R-Ras signaling in vascular biology

血管生物学中的 R-Ras 信号传导

• 批准号: 8056066
• 负责人: Lawrence E Goldfinger
• 金额: $ 38.17万
• 依托单位: TEMPLE UNIV OF THE COMMONWEALTH
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-15 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8056066
• 关键词: 1-Phosphatidylinositol 3-Kinase; Address; Adhesions; Adhesiveness; Affect; Apoptosis; Arterial Injury; Balloon Dilatation; Binding; Binding Sites; Biochemical; Biological; Biology; Blood Vessels; Bypass; Cardiovascular Diseases; Cell Differentiation process; Cell Proliferation; Cell physiology; Cells; Complement; Complex; Development; Family; Family member; Growth; Guanosine Triphosphate Phosphohydrolases; Human; Hyperplasia; In Vitro; Injury; Knockout Mice; Maps; Mediating; Molecular; Monomeric GTP-Binding Proteins; Mutation; Natural regeneration; Null Lymphocytes; Operative Surgical Procedures; Outcome; Pathway interactions; Physiological; Physiological Processes; Point Mutation; Process; Proteins; Proteomics; Regulation; Role; Scaffolding Protein; Signal Pathway; Signal Transduction; Site; Stents; System; Testing; Tumor Angiogenesis; Vascular Proliferation; Vascularization; angiogenesis; base; cell motility; in vivo; insight; migration; mouse model; mutant; new therapeutic target; novel; protein complex; public health relevance; ras Proteins; reconstitution; research study; response; response to injury; restenosis; scaffold; tumor; tumor growth; tumorigenesis

DESCRIPTION (provided by applicant): Support is requested to analyze the interaction between the Ras family small GTPase R- Ras and a novel effector molecule, RLIP76; the effect of this interaction on R-Ras signaling; the mechanisms by which R-Ras/RLIP76 interactions and signaling regulate vascular cell spreading, migration, proliferation and differentiation; and the roles of this signaling node in angiogenesis and injury-induced neointimal hyperplasia leading to arterial restenosis. Ras GTPases regulate cell proliferation, differentiation, apoptosis, adhesion and migration. The binding of specific effectors to activated Ras proteins propagates signaling cascades resulting in unique outcomes depending on the Ras family isotype. R-Ras in particular functions to regulate adhesiveness, motility, proliferation and differentiation of cells of the vessel wall, and to modulate these processes during angiogenesis and vascular regeneration in response to injury. Thus R-Ras signaling has unique, pleiotropic effects in vascular cells and in vascular functions, but the specific pathways involved are unknown. We identified RLIP76 in a proteomic screen for R-Ras effectors and found that RLIP76 regulates some of the unique cellular functions of R-Ras including cell signaling, spreading, migration, and angiogenesis in vitro. This is the first identification of a specific, unique effector for R-Ras with these distinct cellular functions. We hypothesize that R-Ras/RLIP76 binding controls distinct signaling pathways to mediate vascular cell functions and the unique effects of R-Ras in the vasculature. To test this hypothesis we will map the binding sites in R-Ras and RLIP76 and will identify mutations which will selectively disrupt this interaction. We will use these mutants to determine the effect of blockade of R- Ras/RLIP76 interaction on R-Ras signaling in cells of the vessel wall. We will then evaluate a putative scaffolding function for RLIP76 and will map the protein components of the RLIP76/R- Ras signaling complex in vascular cells. Next we will investigate the contributions of R- Ras/RLIP76 binding and the characterized signaling pathways to R-Ras-mediated vascular cell spreading, migration, proliferation and differentiation. Lastly, we will investigate a role for this signaling axis in R-Ras functions in vivo, namely blockade of angiogenesis, and injury-induced neointimal hyperplasia and arterial restenosis. These studies will characterize the regulation and mechanisms of novel signaling pathways that control cell signaling, migration, proliferation and vascular function. Therefore these studies will provide new insights into processes essential in physiological and pathophysiological function and may indicate new therapeutic targets in the treatment of cardiovascular disease. PUBLIC HEALTH RELEVANCE: We propose to investigate the molecular and cellular mechanisms of a process regulating the growth and migration of cells in two major pathological responses in the vasculature: 1) new blood vessel formation (angiogenesis), which occurs at sites of injury and during tumor development, in which new blood vessels are required for tumor growth, and 2) arterial restenosis, a vessel-occluding response to injury resulting from arterial bypass, stent insertion and balloon dilatation surgeries, which affects as many as 400,000 people in the U.S. per year. We have identified candidate molecular signaling pathways which we will examine as unique and selective agents of tumor angiogenesis and post-surgical restenosis. Thus we will use a combination of biochemical, cell biological and physiological approaches in mouse models of angiogenesis and arterial restenosis to identify and characterize novel therapeutic targets for the treatment of human cardiovascular disease.

描述(申请人提供)：需要支持分析RAS家族小GTP酶R-RAS与新的效应分子RLIP76之间的相互作用；这种相互作用对R-RAS信号的影响；R-RAS/RLIP76相互作用和信号调节血管细胞扩散、迁移、增殖和分化的机制；以及该信号节点在血管生成和损伤诱导的新生内膜增生导致动脉再狭窄中的作用。RAS GTP酶调控细胞的增殖、分化、凋亡、黏附和迁移。特定效应器与激活的RAS蛋白的结合传播信号级联，导致取决于RAS家族同型的独特结果。R-RAS的功能主要是调节血管壁细胞的黏附、运动、增殖和分化，并在血管生成和损伤后的血管再生过程中调节这些过程。因此，R-RAS信号在血管细胞和血管功能中具有独特的多效性作用，但具体涉及的途径尚不清楚。我们在R-RAS效应器的蛋白质组筛选中鉴定了RLIP76，并发现RLIP76调节R-RAS的一些独特的细胞功能，包括细胞信号、扩散、迁移和体外血管生成。这是首次发现具有这些不同细胞功能的R-RAS的特定、独特的效应因子。我们假设R-RAS/RLIP76结合控制不同的信号通路来调节血管细胞功能以及R-RAS在血管系统中的独特作用。为了验证这一假设，我们将映射R-RAS和RLIP76中的结合位点，并识别选择性地破坏这种相互作用的突变。我们将利用这些突变体来确定阻断R-RAS/RLIP76相互作用对管壁细胞中R-RAS信号的影响。然后，我们将评估RLIP76的假定支架功能，并将在血管细胞中定位RLIP76/R-RAS信号复合体的蛋白质组分。接下来，我们将研究R-RAS/RLIP76结合在R-RAS介导的血管细胞扩散、迁移、增殖和分化中的作用及其所特有的信号通路。最后，我们将研究这个信号轴在体内R-RAS功能中的作用，即阻断血管生成，以及损伤诱导的新生内膜增生和动脉再狭窄。这些研究将描述控制细胞信号、迁移、增殖和血管功能的新信号通路的调节和机制。因此，这些研究将为生理和病理生理功能中必不可少的过程提供新的见解，并可能为心血管疾病的治疗指明新的治疗靶点。 与公共卫生相关：我们建议在血管系统的两个主要病理反应中研究调控细胞生长和迁移的分子和细胞机制：1)新血管形成(血管生成)，在损伤部位和肿瘤发展过程中，肿瘤生长需要新血管；2)动脉再狭窄，动脉旁路手术、支架插入和球囊扩张手术导致的损伤导致的血管闭塞反应，每年在美国影响多达40万人。我们已经确定了候选的分子信号通路，我们将研究它们作为肿瘤血管生成和手术后再狭窄的独特和选择性的试剂。因此，我们将在血管生成和动脉再狭窄的小鼠模型中使用生化、细胞生物学和生理学方法的组合来识别和表征治疗人类心血管疾病的新的治疗靶点。