Patient-derived Models of Synaptic Pruning in Schizophrenia

精神分裂症是一种慢性、致残性和遗传性很强的疾病。验尸研究表明 精神分裂症患者皮质树突棘密度与结构神经成像的一致性 学习。同样，基因组数据将与精神分裂症相关的常见风险变量联系在一起，影响最大 打乱了啮齿动物模型中的修剪。这些一致的证据表明，小胶质细胞介导的 修剪异常可能是精神分裂症观察到的神经病理的原因，延长了 认识到小胶质细胞选择性吞噬突触作为一种修剪手段在正常人中的重要性 神经发育。然而，人类小胶质细胞在疾病中的大规模功能研究受到阻碍。 由于难以从精神分裂症患者身上获得适合快速筛查和 定量功能评估。 研究人员最近开发并验证了患者特有的小胶质细胞介导的模型 重编程修剪患者外周血分离单核细胞诱导的小胶质细胞 它们具有分离的突触(突触体)，这些突触来自与诱导分化的神经培养物 多能干细胞(IPSCs)。在初步研究中，他们已经证明了强有力的证据 精神分裂症患者的小胶质细胞和突触体异常，并被抢救 用小分子探针以剂量反应的方式显示这种异常。 拟议的调查将证实并扩展这些结果，使用一个非常大的患者来源 研究人员开发的细胞生物库。具体地说，这项研究将产生新的和充分的 50例急性髓细胞白血病患者的诱导小胶质细胞培养和IPSC来源的神经培养 精神分裂症和50名年龄、性别和血统匹配的健康对照组。这些患者衍生的试剂将 用于检测小胶质细胞介导的突触修剪的功能差异 患者和对照组(目标1)。这些分析也将被应用于筛选小分子以识别 突触修剪的额外调节器，建立在有希望的初步数据基础上(目标2)。并行，高 通过化学基因组方法将被用来表征这些小分子的转录效应。 小胶质细胞上的分子微扰剂，为深入了解作用机制和促进进一步 化学筛选(目标3)。 总而言之，这些研究将进一步验证该平台对未来高通量筛查工作的目标 在新疗法方面。该项目汇集了一支在细胞建模方面拥有专业知识的团队， 转录学、临床表型和小分子筛选。除了调查这些委托人 假设，该项目将为神经生物学社区创造一个关键资源，具有很高的- 维度数据扩展了患者和健康对照细胞的完全注释和可共享的生物库。

Schizophrenia is a chronic, disabling, and strongly heritable illness. Postmortem studies suggest reduced cortical dendritic spine density among schizophrenia patients, consistent with structural neuroimaging studies. Likewise, genomic data links schizophrenia-associated common risk variants of greatest effect to disrupted pruning in a rodent model. These convergent lines of evidence suggest that microglia-mediated pruning abnormalities may be responsible for the observed neuropathology in schizophrenia, extending the recognized importance of selective engulfment of synapses by microglia as a means of pruning in normal neurodevelopment. However, large-scale functional studies of human microglia in disease are hampered by difficulties in obtaining living cells from individuals with schizophrenia amenable to rapid screening and quantitative functional assessments. The investigators have recently developed and validated patient-specific models of microglia-mediated pruning by reprogramming induced microglial cells from patient blood isolated monocytes, and assaying them with isolated synapses (synaptosomes) derived from neural cultures differentiated from induced pluripotent stem cells (iPSCs). In preliminary studies, they have demonstrated robust evidence of abnormalities in both microglia as well as synaptosomes from individuals with schizophrenia, and rescued such abnormalities in a dose-responsive fashion with a small molecule probe. The proposed investigation will confirm and extend these results using a very large patient-derived cellular biobank developed by the investigators. Specifically, this study will generate new and fully characterized induced microglia cultures and iPSC-derived neural cultures from 50 individuals with schizophrenia and 50 age, sex, and ancestry-matched healthy controls. These patient-derived reagents will be utilized in an assay to examine functional differences in microglia-mediated synaptic pruning from patients and controls (Aim 1). These assays will also be applied to screen small molecules to identify additional modulators of synaptic pruning, building on promising preliminary data (Aim 2). In parallel, high throughput chemical genomic methods will be applied to characterize transcriptomic effects of these small molecule perturbagens on microglia, providing insight into mechanism of action and facilitating further chemical screens (Aim 3). Together, these studies will further validate the platform for future high-throughput screening efforts aimed at novel therapeutics. The project brings together a team with expertise in cellular modeling, transcriptomics, clinical phenotyping, and small molecule screening. Beyond investigating these principal hypotheses, the project will create a critical resource for the neurobiological community, with high- dimensionality data extending a fully annotated and shareable biobank of patient and healthy control cells.