Expression of Signal Transducers and Activator of Transcription 3 in Airway Epithelial Cells of Asthmatic Mouse Model and Its Role in Airway Remodeling

Objective To study the expression of signal transducers and activators of transcription 3(STAT3) in airway epithelial cells of asthmatic mouse model and its association with airway remodeling,explore the role of signal-transduction pathway in airway remodeling.Methods Thirty Balb/c mice were randomly divided into normal control group(n=10),asthma without intervention group(n=10) and AG490 intervention group(n=10).The mice were sensitized with ovalbumin to establish the asthmatic model.The histological changes were evaluated by HE staining,total brochial wall thickness(Wat)and smooth muscle thickness(Wam) were measured by image analysis system,the percentages of collagen deposition were detected by Masson′s trichrome staining,the expression of STAT3 in airway were detected by immunohistochemistry technique;lung tissue extracts were analyzed for phosphorylation of STAT3(p-STAT3)by Western blot.SPSS 13.0 software was used to analyze the data.Results 1.The histological changes including airway thickness,airway smooth cell proliferation and excessive collagen deposition in subepithelial aera were found under light microscope in asthmatic mice.2.The level of STAT3 and p-STAT3 in asthma without intervention group were significantly higher than those in normal control group(Pa0.01,0.05),the level of p-STAT3,Wat and Wam in AG490 intervention group were significantly lower than those in asthma without intervention group(Pa0.05).3.The level of STAT3 in epithelial of mouse in asthma without intervention had positive correlations with Wat(r=0.58,P0.05),Wam(r=0.61,P0.05),and the level of p-STAT3 in lung tissue had positive correlations with Wat(r=0.46,P0.05) and Wam(r=0.53,P0.05),respectively.Conclusions Airway remodeling is the main pathological changes of chronic asthma,epithelial STAT3 showes excess expression and constitutive activation in asthma models,which is significantly correlated with airway remodeling,blocking signal pathway of epithelial STAT3 can ameliorate airway remodeling.STAT3 signal transduction pathway of epithelial may paly an important role in asthma airway remo-deling.