穿山龙对支气管哮喘小鼠气道重构和上皮-间质转化的干预作用

Effects of Dioscoreae Nipponicae Rhizoma on airway remodeling and epithelial- mesenchymal transformation in asthmatic mice

目的:研究穿山龙对支气管哮喘小鼠气道重构和上皮-间质转化的作用。方法:60只SPF级雌性ICR小鼠随机分为空白对照组,模型组,低、中、高剂量穿山龙组,地塞米松对照组,每组10只。卵白蛋白致敏建立支气管哮喘气道重构模型。测定乙酰甲胆碱(Mch)激发下的小鼠基础增强呼气间歇(Penh)值,HE染色观察气道组织病理改变,Real-Time PCR法检测转化生长因子-β1(TGF-β1)及上皮-间质转化标志物mRNA表达。结果:与空白对照组比较,Mch浓度从6.25 g/L起,模型组Penh显著升高(P<0.01);模型组气道上皮层增厚,气道狭窄,炎症细胞浸润,气道平滑肌增厚,TGF-β1、α-平滑肌肌动蛋白(α-SMA)、基质金属蛋白酶-9(MMP-9)和波形蛋白(Vimentin)mRNA表达升高(P<0.01),E-钙黏蛋白(E-cadherin)mRNA表达降低(P<0.01);与模型组比较,Mch浓度为12.5、25 g≤时中、高剂量穿山龙组Penh显著降低(P<0.05),Mch浓度从25g/L起,穿山龙浓度越高,Penh值越低,气道炎症细胞浸润、肺泡壁水肿及支气管平滑肌增厚的改善程度越高,中、高剂量穿山龙组TGF-β1、MMP-9、Vimentin mRNA表达降低(P<0.01,P<0.05),高剂量穿山龙组α-SMA mRNA表达降低(P<0.01),E-cadherin mRNA表达增高(P<0.01)。结论:穿山龙可抑制哮喘小鼠肺功能下降,并可通过抑制TGF-β1介导的上皮-间质转化从而改善气道重构状态。

Objective:To study the effects of Dioscoreae Nipponicae Rhizoma(DNR)on airway remodeling and epithelial-mesenchymal transformation(EMT)of asthmatic mice.Methods:Sixty SPF ICR female mice were randomly divided into control group,model group,low-dose DNR group,medium-dose DNR group,high-dose RDN group,dexamethasone(DXM)group,10 mice in each group.The six groups except control group were induced as chronic asthmatic model with ovalbumin.We measured the enhanced pause(Penh)after stimulating by different concentrations of methacholine(Mch).HE staining was used to observe the pathological changes of airway tissue.Real-Time PCR was used to detect the mRNA expression of transforming growth factor-β1 and epithelial-mesenchymal transition markers.Results:Compared with blank control group,from the concentration of Mch 6.25 g/L,the level of Penh in model group was significantly increased(P<0.01).The pathological changes of lung tissue showed thickening of airway epithelium,airway stenosis,inflammatory cell infiltration and thickening of airway smooth muscle.The mRNA expressions of transforming growth factor-β1(TGF-β1),α-smooth muscle actin(α-SMA),matrix metalloproteinase-9(MMP-9)and vimentin were increased(P<0.01),while the mRNA expression of E-cadherin was decreased(P<0.01).Compared with model group,when the concentration of Mch was 12.5 and 25 g/L,the Penh was significantly decreased in medium-dose and high-dose treatment groups(P<0.05).Meanwhile,after increasing the concentrations of Mch from 25 g/L,the higher the Mch concentration was,the lower the Penh value was.The airway inflammatory cell infiltration,alveolar wall edema and bronchial smooth muscle thickening of all the treatment groups were all improved,and the improvement degree was consistent with the increasing trend of dose.The levels of TGF-β1,vimentin and MMP-9 mRNA in medium-and high-dose treatment group were decreased(P<0.01,P<0.05),and the level of α-SMA mRNA was decreased(P<0.01)while E-cadherin mRNA was increased(P<0.01)in high-dose treatment group.Conclusion:DNR can inhibit the decline of lung function in asthmatic mice,and improve airway remodeling by inhibiting TGF-β1-mediated EMT.