PTEN在哮喘大鼠肺部的表达及罗红霉素的干预效果

目的研究哮喘大鼠与张力蛋白同源的10号染色体缺失的磷酸酶基因(PTEN)的表达和罗红霉素(RXM)对其表达的影响。方法24只体质量(200±10)g的SPF级雄性SD大鼠,随机分为3组:健康对照组(C组)、哮喘组(A组)、罗红霉素组(R组)。对支气管肺泡灌洗液(BALF)进行细胞分类计数;应用双抗体夹心酶联免疫吸附法测定BALF中白细胞介素(IL)-4浓度;采用免疫组织化学法和Westernblot法分别检测PTEN的表达及各组大鼠肺组织PTEN量的变化。结果①健康对照组、罗红霉素组支气管PTEN蛋白的表达分别为(2.50±0.56),(1.69±0.24)]均高于哮喘组(1.12±0.26)](P<0.05),其主要表达细胞是支气管上皮细胞;②哮喘组大鼠BALF中IL-4表达明显升高,明显高于健康对照组,罗红霉素干预组BALFIL-4量明显下降,与哮喘组比差异有统计学意义。③哮喘组大鼠支气管PTEN蛋白与BALF中的IL-4浓度呈负相关(r=-0.735,P<0.01),与BALF中的嗜酸粒细胞(EOS)%呈显著负相关,(r=-0.761,P<0.01)。结论气道上皮细胞是PTEN主要表达细胞,哮喘大鼠PTEN蛋白表达明显减少,PTEN能减少Th2因子的表达;罗红霉素可以促进PTEN的表达,可能为其抑制哮喘气道炎症形成的重要作用机制。

Expression of PTEN in rat asthma model and the modulatory effect of Roxithromycin

Objective To study the expression of PTEN in asthma rat models and the modulatory effects of Roxithromycin （RXM）. Methods Twenty-four SD rats were randomly divided into three groups：the control group（group C） ,asthma group（group A） and RXM group（group R）. The lung tissue was sampled from the left lung.Bronchoalveolar lavage fluid （BALF） was collected from the right lung. The differential cell counts in BALF were measured. The concentration of the IL-4 in BALF was measured by Sandwich ELISA. The PTEN protein was determined using immunohistochemistry technique and the level of PTEN in lung homogenate measured by western blot. Result （1）PTEN protein was observed in the epthelial cells of bronchus ,and the level of PTEN protein in lung homogenate of control group（2.50±0.56） and RXM group（1.69±0.24） were signigicantly higher than that in asthma group（1.12±0.26）（P〈0.05）. （2）The concentration of IL-4 in BALF of group A and group R were significantly higher than that in the group C （P〈 0.01）,and that of group R was significantly less than group A（P〈0.01）. （3）Negative correlations were found between the expression of PTEN protein in lung homogenate and the level of IL-4 and EOS% in BALF （r1=-0.735,r2=-0.761 ,P〈 0.01）. Conclusion The protein of PTEN was decreased in asthma rat models and the epithelial cells were the chief expression cells. Roxithromycin had an inhibitory effect on airway inflammmation. It significantly increased the PTEN expression,which may be an important action in modulatory mechanism of asthma.