The Role of GATOR1 in Cortical Malformations

项目摘要 皮质发育畸形（MCD）是一组神经发育异常， 特征为一系列形态和结构异常的疾病， 反映胚胎大脑发育错误的大脑皮层。MCD与 患有医学难治性癫痫，可能需要手术切除受影响的 脑组织一些MCD是由神经胶质祖细胞发生的体细胞突变引起的。 这种细胞会导致大脑中一个有限区域的皮质发育异常， 局灶性皮质发育不良（FCD）。特别是，影响基因的体细胞突变， 哺乳动物雷帕霉素靶蛋白（mTOR）信号通路与 FCD。最近，编码GATOR 1的mTOR调节基因的突变 复杂的例如，DEPDC5、NPRL2、NPLR3与FCD相关。而 已知GATOR 1响应于细胞氨基酸水平调节mTOR信号传导 在非神经元系统中，迄今为止，还没有研究调查 这些基因在神经元或大脑发育过程中。因此，在目标1中，我们将定义 GATOR 1亚基敲低（KD）对细胞大小和细胞迁移的影响，并评估 这些效应是否依赖于mTOR。在目标2中，我们研究了 GATOR 1在蛋白质合成、亚细胞定位和神经元兴奋性中的作用。在 目的3，我们评估GATOR 1 KD如何改变大脑皮层分层，并产生一个新的神经元。 FCD小鼠模型。我们将证明，在这个模型中，FCD可以预防， mTOR抑制剂。这些研究将有助于了解GATOR 1在肿瘤发生中的作用。 皮质发育，并提供mTOR抑制剂的临床前评估， 未来可能用于GATOR 1相关癫痫。

PROJECT SUMMARY Malformations of cortical development (MCD) are a group of neurodevelopmental disorders characterized by a range of morphological and structural abnormalities of the cerebral cortex reflecting errors in embryonic brain development. MCD are associated with medically refractory epilepsy and may require the surgical removal of the affected brain tissue. Some MCD result from somatic mutations occurring in neuroglial progenitor cells that result in abnormal cortical development in a restricted area of the brain known as focal cortical dysplasia (FCD). In particular, somatic mutations affecting genes in the mammalian target of rapamycin (mTOR) signaling pathway are highly associated with FCD. Recently, mutations in the mTOR regulatory genes encoding the GATOR1 complex e.g., DEPDC5, NPRL2, NPLR3, have been associated with FCD. While GATOR1 is known to modulate mTOR signaling in response to cellular amino acid levels in non-neuronal systems, to date, no studies have investigated the functional role for these genes in neurons or during brain development. Thus, in Aim 1, we will define the effects of GATOR1 subunit knockdown (KD) on cell size and cell migration and assess whether these effects are mTOR dependent. In Aim 2, we investigate the functional roles of GATOR1 in protein synthesis, subcellular localization, and neuronal excitability. In Aim 3, we assess how GATOR1 KD alters cerebral cortical lamination and generate a new mouse model of FCD. We will show that FCD in this model can be prevented with mTOR inhibitors. These studies will help to understand the role of GATOR1 during in cortical development and provide pre-clinical assessment of mTOR inhibitors for possible future use in GATOR1-associated epilepsies.