Down-regulatory effects of budesonide on expression of STAT6 and ORMDL3 in lung tissues of asthmatic mice

Abstract:

Objective To investigate the roles of signal transduction and activator of transcription 6 (STAT6) and orosomucoid 1-like 3 (ORMDL3) in airway remodeling among asthmatic mice and to observe the effects of budesonide (BUD) on their expression. Methods Thirty BALB/c mice were randomly divided into control, asthma, and BUD intervention group. The mice were sensitized and challenged with ovalbumin (OVA) to establish a mouse model of asthma. The BUD intervention group received aerosol inhalation of BUD dissolved in normal saline 30 minutes before each OVA challenge, while normal saline was used instead of OVA solution in the control group. The pathological changes in the airway were observed by hematoxylin-eosin staining and Masson staining. The interleukin-13 (IL-13) level in lung homogenate was measured by enzyme-linked immunosorbent assay. The mRNA expression of STAT6 and ORMDL3 was measured by RT-PCR. Results The asthma group showed more pathological changes in the airway than the control and BUD intervention groups, and the BUD intervention group had reduced pathological changes in the airway compared with the asthma group. The asthma and BUD intervention groups had significantly higher IL-13 levels and mRNA expression of STAT6 and ORMDL3 than the control group (P<0.05), and these indices were significantly higher in the asthma group than in the BUD intervention group (P<0.05). The Pearson correlation analysis showed that STAT6 mRNA expression was positively correlated with ORMDL3 mRNA expression (r=0.676, P=0.032). Conclusions STAT6 and ORMDL3 may be involved in the airway remodeling of mice, and BUD can reduce airway remodeling in asthmatic mice, possibly by down-regulating mRNA expression of STAT6 and ORMDL3.