Transcriptional and physiological analysis of cardiac HIF1

描述（由申请人提供）：缺氧诱导因子-1是所有脊椎动物的主要氧感应分子。它是一种受环境氧浓度对其稳定性影响的转录因子。HIF1调节一系列参与缺氧反应的基因，包括增强血管生成和促进糖酵解代谢的因子。这些反应在心脏中引起的兴趣最大，在发达国家，冠状动脉疾病引起的缺氧是发病率和死亡率的主要原因。因此，我们试图确定HIF1在心脏中的作用，以更好地了解对缺氧的内源性生理反应。我们已经创建了一个转基因模型，其中HIF可以以一种受调节的、特定于心脏的方式表达。我们已经产生了不受氧浓度影响的抗降解HIF1转基因动物。我们的基本假设是，心脏特异性的HIF1活性升高将引导心脏重现缺氧反应。我们的具体目标是通过结合分子、代谢和生理技术来检验这一假设。特异性目的1：确定体内HIF1转录激活的直接下游靶点。随着HIF1活性的增加，我们将对我们的模型进行全面的转录分析，以捕捉第一反应并识别受HIF1调节的新基因。特定目的2：测量特定生化途径对心脏中hif1介导的从氧化代谢到糖酵解代谢的转换的贡献。这将通过自旋标记底物的磁共振波谱来完成。特异性目的3：明确HIF1过表达在心脏中的血管生成作用。这将需要组织学和生理学分析，并将在缺氧和梗死模型中进行探索。

DESCRIPTION (provided by applicant): Hypoxia inducible factor-1 is a principal oxygen sensing molecule in all vertebrates. It is a transcription factor that is regulated by the effect of ambient oxygen concentration on its stability. HIF1 regulates a panoply of genes involved in response to hypoxia, including factors that augment angiogenesis and favor glycolytic metabolism. Nowhere are these responses of greater interest than in the heart, where hypoxia due to coronary artery disease is a major cause of morbidity and mortality in the developed world. We thus seek to determine the effects of HIF1 in the heart, to better understand the endogenous physiological response to hypoxia. We have created a transgenic model where HIF can be expressed in a regulated, cardiac-specific manner. We have generated our transgenic animal with a degradation-resistant HIF1 that is not affected by oxygen concentration. Our underlying hypothesis is that cardiac-specific elevation of HIF1 activity will direct the heart to recapitulate hypoxic responses. Our specific aims test this hypothesis using a combination of molecular, metabolic and physiological techniques. Specific Aim 1: To identify the immediate down-stream targets of HIF1 transcriptional activation in vivo. We will apply comprehensive transcriptional analysis to our model as HIF1 activity increases to catch the first response and identify novel genes that are regulated by HIF1. Specific Aim 2: To measure the contribution of specific biochemical pathways to the HIF1-mediated switch from oxidative to glycolytic metabolism in the heart. This will be accomplished with the magnetic resonance spectroscopy of spin-labeled substrates. Specific Aim 3: To define the angiogenic effects of HIF1 overexpression in the heart. This will require histological and physiological analysis and will be explored in models of hypoxia and infarction.