库普弗细胞内毒素耐受时白细胞介素-1受体相关激酶-4的表达变化

目的观察库普弗细胞（KCs）内毒素耐受形成后白细胞介素-1受体相关激酶4（IRAK-4）表达的变化，探讨KCs内毒素耐受形成的相关机制。方法分离培养Balb／c小鼠KCs，分为非内毒素耐受组与内毒素耐受组[给予脂多糖（LPS）10ng／ml预处理24h]。用LPS100ng／ml刺激后，蛋白免疫印迹法及逆转录聚合酶链反应法测定两组细胞IRAK-4蛋白及mRNA的表达水平；酶联免疫吸附法检测两组细胞核因子-κB（NF-κB）活性及培养上清液肿瘤坏死因子α（TNFα）含量。结果LPS刺激在两组细胞均引起IRAK-4 mRNA表达及NF-κB活性增强、TNFα释放增加，但内毒素耐受组3种指标的高峰值明显低于非内毒素耐受组（t值分别为l2．4、l7．4、l38．9，P值均〈0．01）。结论LPS预处理可诱导KCs形成内毒素耐受状态，IRAK4表达受到抑制可能是KCs内毒素耐受形成的机制之一。

Expression changes of interleukin-1 receptor associated kinase-4 during endotoxin tolerance development in kupffer cells

OBJECTIVE: To explore the mechanism of endotoxin tolerance (ET) through observing the expression of interleukin 1 receptor associated kinase-4 (IRAK-4) during endotoxin tolerance development in Kupffer cells (KCs). METHODS: Isolated KCs of Balb/c mouse were divided into two groups: the non-endotoxin tolerance (NET) group and the endotoxin tolerance (ET) group, which were pretreated with 10 ng/ml lipopolysaccharide (LPS) for 24 h. Then, the two groups were treated with 100 ng/ml LPS. The expressions of IRAK-4 gene and protein level were determined by RT-PCR and Western blot. The activities of NF-kappaB of KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h after LPS stimulation. RESULTS: The ultimate level of IRAK-4, the activities of NF-kappaB and the TNFalpha level were evidently lower in the ET group than those in the NET group (t = 12.4, 17.4 and 138.9 respectively, P<0.01). CONCLUSIONS: Pretreatment with LPS on KCs could induce endotoxin tolerance of KCs and inhibition of IRAK-4 expression may be one of the reasons for its development.