Interrogating neurogenic defects in complex assembloid models of fragile X syndrome

探讨脆性 X 综合征复杂组合体模型中的神经源性缺陷

• 批准号: 10727933
• 负责人: Nisha Raj
• 金额: $ 43.04万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2025-08-14
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10727933
• 关键词: 3-Dimensional; Animal Model; Autopsy; Binding Proteins; Biology; Brain; Cell Proliferation; Cell model; Cells; Clinical Trials; Complex; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cytoskeleton; Data; Defect; Development; Disease; Dorsal; Evaluation; Event; FMR1; FMRP; Fragile X Syndrome; Gene Silencing; Genetic; Glutamates; Goals; Human; Human Development; Hybrids; Impairment; Inherited; Intellectual functioning disability; Interneurons; Messenger RNA; Microtubule-Associated Proteins; Modeling; Molecular; Morphology; Neurodevelopmental Disorder; Neuronal Differentiation; Neurons; Organoids; Outcome Measure; PIK3CG gene; Pathway interactions; Patients; Pattern; Pharmaceutical Preparations; Phase; Phase II Clinical Trials; Phosphodiesterase Inhibitors; Phosphorylation; Physiological; Play; Process; Proliferating; Protein Biosynthesis; Proteins; Publishing; RNA-Binding Proteins; Research; Role; Signal Pathway; Signal Transduction; Synapses; System; Testing; Therapeutic; Therapeutic Intervention; Tissues; Translations; autism spectrum disorder; cell type; comparison control; design; dosage; doublecortin protein; drug efficacy; drug testing; efficacy testing; excitatory neuron; human model; in vitro Model; induced pluripotent stem cell; inhibitory neuron; insight; loss of function mutation; lymphoblast; migration; molecular phenotype; nervous system disorder; neural; neural circuit; neural patterning; neurodevelopment; neurogenesis; novel; pre-clinical; preclinical study; proteostasis; spatiotemporal; synaptic function; therapeutic target

PROJECT SUMMARY/ABSTRACT Human neural development is a dynamic process that requires a precise orchestration of a sequence of cellular, molecular and genetic events allowing for the establishment of appropriate neural circuitry and functional connectivity in the brain. Disruptions to this process have profound consequences, and several neurodevelopmental disorders converge on molecular pathways that regulate protein synthesis, proliferation, migration and differentiation in neural cells. One such disorder is Fragile X syndrome (FXS), which is the leading form of inherited intellectual disability and the most common monogenic cause of autism. Transcriptional silencing of FMR1 and subsequent loss of the RNA-binding protein FMRP leads to altered proliferation, dysregulated protein synthesis, and disrupted signal transduction in animal models of FXS; however, the consequence of loss of FMRP on early events in neurogenesis in humans remains relatively unknown. While several highly promising preclinical studies have demonstrated that targeting key signaling pathways ameliorates multiple defects in animal models, most of these have not translated into successful human therapeutic interventions. We believe that a major gap in the preclinical phase may have been the lack of a human neuronal model to test drug efficacy in a developmentally-relevant manner. Recently, a phase 2 clinical trial using a phosphodiesterase inhibitor to inhibit degradation of cyclic adenosine monophosphate (cAMP) in FXS patients showed highly promising results on several outcome measures. This proposal aims to provide a novel human cellular platform with robust cellular and molecular readouts to further test the efficacy of therapeutic interventions. Here, we propose to use 3D organoids to determine whether cAMP signaling is disrupted throughout early brain development in FXS, and whether aberrant cAMP signaling underlies defects in neurogenesis and cell fate commitment. We will also investigate the therapeutic potential of targeting the microtubule-associated protein doublecortin (DCX), which is an mRNA target of FMRP as well as a downstream target of the cAMP intracellular cascade (Aim 1). We will further employ a novel assembloid system to study cell fate commitment of excitatory and inhibitory neurons as well as interneuron migration in FXS, and to determine the contribution of altered DCX expression and cAMP signaling to interneuron development and differentiation (Aim 2). These findings will provide critical insight into the underlying pathomechanisms in FXS, as well as into the biology of FMRP during early human development. Ultimately, this may aid in the development of targeted patient-specific therapeutic strategies that have broader implications for other neurodevelopmental disorders.

项目总结/摘要 人类神经发育是一个动态的过程，需要对一系列细胞， 分子和遗传事件允许建立适当的神经回路和功能 大脑中的连通性。这一进程的中断会产生深远的后果， 神经发育障碍集中在调节蛋白质合成，增殖， 神经细胞的迁移和分化。其中一种疾病是脆性X综合征（FXS），这是主要的 一种遗传性智力残疾，也是自闭症最常见的单基因原因。转录 FMR 1的沉默和随后的RNA结合蛋白FMRP的丧失导致改变的增殖， 在FXS动物模型中，蛋白质合成失调，信号转导中断;然而， FMRP缺失对人类神经发生早期事件的影响仍然相对未知。而 几项非常有前途的临床前研究表明，靶向关键信号通路可以改善 动物模型中存在多种缺陷，其中大多数尚未转化为成功的人类治疗方法。 干预措施。我们认为，在临床前阶段的一个主要差距可能是缺乏一个人类神经元， 模型，以开发相关的方式测试药物疗效。最近，一项2期临床试验使用 磷酸二酯酶抑制剂抑制FXS患者中环磷酸腺苷（cAMP）降解 在几个结果指标上显示出非常有希望的结果。该提案旨在提供一种新的人类 细胞平台，具有强大的细胞和分子读数，以进一步测试治疗效果。 干预措施。在这里，我们建议使用3D类器官来确定cAMP信号传导是否被破坏， 在FXS的早期脑发育中，以及异常的cAMP信号传导是否是 神经发生和细胞命运定型。我们还将研究靶向的治疗潜力， 微管相关蛋白doublecortin（DCX）是FMRP的mRNA靶点，也是FMRP的下游靶点。 cAMP细胞内级联的靶点（Aim 1）。我们将进一步采用一种新的类胶质细胞系统来研究细胞 FXS中兴奋性和抑制性神经元的命运承诺以及神经元间迁移，并确定 改变的DCX表达和cAMP信号传导对中间神经元发育和分化的贡献 (Aim 2）。这些发现将为FXS的潜在病理机制提供重要的见解， FMRP在人类早期发育过程中的生物学。最终，这可能有助于发展有针对性的 患者特异性治疗策略，对其他神经发育障碍有更广泛的影响。