The Role of DEPDC5 in Epileptogenesis and Brain Malformations

项目摘要/摘要 癫痫影响了大约1%的人口和每200名儿童中就有一名。在许多方面发生了颠覆 癫痫相关基因改变雷帕霉素途径机制靶点(MTOR)介导的信号转导， 它不仅与癫痫有关，还与大脑畸形和自闭症有关。MTOR情结 1(MTORC1)通过生长因子和氨基酸协调细胞新陈代谢 汇聚的平行通道。生长因子激活mTORC1与结节性硬化症的调节 复合体(TSC)在脑发育和神经元活动的调节中发挥了重要作用。在……里面 相比之下，mTORC1的氨基酸激活和含DEP结构域的5(DEPDC5)的调节还没有 在大脑中进行严格的研究。在慢性阻塞性肺疾病患者中发现了DEPDC5基因的遗传变异 癫痫和脑发育的结构变化(即皮质发育畸形)提示 它的蛋白质产物DEPDC5在大脑中扮演着重要的角色。还有几个问题是关于 DEPDC5调节神经元mTORC1的机制及其对大脑发育的影响 包括DEPDC5是否调节氨基酸介导的神经元中的mTORC1信号。回答这些问题 问题可能会开启治疗调节营养信号作为癫痫治疗的可能性。 该项目将建立Depdc5缺乏症的体内和体外模型，并解决关键的 通过定义DEPDC5缺失对神经元信号和大脑发育的影响来确定知识差距。 最近，我产生了一个大脑特有的Depdc5缺失的小鼠模型，它有几个类似的特征 与DEPDC5相关的癫痫患者(Yuskaitis等人，Neurobiol Dis 2018年)。这些老鼠会癫痫发作， 异常神经元具有高度活跃的mTORC1活性，并在成年后因不明原因过早死亡。 提议的项目的第一个目标是确定1)大脑特异的Depdc5基因敲除小鼠是否会死亡 以及2)药物雷帕霉素(一种mTORC1抑制剂)是否可以延长生存期和 停止这些老鼠的癫痫发作。其次，我将研究DEPDC5的缺失是否会影响营养信号转导 神经元。第三，我将建立一个新的小鼠模型来确定Depdc5丢失的时间是否影响 癫痫与脑发育独立。拟议的研究将提供对 研究大脑发育的潜在机制，并确定癫痫的潜在治疗方法。 我的职业目标是成为一名独立的神经遗传学科学家，专注于使用细胞和 小鼠模型，以辨别大脑发育和癫痫发生的基本机制。我的 提案结合了专注的研究项目、卓越的指导和丰富的机构资源， 波士顿儿童医院和哈佛医学院，这为我过渡到 一位独立资助的内科科学家获奖。

PROJECT SUMMARY/ABSTRACT Epilepsy affects approximately 1% of the population and one in 200 children. Disruption in many epilepsy-related genes alters signaling mediated by the mechanistic target of rapamycin (mTOR) pathway, which has been implicated not only in epilepsy but also in brain malformations and autism. The mTOR complex 1 (mTORC1) coordinates cellular metabolism through growth factors and amino acids that operate on two converging parallel pathways. Growth factor activation of mTORC1 and regulation by the tuberous sclerosis complex (TSC) have demonstrated roles in the regulation of brain development and neuronal activity. In contrast, amino acid activation of mTORC1 and regulation by DEP domain-containing 5 (DEPDC5) are yet to be rigorously studied in the brain. Genetic variants in the DEPDC5 gene have been found in patients with epilepsy and structural alterations in brain development (i.e. malformations of cortical development) suggesting that its protein product DEPDC5 plays an important role in the brain. Several questions remain about the mechanisms by which DEPDC5 regulates mTORC1 in neurons and how this impacts brain development, including whether DEPDC5 regulates amino acid mediated mTORC1 signaling in neurons. Answering these questions may open the possibility of therapeutically modulating nutrient signaling as a treatment for epilepsy. This project will establish in vivo and in vitro models of Depdc5 deficiency and address a crucial knowledge gap by defining the impact of DEPDC5 loss on neuronal signaling and brain development. Recently, I generated a mouse mode with brain-specific Depdc5 loss that has several features similar to patients with DEPDC5-related epilepsy (Yuskaitis et al., Neurobiol Dis 2018). These mice have seizures, abnormal neurons with hyperactive mTORC1 activity, and die prematurely in adulthood of an unknown cause. The first aim of the proposed project is to determine 1) whether the brain-specific Depdc5 knockout mice die prematurely from seizures, and 2) whether the drug rapamycin (an mTORC1 inhibitor) can prolong survival and stop seizures of these mice. Second, I will investigate whether DEPDC5 loss affects nutrient signaling in neurons. Third, I will establish a novel mouse model to determine whether the timing of Depdc5 loss impacts epilepsy and brain development independently. The proposed research will provide essential insights into the mechanisms underlying brain development and identify potential treatments for epilepsy. My career goal is to become an independent neurogenetics scientist with a focus on using cellular and mouse models to discern the fundamental mechanisms underlying brain development and epileptogenesis. My proposal combines a focused research project, exceptional mentorship, and rich institutional resources at Boston Children's Hospital and Harvard Medical School, which provide a solid foundation for my transition into an independently funded physician-scientist during this award.