Chronic exposure of diesel exhaust particles induces alveolar enlargement in mice
| Autor: | Ana Paula Ligeiro de Oliveira, Sandra Ferzilan, Luiz Ff Silva, P. H. Saldiva, Mariangela Macchione, Sandra Hp Farsky, Kelly Yoshizaki, Milton A. Martins, Isabel Daufenback Machado, Thais Mauad, Alessandra Choqueta de Toledo, Jôse Mára Brito, Henrique Takachi Moriya |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Pulmonary and Respiratory Medicine
Male Pathology medicine.medical_specialty Time Factors T cell Lymphocyte Air pollution Mucin 5AC RATOS Andrology Mice Parenchyma medicine Animals RNA Messenger Respiratory system Lung Vehicle Emissions Diesel exhaust particulate Air Pollutants Mice Inbred BALB C medicine.diagnostic_test Chemistry Research Macrophages Pneumonia respiratory system Elastic Tissue Lymphocyte Subsets respiratory tract diseases POLUIÇÃO ATMOSFÉRICA Pulmonary Alveoli medicine.anatomical_structure Bronchoalveolar lavage Respiratory Mechanics Cytokines Collagen Inflammation Mediators Bronchoalveolar Lavage Fluid CD8 Brazil Respiratory tract |
| Zdroj: | Respiratory Research Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| ISSN: | 1465-993X 1465-9921 |
| Popis: | Background Diesel exhaust particles (DEPs) are deposited into the respiratory tract and are thought to be a risk factor for the development of diseases of the respiratory system. In healthy individuals, the timing and mechanisms of respiratory tract injuries caused by chronic exposure to air pollution remain to be clarified. Methods We evaluated the effects of chronic exposure to DEP at doses below those found in a typical bus corridor in Sao Paulo (150 μg/m3). Male BALB/c mice were divided into mice receiving a nasal instillation: saline (saline; n = 30) and 30 μg/10 μL of DEP (DEP; n = 30). Nasal instillations were performed five days a week, over a period of 90 days. Bronchoalveolar lavage (BAL) was performed, and the concentrations of interleukin (IL)-4, IL-10, IL-13 and interferon-gamma (INF-γ) were determined by ELISA-immunoassay. Assessment of respiratory mechanics was performed. The gene expression of Muc5ac in lung was evaluated by RT-PCR. The presence of IL-13, MAC2+ macrophages, CD3+, CD4+, CD8+ T cells and CD20+ B cells in tissues was analysed by immunohistochemistry. Bronchial thickness and the collagen/elastic fibers density were evaluated by morphometry. We measured the mean linear intercept (Lm), a measure of alveolar distension, and the mean airspace diameter (D0) and statistical distribution (D2). Results DEP decreased IFN-γ levels in BAL (p = 0.03), but did not significantly alter IL-4, IL-10 and IL-13 levels. MAC2+ macrophage, CD4+ T cell and CD20+ B cell numbers were not altered; however, numbers of CD3+ T cells (p ≤ 0.001) and CD8+ T cells (p ≤ 0.001) increased in the parenchyma. Although IL-13 (p = 0.008) expression decreased in the bronchiolar epithelium, Muc5ac gene expression was not altered in the lung of DEP-exposed animals. Although respiratory mechanics, elastic and collagen density were not modified, the mean linear intercept (Lm) was increased in the DEP-exposed animals (p ≤ 0.001), and the index D2 was statistically different (p = 0.038) from the control animals. Conclusion Our data suggest that nasal instillation of low doses of DEP over a period of 90 days results in alveolar enlargement in the pulmonary parenchyma of healthy mice. Electronic supplementary material The online version of this article (doi:10.1186/s12931-015-0172-z) contains supplementary material, which is available to authorized users. |
| Databáze: | OpenAIRE |
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