Regulation of Purine Metabolism by Protein Methyltransferase Smyd1

蛋白甲基转移酶 Smyd1 对嘌呤代谢的调节

• 批准号: 10372904
• 负责人: Magnus Creed
• 金额: $ 4.68万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 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/10372904
• 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

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理解已从单纯的血液动力学障碍转变为 一个更复杂的综合征，包括神经激素，免疫，转录的变化和失衡 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），这是嘌呤代谢的最终产物。具体而言，研究有 表现出血清尿酸水平与心血管发病率和死亡率之间有很强的关联，尤其是 在患有高心血管风险的人中，包括高血压，糖尿病和充血性心脏的人 失败。异常嘌呤代谢也因其对ROS生产的贡献而闻名 氧化酶，该途径中的最终酶，越来越多地认为这是两者的重要因素 慢性心力衰竭以及疾病进展的症状。确实，治疗性抑制 心力衰竭患者中的​​黄嘌呤氧化酶活性（通过别嘌醇）的增加已被证明可以抵消 嘌呤代谢的不良适应性慢性上调，在外周血流动中观察到的特定益处 并减少了自由氧自由基的生成，这表明可以治疗靶向该途径 对心力衰竭患者有益。但是，驱动这些变化的嘌呤的基本机制 心肌细胞中的代谢以及心力衰竭患者的ROS和尿酸积累仍然存在 在很大程度上未知。 我们最近发现，甲基转移酶Smyd1b在细胞质和 核与代谢酶ADSS（腺苷酸化合物合成酶）相互作用，这是嘌呤的关键成分 心脏中的代谢。我们已经确认SMYD1B和ADS之间的这种新颖的相互作用在期间增强了 苯肾上腺素诱导的心肌细胞肥厚性生长，与甲基化增加有关 adss。此外，我们已经表明SMYD1增强了ADS的酶活性，因为它将IMP转换为 体外。尽管这些有趣的结果，SMYD1如何调节ADSS活动及其对嘌呤的影响 代谢和产生尿酸是完全未知的。我的奖学金申请将利用独特的遗传 动物模型和最先进的蛋白质组学技术，从概念上提高我们对肌细胞的理解 生物学和生理学。具体而言，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的过表达是否可以抑制这些有害过程。在一起，我的实验将建立 根据我们以前的结果，我允许我阐明smyd1b的特定分子机制 调节心脏中的嘌呤代谢，以及如何在正常和肥厚的情况下调节该过程 状况。