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Fussell JC, Kelly FJ. Mechanisms underlying the health effects of desert sand dust. ENVIRONMENT INTERNATIONAL 2021; 157:106790. [PMID: 34333291 PMCID: PMC8484861 DOI: 10.1016/j.envint.2021.106790] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/21/2021] [Accepted: 07/19/2021] [Indexed: 05/28/2023]
Abstract
Desertification and climate change indicate a future expansion of the global area of dry land and an increase in the risk of drought. Humans may therefore be at an ever-increasing risk of frequent exposure to, and resultant adverse health effects of desert sand dust. This review appraises a total of 52 experimental studies that have sought to identify mechanisms and intermediate endpoints underlying epidemiological evidence of an impact of desert dust on cardiovascular and respiratory health. Toxicological studies, in main using doses that reflect or at least approach real world exposures during a dust event, have demonstrated that virgin sand dust particles and dust storm particles sampled at remote locations away from the source induce inflammatory lung injury and aggravate allergen-induced nasal and pulmonary eosinophilia. Effects are orchestrated by cytokines, chemokines and antigen-specific immunoglobulin potentially via toll-like receptor/myeloid differentiation factor signaling pathways. Findings suggest that in addition to involvement of adhered chemical and biological pollutants, mineralogical components may also be implicated in the pathogenesis of human respiratory disorders during a dust event. Whilst comparisons with urban particulate matter less than 2.5 μm in diameter (PM2.5) suggest that allergic inflammatory responses are greater for microbial element-rich dust- PM2.5, aerosols generated during dust events appear to have a lower oxidative potential compared to combustion-generated PM2.5 sampled during non-dust periods. In vitro findings suggest that the significant amounts of suspended desert dust during storm periods may provide a platform to intermix with chemicals on its surfaces, thereby increasing the bioreactivity of PM2.5 during dust storm episodes, and that mineral dust surface reactions are an unrecognized source of toxic organic chemicals in the atmosphere, enhancing toxicity of aerosols in urban environments. In summary, the experimental research on desert dust on respiratory endpoints go some way in clarifying the mechanistic effects of atmospheric desert dust on the upper and lower human respiratory system. In doing so, they provide support for biological plausibility of epidemiological associations between this particulate air pollutant and events including exacerbation of asthma, hospitalization for respiratory infections and seasonal allergic rhinitis.
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Affiliation(s)
- Julia C Fussell
- National Institute for Health Research Health Protection Research Unit in Environmental Exposures and Health, School of Public Health, Sir Michael Uren Building, Imperial College London, White City Campus, 80-92 Wood Lane, London W12 0BZ, United Kingdom.
| | - Frank J Kelly
- National Institute for Health Research Health Protection Research Unit in Environmental Exposures and Health, School of Public Health, Sir Michael Uren Building, Imperial College London, White City Campus, 80-92 Wood Lane, London W12 0BZ, United Kingdom
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Yan L, Gong C, Ying L, Fu W, Liu S, Dai J, Fu Z. PM2.5 affects establishment of immune tolerance in newborn mice by reducing PD-L1 expression. J Biosci 2019. [DOI: 10.1007/s12038-019-9858-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Yan LI, Gong C, Ying L, Fu W, Liu S, Dai J, Fu Z. PM2.5 affects establishment of immune tolerance in newborn mice by reducing PD-L1 expression. J Biosci 2019; 44:41. [PMID: 31180054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This study was conducted to determine whether exposure to particulate matter 2.5 (PM2.5) affects the immune tolerance of neonatal mice via the regulation of PD-L1 expression. One-week-old BALB/c mice were exposed to PM2.5 for 8 days. From day 8 to day 18, the mice were treated with 5 μg house dust mite (HDM) (i. n.) every two days. Adenovirus-carried PD-L1 overexpression vectors were infected into mice via nasal inhalation 6 days after exposure to PM2.5. Airway hyperresponsiveness (AHR) was examined in mice 19 days after exposure to PM2.5, and the related parameters of airway inflammation were studied on day 22. Co-exposure to PM2.5 and HDM reduced PD-L1 expression but greatly increased infiltration of inflammatory cells, which was reversed by PD-L1 overexpression. Co-exposure to PM2.5 and HDM also elevated serum IL-4, IL-5 and IL-13 levels and reduced TGF-β level. Exposure to PM2.5 alone slightly increased the numbers of dendritic cells (DCs) but reduced the numbers of antigen-presenting cells expressing PD-L1 and Treg cells. Therefore, early exposure to PM2.5 reduced PD-L1 expression in the lungs of neonatal mice, which interfered with immune tolerance establishment and subsequently resulted in allergic airway inflammation.
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Affiliation(s)
- L I Yan
- Department of Respiration Center, Children's Hospital of Chongqing Medical University, Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, People's Republic of China
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A Systematic Review of Global Desert Dust and Associated Human Health Effects. ATMOSPHERE 2016. [DOI: 10.3390/atmos7120158] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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He M, Ichinose T, Liu B, Song Y, Yoshida Y, Kobayashi F, Maki T, Yoshida S, Nishikawa M, Takano H, Sun G. Silica-carrying particulate matter enhances Bjerkandera adusta-induced murine lung eosinophilia. ENVIRONMENTAL TOXICOLOGY 2016; 31:93-105. [PMID: 25044538 DOI: 10.1002/tox.22025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 06/22/2014] [Accepted: 06/29/2014] [Indexed: 06/03/2023]
Abstract
Bjerkandera adusta (B. adusta) causes fungus-associated chronic cough. However, the inflammatory response is not yet fully understood. Recently, B. adusta was identified in Asian sand dust (ASD) aerosol. This study investigated the enhancing effects of ASD on B. adusta-induced lung inflammation. B. adusta was inactivated by formalin. ASD was heated to remove toxic organic substances. ICR mice were intratracheally instilled with saline, B. adusta 0.2 µg, or B. adusta 0.8 µg with or without heated ASD 0.1 mg (H-ASD), four times at 2-week intervals. Two in vitro experiments were conducted to investigate any enhancing effects using bone marrow-derived macrophages (BMDM) from Toll-like receptor (TLR) knockout mice and ICR mice. Co-exposure to H-ASD and B. adusta, especially at high doses, caused eosinophil infiltration, proliferation of goblet cells in the airway, and fibrous thickening of the subepithelial layer, and remarkable increases in expression of Th2 cytokines and eosinophil-related cytokine and chemokine expression in bronchoalveolar lavage fluid. In the in vitro study using BMDM from wild-type, TLR2-/-, and TLR4-/- mice, the TLR-signaling pathway for cytokine production caused by B. adusta was predominantly TLR2 rather than TLR4. H-ASD increased the expression of NF-κB and cytokine production by B. adusta in BMDM from ICR mice. The results suggest that co-exposure to H-ASD and B. adusta caused aggravated lung eosinophilia via remarkable increases of pro-inflammatory mediators. The aggravation of inflammation may be related, at least in part, to the activation of the TLR2-NF-κB signaling pathway in antigen presenting cells by H-ASD.
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Affiliation(s)
- Miao He
- Environment and Chronic Non-Communicable Disease Research Center, School of Public Health, China Medical University, 11001, Shenyang, China
- Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201, Oita, Japan
| | - Takamichi Ichinose
- Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201, Oita, Japan
| | - Boying Liu
- Environment and Chronic Non-Communicable Disease Research Center, School of Public Health, China Medical University, 11001, Shenyang, China
- Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201, Oita, Japan
| | - Yuan Song
- Department of Immunology and Parasitology, School of Medicine, University of Occupational and Environmental Health, 807-8555, Fukuoka, Japan
| | - Yasuhiro Yoshida
- Department of Immunology and Parasitology, School of Medicine, University of Occupational and Environmental Health, 807-8555, Fukuoka, Japan
| | - Fumihisa Kobayashi
- Faculty of Natural System, College of Science and Engineering, Kanazawa University, 920-1192, Ishikawa, Japan
| | - Teruya Maki
- Faculty of Chemistry, Institute of Science and Engineering, Kanazawa University, 920-1192, Ishikawa, Japan
| | - Seiichi Yoshida
- Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201, Oita, Japan
| | - Masataka Nishikawa
- Division of Environmental Chemistry, National Institute for Environmental Studies, 305-8506, Ibaraki, Japan
| | - Hirohisa Takano
- Division of Environmental Health, Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, 615-8530, Kyoto, Japan
| | - Guifan Sun
- Environment and Chronic Non-Communicable Disease Research Center, School of Public Health, China Medical University, 11001, Shenyang, China
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Horie M, Stowe M, Tabei M, Kuroda E. Pharyngeal aspiration of metal oxide nanoparticles showed potential of allergy aggravation effect to inhaled ovalbumin. Inhal Toxicol 2015; 27:181-90. [DOI: 10.3109/08958378.2015.1026618] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Ren Y, Ichinose T, He M, Arashidani K, Yoshida Y, Yoshida S, Nishikawa M, Takano H, Sun G, Shibamoto T. Aggravation of ovalbumin-induced murine asthma by co-exposure to desert-dust and organic chemicals: an animal model study. Environ Health 2014; 13:83. [PMID: 25326908 PMCID: PMC4216376 DOI: 10.1186/1476-069x-13-83] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 10/09/2014] [Indexed: 05/06/2023]
Abstract
BACKGROUND The organic chemicals present in Asian sand dust (ASD) might contribute to the aggravation of lung eosinophila. Therefore, the aggravating effects of the Tar fraction from ASD on ovalbumin (OVA)-induced lung eosinophilia were investigated. METHODS The Tar fraction was extracted from ASD collected from the atmosphere in Fukuoka, Japan. ASD collected from the Gobi desert was heated at 360°C to inactivate toxic organic substances (H-ASD). ICR mice were instilled intratracheally with 12 different test samples prepared with Tar (1 μg and 5 μg), H-ASD, and OVA in a normal saline solution containing 0.02% Tween 80. The lung pathology, cytological profiles in the bronchoalveolar lavage fluid (BALF), inflammatory cytokines/chemokines in BALF and OVA-specific immunoglobulin in serum were investigated. RESULTS Several kinds of polycyclic aromatic hydrocarbons (PAHs) were detected in the Tar sample. H-ASD + Tar 5 μg induced slight neutrophilic lung inflammation. In the presence of OVA, Tar 5 μg increased the level of eosinophils slightly and induced trace levels of Th2 cytokines IL-5 and IL-13 in BALF. Also mild to moderate goblet cell proliferation and mild infiltration of eosinophils in the submucosa of airway were observed. These pathological changes caused by H-ASD + OVA were relatively small. However, in the presence of OVA and H-ASD, Tar, at as low a level as 1 μg, induced severe eosinophil infiltration and proliferation of goblet cells in the airways and significantly increased Th2 cytokines IL-5 and IL-13 in BALF. The mixture showed an adjuvant effect on OVA-specific IgG1 production. CONCLUSIONS These results indicate that H-ASD with even low levels of Tar exacerbates OVA-induced lung eosinophilia via increases of Th2-mediated cytokines. These results suggest that ASD-bound PAHs might contribute to the aggravation of lung eosinophila.
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Affiliation(s)
- Yahao Ren
- />Department of Nutritional and Food Hygiene, College of Public Health, China Medical University, Shenyang, China
| | - Takamichi Ichinose
- />Department of Health Sciences, Oita University of Nursing and Health Sciences, Oita, Japan
| | - Miao He
- />Environment and Chronic Non-communicable Disease Research Center, School of Public Health, College of Public Health, China Medical University, 11001 Shenyang, China
| | - Keiichi Arashidani
- />Department of Immunology and Parasitology, School of Medicine, University of Occupational and Environmental Health, 807-8555 Fukuoka, Japan
| | - Yasuhiro Yoshida
- />Department of Immunology and Parasitology, School of Medicine, University of Occupational and Environmental Health, 807-8555 Fukuoka, Japan
| | - Seiichi Yoshida
- />Department of Health Sciences, Oita University of Nursing and Health Sciences, Oita, Japan
| | - Masataka Nishikawa
- />Environmental Chemistry Division, National Institute for Environmental Studies, 305-8506 Ibaraki, Japan
| | - Hirohisa Takano
- />Environmental Health Division, Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, 615-8530 Kyoto, Japan
| | - Guifan Sun
- />Environment and Chronic Non-communicable Disease Research Center, School of Public Health, College of Public Health, China Medical University, 11001 Shenyang, China
| | - Takayuki Shibamoto
- />Department of Environmental Toxicology, University of California, Davis, CA 95616 USA
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Ren Y, Ichinose T, He M, Song Y, Yoshida Y, Yoshida S, Nishikawa M, Takano H, Sun G, Shibamoto T. Enhancement of OVA-induced murine lung eosinophilia by co-exposure to contamination levels of LPS in Asian sand dust and heated dust. Allergy Asthma Clin Immunol 2014; 10:30. [PMID: 24982682 PMCID: PMC4058696 DOI: 10.1186/1710-1492-10-30] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 05/03/2014] [Indexed: 12/18/2022] Open
Abstract
Background A previous study has shown that the aggravation of Asian sand dust (ASD) on ovalbumin (OVA)-induced lung eosinphilia was more severe in lipopolysaccharide (LPS)-rich ASD than in SiO2-rich ASD. Therefore, the effects of different LPS contamination levels in ASD on the aggravation of OVA-induced lung eosinophilia were investigated in the present study. Methods Before beginning the in vivo experiment, we investigated whether the ultra-pure LPS would act only on TLR4 or not using bone marrow-derived macrophages (BMDMs) of wild–type, TLR2-/-, TLR4-/- and MyD88-/- BALB/c mice. ASD collected from the desert was heated to remove toxic organic substances (H-ASD). BALB/c mice were instilled intratracheally with 12 different testing samples prepared with LPS (1 ng and 10 ng), H-ASD, and OVA in a normal saline solution. The lung pathology, cytological profiles in the bronchoalveolar lavage fluid (BALF), the levels of inflammatory cytokines/chemokines in BALF and OVA-specific immunoglobulin in serum were investigated. Results The LPS exhibited no response to the production of TNF-α and IL-6 in BMDMs from TLR4-/-, but did from TLR2-/-. H-ASD aggravated the LPS-induced neutrophilic lung inflammation. In the presence of OVA, LPS increased the level of eosinophils slightly and induced trace levels of Th2 cytokines IL-5 and IL-13 at the levels of 1 ng and 10 ng. In the presence of OVA and H-ASD, LPS induced severe eosinophil infiltration and proliferation of goblet cells in the airways as well as remarkable increases in Th2 cytokines IL-5 and IL-13 in BALF. The mixture containing LPS (1 ng) showed adjuvant activity on OVA-specific IgE and IgG1 production. Conclusions The results suggest that H-ASD with naturally-occurring levels of LPS enhances OVA-induced lung eosinophilia via increases in Th2-mediated cytokines and antigen-specific immunoglobulin. These results indicate that LPS is a strong candidate for being a major aggravating substance in ASD.
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Affiliation(s)
- Yahao Ren
- Department of Nutritional and Food Hygiene, College of Public Health, China Medical University, Shenyang, China
| | - Takamichi Ichinose
- Department of Health Sciences, Oita University of Nursing and Health Sciences, Oita 870-1201, Japan
| | - Miao He
- Department of Environmental and Occupational Health, College of Public Health, China Medical University, Shenyang, China
| | - Yuan Song
- Department of Immunology and Parasitology, School of Medicine, University of Occupational and Environmental Health, Japan, Fukuoka 807-8555, Japan
| | - Yasuhiro Yoshida
- Department of Immunology and Parasitology, School of Medicine, University of Occupational and Environmental Health, Japan, Fukuoka 807-8555, Japan
| | - Seiichi Yoshida
- Department of Health Sciences, Oita University of Nursing and Health Sciences, Oita 870-1201, Japan
| | - Masataka Nishikawa
- Environmental Chemistry Division, National Institute for Environmental Studies, Ibaraki 305-8506, Japan
| | - Hirohisa Takano
- Environmental Health Division, Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8530, Japan
| | - Guifan Sun
- Department of Environmental and Occupational Health, College of Public Health, China Medical University, Shenyang, China
| | - Takayuki Shibamoto
- Department of Environmental Toxicology, University of California, Davis, CA 95616, USA
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Asian dust particles induce macrophage inflammatory responses via mitogen-activated protein kinase activation and reactive oxygen species production. J Immunol Res 2014; 2014:856154. [PMID: 24987712 PMCID: PMC4058895 DOI: 10.1155/2014/856154] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 05/18/2014] [Indexed: 12/19/2022] Open
Abstract
Asian dust is a springtime meteorological phenomenon that originates in the deserts of China and Mongolia. The dust is carried by prevailing winds across East Asia where it causes serious health problems. Most of the information available on the impact of Asian dust on human health is based on epidemiological investigations, so from a biological standpoint little is known of its effects. To clarify the effects of Asian dust on human health, it is essential to assess inflammatory responses to the dust and to evaluate the involvement of these responses in the pathogenesis or aggravation of disease. Here, we investigated the induction of inflammatory responses by Asian dust particles in macrophages. Treatment with Asian dust particles induced greater production of inflammatory cytokines interleukin-6 and tumor necrosis factor-α (TNF-α) compared with treatment with soil dust. Furthermore, a soil dust sample containing only particles ≤10 μm in diameter provoked a greater inflammatory response than soil dust samples containing particles >10 μm. In addition, Asian dust particles-induced TNF-α production was dependent on endocytosis, the production of reactive oxygen species, and the activation of nuclear factor-κB and mitogen-activated protein kinases. Together, these results suggest that Asian dust particles induce inflammatory disease through the activation of macrophages.
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Liu B, Ichinose T, He M, Kobayashi F, Maki T, Yoshida S, Yoshida Y, Arashidani K, Takano H, Nishikawa M, Sun G, Shibamoto T. Lung inflammation by fungus, Bjerkandera adusta isolated from Asian sand dust (ASD) aerosol and enhancement of ovalbumin-induced lung eosinophilia by ASD and the fungus in mice. Allergy Asthma Clin Immunol 2014; 10:10. [PMID: 24499133 PMCID: PMC3918174 DOI: 10.1186/1710-1492-10-10] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Accepted: 01/30/2014] [Indexed: 12/24/2022] Open
Abstract
Background Bjerkandera adusta (B. adusta) is one of the most important etiological fungi associated with chronic cough. However, precise details of the inflammatory response to exposure are not well understood yet. B. adusta was recently identified in Asian sand dust (ASD) aerosol. Therefore, in the present study the exacerbating effects of ASD on B. adusta-induced lung inflammation and B. adusta + ASD on ovalbumin (OVA)-induced murine lung eosinophilia were investigated using experimental mice. Methods In order to prepare testing samples, B. adusta obtained from ASD aerosol was inactivated by formalin and ASD collected from the atmosphere was heated to remove toxic organic substances (H-ASD). CD-1 mice were instilled intratracheally with 12 different samples prepared with various combinations of B. adusta, H-ASD, and OVA in a normal saline solution. The lung pathology, cytological profiles in bronchoalveolar lavage fluid (BALF), and the levels of inflammatory cytokines/chemokines in BALF were investigated. Results H-ASD aggravated the lung eosinophilia induced by B. adusta alone, which also aggravated the lung eosinophilia induced by OVA. The mixture of OVA, H-ASD, and B. adusta caused serious fibrous thickening of the subepithelial layer, eosinophil infiltration, and proliferation of goblet cells in the airways along with remarkable increases of IL-13, eotaxin, IL-5, and MCP-3 in BALF. Conclusions The results of the present study demonstrated that B. adusta isolated from ASD aerosol induces allergic lung diseases. H-ASD enhanced allergic reactions caused by OVA or B. adusta. A mixture of B. adusta, H-ASD, and OVA caused the most remarkable exacerbation to the allergic airway inflammation via remarkable increases of pro-inflammatory mediators.
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Affiliation(s)
| | - Takamichi Ichinose
- Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201 Oita, Japan.
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He M, Ichinose T, Song Y, Yoshida Y, Arashidani K, Yoshida S, Liu B, Nishikawa M, Takano H, Sun G. Effects of two Asian sand dusts transported from the dust source regions of Inner Mongolia and northeast China on murine lung eosinophilia. Toxicol Appl Pharmacol 2013; 272:647-55. [PMID: 23896513 DOI: 10.1016/j.taap.2013.07.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 07/08/2013] [Accepted: 07/16/2013] [Indexed: 11/18/2022]
Abstract
The quality and quantity of toxic materials adsorbed onto Asian sand dust (ASD) are different based on dust source regions and passage routes. The aggravating effects of two ASDs (ASD1 and ASD2) transported from the source regions of Inner Mongolia and northeast China on lung eosinophilia were compared to clarify the role of toxic materials in ASD. The ASDs contained different amounts of lipopolysaccharides (LPS) and β-glucan (ASD1<ASD2) and SiO2 (ASD1>ASD2). CD-1 mice were instilled intratracheally with ASD1, ASD2 and/or ovalbumin (OVA) four times at 2-week intervals. ASD1 and ASD2 enhanced eosinophil recruitment induced by OVA in the submucosa of the airway, with goblet cell proliferation in the bronchial epithelium. ASD1 and ASD2 synergistically increased OVA-induced eosinophil-relevant cytokines interleukin-5 (IL-5), IL-13 (ASD1<ASD2) and chemokine eotaxin (ASD1>ASD2) in bronchoalveolar lavage fluid. ASD2 aggravating effects on lung eosinophilia were greater than ASD1. The role of LPS and β-glucan in ASD2 on the production of pro-inflammatory mediators was assessed using in vitro bone marrow-derived macrophages (BMDMs) from wild type, Toll-like receptor 2-deficient (TLR2-/-), TLR4-/-, and MyD88-/- mice (on Balb/c background). ASD2-stimulated TLR2-/- BMDMs enhanced IL-6, IL-12, TNF-α, MCP-1 and MIP-1α secretion compared with ASD2-stimulated TLR4-/- BMDMs. Protein expression from ASD2-stimulated MyD88-/- BMDM were very low or undetectable. The in vitro results indicate that lung eosinophilia caused by ASD is TLR4 dependent. Therefore, the aggravation of OVA-related lung eosinophilia by ASD may be dependent on toxic substances derived from microbes, such as LPS, rather than SiO2.
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Affiliation(s)
- Miao He
- Environment and Chronic Non-communicable Disease Research Center, College of Public Health, China Medical University, 11001 Shenyang, China; Department of Health Sciences, Oita University of Nursing and Health Sciences, 870-1201 Oita, Japan.
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