LPS诱导鼠肝脏和腹腔巨噬细胞TLR4表达和肝损伤的动态分析

目的观察LPS刺激后不同时间点肝脏和腹腔巨噬细胞的TLR4表达,以及分析TLR4动态变化规律.方法以BALB/c小鼠为模型,腹腔注射LPS后不同时间取肝脏和腹腔巨噬细胞抽提RNA,逆转录-聚合酶链式反应半定量分析TLR4mRNA各时相的表达.体外培养的腹腔巨噬细胞不同剂量LPS刺激后观察TLR4mRNA的表达规律.结果注射LPS 3 h后肝脏和腹腔巨噬细胞TLR4mRNA开始明显下降,第6、12 h基本检测不到,24 h后逐渐恢复,30 h小鼠死亡时基本恢复到正常.不同浓度LPS均下调腹腔巨噬细胞TLR4mRNA的表达,剂量之间差异无显著性.血中ALT在3h开始升高,6h达高峰,肝细胞病理变化出现在12 h,随时间的延长而加重.结论LPS可直接损伤肝细胞,这种损伤与TLR4无关.LPS可能通过TLR4介导肝组织的病理改变.

Dynamic analysis of expression of TLR4 in liver and peritoneum macrophage after LPS stimulation

Objective] To observe the expression of TLR4 at different time points afer LPS stimulation in liver and abdominal macrophage, and analyze the regulation of these changes. Methods] LPS-induced endotoxemic mouse were sacrificed at different time points to obtain livers and abdominal macrophage, then their RNA were taken out and RT-PCR half-quantitative method was used to analyze the expression of TLR4. Observe the expression regulation of abdominal macrophage in vitro after different dose LPS stimulation. Result] The expression of TLR4mRNA descended evidently in the 3th hours after LIPS stimulation, and disappeared completely in the 6th and 12th hours, then recovered gradually in the 24th hours. When the mouse died in the 30th hours, it was recovered to the level before LIPS stimulation. Though TLR4 can be downregulated by different dose LPS, the reaction is all the same. ALT level in serum began to go up at 3 hour timepoint and arrived at highest point at the 6 hour. Conclusion] The LPS can damege directly the livel cells and make the ALT increase. The result would be asaociated wiath TLR4mRNA expression, The LPS made the injury of liivel tilssue through TLR4.