miR-155在哮喘患儿痰液的表达及对哮喘小鼠气道炎症的影响

Expression of miR-155 in sputum of asthmatic children and its effect on airway inflammation in asthmatic mice

目的探讨miR-155在哮喘患儿及哮喘小鼠中的表达及其对气道炎症的作用。方法应用realtime PCR方法检测哮喘患儿和健康儿童痰液,以及卵清蛋白诱导的哮喘小鼠和正常小鼠肺组织中miR-155的表达;化学合成miR-155模拟物与阴性对照,并分别鼻滴至哮喘小鼠,HE染色验证哮喘小鼠模型的成功建立,免疫荧光方法和western blot方法检测各组小鼠肺组织TNF-α与NF-κB的蛋白表达。结果与对照组相比,哮喘患儿痰液及哮喘小鼠肺组织中miR-155表达显著降低(P<0.01);HE染色显示哮喘模型组小鼠炎症细胞浸润明显高于正常对照组,哮喘小鼠模型成功建立。miR-155模拟物滴入后,哮喘小鼠肺组织TNF-α与NF-κB的蛋白表达显著降低(P<0.01)。结论 miR-155在支气管哮喘患儿及支气管哮喘小鼠模型中低表达,miR-155模拟物能够抑制哮喘小鼠的气道炎症。

Objective To investigate the expression of miR-155 in asthmatic children and asthmatic mice and its effects on airway inflammation. Methods The expression of miR-155 in the sputum of asthmatic and healthy children, in lung tissue of ovalbumin induced asthmatic mice and normal mice was detected by real-time PCR method, miR-155 mimics and negative controls were chemically synthesized, and administered to nasal cavity of the asthmatic mice respectively. HE staining was used to verify the establishment of the mouse asthmatic model successfully, the expressions of tumor necrosis factor- α （TNF- α ） and nuclear factor-kappa B（NF- κB） were detected by immunofluorescence and Western blot. Results Compared with the control group, the level of miR-155 in sputum of children with asthma and in lung tissue of the asthmatic mice was significantly decreased （P〈0.01）. The infiltration inflammatory ceils in lung tissues were significantly higher in asthmatic group than in the control group, asthmatic mouse model was successfully established. The expression levels of TNF-α and NF- κB in lung tissue were decreased significantly in asthmatic mice than in miR-155 mimics（P〈0.01）. Conclusion The level of miR-155 was downregulated in asthmatic children and asthmatic mice, and miR-155 mimics could inhibit airway inflammation of asthmatic mice.