Excitable Networks in Directed Cell Migration

定向细胞迁移中的兴奋网络

基本信息

批准号：
9260912
负责人：
Peter N Devreotes
金额：
$ 106.92万
依托单位：
JOHNS HOPKINS UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-05-01 至 2021-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9260912
关键词：
1-Phosphatidylinositol 3-Kinase Address Adult Behavior Biochemical Biochemical Genetics Biosensor Cells Cellular Morphology Chemicals Chemotaxis Cues Cultured Cells Development Disease Disseminated Malignant Neoplasm Embryo Equilibrium Event Feedback G-substrate GTP-Binding Proteins Genes Genetic Screening Genetic screening method Homologous Gene Human In Vitro Lead Link Mammary gland Membrane Molecular Monitor Morphology Movement Mutation Oncogenic Organoids Pacemakers Pathology Pathway interactions Phosphatidylinositol 4,5-Diphosphate Physiological Physiology Post-Translational Protein Processing Process Role Scheme Series Signal Transduction Stimulus Textbooks cancer cell cell motility design enzyme activity experimental study fascinate genetic analysis inhibitor/antagonist migration neutrophil novel novel therapeutic intervention public health relevance reconstitution tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Directed cell migration is vital in development and physiology and a potential point of vulnerability in numerous diseases, including metastatic cancer. The overall process is comprised of directional sensing, motility, and polarity. Whereas the textbook view implies that autonomous cytoskeletal activity underlies motility and that signal transduction events provide guidance, recent studies suggest that excitable behavior of the signal transduction network is an essential "pacemaker" that drives movement. Local modulation of this biochemical excitability by external gradients and internal polarity cues can guide cells and large global perturbations can have profound morphological consequences. We are addressing the important questions raised by this "biased excitable network" view of directed cell migration. What molecular mechanisms make the signal transduction network excitable? We are pursuing a working hypothesis that positive and delayed negative feedbacks, involving control of RasGTPase, PI 3- kinase, and PLC activities in local regions of the membrane, are the basis of excitability. We are using synthetic actuators, induced sequestration, and biosensors to perturb and monitor enzyme activities and membrane states to find the feedback loops. Initial experiments show that gradual decreases in PIP2 or increases in Ras signaling progressively cause cells to shift from amoeboid, to fan-like, to oscillatory, to persistently spread forms as would be expected if cell morphology is controlled by an excitable network. How can cells sense, integrate, and adapt to temporal and spatial cues? To explain how cells to respond to differences and adapt to uniform chemotactic stimuli, we proposed that a local excitation-global inhibition scheme biases the excitable network. To identify the inhibitor that balances G-protein excitation, we are focusing on physiological relevant protein modifications, genetic screens, and in vitro reconstitution. What is the overall complexity of the chemotactic networks? In forward genetic screens, we have identified a large series of novel regulators of directed migration. With a combination of established biochemical and genetic analyses we are defining the links of these new genes to the existing networks and their roles in directional sensing, motility, and polarity. Many of these genes have human homologues that we will target in neutrophils and mammary cells to investigate effects on chemotaxis. How can these new concepts be exploited to control migration and target specific cells? We recently discovered that persistent activation of multiple parallel migration pathways causes cells to spread excessively, fragment, and die. Since many of these perturbations are also involved in oncogenesis, we are pursuing the admittedly unconventional concept that the most aggressive cancer cells can be targeted by even further activation. As proof of principle, we are testing genetic and chemical perturbations, which selectively target cultured cells with defined oncogenic mutations, in xenographs and organoids.

描述（由申请人提供）：定向细胞迁移对于发育和生理学至关重要，也是许多疾病（包括转移性癌症）的潜在脆弱点。整个过程由定向传感、运动和极性自主细胞骨架活动组成。信号转导事件提供了指导，最近的研究表明信号转导网络的兴奋行为是驱动这种生化运动的重要“起搏器”。外部梯度和内部极性线索的兴奋性可以引导细胞，而大的全局扰动可以产生深远的形态学后果，我们正在解决这种定向细胞迁移的“偏向兴奋网络”观点所提出的重要问题。 ? 我们正在追求一个工作假设，即正反馈和延迟负反馈，涉及膜局部区域的 RasGTPase、PI 3-激酶和 PLC 活动的控制，是兴奋性的基础。使用合成执行器、诱导隔离和生物传感器来干扰和监测酶活性和膜状态，以找到反馈环路，初步实验表明，PIP2 的逐渐减少或 Ras 信号的增加会逐渐导致细胞从变形虫状转变为扇状。如果细胞形态由可兴奋的整合网络控制，那么细胞如何感知、整合和适应时间和空间线索？为了响应差异并适应均匀的趋化刺激，我们提出了一种局部兴奋-全局抑制方案来偏向可兴奋网络来识别抑制剂。平衡 G 蛋白兴奋，我们关注的是生理相关的蛋白质修饰、遗传筛选和体外重建，在正向遗传筛选中，我们已经确定了一系列新型定向调节剂。通过结合已建立的生化和遗传分析，我们正在定义这些新基因与现有网络的联系及其在方向感测、运动和极性中的作用，其中许多基因具有我们将在中性粒细胞中定位的人类同源物。我们最近发现，多个平行迁移途径的持续激活会导致细胞过度扩散、破碎和死亡。扰动也参与肿瘤发生，我们正在追求公认的非常规概念，即可以通过进一步激活来靶向最具侵袭性的癌细胞。作为原理证明，我们正在测试遗传和化学扰动，这些扰动选择性地针对具有明确定义的培养细胞。异种移植和类器官中的致癌突变。