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（由适用提供）：定向细胞迁移在发育和生理学以及包括转移性癌症在内的许多疾病中的脆弱性重要点至关重要。总体过程完成了定向感应，运动性和极性。教科书观点意味着自主细胞骨架活动是运动的基础，并且信号转导事件提供了指导，但最近的研究表明，信号转导网络的令人兴奋的行为是驱动运动的必不可少的“起搏器”。外部梯度和内部极性提示对这种生化令人兴奋的局部调节可以指导细胞，并且大量的全球扰动可以带来深远的形态后果。我们正在解决这种定向细胞迁移的“偏见令人兴奋的网络”观点提出的重要问题。哪些分子机制使信号转导网络令人兴奋？我们正在提出一个可行的假设，即涉及对膜当地地区RasGTPase，Pi 3-激酶和PLC活动的积极和延迟的负面反馈是兴奋的基础。我们使用合成执行器，诱导的会话和生物传感器来扰动和监测酶活性和膜状态以找到反馈回路。最初的实验表明，PIP2的级别下降或RAS信号的增加会导致细胞从变形虫，粉丝样转向振荡，持续扩散形式，如果细胞形态受到令人兴奋的网络的控制，则可以预期。细胞如何感知，整合和适应临时和空间提示？为了解释细胞如何应对差异并适应统一的趋化刺激，我们提出，局部令人兴奋的全球抑制方案偏向令人兴奋的网络。识别抑制剂这可以平衡G蛋白兴奋，我们专注于物理相关的蛋白质修饰，遗传筛选和体外重构。趋化网络的总体复杂性是什么？在正向遗传筛选中，我们已经确定了一系列定向迁移的新型调节剂。通过既定的生化和遗传分析的结合，我们将这些新基因与现有网络的联系及其在定向灵敏度，运动性和极性中的作用。这些基因中的许多具有人类同源物，我们将在中性粒细胞和乳腺细胞中靶向以研究对趋化性的影响。如何探索这些新概念以控制迁移并靶向特定的细胞？我们最近发现，多个平行迁移途径的持续激活会导致细胞极度扩散，碎片和死亡。由于这些扰动中的许多也参与了肿瘤发生，因此我们正在追求公认的非常规的概念，即最具侵略性的癌细胞可以通过进一步的激活来瞄准。作为原理的证明，我们正在测试遗传和化学扰动，这些遗传和化学扰动有选择性地靶向具有定义的致癌突变的培养细胞。