Inhibition of 1,25-(OH)_2D_3 on the α-SMA expression and airway remodeling in a murine model of chronic asthma

Objective To investigate the effects of 1,25-(OH)2D3 on the expression of α-smooth muscle actin(α-SMA) and airway remodeling in a murine model of chronic asthma.Methods BALB/c mice were sensitized and challenged with ovalbumin to establish chronic asthmatic model.They were randomly divided into control group,asthma group and VD group(n = 6).Lung sections from the mice were stained by Hematoxylin and Eosin and Sirius Red,respectively.Morphometric analysis of the stained sections was performed using computerized image analysis system.The expression of α-SMA was detected by western blot and real-time RT-PCR.Results(1) Prominent airway remodeling exsited in the asthma group,including the infiltration of inflammatory cells,epithelial loss,subepithelial collagen deposition and increased airway smooth muscle mass.In contrast,1,25-(OH)2D3 treatment attenuated these established structural changes of the airways.(2) The mRNA and protein level of α-SMA in the VD group were both decreased when compared with those in the asthma group(P 0.05),but they were still higher than those in the control group(P 0.05).Conclusion 1,25-(OH)2D3 could markedly inhibit the expression of α-SMA,thus alleviating the asthmatic airway remodeling.