A Research On P55pik Expression And Role In Inflammation Induced By Cigarette Smoke Extracts In Human Airway Epithelia

Object: Analysis of differentiation of p55 pik expression among groups of variant smoking history and lung function, and the research on the role of p55 pik plays in epithelial inflammation induced by cigarette smoke extract.Methods: Collection of seventeen human lung tissues during surgery for benign lung disease and immunohistochemistry were conducted to test the expression level of p55 pik, then analysis of correlation between p55 pik expression level and smoke history or lung function(FEV1% and FEV1/FVC) was carried out. Western blot tested for p55 pik expression was performed after the human bronchial epithelia cells were treated with diverse concentrations of cigarette smoke extracts. Small interference RNA was used to block the protein expression of p55 pik in HBE cells and IL-6 and IL-8 secretion level after CSE stimulation were tested by ELISA.Results: The p55 pik expression level in human airway epithelia shows an ascending trend in smokers with or without COPD compared with non-smokers. There exists a tendency that lung function(FEV1% and FEV1/FVC) was reversely correlated with p55 pik expression. P55 pik Expression was enhanced after stimulation of CSE in human bronchial epithelia cells(p<0.05) and reduced p55 pik by si RNA led to decreased secretion level of IL-6(p<0.05) and IL-8(p<0.01) induced by CSE.Conclusion: P55 pik was upregulated after the exposure to cigarette smoke, and this increase might be correlated with the descending lung function. Downregulation of p55 pik expression might contribute to the inhibition of airway inflammation by lowering cytokines such as IL-6 and IL-8 production, which might come to be a potentially novel treatment target for chronic airway inflammatory disease triggered by smoking such as COPD.