Uncovering the Role of TRIO in Synaptic Function and Autism Spectrum Disorder

项目主任/首席调查员(最后、第一、中间)：鲱鱼、布鲁斯、E. 项目总结 自闭症谱系障碍(ASD)是导致精神障碍的主要原因，目前还没有已知的治疗方法。 越来越多的证据表明，肌动蛋白介导的突触后谷氨酸能调节的变化趋于一致 突触是ASD的基础。我们最近发现了与ASD相关的史无前例的集群 突触肌动蛋白调节蛋白TRIO的GEF1结构域的突变导致全基因组范围内的强烈突变 TRIO基因与ASD的统计相关性。我们研究的长期目标是确定核心突触 众多导致ASD的因素汇聚在一起的监管机制。突触的识别 ASD风险基因的“聚合点”将有助于简化这种疾病的遗传图景，从而有助于 开发新的策略来治疗具有不同ASD致病因素的个体。我们的中央 假说是TRIO中的ASD突变扰乱了许多突触调节通路，而这种扰乱 这些途径中的一种导致谷氨酸能突触功能障碍，从而促进ASD的发展。 相关的行为表型。在强劲的初步数据的指导下，我们将从三个具体方面来探讨这一假设 目标。在目标1中，我们将结合蛋白质组学、生化、电生理和超分辨率成像 识别涉及TRIO的新的突触调节机制的技术。在目标2中，我们将把这些相同的东西结合起来 用计算模型揭示TRIO相关突触调节机制的方法 和自闭症相关突变，并提供了由以下原因引起的突触破坏的全面图景 自闭症特有的三联症功能障碍。对于Aim 3，我们设计了一种有条件的敲入鼠标，允许 依赖Cre的ASD相关突变形式Trio的表达。使用这种新的强大的基因工具，我们 将进行一系列行为测试，以评估与ASD相关的Trio突变对哺乳动物的影响 行为。现在越来越多的证据表明，神经感觉处理缺陷是导致 许多常见的自闭症相关行为表型的发展。正因为如此，我们建议使用 最先进的技术，允许仔细检查这些小鼠的体感过程。这个 本提案具有创新性，因为它汇集了一个具有不同专业领域和 部署了新的强大的基因工具，将允许多维方法了解如何 突触功能障碍会导致ASD。这项提议意义重大，因为它将确定一个重要的 突触信号中枢，连接许多先前与ASD有关的突触蛋白，并将垂直连接 推动我们对ASD从突触到回路再到行为的理解。这项建议正好符合这一使命。 NINDS的目标，因为其重点是突触功能障碍最终如何导致关键的神经功能障碍 这可能是与ASD相关的许多核心行为表型的基础。 OMB编号0925-0001/0002(01/18修订版批准至2020年3月31日)续格式页

Program Director/Principal Investigator (Last, First, Middle): Herring, Bruce, E. PROJECT SUMMARY Autism Spectrum Disorder (ASD) is a leading cause of mental impairment for which there is no known cure. Mounting evidence points to a convergence on altered actin-mediated regulation of postsynaptic glutamatergic synaptic function as a basis for ASD. We have recently identified an unprecedented clustering of ASD-related mutations in the GEF1 domain of the synaptic actin regulatory protein, Trio, that results in a strong genome-wide statistical association of the TRIO gene with ASD. The long-term goal of our research is to identify core synaptic regulatory machinery onto which numerous ASD causing factors converge. Identification of synaptic “convergence points” of ASD-risk genes will help simplify the genetic landscape of this disorder and thus, aid in the development of new strategies to treat individuals with a diverse array of ASD-causing factors. Our central hypothesis is that ASD mutations in Trio disrupt a multitude of synaptic regulatory pathways, and that disruption of these pathways results in glutamatergic synapse dysfunction that contributes to the development of ASD- related behavioral phenotypes. Guided by strong preliminary data we will pursue this hypothesis in three specific aims. In Aim 1, we will combine proteomic, biochemical, electrophysiological, and super-resolution imaging techniques to identify novel synaptic regulatory mechanisms involving Trio. In Aim 2, we will combine these same approaches with computational modeling to reveal Trio-related synaptic regulatory mechanisms disrupted by Autism-related mutations and provide a comprehensive picture of the synaptic disruption that results from Autism-specific Trio dysfunction. And, for Aim 3, we have engineered a conditional knock-in mouse that allows CRE-dependent expression of an ASD-related mutant form of Trio. Using this new and powerful genetic tool, we will conduct a battery of behavioral tests to assess the impact of ASD-related Trio mutations on mammalian behavior. Growing evidence now suggests that neurological sensory processing deficits underlie the development of many common ASD-related behavioral phenotypes. Because of this, we propose the use of state-of-the-art techniques that allow careful examination of somatosensory processing in these mice. The present proposal is innovative because it assembles a team of collaborators with diverse areas of expertise and deploys new and powerful genetic tools that will allow a multi-dimensional approach to understanding how disruption of synaptic function leads to ASD. The proposal is significant because it stands to identify an important synaptic signaling hub that links numerous synaptic proteins previously implicated in ASD and will vertically advance our understanding of ASD from synapse to circuit to behavior. This proposal squarely meets the mission objectives of the NINDS given its focus on how synaptic dysfunction ultimately leads to key neurological deficits that likely underlie many core behavioral phenotypes associated with ASD. OMB No. 0925-0001/0002 (Rev. 01/18 Approved Through 03/31/2020) Continuation Format Page