Promotion Of Brg1 On Asthma Mucus Hypersecretion

OBJECTIVE:This experiment was designed to investigate the effect and mechanism of Brg1（Brahma-related gene 1）on mucus hypersecretion in the airways of asthmatic mice.METHODS:Female C57bl/6 mice aged 6⁸ weeks were randomly divided into four groups:Control group、Asthma group、Brg1^-/-group and Brg1^-/-+Asthma group（10 in each group）.Brg1^-/-mouse was knocked down of Brg1 gene in type II alveolar epithelial cells（AEC2s）in C57bl/6mice.Asthma group and Brg1^-/-+Asthma group were sensitized with ovalbumin（OVA）to established C57bl/6 mouse asthma model.The number of goblet cells and mucus in airways were stained by PAS staining and real-time PCR was to detect the level of MUC5AC mRNA in lung tissues.MucinMUC5ACandIL-13wasdetectedbyELISAand immunohistochemistry in BALF of lung tissues.The expression of STAT6and p-STAT6 were detected by Western blot analyses.RESULTS:Compared with control group,Asthma group induced airway mucus hypersecretion and the increase of MUC5AC mRNA.The expression of IL-13 and MUC5AC in BALF were significantly higher than those of the controls,as well as the activation of p-STAT6 in lung tissues（P<0.05）.However,When the Brg1 gene was knocked down in AEC2s in C57bl/6 mice,the airway mucus and MUC5AC mRNA were reduced.The expression of IL-13 and MUC5AC in BALF,p-STAT6 in lung tissues were also significantly down-regulated（P<0.05）.CONCLUSION:The effect of knocking down of Brg1 gene in AEC2s in C57bl/6 mice alleviates bronchial asthma airway mucus hypersecretion and reduces the expression of MUC5AC,which may be explained by inhibiting STAT6 activation.These Suggest Brg1 can promote asthma airway mucus hypersecretion.