MicroRNAs (miRNAs)可促进细胞间通过胞外囊泡(EVs)进行信息传递。EVs中miRNAs在过敏性气道炎症中的生物学作用尚不清楚。方法:从小鼠支气管肺泡灌洗液(BALF)和屋尘螨(HDM)致敏小鼠中分离出呼吸道分泌性EVs (AEVs)。采用miRNA芯片对肺组织中AEVs、miRNA和mRNAs的表达情况进行分析。结果:与（假药）对照小鼠相比，户尘螨暴露小鼠的BALF中AEV增加了8.9倍。HDM暴露导致EVs中139个miRNAs和肺组织中175个miRNAs的表达发生显著变化，两个样本中共有54个共同miRNAs。HDM暴露后，这54个miRNA在AEVs和肺组织中的表达变化呈负相关性。计算分析显示，31个基因，包括IL-13和IL-5Ra，是AEVs中上调而HDM暴露后肺组织中下调的miRNA的可能靶点。使用神经磷脂酶抑制剂 GW4869可以减少HDM暴露后BALF中AEV的含量。GW4869可以降低BALFs中Th2细胞因子和嗜酸性粒细胞计数，减少气道壁和粘膜中嗜酸性粒细胞的聚集。
Clin Exp Allergy
Selective release of miRNAs via extracellular vesicles is associated with house-dust mite allergen-induced airway inflammation
Background: MicroRNAs (miRNAs) may facilitate cell-to-cell communication via extracellular vesicles (EVs). The biological roles of miRNAs in EVs on allergic airway inflammation are unclear. Methods: Airway-secreted EVs (AEVs) were isolated from bronchoalveolar lavage fluid (BALF) of control and house-dust mite (HDM) allergen-exposed HDM-sensitized mice. The expression of miRNAs in AEVs or miRNAs and mRNAs in lung tissue was analysed using miRNA microarray. Results: The amount of AEV increased 8.9-fold in BALF from HDM-exposed mice compared with that from sham-control mice. HDM exposure resulted in significant changes in the expression of 139 miRNAs in EVs and 175 miRNAs in lung tissues, with 54 miRNAs being common in both samples. Expression changes of these 54 miRNAs between miRNAs in AEVs and lung tissues after HDM exposure were inversely correlated. Computational analysis revealed that 31 genes, including IL-13 and IL-5Ra, are putative targets of the miRNAs up-regulated in AEVs but downregulated in lung tissues after HDM exposure. The amount of AEV in BALF after HDM exposure was diminished by treatment with the sphingomyelinase inhibitor GW4869. The treatment with GW4869 also decreased Th2 cytokines and eosinophil counts in BALFs and reduced eosinophil accumulation in airway walls and mucosa.
Conclusion: These results indicate that selective sorting of miRNA including Th2 inhibitory miRNAs into AEVs and increase release to the airway after HDM exposure would be involved in the pathogenesis of allergic airway inflammation.
Y. Gon1 | S. Maruoka1 | T. Inoue1 | K. Kuroda2 | K. Yamagishi3 | Y. Kozu1 | S. Shikano1 | K. Soda1 | J. Lotvall € 4,5 | S. Hashimoto1