Effects of Aspergillus fumigatus extract on expression of GM-CSF in human bronchial epithelial cells / 第二军医大学学报

ABSTRACT

Objective: To investigate the effects of Aspergillus fumigatus extract (AFE) on the expression of GM-CSF in human bronchial epithelial cells and its possible mechanism. Methods: Human bronchial epithelial cells (16HBE-14o) were cultured in vitro and were exposed to different concentrations of AFE (0, 8, 16 and 20 mg/L) for different peroids (12, 24, 48, 72 h). Moreover, heat-treated AFE, serine protease inhibitors (aprotinin), protease-activated receptor-2 (PAR 2) agonist (SLIGLV-NH2) and PAR-2 antagonist (FSLLRY-NH2) were also used to treat 16HBE-14o cells. The production and release of GM-CSF in different supernatants was determined by ELISA. The expression of GM-CSF mRNA was measured by RT-PCR. Results: 16HBE-14o cells in the normal control group only had slight expression of GM CSF; the expression was significantly increased after AFE treatment(P<0.01); and the effect of AFE was in a time- and dose-dependent manner. PAR 2 agonist also promoted release of GM-CSF. Aprotinin and PAR-2 antagonist (FSLLRY-NH2) almost totally inhibited the effect of AFE on GM-CSF production by 16HBE-14o cells. Heat-treated AFE, which lost protease activities, exerted no effect on GM-CSF production. Conclusion: AFE, with its protease activity, can activate PAR 2, and subsequently causes GM-CSF synthesis and release by airway epithelial cells, which may contribute to the development and deterioration of asthma.