TLR2／4蛋白在小鼠全肝缺血再灌注损伤肝脏的表达及意义

Expression of TLR2/4 protein in mouse total hepatic ischemia/reperfusion injury process and its significance

目的观察Toll样受体2／4蛋白在小鼠全肝缺血再灌注损伤中肝脏的表达，并分析其与肝功能损伤的关系。方法通过夹闭BALB／c小鼠肝门，复制小鼠全肝缺血再灌注损伤模型。采用Western blot方法定量检测缺血肝叶中TLR2／4蛋白的表达变化，并检测门静脉血浆丙氨酸氨基转移酶（pALT）、肿瘤坏死因-α（TNF-α）及门静脉血清内毒素（endotoxin，EN）水平。结果与假手术组（sham-operated group，SH组）相比：（1）全肝缺血20min并行再灌注后，缺血再灌注组（ischemic／reperfusion group，I／R组）血清ALT在再灌注1h即明显升高，且在再灌注3h时较1h时明显升高；（2）I／R组缺血肝脏TLR2／4蛋白的表达（OD值）明显升高，TLR2蛋白的表达在再灌注3h较1h明显高；而TLR4蛋白的表达以再灌注1h时水平最高。（3）I／R组中门静脉血清TNF-α在再灌注1h即开始高，在再灌注3h达高峰。（4）门静脉血清内毒素水平明显升高（与SH相比，P〈0．01），但I／R组在不同灌注时间点之间无显著性差异（P〉0．05）。结论TLR2／4蛋白表达的上调参与了小鼠全肝脏缺血再灌注中肝脏的损伤。

Objective To investigate the expression of TLR2/4 protein in mouse total hepatic ischemia/reperfusion （I/R） injury process and explore its relation to liver functional damage. Methods BALB/c mice were used to establish the model of total hepatic I/R injury by obstructing the portal vein. The changes of TLR2/4 protein in ischemic liver lobes were determined by Western blot. Meanwhile, the levels of plasma ALT, endotoxin and serum TNF-α in portal vein were measured. Results 1） After 20 minutes of total liver ischemia, the AST level in I/R group was significantly increased as compared with the sham-operated （SH） group, and AST level at the 3rd reperfusion was markedly higher than that at the 1st reperfusion （P〈0. 01）. 2） The expression of TLR2/4 protein was remarkably up-regulated in I/R group than in the SH group at the time point of 1st and 3rd h reperiusion. The expression of TR2 protein was higher at 3rd h reperfusion than that at the 1st h. TLR4 peaked at the 1st h. 3） the level of portal vein TNF-α significantly increased in the I/R group, and the data at the 3rd h reperiusion were higher than those at the 1st h. 4） Endotoxin in the portal vein was markedly higher in I/R group than in the SH group （P〈0. 01）. However, there was no difference at the 1st h and 3rd h reperfusion （P〉0. 05）. Conclusions The up-regulation of TLR2/4 protein in mouse total hepatic I/R injury process might be involved in the process of liver injury.