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Bellamri M, Brandt K, Cammerrer K, Syeda T, Turesky RJ, Cannon JR. Nuclear DNA and Mitochondrial Damage of the Cooked Meat Carcinogen 2-Amino-1-methyl-6-phenylimidazo[4,5- b]pyridine in Human Neuroblastoma Cells. Chem Res Toxicol 2023; 36:1361-1373. [PMID: 37421305 PMCID: PMC10626466 DOI: 10.1021/acs.chemrestox.3c00109] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2023]
Abstract
Animal fat and iron-rich diets are risk factors for Parkinson's disease (PD). The heterocyclic aromatic amines (HAAs) harman and norharman are neurotoxicants formed in many foods and beverages, including cooked meats, suggesting a role for red meat in PD. The structurally related carcinogenic HAAs 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylmidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-9H-pyrido[2,3-b]indole (AαC) also form in cooked meats. We investigated the cytotoxicity, DNA-damaging potential, and mitochondrial damage of HAAs and their genotoxic HONH-HAA metabolites in galactose-dependent SH-SY5Y cells, a human neuroblastoma cell line relevant for PD-related neurotoxicity. All HAAs and HONH-HAAs induced weak toxicity except HONH-PhIP, which was 1000-fold more potent than the other chemicals. HONH-PhIP DNA adduct formation occurred at 300-fold higher levels than adducts formed with HONH-MeIQx and HONH-AαC, assuming similar cellular uptake rates. PhIP-DNA adduct levels occurred at concentrations as low as 1 nM and were threefold or higher and more persistent in mitochondrial DNA than nuclear DNA. N-Acetyltransferases (NATs), sulfotransferases, and kinases catalyzed PhIP-DNA binding and converted HONH-PhIP to highly reactive ester intermediates. DNA binding assays with cytosolic, mitochondrial, and nuclear fractions of SH-SY5Y fortified with cofactors revealed that cytosolic AcCoA-dependent enzymes, including NAT1, mainly carried out HONH-PhIP bioactivation to form N-acetoxy-PhIP, which binds to DNA. Furthermore, HONH-PHIP and N-acetoxy-PhIP inhibited mitochondrial complex-I, -II, and -III activities in isolated SH-SY5Y mitochondria. Mitochondrial respiratory chain complex dysfunction and DNA damage are major mechanisms in PD pathogenesis. Our data support the possible role of PhIP in PD etiology.
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Affiliation(s)
- Medjda Bellamri
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, Minnesota 55455, United States
| | - Kyle Brandt
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, Minnesota 55455, United States
| | - Kari Cammerrer
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, Minnesota 55455, United States
| | - Tauqeerunnisa Syeda
- School of Health Sciences, Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana 47907, United States
| | - Robert J Turesky
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, Minnesota 55455, United States
| | - Jason R Cannon
- School of Health Sciences, Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, Indiana 47907, United States
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, Indiana 47907, United States
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2
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Bellamri M, Walmsley SJ, Turesky RJ. Metabolism and biomarkers of heterocyclic aromatic amines in humans. Genes Environ 2021; 43:29. [PMID: 34271992 PMCID: PMC8284014 DOI: 10.1186/s41021-021-00200-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/27/2021] [Indexed: 12/15/2022] Open
Abstract
Heterocyclic aromatic amines (HAAs) form during the high-temperature cooking of meats, poultry, and fish. Some HAAs also arise during the combustion of tobacco. HAAs are multisite carcinogens in rodents, inducing cancer of the liver, gastrointestinal tract, pancreas, mammary, and prostate glands. HAAs undergo metabolic activation by N-hydroxylation of the exocyclic amine groups to produce the proposed reactive intermediate, the heteroaryl nitrenium ion, which is the critical metabolite implicated in DNA damage and genotoxicity. Humans efficiently convert HAAs to these reactive intermediates, resulting in HAA protein and DNA adduct formation. Some epidemiologic studies have reported an association between frequent consumption of well-done cooked meats and elevated cancer risk of the colorectum, pancreas, and prostate. However, other studies have reported no associations between cooked meat and these cancer sites. A significant limitation in epidemiology studies assessing the role of HAAs and cooked meat in cancer risk is their reliance on food frequency questionnaires (FFQ) to gauge HAA exposure. FFQs are problematic because of limitations in self-reported dietary history accuracy, and estimating HAA intake formed in cooked meats at the parts-per-billion level is challenging. There is a critical need to establish long-lived biomarkers of HAAs for implementation in molecular epidemiology studies designed to assess the role of HAAs in health risk. This review article highlights the mechanisms of HAA formation, mutagenesis and carcinogenesis, the metabolism of several prominent HAAs, and the impact of critical xenobiotic-metabolizing enzymes on biological effects. The analytical approaches that have successfully biomonitored HAAs and their biomarkers for molecular epidemiology studies are presented.
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Affiliation(s)
- Medjda Bellamri
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN, 55455, USA.,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Scott J Walmsley
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN, 55455, USA.,Institute of Health Informatics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Robert J Turesky
- Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiovascular Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN, 55455, USA. .,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, 55455, USA.
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Rider CV, McHale CM, Webster TF, Lowe L, Goodson WH, La Merrill MA, Rice G, Zeise L, Zhang L, Smith MT. Using the Key Characteristics of Carcinogens to Develop Research on Chemical Mixtures and Cancer. ENVIRONMENTAL HEALTH PERSPECTIVES 2021; 129:35003. [PMID: 33784186 PMCID: PMC8009606 DOI: 10.1289/ehp8525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 02/19/2021] [Accepted: 03/10/2021] [Indexed: 05/09/2023]
Abstract
BACKGROUND People are exposed to numerous chemicals throughout their lifetimes. Many of these chemicals display one or more of the key characteristics of carcinogens or interact with processes described in the hallmarks of cancer. Therefore, evaluating the effects of chemical mixtures on cancer development is an important pursuit. Challenges involved in designing research studies to evaluate the joint action of chemicals on cancer risk include the time taken to perform the experiments because of the long latency and choosing an appropriate experimental design. OBJECTIVES The objectives of this work are to present the case for developing a research program on mixtures of environmental chemicals and cancer risk and describe recommended approaches. METHODS A working group comprising the coauthors focused attention on the design of mixtures studies to inform cancer risk assessment as part of a larger effort to refine the key characteristics of carcinogens and explore their application. Working group members reviewed the key characteristics of carcinogens, hallmarks of cancer, and mixtures research for other disease end points. The group discussed options for developing tractable projects to evaluate the joint effects of environmental chemicals on cancer development. RESULTS AND DISCUSSION Three approaches for developing a research program to evaluate the effects of mixtures on cancer development were proposed: a chemical screening approach, a transgenic model-based approach, and a disease-centered approach. Advantages and disadvantages of each are discussed. https://doi.org/10.1289/EHP8525.
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Affiliation(s)
- Cynthia V. Rider
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
| | - Cliona M. McHale
- Division of Environmental Health Sciences, University of California Berkeley, School of Public Health, Berkeley, California, USA
| | - Thomas F. Webster
- Department of Environmental Health, School of Public Health, Boston University, Boston, Massachusetts, USA
| | - Leroy Lowe
- Getting to Know Cancer (NGO), Truro, Nova Scotia, Canada
| | - William H. Goodson
- Department of Surgery, California Pacific Medical Center Research Institute, San Francisco, California, USA
| | - Michele A. La Merrill
- Department of Environmental Toxicology, University of California Davis, Davis, California, USA
| | - Glenn Rice
- Office of Research & Development, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Cincinnati, Ohio, USA
| | - Lauren Zeise
- Office of the Director, Office of Environmental Health and Hazard Assessment, California Environmental Protection Agency, Sacramento, California, USA
| | - Luoping Zhang
- Division of Environmental Health Sciences, University of California Berkeley, School of Public Health, Berkeley, California, USA
| | - Martyn T. Smith
- Division of Environmental Health Sciences, University of California Berkeley, School of Public Health, Berkeley, California, USA
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Syeda T, Foguth RM, Llewellyn E, Cannon JR. PhIP exposure in rodents produces neuropathology potentially relevant to Alzheimer's disease. Toxicology 2020; 437:152436. [PMID: 32169473 PMCID: PMC7218929 DOI: 10.1016/j.tox.2020.152436] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 03/01/2020] [Accepted: 03/09/2020] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a public health crisis due to debilitating cognitive symptoms and lack of curative treatments, in the context of increasing prevalence. Thus, it is critical to identify modifiable risk factors. High levels of meat consumption may increase AD risk. Many toxins are formed during meat cooking such as heterocyclic aromatic amines (HAAs). Our prior studies have shown that HAAs produce dopaminergic neurotoxicity. Given the mechanistic and pathological overlap between AD and dopaminergic disorders we investigated whether exposure to 2-amino-1-methyl-6-phenylimidazo [4,5-b] pyridine (PhIP), a prevalent dietary HAA formed during high-temperature meat cooking, may produce AD-relevant neurotoxicity. Here, C57BL/6 mice were treated with 100 or 200 mg/kg PhIP for 8 h or 75 mg/kg for 4 weeks and 16 weeks. PhIP exposure for 8 h produced oxidative damage, and AD-relevant alterations in hippocampal synaptic proteins, Amyloid-beta precursor protein (APP), and β-Site amyloid precursor protein cleaving enzyme 1 (BACE1). PhIP exposure for 4 weeks resulted in an increase in BACE1. PhIP exposure for 16 weeks resulted in increased hippocampal oxidative damage, APP, BACE1, Aβ aggregation, and tau phosphorylation. Quantification of intracellular nitrotyrosine revealed oxidative damage in cholinergic neurons after 8 h, 4 weeks and 16 weeks of PhIP exposure. Our study demonstrates that increase in oxidative damage, APP and BACE1 might be a possible mechanism by which PhIP promotes Aβ aggregation. Given many patients with AD or PD exhibit neuropathological overlap, our study suggests that HAA exposure should be further studied for roles in mediating pathogenic overlap.
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Affiliation(s)
- Tauqeerunnisa Syeda
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Rachel M Foguth
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States
| | - Emily Llewellyn
- Summer Research Opportunities Program, Purdue, University, West Lafayette, IN, 47907, United States; Department of Biology, Utah Valley University, Orem, Utah, 84058, United States
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, IN, 47907, United States; Purdue Institute for Integrative Neurosciences, Purdue University, West Lafayette, IN, 47907, United States.
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5
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Chen X, Jia W, Zhu L, Mao L, Zhang Y. Recent advances in heterocyclic aromatic amines: An update on food safety and hazardous control from food processing to dietary intake. Compr Rev Food Sci Food Saf 2019; 19:124-148. [DOI: 10.1111/1541-4337.12511] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 10/17/2019] [Accepted: 10/30/2019] [Indexed: 01/14/2023]
Affiliation(s)
- Xiaoqian Chen
- Zhejiang Key Laboratory for Agro‐Food Processing, National Engineering Laboratory of Intelligent Food Technology and Equipment, College of Biosystems Engineering and Food ScienceZhejiang University Hangzhou China
| | - Wei Jia
- Zhejiang Key Laboratory for Agro‐Food Processing, National Engineering Laboratory of Intelligent Food Technology and Equipment, College of Biosystems Engineering and Food ScienceZhejiang University Hangzhou China
| | - Li Zhu
- Zhejiang Key Laboratory for Agro‐Food Processing, National Engineering Laboratory of Intelligent Food Technology and Equipment, College of Biosystems Engineering and Food ScienceZhejiang University Hangzhou China
| | - Lei Mao
- Department of NutritionSchool of Public Health, Zhejiang University School of Medicine Hangzhou China
| | - Yu Zhang
- Zhejiang Key Laboratory for Agro‐Food Processing, National Engineering Laboratory of Intelligent Food Technology and Equipment, College of Biosystems Engineering and Food ScienceZhejiang University Hangzhou China
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6
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Bellamri M, Wang Y, Yonemori K, White KK, Wilkens LR, Le Marchand L, Turesky RJ. Biomonitoring an albumin adduct of the cooked meat carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine in humans. Carcinogenesis 2019; 39:1455-1462. [PMID: 30247550 DOI: 10.1093/carcin/bgy125] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 09/18/2018] [Indexed: 01/12/2023] Open
Abstract
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is formed in cooked meats and may be linked to dietary-associated colorectal, prostate and mammary cancers. Genotoxic N-oxidized metabolites of PhIP react with the Cys34 of albumin (Alb) to form a sulfinamide adduct, a biomarker of the biologically effective dose. We examined the kinetics of PhIP-Alb adduct formation in plasma of volunteers on a 4-week semicontrolled diet of cooked meat containing known quantities of PhIP. The adduct was below the limit of detection (LOD) (10 femtograms PhIP/mg Alb) in most subjects before the meat feeding but increased by up to 560-fold at week 4 in subjects who ate meat containing 8.0 to 11.7 μg of PhIP per 150-200 g serving. In contrast, the adduct remained below the LOD in subjects who ingested 1.2 or 3.0 μg PhIP per serving. Correlations were not seen between PhIP-Alb adduct levels and PhIP intake levels (P = 0.76), the amount of PhIP accrued in hair (P = 0.13), the amounts of N-oxidized urinary metabolites of PhIP (P = 0.66) or caffeine CYP1A2 activity (P = 0.55), a key enzyme involved in the bioactivation of PhIP. The half-life of the PhIP-Alb adduct was <2 weeks, signifying that the adduct was not stable. PhIP-Alb adduct formation is direct evidence of bioactivation of PhIP in vivo. However, the PhIP hair biomarker is a longer lived and more sensitive biomarker to assess exposure to this potential human carcinogen.
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Affiliation(s)
- Medjda Bellamri
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
| | - Yi Wang
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA.,Department of Medicinal Chemistry, Medical Science Building, University of Florida, Gainesville, FL, USA
| | - Kim Yonemori
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA
| | - Kami K White
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA
| | - Lynne R Wilkens
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA
| | - Loïc Le Marchand
- Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA
| | - Robert J Turesky
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN, USA.,Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN, USA
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7
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Preston GW, Phillips DH. Protein Adductomics: Analytical Developments and Applications in Human Biomonitoring. TOXICS 2019; 7:E29. [PMID: 31130613 PMCID: PMC6631498 DOI: 10.3390/toxics7020029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 02/07/2023]
Abstract
Proteins contain many sites that are subject to modification by electrophiles. Detection and characterisation of these modifications can give insights into environmental agents and endogenous processes that may be contributing factors to chronic human diseases. An untargeted approach, utilising mass spectrometry to detect modified amino acids or peptides, has been applied to blood proteins haemoglobin and albumin, focusing in particular on the N-terminal valine residue of haemoglobin and the cysteine-34 residue in albumin. Technical developments to firstly detect simultaneously multiple adducts at these sites and then subsequently to identify them are reviewed here. Recent studies in which the methods have been applied to biomonitoring human exposure to environmental toxicants are described. With advances in sensitivity, high-throughput handling of samples and robust quality control, these methods have considerable potential for identifying causes of human chronic disease and of identifying individuals at risk.
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Affiliation(s)
- George W Preston
- Environmental Research Group, Department of Analytical, Environmental and Forensic Science, School of Population Health and Environmental Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
| | - David H Phillips
- Environmental Research Group, Department of Analytical, Environmental and Forensic Science, School of Population Health and Environmental Sciences, King's College London, Franklin-Wilkins Building, 150 Stamford Street, London SE1 9NH, UK.
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Nunes J, Charneira C, Morello J, Rodrigues J, Pereira SA, Antunes AMM. Mass Spectrometry-Based Methodologies for Targeted and Untargeted Identification of Protein Covalent Adducts (Adductomics): Current Status and Challenges. High Throughput 2019; 8:ht8020009. [PMID: 31018479 PMCID: PMC6631461 DOI: 10.3390/ht8020009] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 04/18/2019] [Accepted: 04/20/2019] [Indexed: 12/12/2022] Open
Abstract
Protein covalent adducts formed upon exposure to reactive (mainly electrophilic) chemicals may lead to the development of a wide range of deleterious health outcomes. Therefore, the identification of protein covalent adducts constitutes a huge opportunity for a better understanding of events underlying diseases and for the development of biomarkers which may constitute effective tools for disease diagnosis/prognosis, for the application of personalized medicine approaches and for accurately assessing human exposure to chemical toxicants. The currently available mass spectrometry (MS)-based methodologies, are clearly the most suitable for the analysis of protein covalent modifications, providing accuracy, sensitivity, unbiased identification of the modified residue and conjugates along with quantitative information. However, despite the huge technological advances in MS instrumentation and bioinformatics tools, the identification of low abundant protein covalent adducts is still challenging. This review is aimed at summarizing the MS-based methodologies currently used for the identification of protein covalent adducts and the strategies developed to overcome the analytical challenges, involving not only sample pre-treatment procedures but also distinct MS and data analysis approaches.
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Affiliation(s)
- João Nunes
- Centro de Química Estrutural, Instituto Superior Técnico, ULisboa, 1049-001 Lisboa, Portugal.
| | - Catarina Charneira
- Centro de Química Estrutural, Instituto Superior Técnico, ULisboa, 1049-001 Lisboa, Portugal.
| | - Judit Morello
- Centro de Química Estrutural, Instituto Superior Técnico, ULisboa, 1049-001 Lisboa, Portugal.
| | - João Rodrigues
- Clarify Analytical, Rua dos Mercadores 128A, 7000-872 Évora, Portugal.
| | - Sofia A Pereira
- CEDOC, Chronic Diseases Research Centre, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, 1169-006 Lisboa, Portugal.
| | - Alexandra M M Antunes
- Centro de Química Estrutural, Instituto Superior Técnico, ULisboa, 1049-001 Lisboa, Portugal.
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Wang Y, Villalta PW, Peng L, Dingley K, Malfatti MA, Turteltaub KW, Turesky RJ. Mass Spectrometric Characterization of an Acid-Labile Adduct Formed with 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and Albumin in Humans. Chem Res Toxicol 2017; 30:705-714. [PMID: 27984695 DOI: 10.1021/acs.chemrestox.6b00426] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogenic heterocyclic aromatic amine formed during the high-temperature cooking of meats. The cytochrome P450-mediated N-hydroxylation of the exocyclic amine group of PhIP produces 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine, an electrophilic metabolite that forms adducts with DNA and proteins. Previous studies conducted by our laboratory showed that the reaction of N-oxidized PhIP metabolites with human albumin in vitro primarily occurs at the Cys34 residue, to produce an acid-labile linked sulfinamide adduct. On the basis of these findings, we developed a sensitive ultraperformance liquid chromatography-mass spectrometry method to measure acid-labile albumin-PhIP adducts in human volunteers administered a dietary-relevant dose of 14C-labeled PhIP [Dingley, K. H., et al. (1999) Cancer Epidemiol., Biomarkers Prev. 8, 507-512]. Mild acid treatment of albumin (0.1 N HCl, 37 °C for 1 h) or proteolytic digestion with Pronase [50 mM ammonium bicarbonate buffer (pH 8.5) at 37 °C for 18 h] released similar amounts of covalently bound PhIP, which was characterized by multistage scanning and quantified by Orbitrap mass spectrometry. The amount of [14C]PhIP recovered by acid treatment of albumin 24 h following dosing accounted for 7.2-21.3% of the [14C]PhIP bound to albumin based on accelerator mass spectrometry measurements. 2-Amino-1-methyl-6-(5-hydroxy)phenylimidazo[4,5-b]pyridine, a hydrolysis product of the Cys34 S-N linked sulfenamide adduct of PhIP, was not detected in either acid-treated or protease-treated samples. These findings suggest that a portion of the PhIP bound to albumin in vivo probably occurs as an acid-labile sulfinamide adduct formed at the Cys34 residue.
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Affiliation(s)
| | | | - Lijuan Peng
- School of Food Science and Engineering, Wuhan Polytechnic University , ChangQing Garden, Hankou, Wuhan 430023, P. R. China
| | - Karen Dingley
- Biosciences and Biotechnology Division, Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory , Livermore, California 94550, United States
| | - Michael A Malfatti
- Biosciences and Biotechnology Division, Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory , Livermore, California 94550, United States
| | - K W Turteltaub
- Biosciences and Biotechnology Division, Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory , Livermore, California 94550, United States
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10
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Sabbioni G, Turesky RJ. Biomonitoring Human Albumin Adducts: The Past, the Present, and the Future. Chem Res Toxicol 2017; 30:332-366. [PMID: 27989119 PMCID: PMC5241710 DOI: 10.1021/acs.chemrestox.6b00366] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Indexed: 12/21/2022]
Abstract
Serum albumin (Alb) is the most abundant protein in blood plasma. Alb reacts with many carcinogens and/or their electrophilic metabolites. Studies conducted over 20 years ago showed that Alb forms adducts with the human carcinogens aflatoxin B1 and benzene, which were successfully used as biomarkers in molecular epidemiology studies designed to address the role of these chemicals in cancer risk. Alb forms adducts with many therapeutic drugs or their reactive metabolites such as β-lactam antibiotics, acetylsalicylic acid, acetaminophen, nonsteroidal anti-inflammatory drugs, chemotherapeutic agents, and antiretroviral therapy drugs. The identification and characterization of the adduct structures formed with Alb have served to understand the generation of reactive metabolites and to predict idiosyncratic drug reactions and toxicities. The reaction of candidate drugs with Alb is now exploited as part of the battery of screening tools to assess the potential toxicities of drugs. The use of gas chromatography-mass spectrometry, liquid chromatography, or liquid chromatography-mass spectrometry (LC-MS) enabled the identification and quantification of multiple types of Alb xenobiotic adducts in animals and humans during the past three decades. In this perspective, we highlight the history of Alb as a target protein for adduction to environmental and dietary genotoxicants, pesticides, and herbicides, common classes of medicinal drugs, and endogenous electrophiles, and the emerging analytical mass spectrometry technologies to identify Alb-toxicant adducts in humans.
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Affiliation(s)
- Gabriele Sabbioni
- Institute of Environmental and Occupational Toxicology, CH-6780 Airolo, Switzerland
- Alpine Institute of Chemistry and Toxicology, CH-6718 Olivone, Switzerland
- Walther-Straub-Institut für Pharmakologie
und Toxikologie, Ludwig-Maximilians-Universität München, D-80336 München, Germany
| | - Robert J. Turesky
- Masonic Cancer Center and Department of
Medicinal Chemistry, College of Pharmacy, University of Minnesota, 2231 Sixth Street SE, Minneapolis, Minnesota 55455, United States
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11
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Sheng J, Wang Y, Turesky RJ, Kluetzman K, Zhang QY, Ding X. Novel Transgenic Mouse Model for Studying Human Serum Albumin as a Biomarker of Carcinogenic Exposure. Chem Res Toxicol 2016; 29:797-809. [PMID: 27028147 DOI: 10.1021/acs.chemrestox.5b00529] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Albumin is a commonly used serum protein for studying human exposure to xenobiotic compounds, including therapeutics and environmental pollutants. Often, the reactivity of albumin with xenobiotic compounds is studied ex vivo with human albumin or plasma/serum samples. Some studies have characterized the reactivity of albumin with chemicals in rodent models; however, differences between the orthologous peptide sequences of human and rodent albumins can result in the formation of different types of chemical-protein adducts with different interaction sites or peptide sequences. Our goal is to generate a human albumin transgenic mouse model that can be used to establish human protein biomarkers of exposure to hazardous xenobiotics for human risk assessment via animal studies. We have developed a human albumin transgenic mouse model and characterized the genotype and phenotype of the transgenic mice. The presence of the human albumin gene in the genome of the model mouse was confirmed by genomic PCR analysis, whereas liver-specific expression of the transgenic human albumin mRNA was validated by RT-PCR analysis. Further immunoblot and mass spectrometry analyses indicated that the transgenic human albumin protein is a full-length, mature protein, which is less abundant than the endogenous mouse albumin that coexists in the serum of the transgenic mouse. The transgenic protein was able to form ex vivo adducts with a genotoxic metabolite of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, a procarcinogenic heterocyclic aromatic amine formed in cooked meat. This novel human albumin transgenic mouse model will facilitate the development and validation of albumin-carcinogen adducts as biomarkers of xenobiotic exposure and/or toxicity in humans.
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Affiliation(s)
- Jonathan Sheng
- Wadsworth Center, New York State Department of Health , Albany, New York 12201, United States
| | - Yi Wang
- Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Robert J Turesky
- Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota , Minneapolis, Minnesota 55455, United States
| | - Kerri Kluetzman
- Wadsworth Center, New York State Department of Health , Albany, New York 12201, United States
| | - Qing-Yu Zhang
- Wadsworth Center, New York State Department of Health , Albany, New York 12201, United States
| | - Xinxin Ding
- College of Nanoscale Science, SUNY Polytechnic Institute , Albany, New York 12203, United States
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Pathak KV, Chiu TL, Amin EA, Turesky RJ. Methemoglobin Formation and Characterization of Hemoglobin Adducts of Carcinogenic Aromatic Amines and Heterocyclic Aromatic Amines. Chem Res Toxicol 2016; 29:255-69. [PMID: 26824300 PMCID: PMC4801648 DOI: 10.1021/acs.chemrestox.5b00418] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Arylamines (AAs) and heterocyclic aromatic amines (HAAs) are structurally related carcinogens formed during the combustion of tobacco or cooking of meat. They undergo cytochrome P450 mediated N-hydroxylation to form metabolites which bind to DNA and lead to mutations. The N-hydroxylated metabolites of many AAs also can undergo a co-oxidation reaction with oxy-hemolgobin (HbO2) to form methemoglobin (met-Hb) and the arylnitroso intermediates, which react with the β-Cys(93) chain of Hb to form Hb-arylsulfinamide adducts. The biochemistry of arylamine metabolism has been exploited to biomonitor certain AAs through their Hb arylsulfinamide adducts in humans. We examined the reactivity of HbO2 with the N-hydroxylated metabolites of 4-aminobiphenyl (ABP, HONH-ABP), aniline (ANL, HONH-ANL), and the HAAs 2-amino-9H-pyrido[2,3-b]indole (AαC, HONH-AαC), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP, HONH-PhIP), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx, HONH-MeIQx). HONH-ABP, HO-ANL, and HONH-AαC induced methemoglobinemia and formed Hb sulfinamide adducts. However, HONH-MeIQx and HONH-PhIP did not react with the oxy-heme complex, and met-Hb formation and chemical modification of the β-Cys(93) residue were negligible. Molecular modeling studies showed that the distances between the H-ON-AA or H-ON-HAA substrates and the oxy-heme complex of HbO2 were too far away to induce methemoglobinemia. Different conformational changes in flexible helical and loop regions around the heme pocket induced by the H-ON-AA or H-ON-HAAs may explain the different proclivities of these chemicals to induce methemoglobinemia. Hb-Cys(93β) sulfinamide and sulfonamide adducts of ABP, ANL, and AαC were identified, by Orbitrap MS, following the proteolysis of Hb with trypsin, Glu-C, or Lys-C. Hb sulfinamide and sulfonamide adducts of ABP were identified in the blood of mice exposed to ABP, by Orbitrap MS. This is the first report of the identification of intact Hb sulfinamide adducts of carcinogenic AAs in vivo. The high reactivity of HONH-AαC with HbO2 suggests that the Hb sulfinamide adduct of AαC may be a promising biomarker of exposure to this HAA in humans.
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Affiliation(s)
| | - Ting-Lan Chiu
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
| | | | - Robert J. Turesky
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
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Cooper KM, Brennan SF, Woodside JV, Cantwell M, Guo X, Mooney M, Elliott CT, Cuskelly GJ. Acid-labile protein-adducted heterocyclic aromatic amines in human blood are not viable biomarkers of dietary exposure: A systematic study. Food Chem Toxicol 2016; 91:100-7. [PMID: 26993956 DOI: 10.1016/j.fct.2016.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/08/2016] [Accepted: 03/11/2016] [Indexed: 01/13/2023]
Abstract
Heterocyclic aromatic amines (HCA) are carcinogenic mutagens formed during cooking of protein-rich foods. HCA residues adducted to blood proteins have been postulated as biomarkers of HCA exposure. However, the viability of quantifying HCAs following hydrolytic release from adducts in vivo and correlation with dietary intake are unproven. To definitively assess the potential of labile HCA-protein adducts as biomarkers, a highly sensitive UPLC-MS/MS method was validated for four major HCAs: 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline (7,8-DiMeIQx). Limits of detection were 1-5 pg/ml plasma and recoveries 91-115%. Efficacy of hydrolysis was demonstrated by HCA-protein adducts synthesised in vitro. Plasma and 7-day food diaries were collected from 122 fasting adults consuming their habitual diets. Estimated HCA intakes ranged from 0 to 2.5 mg/day. An extensive range of hydrolysis conditions was examined for release of adducted HCAs in plasma. HCA was detected in only one sample (PhIP, 9.7 pg/ml), demonstrating conclusively for the first time that acid-labile HCA adducts do not reflect dietary HCA intake and are present at such low concentrations that they are not feasible biomarkers of exposure. Identification of biomarkers remains important. The search should concentrate on stabilised HCA-peptide markers and use of untargeted proteomic and metabolomic approaches.
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Affiliation(s)
- Kevin M Cooper
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, United Kingdom.
| | - Sarah F Brennan
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast, BT12 6BA, United Kingdom
| | - Jayne V Woodside
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast, BT12 6BA, United Kingdom
| | - Marie Cantwell
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Science, Queen's University Belfast, Belfast, BT12 6BA, United Kingdom
| | - Xiaoxiao Guo
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, United Kingdom
| | - Mark Mooney
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, United Kingdom
| | - Christopher T Elliott
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, United Kingdom
| | - Geraldine J Cuskelly
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, BT9 5BN, United Kingdom
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Pathak KV, Bellamri M, Wang Y, Langouët S, Turesky RJ. 2-Amino-9H-pyrido[2,3-b]indole (AαC) Adducts and Thiol Oxidation of Serum Albumin as Potential Biomarkers of Tobacco Smoke. J Biol Chem 2015; 290:16304-18. [PMID: 25953894 PMCID: PMC4481229 DOI: 10.1074/jbc.m115.646539] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 05/05/2015] [Indexed: 12/30/2022] Open
Abstract
2-Amino-9H-pyrido[2,3-b]indole (AαC) is a carcinogenic heterocyclic aromatic amine formed during the combustion of tobacco. AαC undergoes bioactivation to form electrophilic N-oxidized metabolites that react with DNA to form adducts, which can lead to mutations. Many genotoxicants and toxic electrophiles react with human serum albumin (albumin); however, the chemistry of reactivity of AαC with proteins has not been studied. The genotoxic metabolites, 2-hydroxyamino-9H-pyrido[2,3-b]indole (HONH-AαC), 2-nitroso-9H-pyrido[2,3-b]indole (NO-AαC), N-acetyloxy-2-amino-9H-pyrido[2,3-b]indole (N-acetoxy-AαC), and their [(13)C6]AαC-labeled homologues were reacted with albumin. Sites of adduction of AαC to albumin were identified by data-dependent scanning and targeted bottom-up proteomics approaches employing ion trap and Orbitrap MS. AαC-albumin adducts were formed at Cys(34), Tyr(140), and Tyr(150) residues when albumin was reacted with HONH-AαC or NO-AαC. Sulfenamide, sulfinamide, and sulfonamide adduct formation occurred at Cys(34) (AαC-Cys(34)). N-Acetoxy-AαC also formed an adduct at Tyr(332). Albumin-AαC adducts were characterized in human plasma treated with N-oxidized metabolites of AαC and human hepatocytes exposed to AαC. High levels of N-(deoxyguanosin-8-yl)-AαC (dG-C8-AαC) DNA adducts were formed in hepatocytes. The Cys(34) was the sole amino acid of albumin to form adducts with AαC. Albumin also served as an antioxidant and scavenged reactive oxygen species generated by metabolites of AαC in hepatocytes; there was a strong decrease in reduced Cys(34), whereas the levels of Cys(34) sulfinic acid (Cys-SO2H), Cys(34)-sulfonic acid (Cys-SO3H), and Met(329) sulfoxide were greatly increased. Cys(34) adduction products and Cys-SO2H, Cys-SO3H, and Met(329) sulfoxide may be potential biomarkers to assess exposure and oxidative stress associated with AαC and other arylamine toxicants present in tobacco smoke.
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Affiliation(s)
- Khyatiben V Pathak
- From the Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455 and
| | - Medjda Bellamri
- UMR INSERM 1085 IRSET, Rennes 1 University, UMS 3480 Biosit, F-35043 Rennes, France
| | - Yi Wang
- From the Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455 and
| | - Sophie Langouët
- UMR INSERM 1085 IRSET, Rennes 1 University, UMS 3480 Biosit, F-35043 Rennes, France
| | - Robert J Turesky
- From the Masonic Cancer Center and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455 and
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Wang Y, Peng L, Bellamri M, Langouët S, Turesky RJ. Mass Spectrometric Characterization of Human Serum Albumin Adducts Formed with N-Oxidized Metabolites of 2-Amino-1-methylphenylimidazo[4,5-b]pyridine in Human Plasma and Hepatocytes. Chem Res Toxicol 2015; 28:1045-59. [PMID: 25815793 DOI: 10.1021/acs.chemrestox.5b00075] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic heterocyclic aromatic amine formed in cooked meats, is metabolically activated to electrophilic intermediates that form covalent adducts with DNA and protein. We previously identified an adduct of PhIP formed at the Cys(34) residue of human serum albumin following reaction of albumin with the genotoxic metabolite 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (HONH-PhIP). The major adducted peptide recovered from a tryptic/chymotryptic digest was identified as the missed-cleavage peptide LQQC*([SO2PhIP])PFEDHVK, a [cysteine-S-yl-PhIP]-S-dioxide linked adduct. In this investigation, we have characterized the albumin adduction products of N-sulfooxy-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-sulfooxy-PhIP), which is thought to be a major genotoxic metabolite of PhIP formed in vivo. Targeted and data-dependent scanning methods showed that N-sulfooxy-PhIP adducted to the Cys(34) of albumin in human plasma to form LQQC*([SO2PhIP])PFEDHVK at levels that were 8-10-fold greater than the adduct levels formed with N-(acetyloxy)-2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-acetoxy-PhIP) or HONH-PhIP. We also discovered that N-sulfooxy-PhIP forms an adduct at the sole tryptophan (Trp(214)) residue of albumin in the sequence AW*([PhIP])AVAR. However, stable adducts of PhIP with albumin were not detected in human hepatocytes. Instead, PhIP and 2-amino-1-methyl-6-(5-hydroxy)phenylimidazo[4,5-b]pyridine (5-HO-PhIP), a solvolysis product of the proposed nitrenium ion of PhIP, were recovered during the proteolysis, suggesting a labile sulfenamide linkage had formed between an N-oxidized intermediate of PhIP and Cys(34) of albumin. A stable adduct was formed at the Tyr(411) residue of albumin in hepatocytes and identified as a deaminated product of PhIP, Y(*[desaminoPhIP])TK, where the 4-HO-tyrosine group bound to the C-2 imidazole atom of PhIP.
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Affiliation(s)
- Yi Wang
- †Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiology Research Building, University of Minnesota, 2231 6th Street, Minneapolis, Minnesota 55455, United States
| | - Lijuan Peng
- ‡School of Chemical and Environmental Engineering, Wuhan Polytechnic University, ChangQing Garden, Hankou, Wuhan 430023, P. R. China
| | - Medjda Bellamri
- §Institut National de la Santé et de la Recherche Médicale (Inserm), U.1085, Institut de Recherche Santé Environnement et Travail (IRSET), Université de Rennes 1, UMS 3480 Biosit, F-35043 Rennes, France.,∥ANSES Laboratoire de Fougères, La Haute Marche-Javené, BP 90203, 350302 Fougères, France
| | - Sophie Langouët
- §Institut National de la Santé et de la Recherche Médicale (Inserm), U.1085, Institut de Recherche Santé Environnement et Travail (IRSET), Université de Rennes 1, UMS 3480 Biosit, F-35043 Rennes, France
| | - Robert J Turesky
- †Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiology Research Building, University of Minnesota, 2231 6th Street, Minneapolis, Minnesota 55455, United States
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Cooper KM, Jankhaikhot N, Cuskelly G. Optimised extraction of heterocyclic aromatic amines from blood using hollow fibre membrane liquid-phase microextraction and triple quadrupole mass spectrometry. J Chromatogr A 2014; 1358:20-8. [DOI: 10.1016/j.chroma.2014.06.061] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/03/2014] [Accepted: 06/19/2014] [Indexed: 10/25/2022]
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Griggs AM, Agim ZS, Mishra VR, Tambe MA, Director-Myska AE, Turteltaub KW, McCabe GP, Rochet JC, Cannon JR. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is selectively toxic to primary dopaminergic neurons in vitro. Toxicol Sci 2014; 140:179-89. [PMID: 24718704 DOI: 10.1093/toxsci/kfu060] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Parkinson's disease (PD) is the second most common neurodegenerative disease. Much data has linked the etiology of PD to a variety of environmental factors. The majority of cases are thought to arise from a combination of genetic susceptibility and environmental factors. Chronic exposures to dietary factors, including meat, have been identified as potential risk factors. Although heterocyclic amines that are produced during high-temperature meat cooking are known to be carcinogenic, their effect on the nervous system has yet to be studied in depth. In this study, we investigated neurotoxic effects of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a highly abundant heterocyclic amine in cooked meat, in vitro. We tested toxicity of PhIP and the two major phase I metabolites, N-OH-PhIP and 4'-OH-PhIP, using primary mesencephalic cultures from rat embryos. This culture system contains both dopaminergic and nondopaminergic neurons, which allows specificity of neurotoxicity to be readily examined. We find that exposure to PhIP or N-OH-PhIP is selectively toxic to dopaminergic neurons in primary cultures, resulting in a decreased percentage of dopaminergic neurons. Neurite length is decreased in surviving dopaminergic neurons. Exposure to 4'-OH-PhIP did not produce significant neurotoxicity. PhIP treatment also increased formation of oxidative damage markers, 4-hydroxy-2-nonenal (HNE) and 3-nitrotyrosine in dopaminergic neurons. Pretreatment with N-acetylcysteine was protective. Finally, treatment with blueberry extract, a dietary factor with known antioxidant and other protective mechanisms, prevented PhIP-induced toxicity. Collectively, our study suggests, for the first time, that PhIP is selectively toxic to dopaminergic neurons likely through inducing oxidative stress.
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Affiliation(s)
- Amy M Griggs
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907 Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907 Cook MED Institute, West Lafayette, Indiana 47906
| | - Zeynep S Agim
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907
| | - Vartika R Mishra
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Mitali A Tambe
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Alison E Director-Myska
- Chemical/Biological Technologies, Defense Threat Reduction Agency, Fort Belvoir, Virginia 22060
| | - Kenneth W Turteltaub
- Biosciences & Biotechnology Division, Lawrence Livermore National Laboratory, Livermore, California 94551
| | - George P McCabe
- Department of Statistics, Purdue University, West Lafayette, Indiana 47907
| | - Jean-Christophe Rochet
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana 47907
| | - Jason R Cannon
- School of Health Sciences, Purdue University, West Lafayette, Indiana 47907
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Peng L, Turesky RJ. Optimizing proteolytic digestion conditions for the analysis of serum albumin adducts of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine, a potential human carcinogen formed in cooked meat. J Proteomics 2014; 103:267-78. [PMID: 24698664 DOI: 10.1016/j.jprot.2014.03.023] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Revised: 03/08/2014] [Accepted: 03/21/2014] [Indexed: 01/05/2023]
Abstract
UNLABELLED Heterocyclic aromatic amines (HAAs) are carcinogens formed during the cooking of meats or arise in tobacco smoke. The genotoxic N-oxidized metabolites of HAAs bind to Cys residues of proteins to form arylsulfinamide adducts. However, these adducts are unstable and undergo hydrolysis during enzymatic digestion, and thus have been precluded as biomarkers of exposure to HAAs. Arylsulfinamide adducts of HAAs can undergo oxidation to form stable arylsulfonamide linkages, which are chemically stable and amenable for analysis. 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a carcinogen present in cooked meat. We established a quantitative MS-based method to measure the sulfinamide adduct of PhIP formed at the cysteine(34) (Cys(34)) residue of human serum albumin (SA), following chemical oxidation of PhIP-modified SA with m-chloroperoxybenzoic acid. Different enzyme systems (trypsin; chymotrypsin; trypsin/chymotrypsin; proteinase K; pronase E; and pronase E/leucine aminopeptidase/prolidase) were evaluated for their proficiency of digestion of SA modified with PhIP. The strongest signal was observed for the L(31)QQC*PFEDHVK(41) peptide, by ultraperformance liquid chromatography and ion trap MS. A limit of quantification value was 0.3fmol of LQQC*PFEDHVK per μg SA, or 2.5 adducts per 10(5) SA molecules, when assaying 0.75μg of SA. BIOLOGICAL SIGNIFICANCE This article describes a mass spectrometric based method to characterize and measure human serum albumin (SA) adducts of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic heterocyclic aromatic amine formed in cooked meats and tobacco smoke. PhIP undergoes metabolic activation to form reactive N-oxidized intermediates that bind to DNA and proteins. N-oxidized PhIP metabolites bind to the Cys(34) residue of SA to form a sulfinamide linkage. However, the linkage undergoes hydrolysis during proteolysis, precluding the employment of this adduct as a biomarker in human studies. We have shown that the sulfinamide linkage undergoes oxidation to form the [cysteine-S-yl-PhIP]-S-dioxide, a sulfonamide linked adduct which is stable toward proteolysis. The specificity and efficiency of several different proteases toward the digestion of the SA-Cys(34)-PhIP adduct were examined. The combination of trypsin and chymotrypsin produced the single-missed cleaved peptide LQQC*PFEDHVK in high yield. Moreover, denaturation and chemical reduction of the internal Cys disulfide bonds of SA were not required for the recovery of LQQC*PFEDHVK. The novel chemistry and proteomic approaches developed in this study may be applied to monitor biologically reactive N-oxidized intermediates of arylamines through their adduction products formed at nucleophilic Cys residues of proteins.
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Affiliation(s)
- Lijuan Peng
- School of Chemical and Environmental Engineering, Wuhan Polytechnic University, ChangQing Garden, Hankou, Wuhan 430023, PR China; Division of Environmental Health Sciences,Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA.
| | - Robert J Turesky
- Division of Environmental Health Sciences,Wadsworth Center, New York State Department of Health, Albany, NY 12201, USA; Masonic Cancer Center and Department of Medicinal Chemistry, Cancer and Cardiology Research Building, University of Minnesota, 2231 6th Street, Minneapolis, MN 55455, USA.
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Peng L, Turesky RJ. Capturing labile sulfenamide and sulfinamide serum albumin adducts of carcinogenic arylamines by chemical oxidation. Anal Chem 2012; 85:1065-72. [PMID: 23240913 DOI: 10.1021/ac3028273] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aromatic amines and heterocyclic aromatic amines (HAAs) are a class of structurally related carcinogens that are formed during the combustion of tobacco or during the high temperature cooking of meats. These procarcinogens undergo metabolic activation by N-oxidation of the exocyclic amine group to produce N-hydroxylated metabolites, which are critical intermediates implicated in toxicity and DNA damage. The arylhydroxylamines and their oxidized arylnitroso derivatives can also react with cysteine (Cys) residues of glutathione or proteins to form, respectively, sulfenamide and sulfinamide adducts. However, sulfur-nitrogen linked adducted proteins are often difficult to detect because they are unstable and undergo hydrolysis during proteolytic digestion. Synthetic N-oxidized intermediates of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a carcinogenic HAA produced in cooked meats, and 4-aminobiphenyl, a carcinogenic aromatic amine present in tobacco smoke, were reacted with human serum albumin (SA) and formed labile sulfenamide or sulfinamide adducts at the Cys(34) residue. Oxidation of the carcinogen-modified SA with m-chloroperoxybenzoic acid (m-CPBA) produced the arylsulfonamide adducts, which were stable to heat and the chemical reduction conditions employed to denature SA. The sulfonamide adducts of PhIP and 4-ABP were identified, by liquid chromatography/mass spectrometry, in proteolytic digests of denatured SA. Thus, selective oxidation of arylamine-modified SA produces stable arylsulfonamide-SA adducts, which may serve as biomarkers of these tobacco and dietary carcinogens.
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Affiliation(s)
- Lijuan Peng
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York 12201, USA
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