灵芝多糖对哮喘大鼠肺泡巨噬细胞GITR/GITRL信号系统表达的影响

Effect of Ganoderma Lucidum Polysaccharides on the Expression of GITR/GITRL Signal System at Asthmatic Rat Alveolar Macrophages

目的通过观察灵芝多糖对哮喘大鼠肺泡巨噬细胞糖皮质激素诱导的肿瘤坏死因子受体(GITR)及其配体(GITRL)表达水平的影响,探讨灵芝多糖治疗哮喘炎症的机制。方法将40只清洁级SD大鼠随机分为对照组、哮喘组、地塞米松(DXM)干预组和灵芝多糖干预组4组,分离提纯支气管肺泡灌洗液(BALF)中肺泡巨噬细胞,分别采用实时荧光定量逆转录聚合酶链反应(QRT-PCR)及免疫细胞化学方法检测GITR/GITRL m RNA及蛋白在肺泡巨噬细胞上的表达。结果哮喘组BALF中肺泡巨噬细胞GITR/GITRL m RNA和蛋白的表达水平显著高于对照组(P<0.05或P<0.01);灵芝多糖干预组和DXM干预组GITR/GITRL m RNA和蛋白的表达水平显著低于哮喘组(P<0.05或P<0.01);灵芝多糖干预组GITR/GITRL蛋白的表达水平显著高于DXM干预组(P<0.05),而2组间GITR/GITRL m RNA的表达水平差异无统计学意义。灵芝多糖干预组BALF中细胞总数计数显著低于哮喘组(P<0.01),肺组织炎性病理改变较哮喘组显著减轻。GITR/GITRL m RNA及蛋白均显著呈直线正相关(P<0.01)。结论灵芝多糖能下调肺泡巨噬细胞GITR/GITRL信号系统的表达、降低BALF中细胞总数计数、减轻肺组织炎性病理改变,起到治疗哮喘的作用,但此作用弱于DXM。

OBJECTIVE To explore the possible therapy mechanisms of ganoderma lucidum polysaccharides on asthma inflammation, the expression of glucocorticoid-induced tumor necrosis factor receptor（GITR） and its ligand（GITRL）at asthmatic rat alveolar macrophages were observed. METHODS Forty Clean-level SD rats were randomly divided into four groups including asthma group, control group, dexamethasone intervention group（DXM group） and ganoderma lucidum polysaccharides intervention group, alveolar macrophages were separated and purificated from the bronchoalveolar lavage fluid（BALF）. And the expressions of GITR/GITRL m RNA and protein at alveolar macrophages were detected respectively by Real-time quantitative reverse transcription polymerase chain reaction（QRT-PCR） and immunocytochemistry. RESULTS The expressions of GITR/GITRL m RNA and protein in asthma group were significantly higher than those in the control group（P〈0.05 or P〈0.01）. Moreover, the expressions of them in ganoderma lucidum polysaccharides intervention group and in DXM group were significantly lower than those in asthma group（P〈0.05 or P〈0.01）. Dramatically, the expressions of GITR/GITRL protein in ganoderma lucidum polysaccharides intervention group were significantly higher than those in DXM group（all P〈0.05）. But there was no statistically significant difference of GITR/GITRL m RNA between two groups. Furthermore, in ganoderma lucidum polysaccharides intervention group, the total number of cells calculation in BALF was significantly lower than that in asthma group（P〈0.01）. And the pathological inflammation change in lung tissue were strongly lessened either. And there were significantly positive correlated between GITR and GITRL about m RNA or protein（all P〈0.01）. CONCLUSION Ganoderma lucidum polysaccharides can down regulated the GITR/GITRL signal system at alveolar macrophages, and reduces the total number of cells calculation in BALF, and lessened the pathological inflammation in lung tissue. Result shows there are some therapy roles of ganoderma lucidum polysaccharides on ansthma. But this function is weaker than dexamethasone.