蛛网膜下腔出血大鼠脑基底动脉和海马组织Toll样受体3表达增强

Enhanced expression of Toll-like receptor 3 in the basilar arteries and hippocampus of subarachnoid hemorrhage rats

目的观察Toll样受体3(TLR3)在蛛网膜下腔出血(SAH)模型中的动态表达变化及意义。方法采用枕大池注血法构建SAH模型。SD大鼠60只,随机分为:假手术组、SAH组,每组15只。SAH组再次分为1、3、7 d组。假手术组除注入生理盐水外,其余操作方法同SAH组。模型成功后,于不同时间点取基底动脉和脑,通过反转录PCR检测TLR3 mRNA的表达,Western blot法和免疫组织化学技术检测TLR3蛋白表达。同时采用免疫荧光双标记技术分析其分布规律。结果 TLR3 mRNA、蛋白在假手术组中呈微弱表达;SAH组中均高表达,并且以3 d SAH组表达量最高。免疫组织化学结果显示,TLR3在血管内皮与海马神经元均高表达,假手术组TLR3呈微弱表达于细胞质,而模型组TLR3在细胞核与细胞质均有强表达。免疫荧光双标记结果提示,TLR3与内皮细胞标志CD34共表达。结论 SAH后大鼠脑基底动脉和海马组织TLR3表达增强,提示TLR3在SAH发病过程中可能起着一定作用。

Objective To observe the dynamic expression and significance of Toll-like receptor 3 （TLR3） in subarachnoid hemorrhage （SAH） model. Methods SAH model was established using blood injection into the prechiasmaUc cistern. Sixty SD rats were randomly divided into sham group and SAH groups （including SAH ]-, 3-, 7-day groups）, each with 15 rats. The operation steps were the same in groups except the sham group that was injected with normal saline instead. At different time points after modeling, the basilar arteries and brain were obtained. The mRNA and protein expression of TLR3 was detected using reverse transcription PCR, Western blotting and immunohlstochamistry, respectively. Meanwhile, the distribution of TLR3 was analyzed using the immunofluorascence double labeling technique. Resalts The mRNA and protein expression of TLR3 was weak in sham group and highly expressed in SAH groups, and the highest expression were found in SAH 3-day group. Immunohistochemistry showed that TLR3 was highly expressed in vascular endothelial and blppocampal neurons. The sham group showed a weak TLR3 expression in the cytoplasm, while the SHA group showed the strongly expressed TLR3 mainly in the nucleus result of immunofluorescence double labeling also suggested TLR3 was co-iccalization with CD34 in the endothelial cells. Conclusion The TLR3 expression was enhanced in the basilar arteries and hippocarnpus when the rats suffered from SAH, which suggested TLR3 might play a certain role in the pathogenesis of SAH.