Effects of 1,25-(OH_2)D_3 on airway remodeling and expression of matrix metalloprotease-9 in murine model of chronic bronchial asthma

Objective To investigate the effects of 1,25-(OH)2D3 on airway remodeling and the expression of matrix metalloprotease-9(MMP-9) in a murine model of chronic bronchial asthma(asthma),and to explore the potential role of 1,25-(OH)2D3 in the treatment of asthma.Methods BALB/c mice were sensitized and challenged with ovalbumin to establish the chronic asthmatic model.They were randomly divided into three groups:control group,asthma group and 1,25-(OH)2D3 group.The characteristic airway inflammation and alteration of airway structure were detected by HE staining.Morphometric analysis of the stained sections was performed using computerized image analysis system.The expression of MMP-9 in the mRNA level was detected by RT-PCR.Results ①The infiltration of inflammatory cells,epithelial loss,smooth muscle cell layer thickening were decreased in 1,25-(OH)2D3 group when compared with those in the asthma group (P0.05),but these changes were more significant than those in the control group (P0.05);②WAm/Pbm、WAi/Pbm and N/Pbm decreased significantly in 1,25-(OH)2D3 group when compared with those in asthma group (P0.05).but they were still higher than those in the control group (P0.05);③The mRNA level of MMP-9 in 1,25-(OH)2D3 group was decreased when compared with that in asthma group (P0.05).But it was still higher than that in the control group (P0.05).Conclusions Intervention with 1,25-(OH)2D3 could markly alleviate the asthmatic airway remodeling and partly restore of appropriate structure of airway wall.It could also lower the expression of MMP-9 in the lung tissue on asthmatic condition,thus delay the process of airway remodeling.