Molecular Signaling in Hypertrophic Cardiomyopathy

肥厚型心肌病的分子信号转导

• 批准号: 7345432
• 负责人: JONATHAN G SEIDMAN
• 金额: $ 42.25万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7345432
• 关键词: Address; Atrial Natriuretic Factor; Biochemical; Biological Markers; Candidate Disease Gene; Cardiac; Cardiomyopathies; Cells; Childhood; Clinical; Complex; Data; Development; Disease; Elderly; Environmental Risk Factor; Familial Hypertrophic Cardiomyopathy; Fibrosis; Framingham Heart Study; Galactosidase; Gene Expression; Gene Mutation; Gene Targeting; Genes; Genetic Transcription; Heart; Histopathology; Homeobox; Hop protein; Human; Hypertrophic Cardiomyopathy; Hypertrophy; Investigation; LacZ Genes; Left Ventricular Hypertrophy; Left Ventricular Mass; Left ventricular structure; Metabolism; Methods; Molecular; Molecular Genetics; Molecular Profiling; Monitor; Mus; Muscle Cells; Mutation; Myocardium; Myosin Heavy Chains; Participant; Pathologic; Pathway interactions; Population; Predisposing Factor; Prevalence; Process; Proteins; RNA; Reporter Genes; Role; Sampling; Sarcomeres; Signal Pathway; Signal Transduction; Signaling Protein; Techniques; Technology; Tissues; Variant; Ventricular; Ventricular Remodeling; base; cardiovascular risk factor; hemodynamics; mouse model; new technology; promoter; research study; response; trait; transcription factor

DESCRIPTION (provided by applicant): Sarcomere protein gene mutations cause familial hypertrophic cardiomyopathy (HCM), sporadic HCM, pediatric HCM and HCM of the elderly and occur in approximately 1 million people in the US. The molecular mechanisms by which these mutations produce the clinical features of LVH remain largely unknown. We have produced mouse models that carry selective human mutations, characterized the development of histopathology, assessed candidate molecules for triggering hypertrophic signaling, and performed comprehensive (SAGE) transcriptional profiling early and late in pathologic remodeling of ventricular myocardium. Phenotypic characterization of genetically identical HCM mice demonstrated that responses to sarcomere protein gene mutations are complex, activating different molecular pathways in different myocytes within the same heart. These different cellular pathways must be activated by different environmental factors. The central hypotheses of this application is that different myocyte populations will be distinguished by different expression profile signatures and that definition of these RNA signatures will help to identify key molecules that are involved in directing each facet of the hypertrophic response. Our previous efforts to identify transcriptional signatures of HCM have involved using existing techniques to assess RNA expression in the entire left ventricle of HCM mice. Our initial efforts to identify RNA profile signatures were confounded by three technical problems: 1) Existing transcriptional profiling technologies did not allow assessment of RNAs that are expressed at low levels; 2) Cardiac tissue was treated as a homogenous cell population; 3) The response to sarcomere protein gene mutations varies considerably even between genetically identical mice. Here we propose two approaches to overcome the technical difficulties encountered in characterizing the hypertrophic response. First, we will isolate specific cell populations in which a particular molecular marker of a hypertrophic response has been activated. For example, we will use a marker gene in which the (3-myosin heavy chain (MHC) gene promoter drives a fluorescent yellow protein to isolate cells in which this molecular hypertrophy marker is activated. Second, we have recently developed a modified RNA profiling method, we have termed PMAGE (polony multiplex analysis of gene expression), which provides about 100 fold more sensitivity than existing techniques. We propose to define the role of proteins whose expression is altered in different myocyte subsets. Specifically we propose to: 1) Isolate mouse myocyte populations with shared molecular responses to HCM mutations. 2) Employ a highly sensitive RNA profiling technique PMAGE to define RNA profiles in mouse myocyte populations. 3) Assess roles of signaling proteins in hypertrophic pathways triggered by sarcomere gene mutations. 4) Assess RNA profiles and screen candidate genes for mutations in human HCM samples.

描述（由申请人提供）：肌节蛋白基因突变引起家族性肥厚性心肌病（HCM），零星的HCM，小儿HCM和老年人的HCM，在美国大约有100万人发生。这些突变产生LVH的临床特征的分子机制在很大程度上未知。我们制作了携带选择性人类突变的小鼠模型，表征了组织病理学的发展，评估了候选分子以触发肥厚的信号传导，并在心室心肌的病理学重塑中进行了全面的（SAGE）转录分析。遗传上相同的HCM小鼠的表型表征表明，对肌节蛋白基因突变的反应很复杂，激活了同一心脏内不同肌细胞中不同的分子途径。这些不同的细胞途径必须通过不同的环境因素激活。该应用的中心假设是，不同的肌细胞种群将通过不同的表达谱特征来区分，这些RNA签名的定义将有助于识别指向指导肥厚反应的每个方面的关键分子。我们以前识别HCM转录特征的努力涉及使用现有技术评估HCM小鼠整个左心室的RNA表达。我们最初的识别RNA概况签名的努力是由三个技术问题混淆的：1）现有的转录分析技术不允许评估低级别表达的RNA； 2）心脏组织被视为同质细胞群； 3）对肌节蛋白基因突变的反应甚至在遗传相同的小鼠之间也有很大变化。在这里，我们提出了两种方法来克服表征肥厚反应时遇到的技术困难。首先，我们将分离特定的细胞群，其中已经激活了肥厚反应的特定分子标记。 For example, we will use a marker gene in which the (3-myosin heavy chain (MHC) gene promoter drives a fluorescent yellow protein to isolate cells in which this molecular hypertrophy marker is activated. Second, we have recently developed a modified RNA profiling method, we have termed PMAGE (polony multiplex analysis of gene expression), which provides about 100 fold more sensitivity than existing techniques. We propose to define the role of在不同的肌细胞亚群中，表达改变的蛋白质。 2）采用高度敏感的RNA分析技术PMAGE来定义小鼠肌细胞种群中的RNA谱。 3）评估信号蛋白在由肉瘤基因突变触发的肥厚途径中的作用。 4）评估人类HCM样品中突变的RNA谱和筛选候选基因。