TLR4、MRP8在内侧颞叶癫痫幼大鼠海马中表达的动态变化

Expression of TLR4 and MRP8 in the developing immature rats with mesial temporal lobe epilepsy

目的观察氯化锂-匹罗卡品致痫幼大鼠各期海马中Toll-样受体4(TLR4)、髓样相关蛋白8(MRP8)表达的变化,探讨其是否与内侧颞叶癫痫(MTLE)发生有关。方法 21d SD雄性大鼠90只,随机分对照组(30只)和模型组(60只),腹腔注射氯化锂。17～18h后模型组腹腔注射匹罗卡品诱导癫痫持续状态(SE);对照组予等量生理盐水取代匹罗卡品腹腔注射。按自发发作出现和稳定时间(自发痫性发作在致痫后约3w出现,8w趋稳定),对照组和模型组随机分6个亚组:急性模型组(SE后2h)、潜伏模型组(SE后3w)、慢性自发发作组(SE后8w)及相对应时间点对照组。每亚组动物10只。免疫组化、免疫印迹、RT-PCR技术测定各亚组幼大鼠海马内TLR4、MRP8的表达。结果 TLR4、MRP8在模型组海马内表达明显增多,以CA3、CA1、DG区显著;与对照组相比,差异有显著性(P<0.05)。模型亚组内,TLR4、MRP8在急性期和慢性期表达明显增高,而潜伏期无明显表达变化;3组比较差异有显著性(P<0.05)。结论大鼠海马内TLR4、MRP8表达增多可能与MTLE发生有关。探讨其机制可能为MTLE的治疗提供新的靶点。

Objective To investigate the dynamic expression changes of TLR4 and MRP8 in hippocampus of the im- mature epileptic rats during the development of epilepsy, and to explore whether they induced the pathogenisis of mesial temporal lobe epilepsy（MTLE）. Methods 90 male 3-week-old healthy Sprague-Dawley rats were divided randomly into control group and LiC1-Pilocarpine experimental group. The experimental rats were intraperitoneally injected with LiC1 （127mg/kg） and Pilocarpine（50mg/kg）to induce status epileptieus（SE）. SE was stopped with 10% chloral hydrate intra- peritoneally injecting 90 minutes later. Survival rats were continuously observed for onset and recurrence of spontaneous sei- zures every day and were grouped and sacrificed at 2h（ acute group） ,3w（ latent group） and 8w（ chronic group） after the last pilocarpine injection respectively. The control rats were mitted tales doses of 0.9% saline and grouped and sacrificed at 2h ,3w ,8w after the saline injection. And all groups were executed by using immunohistochemistry, Western-blotting and RT-PCR analysis to examine the dynamic expression of TLR4 and MRP8 in the subfields of each gourps＇ hippocampus. Results Compared with control group, the expression of TLR4 and MRP8 increased in all of the model group （P 〈 O. 05 ）. Both of TLR4 and MRP8 elevated at the areas of CA3 , CA1 and DG. In all of model group, the expression of TLR4 and MRP8 increased more significantly in acute stage and chronic stage than the latent stage （ P 〈 0.05 ）. Conclusion The evelated expressions of TLR4 and MRP8 in MTLE model rat indicate they could be responsible for the epileptogensis of MTLE. The TLR4/MRP8 pathway may play an important role in the pathogenisis of MTLE.