miR-21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 mi R-21 in sputum of asthmatic children and its effects on airway inflammation in asthmatic mice

目的探讨miR-21在哮喘患儿及哮喘小鼠中的表达及其对气道炎症的作用。方法应用实时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-21的表达;化学合成miR-21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肿瘤坏死因子-α(TNF-α)与核转录因子-κB(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-21表达显著升高(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-21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-21在支气管哮喘患儿及支气管哮喘小鼠模型中高表达,miR-21模拟物能够抑制哮喘小鼠的气道炎症。

Objective To investigate the expression of miR-21 in asthmatic children and asthmatic mice and its ef- fects on airway inflammation. Methods The expression of miR-21 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-21 mimics and negative controls were chemically synthesized, and then nasal instillation was administered to asthmatic mice respectively. HE staining was used to verify whether the mouse asthmatic model was successfully established, The expressions of tumor necrosis factor-α （TNF-α） and nuclear factor-kappa B （NF-KB） were detected by immunofluorescence method and West- ern blot method. Results compared with the control group, the level of miR-21in sputum of children with asthma and in lung tissue of asthmatic mice was significantly increased （P〈0.01） ; HE staining showed that the infiltration of inflammatory cells in lung tissues of mice in asthmatic group were significantly higher than the control group, asthmatic mouse model was successfully established. The expressions of TNF-α and NF-KB in lung tissue of asthmatic mice were decreased significantly after nasal drops of miR-21mimics （P〈0.01）. Conclusion The level of miR-21was upregulated in asthmatic children and asthmatic mice, and miR-21mimics could inhibit airway inflammation of asthmatic mice.