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（申请人提供）：肌节蛋白基因突变导致家族性肥厚型心肌病 (HCM)、散发性 HCM、儿童 HCM 和老年人 HCM，在美国约有 100 万人发生。这些突变产生 LVH 临床特征的分子机制仍然很大程度上未知。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，评估了触发肥厚信号的候选分子，并在心室心肌病理重塑的早期和晚期进行了全面的（SAGE）转录分析。遗传相同的 HCM 小鼠的表型特征表明，对肌节蛋白基因突变的反应是复杂的，激活同一心脏内不同心肌细胞的不同分子途径。这些不同的细胞途径必须由不同的环境因素激活。该应用的中心假设是，不同的肌细胞群将通过不同的表达谱特征来区分，并且这些 RNA 特征的定义将有助于识别参与指导肥大反应各个方面的关键分子。我们之前鉴定 HCM 转录特征的努力涉及使用现有技术来评估 HCM 小鼠整个左心室的 RNA 表达。我们最初识别 RNA 谱特征的努力受到三个技术问题的困扰：1) 现有的转录谱技术不允许评估低水平表达的 RNA； 2）将心脏组织视为同质细胞群； 3）即使在基因相同的小鼠之间，对肌节蛋白基因突变的反应也有很大差异。在这里，我们提出了两种方法来克服在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，其中肥大反应的特定分子标记已被激活。例如，我们将使用（3-肌球蛋白重链（MHC）基因启动子驱动荧光黄色蛋白的标记基因来分离该分子肥大标记被激活的细胞。其次，我们最近开发了一种改良的RNA分析方法我们将这种方法称为 PMAGE（基因表达的聚合多重分析），其灵敏度比现有技术高出约 100 倍，我们建议定义在不同肌细胞亚群中表达发生改变的蛋白质的作用：1)分离对 HCM 突变具有共同分子反应的小鼠肌细胞群。 2) 采用高度灵敏的 RNA 分析技术 PMAGE 来定义小鼠肌细胞群中的 RNA 谱。 3) 评估信号蛋白在肌节基因突变触发的肥大途径中的作用。 4) 评估 RNA 谱并筛选人类 HCM 样本中突变的候选基因。