卡介苗对支气管哮喘大鼠气道重塑及血清TGF-β1表达的影响

Influence of BCG on airway remodeling in bronchial asthma rats and the expression of TGF-β in serum

目的探讨卡介苗(BCG)干预下,支气管哮喘大鼠气道重塑以及血清转化生长因子-β1(TGF-β1)的表达情况。方法将30只清洁级健康雄性Sprague-Dawley(SD)大鼠作为研究对象,随机分为对照组(A组)、哮喘组(B组)和BCG治疗组(C组)三组,每组各10只。B组大鼠采用腹腔注射10%卵清蛋白(OVA)+氢氧化铝混合液致敏,再用1%OVA超声雾化吸入的方法进行激发制作支气管哮喘模型;A组大鼠采用相同的制模方法,但在相应的时间点使用生理盐水替代致敏剂,进行腹腔注射和超声雾化吸入处理。C组大鼠制模方法与B组相同,每天雾化前半小时皮内注射BCG 0.025 mg进行干预治疗。三组大鼠在末次激发24小时后收集血清标本,采用ELISA法检测TGF-β1含量,采血后处死大鼠并制作气管和肺组织病理切片,观察大鼠气道炎症及气管重塑情况。结果对照组大鼠肺组织中肺泡、气管、血管结构均正常;哮喘组大鼠肺泡壁明显增厚,气管腔可见粘液残留,部分可见肺泡腔内出血;BCG治疗组大鼠肺组织整体结构趋于正常。哮喘组大鼠血清中TGF-β1含量较对照组显著升高,经卡介苗干预后,大鼠血清TGF-β1显著降低(P<0.05)。结论支气管哮喘大鼠经过BCG干预治疗,气道重塑减轻,可能是通过抑制TGF-β1的表达来发挥作用。

Objective To investigate the airway remodeling and serum transforming growth factor-beta 1(TGF-β1) expression in rats with bronchial asthma those intervened byBCG.Methods 30 male healthy sprague-dawley(SD) rats were enrolled as the study subjects and they were randomly divided into control group(group A), asthma group(group B) and BCG treatment group(group C), with 10 rats in each group. Rats in group B were sensitized by intraperitoneal injection of 10% ovalbumin(OVA) and aluminum hydroxide mixture, and then stimulated by 1% OVA ultrasonic atomization inhalation to make bronchial asthma model. The rats in group A adopted the same modeling method, but at the corresponding time point, normal saline was used instead of sensitizer for intraperitoneal injection and ultrasonic atomization inhalation.Rats in group C were molded through the same way as in group B, and BCG 0.025 mg was injected intra-dermal half an hour before atomization every day for intervention. Serum samples of the three groups of rats were collected 24 hours after the last stimulation, and the content of TGF-β1 was detected by ELISA. After blood collection, the rats were sacrificed and the trachea and lung histopathology sections were made to observe the airway inflammation and tracheal remodeling in the rats.Results The structures of alveoli, trachea and blood vessels in the control group were normal. In the asthma group, the alveolar wall was significantly thickened, mucus remained in the trachea cavity, and intra-alveolar hemorrhage was partially observed. The overall structure of the lung tissues of rats in BCG treatment group tended to be normal. The content of TGF-β1 in the serum of rats in the asthma group was significantly higher than that in the control group. After BCG intervention, the level of TGF-β1 in the serum of rats was significantly decreased(P<0.05).Conclusions After BCG intervention treatment, airway remodeling was alleviated in bronchial asthma rats, the mechanism may possibly by inhibiting TGF-β1 expression.