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Kang B, Wang J, Guo S, Yang L. Mercury-induced toxicity: Mechanisms, molecular pathways, and gene regulation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 943:173577. [PMID: 38852866 DOI: 10.1016/j.scitotenv.2024.173577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/01/2024] [Accepted: 05/25/2024] [Indexed: 06/11/2024]
Abstract
Mercury is a well-known neurotoxicant for humans and wildlife. The epidemic of mercury poisoning in Japan has clearly demonstrated that chronic exposure to methylmercury (MeHg) results in serious neurological damage to the cerebral and cerebellar cortex, leading to the dysfunction of the central nervous system (CNS), especially in infants exposed to MeHg in utero. The occurrences of poisoning have caused a wide public concern regarding the health risk emanating from MeHg exposure; particularly those eating large amounts of fish may experience the low-level and long-term exposure. There is growing evidence that MeHg at environmentally relevant concentrations can affect the health of biota in the ecosystem. Although extensive in vivo and in vitro studies have demonstrated that the disruption of redox homeostasis and microtube assembly is mainly responsible for mercurial toxicity leading to adverse health outcomes, it is still unclear whether we could quantitively determine the occurrence of interaction between mercurial and thiols and/or selenols groups of proteins linked directly to outcomes, especially at very low levels of exposure. Furthermore, intracellular calcium homeostasis, cytoskeleton, mitochondrial function, oxidative stress, neurotransmitter release, and DNA methylation may be the targets of mercury compounds; however, the primary targets associated with the adverse outcomes remain to be elucidated. Considering these knowledge gaps, in this article, we conducted a comprehensive review of mercurial toxicity, focusing mainly on the mechanism, and genes/proteins expression. We speculated that comprehensive analyses of transcriptomics, proteomics, and metabolomics could enhance interpretation of "omics" profiles, which may reveal specific biomarkers obviously correlated with specific pathways that mediate selective neurotoxicity.
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Affiliation(s)
- Bolun Kang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China
| | - Jinghan Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China
| | - Shaojuan Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China
| | - Lixin Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 100012 Beijing, China.
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Iijima Y, Miki R, Takasugi N, Fujimura M, Uehara T. Characterization of pathological changes in the olfactory system of mice exposed to methylmercury. Arch Toxicol 2024; 98:1163-1175. [PMID: 38367039 PMCID: PMC10944439 DOI: 10.1007/s00204-024-03682-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 01/15/2024] [Indexed: 02/19/2024]
Abstract
Methylmercury (MeHg) is a well-known environmental neurotoxicant that causes severe brain disorders such as Minamata disease. Although some patients with Minamata disease develop olfactory dysfunction, the underlying pathomechanism is largely unknown. We examined the effects of MeHg on the olfactory system using a model of MeHg poisoning in which mice were administered 30 ppm MeHg in drinking water for 8 weeks. Mice exposed to MeHg displayed significant mercury accumulation in the olfactory pathway, including the nasal mucosa, olfactory bulb, and olfactory cortex. The olfactory epithelium was partially atrophied, and olfactory sensory neurons were diminished. The olfactory bulb exhibited an increase in apoptotic cells, hypertrophic astrocytes, and amoeboid microglia, mainly in the granular cell layer. Neuronal cell death was observed in the olfactory cortex, particularly in the ventral tenia tecta. Neuronal cell death was also remarkable in higher-order areas such as the orbitofrontal cortex. Correlation analysis showed that neuronal loss in the olfactory cortex was strongly correlated with the plasma mercury concentration. Our results indicate that MeHg is an olfactory toxicant that damages the central regions involved in odor perception. The model described herein is useful for analyzing the mechanisms and treatments of olfactory dysfunction in MeHg-intoxicated patients.
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Affiliation(s)
- Yuta Iijima
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700‑8530, Japan
| | - Ryohei Miki
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700‑8530, Japan
| | - Nobumasa Takasugi
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700‑8530, Japan
| | - Masatake Fujimura
- Department of Basic Medical Science, National Institute for Minamata Disease, Kumamoto, 867‑0008, Japan
| | - Takashi Uehara
- Department of Medicinal Pharmacology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, 700‑8530, Japan.
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Yamashita N, Uchiyama M, Yamagata R, Hwang GW. Methylmercury Induces Apoptosis in Mouse C17.2 Neural Stem Cells through the Induction of OSGIN1 Expression by NRF2. Int J Mol Sci 2024; 25:3886. [PMID: 38612696 PMCID: PMC11011283 DOI: 10.3390/ijms25073886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/24/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Methylmercury is a known environmental pollutant that exhibits severe neurotoxic effects. However, the mechanism by which methylmercury causes neurotoxicity remains unclear. To date, we have found that oxidative stress-induced growth inhibitor 1 (OSGIN1), which is induced by oxidative stress and DNA damage, is also induced by methylmercury. Therefore, in this study, we investigated the relationship between methylmercury toxicity and the induction of OSGIN1 expression using C17.2 cells, which are mouse brain neural stem cells. Methylmercury increased both OSGIN1 mRNA and protein levels in a time- and concentration-dependent manner. Moreover, these increases were almost entirely canceled out by pretreatment with actinomycin D, a transcription inhibitor. Furthermore, similar results were obtained from cells in which expression of the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) was suppressed, indicating that methylmercury induces OSGIN1 expression via NRF2. Methylmercury causes neuronal cell death by inducing apoptosis. Therefore, we next investigated the role of OSGIN1 in methylmercury-induced neuronal cell death using the activation of caspase-3, which is involved in apoptosis induction, as an indicator. As a result, the increase in cleaved caspase-3 (activated form) induced by methylmercury exposure was decreased by suppressing OSGIN1, and the overexpression of OSGIN1 further promoted the increase in cleaved caspase-3 caused by methylmercury. These results suggest, for the first time, that OSGIN1 is a novel factor involved in methylmercury toxicity, and methylmercury induces apoptosis in C17.2 cells through the induction of OSGIN1 expression by NRF2.
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Affiliation(s)
| | | | | | - Gi-Wook Hwang
- Laboratory of Environmental and Health Sciences, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Miyagi, Japan; (N.Y.); (R.Y.)
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Toyama T, Xu S, Kanemitsu Y, Hasegawa T, Noguchi T, Lee JY, Matsuzawa A, Naganuma A, Hwang GW. Methylmercury directly modifies the 105th cysteine residue in oncostatin M to promote binding to tumor necrosis factor receptor 3 and inhibit cell growth. Arch Toxicol 2023; 97:1887-1897. [PMID: 37193757 DOI: 10.1007/s00204-023-03520-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 05/11/2023] [Indexed: 05/18/2023]
Abstract
We previously found that methylmercury induces expression of oncostatin M (OSM), which is released extracellularly and binds to tumor necrosis factor receptor 3 (TNFR3), possibly enhancing its own toxicity. However, the mechanism by which methylmercury causes OSM to bind to TNFR3 rather than to its known receptors, OSM receptor and LIFR, is unknown. In this study, we aimed to elucidate the effect of methylmercury modification of cysteine residues in OSM on binding to TNFR3. Immunostaining of TNFR3-V5-expressing cells suggested that methylmercury promoted binding of OSM to TNFR3 on the cell membrane. In an in vitro binding assay, OSM directly bound to the extracellular domain of TNFR3, and this binding was promoted by methylmercury. Additionally, the formation of a disulfide bond in the OSM molecule was essential for the binding of both proteins, and LC/MS analysis revealed that methylmercury directly modified the 105th cysteine residue (Cys105) in OSM. Next, mutant OSM, in which Cys105 was replaced by serine or methionine, increased the binding to TNFR3, and a similar effect was observed in immunoprecipitation using cultured cells. Furthermore, cell proliferation was inhibited by treatment with Cys105 mutant OSMs compared with wildtype OSM, and this effect was cancelled by TNFR3 knockdown. In conclusion, we revealed a novel mechanism of methylmercury toxicity, in which methylmercury directly modifies Cys105 in OSM, thereby inhibiting cell proliferation via promoting binding to TNFR3. This indicates a chemical disruption in the interaction between the ligand and the receptor is a part of methylmercury toxicity.
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Affiliation(s)
- Takashi Toyama
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Sidi Xu
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Yoshitomi Kanemitsu
- Clinical and Translational Research Center, Niigata University Medical and Dental Hospital, 2-5274 Gakkochodori, Chuo-ku, Niigata, Niigata, 980-8574, Japan
| | - Takashi Hasegawa
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Takuya Noguchi
- Laboratory of Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Jin-Yong Lee
- Laboratory of Pharmaceutical Health Sciences, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, 951-8514, Japan
| | - Atsushi Matsuzawa
- Laboratory of Health Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Akira Naganuma
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan
| | - Gi-Wook Hwang
- Laboratory of Molecular and Biochemical Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi, 980-8578, Japan.
- Laboratory of Environmental and Health Sciences, Faculty of Pharmaceutical Sciences, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai, Miyagi, 981-8558, Japan.
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Puty B, Bittencourt LO, Plaça JR, de Oliveira EHC, Lima RR. Astrocyte-Like Cells Transcriptome Changes After Exposure to a Low and Non-cytotoxic MeHg Concentration. Biol Trace Elem Res 2023; 201:1151-1162. [PMID: 35378667 DOI: 10.1007/s12011-022-03225-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 03/29/2022] [Indexed: 02/07/2023]
Abstract
The central nervous system is the main target of MeHg toxicity and glial cells are the first line of defense; however, their true role remains unclear. This study aimed to identify the global map of human glial-like (U87) cells transcriptome after exposure to a non-toxic and non-lethal MeHg concentration and to investigate the related molecular changes. U87 cells were exposed upon 0.1, 0.5, and 1 µM MeHg for 4 and 24 h. Although no changes were observed in the percentage of viable cells, the metabolic viability was significantly decreased after exposure to 1 µM MeHg for 24 h; thus, the non-toxic concentration of 0.1 µM MeHg was chosen to perform microarray analysis. Significant changes in U87 cells transcriptome were observed only after 24 h. The expression of 392 genes was down regulated while 431 genes were up-regulated. Gene ontology showed alterations in biological processes (75%), cellular components (21%), and molecular functions (4%). The main pathways showed by KEGG and Reactome were cell cycle regulation and Rho GTPase signaling. The complex mechanism of U87 cells response against MeHg exposure indicates that even a low and non-toxic concentration is able to alter the gene expression profile.
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Affiliation(s)
- Bruna Puty
- Laboratory of Functional and Structural Biology, Institute of Biological Science, Federal University of Pará, Belém, Brazil
- Laboratory of Tissue Culture and Cytogenetics, Environmental Section, Evandro Chagas Institute, Ananindeua, Brazil
| | - Leonardo Oliveira Bittencourt
- Laboratory of Functional and Structural Biology, Institute of Biological Science, Federal University of Pará, Belém, Brazil
| | - Jéssica Rodrigues Plaça
- National Institute of Science and Technology in Stem Cell and Cell Therapy (INCT/CNPq) and Center for Cell-Based Therapy, CEPID/FAPESP, Ribeirão Preto, Brazil
| | | | - Rafael Rodrigues Lima
- Laboratory of Functional and Structural Biology, Institute of Biological Science, Federal University of Pará, Belém, Brazil.
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Lacerda Leocádio PC, Dias RP, Pinto DV, Reis JM, Rodrigues Nascimento JC, Anne de Castro Brito G, Valença JT, Foureaux G, Ferreira AJ, Windmöller CC, Crespo-Lopez ME, Santos FA, Oriá RB, Alvarez-Leite JI. Pollutants and nutrition: Are methylmercury effects on blood pressure and lipoprotein profile comparable to high-fat diet in mice? ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 204:111036. [PMID: 32784013 DOI: 10.1016/j.ecoenv.2020.111036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 07/10/2020] [Accepted: 07/11/2020] [Indexed: 06/11/2023]
Abstract
Human exposure to methylmercury (MeHg) due to contaminated fish intake as part of a high-fat (HFD), high-carbohydrate diets is a reality today for many populations. HFD is associated with hypertension and hyperlipidemia, primary cardiovascular disease (CVD) risk factors. Some studies suggest that MeHg induces those risk factors. We evaluated the effect of MeHg exposure in mice fed with HFD or control diet for eight weeks. In the last experimental 15 days, the half group received a MeHg solution (20 mg/L) replacing water. Blood pressure (BP), heart rate, lipoprotein concentrations, and paraoxonase activity were evaluated. Liver cholesterol, triacylglycerol, and IBA-1+ cells, as well as transcriptional levels of genes related to lipid metabolism and inflammatory response, were also assessed. HFD and both MeHg groups presented increased BP and total cholesterol (TC). In the liver, HFD but not MeHg was related to an increase in TC. Also, MeHg intoxication reduced paraoxonase activity regardless of diet. MeHg intoxication and HFD increased steatosis and the number of IBA-1+ cells and modified some gene transcripts associated with lipid metabolism. In conclusion, we demonstrated that MeHg effects on CVD risk factors resemble those caused by HFD.
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Yang T, Xu Z, Liu W, Xu B, Deng Y. Oxidative stress accelerates synaptic glutamate dyshomeostasis and NMDARs disorder during methylmercury-induced neuronal apoptosis in rat cerebral cortex. ENVIRONMENTAL TOXICOLOGY 2020; 35:683-696. [PMID: 32061141 DOI: 10.1002/tox.22904] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 01/10/2020] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
Methylmercury (MeHg) is a potent neurotoxin,which leads to a wide range of intracellular effects. The molecular mechanismsassociated to MeHg-induced neurotoxicity have not been fully understood.Oxidative stress, as well as synaptic glutamate (Glu) dyshomeostasis have beenidentified as two critical mechanisms during MeHg-mediated cytotoxicity. Here,we developed a rat model of MeHg poisoning to evaluate its neurotoxic effectsby focusing on cellular oxidative stress and synaptic Glu disruption. Inaddition, we investigated the neuroprotective role of alpha-lipoic acid (α-LA), a natural antioxidant, todeeply explore the underlying interaction between them. Fifty-six rats wererandomly divided into four groups: saline control, MeHg treatment (4 or 12μmol/kg MeHg), and α-LApre-treatment (35 μmol/kg α-LA+12μmol/kg MeHg). Rats exposed to 12 μmol/kg MeHg induced neuronal oxidativestress, with ROS accumulation and cellular antioxidant system impairment. Nrf2 andxCT pathways were activated with MeHg treatment. The enzymatic or non-enzymaticof cellular GSH synthesis were also disrupted by MeHg. On the other hand, the abnormalactivities of GS and PAG disturbed the "Glu-Gln cycle", leading to NMDARsover-activation, Ca2+ overload, and the calpain activation, which acceleratedNMDARs degradation. Meanwhile, the high expressions of phospho-p44/42 MAPK,phospho-p38 MAPK, phospho-CREB, and the high levels of caspase 3 and Bax/Bcl-2 finallyindicated the neuronal apoptosis after MeHg exposure. Pre-treatment with α-LA significantly preventedMeHg-induced neurotoxicity. In conclusion, the oxidative stress and synapticGlu dyshomeostasis contributed to MeHg-induced neuronal apoptosis. Alpha-LAattenuated these toxic effects through mechanisms of anti-oxidation andindirect Glu dyshomeostasis prevention.
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Affiliation(s)
- Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Zhaofa Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, People's Republic of China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, Shenyang, Liaoning Province, People's Republic of China
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Shinoda Y, Tatsumi S, Yoshida E, Takahashi T, Eto K, Kaji T, Fujiwara Y. Gene expression profiles in the dorsal root ganglia of methylmercury-exposed rats. J Toxicol Sci 2019; 44:549-558. [PMID: 31378766 DOI: 10.2131/jts.44.549] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Methylmercury (MeHg) exposure is known to induce neurodegeneration in both the central nervous system (CNS) and peripheral nervous system (PNS). Molecular mechanisms of MeHg-induced neurotoxicity have been well investigated in the CNS, however, it remains unclear in the PNS. In the present study, comprehensive gene expression analysis was performed by analyzing MeHg-exposed adult rat dorsal root ganglion (DRG) by DNA microarray. Methylmercuric chloride (6.7 mg/kg/day) was administered to nine-week-old male Wistar rats for five days, followed by two days without administration; this cycle was repeated once. Rats were anesthetized at 7 or 14 days after commencement of MeHg exposure, and their DRGs were removed and homogenized to make total RNA samples. DNA microarray data from Day 7 samples identified 100 out of 18,513 detected genes as annotated genes with more than two-fold upregulated or downregulated expression compared with controls. Database for Annotation, Visualization, and Integrated Discovery (DAVID) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses suggested strong involvement of immune activation and inflammation pathways in rat DRG exposed to MeHg, and some genes overlapped with previously reported genes affected by MeHg exposure in the cerebellum. The present results suggest that MeHg-induced neurotoxicity is associated with immune activation and inflammatory responses in rat DRG.
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Affiliation(s)
- Yo Shinoda
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Satoshi Tatsumi
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Eiko Yoshida
- Department of Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science
| | - Tsutomu Takahashi
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
| | - Komyo Eto
- Health and Nursing Facilities for the Aged, Jushindai, Shinwakai
| | - Toshiyuki Kaji
- Department of Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science
| | - Yasuyuki Fujiwara
- Department of Environmental Health, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences
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Branco V, Caito S, Farina M, Teixeira da Rocha J, Aschner M, Carvalho C. Biomarkers of mercury toxicity: Past, present, and future trends. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2017; 20:119-154. [PMID: 28379072 PMCID: PMC6317349 DOI: 10.1080/10937404.2017.1289834] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Mercury (Hg) toxicity continues to represent a global health concern. Given that human populations are mostly exposed to low chronic levels of mercurial compounds (methylmercury through fish, mercury vapor from dental amalgams, and ethylmercury from vaccines), the need for more sensitive and refined tools to assess the effects and/or susceptibility to adverse metal-mediated health risks remains. Traditional biomarkers, such as hair or blood Hg levels, are practical and provide a reliable measure of exposure, but given intra-population variability, it is difficult to establish accurate cause-effect relationships. It is therefore important to identify and validate biomarkers that are predictive of early adverse effects prior to adverse health outcomes becoming irreversible. This review describes the predominant biomarkers used by toxicologists and epidemiologists to evaluate exposure, effect and susceptibility to Hg compounds, weighing on their advantages and disadvantages. Most importantly, and in light of recent findings on the molecular mechanisms underlying Hg-mediated toxicity, potential novel biomarkers that might be predictive of toxic effect are presented, and the applicability of these parameters in risk assessment is examined.
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Affiliation(s)
- Vasco Branco
- a Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
| | - Sam Caito
- b Department of Molecular Pharmacology , Albert Einstein College of Medicine , Bronx , New York , USA
| | - Marcelo Farina
- c Departamento de Bioquímica, Centro de Ciências Biológicas , Universidade Federal de Santa Catarina , Florianópolis , Brazil
| | - João Teixeira da Rocha
- d Departamento Bioquímica e Biologia Molecular , Universidade Federal de Santa Maria , Santa Maria , RS , Brazil
| | - Michael Aschner
- b Department of Molecular Pharmacology , Albert Einstein College of Medicine , Bronx , New York , USA
| | - Cristina Carvalho
- a Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
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Takeda S, Okazaki H, Ikeda E, Abe S, Yoshioka Y, Watanabe K, Aramaki H. Down-regulation of cyclooxygenase-2 (COX-2) by cannabidiolic acid in human breast cancer cells. J Toxicol Sci 2015; 39:711-6. [PMID: 25242400 DOI: 10.2131/jts.39.711] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Metastases are known to be responsible for approximately 90% of breast cancer-related deaths. Cyclooxygenase-2 (COX-2) is involved not only in inflammatory processes, but also in the metastasis of cancer cells; it is expressed in 40% of human invasive breast cancers. To comprehensively analyze the effects of cannabidiolic acid (CBDA), a selective COX-2 inhibitor found in the fiber-type cannabis plant (Takeda et al., 2008), on COX-2 expression and the genes involved in metastasis, we performed a DNA microarray analysis of human breast cancer MDA-MB-231 cells, which are invasive breast cancer cells that express high levels of COX-2, treated with CBDA for 48 hr at 25 µM. The results obtained revealed that COX-2 and Id-1, a positive regulator of breast cancer metastasis, were down-regulated (0.19-fold and 0.52-fold, respectively), while SHARP1 (or BHLHE41), a suppressor of breast cancer metastasis, was up-regulated (1.72-fold) and CHIP (or STUB1) was unaffected (1.03-fold). These changes were confirmed by real-time RT-PCR analyses. Taken together, the results obtained here demonstrated that i) CBDA had dual inhibitory effects on COX-2 through down-regulation and enzyme inhibition, and ii) CBDA may possess the ability to suppress genes that are positively involved in the metastasis of cancer cells in vitro.
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Affiliation(s)
- Shuso Takeda
- Department of Molecular Biology, Daiichi University of Pharmacy
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11
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Marzotto M, Olioso D, Bellavite P. Gene expression and highly diluted molecules. Front Pharmacol 2014; 5:237. [PMID: 25429268 PMCID: PMC4228849 DOI: 10.3389/fphar.2014.00237] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 10/17/2014] [Indexed: 01/22/2023] Open
Affiliation(s)
- Marta Marzotto
- Section of General Pathology, Department of Pathology and Diagnostics, University of Verona Verona, Italy
| | - Debora Olioso
- Section of General Pathology, Department of Pathology and Diagnostics, University of Verona Verona, Italy
| | - Paolo Bellavite
- Section of General Pathology, Department of Pathology and Diagnostics, University of Verona Verona, Italy
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12
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Shinkai Y, Nakajima S, Eiguren-Fernandez A, Di Stefano E, Schmitz DA, Froines JR, Cho AK, Kumagai Y. Ambient vapor samples activate the Nrf2-ARE pathway in human bronchial epithelial BEAS-2B cells. ENVIRONMENTAL TOXICOLOGY 2014; 29:1292-300. [PMID: 23649983 PMCID: PMC4318252 DOI: 10.1002/tox.21860] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 02/17/2013] [Accepted: 02/20/2013] [Indexed: 05/25/2023]
Abstract
Ambient air pollutants have been reported to induce oxidative stress based inflammatory responses in humans and experimental animals. However, most of these reports describe the actions of the particulate phase of ambient and exhaust samples. We describe here results of studies investigating the actions of the vapor phase of ambient air samples collected in the midtown area of Los Angeles on human bronchial epithelial BEAS-2B cells using DNA microarray analysis. Among 26 genes whose expression increased fourfold or more, four genes were associated with detoxifying genes regulated by the transcription factor Nrf2. Consistent with these results, the vapor samples activate the Nrf2-ARE pathway, resulting in up-regulation of heme oxygenase-1 (HO-1), glutamate cysteine ligase modifier subunit, and cystine transporter (xCT) mRNA and proteins. No appreciable increases in pro-inflammatory genes were observed. These results suggest that ambient vapor samples activate the Nrf2-ARE pathway but not an inflammatory response. Also, treatment of the vapor samples with glutathione resulted in reduction in the Nrf2 activation and HO-1 induction, suggesting that electrophiles in vapor samples contribute to this Nrf2-dependent antioxidant or adaptive response.
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Affiliation(s)
- Yasuhiro Shinkai
- Environmental Biology Section, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
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Olsvik PA, Williams TD, Tung HS, Mirbahai L, Sanden M, Skjaerven KH, Ellingsen S. Impacts of TCDD and MeHg on DNA methylation in zebrafish (Danio rerio) across two generations. Comp Biochem Physiol C Toxicol Pharmacol 2014; 165:17-27. [PMID: 24878852 DOI: 10.1016/j.cbpc.2014.05.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/06/2014] [Accepted: 05/18/2014] [Indexed: 12/30/2022]
Abstract
This study aimed to investigate whether dioxin (TCDD) and methylmercury (MeHg) pose a threat to offspring of fish exposed to elevated concentrations of these chemicals via epigenetic-based mechanisms. Adult female zebrafish were fed diets added either 20 μg/kg 2,3,7,8 TCDD or 10 mg/kg MeHg for 47 days, or 10 mg/kg 5-aza-2'-deoxycytidine (5-AZA), a hypomethylating agent, for 32 days, and bred with unexposed males in clean water to produce F1 and F2 offspring. Global DNA methylation, promoter CpG island methylation and target gene transcription in liver of adult females and in 3 days post fertilization (dpf) F1 and F2 embryos were determined with HPLC, a novel CpG island tiling array containing 54,933 different probes and RT-qPCR, respectively. The results showed that chemical treatment had no significant effect on global DNA methylation levels in F1 (MeHg and TCDD) and F2 (MeHg) embryos and only a limited number of genes were identified with altered methylation levels at their promoter regions. CYP1A1 transcription, an established marker of TCDD exposure, was elevated 27-fold in F1 embryos compared to the controls, matching the high levels of CYP1A1 expression observed in F0 TCDD-treated females. This suggests that maternal transfer of TCDD is a significant route of exposure for the F1 offspring. In conclusion, the selected doses of TCDD and MeHg, two chemicals often found in high concentrations in fish, appear to have only modest effects on DNA methylation in F1 (MeHg and TCDD) and F2 (MeHg) embryos of treated F0 females.
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Affiliation(s)
- Pål A Olsvik
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway.
| | - Timothy D Williams
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Hui-shan Tung
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| | - Leda Mirbahai
- School of Biosciences, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Monica Sanden
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| | - Kaja H Skjaerven
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
| | - Ståle Ellingsen
- National Institute of Nutrition and Seafood Research, Nordnesboder 1-2, N-5005 Bergen, Norway
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Kanda H, Shinkai Y, Kumagai Y. S-Mercuration of cellular proteins by methylmercury and its toxicological implications. J Toxicol Sci 2014; 39:687-700. [DOI: 10.2131/jts.39.687] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Hironori Kanda
- Doctoral Program in Biomedical Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba
| | - Yasuhiro Shinkai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba
| | - Yoshito Kumagai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba
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Takeda S, Nishimura H, Koyachi K, Matsumoto K, Yoshida K, Okamoto Y, Amamoto T, Shindo M, Aramaki H. (-)-Xanthatin induces the prolonged expression of c-Fos through an N-acetyl-L-cysteine (NAC)-sensitive mechanism in human breast cancer MDA-MB-231 cells. J Toxicol Sci 2013; 38:547-57. [PMID: 23824011 DOI: 10.2131/jts.38.547] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
We reported that (-)-xanthatin, a xanthanolide sesquiterpene lactone present in the Cocklebur plant, exhibited potent anti-proliferative effects on human breast cancer cells, in which GADD45γ, a novel tumor suppressor gene, was induced. Mechanistically, topoisomerase IIα (Topo IIα) inhibition by (-)-xanthatin was shown to be the upstream trigger that stimulated the expression of GADD45γ mRNA and concomitantly produced reactive oxygen species (ROS) to maintain this expression. Since the anti-cancer drug etoposide, a selective Topo IIα inhibitor, has also been shown to induce intracellular ROS, (-)-xanthatin may exert its anti-proliferative effects on cancer cells in a similar manner to those of etoposide. In the present study, to generalize its applicability to cancer therapy, we further investigated the biological activities of (-)-xanthatin by comparing its activities to those of the established anti-cancer drug etoposide. After the exposure of breast cancer cells to (-)-xanthatin or etoposide, a prolonged and marked up-regulation in the expression of c-fos, a proapoptotic molecule, was detected together with GADD45γ; and the expression of these molecules was stabilized by ROS and abrogated by the pretreatment with N-acetyl-L-cysteine (NAC), a potent ROS scavenger. (-)-Xanthatin in particular exhibited stronger anti-proliferative potential than that of etoposide, which underlies the marked induction of c-fos/GADD45γ and ROS production.
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Affiliation(s)
- Shuso Takeda
- Department of Molecular Biology, Daiichi University of Pharmacy, Japan
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Takeda S, Harada M, Su S, Okajima S, Miyoshi H, Yoshida K, Nishimura H, Okamoto Y, Amamoto T, Watanabe K, Omiecinski CJ, Aramaki H. Induction of the fatty acid 2-hydroxylase (FA2H) gene by Δ(9)-tetrahydrocannabinol in human breast cancer cells. J Toxicol Sci 2013; 38:305-8. [PMID: 23535410 PMCID: PMC4018719 DOI: 10.2131/jts.38.305] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To investigate gene(s) being regulated by ∆(9)-tetrahydrocannabinol (∆(9)-THC), we performed DNA microarray analysis of human breast cancer MDA-MB-231 cells, which are poorly differentiated breast cancer cells, treated with ∆(9)-THC for 48 hr at an IC50 concentration of approximately 25 µM. Among the highly up-regulated genes (> 10-fold) observed, fatty acid 2-hydroxylase (FA2H) was significantly induced (17.8-fold). Although the physiological role of FA2H has not yet been fully understood, FA2H has been shown to modulate cell differentiation. The results of Oil Red O staining after ∆(9)-THC exposure showed the distribution of lipid droplets (a sign of the differentiated phenotype) in cells. Taken together, the results obtained here indicate that FA2H is a novel ∆(9)-THC-regulated gene, and that ∆(9)-THC induces differentiation signal(s) in poorly differentiated MDA-MB-231 cells.
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Affiliation(s)
- Shuso Takeda
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Mari Harada
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Shengzhong Su
- Center for Molecular Toxicology and Carcinogenesis, 101 Life Sciences Building, Pennsylvania State University, University Park, PA 16802, USA
| | - Shunsuke Okajima
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Hiroko Miyoshi
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Kazutaka Yoshida
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Hajime Nishimura
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Yoshiko Okamoto
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
| | - Toshiaki Amamoto
- NEUES Corporation, Yaesu Center Building 3F, 1-6-6 Yaesu, Chuo-ku, Tokyo 103-0028, Japan
| | - Kazuhito Watanabe
- Department of Hygienic Chemistry, Faculty of Pharmaceutical Sciences, Hokuriku University, Ho-3 Kanagawa-machi, Kanazawa 920-1181, Japan
| | - Curtis J Omiecinski
- Center for Molecular Toxicology and Carcinogenesis, 101 Life Sciences Building, Pennsylvania State University, University Park, PA 16802, USA
| | - Hironori Aramaki
- Department of Molecular Biology, Daiichi University of Pharmacy, 22-1 Tamagawa-cho, Minami-ku, Fukuoka 815-8511, Japan
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