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: 8889763
• 负责人: Ondine B Cleaver
• 金额: $ 3.2万
• 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/8889763
• 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（由申请人提供）：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。迄今为止，这一过程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，从肿瘤血管生成中的血管阻断到伤口愈合中的血管促进。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，并鉴定了一种称为Rasip 1的GTP酶相互作用蛋白。Rasip 1在胚胎EC中特异性表达，在小鼠中去除Rasip 1可阻断胚胎血管小管形成和血管形成。我们展示了那些Rasip 1与小GTP酶及其效应物的复合物，以促进Cdc 42和Rac 1，并抑制RhoA。Rasip 1-/- cords（E8.0-8.5）的关键缺陷包括：成血管细胞极性的丧失和极性决定子Par 3的正确定位，以及1整合素介导的与ECM的粘附和细胞骨架的破坏。主要假设是Rasip 1调节不同的下游GT3信号通路，如Rho、Rac和Cdc 42，这些通路调节不同的细胞过程，协调驱动血管小管发生。该提案询问了Rasip 1介导的细胞极性、收缩性和粘附性如何影响内皮小管形成，并使用小鼠遗传学、体外模型和生物化学分析了Rasip 1下游的通路。对于小鼠突变体的分析，将评估简单参数以研究E8.0-8.5小鼠背侧骨中的管腔形成（成血管细胞形态和组织，以及极性和粘附标记物）。具体目标是：1。研究Rasip 1依赖性细胞极性的作用和血管腔形成过程中顶端/腔膜形成的机制（Par 3和Crb 3）。2.确定血管腔形成过程中不同Rasip 1调节的GT3信号通路Rho、Rac 1和Cdc 42的细胞结果，并评估哪些通路可以挽救或加剧Rasip 1空腔衰竭。3.通过鉴定管腔形成“信号复合物”组分，阐明Rasip 1依赖性管腔形成的机制。这些研究的短期目标是阐明Rasip 1调节的途径，并进一步了解心血管发育。长期目标是找到新的分子靶点，通过阻断管腔形成来阻断疾病中的血管生长，例如生长中的肿瘤。!