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。

• 批准号: 8454424
• 负责人: Ondine B Cleaver
• 金额: $ 37.84万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 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/8454424
• 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

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. !

描述(申请人提供)：在血管中心形成载血通道(管腔形成或“小管生成”)是心血管发育过程中最关键的步骤之一。到目前为止，这一过程背后的分子机制仍然不清楚。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到促进伤口愈合。对胚胎内皮细胞(ECs)进行了转录图谱分析，以发现调控血管形成的因素，并鉴定了一种名为Rasip1的GTPase相互作用蛋白。Rasip1在胚胎内皮细胞中特异表达，在小鼠体内去除Rasip1可阻断胚胎血管小管的形成和血管的形成。我们展示了这些Rasip1与小的GTP酶及其效应物的复合物，促进CDC42和rac1，并抑制RhoA。Rasip1/-CORDS(E8.0-8.5)的主要缺陷包括：血管母细胞极性的丧失和极性决定簇Par3的正确定位，以及1整合素介导的与ECM和细胞骨架的黏附中断。主要的假设是Rasip1调节不同的下游GTPase信号通路，如Rho、Rac和CDC42，这些信号通路调节不同的细胞过程，这些过程相互协调，驱动血管小管的形成。这项提案询问了Rasip1介导的细胞极性、收缩和黏附如何影响内皮小管形成，并利用小鼠遗传学、体外模型和生物化学剖析了Rasip1下游的途径。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(血管母细胞的形态和组织，以及极性和黏附标记)。具体目标是：1.研究Rasip1依赖的细胞极性在血管腔形成过程中的作用和顶膜/腔膜的形成机制(Par3和Crb3)。2.确定Rasip1调控的不同GTPase信号通路Rho、rac1和CDc42在血管腔形成过程中的细胞结局，并评估哪些途径可以挽救或加重Rasip1缺失的管腔衰竭。3.通过鉴定管腔形成“信号复合体”成分，阐明Rasip1依赖的管腔形成机制。这些研究的短期目标是阐明Rasip1调节的通路，并加深我们对心血管发育的理解。长期目标是寻找新的分子靶点，通过阻断管腔形成来阻止疾病中的血管生长，例如正在生长的肿瘤。好了！