The Role of Raptor in Temporal Lobe Eplieptogenesis

项目摘要 尽管有抗癫痫药物，但美国340万癫痫患者中有三分之一在医学上 顽固性癫痫，尽管治疗，仍然经历癫痫发作。没有有效的治疗方法， 预防高危患者出现这种衰弱状况（抗癫痫药）。 调节神经元可塑性和生长的雷帕霉素（mTOR）通路的机制靶点， 成为抗癫痫治疗发展的一个有前途的候选者。药理 mTOR通路的拮抗剂已经显示出在癫痫动物模型中预防癫痫发作发生的功效， 然而，对于癫痫，介导这些作用的细胞靶点和信号复合物尚不清楚。 海马齿状回颗粒细胞（DGC）可能是mTOR介导的病理变化的主要靶点 常见于颞叶癫痫（TLE）。mTOR信号传导在DGC中增加， 用雷帕霉素治疗可以阻断非典型DGC形态的形成。我们的实验室显示 mTOR抑制剂、磷酸酶和张力蛋白同源物（PTEN）从新生海马齿状回缺失 颗粒细胞（DGCs）导致苔藓纤维发芽和索马肥大与癫痫有关。 这些异常表现在DGC被认为与齿状回的破坏有关。 能够过滤来自内嗅皮层的信息，创造出高度兴奋的海马回路， 导致自发性复发性癫痫。我们假设雷帕霉素产生其疾病修饰作用， 通过阻断DGC中的mTOR信号传导来实现。为了验证这一假设，我们将从基因上删除 mTORC 1衔接蛋白raptor从小鼠TLE模型中的颗粒细胞中分离，并确定mTORC 1衔接蛋白raptor是否 治疗降低了癫痫发作的发生率并防止了DGC中的畸形发生（目的1）。评估的作用 我们已经开发了一种病毒策略，其中LoxP侧翼的猛禽可以在癫痫发生后被删除。 通过给转基因动物注射AAV 9.CamKII.HI.eGFP-Cre. Cre- 海马神经元中介导的重组将导致raptor的缺失，阻止mTORC 1活性 在这些细胞中。(Aim 2）阻断海马DGC可能参与了TLE的发病机制。 我们的提案利用合作、概念和方法创新来取得有意义的进展 探讨mTORC 1和mTORC 2在癫痫发病机制中的作用。结果，在一起 通过指导培训，将为致力于癫痫和其他疾病的新解决方案提供基础。 神经系统疾病

Project Summary Despite availability of anti-epileptic drugs, one-third of the 3.4 million US patients with epilepsy have medically intractable epilepsy and still experience seizures despite treatment. There are no effective treatments to prevent the development of this debilitating condition (antiepileptogenic) in at-risk patients. The mechanistic target of rapamycin (mTOR) pathway, which regulates neuronal plasticity and growth, has emerged as a promising candidate for the development of anti-epileptogenic therapies. Pharmacological antagonists of the mTOR pathway have shown efficacy at preventing seizure occurrence in animal models of epilepsy, however, the cellular targets and signaling complexes mediating these effects are unclear. Hippocampal dentate granule cells (DGCs) may be prime targets of mTOR mediated pathological changes seen in temporal lobe epilepsy (TLE). mTOR signaling is increased among DGCs during the development of TLE, and treatment with rapamycin can block the formation of atypical DGC morphology. Our lab has shown that deletion of mTOR inhibitor, phosphatase and tensin homolog (PTEN) from newborn hippocampal dentate granule cells (DGCs) resulted in the mossy fiber sprouting and soma hypertrophy associated with epilepsy. These abnormalities exhibited in DGCs are thought to be associated with breakdown of the dentate gyrus’ ability to filter incoming information from the entorhinal cortex, creating hyper-excitable hippocampal circuits, resulting in spontaneous recurrent seizures. We hypothesize that rapamycin produces its diseasing modifying effects by blocking mTOR signaling in DGCs. To test this hypothesis, we will genetically delete the essential mTORC1 adaptor protein raptor from granule cells in a mouse TLE model and determine whether the treatment reduces seizure incidence and prevents dysmorphogenesis in DGCs (Aim 1). To assess the role of raptor in epileptogenesis, we have developed a viral strategy in which LoxP-flanked raptor can be deleted after pilocarpine-induced status epilepticus by injecting transgenic animals with AAV9.CamKII.HI.eGFP-Cre. Cre- mediated recombination in hippocampal neurons will lead to the deletion of raptor, preventing mTORC1 activity in these cells. (Aim 2) We predict that blocking hippocampal DGCs plays a role in the pathogenesis of TLE. Our proposal leverages collaborative, conceptual, and methodological innovation to make meaningful progress towards delineating the roles of mTORC1 and mTORC2 in the pathogenesis of epilepsy. The results, together with mentored training, will provide a foundation for working toward new solutions for epilepsy and other neurological disorders.