The Role of Fos and the BAF Complex in Neuronal Activity-Dependent Chromatin Remodeling and Gene Expression

儿童神经发育障碍(NDD)，包括儿童癫痫、自闭症谱系障碍和 智力残疾是发病率的主要来源，但我们的治疗选择仍然有限。 NDD新疗法的开发将需要对正常和 大脑发育异常。这项提案侧重于激活的遗传程序，以响应 神经元活动是正常神经发育和正在进行的神经元可塑性的基础 在一生中。Fos是一种主要的活性依赖的转录因子，它与末端增强子元件结合，并 以特定细胞类型的方式调节下游依赖活性的遗传程序，以促进关键 过程，包括突触修剪和在发育中的大脑中重新招募抑制。尽管它在 关键的发育过程，我们不知道Fos是如何针对特定细胞类型的不同靶点的 结合部位，以及这些部位的遗传变异如何影响神经发育和神经元功能。 有趣的是，Fos已经被证明与BAF染色质重塑复合体物理上相互作用，而且它是 这种相互作用可能是Fos功能的关键。许多BAF亚单位，最常见的是ARID1B，是 与人类NDD有关，但BAF复合体是否调节神经元活动依赖的基因 计划，以及这如何支撑与BAF复合体相关的NDD的各个方面，以前都是未知的。这项研究 这项提议将通过以下方式解决这些知识空白：(A)分析Fos和BAF复合神经元结合 (B)评估新城疫和新城疫患者在这些位置上的人类遗传变异。 对照；以及(C)确定BAF复合体扰动对神经元活动依赖的遗传的影响 体外和体内的程序。总体而言，这项工作将导致更深入地了解依赖活动的基因是如何 程序参与了新城疫的发病机制。此外，通过识别特定的活性调节基因和 在Fos和BAF复合体下游被错误调控的通路，这些实验可能会突出 治疗新城疫的新靶点。 这项研究是一个为期五年的职业发展计划的基础，该计划旨在以特罗布里奇博士的 分子神经科学、儿科神经学/癫痫和神经遗传学背景，为她提供 在分析人类测序数据、使用体外和体内NDD模型方面的额外培训，以及下一步- 世代排序技术。她的主要导师迈克·格林伯格博士和她的科学建议 委员会，Annapurna Poduri博士和Chris Walsh博士将在这些领域提供指导，以及指导 在翻译神经科学研究的严谨和道德方面。因此，拟议的培训计划将 定位特罗布里奇博士，开始她的独立职业生涯，成为一名专注于了解 依赖活动的遗传程序在新城疫中的作用。

Pediatric neurodevelopmental disorders (NDD), including pediatric epilepsy, autism spectrum disorder, and intellectual disability, represent a major source of morbidity, yet our therapeutic options remain limited. Development of novel therapies for NDD will require a deeper mechanistic understanding of normal and abnormal brain development. This proposal focuses on genetic programs that are activated in response to neuronal activity and that are fundamental to normal neurodevelopment and on-going neuronal plasticity throughout life. Fos is a major activity-dependent transcription factor that binds to distal enhancer elements and regulates downstream activity-dependent genetic programs in a cell-type-specific manner to promote key processes, including synaptic pruning and the recruitment of inhibition in the developing brain. Despite its role in key developmental processes, we do not understand how Fos is differentially targeted to cell-type-specific binding sites, nor how genetic variation at these sites impacts neurodevelopment and neuronal function. Interestingly, Fos has been shown to physically interact with the BAF chromatin remodeling complex, and it is possible that this interaction is critical to Fos function. Many BAF subunits, most frequently ARID1B, are implicated in human NDD, but whether the BAF complex regulates neuronal activity-dependent genetic programs, and how this underlies aspects of BAF complex-related NDD, is previously unexplored. The research in this proposal will address these gaps in knowledge by: (a) profiling Fos and BAF complex neuronal binding sites across the human genome; (b) assessing human genetic variants at these sites in individuals with NDD vs controls; and (c) determining the effects of BAF complex perturbation on neuronal activity-dependent genetic programs in vitro and in vivo. Overall, this work will lead to greater insight into how activity-dependent genetic programs contribute to NDD pathogenesis. Additionally, by identifying specific activity-regulated genes and pathways that are mis-regulated downstream of Fos and the BAF complex, these experiments could highlight novel therapeutic targets for NDD. This research is the basis for a five-year career development program designed to build on Dr. Trowbridge’s background in molecular neuroscience, pediatric neurology/epilepsy, and neurogenetics, by providing her with additional training in analysis of human sequencing data, use of in vitro and in vivo models of NDD, and next- generation sequencing technologies. Her primary mentor, Dr. Mike Greenberg, and her scientific advisory committee, Drs. Annapurna Poduri and Chris Walsh, will provide guidance in these areas, as well as mentorship in the rigorous and ethical conduct of translational neuroscience research. Thus the proposed training plan will position Dr. Trowbridge to launch her independent career as a clinician-scientist focused on understanding the role of activity-dependent genetic programs in NDD.