三步序贯法对哮喘大鼠模型激素撤减中转化生长因子β1及胶原表达的影响

Effects of three-stage sequential therapy on expression of TGF-β1 and collagen of asthma rats in process of steroid withdrawal

目的:观察三步序贯法对哮喘模型大鼠激素撤减过程中转化生长因子-β(T G F-β)及胶原(Collagen)表达的影响。方法:将150只雄性SD大鼠随机分为正常对照组、气道重塑组、地塞米松组、普米克令舒组及三步序贯组。模型建立方法:以卵蛋白100mg加氢氧化铝100mg致敏,1%卵蛋白激发,自激发之日开始,于激发前30min给予地塞米松0.5mg/kg腹腔注射,连续2周,从第3周开始,按每周0.1mg/kg速度递减地塞米松用量,至第7周地塞米松全部撤除。三步序贯组在地塞米松干预基础上,于实验第15-28天(地塞米松撤前)给予第1步方颗粒灌胃,第29-63天(地塞米松撤中)给予第2步方颗粒灌胃,第64-77天(地塞米松撤后)给予第3步方颗粒灌胃,每日1次。各组于实验流程第28、63、77天末次激发2h后取左肺组织行免疫组化检测,比较各组TGF-β1、CollagenⅠ、CollagenⅢ蛋白表达变化。结果:在撤减过程中,与正常对照组比较,气道重塑组和地塞米松组CollagenⅠ蛋白表达升高(P<0.05),TGF-β1、CollagenⅢ均显著升高(P<0.01);与地塞米松组比较,三步序贯组TGF-β1、CollagenⅠ显著降低(P<0.01,P<0.05),CollagenⅢ在撤减中后期降低(P<0.05)。结论:三步序贯法对哮喘模型大鼠撤减激素过程中气道重塑的阻抑作用可能是通过降低TGF-β1,调控其介导的信号通路,进而减少CollagenⅠ和CollagenⅢ沉积来实现的。

Objective： To observe the influence of three-stage sequential therapy on expression of TGF-β1 and collagen of asthma rats during process of steroid withdrawal. Methods： One hundred and fifty male SD rats were randomly divided into blank control group, airway remodeling group, hexadecadrol intervening group, pulmicort respules group and three-stage sequential therapy group. The rat models were established by using sensitization of ovalbu-min（OVA）（100mg） and aluminium hydroxide（100mg）. The models were stimulated by using 1% OVA, and from the third week, hexadecadrol（0.5mg/kg） was injected intraperitoneally on the first 30 min before stimulation, and lasted for 2 weeks. The dosage of hexadecadrol was decreased according to the speed of 0.1mg/kg per week, and it was removed until to the 7th week. Based on the intervening of hexadecadrol, rats in the three-stage sequential therapy group received gavage administration with the frist-stage formula in the 15 th day to 28 th day during experiment, the rats received gavage administration with the second-stage formula in the 29 th day to 63 rd day during experiment, and rats received gavage administration with the third-stage formula in the 64 th day to 77 th day during experiment daily. The left lung tissues of rats were obtained on the 28 th day, 63 rd day, and 77 th day after 2 hours of the last stimulation, and the expression of TGF-β1, Collagen I, and Collagen III proteins in lung tissues of rats were compared by using immunohistochemistry. Results： In the process of steroid withdrawal, the expression of Collagen I, TGF-β1, and Collagen III of rats in hexadecadrol intervening group, airway remodeling group were significantly higher than that of blank control group（P〈0.05, P〈0.01）. Compared with hexadecadrol intervening group, the expression of Collagen I and TGF-β1 of rats in the threestage sequential therapy group decreased significantly, and the expression of Collagen III decreased in the later period of steroid withdrawal. Conclusion： The inhibition of the three-stage sequential therapy on airway remodeling of rats in the process of steroid withdrawal might be relate with the lower expression of TGF-β1, so that it could regulate the TGF-β1-mediate signaling pathway and reduce the deposition of Collagen I and Collagen III.