地塞米松对哮喘小鼠气道炎症反应和STAT6表达的影响

Effect of dexamethasone on airway inflammation and the expression of signal transducers and activators of transcription 6 in asthmatic mice

目的:研究地塞米松对支气管哮喘小鼠急性气道炎症反应的作用及对信号转导子和转录激活子6(STAT6)表达的影响。方法:用免疫组织化学法检测给予地塞米松后哮喘小鼠肺组织中STAT6的表达。结果:哮喘组小鼠肺泡灌洗液(BALF)中细胞总数、嗜酸粒细胞(EOS)绝对值显著高于对照组(P<0.01),上述炎症细胞计数地塞米松组比哮喘组明显减少(P<0.01)。HE染色示地塞米松组小鼠气道炎症反应程度较哮喘组减轻。STAT6在气道上皮细胞表达,哮喘组气道上皮细胞中STAT6表达较对照组增加,地塞米松组STAT6表达与哮喘组比较明显减少,较对照组增加。支气管上皮细胞STAT6蛋白与BALF中的EOS绝对值呈显著正相关。结论:地塞米松可在一定程度上减轻哮喘小鼠的气道炎症反应,作用机制可能是通过下调肺脏组织中STAT6蛋白的过度表达,从而抑制依赖于STAT6/IL-4通路的急性气道炎症反应。

Objective To investigate the effects of dexamethasone （DXM） on the airway inflammation and the expression of signal transducers and activators of transcription 6 （ STAT6 ） in asthmatic mice. Method The protein expressions of STAT6 in DXM group were detected by immunohistoehemistry techniques. Results The total cell numbers in BALF,the absolute numbers of EOS in asthma group were all significantly higher than those in the control group（P 〈 0. 01 ） ;the total cell numbers in BALF, the absolute numbers of EOS in DXM group were all significantly lower than those in asthma group （P 〈 0. 01 ） , DXM attenuated the airway inflammation of asthmatic mice. The expressions of STAT6 were mainly on the bronchial epithelium. STAT6 protein levels increased in lung tissues in asthma group. DXM signifi cantly reduced the levels of STAT6 protein. There was a significant positive correlation between the absolute numbers of EOS in BALF and the content of STAT6 in the epithelial cells. Conclusion DXM can ameliorate the progression of airway inflammation following prolonged allergen challenge via regulation of STAT6/IL-4 signal pathway.