Expression Level of MiRNA-126 in Serum Exosomes of Allergic Asthma Patients and Lung Tissues of Asthmatic Mice

Background: To investigate MiRNA-126 amounts in serum exosomes from allergic asthma patients as well as lung tissues of asthmatic mice, evaluating the expression of its target gene DNMT1 in mouse specimens. Methods: MiRNA-126 amounts in serum exosomes from asthmatic patients were detected by real-time PCR. The mouse model of allergic asthma was established by OVA-sensitization, and allergic symptoms were recorded; serum IL-4 and sIgE level evaluation (ELISA), broncho alveolar lavage fluid (BALF) cell count and ME staining were performed to assess airway inflammation. MiRNA-126 and DNMTI levels in the lung of asthmatic and control mice were detected by real-time PCR; DNMTI protein levels were detected by immunoblot. Results: MiRNA-126 amounts in peripheral blood exosomes from patients with allergic asthma were significantly higher than that of healthy volunteers (P<0.05). The frequencies of scratching of both sides of the nose and sneezing were elevated within 10 min of excitation in asthmatic rats compared with controls. Meanwhile, OVA-sIgE and IL-4 levels were significantly higher in asthmatic animals than controls (P<0.05). In the asthma group, narrowed bronchial lumen and thickened wall were observed, and bronchial and peripheral vessels showed overt inflammatory cell infiltration. Eosinophil, neutrophil and mast cell amounts in the BALF of asthmatic mice were significantly higher than control values. Furthermore, lung miRNA-126 expression in asthmatic mice was significantly higher than that of controls. Finally, DNMTI mRNA and protein levels were significantly lower in asthmatic animals compared with controls (P < 0.01). Conclusion: MiRNA-126 is highly expressed in serum exosomes from allergic asthma patients and lung tissues of asthmatic mice, suggesting that it may be involved in the pathogenesis of bronchial asthma.