地塞米松对哮喘小鼠Th17细胞因子IL-17表达的影响

Effects of dexamethasone on intracellular expression of Th17 cytokine interleukin 17 in asthmatic mice

目的初步探讨地塞米松对哮喘小鼠肺组织中Th17细胞因子IL-17的影响及其机制。方法采用卵清蛋白致敏方法建立支气管哮喘小鼠模型,Balb/c小鼠30只随机分为对照组、哮喘组、地塞米松治疗组各10只。采用ELISA检测小鼠肺泡灌洗液、IL-17水平;HE染色评价各组小鼠气道炎症程度;RT-PCR检测肺组织IL-17、RORγt mRNA表达水平。免疫组织化学方法检测肺组织RORγt蛋白表达水平。结果哮喘组小鼠肺组织RORγt、IL-17 mRNA和蛋白水平均高于对照组(P<0.01),地塞米松治疗组RORγt、IL-17 mRNA和蛋白水平均低于哮喘组(P<0.05)。结论地塞米松可抑制哮喘小鼠肺组织RORγt表达,阻止Th17的分化,从而减少IL-17的分泌,减轻哮喘气道炎症反应。

Objective To study the effects ofdexamethasone on intracellular expression of Th17 cytokine interleukin 17 and the mechanisms in asthmatic mice. Methods Experimental asthma was induced by ovalbumin （OVA） sensitization in 20 in female Blab/c mice with （dexamethasone group, n=10） or without dexamethasone treatment （model group, n=10）, with another 10 serving as the control group. The levels of IL-17 in the bronchoalveolar lavage fluid （BALF） and serum of the mice were measured by enzyme-linked immunosorbent assay （ELISA）, and the airway inflammation was evaluated by HE staining. The expressions of IL-17 and RORγt mRNA were measured by reverse transcription-polymerase chain reaction （RT-PCR）, and the expression of RORγt protein was measured by immunohistochemical staining. Results The levels of ROR3,t and IL-17 mRNA and protein in the asthmatic model group were significantly higher than those in the control group （P〈0.01）, and the increased expressions of ROR＇yt and IL-17 mRNA and protein in the asthmatic mice were significantly reduced by dexamethasone treatment （P〈0.05）. Conclusions Dexamethasone can inhibit the release of IL-17 probably by inhibiting RORγt expression and blocking Th 17 differentiation in asthmatic mice.