Regulation of Purine Metabolism by Protein Methyltransferase Smyd1

蛋白甲基转移酶 Smyd1 对嘌呤代谢的调节

基本信息

批准号：
10249944
负责人：
Magnus Creed
金额：
$ 4.6万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-04-01 至 2023-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10249944
关键词：
Acute Address Adult Affect Allopurinol Allosteric Regulation Animal Genetics Animal Model Binding Biochemical Biological Biological Assay Biological Process Biology Blood flow Cardiac Cardiac Myocytes Cardiovascular system Cell Nucleus Cells Chronic Chronic stress Citric Acid Cycle Complex Congestive Heart Failure Coupled Cytosol Data Diabetes Mellitus Disease Disease Progression EFRAC Enzymes Family Fellowship Fibrosis Gene Expression Generations Genetic Transcription Glycolysis Growth Heart Heart Diseases Heart failure High Pressure Liquid Chromatography Histones Hypertension Hypertrophy Hyperuricemia Immune In Vitro Increased Uric Acid Level Individual Knockout Mice Lead Ligase Lysine Mass Spectrum Analysis Measures Mediating Metabolic Metabolism Methylation Methyltransferase Modification Molecular Molecular Analysis Morbidity - disease rate Muscle Cells Names Nuclear Organ Oxidative Phosphorylation Pathway interactions Patients Phenotype Phenylephrine Phosphorylation Physiology Point Mutation Process Production Protein Methyltransferases Proteins Proteomics RNA Processing RNA chemical synthesis Rattus Reactive Oxygen Species Regulation Role SET Domain Serum Site Small Interfering RNA Stress Syndrome Technology Therapeutic Tissues Transcript Transcriptional Regulation Up-Regulation Uric Acid Variant Ventricular Work Xanthine Oxidase adenoviral-mediated cardiovascular risk factor cell growth experimental study fatty acid oxidation free radical oxygen functional decline heart metabolism hemodynamics in vitro Assay knock-down mortality mutant novel overexpression peripheral blood persistent symptom purine metabolism

项目摘要

PROJECT ABSTRACT The pathophysiological understanding of chronic heart failure has shifted from a mere hemodynamic disorder to a much more complex syndrome including changes and imbalances in neurohormonal, immune, transcriptional and metabolic functions. Among the metabolic abnormalities, chronic heart failure has been associated with increased levels of uric acid (hyperuricemia), the end product of purine metabolism. Specifically, studies have shown a strong association between serum uric acid levels and cardiovascular morbidity and mortality, especially among individuals with high cardiovascular risk, including those with hypertension, diabetes and congestive heart failure. Abnormal purine metabolism is also known for its contribution to ROS production through xanthine oxidase, the final enzyme in this pathway, which is increasingly appreciated as an important contributor to both symptoms of chronic heart failure as well as progression of the disease. Indeed, therapeutic inhibition of increased xanthine oxidase activity (via allopurinol) in heart failure patients has been shown to counteract maladaptive chronic upregulation of purine metabolism with specific benefits observed in peripheral blood flow and decreased free oxygen radical generation, suggesting that targeting this pathway therapeutically can be beneficial for heart failure patients. However, the underlying mechanisms which drive these changes in purine metabolism in the cardiomyocyte and ultimately ROS and uric acid accumulation in heart failure patients remain largely unknown. We recently discovered that the methyltransferase Smyd1b, which displays unique roles in both the cytosol and nucleus, interacts with the metabolic enzyme Adss (Adenylossuccinate Synthatase), a key component of purine metabolism in the heart. We have confirmed this novel interaction between Smyd1b and Adss is enhanced during phenylephrine-induced hypertrophic growth in the cardiomyocyte and is associated with increased methylation of Adss. In addition, we have shown that Smyd1 enhances the enzymatic activity of Adss as it converts IMP to sAMP in vitro. Despite these intriguing results, how Smyd1 regulates Adss activity and its effect on purine metabolism and uric acid production is completely unknown. My fellowship application will utilize a unique genetic animal model and state-of-the-art proteomic technologies to conceptually advance our understanding of myocyte biology and physiology. Specifically, this work will determine the role of Smyd1 in regulating Adss activity in the adult heart, characterize its ability to influence ROS production and uric acid accumulation, and determine whether overexpression of Smyd1 can inhibit these deleterious processes. Together, my experiments will build upon our previous results and allow me to elucidate the specific molecular mechanism by which Smyd1b regulates purine metabolism in the heart and how this process is regulated under normal and hypertrophic conditions.

项目摘要对慢性心力衰竭的病理生理学理解已经从单纯的血流动力学障碍转变为一种更为复杂的综合征，包括神经激素、免疫、转录的变化和不平衡和代谢功能。在代谢异常中，慢性心力衰竭与尿酸水平升高（高尿酸血症），尿酸是嘌呤代谢的最终产物。具体来说，研究有研究表明，血清尿酸水平与心血管疾病发病率和死亡率之间存在密切关联，尤其是心血管疾病高危人群，包括高血压、糖尿病和充血性心脏病患者失败。嘌呤代谢异常还因其通过黄嘌呤促进 ROS 产生而闻名氧化酶是该途径中的最终酶，它越来越被认为是这两种酶的重要贡献者慢性心力衰竭的症状以及疾病的进展。事实上，治疗性抑制心力衰竭患者中黄嘌呤氧化酶活性的增加（通过别嘌呤醇）已被证明可以抵消嘌呤代谢的适应不良性慢性上调，在外周血流中观察到特定的益处并减少自由基的产生，这表明治疗上可以针对该途径对心力衰竭患者有益。然而，驱动嘌呤变化的潜在机制心力衰竭患者心肌细胞的代谢以及最终的活性氧和尿酸积累仍然存在很大程度上不为人知。我们最近发现甲基转移酶 Smyd1b，它在细胞质和细胞核，与代谢酶 Adss（腺苷酸琥珀酸合酶）相互作用，Adss 是嘌呤的关键成分心脏的新陈代谢。我们已经证实 Smyd1b 和 Adss 之间的这种新颖的相互作用在去氧肾上腺素诱导心肌细胞肥大性生长，并与甲基化增加相关的广告。此外，我们还发现 Smyd1 可以增强 Adss 的酶活性，因为它将 IMP 转化为 sAMP 体外。尽管有这些有趣的结果，Smyd1 如何调节 Adss 活性及其对嘌呤的影响新陈代谢和尿酸的产生是完全未知的。我的奖学金申请将利用独特的基因动物模型和最先进的蛋白质组技术从概念上增进我们对肌细胞的理解生物学和生理学。具体来说，这项工作将确定 Smyd1 在调节 Adss 活动中的作用成人心脏，表征其影响 ROS 产生和尿酸积累的能力，并确定 Smyd1 的过度表达是否可以抑制这些有害过程。我的实验将共同建立根据我们之前的结果，让我阐明 Smyd1b 的具体分子机制调节心脏中的嘌呤代谢以及在正常和肥厚情况下如何调节该过程状况。