Abstract: Objective To investigate the expression of Toll-like receptor 4 (TLR4) protein in hippocampus of rat model with temporal lobe epilepsy after status epilepticus (SE) and explore its function in the pathogenesis of temporal lobe epilepsy.  Methods  Rat model with temporal lobe epilepsy was induced by lithium chloride (LiCl)-pilocarpine. Total protein was extracted from hippocampus and rat brain slices were obtained at different time points (0, 1, 6, 12, 24, 48 h and 7, 10, 30, 50 d) after SE. Western blotting and immunohistochemical staining were used for detection of the expression of TLR4 in the hippocampus.  Results  The results of Western blotting showed the TLR4 protein expression at 0, 1, 6, 12, 24, 48 h and 7, 10, 30 d after SE was higher than that in the control group (P < 0.05, for all), and the TLR4 protein expression at 50 d after SE showed no significant difference compared with the control group (P = 0.714). There was no significant difference between LiCl group and control group (P = 0.590). The results of immunohistochemistry showed the number of TLR4 positive neuron in CA3 area at 1, 6, 12, 24, 48 h and 7, 10, 30, 50 d after SE was higher than that in the control group (P < 0.05, for all), but showed no significant difference at 0 h after SE (P = 0.326). There was no significant difference between LiCl group and model group at 0 h after SE (P = 0.451). The difference in CA1 and CA2 area in different groups was not statistically significant (P > 0.05).  Conclusion  TLR4 protein was mainly expressed in cytoplasm of pyramidal cells in CA3 area of hippocampus. TLR4 protein expression in the hippocampus was increased in varying degrees at different observation time points after SE, indicating that TLR4 may play an important role in the development of epilepsy.

Key words: Toll-like receptor 4, Epilepsy, temporal lobe, Hippocampus, Immunoblotting, Disease models, animal

摘要： 目的 观察癫痫持续状态大鼠海马组织Toll 样受体4（TLR4）蛋白表达变化，探讨其在颞叶癫痫发病机制中的作用。方法 采用氯化锂-匹罗卡品方法制备颞叶癫痫大鼠模型，于癫痫持续状态后不同观察时间点分别提取海马总蛋白，Western blotting 法和免疫组织化学染色检测TLR4 蛋白表达变化。结果 Western blotting 检测显示，癫痫持续状态后即刻（0 h）、1、6、12、24、48 h 及7、10、30 d 时海马TLR4 蛋白表达高于正常水平（均P < 0.05），于发作50 d 时恢复至正常值范围（P = 0.714）；免疫组织化学染色显示，癫痫持续状态后1、6、12、24、48 h 及7、10、30、50 d 时海马CA3 区TLR4 阳性神经元数目增加（均P < 0.05），但发作即刻差异无统计学意义（P = 0.326）。模型组与氯化锂组大鼠发作即刻（P = 0.451），以及不同处理组海马CA1 和CA2 区TLR4 蛋白表达水平差异均无统计学意义（P > 0.05）。结论 TLR4蛋白主要在海马CA3 区锥体细胞胞质表达。癫痫持续状态后各观察时间点TLR4 蛋白表达水平均有不同程度增加。提示TLR4蛋白可能在癫痫发生过程中起重要作用。

关键词: Toll样受体4, 癫痫, 颞叶, 海马, 免疫印迹法, 疾病模型, 动物