Blood vessel tubulogenesis: Rasip1-directed GTPase signaling and cell polarity.

血管管发生：Rasip1 引导的 GTPase 信号传导和细胞极性。

基本信息

批准号：
8274559
负责人：
Ondine B Cleaver
金额：
$ 39.7万
依托单位：
UT SOUTHWESTERN MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-04-05 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8274559
关键词：
Ablation Adhesions Affect Angioblast Aorta Apical Binding Biochemistry Biological Assay Blood Blood Vessels Cardiovascular system Cell Polarity Cell Shape Cell physiology Clinical Co-Immunoprecipitations Complex Cytoskeleton Defect Development Disease Dorsal Drug Design Embryo Endothelial Cells Extracellular Matrix Failure Future Genetic Goals Growth Guanosine Triphosphate Phosphohydrolases Heart In Situ Hybridization In Vitro Mass Spectrum Analysis Mediating Membrane Molecular Molecular Target Monomeric GTP-Binding Proteins Morphology Mus Mutant Strains Mice Outcome Outcome Study Pathway interactions Process Proteins Regulation Role Signal Pathway Signal Transduction Small Interfering RNA Staging Testing Time Tube Tumor Angiogenesis Wound Healing antiangiogenesis therapy apical membrane ezrin gain of function in vitro Model in vivo loss of function luminal membrane rho segregation tumor vasculogenesis

项目摘要

DESCRIPTION (provided by applicant): Formation of blood-carrying channels at the heart of blood vessels (lumen formation or 'tubulogenesis') is one of the most critical steps during cardiovascular development. To date, the molecular mechanisms underlying this process remain unclear. Understanding and ultimately controlling blood vessel growth are key goals of many clinical approaches, ranging from blocking vessels in tumor angiogenesis to promoting vessels in wound healing. Transcriptional profiling of embryonic endothelial cells (ECs) was carried out to discover factors that regulate blod vesel formation, and identified a GTPase-interacting protein called Rasip1. Rasip1 was found to be expressed specificaly in embryonic ECs, and ablation of Rasip1 in mice blocks embryonic vascular tubulogenesis and blood vessel formation. We showed those Rasip1 complexes with small GTPases and their effectors, to promote Cdc42 and Rac1, and suppress RhoA. Key defects in Rasip1-/- cords (E8.0-8.5) include: loss of angioblast cell polarity and of proper localization of the polarity determinant Par3, as well as disruption of 1integrin-mediated adhesion to ECM and of the cytoskeleton. The main hypothesis is that Rasip1 regulates distinct downstream GTPase signaling pathways, such as Rho, Rac and Cdc42, which regulate distinct cellular processes that coordinate to drive vascular tubulogenesis. This proposal asks how Rasip1-mediated cell polarity, contractility and adhesion influence endothelial tubulogenesis, and dissects pathways downstream of Rasip1 using mouse genetics, in vitro models and biochemistry. For analysis of mouse mutants, simple parameters will be assessed to study lumen formation in E8.0-8.5 mouse dorsal aortae (angioblast morphology and organization, as well as polarity and adhesion markers). Specific aims are: 1. To examine role of Rasip1-dependent cell polarity and mechanisms of apical/luminal membrane formation during vascular lumen formation (Par3 and Crb3). 2. To identify the cellular outcomes of the different Rasip1-regulated GTPase signaling pathways, Rho, Rac1 and Cdc42, during vascular lumen formation, and assess which pathways can rescue or exacerbate the Rasip1 null lumen failure. 3. To elucidate mechanism of Rasip1-dependent lumen formation via identification of lumen formation 'signaling complex' components. The short-term objective of these studies is to elucidate Rasip1 regulated pathways and further our understanding of cardiovascular development. The long-term objective is to find new molecular targets to block blood vessel growth in disease, such as in growing tumors, by blocking lumen formation. ! PUBLIC HEALTH RELEVANCE: Blood vessel growth and function depend on the formation of blood-carrying channels at their core, via a process called 'lumen formation' or 'tubulogenesis'. Here, we investigate a molecule, Rasip1, and its regulation of the activity of small molecular switches called GTPases that control endothelial cell shape and organization during vascular tubulogenesis. The ultimate goal is to find new molecular targets to block blood vessel growth in disease, such as in growing tumors, by blocking lumen formation. !

描述（由申请人提供）：血管心脏处的血液输送通道的形成（管腔形成或“肾小管形成”）是心血管发育过程中最关键的步骤之一。迄今为止，这一过程背后的分子机制仍不清楚。了解并最终控制血管生长是许多临床方法的关键目标，从阻断肿瘤血管生成中的血管到促进伤口愈合中的血管。对胚胎内皮细胞 (EC) 进行转录谱分析，以发现调节血管形成的因子，并鉴定出一种名为 Rasip1 的 GTP 酶相互作用蛋白。 Rasip1被发现在胚胎EC中特异性表达，并且小鼠中Rasip1的消除会阻断胚胎血管发生和血管形成。我们展示了那些 Rasip1 与小 GTPases 及其效应子的复合物，以促进 Cdc42 和 Rac1，并抑制 RhoA。 Rasip1-/- 索 (E8.0-8.5) 的主要缺陷包括：成血管细胞极性的丧失和极性决定子 Par3 的正确定位，以及 1 整合素介导的 ECM 和细胞骨架粘附的破坏。主要假设是 Rasip1 调节不同的下游 GTPase 信号通路，例如 Rho、Rac 和 Cdc42，这些通路调节协调驱动血管生成的不同细胞过程。该提案探讨了 Rasip1 介导的细胞极性、收缩性和粘附性如何影响内皮小管发生，并利用小鼠遗传学、体外模型和生物化学剖析了 Rasip1 下游的通路。为了分析小鼠突变体，将评估简单的参数来研究 E8.0-8.5 小鼠背主动脉的管腔形成（成血管细胞形态和组织，以及极性和粘附标记）。具体目标是： 1. 研究 Rasip1 依赖性细胞极性的作用以及血管腔形成过程中顶/腔膜形成的机制（Par3 和 Crb3）。 2. 确定不同 Rasip1 调节的 GTPase 信号通路 Rho、Rac1 和 Cdc42 在血管腔形成过程中的细胞结果，并评估哪些通路可以挽救或加剧 Rasip1 空腔故障。 3.通过鉴定管腔形成“信号复合物”成分来阐明Rasip1依赖性管腔形成的机制。这些研究的短期目标是阐明 Rasip1 调节途径并进一步了解心血管发育。长期目标是找到新的分子靶标，通过阻止管腔形成来阻止疾病中的血管生长，例如生长中的肿瘤。！公共健康相关性：血管生长和功能取决于其核心的血液输送通道的形成，通过称为“管腔形成”或“管形成”的过程。在这里，我们研究了 Rasip1 分子及其对称为 GTPases 的小分子开关活性的调节，GTPase 在血管生成过程中控制内皮细胞的形状和组织。最终目标是找到新的分子靶标，通过阻止管腔形成来阻止疾病中的血管生长，例如生长中的肿瘤。！