Novel genes for dilated cardiomyopathy: molecular basis of the disease

扩张型心肌病的新基因：该疾病的分子基础

• 批准号: 6423879
• 负责人: Robert E Roberts
• 金额: $ 18.5万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-01 至 2002-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6423879
• 关键词: artificial chromosomes; autosomal dominant trait; clinical research; family genetics; fibrous protein; gene mutation; genetic mapping; genetically modified animals; growth factor; human subject; idiopathic dilated cardiomyopathy; laboratory mouse; microfilaments; molecular assembly /self assembly; molecular pathology; morphometry; tissue /cell culture; transfection /expression vector

The overall objective of the current SCOR and the PROPOSED RENEWAL is to elucidate the molecular basis for the long-term adaptive response of the heart to injury, both inherited and acquired, whether manifested by hypertrophy or dilatation. In this project we focus on the paradigm of dilated cardiomyopathy affecting primarily the left ventricle. Although six genetic loci are associated with the disease, none of the causative genes have been identified. We propose to identify two of these genes, mapped to1q32 and 10q23 in our families, using either a positional candidate or positional cloning approach. We will use physical mapping information available on the World Wide Web to identify YAC clones and ESTs which map to the critical regions. We will use this cloned material to identify new genetic markers to further delineate the region as well as new candidate genes to be sequenced in our families. We further propose to map a novel locus in a family we have identified that is no linked to any known FDCM locus and ultimately to identify that gene as well. Having identified a missense mutation (Il3451/Met) in the desmin gene which is responsible for DCM in a family, we will conduct in vitro studies to investigate the effect of this mutation on filament assembly and through expression in myocytes attempt to determine the reason for the cardiac restricted phenotype. In vivo studies will be conducted following expression in the transgenic mouse to ascertain the morphological changes and their temporal evolution in relationship to evolving ventricular dysfunction. Utilizing cell morphometry it will be determined whether there is a hypertrophic as well as a dilatory response as determined by the extent of myocyte thickening versus myocyte elongation. Should the phenotype be primarily ventricular dilation as expected from the phenotype in patients with FDCM, it will be of great interest despite a dilatory response to determine whether the usual growth factors (FAS, IGF-1, TGFbeta) or cytoskeletal pathways (integrin kinase, Rho-A, FAK) involved in hypertrophy are also up-regulated. These objectives address the hypothesis that identifying genetic defects and unraveling the molecular basis for familial DCM will provide insight fundamental to the understanding of ventricular dilatation and failure observed in response to a variety of other familial and acquired diseases.

当前 SCOR 和拟议更新的总体目标是阐明心脏对遗传性和后天性损伤（无论表现为肥大还是扩张）的长期适应性反应的分子基础。在这个项目中，我们重点关注主要影响左心室的扩张型心肌病的范例。尽管有六个基因位点与该疾病相关，但尚未确定任何致病基因。我们建议使用位置候选或位置克隆方法来识别其中两个基因，映射到我们家族中的 1q32 和 10q23。我们将使用万维网上提供的物理映射信息来识别映射到关键区域的 YAC 克隆和 EST。我们将使用这种克隆材料来识别新的遗传标记，以进一步描绘该区域以及要在我们的家族中进行测序的新候选基因。我们进一步建议在我们已鉴定的家族中绘制一个与任何已知 FDCM 基因座无关的新基因座，并最终鉴定该基因。在确定了负责家族 DCM 的结蛋白基因中的错义突变 (Il3451/Met) 后，我们将进行体外研究，以研究该突变对肌丝组装的影响，并通过在肌细胞中的表达尝试确定心脏受限表型的原因。在转基因小鼠中表达后将进行体内研究，以确定形态变化及其与心室功能障碍演变相关的时间演变。利用细胞形态计量学，将确定是否存在肥大以及扩张反应，这通过肌细胞增厚程度与肌细胞伸长的关系来确定。如果表型主要是 FDCM 患者表型所预期的心室扩张，那么尽管反应缓慢，但确定参与肥大的常见生长因子（FAS、IGF-1、TGFbeta）或细胞骨架途径（整联蛋白激酶、Rho-A、FAK）是否也上调，仍将引起极大兴趣。这些目