Mapping the Time Course of mTORC1-Driven Tumorigenesis in the Developing Brain

绘制发育中大脑中 mTORC1 驱动的肿瘤发生的时间进程

基本信息

批准号：
10672049
负责人：
Laura Catherine Geben
金额：
$ 0.25万
依托单位：
VANDERBILT UNIVERSITY
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：
2022-07-28 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10672049
关键词：
Adult Affect Benign Binding Proteins Brain Brain Neoplasms Cell Cycle Cell Differentiation process Cell Proliferation Cell Size Cell model Cells Cerebrum Characteristics Clinical Complex Custom Cytometry Cytostatics Data Development Disease Disease model Dorsal Early Diagnosis Embryo Embryonic Development Etiology Eukaryotic Initiation Factors Event FRAP1 gene Flow Cytometry Genes Genetic Transcription Glean Goals Growth Health Human Image Cytometry In Vitro Knowledge Lead Magnetic Resonance Imaging Maps Measures Mediator of activation protein Microscopy Mitotic Mitotic Activity Modeling Mus Mutate Mutation Neurodevelopmental Disorder Newborn Infant Organoids Pathway interactions Patients Pattern Pharmacology Phosphoproteins Phosphorylation Phosphotransferases Population Positioning Attribute Predisposition Prevention Process Proteins Regulation Research Research Project Grants Resected Ribosomal Protein S6 Role Signal Pathway Signal Transduction Subependymal Giant Cell Astrocytoma TSC2 gene Testing Therapeutic Intervention Time TimeLine Training Translating Tuberous Sclerosis Ventricular Wild Type Mouse Work antibody conjugate body system cell growth developmental disease human model in vivo induced pluripotent stem cell inhibitor insight loss of function loss of function mutation mTORopathies mouse model mutant nerve stem cell neurodevelopment neurogenesis novel pediatric patients perinatal development postnatal postnatal development prenatal prevent stem cell fate stem cell niche subventricular zone tumor tumor growth tumorigenesis tumorigenic

项目摘要

SUMMARY The mammalian target of rapamycin complex 1 (mTORC1) signaling pathway regulates cell size and growth and is frequently mutated in disease, including in a class of neurodevelopmental disorders known as “mTORopathies.” One such disorder, Tuberous Sclerosis Complex (TSC), affects nearly 1 in every 6,000 newborns and is characterized by the growth of benign tumors throughout the body. TSC is caused by an inactivating mutation in the genes that encode the negative regulators of mTORC1, leading to protein loss of function, hyperactivation of mTORC1, and increased cell proliferation through phosphorylation of ribosomal protein S6 (p-S6) and eukaryotic translation initiation factor 4E-binding protein 1 (p-4EBP1). Twenty percent of TSC patients develop a large tumor that preferentially presents near the ventral region of the ventricular- subventricular zone (V-SVZ), the largest neural stem cell niche in the adult brain. Recent studies of neural stem cells in the V-SVZ revealed variable transcriptional and functional capabilities corresponding to a cell’s position along the dorsoventral axis of the V-SVZ, including differential activation of mTORC1 and susceptibility to TSC tumor formation. Further, different populations of neural stem cells in the niche are mitotically active at different times throughout pre- and postnatal neural development. Postnatally, mTORC1 has been shown to be important in regulating neural stem cell quiescence, but mTORC1 signaling in the prenatal V-SVZ and its effect on quiescence in embryonic neural stem cells has not been investigated. The goal of this project is to determine the developmental stage when differential mTORC1 activity emerges along the dorsoventral axis of the V-SVZ and the extent to which dysregulated mTORC1 signaling alters cell fate. The central hypothesis of this project is that levels of mTORC1-dependent p-4EBP1, but not p-S6, determine both a prenatal neural stem cell's mitotic activity and susceptibility to TSC tumor development. To test this hypothesis, an inducible mouse model and pharmacologic agents will be used to manipulate mTORC1 signaling during embryogenesis. To map the emergence of differences in mTORC1 activity in healthy and disease states, per-cell levels of mTORC1-dependent phosphorylation events will be quantified via imaging and flow cytometry analyses of embryonic neural stem cells. To compare results across species and platforms, mTORC1-dependent signaling will be quantified in cerebral organoid models grown from induced pluripotent stem cells derived from TSC patients. Through this project, I will build upon my prior training to evaluate cell signaling and differentiation in human and mouse models of disease. Results of this work will determine the role of mTORC1 in regulating prenatal neural stem cell fate in health and disease. Clinically, this work will provide a greater understanding of the dysregulated signaling mechanisms that lead to perinatal development of tumors in the V-SVZ and identify potential suitable time points for therapeutic interventions for patients with TSC and other mTORopathies.

概括哺乳动物雷帕霉素靶标复合物 1 (mTORC1) 信号通路调节细胞大小和生长并且在疾病中经常发生突变，包括一类被称为“神经发育障碍”的疾病 “mTORopathies”。这种疾病，结节性硬化症 (TSC)，影响着每 6,000 人中近 1 人。新生儿的 TSC 的特点是全身良性肿瘤的生长。编码 mTORC1 负调节因子的基因发生失活突变，导致蛋白质丢失 mTORC1 的功能、过度激活以及通过核糖体磷酸化增加细胞增殖蛋白 S6 (p-S6) 和真核翻译起始因子 4E 结合蛋白 1 (p-4EBP1) 的 20%。 TSC 患者会出现一个大肿瘤，优先出现在心室腹侧区域附近。脑室下区（V-SVZ）是成人大脑中最大的神经干细胞生态位。 V-SVZ 中的干细胞揭示了与细胞的功能相对应的可变转录和功能能力沿 V-SVZ 背腹轴的位置，包括 mTORC1 的差异激活和敏感性此外，微环境中不同群体的神经干细胞在有丝分裂中处于活跃状态。 mTORC1 已被证明在产前和产后神经发育的不同时期发挥作用。 mTORC1 在调节神经干细胞静止中很重要，但产前 V-SVZ 中的 mTORC1 信号传导及其影响尚未研究胚胎神经干细胞的静止状态。确定当差异 mTORC1 活性沿背腹轴出现时的发育阶段 V-SVZ 以及失调的 mTORC1 信号传导改变细胞命运的程度。该项目是 mTORC1 依赖性 p-4EBP1（而非 p-S6）的水平决定了产前神经干细胞的有丝分裂活性和对 TSC 肿瘤发展的易感性为了验证这一假设，我们使用了诱导型小鼠。模型和药物制剂将用于在胚胎发生过程中操纵 mTORC1 信号传导。绘制健康和疾病状态下 mTORC1 活性差异的出现、每细胞水平 mTORC1 依赖性磷酸化事件将通过成像和流式细胞术分析来量化胚胎神经干细胞比较不同物种和平台的结果，mTORC1 依赖性信号传导。将在由 TSC 诱导多能干细胞培养的脑类器官模型中进行量化通过这个项目，我将在之前的培训基础上评估细胞信号传导和分化。这项工作的结果将确定 mTORC1 在调节中的作用。在临床上，这项工作将提供对健康和疾病中的产前神经干细胞命运的更深入的了解。导致 V-SVZ 肿瘤围产期发育的失调信号机制，并确定对 TSC 和其他 mTORopathies 患者进行治疗干预的潜在合适时间点。