Regulation of Peroxisomal Metabolism by Lysine Acylation

赖氨酸酰化对过氧化物酶体代谢的调节

• 批准号: 10206781
• 负责人: ERIC S GOETZMAN
• 金额: $ 44.59万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10206781
• 关键词: Ablation; Acetates; Acetylation; Acylation; Affect; Aging; Automobile Driving; Carbon; Catabolism; Citric Acid Cycle; Cultured Cells; Data; Diabetes Mellitus; Dicarboxylic Acids; Disease; Energy-Generating Resources; Enoyl-CoA Hydratase; Enzyme Stability; Enzymes; Exposure to; Fasting; Fatty Acids; Functional disorder; Grant; Hand Strength; Heart; Human; Impairment; Individual; Injury to Kidney; Knowledge; Lipids; Literature; Liver; Lysine; Malignant Neoplasms; Metabolic Pathway; Metabolism; Mitochondria; Mus; Muscle; Muscle function; Myocardium; Nature; Organ; Organism; Oxidative Stress; Oxides; Pathology; Pathway interactions; Patients; Peripheral; Pharmacology; Post-Translational Protein Processing; Production; Proteins; Recombinant Proteins; Regulation; Research; Sirtuins; Site; Stress; Structure; Succinates; Symptoms; Testing; Therapeutic; Therapeutic Effect; Tissues; acyl-CoA dehydrogenase; acyl-CoA oxidase; enzyme pathway; fatty acid oxidation; feeding; gain of function; heart function; improved; lipid metabolism; liver function; long chain fatty acid; metabolomics; mouse model; peroxisome; response; succinyl-coenzyme A

Long-chain fatty acid oxidation disorders (LC-FAODs) are a heterogenous group of disorders characterized by the inability to break down long-chain fatty acids in the mitochondria for energy. Peroxisomal fatty acid oxidation (FAO) is a parallel pathway to mitochondrial FAO that could be leveraged to alleviate fatty acid accumulation in patients with LC-FAODs. However, there is currently no pharmacological means of stimulating peroxisomal FAO in humans. The ability to develop new peroxisome-stimulating therapies is limited by knowledge gaps regarding the factors that regulate activity of peroxisomal FAO enzymes. Here, it is proposed that sirtuin-5 (Sirt5) and lysine succinylation—a post-translational modification reversed by Sirt5—represent a new mechanism for manipulating peroxisomal function. When mice are fed a class of fatty acids called dicarboxylic acids (DCAs), lysine succinylation accumulates on peroxisomal proteins. Further preliminary data suggest that lysine succinylation increases peroxisomal function. The capacity of Sirt5 to reverse these effects remains unclear. The central hypothesis of this grant is that feeding DCAs can improve disease pathology in mouse models of mitochondrial LC-FAOD by driving protein succinylation and peroxisomal activation. This is supported by preliminary data in which seven days of DCA feeding improved muscle function in an LC-FAOD mouse model. The central hypothesis will be fully explored in three Specific Aims. 1) Aim 1 will quantify the effects of DCA feeding and Sirt5 ablation on the peroxisomal acylome. Sirt5 partially localizes to the peroxisome but its activity there has not been characterized. A quantitative, site-level lysine “acylome” ± DCA feeding will be compiled for liver, muscle, and heart—the key tissues affected in LC-FAODs—and all Sirt5 target sites identified. 2) Aim 2 is to delineate the effects of DCA feeding ± Sirt5 ablation on the function of peroxisomal enzymes and pathway fluxes. This will be done using purified recombinant proteins, cultured cells with manipulated Sirt5 levels in the peroxisome, and Sirt5-deficient mice. Metabolomics, 14C-substrate flux studies, and enzyme stability/function testing will be used to determine how reversible lysine PTMs affect the peroxisome. 3) Aim 3 will be to test DCA feeding as a therapeutic strategy in LC-FAOD mouse models. It is proposed that DCAs will distribute beyond the liver to the peripheral organs, serving as a source of energy via partial chain shortening and peroxisomal gain-of-function. Mild and severe LC-FAOD mouse models ± long- term DCA feeding will be evaluated for liver, heart, and muscle functioning as well as the response to fasting stress. Ablation of Sirt5 in this context may further enhance peroxisomal function. To test this, the LC-FAOD mouse models will be crossed onto a Sirt5-/- background. Together, completion of these Specific Aims will form critical new knowledge for manipulating peroxisomal function to treat LC-FAODs. These mechanisms are also relevant to aging, kidney injury, diabetes, cancer, and many other diseases characterized by impaired peroxisomal function and dysfunctional lipid metabolism.

长链脂肪酸氧化障碍（LC-FAODS）是一组异性疾病，其特征是 无法分解线粒体中的长链脂肪酸的能量。过氧化物体脂肪酸 氧化（FAO）是通往线粒体FAO的平行途径，可以利用以减轻脂肪酸 LC-FAOD患者的积累。但是，目前没有刺激的药物 人类的过氧化物群。开发新的过氧化物组刺激疗法的能力受到限制 关于调节过氧化物疫蛋白酶活性的因素的知识差距。在这里提议 SIRTUIN-5（SIRT5）和赖氨酸琥珀酰化（通过SIRT5逆转后的翻译后修饰）代表A 操纵过氧化物体功能的新机制。当小鼠喂食一类称为脂肪酸时 二羧酸（DCAS），赖氨酸琥珀酰化积聚在过氧化物体蛋白上。进一步的初步数据 表明赖氨酸琥珀酰化会增加过氧化物体功能。 SIRT5扭转这些效果的能力 仍然不清楚。该赠款的中心假设是喂养DCA可以改善疾病病理 线粒体LC-FAOD的小鼠模型通过驱动蛋白琥珀酰化和过氧化物体激活。这是 在初步数据的支持下，DCA喂养的7天在LC-FAOD中提高了肌肉功能 鼠标模型。中心假设将在三个特定目标中进行全面探讨。 1）AIM 1将量化 DCA喂养和SIRT5消融对过氧化物体酰基组的影响。 SIRT5部分本地化 过氧化物组，但其活性尚未表征。定量的现场赖氨酸“酰基”±DCA 喂食将用于肝脏，肌肉和心脏（在LC-FAOD中受影响的关键组织）和所有SIRT5 确定的目标站点。 2）目标2是描述DCA喂养±SIRT5消融对功能的影响 过氧化物体酶和通路通量。这将使用纯化的重组蛋白，培养的细胞进行 在过氧组合体中操纵SIRT5水平和SIRT5缺陷小鼠。代谢组学，14C底物通量 研究和酶稳定性/功能测试将用于确定可逆赖氨酸PTM如何影响 过氧化素。 3）AIM 3将是在LC-FAOD小鼠模型中测试DCA喂养作为治疗策略。这是 提议DCA将将肝脏以外分布到外围器官，并通过 部分链缩短和过氧化物体功能获得。轻度和重度LC-FAOD小鼠模型±长期 术语DCA喂养将评估肝脏，心脏和肌肉功能以及对禁食的反应 压力。在这种情况下，SIRT5的消融可能会进一步增强过氧化物体功能。为了测试这一点，LC-FAOD 鼠标模型将被交叉到SIRT5 - / - 背景上。共同完成这些特定目标将形成 处理过氧化物体功能以治疗LC-FAOD的关键新知识。这些机制也是 与衰老，肾脏损伤，糖尿病，癌症和许多其他疾病有关 过氧功能和功能失调的脂质代谢。