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Shen J, Tang ST, Wang YN, Li XT, Chen J, Sarkarai Nadar V, Rosen BP, Zhang J, Zhao FJ. Bifunctional ArsI Dioxygenase from Acidovorax sp. ST3 with Both Methylarsenite [MAs(III)] Demethylation and MAs(III) Oxidation Activities. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024. [PMID: 39226438 DOI: 10.1021/acs.est.4c04835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Methylated arsenicals, including highly toxic species, such as methylarsenite [MAs(III)], are pervasive in the environment. Certain microorganisms possess the ability to detoxify MAs(III) by ArsI-catalyzed demethylation. Here, we characterize a bifunctional enzyme encoded by the arsI gene from Acidovorax sp. ST3, which can detoxify MAs(III) through both the demethylation and oxidation pathways. Deletion of the 22 C-terminal amino acids of ArsI increased its demethylation activity while reducing the oxidation activity. Further deletion of 44 C-terminal residues enhanced the MAs(III) demethylation activity. ArsI has four vicinal cysteine pairs, with the first pair being necessary for MAs(III) demethylation, while at least one of the other three pairs contributes to MAs(III) oxidation. Molecular modeling and site-directed mutagenesis indicated that one of the C-terminal vicinal cysteine pairs is involved in modulating the switch between oxidase and demethylase activity. These findings underscore the critical role of the C-terminal region in modulating the enzymatic activities of ArsI, particularly in MAs(III) demethylation. This research reveals the structure-function relationship of the ArsI enzyme and advances our understanding of the MAs(III) metabolism in bacteria.
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Affiliation(s)
- Jie Shen
- Jiangsu Key Laboratory for Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People's Republic of China
| | - Shi-Tong Tang
- Jiangsu Key Laboratory for Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People's Republic of China
| | - Ya-Nan Wang
- Jiangsu Key Laboratory for Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People's Republic of China
| | - Xue-Ting Li
- Jiangsu Key Laboratory for Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People's Republic of China
| | - Jian Chen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Venkadesh Sarkarai Nadar
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Barry P Rosen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Jun Zhang
- Jiangsu Key Laboratory for Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People's Republic of China
| | - Fang-Jie Zhao
- Jiangsu Key Laboratory for Organic Waste Utilization, Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, People's Republic of China
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Yan Y, Ma JJ, Liang XP, Yin Y, Wu YQ, Yu RL, Hu GR, Zhu YG, Li H. Occurrence and spatiotemporal distribution of arsenic biotransformation genes in urban dust. ENVIRONMENT INTERNATIONAL 2024; 190:108823. [PMID: 38908273 DOI: 10.1016/j.envint.2024.108823] [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: 03/19/2024] [Revised: 05/18/2024] [Accepted: 06/16/2024] [Indexed: 06/24/2024]
Abstract
Microbially-mediated arsenic biotransformation plays a pivotal role in the biogeochemical cycling of arsenic; however, the presence of arsenic biotransformation genes (ABGs) in urban dust remains unclear. To investigate the occurrence and spatiotemporal distributions of ABGs, a total of one hundred and eighteen urban dust samples were collected from different districts of Xiamen city, China in summer and winter. Although inorganic arsenic species, including arsenate [As(V)] and arsenite [As(III)], were found to be predominant, the methylated arsenicals, particularly trimethylarsine oxide [TMAs(V)O] and dimethylarsenate [DMAs(V)], were detected in urban dust. Abundant ABGs were identified in urban dust via AsChip analysis (a high-throughput qPCR chip for ABGs), of which As(III) S-adenosylmethionine methyltransferase genes (arsM), As(V) reductase genes (arsC), As(III) oxidase genes (aioA), As(III) transporter genes (arsB), and arsenic-sensing regulator genes (arsR) were the most prevalent, collectively constituting more than 90 % of ABGs in urban dust. Microbes involved in arsenic methylation were assigned to bacteria (e.g., Actinomycetes and Alphaproteobacteria), archaea (e.g., Halobacteria), and eukaryotes (e.g., Chlamydomonadaceae) in urban dust via the arsM amplicon sequencing. Temperature, a season-dependent environmental factor, profoundly affected the abundance of ABGs and the composition of microbes involved in arsenic methylation. This study provides new insights into the presence of ARGs within the urban dust.
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Affiliation(s)
- Yu Yan
- Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Jin-Jin Ma
- Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Xiu-Peng Liang
- Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Yi Yin
- Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Ya-Qing Wu
- Instrumental Analysis Center of Huaqiao University, Huaqiao University, Xiamen 361021, China
| | - Rui-Lian Yu
- Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Gong-Ren Hu
- Department of Environmental Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Yong-Guan Zhu
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China
| | - Hu Li
- Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China; University of Chinese Academy of Sciences, 19A Yuquan Road, Beijing 100049, China.
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3
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Gomila RM, Frontera A. On the Existence of Pnictogen Bonding Interactions in As(III) S-Adenosylmethionine Methyltransferase Enzymes. Chem Asian J 2024; 19:e202400081. [PMID: 38407495 DOI: 10.1002/asia.202400081] [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: 01/24/2024] [Revised: 02/23/2024] [Accepted: 02/26/2024] [Indexed: 02/27/2024]
Abstract
As(III) S-adenosylmethionine methyltransferases, pivotal enzymes in arsenic metabolism, facilitate the methylation of arsenic up to three times. This process predominantly yields trivalent mono- and dimethylarsenite, with trimethylarsine forming in smaller amounts. While this enzyme acts as a detoxifier in microbial systems by altering As(III), in humans, it paradoxically generates more toxic and potentially carcinogenic methylated arsenic species. The strong affinity of As(III) for cysteine residues, forming As(III)-thiolate bonds, is exploited in medical treatments, notably in arsenic trioxide (Trisenox®), an FDA-approved drug for leukemia. The effectiveness of this drug is partly due to its interaction with cysteine residues, leading to the breakdown of key oncogenic fusion proteins. In this study, we extend the understanding of As(III)'s binding mechanisms, showing that, in addition to As(III)-S covalent bonds, noncovalent O⋅⋅⋅As pnictogen bonding plays a vital role. This interaction significantly contributes to the structural stability of the As(III) complexes. Our crystallographic analysis using the PDB database of As(III) S-adenosylmethionine methyltransferases, augmented by comprehensive theoretical studies including molecular electrostatic potential (MEP), quantum theory of atoms in molecules (QTAIM), and natural bond orbital (NBO) analysis, emphasizes the critical role of pnictogen bonding in these systems. We also undertake a detailed evaluation of the energy characteristics of these pnictogen bonds using various theoretical models. To our knowledge, this is the first time pnictogen bonds in As(III) derivatives have been reported in biological systems, marking a significant advancement in our understanding of arsenic's molecular interactions.
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Affiliation(s)
- Rosa M Gomila
- Department of Chemistry, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122, Palma de Mallorca (Baleares), Spain
| | - Antonio Frontera
- Department of Chemistry, Universitat de les Illes Balears, Crta. de Valldemossa km 7.5, 07122, Palma de Mallorca (Baleares), Spain
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Abstract
In recent times Gallbladder cancer (GBC) incidences increased many folds in India and are being reported from arsenic hotspots identified in Bihar. The study aims to establish association between arsenic exposure and gallbladder carcinogenesis. In the present study, n = 200 were control volunteers and n = 152 confirmed gallbladder cancer cases. The studied GBC patient's biological samples-gallbladder tissue, gallbladder stone, bile, blood and hair samples were collected for arsenic estimation. Moreover, n = 512 gallbladder cancer patients blood samples were also evaluated for the presence of arsenic to understand exposure level in the population. A significantly high arsenic concentration (p < 0.05) was detected in the blood samples with maximum concentration 389 µg/L in GBC cases in comparison to control. Similarly, in the gallbladder cancer patients, there was significantly high arsenic concentration observed in gallbladder tissue with highest concentration of 2166 µg/kg, in gallbladder stones 635 µg/kg, in bile samples 483 µg/L and in hair samples 6980 µg/kg respectively. Moreover, the n = 512 gallbladder cancer patient's blood samples study revealed very significant arsenic concentration in the population of Bihar with maximum arsenic concentration as 746 µg/L. The raised arsenic concentration in the gallbladder cancer patients' biological samples-gallbladder tissue, gallbladder stone, bile, blood, and hair samples was significantly very high in the arsenic exposed area. The study denotes that the gallbladder disease burden is very high in the arsenic exposed area of Bihar. The findings do provide a strong link between arsenic contamination and increased gallbladder carcinogenesis.
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Douillet C, Miller M, Cable PH, Shi Q, El-Masri H, Matoušek T, Koller BH, Thomas DJ, Stýblo M. Fate of arsenicals in mice carrying the human AS3MT gene exposed to environmentally relevant levels of arsenite in drinking water. Sci Rep 2023; 13:3660. [PMID: 36871058 PMCID: PMC9985638 DOI: 10.1038/s41598-023-30723-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Although mice are widely used to study adverse effects of inorganic arsenic (iAs), higher rates of iAs methylation in mice than in humans may limit their utility as a model organism. A recently created 129S6 mouse strain in which the Borcs7/As3mt locus replaces the human BORCS7/AS3MT locus exhibits a human-like pattern of iAs metabolism. Here, we evaluate dosage dependency of iAs metabolism in humanized (Hs) mice. We determined tissue and urinary concentrations and proportions of iAs, methylarsenic (MAs), and dimethylarsenic (DMAs) in male and female Hs and wild-type (WT) mice that received 25- or 400-ppb iAs in drinking water. At both exposure levels, Hs mice excrete less total arsenic (tAs) in urine and retain more tAs in tissues than WT mice. Tissue tAs levels are higher in Hs females than in Hs males, particularly after exposure to 400-ppb iAs. Tissue and urinary fractions of tAs present as iAs and MAs are significantly greater in Hs mice than in WT mice. Notably, tissue tAs dosimetry in Hs mice resembles human tissue dosimetry predicted by a physiologically based pharmacokinetic model. These data provide additional support for use of Hs mice in laboratory studies examining effects of iAs exposure in target tissues or cells.
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Affiliation(s)
- Christelle Douillet
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7461, USA
| | - Madison Miller
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7461, USA
| | - Peter H Cable
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7461, USA
| | - Qing Shi
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7461, USA
| | - Hisham El-Masri
- Chemical Characterization and Exposure Division, Center for Computational Toxicology & Exposure, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, 27709, USA
| | - Tomáš Matoušek
- Institute of Analytical Chemistry of the Czech Academy of Sciences, v. v. i., Veveří 97, 602 00, Brno, Czech Republic
| | - Beverly H Koller
- Department of Genetics, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - David J Thomas
- Dinkey Creek Consulting, LLC, Chapel Hill, NC, 27517, USA
| | - Miroslav Stýblo
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599-7461, USA.
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Abstract
Arsenic is a naturally occurring hazardous element that is environmentally ubiquitous in various chemical forms. Upon exposure, the human body initiates an elimination pathway of progressive methylation into relatively less bioreactive and more easily excretable pentavalent methylated forms. Given its association with decreasing the internal burden of arsenic with ensuing attenuation of its related toxicities, biomethylation has been applauded for decades as a pure route of arsenic detoxification. However, the emergence of detectable trivalent species with profound toxicity has opened a long-standing debate regarding whether arsenic methylation is a detoxifying or bioactivating mechanism. In this review, we approach the topic of arsenic metabolism from both perspectives to create a complete picture of its potential role in the mitigation or aggravation of various arsenic-related pathologies.
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Affiliation(s)
- Mahmoud A El-Ghiaty
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada;
| | - Ayman O S El-Kadi
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Canada;
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Speer RM, Zhou X, Volk LB, Liu KJ, Hudson LG. Arsenic and cancer: Evidence and mechanisms. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2022; 96:151-202. [PMID: 36858772 DOI: 10.1016/bs.apha.2022.08.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Arsenic is a potent carcinogen and poses a significant health concern worldwide. Exposure occurs through ingestion of drinking water and contaminated foods and through inhalation due to pollution. Epidemiological evidence shows arsenic induces cancers of the skin, lung, liver, and bladder among other tissues. While studies in animal and cell culture models support arsenic as a carcinogen, the mechanisms of arsenic carcinogenesis are not fully understood. Arsenic carcinogenesis is a complex process due its ability to be metabolized and because of the many cellular pathways it targets in the cell. Arsenic metabolism and the multiple forms of arsenic play distinct roles in its toxicity and contribute differently to carcinogenic endpoints, and thus must be considered. Arsenic generates reactive oxygen species increasing oxidative stress and damaging DNA and other macromolecules. Concurrently, arsenic inhibits DNA repair, modifies epigenetic regulation of gene expression, and targets protein function due its ability to replace zinc in select proteins. While these mechanisms contribute to arsenic carcinogenesis, there remain significant gaps in understanding the complex nature of arsenic cancers. In the future improving models available for arsenic cancer research and the use of arsenic induced human tumors will bridge some of these gaps in understanding arsenic driven cancers.
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Affiliation(s)
- Rachel M Speer
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, NM, United States
| | - Xixi Zhou
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, NM, United States
| | - Lindsay B Volk
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, NM, United States
| | - Ke Jian Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, NM, United States; Stony Brook Cancer Center, Renaissance School of Medicine, State University of New York Stony Brook, Stony Brook, NY, United States.
| | - Laurie G Hudson
- Department of Pharmaceutical Sciences, College of Pharmacy, University of New Mexico, Albuquerque, NM, United States
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Pasha SS, Banerjee A, Sreedharan S, Singh S, Kandoth N, Vallis KA, Pal SK, Pramanik SK, Das A. Ultrasensitive Reagent for Ratiometric Detection and Detoxification of iAsIII in Water and Mitochondria. Inorg Chem 2022; 61:13115-13124. [PMID: 35950896 DOI: 10.1021/acs.inorgchem.2c01761] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Toxicity induced by inorganic arsenic as AsO33- (iAsIII) is of global concern. Reliable detection of the maximum allowed contaminant level for arsenic in drinking water and in the cellular system remains a challenge for the water quality management and assessment of toxicity in the cellular milieu, respectively. A new Ir(III)-based phosphorescent molecule (AS-1; λExt = 415 nm and λEms = 600 nm, Φ = 0.3) is synthesized for the selective detection of iAsIII in an aqueous solution with a ratiometric luminescence response even in the presence of iAsV and all other common inorganic cations and anions. The relatively higher affinity of the thioimidazole ligand (HPBT) toward iAsIII led to the formation of a fluorescent molecule iAsV-HPBT (λExt = 415 nm and λEms = 466 nm, Φ = 0.28) for the reaction of iAsIII and AS-1. An improved limit of quantitation (LOQ) down to 0.2 ppb is achieved when AS-1 is used in the CTAB micellar system. Presumably, the cationic surfactants favor the localization of AS-1@CTABMicelle in mitochondria of MCF7 cells, and this is confirmed from the images of the confocal laser fluorescence scanning microscopic studies. Importantly, cell viability assay studies confirm that AS-1@CTABMicelle induces dose-dependent detoxification of iAsIII in live cells. Further, luminescence responses at 466 nm could be utilized for developing a hand-held device for the in-field application. Such a reagent that allows for ratiometric detection of iAsIII with LOQ of 2.6 nM (0.5 ppb) in water, as well as helps in visualizing its distribution in mitochondria with a detoxifying effect, is rather unique in contemporary literature.
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Affiliation(s)
- Sheik Saleem Pasha
- Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat, India
| | - Amrita Banerjee
- Technical Research Centre, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, West Bengal 700106, India
| | - Sreejesh Sreedharan
- Oxford Institute for Radiation Oncology, University of Oxford, Oxford OX3 7DQ, U.K.,Human Sciences Research Centre, University of Derby, Derby DE221GB, U.K
| | - Soumendra Singh
- Technical Research Centre, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, West Bengal 700106, India
| | - Noufal Kandoth
- Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Katherine A Vallis
- Oxford Institute for Radiation Oncology, University of Oxford, Oxford OX3 7DQ, U.K
| | - Samir Kumar Pal
- Technical Research Centre, Department of Chemical, Biological & Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata, West Bengal 700106, India
| | - Sumit Kumar Pramanik
- Central Salt and Marine Chemicals Research Institute, Bhavnagar 364002, Gujarat, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Amitava Das
- Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Mersaoui SY, Guilbert C, Chou H, Douillet C, Bohle DS, Stýblo M, Richard S, Mann KK. Arsenic 3 methyltransferase (AS3MT) automethylates on cysteine residues in vitro. Arch Toxicol 2022; 96:1371-1386. [PMID: 35244730 PMCID: PMC9013690 DOI: 10.1007/s00204-022-03248-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 02/02/2022] [Indexed: 11/25/2022]
Abstract
Arsenic toxicity is a global concern to human health causing increased incidences of cancer, bronchopulmonary, and cardiovascular diseases. In human and mouse, inorganic arsenic (iAs) is metabolized in a series of methylation steps catalyzed by arsenic (3) methyltransferase (AS3MT), forming methylated arsenite (MAsIII), dimethylarsenite (DMAIII) and the volatile trimethylarsine (TMA). The methylation of arsenic is coordinated by four conserved cysteines proposed to participate in catalysis, namely C33, C62, C157, and C207 in mouse AS3MT. The current model consists of AS3MT methylating iAs in the presence of the cofactor S-adenosyl-L-methionine (SAM), and the formation of intramolecular disulfide bonds following the reduction of MAsV to MAsIII. In the presence of endogenous reductants, these disulfide bonds are reduced, the enzyme re-generates, and the second round of methylation ensues. Using in vitro methylation assays, we find that AS3MT undergoes an initial automethylation step in the absence of iAs. This automethylation is enhanced by glutathione (GSH) and dithiothreitol (DTT), suggesting that reduced cysteines accept methyl groups from SAM to form S-methylcysteines. Following the addition of iAs, automethylation of AS3MT is decreased. Furthermore, using a Flag-AS3MT immunoprecipitation coupled to MS/MS, we identify both C33 and C62 as acceptors of the methyl group in vivo. Site-directed mutagenesis (C to A) revealed that three of the previously described cysteines were required for AS3MT automethylation. In vitro experiments show that automethylated AS3MT can methylate iAs in the presence of SAM. Thus, we propose that automethylated may represent an active conformation of AS3MT.
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Affiliation(s)
- Sofiane Y Mersaoui
- Segal Cancer Center, Lady Davis Institute for Medical Research and Departments of Oncology and Medicine, McGill University, Montréal, Québec, H3T 1E2, Canada
| | - Cynthia Guilbert
- Segal Cancer Center, Lady Davis Institute for Medical Research and Departments of Oncology and Medicine, McGill University, Montréal, Québec, H3T 1E2, Canada
| | - Hsiang Chou
- Segal Cancer Center, Lady Davis Institute for Medical Research and Departments of Oncology and Medicine, McGill University, Montréal, Québec, H3T 1E2, Canada
| | - Christelle Douillet
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB# 7461, Chapel Hill, NC, 27599, USA
| | - D Scott Bohle
- Department of Chemistry, McGill University, Otto Maass 233A, Montréal, Québec, H3A 0B8, Canada
| | - Miroslav Stýblo
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB# 7461, Chapel Hill, NC, 27599, USA
| | - Stéphane Richard
- Segal Cancer Center, Lady Davis Institute for Medical Research and Departments of Oncology and Medicine, McGill University, Montréal, Québec, H3T 1E2, Canada.
| | - Koren K Mann
- Segal Cancer Center, Lady Davis Institute for Medical Research and Departments of Oncology and Medicine, McGill University, Montréal, Québec, H3T 1E2, Canada.
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10
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Radhakrishnan M, Packianathan C, Sankaran B, Kandavelu P, Rosen BP. Purification, Crystallization, and Preliminary Crystallographic Studies of Human As(III) S-Adenosylmethionine Methyltransferase (hAS3MT). CRYSTALLOGR REP+ 2021; 66:1311-1315. [PMID: 35221644 PMCID: PMC8879404 DOI: 10.1134/s1063774521070129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 09/13/2020] [Accepted: 09/16/2020] [Indexed: 12/16/2022]
Abstract
Exposure to environmental arsenic is associated with serious of health issues such as cancer, diabetes and developmental delays in infants and children. In human liver, As(III) S-adenosylmethionine methyl transferase (hAS3MT) (EC 2.1.1.137) was proposed to be an detoxification process by methylation of inorganic arsenite into pentavalent methyl MAs(V) and dimethyl arsenite DMAs(V). More recently the first product was shown to be highly toxic and potentially carcinogenic trivalent methylarsenite (MAs(III)). Our studies are designed to elucidate the mechanism of AS3MT and its contribution to arsenic-related diseases. Here, we report the first crystallization and preliminary X-ray diffraction analysis of the human AS3MT enzyme. The crystals belong to the monoclinic P1211 space group with unit cell parameters of a = 135.03 Å, b = 260.44 Å, c = 279.03 Å, α = 90.00°, β = 93.36°, γ = 90.00°.
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Affiliation(s)
- M. Radhakrishnan
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL.33199 USA
| | - C. Packianathan
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL.33199 USA
- Department of Chemistry, Texas A&M University, College Station, Texas, TX USA
| | - B. Sankaran
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley Laboratory, BLDG 6R2100, Berkeley, CA 94720 USA
| | - P. Kandavelu
- SER-CAT and the Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602 USA
| | - B. P. Rosen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL.33199 USA
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11
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Ni G, Tan J, Wang M, Ping N, Liu M, He Y. Polymorphisms of the AS3MT gene are associated with arsenic methylation capacity and damage to the P21 gene in arsenic trioxide plant workers. Toxicol Ind Health 2021; 37:727-736. [PMID: 34730462 DOI: 10.1177/07482337211013321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Epidemiological evidence suggests that the metabolic profiles of each individual exposed to arsenic (As) are related to the risk of cancer, coronary heart disease, and diabetes. The arsenite methyltransferase (AS3MT) gene plays a key role in As metabolism. Several single nucleotide polymorphisms in the AS3MT gene may affect both enzyme activity and gene transcription. AS3MT polymorphisms are associated with the proportions of monomethylarsenic acid (MMA) and dimethylarsenic acid (DMA) in urine as well as the incidence of cancer. P21 protein is a cyclin-dependent kinase inhibitor. Mutations of the P21 gene have been found in cancer patients. In our study, we investigate whether polymorphisms of the AS3MT gene alter As methylation capacity and adversely affect the P21 gene in arsenic trioxide plant workers. The DNA damage was examined by the quantitative polymerase chain reaction. Restriction fragment length polymorphism was used to analyze the genotype of the AS3MT gene. The results showed that DNA damage in P21 gene fragments was greater in those individuals exposed to high levels of As. There was a strong positive correlation between the DNA damage to P21 gene fragments and the percentage of MMA in urine. However, DNA damage in P21 gene fragments was negatively associated with the percentage of DMA in urine (%uDMA), primary methylation index (PMI), and secondary methylation index. We found that subjects with the rs7085104 GG or GA allele were associated with higher %uDMA and PMI and less DNA damage. The subjects with the rs11191454 GG+GA or GA allele were also associated with higher %uDMA and PMI and less DNA damage. Our results suggest that rs1191454 and rs7085104 in the AS3MT gene affect the As-induced DNA damage by altering individual metabolic efficiency.
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Affiliation(s)
- Guanghui Ni
- School of Chinese Material Medica, Yunnan University of Chinese Medicine, Kunming, Yunnan, China
| | - Jingwen Tan
- School of Public Health, Kunming Medical University, Kunming, Yunnan, China
| | - Mengjie Wang
- School of Public Health, Kunming Medical University, Kunming, Yunnan, China
| | - Nina Ping
- School of Public Health, Kunming Medical University, Kunming, Yunnan, China
| | - Min Liu
- School of Public Health, Kunming Medical University, Kunming, Yunnan, China
| | - Yuefeng He
- School of Public Health, Kunming Medical University, Kunming, Yunnan, China
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12
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Jing N, Wang X, Yang X, Liu Q, Wang H, Dong F, He K, Wang N. Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry for the Analysis of Complex Compounds in Serum and Its Application in Accurate Detection of Early Arsenic Exposure. ACS OMEGA 2021; 6:28326-28333. [PMID: 34723029 PMCID: PMC8552457 DOI: 10.1021/acsomega.1c04517] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
With the acceleration of industrialization, environmental arsenic pollution is threatening human health. However, by the time clinical symptoms appear, arsenic toxicity has usually caused irreversible damage to the body, so it is important to establish a rapid and accurate screening method for early arsenic exposure. In this work, 32 female C57BL/6 mice were exposed to different concentrations of inorganic arsenic in drinking water for a week. By analyzing the changes in serum, more than 20 compounds were detected to increase or decrease with the increase of arsenic intake. The abnormal increase in inosine, xanthine, xanthosine, and hypoxanthine and the abnormal purine pathway were found at the same time. Dimethylarsenic acid, an important inorganic arsenic metabolite in the body, was also found in serum. Combined with statistical analysis, early arsenic exposure can be easily and quickly detected, and the potential health risks of short-term exposure can be revealed simultaneously.
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13
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Ghiuzeli CM, Stýblo M, Saunders J, Calabro A, Budman D, Allen S, Devoe C, Dhingra R. The pharmacokinetics of therapeutic arsenic trioxide in acute promyelocytic leukemia patients. Leuk Lymphoma 2021; 63:653-663. [PMID: 34689693 DOI: 10.1080/10428194.2021.1978084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Arsenic trioxide (ATO) treats Acute Promyelocytic Leukemia (APL). ATO is converted from inorganic arsenic (iAs) to methylated (MAs) and dimethylated (DMAs) metabolites, which are excreted in the urine. Methylation of iAs is important in detoxification, as iAs exposure is deleterious to health. We examined ATO metabolism in 25 APL patients, measuring iAs, MAs, and DMAs. Plasma total iAs increased after ATO administration, followed by a rapid decline, reaching trough levels by 4-6 h. We identified two patterns of iAs metabolism between 6 and 24 h after infusion: in Group 1, iAs increased and were slowly converted to MAs and DMAs, whereas in Group 2, iAs was rapidly metabolized. These patterns were associated with smoking and different treatments: ATO with all-trans retinoic acid (ATRA) alone vs. ATO preceded by ATRA and chemotherapy. Our data suggest that smoking and prior chemotherapy exposure may be associated with ATO metabolism stimulation, thus lowering the effective blood ATO dose.
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Affiliation(s)
- Cristina M Ghiuzeli
- Northwell Health Cancer Institute, Zucker School of Medicine at Hofstra/Northwell, New York, NY, USA
| | - Miroslav Stýblo
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Institute for Environmental Health Solutions, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jesse Saunders
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Anthony Calabro
- Department of Medicine, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA
| | - Daniel Budman
- Northwell Health Cancer Institute, Zucker School of Medicine at Hofstra/Northwell, New York, NY, USA
| | - Steven Allen
- Northwell Health Cancer Institute, Zucker School of Medicine at Hofstra/Northwell, New York, NY, USA
| | - Craig Devoe
- Northwell Health Cancer Institute, Zucker School of Medicine at Hofstra/Northwell, New York, NY, USA
| | - Radhika Dhingra
- Institute for Environmental Health Solutions, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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14
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Rehman MU, Khan R, Khan A, Qamar W, Arafah A, Ahmad A, Ahmad A, Akhter R, Rinklebe J, Ahmad P. Fate of arsenic in living systems: Implications for sustainable and safe food chains. JOURNAL OF HAZARDOUS MATERIALS 2021; 417:126050. [PMID: 34229383 DOI: 10.1016/j.jhazmat.2021.126050] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 04/27/2021] [Accepted: 04/29/2021] [Indexed: 06/13/2023]
Abstract
Arsenic, a group 1 carcinogen for humans, is abundant as compared to other trace elements in the environment and is present mainly in the Earth's crust and soil. The arsenic distributions in different geographical regions are dependent on their geological histories. Anthropogenic activities also contribute significantly to arsenic release into the environment. Arsenic presents several complications to humans, animals, and plants. The physiology of plants and their growth and development are affected by arsenic. Arsenic is known to cause cancer and several types of organ toxicity, such as cardiotoxicity, nephrotoxicity, and hepatotoxicity. In the environment, arsenic exists in variable forms both as inorganic and organic species. From arsenic containing compartments, plants can absorb and accumulate arsenic. Crops grown on these contaminated soils pose several-fold higher toxicity to humans compared with drinking water if arsenic enters the food chain. Information regarding arsenic transfer at different trophic levels in food chains has not been summarized until now. The present review focuses on the food chain perspective of arsenic, which affects all components of the food chain during its course. The circumstances that facilitate arsenic accumulation in flora and fauna, as components of the food chain, are outlined in this review.
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Affiliation(s)
- Muneeb U Rehman
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.
| | - Rehan Khan
- Department of Nano-Therapeutics, Institute of Nano Science & Technology, Habitat Centre, Phase 10, Sector 64, Mohali, Punjab 160062, India
| | - Andleeb Khan
- Department of Pharmacology and Toxicology, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia
| | - Wajhul Qamar
- Department of Pharmacology and Toxicology and Central Lab, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Azher Arafah
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Anas Ahmad
- Department of Nano-Therapeutics, Institute of Nano Science & Technology, Habitat Centre, Phase 10, Sector 64, Mohali, Punjab 160062, India
| | - Ajaz Ahmad
- Department of Clinical Pharmacy, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia
| | - Rukhsana Akhter
- Department of Clinical Biochemistry, Govt. Degree College (Baramulla), Khawaja Bagh, Baramulla, Jammu and Kashmir, India
| | - Jörg Rinklebe
- University of Wuppertal, School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water, and Waste-Management, Laboratory of Soil, and Groundwater-Management, Pauluskirchstraße 7, 42285 Wuppertal, Germany; Department of Environment, Energy and Geoinformatics, Sejong University, Seoul 05006, South Korea
| | - Parvaiz Ahmad
- Botany and Microbiology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
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15
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Olmos V, Astolfo MA, Sassone AH, Villaamil Lepori EC. The level of exposure affects the arsenic urinary methylation profile of a population of children. JOURNAL OF HAZARDOUS MATERIALS 2021; 415:125623. [PMID: 33740719 DOI: 10.1016/j.jhazmat.2021.125623] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/29/2020] [Accepted: 03/06/2021] [Indexed: 06/12/2023]
Abstract
Differences in the As methylation capacity of Argentine children, exposed to different levels of As in drinking water were evaluated, considering the gender and the presence of the As3MT T860C gene polymorphism. Inorganic As (%IAs), monomethylated As (%MMA) and dimethylated As (%DMA), primary methylation index (PMI) and secondary methylation index (SMI) were evaluated and represented the As methylation capacity. Urinary As ranged from 18 to 5106 µg/g creatinine. Comparisons were performed between lowest and highest quartiles of urinary As. The level of exposure was positively related to urinary %MMA and negatively to %DMA and to SMI. Considering the presence of the As3MT T860C polymorphism, the level of exposure increased %MMA, and decreased %DMA and the SMI in carriers of the T/T genotype. SMI OR for T/T carriers was 10.61 (95% CI: 2.16-52.16, p: 0.0036). Regarding the gender, the level of exposure increased %MMA, and decreased %DMA and the SMI in girls and boys. SMI OR for girls was 8.71 (95% CI: 1.48-51.08, p: 0.0165) and for boys, OR: 18.15 (95% CI: 2.03-162.35, p: 0.0095). It was possible to identify the level of exposure as a factor that can modify the influence that other factors have on the methylation of As.
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Affiliation(s)
- Valentina Olmos
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Toxicología y Química Legal, Junin 956, 7th Floor, Buenos Aires C1113AAD, Argentina.
| | - María Agustina Astolfo
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Toxicología y Química Legal, Junin 956, 7th Floor, Buenos Aires C1113AAD, Argentina
| | - Adriana H Sassone
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Toxicología y Química Legal, Junin 956, 7th Floor, Buenos Aires C1113AAD, Argentina
| | - Edda C Villaamil Lepori
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Cátedra de Toxicología y Química Legal, Junin 956, 7th Floor, Buenos Aires C1113AAD, Argentina
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16
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Insights into S-adenosyl-l-methionine (SAM)-dependent methyltransferase related diseases and genetic polymorphisms. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2021; 788:108396. [PMID: 34893161 DOI: 10.1016/j.mrrev.2021.108396] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 10/03/2021] [Accepted: 10/05/2021] [Indexed: 12/11/2022]
Abstract
Enzymatic methylation catalyzed by methyltransferases has a significant impact on many human biochemical reactions. As the second most ubiquitous cofactor in humans, S-adenosyl-l-methionine (SAM or AdoMet) serves as a methyl donor for SAM-dependent methyltransferases (MTases), which transfer a methyl group to a nucleophilic acceptor such as O, As, N, S, or C as the byproduct. SAM-dependent methyltransferases can be grouped into different types based on the substrates. Here we systematically reviewed eight types of methyltransferases associated with human diseases. Catechol O-methyltransferase (COMT), As(III) S-adenosylmethionine methyltransferase (AS3MT), indolethylamine N-methyltransferase (INMT), phenylethanolamine N-methyltransferase (PNMT), histamine N-methyltransferase (HNMT), nicotinamide N-methyltransferase (NNMT), thiopurine S-methyltransferase (TPMT) and DNA methyltansferase (DNMT) are classic SAM-dependent MTases. Correlations between genotypes and disease susceptibility can be partially explained by genetic polymorphisms. The physiological function, substrate specificity, genetic variants and disease susceptibility associated with these eight SAM-dependent methyltransferases are discussed in this review.
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17
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Park D, Propper CR, Wang G, Salanga MC. Synonymous single nucleotide polymorphism in arsenic (+3) methyltransferase of the Western mosquitofish (Gambusia affinis) and its gene expression among field populations. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:711-718. [PMID: 33811567 PMCID: PMC8060185 DOI: 10.1007/s10646-021-02376-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/22/2021] [Indexed: 05/05/2023]
Abstract
Naturally occurring arsenic is toxic at extremely low concentrations, yet some species persist even in high arsenic environments. We wanted to test if these species show evidence of evolution associated with arsenic exposure. To do this, we compared allelic variation across 872 coding nucleotides of arsenic (+3) methyltransferase (as3mt) and whole fish as3mt gene expression from three field populations of Gambusia affinis, from water sources containing low (1.9 ppb), medium-low (3.3 ppb), and high (15.7 ppb) levels of arsenic. The high arsenic site exceeds the US EPA's Maximum Contamination Level for drinking water. Medium-low and high populations exhibited homozygosity, and no sequence variation across all animals sampled. Eleven of 24 fish examined (45.8%) in the low arsenic population harbored synonymous single nucleotide polymorphisms (SNPs) in exons 4 and/or 10. SNP presence in the low arsenic population was not associated with differences in as3mt transcript levels compared to fish from the medium-low site, where SNPs were noted; however, as3mt expression in fish from the high arsenic concentration site was significantly lower than the other two sites. Low sequence variation in fish populations from sites with medium-low and high arsenic concentrations suggests greater selective pressure on this allele, while higher variation in the low population suggests a relaxed selection. Our results suggest gene regulation associated with arsenic detoxification may play a more crucial role in influencing responses to arsenic than polymorphic gene sequence. Understanding microevolutionary processes to various contaminants require the evaluation of multiple populations across a wide range of pollution exposures.
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Affiliation(s)
- Daesik Park
- Division of Science Education, Kangwon National University, Chuncheon, Kangwon, 24341, South Korea
| | - Catherine R Propper
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Guangning Wang
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Matthew C Salanga
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, 86011, USA.
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18
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Douillet C, Ji J, Meenakshi IL, Lu K, de Villena FPM, Fry RC, Stýblo M. Diverse genetic backgrounds play a prominent role in the metabolic phenotype of CC021/Unc and CC027/GeniUNC mice exposed to inorganic arsenic. Toxicology 2021; 452:152696. [PMID: 33524430 DOI: 10.1016/j.tox.2021.152696] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/12/2020] [Accepted: 01/23/2021] [Indexed: 12/30/2022]
Abstract
Arsenic methyltransferase (AS3MT) is the key enzyme in the pathway for the methylation of inorganic arsenic (iAs), a potent human carcinogen and diabetogen. AS3MT converts iAs to mono- and dimethylated arsenic species (MAs, DMAs) that are excreted mainly in urine. Polymorphisms in AS3MT is a key genetic factor affecting iAs metabolism and toxicity. The present study examined the role of As3mt polymorphisms in the susceptibility to the diabetogenic effects of iAs exposure using two Collaborative Cross mouse strains, CC021/Unc and CC027/GeniUnc, carrying different As3mt haplotypes. Male mice from the two strains were exposed to iAs in drinking water (0, 0.1 or 50 ppm) for 11 weeks. Blood glucose and plasma insulin levels were measured after 6-h fasting and 15 min after i.p. injection of glucose. Body composition was determined using magnetic resonance imaging. To asses iAs metabolism, the concentrations of iAs, MAs and DMAs were measured in urine. The results show that CC021 mice, both iAs-exposed and controls, had higher body fat percentage, lower fasting blood glucose, higher fasting plasma insulin, and were more insulin resistant than their CC027 counterparts. iAs exposure had a minor effect on diabetes indicators and only in CC027 mice. Blood glucose levels 15 min after glucose injection were significantly higher in CC027 mice exposed to 0.1 ppm iAs than in control mice. No significant differences were found in the concentrations or proportions of arsenic species in urine of CC021 and CC027 mice at the same exposure level. These results suggest that the differences in As3mt haplotypes did not affect the profiles of iAs or its metabolites in mouse urine. The major differences in diabetes indicators were associated with the genetic backgrounds of CC021 and CC027 mice. The effects of iAs exposure, while minor, were genotype- and dose-dependent.
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Affiliation(s)
- Christelle Douillet
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Jinglin Ji
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Immaneni Lakshmi Meenakshi
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kun Lu
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Fernando Pardo-Manuel de Villena
- Department of Genetics, Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Rebecca C Fry
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Miroslav Stýblo
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
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19
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Arsenic Methyltransferase and Methylation of Inorganic Arsenic. Biomolecules 2020; 10:biom10091351. [PMID: 32971865 PMCID: PMC7563989 DOI: 10.3390/biom10091351] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 09/11/2020] [Accepted: 09/18/2020] [Indexed: 12/17/2022] Open
Abstract
Arsenic occurs naturally in the environment, and exists predominantly as inorganic arsenite (As (III) and arsenate As (V)). Arsenic contamination of drinking water has long been recognized as a major global health concern. Arsenic exposure causes changes in skin color and lesions, and more severe health conditions such as black foot disease as well as various cancers originating in the lungs, skin, and bladder. In order to efficiently metabolize and excrete arsenic, it is methylated to monomethylarsonic and dimethylarsinic acid. One single enzyme, arsenic methyltransferase (AS3MT) is responsible for generating both metabolites. AS3MT has been purified from several mammalian and nonmammalian species, and its mRNA sequences were determined from amino acid sequences. With the advent of genome technology, mRNA sequences of AS3MT have been predicted from many species throughout the animal kingdom. Horizontal gene transfer had been postulated for this gene through phylogenetic studies, which suggests the importance of this gene in appropriately handling arsenic exposures in various organisms. An altered ability to methylate arsenic is dependent on specific single nucleotide polymorphisms (SNPs) in AS3MT. Reduced AS3MT activity resulting in poor metabolism of iAs has been shown to reduce expression of the tumor suppressor gene, p16, which is a potential pathway in arsenic carcinogenesis. Arsenic is also known to induce oxidative stress in cells. However, the presence of antioxidant response elements (AREs) in the promoter sequences of AS3MT in several species does not correlate with the ability to methylate arsenic. ARE elements are known to bind NRF2 and induce antioxidant enzymes to combat oxidative stress. NRF2 may be partly responsible for the biotransformation of iAs and the generation of methylated arsenic species via AS3MT. In this article, arsenic metabolism, excretion, and toxicity, a discussion of the AS3MT gene and its evolutionary history, and DNA methylation resulting from arsenic exposure have been reviewed.
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20
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Maimaitiyiming Y, Zhu HH, Yang C, Naranmandura H. Biotransformation of arsenic trioxide by AS3MT favors eradication of acute promyelocytic leukemia: revealing the hidden facts. Drug Metab Rev 2020; 52:425-437. [PMID: 32677488 DOI: 10.1080/03602532.2020.1791173] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Arsenic trioxide (ATO) is one of the most effective drugs for treatment of acute promyelocytic leukemia (APL). It could specifically target the PML/RARα fusion oncoprotein stability and induces APL cell differentiation as well as apoptosis. Although many studies have been conducted to document the anticancer effects and mechanism of ATO, there is little information about the association between biotransformation of ATO to active arsenic metabolites and APL therapy. Generally, ATO can be rapidly converted into trivalent methylated metabolites by arsenic (+3 oxidation state) methyltransferase (AS3MT) mostly in liver and redistributed to bloodstream of APL patients who receiving ATO treatment, thereby leading to a balance between cytotoxicity and differentiation, which is proposed to be the key event in successful treatment of APL. In this review, we comprehensively discussed possible roles of AS3MT and methylated arsenic metabolites in APL therapy, so as to reveal the association between individual differences of AS3MT expression and activity with the therapeutic efficacy of ATO in APL patients.
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Affiliation(s)
- Yasen Maimaitiyiming
- Department of Hematology of First Affiliated Hospital, and Department of Public Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Hong-Hu Zhu
- Department of Hematology, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Chang Yang
- Department of Hematology of First Affiliated Hospital, and Department of Public Health, Zhejiang University School of Medicine, Hangzhou, China
| | - Hua Naranmandura
- Department of Hematology of First Affiliated Hospital, and Department of Public Health, Zhejiang University School of Medicine, Hangzhou, China
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21
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Zdraljevic S, Fox BW, Strand C, Panda O, Tenjo FJ, Brady SC, Crombie TA, Doench JG, Schroeder FC, Andersen EC. Natural variation in C. elegans arsenic toxicity is explained by differences in branched chain amino acid metabolism. eLife 2019; 8:40260. [PMID: 30958264 PMCID: PMC6453569 DOI: 10.7554/elife.40260] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 03/26/2019] [Indexed: 12/29/2022] Open
Abstract
We find that variation in the dbt-1 gene underlies natural differences in Caenorhabditis elegans responses to the toxin arsenic. This gene encodes the E2 subunit of the branched-chain α-keto acid dehydrogenase (BCKDH) complex, a core component of branched-chain amino acid (BCAA) metabolism. We causally linked a non-synonymous variant in the conserved lipoyl domain of DBT-1 to differential arsenic responses. Using targeted metabolomics and chemical supplementation, we demonstrate that differences in responses to arsenic are caused by variation in iso-branched chain fatty acids. Additionally, we show that levels of branched chain fatty acids in human cells are perturbed by arsenic treatment. This finding has broad implications for arsenic toxicity and for arsenic-focused chemotherapeutics across human populations. Our study implicates the BCKDH complex and BCAA metabolism in arsenic responses, demonstrating the power of C. elegans natural genetic diversity to identify novel mechanisms by which environmental toxins affect organismal physiology. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Stefan Zdraljevic
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, United States.,Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - Bennett William Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
| | | | - Oishika Panda
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States.,The Buck Institute for Research on Aging, Novato, United States
| | - Francisco J Tenjo
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
| | - Shannon C Brady
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, United States.,Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - Tim A Crombie
- Department of Molecular Biosciences, Northwestern University, Evanston, United States
| | - John G Doench
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, United States
| | - Erik C Andersen
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, United States.,Department of Molecular Biosciences, Northwestern University, Evanston, United States.,Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Northwestern University, Chicago, United States
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22
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Tsuji JS, Chang ET, Gentry PR, Clewell HJ, Boffetta P, Cohen SM. Dose-response for assessing the cancer risk of inorganic arsenic in drinking water: the scientific basis for use of a threshold approach. Crit Rev Toxicol 2019; 49:36-84. [DOI: 10.1080/10408444.2019.1573804] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Ellen T. Chang
- Exponent, Inc., Menlo Park, CA and Stanford Cancer Institute, Stanford, CA, USA
| | | | | | - Paolo Boffetta
- Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Samuel M. Cohen
- Havlik-Wall Professor of Oncology, Department of Pathology and Microbiology and the Fred and Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, USA
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23
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Twaddle NC, Vanlandingham M, Beland FA, Doerge DR. Metabolism and disposition of arsenic species after repeated oral dosing with sodium arsenite in drinking water. II. Measurements in pregnant and fetal CD-1 mice. Food Chem Toxicol 2018. [PMID: 29530638 DOI: 10.1016/j.fct.2018.03.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Arsenic is ubiquitous in the earth's crust, and human diseases are linked with exposures that are similar to dietary intake estimates. Metabolic methylation of inorganic arsenic facilitates excretion of pentavalent metabolites and decreases acute toxicity; however, tissue binding of trivalent arsenic intermediates is evidence for concomitant metabolic activation. Pregnant and fetal CD-1 mice comprise a key animal model for arsenic carcinogenesis since adult-only exposures have minimal effects. This study evaluated inorganic arsenic and its metabolites in pentavalent and trivalent states in blood and tissues from maternal and fetal CD-1 mice after repeated administration of arsenite through drinking water. After 8 days of exposure, DMA species were ubiquitous in dams and fetuses. Despite the presence of MMAIII in dams, none was observed in any fetal sample. This difference may be important in assessing fetal susceptibility to arsenic toxicity because MMA production has been linked with human disease. Binding of DMAIII in fetal tissues provided evidence for metabolic activation, although the role for such binding in arsenic toxicity is unclear. This study provides links between administered dose, metabolism, and internal exposures from a key animal model of arsenic toxicity to better understand risks from human exposure to environmental arsenic.
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Affiliation(s)
- Nathan C Twaddle
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Michelle Vanlandingham
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Frederick A Beland
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Daniel R Doerge
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States.
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24
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Twaddle NC, Vanlandingham M, Churchwell MI, Doerge DR. Metabolism and disposition of arsenic species from controlled oral dosing with sodium arsenite in adult female CD-1 mice. I. Pilot study to determine dosing, analytical measurements, and sampling strategies. Food Chem Toxicol 2017; 111:482-493. [PMID: 29217265 DOI: 10.1016/j.fct.2017.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/07/2017] [Accepted: 12/02/2017] [Indexed: 12/21/2022]
Abstract
Arsenic (As) is ubiquitous in the earth's crust, with typical dietary intake in developed countries <1 μg/kg bw/d, and atypical groundwater exposures in developing countries approaching 50 μg/kg bw/d. Arsenic exposures are linked with human diseases and doses of toxicological concern are similar to typical dietary intake estimates. The methylation of arsenite by arsenite-3-methyltransferase (As3MT) promotes the clearance of arsenic as pentavalent species, but also generates reactive trivalent intermediates. This study measured inorganic arsenic and its metabolites in pentavalent and trivalent states in blood, tissues, and excreta after oral administration of arsenite (50-200 μg/kg bw). While liver was a major site for clearance of arsenite and formation of methylated species, it also had extensive binding of trivalent intermediates; however, thiol exchange and oxidation reactions of trivalent arsenic were facile since dimethylarsinic acid (DMAV) was the predominant species in blood and urine. Consistent evidence was observed for a non-linear relationship between doses above 50 μg/kg bw and levels of bound trivalent As metabolites. The abundance of protein-bound trivalent arsenic within target tissues should correlate with disruption of critical cellular processes, which rely on defined interactions of thiol functional groups, and could provide dose-response relationships from animal models for human risk assessment.
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Affiliation(s)
- Nathan C Twaddle
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Michelle Vanlandingham
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Mona I Churchwell
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States
| | - Daniel R Doerge
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, AR 72079, United States.
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25
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Pawitwar SS, Nadar VS, Kandegedara A, Stemmler TL, Rosen BP, Yoshinaga M. Biochemical Characterization of ArsI: A Novel C-As Lyase for Degradation of Environmental Organoarsenicals. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11115-11125. [PMID: 28936873 PMCID: PMC5870903 DOI: 10.1021/acs.est.7b03180] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Organoarsenicals such as the methylarsenical methylarsenate (MAs(V)) and aromatic arsenicals including roxarsone (4-hydroxy-3-nitrobenzenearsenate or Rox(V)) have been extensively used as an herbicide and growth enhancers in animal husbandry, respectively. They undergo environmental degradation to more toxic inorganic arsenite (As(III)) that contaminates crops and drinking water. We previously identified a bacterial gene (arsI) responsible for aerobic demethylation of methylarsenite (MAs(III)). The gene product, ArsI, is an Fe(II)-dependent extradiol dioxygenase that cleaves the carbon-arsenic (C-As) bond in MAs(III) and in trivalent aromatic arsenicals. The objective of this study was to elucidate the ArsI mechanism. Using isothermal titration calorimetry, we determined the dissociation constants and ligand-to-protein stoichiometry of ArsI for Fe(II), MAs(III), and aromatic phenylarsenite. Using a combination of methods including chemical modification, site-directed mutagenesis, and fluorescent spectroscopy, we demonstrated that amino acid residues predicted to participate in Fe(II)-binding (His5-His62-Glu115) and substrate binding (Cys96-Cys97) are involved in catalysis. Finally, the products of Rox(III) degradation were identified as As(III) and 2-nitrohydroquinone, demonstrating that ArsI is a dioxygenase that incorporates one oxygen atom from dioxygen into the carbon and the other to the arsenic to catalyze cleavage of the C-As bond. These results augment our understanding of the mechanism of this novel C-As lyase.
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Affiliation(s)
- Shashank S. Pawitwar
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Venkadesh S. Nadar
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Ashoka Kandegedara
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Timothy L. Stemmler
- Department of Pharmaceutical Sciences, Eugene Applebaum College of Pharmacy and Health Sciences, Wayne State University, Detroit, Michigan 48201, United States
| | - Barry P. Rosen
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
| | - Masafumi Yoshinaga
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States
- Corresponding Author: Phone: 305-348-1489; fax: 305-348-0651; ; http://orcid.org/0000-0002-7243-1761
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