Induced neuronal cells: A novel tool to study neuropsychiatric diseases

 描述(由申请人提供)：此申请是我们当前R01的续签申请，用于资助维尔尼希实验室和Südhof实验室的成功合作。这笔赠款的前一个资助期的目标是开发诱导神经元(IN)细胞方案，以提供原则证明，可以在携带自闭症相关突变的人类神经元中研究细胞生物学表型。我们已经实现了这一目标，这使得我们现在可以将细胞纳入我们的模型系统组合，以研究神经精神疾病中受影响的突触分子及其相关因素。在这次更新申请中，我们建议现在应用上一个资助期开发的技术，并使用它来实际研究人类神经元的神经细胞生物学。这一更新应用的目标是了解正常和突变神经连接蛋白的分子功能，包括它们对特定突触特化的分类，它们关键结合伙伴的识别，它们在突触调节中的详细作用，以及自闭症中发现的神经连接蛋白突变形式的作用机制。神经连接蛋白是一种重要的突触细胞黏附分子，定位于突触后膜，以同源或异源二聚体形式存在。它们的大的胞外结构域与Neurexins相互作用，可能与其他突触前膜蛋白相互作用，它们的较小的胞内结构域与各种突触后支架蛋白相互作用，如PSD-95。我们将使用成熟和被广泛接受的小鼠模型来定义正常和实验修改的神经连接蛋白的功能性神经连接素域和相互作用伙伴。大多数与自闭症相关的神经连接蛋白突变都在X染色体的NLGN4基因中发现。然而，小鼠Nlgn4在蛋白质水平上的序列相似性仅为51%，并不是很保守，而且表达水平远低于NLGN1-3，这质疑了小鼠研究人类疾病的相关性。为此，我们建议利用我们开发的人类细胞内系统来研究正常和突变的NLGN4突触功能。维尔尼希和S的联合实验室提供了互补的专业知识，使这类实验在现实中可行。

 DESCRIPTION (provided by applicant): This application is the renewal application for our current R01 that funds the successful collaborative work of the Wernig and Südhof laboratories. The goal of the previous funding period of this grant was to develop induced neuronal (iN) cell protocols to provide the proof-of-principle that cell biological phenotypes can be studied in human neurons carrying autism-associated mutations. We have accomplished this goal which allows us now to include iN cells into our portfolio of model systems to investigate synaptic molecules affected in and relevant for neuropsychiatric diseases. In this renewal application, we propose to now apply the technologies developed in the previous funding period and use it to actually study neuronal cell biology in human neurons. The goal of this renewal application is to understand the molecular functions of normal and mutant neuroligins including their sorting to specific synaptic specializations, the identification of their critical binding partners, their detiled role on synaptic modulation, and the mechanism of action of mutant forms of neuroligins found in autism. Neuroligins are critical synaptic cell-adhesion molecules localized as constitutive homo- or heterodimers at the post-synaptic membrane. Their large extracellular domain interacts with neurexins and potentially other presynaptic membrane proteins, their smaller intracellular domain with various postsynaptic scaffold proteins such as PSD-95. We will employ well-established and widely accepted mouse models to define functional neuroligin domains and interaction partners of normal and experimentally modified neuroligins. Most autism-associated neuroligin mutations are found in the X-chromosomal NLGN4 gene. The mouse Nlgn4, however, is not well conserved with a mere 51% sequence similarity on the protein level and is much lower expressed than Nlgn1-3, which questions the relevance of mouse studies for human disease. For this reason, we propose to utilize the human iN cell systems that we developed to investigate normal and mutant NLGN4 synaptic function. The combined Wernig and Südhof laboratories provide the complementary expertise to make such experiments realistically feasible.