Effects of budesonide inhalation on transforming growth factor-β1, Smad in an asthmatic mouse model of airway remodeling

Objective To observe the effects of aerosol budesonide on the airway remodeling and the expression of transforming growth factor-β1 （TGF-β1）, Smad 2, Smad 3, Smad 7 in an asthmatic mouse model. Methods Thirty BALB/c mice were divided into model group, budesonide group and normal group, ten in each group. Model group was sensitized on days 0 and 14 by ovalbumin（OVA） and challenged from days 24 to 51 by OVA repeatedly to establish a chronic model of asthma characterized by airway remodeling. Budesonide group was interfered with aerosol budesonide 30 rain before challenge. Normal group was treated with saline instead of OVA. The airway wall thickness（WAt/Pi）, bronchial smooth muscle thickness（WArn/Pi）, bronchial smooth nucleus counts（N/Pi） were measured by image analysis system. The expression of TGF-β1, TGF-β1 mRNA, Smad 2 mRNA, Smad 3 mRNA, Smad 7 mRNA were detected by immunohistochemistry and RT-PCR. Results ①WAt/Pi, WAm/Pi, N/Pi in model group were all significantly higher than those in normal group（ P〈0. 05） ,while decreased in budesonide group （ P〈0. 05）. ②The expression of TGF-β1 , TGF-β1 mRNA and Smad 2,Smad 3 mRNA in model group were higher than those in normal group（ P〈0.05） ,while decreased in budesonide group as compared with model group（ P〈0.05）. ③The expression of Smad 7 mRNA in budesonide group was significantly higher than that in model group. Conclusions Budesonide inhalation could decrease the expression of TGF-β1, TGF-β1 mRNA, Smad 2, Smad 3 rnRNA, increase the expression of Srnad 7 rnRNA in a chronic asthmatic mouse model and inhibit airway remodeling. Key words: Asthma ;  Airway remodeling ;  Transforming growth factor-β1 Smad ;  Budesonide