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

• 批准号: 10881289
• 负责人: ALICIA DIONE GUEMEZ GAMBOA
• 金额: $ 2.33万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10881289
• 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

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.

项目摘要 神经发育障碍（NDD）是异质性的，通常具有复杂的病因。个人 这些疾病伴随着终身的认知障碍;然而， 了解他们的神经基础患者和他们的家人迫切需要改善疾病 治疗然而，为了开发有效的治疗方法，必须了解分子水平的调节异常。 以及导致这些状况的细胞过程。PACS 1综合征是由单个R203 W引起的NDD 在200多名患者中发现了磷酸弗林酸性簇分选1（PACS 1）蛋白的取代。此外，委员会认为， 全基因组关联研究（GWAS）将人类PACS 1基因座确定为重度脑梗死的易感基因。 早发性肥胖、发育迟缓和双相情感障碍，这表明在大脑发育中有更广泛的作用。 PACS 1编码一种多功能蛋白，其在分泌途径中的典型胞质功能是指导 然而，PACS 1还包含一个核定位信号（NLS），穿梭于 在S期细胞核中，至少在高度增殖的癌细胞中，调节染色质稳定性 通过与HDAC蛋白的相互作用。尽管先前的研究已经揭示了PACS 1的关键功能， PACS 1在核内的作用以及PACS 1 R203 W变体在神经系统中的作用还没有被证实。 有待确定。因此，我们已经产生了患者诱导的多能干细胞（iPSC）衍生的脑细胞， 类器官，以研究发育中的模式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的数据集，强烈表明调控基因表达程序的重要性， 用于谷氨酸能/GABA能结局质量标准。总之，关于PACS 1核定位的证据， 除了我们的初步数据，表明PACS 1有一个未探索的核功能，可能是通过 调节神经祖细胞中的基因表达。因此，我们假设PACS 1调节 谷氨酸能/GABA能平衡通过非典型核功能，随着神经发生而降低 收益。因此，PACS 1缺陷导致向GABA能命运的转变，产生异位GABA能神经元， 随后是谷氨酸能/GABA能失衡，最后是NDD表型。我们将通过以下方式检验这一假设： 解决PACS 1是否具有在神经分化（aim 1）中不同的背景特异性功能， PACS 1核功能的缺陷改变谷氨酸能/GABA能特异性平衡（aim 2）。结果 这一建议将大大提高我们对PACS 1缺陷如何影响发育中的神经系统的理解。 系统，通过揭示目前被忽视的核功能。此外，我们的工作将扩大我们的知识 谷氨酸能/γ-氨基丁酸能失衡的分子基础和后果，已经 被反复描述为许多NDD的前兆，指向一种可能的共同机制， 遗传异质性起源，并可能最终揭示收敛的治疗目标。