[Inhibitory effect of miR-20b on airway inflammation in asthmatic mice]

To explore the effect of miR-20b in inhibiting airway inflammation in a mouse model of asthma.

Female BALB/c mouse models of asthma, established by sensitizing and challenging the mice with a mixture of ovalbumin and aluminum hydroxide, were subjected to intranasal instillation of 20 µg miR-20b mimics or a miR-20b scramble every 3 days. On day 49, bronchoalveolar lavage fluid (BALF) was collected from the mice to examine the counts of total cells and different cell populations; HE staining was used to observe the pathological changes of the lung tissue, and the concentration of vascular endothelial growth factor (VEGF) in BALF was detected by ELISA.

Treatment of the asthmatic mice with miR-20b mimics decreased not only the counts of the total leukocytes, neutrophils and eosinophils in the BALF but also mucus secretion in the airway and inflammatory cell infiltration around the bronchus, and lessened thickening of the airway mucosa. Instillation with miR-20b mimics significantly reduced the concentration of VEGF in BALF from 28.55±3.42 pg/mL in the asthma model group to 18.19±3.67 pg/mL (P<0.01).

MiR-20b can inhibit airway inflammation in asthmatic mice possibly by reducing the expression of VEGF.