地塞米松抑制聚肌胞苷酸诱导人气道上皮细胞趋化因子表达及机制的初步研究

目的 初步探讨地塞米松对聚肌胞苷酸刺激气道上皮细胞后趋化因子表达的影响及其机制.方法 将人气道上皮细胞16hBE给予不同浓度的聚肌胞苷酸(0.001、0.01、0.1、1 μg/ml)及地塞米松(0.1、1、10 μmol/L)处理,用RT-PCR检测刺激6h后IL-8、IP-10 mRNA的表达水平,用ELISA法检测刺激24 h后培养上清液中IL-8和IP-10蛋白含量,用免疫组化方法检测细胞NF-κB p65亚单位的表达强度.结果 0.001、0.01、0.1 μg/ml聚肌胞苷酸处理16hBE细胞后IL-8和IP-10mRNA表达水平和蛋白分泌量呈浓度依赖性升高,在0.01 μg/ml及0.1 μg/ml浓度时,与对照组比较差异有统计学意义(P＜0.05,P＜0.01);但在聚肌胞苷酸浓度为1μg/ml时,IL-8和IP-10 mRNA表达水平和蛋白分泌量都出现了下降.地塞米松(1、10 μmol/L)预处理0.5h明显抑制聚肌胞苷酸诱导的IL-8和IP-10 mRNA表达及蛋白分泌(P＜0.05,P＜0.01).1 μmol/L地塞米松预处理明显抑制了聚肌胞苷酸诱导的NF-κB p65表达强度(P＜0.01).结论 糖皮质激素可抑制聚肌胞苷酸诱导的气道上皮细胞趋化因子的表达,其机制可能与NF-κB的活化有关.

Inhibitory effects of dexamethasone against polyinosinic:polycytidylic acid-induced chemotactic factor expression in bronchial epithelial cells and the underlying mechanism

Objective To investigate the effect of dexamethasone on polyinosinic: polycytidylic acid(PIC)-induced chemotactic factor expression in human bronchial epithelial(16hBE) cells and the underlying mechanism.Methods 16hBE cells were treated with different concentrations of PIC(0.001,0.01,0.1,and 1 μg/ml) and dexamethasone(0.1,1,and 10 μmol/L).IL 8 and IP-10 mRNA levels were detected by RT-PCR 6 h after stimulation.IL-8 and IP-10 protein levels in the culture supernatant were detected by ELISA 24 h after stimulation.NF-κB p65 subunit expression was detected by immunohistochemical staining.Results PIC concentration-dependently(0.001,0.01,and 0.1 μg/ml) increased the expression of IL-8 and IP-10 mRNA and protein compared with the control group,with significant differences found when PIC at 0.01 μg/ml and 0.1 μg/ml(P<0.05,P<0.01).When the concentration of PIC was 1 μg/ml,the expressions of IL-8 and IP-10 were decreased at both mRNA and protein levels.Pretreatment with dexamethasone(1 μmol/L and 10 μmol/L) for 0.5 h significantly inhibited the IL-8 and IP-10 expression at both mRNA and protein levels(P<0.05,P<0.01).Dexamethasone pretreatment(1 μmol/L) significantly inhibited PIC-induced NF-κB p65 subunit expression(P<0.01).Conclusion Glucocorticoids can suppress PIC-induced IL-8 and IP-10 expression in human bronchial epithelial cells,probably through activation of NF-κB pathway.