The Role of Raptor in Temporal Lobe Eplieptogenesis

项目摘要 尽管有抗癫痫药物可用，但在美国340万癫痫患者中，有三分之一的人在医学上 顽固性癫痫，尽管接受了治疗，但仍有癫痫发作。目前还没有有效的治疗方法 防止这种衰弱状态(抗癫痫)在高危患者中的发展。 雷帕霉素(MTOR)途径的机制靶点，调节神经元的可塑性和生长 成为开发抗癫痫治疗的有希望的候选药物。药理作用 MTOR通路的拮抗剂在预防癫痫发作的动物模型中显示出有效性。 然而，癫痫的细胞靶点和信号复合体介导这些作用尚不清楚。 海马齿状回颗粒细胞可能是mTOR介导的病理改变的主要靶点 可见于颞叶癫痫(TLE)。在DGC的发展过程中，mTOR信号在DGC中增加 TLE，雷帕霉素处理可阻断非典型DGC形态的形成。我们的实验室已经证明 新生海马齿状回mTOR抑制物、磷酸酶和张力蛋白同源物(PTEN)的缺失 颗粒细胞(DGC)导致癫痫相关的苔藓纤维萌发和胞体肥大。 这些在DGC中表现出的异常被认为与齿状回的破坏有关。 过滤来自内嗅皮层的传入信息的能力，创建超兴奋的海马体电路， 导致自发性反复发作。我们假设雷帕霉素产生其令人不适的修饰 阻断mTOR信号在DGC中的作用。为了检验这一假设，我们将从基因上删除必要的 在小鼠TLE模型中从颗粒细胞中提取mTORC1接头蛋白猛禽，并确定是否 治疗可减少DGC的癫痫发生率并防止畸形发生(目标1)。评估……的作用 猛禽在癫痫发生中的作用，我们开发了一种病毒策略，在这种策略中，loxP侧翼的猛禽可以在 转基因动物注射AAV9诱导匹罗卡品癫痫持续状态CRE- 海马神经元介导的重组将导致Raptor基因的缺失，从而阻止mTORC1的活性 在这些牢房里。(目的2)我们预测阻断海马区DGC在TLE的发病机制中起一定作用。 我们的提案利用协作、概念和方法创新来取得有意义的进展 旨在阐明mTORC1和mTORC2在癫痫发病机制中的作用。结果，合在一起 通过有指导的培训，将为癫痫和其他疾病提供新的解决方案 神经紊乱。

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.