摘要
目的 研究脂多糖 (LPS)的跨膜信号传导分子TLR4和MD 2在巨噬细胞内毒素耐受发生中的调节变化和作用。方法 分离小鼠腹腔巨噬细胞 ,活化组直接以 1mg/LLPS刺激一定时间 ,耐受组先用不同剂量LPS预处理 2 0h ,再用 1mg/LLPS刺激。利用逆转录 聚合酶链反应(RT PCR)测定各基因的转录调节变化。结果 在活化组细胞LPS刺激可显著诱导肿瘤坏死因子(TNF) α的基因转录和蛋白分泌 ,但是LPS预处理可使耐受组细胞TNF α的mRNA和蛋白水平均明显低于活化组 (P <0 .0 1) ;耐受组细胞中TLR4的基因表达水平也比活化组明显低 (P <0 .0 1) ,但MD 2的基因表达水平不受LPS刺激的影响。结论 内毒素耐受的巨噬细胞表现为抑制的炎症细胞因子产生 ,TLR4基因的表达下调可能是内毒素耐受发生的机制之一。
Objective To study the regulation of the gene expression of LPS signaling receptor TLR4 and MD-2 in endotoxin tolerant macrophages.Methods Murine peritoneal macrophages was isolated.In the activating group,the macrophages was stimulated with 1 mg/L LPS,while in the tolerant group,the macrophages were pretreated with different doses of LPS for 20 h,then rechallenged with 1 mg/L LPS.Using RT-PCR,the gene expression changes in TNF-α,TLR4 and MD-2 were detected.Results In the LPS activated macrophages the levels of TNF-α mRNA and protein were significantly increased.However,the TNF-α production in the tolerant group was significantly less than in the activating group ( P <0.01).The gene expression of TLR4 in tolerant macrophages was lower than in activating macrophages.The MD-2 gene expression was not changed by LPS stimulation.Conclusion In endotoxin tolerant macrophages the cytokine gene expression was inhibited compared to that in LPS activated macrophages.The down-regulation of TLR4 gene expression is one of the possible mechanisms responsible for LPS tolerance.
出处
《中华实验外科杂志》
CAS
CSCD
北大核心
2004年第1期28-30,共3页
Chinese Journal of Experimental Surgery
基金
国家自然科学基金资助项目 (30 1 0 0 1 76
30 0 0 0 1 61 )
