Genetic and Cellular Basis of Resistance/Sensitivity to Myocardial Ischemia

描述（由申请人提供）：心肌梗死（MI）是美国的主要健康问题。心脏对缺血的抵抗力和/或敏感性的多基因特性已被广泛接受。人类研究和动物模型的全基因组关联研究和连锁分析已经揭示了大量与冠状动脉疾病（CAD）和心肌梗死有关的染色体位点。不幸的是，在确定与缺血性损伤反应直接相关的因果多态性方面进展甚微。与人类研究相比，动物模型提供了通过使用具有不同表型的心肌缺血特定遗传模型（如敏感的Dahl盐敏感和耐药的Brown Norway菌株）来识别复杂相互作用的能力。为了剖析这种复杂性，我们建议：1。鉴定大鼠6号染色体上负责抵抗缺血的基因。我们将把最初的定位克隆工作集中在SS.BN6最小同源基因上，该基因全长3.9Mb，包含36个基因。这个目标的意义在于，我们很可能在这个区间内识别和验证因果突变。利用工程心脏组织（EHT）来加速发现和提高我们研究突变机制特性的能力是创新的。2. 继续在大鼠3号和12号染色体上寻找与缺血抵抗有关的基因。利用SS.BN3和SS.BN12经济序列，我们已经产生了基因，并证明我们可以使用体外（Langendorff）和EHT模型来寻找这两条染色体上的位点。此外，利用另外两个菌株/染色体将有助于更好地了解心肌缺血的复杂性。3. 负责抵抗缺血的基因的功能验证。证明基因是因果关系的黄金标准需要某种形式的拯救实验。我们将采用转基因拯救方法来验证6号染色体位点。这一目标的意义在于证明突变是偶然的，并使用创新的解决方案来产生转基因救援动物。最后，动物模型将提供给研究界进行进一步的研究。

DESCRIPTION (provided by applicant): Myocardial infarction (MI) is a major health problem in the United States. The polygenic nature of the resistance and/or sensitivity of the heart to ischemia are well accepted. Genome wide association studies and linkage analyses in both human studies and animal models have revealed a large number of chromosomal loci involved in coronary artery diseases (CAD) and MI. Unfortunately, little progress has been made in identifying causal polymorphisms directly related to the response to ischemic injury. In contrast to human studies, animal models provide the ability to identify the complex interactions through the use of specific genetic models with divergent phenotypes for myocardial ischemia such as the sensitive Dahl Salt-Sensitive and resistant Brown Norway strains. To dissect this complexity accordingly we propose: 1. Identify a gene on rat chromosome 6 responsible for resistance to ischemia. We will focus our initial positional cloning efforts on the SS.BN6 minimal congenic encompassing 3.9Mb containing 36 genes. The significance of this aim is that we are very likely to identify and validate the causal mutation in this interval. The use of engineered heart tissue (EHT) to accelerate discovery and enhancing our ability to study the mechanistic properties of the mutation is innovative. 2. Pursue the identification of the genes responsible for resistance to ischemia on rat chromosomes 3 and 12. Using SS.BN3 and SS.BN12 consomics we have already generated congenics and demonstrated that we can use our in vitro (Langendorff) and EHT models to pursue loci on these two chromosomes. Moreover, utilizing another two strains/chromosomes will lead to better understanding complexity of myocardial ischemia. 3. Functional validation of the gene(s) responsible for the resistance to ischemia. The gold standard for proving that a gene is causal requires some form of rescue experiment. We will deploy a transgenic rescue approach to validate the chromosome 6 locus. The significance of this aim is proving a mutation is casual and uses innovative solutions to generate the transgenic rescue animals. Finally, the animal models will be made available to the research community for further studies. PUBLIC HEALTH RELEVANCE: Cardiovascular disease is one of the leading causes of death worldwide and is responsible for 45% of deaths in the Western world and 24.5% of deaths in the developing countries. Myocardial infarction remains a major cause of morbidity and mortality despite anti-atherosclerotic therapies, reperfusion strategies, and anti-platelet treatment, due in part to the large heterogeneity in the response to ischemia among patients. The overall goal of this project is to identify genes and mechanisms involved in resistance to myocardial infarction.