Induced neuronal cells: A novel tool to study neuropsychiatric diseases

 描述（由申请人提供）：本申请是我们当前R 01的更新申请，该申请为Wernig和Südhof实验室的成功合作提供了资金。该资助的上一个资助期的目标是开发诱导神经元（iN）细胞方案，以提供原理证明，即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，这使我们现在可以将iN细胞纳入我们的模型系统组合中，以研究神经精神疾病中受影响的突触分子。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，并将其用于实际研究人类神经元中的神经元细胞生物学。这个更新应用程序的目标是了解正常和突变的神经连接素的分子功能，包括它们对特定突触专业化的分类，它们的关键结合伴侣的鉴定，它们对突触调制的详细作用，以及自闭症中发现的神经连接素突变形式的作用机制。神经连接素是重要的突触细胞粘附分子，定位为突触后膜上的组成性同源或异源二聚体。它们的大的细胞外结构域与neurexins和潜在的其他突触前膜蛋白相互作用，它们的较小的细胞内结构域与各种突触后支架蛋白如PSD-95相互作用。我们将采用完善的和广泛接受的小鼠模型来定义正常和实验修饰的神经连接蛋白的功能性神经连接蛋白结构域和相互作用伙伴。大多数自闭症相关的神经配蛋白突变发现于X染色体NLGN 4基因中。然而，小鼠Nlgn 4在蛋白质水平上没有很好地保守，只有51%的序列相似性，并且比Nlgn 1 -3表达低得多，这质疑了小鼠研究与人类疾病的相关性。出于这个原因，我们建议利用我们开发的人类iN细胞系统来研究正常和突变的NLGN 4突触功能。Wernig和Südhof联合实验室提供了互补的专业知识，使此类实验切实可行。

 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.