To further explore miR-146a-3p-mediated Th17 differentiation in severe asthma by targeting MBD2, we isolated murine BECs from murine bronchi or tracheas. After isolation, immunofluorescence identification results showed that the rate of cytokeratin positive cell population of BECs in mice was more than 90% (Fig. 4A).  Then BECs were then irritated with HDM and LPS and transfected with the inhibitor miR-146a-3p, mimic miR-146a-3p, si-MBD2, OE-MBD2. This evidence concerns the gene MBD2 and asthma.