PTEN在哮喘大鼠肺部的表达及地塞米松的干预

目的：研究哮喘大鼠PTEN的表达和地塞米松（DXM）对其表达的影响。方法：24只体重（200±10）g的SPF级雄性SD大鼠,随机分为3组：正常对照组、哮喘组、地塞米松组。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试验法测定BALF中IL-13浓度;采用免疫组化法和Western blot法分别检测PTEN的表达及各组大鼠肺组织PTEN量的变化。结果：正常对照组、地塞米松组支气管PTEN蛋白的表达分别为7.87±0.80、1.80±0.23,均高于哮喘组（0.92±0.23,均为P〈0.01）,其主要表达细胞是支气管上皮细胞;哮喘组大鼠BALF中IL-13表达明显升高,明显高于正常对照组;地塞米松组BALF中IL-13量明显下降,与哮喘组比有统计学意义。哮喘组大鼠支气管PTEN蛋白与BALF中的IL-13浓度呈显著负相关（r=-0.675,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;DXM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 and the intervention effect of dexamethasone in the asthma rat model

AIM:To study the expression of PTEN and the intervention effect of dexamethasone(DXM) in the asthma mt model.METHODS:Twenty-four(200±10) g SD rats were randomly divided into three groups:control group(Group C),asthma group(Group A)and DXM group(Group DXM).The lung tissue was sampled from the left lung.The bronchoalveolar lavage fluid(BALF) was collected from the right lung.The differential count of cells in BALF was measured.The concentration of IL-13 in BALF was measured by Sandwich ELISA.The expression of PTEN protein and the changes of PTEN level in lung homogenate of each group were detected by immunohistochemical and Westem blot method.RESULTS:The expression of bronchial PTEN protein in Group C and Group DXM were 7.87±0.80,1.80±0.23 which were higher than that in Group A(0.92±0.23,all P＜0.01),and the bronchial epithelial cell was the main expression cell.The expression of IL-13 in BALF of Group A was significantly increased,and which was higher than that in Group C(P＜0.01),and which in Group DXM was significantly decreased,compared with Group A,there was significant difference.There were significantly negative correlations between the expression of PTEN protein in lung homogenate and the level of IL-13 in BALF(r =-0.675,P＜0.01).CONCLUSION:The PTEN chief expression cell was tracheal epithelial cell.The expressions of PTEN protein in Group A were decreased.PTEN could decrease the expression of Th_2 factor.Dexamethasone could promote the expression of PTEN,which may be an important mechanism of inhibiting asthmatic airway inflammation formation.