红霉素对慢性阻塞性肺疾病大鼠转化生长因子-β1和分泌型白细胞蛋白酶抑制剂表达水平的影响

The effect of erythromycin on transforming growth factor-β1 and secretory leukocyte proteinase inhibitor in a rat model of chronic obstructive pulmonary disease

目的 探讨红霉素在COPD发病过程中的保护性作用.方法 健康SPF级雄性Wistar大鼠36只,体重（220±20）g,用随机数字表法分为模型组、干预组和对照组,每组12只.采用香烟烟雾暴露及气管内滴加脂多糖复制COPD大鼠模型.观察3组大鼠在红霉素干预前后的肺功能及病理变化,免疫组织化学及逆转录PCR法检测支气管肺组织中转化生长因子-β1（TGF-β1）和分泌型白细胞蛋白酶抑制剂（SLPI）表达的变化.多组间比较采用单因素方差分析,组间两两比较采用SNK-q检验,采用直线相关分析进行相关性检验.结果 模型组大鼠的饮食和活动逐渐减少,平均体重较对照组减轻,后期可见毛发干枯、发黄,可有明显喘息音;干预组大鼠的症状较轻,对照组大鼠未出现上述情况.模型组大鼠FEV0.3/FVC[（58±7）%]和动态肺顺应性[（0.16±0.07） L/cm H2O,1 cm H2O=0.098 kPa]均明显低于对照组[（83±7）%和（0.33±0.16） L/cm H2O],气道阻力[（0.69±0.14） cm H2O·L-1·s-1] 明显高于对照组[（0.33±0.11） cm H2O·L-1·s-1];干预组大鼠FEV0.3/FVC[（65±9）%]和动态肺顺应性[（0.23±0.08） L/cm H2O]均明显高于模型组[（58±7）%和（0.16±0.07） L/cm H2O],气道阻力[（0.50±0.13） cm H2O·L-1·s-1]明显低于模型组[（0.69±0.14） cm H2O·L-1·s-1];干预组大鼠支气管肺组织中TGF-β1的蛋白（积分吸光度值×103）和mRNA（吸光度值）表达（6.7±1.5和0.45±0.13）均明显低于模型组（10.7±1.9和0.66±0.18）,SLPI的蛋白和mRNA表达（9.9±1.7和0.69±0.34）均明显高于模型组（8.1±1.7和0.41±0.27）;TGF-β1与SLPI表达呈显著负相关（r=-0.686,P〈0.05）.结论 COPD大鼠的支气管肺组织中SLPI 表达明显减少,TGF-β1表达明显升高,两者呈负相关.红霉素可以抑制大鼠的气道炎症反应,使TGF-β1对SLPI的抑制作用减弱,提示红霉素可能具有局部保护作用.

Objective To study the protective mechanism of erythromycin in the process of COPD. Methods Thirty-six male Wistar rats, grade SPF, weight （220±20） g, were randomly divided into 3 groups, 12 each： a control group, a COPD model group and an erythromycin treated group. Measurement of rat pulmonary function and the pathological changes were performed, and the expression of transforming growth factor-β1 （TGF-β1） and secretory leukocyte proteinase inhibitor （SLPI） in the lung of rats were evaluated by immunohistochemistry and reverse transcription polymerase chain reaction （RT-PCR）. Analysis of variance, pairwise comparison between groups using SNK-q test, Pearson linear correlation analysis were carried out for statistical analysis. Results The rats in the COPD model group showed sign of less activity, loss of appetite and weight, dry and yellow hair, and sometimes wheezing, which were less or milder in the group treated with erythromycin. FEV0.3/FVC [（58±7）%] and Cdyn [（0.16±0.07） L/cm H2O, 1 cm H2O=0.098 kPa] were significantly lower in the model group as compared to the control group [（83±7）% and （0.33±0.16） L/cm H2O], RI [（0.69±0.14） cm H2O·L-1·s-1] , but was significantly higher than the control group [（0.33±0.11） cm H2O·L-1·s-1]. FEV0.3/FVC [（65±9）%] and Cdyn [（0.23±0.08） L/cm H2O] were significantly higher in the erythromycin treated group as compared to the model group [（58±7）% and （0.16±0.07） L/cm H2O], RI [（0.50±0.13） cm H2O·L-1·s-1], but was significantly lower than the model group [（0.69±0.14） cm H2O·L-1·s-1]. The expression of TGF-β1 protein （integral optical density value） and mRNA （absorbance value） （6.7±1.5 and 0.45±0.13） were lower in the erythromycin treated group as compared to the model group （10.7±1.9 and 0.66±0.18）, but the expression of SLPI protein （integral optical density value） and mRNA （absorbance value） （9.9±1.7 and 0.69±0.34） were higher than those of the model group （8.1±1.7 and 0.41±0.27）. The expressions of TGF-β1 and SLPI were negatively associated （r=-0.686, P〈0.05）. Conclusions The expression of SLPI was decreased but the expression of TGF-β1 was increased significantly in the bronchial and lung tissues of rats with COPD. Airway inflammation was inhibited by erythromycin which was able to reduce the inhibitory effect of TGF-β1 to SLPI, indicating a partial protective effect of erythromycin.