Characterization of hiPSC-neurons from psychosis patients with neurexin-1 deletions

项目摘要 突触前细胞黏附分子Neuresin-1(NRXN1)的杂合缺失与 神经精神障碍和精神病。NRXN1是高度选择性剪接的，最近是这些 神经元识别中的剪接异构体已经被提出；然而，NRXN1异构体还没有被表征 在人类神经元中。NRXN1缺失的动物模型显示出行为和神经元活动的缺陷。然而， 动物模型不能概括无数患者特定缺失在其他风险背景下的影响 患者基因组中的变异；这些效应加在一起可能影响NRXN1的可变外显率 缺失，这提供了一套不同的临床诊断。使用来自一组罕见的 四名携带NRXN1缺失的精神病患者，这项建议将调查这些患者的偶然贡献 兴奋性HiPSC神经元中基因表达、选择性剪接和神经元表型的缺失。那里 有三个目标：第一个目的是识别NRXN1缺失的HiPSC神经元中选择性剪接的差异， 第二是修复亚型缺陷并操纵HIPSC神经元中NRXN1的表达，第三是 目的：探讨NRXN1缺失在HiPSC神经元中的功能意义。我的假设是 来自四个精神病患者的HiPSC神经元将显示NRXN1亚型的差异表达，其中 对于正常的神经元活动和形态是至关重要的。我们包括了强有力的初步数据，证明了 我们的方案的可行性；此外，我们已经观察到NRXN1 HiPSC神经元表达 野生型和缺失等位基因变异。我们希望这些实验将提高我们对 神经精神疾病遗传风险的分子机制。

Project Summary Heterozygous deletion of neurexin-1 (NRXN1), a presynaptic cell adhesion molecule, is strongly associated with neuropsychiatric disorders and psychosis. NRXN1 is highly alternatively spliced and recently a role for these splice isoforms in neuronal identity has been suggested; however, NRXN1 isoforms have not been characterized in human neurons. Animal models of NRXN1 deletion display deficits in behavior and neuronal activity. However, animal models cannot recapitulate the effect of myriad patient-specific deletions in the context of other risk variants within a patient’s genome; together, these effects likely influence the variable penetrance of NRXN1 deletions, which confer a diverse set of clinical diagnoses. Using hiPSC-neurons derived from a rare cohort of four psychosis patients carrying NRXN1 deletions, this proposal will investigate the casual contribution of these deletions on gene expression, alternative splicing and neuronal phenotypes in excitatory hiPSC-neurons. There are three aims: the first is identify differences in alternative splicing in NRXN1 deletion hiPSC-neurons, the second is to restore isoform deficiencies and manipulate NRXN1 expression in hiPSC-neurons, and the third is to establish the functional significance of NRXN1 deletion in hiPSC-neurons. My hypothesis is that excitatory hiPSC-neurons derived from four psychosis patients will exhibit differential expression of NRXN1 isoforms which are crucial for proper neuronal activity and morphology. We include strong preliminary data demonstrating the feasibility of our proposal; moreover, we have already observed that NRXN1 hiPSC-neurons express both wildtype and deleted allele variants. Our hope is that these experiments will improve our understanding of the molecular mechanisms underlying genetic risk for neuropsychiatric disorders.