p38蛋白激酶对支气管哮喘大鼠Th2类细胞因子表达的调控

目的：探讨p38蛋白激酶（p38 MAPK）对支气管哮喘大鼠Th2类细胞因子IL-4、IL-5表达的调控作用。 方法： 分离培养正常和哮喘大鼠外周血T淋巴细胞。采用蛋白质印迹方法检测细胞核蛋白p38蛋白激酶，采用原位分子杂交方法检测IL-4、IL-5的mRNA，采用ELISA方法检测上清液中IL-4、IL-5的蛋白质浓度。 结果： 哮喘对照组T淋巴细胞核蛋白p38蛋白激酶、IL-4、IL-5的mRNA表达阳性细胞数百分比以及上清液中IL-4、IL-5的蛋白质浓度均显著高于正常对照组（P<0.01）。加入递增浓度的SB203580处理后，上述指标均较哮喘对照组显著降低（P<0.05）。T淋巴细胞核蛋白p38蛋白激酶含量与IL-4、IL-5 mRNA原位分子杂交染色阳性细胞的百分比均呈显著正相关（r=0.71、0.63，P<0.01），与培养上清液中IL-4、IL-5蛋白质含量之间亦均呈显著正相关（r=0.68、0.57，P<0.01）。 结论： p38蛋白激酶在转录和翻译水平调控支气管哮喘IL-4和IL-5的表达。p38蛋白激酶抑制剂可望成为临床治疗哮喘的新途径。

Regulation of the expression of Th2 cytokines by p38MAPK in asthmatic rats

AIM: To explore the role of p38 mitogen-activated protein kinase (p38 MAPK) in the regulation of IL-4 and IL-5 expression in asthmatic rats. METHODS: T lymphocytes were isolated and purified from blood of normal or asthmatic rats. p38MAPK in nuclear extracts, mRNA and protein of IL-4 and IL-5 in supernatants were measured by Western blotting, in situ hybridization and ELISA, respectively. RESULTS: The expression of p38MAPK, the percentage of IL-4 and IL-5 mRNA positive cells, IL-4 and IL-5 protein in supernatants were significantly increased in asthmatic T lymphocytes and was blocked by SB203580, a selective inhibitor of p38MAPK. There were good positive correlation between the expression of p38MAPK and either the percentage of positive cells of IL-4 and IL-5 mRNA (r=0.71, 0.63, P<0.01), or IL-4 and IL-5 protein in supernatants (r=0.68, 0.57, P<0.01). CONCLUSION: p38 MAPK pathway regulates the expression of IL-4 and IL-5 at the levels of mRNA and protein, which play an important role in the pathogenesis of asthma.