摘要
目的探讨卡介苗(BCG)对支气管哮喘气道炎症发生的预防治疗作用及机制。方法Wistar雄性大鼠40只随机分为对照组、哮喘组、卡介苗治疗组(BCG组)、地塞米松治疗组(地米组)、卡介苗接种组(BCG接种组),每组8只。除对照组外余各组每只大鼠于实验第1、8天腹腔注射10%卵白蛋白抗原混悬液致敏,第15天始超声雾化吸入1%卵白蛋白,20 min/d,共2周,制备哮喘气道炎症模型,各治疗组每次雾化前0.5 h分别给予BCG、地米;卡介苗接种组在OVA致敏前7、3、1 d,每只大鼠分别皮内注射BCG,余治疗同对照组用蒸馏水替代。各组于末次激发24 h后收集标本,检测大鼠支气管肺泡灌洗液(BALF)细胞总数及嗜酸性粒细胞(EOS)计数;HE染色观察气道重塑情况,计算机图像分析气道形态学参数,衡量气道重塑程度;ELISA法检测肺泡灌洗液及血清中转化生长因子-β1(TGF-β1)含量;免疫组织化学(SABC)法检测E钙黏蛋白(E-cadherin)、α平滑肌肌动蛋白(α-SMA)、纤维连接蛋白(Fibronectin)的表达。结果哮喘大鼠支气管肺泡灌洗液细胞总数及嗜酸性粒细胞计数明显增多;HE染色光镜下可见哮喘组支气管管壁变厚、气道变窄,气道上皮受损肿胀,部分可见脱落;哮喘组BALF及血清中TGF-β1含量增加,上皮标志物E-cadherin表达下降,间质的标志物Fibronectin、α-SMA表达增加;BCG和地米治疗组及BCG接种组,BALF细胞总数、EOS计数及气道改变程度等较哮喘组明显减轻,BALF及血清TGF-β1含量较哮喘组下降,E-cadherin表达升高,Fibronectin、α-SMA的表达下降,与哮喘组、对照组相比差异均有统计学意义(P<0.01)。结论①变应原刺激导致TGF-β1分泌增加,进而引起上皮细胞损伤间质转化是导致哮喘性气道炎症形成的重要机制之一;②卡介苗通过免疫调节作用减轻TGF-β1所致的气道上皮细胞损伤及间质转化对哮喘性气道炎症和气道阻塞的作用;③接种BCG可达到与地塞米松同样减轻气道炎症的作用。
Objective To Investigate the prevention and therapeutic effect of BCG on airway inflammation of asthma. Methods 40 male Wistar rats were randomly divided into 5 groups including control group, asthma group, BCG treatment group, dexamethasone treatment group, Bacillus Calmette Guérin（BCG） vaccination group, with 8 rats in each group. In every group expect the control, each rat was sensitized by intraperitoneal injection of 10% ovalbumin antigen suspension in the first and eighth day of the experiment. Starting from the fifteenth day, rats were treated with ultrasonic atomization by 1% of ovalbumin with 20minutes per day for 2 weeks to establish the asthmatic airway inflammatory model. Furthermore, rats were given BCG or dexamethasone in BCG and dexamethasone treatment group half an hour before each ultrasonic atomization. In BCG vaccination group, rats were vaccinated by intradermal injection of BCG at the first, third and seventh day before OVA sensitization. Rats in the control were given the same treatment with distilled water. Specimens were collected at 24 hours after the last stimulation. Briefly, total cell and eosinophil cell counts in the bronchoalveolar lavage fluid （BALF） were detected, airway remodeling were tested by HE staining, the degree of airway remodeling were decided by analysis of morphological parameters with computer image analysis software. Besides, transforming growth factor beta 1 （TGF-β1 ） in BALF and serum were measured using ELISA and expressions of E cadherin, alpha smooth muscle actin （α-SMA） and fibronectin were detected with immunohistochemistry. Results The total cell and eosinophil cell counts in BALF were significantly increased in asthma rats. HE staining showed that the bronchial wall was obviously thickened, the airway was narrowed and airway epithelium was greatly damaged with swelling and partial deletion in asthmatic airway under light microscope. Moreover, levels of TGF-β1 in both BALF and serum were significantly increased. Expression of epithelial marker, E-cadherin was decreased and expressions of mesenchymal markers, Fibronectin, α-SMA were increased. Giving the BCG or dexamethasone or BCG vaccination treatment, asthma was significantly relieved with indicators above reversed （P 〈 0.01 ）. Conclusions ①Allergen stimulation leads to increased secretion of TGF-β1, resulting in epithelial cell injury and epithelial-mesenchymal transition, which is one of the critical mechanisms of asthmatic airway inflammation; ②BCG plays important roles in reducing the epithelial cell injury and epithelial-mesenchymal transition induced by TGF-β1 ; ③Vaccination of BCG has similar therapeutic effects as dexamethasone on asthmatic airway inflammation.
出处
《中华肺部疾病杂志（电子版）》
CAS
2014年第3期25-29,共5页
Chinese Journal of Lung Diseases(Electronic Edition)
基金
山西省自然科学基金资助项目(2013011055-1)
山西省留学人员科研资助项目(2011-104)
关键词
支气管哮喘
卡介苗
气道炎症
转化生长因子-Β1
上皮细胞
间质转化
Bronchial asthma
Bacillus Calmette Guérin
Airway inflammation
Transforming gronth factor beta 1
The epithelial cells
Mesenchymal transition
