Effect Of Bronchial Epithelial Cells On The Airway Remodeling Of Asthma

Objective:To investigate the effect and mechanism of bronchial epithelial cell on the airway remodeling of asthma by using Western blot and RT-PCR to study the change of TGF-β₁,Smad2,IL-13 and TGF-β1 mRNA,Smad2 mRNA,IL-13 mRNA expressed by human bronchial epithelial cell line(BEP2D)sensitized by house dust mite Dermatophagoides pteronyssinus allergen of various consistency and using immunochemistry to detect the change of fibronectin(FN)andα-smooth muscle actin(α-SMA)expressed by human embryonic lung fibroblast(HLF) stimulated by different-dosage house dust mite Dermatophagoides pteronyssinus allergen 1 and culture media used by BEP2D.Methods:(1)BEP2D were cultured and devided into 4 groups according to the consistency of Der p1:control group,0.2μg/mL Der p1 group,2.0μg/mL Der p1 group and 10.0μg/mL Der p1 group,and were devided into 3 groups based on the incubation time:24 h group,48 h group and 72 h group,then detected the expression of TGF-β₁,Smad2,IL-13 by Western blot and TGF-β₁ mRNA,Smad2 mRNA,IL-13 mRNA by RT-PCR.(2)HLF were cultured and devided into 5 groups:control group,0.2μg/mL Der pl group,2.0μg/mL Der pl group,10.0μg/mL Der p1 group and LHC-8^*(LHC-8 cultured BEP2D for 72 h with 10.0μg/mL Der p1)group, and were devided into 3 groups based on the incubation time:24 h group, 48 h group and 72 h group,then detected the expression of FN and a -SMA by immunocytochemical method.(3)SPSS10.0 statistic software were used to to analysis all the data,the average of all the samples used t test,the relation of variables were calculated by Pearson linear correlation analysis,a P value of＜0.05 was considered statistically significant.Results:(1)Based on the results of Western blot and RT-PCR,the expression of TGF-β₁,Smad2,IL-13,TGF-β₁ mRNA,Smad2 mRNA,IL-13 mRNA by the BEP2D had no difference between the 0.2 ug/mL Der pl group and the control group.But these factors and mRNA of 2.0ug/mL group of all incubation time were significantly higher than 0.2 ug/mL Der pl group cultured for the same time,the p value were less than 0.05,and so was the 10 ug/mLgroup than the 2.0 ug/mL group(p＜0.05).(2)The expression of FN andα-SMA by the HLF were negative or low positive in the four Der p1 groups and 3 incubation time groups and had no statistically significant.The expression of FN andα-SMA in the LHC-8^* group were significantly increased,especially in the 72 h group,the difference of the expression between all the incubation time groups have statistically significant(p＜0.05).Conclusions:The house dust mite Dermatophagoides pteronyssinus allergen had no direct effect on the lung fibroblast,but it could greatly increase the expression of TGF-β₁,Smad2,IL-13 by sensitizing the bronchial epithelial cells,then lead to an increase of airway inflammation and may induce or aggravate asthma.The allergen then had an effect on the lung fibroblast throughing the cytokine expression by the bronchial epithelial cells,then increases the expression of FN andα-SMA and has an effect in the fibrosis process of lung basal membrane,indicating the role of house dust mite Dermatophagoides pteronyssinus allergen in the airway remodeling.