1
|
Brown S, Evans SJ, Burgum MJ, Meldrum K, Herridge J, Akinbola B, Harris LG, Jenkins R, Doak SH, Clift MJD, Wilkinson TS. An In Vitro Model to Assess Early Immune Markers Following Co-Exposure of Epithelial Cells to Carbon Black (Nano)Particles in the Presence of S. aureus: A Role for Stressed Cells in Toxicological Testing. Biomedicines 2024; 12:128. [PMID: 38255233 PMCID: PMC10813740 DOI: 10.3390/biomedicines12010128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/21/2023] [Accepted: 12/25/2023] [Indexed: 01/24/2024] Open
Abstract
The exposure of human lung and skin to carbon black (CB) is continuous due to its widespread applications. Current toxicological testing uses 'healthy' cellular systems; however, questions remain whether this mimics the everyday stresses that human cells are exposed to, including infection. Staphylococcus aureus lung and skin infections remain prevalent in society, and include pneumonia and atopic dermatitis, respectively, but current in vitro toxicological testing does not consider infection stress. Therefore, investigating the effects of CB co-exposure in 'stressed' infected epithelial cells in vitro may better approximate true toxicity. This work aims to study the impact of CB exposure during Staphylococcus aureus infection stress in A549 (lung) and HaCaT (skin) epithelial cells. Physicochemical characterisation of CB confirmed its dramatic polydispersity and potential to aggregate. CB significantly inhibited S. aureus growth in cell culture media. CB did not induce cytokines or antimicrobial peptides from lung and skin epithelial cells, when given alone, but did reduce HaCaT and A549 cell viability to 55% and 77%, respectively. In contrast, S. aureus induced a robust interleukin (IL)-8 response in both lung and skin epithelial cells. IL-6 and human beta defensin (hβD)-2 could only be detected when cells were stimulated with S. aureus with no decreases in cell viability. However, co-exposure to CB (100 µg/mL) and S. aureus resulted in significant inhibition of IL-8 (compared to S. aureus alone) without further reduction in cell viability. Furthermore, the same co-exposure induced significantly more hβD-2 (compared to S. aureus alone). This work confirms that toxicological testing in healthy versus stressed cells gives significantly different responses. This has significant implications for toxicological testing and suggests that cell stresses (including infection) should be included in current models to better represent the diversity of cell viabilities found in lung and skin within a general population. This model will have significant application when estimating CB exposure in at-risk groups, such as factory workers, the elderly, and the immunocompromised.
Collapse
Affiliation(s)
- Scott Brown
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Stephen J. Evans
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Michael J. Burgum
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Kirsty Meldrum
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Jack Herridge
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Blessing Akinbola
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Llinos G. Harris
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Rowena Jenkins
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| | - Shareen H. Doak
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Martin J. D. Clift
- In Vitro Toxicology Group, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK (M.J.D.C.)
| | - Thomas S. Wilkinson
- Microbiology and Infectious Disease, Institute of Life Science, Swansea University Medical School (SUMS), Swansea SA2 8PP, UK
| |
Collapse
|
2
|
New Approach Methods to Evaluate Health Risks of Air Pollutants: Critical Design Considerations for In Vitro Exposure Testing. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17062124. [PMID: 32210027 PMCID: PMC7143849 DOI: 10.3390/ijerph17062124] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/11/2020] [Accepted: 03/19/2020] [Indexed: 12/20/2022]
Abstract
Air pollution consists of highly variable and complex mixtures recognized as major contributors to morbidity and mortality worldwide. The vast number of chemicals, coupled with limitations surrounding epidemiological and animal studies, has necessitated the development of new approach methods (NAMs) to evaluate air pollution toxicity. These alternative approaches include in vitro (cell-based) models, wherein toxicity of test atmospheres can be evaluated with increased efficiency compared to in vivo studies. In vitro exposure systems have recently been developed with the goal of evaluating air pollutant-induced toxicity; though the specific design parameters implemented in these NAMs-based studies remain in flux. This review aims to outline important design parameters to consider when using in vitro methods to evaluate air pollutant toxicity, with the goal of providing increased accuracy, reproducibility, and effectiveness when incorporating in vitro data into human health evaluations. This review is unique in that experimental considerations and lessons learned are provided, as gathered from first-hand experience developing and testing in vitro models coupled to exposure systems. Reviewed design aspects include cell models, cell exposure conditions, exposure chambers, and toxicity endpoints. Strategies are also discussed to incorporate in vitro findings into the context of in vivo toxicity and overall risk assessment.
Collapse
|
3
|
Da Silva E, Kembouche Y, Tegner U, Baun A, Jensen KA. Interaction of biologically relevant proteins with ZnO nanomaterials: A confounding factor for in vitro toxicity endpoints. Toxicol In Vitro 2019; 56:41-51. [PMID: 30611880 DOI: 10.1016/j.tiv.2018.12.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 11/15/2022]
Abstract
The results of in vitro toxicological studies for manufactured nanomaterials (MNs) are often contradictory and not reproducible. Interference of the MNs with assays has been suggested. However, understanding for which materials and how these artefacts occur remains a major challenge. This study investigated interactions between two well-characterized ZnO MNs (NM-110 and NM-111) and lactate dehydrogenase (LDH), and two interleukins (IL-6 and IL-8). Particles (10 to 640 μg/mL) and proteins were incubated for up to 24 h in routine in vitro assays test conditions. LDH activity (ODLDH), but not interleukins concentrations, decreased sharply in a dose-dependent manner within an hour after exposure (ODLDH < 60% of ODref for both MNs at 10 μg/mL). A Freundlich adsorption isotherm was successfully applied, indicating multilayer adsorption of LDH. ZnO MNs and LDH had neutral to slightly negative surface charges in dispersion, precluding electrostatic attachment. Particle sedimentation was not a limiting factor. Fast dissolution of ZnO MNs was shown and Zn2+ could play a role in the ODLDH drop. To summarize, ZnO MNs quickly reduced ODLDH due to concentration-dependent adsorption and LDH inhibition by interaction with dissolved Zn. The control of particle interference in toxicological in vitro assays should become mandatory to avoid misleading interpretation of results.
Collapse
Affiliation(s)
- Emilie Da Silva
- The National Research Center for the Working Environment, Lersø Parkallé 105, Copenhagen, Denmark; Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet 115, Kgs. Lyngby, Denmark.
| | - Yahia Kembouche
- The National Research Center for the Working Environment, Lersø Parkallé 105, Copenhagen, Denmark.
| | - Ulla Tegner
- The National Research Center for the Working Environment, Lersø Parkallé 105, Copenhagen, Denmark.
| | - Anders Baun
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet 115, Kgs. Lyngby, Denmark.
| | - Keld A Jensen
- The National Research Center for the Working Environment, Lersø Parkallé 105, Copenhagen, Denmark.
| |
Collapse
|
4
|
Moretti S, Smets W, Hofman J, Mubiana KV, Oerlemans E, Vandenheuvel D, Samson R, Blust R, Lebeer S. Human inflammatory response of endotoxin affected by particulate matter-bound transition metals. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 244:118-126. [PMID: 30326385 DOI: 10.1016/j.envpol.2018.09.148] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/11/2018] [Accepted: 09/29/2018] [Indexed: 06/08/2023]
Abstract
Bacterial endotoxins are a component of particulate matter (PM) with anticipated health implications, yet we know little about how host reception of endotoxin through toll-like receptor 4 (TLR4) is affected by its association with other PM components. Subsequently, we investigated the relationship between endotoxin concentration (recombinant Factor C (rFC) assay) and host recognition (HEK Blue-TLR4 NF-kB reporter cell line based assay) in various compositions of urban PM, including road traffic, industrial and urban green land use classes. While the assays did not correlate strongly between each other, the TLR4 reporter cell line was found to be better correlated to the IL-8 response of PM. Furthermore, the ability of the quantified endotoxin (rFC assay) to stimulate the TLR4/MD-2 complex was significantly affected by the urban land use class, where traffic locations were found to be significantly higher in bioactive endotoxin than the industrial and green locations. We subsequently turned our attention to PM composition and characterized the samples based on transition metal content (through ICP-MS). The effect of nickel and cobalt - previously reported to activate the hTLR4/MD-2 complex - was found to be negligible in comparison to that of iron. Here, the addition of iron as a factor significantly improved the regression model between the two endotoxin assays, explaining 77% of the variation of the TLR4 stimulation and excluding the significant effect of land use class. Moreover, the effect of iron proved to be more than a correlation, since dosing LPS with Fe2+ led to an increase up to 64% in TLR4 stimulation, while Fe2+ without LPS was unable to stimulate a response. This study shows that endotoxin quantification assays (such as the rFC assay) may not always correspond to human biological recognition of endotoxin in urban PM, while its toxicity can be synergistically influenced by the associated PM composition.
Collapse
Affiliation(s)
- Serena Moretti
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Wenke Smets
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Jelle Hofman
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Kayawe Valentine Mubiana
- Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Eline Oerlemans
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Dieter Vandenheuvel
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Roeland Samson
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Ronny Blust
- Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Sarah Lebeer
- Environmental Ecology and Applied Microbiology (ENdEMIC), Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium.
| |
Collapse
|
5
|
Herseth JI, Volden V, Bolling AK. Particulate matter-mediated release of long pentraxin 3 (PTX3) and vascular endothelial growth factor (VEGF) in vitro: Limited importance of endotoxin and organic content. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2017; 80:105-119. [PMID: 28071984 DOI: 10.1080/15287394.2016.1257399] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 11/02/2016] [Indexed: 06/06/2023]
Abstract
Exposure to particulate matter (PM) is associated with adverse health effects, but it is still relatively unknown which role PM sources and physicochemical properties play in the observed effects. It was postulated that PM in vitro induces release of long pentraxin 3 (PTX3) and vascular endothelial growth factor (VEGF) and that endotoxin and organic compounds present in the PM regulate this release. A contact coculture of THP-1 human leukemia monocytes and A549 human adenocarcinoma alveolar pneumocytes was exposed to PM from Traffic, Wood, Diesel, and Quartz (10-40 µg/cm2) for 12-64 h to determine release of PTX3 and VEGF. The role of endotoxin and the organic fraction in the mediator release was assessed using polymyxin B sulfate and organic extracts, respectively. Finally, antagonists were used to investigate whether the early proinflammatory cytokines interleukin (IL)-1 and tumor necrosis factor (TNF)-α affected the PTX3 and VEGF release. All PM samples induced a time-dependent release of both PTX3 and VEGF. Traffic mediated the greatest release of PTX3, whereas Wood and Diesel were more potent inducers of VEGF. The endotoxin content did not markedly affect release of either mediator, while the organic fraction exerted no significant effect on VEGF release and limited influence on PTX3 release. In addition, the IL-1 and TNF-α agonists affected PTX3 release more strongly than VEGF release. In conclusion, the current data show a limited impact of endotoxin and organic compounds on PTX3 and VEGF release. Further, the observed differences in response patterns may point toward differential regulation of PM-mediated release of PTX3 and VEGF.
Collapse
Affiliation(s)
- J I Herseth
- a Faculty of Health Sciences , Oslo and Akershus University College of Applied Sciences , Oslo , Norway
| | - V Volden
- a Faculty of Health Sciences , Oslo and Akershus University College of Applied Sciences , Oslo , Norway
| | - A K Bolling
- b Department of Air Pollution and Noise , Norwegian Institute of Public Health , Oslo , Norway
| |
Collapse
|
6
|
Zarcone MC, Duistermaat E, van Schadewijk A, Jedynska A, Hiemstra PS, Kooter IM. Cellular response of mucociliary differentiated primary bronchial epithelial cells to diesel exhaust. Am J Physiol Lung Cell Mol Physiol 2016; 311:L111-23. [PMID: 27190060 DOI: 10.1152/ajplung.00064.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 05/17/2016] [Indexed: 12/22/2022] Open
Abstract
Diesel emissions are the main source of air pollution in urban areas, and diesel exposure is linked with substantial adverse health effects. In vitro diesel exposure models are considered a suitable tool for understanding these effects. Here we aimed to use a controlled in vitro exposure system to whole diesel exhaust to study the effect of whole diesel exhaust concentration and exposure duration on mucociliary differentiated human primary bronchial epithelial cells (PBEC). PBEC cultured at the air-liquid interface were exposed for 60 to 375 min to three different dilutions of diesel exhaust (DE). The DE mixture was generated by an engine at 47% load, and characterized for particulate matter size and distribution and chemical and gas composition. Cytotoxicity and epithelial barrier function was assessed, as well as mRNA expression and protein release analysis. DE caused a significant dose-dependent increase in expression of oxidative stress markers (HMOX1 and NQO1; n = 4) at 6 h after 150 min exposure. Furthermore, DE significantly increased the expression of the markers of the integrated stress response CHOP and GADD34 and of the proinflammatory chemokine CXCL8, as well as release of CXCL8 protein. Cytotoxic effects or effects on epithelial barrier function were observed only after prolonged exposures to the highest DE dose. These results demonstrate the suitability of our model and that exposure dose and duration and time of analysis postexposure are main determinants for the effects of DE on differentiated primary human airway epithelial cells.
Collapse
Affiliation(s)
- Maria C Zarcone
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands;
| | - Evert Duistermaat
- Netherlands Organization for Applied Scientific Research, Zeist, The Netherlands; and
| | | | - Aleksandra Jedynska
- Netherlands Organization for Applied Scientific Research Utrecht, The Netherlands
| | - Pieter S Hiemstra
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
| | - Ingeborg M Kooter
- Netherlands Organization for Applied Scientific Research Utrecht, The Netherlands
| |
Collapse
|
7
|
Kendall M, Hodges NJ, Whitwell H, Tyrrell J, Cangul H. Nanoparticle growth and surface chemistry changes in cell-conditioned culture medium. Philos Trans R Soc Lond B Biol Sci 2015; 370:20140100. [PMID: 25533102 DOI: 10.1098/rstb.2014.0100] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
When biomolecules attach to engineered nanoparticle (ENP) surfaces, they confer the particles with a new biological identity. Physical format may also radically alter, changing ENP stability and agglomeration state within seconds. In order to measure which biomolecules are associated with early ENP growth, we studied ENPs in conditioned medium from A549 cell culture, using dynamic light scattering (DLS) and linear trap quadrupole electron transfer dissociation mass spectrometry. Two types of 100 nm polystyrene particles (one uncoated and one with an amine functionalized surface) were used to measure the influence of surface type. In identically prepared conditioned medium, agglomeration was visible in all samples after 1 h, but was variable, indicating inter-sample variability in secretion rates and extracellular medium conditions. In samples conditioned for 1 h or more, ENP agglomeration rates varied significantly. Agglomerate size measured by DLS was well correlated with surface sequestered peptide number for uncoated but not for amine coated polystyrene ENPs. Amine-coated ENPs grew much faster and into larger agglomerates associated with fewer sequestered peptides, but including significant sequestered lactose dehydrogenase. We conclude that interference with extracellular peptide balance and oxidoreductase activity via sequestration is worthy of further study, as increased oxidative stress via this new mechanism may be important for cell toxicity.
Collapse
Affiliation(s)
- Michaela Kendall
- School of Metallurgy and Materials, University of Birmingham, Birmingham B15 2TT, UK Child Health, Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Nikolas J Hodges
- School of Biosciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Harry Whitwell
- Child Health, Human Development and Health, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
| | - Jess Tyrrell
- European Centre of Environment and Human Health, University of Exeter Medical School, Truro, Cornwall, UK
| | - Hakan Cangul
- Centre for Rare Diseases and Personalised Medicine, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, UK
| |
Collapse
|
8
|
Development of an in vitro cytotoxicity model for aerosol exposure using 3D reconstructed human airway tissue; application for assessment of e-cigarette aerosol. Toxicol In Vitro 2015; 29:1952-62. [DOI: 10.1016/j.tiv.2015.05.018] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 04/07/2015] [Accepted: 05/23/2015] [Indexed: 11/18/2022]
|
9
|
Bach N, Bølling AK, Brinchmann BC, Totlandsdal AI, Skuland T, Holme JA, Låg M, Schwarze PE, Øvrevik J. Cytokine responses induced by diesel exhaust particles are suppressed by PAR-2 silencing and antioxidant treatment, and driven by polar and non-polar soluble constituents. Toxicol Lett 2015; 238:72-82. [PMID: 26160521 DOI: 10.1016/j.toxlet.2015.07.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 12/14/2022]
Abstract
Adsorbed soluble organics seem to be the main drivers of inflammatory responses induced by diesel exhaust particles (DEP). The specific compounds contributing to this process and the cellular mechanisms behind DEP-induced inflammation are not well known. We have assessed pro-inflammatory effects of DEP and various soluble DEP fractions, in human bronchial epithelial cells (BEAS-2B). DEP increased the expression of interleukin (IL)-6 and CXCL8. Silencing of the aryl hydrocarbon receptor (AhR) by siRNA or pretreatment with AhR-antagonists did not attenuate DEP-induced IL-6 and CXCL8 responses. However, the halogenated aromatic hydrocarbon (HAH)-selective AhR antagonist CH223191 caused a considerable reduction in DEP-induced CYP1A1 expression indicating that this response may be due to dioxin or dioxin-like constituents in DEP. Knock-down of protease activated receptor (PAR)-2 attenuated IL-6 responses without affecting CXCL8. Antioxidants did not affect IL-6 expression after 4h DEP-exposure and only partly reduced CXCL8 expression. However, after 24h exposure antioxidant treatment partly suppressed IL-6 protein release and completely blocked CXCL8 release. Furthermore, a heptane-soluble (non-polar) extract of DEP induced both IL-6 and CXCL8 release, whereas a PBS-soluble (highly polar) extract induced only IL-6. Thus, pro-inflammatory responses in DEP-exposed epithelial cells appear to be the result of both reactive oxygen species and receptor signaling, mediated through combinatorial effects between both non-polar and polar constituents adhered to the particle surface.
Collapse
Affiliation(s)
- Nicolai Bach
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway; Department of Biology, Faculty of Mathematics and Natural Sciences, University of Oslo, Norway
| | - Anette Kocbach Bølling
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Bendik C Brinchmann
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Annike I Totlandsdal
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Tonje Skuland
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Jørn A Holme
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Marit Låg
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Per E Schwarze
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway
| | - Johan Øvrevik
- Department of Air Pollution and Noise, Division of Environmental Medicine, Norwegian Institute of Public Health, Norway.
| |
Collapse
|
10
|
Hawley B, L'Orange C, Olsen DB, Marchese AJ, Volckens J. Oxidative stress and aromatic hydrocarbon response of human bronchial epithelial cells exposed to petro- or biodiesel exhaust treated with a diesel particulate filter. Toxicol Sci 2014; 141:505-14. [PMID: 25061111 PMCID: PMC4833025 DOI: 10.1093/toxsci/kfu147] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/07/2014] [Indexed: 11/14/2022] Open
Abstract
The composition of diesel exhaust has changed over the past decade due to the increased use of alternative fuels, like biodiesel, and to new regulations on diesel engine emissions. Given the changing nature of diesel fuels and diesel exhaust emissions, a need exists to understand the human health implications of switching to "cleaner" diesel engines run with particulate filters and engines run on alternative fuels like biodiesel. We exposed well-differentiated normal human bronchial epithelial cells to fresh, complete exhaust from a diesel engine run (1) with and without a diesel particulate filter and (2) using either traditional petro- or alternative biodiesel. Despite the lowered emissions in filter-treated exhaust (a 91-96% reduction in mass), significant increases in transcripts associated with oxidative stress and polycyclic aromatic hydrocarbon response were observed in all exposure groups and were not significantly different between exposure groups. Our results suggest that biodiesel and filter-treated diesel exhaust elicits as great, or greater a cellular response as unfiltered, traditional petrodiesel exhaust in a representative model of the bronchial epithelium.
Collapse
Affiliation(s)
- Brie Hawley
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523
| | - Christian L'Orange
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523
| | - Dan B Olsen
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523
| | - Anthony J Marchese
- Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523
| | - John Volckens
- Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, Colorado 80523 Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523
| |
Collapse
|
11
|
Time course of bronchial cell inflammation following exposure to diesel particulate matter using a modified EAVES. Toxicol In Vitro 2014; 28:829-37. [DOI: 10.1016/j.tiv.2014.03.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 02/26/2014] [Accepted: 03/01/2014] [Indexed: 11/22/2022]
|
12
|
Zavala J, Lichtveld K, Ebersviller S, Carson JL, Walters GW, Jaspers I, Jeffries HE, Sexton KG, Vizuete W. The Gillings Sampler--an electrostatic air sampler as an alternative method for aerosol in vitro exposure studies. Chem Biol Interact 2014; 220:158-68. [PMID: 25010910 DOI: 10.1016/j.cbi.2014.06.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/23/2014] [Accepted: 06/29/2014] [Indexed: 11/17/2022]
Abstract
There is growing interest in studying the toxicity and health risk of exposure to multi-pollutant mixtures found in ambient air, and the U.S. Environmental Protection Agency (EPA) is moving towards setting standards for these types of mixtures. Additionally, the Health Effects Institute's strategic plan aims to develop and apply next-generation multi-pollutant approaches to understanding the health effects of air pollutants. There's increasing concern that conventional in vitro exposure methods are not adequate to meet EPA's strategic plan to demonstrate a direct link between air pollution and health effects. To meet the demand for new in vitro technology that better represents direct air-to-cell inhalation exposures, a new system that exposes cells at the air-liquid interface was developed. This new system, named the Gillings Sampler, is a modified two-stage electrostatic precipitator that provides a viable environment for cultured cells. Polystyrene latex spheres were used to determine deposition efficiencies (38-45%), while microscopy and imaging techniques were used to confirm uniform particle deposition. Negative control A549 cell exposures indicated the sampler can be operated for up to 4h without inducing any significant toxic effects on cells, as measured by lactate dehydrogenase (LDH) and interleukin-8 (IL-8). A novel positive aerosol control exposure method, consisting of a p-tolualdehyde (TOLALD) impregnated mineral oil aerosol (MOA), was developed to test this system. Exposures to the toxic MOA at a 1 ng/cm(2) dose of TOLALD yielded a reproducible 1.4 and 2-fold increase in LDH and IL-8 mRNA levels over controls. This new system is intended to be used as an alternative research tool for aerosol in vitro exposure studies. While further testing and optimization is still required to produce a "commercially ready" system, it serves as a stepping-stone in the development of cost-effective in vitro technology that can be made accessible to researchers in the near future.
Collapse
Affiliation(s)
- Jose Zavala
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States
| | - Kim Lichtveld
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States
| | - Seth Ebersviller
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States
| | - Johnny L Carson
- Department of Pediatrics, University of North Carolina at Chapel Hill, United States; Center for Environmental Medicine and Lung Biology, University of North Carolina at Chapel Hill, United States
| | - Glenn W Walters
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States
| | - Ilona Jaspers
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States; Department of Pediatrics, University of North Carolina at Chapel Hill, United States; Center for Environmental Medicine and Lung Biology, University of North Carolina at Chapel Hill, United States
| | - Harvey E Jeffries
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States
| | - Kenneth G Sexton
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States
| | - William Vizuete
- Department of Environmental Sciences & Engineering, University of North Carolina at Chapel Hill, United States.
| |
Collapse
|
13
|
Sarkar S, Zhang L, Subramaniam P, Lee KB, Garfunkel E, Strickland PAO, Mainelis G, Lioy PJ, Tetley TD, Chung KF, Zhang J, Ryan M, Porter A, Schwander S. Variability in bioreactivity linked to changes in size and zeta potential of diesel exhaust particles in human immune cells. PLoS One 2014; 9:e97304. [PMID: 24825358 PMCID: PMC4019517 DOI: 10.1371/journal.pone.0097304] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 04/17/2014] [Indexed: 01/11/2023] Open
Abstract
Acting as fuel combustion catalysts to increase fuel economy, cerium dioxide (ceria, CeO2) nanoparticles have been used in Europe as diesel fuel additives (Envirox™). We attempted to examine the effects of particles emitted from a diesel engine burning either diesel (diesel exhaust particles, DEP) or diesel doped with various concentrations of CeO2 (DEP-Env) on innate immune responses in THP-1 and primary human peripheral blood mononuclear cells (PBMC). Batches of DEP and DEP-Env were obtained on three separate occasions using identical collection and extraction protocols with the aim of determining the reproducibility of particles generated at different times. However, we observed significant differences in size and surface charge (zeta potential) of the DEP and DEP-Env across the three batches. We also observed that exposure of THP-1 cells and PBMC to identical concentrations of DEP and DEP-Env from the three batches resulted in statistically significant differences in bioreactivity as determined by IL-1β, TNF-α, IL-6, IFN-γ, and IL-12p40 mRNA (by qRT-PCR) and protein expression (by ELISPOT assays). Importantly, bioreactivity was noted in very tight ranges of DEP size (60 to 120 nm) and zeta potential (-37 to -41 mV). Thus, these physical properties of DEP and DEP-Env were found to be the primary determinants of the bioreactivity measured in this study. Our findings also point to the potential risk of over- or under- estimation of expected bioreactivity effects (and by inference of public health risks) from bulk DEP use without taking into account potential batch-to-batch variations in physical (and possibly chemical) properties.
Collapse
Affiliation(s)
- Srijata Sarkar
- Rutgers School of Public Health, Department of Environmental and Occupational Health, Piscataway New Jersey, United States of America
| | - Lin Zhang
- Rutgers School of Public Health, Department of Environmental and Occupational Health, Piscataway New Jersey, United States of America
| | - Prasad Subramaniam
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, United States of America
| | - Ki-Bum Lee
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, United States of America
| | - Eric Garfunkel
- Department of Chemistry and Chemical Biology, Rutgers University, Piscataway, New Jersey, United States of America
| | - Pamela A. Ohman. Strickland
- Rutgers School of Public Health, Department of Biostatistics, Piscataway, New Jersey, United States of America
| | - Gediminas Mainelis
- Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey, United States of America
- Environmental and Occupational Health Sciences Institute Rutgers University, Piscataway, New Jersey, United States of America
| | - Paul J. Lioy
- Environmental and Occupational Health Sciences Institute Rutgers University, Piscataway, New Jersey, United States of America
- Robert Wood Johnson Medical School, Rutgers University, Piscataway, New Jersey, United States of America
| | - Teresa D. Tetley
- National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Kian Fan Chung
- National Heart and Lung Institute, Imperial College, London, United Kingdom
| | - Junfeng Zhang
- Nicholas School of the Environment and Duke Global Health Institute, Duke University, Durham, North Carolina, United States of America
| | - Mary Ryan
- Department of Materials and London Center for Nanotechnology, Imperial College, London, United Kingdom
| | - Alex Porter
- Department of Materials and London Center for Nanotechnology, Imperial College, London, United Kingdom
| | - Stephan Schwander
- Rutgers School of Public Health, Department of Environmental and Occupational Health, Piscataway New Jersey, United States of America
- Environmental and Occupational Health Sciences Institute Rutgers University, Piscataway, New Jersey, United States of America
- Rutgers School of Public Health, Center for Global Public Health, Piscataway, New Jersey, United States of America
- * E-mail:
| |
Collapse
|
14
|
Kooter IM, Alblas MJ, Jedynska AD, Steenhof M, Houtzager MM, Ras MV. Alveolar epithelial cells (A549) exposed at the air–liquid interface to diesel exhaust: First study in TNO’s powertrain test center. Toxicol In Vitro 2013; 27:2342-9. [DOI: 10.1016/j.tiv.2013.10.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 09/10/2013] [Accepted: 10/11/2013] [Indexed: 01/31/2023]
|
15
|
The challenge of obtaining correct data for cellular release of inflammatory mediators after in vitro exposure to particulate matter. Toxicol Lett 2013; 221:110-7. [DOI: 10.1016/j.toxlet.2013.06.209] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 05/31/2013] [Accepted: 06/04/2013] [Indexed: 01/18/2023]
|
16
|
Hawley B, Volckens J. Proinflammatory effects of cookstove emissions on human bronchial epithelial cells. INDOOR AIR 2013; 23:4-13. [PMID: 22672519 PMCID: PMC3449229 DOI: 10.1111/j.1600-0668.2012.00790.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
UNLABELLED Approximately half of the world's population uses biomass fuel for indoor cooking and heating. This form of combustion typically occurs in open fires or primitive stoves. Human exposure to emissions from indoor biomass combustion is a global health concern, causing an estimated 1.5 million premature deaths each year. Many 'improved' stoves have been developed to address this concern; however, studies that examine exposure-response with cleaner-burning, more efficient stoves are few. The objective of this research was to evaluate the effects of traditional and cleaner-burning stove emissions on an established model of the bronchial epithelium. We exposed well-differentiated, normal human bronchial epithelial cells to emissions from a single biomass combustion event using either a traditional three-stone fire or one of two energy-efficient stoves. Air-liquid interface cultures were exposed using a novel, aerosol-to-cell deposition system. Cellular expression of a panel of three pro-inflammatory markers was evaluated at 1 and 24 h following exposure. Cells exposed to emissions from the cleaner-burning stoves generated significantly fewer amounts of pro-inflammatory markers than cells exposed to emissions from a traditional three-stone fire. Particulate matter emissions from each cookstove were substantially different, with the three-stone fire producing the largest concentrations of particles (by both number and mass). This study supports emerging evidence that more efficient cookstoves have the potential to reduce respiratory inflammation in settings where solid fuel combustion is used to meet basic domestic needs. PRACTICAL IMPLICATIONS Emissions from more efficient, cleaner-burning cookstoves produced less inflammation in well-differentiated bronchial lung cells. The results support evidence that more efficient cookstoves can reduce the health burden associated with exposure to indoor pollution from the combustion of biomass.
Collapse
Affiliation(s)
- Brie Hawley
- Department of Environmental and Radiological Health Sciences, 1681 Campus Delivery, Colorado State University, Fort Collins, CO, USA 80523
| | - John Volckens
- Department of Environmental and Radiological Health Sciences, 1681 Campus Delivery, Colorado State University, Fort Collins, CO, USA 80523
| |
Collapse
|
17
|
Yang JY, Kim JY, Jang JY, Lee GW, Kim SH, Shin DC, Lim YW. Exposure and toxicity assessment of ultrafine particles from nearby traffic in urban air in seoul, Korea. ENVIRONMENTAL HEALTH AND TOXICOLOGY 2013; 28:e2013007. [PMID: 23882447 PMCID: PMC3717416 DOI: 10.5620/eht.2013.28.e2013007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Accepted: 04/26/2013] [Indexed: 05/05/2023]
Abstract
OBJECTIVES We investigated the particle mass size distribution and chemical properties of air pollution particulate matter (PM) in the urban area and its capacity to induce cytotoxicity in human bronchial epithelial (BEAS-2B) cells. METHODS To characterize the mass size distributions and chemical concentrations associated with urban PM, PM samples were collected by a 10-stage Micro-Orifice Uniform Deposit Impactor close to nearby traffic in an urban area from December 2007 to December 2009. PM samples for in vitro cytotoxicity testing were collected by a mini-volume air sampler with PM10 and PM2.5 inlets. RESULTS The PM size distributions were bi-modal, peaking at 0.18 to 0.32 and 1.8 to 3.2 µm. The mass concentrations of the metals in fine particles (0.1 to 1.8 µm) accounted for 45.6 to 80.4% of the mass concentrations of metals in PM10. The mass proportions of fine particles of the pollutants related to traffic emission, lead (80.4%), cadmium (69.0%), and chromium (63.8%) were higher than those of other metals. Iron was the dominant transition metal in the particles, accounting for 64.3% of the PM10 mass in all the samples. We observed PM concentration-dependent cytotoxic effects on BEAS-2B cells. CONCLUSIONS We found that exposure to PM2.5 and PM10 from a nearby traffic area induced significant increases in protein expression of inflammatory cytokines (IL-6 and IL-8). The cell death rate and release of cytokines in response to the PM2.5 treatment were higher than those with PM10. The combined results support the hypothesis that ultrafine particles from vehicular sources can induce inflammatory responses related to environmental respiratory injury.
Collapse
Affiliation(s)
- Ji-Yeon Yang
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
| | - Jin-Yong Kim
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
| | - Ji-Young Jang
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
| | - Gun-Woo Lee
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
| | - Soo-Hwan Kim
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
| | - Dong-Chun Shin
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
- Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Young-Wook Lim
- Institute for Environmental Research, Yonsei University College of Medicine, Seoul, Korea
| |
Collapse
|
18
|
Patel H, Kwon S. Multi-walled carbon nanotube-induced inflammatory response and oxidative stress in a dynamic cell growth environment. J Biol Eng 2012; 6:22. [PMID: 23148460 PMCID: PMC3552678 DOI: 10.1186/1754-1611-6-22] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Accepted: 11/10/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND Rapid increase in multi-walled carbon nanotube (MWCNT) production for their industrial and biomedical applications has led to concerns over the effects of MWCNTs on human health and the environment. Both animal and in vitro studies have provided important findings about MWCNT-induced effects on the lung cells or tissues. In vitro studies have provided a considerable amount of fundamental information on MWCNT-induced effects on the specific lung cells. However, the cell culture systems used in those studies were limited by the absence of dynamic nature of lung tissues. We hypothesized that MWCNT-induced cellular responses such as proliferation, inflammation, and oxidative stress under dynamic cell growth environment may differ from those under static cell growth environment. RESULTS In this study, we used a dynamic cell growth condition to mimic mechanically dynamic environment of the lung and characterized interleukin 8 (IL-8), reactive oxygen species (ROS), glutathione (GSH), and cell proliferation for three days following exposure of MWCNTs at different concentrations (5, 10, and 20 μg/ml) to A549 cell monolayer under both static and dynamic cell growth conditions. Our results demonstrated the distinct differences in the levels of inflammatory response and oxidative stress between static and dynamic cell growth conditions. CONCLUSIONS In conclusion, the dynamic cell growth system used in this study provided important changes in cellular responses that were not found in the static cell growth system and were similar to animal studies. The dynamic cell growth system can be considered as a viable alternative to in vivo test system in combination with existing in vitro static cell growth systems to evaluate the effect of MWCNTs on cellular responses in the respiratory system.
Collapse
Affiliation(s)
- Hemang Patel
- Department of Biological Engineering, Utah State University, 4105 Old Main Hill, 84322-4105, Logan, UT, USA.
| | | |
Collapse
|
19
|
Chuang HC, Fan CW, Chen KY, Chang-Chien GP, Chan CC. Vasoactive alteration and inflammation induced by polycyclic aromatic hydrocarbons and trace metals of vehicle exhaust particles. Toxicol Lett 2012; 214:131-6. [PMID: 22940192 DOI: 10.1016/j.toxlet.2012.08.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 08/14/2012] [Accepted: 08/14/2012] [Indexed: 12/19/2022]
Abstract
Exposure to particulate matter (PM) increases the incidence of cardiovascular disease, but the underlying mechanisms remain unclear. To characterise ambient PM collected from a coach station in an urban area, particulate polycyclic aromatic hydrocarbons (PAHs) and trace metals were evaluated, and diagnostic ratios were then used to determine the sources based on the PAHs identified in PM. To elucidate the mechanism of PM-induced vascular toxicology, human coronary artery endothelial cells (HCAECs) were exposed to PM, PM-free supernatant and residual PM, and the associations between PAHs and trace metals, nitric oxide (NO), endothelin-1 (ET-1) and interleukin-6 (IL-6) were investigated. Petrogenic-related particulate emissions, such as vehicle exhaust, accounted for 68.75% and 75.00% of mass in the 0.1-1-μm PM (PM(0.1-1)) and <0.1-μm PM (PM(0.1)) size fractions, respectively. Vehicle exhaust particles (VEPs) caused significant NO suppression and increase in ET-1 and IL-6, whereas residual PM caused an increase in NO, ET-1 and IL-6 compared with the effects of the corresponding supernatants. PAHs in PM, particularly those with 4-6 rings, were associated with NO suppression, and ET-1 and IL-6 were positively correlated with the amount of trace metal compounds. These findings suggest that chemical components affect the regulation of vasoactive function and inflammation.
Collapse
Affiliation(s)
- Hsiao-Chi Chuang
- School of Respiratory Therapy, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | | | | | | | | |
Collapse
|
20
|
Holder AL, Goth-Goldstein R, Lucas D, Koshland CP. Particle-induced artifacts in the MTT and LDH viability assays. Chem Res Toxicol 2012; 25:1885-92. [PMID: 22799765 DOI: 10.1021/tx3001708] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In vitro testing is a common first step in assessing combustion-generated and engineered nanoparticle-related health hazards. Commercially available viability assays are frequently used to compare the toxicity of different particle types and to generate dose-response data. Nanoparticles, well-known for having large surface areas and chemically active surfaces, may interfere with viability assays, producing a false assessment of toxicity and making it difficult to compare toxicity data. The objective of this study is to measure the extent of particle interference in two common viability assays, the MTT reduction and the lactate dehydrogenase (LDH) release assays. Diesel particles, activated carbon, flame soot, oxidized flame soot, and titanium dioxide particles are assessed for interactions with the MTT and LDH assay under cell-free conditions. Diesel particles, at concentrations as low as 0.05 μg/mL, reduce MTT. Other particle types reduce MTT only at a concentration of 50 μg/mL and higher. The activated carbon, soot, and oxidized soot particles bind LDH to varying extents, reducing the concentration measured in the LDH assay. The interfering effects of the particles explain in part the different toxicities measured in human bronchial epithelial cells (16HBE14o). We conclude that valid particle toxicity assessments can only be assured after first performing controls to verify that the particles under investigation do not interfere with a specific assay at the expected concentrations.
Collapse
Affiliation(s)
- Amara L Holder
- Division of Environmental Health Sciences, University of California, Berkeley, CA 94720, USA
| | | | | | | |
Collapse
|
21
|
KENDALL MICHAELA, HOLGATE STEPHEN. Health impact and toxicological effects of nanomaterials in the lung. Respirology 2012; 17:743-58. [DOI: 10.1111/j.1440-1843.2012.02171.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
|
22
|
Bauer M, Gräbsch C, Gminski R, Ollmann AIH, Borm P, Dietz A, Herbarth O, Wichmann G. Cement-related particles interact with proinflammatory IL-8 chemokine from human primary oropharyngeal mucosa cells and human epithelial lung cancer cell line A549. ENVIRONMENTAL TOXICOLOGY 2012; 27:297-306. [PMID: 20803486 DOI: 10.1002/tox.20643] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 07/02/2010] [Accepted: 07/14/2010] [Indexed: 05/29/2023]
Abstract
Epidemiological studies have shown that respirable exposure to emitted cement particulate matter is associated with adverse health risk for human. The underlying mechanisms, however, are poorly understood. To examine the effect of cement, nine blinded cement-related particulates (<10 μm) were assessed with regard to their induction of the proinflammatory cytokines IL-6 and IL-8 in human primary epithelial cells (pEC) from oropharyngeal mucosa as well as from nonsmall-cell lung carcinoma (non-SCLC) cells A549. It was demonstrated that the cement specimens did not act cytotoxic as assessed by the lactate dehydrogenase (LDH) assay. The basal and IL-1β-induced IL-8 expression was suppressed, in contrast to an unchanged IL-6. At the transcript level the basal and induced IL-6 and IL-8 gene expression was not influenced by cement dust. To discover the mechanism by which cement influenced the IL-8 expression the following experiments were performed. Submerse exposure experiments have shown that the release of IL-8 was suppressed by cement dust. Furthermore, the incubation of IL-8 with cement-related specimens under cell-free condition led to a loss of immunoreactive IL-8. An immunological masking of IL-8 by free soluble components of respiratory epithelial cells was excluded. Thus, the decrease of IL-8 protein content after cement exposure seems to be a result of the adsorption of IL-8 protein to cement particles and the inhibition of IL-8 release. In conclusion, due to absent cytotoxic and inflammatory effects of cement-related specimens in both human pEC and A549 cell models it remains open how cement exposure may lead to the respiratory adverse effects in humans.
Collapse
Affiliation(s)
- Mario Bauer
- Department of Environmental Immunology, Helmholtz Centre for Environmental Research-UFZ, Permoserstr. 15, 04318 Leipzig, Germany.
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Kroll A, Pillukat MH, Hahn D, Schnekenburger J. Interference of engineered nanoparticles with in vitro toxicity assays. Arch Toxicol 2012; 86:1123-36. [DOI: 10.1007/s00204-012-0837-z] [Citation(s) in RCA: 218] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 03/01/2012] [Indexed: 10/28/2022]
|
24
|
Sarkar S, Song Y, Sarkar S, Kipen HM, Laumbach RJ, Zhang J, Strickland PAO, Gardner CR, Schwander S. Suppression of the NF-κB pathway by diesel exhaust particles impairs human antimycobacterial immunity. THE JOURNAL OF IMMUNOLOGY 2012; 188:2778-93. [PMID: 22345648 DOI: 10.4049/jimmunol.1101380] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Epidemiological studies suggest that chronic exposure to air pollution increases susceptibility to respiratory infections, including tuberculosis in humans. A possible link between particulate air pollutant exposure and antimycobacterial immunity has not been explored in human primary immune cells. We hypothesized that exposure to diesel exhaust particles (DEP), a major component of urban fine particulate matter, suppresses antimycobacterial human immune effector cell functions by modulating TLR-signaling pathways and NF-κB activation. We show that DEP and H37Ra, an avirulent laboratory strain of Mycobacterium tuberculosis, were both taken up by the same peripheral human blood monocytes. To examine the effects of DEP on M. tuberculosis-induced production of cytokines, PBMC were stimulated with DEP and M. tuberculosis or purified protein derivative. The production of M. tuberculosis and purified protein derivative-induced IFN-γ, TNF-α, IL-1β, and IL-6 was reduced in a DEP dose-dependent manner. In contrast, the production of anti-inflammatory IL-10 remained unchanged. Furthermore, DEP stimulation prior to M. tuberculosis infection altered the expression of TLR3, -4, -7, and -10 mRNAs and of a subset of M. tuberculosis-induced host genes including inhibition of expression of many NF-κB (e.g., CSF3, IFNG, IFNA, IFNB, IL1A, IL6, and NFKBIA) and IFN regulatory factor (e.g., IFNG, IFNA1, IFNB1, and CXCL10) pathway target genes. We propose that DEP downregulate M. tuberculosis-induced host gene expression via MyD88-dependent (IL6, IL1A, and PTGS2) as well as MyD88-independent (IFNA, IFNB) pathways. Prestimulation of PBMC with DEP suppressed the expression of proinflammatory mediators upon M. tuberculosis infection, inducing a hyporesponsive cellular state. Therefore, DEP alters crucial components of antimycobacterial host immune responses, providing a possible mechanism by which air pollutants alter antimicrobial immunity.
Collapse
Affiliation(s)
- Srijata Sarkar
- Department of Environmental and Occupational Health, University of Medicine and Dentistry of New Jersey-School of Public Health, Piscataway, NJ 08854, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Ebersviller S, Lichtveld K, Sexton KG, Zavala J, Lin YH, Jaspers I, Jeffries HE. Gaseous VOCs rapidly modify particulate matter and its biological effects - Part 1: Simple VOCs and model PM. ATMOSPHERIC CHEMISTRY AND PHYSICS DISCUSSIONS : ACPD 2012; 12:5065-5105. [PMID: 23457430 PMCID: PMC3583354 DOI: 10.5194/acpd-12-5065-2012] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This is the first of a three-part study designed to demonstrate dynamic entanglements among gaseous organic compounds (VOC), particulate matter (PM), and their subsequent potential biological effects. We study these entanglements in increasingly complex VOC and PM mixtures in urban-like conditions in a large outdoor chamber. To the traditional chemical and physical characterizations of gas and PM, we added new measurements of gas-only- and PM-only-biological effects, using cultured human lung cells as model indicators. These biological effects are assessed here as increases in cellular damage or expressed irritation (i.e., cellular toxic effects) from cells exposed to chamber air relative to cells exposed to clean air. The exposure systems permit gas-only- or PM-only-exposures from the same air stream containing both gases and PM in equilibria, i.e., there are no extractive operations prior to cell exposure.Our simple experiments in this part of the study were designed to eliminate many competing atmospheric processes to reduce ambiguity in our results. Simple volatile and semi-volatile organic gases that have inherent cellular toxic properties were tested individually for biological effect in the dark (at constant humidity). Airborne mixtures were then created with each compound and PM that has no inherent cellular toxic properties for another cellular exposure. Acrolein and p-tolualdehyde were used as model VOCs and mineral oil aerosol (MOA) was selected as a surrogate for organic-containing PM. MOA is appropriately complex in composition to represent ambient PM, and it exhibits no inherent cellular toxic effects and thus did not contribute any biological detrimental effects on its own.Chemical measurements, combined with the responses of our biological exposures, clearly demonstrate that gas-phase pollutants can modify the composition of PM (and its resulting detrimental effects on lung cells) - even if the gas-phase pollutants are not considered likely to partition to the condensed phase: the VOC-modified-PM showed significantly more damage and inflammation to lung cells than did the original PM. Because gases and PM are transported and deposited differently within the atmosphere and the lungs, these results have significant consequences. For example, current US policies for research and regulation of PM do not recognize this "effect modification" phenomena (NAS, 2004).These results present an unambiguous demonstration that - even in these simple mixtures - physical and thermal interactions alone can cause a modification of the distribution of species among the phases of airborne pollution mixtures and can result in a non-toxic phase becoming toxic due to atmospheric thermal processes only. Subsequent work extends the simple results reported here to systems with photochemical transformations of complex urban mixtures and to systems with diesel exhaust produced by different fuels.
Collapse
Affiliation(s)
- S. Ebersviller
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
| | - K. Lichtveld
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
| | - K. G. Sexton
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
| | - J. Zavala
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
| | - Y-H. Lin
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
| | - I. Jaspers
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
- Center for Environmental Medicine and Lung Biology, Human Studies Facility, The University of North Carolina at Chapel Hill, USA
| | - H. E. Jeffries
- Environmental Sciences and Engineering, Gillings School of Global Public Health, The University of North Carolina at Chapel Hill, USA
| |
Collapse
|
26
|
Toxic effects following phosgene exposure of human epithelial lung cells in vitro using a CULTEX® system. Toxicol In Vitro 2011; 25:2080-7. [PMID: 21945045 DOI: 10.1016/j.tiv.2011.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 09/05/2011] [Accepted: 09/06/2011] [Indexed: 11/22/2022]
Abstract
The aim of the present study was to investigate toxic effects following phosgene exposure of human epithelial lung cells (A549) in vitro using a CULTEX® system. In particular, toxic effects regarding early biomarkers emerging during the latency period following exposure might be of great value for medical treatment. Cells cultured on semi-permeable membranes were directly exposed at the liquid-air interface to different concentrations of phosgene, or dry medical air. Cell membrane integrity (leakage of LDH), metabolic activity (reduction of Alamar Blue), oxidative damage (GSH, and HO-1, in cell lysates), and release of IL-8, were studied. For most of the above-mentioned biological end-point markers, significant changes could be assessed following a 20 min exposure to 1.0 ppm and 2.0 ppm phosgene. Moreover, except for IL-8, all biological marker profiles showed to be in line with results obtained by others in animal studies. The C×t value of 40 ppm min appeared to be constant. The overall results suggest that at 4 h post-exposure a maximal level of toxicity was achieved. Our results demonstrate the suitability of a CULTEX® system to detect toxic effects induced by phosgene on human epithelial lung cells, which may contribute to the discovery of early biomarkers for new medical countermeasures.
Collapse
|
27
|
McDonald JD, Campen MJ, Harrod KS, Seagrave J, Seilkop SK, Mauderly JL. Engine-operating load influences diesel exhaust composition and cardiopulmonary and immune responses. ENVIRONMENTAL HEALTH PERSPECTIVES 2011; 119:1136-41. [PMID: 21524982 PMCID: PMC3237353 DOI: 10.1289/ehp.1003101] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 04/25/2011] [Indexed: 05/09/2023]
Abstract
BACKGROUND The composition of diesel engine exhaust (DEE) varies by engine type and condition, fuel, engine operation, and exhaust after treatment such as particle traps. DEE has been shown to increase inflammation, susceptibility to infection, and cardiovascular responses in experimentally exposed rodents and humans. Engines used in these studies have been operated at idle, at different steady-state loads, or on variable-load cycles, but exposures are often reported only as the mass concentration of particulate matter (PM), and the effects of different engine loads and the resulting differences in DEE composition are unknown. OBJECTIVES We assessed the impacts of load-related differences in DEE composition on models of inflammation, susceptibility to infection, and cardiovascular toxicity. METHODS We assessed inflammation and susceptibility to viral infection in C57BL/6 mice and cardiovascular toxicity in APOE-/- mice after being exposed to DEE generated from a single-cylinder diesel generator operated at partial or full load. RESULTS At the same PM mass concentration, partial load resulted in higher proportions of particle organic carbon content and a smaller particle size than did high load. Vapor-phase hydrocarbon content was greater at partial load. Compared with high-load DEE, partial-load DEE caused greater responses in heart rate and T-wave morphology, in terms of both magnitude and rapidity of onset of effects, consistent with previous findings that systemic effects may be driven largely by the gas phase of the exposure atmospheres. However, high-load DEE caused more lung inflammation and greater susceptibility to viral infection than did partial load. CONCLUSIONS Differences in engine load, as well as other operating variables, are important determinants of the type and magnitude of responses to inhaled DEE. PM mass concentration alone is not a sufficient basis for comparing or combining results from studies using DEE generated under different conditions.
Collapse
Affiliation(s)
- Jacob D McDonald
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Cellular response to the deposition of diesel exhaust particle aerosols onto human lung cells grown at the air-liquid interface by inertial impaction. Toxicol In Vitro 2011; 25:1953-65. [PMID: 21756993 DOI: 10.1016/j.tiv.2011.06.019] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2009] [Revised: 06/24/2011] [Accepted: 06/30/2011] [Indexed: 11/20/2022]
Abstract
The pathogenesis of disease resulting from exposure to diesel exhaust particles (DEP) is often studied using cultured lung cells. Frequently, researchers expose cells to DEP by spiking a suspension of particles in liquid onto the apical surface. This is not representative of in vivo exposure, where aerosols are deposited onto cell surfaces at the air-liquid interface (ALI). Inertial impaction provides an opportunity to deliver high doses of particles with aerodynamic diameters>∼1 μm to the surface of cells in seconds in a reproducible and predictable manner. A custom device was constructed to deposit DEP aerosols onto the surface of Calu-3 and A549 cells grown at the ALI. The pro-inflammatory and toxic cellular response to exposure to the deposited DEP aerosols was measured and compared to the response of cells exposed to DEP as suspensions. Calu-3 cells showed evidence of an oxidative stress response for both exposure types, while there was strong evidence to suggest that the method of aerosol delivery was harmful to the A549 cells.
Collapse
|
29
|
Akhtar US, McWhinney RD, Rastogi N, Abbatt JPD, Evans GJ, Scott JA. Cytotoxic and proinflammatory effects of ambient and source-related particulate matter (PM) in relation to the production of reactive oxygen species (ROS) and cytokine adsorption by particles. Inhal Toxicol 2010; 22 Suppl 2:37-47. [DOI: 10.3109/08958378.2010.518377] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
30
|
Patel H, Eo S, Kwon S. Effects of diesel particulate matters on inflammatory responses in static and dynamic culture of human alveolar epithelial cells. Toxicol Lett 2010; 200:124-31. [PMID: 21094226 DOI: 10.1016/j.toxlet.2010.11.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Revised: 11/10/2010] [Accepted: 11/11/2010] [Indexed: 10/18/2022]
Abstract
Diesel particulate matter (DPM) possesses the potential to induce acute and chronic health issues upon occupational and daily exposure. Many recent studies have focused on understanding molecular mechanisms to depict DPM's side effects inside the lung using static in vitro cell culture models. These studies have provided abundant fundamental information on DPM's adverse effects on cellular responses, but these systems were limited by the absence of dynamic nature to access relevant cellular responses and functionality. We hypothesized that the exposure of DPM under dynamic environment may affect the levels of cellular inflammation and reactive oxygen species, which may be different from those under static environments. In this study, we used the dynamic cell growth condition to mimic mechanically dynamic environment similar to the normal breathing in vivo. We also used high (20, 10, and 5 ppm) and low (3, 1, 0.1, and 0.01 ppm) ranges of DPM exposure to mimic different levels of exposure, respectively. Following 24-, 48-, and 72-h exposure of DPM, Interleukin-8 (IL-8), C-reactive protein (CRP), reactive oxygen species (ROS), and total amount of protein were analyzed. Our results demonstrated the distinct differences in the profiles of inflammatory mediators (IL-8, CRP, and ROS) between the static and dynamic cell growth conditions.
Collapse
Affiliation(s)
- Hemang Patel
- Department of Biological Engineering, Utah State University, 4105 Old Main Hill, Logan, UT 84322-4105, USA
| | | | | |
Collapse
|
31
|
Brown DM, Dickson C, Duncan P, Al-Attili F, Stone V. Interaction between nanoparticles and cytokine proteins: impact on protein and particle functionality. NANOTECHNOLOGY 2010; 21:215104. [PMID: 20431193 DOI: 10.1088/0957-4484/21/21/215104] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
There is increased use of nanomaterials in many applications due to their unique properties, such as their high surface area and surface reactivity. However, the potential health effects to workers, consumers and the environment exposed to nanoparticles (NPs) is unknown. The aim of this study was to investigate whether NPs which may enter the body could adsorb proteins and whether this interaction affects both the particle and the protein function. The cytokines IL-8 and TNF-alpha were adsorbed significantly more by 14 nm carbon black (CB) compared with a similar dose of 260 nm CB. Uncoated 14 nm CB particles produced a significant increase in intracellular calcium [Ca(2 + )](i) which was greater than a similar mass dose of 260 nm CB. The 260 nm CB produced an increase in ICAM-1 expression in A549 epithelial cells at a comparable dose of 14 nm CB, and after coating with TNF-alpha 260 nm CB produced significantly more ICAM-1 expression compared with control cells. TNF-alpha bound to 14 nm CB induced a level of ICAM-1 expression that was no greater than the control level, suggesting that the TNF-alpha activity may be inhibited. These results suggest that NP-protein interaction results both in a decrease in protein function and particle activity in the cellular assays tested and this is currently being investigated.
Collapse
Affiliation(s)
- David M Brown
- School of Life Sciences, Edinburgh Napier University, 10 Colinton Road, Edinburgh, EH10 5DT, UK
| | | | | | | | | |
Collapse
|
32
|
Seagrave J, Dunaway S, McDonald JD, Mauderly JL, Hayden P, Stidley C. RESPONSES OF DIFFERENTIATED PRIMARY HUMAN LUNG EPITHELIAL CELLS TO EXPOSURE TO DIESEL EXHAUST AT AN AIR-LIQUID INTERFACE. Exp Lung Res 2009; 33:27-51. [PMID: 17364910 DOI: 10.1080/01902140601113088] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
In vitro responses of potential target cell types to air pollutants under physiological conditions may be useful in understanding the health effects of air pollution exposure. The study evaluated responses of human primary airway epithelial cells to diesel exhaust (DE). Cultures of cells from 3 donors, differentiated by culture on membranes with the apical surfaces exposed to the atmosphere, were exposed to filtered air or DE. Some exposure-related effects were similar among donors, whereas others were affected by the donor, consistent with human population heterogeneity. This model may be useful for mechanistic and comparative toxicology studies.
Collapse
|
33
|
Limitations and relative utility of screening assays to assess engineered nanoparticle toxicity in a human cell line. Toxicol Appl Pharmacol 2009; 234:222-35. [DOI: 10.1016/j.taap.2008.09.030] [Citation(s) in RCA: 475] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 09/24/2008] [Accepted: 09/30/2008] [Indexed: 11/22/2022]
|
34
|
Seagrave J, McDonald JD, Reed MD, Seilkop SK, Mauderly JL. Responses to Subchronic Inhalation of Low Concentrations of Diesel Exhaust and Hardwood Smoke Measured in Rat Bronchoalveolar Lavage Fluid. Inhal Toxicol 2008; 17:657-70. [PMID: 16087572 DOI: 10.1080/08958370500189529] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Air pollution exposure is associated with adverse health effects, but the causal components and mechanisms are unclear. We compared effects of daily exposure for 6 mo to diesel exhaust (DE) or hardwood smoke (HWS) at 4 concentrations between 30 and 1000 microg/(3) of total particulate matter, or filtered air, in male and female rats. Lung lavage fluid was assayed for toxicity indicators, cytokines, and glutathione. Statistical analyses included pairwise comparisons with control and exposure-related trends, modeled using techniques that facilitated evaluation of nonlinear exposure effects. Lactate dehydrogenase increased with exposure concentration in DE-exposed females, but in other groups, low exposure concentrations caused increases while higher concentrations had less effect. Total protein in the HWS-exposed males and females followed similar patterns. Alkaline phosphatase increased in DE-exposed females, but decreased in HWS-exposed males and females. Beta-Glucuronidase decreased in HWS- and DE-exposed males, but HWS-exposed females showed decreases at low exposure concentrations and weak increases at higher exposure concentrations. Macrophage inflammatory protein-2 decreased in HWS-exposed males and females and DE-exposed females. Tumor necrosis factor-alpha levels decreased in DE-exposed females and males, but HWS-exposed males showed small increases. DE did not affect total glutathione in either gender, but HWS decreased glutathione in females, while in males, increases at low exposure concentrations but not at higher exposure levels were observed. Thus, these two combustion emissions differentially affect lung responses, with gender affecting response patterns. Furthermore, effects may be nonmonotonic functions of exposure levels, with maximal responses in environmentally or occupationally relevant exposure ranges.
Collapse
Affiliation(s)
- JeanClare Seagrave
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA.
| | | | | | | | | |
Collapse
|
35
|
Seagrave J. Mechanisms and implications of air pollution particle associations with chemokines. Toxicol Appl Pharmacol 2008; 232:469-77. [PMID: 18755206 DOI: 10.1016/j.taap.2008.08.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 07/24/2008] [Accepted: 08/03/2008] [Indexed: 11/29/2022]
Abstract
Inflammation induced by inhalation of air pollutant particles has been implicated as a mechanism for the adverse health effects associated with exposure to air pollution. The inflammatory response is associated with upregulation of various pro-inflammatory cytokines and chemokines. We have previously shown that diesel exhaust particles (DEP), a significant constituent of air pollution particulate matter in many urban areas, bind and concentrate IL-8, an important human neutrophil-attracting chemokine, and that the chemokine remains biologically active. In this report, we examine possible mechanisms of this association and the effects on clearance of the chemokine. The binding appears to be the result of ionic interactions between negatively charged particles and positively charged chemokine molecules, possibly combined with intercalation into small pores in the particles. The association is not limited to diesel exhaust particles and IL-8: several other particle types also adsorb the chemokine and several other cytokines are adsorbed onto the diesel particles. However, there are wide ranges in the effectiveness of various particle types and various cytokines. Finally, male Fisher 344 rats were intratracheally instilled with chemokine alone or combined with diesel exhaust or silica particles under isofluorane anesthesia. In contrast to silica particles, which do not bind the chemokine, the presence of diesel exhaust particles, which bind the chemokine, prolonged the retention of the chemokine.
Collapse
Affiliation(s)
- Jeanclare Seagrave
- Lovelace Respiratory Research Institute, 2425 Ridgecrest Dr. SE, Albuquerque, NM 87108, USA.
| |
Collapse
|
36
|
Newland N, Richter A. Agents associated with lung inflammation induce similar responses in NCI-H292 lung epithelial cells. Toxicol In Vitro 2008; 22:1782-8. [PMID: 18684396 DOI: 10.1016/j.tiv.2008.07.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 05/28/2008] [Accepted: 07/04/2008] [Indexed: 10/21/2022]
Abstract
The aim of this study was to investigate an in vitro lung epithelial model for assessment of potential inhalation toxicity. The selected NCI-H292 lung carcinoma cell line is sensitive to cigarette smoke, responds in a similar manner to primary human lung epithelial cells and produces airway mucins. The following agents associated with inhalation toxicity were tested in the model: cigarette smoke total particulate matter, fly ash, bleomycin, lipopolysaccharide, vanadyl sulphate, diesel exhaust particles and carbon black. Polystyrene, poly-methylmethacrylate and dimethyl sulphoxide were used as negative controls. Response markers were chosen on the basis of reported injurious effects of lung toxicants in humans, and included pro-inflammatory cytokines, matrix metalloprotease-1, the airway mucin MUC5AC and heparin-binding epidermal growth factor-like growth factor. Markers were quantified at the mRNA and/or protein level in control and treated cells. Many of the selected markers were regulated in a similar manner by cigarette smoke and the other toxic substances in the H292 cell model. By comparison, the negative control agents were largely ineffective. We conclude that, with further validation, this assay may form part of a tiered strategy for toxicological assessment of inhaled agents prior to more complex primary cell models and animal inhalation studies.
Collapse
Affiliation(s)
- Nik Newland
- British American Tobacco, Group R&D, Regents Park Road, Southampton, SO15 8TL Hants, UK
| | | |
Collapse
|
37
|
Differential binding of cytokines to environmentally relevant particles: a possible source for misinterpretation of in vitro results? Toxicol Lett 2007; 176:131-7. [PMID: 18079072 DOI: 10.1016/j.toxlet.2007.10.014] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Revised: 10/26/2007] [Accepted: 10/29/2007] [Indexed: 11/21/2022]
Abstract
Inflammation is considered as a key event in adverse health effects associated with exposure to ambient particulate matter. The inflammatory potential of particles is often compared using in vitro cell systems, where the particle-induced release of pro-inflammatory cytokines is measured. A major concern in these assays is the potential of particles to bind cytokines, which may lead to an underestimation of the inflammatory potential. We therefore investigated the cytokine binding to a selection of particle samples, including particles collected from outdoor sources (wood combustion, traffic) and particles commonly used to model environmental sources (ultrafine carbon black, diesel, quartz), for a range of pro-inflammatory cytokines (TNF-alpha, IL-1beta, IL-6, IL-8). Furthermore, the influence of serum proteins and particle- and cytokine concentrations on the cytokine binding was studied. Cytokines primarily bound to carbonaceous particles (up to 85%), not to mineral particles. Furthermore, depending on the type of cytokine, the cytokine binding could be reduced partly or completely by adding serum proteins to the cell growth medium or particle suspensions. Based on these observations we recommend either to adjust culturing and exposure conditions to prevent cytokine binding, or to adjust the measured cytokine release by application of correction factors obtained from cytokine binding experiments.
Collapse
|
38
|
Watterson TL, Sorensen J, Martin R, Coulombe RA. Effects of PM2.5 collected from Cache Valley Utah on genes associated with the inflammatory response in human lung cells. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:1731-44. [PMID: 17885930 DOI: 10.1080/15287390701457746] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
In January 2004, the normally picturesque Cache Valley in northern Utah made national headlines with the highest PM2.5 levels in the nation. Epidemiological studies linked exposure to particulate air pollution in other locations with stroke and Alzheimer's disease and to early mortality from all causes, cancer, and cardiopulmonary diseases. To determine potential effects of these particles on human health, human bronchial epithelial cells (BEAS-2B) were cultured with PM2.5 collected from various locations in the Cache Valley. These particles were slightly cytotoxic, but more potent than NH4NO3, the major chemical component of Cache Valley PM2.5. Gene expression analysis of PM2.5-exposed cells was performed using microarray and quantitative reverse-transcription polymerase chain reaction (RT-PCR). Among other genes, PM2.5 exposure induced genes and proteins involved in the inflammatory response. Most notably, PM2.5-exposed cells showed significant gene level upregulation of activating receptors to interleukins 1 and 6 (IL-1R1 and IL-6R), as well as concomitant increases in protein. Increases in IL-1 receptor associated kinase-1 (IRAK) protein were observed. PM2.5 exposure resulted in release of IL-6, as well phosphorylated STAT3 protein, providing evidence that PM activates the IL-6/gp130/STAT3 signaling pathway in BEAS-2B cells. IL-20 and major histocompatibility complex peptide class-1 (MICA) were upregulated and cleavage of caspase-12 was detected. In total, our results indicate that Cache Valley PM2.5 produces the upregulation of important cytokine receptors and is able to activate both IL-1R- and IL-6R-mediated signaling pathways in human lung cells. These observations are generally consistent with the adverse effects associated with inhalation of fine particulate matter like PM2.5.
Collapse
Affiliation(s)
- Todd L Watterson
- Graduate Program in Toxicology, Department of Veterinary Sciences, Utah State University, Logan, Utah 84322-4620, USA
| | | | | | | |
Collapse
|
39
|
Grahame TJ, Schlesinger RB. Health effects of airborne particulate matter: do we know enough to consider regulating specific particle types or sources? Inhal Toxicol 2007; 19:457-81. [PMID: 17497526 DOI: 10.1080/08958370701382220] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Researchers and regulators have often considered preferentially regulating the types of ambient airborne particulate matter (PM) most relevant to human health effects. While few would argue the inherent merits of such a policy, many believe there may not yet be enough information to differentially regulate PM species. New evidence, using increasingly sophisticated methodologies, has become available in the last several years, allowing more accurate assessment of exposure and resultant associations with specific types of PM, or PM derived from different sources. Such new studies may also allow differentiation of effects from different chemical components in the same study against the same health endpoints. This article considers whether this new evidence might be adequate to allow us to "speciate" PM types or sources by severity of health effects. We address this issue with respect to two widespread sources of PM, emissions from motor vehicles and coal-fired power plants. Emissions from less widespread sources, residual oil and steel/coking facilities, are also discussed in order to illustrate how health effects associated with such emissions might instead be associated with more widespread sources when accurate exposure information is unavailable. Based upon evaluation of studies and methodologies which appear to contain the most accurate information on exposure and response to important emissions, including variable local emissions, it is concluded that public health will likely be better protected by reduction of various vehicular emissions than by continued regulation of the total mass of fine PM (PM <2.5 microm, or PM2.5) as if all PM in this mode is equitoxic. However, the knowledge base is incomplete. Important remaining research questions are identified.
Collapse
|
40
|
Yin XJ, Dong CC, Ma JYC, Roberts JR, Antonini JM, Ma JKH. Suppression of phagocytic and bactericidal functions of rat alveolar macrophages by the organic component of diesel exhaust particles. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART A 2007; 70:820-8. [PMID: 17454558 DOI: 10.1080/15287390701209766] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Exposure to diesel exhaust particles (DEP) was shown to increase the susceptibility of the lung to bacterial infection in rats. In this study, the effects of DEP on alveolar macrophage (AM) phagocytic and bactericidal functions and cytokine secretion by AM and lymphocytes in response to Listeria monocytogenes infection were investigated in vitro and the roles of different DEP components in these processes were compared. Exposure to DEP or the organic extracts of DEP (eDEP) significantly decreased the phagocytosis and killing of L. monocytogenes by AM obtained from normal rats. Washed DEP (wDEP) also decreased AM phagocytosis and bacterial killing to a lesser extent, whereas carbon black (CB) reduced AM phagocytosis but had no significant effect on AM bactericidal activity. DEP or eDEP concentration-dependently suppressed L. monocytogenes-induced secretion of tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-12 by AM and of IL-2 and interferon-gamma by lymphocytes obtained from L. monocytogenes-infected rats, but augmented the AM secretion of IL-10. wDEP or CB, however, exerted little or no effect on these L. monocytogenes-induced cytokines. These results provide direct evidence that DEP, through the actions of organic components, suppresses AM phagocytic and bactericidal functions in vitro. Inhibition of AM phagocytic function and alterations of AM and lymphocyte cytokine secretion by DEP and DEP organic compounds may be implicated in the diminished AM bactericidal activity and the lymphatic arm of the host immune system, thus resulting in an suppressed pulmonary clearance of L. monocytogenes and an increased susceptibility of the lung to bacterial infection.
Collapse
Affiliation(s)
- Xuejun J Yin
- School of Medicine, West Virginia University, Morgantown, West Virginia 26506-9203, USA.
| | | | | | | | | | | |
Collapse
|
41
|
Veranth JM, Kaser EG, Veranth MM, Koch M, Yost GS. Cytokine responses of human lung cells (BEAS-2B) treated with micron-sized and nanoparticles of metal oxides compared to soil dusts. Part Fibre Toxicol 2007. [PMID: 17326846 DOI: 10.1186/1743‐8977‐4‐2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of Al2O3, CeO2, Fe2O3, NiO, SiO2, and TiO2, with soil-derived particles from fugitive dust sources, and with the positive controls LPS, TNF-alpha, and VOSO4. RESULTS The nano-sized particles were not consistently more potent than an equal mass of micron-sized particles of the same nominal composition for the induction of IL-6 and IL-8 secretion in the in vitro models used in this study. The manufactured pure oxides were much less potent than natural PM2.5 particles derived from soil dust, and the cells were highly responsive to the positive controls. The nano-sized particles in the media caused artifacts in the measurement of IL-6 by ELISA due to adsorption of the cytokine on the high-surface-area particles. The potency for inducing IL-6 secretion by BEAS-2B cells did not correlate with the generation of reactive oxygen species in cell-free media. CONCLUSION Direct comparisons of manufactured metal oxide nanoparticles and previously studied types of particles and surrogate proinflammatory agonists showed that the metal oxide particles have low potency to induce IL-6 secretion in BEAS-2B cells. Particle artifacts from non-biological effects need to be considered in experiments of this type, and the limitations inherent in cell culture studies must be considered when interpreting in vitro results. This study suggests that manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles.
Collapse
Affiliation(s)
- John M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA.
| | | | | | | | | |
Collapse
|
42
|
Veranth JM, Kaser EG, Veranth MM, Koch M, Yost GS. Cytokine responses of human lung cells (BEAS-2B) treated with micron-sized and nanoparticles of metal oxides compared to soil dusts. Part Fibre Toxicol 2007; 4:2. [PMID: 17326846 PMCID: PMC1821039 DOI: 10.1186/1743-8977-4-2] [Citation(s) in RCA: 187] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 02/27/2007] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The induction of cytokines by airway cells in vitro has been widely used to assess the effects of ambient and occupational particles. This study measured cytotoxicity and the release of the proinflammatory cytokines IL-6 and IL-8 by human bronchial epithelial cells treated with manufactured nano- and micron-sized particles of Al2O3, CeO2, Fe2O3, NiO, SiO2, and TiO2, with soil-derived particles from fugitive dust sources, and with the positive controls LPS, TNF-alpha, and VOSO4. RESULTS The nano-sized particles were not consistently more potent than an equal mass of micron-sized particles of the same nominal composition for the induction of IL-6 and IL-8 secretion in the in vitro models used in this study. The manufactured pure oxides were much less potent than natural PM2.5 particles derived from soil dust, and the cells were highly responsive to the positive controls. The nano-sized particles in the media caused artifacts in the measurement of IL-6 by ELISA due to adsorption of the cytokine on the high-surface-area particles. The potency for inducing IL-6 secretion by BEAS-2B cells did not correlate with the generation of reactive oxygen species in cell-free media. CONCLUSION Direct comparisons of manufactured metal oxide nanoparticles and previously studied types of particles and surrogate proinflammatory agonists showed that the metal oxide particles have low potency to induce IL-6 secretion in BEAS-2B cells. Particle artifacts from non-biological effects need to be considered in experiments of this type, and the limitations inherent in cell culture studies must be considered when interpreting in vitro results. This study suggests that manufactured metal oxide nanoparticles are not highly toxic to lung cells compared to environmental particles.
Collapse
Affiliation(s)
- John M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Erin G Kaser
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Martha M Veranth
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Michael Koch
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| | - Garold S Yost
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, Utah, USA
| |
Collapse
|
43
|
Bai N, Khazaei M, van Eeden SF, Laher I. The pharmacology of particulate matter air pollution-induced cardiovascular dysfunction. Pharmacol Ther 2006; 113:16-29. [PMID: 16920197 DOI: 10.1016/j.pharmthera.2006.06.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Accepted: 06/14/2006] [Indexed: 01/30/2023]
Abstract
Since the London fog of 1952, in which more than 4000 people were killed in 4 days, the combined efforts of scientists from several disciplines, including those from the environmental health, clinical and biomedical disciplines, have raised serious concerns about the impact of air pollutants on human health. These environmental pollutants are rapidly being recognized as important and independent risk factors for several diseases such as asthma, chronic obstructive pulmonary disease, lung cancer, atherosclerosis, ischemic heart disease and stroke. Although the relative effects of particulate matter air pollution (aerodynamic diameter <10 microm, or PM(10)) are greater for respiratory than for cardiovascular deaths, the number of deaths attributable to PM(10) is much larger for cardiovascular than for respiratory reasons due to the higher prevalence of cardiovascular disease in the general population. This review summarizes current understanding of the mechanisms underlying the associations between PM(10) exposure and cardiovascular morbidity and mortality.
Collapse
Affiliation(s)
- Ni Bai
- University of British Columbia, Department of Pharmacology and Therapeutics, Faculty of Medicine, 2176 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | | | | | | |
Collapse
|
44
|
Sullivan JA, Keane O. The combustion of carbon particulates using NO/O2 mixtures: The influence of SO42− and NOx trapping materials. Catal Today 2006. [DOI: 10.1016/j.cattod.2006.02.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
45
|
Mamessier E, Nieves A, Vervloet D, Magnan A. Diesel exhaust particles enhance T-cell activation in severe asthmatics. Allergy 2006; 61:581-8. [PMID: 16629788 DOI: 10.1111/j.1398-9995.2006.01056.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Prevalence of asthma is increasing in westernized countries. Epidemiological studies showed the impact of traffic pollution on the triggering of asthma symptoms and exacerbations, and this effect is mainly attributed to the polycyclic aromatic hydrocarbon core of diesel exhaust particles (DEP). However, although DEP induce IgE synthesis, little is known of their role on T-cell activation, the main cells orchestrating asthma inflammation. We assessed the effect of DEP on T-cell activation in severe uncontrolled asthmatics during (n = 13) and outside (n = 19) exacerbations. Results were compared with data obtained in healthy controls (n = 14). Peripheral blood mononuclear cells were cultured in the presence of low-dose DEP. T-cell activation markers, CD69 and CD25, interleukin-4 (IL-4) and interferon (IFN)-gamma production and T-cell proliferation were assessed by flow cytometry. DEP exposure increased the proportion of CD3+CD69+ T cells in all subjects. The proportion of CD25+ T cells increased under DEP stimulation in the exacerbation group only. IFN-gamma- and IL-4-producing T cells increased in both asthmatic groups, especially during exacerbations, but not in controls. This effect was more pronounced for IL-4. In response to DEP stimulation, T-cell proliferation increased in higher proportion in asthmatics compared with controls. These results show that DEP activate T cells in asthmatics only, with a higher effect during exacerbations. This is in keeping with epidemiological data which demonstrated that DEP trigger respiratory symptoms in asthmatics but not in controls. The higher effect of DEP in exacerbated asthmatics suggests that uncontrolled asthma is a risk factor for aggravation under exposure to traffic pollutants.
Collapse
Affiliation(s)
- E Mamessier
- UPRES 3287, Université de la Méditerranée, IPHM IFR 125, Marseille, France
| | | | | | | |
Collapse
|
46
|
Arhami M, Kuhn T, Fine PM, Delfino RJ, Sioutas C. Effects of sampling artifacts and operating parameters on the performance of a semicontinuous particulate elemental carbon/organic carbon monitor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2006; 40:945-54. [PMID: 16509341 DOI: 10.1021/es0510313] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The carbonaceous component of atmospheric particulate matter (PM) is considered very important with respect to the observed adverse health effects of PM. Particulate organic and elemental carbon have traditionally been measured off-line after daily, time-integrated particle collection on filters. However, the subdaily or hourly variability of elemental carbon (EC) and organic carbon (OC) can help to assess the variability of sources, ambient levels, and human exposure. In this study, the performance of the Sunset Laboratory Inc. semicontinuous EC/OC monitorwas assessed in a Los Angeles location representing typical urban pollution. An intermonitor comparison showed high precision (R2 of 0.98 and 0.97 for thermal OC and EC, respectively). By changing the inlet configurations of one of the monitors (adding a denuder, a Teflon filter, or both), the influences of positive and negative sampling artifacts were investigated. The positive artifact was found to be relatively large (7.59 microg/m3 on average), more than 50% of measured OC, but it was practically eliminated with a denuder. The negative artifact was much smaller (less than 20% of the positive artifact) and may be neglected in most cases. A comparison of different temperature profiles, including a fast 4-min analysis using optical EC correction, showed good agreement among methods. Finally, a novel configuration using a size selective inlet impactor removing particles greater than 250 nm in diameter allowed for semicontinuous size-fractionated EC/OC measurements. Evolution of OC at different temperatures of the thermal analysis showed higher volatility OC in larger particles.
Collapse
Affiliation(s)
- Mohammad Arhami
- Department of Civil and Environmental Engineering, University of Southern California, 3620 South Vermont Avenue, Los Angeles, California 90089, USA
| | | | | | | | | |
Collapse
|
47
|
Mundandhara SD, Becker S, Madden MC. Effects of diesel exhaust particles on human alveolar macrophage ability to secrete inflammatory mediators in response to lipopolysaccharide. Toxicol In Vitro 2005; 20:614-24. [PMID: 16360300 DOI: 10.1016/j.tiv.2005.10.018] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Revised: 10/11/2005] [Accepted: 10/28/2005] [Indexed: 11/29/2022]
Abstract
Ambient particulate matter (PM) has been shown to be associated with mortality and morbidity. Diesel exhaust particles (DEP) contribute to ambient PM. Alveolar macrophages (AM) are important targets for PM effects in the lung. The effects of DEP exposure on human AM response to lipopolysachharide (LPS; from gram-negative bacteria) challenge in vitro were determined by monitoring the production of interleukin 8 (IL-8), tumor necrosis factor-alpha (TNF-alpha) and prostaglandin E(2) (PGE(2)). The roles of organic compounds and carbonaceous core of DEP in response to LPS were evaluated by comparing the DEPs effect to that of carbon black (CB), a carbonaceous particle with few adsorbed organic compounds. AMs were exposed in vitro to Standard Reference Material (SRM) DEP 2975, SRM DEP 1650, SRM 1975 (a dichloromethane extract of SRM DEP 2975) and CB particles for 24 h. DEPs induced a decreased secretion of IL-8, TNF-alpha and PGE(2) in response to a subsequent LPS stimulation. DEPs also show suppressive effect on the release of inflammatory mediators when stimulated with lipoteichoic acid, a product of gram positive bacteria. In summary, in vitro exposure of human AM to DEPs significantly suppress AM responsiveness to gram-negative and positive bacterial products, which may be a contributing factor to the impairment of pulmonary defense.
Collapse
Affiliation(s)
- Sailaja D Mundandhara
- Center for Environmental Medicine, Asthma, and Lung Biology, University of North Carolina, Chapel Hill, NC, USA
| | | | | |
Collapse
|
48
|
Sullivan JA, Keane O, Maguire L. The influence of SO42- on the catalytic combustion of soot using O2 and NO/O2 mixtures over Na-promoted Al2O3 catalysts. CATAL COMMUN 2005. [DOI: 10.1016/j.catcom.2005.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|