Identifying pathogenic mechanisms underlying PACS1 Syndrome: implications for neural development

识别 PACS1 综合征的致病机制：对神经发育的影响

基本信息

批准号：
10676187
负责人：
ALICIA DIONE GUEMEZ GAMBOA
金额：
$ 53.13万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-08-05 至 2027-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10676187
关键词：
3-Dimensional Address Affect Arginine Binding Bipolar Disorder Brain Cell Death Cell Line Cell Nucleus Cell Proliferation Cell physiology Cells Cerebral cortex Cerebrum Chromatin Complex Cytoplasm Data Data Set Defect Development Developmental Delay Disorders Disease Dorsal Endosomes Equilibrium Etiology FOXG1B gene Family Foundations Funding Gene Expression Generations Genes Genetic Genetic Transcription Glutamates Goals Histone Deacetylase Human Impaired cognition Individual Knowledge Label Lentivirus Location Mediating Modernization Molecular Molecular Biology Nervous System Neurodevelopmental Disorder Neurologic Neuronal Differentiation Neurons Neurophysiology - biologic function Neurosciences Nuclear Nuclear Localization Signal Organoids PACS1 Syndrome Pathogenicity Pathway interactions Patients Pattern Phenotype Process Proliferating Prosencephalon Proteins Recurrence Research Role S phase SWI1 Sorting Specific qualifier value Stains Structure Susceptibility Gene Techniques Testing Tissue-Specific Gene Expression Tryptophan Variant Work cancer cell cell type design differential expression effective therapy experimental study genome wide association study induced pluripotent stem cell myocyte-specific enhancer-binding-factor 2C nerve stem cell nervous system development neural neurodevelopment neurogenesis neuromechanism programs protein transport severe early onset obesity single-cell RNA sequencing stem cells synaptogenesis targeted treatment tool trans-Golgi Network transcriptome

项目摘要

Project Summary Neurodevelopmental disorders (NDDs) are heterogenous and usually present with complex etiology. Individuals with these conditions present with cognitive impairment accompanied by lifelong deficits; yet remarkably little is known about their neurological basis. Patients and their families are in desperate need for disease-modifying therapies. However, to develop effective treatments, it is imperative to understand the dysregulation of molecular and cellular processes leading to these conditions. PACS1 Syndrome is a NDD caused by a single R203W substitution in the Phosphofurin Acidic Cluster Sorting 1 (PACS1) protein in over 200 patients. Moreover, genome-wide association studies (GWAS) identified the human PACS1 locus as a susceptibility gene in severe early-onset obesity, developmental delay, and bipolar disorder, suggesting a broader role in brain development. PACS1 encodes a multifunctional protein which canonical cytosolic function in the secretory pathway is to direct its cargo to the trans-Golgi Network.However, PACS1 also contains a nuclear localization signal (NLS), shuttles to the nucleus during S phase, and, at least in highly proliferative cancer cells, regulates chromatin stability through interaction with HDAC proteins. Despite previous studies have revealed critical PACS1 functions, the role of PACS1 within the nucleus as well as the effect of the PACS1 R203W variant in the nervous system yet to be determined. Thus, we have generated patient induced pluripotent stem cells (iPSCs)-derived cerebral organoids to investigate the transcriptome of a developing patterned, three-dimensional neural structure with the patient genetic background. By performing single cell RNA Sequencing in organoids during early development, we generated a preliminary dataset that strongly indicate that regulates a gene expression program important for Glutamatergic/GABAergic fate specification. Altogether, evidence regarding nuclear localization of PACS1, in addition to our preliminary data, suggests that PACS1 has an unexplored nuclear function, possibly by regulating gene expression in neural progenitors. Therefore, we hypothesize that PACS1 regulates Glutamatergic/GABAergic balance through a non-canonical nuclear function that decreases as neurogenesis proceeds. Thus, PACS1 deficits result in a shift towards GABAergic fate, generating ectopic GABAergic neurons, subsequent Glutamatergic/GABAergic imbalance, and finally NDD phenotypes. We will test this hypothesis by addressing whether PACS1 possesses context specific functions that differ across neural differentiation (aim1), and deficits in PACS1 nuclear function alter Glutamatergic/GABAergic specification balance (aim2). Results from this proposal will greatly enhance our understanding of how the PACS1 deficits affect the developing nervous system, by uncovering a currently disregarded nuclear function. Moreover, our work will expand our knowledge of the molecular underpinnings and consequences of the Glutamatergic/GABAergic imbalance, that has repeatedly been described as a precursor of many NDDs, pointing towards a possible common mechanism from genetically heterogeneous origins and may ultimately reveal convergent therapy targets.

项目概要神经发育障碍 (NDD) 具有异质性，通常病因复杂。个人患有这些疾病的人会出现认知障碍并伴有终生缺陷；但非常少的是了解它们的神经学基础。患者及其家人迫切需要疾病缓解疗法。然而，为了开发有效的治疗方法，必须了解分子的失调和导致这些情况的细胞过程。 PACS1 综合症是由单个 R203W 引起的 NDD 在 200 多名患者中替代磷酸呋喃酸性簇分选 1 (PACS1) 蛋白。而且，全基因组关联研究 (GWAS) 确定人类 PACS1 基因座是重症患者的易感基因早发性肥胖、发育迟缓和双相情感障碍，表明其在大脑发育中发挥着更广泛的作用。 PACS1 编码一种多功能蛋白，分泌途径中的典型胞质功能是指导它的货物到跨高尔基体网络。然而，PACS1 还包含核定位信号 (NLS)、穿梭机在 S 期进入细胞核，并且至少在高度增殖的癌细胞中调节染色质稳定性通过与 HDAC 蛋白相互作用。尽管之前的研究已经揭示了 PACS1 的关键功能， PACS1 在细胞核内的作用以及 PACS1 R203W 变体在神经系统中的作用待定。因此，我们产生了源自患者的诱导多能干细胞 (iPSC) 脑细胞类器官研究发育中的图案化三维神经结构的转录组患者遗传背景。通过在早期发育过程中对类器官进行单细胞 RNA 测序，我们生成了一个初步数据集，强烈表明调节基因表达程序很重要谷氨酸/GABA 能命运规范。总而言之，有关 PACS1 核定位的证据，除了我们的初步数据外，表明 PACS1 具有未开发的核功能，可能是通过调节神经祖细胞中的基因表达。因此，我们假设PACS1调节通过非规范核功能实现谷氨酸/GABA能平衡，该功能随着神经发生而减少收益。因此，PACS1缺陷导致GABA能命运的转变，产生异位GABA能神经元，随后的谷氨酸/GABA 能失衡，最后是 NDD 表型。我们将通过以下方式检验这个假设解决 PACS1 是否具有因神经分化而异的上下文特定功能 (aim1)， PACS1 核功能的缺陷会改变谷氨酸能/GABA 能规范平衡 (aim2)。结果来自该提案将极大地增强我们对 PACS1 缺陷如何影响神经发育的理解系统，通过发现目前被忽视的核功能。此外，我们的工作将扩展我们的知识谷氨酸/GABA能失衡的分子基础和后果，多次被描述为许多 NDD 的先驱，指出了一种可能的共同机制遗传异质起源，可能最终揭示趋同的治疗目标。