B-Arrestins and G Protein-Coupled Receptor Kinases in Cardiovascular Function

B-抑制蛋白和 G 蛋白偶联受体激酶对心血管功能的影响

• 批准号: 7314334
• 负责人: ROBERT J LEFKOWITZ
• 金额: $ 39万
• 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 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7314334
• 关键词: Acute; Adrenergic Receptor; Agonist; Angioplasty; Angiotensin II; Angiotensins; Arrestin; Arrestins; Binding; Biological Assay; Blood Pressure; Blood Vessels; Bypass; Calsequestrin; Cardiac; Cardiac Myocytes; Cardiovascular Physiology; Cardiovascular system; Catecholamines; Cells; Chemotaxis; Chronic; Development; Fluorescence Resonance Energy Transfer; G protein coupled receptor kinase; G-Protein-Coupled Receptors; GTP-Binding Proteins; Generations; Heart; Heart failure; Hyperplasia; Hypertension; In Vitro; Individual; Kinetics; Knockout Mice; Ligands; MAP Kinase Modules; Mediating; Mitogen-Activated Protein Kinases; Mitogens; Modeling; Mus; Operative Surgical Procedures; Pathway interactions; Phosphotransferases; Physiological; Play; Primary Myocardial Diseases; Protein Isoforms; Protein Overexpression; Receptor Activation; Regulation; Role; Second Messenger Systems; Signal Transduction; Small Interfering RNA; Smooth Muscle Myocytes; Specificity; Stimulation of Cell Proliferation; System; Testing; Transgenic Mice; Vasodilation; analog; arrestin B; arrestin3; attenuation; cell growth; desensitization; in vivo; migration; mutant; novel; novel therapeutics; receptor; research study; scaffold; second messenger; vascular smooth muscle cell migration; vasoconstriction

DESCRIPTION (provided by applicant): P-ARRESTINS AND GRKs IN CARDIOVASCULAR FUNCTION. G protein coupled receptors (GPCRs) such as those for catecholamines and angiotensin II regulate cardiovascular functions including vasoconstriction and vasodilation; vascular smooth muscle cell (VSM) mitogenesis and migration; and cardiac inotropy and chronotropy. These functions may be perturbed in hypertension, in pathological intimal hyperplasia as after bypass surgery or angioplasty, or in heart failure. Following GPCR activation, the receptors are phosphorylated by one of several G protein coupled receptor kinases (GRKs) and then bind one of the two isoforms of p-arrestin. p-arrestin binding sterically interdicts further signaling to G proteins leading to receptor desensitization and attenuation of second messenger generation, p-arrestins also play positive roles in signaling, serving as adaptors and scaffolds to organize receptor-mediated activation of MAP kinase cascades and other pathways. These MAP kinases regulate mitogenesis and migration of vascular smooth muscle cells. Recently we have found that receptor ligands may vary dramatically in their ability to stimulate G protein versus p-arrestin-mediated signaling. However, the cellular and physiological consequences of p-arrestin/GRK mediated signaling in cardiovascular (or other) systems are largely unknown. Accordingly, we will use several approaches to test our central hypothesis that p-arrestin/GRK- mediated signaling contributes significantly to the short and long-term regulation of cardiovascular function. Our approaches will include the use of mutant receptors and specific agonists which can selectively activate p-arrestin but not G protein signaling; siRNA to p-arrestins and GRKs; knock-out mice which we have previously developed lacking each of the p-arrestins and GRKs; and cells derived there from. Utilizing the p-adrenergic receptors and angiotensin IMA receptor as our models our specific aims are to determine: 1) the specificity of individual p-arrestins and GRKs in desensitizing G protein mediated second messenger generation and to compare this with their roles in mediating signaling, as for example through ERK activation. 2) The physiological effects of P-arrestin-mediated signaling, a) In vitro on cardiac myocytes and vascular smooth muscle cells, and b) In vivo on cardiac inotropy and chronotropy and on systemic blood pressure, c) The in vivo consequences of cardiac signaling by mutant p-adrenergic receptors and angiotensin II1A receptors which are uncoupled from G proteins but signal through p-arrestins. 3) The chronic effects of an ang analog (SII ang) which signals only through p-arrestins, on the development and course of CHF in a transgenic mouse overexpressing calsequestrin in the heart. These experiments have the potential to delineate an entirely novel and general mode of receptor-mediated signaling and to point the way to the development of novel therapeutics which target this recently discovered signaling mechanism.

描述（由申请人提供）：心血管功能中的P-arrestins和Grks。 G蛋白偶联受体（GPCR），例如儿茶酚胺和血管紧张素II的受体调节心血管功能，包括血管收缩和血管舒张；血管平滑肌细胞（VSM）有丝分裂和迁移；和心脏障碍和表年。这些功能在高血压，病理内膜增生中可能会受到干扰，例如旁路手术或血管成形术或心力衰竭。 GPCR激活后，受体被几种G蛋白偶联受体激酶（GRKS）之一磷酸化，然后结合P- arrestin的两种同工型之一。 p- arrestin结合在空间上固定在G蛋白上进一步信号传导，导致受体脱敏和第二信使产生的衰减，p- arrestin在信号传导中也起着积极的作用，作为衔接子和脚手架，以组织受体介导的MAP激酶级数和其他途径的受体介导的激活。这些MAP激酶调节血管平滑肌细胞的有丝分裂和迁移。最近，我们发现受体配体在刺激G蛋白与p- arrestin介导的信号传导的能力上可能会发生巨大变化。然而，心血管（或其他）系统中P-甲蛋白/GRK介导的信号传导的细胞和生理后果在很大程度上是未知的。因此，我们将使用几种方法来测试我们的中心假设，即P- arrestin/grk-介导的信号传导对心血管功能的短期和长期调节产生了重大贡献。我们的方法将包括使用突变受体和特定的激动剂，这些受体可以选择性地激活p- arrestin，而不是G蛋白信号传导； sirna to p-arrestins and Grks；我们以前缺乏每种p-arrestins和grks的敲除老鼠；和源自那里的细胞。利用P-肾上腺素能受体和血管紧张素IMA受体作为我们的模型，我们的具体目的是确定：1​​）单个P- arrestins和GRK在脱敏G蛋白介导的第二信使生成中的特异性，并将其与它们在介导信号中的作用，例如通过ERK激活。 2) The physiological effects of P-arrestin-mediated signaling, a) In vitro on cardiac myocytes and vascular smooth muscle cells, and b) In vivo on cardiac inotropy and chronotropy and on systemic blood pressure, c) The in vivo consequences of cardiac signaling by mutant p-adrenergic receptors and angiotensin II1A receptors which are uncoupled from G proteins but signal through P-arrestins。 3）ANG类似物（SII ANG）的慢性效应仅通过p-arrestin发出信号，对过表达心脏的CALSESESTRIN的转基因小鼠中CHF的发育和过程。这些实验有可能描绘一种完全新颖的受体介导信号传导模式，并为针对该最近发现的信号机制的新型治疗剂的发展指向开发的道路。