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 H&E staining were
performed to assess airway inflammation. MiRNA-126 and DNMT1 levels in the lung of asthmatic and control mice
were detected by real-time PCR; DNMT1 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, DNMT1 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.