Methylarginines and Vascular Injury

描述(申请人提供)：这项提案的长期目标是建立蛋白质精氨酸甲基转移酶和二甲基精氨酸二甲氨基水解酶(DDAH)，这两种酶负责甲基精氨酸的合成和代谢，作为内皮功能的关键调节因子。我们的假设是，在心血管疾病中观察到的血浆ADMA增加是DDAH活性的生物标志物，许多归因于ADMA的内皮影响是通过DDAH-PRMT活性的改变直接表现出来的。我们已经证明，除了ADMA对eNOS活性的直接影响外，DDAH还通过ADMA独立的涉及蛋白质甲基化和氨基酸代谢的机制来调节内皮NO的产生。目前建议的目标是：1)确定ADMA在内皮细胞中的代谢途径；2)确定DDAH调控内皮细胞蛋白质-精氨酸甲基化的机制，明确蛋白质甲基化对内皮功能的影响；确定脱氢表雄酮调节血管内皮细胞L-精氨酸代谢的机制及其对血管内皮细胞产生一氧化氮的影响；明确PRMT-DDAH-ADMA轴调节内皮功能和动脉粥样硬化的机制。对于这些目标中的每一个，将结合细胞、分子、生物物理和生理方法，利用体外和体内模型来表征DDAH对内皮功能的影响。这些研究的结果将提供有关PRMT-DDAH-ADMA轴调节细胞功能的机制的基本机制信息，并可能导致治疗血管疾病的新方法。 公共卫生相关性：这项研究与公共健康相关，因为动脉粥样硬化是美国人发病率和死亡率的主要原因之一。我们的研究发现了与血管疾病发展有关的新的细胞通路。由这笔赠款支持的研究可能有助于确定治疗动脉病变的新药，并可能改善心血管疾病患者的生活质量。

DESCRIPTION (provided by applicant): The long term objective of this proposal is to establish Protein Arginine Methyltransferases and Dimethyarginine Dimethylaminohydrolase (DDAH), the enzymes responsible for methylarginine synthesis and metabolism, as a key regulator of endothelial function. It is our hypothesis that the increased plasma ADMA observed in cardiovascular disease is a biomarker of DDAH activity and that many of the endothelial affects attributed to ADMA are directly manifested through altered DDAH-PRMT activity. We have shown that in addition to the direct effects of ADMA on eNOS activity, DDAH modulates endothelial NO production through ADMA independent mechanisms involving altered protein-methylation and amino acid metabolism. The goals of the current proposal are to: 1) identify the pathways of ADMA metabolism in the endothelium; 2.) determine the mechanisms through which DDAH modulates endothelial protein-arginine methylation and define the effects of protein methylation on endothelial function; 3.) determine the mechanisms through which DDAH regulates endothelial L-arginine metabolism and the consequences on endothelial NO production; and 4.) identify the mechanisms through which the PRMT-DDAH-ADMA axis regulates endothelial function and atherosusceptibility. For each of these aims, a combination of cellular, molecular, biophysical and physiological approaches will be used to characterize the effects of DDAH on endothelial function using in vitro and in vivo models. Results from these studies will provide fundamental mechanistic information regarding the mechanisms through which the PRMT-DDAH-ADMA axis modulates cellular function and may lead to new approaches to treat vascular disease. PUBLIC HEALTH RELEVANCE: This research is relevant to public health since atherosclerosis is among the leading cause morbidity and mortality in Americans. Our research has discovered new cellular pathways that are involved in the development of vascular diseases. Research supported by this grant may help identify new drugs to treat arterial pathology and could improve the quality of life of people suffering from cardiovascular disease.