转录因子T-bet与哮喘大鼠气道炎症及川芎嗪的干预效应

Effect of ligustrazine on airway inflammation and transcription factor T-bet expression in asthmatic rats

目的:转录因子T-bet在支气管哮喘的发病中起重要作用,川芎嗪治疗哮喘有效。实验拟观察川芎嗪对哮喘大鼠气道炎症的影响和转录因子T-bet的调控作用。方法:实验于2005-11/2006-06在南京医科大学完成。①实验材料及分组:72只SPF级SD大鼠随机分为正常对照组、哮喘模型组、川芎嗪小剂量组(20mg/kg)、川芎嗪中剂量组(40mg/kg)、川芎嗪大剂量组(80mg/kg)和地塞米松组,每组12只。实验用磷酸川芎嗪注射液为丽珠集团利民制药厂生产)。②实验过程及评估:以卵蛋白腹腔注射并雾化吸入制备大鼠哮喘模型,末次雾化后24h内麻醉后处死大鼠。观察6组大鼠肺组织形态学变化;测定支气管壁厚度、支气管平滑肌厚度、嗜酸粒细胞和淋巴细胞数。采用免疫组织化学半定量法测定肺组织T-bet蛋白的表达;进行转录因子T-bet蛋白表达量与气道炎症的相关性分析。实验过程中对动物处置符合动物伦理学标准。结果:①哮喘模型组嗜酸粒细胞、淋巴细胞、支气管壁厚度和支气管平滑肌厚度,明显高于正常对照组相应指标(P均<0.01);与哮喘模型组比较,川芎嗪小、中、大剂量组和地塞米松组上述4项指标均减少(P均<0.01)。②哮喘模型组、川芎嗪小、中、大剂量组和地塞米松组的T-bet表达量低于正常对照组(P均<0.01);与哮喘模型组比较,川芎嗪小、中、大剂量组T-bet表达量增加(P均<0.01);随着川芎嗪剂量增加,T-bet表达量亦相应增加,川芎嗪小、中、大剂量组之间两两比较,差异均有统计学意义(P均<0.01)。③相关分析显示哮喘模型组T-bet蛋白表达量与嗜酸性粒细胞和淋巴细胞浸润数呈负相关(r=-0.81,-0.85,P<0.01),与支气管管壁厚度和支气管平滑肌厚度呈负相关(r=-0.77,-0.79,P<0.01)。结论:支气管哮喘大鼠存在T-bet低表达;川芎嗪可抑制气道炎症,增加转录因子T-bet蛋白的表达,纠正Th1/Th2失衡,从而治疗支气管哮喘。

AIM： Transcription factor T-bet plays an essential role in the onset of bronchial asthma. Ligustrazine is effective in the treatment of bronchial asthma. In this study, we observed the effect of ligustrazine on airway inflammation and transcription factor T-bet in asthmatic rats. METHODS： The experiment was carded out in Nanjing Medical University from November 2005 to June 2006. （1） Seventy-two SD rats （SPF） were randomly divided into normal control group, asthmatic model group, low （20 mg/kg）, middle （40 mg/kg） and high-dose （80 mg/kg） ligustrazine groups and dexamethasone group with 12 rats in each group. （2）The asthmatic model was established by immunization with intraperitoneal injection and inhaled ovalbumin. The animals were executed under anesthesia within 24 hours after the last atomization. The morphological changes in lung tissues of rats were observed. The thickness of airway wall and airway smooth muscle, and the numbers of eosinophils and lymphocytes were measured. Expressions of T-bet were measured semiquantitatively by immunohistochemistry, and the correlation between T-bet expression and airway inflammation was analyzed. All the experiment procedure was accorded with the Animal Ethical Standards. RESULTS： （1）In asthmatic model group, the numbers of eosinophils and lymphocytes, and the thickness of airway wall and airway smooth muscle were all significantly higher than those in normal control group （all P 〈 0.01）. The four indexes in ligustrazine groups and dexamethasone group were all significantly lower than asthmatic model group （all P 〈 0.01）. （2）Expression of T-bet in asthmatic model group, three ligustrazine groups and dexamethasone group were all significantly lower than that in normal control group （P 〈 0.01）. Compared with asthmatic model group, the expressions of T-bet in low, middle and high dose ligustrazine groups were significantly higher （P 〈 0.01）. The expression of T-bet was elevated with the increase in ligustrazine dose. There were significant differences between any two ligustrazine groups （all P 〈 0.01 ）. （3）The correlation analysis indicated that in asthmatic model group, T-bet was negatively correlated with the number of eosinophils and lymphocytes （r =-0.81, -0.85, P 〈 0.01）, and the thickness of airway wall and airway smooth muscle （r=-0.77, -0.79, P 〈 0.01）. CONCLUSION： The expressions of T-bet are low in bronchial asthmatic rats. Ligustrazine can lessen airway inflammation, increase the expression of T-bet, correct Th1/Th2 imbalance, and finally cure bronchial asthma.