过敏性哮喘是一种常见的慢性气道炎症性疾病，目前仍缺乏有效的治疗方法。我们预实验结果发现人脐带间质干细胞来源的外泌体（hucMSC-ex）能够改善尘螨诱导的小鼠哮喘，体外能够降低支气管上皮细胞炎症因子的分泌。但是hucMSC-ex中发挥改善作用的关键分子不是很清楚。我们通过small RNA测序筛选出hucMSC-ex中携带的miR-615-3p对哮喘有改善作用，但具体机制有待阐明。因此，本研究将采用miRNA载体构建、荧光素酶活性等分子技术，对靶基因进行筛选、验证及干预，寻找miR-615-3p调控的支气管上皮细胞炎症反应相关靶基因及信号传导通路，阐明hucMSC-ex改善哮喘的作用机制。本研究将为hucMSC-ex治疗哮喘提供新的思路和实验依据，具有十分重要的价值和临床应用前景。

Allergic asthma is a common chronic airway inflammatory disease and there is still no effective treatment. We have found that human umbilical cord mesenchymal stem cell-derived exosomes (hucMSC-ex) can significantly improve asthma induced by house dust mites in mice and decrease the secretion of inflammatory cytokines in bronchial epithelial cells in vitro. But the key molecules in hucMSC-ex are not clear. We screened the miR-615-3p in hucMSC-ex by small RNA sequencing, which had an improvement effect on asthma, but the specific mechanism remains to be clarified. Therefore, this study will use miRNA vector construction，luciferase activity and other cellular and molecular biology techniques to screen, verify and intervene target genes, investigate the target genes and signal transduction pathways related to the inflammatory response of bronchial epithelial cells regulated by miR-615-3p. We expect to elucidate the mechanism of hucMSC-ex in improving asthma. This study will provide a new idea and experimental basis for hucMSC-ex in the treatment of asthma, which has a very important value and clinical application prospect.