布地奈德抑制哮喘小鼠肺组织OX40、气道炎症和气道高反应性的研究

Inhibitory effects of budesonide on pulmonary OX40 expression ,airway inflammation,and airway hyperresponsiveness in asthmatic mice

目的:研究布地奈德对哮喘模型小鼠肺组织OX40(CD134)表达、气道炎症和气道高反应性的干预作用。方法:18只SPF级BALB/c小鼠随机分为正常组、哮喘组、布地奈德组。卵蛋白(ovalbumin,OVA)致敏和激发建立哮喘模型。末次激发24 h后,测定气道反应性,HE染色观察炎症细胞浸润,ELISA法分别检测血清总IgE、OVA特异性IgE(OVA-sIgE)以及支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)中的IL-4和IL-13。Western blot检测肺组织OX40蛋白表达。结果:随着氯化乙酰胆碱(Ach)浓度的增加,哮喘组小鼠气道阻力明显增加,正常组仅轻度增加,布地奈德组小鼠气道阻力的增加程度低于哮喘组小鼠(P<0.05);在BALF中炎症细胞总数和嗜酸性粒细胞分类计数方面,哮喘组小鼠高于正常组小鼠(P<0.05),布地奈德组小鼠与哮喘组小鼠相比明显降低(P<0.05);在BALF中IL-4、IL-13和血清总IgE、OVA-sIgE方面,哮喘组高于正常组(P<0.05),布地奈德组低于哮喘组小鼠(P<0.05);哮喘组小鼠肺组织OX40高于正常组(P<0.05),布地奈德组与哮喘组相比小鼠肺组织OX40降低(P<0.05)。结论:布地奈德可抑制哮喘模型小鼠气道炎症和气道高反应性,可能与抑制OX40/OX40L协同刺激通路有关。

Objective：To investigate the inhibitory effects of budesonide on the expression of OX40 （CD134）,airway inflammation, and airway hyperresponsiveness in a murine model of asthma. Methods：Total 18 BALB/c mice were randomly divided into 3 groups. They were control group,ovalbumin（OVA） group and budesonide group. Mice were sensitized and challenged by OVA. Airway responsiveness to acetylcholine chloride was measured. Hematoxylin ＆ eosin staining was used to assess the inflammatory cell infiltrates. Levels of IL-4 and IL-13 in bronchoalveolar lavage fluid（BALF）, and total IgE and OVA-specific IgE（OVA-sIgE） in serum were detected by ELISA. The protein expression of OX40 was determined by Western blot analysis. Results：The airway resistance in the OVA group was obviously increased in a dose-dependent manner by administration of ACh,whereas only a slight increase could be detected in the control group. There were no significant differences in baseline airway resistance among three groups （P 〉 0.05）. Treatment with budesonide led to a sharp decrease in airway resistance compared with the OVA group （P 〈 0.05）. The number of eosinophils and total inflammatory cells in BALF in the OVA group increased significantly compared with the control group （P 〈 0.05） ,which was significantly decreased by treatment with budesonide（P 〈 0.05）. The levels of the 1L-4 and IL-13 in BALF,and the levels of total serum IgE and OVA-sIgE were significantly increased in OVA-sensitized/challenged mice compared with the control group （P 〈 0.05）. Administration of budesonide reduced the levels of those Th2 cytokines in BALF, and the levels of total serum IgE and OVA-sIgE,when compared with the OVA group （P 〈 0.05）. Treatment with budesonide increased the ratio of OX40,compared with that in the OVA group （P 〈 0.05）. Conclusion：Budesonide could inhibit the airway inflammation and hyperresponsivenes by down-regulating the expression of OX40.