IL-1β诱导人气道上皮细胞hBD2表达及其分子机制

Expression of the hBD-2 in human airway epithelium induced by IL-1β in vitro and its molecular mechanism

目的观察白介素1β(IL1β)诱导人气道上皮细胞人β防御素2(hBD2)的表达及抑制因子IκBα蛋白、核转录因子κB(NFκB)活性的变化,探讨人气道上皮hBD2表达的分子机制。方法用IL1β和(或)NFκB抑制剂PDTC处理人原代气道上皮细胞,RTPCR法检测hBD2mRNA的表达,Westernblot检测胞浆IκBα蛋白,凝胶迁移实验(EMSA)检测NFκB活性的变化。结果加入IL1β1μg/L刺激0.5h,可见IκBα活性降低;刺激1.5h可见hBD2mRNA表达。NFκB抑制剂PDTC可抑制hBD2mRNA的表达,EMSA显示NFκB的异型二聚体p65p50参与了hBD2表达的转录。结论一定剂量的IL1β可诱导人气道上皮细胞hBD2mRNA表达,NFκBp65/p50异型二聚体参与了IL1β诱导人气道上皮细胞hBD2mRNA表达的转录调控。

Objective To investigate induction of the expression of human β-defensin-2 （hBD-2） mRNA and the changes in activation of I-κBa and NF-κB by IL-1β in the human airway epithelium. Methods Primary human respiratory tract epithelium were stimulated with IL-1β and and/or PDTC. The expression of hBD-2 mRNA was detected by reverse transcription polymerase chain reaction （RT-PCR）. The I-κBa protein level in the cytoplasm was determined by Western blot, and the nuclear factor-kappaB （NF-κB） binding activity was analyzed by electrophoretic mobility shift assays. Results The hBD-2 mRNA expression could be detected after 1. 5 hours of IL-1β stimulation at concentration of 1μg/L, and the expression of HBD-2 was in a dose dependent manner. Stimulation with IL-1β resulted in a reduction of I-κBα protein levels. The supershifts assays indicated that the p65-p50 heterodimer complexes of NF-κB were involved in the activation of NF-κB. Conclusions I-κBa can induce the expression of HBD-2 mRNA in a dose dependent manner; the p65- p60 heterodimer complexes of NF-κB play an important role in the regulation of hBD-2 gene expression in response to IL-1β.