Role of NgBR

NgBR 的作用

• 批准号: 8155314
• 负责人: QING MIAO
• 金额: $ 37.5万
• 依托单位: MEDICAL COLLEGE OF WISCONSIN
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8155314
• 关键词: Adaptor Signaling Protein; Amino Acids; Binding; Biological Assay; Biology; Blood Vessels; Cell Proliferation; Cell membrane; Cell physiology; Cellular biology; Cytoplasmic Tail; Data; Diabetic Retinopathy; Diphosphates; Disease; Endothelial Cells; Event; Goals; Grant; HRAS gene; In Vitro; Inflammatory; Investigation; Laboratories; Malignant Neoplasms; Mediating; Membrane; Oncogenes; Outcome; Pathogenesis; Pathologic Neovascularization; Pathway interactions; Phosphorylation; Play; Public Health; Quality of life; Recruitment Activity; Regulatory Pathway; Reporting; Research; Research Support; Retinal Diseases; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Site; Small Interfering RNA; Son of Sevenless Proteins; Testing; Tumor Angiogenesis; Vascular Endothelial Growth Factor Receptor; Vascular Endothelial Growth Factors; Zebrafish; angiogenesis; antiangiogenesis therapy; base; cell motility; improved; in vivo; innovation; insight; loss of function; malformation; migration; mutant; new therapeutic target; novel; ras Oncogene; receptor; receptor binding; therapeutic angiogenesis; tumor; tumor growth

DESCRIPTION (provided by applicant): Endothelial cell (EC) activation and directional migration is an initial step in angiogenesis that is involved in the pathogenesis of tumor growth and diabetic retinopathy. We previously identified NgBR as a new receptor that is essential for Nogo-B-stimulated EC migration in vitro. Recently, we demonstrated that NgBR is essential for in vivo angiogenesis in zebrafish. In Preliminary Results, we present new data showing that NgBR binds farnesylated Ras (F-Ras) and in so doing, activate Ras-PI3K-Akt dependent pathways to induce EC migration. Although Ras, an oncogene, is well studied in cancer, its role in endothelial cell biology remains relatively unclear. In fact, VEGF can remarkably increase Ras activation in EC. Constitutively activated Ras can stimulate the phosphorylation of Akt, a key player for EC migration. Our preliminary data show that Ras knockdown decreases VEGF-induced EC migration by about 50% and completely abolishes Nogo-B-induced EC migration. It suggests that the role of Ras in regulating EC migration deserves further investigation. Further, considering the fact that NgBR knockdown decreases VEGF-induced EC migration by about 60% and completely abolishes Nogo-B-induced EC migration, NgBR-mediated Ras-PI3K-Akt signaling likely represents a much more prominent pathway than previously considered. In this application, we will determine the mechanisms by which NgBR interacts with F-Ras to initiate Ras-dependent EC migration. The hypothesis of our application is: "NgBR recruits F-Ras via specific sites in its cytoplasmic domain, which is an essential step for Nogo-B- and VEGF-stimulated endothelial cell migration." To test this hypothesis, we will: 1. identify which regions in the cytoplasmic domain of NgBR are required for binding F-Ras. Furthermore, we will use NgBR loss of function mutants to determine if and the extent to which EC migration and angiogenesis are dependent on NgBR-mediated Ras translocation; 2. determine the mechanism by which NgBR regulates Nogo-B/VEGF- stimulated Ras activation; 3. determine the roles of NgBR in coordinating with VEGFR2 to induce Ras- dependent EC migration and angiogenesis. This application is innovative because it is the first to define the role of NgBR as a novel scaffold protein in modulating Ras translocation and in activating Ras-PI3K-akt pathway. Successful findings from this application have a "huge" impact on vascular biology because it will have uncovered or revealed an entirely new pathway for stimulating EC migration and angiogenesis. Although Ras is a well-studied oncogene in cancer, the exact mechanisms by which Ras translocates to plasma membrane to influence EC function are unknown. Our proposed studies will be the first to define the mechanisms by which NgBR mediates Ras activation to influence EC migration. Findings from these studies will allow us to develop new and novel anti-angiogenic therapies to protect against diabetic retinopathy and tumor angiogenesis. PUBLIC HEALTH RELEVANCE: This research is relevant to public health since endothelial cell proliferation and migration is a major contribution to pathological angiogenesis, which is a hallmark of cancer as well as various ischemic and inflammatory diseases. Our research has demonstrated NgBR as a new Ras modulator to activate a novel signaling pathway to promote blood vessel formation. Research supported by this grant may help identify new therapeutic targets to reduce pathological blood vessel formation so as to improve the quality of life of people suffering with tumor growth and other vascular malformation diseases.

描述（由申请人提供）：内皮细胞（EC）激活和定向迁移是血管生成的第一步，涉及肿瘤生长和糖尿病性视网膜病的发病机理。我们先前将NGBR鉴定为一种新受体，对于NOGO-B刺激的EC迁移至关重要。最近，我们证明了NGBR对于斑马鱼中的体内血管生成至关重要。在初步结果中，我们提供了新的数据，表明NGBR结合了Farnesyration的RAS（F-RAS），并且这样做，激活RAS-PI3K-AKT依赖途径诱导EC迁移。尽管RAS是一种癌基因，在癌症中进行了很好的研究，但其在内皮细胞生物学中的作用仍然相对不清楚。实际上，VEGF可以显着增加EC中的RAS激活。组成型激活的RA可以刺激AKT的磷酸化，Akt是EC迁移的关键参与者。我们的初步数据表明，RAS敲低可将VEGF诱导的EC迁移降低约50％，并完全废除Nogo-B诱导的EC迁移。这表明RA在调节EC迁移中的作用值得进一步研究。此外，考虑到NGBR敲低可将VEGF诱导的EC迁移降低约60％，并完全废除NOGO-B诱导的EC迁移的事实，NGBR介导的RAS-PI3K-AKT信号可能代表了比以前考虑的更为突出的途径。在此应用中，我们将确定NGBR与F-RAS相互作用以启动RAS依赖性EC迁移的机制。我们应用的假设是：“ NGBR通过其细胞质结构域中的特定部位募集F-RAS，这是Nogo-B-和VEGF刺激的内皮细胞迁移的重要步骤。”为了检验该假设，我们将：1。确定NGBR的胞质结构域中的哪些区域是结合F-RAS的。此外，我们将使用NGBR的功能突变体丧失来确定EC迁移和血管生成的程度是否取决于NGBR介导的RAS易位； 2。确定NGBR调节NOGO-B/VEGF刺激的RAS激活的机制； 3。确定NGBR与VEGFR2协调以诱导Ras依赖性EC迁移和血管生成的作用。该应用具有创新性，因为它是第一个定义NGBR作为一种新型脚手架蛋白在调节RAS易位和激活Ras-Pi3K-Akt途径中的作用的作用。该应用程序的成功发现对血管生物学产生了“巨大”影响，因为它将发现或揭示了刺激EC迁移和血管生成的全新途径。尽管RAS是癌症中良好的癌基因，但RAS转移到质膜以影响EC功能的确切机制尚不清楚。我们提出的研究将是第一个定义NGBR介导RAS激活以影响EC迁移的机制的研究。这些研究的发现将使我们能够开发新的和新型的抗血管生成疗法，以防止糖尿病性视网膜病变和肿瘤血管生成。 公共卫生相关性：这项研究与公共卫生有关，因为内皮细胞增殖和迁移是对病理血管生成的主要贡献，这是癌症以及各种缺血性和炎症性疾病的标志。我们的研究表明，NGBR是一种新的RAS调节剂，以激活一种新的信号传导途径来促进血管形成。这项赠款支持的研究可能有助于确定新的治疗靶标，以减少病理血管的形成，从而改善患有肿瘤生长和其他血管畸形疾病患者的生活质量。