苜蓿素对哮喘小鼠肺泡巨噬细胞TLR4/MyD88/NF-κB通路的抑制作用

Tricin's inhibitory effects on TLR4/MyD88/NF-κB pathway of alveolar macrophages in asthma mice

目的观察苜蓿素对低剂量脂多糖(LPS)诱导的哮喘小鼠气道炎症的抑制作用。方法采用低剂量LPS+卵白蛋白(OVA)建立BALB/c小鼠哮喘气道炎症反应模型,随机分为哮喘模型组、苜蓿素组、地塞米松(阳性药)组,另设空白对照组。ELISA法对小鼠支气管肺泡灌洗液(BALF)炎症介质NO、肿瘤坏死因子α(TNF-α)和白细胞介素-1β(IL-1β)水平进行检测;HE染色观察小鼠肺组织病理情况;RT-PCR法和Western blot法对小鼠肺泡巨噬细胞的Toll样受体4(TLR4)、髓样分化因子88(My D88)、核因子κB p65(NF-κB p65)mRNA及蛋白表达进行检测。结果苜蓿素可显著降低哮喘小鼠BALF液中NO、TNF-α、IL-1β水平,有效改善哮喘小鼠肺部炎症,显著下调肺泡巨噬细胞的TLR4、My D88、NF-κB p65 mRNA和蛋白相对表达量。结论苜蓿素对哮喘小鼠气道炎症有抑制作用,其机制可能与干预TLR4/My D88/NF-κB通路有关。

AIM To observe the inhibitory effects of tricin on the airway inflammation in low concentration LPS induced asthma mice.METHODS The model of asthma mice with airway inflammation was induced by low concentration LPS plus OVA.There were four groups：blank control group,asthma model group,tricin treatment group and dexamethasone（positive drug） treatment group.The levels of inflammatory factors,including NO,TNF-α and IL-1β,in bronchoalveolar lavage fluid（BALF） were detected by ELISA;the pathology of lung tissue was observed by HE staining;the mRNA and protein expressions of TLR4,MyD88 and NF-κB p65 in alveolar macrophages were detected using real-time quantitative PCR（RT-PCR） and Western blot.RESULTS Tricin could significantly decrease the levels of NO,TNF-α and IL-1β in BALF of asthma mice and improve lung inflammation.It could also down-regulate the relative mRNA and protein expressions of TLR4,MyD88 and NF-κB p65.CONCLUSION Tricin has inhibitory effects on airway inflammation in asthma mice,whose mechanism may be related to the intervention of TLR4/MyD88/NF-κB pathway.