Role of NgBR

NgBR 的作用

基本信息

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
项目类别：
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

项目摘要

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，血管生成涉及肿瘤生长和糖尿病视网膜病变的发病机制。我们之前将 NgBR 确定为一种新受体，对于 Nogo-B 刺激的 EC 体外迁移至关重要。最近，我们证明 NgBR 对于斑马鱼体内血管生成至关重要。在初步结果中，我们提出的新数据表明 NgBR 结合法尼基化 Ras (F-Ras)，从而激活 Ras-PI3K-Akt 依赖性途径以诱导 EC 迁移。尽管 Ras 是一种癌基因，在癌症中已得到充分研究，但其在内皮细胞生物学中的作用仍相对不清楚。事实上，VEGF 可以显着增加 EC 中 Ras 的激活。组成型激活的 Ras 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 敲低使 VEGF 诱导的 EC 迁移减少约 50%，并完全消除 Nogo-B 诱导的 EC 迁移。这表明 Ras 在调节 EC 迁移中的作用值得进一步研究。此外，考虑到 NgBR 敲低使 VEGF 诱导的 EC 迁移减少约 60% 并完全消除 Nogo-B 诱导的 EC 迁移，NgBR 介导的 Ras-PI3K-Akt 信号传导可能代表了比之前认为的更为重要的途径。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 通过其胞质域中的特定位点招募 F-Ras，这是 Nogo-B 和 VEGF 刺激的内皮细胞迁移的重要步骤。”为了检验这一假设，我们将： 1. 确定 NgBR 细胞质结构域中的哪些区域是结合 F-Ras 所必需的。此外，我们将使用 NgBR 功能丧失突变体来确定 EC 迁移和血管生成是否以及在多大程度上依赖于 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在与VEGFR2协调诱导Ras依赖性EC迁移和血管生成中的作用。该应用具有创新性，因为它首次定义了 NgBR 作为新型支架蛋白在调节 Ras 易位和激活 Ras-PI3K-akt 通路中的作用。该应用的成功发现对血管生物学产生“巨大”影响，因为它将发现或揭示刺激内皮细胞迁移和血管生成的全新途径。尽管 Ras 是一种经过充分研究的癌症癌基因，但 Ras 易位至质膜以影响 EC 功能的确切机制尚不清楚。我们提出的研究将首次定义 NgBR 介导 Ras 激活以影响 EC 迁移的机制。这些研究的结果将使我们能够开发新的抗血管生成疗法，以预防糖尿病视网膜病变和肿瘤血管生成。公共健康相关性：这项研究与公共健康相关，因为内皮细胞增殖和迁移是病理性血管生成的主要贡献，而病理性血管生成是癌症以及各种缺血性和炎症性疾病的标志。我们的研究证明 NgBR 作为一种新的 Ras 调节剂，可以激活新的信号通路，促进血管形成。该资助支持的研究可能有助于确定新的治疗靶点，以减少病理性血管形成，从而改善患有肿瘤生长和其他血管畸形疾病的人们的生活质量。