哮喘小鼠CD4+CD25+Foxp3+调节T细胞和Foxp3蛋白的变化及淫羊藿苷干预作用

摘要

目的:研究哮喘小鼠CD4+CD25+Foxp3+调节T(Treg)细胞和Foxp3蛋白的变化,探讨淫羊藿苷对哮喘干预机制.方法:将BALB/c小鼠32只随机分为正常对照组、哮喘模型组、淫羊藿苷组、地塞米松阳性对照组,每组8只.哮喘模型制备用卵白蛋白(OVA)致敏大鼠并雾化吸入刺激,治疗组采用相应药物灌胃给药,对照组用等量生理盐水代替.最后一次激发24小时后,采用Buxco肺功能仪有创法检测小鼠气道反应性;HE染色评价观察小鼠肺组织病理形态学改变;流式细胞术检测脾脏CD4+CD25+Foxp3+Treg细胞比例及Foxp3蛋白表达量;免疫印迹法测定肺组织Foxp3蛋白表达量;ELISA法测定血清及肺泡灌洗液(BALF)IL-10水平.结果:与正常对照组比较:模型组气道阻力及气道炎症指数显著增加(P< 0.05);脾Treg细胞比例无明显变化(P> 0.05);脾Foxp3蛋白表达显著下降(P< 0.05),肺组织Foxp3蛋白表达显著升高(P< 0.05),外周血IL-10水平显著下降(P< 0.05),BALF中IL-10无显著差异(P> 0.05);与模型组比较:淫羊藿苷组气道阻力和气道炎症明显减轻(P< 0.05);脾Treg细胞比例和脾Foxp3蛋白表达水平无显著变化(P> 0.05),但淫羊藿苷可进一步上调哮喘小鼠肺组织Foxp3蛋白表达量(P< 0.05),并增加外周血IL-10水平(P< 0.05).结论:哮喘小鼠脾脏CD4+CD25+Foxp3+ Treg细胞Foxp3蛋白表达水平下降,淫羊藿苷可显著改善哮喘小鼠气道炎症和气道高反应,可能与其上调肺组织Foxp3蛋白表达和增加外周血IL-10水平相关.%Objective:To investigate the change of CD4 + CD25+ Foxp3 + Treg cells and Foxp3 expression in a mouse model, and explore the antiasmatic effects of icariin. Methods: 32 BALB/c mice were randomly divided into 4 groups; the normal conlrol group, the model group, the Icariin group and the dexamethasone group, with 8 mice in each group. Asthma model was established by ovalbumin sensitization and aerosol challenge in all groups except the control group. The trealment groups were administraled with dexamethasone and Icariin respectively by gavage, while normal group were administrated with physiological saline. Within 24 hours after the last ovalbumin challenge, airway reactivity was measured by the invasive measuremenl system. Changs in airway histopathology were examined by HE slaining. Polychromatic flow cytometry was applied to delineate the CD4+ CD25 + Foxp3 + Treg cells in spleen. The expression of Foxp3 protein in lung tissue was assessed by Western blot. IL-10 in BALF and serum were measured by ELISA. Results :Compared with the control group, mice in model group exbited increased airway hyperresponsiveness and airway inflammation (P < 0.05). No significant difference was observed of the percentage of Treg cells in spleen (P > 0.05). The expression of Foxp3 was significantly decreased in spleen, but was remarkably increased in lung tissues (P < 0. 05) . In addition, the level of IL-10 in serum of model group was significantly decreased ( P < 0. 05 ) . Icariin significantly attenuated airway hyperresponsiveness and inflammation, and further markedly enhanced expression of Foxp3 in lung tissues and IL-10 levels in serum, as compared lo OVA-exposed mice. Conclusion: The expression of Foxp3 protein is decreased within spleen CD4+ CD25 + Foxp3 + Treg cells in asthma. Icariin can increase the Foxp3 expression in lung tissue and levels of serum IL-10, which may contribute lo its antiaslhmalic effecls.