白介素-13(IL-13)和白介素-18(IL-18)调节支气管哮喘大鼠神经生长因子mRNA(NGF mRNA)的实验研究

Interleukin-13 and interleukin-18 on the expression of nerve growth factor mRNA in bronchial asthma model of rats

目的:初步探讨IL-13和IL-18对支气管哮喘大鼠神经生长因子mRNA(NGFmRNA)表达的影响。方法:建立Wistar大鼠哮喘模型,分离脾淋巴细胞并培养,通过逆转录-聚合酶链反应(RT-PCR)半定量法测定NGF mRNA的基础水平,并观察予以IL-18和IL-13干预后NGF mRNA表达的情况。结果:哮喘大鼠脾淋巴细胞在基础状态下具有表达NGF mRNA的功能,并在ConA刺激下呈时间依赖性增强。空白对照组培养脾淋巴细胞0、12、24、48h时基础NGF mRNA表达量随着时间的延长逐渐升高,IL-13组随着时间的延长基础NGF mRNA表达量逐渐升高。随着时间的延长,IL-13组NGF mRNA表达相对值逐渐升高,并且至12h后分别显著高于各时间点的空白对照组(P<0.01)(表1)。同时随着IL-13干预浓度的依次增高,NGF mRNA表达相对值逐渐升高,并且分别与前一梯度低浓度处理组相比较有显著差异(P<0.05);而随着IL-18干预浓度的依次增高,NGF mRNA表达相对值却逐渐降低。结论:在哮喘中Th2类细胞因子IL-13可上调淋巴细胞NGF mRNA表达,Th1类细胞因子IL-18可下调淋巴细胞NGF mRNA表达,两者均呈时间和浓度依赖性;Th1/Th2类细胞因子免疫失衡可能通过调控NGF mRNA表达间接促进其诱导神经源性炎症。

Objective：To investigate the effect of interleukin-13 and interleukin-18 on the expression of nerve growth factor mRNA in bronchial asthma model of rats.Methods：Four Wistar rats were sensitized and challenged with ovalbumin to establish an asthma model,and the rat splenic lymphocytes were isolated and cultured with ConA.The expression of NGF mRNA was detected by reverse transcription-polymerase chain reaction（RT-PCR）,and were observed after the lymphocytes were exogenously added with IL-18 or IL-13.Results：The lymphocytes of the asthma model stimulated by ConA in vitro expressed NGF mRNA in a time-dependent manner.After the lymphocytes had been cultured with IL-13 for 12,24 h and 48 h,IL-13 upregulated the expressions of NGF mRNA in a time-dependent manner and all the NGF mRNA expressions were signif-icantly higher than the basal values at the same time（P0.05）.After 0,10,50μg/L and 100μg/L IL-13 had been added for 24 h,IL-13 upregulated the expressions of NGF mRNA in a dose-dependent manner and the NGF mRNA expressions were all significantly higher than the values of the lower dose IL-13（P0.05）.After the lymphocytes had been cultured with 10μg/L IL-18 for 0,12,24 h and 48 h, IL-18 downregulated the expressions of NGF mRNA in a time-dependent manner and all the NGF mRNA expressions were significantly lower than the basal values at the same tim（eP0.05）.After 0,1,10,and 50μg/L IL-18 have been added for 24 h,IL-18 downregulat-ed the expressions of NGF mRNA in a dose-dependent manner and all the NGF mRNA expressions were significantly lower than the val-ues of the lower IL-18 dose（all P0.05）.Conclusion：In the asthma model of rats,IL-13,one of the Th2 cytokines,can upregulate the expressions of NGF;IL-18,one of the Thl cytokines,and downregulate the expressions of NGF,both in a time-dependent manner and dose-dependent manner.Th1/Th2 cytokine immune imbalance may indirectly induce the airway neurogenic inflammation by regulating the NGF mRNA expression.