The effects of air-borne particulate matters on the alveolar macrophages for the TNF-α and IL-1β secretion

Background: PM is known to induce various pulmonary diseases, including asthma, cancer, fibrosis and chronic bronchitis. Despite the epidemiological evidence the pathogenesis of PM-related pulmonary diseases is unclear. Methods: This study examined the effects of PM exposure on the secretion of TNF-α and IL-1β in the cultured alveolar macrophages. The cultured primary alveolar macrophages were treated with the medium, PM (5-20μg/cm ²), LPS (5ng/ml), and PM with LPS for 24h and 48h respectively. ELISA was used to assay the secreted TNF-α and IL-1β in the culture medium. Western blotting was used to identify and determine the level of proteins isolated from the culture cells. The cells cultured in the Lab-Tek® chamber slides were stained with immunocytochemical stains. Results: PM induced TNF-α and IL-1β secretion in the culturing alveolar macrophages, collected from the SPF and inflammatory rats. However, the effects were only dose-dependent in the inflammatory macrophages. When the cells were co-treated with PM and LPS, there was a significant synergistic effect compared with the IPS in the both cell types. Conclusion: PM might be play an important role in the induction and/or potentiation of various lung diseases by oversecretion of TNF-α and IL-1β.