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Chu CY, Kim SY, Pryhuber GS, Mariani TJ, McGraw MD. Single-cell resolution of human airway epithelial cells exposed to bronchiolitis obliterans-associated chemicals. Am J Physiol Lung Cell Mol Physiol 2024; 326:L135-L148. [PMID: 38084407 PMCID: PMC11279737 DOI: 10.1152/ajplung.00304.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/31/2023] [Accepted: 11/23/2023] [Indexed: 01/24/2024] Open
Abstract
Bronchiolitis obliterans (BO) is a fibrotic lung disease characterized by progressive luminal narrowing and obliteration of the small airways. In the nontransplant population, inhalation exposure to certain chemicals is associated with BO; however, the mechanisms contributing to disease induction remain poorly understood. This study's objective was to use single-cell RNA sequencing for the identification of transcriptomic signatures common to primary human airway epithelial cells after chemical exposure to BO-associated chemicals-diacetyl or nitrogen mustard-to help explain BO induction. Primary airway epithelial cells were cultured at air-liquid interface and exposed to diacetyl, nitrogen mustard, or control vapors. Cultures were dissociated and sequenced for single-cell RNA. Differential gene expression and functional pathway analyses were compared across exposures. In total, 75,663 single cells were captured and sequenced from all exposure conditions. Unbiased clustering identified 11 discrete phenotypes, including 5 basal, 2 ciliated, and 2 secretory cell clusters. With chemical exposure, the proportion of cells assigned to keratin 5+ basal cells decreased, whereas the proportion of cells aligned to secretory cell clusters increased compared with control exposures. Functional pathway analysis identified interferon signaling and antigen processing/presentation as pathways commonly upregulated after diacetyl or nitrogen mustard exposure in a ciliated cell cluster. Conversely, the response of airway basal cells differed significantly with upregulation of the unfolded protein response in diacetyl-exposed basal cells, not seen in nitrogen mustard-exposed cultures. These new insights provide early identification of airway epithelial signatures common to BO-associated chemical exposures.NEW & NOTEWORTHY Bronchiolitis obliterans (BO) is a devastating fibrotic lung disease of the small airways, or bronchioles. This original manuscript uses single-cell RNA sequencing for identifying common signatures of chemically exposed airway epithelial cells in BO induction. Chemical exposure reduced the proportion of keratin 5+ basal cells while increasing the proportion of keratin 4+ suprabasal cells. Functional pathways contributory to these shifts differed significantly across exposures. These new results highlight similarities and differences in BO induction across exposures.
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Affiliation(s)
- Chin-Yi Chu
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, United States
| | - So-Young Kim
- Division of Pediatric Pulmonology, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, United States
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
| | - Gloria S Pryhuber
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, United States
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
| | - Thomas J Mariani
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, United States
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
| | - Matthew D McGraw
- Division of Pediatric Pulmonology, Department of Pediatrics, University of Rochester Medical Center, Rochester, New York, United States
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York, United States
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2
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Wu S, Kim E, Vethanayagam D, Zhao R. Indoor partitioning and potential thirdhand exposure to carbonyl flavoring agents added in e-cigarettes and hookah tobacco. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2022; 24:2294-2309. [PMID: 36408779 DOI: 10.1039/d2em00365a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Flavoring agents added to the e-cigarettes and hookah tobacco have increased the attractiveness of novel nicotine products. Many widely used flavorings are carbonyls, which are toxic to humans. In an indoor environment, residents can be exposed to such harmful flavorings previously emitted to the surrounding environment, through a process termed thirdhand exposure. The recent discovery of a large volume of indoor reservoirs emphasizes the importance of indoor partitioning, which is responsible for thirdhand exposure. Indoor partitioning can be expressed with partitioning coefficients, such as Henry's law solubility constant (H). However, reliable H values for many key flavorings are currently lacking. To better understand their environmental behavior, this study experimentally determined the effective Henry's law constant (Hcps,eff) using the inert gas stripping (IGS) method. Further, the influence of the hydration process for target flavorings was quantified using proton nuclear magnetic resonance (1H NMR) spectroscopy. We found that hydration of α-dicarbonyls (diacetyl and 2,3-pentanedione) enhanced their Hcps,eff from their intrinsic Henry's law constant (Hcps) by a factor of 3.52 and 2.88, respectively. The two-dimensional partitioning plots were employed to simulate the indoor phase distribution and evaluate the pathways of human exposure. Our findings show that the indoor partitioning of many harmful flavorings is highly sensitive to temperature and the size of indoor reservoirs, indicating that residents are likely to experience third-hand exposure.
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Affiliation(s)
- Shuang Wu
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
| | - Erica Kim
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
| | - Dilini Vethanayagam
- Department of Medicine, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada
| | - Ran Zhao
- Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
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3
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McGraw MD, Yee M, Kim SY, Dylag AM, Lawrence BP, O'Reilly MA. Diacetyl inhalation impairs airway epithelial repair in mice infected with influenza A virus. Am J Physiol Lung Cell Mol Physiol 2022; 323:L578-L592. [PMID: 36068185 PMCID: PMC9639765 DOI: 10.1152/ajplung.00124.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 08/12/2022] [Accepted: 08/29/2022] [Indexed: 01/11/2023] Open
Abstract
Bronchiolitis obliterans (BO) is a debilitating disease of the small airways that can develop following exposure to toxic chemicals as well as respiratory tract infections. BO development is strongly associated with diacetyl (DA) inhalation exposures at occupationally relevant concentrations or severe influenza A viral (IAV) infections. However, it remains unclear whether lower dose exposures or more mild IAV infections can result in similar pathology. In the current work, we combined these two common environmental exposures, DA and IAV, to test whether shorter DA exposures followed by sublethal IAV infection would result in similar airways disease. Adult mice exposed to DA vapors 1 h/day for 5 consecutive days followed by infection with the airway-tropic IAV H3N2 (HKx31) resulted in increased mortality, increased bronchoalveolar lavage (BAL) neutrophil percentage, mixed obstruction and restriction by lung function, and subsequent airway remodeling. Exposure to DA or IAV alone failed to result in significant pathology, whereas mice exposed to DA + IAV showed increased α-smooth muscle actin (αSMA) and epithelial cells coexpressing the basal cell marker keratin 5 (KRT5) with the club cell marker SCGB1A1. To test whether DA exposure impairs epithelial repair after IAV infection, mice were infected first with IAV and then exposed to DA during airway epithelial repair. Mice exposed to IAV + DA developed similar airway remodeling with increased subepithelial αSMA and epithelial cells coexpressing KRT5 and SCGB1A1. Our findings reveal an underappreciated concept that common environmental insults while seemingly harmless by themselves can have catastrophic implications on lung function and long-term respiratory health when combined.
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Affiliation(s)
- Matthew D McGraw
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York
| | - Min Yee
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York
| | - So-Young Kim
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York
| | - Andrew M Dylag
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York
| | - B Paige Lawrence
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York
| | - Michael A O'Reilly
- Department of Pediatrics, University of Rochester Medical Center, Rochester, New York
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, New York
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4
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Zhang Z, Morstein J, Ecker AK, Guiley KZ, Shokat KM. Chemoselective Covalent Modification of K-Ras(G12R) with a Small Molecule Electrophile. J Am Chem Soc 2022; 144:15916-15921. [PMID: 36001446 PMCID: PMC9460778 DOI: 10.1021/jacs.2c05377] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
![]()
KRAS mutations are one of the most common
oncogenic
drivers in human cancer. While small molecule inhibitors for the G12C
mutant have been successfully developed, allele-specific inhibition
for other KRAS hotspot mutants remains challenging.
Here we report the discovery of covalent chemical ligands for the
common oncogenic mutant K-Ras(G12R). These ligands bind in the Switch
II pocket and irreversibly react with the mutant arginine residue.
An X-ray crystal structure reveals an imidazolium condensation product
formed between the α,β-diketoamide ligand and the ε-
and η-nitrogens of arginine 12. Our results show that arginine
residues can be selectively targeted with small molecule electrophiles
despite their weak nucleophilicity and provide the basis for the development
of mutant-specific therapies for K-Ras(G12R)-driven cancer.
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Affiliation(s)
- Ziyang Zhang
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California 94158, United States.,Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Johannes Morstein
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California 94158, United States
| | - Andrew K Ecker
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California 94158, United States
| | - Keelan Z Guiley
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California 94158, United States
| | - Kevan M Shokat
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California San Francisco, San Francisco, California 94158, United States
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5
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Santos J, Calabrese DR, Greenland JR. Lymphocytic Airway Inflammation in Lung Allografts. Front Immunol 2022; 13:908693. [PMID: 35911676 PMCID: PMC9335886 DOI: 10.3389/fimmu.2022.908693] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 06/16/2022] [Indexed: 11/16/2022] Open
Abstract
Lung transplant remains a key therapeutic option for patients with end stage lung disease but short- and long-term survival lag other solid organ transplants. Early ischemia-reperfusion injury in the form of primary graft dysfunction (PGD) and acute cellular rejection are risk factors for chronic lung allograft dysfunction (CLAD), a syndrome of airway and parenchymal fibrosis that is the major barrier to long term survival. An increasing body of research suggests lymphocytic airway inflammation plays a significant role in these important clinical syndromes. Cytotoxic T cells are observed in airway rejection, and transcriptional analysis of airways reveal common cytotoxic gene patterns across solid organ transplant rejection. Natural killer (NK) cells have also been implicated in the early allograft damage response to PGD, acute rejection, cytomegalovirus, and CLAD. This review will examine the roles of lymphocytic airway inflammation across the lifespan of the allograft, including: 1) The contribution of innate lymphocytes to PGD and the impact of PGD on the adaptive immune response. 2) Acute cellular rejection pathologies and the limitations in identifying airway inflammation by transbronchial biopsy. 3) Potentiators of airway inflammation and heterologous immunity, such as respiratory infections, aspiration, and the airway microbiome. 4) Airway contributions to CLAD pathogenesis, including epithelial to mesenchymal transition (EMT), club cell loss, and the evolution from constrictive bronchiolitis to parenchymal fibrosis. 5) Protective mechanisms of fibrosis involving regulatory T cells. In summary, this review will examine our current understanding of the complex interplay between the transplanted airway epithelium, lymphocytic airway infiltration, and rejection pathologies.
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Affiliation(s)
- Jesse Santos
- Department of Medicine University of California, San Francisco, San Francisco, CA, United States
| | - Daniel R. Calabrese
- Department of Medicine University of California, San Francisco, San Francisco, CA, United States
- Medical Service, Veterans Affairs Health Care System, San Francisco, CA, United States
| | - John R. Greenland
- Department of Medicine University of California, San Francisco, San Francisco, CA, United States
- Medical Service, Veterans Affairs Health Care System, San Francisco, CA, United States
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6
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Bruner J, Marcus A, Fox G. Changes in Diacetyl and Amino Acid Concentration during the Fermentation of Dry-Hopped Beer: A Look at Twelve Saccharomyces Species and Strains. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2022. [DOI: 10.1080/03610470.2022.2078946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- James Bruner
- Food Science and Technology Department, University of California, Davis, CA, U.S.A
- Creature Comforts Brewing Company, Los Angeles, CA, U.S.A
| | - Andrew Marcus
- Food Science and Technology Department, University of California, Davis, CA, U.S.A
| | - Glen Fox
- Food Science and Technology Department, University of California, Davis, CA, U.S.A
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7
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Kim SY, McGraw MD. Post-translational modifications to hemidesmosomes in human airway epithelial cells following diacetyl exposure. Sci Rep 2022; 12:9738. [PMID: 35697719 PMCID: PMC9192738 DOI: 10.1038/s41598-022-14019-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
Abstract
Diacetyl (DA; 2,3-butanedione) is a highly reactive alpha (α)-diketone. Inhalation exposure to DA can cause significant airway epithelial cell injury, however, the mechanisms of toxicity remain poorly understood. The purpose of these experiments was to assess for changes in abundance and distribution of hemidesmosome-associated proteins following DA exposure that contribute to DA-induced epithelial toxicity. Human bronchial epithelial cells were grown in submerged cultures and exposed to three occupationally-relevant concentrations of DA (5.7, 8.6, or 11.4 mM) for 1 h. Following DA exposure, epithelial cells were cultured for 4 days to monitor for cell viability by MTT and WST-1 assays as well as for changes in cellular distribution and relative abundance of multiple hemidesmosome-associated proteins, including keratin 5 (KRT5), plectin (PLEC), integrin alpha 6 (ITGα6) and integrin beta 4 (ITGβ4). Significant toxicity developed in airway epithelial cells exposed to DA at concentrations ≥ 8.6 mM. DA exposure resulted in post-translational modifications to hemidesmosome-associated proteins with KRT5 crosslinking and ITGβ4 cleavage. Following DA exposure at 5.7 mM, these post-translational modifications to KRT5 resolved with time. Conversely, at DA concentrations ≥ 8.6 mM, modifications to KRT5 persisted in culture with decreased total abundance and perinuclear aggregation of hemidesmosome-associated proteins. Significant post-translational modifications to hemidesmosome-associated proteins develop in airway epithelial cells exposed to DA. At DA concentrations ≥ 8.6 mM, these hemidesmosome modifications persist in culture. Future work targeting hemidesmosome-associated protein modifications may prevent the development of lung disease following DA exposure.
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Affiliation(s)
- So-Young Kim
- Division of Pulmonary Medicine, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 850, Rochester, NY, 14642, USA
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Matthew D McGraw
- Division of Pulmonary Medicine, Department of Pediatrics, University of Rochester Medical Center, 601 Elmwood Avenue, Box 850, Rochester, NY, 14642, USA.
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, 14642, USA.
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8
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Zhang Q, Huang Z, Li H, Cen C, Zheng R, Lili C, Zhang S, Wang Y, Fu L. Deciphering Changes in the Structure and IgE-Binding Ability of Ovalbumin Glycated by α-Dicarbonyl Compounds under Simulated Heating. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:1984-1995. [PMID: 35112874 DOI: 10.1021/acs.jafc.1c06939] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
As a complex reaction, biological consequences of the Maillard reaction (MR) on dietary proteins need to be deciphered. Despite previous studies on the structural and antigenic properties of ovalbumin (OVA) by MR, associated changes induced by specific MR intermediates and their downstream products are largely unknown. This study focused on the impacts of glycation by α-dicarbonyl compounds (α-DCs), intermediates of MR and precursors of advanced glycation end-products (AGEs), on the structural and IgE-binding properties of ovalbumin (OVA) under simulated heating. Methylglyoxal (MGO), glyoxal (GO), and butanedione (BU) were selected as typical α-DCs to generate glycated OVA with different AGE-modifications (AGE-Ms). The results showed that reactions between OVA and α-DCs generated OVA-AGE with various degrees of modification and conformational unfolding, and the reactivity of α-DCs followed the order GO > MGO > BU. Depending on the precursor type, the levels of 10 specific AGEs were verified, and the amounts of total AGEs increased with heating temperature and α-DC dosage. Compared to native OVA, glycated OVA showed reduced IgE-binding levels but with sRAGE-binding ligands, the extent of which was associated with the contents of total AGEs and Nε-carboxymethyllysine, and changes in certain protein conformational structures. High-resolution mass spectrometry further identified different AGE-Ms on the Lys and Arg residues of OVA, confirming variations in the glycation sites and their associations with the immunoreactive epitopes of OVA under different conditions.
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Affiliation(s)
- Qiaozhi Zhang
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, P. R. China
| | - Zhijie Huang
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, P. R. China
| | - Huatao Li
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, P. R. China
| | - Congnan Cen
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, P. R. China
| | - Ruixing Zheng
- Ningbo Academy of Product and Food Quality Inspection (Ningbo Fibre Inspection Institute), Ningbo 315048, P. R. China
| | - Cao Lili
- Ningbo Academy of Product and Food Quality Inspection (Ningbo Fibre Inspection Institute), Ningbo 315048, P. R. China
| | - Shufen Zhang
- Ningbo Academy of Product and Food Quality Inspection (Ningbo Fibre Inspection Institute), Ningbo 315048, P. R. China
| | - Yanbo Wang
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, P. R. China
| | - Linglin Fu
- Food Safety Key Laboratory of Zhejiang Province, School of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou 310018, P. R. China
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9
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House EL, Kim SY, Johnston CJ, Groves AM, Hernady E, Misra RS, McGraw MD. Diacetyl Vapor Inhalation Induces Mixed, Granulocytic Lung Inflammation with Increased CD4 +CD25 + T Cells in the Rat. TOXICS 2021; 9:359. [PMID: 34941793 PMCID: PMC8707442 DOI: 10.3390/toxics9120359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 11/16/2022]
Abstract
Diacetyl (DA) is a highly reactive alpha diketone associated with flavoring-related lung disease. In rodents, acute DA vapor exposure can initiate an airway-centric, inflammatory response. However, this immune response has yet to be fully characterized in the context of flavoring-related lung disease progression. The following studies were designed to characterize the different T cell populations within the lung following repetitive DA vapor exposures. Sprague-Dawley rats were exposed to 200 parts-per-million DA vapor for 5 consecutive days × 6 h/day. Lung tissue and bronchoalveolar lavage fluid (BALF) were analyzed for changes in histology by H&E and Trichrome stain, T cell markers by flow cytometry, total BALF cell counts and differentials, BALF IL17a and total protein immediately, 1 and 2 weeks post-exposure. Lung histology and BALF cell composition demonstrated mixed, granulocytic lung inflammation with bronchial lymphoid aggregates at all time points in DA-exposed lungs compared to air controls. While no significant change was seen in percent lung CD3+, CD4+, or CD8+ T cells, a significant increase in lung CD4+CD25+ T cells developed at 1 week that persisted at 2 weeks post-exposure. Further characterization of this CD4+CD25+ T cell population identified Foxp3+ T cells at 1 week that failed to persist at 2 weeks. Conversely, BALF IL-17a increased significantly at 2 weeks in DA-exposed rats compared to air controls. Lung CD4+CD25+ T cells and BALF IL17a correlated directly with BALF total protein and inversely with rat oxygen saturations. Repetitive DA vapor exposure at occupationally relevant concentrations induced mixed, granulocytic lung inflammation with increased CD4+CD25+ T cells in the rat lung.
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Affiliation(s)
- Emma L. House
- Department of Pathology, University of Rochester Medical Center, Rochester, NY 14642, USA;
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
| | - So-Young Kim
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
| | - Carl J. Johnston
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14642, USA;
| | - Angela M. Groves
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Eric Hernady
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
- Department of Radiation Oncology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Ravi S. Misra
- Division of Neonatology, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14642, USA;
| | - Matthew D. McGraw
- Division of Pediatric Pulmonology, Department of Pediatrics, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (S.-Y.K.); (A.M.G.)
- Department of Environmental Medicine, School of Medicine & Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA; (C.J.J.); (E.H.)
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White AV, Wambui DW, Pokhrel LR. Risk assessment of inhaled diacetyl from electronic cigarette use among teens and adults. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 772:145486. [PMID: 33770882 DOI: 10.1016/j.scitotenv.2021.145486] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/24/2021] [Accepted: 01/24/2021] [Indexed: 06/12/2023]
Abstract
Diacetyl (C4H6O2) is a toxicant commonly found in electronic cigarettes (e-Cigs) as a flavoring component and an enhancer of e-juices. Lung injury in current and former workers in popcorn manufacturing suggests a possible association with diacetyl inhalation exposure. Although the number of e-Cig users continues to rise steadily among the teens and adults, the potential risk of pulmonary disease has not been characterized. A systematic review of the open literature identified bronchiolitis obliterans-a pathological inflammation resulting in fibrosis of the bronchioles leading to an irreversible limitation to airflow in lungs-as the primary outcome of diacetyl exposures. Following the deterministic United States National Research Council/Environmental Protection Agency's risk assessment framework, that consists of four key steps: hazard identification, dose-response assessment, exposure assessment and risk characterization, we estimated noncarcinogenic (systemic) risks using a Hazard Quotient (HQ) approach upon exposure to diacetyl among teens and adults who use e-Cigs. Based on the NIOSH Benchmark Dose (BMD; 0.0175 mg/kg-day) and modelled Average Daily Doses (ADDs; range 0.11-5.2 mg/kg-day), we estimated 12 different HQ values-a measure of non-carcinogenic risk for diacetyl inhalation exposures-all of which were greater than 1 (range 6.2875-297.1429), suggesting a significantly higher non-carcinogenic risk from diacetyl exposures among the teens and adults who use e-Cigs. These results underscore the need to regulate e-Cigs to protect teens and adults from diacetyl exposures and risk of developing lung injuries, including bronchiolitis obliterans.
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Affiliation(s)
- Avian V White
- Department of Public Health, The Brody School of Medicine, East Carolina University, Greenville, NC, USA; Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC, USA
| | - David W Wambui
- Department of Public Health, The Brody School of Medicine, East Carolina University, Greenville, NC, USA
| | - Lok R Pokhrel
- Department of Public Health, The Brody School of Medicine, East Carolina University, Greenville, NC, USA; Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC, USA.
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11
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Xie W, Kim KH, Vince R, More SS. The Amyloid Aggregation Accelerator Diacetyl Prevents Cognitive Decline in Alzheimer's Mouse Models. Chem Res Toxicol 2021; 34:1355-1366. [PMID: 33857375 DOI: 10.1021/acs.chemrestox.1c00089] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Diacetyl (DA), a food flavorant, is linked with occupational lung disease. Our in vitro experiments described the formation of a covalent adduct by DA with Arg5 of the Aβ1-42 peptide, which resulted in only a transient increase in neurotoxicity in SH-SY5Y cells. However, in vivo implications of these effects on Alzheimer's disease (AD) pathogenesis and the underlying mechanisms remain poorly understood. In the APP/PS1 transgenic AD mouse model, DA treatment did not exacerbate learning and memory deficits in the Morris water maze test. Moreover, DA increased the Aβ1-42 plaque burden and decreased neuronal inflammation in the transgenic AD mice. Additionally, cognitive impairment induced by intracerebroventricular Aβ1-42 was restored by the DA treatment, as assessed by the T-maze test. A corresponding mitigation of neuronal inflammation was also observed in the hippocampus of these nontransgenic mice due to the acceleration of Aβ1-42 aggregation by DA into nontoxic plaques. The data from SDS-PAGE, dot-blot, and TEM in vitro experiments corroborated the acceleration of the Aβ1-42 aggregation observed in vivo in AD animal models and characterized the DA-induced formation of Aβ1-42 fibrils. Such Aβ1-42-DA fibrils were unstable in the presence of detergent and amenable to detection by the thioflavin T reagent, thus underscoring the distinct assembly of these fibrils compared to that of the fibrils of the native Aβ1-42. Taken together, the results of this study present for the first time the in vivo implications of the DA-induced acceleration of Aβ1-42 and may provide a strategy for the rational design of Aβ1-42 aggregation accelerators as AD therapeutics that promote oligomer-free Aβ1-42 fibril formation.
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Affiliation(s)
- Wei Xie
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Kwan Hyun Kim
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Robert Vince
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Swati S More
- Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, Minnesota 55455, United States
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12
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Zhao D, Sheng B, Li H, Wu Y, Xu D, Li C. Glycation from α-dicarbonyl compounds has different effects on the heat-induced aggregation of bovine serum albumin and β-casein. Food Chem 2020; 340:128108. [PMID: 33010643 DOI: 10.1016/j.foodchem.2020.128108] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 08/24/2020] [Accepted: 09/12/2020] [Indexed: 10/23/2022]
Abstract
α-Dicarbonyl compounds are generated in large amounts during heat treatment in food production. This work compared the influence of glycation by α-dicarbonyl on the hydrothermal aggregation of bovine serum albumin (BSA) and of β-casein (β-CN). Glycation by α-dicarbonyl compounds was found to be more efficient than glycation by glucose in reducing the free amino groups, surface hydrophobicity and isoelectric point of BSA, thus greatly inhibited the hydrothermal aggregation of BSA. In addition, glycation by α-dicarbonyl greatly transformed the rigid BSA aggregates into flexible structures, based on analysis by fluorescence spectrum, transmission electron microscope and small-angle X-ray scattering. In contrast, both the aggregation process and aggregates conformation of β-CN were found to be minimally affected by glycation, possibly due to the intrinsic disorder of β-CN. This work highlights the substantial influences of α-dicarbonyl on dietary proteins during heat treatment depending on the protein structural characteristics.
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Affiliation(s)
- Di Zhao
- Key Laboratory of Meat Processing, MOA, Key Laboratory of Meat Processing and Quality Control, MOE, Jiang Synergetic Innovation Center of Meat Production, Processing and Quality Control, Nanjing Agricultural University, Nanjing 210095, PR China.
| | - Bulei Sheng
- Department of Food Science, Aarhus University, Blichers Allé 20, Tjele 8830, Denmark
| | - Hao Li
- Key Laboratory of Meat Processing, MOA, Key Laboratory of Meat Processing and Quality Control, MOE, Jiang Synergetic Innovation Center of Meat Production, Processing and Quality Control, Nanjing Agricultural University, Nanjing 210095, PR China
| | - Yi Wu
- College of Food Science and Engineering, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, PR China
| | - Dan Xu
- College of Food Science and Engineering, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, PR China
| | - Chunbao Li
- Key Laboratory of Meat Processing, MOA, Key Laboratory of Meat Processing and Quality Control, MOE, Jiang Synergetic Innovation Center of Meat Production, Processing and Quality Control, Nanjing Agricultural University, Nanjing 210095, PR China
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13
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Anantharamkrishnan V, Hoye T, Reineccius GA. Covalent Adduct Formation Between Flavor Compounds of Various Functional Group Classes and the Model Protein β-Lactoglobulin. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:6395-6402. [PMID: 32390422 DOI: 10.1021/acs.jafc.0c01925] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The formation of covalent bonds between 47 flavor compounds belonging to 13 different classes of functional groups and β-lactoglobulin (BLG) has been evaluated using electrospray ionization protein mass spectrometry. Covalent bond formation was determined by the appearance of ions in the mass spectra corresponding to BLG + flavor molecule(s). The observed processes for covalent bond formation were Schiff base, Michael addition, and disulfide linkages. Some reactions resulted in protein cross-linking. Aldehydes, sulfur-containing molecules (especially thiols), and functional group-containing furans were the most reactive flavor components. The thiol-containing compounds cleaved one or both electrophilic disulfide linkages in BLG to form disulfide linkages and the sulfides formed covalent bonds with the free cysteine group. Ketones were generally stable, but α-diketones (e.g., diacetyl) were reactive. Some bases (e.g., pyrazines and pyridines) were interactive, while the nucleophilic allylamine was reactive. Hydrocarbons, alcohols, acids, esters, lactones, and pyrans did not give observable levels of adduct formation within the period studied. The formation of covalent bonding (flavor protein) is potentially responsible for the loss of flavor, limiting the shelf-life of many foods.
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Affiliation(s)
| | - Thomas Hoye
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Gary A Reineccius
- Department of Food Science and Nutrition, University of Minnesota, St. Paul, Minnesota 55108, United States
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14
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McGraw MD, Kim SY, Reed C, Hernady E, Rahman I, Mariani TJ, Finkelstein JN. Airway basal cell injury after acute diacetyl (2,3-butanedione) vapor exposure. Toxicol Lett 2020; 325:25-33. [PMID: 32112875 DOI: 10.1016/j.toxlet.2020.02.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/15/2020] [Accepted: 02/25/2020] [Indexed: 01/22/2023]
Abstract
RATIONALE Diacetyl (DA; 2,3-butanedione) is a chemical found commonly in foods and e-cigarettes. When inhaled, DA causes epithelial injury, though the mechanism of repair remain poorly understood. The objective of this study was to evaluate airway basal cell repair after DA vapor exposure. METHODS Primary human bronchial epithelial cells were exposed to DA or PBS for 1 h. Lactate dehydrogenase, cleaved caspase 3/7 and trans-epithelial electrical resistance were measured prior to and following exposure. Exposed cultures were analyzed for the airway basal cell markers keratin 5 and p63 as well as ubiquitin and proteasome activity. Cultures were also treated with a proteasome inhibitor (MG132). RESULTS DA vapor exposure caused a transient decrease in trans-epithelial electrical resistance in all DA-exposed cultures. Supernatant lactate dehydrogenase and cleaved caspase 3/7 increased significantly at the highest DA concentration but not at lower DA concentrations. Increased keratin 5 ubiquitination occurred after DA exposure but resolved by day 3. Damage to airway basal cells persisted at day 3 in the presence of MG132. CONCLUSIONS Diacetyl exposure results in airway basal cell injury with keratin 5 ubiquitination and decreased p63 expression. The ubiquitin-proteasome-pathway partially mediates airway basal cell repair after acute DA exposure.
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Affiliation(s)
- Matthew D McGraw
- Department of Pediatrics, Division of Pulmonology, Rochester, NY, United States; Department of Environmental Medicine, Rochester, NY, United States.
| | - So-Young Kim
- Department of Pediatrics, Division of Pulmonology, Rochester, NY, United States
| | - Christina Reed
- Department of Environmental Medicine, Rochester, NY, United States; Department of Pediatrics, Division of Neonatology, Rochester, NY, United States
| | - Eric Hernady
- Department of Environmental Medicine, Rochester, NY, United States
| | - Irfan Rahman
- Department of Environmental Medicine, Rochester, NY, United States
| | - Thomas J Mariani
- Department of Pediatrics, Division of Pulmonology, Rochester, NY, United States; Department of Pediatrics, Division of Neonatology, Rochester, NY, United States; Department of Pediatrics, Program in Pediatric Molecular and Personalized Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Jacob N Finkelstein
- Department of Environmental Medicine, Rochester, NY, United States; Department of Pediatrics, Division of Neonatology, Rochester, NY, United States
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15
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Landman ST, Dhaliwal I, Mackenzie CA, Martinu T, Steel A, Bosma KJ. Life-threatening bronchiolitis related to electronic cigarette use in a Canadian youth. CMAJ 2019; 191:E1321-E1331. [PMID: 31753841 PMCID: PMC6887563 DOI: 10.1503/cmaj.191402] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2019] [Indexed: 11/01/2022] Open
Abstract
BACKGROUND Although electronic cigarettes (e-cigarettes) were initially marketed as a potential smoking-cessation aid and a safer alternative to smoking, the long-term health effect of e-cigarette use ("vaping") is unknown. Vaping e-liquids expose the user to several potentially harmful chemicals, including diacetyl, a flavouring compound known to cause bronchiolitis obliterans with inhalational exposure ("popcorn worker's lung"). CASE DESCRIPTION We report the case of a 17-year-old male who presented with intractable cough, progressive dyspnea and malaise after vaping flavoured e-liquids and tetrahydrocannabinol intensively. Initial physical examination showed fever, tachycardia, hypoxemia, and bibasilar inspiratory crackles on lung auscultation. Computed tomography of the chest showed diffuse centrilobular "tree-inbud" nodularity, consistent with acute bronchiolitis. Multiple cultures, including from 2 bronchoalveolar lavage samples, and biopsy stains, were negative for infection. He required intubation, invasive mechanical ventilation and venovenous extracorporeal membrane oxygenation (ECMO) for refractory hypercapnia. The patient's condition improved with high-dose corticosteroids. He was weaned off ECMO and mechanical ventilation, and discharged home after 47 days in hospital. Several months after hospital discharge, his exercise tolerance remained limited and pulmonary function tests showed persistent, fixed airflow obstruction with gas trapping. The patient's clinical picture was suggestive of possible bronchiolitis obliterans, thought to be secondary to inhalation of flavouring agents in the e-liquids, although the exact mechanism of injury and causative agent are unknown. INTERPRETATION This case of severe acute bronchiolitis, causing near-fatal hypercapnic respiratory failure and chronic airflow obstruction in a previously healthy Canadian youth, may represent vaping-associated bronchiolitis obliterans. This novel pattern of pulmonary disease associated with vaping appears distinct from the type of alveolar injury predominantly reported in the recent outbreak of cases of vaping-associated pulmonary illness in the United States, underscoring the need for further research into all potentially toxic components of e-liquids and tighter regulation of e-cigarettes.
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Affiliation(s)
- Simon T Landman
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Inderdeep Dhaliwal
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Constance A Mackenzie
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Tereza Martinu
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Andrew Steel
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont
| | - Karen J Bosma
- Divisions of Respirology (Landman, Dhaliwal, Mackenzie, Bosma), Clinical Pharmacology and Toxicology (Mackenzie), and Critical Care Medicine (Bosma), Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, Ont.; Ontario, Manitoba and Nunavut Poison Centres (Mackenzie), The Hospital for Sick Children; Division of Respirology (Martinu), Department of Medicine, Toronto Lung Transplant Program, University Health Network; Interdepartmental Division of Critical Care Medicine (Steel), Department of Anesthesiology, Faculty of Medicine, University of Toronto, Toronto, Ont.
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16
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Hubbs AF, Kreiss K, Cummings KJ, Fluharty KL, O'Connell R, Cole A, Dodd TM, Clingerman SM, Flesher JR, Lee R, Pagel S, Battelli LA, Cumpston A, Jackson M, Kashon M, Orandle MS, Fedan JS, Sriram K. Flavorings-Related Lung Disease: A Brief Review and New Mechanistic Data. Toxicol Pathol 2019; 47:1012-1026. [PMID: 31645208 DOI: 10.1177/0192623319879906] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Flavorings-related lung disease is a potentially disabling and sometimes fatal lung disease of workers making or using flavorings. First identified almost 20 years ago in microwave popcorn workers exposed to butter-flavoring vapors, flavorings-related lung disease remains a concern today. In some cases, workers develop bronchiolitis obliterans, a severe form of fixed airways disease. Affected workers have been reported in microwave popcorn, flavorings, and coffee production workplaces. Volatile α-dicarbonyl compounds, particularly diacetyl (2,3-butanedione) and 2,3-pentanedione, are implicated in the etiology. Published studies on diacetyl and 2,3-pentanedione document their ability to cause airway epithelial necrosis, damage biological molecules, and perturb protein homeostasis. With chronic exposure in rats, they produce airway fibrosis resembling bronchiolitis obliterans. To add to this knowledge, we recently evaluated airway toxicity of the 3-carbon α-dicarbonyl compound, methylglyoxal. Methylglyoxal inhalation causes epithelial necrosis at even lower concentrations than diacetyl. In addition, we investigated airway toxicity of mixtures of diacetyl, acetoin, and acetic acid, common volatiles in butter flavoring. At ratios comparable to workplace scenarios, the mixtures or diacetyl alone, but not acetic acid or acetoin, cause airway epithelial necrosis. These new findings add to existing data to implicate α-dicarbonyl compounds in airway injury and flavorings-related lung disease.
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Affiliation(s)
- Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Kathleen Kreiss
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Kristin J Cummings
- Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Kara L Fluharty
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Ryan O'Connell
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Allison Cole
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Tiana M Dodd
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Sidney M Clingerman
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Jordan R Flesher
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Rebecca Lee
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Samantha Pagel
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA.,West Virginia University, Morgantown, WV, USA. Cummings is now with California Department of Public Health, Richmond, CA, USA. O'Connell is now with Department of Biochemistry, West Virginia, University, Morgantown, WV, USA. Flesher is now with Department of Biology, West Virginia University, Morgantown, WV, USA. Cole is now with Department of Pediatrics-Hematology/Oncology, University of Colorado School of Medicine, Aurora, CO, USA. Kreiss (retired) is in Sitka, AK, USA
| | - Lori A Battelli
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Amy Cumpston
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Mark Jackson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Michael Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Marlene S Orandle
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
| | - Krishnan Sriram
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, WV, USA
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17
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Jedlicka LDL, Silva JDC, Balbino AM, Neto GB, Furtado DZS, da Silva HDT, Cavalcanti FDBC, van der Heijden KM, Penatti CAA, Bechara EJH, Assunção NA. Effects of Diacetyl Flavoring Exposure in Mice Metabolism. BIOMED RESEARCH INTERNATIONAL 2018; 2018:9875319. [PMID: 30065948 PMCID: PMC6051334 DOI: 10.1155/2018/9875319] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 04/27/2018] [Accepted: 05/08/2018] [Indexed: 01/06/2023]
Abstract
Diacetyl is a flavoring that imparts a buttery flavor to foods, but the use or exposure to diacetyl has been related to some diseases. We investigated the effect of oral intake of diacetyl in male and female C57/Bl mice. We performed a target metabolomics assay using ultraperformance liquid chromatography paired with triple quadrupole mass spectrometry (UPLC-MS/MS) for the determination and quantification of plasmatic metabolites. We observed alterations in metabolites present in the urea and tricarboxylic acid (TCA) cycles. Peroxynitrite plasmatic levels were evaluated by a colorimetric method, final activity of superoxide dismutase (SOD) was evaluated by an enzymatic method, and mouse behavior was evaluated. Majority of the assay showed differences between control and treatment groups, as well as between genders. This may indicate the involvement of sex hormones in the regulation of a normal metabolic profile, and the implication of sex differences in metabolite disease response.
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Affiliation(s)
- Letícia Dias Lima Jedlicka
- Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, SP, Brazil
- Instituto de Estudos em Saúde e Biológicas, Universidade Federal do Sul e Sudeste do Pará, Marabá, PA, Brazil
| | | | - Aleksandro Martins Balbino
- Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Giuseppe Bruno Neto
- Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | | | | | | | | | | | | | - Nilson Antonio Assunção
- Instituto de Ciências Ambientais, Químicas e Farmacêuticas, Universidade Federal de São Paulo, Diadema, SP, Brazil
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18
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Ebert B, Ebert D, Koebsch K, Maser E, Kisiela M. Carbonyl reductases from Daphnia are regulated by redox cycling compounds. FEBS J 2018; 285:2869-2887. [PMID: 29893480 DOI: 10.1111/febs.14578] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 05/20/2018] [Accepted: 06/11/2018] [Indexed: 01/22/2023]
Abstract
Oxidative stress is a major source of reactive carbonyl compounds that can damage cellular macromolecules, leading to so-called carbonyl stress. Aside from endogenously formed carbonyls, including highly reactive short-chain aldehydes and diketones, air pollutants derived from diesel exhaust like 9,10-phenanthrenequinone (PQ) can amplify oxidative stress by redox cycling, causing tissue damage. Carbonyl reductases (CRs), which are inducible in response to ROS, represent a fundamental enzymatic defense mechanism against oxidative stress. While commonly two carbonyl reductases (CBR1 and CBR3) are found in mammalian genomes, invertebrate model organisms like Drosophila melanogaster express no CR but a functional homolog to human CBR1, termed sniffer. The microcrustacean Daphnia is an ideal model organism to investigate the function of CRs because of its unique equipment with even four copies of the CR gene (CR1, CR2, CR3, CR4) in addition to one sniffer gene. Cloning and catalytic characterization of two carbonyl reductases CR1 and CR3 from D. magna and D. pulex arenata revealed that both proteins reductively metabolize aromatic dicarbonyls (e.g., menadione, PQ) and aliphatic α-diketones (e.g., 2,3-hexanedione), while sugar-derived aldehydes (methylglyoxal, glyoxal) and lipid peroxidation products such as acrolein and butanal were poor substrates, indicating no physiological function in the metabolism of short-chain aldehydes. Treatment of D. magna with redox cyclers like menadione and the pesticide paraquat led to an upregulation of CR1 and CR3 mRNA, suggesting a role in oxidative stress defense. Further studies are needed to investigate their potential to serve as novel biomarkers for oxidative stress in Daphnia.
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Affiliation(s)
- Bettina Ebert
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany
| | - Dieter Ebert
- Departement Environmental Sciences, Zoology, Basel University, Switzerland
| | - Katrin Koebsch
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany
| | - Edmund Maser
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany
| | - Michael Kisiela
- Institute of Toxicology and Pharmacology for Natural Scientists, University Medical School Schleswig-Holstein, Kiel, Germany.,Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Germany
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19
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Kaur G, Muthumalage T, Rahman I. Mechanisms of toxicity and biomarkers of flavoring and flavor enhancing chemicals in emerging tobacco and non-tobacco products. Toxicol Lett 2018; 288:143-155. [PMID: 29481849 PMCID: PMC6549714 DOI: 10.1016/j.toxlet.2018.02.025] [Citation(s) in RCA: 110] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 02/19/2018] [Accepted: 02/21/2018] [Indexed: 01/11/2023]
Abstract
Tobacco products containing flavorings, such as electronic nicotine delivery devices (ENDS) or e-cigarettes, cigars/cigarillos, waterpipes, and heat-not-burn devices (iQOS) are continuously evolving. In addition to increasing the exposure of teenagers and adults to nicotine containing flavoring products and flavoring enhancers, chances of nicotine addiction through chronic use and abuse also increase. These flavorings are believed to be safe for ingestion, but little information is available about their effects on the lungs. In this review, we have discussed the in vitro and in vivo data on toxicity of flavoring chemicals in lung cells. We have further discussed the common flavoring agents, such as diacetyl and menthol, currently available detection methods, and the toxicological mechanisms associated with oxidative stress, inflammation, mucociliary clearance, and DNA damage in cells, mice, and humans. Finally, we present potential biomarkers that could be utilized for future risk assessment. This review provides crucial parameters important for evaluation of risk associated with flavoring agents and flavoring enhancers used in tobacco products and ENDS. Future studies can be designed to address the potential toxicity of inhaled flavorings and their biomarkers in users as well as in chronic exposure studies.
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Affiliation(s)
- Gurjot Kaur
- Human and Environmental Toxicology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Thivanka Muthumalage
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Irfan Rahman
- Department of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA.
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20
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Jedlicka LDL, Guterres SB, Balbino AM, Neto GB, Landgraf RG, Fernandes L, Carrilho E, Bechara EJH, Assuncao NA. Increased chemical acetylation of peptides and proteins in rats after daily ingestion of diacetyl analyzed by Nano-LC-MS/MS. PeerJ 2018; 6:e4688. [PMID: 29713565 PMCID: PMC5923218 DOI: 10.7717/peerj.4688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 04/10/2018] [Indexed: 01/23/2023] Open
Abstract
Background Acetylation alters several protein properties including molecular weight, stability, enzymatic activity, protein-protein interactions, and other biological functions. Our previous findings demonstrating that diacetyl/peroxynitrite can acetylate L-lysine, L-histidine, and albumin in vitro led us to investigate whether diacetyl-treated rats suffer protein acetylation as well. Methods Wistar rats were administered diacetyl daily for four weeks, after which they were sacrificed, and their lung proteins were extracted to be analysed by Nano-LC-MS/MS (Q-TOF). A C18 reversed-phase column and gradient elution with formic acid/acetonitrile solutions from 2 to 50% over 150 min were used to separate the proteins. Protein detection was performed using a microTOF-Q II (QTOF) equipped with captive source and an electrospray-ionization source. The data from mass spectrometry were processed using a Compass 1.7 and analyzed using Protein Scape, software that uses Mascot algorithms to perform protein searches. Results A set of 3,162 acetylated peptides derived from 351 acetylated proteins in the diacetyl-treated group was identified. Among them, 23 targeted proteins were significantly more acetylated in the diacetyl-treated group than in the PBS control. Protein acetylation of the group treated with 540 mg/kg/day of diacetyl was corroborated by Western blotting analysis. Conclusions These data support our hypothesis that diacetyl exposure in animals may lead to the generation of acetyl radicals, compounds that attach to proteins, affecting their functions and triggering adverse health problems.
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Affiliation(s)
- Leticia Dias Lima Jedlicka
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil.,Institute of Studies in Health and Biological, Collective Health, Universidade Federal do Sul e Sudeste do Pará, Maraba, PA, Brazil
| | - Sheila Barreto Guterres
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil.,Department of Chemistry, Fundação Universidade Federal de Rondônia, Porto Velho, RO, Brazil
| | - Aleksandro Martins Balbino
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Giuseppe Bruno Neto
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Richardt Gama Landgraf
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Liliam Fernandes
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil
| | - Emanuel Carrilho
- São Carlos Institute of Chemistry, Universidade de São Paulo, São Carlos, SP, Brazil
| | - Etelvino José Henriques Bechara
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil.,Department of Fundamental Chemistry, Institute of Chemistry, Universidade de São Paulo, São Paulo, SP, Brazil
| | - Nilson A Assuncao
- Institute of Environmental, Chemical and Pharmaceutical Sciences, Universidade Federal de São Paulo, Diadema, SP, Brazil
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21
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Digestibility of Bovine Serum Albumin and Peptidomics of the Digests: Effect of Glycation Derived from α-Dicarbonyl Compounds. Molecules 2018; 23:molecules23040712. [PMID: 29561799 PMCID: PMC6017377 DOI: 10.3390/molecules23040712] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/02/2018] [Accepted: 03/07/2018] [Indexed: 11/16/2022] Open
Abstract
α-Dicarbonyl compounds, which are widely generated during sugar fragmentation and oil oxidation, are important precursors of advanced glycation end products (AGEs). In this study, the effect of glycation derived from glyoxal (GO), methylglyoxal (MGO) and diacetyl (DA) on the in vitro digestibility of bovine serum albumin (BSA) was investigated. Glycation from α-dicarbonyl compounds reduced digestibility of BSA in both gastric and intestinal stage of digestion according to measurement of degree of hydrolysis. Changes in peptide composition of digests induced by glycation were displayed, showing absence of peptides, occurrence of new peptides and formation of peptide-AGEs, based on the results obtained using liquid chromatography electron-spray-ionization tandem mass spectrometry (LC-ESI-MS/MS). Crosslinked glycation structures derived from DA largely reduced the sensitivity of glycated BSA towards digestive proteases based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results. Network structures were found to remain in the digests of glycated samples by transmission electron microscope (TEM), thus the impact of AGEs in unabsorbed digests on the gut flora should be an interest for further studies.
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22
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Effect of glycation derived from α-dicarbonyl compounds on the in vitro digestibility of β-casein and β-lactoglobulin: A model study with glyoxal, methylglyoxal and butanedione. Food Res Int 2017; 102:313-322. [DOI: 10.1016/j.foodres.2017.10.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 12/23/2022]
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23
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An enzyme-linked immunosorbent assay for the detection of diacetyl (2,3-butanedione). Anal Biochem 2017; 535:12-18. [DOI: 10.1016/j.ab.2017.07.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2017] [Revised: 06/23/2017] [Accepted: 07/20/2017] [Indexed: 11/23/2022]
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24
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Diacetyl and related flavorant α-Diketones: Biotransformation, cellular interactions, and respiratory-tract toxicity. Toxicology 2017; 388:21-29. [PMID: 28179188 DOI: 10.1016/j.tox.2017.02.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 01/26/2023]
Abstract
Exposure to diacetyl and related α-diketones causes respiratory-tract damage in humans and experimental animals. Chemical toxicity is often associated with covalent modification of cellular nucleophiles by electrophilic chemicals. Electrophilic α-diketones may covalently modify nucleophilic arginine residues in critical proteins and, thereby, produce the observed respiratory-tract pathology. The major pathway for the biotransformation of α-diketones is reduction to α-hydroxyketones (acyloins), which is catalyzed by NAD(P)H-dependent enzymes of the short-chain dehydrogenase/reductase (SDR) and the aldo-keto reductase (AKR) superfamilies. Reduction of α-diketones to the less electrophilic acyloins is a detoxication pathway for α-diketones. The pyruvate dehydrogenase complex may play a significant role in the biotransformation of diacetyl to CO2. The interaction of toxic electrophilic chemicals with cellular nucleophiles can be predicted by the hard and soft, acids and bases (HSAB) principle. Application of the HSAB principle to the interactions of electrophilic α-diketones with cellular nucleophiles shows that α-diketones react preferentially with arginine residues. Furthermore, the respiratory-tract toxicity and the quantum-chemical reactivity parameters of diacetyl and replacement flavorant α-diketones are similar. Hence, the identified replacement flavorant α-diketones may pose a risk of flavorant-induced respiratory-tract toxicity. The calculated indices for the reaction of α-diketones with arginine support the hypothesis that modification of protein-bound arginine residues is a critical event in α-diketone-induced respiratory-tract toxicity.
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25
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Cichocki JA, Morris JB. Inhalation dosimetry modeling provides insights into regional respiratory tract toxicity of inhaled diacetyl. Toxicology 2016; 388:30-39. [PMID: 27851905 DOI: 10.1016/j.tox.2016.11.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/04/2016] [Accepted: 11/07/2016] [Indexed: 11/15/2022]
Abstract
Vapor dosimetry models provide a means of assessing the role of delivered dose in determining the regional airway response to inspired vapors. A validated hybrid computational fluid dynamics physiologically based pharmacokinetic model for inhaled diacetyl has been developed to describe inhaled diacetyl dosimetry in both the rat and human respiratory tracts. Comparison of the distribution of respiratory tract injury with dosimetry estimates provides strong evidence that regional delivered dose rather than regional airway tissue sensitivity to diacetyl-induced injury is the critical determinant of the regional respiratory tract response to this water soluble reactive vapor. In the rat, inhalation exposure to diacetyl causes much lesser injury in the distal bronchiolar airways compared to nose and large tracheobronchial airways. The degree of injury correlates very strongly to model based estimates of local airway diacetyl concentrations. According to the model, regional dosimetry patterns of diacetyl in the human differ greatly from those in the rat with much greater penetration of diacetyl to the bronchiolar airways in the lightly exercising mouth breathing human compared to the rat, providing evidence that rat inhalation toxicity studies underpredict the risk of bronchiolar injury in the human. For example, repeated exposure of the rat to 200ppm diacetyl results in bronchiolar injury; the estimated bronchiolar tissue concentration in rats exposed to 200ppm diacetyl would occur in lightly exercising mouth breathing humans exposed to 12ppm. Consideration of airway dosimetry patterns of inspired diacetyl is critical to the proper evaluation of rodent toxicity data and its relevance for predicting human risk.
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Affiliation(s)
- Joseph A Cichocki
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, United States
| | - John B Morris
- Toxicology Program, Department of Pharmaceutical Sciences, School of Pharmacy, University of Connecticut, 69 N. Eagleville Road, Storrs, CT 06269, United States.
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26
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Hubbs AF, Fluharty KL, Edwards RJ, Barnabei JL, Grantham JT, Palmer SM, Kelly F, Sargent LM, Reynolds SH, Mercer RR, Goravanahally MP, Kashon ML, Honaker JC, Jackson MC, Cumpston AM, Goldsmith WT, McKinney W, Fedan JS, Battelli LA, Munro T, Bucklew-Moyers W, McKinstry K, Schwegler-Berry D, Friend S, Knepp AK, Smith SL, Sriram K. Accumulation of Ubiquitin and Sequestosome-1 Implicate Protein Damage in Diacetyl-Induced Cytotoxicity. THE AMERICAN JOURNAL OF PATHOLOGY 2016; 186:2887-2908. [PMID: 27643531 PMCID: PMC5222965 DOI: 10.1016/j.ajpath.2016.07.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 07/09/2016] [Accepted: 07/21/2016] [Indexed: 01/12/2023]
Abstract
Inhaled diacetyl vapors are associated with flavorings-related lung disease, a potentially fatal airway disease. The reactive α-dicarbonyl group in diacetyl causes protein damage in vitro. Dicarbonyl/l-xylulose reductase (DCXR) metabolizes diacetyl into acetoin, which lacks this α-dicarbonyl group. To investigate the hypothesis that flavorings-related lung disease is caused by in vivo protein damage, we correlated diacetyl-induced airway damage in mice with immunofluorescence for markers of protein turnover and autophagy. Western immunoblots identified shifts in ubiquitin pools. Diacetyl inhalation caused dose-dependent increases in bronchial epithelial cells with puncta of both total ubiquitin and K63-ubiquitin, central mediators of protein turnover. This response was greater in Dcxr-knockout mice than in wild-type controls inhaling 200 ppm diacetyl, further implicating the α-dicarbonyl group in protein damage. Western immunoblots demonstrated decreased free ubiquitin in airway-enriched fractions. Transmission electron microscopy and colocalization of ubiquitin-positive puncta with lysosomal-associated membrane proteins 1 and 2 and with the multifunctional scaffolding protein sequestosome-1 (SQSTM1/p62) confirmed autophagy. Surprisingly, immunoreactive SQSTM1 also accumulated in the olfactory bulb of the brain. Olfactory bulb SQSTM1 often congregated in activated microglial cells that also contained olfactory marker protein, indicating neuronophagia within the olfactory bulb. This suggests the possibility that SQSTM1 or damaged proteins may be transported from the nose to the brain. Together, these findings strongly implicate widespread protein damage in the etiology of flavorings-related lung disease.
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Affiliation(s)
- Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia.
| | - Kara L Fluharty
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Rebekah J Edwards
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia
| | - Jamie L Barnabei
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; College of Veterinary Medicine, University of Georgia, Athens, Georgia
| | - John T Grantham
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; School of Medicine, West Virginia University, Morgantown, West Virginia
| | - Scott M Palmer
- Duke University School of Medicine, Durham, North Carolina
| | - Francine Kelly
- Duke University School of Medicine, Durham, North Carolina
| | - Linda M Sargent
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Steven H Reynolds
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Robert R Mercer
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Madhusudan P Goravanahally
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Centers for Neuroscience, West Virginia University, Morgantown, West Virginia
| | - Michael L Kashon
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - John C Honaker
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Mark C Jackson
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Amy M Cumpston
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - William T Goldsmith
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Walter McKinney
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Jeffrey S Fedan
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Lori A Battelli
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Tiffany Munro
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Winnie Bucklew-Moyers
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Kimberly McKinstry
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Diane Schwegler-Berry
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Sherri Friend
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Alycia K Knepp
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia
| | - Samantha L Smith
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia; Department of Forensic and Investigative Science, West Virginia University, Morgantown, West Virginia
| | - Krishnan Sriram
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
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27
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Delineation of the structural and functional role of Arg111 in GSTU4-4 from Glycine max by chemical modification and site-directed mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:1315-21. [PMID: 27375050 DOI: 10.1016/j.bbapap.2016.06.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 06/20/2016] [Accepted: 06/29/2016] [Indexed: 12/16/2022]
Abstract
The structural and functional role of Arg111 in GSTU4-4 from Glycine max (GmGSTU4-4) was studied by chemical modification followed by site-directed mutagenesis. The arginine-specific reagent 2,3-butanedione (BTD) inactivates the enzyme in borate buffer at pH8.0, with pseudo-first-order saturation kinetics. The rate of inactivation exhibited a non-linear dependence on the concentration of BTD which can be described by reversible binding of reagent to the enzyme (KD 81.2±9.2mM) prior to the irreversible reaction, with maximum rate constants of 0.18±0.01min(-1). Protection from inactivation was afforded by substrate analogues demonstrating the specificity of the reaction. Structural analysis suggested that the modified residue is Arg111, which was confirmed by protein chemistry experiments. Site-directed mutagenesis was used in dissecting the role of Arg111 in substrate binding, specificity and catalytic mechanism. The mutant Arg111Ala enzyme exhibited unchanged Km value for GSH but showed reduced affinity for the xenobiotic substrates, higher kcat and specific activities towards aromatic substrates and lower specific activities towards aliphatic substrates. The biological significance of the specific modification of Arg111 by dicarbonyl compounds and the role of Arg111 as a target for engineering xenobiotic substrate specificity were discussed.
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28
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Kreiss K. Recognizing occupational effects of diacetyl: What can we learn from this history? Toxicology 2016; 388:48-54. [PMID: 27326900 DOI: 10.1016/j.tox.2016.06.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 06/08/2016] [Accepted: 06/10/2016] [Indexed: 10/21/2022]
Abstract
For half of the 30-odd years that diacetyl-exposed workers have developed disabling lung disease, obliterative bronchiolitis was unrecognized as an occupational risk. Delays in its recognition as an occupational lung disease are attributable to the absence of a work-related temporal pattern of symptoms; failure to recognize clusters of cases; complexity of exposure environments; and absence of epidemiologic characterization of workforces giving rise to case clusters. Few physicians are familiar with this rare disease, and motivation to investigate the unknown requires familiarity with what is known and what is anomalous. In pursuit of the previously undescribed risk, investigators benefited greatly from multi-disciplinary collaboration, in this case including physicians, epidemiologists, environmental scientists, toxicologists, industry representatives, and worker advocates. In the 15 years since obliterative bronchiolitis was described in microwave popcorn workers, α-dicarbonyl-related lung disease has been found in flavoring manufacturing workers, other food production workers, diacetyl manufacturing workers, and coffee production workers, alongside case reports in other industries. Within the field of occupational health, impacts include new ventures in public health surveillance, attention to spirometry quality for serial measurements, identifying other indolent causes of obliterative bronchiolitis apart from accidental over-exposures, and broadening the spectrum of diagnostic abnormalities in the disease. Within toxicology, impacts include new attention to appropriate animal models of obliterative bronchiolitis, pertinence of computational fluid dynamic-physiologically based pharmacokinetic modeling, and contributions to mechanistic understanding of respiratory epithelial necrosis, airway fibrosis, and central nervous system effects. In these continuing efforts, collaboration between laboratory scientists, clinicians, occupational public health practitioners in government and industry, and employers remains critical for improving the health of workers inhaling volatile α-dicarbonyl compounds.
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Affiliation(s)
- Kathleen Kreiss
- Division of Respiratory Health, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown WV, United States.
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29
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Aunsbjerg SD, Andersen KR, Knøchel S. Real-time monitoring of fungal inhibition and morphological changes. J Microbiol Methods 2015; 119:196-202. [PMID: 26541062 DOI: 10.1016/j.mimet.2015.10.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 10/29/2015] [Accepted: 10/29/2015] [Indexed: 10/22/2022]
Abstract
Mold growth constitutes a problem in many food and clinical environments and there is therefore focus on studying antifungal activity. Methods for determining growth inhibition by measuring colony growth or biomass are, however, time-taking and rapid methods for evaluation of antifungal effects are needed. Propionic acid and diacetyl are antifungal compounds produced by a range of dairy-associated bacteria. Their activity against Penicillium spp. was monitored real-time using an optical detection system with tilted focus plane to assess growth and morphological changes of Penicillium spp. by image recording inside a 96 well microplate. Images were used for generation of growth curves by using a segmentation and extraction of surface areas (SESA) algorithm and for quantifying morphology changes. Using image analysis growth could be detected within 15 h compared with more than 30 h when using standard optical density measurements. Induced morphological changes of fungi could furthermore be visualized and quantified using morphological descriptors such as circularity, branch points, perimeter and area of spores and growing hyphae. Propionic acid inhibited two out of two Penicillium spp. while morphological changes were strain dependent at the concentrations tested. Diacetyl inhibited six out of six Penicillium spp. strains and increased spore size and number of germination sites in two out of six of the strains prior to germination.
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Affiliation(s)
- S D Aunsbjerg
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark.
| | | | - S Knøchel
- Department of Food Science, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
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30
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Kerger BD, Fedoruk MJ. Pathology, toxicology, and latency of irritant gases known to cause bronchiolitis obliterans disease: Does diacetyl fit the pattern? Toxicol Rep 2015; 2:1463-1472. [PMID: 28962489 PMCID: PMC5598164 DOI: 10.1016/j.toxrep.2015.10.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 10/21/2015] [Indexed: 12/22/2022] Open
Abstract
Bronchiolitis obliterans (BO) is a rare disease involving concentric bronchiolar fibrosis that develops rapidly following inhalation of certain irritant gases at sufficiently high acute doses. While there are many potential causes of bronchiolar lesions involved in a variety of chronic lung diseases, failure to clearly define the clinical features and pathological characteristics can lead to ambiguous diagnoses. Irritant gases known to cause BO follow a similar pathologic process and time course of disease onset in humans. Studies of inhaled irritant gases known to cause BO (e.g., chlorine, hydrochloric acid, ammonia, nitrogen oxides, sulfur oxides, sulfur or nitrogen mustards, and phosgene) indicate that the time course between causal chemical exposures and development of clinically significant BO disease is typically limited to a few months. The mechanism of toxic action exerted by these irritant gases generally involves widespread and severe injury of the epithelial lining of the bronchioles that leads to acute respiratory symptoms which can include lung edema within days. Repeated exposures to inhaled irritant gases at concentrations insufficient to cause marked respiratory distress or edema may lead to adaptive responses that can reduce or prevent severe bronchiolar fibrotic changes. Risk of BO from irritant gases is driven substantially by toxicokinetics affecting concentrations occurring at the bronchiolar epithelium. Highly soluble irritant gases that cause BO like ammonia generally follow a threshold-dependent cytotoxic mechanism of action that at sufficiently high doses results in severe inflammation of the upper respiratory tract and the bronchiolar epithelium concurrently. This is followed by acute respiratory distress, pulmonary edema, and post inflammatory concentric fibrosis that become clinically obvious within a few months. In contrast, irritant gases with lower solubility like phosgene also follow a threshold-dependent mechanism of cytotoxicity action but can exhibit more insidious and isolated bronchiolar tissue damage with a similar latency to fibrosis. To date, animal and human studies on the highly soluble gas, diacetyl, have not identified a coherent pattern of pathology and latency that would be expected based on studies of other known causes of bronchiolitis obliterans disease.
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31
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Zaccone EJ, Goldsmith WT, Shimko MJ, Wells JR, Schwegler-Berry D, Willard PA, Case SL, Thompson JA, Fedan JS. Diacetyl and 2,3-pentanedione exposure of human cultured airway epithelial cells: Ion transport effects and metabolism of butter flavoring agents. Toxicol Appl Pharmacol 2015; 289:542-9. [PMID: 26454031 DOI: 10.1016/j.taap.2015.10.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 09/04/2015] [Accepted: 10/06/2015] [Indexed: 11/29/2022]
Abstract
Inhalation of butter flavoring by workers in the microwave popcorn industry may result in “popcorn workers' lung.” In previous in vivo studies rats exposed for 6 h to vapor from the flavoring agents, diacetyl and 2,3-pentanedione, acquired flavoring concentration-dependent damage of the upper airway epithelium and airway hyporeactivity to inhaled methacholine. Because ion transport is essential for lung fluid balance,we hypothesized that alterations in ion transport may be an early manifestation of butter flavoring-induced toxicity.We developed a system to expose cultured human bronchial/tracheal epithelial cells (NHBEs) to flavoring vapors. NHBEs were exposed for 6 h to diacetyl or 2,3-pentanedione vapors (25 or ≥ 60 ppm) and the effects on short circuit current and transepithelial resistance (Rt) were measured. Immediately after exposure to 25 ppm both flavorings reduced Na+ transport,without affecting Cl- transport or Na+,K+-pump activity. Rt was unaffected. Na+ transport recovered 18 h after exposure. Concentrations (100-360 ppm) of diacetyl and 2,3-pentanedione reported earlier to give rise in vivo to epithelial damage, and 60 ppm, caused death of NHBEs 0 h post-exposure. Analysis of the basolateral medium indicated that NHBEs metabolize diacetyl and 2,3-pentanedione to acetoin and 2-hydroxy-3-pentanone, respectively. The results indicate that ion transport is inhibited transiently in airway epithelial cells by lower concentrations of the flavorings than those that result in morphological changes of the cells in vivo or in vitro.
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Affiliation(s)
- Eric J Zaccone
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA
| | - W Travis Goldsmith
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Michael J Shimko
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA
| | - J R Wells
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Diane Schwegler-Berry
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Patsy A Willard
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Shannon L Case
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Janet A Thompson
- Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
| | - Jeffrey S Fedan
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV, USA; Pathology and Physiology Research Branch, National Institute for Occupational Safety and Health, Morgantown, WV, USA
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32
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Cummings KJ, Kreiss K. Occupational and environmental bronchiolar disorders. Semin Respir Crit Care Med 2015; 36:366-78. [PMID: 26024345 DOI: 10.1055/s-0035-1549452] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Occupational and environmental causes of bronchiolar disorders are recognized on the basis of case reports, case series, and, less commonly, epidemiologic investigations. Pathology may be limited to the bronchioles or also involve other components of the respiratory tract, including the alveoli. A range of clinical, functional, and radiographic findings, including symptomatic disease lacking abnormalities on noninvasive testing, poses a diagnostic challenge and highlights the value of surgical biopsy. Disease clusters in workplaces and communities have identified new etiologies, drawn attention to indolent disease that may otherwise have been categorized as idiopathic, and expanded the spectrum of histopathologic responses to an exposure. More sensitive noninvasive diagnostic tools, evidence-based therapies, and ongoing epidemiologic investigation of at-risk populations are needed to identify, treat, and prevent exposure-related bronchiolar disorders.
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Affiliation(s)
- Kristin J Cummings
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
| | - Kathleen Kreiss
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia
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33
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Fennell TR, Morgan DL, Watson SL, Dhungana S, Waidyanatha S. Systemic uptake, albumin and hemoglobin binding of [(14)C]2,3-butanedione administered by intratracheal instillation in male Harlan Sprague Dawley rats and oropharyngeal aspiration in male B6C3F1/N mice. Chem Biol Interact 2015; 227:112-9. [PMID: 25559854 DOI: 10.1016/j.cbi.2014.12.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 11/17/2022]
Abstract
2,3-Butanedione (BD) is a reactive diketone in artificial butter flavors that is thought to cause bronchiolitis obliterans in workers in microwave popcorn manufacturing. Bronchiolitis obliterans is generally not diagnosed until irreversible damage has occurred; therefore a biomarker of early exposure is needed. The potential systemic uptake of BD from inhalation exposure has not been evaluated. The objective here was to evaluate the systemic exposure of BD and binding to hemoglobin and albumin. [(14)C]BD was administered to male Harlan Sprague Dawley rats (100 mg/kg, intratracheal instillation) and B6C3F1/N mice (157 mg/kg, oropharyngeal aspiration). Blood and plasma was collected 24 h after administration and analyzed for (14)C content. At 24h, 0.88±0.07% of the administered dose was in rat blood, 0.66±0.06% in rat plasma, 0.38±0.13% in mouse blood and 0.17±0.05% in mouse plasma. Albumin binding in rats was 269±24.2 ng equiv./mg, which accounts for 38% of the radioactivity in plasma. In mice, binding was 85.0±22.3 ng equiv./mg albumin, which accounts for 51% of the radioactivity in plasma. The binding to hemoglobin in rats was 38.2±17.6 ng equiv./mg, and to globin was 29.1±3.96 ng equiv./mg. In mice, the binding to hemoglobin was 16.2±9.0 ng equiv./mg. The site(s) of adduction on hemoglobin and albumin was investigated by mass spectrometry. In rat globin, arginine adducts were detected at R-30 and R-104 of the beta chain in vitro and in vivo. In rat albumin, adducts were detected in vitro on R-219/221, R-360, and R-368, and in vivo on a variety of arginine residues. This study demonstrated that BD enters the systemic circulation and reacts with arginine on hemoglobin and albumin. These results indicate that hemoglobin and albumin adducts may be useful as biomarkers of BD exposure in humans.
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Affiliation(s)
| | - Daniel L Morgan
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States
| | - Scott L Watson
- RTI International, Research Triangle Park, NC, United States
| | - Suraj Dhungana
- RTI International, Research Triangle Park, NC, United States
| | - Suramya Waidyanatha
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, United States.
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Farsalinos KE, Kistler KA, Gillman G, Voudris V. Evaluation of electronic cigarette liquids and aerosol for the presence of selected inhalation toxins. Nicotine Tob Res 2014; 17:168-74. [PMID: 25180080 DOI: 10.1093/ntr/ntu176] [Citation(s) in RCA: 221] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
INTRODUCTION The purpose of this study was to evaluate sweet-flavored electronic cigarette (EC) liquids for the presence of diacetyl (DA) and acetyl propionyl (AP), which are chemicals approved for food use but are associated with respiratory disease when inhaled. METHODS In total, 159 samples were purchased from 36 manufacturers and retailers in 7 countries. Additionally, 3 liquids were prepared by dissolving a concentrated flavor sample of known DA and AP levels at 5%, 10%, and 20% concentration in a mixture of propylene glycol and glycerol. Aerosol produced by an EC was analyzed to determine the concentration of DA and AP. RESULTS DA and AP were found in 74.2% of the samples, with more samples containing DA. Similar concentrations were found in liquid and aerosol for both chemicals. The median daily exposure levels were 56 μg/day (IQR: 26-278 μg/day) for DA and 91 μg/day (IQR: 20-432 μg/day) for AP. They were slightly lower than the strict NIOSH-defined safety limits for occupational exposure and 100 and 10 times lower compared with smoking respectively; however, 47.3% of DA and 41.5% of AP-containing samples exposed consumers to levels higher than the safety limits. CONCLUSIONS DA and AP were found in a large proportion of sweet-flavored EC liquids, with many of them exposing users to higher than safety levels. Their presence in EC liquids represents an avoidable risk. Proper measures should be taken by EC liquid manufacturers and flavoring suppliers to eliminate these hazards from the products without necessarily limiting the availability of sweet flavors.
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Affiliation(s)
| | - Kurt A Kistler
- Department of Chemistry, Pennsylvania State University Brandywine, Media, PA
| | | | - Vassilis Voudris
- Department of Cardiology, Onassis Cardiac Surgery Center, Kallithea, Greece
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Cichocki JA, Smith GJ, Morris JB. Tissue sensitivity of the rat upper and lower extrapulmonary airways to the inhaled electrophilic air pollutants diacetyl and acrolein. Toxicol Sci 2014; 142:126-36. [PMID: 25145656 DOI: 10.1093/toxsci/kfu165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The target site for inhaled vapor-induced injury often differs in mouth-breathing humans compared with nose-breathing rats, thus complicating the use of rat inhalation toxicity data for assessment of human risk. We sought to examine sensitivity of respiratory/transitional nasal (RTM) and tracheobronchial (TBM) mucosa to two electrophilic irritant vapors: diacetyl and acrolein. Computational fluid dynamic physiologically based pharmacokinetic modeling was coupled with biomarker assessment to establish delivered dose-response relationships in RTM and TBM in male F344 rats following 6 h exposure to diacetyl or acrolein. Biomarkers included glutathione status, proinflammatory and antioxidant gene mRNA levels, and nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Modeling revealed that 0.0094-0.1653 μg acrolein/min-cm(2) and 3.9-21.6 μg diacetyl/min-cm(2) were deposited into RTM/TBM. Results indicate RTM and TBM were generally of similar sensitivity to diacetyl and acrolein. For instance, both tissues displayed induction of antioxidant and proinflammatory genes, and nuclear accumulation of Nrf2 after electrophile exposure. Hierarchical cellular response patterns were similar in RTM and TBM but differed between vapors. Specifically, diacetyl exposure induced proinflammatory and antioxidant genes concomitantly at low exposure levels, whereas acrolein induced antioxidant genes at much lower exposure levels than that required to induce proinflammatory genes. Generally, diacetyl was less potent than acrolein, as measured by maximal induction of transcripts. In conclusion, the upper and lower extrapulmonary airways are of similar sensitivity to inhaled electrophilic vapors. Dosimetrically based extrapolation of nasal responses in nose-breathing rodents may provide an approach to predict risk to the lower airways of humans during mouth-breathing.
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Affiliation(s)
- Joseph A Cichocki
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269
| | - Gregory J Smith
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269
| | - John B Morris
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut 06269
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Wallace KB, Veith GD. Safe exposure level for diacetyl. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2014; 20:4-5. [PMID: 24804334 DOI: 10.1179/1077352513z.000000000100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Breath gas metabolites and bacterial metagenomes from cystic fibrosis airways indicate active pH neutral 2,3-butanedione fermentation. ISME JOURNAL 2014; 8:1247-58. [PMID: 24401860 PMCID: PMC4030226 DOI: 10.1038/ismej.2013.229] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 12/20/2022]
Abstract
The airways of cystic fibrosis (CF) patients are chronically colonized by patient-specific polymicrobial communities. The conditions and nutrients available in CF lungs affect the physiology and composition of the colonizing microbes. Recent work in bioreactors has shown that the fermentation product 2,3-butanediol mediates cross-feeding between some fermenting bacteria and Pseudomonas aeruginosa, and that this mechanism increases bacterial current production. To examine bacterial fermentation in the respiratory tract, breath gas metabolites were measured and several metagenomes were sequenced from CF and non-CF volunteers. 2,3-butanedione was produced in nearly all respiratory tracts. Elevated levels in one patient decreased during antibiotic treatment, and breath concentrations varied between CF patients at the same time point. Some patients had high enough levels of 2,3-butanedione to irreversibly damage lung tissue. Antibiotic therapy likely dictates the activities of 2,3-butanedione-producing microbes, which suggests a need for further study with larger sample size. Sputum microbiomes were dominated by P. aeruginosa, Streptococcus spp. and Rothia mucilaginosa, and revealed the potential for 2,3-butanedione biosynthesis. Genes encoding 2,3-butanedione biosynthesis were disproportionately abundant in Streptococcus spp, whereas genes for consumption of butanedione pathway products were encoded by P. aeruginosa and R. mucilaginosa. We propose a model where low oxygen conditions in CF lung lead to fermentation and a decrease in pH, triggering 2,3-butanedione fermentation to avoid lethal acidification. We hypothesize that this may also increase phenazine production by P. aeruginosa, increasing reactive oxygen species and providing additional electron acceptors to CF microbes.
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Egilman DS, Schilling JH. Bronchiolitis obliterans and consumer exposure to butter-flavored microwave popcorn: a case series. INTERNATIONAL JOURNAL OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH 2013; 18:29-42. [DOI: 10.1179/1077352512z.0000000005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Fazavana J, Bianchini EP, Saller F, Smadja C, Picard V, Taverna M, Borgel D. A chemically-modified inactive antithrombin as a potent antagonist of fondaparinux and heparin anticoagulant activity. J Thromb Haemost 2013; 11:1128-36. [PMID: 23581397 DOI: 10.1111/jth.12249] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Indexed: 11/30/2022]
Abstract
BACKGROUND Heparin and its analogs, mediating their anticoagulant activity through antithrombin (AT) activation, remain largely used for the preventive and curative treatment of thrombosis. The major adverse reaction of these drugs is the bleeding risk associated with overdose. Unfractionnated heparin (UFH) can be efficiently and rapidly neutralized by protamine sulfate, but this reversal partially neutralizes low-molecular-weight heparin (LMWH) and is inefficient in reversing fondaparinux. To secure administration of AT-mediated anticoagulants and counteract bleeding disorders, we previously designed a recombinant inactive AT as an antidote to heparin derivatives. OBJECTIVES To get around the limited production level of recombinant AT, we propose in this study an alternative strategy to produce a chemically modified inactive AT, exhibiting increased heparin affinity, as an antagonist of heparin analogs. METHODS Plasma-derived AT was chemically modified with 2,3 butanedione, a diketone known to specifically react with the arginine side chain. The chemical reaction was conducted in the presence of heparin to preserve basic residues within the heparin binding site from modifications. RESULTS AT treated by butanedione and selected for its high heparin affinity (AT-BD) was indeed modified on reactive Arg393 and thus exhibited decreased anticoagulant activity and increased heparin affinity. AT-BD was able to neutralize anticoagulant activity of heparin derivatives in vitro and in vivo and was devoid of intrinsic anticoagulant activity, as assessed by activated partial thromboplastin time assay. CONCLUSIONS AT-BD appears to be as efficient as protamine to neutralize UFH in vivo but could be more largely used because it also reverses fondaparinux and LMWH.
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Affiliation(s)
- J Fazavana
- Laboratoire d'Hématologie, University Paris-Sud-XI, Châtenay-Malabry Cedex, France
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Zaccone EJ, Thompson JA, Ponnoth DS, Cumpston AM, Goldsmith WT, Jackson MC, Kashon ML, Frazer DG, Hubbs AF, Shimko MJ, Fedan JS. Popcorn flavoring effects on reactivity of rat airways in vivo and in vitro. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2013; 76:669-689. [PMID: 23941636 PMCID: PMC4499850 DOI: 10.1080/15287394.2013.796302] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
"Popcorn workers' lung" is an obstructive pulmonary disease produced by inhalation of volatile artificial butter flavorings. In rats, inhalation of diacetyl, a major component of butter flavoring, and inhalation of a diacetyl substitute, 2,3-pentanedione, produce similar damage to airway epithelium. The effects of diacetyl and 2,3-pentanedione and mixtures of diacetyl, acetic acid, and acetoin, all components of butter flavoring, on pulmonary function and airway reactivity to methacholine (MCh) were investigated. Lung resistance (RL) and dynamic compliance (Cdyn) were negligibly changed 18 h after a 6-h inhalation exposure to diacetyl or 2,3-pentanedione (100-360 ppm). Reactivity to MCh was not markedly changed after diacetyl, but was modestly decreased after 2,3-pentanedione inhalation. Inhaled diacetyl exerted essentially no effect on reactivity to mucosally applied MCh, but 2,3-pentanedione (320 and 360 ppm) increased reactivity to MCh in the isolated, perfused trachea preparation (IPT). In IPT, diacetyl and 2,3-pentanedione (≥3 mM) applied to the serosal and mucosal surfaces of intact and epithelium-denuded tracheas initiated transient contractions followed by relaxations. Inhaled acetoin (150 ppm) exerted no effect on pulmonary function and airway reactivity in vivo; acetic acid (27 ppm) produced hyperreactivity to MCh; and exposure to diacetyl + acetoin + acetic acid (250 + 150 + 27 ppm) led to a diacetyl-like reduction in reactivity. Data suggest that the effects of 2,3-pentanedione on airway reactivity are greater than those of diacetyl, and that flavorings are airway smooth muscle relaxants and constrictors, thus indicating a complex mechanism.
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Affiliation(s)
- Eric J. Zaccone
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, West Virginia, USA
| | - Janet A. Thompson
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Dovenia S. Ponnoth
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Amy M. Cumpston
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - W. Travis Goldsmith
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Mark C. Jackson
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Michael L. Kashon
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - David G. Frazer
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Ann F. Hubbs
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
| | - Michael J. Shimko
- Department of Basic Pharmaceutical Sciences, West Virginia University, Morgantown, West Virginia, USA
| | - Jeffrey S. Fedan
- Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, Morgantown, West Virginia, USA
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Hubbs AF, Cumpston AM, Goldsmith WT, Battelli LA, Kashon ML, Jackson MC, Frazer DG, Fedan JS, Goravanahally MP, Castranova V, Kreiss K, Willard PA, Friend S, Schwegler-Berry D, Fluharty KL, Sriram K. Respiratory and olfactory cytotoxicity of inhaled 2,3-pentanedione in Sprague-Dawley rats. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:829-44. [PMID: 22894831 DOI: 10.1016/j.ajpath.2012.05.021] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 04/20/2012] [Accepted: 05/22/2012] [Indexed: 10/28/2022]
Abstract
Flavorings-related lung disease is a potentially disabling disease of food industry workers associated with exposure to the α-diketone butter flavoring, diacetyl (2,3-butanedione). To investigate the hypothesis that another α-diketone flavoring, 2,3-pentanedione, would cause airway damage, rats that inhaled air, 2,3-pentanedione (112, 241, 318, or 354 ppm), or diacetyl (240 ppm) for 6 hours were sacrificed the following day. Rats inhaling 2,3-pentanedione developed necrotizing rhinitis, tracheitis, and bronchitis comparable to diacetyl-induced injury. To investigate delayed toxicity, additional rats inhaled 318 (range, 317.9-318.9) ppm 2,3-pentanedione for 6 hours and were sacrificed 0 to 2, 12 to 14, or 18 to 20 hours after exposure. Respiratory epithelial injury in the upper nose involved both apoptosis and necrosis, which progressed through 12 to 14 hours after exposure. Olfactory neuroepithelial injury included loss of olfactory neurons that showed reduced expression of the 2,3-pentanedione-metabolizing enzyme, dicarbonyl/L-xylulose reductase, relative to sustentacular cells. Caspase 3 activation occasionally involved olfactory nerve bundles that synapse in the olfactory bulb (OB). An additional group of rats inhaling 270 ppm 2,3-pentanedione for 6 hours 41 minutes showed increased expression of IL-6 and nitric oxide synthase-2 and decreased expression of vascular endothelial growth factor A in the OB, striatum, hippocampus, and cerebellum using real-time PCR. Claudin-1 expression increased in the OB and striatum. We conclude that 2,3-pentanedione is a respiratory hazard that can also alter gene expression in the brain.
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Affiliation(s)
- Ann F Hubbs
- Health Effects Laboratory Division, National Institute for Occupational Safety and Health, Morgantown, West Virginia 26505, USA.
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More SS, Vartak AP, Vince R. The butter flavorant, diacetyl, exacerbates β-amyloid cytotoxicity. Chem Res Toxicol 2012; 25:2083-91. [PMID: 22731744 DOI: 10.1021/tx3001016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Diacetyl (DA), an ubiquitous butter-flavoring agent, was found to influence several aspects of amyloid-β (Aβ) aggregation--one of the two primary pathologies associated with Alzheimer's disease. Thioflavin T fluorescence and circular dichroism spectroscopic measurements revealed that DA accelerates Aβ¹⁻⁴² aggregation into soluble and ultimately insoluble β-pleated sheet structures. DA was found to covalently bind to Arg⁵ of Aβ¹⁻⁴² through proteolytic digestion-mass spectrometric experiments. These biophysical and chemical effects translated into the potentiation of Aβ¹⁻⁴² cytotoxicity by DA toward SH-SY5Y cells in culture. DA easily traversed through a MDR1-MDCK cell monolayer, an in vitro model of the blood-brain barrier. Additionally, DA was found not only to be resistant to but also inhibitory toward glyoxalase I, the primary initiator of detoxification of amyloid-promoting reactive dicarbonyl species that are generated naturally in large amounts by neuronal tissue. In light of the chronic exposure of industry workers to DA, this study raises the troubling possibility of long-term neurological toxicity mediated by DA.
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Affiliation(s)
- Swati S More
- Center for Drug Design, Academic Health Center, University of Minnesota , 308 Harvard Street SE, 8-123A WDH, Minneapolis, Minnesota 55455, USA
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More SS, Raza A, Vince R. The butter flavorant, diacetyl, forms a covalent adduct with 2-deoxyguanosine, uncoils DNA, and leads to cell death. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:3311-3317. [PMID: 22385266 DOI: 10.1021/jf300180e] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Diacetyl (DA), a natural butter flavorant, is a causative agent for the lung disease obliterative bronchiolitis. Mutagenic properties of 1,2-dicarbonyls have previously been empirically linked to their possible interaction with DNA nucleobases. This study for the first time identifies chemically the adduct of DA with 2-deoxyguanosine. Selective reactivity of DA with 5'-TTTGTTTTT-3' over 5'-TTTTTTTTT-3' indicated its propensity to modify specifically the guanosine residue. Treatment of plasmid DNA, pBR322, with DA induced changes in electrophoretic mobility that are typical of ternary structure disruption. Such DNA nucleobase interaction of DA translated into increased apoptosis in DA-treated SH-SY5Y cells in a dose-dependent manner (IC(50) = 0.114 ± 0.0421 mM). The traditional carbonyl scavengers metformin, 2-thiobarbituric acid, and d-penicillamine protected cells from DA toxicity in proportion to their rates of reaction with DA, with d-penicillamine causing a maximal increase in the IC(50) to 5.23 ± 0.0992 mM when co-incubated with DA.
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Affiliation(s)
- Swati S More
- Center for Drug Design, Academic Health Center, University of Minnesota, Minneapolis, Minnesota 55455, USA
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Gloede E, Cichocki JA, Baldino JB, Morris JB. A validated hybrid computational fluid dynamics-physiologically based pharmacokinetic model for respiratory tract vapor absorption in the human and rat and its application to inhalation dosimetry of diacetyl. Toxicol Sci 2011; 123:231-46. [PMID: 21705714 DOI: 10.1093/toxsci/kfr165] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Diacetyl vapor is associated with bronchiolar injury in man but primarily large airway injury in the rat. The goal of this study was to develop a physiologically based pharmacokinetic model for inspired vapor dosimetry and to apply the model to diacetyl. The respiratory tract was modeled as a series of airways: nose, trachea, main bronchi, large bronchi, small bronchi, bronchioles, and alveoli with tissue dimensions obtained from the literature. Airborne vapor was allowed to absorb (or desorb) from tissues based on mass transfer coefficients. Transfer of vapor within tissues was based on molecular diffusivity with direct reaction with tissue substrates and/or metabolism being allowed in each tissue compartment. In vitro studies were performed to provide measures of diacetyl metabolism kinetics and direct reaction rates allowing for the development of a model with no unassigned variables. Respiratory tract uptake of halothane, acetone, ethanol and diacetyl was measured in male F344 rat to obtain data for model validation. The human model was validated against published values for inspired vapor uptake. For both the human and rat models, a close concordance of model estimates with experimental measurements was observed, validating the model. The model estimates that limited amounts of inspired diacetyl penetrate to the bronchioles of the rat (<2%), whereas in the lightly exercising human, 24% penetration to the bronchioles is estimated. Bronchiolar tissue concentrations of diacetyl in the human are estimated to exceed those in the rat by 40-fold. These inhalation dosimetric differences may contribute to the human-rat differences in diacetyl-induced airway injury.
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Affiliation(s)
- Eric Gloede
- Department of Pharmaceutical Sciences, Toxicology Program, University of Connecticut, Storrs, Connecticut 06269-3092, USA
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