TLR4对脑缺血再灌注小鼠海马TRIF表达的影响

Effect of Toll-like receptor 4 (TLR4) on expression of TRIF during cerebral ischemia reperfusion in hippocampal CA1 region in mice

目的探讨Toll样受体4(TLR4)对脑缺血再灌注小鼠海马TRIF表达的影响。方法采用TLR4抗体封闭阻断TLR4,Western blot和RT-PCR检测海马TLR4蛋白、IFN-β蛋白和TLR4 mRNA表达量,免疫组化方法检测TRIF表达变化。小鼠随机分为3组:假手术组(S组)、缺血再灌注组(I组)、TLR4阻断组(T组),各组又分1、2、3及4d4个时间点组。结果缺血再灌注组TLR4蛋白、TLR4 mRNA、IFN-β和TRIF表达水平明显高于假手术组表达水平(P<0.05),而TLR4阻断组TLR4蛋白、TLR4 mRNA、IFN-β和TRIF表达水平明显少于缺血再灌注组(P<0.05)。结论缺血再灌注可激活TLR4,并引起TRIF和IFN-β表达量增加,而采用TLR4抗体封闭阻断TLR4后,TRIF和IFN-β表达量减少。本研究提示,TLR4通过上调TRIF表达参与脑缺血再灌注的反应机制。

ObjectiveTo study the effect of Toll-like receptor 4 （TLR4） on the expression of TRIF during the inflammatory reaction induced by cerebral ischemia reperfusion in mice. MethodsAfter blockade of TLR4 by TLR4 antibody, the expression of TLR4 at the protein and mRNA levels and IFN-β at the protein level in hippocampus were examined by Western blot and RT-PCR, respectively. The expression of TRIF was tested by immunohistochemistry stain. Mice were randomly divided into sham group （group S）, ischemia reperfusion group （group I） and TLR4 blocking group （group T） who were subdivided according to different time points （1, 2, 3 and 4 d）.ResultsIn the right side＇s hippocampus, TLR4 protein, TLR4 mRNA, IFN-β and TRIF expressions of group I were distinctly higher than those of groups S and T （P 0.05）. ConclusionTLR4 is activated by cerebral ischemia reperfusion in hippocampus in mice while the expressions of TRIF and IFN-β are decreased after TLR4 is blocked by TLR4 antibody, which indicates that TLR4 participates in cerebral ischemia reperfusion through upregulating the expression of TRIF.