儿童过敏性鼻炎启动过程中miR-375对AhR/TSLP/ILC2轴的调节作用

Activated group 2 innate lymphoid cells (ILC2) have emerged as the critical factor for the initiation of allergic cascade. However, the underlying regulation has not been fully understood. In or previous study, we demonstrated that miR molecules such as miR-146a is able to play a suppressive role in allergen-induced local allergic response in nasal epithelium (Sci Rep, 2015). Based on the findings that allergen can induce thymic stromal lymphopoietin (TSLP) production in cultured airway epithelial cells, and TSLP can activate ILC2 in allergic airway inflammation, and bioinformatics analysis and preliminary indicated miR-375 can target AhR, a negative modulator of TSLP, we hypothesized epithelial cell-derived miR-375 plays an essential role in the initiation of local allergic response by targeting AhR/TSLP/ILC2 axis, which can be regulated by steroid or curcumin. To address this issue, we plan to examine the expression of miR-375, AhR, TSLP and ILC2 in nasal mucosa of allergic rhinitis or local allergic rhinitis of children patients and mouse model, and evaluate the association of miR-375, AhR, TSLP and ILC2. Moreover, we plan to examine the regulatory effect of miR-375 mimics or inhibitor transfection on allergen-induced TSLP expression cultured epithelial cells, and investigate the effect of lentivirus-contained miR-375 mimics or inhibitor on the level of AhR, TSLP, IL-25 and IL-33, as well as the activation of ILC2 and the histological changed in nasal mucosa of mouse model, thus to confirm miR-375 is able to modulate local allergic response by targeting AhR/TSLP/ILC2 axis. This study will expand our understanding on the molecular mechanism underlying local allergic response in light of ILC2 regulation, and contribute to identify novel molecular target for future improved management.

2型天然淋巴样细胞（ILC2）活化是气道过敏反应级联启动的关键因素，但其调节机制不明。我们前期的研究证实，miRNA小分子如miR-146a对过敏原诱导的局部黏膜反应有重要抑制作用（Sci Rep, 2015）。最新研究、生物信息学分析和预实验证实miR-375能够作用于TSLP的负性调节基因芳香烃受体（AhR）。我们假设过敏原暴露过程中，上皮细胞来源的miR-375通过抑制AhR导致TSLP/ILC2轴的增强是局部过敏反应级联启动的关键环节。为此，我们拟在检测几类儿童变应性鼻炎患者（AR和LAR）和小鼠模型鼻黏膜组织中miR-375、AhR、TSLP和ILC2的关联性的基础上，通过体外实验和动物实验证实miR-375能够通过AhR/TSLP/ILC2调节鼻黏膜过敏反应级联，可以作为激素或姜黄素的干预靶点。这个研究有助于理解AR发病的局部机制，为建立可能的干预手段寻找到新的分子靶点。

研究表明，变应性鼻炎（AR）患者外周血中II型先天淋巴样细胞（ILC2）的数量和功能显着增加。研究通过体内和体外研究评估miR-375在调控ILC2分化和功能中的作用。通过实时聚合酶链反应（PCR），酶联免疫吸附测定（ELISA）和流式细胞术分别检测和比较了24例AR患者和20例对照者中miR-375、胸腺基质淋巴细胞生成素（TSLP）和ILC2的表达。将miR-375模拟物或抑制剂转染到人鼻上皮细胞（HNEC）中，并通过ELISA检测TSLP的表达。共培养HNEC和ILC2，以探索miR-375对ILC2的作用。建立AR小鼠模型以探索miR-375在体内对ILC2的作用。与对照组相比，AR患者中TSLP，miR-375和ILC2的表达明显更高。升高的miR-375水平也与TSLP和ILC2的表达显着相关。我们发现，用miR-375模拟物转染的HNECs的TSLP表达明显高于用miR-control和miR-375抑制剂转染的TSLP。在共培养系统中，用miR-375模拟物转染的HNEC促进了ILC2产生的II型细胞因子，这种作用能被抗TSLP阻断。我们的结果还表明，miR-375抑制剂可减轻AR小鼠的过敏症状和II型细胞因子的产生。我们的发现表明，miR-375通过TSLP介导了ILC2细胞调节，为AR提供了新的潜在治疗靶标。