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Role of p67phox in myocardial hypertrophy

p67phox 在心肌肥厚中的作用

基本信息

批准号：
7460197
负责人：
Lei Xiao
金额：
$ 36.38万
依托单位：
UNIVERSITY OF ILLINOIS AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-09-03 至 2013-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7460197
关键词：
Adrenergic Agents Adrenergic Receptor Adult Age Animal Model Blood Vessels Breeding Cardiac Cardiac Myocytes Cardiovascular Diseases Chronic Congestive Heart Failure Crossbreeding Data Development Dominant-Negative Mutation Enzymes Extracellular Signal Regulated Kinases Gender Generations Genes Goals Heart Heart Hypertrophy Heart failure Human Hybrids Hypertrophy In Vitro Laboratories Lead MEKs Measures Mechanical Stress Mechanics Mediating Mitogen-Activated Protein Kinases Modeling Molecular Mus Muscle Cells Myocardial Myocardium NAD(P)H oxidase NADPH Oxidase Neonatal Operative Surgical Procedures Parents Phagocytes Phenotype Phosphotransferases Play Production Protein Biosynthesis Protein Overexpression Proteins Public Health Rate Rattus Reactive Oxygen Species Reporting Research Research Personnel Role Scaffolding Protein Signal Transduction Smooth Muscle Myocytes Stimulus Stretching System Testing Transgenes Transgenic Mice Transgenic Organisms Ventricular Wild Type Mouse adrenergic aorta constriction base disability enzyme activity fetal hemodynamics in vivo inhibitor/antagonist mortality mouse model mutant neutrophil cytosol factor 67K novel pressure prevent protein protein interaction

项目摘要

DESCRIPTION (provided by applicant): NADPH oxidase (NOX) appears to play a role in the development of myocardial hypertrophy and subsequent progression of heart failure. However, the signaling mechanisms of NOX in cardiac myocytes is unknown. The long-term goal of this research is to understand the signaling mechnisms of NOX in the development of myocardial hypertrophy and heart failure induced by excessive adrenergic stimulation and hemodynamic pressure overload. Our prelminary data indicate that p67phox, the major cytosolic subunit of NOX, mediates the development of myocardial hypertrophy through a novel reactive oxygen species (ROS) - independent mechanism. Based on these data, we hypothesize that NOX/p67phox mediates myocardial hypertrophy that is induced by hypertrophic stimuli including 11-AR-stimulation and hemodynamic pressure overload, and its signaling function involve a novel ROS-independent mechanism. To test this hypothesis, we proposed the following three Specific Aims: In Specific Aim 1, we will determine whether NOX/p67phox mediates 11-adrenergic receptor (11-AR)- stimulated myocardial hypertrophy and whether this involves a novel ROS-independent signaling mechanism in vitro. Dominant negative (DN) mutants and wild type (WT) contstructs of two NOX cytosolic subunits, p67phox and p47phox. Mutants or WT constructs will be overexpressed in cultured adult rat ventricular myocytes (ARVM). The effects of these mutants or WT constructs on 11-AR stimulation-induced hypertrophy and NOX enzyme activity will be determined. The potential protein-protein interaction between p67phox and MEK-ERK cascade will also be determined in this aim. In Specific Aim 2, we will test if p67phox mediates 11-AR-stimulated cardiac hypertrophy in vivo. We will use the newly generated heterozygous DN-p67 transgenic (TG) mice with cardiac-specific overexpression of the DN p67phox mutant to generate homozygous DN-p67 TG mice. Since the commercially available TG mice with cardiac-specific overexpression of a constitutively activated mutant of 11B-AR (CAM-11B-AR) develop cardiac hypertrophy, we will crossbreed these two TG lines (DN-p67 and CAM-11B-AR) to study the effect of overexperssion of DN p67phox mutant protein in the heart on 11B-AR-induced myocardial hypertrophy in vivo. In Specific Aim 3, we will test the role of myocardial p67phox in mediating hemodynamic overload- induced myocardial hypertrophy in vivo. The homozygous DN-p67 TG mice and age- and gender-matched WT control mice will be subjected to chronic pressure overload caused by ascending aorta constriction (AAC). The cardiac phenotypes and function of these TG and WT mice with AAC or sham operation will be studied to determine the role of p67phox in mediating chronic pressure overload-induced myocardial hypertrophy in vivo. Our studies will provide new understanding of the role and novel mechanisms of NOX/p67phox in the development of cardiac hypertrophy that should lead to novel treatments for congestive heart failure. PUBLIC HEALTH RELEVANCE Our studies will provide new understanding of the novel pathological mechanisms of p67phox and NADPH oxidase in the development of hypertrophy in the heart, which could lead to the major cardiovascular disease, heart failure. Therefore, our research will have direct relevance to a common cause of heart failure, which has a high mortality and disability rate and is a major threat to the public health.

描述（由申请人提供）：NADPH氧化酶（NOX）似乎在心肌肥厚的发展和随后的心力衰竭进展中发挥作用。然而，一氧化氮在心肌细胞中的信号传导机制尚不清楚。本研究的长期目标是了解NOX在肾上腺素能刺激过度和血流动压过载引起的心肌肥厚和心力衰竭发展中的信号机制。我们的初步数据表明，p67phox是NOX的主要细胞质亚基，通过一种新的不依赖活性氧（ROS）的机制介导心肌肥厚的发生。基于这些数据，我们假设NOX/p67phox介导了肥厚刺激（包括11- ar刺激和血流动力学压力过载）诱导的心肌肥厚，其信号功能涉及一种新的ros独立机制。为了验证这一假设，我们提出了以下三个特定目的：在特定目的1中，我们将确定NOX/p67phox是否介导11-肾上腺素能受体（11-AR）刺激的心肌肥大，以及这是否涉及一种新的体外ros独立信号机制。两种NOX细胞质亚基p67phox和p47phox的显性阴性（DN）突变体和野生型（WT）构建体。突变体或WT构建体将在培养的成年大鼠心室肌细胞（ARVM）中过表达。这些突变体或WT构建体对11-AR刺激诱导的肥大和NOX酶活性的影响将被确定。p67phox和MEK-ERK级联之间潜在的蛋白-蛋白相互作用也将在此目的中确定。在Specific Aim 2中，我们将在体内测试p67phox是否介导11- ar刺激的心脏肥厚。我们将使用新产生的具有心脏特异性过表达DN p67phox突变体的杂合子DN-p67转基因（TG）小鼠来产生纯合子DN-p67 TG小鼠。由于市售的具有心脏特异性的11B-AR组成型激活突变体（CAM-11B-AR）过表达的TG小鼠会发生心肌肥大，我们将对这两种TG系（DN-p67和CAM-11B-AR）进行杂交，以研究心脏中DN p67phox突变体蛋白过表达对11B-AR诱导的心肌肥大的影响。在特异性目的3中，我们将测试心肌p67phox在体内介导血流动力学超载引起的心肌肥大中的作用。纯合子DN-p67 TG小鼠和年龄和性别匹配的WT对照小鼠将遭受升主动脉收缩（AAC）引起的慢性压力过载。我们将研究AAC或假手术后TG和WT小鼠的心脏表型和功能，以确定p67phox在体内介导慢性压力过载引起的心肌肥大中的作用。我们的研究将为NOX/p67phox在心脏肥厚发展中的作用和新机制提供新的认识，这将导致充血性心力衰竭的新治疗方法。我们的研究将为p67phox和NADPH氧化酶在心脏肥厚发展中的新的病理机制提供新的认识，而心脏肥厚可能导致主要的心血管疾病——心力衰竭。因此，我们的研究将与心力衰竭的常见原因直接相关，心力衰竭具有高死亡率和致残率，是对公众健康的主要威胁。