布地奈德对哮喘大鼠肺泡巨噬细胞GITR/GITRL信号系统表达的调控作用

The Regulation of Budesonide on the Expression of GITR /GITRL Signaling System in Alveolar Macrophages in Asthmatic Rat

目的:通过观察布地奈德对大鼠肺泡巨噬细胞(Mφ)GITR/GITRL表达的影响,探讨GITR/GITRL信号系统参与哮喘炎症反应的机制。方法:将30只SD大鼠随机分为哮喘组、对照组、布地奈德组,每组10只,卵白蛋白建立哮喘模型。行支气管肺泡灌洗分离提纯肺泡Mφ,分别采用实时荧光定量PCR法和细胞免疫化学法测定肺泡MφGITR/GITRL mRNA和蛋白的表达。结果:哮喘组肺泡MφGITR/GITRL mRNA△CT值(11.05±0.23,9.82±1.24)和蛋白OD值(0.64±0.08,0.71±0.05)表达水平显著高于对照组△CT值(12.79±1.28,11.88±1.37)和蛋白OD值(0.37±0.09,0.39±0.04)(P均<0.05);布地奈德组肺泡MφGITR/GITRL mRNA△CT值(12.97±0.97,11.16±1.42)和蛋白OD值(0.40±0.06,0.40±0.07)表达量显著低于哮喘组(P均<0.05),但与对照组比较差异无统计学意义(P均>0.05)。结论:哮喘大鼠肺泡MφGITR/GITRL的表达升高,肺泡Mφ可能通过GITR/GITRL信号系统起到促进哮喘气道炎症的作用,而糖皮质激素布地奈德可能通过抑制肺泡MφGITR/GITRL信号通路在哮喘治疗中起作用。

Objective： To investigate the potential roles of glucocorticoid-induced tumor necrosis factor receptor/glucocorticoid-induced tumor necrosis factor receptor ligand（ GITR /GITRL） signaling system in pathogenesis of asthma inflammation. The regulation of budesonide on the expression of GITR /GITRL signaling system in alveolar macrophages（Mφ） in asthmatic rat was observed. Methods：Thirty SD rats were randomly divided into three groups,including asthma group,control group,budesonide group,and the rat asthma model was established with ovalbumin（OVA）. Alveolar macrophages were separated from bronchoalveolar lavage fluid. The expression of GITR /GITRL mRNA in alveolar macrophages were detected by Real-time PCR. And the expression of GITR /GITRL protein in alveolar macrophages were also detected by immunocytochemistry. Results： The expression of GITR /GITRL mRNA（ △CT = 11. 05 ±0. 23,9. 82 ± 1. 24,respectively） and protein（ OD = 0. 64 ± 0. 08,0. 71 ± 0. 05,respectively） in asthma group were significantly higher than that of control group（ △CT = 12. 79 ± 1. 28,11. 88 ± 1. 37,respectively and OD = 0. 37 ± 0. 09,0. 39 ± 0. 04,respectively）（P 0. 05）. Moreover,in budesonide group,the expression of GITR /GITRL mRNA（ △CT = 12. 97 ± 0. 97,11. 16 ±1. 42,respectively） and protein（OD = 0. 40 ± 0. 06,0. 40 ± 0. 07,respectively） were dramaticly lower than that of asthma group（all P 〈0. 05）. Furthermore,there were no statistical significance between control group and budesonide group（all P 〉0. 05）. Conclusions：Expression of GITR /GITRL at alveolar macrophages were increased in asthmatic rats,and perhaps alveolar macrophages participated in the pathogenesis of asthma inflammation via GITR /GITRL signaling system. Glucocorticoid may involve in the treatment of asthma by inhibiting GITR /GITRL pathway.