1
|
Clapp PW, Pawlak EA, Lackey JT, Keating JE, Reeber SL, Glish GL, Jaspers I. Flavored e-cigarette liquids and cinnamaldehyde impair respiratory innate immune cell function. Am J Physiol Lung Cell Mol Physiol 2017; 313:L278-L292. [PMID: 28495856 PMCID: PMC5582929 DOI: 10.1152/ajplung.00452.2016] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 05/04/2017] [Accepted: 05/04/2016] [Indexed: 11/22/2022] Open
Abstract
Innate immune cells of the respiratory tract are the first line of defense against pathogenic and environmental insults. Failure of these cells to perform their immune functions leaves the host susceptible to infection and may contribute to impaired resolution of inflammation. While combustible tobacco cigarettes have been shown to suppress respiratory immune cell function, the effects of flavored electronic cigarette liquids (e-liquids) and individual flavoring agents on respiratory immune cell responses are unknown. We investigated the effects of seven flavored nicotine-free e-liquids on primary human alveolar macrophages, neutrophils, and natural killer (NK) cells. Cells were challenged with a range of e-liquid dilutions and assayed for their functional responses to pathogenic stimuli. End points included phagocytic capacity (neutrophils and macrophages), neutrophil extracellular trap formation, proinflammatory cytokine production, and cell-mediated cytotoxic response (NK cells). E-liquids were then analyzed via mass spectrometry to identify individual flavoring components. Three cinnamaldehyde-containing e-liquids exhibited dose-dependent broadly immunosuppressive effects. Quantitative mass spectrometry was used to determine concentrations of cinnamaldehyde in each of the three e-liquids, and cells were subsequently challenged with a range of cinnamaldehyde concentrations. Cinnamaldehyde alone recapitulated the impaired function observed with e-liquid exposures, and cinnamaldehyde-induced suppression of macrophage phagocytosis was reversed by addition of the small-molecule reducing agent 1,4-dithiothreitol. We conclude that cinnamaldehyde has the potential to impair respiratory immune cell function, illustrating an immediate need for further toxicological evaluation of chemical flavoring agents to inform regulation governing their use in e-liquid formulations.
Collapse
Affiliation(s)
- Phillip W Clapp
- Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
- Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina; and
| | - Erica A Pawlak
- Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina; and
| | - Justin T Lackey
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - James E Keating
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Steven L Reeber
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Gary L Glish
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina
| | - Ilona Jaspers
- Curriculum in Toxicology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina;
- Center for Environmental Medicine, Asthma, and Lung Biology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina; and
| |
Collapse
|
2
|
Ghosh A, Abdelwahab SH, Reeber SL, Reidel B, Marklew AJ, Garrison AJ, Lee S, Dang H, Herring AH, Glish GL, Kesimer M, Tarran R. Little Cigars are More Toxic than Cigarettes and Uniquely Change the Airway Gene and Protein Expression. Sci Rep 2017; 7:46239. [PMID: 28447619 PMCID: PMC5406835 DOI: 10.1038/srep46239] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 03/14/2017] [Indexed: 12/02/2022] Open
Abstract
Little cigars (LCs) are regulated differently than cigarettes, allowing them to be potentially targeted at youth/young adults. We exposed human bronchial epithelial cultures (HBECs) to air or whole tobacco smoke from cigarettes vs. LCs. Chronic smoke exposure increased the number of dead cells, lactate dehydrogenase release, and interleukin-8 (IL-8) secretion and decreased apical cilia, cystic fibrosis transmembrane conductance regulator (CFTR) protein levels, and transepithelial resistance. These adverse effects were significantly greater in LC-exposed HBECs than cigarette exposed cultures. LC-exposure also elicited unique gene expression changes and altered the proteomic profiles of airway apical secretions compared to cigarette-exposed HBECs. Gas chromatography-mass spectrometry (GC-MS) analysis indicated that LCs produced more chemicals than cigarettes, suggesting that the increased chemical load of LCs may be the cause of the greater toxicity. This is the first study of the biological effects of LCs on pulmonary epithelia and our observations strongly suggest that LCs pose a more severe danger to human health than cigarettes.
Collapse
Affiliation(s)
- Arunava Ghosh
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Sabri H. Abdelwahab
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Steven L. Reeber
- Department of Chemistry, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Boris Reidel
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Abigail J. Marklew
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Andrew J. Garrison
- Department of Biostatistics, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Shernita Lee
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Hong Dang
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Amy H. Herring
- Department of Biostatistics, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Gary L. Glish
- Department of Chemistry, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Mehmet Kesimer
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, NC, 27599, USA
| | - Robert Tarran
- Marsico Lung Institute, The University of North Carolina at Chapel Hill, NC, 27599, USA
- Department of Cell Biology & Physiology, The University of North Carolina at Chapel Hill, NC, 27599, USA
| |
Collapse
|
3
|
Rowell TR, Reeber SL, Lee SL, Harris RA, Nethery RC, Herring AH, Glish GL, Tarran R. Flavored e-cigarette liquids reduce proliferation and viability in the CALU3 airway epithelial cell line. Am J Physiol Lung Cell Mol Physiol 2017; 313:L52-L66. [PMID: 28428175 DOI: 10.1152/ajplung.00392.2016] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 03/28/2017] [Accepted: 04/14/2017] [Indexed: 01/11/2023] Open
Abstract
E-cigarettes are generally thought of as a safer smoking alternative to traditional cigarettes. However, little is known about the effects of e-cigarette liquids (e-liquids) on the lung. Since over 7,000 unique flavors have been identified for purchase in the United States, our goal was to conduct a screen that would test whether different flavored e-liquids exhibited different toxicant profiles. We tested the effects of 13 different flavored e-liquids [with nicotine and propylene glycol/vegetable glycerin (PG/VG) serving as controls] on a lung epithelial cell line (CALU3). Using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay as an indicator of cell proliferation/viability, we demonstrated a dose-dependent decrease of MTT metabolism by all flavors tested. However, a group of four flavors consistently showed significantly greater toxicity compared with the PG/VG control, indicating the potential for some flavors to elicit more harmful effects than others. We also tested the aerosolized "vapor" from select e-liquids on cells and found similar dose-dependent trends, suggesting that direct e-liquid exposures are a justifiable first-pass screening approach for determining relative e-liquid toxicity. We then identified individual chemical constituents for all 13 flavors using gas chromatography-mass spectrometry. These data revealed that beyond nicotine and PG/VG, the 13 flavored e-liquids have diverse chemical constituents. Since all of the flavors exhibited some degree of toxicity and a diverse array of chemical constituents with little inhalation toxicity available, we conclude that flavored e-liquids should be extensively tested on a case-by-case basis to determine the potential for toxicity in the lung and elsewhere.
Collapse
Affiliation(s)
- Temperance R Rowell
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, North Carolina.,Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, North Carolina
| | - Steven L Reeber
- Department of Chemistry, The University of North Carolina, Chapel Hill, North Carolina; and
| | - Shernita L Lee
- Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, North Carolina
| | - Rachel A Harris
- Department of Chemistry, The University of North Carolina, Chapel Hill, North Carolina; and
| | - Rachel C Nethery
- Department of Biostatistics-Gillings School of Global Public Health, The University of North Carolina, Chapel Hill, North Carolina
| | - Amy H Herring
- Department of Biostatistics-Gillings School of Global Public Health, The University of North Carolina, Chapel Hill, North Carolina
| | - Gary L Glish
- Department of Chemistry, The University of North Carolina, Chapel Hill, North Carolina; and
| | - Robert Tarran
- Marsico Lung Institute, The University of North Carolina, Chapel Hill, North Carolina; .,Department of Cell Biology and Physiology, The University of North Carolina, Chapel Hill, North Carolina
| |
Collapse
|
4
|
Spáčil Z, Elliott S, Reeber SL, Gelb MH, Scott CR, Tureček F. Comparative triplex tandem mass spectrometry assays of lysosomal enzyme activities in dried blood spots using fast liquid chromatography: application to newborn screening of Pompe, Fabry, and Hurler diseases. Anal Chem 2011; 83:4822-8. [PMID: 21548611 DOI: 10.1021/ac200417u] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a comparative study of triplex tandem mass spectrometry (MS/MS) based assays of lysosomal enzymes in dried blood spots for the early detection of Pompe, Fabry, and Hurler diseases in newborns. Four methods have been evaluated that differed in sample handling and the equipment used. A newly developed method uses assay quenching with acetonitrile to precipitate blood proteins followed by analysis on an LC-electrospray/MS/MS system capable of multiple consecutive sample injections on two parallel chromatographic columns. This method requires 1.5 min per a triplex analysis of enzyme products and internal standards, which matches the throughput of the previously reported flow injection method. LC separation reduces matrix effects and allows for more facile sample workup. The new LC-based method showed figures of merit that were superior to those of the currently used method based on liquid-liquid extraction into ethyl acetate and flow injection into the mass spectrometer. The other methods we investigated for comprehensive comparison involved liquid-liquid extraction into ethyl acetate followed by LC-ESI-MS/MS and acetonitrile quenching followed by direct flow injection. Both methods using acetonitrile quenching were found to be robust and provide good quality data while requiring fewer liquid transfer steps and less disposable material and labor than did the extraction methods. The individual merits of the new methods are discussed to present an evaluated alternative approach to high-throughput analysis in newborn screening laboratories.
Collapse
Affiliation(s)
- Zdeněk Spáčil
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | | | | | | | | | | |
Collapse
|