雷帕霉素脑靶向制剂对大鼠癫痫的治疗作用

目的: 比较雷帕霉素靶向制剂与雷帕霉素普通制剂治疗癫痫的差异。方法: 制备脑靶向的雷帕霉素纳米粒。采用毛果芸香碱诱发大鼠癫痫发作。脑电描记术监测自发性癫痫的发作；蛋白质印迹法检测不同剂型雷帕霉素对mTOR信号通路的影响；Fluoro-Jade B染色观察海马区神经元活性；Timm染色观察海马区苔藓纤维出芽情况。结果: 脑靶向制剂可降低大鼠自发性癫痫发作频率，作用效果较普通制剂明显（P < 0.05）；以磷酸化S6K和S6为指征，脑靶向制剂比普通制剂雷帕霉素对mTOR信号通路异常激活的抑制作用更强（均P < 0.05）；脑靶向制剂可显著改善神经元凋亡，但与普通制剂无差异（P > 0.05）；脑靶向制剂可减少海马区苔藓纤维出芽，作用效果较普通制剂明显（P < 0.05）；脑靶向制剂对大鼠体质量增长的抑制作用较普通制剂减弱（P < 0.05）。结论: 雷帕霉素脑靶向制剂对癫痫的治疗作用优于普通制剂，且其不良反应小于普通制剂。

Efficacy of brain-targeted rapamycin for treatment of epilepsy in rats

Objective: To investigate the efficacy of brain-targeted rapamycin (T-Rap) in treatment of epilepsy in rats. Methods: Rapamycin nanoparticles targeting brain were prepared. The epilepsy model was induced by injection of pilocarpine in rats. The rats with pilocarpine-induced epilepsy were treated with rapamycin (Rap group) or brain-targeted rapamycin (T-Rap group). Seizure activity was observed by electroencephalography; the effect on mTOR signaling pathway was detected by Western blot; neuronal death and moss fiber sprouting were analyzed by Fluoro-Jade B (FJB) and Timm's staining, respectively. Results: Electroencephalography showed that both preparation of rapamycin significantly reduced the frequency of spontaneous seizures in rats, and the effect of T-Rap was stronger than that of conventional rapamycin (P < 0.05). Western blot showed that the phosphorylation levels of S6K and S6 in T-Rap group were lower than those in Rap group (all P < 0.05), indicating that T-Rap had a stronger inhibitory effect on mTOR signaling pathway. FJB staining showed that T-Rap significantly decreased neuronal death, but there was no significant difference as compared with Rap group. Timm's staining showed that both preparations of rapamycin significantly reduced the germination of mossy fibers, while the effect of T-Rap was more pronounced than Rap group (P < 0.05). The inhibition of body weight gain of T-Rap group was less than that of Rap group (P < 0.05). Conclusion: T-Rap has a better therapeutic effect on epilepsy than conventional rapamycin with a less adverse effects in rats.