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: 6302321
• 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: 2000
• 资助国家: 美国
• 起止时间: 2000-02-07 至 2001-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6302321
• 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损伤（包括遗传性和获得性损伤，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，我们专注于主要影响左心室的扩张型心肌病的范例。虽然有六个基因位点与该病有关，但尚未发现任何致病基因。我们建议确定这些基因中的两个，定位到1 q32和10 q23在我们的家庭，使用位置候选或位置克隆的方法。我们将利用万维网上的物理图谱信息来确定YAC克隆和EST，它们映射到关键区域。我们将使用这种克隆材料来确定新的遗传标记，以进一步描绘该地区以及新的候选基因在我们的家庭测序。我们还建议在我们已经确定的一个家族中绘制一个新的基因座，该基因座与任何已知的FDCM基因座无关，并最终确定该基因。在一个家族中鉴定了导致DCM的结蛋白基因中的错义突变（Il 3451/Met）后，我们将进行体外研究以研究该突变对细丝组装的影响，并通过在肌细胞中的表达试图确定心脏限制表型的原因。将在转基因小鼠中表达后进行体内研究，以确定形态学变化及其与心室功能障碍演变的时间演变。利用细胞形态测定法，将确定是否存在肥大以及扩张反应，如通过肌细胞增厚相对于肌细胞伸长的程度所确定的。如果表型主要是心室扩张，如从FDCM患者的表型所预期的那样，则尽管存在扩张反应，但确定参与肥大的常见生长因子（FAS、IGF-1、TGF β）或细胞骨架途径（整合素激酶、Rho-A、FAK）是否也上调将是非常有意义的。这些目标解决的假设，确定遗传缺陷和解开家族性DCM的分子基础，将提供洞察力的理解心室扩张和失败的基础上观察到的各种其他家族性和获得性疾病。