindness children of age groups (3-7) and (8-12) years. ENVIRONMENTAL MONITORING AND ASSESSMENT 2015; 187:82. [PMID: 25655123 DOI: 10.1007/s10661-014-4201-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 12/01/2014] [Indexed: 06/04/2023]
Abstract
The causes of night blindness in children are multifactorial and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological sample composition. This study was designed to compare the levels of selenium (Se) and mercury (Hg) in scalp hair, blood, and urine of night blindness children age ranged (3-7) and (8-12) years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment for the determination of Se and Hg in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The Se and Hg in biological samples were measured by electrothermal atomic absorption spectrometry and cold vapor atomic absorption spectrometry, prior to microwave acid digestion, respectively. The concentration of Se was decreased in scalp hair and blood samples of male and female night blindness children while Hg was higher in all biological samples as compared to referent subjects. The Se concentration was inversely associated with the risk of night blindness in both genders. These results add to an increasing body of evidence that Se is a protecting element for night blindness. These data present guidance to clinicians and other professional investigating deficiency of essential micronutrients in biological samples (scalp hair and blood) of night blindness children.
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Affiliation(s)
- Hassan Imran Afridi
- National Center of Excellence in Analytical Chemistry, University of Sindh, 76080, Jamshoro, Pakistan,
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Choi B, Yeum KJ, Park SJ, Kim KN, Joo NS. Elevated serum ferritin and mercury concentrations are associated with hypertension; analysis of the fourth and fifth Korea national health and nutrition examination survey (KNHANES IV-2, 3, 2008-2009 and V-1, 2010). ENVIRONMENTAL TOXICOLOGY 2015; 30:101-108. [PMID: 23929718 DOI: 10.1002/tox.21899] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 07/11/2013] [Indexed: 06/02/2023]
Abstract
The impact of simultaneously elevated serum ferritin and mercury concentrations on hypertension in the general population is not known. To determine the association of serum ferritin and mercury concentrations with hypertension, 6213 subjects (3060 men and 3153 women) over 20 years of age from 2008 to 2010 Korea National Health and Nutrition Examination Survey were divided into tertiles according to serum ferritin and mercury concentrations in each gender. Serum ferritin (258.2 vs. 94.8 pmol/L) and mercury concentrations (28.4 vs. 19.9 nmol/L) were higher in men than in women. Serum ferritin (men; P = 0.029, women; P < 0.001) and mercury (men; P < 0.001, women; P = 0.003) concentrations were significantly associated with the prevalence of hypertension. In addition, significant correlation between serum ferritin and mercury concentrations in both men (r = 0.193, P < 0.001) and women (r = 0.145, P < 0.001) were found. Also, the increase of serum ferritin concentrations were more prominent in men (P < 0.001) than in women (P = 0.017) as the serum mercury tertiles increased after proper adjustments. Furthermore, significantly higher odds ratios of hypertension were found in the second (OR = 1.86, 95% CI; 1.05-3.30), and third (OR = 1.84, 95% CI; 1.01-3.36) tertiles of serum ferritin with the top tertile of serum mercury in men. The current study indicate that serum ferritin and mercury concentrations are associated with the prevalence of hypertension and that simultaneously elevated serum ferritin and mercury concentrations are related to the risk for hypertension in men.
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Affiliation(s)
- Beomhee Choi
- CHA Antiaging Institute, CHA University, Seoul, Republic of Korea
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Dietary selenium protect against redox-mediated immune suppression induced by methylmercury exposure. Food Chem Toxicol 2014; 72:169-77. [DOI: 10.1016/j.fct.2014.07.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/20/2014] [Accepted: 07/14/2014] [Indexed: 12/24/2022]
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Mak A, Tay SH. Environmental factors, toxicants and systemic lupus erythematosus. Int J Mol Sci 2014; 15:16043-56. [PMID: 25216337 PMCID: PMC4200809 DOI: 10.3390/ijms150916043] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 08/01/2014] [Accepted: 08/27/2014] [Indexed: 01/10/2023] Open
Abstract
Systemic lupus erythematosus (SLE) is an immune-complex-mediated multi-systemic autoimmune condition of multifactorial etiology, which mainly affects young women. It is currently believed that the onset of SLE and lupus flares are triggered by various environmental factors in genetically susceptible individuals. Various environmental agents and toxicants, such as cigarette smoke, alcohol, occupationally- and non-occupationally-related chemicals, ultraviolet light, infections, sex hormones and certain medications and vaccines, have been implicated to induce SLE onset or flares in a number case series, case-control and population-based cohort studies and very few randomized controlled trials. Here, we will describe some of these recognized environmental lupus triggering and perpetuating factors and explain how these factors potentially bias the immune system towards autoimmunity through their interactions with genetic and epigenetic alterations. Further in-depth exploration of how potentially important environmental factors mechanistically interact with the immune system and the genome, which trigger the onset of SLE and lupus flares, will certainly be one of the plausible steps to prevent the onset and to decelerate the progress of the disease.
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Affiliation(s)
- Anselm Mak
- Division of Rheumatology, Department of Medicine, University Medicine Cluster, National University Health System, 1E Kent Ridge Road, Level 10, NUHS Tower Block 119228, Singapore.
| | - Sen Hee Tay
- Division of Rheumatology, Department of Medicine, University Medicine Cluster, National University Health System, 1E Kent Ridge Road, Level 10, NUHS Tower Block 119228, Singapore.
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Moon SS. Additive effect of heavy metals on metabolic syndrome in the Korean population: the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. Endocrine 2014; 46:263-71. [PMID: 24065312 DOI: 10.1007/s12020-013-0061-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 09/12/2013] [Indexed: 01/20/2023]
Abstract
There have been increasing concerns regarding health problems due to endocrine disrupting chemicals (EDCs). We investigated association of heavy metals, including lead, mercury, and cadmium, with metabolic syndrome (MS) and its individual components in the Korean population. Participants included 1,961 males and 1,989 females 20 years of age or older from the fourth and fifth Korea National Health and Nutritional Examination Surveys of the Korean population (2009 and 2010). We examined the relationship of blood lead, mercury, and cadmium levels with MS and the additive effect of three heavy metals on MS after adjustment for age, sex, body mass index (BMI), region, smoking, alcohol consumption, and regular exercise. Blood concentration of lead showed a significant but modest association with prevalence of MS (P = 0.04). Other heavy metals did not show such a relationship with MS. When the participants were classified according to the sum of category numbers of the three heavy metals, adjusted odds ratios were 1.0, 1.355, 1.638, and 1.556 (P < 0.01). Among components of MS, significant relationship of the sum of heavy metals with hypertension and elevated triglyceride was demonstrated. Blood concentration of lead was positively associated with the prevalence of MS. Of particular interest, cumulative effect of a mixture of lead, mercury, and cadmium on prevalence of MS was stronger than the sum of effect of each heavy metal. Accumulative effect of exposure to heavy metals could be more additive or synergistic than individual exposure in the general population.
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Affiliation(s)
- Seong-Su Moon
- Department of Internal Medicine, Dongguk University College of Medicine, Dongdae-ro 87, Gyeongju, Gyeongbuk Province, 780-350, South Korea,
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Acute mercury toxicity modulates cytochrome P450, soluble epoxide hydrolase and their associated arachidonic acid metabolites in C57Bl/6 mouse heart. Toxicol Lett 2014; 226:53-62. [DOI: 10.1016/j.toxlet.2014.01.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 01/14/2014] [Accepted: 01/15/2014] [Indexed: 02/06/2023]
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Chen Y, Wang R, Shen H, Li W, Chen H, Huang Y, Zhang Y, Chen Y, Su S, Lin N, Liu J, Li B, Wang X, Liu W, Coveney RM, Tao S. Global mercury emissions from combustion in light of international fuel trading. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:1727-1735. [PMID: 24433051 DOI: 10.1021/es404110f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The spatially resolved emission inventory is essential for understanding the fate of mercury. Previous global mercury emission inventories for fuel combustion sources overlooked the influence of fuel trading on local emission estimates of many countries, mostly developing countries, for which national emission data are not available. This study demonstrates that in many countries, the mercury content of coal and petroleum locally consumed differ significantly from those locally produced. If the mercury content in locally produced fuels were used to estimate emission, then the resulting global mercury emissions from coal and petroleum would be overestimated by 4.7 and 72%, respectively. Even higher misestimations would exist in individual countries, leading to strong spatial bias. On the basis of the available data on fuel trading and an updated global fuel consumption database, a new mercury emission inventory for 64 combustion sources has been developed. The emissions were mapped at 0.1° × 0.1° resolution for 2007 and at country resolution for a period from 1960 to 2006. The estimated global total mercury emission from all combustion sources (fossil fuel, biomass fuel, solid waste, and wildfires) in 2007 was 1454 Mg (1232-1691 Mg as interquartile range from Monte Carlo simulation), among which elementary mercury (Hg(0)), divalent gaseous mercury (Hg(2+)), and particulate mercury (Hg(p)) were 725, 548, and 181 Mg, respectively. The total emission from anthropogenic sources, excluding wildfires, was 1040 Mg (886-1248 Mg), with coal combustion contributing more than half. Globally, total annual anthropogenic mercury emission from combustion sources increased from 285 Mg (263-358 Mg) in 1960 to 1040 Mg (886-1248 Mg) in 2007, owing to an increased fuel consumption in developing countries. However, mercury emissions from developed countries have decreased since 2000.
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Affiliation(s)
- Yilin Chen
- Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, People's Republic of China
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Qu M, Nan X, Gao Z, Guo B, Liu B, Chen Z. Protective effects of lycopene against methylmercury-induced neurotoxicity in cultured rat cerebellar granule neurons. Brain Res 2013; 1540:92-102. [PMID: 24120987 DOI: 10.1016/j.brainres.2013.10.005] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 09/23/2013] [Accepted: 10/03/2013] [Indexed: 12/24/2022]
Abstract
Methylmercury (MeHg) is a neurotoxin that induces neuronal degeneration in the central nervous system. Oxidative stress and mitochondrial dysfunction are widely accepted as central pathogenic mechanisms of MeHg-mediated neurotoxicity. Lycopene, a carotenoid compound, is a potent antioxidant with demonstrated neuroprotective properties in several experimental models of oxidative damage. The present study was designed to investigate whether lycopene could provide protective effects against MeHg-induced neurotoxicity in cultured rat cerebellar granule neurons (CGNs). The cultured CGNs were pretreated with different dose of lycopene for 2h, followed by the challenge with 500nM MeHg for 12h. It was found that MeHg exposure caused the loss of cell viability and the LDH release. Furthermore, we demonstrated that MeHg exposure significantly elevated intracellular reactive oxygen species generation and mitochondria-derived superoxide production, caused disruption of mitochondrial membrane potential and opening of mPTP, inhibited mitochondrial complex enzyme activities (complex III and complex IV), reduced ATP generation and decreased mtDNA copy numbers and mtDNA transcript levels. However, each of these oxidative damages was efficiently attenuated by lycopene pretreatment. Collectively, these results suggest that lycopene affords protection against MeHg-induced neurotoxicity in CGNs, and these beneficial effects of lycopene may be attributable to its roles in preventing mitochondrial dysfunction.
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Affiliation(s)
- Mingyue Qu
- Center for Health Protection of the Second Artillery Force of PLA, Beijing 100071, PR China.
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32
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Moon SS. Association of lead, mercury and cadmium with diabetes in the Korean population: the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010. Diabet Med 2013; 30:e143-8. [PMID: 23278294 DOI: 10.1111/dme.12103] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 10/25/2012] [Accepted: 12/18/2012] [Indexed: 12/23/2022]
Abstract
AIM Despite increasing concern regarding health problems as a result of environmental pollutants, no association of toxic heavy metals with diabetes has been demonstrated in the general population. We investigated the association of heavy metals, including lead, mercury and cadmium, with diabetes in the Korean population. METHODS This cross-sectional study is based on data from the fourth and fifth Korea National Health and Nutritional Examination Surveys, which were conducted in 2009 and 2010 among members of the Korean population. Participants included 1588 men and 1596 women, 30 years of age or older, who were selected from all of the 16 administrative districts of South Korea. Measurements of blood lead, mercury and cadmium levels were performed. Homeostatic model assessment of insulin resistance and homeostatic model assessment of β-cell function were calculated in participants without diabetes. RESULTS Blood concentration of lead, mercury and cadmium were slightly higher, but non-significantly, in participants with diabetes, compared with those without. After adjustment for age, sex, region, smoking, alcohol consumption and regular exercise, the prevalence of diabetes did not differ among quartiles of blood heavy metal concentrations. Correlation analysis of heavy metals with homeostatic model assessment of insulin resistance and β-cell function did not indicate a significant relationship. The relationship of sum of heavy metal mixture with prevalent diabetes was also not significant. CONCLUSIONS Blood lead, mercury and cadmium have no significant relationship with diabetes in the general Korean population.
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Affiliation(s)
- S-S Moon
- Department of Internal Medicine, Dongguk University College of Medicine, Gyeongju, South Korea.
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Houston MC. Role of mercury toxicity in hypertension, cardiovascular disease, and stroke. J Clin Hypertens (Greenwich) 2011; 13:621-7. [PMID: 21806773 DOI: 10.1111/j.1751-7176.2011.00489.x] [Citation(s) in RCA: 247] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mercury has a high affinity for sulfhydryl groups, inactivating numerous enzymatic reactions, amino acids, and sulfur-containing antioxidants (N-acetyl-L-cysteine, alpha-lipoic acid, L-glutathione), with subsequent decreased oxidant defense and increased oxidative stress. Mercury binds to metallothionein and substitute for zinc, copper, and other trace metals, reducing the effectiveness of metalloenzymes. Mercury induces mitochondrial dysfunction with reduction in adenosine triphosphate, depletion of glutathione, and increased lipid peroxidation. Increased oxidative stress and reduced oxidative defense are common. Selenium and fish containing omega-3 fatty acids antagonize mercury toxicity. The overall vascular effects of mercury include increased oxidative stress and inflammation, reduced oxidative defense, thrombosis, vascular smooth muscle dysfunction, endothelial dysfunction, dyslipidemia, and immune and mitochondrial dysfunction. The clinical consequences of mercury toxicity include hypertension, coronary heart disease, myocardial infarction, cardiac arrhythmias, reduced heart rate variability, increased carotid intima-media thickness and carotid artery obstruction, cerebrovascular accident, generalized atherosclerosis, and renal dysfunction, insufficiency, and proteinuria. Pathological, biochemical, and functional medicine correlations are significant and logical. Mercury diminishes the protective effect of fish and omega-3 fatty acids. Mercury inactivates catecholaminei-0-methyl transferase, which increases serum and urinary epinephrine, norepinephrine, and dopamine. This effect will increase blood pressure and may be a clinical clue to mercury-induced heavy metal toxicity. Mercury toxicity should be evaluated in any patient with hypertension, coronary heart disease, cerebral vascular disease, cerebrovascular accident, or other vascular disease. Specific testing for acute and chronic toxicity and total body burden using hair, toenail, urine, and serum should be performed.
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Affiliation(s)
- Mark C Houston
- Department of Medicine, Vanderbilt University School of Medicine, Division of Human Nutrition, Saint Thomas Medical Group, Saint Thomas Hospital, Nashville, TN, USA.
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Yin Z, Lee E, Ni M, Jiang H, Milatovic D, Rongzhu L, Farina M, Rocha JBT, Aschner M. Methylmercury-induced alterations in astrocyte functions are attenuated by ebselen. Neurotoxicology 2011; 32:291-9. [PMID: 21300091 PMCID: PMC3079013 DOI: 10.1016/j.neuro.2011.01.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 12/21/2010] [Accepted: 01/08/2011] [Indexed: 12/26/2022]
Abstract
Methylmercury (MeHg) preferentially accumulates in glia of the central nervous system (CNS), but its toxic mechanisms have yet to be fully recognized. In the present study, we tested the hypothesis that MeHg induces neurotoxicity via oxidative stress mechanisms, and that these effects are attenuated by the antioxidant, ebselen. Rat neonatal primary cortical astrocytes were pretreated with or without 10 μM ebselen for 2h followed by MeHg (0, 1, 5, and 10 μM) treatments. MeHg-induced changes in astrocytic [(3)H]-glutamine uptake were assessed along with changes in mitochondrial membrane potential (ΔΨ(m)), using the potentiometric dye tetramethylrhodamine ethyl ester (TMRE). Western blot analysis was used to detect MeHg-induced ERK (extracellular-signal related kinase) phosphorylation and caspase-3 activation. MeHg treatment significantly decreased (p<0.05) astrocytic [(3)H]-glutamine uptake at all time points and concentrations. Ebselen fully reversed MeHg's (1 μM) effect on [(3)H]-glutamine uptake at 1 min. At higher MeHg concentrations, ebselen partially reversed the MeHg-induced astrocytic inhibition of [(3)H]-glutamine uptake [at 1 min (5 and 10 μM) (p<0.05); 5 min (1, 5 and 10 μM) (p<0.05)]. MeHg treatment (1h) significantly (p<0.05) dissipated the ΔΨ(m) in astrocytes as evidenced by a decrease in mitochondrial TMRE fluorescence. Ebselen fully reversed the effect of 1 μM MeHg treatment for 1h on astrocytic ΔΨ(m) and partially reversed the effect of 5 and 10 μM MeHg treatments for 1h on ΔΨ(m). In addition, ebselen inhibited MeHg-induced phosphorylation of ERK (p<0.05) and blocked MeHg-induced activation of caspase-3 (p<0.05-0.01). These results are consistent with the hypothesis that MeHg exerts its toxic effects via oxidative stress and that the phosphorylation of ERK and the dissipation of the astrocytic mitochondrial membrane potential are involved in MeHg toxicity. In addition, the protective effects elicited by ebselen reinforce the idea that organic selenocompounds represent promising strategies to counteract MeHg-induced neurotoxicity.
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MESH Headings
- Analysis of Variance
- Animals
- Animals, Newborn
- Antioxidants/pharmacology
- Astrocytes/drug effects
- Astrocytes/metabolism
- Astrocytes/pathology
- Azoles/pharmacology
- Blotting, Western
- Caspase 3/metabolism
- Cells, Cultured
- Cytoprotection
- Dose-Response Relationship, Drug
- Environmental Pollutants/toxicity
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Glutamine/metabolism
- Isoindoles
- Membrane Potential, Mitochondrial/drug effects
- Mercury Poisoning, Nervous System/etiology
- Mercury Poisoning, Nervous System/metabolism
- Mercury Poisoning, Nervous System/pathology
- Methylmercury Compounds/toxicity
- Microscopy, Fluorescence
- Mitochondria/drug effects
- Mitochondria/metabolism
- Neuroprotective Agents/pharmacology
- Organoselenium Compounds/pharmacology
- Oxidative Stress/drug effects
- Phosphorylation
- Rats
- Rats, Sprague-Dawley
- Time Factors
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Affiliation(s)
- Zhaobao Yin
- Departments of Pediatrics and Pharmacology, the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Eunsook Lee
- Department of Physiology, Meharry Medical College, Nashville, Tennessee
| | - Mingwei Ni
- Departments of Pediatrics and Pharmacology, the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Haiyan Jiang
- Departments of Pediatrics and Pharmacology, the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Dejan Milatovic
- Departments of Pediatrics and Pharmacology, the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Lu Rongzhu
- Departments of Pediatrics and Pharmacology, the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Marcelo Farina
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Joao B. T. Rocha
- Departamento de Bioquímica, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Michael Aschner
- Departments of Pediatrics and Pharmacology, the Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, Tennessee
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Brown D, Goncharov A, Paul E, Simonin H, Carpenter DO. The relationship between Adirondack lake pH and levels of mercury in yellow perch. JOURNAL OF AQUATIC ANIMAL HEALTH 2010; 22:280-290. [PMID: 21413513 DOI: 10.1577/h10-005.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Levels of total mercury in yellow perch Perca flavescens from Adirondack lakes were studied in relation to characteristics of the lakes to determine why some lakes had fish with higher concentrations of mercury. Almost all mercury in fish is in the form of methylmercury, which can pose significant health hazards to humans who consume such fish. Fish mercury concentrations and water chemistry data were analyzed from eight Adirondack lakes. Four lakes (Halfmoon Lake, Sand Pond, Rock Pond, and Upper Sister Lake) had pH values of less than 5.0. Four other lakes (Lake Adirondack, Kings Flow, Harris Lake, and Lake Kushaqua) had pH values of more than 7.0. The acidic lakes also had high levels of aluminum and low acid-neutralizing capacity relative to the neutral lakes. Yellow perch (n = 100) from the acidic lakes had significantly higher levels of mercury than did those (n = 102) from the neutral lakes (P < 0.001), and the total mercury concentration increased with both length and weight of the fish. We conclude that the pH of the lake water is a major factor in determining the concentration of methylmercury in yellow perch.
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Affiliation(s)
- Donald Brown
- Institute for Health and the Environment, University at Albany, 5 University Place, Rensselaer, New York 12144, USA
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36
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Molecular mechanisms of methylmercury-induced cell death in human HepG2 cells. Food Chem Toxicol 2010; 48:1405-11. [PMID: 20226830 DOI: 10.1016/j.fct.2010.03.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2009] [Revised: 03/03/2010] [Accepted: 03/08/2010] [Indexed: 12/29/2022]
Abstract
Methylmercury (MeHg) has been suggested to exert cytotoxicity through multiple mechanisms, but the precise biochemical machinery has not been fully defined. This study was aimed at investigating the time-course (0-24h) effect of 2mg/L MeHg on cell death in human HepG2 cells. MeHg decreased cell viability in a time-dependent manner, which was concomitant with increased LDH leakage, reduced GSH levels, CAT activity and altered activity of the antioxidant enzymes GPx and GR at the longest times of incubation (16 and 24h). Activity of the detoxifying enzyme GST was also early enhanced (2h). Caspase-3 activity reached a maximum value at 8h and continued increased up to 24h. This feature was preceded by an enhancement in the caspase-9 activity (2h), whereas caspase-8 activity remained unchanged. MeHg early diminished Bcl-x(L)/Bcl-x(S) ratio and increased levels of the pro-apoptotic Bax and Bad. Moreover, MeHg-induced cytotoxicity was completely inhibited by the antioxidants (GSH and NAC) and notably by the mitochondrial complex I inhibitor rotenone, but not by the NADH oxidase inhibitor DPI. In summary, MeHg induced an oxidative stress responsible for apoptosis in HepG2 cells through direct activation of the caspase cascade and altered the cellular antioxidant and detoxificant enzymatic system to later provoke necrosis at later stages.
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Jayasekher T. Aerosols near by a coal fired thermal power plant: chemical composition and toxic evaluation. CHEMOSPHERE 2009; 75:1525-1530. [PMID: 19264341 DOI: 10.1016/j.chemosphere.2009.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Revised: 01/28/2009] [Accepted: 02/02/2009] [Indexed: 05/27/2023]
Abstract
Industrial processes discharge fine particulates containing organic as well as inorganic compounds into the atmosphere which are known to induce damage to cell and DNA, both in vitro and in vivo. Source and area specific studies with respect to the chemical composition, size and shape of the particles, and toxicity evaluations are very much limited. This study aims to investigate the trace elements associated with the aerosol particles distributed near to a coal burning thermal power plant and to evaluate their toxicity through Comet assay. PM(10) (particles determined by mass passing an inlet with a 50% cut-off efficiency having a 10-microm aerodynamic diameter) samples were collected using respirable dust samplers. Twelve elements (Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, Se, Hg, and As) were analyzed using ICP-AES. Comet assay was done with the extracts of aerosols in phosphate buffered saline (PBS). Results show that Fe and Zn were found to be the predominant elements along with traces of other analyzed elements. Spherical shaped ultrafine particles of <1 microm aerodynamic diameter were detected through scanning electron microscope. PM(10) particles near to the coal burning power plant produced comets indicating their potential to induce DNA damage. DNA damage property is found to be depending upon the chemical characteristics of the components associated with the particles besides the physical properties such as size and shape.
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Affiliation(s)
- T Jayasekher
- Environmental Laboratory, Tamil Nadu Pollution Control Board, Tuticorin 628003, India.
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Abstract
BACKGROUND Dental amalgam is a widely used restorative material containing 50 percent elemental mercury that emits mercury vapor. No randomized clinical trials have determined whether there are adverse immunological effects associated with this low-level mercury exposure in children. The objective of this study was to evaluate a subpopulation of the participants in the New England Children's Amalgam Trial for in vitro manifestations of immunotoxic effects of dental amalgam. METHODS The authors conducted a randomized clinical trial in which children requiring dental restorative treatment were randomly assigned to receive either amalgam for posterior restorations or resin-based composite restorations. They assessed 66 children, aged 6 to 10 years, for total white blood cell counts, specific lymphocyte (T-cell and B-cell) counts and lymphocyte, neutrophil and monocyte responsiveness across a five-year period. Because of the small number of participants, the authors acknowledge that the study is exploratory in nature and has limited statistical power. RESULTS The mean number of tooth surfaces restored during the five-year period was 7.8 for the amalgam group and 10.1 for the composite group. In the amalgam group, there was a slight, but not statistically significant, decline in responsiveness of T cells and monocytes at five to seven days after treatment; the authors consistently observed no differences at six, 12 or 60 months. CONCLUSIONS The findings of this study confirm that treatment of children with amalgam restorations leads to increased, albeit low-level, exposure to mercury. In this exploratory analysis of immune function, amalgam exposure did not cause overt immune deficits, although small transient effects were observed five to seven days after restoration placement. CLINICAL IMPLICATIONS These findings suggest that immunotoxic effects of amalgam restorations are minimal and transient in children and most likely do not need to be of concern to practitioners considering the use of this restorative dental material.
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Dantzig PI. AGE-RELATED MACULAR DEGENERATION AND CUTANEOUS SIGNS OF MERCURY TOXICITY. Cutan Ocul Toxicol 2008. [DOI: 10.1081/cus-200046177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Bellum S, Thuett KA, Taylor RJ, Abbott LC. Assessment of Mercury Concentrations in Mouse Brain Using Different Routes of Administration and Different Tissue Preparations. Toxicol Mech Methods 2008; 17:165-73. [DOI: 10.1080/15376510601091368] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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41
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LEONARD I. SWEET, DORA R. PASSINO-R. Xenobiotic-induced apoptosis: significance and potential application as a general biomarker of response. Biomarkers 2008; 4:237-53. [DOI: 10.1080/135475099230778] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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42
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Chang JY, Tsai PF. Prevention of methylmercury-induced mitochondrial depolarization, glutathione depletion and cell death by 15-deoxy-delta-12,14-prostaglandin J(2). Neurotoxicology 2008; 29:1054-61. [PMID: 18778734 DOI: 10.1016/j.neuro.2008.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2008] [Revised: 08/05/2008] [Accepted: 08/08/2008] [Indexed: 12/31/2022]
Abstract
Methylmercury (MeHg) is an environmental toxin that causes severe neurological complications in humans and experimental animals. In addition to neurons, glia in the central nervous system are very susceptible to MeHg toxicity. Pretreatment of glia with the prostaglandin derivative, 15-deoxy-delta-12,14-prostaglandin J(2) (15d-PGJ(2)), caused a significant protection against MeHg cytotoxicity. Results with the C6 glioma cells demonstrated that the protection was dependent on the duration of pretreatment, suggesting that time was required for the up-regulation of cellular defenses. Subsequent experiments indicated that 15d-PGJ(2) prevented MeHg induced mitochondrial depolarization. Similar protection against MeHg cytotoxicity was observed in primary cultures of mouse glia. Analysis of cellular glutathione (GSH) levels indicated that 15d-PGJ(2) caused an up-regulation of GSH and prevented MeHg-induced GSH depletion. Buthionine sulfoximine (BSO), a GSH synthesis inhibitor, completely inhibited the GSH induction by 15d-PGJ(2). However, BSO did not prevent the stabilization of mitochondrial potential and only partially prevented the protection caused by 15d-PGJ(2). While induction of heme oxygenase-1 was implicated in the cytoprotection by 15d-PGJ(2) under some experimental conditions, additional experiments indicated that this enzyme was not involved in the cytoprotection observed in this system. Together, these results suggested that while up-regulation of GSH by 15d-PGJ(2) might help cells to defend against MeHg toxicity, there may be other yet unidentified mechanism(s) initiated by 15d-PGJ(2) treatment that contributed to its protection against MeHg cytotoxicity.
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Affiliation(s)
- Jason Y Chang
- Department of Neurobiology & Developmental Sciences, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Eke D, Çelik A. Genotoxicity of thimerosal in cultured human lymphocytes with and without metabolic activation sister chromatid exchange analysis proliferation index and mitotic index. Toxicol In Vitro 2008; 22:927-34. [DOI: 10.1016/j.tiv.2008.01.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2007] [Revised: 12/03/2007] [Accepted: 01/20/2008] [Indexed: 11/29/2022]
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Usuki F, Fujita E, Sasagawa N. Methylmercury activates ASK1/JNK signaling pathways, leading to apoptosis due to both mitochondria- and endoplasmic reticulum (ER)-generated processes in myogenic cell lines. Neurotoxicology 2008; 29:22-30. [DOI: 10.1016/j.neuro.2007.08.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2007] [Revised: 08/21/2007] [Accepted: 08/21/2007] [Indexed: 11/29/2022]
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Coccini T, Randine G, Castoldi AF, Acerbi D, Manzo L. Methylmercury interaction with lymphocyte cholinergic muscarinic receptors in developing rats. ENVIRONMENTAL RESEARCH 2007; 103:229-37. [PMID: 16808911 DOI: 10.1016/j.envres.2006.05.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 05/10/2006] [Accepted: 05/17/2006] [Indexed: 05/10/2023]
Abstract
Cerebral cholinergic muscarinic receptors (MR) have been suggested as one of the sensitive biochemical endpoints of the central nervous system altered by developmental exposure to the widespread seafood contaminant methylmercury (MeHg). In adult rats, MeHg has been shown to alter MR binding both in the brain and lymphocytes, supporting the use of MR in blood cells as a surrogate marker of CNS changes. The effects of MeHg have been evaluated on rat lymphocyte MR binding (using [3H]QNB as specific muscarinic ligand) in vivo (after perinatal exposure) and in vitro. For comparison, in vitro studies were also performed on human lymphocytes. Exposure to 1 mg MeHg/kg/day during pregnancy and lactation (from GD7 to PND7) significantly enhanced lymphocyte MR density in both adult and young rats 21 days after delivery, with a more pronounced effect in the mothers (B(max) increase of 139%) than in the male offspring (+49%) and female offspring (+73%) as compared with their respective controls (33+/-4, 41+/-8, and 37+/-4 fmol/million cells), in accordance with the higher Hg levels detected in the adult blood (11.3+/-2.2 microg/mL) than in pups (1.3+/-0.4 microg/L in both genders). A lower MeHg dose (0.5 mg/kg/day) was without any effect on lymphocyte MRs. In in vitro studies, MeHg was an almost equipotent inhibitor of (3)H-QNB binding to rat and human lymphocyte MRs (IC50 values were 4.1+/-0.29, 5.2+/-0.51, and 5.0+/-0.9 microM for total rat lymphocytes, rat T lymphocytes, and total human lymphocytes, respectively). Notably, the IC50 values for MeHg to lymphocyte MRs were comparable to the Hg levels reached in blood (5-50 microM) of the PND21 rats exposed to MeHg. The finding that the MR binding is a target for the effects of MeHg in peripheral blood cells is in accordance with our previous data in brain [Coccini et al., 2006. Effects of developmental co-exposure to methylmercury and 2,2',4,4',5,5'-hexachlorobiphenyl (PCB153) on cholinergic muscarinic receptors in rat brain. Neurotoxicology, in press], and supports the use of this peripheral endpoint as a biomarker of MeHg-induced cerebral muscarinic alterations. The similarity of MeHg IC50 binding data between human and rat in peripheral tissues suggests the possible application of such biomarker to humans exposed to environmental chemicals.
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Affiliation(s)
- Teresa Coccini
- Toxicology Division, Salvatore Maugeri Foundation IRCCS, Institute of Pavia, Via Maugeri, 10, 27100 Pavia, Italy.
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Yin Z, Milatovic D, Aschner JL, Syversen T, Rocha JB, Souza DO, Sidoryk M, Albrecht J, Aschner M. Methylmercury induces oxidative injury, alterations in permeability and glutamine transport in cultured astrocytes. Brain Res 2006; 1131:1-10. [PMID: 17182013 PMCID: PMC1847599 DOI: 10.1016/j.brainres.2006.10.070] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Revised: 10/09/2006] [Accepted: 10/26/2006] [Indexed: 01/12/2023]
Abstract
The neurotoxicity of high levels of methylmercury (MeHg) is well established both in humans and experimental animals. Astrocytes accumulate MeHg and play a prominent role in mediating MeHg toxicity in the central nervous system (CNS). Although the precise mechanisms of MeHg neurotoxicity are ill-defined, oxidative stress and altered mitochondrial and cell membrane permeability appear to be critical factors in its pathogenesis. The present study examined the effects of MeHg treatment on oxidative injury, mitochondrial inner membrane potential, glutamine uptake and expression of glutamine transporters in primary astrocyte cultures. MeHg caused a significant increase in F(2)-isoprostanes (F(2)-IsoPs), lipid peroxidation biomarkers of oxidative damage, in astrocyte cultures treated with 5 or 10 microM MeHg for 1 or 6 h. Consistent with this observation, MeHg induced a concentration-dependant reduction in the inner mitochondrial membrane potential (DeltaPsi(m)), as assessed by the potentiometric dye, tetramethylrhodamine ethyl ester (TMRE). Our results demonstrate that DeltaPsi(m) is a very sensitive endpoint for MeHg toxicity, since significant reductions were observed after only 1 h exposure to concentrations of MeHg as low as 1 microM. MeHg pretreatment (1, 5 and 10 microM) for 30 min also inhibited the net uptake of glutamine ((3)H-glutamine) measured at 1 min and 5 min. Expression of the mRNA coding the glutamine transporters, SNAT3/SN1 and ASCT2, was inhibited only at the highest (10 microM) MeHg concentration, suggesting that the reduction in glutamine uptake observed after 30 min treatment with lower concentrations of MeHg (1 and 5 microM) was not due to inhibition of transcription. Taken together, these studies demonstrate that MeHg exposure is associated with increased mitochondrial membrane permeability, alterations in glutamine/glutamate cycling, increased ROS formation and consequent oxidative injury. Ultimately, MeHg initiates multiple additive or synergistic disruptive mechanisms that lead to cellular dysfunction and cell death.
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MESH Headings
- Amino Acid Transport Systems, Neutral/genetics
- Animals
- Animals, Newborn
- Astrocytes/drug effects
- Astrocytes/metabolism
- Astrocytes/pathology
- Cell Membrane Permeability/drug effects
- Cell Membrane Permeability/physiology
- Cells, Cultured
- Central Nervous System/drug effects
- Central Nervous System/metabolism
- Central Nervous System/physiopathology
- Dose-Response Relationship, Drug
- Glutamic Acid/metabolism
- Glutamine/metabolism
- Lipid Peroxidation/drug effects
- Lipid Peroxidation/physiology
- Membrane Potential, Mitochondrial/drug effects
- Membrane Potential, Mitochondrial/physiology
- Mercury Poisoning, Nervous System/metabolism
- Mercury Poisoning, Nervous System/physiopathology
- Methylmercury Compounds/toxicity
- Mitochondria/drug effects
- Mitochondria/metabolism
- Mitochondria/pathology
- Mitochondrial Membranes/drug effects
- Mitochondrial Membranes/metabolism
- Mitochondrial Membranes/pathology
- Oxidative Stress/drug effects
- Oxidative Stress/physiology
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
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Affiliation(s)
- Zhaobao Yin
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
| | - Dejan Milatovic
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
| | - Judy L. Aschner
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
| | - Tore Syversen
- Department of Clinical Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Joao B.T. Rocha
- Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Brazil
| | - Diogo O. Souza
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Marta Sidoryk
- Department of Neurotoxicology, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Jan Albrecht
- Department of Neurotoxicology, Medical Research Centre, Polish Academy of Sciences, Warsaw, Poland
| | - Michael Aschner
- Department of Pediatrics, Pharmacology, and the Kennedy Center, Norwegian University of Science and Technology, Trondheim, Norway
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Florea AM, Büsselberg D. Occurrence, use and potential toxic effects of metals and metal compounds. Biometals 2006; 19:419-27. [PMID: 16841251 DOI: 10.1007/s10534-005-4451-x] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2005] [Accepted: 10/26/2005] [Indexed: 11/26/2022]
Abstract
Metals and metal compounds are constituents of our natural environment. Their distribution depends on the existence of natural sources (e.g. volcanoes or erosion) and their use in human's activity. They are transformed naturally (e.g. by bacterial activity) with formation of organic species that influence their mobility and accumulation in abiotic as well as biotic systems. Up to date metal species are released into the environment questioning their influence on human health. Due to their widespread use in human activities such as industry, agriculture and even as medicine (e.g. As, Se, Pt), numerous health risks may be associated with exposure to these substances. Different reports on metal intoxication are documented and studies especially on neurotoxicity, genotoxicity, or carcinogenicity, are previously published in numerous articles. This mini-review gives an overview on the use and the actions of selected metal species of actual scientific concern, with a focus on neuronal cells.
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Affiliation(s)
- Ana-Maria Florea
- Institut für Physiologie Universitätsklinium Essen, Universität Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany
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Drevnick PE, Sandheinrich MB, Oris JT. Increased ovarian follicular apoptosis in fathead minnows (Pimephales promelas) exposed to dietary methylmercury. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2006; 79:49-54. [PMID: 16814880 DOI: 10.1016/j.aquatox.2006.05.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2006] [Revised: 05/01/2006] [Accepted: 05/03/2006] [Indexed: 05/10/2023]
Abstract
Exposure to environmentally relevant concentrations of dietary methylmercury impairs the reproduction of fish. Although specific mechanisms are unknown, recent research has linked altered reproduction in fish to the suppression of circulating levels of sex steroid hormones by methylmercury. We hypothesize that methylmercury induces apoptosis in steroidogenic gonadal cells in fish, thereby interfering with the synthesis of sex steroid hormones critical for the regulation of reproduction. To test this hypothesis, we chronically exposed fathead minnows (Pimephales promelas) to one of three diets contaminated with methylmercury: 0.06 microg Hg g(-1) (control), 0.87 microg Hg g(-1), and 3.93 microg Hg g(-1) dry weight. Apoptosis was evaluated histologically in ovaries of female fathead minnows by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). Methylmercury significantly increased the number of apoptotic follicular cells in primary growth and cortical alveolus stage ovarian follicles. Ovarian follicular cells (i.e., granulosa, theca) are responsible for the production of 17beta-estradiol and other sex steroid hormones. Increased ovarian follicular apoptosis was related to suppressed 17beta-estradiol concentrations and smaller ovary size of female fathead minnows. Our results suggest increased apoptosis of steroidogenic gonadal cells as a possible mechanism for the suppression of sex steroid hormones and ultimately the impairment of reproduction in fish exposed to methylmercury.
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Affiliation(s)
- Paul E Drevnick
- Department of Zoology, Miami University, Oxford, OH 45056, USA.
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Abstract
OBJECTIVE The objective of this study was to determined if there was a relationship between Grover's disease and Parkinson disease. METHODS Fourteen patients with Parkinson disease and 14 control patients were randomly selected and examined for cutaneous eruptions and blood mercury levels. RESULTS Of the 14 patients with Parkinson's disease, 13 had Grover's disease and detectable blood mercury. None of the patients in the control group had a cutaneous eruption and only 2of the 14 had detectable blood mercury. CONCLUSION Mercury may play a role in the etiology of Parkinson disease and Grover's disease.
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Garg TK, Chang JY. Methylmercury causes oxidative stress and cytotoxicity in microglia: Attenuation by 15-deoxy-delta 12, 14-Prostaglandin J2. J Neuroimmunol 2006; 171:17-28. [PMID: 16225932 DOI: 10.1016/j.jneuroim.2005.09.007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Accepted: 09/13/2005] [Indexed: 11/23/2022]
Abstract
Methylmercury (MeHg) causes severe neurological disorders in the central nervous system. This study focused on the effects of MeHg on microglia, macrophage-like cells that reside in the CNS important in neuro-immune interactions. The murine N9 microglial cell line was used in this set of study. MeHg caused reactive oxygen species generation, mitochondrial depolarization and aconitase inactivation, all of which were signs of cellular oxidative stress. MeHg greatly increased microglial IL-6 secretion despite the fact that it severely inhibited protein synthesis. The concentration that caused 50% cell death in 24 h was approximately 9 microM. Pretreatment of microglia with the prostaglandin derivative, 15-deoxy-delta 12, 14-Prostaglandin J2 attenuated MeHg induced cell death. The saving effect did not appear to be mediated through activation of peroxisome proliferator activated receptors (PPAR) since other agonists of these receptors did not prevent MeHg induced microglial death.
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Affiliation(s)
- Tarun K Garg
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham St., Little Rock, AR 72205, USA
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