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Weitz K, Kantner D, Kessler A, Key H, Larson J, Bodnar W, Parvathikar S, Davis L, Robey N, Taylor P, De la Cruz F, Tolaymat T, Weber N, Linak W, Krug J, Phelps L. Review of per- and poly-fluoroalkyl treatment in combustion-based thermal waste systems in the United States. Sci Total Environ 2024; 932:172658. [PMID: 38657813 DOI: 10.1016/j.scitotenv.2024.172658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 04/26/2024]
Abstract
Per- and poly-fluoroalkyl substances (PFAS) are a class of synthetic chemicals known for their widespread presence and environmental persistence. Carbon-fluorine (C-F) bonds are major components among PFAS and among the strongest organic bonds, thus destroying PFAS may present significant challenge. Thermal treatment such as incineration is an effective and approved method for destroying many halogenated organic chemicals. Here, we present the results of existing studies and testing at combustion-based thermal treatment facilities and summarize what is known regarding PFAS destruction and mineralization at such units. Available results suggest the temperature and residence times reached by some thermal treatment systems are generally favorable to the destruction of PFAS, but the possibility for PFAS or fluorinated organic byproducts to escape destruction and adequate mineralization and be released into the air cannot be ruled out. Few studies have been conducted at full-scale operating facilities, and none to date have attempted to characterize possible fluorinated organic products of incomplete combustion (PICs). Further, the ability of existing air pollution control (APC) systems, designed primarily for particulate and acid gas control, to reduce PFAS air emissions has not been determined. These data gaps remain primarily due to the previous lack of available methods to characterize PFAS destruction and PIC concentrations in facility air emissions. However, newly developed stack testing methods offer an improved understanding of the extent to which thermal waste treatment technologies successfully destroy and mineralize PFAS in these waste streams.
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Affiliation(s)
- Keith Weitz
- RTI International, Research Triangle Park, NC, USA
| | | | | | - Haley Key
- RTI International, Research Triangle Park, NC, USA
| | - Judd Larson
- RTI International, Research Triangle Park, NC, USA
| | - Wanda Bodnar
- RTI International, Research Triangle Park, NC, USA
| | | | - Lynn Davis
- RTI International, Research Triangle Park, NC, USA
| | - Nicole Robey
- Innovative Technical Solutions, Gainesville, FL, USA
| | | | - Florentino De la Cruz
- College of Computing, Engineering and Construction, University of North Florida, Jacksonville, FL, USA
| | - Thabet Tolaymat
- Center for Environmental Solutions and Emergency Management, Office of Research and Development, U.S. Environmental Protection Agency, Cincinnati, OH, USA
| | - Nathan Weber
- Oak Ridge Institute for Science and Education, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - William Linak
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jonathan Krug
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Lara Phelps
- Center for Environmental Measurement and Modeling, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA.
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2
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Niture S, Gadi S, Lin M, Qi Q, Niture SS, Moore JT, Bodnar W, Fernando RA, Levine KE, Kumar D. Cadmium modulates steatosis, fibrosis, and oncogenic signaling in liver cancer cells by activating notch and AKT/mTOR pathways. Environ Toxicol 2023; 38:783-797. [PMID: 36602393 DOI: 10.1002/tox.23731] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Revised: 12/17/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Cadmium (Cd) is an environmental pollutant that increases hepatotoxicity and the risk of liver diseases. In the current study, we investigated the effect of a physiologically relevant, low concentration of Cd on the regulation of liver cancer cell proliferation, steatosis, and fibrogenic/oncogenic signaling. Exposure to low concentrations of Cd increased endogenous reactive oxygen species (ROS) production and enhanced cell proliferation in a human bipotent progenitor cell line HepaRG and hepatocellular carcinoma (HCC) cell lines. Acute exposure of Cd increased Jagged-1 expression and activated Notch signaling in HepaRG and HCC cells HepG2 and SK-Hep1. Cd activated AKT/mTOR signaling by increasing phosphorylation of AKT-S473 and mTOR-S-4448 residues. Moreover, a low concentration of Cd also promoted cell steatosis and induced fibrogenic signaling in HCC cells. Chronic exposure to low concentrations of Cd-activated Notch and AKT/mTOR signaling induced the expression of pro-inflammatory cytokines tumor necrosis factor-alpha (TNFα) and its downstream target TNF-α-Induced Protein 8 (TNFAIP8). RNA-Seq data revealed that chronic exposure to low concentrations of Cd modulated the expression of several fatty liver disease-related genes involved in cell steatosis/fibrosis in HepaRG and HepG2 cells. Collectively, our data suggest that low concentrations of Cd modulate steatosis along with fibrogenic and oncogenic signaling in HCC cells by activating Notch and AKT/mTOR pathways.
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Affiliation(s)
- Suryakant Niture
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, North Carolina, USA
- NCCU-RTI Center for Applied Research in Environmental Sciences (CARES), RTI International, Durham, North Carolina, USA
| | - Sashi Gadi
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, North Carolina, USA
| | - Minghui Lin
- The Fourth People's Hospital of Ningxia Hui Autonomous Region, Yinchuan, China
| | - Qi Qi
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, North Carolina, USA
| | - Samiksha S Niture
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, North Carolina, USA
| | - John T Moore
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, North Carolina, USA
| | - Wanda Bodnar
- NCCU-RTI Center for Applied Research in Environmental Sciences (CARES), RTI International, Durham, North Carolina, USA
| | - Reshan A Fernando
- NCCU-RTI Center for Applied Research in Environmental Sciences (CARES), RTI International, Durham, North Carolina, USA
| | - Keith E Levine
- NCCU-RTI Center for Applied Research in Environmental Sciences (CARES), RTI International, Durham, North Carolina, USA
| | - Deepak Kumar
- Julius L. Chambers Biomedical Biotechnology Research Institute, North Carolina Central University Durham, North Carolina, USA
- NCCU-RTI Center for Applied Research in Environmental Sciences (CARES), RTI International, Durham, North Carolina, USA
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3
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Zhou J, Baumann K, Chang N, Morrison G, Bodnar W, Zhang Z, Atkin JM, Surratt JD, Turpin BJ. Per- and Polyfluoroalkyl Substances (PFASs) in Airborne Particulate Matter (PM 2.0) Emitted During Floor Waxing: A Pilot Study. Atmos Environ (1994) 2022; 268:118845. [PMID: 34899026 PMCID: PMC8654107 DOI: 10.1016/j.atmosenv.2021.118845] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Per- and polyfluoroalkyl substances (PFASs), with their water- and heat-resistant properties, have been widely used in industrial and consumer products, including floor waxes. Adverse health effects are associated with PFAS exposures (e.g., increased risk of cancer and immunotoxicity); however, exposures resulting from the use of PFAS-containing products are poorly understood. This study examines PFAS emissions during professional floor stripping/waxing and their potential for occupational exposures. We measured PFASs in dust and airborne particulate matter (PM2.0, aerodynamic diameter ≤ 2.0 μm) before, during, and after floor stripping/waxing activities in three rooms in a university building. PM2.0 samples were analyzed for 34 targeted PFASs by ultra-high performance liquid chromatography coupled to electrospray ionization triple quadrupole mass spectrometer (UHPLC/ESI-MS/MS). In total, ten PFASs were detected in PM2.0 collected during floor waxing. Five were consistently higher during floor stripping/waxing compared to before (two with 95% confidence interval): perfluoro-2-methoxyacetic acid, perfluorobutanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, and perfluorooctane sulfonic acid. For these five, estimated exposures during floor stripping were 80.6, 320.5, 83.8, 29.6, and 157.7 pg m-3 per hour of floor stripping, respectively, one order of magnitude greater than typical residential indoor and two orders of magnitude greater than ambient outdoor concentrations. Estimated emission rates were 3.0, 9.6, 3.4, 1.5, and 6.5 ng h-1m-2, respectively (34.6% uncertainty). Inhalation occupational exposures were in the range of 9.42-23.2 pg per kg body weight per hour of floor stripping across the five PFASs.
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Affiliation(s)
- Jiaqi Zhou
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Karsten Baumann
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Naomi Chang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Glenn Morrison
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Zhenfa Zhang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Joanna. M. Atkin
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Jason D. Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Barbara J. Turpin
- 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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4
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Zhou J, Baumann K, Mead RN, Skrabal SA, Kieber RJ, Avery GB, Shimizu M, DeWitt JC, Sun M, Vance SA, Bodnar W, Zhang Z, Collins LB, Surratt JD, Turpin BJ. PFOS dominates PFAS composition in ambient fine particulate matter (PM 2.5) collected across North Carolina nearly 20 years after the end of its US production. Environ Sci Process Impacts 2021; 23:580-587. [PMID: 33725038 DOI: 10.1039/d0em00497a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Contamination of drinking water by per- and polyfluoroalkyl substances (PFASs) emitted from manufacturing plants, fire-fighting foams, and urban waste streams has received considerable attention due to concerns over toxicity and environmental persistence; however, PFASs in ambient air remain poorly understood, especially in the United States (US). We measured PFAS concentrations in ambient fine particulate matter (PM2.5) at 5 locations across North Carolina over a 1 year period in 2019. Thirty-four PFASs, including perfluoroalkyl carboxylic, perfluoroalkane sulfonic, perfluoroalkyl ether carboxylic and sulfonic acids were analyzed by UHPLC/ESI-MS/MS. Quarterly averaged concentrations ranged from <0.004-14.1 pg m-3. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) ranged from <0.18 to 14.1 pg m-3, comparable to previous PM2.5 measurements from Canada and Europe (<0.02-3.5 pg m-3). Concentrations above 1 pg m-3 were observed in July-September at Charlotte (14.1 pg m-3, PFOA), Wilmington (4.75 pg m-3, PFOS), and Research Triangle Park (1.37 pg m-3, PFOS). Notably, PM2.5 has a short atmospheric lifetime (<2 weeks), and thus, the presence of PFOS in these samples raises questions about their sources, since PFOS production was phased out in the US ∼20 years ago. This is the first US study to provide insights into ambient PFAS concentrations in PM2.5.
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Affiliation(s)
- J Zhou
- 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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5
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Baker SD, Lee JY, White RP, Collins L, Bodnar W, Philips C, Divaris K. Double-Blind, Randomized Clinical Trial Comparing One Percent Buffered Versus Two Percent Unbuffered Lidocaine Injections in Children. Pediatr Dent 2021; 43:88-94. [PMID: 33892831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Purpose: Buffered local anesthetics offer an alternative to conventional, unbuffered anesthetic formulations; however, evidence about their use in children is scant. The purpose of this study was to determine the anesthetic and physiologic differences associated with the use of buffered one percent and unbuffered two percent lidocaine (both with 1:100,000 epinephrine) in children. Methods: In this randomized, double-blinded, crossover study, 25 children ages 10 to 12 years old received two inferior alveolar never blocks, at least one week apart, randomized to alternating sequences of two drug formulations: (1) formula A-three mL buffered one percent lidocaine (i.e., including 0.3 mL of 8.4 percent sodium bicarbonate); or (2) formula B-three mL unbuffered two percent lidocaine. Primary outcomes were mean blood lidocaine levels (15 minutes post-injection), timing of clinical signs onset, response to pain on injection, and duration of anesthesia. Analyses relied upon analysis of variance for crossover study designs and a P<0.05 statistical significance criterion. Results: The buffered formulation resulted in significantly lower mean blood lidocaine levels compared to unbuffered-a 63 percent (P<0.05) weight-adjusted relative decrease. The authors found no important differences in pain upon injection, onset, and duration of anesthesia. Conclusion: The buffered local anesthetic formulation showed equal effectiveness with a double-concentration unbuffered formulation while resulting in lower mean blood lidocaine levels-an important gain for the prevention of anesthetic toxicity.
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Affiliation(s)
- Suzanne D Baker
- Dr. Baker is in private practice, North Carolina State University, Raleigh, N.C., USA
| | - Jessica Y Lee
- Dr. Lee is a distinguished professor and chair, Division of Pediatric and Public Health, and a professor, Department of and Health Policy and Management, Gillings School of Public Health, University of North Carolina at Chapel Hill, Chapel Hill, N.C., USA;,
| | - Raymond P White
- Dr. White is a professor, Division of Craniofacial and Surgical Care, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, N.C., USA
| | - Leonard Collins
- Mr. Collins is a research specialist, Molecular Education, Technology and Research Center, at North Carolina State University, Raleigh, N.C., USA
| | - Wanda Bodnar
- Dr. Bodnar is an assistant professor, Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, N.C., USA
| | - Ceib Philips
- Dr. Phillips is an associate dean of Advanced Education/Graduate Studies, Division of Oral and Cranio-facial Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, N.C., USA
| | - Kimon Divaris
- Dr. Divaris is a professor, Division of Pediatric and Public Health, Adams School of Dentistry, all at the University of North Carolina at Chapel Hill, Chapel Hill, N.C., USA
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6
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Vila J, Tian Z, Wang H, Bodnar W, Aitken MD. Isomer-selective biodegradation of high-molecular-weight azaarenes in PAH-contaminated environmental samples. Sci Total Environ 2020; 707:135503. [PMID: 31780161 PMCID: PMC6981052 DOI: 10.1016/j.scitotenv.2019.135503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/05/2019] [Accepted: 11/11/2019] [Indexed: 05/30/2023]
Abstract
Polycyclic aromatic nitrogen heterocycles, or azaarenes, normally co-occur with polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. We recently reported that nontarget analysis using high resolution mass spectrometry of samples from four PAH-contaminated sites revealed a previously unrecognized diversity and abundance of azaarene isomers and their methylated derivatives. Here we evaluated their biodegradability by natural microbial communities from each site in aerobic microcosm incubations under biostimulated conditions. The removal of total quantifiable azaarenes ranged from 15 to 85%, and was related to the initial degree of weathering for each sample. While three-ring azaarenes were readily biodegradable, the five-ring congeners were the most recalcitrant. Microbial-mediated removal of four-ring congeners varied for different isomers, which might be attributed to the position of the nitrogen atom that also influences the physicochemical properties of azaarenes and possibly the susceptibility to transformation by relevant microbial enzymes. The presence of methyl groups also influenced azaarene biodegradability, which decreased with increasing degree of methylation. Several oxidation products of azaarenes were detected, including ketones and dioxygenated derivatives of three- and four-ring compounds. Our results indicate the susceptibility of some azaarenes to bioremediation, while suggesting the potential implications for risk from the persistence of less-biodegradable isomers and the formation of oxidized-azaarene derivatives.
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Affiliation(s)
- Joaquim Vila
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431, USA.
| | - Zhenyu Tian
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431, USA
| | - Hanyan Wang
- Department of Statistics & Operations Research, University of North Carolina at Chapel Hill, CB 3260, Chapel Hill, NC 27599-3260, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431, USA
| | - Michael D Aitken
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431, USA
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Lewis L, Borowa-Mazgaj B, de Conti A, Chappell GA, Luo YS, Bodnar W, Konganti K, Wright FA, Threadgill DW, Chiu WA, Pogribny IP, Rusyn I. Population-Based Analysis of DNA Damage and Epigenetic Effects of 1,3-Butadiene in the Mouse. Chem Res Toxicol 2019; 32:887-898. [PMID: 30990016 DOI: 10.1021/acs.chemrestox.9b00035] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metabolism of 1,3-butadiene, a known human and rodent carcinogen, results in formation of reactive epoxides, a key event in its carcinogenicity. Although mice exposed to 1,3-butadiene present DNA adducts in all tested tissues, carcinogenicity is limited to liver, lung, and lymphoid tissues. Previous studies demonstrated that strain- and tissue-specific epigenetic effects in response to 1,3-butadiene exposure may influence susceptibly to DNA damage and serve as a potential mechanism of tissue-specific carcinogenicity. This study aimed to investigate interindividual variability in the effects of 1,3-butadiene using a population-based mouse model. Male mice from 20 Collaborative Cross strains were exposed to 0 or 635 ppm 1,3-butadiene by inhalation (6 h/day, 5 days/week) for 2 weeks. We evaluated DNA damage and epigenetic effects in target (lung and liver) and nontarget (kidney) tissues of 1,3-butadiene-induced carcinogenesis. DNA damage was assessed by measuring N-7-(2,3,4-trihydroxybut-1-yl)-guanine (THB-Gua) adducts. To investigate global histone modification alterations, we evaluated the trimethylation and acetylation of histones H3 and H4 across tissues. Changes in global cytosine DNA methylation were evaluated from the levels of methylation of LINE-1 and SINE B1 retrotransposons. We quantified the degree of variation across strains, deriving a chemical-specific human variability factor to address population variability in carcinogenic risk, which is largely ignored in current cancer risk assessment practice. Quantitative trait locus mapping identified four candidate genes related to chromatin remodeling whose variation was associated with interstrain susceptibility. Overall, this study uses 1,3-butadiene to demonstrate how the Collaborative Cross mouse population can be used to identify the mechanisms for and quantify the degree of interindividual variability in tissue-specific effects that are relevant to chemically induced carcinogenesis.
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Affiliation(s)
- Lauren Lewis
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Barbara Borowa-Mazgaj
- Division of Biochemical Toxicology, National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Aline de Conti
- Division of Biochemical Toxicology, National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Grace A Chappell
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Yu-Syuan Luo
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering , University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27516 , United States
| | - Kranti Konganti
- Department of Molecular and Cellular Medicine, College of Medicine , Texas A&M University , College Station , Texas 77843-1114 , United States
| | - Fred A Wright
- Bioinformatics Research Center , North Carolina State University , Raleigh , North Carolina 27695-7566 , United States
| | - David W Threadgill
- Department of Molecular and Cellular Medicine, College of Medicine , Texas A&M University , College Station , Texas 77843-1114 , United States
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Igor P Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research , U.S. Food and Drug Administration , Jefferson , Arkansas 72079 , United States
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences , Texas A&M University , College Station , Texas 77843 , United States
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8
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Lewis L, Chappell GA, Kobets T, O'Brian BE, Sangaraju D, Kosyk O, Bodnar W, Tretyakova NY, Pogribny IP, Rusyn I. Sex-specific differences in genotoxic and epigenetic effects of 1,3-butadiene among mouse tissues. Arch Toxicol 2019; 93:791-800. [PMID: 30552462 PMCID: PMC6451682 DOI: 10.1007/s00204-018-2374-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Accepted: 12/10/2018] [Indexed: 01/31/2023]
Abstract
Exposure to environmental chemicals has been shown to have an impact on the epigenome. One example is a known human carcinogen 1,3-butadiene which acts primarily by a genotoxic mechanism, but also disrupts the chromatin structure by altering patterns of cytosine DNA methylation and histone modifications. Sex-specific differences in 1,3-butadiene-induced genotoxicity and carcinogenicity are well established; however, it remains unknown whether 1,3-butadiene-associated epigenetic alterations are also sex dependent. Therefore, we tested the hypothesis that inhalational exposure to 1,3-butadiene will result in sex-specific epigenetic alterations. DNA damage and epigenetic effects of 1,3-butadiene were evaluated in liver, lung, and kidney tissues of male and female mice of two inbred strains (C57BL/6J and CAST/EiJ). Mice were exposed to 0 or 425 ppm of 1,3-butadiene by inhalation (6 h/day, 5 days/week) for 2 weeks. Strain- and tissue-specific differences in 1,3-butadiene-induced DNA adducts and crosslinks were detected in the liver, lung and kidney; however, significant sex-specific differences in DNA damage were observed in the lung of C57BL/6J mice only. In addition, we assessed expression of the DNA repair genes and observed a marked upregulation of Mgmt in the kidney in female C57BL/6J mice. Sex-specific epigenetic effects of 1,3-butadiene exposure were evident in alterations of cytosine DNA methylation and histone modifications in the liver and lung in both strains. Specifically, we observed a loss of cytosine DNA methylation in the liver and lung of male and female 1,3-butadiene-exposed C57BL/6J mice, whereas hypermethylation was found in the liver and lung in 1,3-butadiene-exposed female CAST/EiJ mice. Our findings suggest that strain- and sex-specific effects of 1,3-butadiene on the epigenome may contribute to the known differences in cancer susceptibility.
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Affiliation(s)
- Lauren Lewis
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Grace A Chappell
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Tetyana Kobets
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Bridget E O'Brian
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Dewakar Sangaraju
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Natalia Y Tretyakova
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, USA
| | - Igor P Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
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9
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Smeester L, Martin EM, Cable P, Bodnar W, Boggess K, Vora NL, Fry RC. Toxic metals in amniotic fluid and altered gene expression in cell-free fetal RNA. Prenat Diagn 2018; 37:1364-1366. [PMID: 29111618 DOI: 10.1002/pd.5183] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 10/26/2017] [Accepted: 10/28/2017] [Indexed: 01/09/2023]
Abstract
Both exposures to toxic metals, as well as deficiencies in essential metals, during pregnancy has been linked to a variety of negative reproductive outcomes. The exact etiologies of such outcomes and the effects of fetal exposure to these metals are largely unknown. Therefore, the ability to assess levels of these elements is critical to determining the underlying causes of such conditions and the effects that both essential and nonessential metals have on fetal development. Thus, using cell-free fetal RNA from amniotic fluid, we set out to measure the association between amniotic fluid levels of toxic and essential metals and fetal gene expression. We find that arsenic was associated with increased expression of 3 genes known to play roles in both birth-related and reproductive effects. The results highlight the potential for detrimental health effects of prenatal metals exposure and the potential to identify biomarkers of environmental exposure during this critical developmental period.
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Affiliation(s)
- Lisa Smeester
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Elizabeth M Martin
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Pete Cable
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Kim Boggess
- Division of Maternal-Fetal Medicine, Department of Obstetrics & Gynecology, University of North Carolina School of Medicine, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Neeta L Vora
- Division of Maternal-Fetal Medicine, Department of Obstetrics & Gynecology, University of North Carolina 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
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10
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Venkatratnam A, Furuya S, Kosyk O, Gold A, Bodnar W, Konganti K, Threadgill DW, Gillespie KM, Aylor DL, Wright FA, Chiu WA, Rusyn I. Editor's Highlight: Collaborative Cross Mouse Population Enables Refinements to Characterization of the Variability in Toxicokinetics of Trichloroethylene and Provides Genetic Evidence for the Role of PPAR Pathway in Its Oxidative Metabolism. Toxicol Sci 2018; 158:48-62. [PMID: 28369613 DOI: 10.1093/toxsci/kfx065] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background Trichloroethylene (TCE) is a known carcinogen in humans and rodents. Previous studies of inter-strain variability in TCE metabolism were conducted in multi-strain panels of classical inbred mice with limited genetic diversity to identify gene-environment interactions associated with chemical exposure. Objectives To evaluate inter-strain variability in TCE metabolism and identify genetic determinants that are associated with TCE metabolism and effects using Collaborative Cross (CC), a large panel of genetically diverse strains of mice. Methods We administered a single oral dose of 0, 24, 80, 240, or 800 mg/kg of TCE to mice from 50 CC strains, and collected organs 24 h post-dosing. Levels of trichloroacetic acid (TCA), a major oxidative metabolite of TCE were measured in multiple tissues. Protein expression and activity levels of TCE-metabolizing enzymes were evaluated in the liver. Liver transcript levels of known genes perturbed by TCE exposure were also quantified. Genetic association mapping was performed on the acquired phenotypes. Results TCA levels varied in a dose- and strain-dependent manner in liver, kidney, and serum. The variability in TCA levels among strains did not correlate with expression or activity of a number of enzymes known to be involved in TCE oxidation. Peroxisome proliferator-activated receptor alpha (PPARα)-responsive genes were found to be associated with strain-specific differences in TCE metabolism. Conclusions This study shows that CC mouse population is a valuable tool to quantitatively evaluate inter-individual variability in chemical metabolism and to identify genes and pathways that may underpin population differences.
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Affiliation(s)
- Abhishek Venkatratnam
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843.,Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Shinji Furuya
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Oksana Kosyk
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Avram Gold
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Kranti Konganti
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas 77843
| | - David W Threadgill
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas 77843
| | - Kevin M Gillespie
- Bioinformatics Research Center and Departments of Statistics and Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - David L Aylor
- Bioinformatics Research Center and Departments of Statistics and Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Fred A Wright
- Bioinformatics Research Center and Departments of Statistics and Biological Sciences, North Carolina State University, Raleigh, North Carolina 27695
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas 77843
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11
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Nagarajan U, Zhang Y, Bodnar W, Kiatthanapaiboon A, Hagan R, O’Connell C, Tripathy MK. CX43 is essential for optimal cGAS function during cytosolic DNA-sensing. The Journal of Immunology 2018. [DOI: 10.4049/jimmunol.200.supp.169.13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
During intracellular Chlamydia infection, cytosolic DNA is sensed by cyclic GMP-AMP synthase (cGAS) that catalyzes the synthesis of cGAMP from ATP and GTP. cGAMP is a key mediator of IFN beta expression during DNA sensing and can also transfer to adjacent uninfected cells through intercellular connexin gap-junctions to induce intrinsic immunity. In this study, we investigated the role of gap junction protein connexin 43 (CX43) during Chlamydia infection. Using RNA-in situ hybridization, we discovered a distinct intracellular contribution of CX43 in IFN beta expression in the infected cells and cells transfected with DNA, a function distinct from its intercellular gap-junction role affecting IFN beta expression in adjacent uninfected cell. CX43 is essential for IFN beta expression during DNA-sensing upstream of STING activation, but not required during RNA-sensing. CX43 co-localized with transfected DNA and on the chlamydial inclusion membrane with cGAS. CX43-depleted cells showed significantly reduced cGAMP production during DNA-sensing. CX43 forms hemichannels on intracellular membrane, which open and close to allow nucleotide transfer. Blocking this transport across CX43 hemichannel reduced IFN beta expression during infection and DNA-sensing, without altering CX43 localization. These results uncover a novel role of CX43 in cGAMP synthesis by cGAS during cytosolic DNA-sensing.
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12
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Tian Z, Vila J, Yu M, Bodnar W, Aitken MD. Tracing the Biotransformation of Polycyclic Aromatic Hydrocarbons in Contaminated Soil Using Stable Isotope-Assisted Metabolomics. Environ Sci Technol Lett 2018; 5:103-109. [PMID: 31572742 PMCID: PMC6767928 DOI: 10.1021/acs.estlett.7b00554] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Biotransformation of organic pollutants may result in the formation of oxidation products more toxic than the parent contaminants. However, to trace and identify those products, and the metabolic pathways involved in their formation, is still challenging within complex environmental samples. We applied stable isotope-assisted metabolomics (SIAM) to PAH-contaminated soil collected from a wood treatment facility. Soil samples were separately spiked with uniformly 13C-labeled fluoranthene, pyrene, or benzo[a]anthracene at a level below that of the native contaminant, and incubated for 1 or 2 weeks under aerobic biostimulated conditions. Combining high-resolution mass spectrometry and automated SIAM workflows, chemical structures of metabolites and metabolic pathways in the soil were proposed. Ring-cleavage products, including previously unreported intermediates such as C11H10O6 and C15H12O5, were detected originating from fluoranthene and benzo[a]anthracene, respectively. Sulfate conjugates of dihydroxy compounds were found as major metabolites of pyrene and benzo[a]anthracene, suggesting the potential role of fungi in their biotransformation in soils. A series of unknown N-containing metabolites were identified from pyrene, but their structural elucidation requires further investigation. Our results suggest that SIAM can be successfully applied to understand the fate of organic pollutants in environmental samples, opening lines of evidence for novel mechanisms of microbial transformation within such complex matrices.
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Affiliation(s)
- Zhenyu Tian
- Department of Environmental Sciences and
Engineering, Gillings School of Global Public Health, University of North Carolina
at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
| | - Joaquim Vila
- Department of Environmental Sciences and
Engineering, Gillings School of Global Public Health, University of North Carolina
at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
| | - Miao Yu
- Department of Chemistry, University of Waterloo,
Waterloo, Ontario, Canada N2L 3G1
| | - Wanda Bodnar
- Department of Environmental Sciences and
Engineering, Gillings School of Global Public Health, University of North Carolina
at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
| | - Michael D. Aitken
- Department of Environmental Sciences and
Engineering, Gillings School of Global Public Health, University of North Carolina
at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
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13
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Israel JW, Chappell GA, Simon JM, Pott S, Safi A, Lewis L, Cotney P, Boulos HS, Bodnar W, Lieb JD, Crawford GE, Furey TS, Rusyn I. Tissue- and strain-specific effects of a genotoxic carcinogen 1,3-butadiene on chromatin and transcription. Mamm Genome 2018; 29:153-167. [PMID: 29429127 PMCID: PMC6095468 DOI: 10.1007/s00335-018-9739-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 02/03/2018] [Indexed: 12/27/2022]
Abstract
Epigenetic effects of environmental chemicals are under intense investigation to fill existing knowledge gaps between environmental/occupational exposures and adverse health outcomes. Chromatin accessibility is one prominent mechanism of epigenetic control of transcription, and understanding of the chemical effects on both could inform the causal role of epigenetic alterations in disease mechanisms. In this study, we hypothesized that baseline variability in chromatin organization and transcription profiles among various tissues and mouse strains influence the outcome of exposure to the DNA damaging chemical 1,3-butadiene. To test this hypothesis, we evaluated DNA damage along with comprehensive quantification of RNA transcripts (RNA-seq), identification of accessible chromatin (ATAC-seq), and characterization of regions with histone modifications associated with active transcription (ChIP-seq for acetylation at histone 3 lysine 27, H3K27ac). We collected these data in the lung, liver, and kidney of mice from two genetically divergent strains, C57BL/6J and CAST/EiJ, that were exposed to clean air or to 1,3-butadiene (~600 ppm) for 2 weeks. We found that tissue effects dominate differences in both gene expression and chromatin states, followed by strain effects. At baseline, xenobiotic metabolism was consistently more active in CAST/EiJ, while immune system pathways were more active in C57BL/6J across tissues. Surprisingly, even though all three tissues in both strains harbored butadiene-induced DNA damage, little transcriptional effect of butadiene was observed in liver and kidney. Toxicologically relevant effects of butadiene in the lung were on the pathways of xenobiotic metabolism and inflammation. We also found that variability in chromatin accessibility across individuals (i.e., strains) only partially explains the variability in transcription. This study showed that variation in the basal states of epigenome and transcriptome may be useful indicators for individuals or tissues susceptible to genotoxic environmental chemicals.
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Affiliation(s)
- Jennifer W Israel
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - Grace A Chappell
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Jeremy M Simon
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - Sebastian Pott
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Alexias Safi
- Department of Pediatrics, Duke Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Lauren Lewis
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Paul Cotney
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - Hala S Boulos
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Jason D Lieb
- Department of Human Genetics, University of Chicago, Chicago, IL, USA
| | - Gregory E Crawford
- Department of Pediatrics, Duke Center for Genomic and Computational Biology, Duke University, Durham, NC, USA
| | - Terrence S Furey
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA.
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA.
- UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA.
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA.
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14
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Robbins Z, Bodnar W, Zhang Z, Gold A, Nylander-French LA. Trisaminohexyl isocyanurate, a urinary biomarker of HDI isocyanurate exposure. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1076:117-129. [PMID: 29406025 DOI: 10.1016/j.jchromb.2018.01.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 01/12/2018] [Accepted: 01/15/2018] [Indexed: 11/17/2022]
Abstract
Biological monitoring of occupational exposure to 1,6-hexamethylene diisocyanate (HDI)-containing spray-paints is limited to analysis of metabolites of HDI monomer although polymeric HDI isocyanurate constitutes the predominant inhalation and skin exposure for workers in the automotive paint industry. A novel method using nanoflow ultra-performance liquid chromatography coupled to nano-electrospray ionization tandem mass spectrometry (nano-UPLC-ESI-MS/MS) was developed to quantify trisaminohexyl isocyanurate (TAHI), a hydrolysis product of HDI isocyanurate, in the urine of spray-painters. Analytical and internal standards were synthesized in-house and weighted linear regression calibration curves were generated using spiked control urine from non-exposed persons (0.06-7.98 μg/L; N = 13; w = x-2; r = 0.998). Urine samples collected from 15 exposed workers (N = 111) were subjected to acid hydrolysis and extracted with dichloromethane, then derivatized with acetic anhydride. The derivatized product, trisacetamidohexyl isocyanurate (TAAHI), was analyzed using nano-UPLC-ESI-MS/MS. The protocol was sensitive and specific for analysis of TAHI in the urine of exposed workers with a method detection limit at 0.03 μg/L. TAHI was detected in 33 of 111 urine samples and in 11 of 15 workers. This biomarker for HDI isocyanurate is critical to determine the relative potency and dose-relationships between the monomer and oligomer exposure on the development of diisocyanate induced health effects in future studies.
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Affiliation(s)
- Zachary Robbins
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, NC 27599, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, NC 27599, USA
| | - Zhenfa Zhang
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, NC 27599, USA
| | - Avram Gold
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, NC 27599, USA
| | - Leena A Nylander-French
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, NC 27599, USA.
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15
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Tian Z, Vila J, Wang H, Bodnar W, Aitken MD. Diversity and Abundance of High-Molecular-Weight Azaarenes in PAH-Contaminated Environmental Samples. Environ Sci Technol 2017; 51:14047-14054. [PMID: 29160699 PMCID: PMC6343503 DOI: 10.1021/acs.est.7b03319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Azaarenes are N-heterocyclic polyaromatic pollutants that co-occur with polycyclic aromatic hydrocarbons (PAHs) in contaminated soils. Despite the known toxicity of some high-molecular-weight azaarenes, their diversity, abundance, and fate in contaminated soils remain to be elucidated. We applied high-resolution mass spectrometry and mass-defect filtering to four PAH-contaminated samples from geographically distant sites and detected 232 azaarene congeners distributed in eight homologous series, including alkylated derivatives and two hitherto unknown series. Four- and five-ring azaarenes were detected among these series, and the most abundant nonalkylated congeners groups (C13H9N, C15H9N, C17H11N, C19H11N, and C21H13N) were quantified. The profiles of congener groups varied among different sites. Three-ring azaarenes presented higher concentrations in unweathered sites, while four- and five-ring azaarenes predominated in weathered sites. Known toxic and carcinogenic azaarenes, such as benzo[c]acridine and dibenzo[a,h]acridine, were detected along with their multiple isomers. Our results highlight a previously unrecognized diversity and abundance of azaarenes in PAH-contaminated sites, with corresponding implications for environmental monitoring and risk assessment.
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Affiliation(s)
- Zhenyu Tian
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
| | - Joaquim Vila
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
- Corresponding Authors; , Phone: +1 919-966-1481
| | - Hanyan Wang
- Department of Statistics & Operations Research, University of North Carolina at Chapel Hill, CB 3260, Chapel Hill, NC 27599-3260 USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
| | - Michael D. Aitken
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, CB 7431, Chapel Hill, NC 27599-7431 USA
- Corresponding Authors; , Phone: +1 919-966-1481
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16
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Chappell GA, Israel JW, Simon JM, Pott S, Safi A, Eklund K, Sexton KG, Bodnar W, Lieb JD, Crawford GE, Rusyn I, Furey TS. Variation in DNA-Damage Responses to an Inhalational Carcinogen (1,3-Butadiene) in Relation to Strain-Specific Differences in Chromatin Accessibility and Gene Transcription Profiles in C57BL/6J and CAST/EiJ Mice. Environ Health Perspect 2017; 125:107006. [PMID: 29038090 PMCID: PMC5944832 DOI: 10.1289/ehp1937] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 08/30/2017] [Accepted: 09/05/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND The damaging effects of exposure to environmental toxicants differentially affect genetically distinct individuals, but the mechanisms contributing to these differences are poorly understood. Genetic variation affects the establishment of the gene regulatory landscape and thus gene expression, and we hypothesized that this contributes to the observed heterogeneity in individual responses to exogenous cellular insults. OBJECTIVES We performed an in vivo study of how genetic variation and chromatin organization may dictate susceptibility to DNA damage, and influence the cellular response to such damage, caused by an environmental toxicant. MATERIALS AND METHODS We measured DNA damage, messenger RNA (mRNA) and microRNA (miRNA) expression, and genome-wide chromatin accessibility in lung tissue from two genetically divergent inbred mouse strains, C57BL/6J and CAST/EiJ, both in unexposed mice and in mice exposed to a model DNA-damaging chemical, 1,3-butadiene. RESULTS Our results showed that unexposed CAST/EiJ and C57BL/6J mice have very different chromatin organization and transcription profiles in the lung. Importantly, in unexposed CAST/EiJ mice, which acquired relatively less 1,3-butadiene-induced DNA damage, we observed increased transcription and a more accessible chromatin landscape around genes involved in detoxification pathways. Upon chemical exposure, chromatin was significantly remodeled in the lung of C57BL/6J mice, a strain that acquired higher levels of 1,3-butadiene-induced DNA damage, around the same genes, ultimately resembling the molecular profile of CAST/EiJ. CONCLUSIONS These results suggest that strain-specific changes in chromatin and transcription in response to chemical exposure lead to a "compensation" for underlying genetic-driven interindividual differences in the baseline chromatin and transcriptional state. This work represents an example of how chemical and environmental exposures can be evaluated to better understand gene-by-environment interactions, and it demonstrates the important role of chromatin response in transcriptomic changes and, potentially, in deleterious effects of exposure. https://doi.org/10.1289/EHP1937.
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Affiliation(s)
- Grace A Chappell
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station , Texas, USA
- Department of Environmental Sciences and Engineering, University of North Carolina , Chapel Hill, North Carolina, USA
| | - Jennifer W Israel
- Department of Genetics, University of North Carolina , Chapel Hill, North Carolina, USA
| | - Jeremy M Simon
- Department of Genetics, University of North Carolina , Chapel Hill, North Carolina, USA
| | - Sebastian Pott
- Department of Human Genetics, University of Chicago , Chicago, Illinois, USA
| | - Alexias Safi
- Department of Pediatrics, Duke Center for Genomic and Computational Biology, Duke University , Durham, North Carolina, USA
| | - Karl Eklund
- Department of Genetics, University of North Carolina , Chapel Hill, North Carolina, USA
| | - Kenneth G Sexton
- Department of Environmental Sciences and Engineering, University of North Carolina , Chapel Hill, North Carolina, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina , Chapel Hill, North Carolina, USA
| | - Jason D Lieb
- Department of Human Genetics, University of Chicago , Chicago, Illinois, USA
| | - Gregory E Crawford
- Department of Pediatrics, Duke Center for Genomic and Computational Biology, Duke University , Durham, North Carolina, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station , Texas, USA
| | - Terrence S Furey
- Department of Genetics, University of North Carolina , Chapel Hill, North Carolina, USA
- Department of Biology, University of North Carolina , Chapel Hill, North Carolina, USA
- UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine , Chapel Hill, North Carolina, USA
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17
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Guilini K, Weber M, de Beer D, Schneider M, Molari M, Lott C, Bodnar W, Mascart T, De Troch M, Vanreusel A. Response of Posidonia oceanica seagrass and its epibiont communities to ocean acidification. PLoS One 2017; 12:e0181531. [PMID: 28792960 PMCID: PMC5549886 DOI: 10.1371/journal.pone.0181531] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 07/03/2017] [Indexed: 11/30/2022] Open
Abstract
The unprecedented rate of CO2 increase in our atmosphere and subsequent ocean acidification (OA) threatens coastal ecosystems. To forecast the functioning of coastal seagrass ecosystems in acidified oceans, more knowledge on the long-term adaptive capacities of seagrass species and their epibionts is needed. Therefore we studied morphological characteristics of Posidonia oceanica and the structure of its epibiont communities at a Mediterranean volcanic CO2 vent off Panarea Island (Italy) and performed a laboratory experiment to test the effect of OA on P. oceanica photosynthesis and its potential buffering capacity. At the study site east of Basiluzzo Islet, venting of CO2 gas was controlled by tides, resulting in an average pH difference of 0.1 between the vent and reference site. P. oceanica shoot and leaf density was unaffected by these levels of OA, although shorter leaves at the vent site suggest increased susceptibility to erosion, potentially by herbivores. The community of sessile epibionts differed in composition and was characterized by a higher species richness at the vent site, though net epiphytic calcium carbonate concentration was similar. These findings suggest a higher ecosystem complexity at the vent site, which may have facilitated the higher diversity of copepods in the otherwise unaffected motile epibiont community. In the laboratory experiment, P. oceanica photosynthesis increased with decreasing pHT (7.6, 6.6, 5.5), which induced an elevated pH at the leaf surfaces of up to 0.5 units compared to the ambient seawater pHT of 6.6. This suggests a temporary pH buffering in the diffusive boundary layer of leaves, which could be favorable for epibiont organisms. The results of this multispecies study contribute to understanding community-level responses and underlying processes in long-term acidified conditions. Increased replication and monitoring of physico-chemical parameters on an annual scale are, however, recommended to assure that the biological responses observed during a short period reflect long-term dynamics of these parameters.
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Affiliation(s)
- Katja Guilini
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
- * E-mail:
| | - Miriam Weber
- HGF-MPG Joint Research Group on Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany
- HYDRA Institute for Marine Sciences, Elba Field Station, Italy
| | - Dirk de Beer
- Microsensor Group, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | | | - Massimiliano Molari
- HGF-MPG Joint Research Group on Deep Sea Ecology and Technology, Max Planck Institute for Marine Microbiology, Bremen, Germany
| | - Christian Lott
- HYDRA Institute for Marine Sciences, Elba Field Station, Italy
| | - Wanda Bodnar
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Thibaud Mascart
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Marleen De Troch
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
| | - Ann Vanreusel
- Marine Biology Research Group, Department of Biology, Ghent University, Ghent, Belgium
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18
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Tripathy MK, Zhang Y, Bodnar W, Nagarajan UM. A novel role for Connexin 43 in IFN beta expression during Chlamydia trachomatis infection and cytosolic DNA-sensing. The Journal of Immunology 2017. [DOI: 10.4049/jimmunol.198.supp.148.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
Background
The DNA sensor cGAS is essential for IFNβ expression in cells infected with Chlamydia. cGAMP generated during DNA sensing can also transfer via intercellular gap-junction proteins, connexins CX43/45 leading to IFNβ expression in adjacent uninfected cells. Present study highlights a novel role for CX43 in IFNβ expression during DNA-sensing and during Chlamydia infection, independent of its gap junction function.
Methods
Total IFNβ transcripts were measured by qRT-PCR following CX43 or CX45 siRNA mediated knockdown (KD). Single cell RNA-ISH method view RNA™ was used to visualize IFNβ mRNA in infected HeLa cells. CX43 localization was studied using IF and confocal microscopy.
Results
CX43-KD in HeLa cells reduced IFNβ expression by >90% (p<0.001) compared to control or CX45 KD, as measured by qRT-PCR. CX43-KD also reduced IFNβ mRNA in dsDNA transfected cells (p<0.001) but not with poly IC RNA. RNA-ISH showed IFNβ mRNA transcripts in infected cells (>90%) and in adjacent uninfected (~10%) cells, but not in distal uninfected cells, suggesting cell contact is required for adjacent-cell effect. Surprisingly, RNA-ISH of CX43-KD cells showed >85% reduction in IFNβ transcripts (p<0.0001) in infected cells, in addition to the loss of transcripts in cells adjacent to infected cells. CX43 localized proximal to the chlamydial inclusion membrane. Co-localization of CX43 was also observed with transfected dsDNA, but not dsRNA.
Conclusion
CX43 depletion has been shown to increase autophagy in cells. Here we show that CX43 depletion decreases IFNβ induction during DNA sensing. Our results suggest that like STING, CX43 could be a key player in both DNA sensing and autophagy, but with opposing roles. (Funded by NIAID R01-AI067678 to UN).
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19
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McEachran AD, Shea D, Bodnar W, Nichols EG. Pharmaceutical occurrence in groundwater and surface waters in forests land-applied with municipal wastewater. Environ Toxicol Chem 2016; 35:898-905. [PMID: 26297815 PMCID: PMC4976290 DOI: 10.1002/etc.3216] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/01/2015] [Accepted: 08/17/2015] [Indexed: 05/08/2023]
Abstract
The occurrence and fate of pharmaceutical and personal care products in the environment are of increasing public importance because of their ubiquitous nature and documented effects on wildlife, ecosystems, and potentially humans. One potential, yet undefined, source of entry of pharmaceuticals into the environment is via the land application of municipal wastewater onto permitted lands. The objective of the present study is to determine the extent to which pharmaceuticals are mitigated by or exported from managed tree plantations irrigated with municipal wastewater. A specific focus of the present study is the presence of pharmaceutical compounds in groundwater and surface water discharge. The study site is a municipality that land-applies secondary treated wastewater onto 930 hectares of a 2000-hectare managed hardwood and pine plantation. A suite of 33 pharmaceuticals and steroid hormones was targeted in the analysis, which consisted of monthly grab sampling of groundwater, surface water, and wastewater, followed by concentration and cleanup via solid phase extraction and separation, detection, and quantification via liquid chromatography coupled with tandem mass spectrometry. More than one-half of all compounds detected in irrigated wastewater were not present in groundwater and subsequent surface water. However, antibiotics, nonsteroidal anti-inflammatory drugs, caffeine, and other prescription and over-the-counter drugs remained in groundwater and were transported into surface water at concentrations up to 10 ng/L. These results provide important documentation for pharmaceutical fate and transport in forest systems irrigated with municipal wastewater, a previously undocumented source of environmental entry.
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Affiliation(s)
- Andrew D. McEachran
- Department of Forestry and Environmental Resources, College of Natural Resources, North Carolina State University, Raleigh, North Carolina, USA
- Address correspondence to
| | - Damian Shea
- Department of Biological Sciences, College of Science, North Carolina State University, Raleigh, North Carolina, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Elizabeth Guthrie Nichols
- Department of Forestry and Environmental Resources, College of Natural Resources, North Carolina State University, Raleigh, North Carolina, USA
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Compton TJ, Bodnar W, Koolhaas A, Dekinga A, Holthuijsen S, ten Horn J, McSweeney N, van Gils JA, Piersma T. Burrowing Behavior of a Deposit Feeding Bivalve Predicts Change in Intertidal Ecosystem State. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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21
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Yoo HS, Cichocki JA, Kim S, Venkatratnam A, Iwata Y, Kosyk O, Bodnar W, Sweet S, Knap A, Wade T, Campbell J, Clewell HJ, Melnyk SB, Chiu WA, Rusyn I. The Contribution of Peroxisome Proliferator-Activated Receptor Alpha to the Relationship Between Toxicokinetics and Toxicodynamics of Trichloroethylene. Toxicol Sci 2015; 147:339-49. [PMID: 26136231 DOI: 10.1093/toxsci/kfv134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Exposure to the ubiquitous environmental contaminant trichloroethylene (TCE) is associated with cancer and non-cancer toxicity in both humans and rodents. Peroxisome proliferator-activated receptor-alpha (PPARα) is thought to be playing a role in liver toxicity in rodents through activation of the receptor by the TCE metabolite trichloroacetic acid (TCA). However, most studies using genetically altered mice have not assessed the potential for PPARα to alter TCE toxicokinetics, which may lead to differences in TCA internal doses and hence confound inferences as to the role of PPARα in TCE toxicity. To address this gap, male and female wild type (129S1/SvImJ), Pparα-null, and humanized PPARα (hPPARα) mice were exposed intragastrically to 400 mg/kg TCE in single-dose (2, 5 and 12 h) and repeat-dose (5 days/week, 4 weeks) studies. Interestingly, following either a single- or repeat-dose exposure to TCE, levels of TCA in liver and kidney were lower in Pparα-null and hPPARα mice as compared with those in wild type mice. Levels of trichloroethanol (TCOH) were similar in all strains. TCE-exposed male mice consistently had higher levels of TCA and TCOH in all tissues compared with females. Additionally, in both single- and repeat-dose studies, a similar degree of induction of PPARα-responsive genes was observed in liver and kidney of hPPARα and wild type mice, despite the difference in hepatic and renal TCA levels. Additional sex- and strain-dependent effects were observed in the liver, including hepatocyte proliferation and oxidative stress, which were not dependent on TCA or TCOH levels. These data demonstrate that PPARα status affects the levels of the putative PPARα agonist TCA following TCE exposure. Therefore, interpretations of studies using Pparα-null and hPPARα mice need to consider the potential contribution of genotype-dependent toxicokinetics to observed differences in toxicity, rather than attributing such differences only to receptor-mediated toxicodynamic effects.
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Affiliation(s)
- Hong Sik Yoo
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Joseph A Cichocki
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Sungkyoon Kim
- Graduate School of Public Health, Seoul National University, Seoul, Republic of Korea
| | - Abhishek Venkatratnam
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina; Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Yasuhiro Iwata
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Oksana Kosyk
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Wanda Bodnar
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina
| | - Stephen Sweet
- Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas
| | - Anthony Knap
- Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas
| | - Terry Wade
- Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas
| | - Jerry Campbell
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina; and
| | - Harvey J Clewell
- The Hamner Institutes for Health Sciences, Research Triangle Park, North Carolina; and
| | - Stepan B Melnyk
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Weihsueh A Chiu
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Ivan Rusyn
- Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA;
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22
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Chappell G, Kobets T, O'Brien B, Tretyakova N, Sangaraju D, Kosyk O, Sexton KG, Bodnar W, Pogribny IP, Rusyn I. Epigenetic events determine tissue-specific toxicity of inhalational exposure to the genotoxic chemical 1,3-butadiene in male C57BL/6J mice. Toxicol Sci 2014; 142:375-84. [PMID: 25237060 PMCID: PMC4250847 DOI: 10.1093/toxsci/kfu191] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
1,3-Butadiene (BD), a widely used industrial chemical and a ubiquitous environmental pollutant, is a known human carcinogen. Although genotoxicity is an established mechanism of the tumorigenicity of BD, epigenetic effects have also been observed in livers of mice exposed to the chemical. To better characterize the diverse molecular mechanisms of BD tumorigenicity, we evaluated genotoxic and epigenotoxic effects of BD exposure in mouse tissues that are target (lung and liver) and non-target (kidney) for BD-induced tumors. We hypothesized that epigenetic alterations may explain, at least in part, the tissue-specific differences in BD tumorigenicity in mice. We evaluated the level of N-7-(2,3,4-trihydroxybut-1-yl)guanine adducts and 1,4-bis-(guan-7-yl)-2,3-butanediol crosslinks, DNA methylation, and histone modifications in male C57BL/6 mice exposed to filtered air or 425 ppm of BD by inhalation (6 h/day, 5 days/week) for 2 weeks. Although DNA damage was observed in all three tissues of BD-exposed mice, variation in epigenetic effects clearly existed between the kidneys, liver, and lungs. Epigenetic alterations indicative of genomic instability, including demethylation of repetitive DNA sequences and alterations in histone-lysine acetylation, were evident in the liver and lung tissues of BD-exposed mice. Changes in DNA methylation were insignificant in the kidneys of treated mice, whereas marks of condensed heterochromatin and transcriptional silencing (histone-lysine trimethylation) were increased. These modifications may represent a potential mechanistic explanation for the lack of tumorigenesis in the kidney. Our results indicate that differential tissue susceptibility to chemical-induced tumorigenesis may be attributed to tissue-specific epigenetic alterations.
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Affiliation(s)
- Grace Chappell
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Tetyana Kobets
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455 *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Bridget O'Brien
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Natalia Tretyakova
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Dewakar Sangaraju
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Oksana Kosyk
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Kenneth G Sexton
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Wanda Bodnar
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Igor P Pogribny
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
| | - Ivan Rusyn
- *Department of Environmental Sciences and Engineering, University of North Carolina, Chapel Hill, North Carolina 27599, Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, Arkansas 72079 and Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455
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Abstract
The concept of the Exposome is a compilation of diseases and one's lifetime exposure to chemicals, whether the exposure comes from environmental, dietary, or occupational exposures; or endogenous chemicals that are formed from normal metabolism, inflammation, oxidative stress, lipid peroxidation, infections, and other natural metabolic processes such as alteration of the gut microbiome. In this review, we have focused on the endogenous exposome, the DNA damage that arises from the production of endogenous electrophilic molecules in our cells. It provides quantitative data on endogenous DNA damage and its relationship to mutagenesis, with emphasis on when exogenous chemical exposures that produce identical DNA adducts to those arising from normal metabolism cause significant increases in total identical DNA adducts. We have utilized stable isotope labeled chemical exposures of animals and cells, so that accurate relationships between endogenous and exogenous exposures can be determined. Advances in mass spectrometry have vastly increased both the sensitivity and accuracy of such studies. Furthermore, we have clear evidence of which sources of exposure drive low dose biology that results in mutations and disease. These data provide much needed information to impact quantitative risk assessments, in the hope of moving towards the use of science, rather than default assumptions.
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Affiliation(s)
- Jun Nakamura
- University of North Carolina, Chapel Hill, NC, United States
| | - Esra Mutlu
- University of North Carolina, Chapel Hill, NC, United States
| | - Vyom Sharma
- University of North Carolina, Chapel Hill, NC, United States
| | - Leonard Collins
- University of North Carolina, Chapel Hill, NC, United States
| | - Wanda Bodnar
- University of North Carolina, Chapel Hill, NC, United States
| | - Rui Yu
- University of North Carolina, Chapel Hill, NC, United States
| | - Yongquan Lai
- University of North Carolina, Chapel Hill, NC, United States
| | - Benjamin Moeller
- University of North Carolina, Chapel Hill, NC, United States; Lovelace Respiratory Research Institute, Albuquerque, NM, United States
| | - Kun Lu
- University of North Carolina, Chapel Hill, NC, United States
| | - James Swenberg
- University of North Carolina, Chapel Hill, NC, United States.
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Currier J, Saunders RJ, Ding L, Bodnar W, Cable P, Matoušek T, Creed JT, Stýblo M. Comparative oxidation state specific analysis of arsenic species by high-performance liquid chromatography-inductively coupled plasma-mass spectrometry and hydride generation-cryotrapping-atomic absorption spectrometry. J Anal At Spectrom 2013; 28:843-852. [PMID: 23687401 PMCID: PMC3655785 DOI: 10.1039/c3ja30380b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The formation of methylarsonous acid (MAsIII) and dimethylarsinous acid (DMAsIII) in the course of inorganic arsenic (iAs) metabolism plays an important role in the adverse effects of chronic exposure to iAs. High-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and hydride generation-cryotrapping-atomic absorption spectrometry (HG-CT-AAS) have been frequently used for the analysis of MAsIII and DMAsIII in biological samples. While HG-CT-AAS has consistently detected MAsIII and DMAsIII, HPLC-ICP-MS analyses have provided inconsistent and contradictory results. This study compares the capacities of both methods to detect and quantify MAsIII and DMAsIII in an in vitro methylation system consisting of recombinant human arsenic (+3 oxidation state) methyltransferase (AS3MT), S-adenosylmethionine as a methyl donor, a non-thiol reductant tris(2-carboxyethyl)phosphine, and arsenite (iAsIII) or MAsIII as substrate. The results show that reversed-phase HPLC-ICP-MS can identify and quantify MAsIII and DMAsIII in aqueous mixtures of biologically relevant arsenical standards. However, HPLC separation of the in vitro methylation mixture resulted in significant losses of MAsIII, and particularly DMAsIII with total arsenic recoveries below 25%. Further analyses showed that MAsIII and DMAsIII bind to AS3MT or interact with other components of the methylation mixture, forming complexes that do not elute from the column. Oxidation of the mixture with H2O2 which converted trivalent arsenicals to their pentavalent analogs prior to HPLC separation increased total arsenic recoveries to ~95%. In contrast, HG-CT-AAS analysis found large quantities of methylated trivalent arsenicals in mixtures incubated with either iAsIII or MAsIII and provided high (>72%) arsenic recoveries. These data suggest that an HPLC-based analysis of biological samples can underestimate MAsIII and DMAsIII concentrations and that controlling for arsenic species recovery is essential to avoid artifacts.
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Affiliation(s)
- Jenna Currier
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
| | - R. Jesse Saunders
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
| | - Lan Ding
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
| | - Peter Cable
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
| | - Tomáš Matoušek
- Institute of Analytical Chemistry of the ASCR, v.v.i., Veveří 97, 602 00 Brno, Czech Republic
| | - John T. Creed
- Microbiological and Chemical Exposure Assessment Research Division, NERL, US EPA, Cincinnati, OH 45628, USA
| | - Miroslav Stýblo
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7461, USA
- Corresponding Author: Tel: (+1) 919-966-5721; Fax: (+1) 919-843-0776;
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25
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Koturbash I, Scherhag A, Sorrentino J, Sexton K, Bodnar W, Swenberg JA, Beland FA, Pardo-Manuel deVillena F, Rusyn I, Pogribny IP. Epigenetic mechanisms of mouse interstrain variability in genotoxicity of the environmental toxicant 1,3-butadiene. Toxicol Sci 2011; 122:448-56. [PMID: 21602187 PMCID: PMC3155089 DOI: 10.1093/toxsci/kfr133] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Accepted: 05/11/2011] [Indexed: 12/18/2022] Open
Abstract
1,3-Butadiene (BD) is a common environmental contaminant classified as "carcinogenic to humans." Formation of BD-induced DNA adducts plays a major role in its carcinogenicity. BD is also an epigenotoxic agent (i.e., it affects DNA and histone methylation in the liver). We used a panel of genetically diverse inbred mice (NOD/LtJ, CAST/EiJ, A/J, WSB/EiJ, PWK/PhJ, C57BL/6J, and 129S1/SvImJ) to assess whether BD-induced genotoxic and epigenotoxic events may be subject to interstrain differences. Mice (male, 7 weeks) were exposed via inhalation to 0 or 625 ppm BD for 6 h/day and 5 days/week for 2 weeks and liver BD-DNA adducts, epigenetic alterations, and liver toxicity were assessed. N-7-(2,3,4-trihydroxybut-1-yl)-guanine adducts were detected in all strains after exposure, yet BD-induced DNA damage in CAST/EiJ mice was two to three times lower. Epigenetic effects of BD were most prominent in C57BL/6J mice where loss of global DNA methylation and loss of trimethylation of histone H3 lysine 9, histone H3 lysine 27, and histone H4 lysine 20, accompanied by dysregulation of liver gene expression indicative of hepatotoxicity, were found. Interestingly, we observed an increase in histone methylation in the absence of changes in gene expression and DNA methylation in CAST/EiJ strain. We hypothesized that mitigated genotoxicity of BD in CAST/EiJ mice may be due to chromatin condensation. Indeed, we show that in response to BD exposure, chromatin condensation occurs in CAST/EiJ, whereas the opposite effect is observed in C57BL/6J mice. These findings demonstrate that interstrain susceptibility to genotoxicity by a well-known environmental carcinogen may be due to strain-specific epigenetic events in response to the exposure.
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Affiliation(s)
- Igor Koturbash
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | - Anne Scherhag
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079
- Technical University of Kaiserslautern, Kaiserslautern, Rheinland-Pfalz 67663, Germany
| | | | | | - Wanda Bodnar
- Department of Environmental Sciences and Engineering
| | - James A. Swenberg
- Curriculum in Toxicology
- Department of Environmental Sciences and Engineering
| | - Frederick A. Beland
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079
| | | | - Ivan Rusyn
- Curriculum in Toxicology
- Department of Environmental Sciences and Engineering
| | - Igor P. Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079
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26
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Koturbash I, Scherhag A, Sorrentino J, Sexton K, Bodnar W, Tryndyak V, Latendresse JR, Swenberg JA, Beland FA, Pogribny IP, Rusyn I. Epigenetic alterations in liver of C57BL/6J mice after short-term inhalational exposure to 1,3-butadiene. Environ Health Perspect 2011; 119:635-40. [PMID: 21147608 PMCID: PMC3094413 DOI: 10.1289/ehp.1002910] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 12/13/2010] [Indexed: 05/25/2023]
Abstract
BACKGROUND 1,3-Butadiene (BD) is a high-volume industrial chemical and a known human carcinogen. The main mode of BD carcinogenicity is thought to involve formation of genotoxic epoxides. OBJECTIVES In this study we tested the hypothesis that BD may be epigenotoxic (i.e., cause changes in DNA and histone methylation) and explored the possible molecular mechanisms for the epigenetic changes. METHODS AND RESULTS We administered BD (6.25 and 625 ppm) to C57BL/6J male mice by inhalation for 2 weeks (6 hr/day, 5 days a week) and then examined liver tissue from these mice for signs of toxicity using histopathology and gene expression analyses. We observed no changes in mice exposed to 6.25 ppm BD, but glycogen depletion and dysregulation of hepatotoxicity biomarker genes were observed in mice exposed to 625 ppm BD. We detected N-7-(2,3,4-trihydroxybut-1-yl)guanine (THB-Gua) adducts in liver DNA of exposed mice in a dose-responsive manner, and also observed extensive alterations in the cellular epigenome in the liver, including demethylation of global DNA and repetitive elements and a decrease in histone H3 and H4 lysine methylation. In addition, we observed down-regulation of DNA methyltransferase 1 (Dnmt1) and suppressor of variegation 3-9 homolog 1, a histone lysine methyltransferase (Suv39h1), and up-regulation of the histone demethylase Jumonji domain 2 (Jmjd2a), proteins responsible for the accurate maintenance of the epigenetic marks. Although the epigenetic effects were most pronounced in the 625-ppm exposure group, some effects were evident in mice exposed to 6.25 ppm BD. CONCLUSIONS This study demonstrates that exposure to BD leads to epigenetic alterations in the liver, which may be important contributors to the mode of BD carcinogenicity.
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Affiliation(s)
- Igor Koturbash
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Anne Scherhag
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
- Technical University of Kaiserslautern, Kaiserslautern, Rheinland-Pfalz, Germany
| | - Jessica Sorrentino
- Curriculum in Toxicology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Kenneth Sexton
- Department of Environmental Sciences and Engineering, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Wanda Bodnar
- Department of Environmental Sciences and Engineering, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Volodymyr Tryndyak
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - John R. Latendresse
- Toxicologic Pathology Associates, National Center for Toxicological Research, Jefferson, Arkansas, USA
| | - James A. Swenberg
- Curriculum in Toxicology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Environmental Sciences and Engineering, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
| | - Frederick A. Beland
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Igor P. Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas, USA
| | - Ivan Rusyn
- Curriculum in Toxicology, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Environmental Sciences and Engineering, University of North Carolina–Chapel Hill, Chapel Hill, North Carolina, USA
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27
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Slade DJ, Pelz NF, Bodnar W, Lampe JW, Watson PS. Indazoles: Regioselective Protection and Subsequent Amine Coupling Reactions. J Org Chem 2009; 74:6331-4. [DOI: 10.1021/jo9006656] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Navratil T, Wells G, Fulcher E, Sorensen S, Bodnar W, Crean C, Lampe J, Peterson W. Novel Rho Kinase Inhibitors with Bronchodilator and Anti‐inflammatory Properties Suitable for Treatment of Respiratory Diseases. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.756.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Willard DH, Bodnar W, Harris C, Kiefer L, Nichols JS, Blanchard S, Hoffman C, Moyer M, Burkhart W, Weiel J. Agouti structure and function: characterization of a potent alpha-melanocyte stimulating hormone receptor antagonist. Biochemistry 1995; 34:12341-6. [PMID: 7547977 DOI: 10.1021/bi00038a030] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The murine agouti gene encodes for a novel 131 amino acid protein. The sequence includes a 22 residue putative secretion signal, an internal basic region, and a C-terminal domain containing 10 cysteines. Agouti has been found to antagonize the binding of certain pro-opiomelanocortin peptides, such as alpha-melanocyte stimulating hormone (alpha-MSH), to the murine melanocortin-1 receptor (MC1-R). We report the purification of a secreted murine agouti to homogeneity by a two-step procedure from baculovirus-infected Trichoplusia ni (T. ni). The protein is glycosylated and exhibits competitive, high-affinity antagonism (Ki = 0.8 nM) versus alpha-MSH in cell-based assays employing B16F10 cells. Association state analysis by analytical ultracentrifugation reveals that agouti exists in a monomer--dimer plus aggregate equilibrium at low micromolar concentrations. Data from secondary structure studies indicate that the protein is highly stable to thermal denaturation. Enzymatic digestion to probe disulfide bond arrangement yielded a discrete C-terminal (Val 83-Cys 131) domain. The isolated highly cysteine-rich C-terminal domain retains alpha-MSH antagonism equipotent with mature agouti. This bioactive domain contains all 10 cysteines which exhibit sequence homology when aligned with several conotoxins.
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Affiliation(s)
- D H Willard
- Department of Biochemistry, Glaxo Wellcome, Inc., Research Triangle Park, North Carolina 27709, USA
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Blackburn MB, Kingan TG, Bodnar W, Shabanowitz J, Hunt DF, Kempe T, Wagner RM, Raina AK, Schnee ME, Ma MC. Isolation and identification of a new diuretic peptide from the tobacco hornworm, Manduca sexta. Biochem Biophys Res Commun 1991; 181:927-32. [PMID: 1764106 DOI: 10.1016/0006-291x(91)92025-f] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A 30-amino acid diuretic peptide was isolated from the corpora cardiaca-corpora allata complexes and, separately, from medial neurosecretory cells of the Sphingid moth, Manduca sexta. The peptide was found to have the following sequence, determined by automated Edman degradation and mass spectrometry: SFSVNPAVDILQHRYMEKV AQNNRNFLNRV-NH2. We have named the peptide Mas-DP II. The peptide was synthesized and shown to possess diuretic activity in decapitated moths. Mas-DP II is related by sequence homology to a 41-amino acid diuretic peptide identified previously from M. sexta, and it belongs to the family of corticotropin releasing factor-like peptides.
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Affiliation(s)
- M B Blackburn
- Department of Entomology, University of Maryland, College Park 20742
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