γ-分泌酶抑制剂(DAPT)调控哮喘小鼠气道炎症

Modulation of airway inflammation byγ-secretase inhibitor(DAPT)in a mouse asthma model

目的:明确气道内给予Notch信号通路抑制剂DAPT对于哮喘小鼠气道炎症的调控作用,为哮喘的治疗提供新的思路与方法。方法:将60只雌性C57BL/6小鼠(6~8周)随机分为4组:阴性对照组、哮喘组、二甲基亚砜(DMSO)对照组及γ-分泌酶抑制剂(DAPT)试验组。除阴性对照组外,各组小鼠于第0、7天给予腹腔致敏,第15、16、17天使用抗原气道内激发建立哮喘小鼠模型,DAPT组在每次激发前30min经气道给予DAPT,DMSO对照组给予等体积DMSO。末次激发24h后,处死小鼠,收集支气管肺泡灌洗液和肺组织,ELISA法检测支气管肺泡灌洗液中Th1/2细胞因子水平变化,显微镜下对BALF中各组炎性细胞计数。分离各组小鼠肺组织,行苏木精-伊红以及过碘酸希夫碱染色,观察肺组织病理学改变以及气道内黏液分泌情况。结果:DAPT组较DMSO对照组和哮喘组气道炎症明显减轻,气道内黏液分泌显著减少(P<0.05);DAPT组气道灌洗液中IL-4分泌水平较DMSO对照组和哮喘组降低,相反,IFN-γ分泌水平增高(P<0.05)。结论:气道内给予DAPT具有抑制过敏原引起的哮喘小鼠气道炎症反应的作用。

Objective:To explore the modulatory effect of Notch signaling pathway inhibitor(DAPT)administered through airway on the airway inflammation of asthma mouse,and to search new treatment methods for asthma.Methods:Sixty female C57BL/6 mice were randomly divided into negative control group,asthma group,DMSO group and DAPT group.All mice but in negative control group were sensitized i.p.with allergen on day 0and 7.Then mice were challenged with allergen through the airway to set up mouse asthma model on day 15,16,17.DAPT and DMSO were administered intratracheally to mice in DAPT and control group respectively 30 minutes before each challenge.Twenty-four hours after the last challenge,mice were sacrificed.BALF were collected to examine the levels of Th1/Th2 cytokines by ELISA and to count inflammatory cells under the microscope.Lungs of mice were fixed and embedded in paraffin.Tissue sections were stained by HE and PAS to observe pathological changes and mucus secretion in the airway.Results:The airway inflammation and mucus secretion were less in DAPT group than those in asthma group and DMSO group(P<0.05).The levels of IL-4in BALF decreased while the levels of IFN-γincreased in DAPT group than those in asthma group and DMSO group(P<0.05).Conclusion:Administration of DAPT intratracheally could down-regulate airway inflammation in mouse asthma model.