白细胞介素-1受体相关激酶-4短发夹RNA阻断库普弗细胞激活效应的实验研究

目的 探讨以白细胞介素-1受体相关激酶-4（IRAK-4）特异性短发夹RNA（shRNA）阻断内毒素诱导的库普弗细胞（KCs）激活效应的可行性。方法 构建两对表达IRAK-4-shRNA的阳性载体质粒（pSfIRAK-4-A，pSfIRAK-4-B）及一对阴性载体质粒（pSⅡRAK-4-C）。分离培养小鼠KCs，分为正常对照组，RNA干扰（RNAi）对照组（转染pSⅡRAK-4-C）与RNAi抑制组（转染pSⅡRAK-4-A，pSⅡRAK-4-B）。质粒转染后24h，加入0．1μg／ml脂多糖（LPS）。6h后，蛋白免疫印迹法及逆转录聚合酶链反应测定IRAK-4蛋白和mRNA表达水平；酶联免疫吸附法检测0、1、3、6、12h后KCs的核因子-κB（NFKB）活性及培养上清液中肿瘤坏死因子α含量。结果 RNAi抑制组IRAK-4表达水平，以及LPS刺激后NFKB活性、肿瘤坏死因子α峰值均明显低于正常对照组和RNAi对照组，t值分别为22．50，4．18及958．49，P〈0．01；尤其是pSⅡRAK-4-A组，抑制效果明显优于pSⅡRAK-4-B，t值分别为12．60，3．36及256．39，P〈0．01。结论 以IRAK-4为靶点的shRNA能有效的阻断内毒素诱导的KCs激活效应。

An experimental study of the inhibitory effects on the activation of endotoxin-induced Kupffer cells through short hairpin RNA targeting interleukin-1 receptor associated kinase-4 gene

OBJECTIVE: To explore the inhibitory effects on the activation of endotoxin-induced Kupffer cells (KCs) through short hairpin RNA (shRNA) targeting interleukin-1 receptor associated kinase-4 (IRAK-4) gene. METHODS: Two effective transfection shRNA plasmid (pSIIRAK-4-A, pSIIRAK-4-B) and one invalidated plasmids (pSIIRAK-4-C) targeting IRAK-4 gene were constructed. The isolated mouse KCs were divided into three groups: the normal control group, the RNAi control group (pSIIRAK-4-C) and the RNAi effective group (pSIIRAK-4-A, pSIIRAK-4-B). Then KCs were stimulated with 0.1 microg/ml lipopolysaccharide (LPS) after 24 h transfection with the constructed plasmid. The expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blot at 6 h after LPS stimulation, and the activities of NF-kappaB in KCs and the TNFalpha level were estimated by ELISA at 0 h, 1 h, 3 h, 6 h and 12 h. RESULTS: The level of IRAK-4, the activities of NF-kappaB and the TNF-alpha level in the RNAi effective group were evidently lower than those in normal and RNAi control groups (P < 0.01) at 1 h, 3 h, and 6 h. Especially, the pSIIRAK-4-A group in which the changes of the above indices were of no difference (P > 0.05), had better inhibited effects than that of the pSIIRAK-4-B group (P < 0.01). CONCLUSION: The shRNA targeting IRAK-4 gene could effectively inhibit the activation of endotoxin-induced KCs.