Impact of Dexamethasone on Expression of ORMDL3 and STAT6 in Murine Models of Asthma

Background: Orosomucoid 1-like protein 3 (ORMDL3) and STAT6 have roles in the pathogenesis of asthma. Objectives: To explore the expression of STAT6 and ORMDL3 in a murine model of bronchial asthma and determine potential correlations between ORMDL3 and STAT6, interleukin (IL)-4, and IL-13. The effects of dexamethasone on the expression of STAT6 and ORMDL3 were also investigated. Methods: Female BALB/c mice were randomly separated into three groups: control group, asthma group and dexamethasone group. The asthma and dexamethasone groups were sensitized with ovalbumin (OVA) by intraperitoneal injection in the presence of aluminum hydroxide followed by several inhalation challenges with OVA. The dexamethasone group was intraperitoneally injected with dexamethasone before challenge. The levels of IL-4 and IL-13 in serum were detected by enzyme-linked immunosorbent assay. The expression of STAT6 and ORMDL3 in lungs was measured by real-time PCR, western blot and immunohistochemistry. Results: The concentrations of IL-4 and IL-13 and the expression of STAT6 and ORMDL3 were significantly up-regulated in the asthma group compared with the control group and were markedly suppressed by dexamethasone treatment. Conclusions: The expression of ORMDL3 in asthmatic mice was closely related to STAT6, IL-4, and IL-13. Dexamethasone inhibited the expression of ORMDL3 and alleviated airway hyperresponsiveness.