B-Arrestins and GPCR Kinases in Vascular Function/Growth

B-抑制蛋白和 GPCR 激酶在血管功能/生长中的作用

• 批准号: 6629406
• 负责人: ROBERT J LEFKOWITZ
• 金额: $ 38.5万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-06-01 至 2006-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6629406
• 关键词: G protein coupled receptor kinase; angiogenesis; arrestins; biological signal transduction; blood pressure; cardiovascular injury; cell growth regulation; cell proliferation; gene targeting; genetically modified animals; laboratory mouse; mitogen activated protein kinase; protein protein interaction; second messengers; vascular smooth muscle; vasomotion

DESCRIPTION (provided by the applicant): G protein-coupled receptors (GPCRs) including those for catecholamines and angiotensin II regulate vascular reactivity, including vasoconstriction and vasodilation, as well as vascular smooth muscle (VSM) cell mitogenesis and migration. Vascular reactivity may be perturbed in hypertension, whereas altered VSM mitogenesis and migration characterize pathological intimal hyperplasia following surgical bypass or restenosis after arterial angioplasty. Following GPCR activation, GPCRs are phosphorylated by one of seven GPCR kinases (GRKs) and then one of two isoforms of b-arrestin is recruited to the receptor. b-arrestin binding sterically interdicts further signaling to G proteins, leading to receptor desensitization and attenuation of signaling. b-arrestins also play positive roles in signaling, serving as adapters and scaffolds to organize GPCR- mediated activation of MAP kinase cascades, such as the extracellular signal regulated kinases (ERK 1/2). These MAP kinases regulate mitogenesis and migration of VSM cells and other cell types. Our group has developed mice in which the GRKs and b-arrestins have been individually knocked out. We will utilize these animals, and VSM cells from them, to test the central hypothesis that regulation of GPCR signaling by b-arrestins and GRKs is critical for normal vascular homeostasis. Our specific aims are 1) To elucidate the vascular phenotype of b-arrestin and GRK knockout mice by analyzing conscious and anesthetized blood pressure responses and vascular reactivity using isolated aortic rings; 2) To elucidate the roles of b-arrestins and GRKs in signaling via endogenous GPCRs in isolated arterial and venous VSM cells from wild type and knockout mice by determining both A) the specificity of b-arrestins and GRKs in desensitizing second messenger signaling via endogenous GPCRs and B) the roles of b-arrestins and GRKs in GPCR stimulated ERK activation, proliferation, and migration of VSM cells; and 3) To determine if the loss of specific b-arrestins or GRKs alters in vivo proliferative intimal hyperplasia following mouse vein-graft surgery or arterial injury. These experiments have the potential to lead to the development of new strategies for limiting vein graft failure and restenosis.

描述(由申请人提供)：G蛋白偶联受体(GPCRs)，包括儿茶酚胺和血管紧张素II受体，调节血管反应性，包括血管收缩和血管扩张，以及血管平滑肌(VSM)细胞的有丝分裂和迁移。高血压患者的血管反应性可能受到干扰，而VSM有丝分裂和迁移的改变则是外科手术搭桥或动脉血管成形术后再狭窄后病理性内膜增生的特征。在GPCR激活后，GPCRs被七个GPCRK中的一个磷酸化，然后b-arrestin的两个亚型中的一个被招募到受体上。与B-arrestin的空间结合阻断了对G蛋白的进一步信号传递，导致受体脱敏和信号减弱。B-arrestins还在信号转导中发挥积极作用，作为接头和支架来组织GPCR介导的MAP激活级联反应，如细胞外信号调节激酶(ERK 1/2)。这些MAP激酶调节VSM细胞和其他类型细胞的有丝分裂和迁移。我们的团队已经培育出了GRKs和b-arrestins分别被敲除的小鼠。我们将利用这些动物和来自它们的VSM细胞来验证中心假设，即b-arrestins和GRKs对GPCR信号的调节对于正常的血管内稳态至关重要。我们的具体目标是：1)通过分析清醒和麻醉的血压反应和血管反应性，阐明b-arrestin和GRK基因敲除小鼠的血管表型；2)通过确定b-arrestins和GRKs在野生型和基因敲除小鼠动、静脉VSM细胞内源性GPCRs激活、增殖和迁移中的作用，阐明b-arrestins和GRKs在GPCR刺激的VSM细胞ERK激活、增殖和迁移中的作用；3)确定在小鼠静脉移植手术或动脉损伤后，体内增生性内膜增生是否会发生特异性b-拦截素或GRKs的丢失。这些实验有可能导致开发限制静脉移植失败和再狭窄的新策略。