Effects of PFOA exposure on inflammatory mediators IL-4, IFN-γand glucocorticoid receptor in asthmatic mice / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effects of perfluorooctanoic acid(PFOA)exposure on the changes of asth-matic mouse airway inflammation,inflammatory mediators interleukin-4(IL-4)and interferon-γ(IFN-γ)in serum, and glucocorticoid receptor(GR)expression in the lung tissue.METHODS:BALB/c mice(n=30)were randomly divided into 5 groupsnormal control(C)group,asthma(A)group,asthma+low-dose PFOA(AP10)group,asthma+mode-rate-dose PFOA(AP50)group and asthma+high-dose PFOA(AP100)group.Asthma model and PFOA exposure model of mice were established according to the grouping.The animals were sacrificed and their lungs were collected for HE stai-ning,transmission electron microscopy,Western blot and immunohistochemical staining.ELISA was applied to detect the levels of IL-4 and IFN-γin the serum.RESULTS: HE staining of the lungs showed that the asthmatic mice, compared with the normal control mice,had obvious mucus secretion around the airways and infiltration of inflammatory cells around airways and blood vessels,and the effects were much more marked in AP groups.Ultrastructural alteration of the lung tis-sues in the asthmatic mice were indicated by transmission electron microscopy.Compared with C group, the results of ELISA in A group and AP groups proved that IL-4 in the serum was increased and IFN-γwas decreased significantly(P<0.05).Compare with A group,IL-4 was significantly increased and IFN-γwas decreased in AP100 group(P<0.05), and no difference of those between AP 10 group and AP50 group was found.The results of Western blot indicated that GR protein expression in the asthmatic mice were decreased compare with the normal mice(P<0.05), and no difference of that among A group and AP groups was observed.Immunohistochemical staining manifested that GR protein was mainly lo-cated in the cytoplasm of bronchial columnar epithelial cells,airway smooth muscle cells and vascular smooth muscle cells. CONCLUSION:Acute airway PFOA exposure in asthmatic mice dose-dependently exacebates lung inflammation by indu-cing Th2 type immune responses, promotes infiltration of inflammatory cells and mucus secretion around the airways and blood vessels,and destroys the ultrastructure of the lung tissues.