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-FAOD) 是一组异质性疾病，其特征为 无法分解线粒体中的长链脂肪酸来获取能量。过氧化物酶体脂肪酸 氧化（FAO）是线粒体FAO的平行途径，可用于减轻脂肪酸 LC-FAOD 患者体内的蓄积。然而，目前还没有任何药物手段可以刺激 人类过氧化物酶体FAO。开发新的过氧化物酶体刺激疗法的能力受到以下因素的限制 关于调节过氧化物酶体FAO酶活性的因素的知识差距。在此，建议 Sirtuin-5 (Sirt5) 和赖氨酸琥珀酰化（Sirt5 逆转的翻译后修饰）代表了 操纵过氧化物酶体功能的新机制。当老鼠被喂食一类称为 二羧酸（DCA），赖氨酸琥珀酰化在过氧化物酶体蛋白上积累。进一步的初步数据 表明赖氨酸琥珀酰化增加过氧化物酶体功能。 Sirt5 逆转这些影响的能力 仍不清楚。这项资助的中心假设是，喂养 DCA 可以改善疾病病理学 通过驱动蛋白质琥珀酰化和过氧化物酶体激活的线粒体 LC-FAOD 小鼠模型。这是 得到初步数据的支持，其中 7 天的 DCA 喂养改善了 LC-FAOD 中的肌肉功能 鼠标模型。中心假设将在三个具体目标中得到充分探讨。 1) 目标 1 将量化 DCA 喂养和 Sirt5 消融对过氧化物酶体酰基组的影响。 Sirt5 部分本地化 过氧化物酶体，但其活性尚未得到表征。定量的位点水平赖氨酸“酰基组”± DCA 将对肝脏、肌肉和心脏（LC-FAOD 中受影响的关键组织）以及所有 Sirt5 的喂养进行编译 确定的目标站点。 2) 目标 2 是描绘 DCA 喂养 ± Sirt5 消融对功能的影响 过氧化物酶体酶和途径通量。这将使用纯化的重组蛋白、培养细胞来完成 操纵过氧化物酶体中的 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 过氧化物酶体。 3) 目标 3 将测试 DCA 喂养作为 LC-FAOD 小鼠模型的治疗策略。这是 提出 DCA 将分布到肝脏以外的周围器官，通过 部分链缩短和过氧化物酶体功能获得。轻度和重度 LC-FAOD 小鼠模型 ± 长- 将评估足月 DCA 喂养的肝脏、心脏和肌肉功能以及对禁食的反应 压力。在这种情况下消除 Sirt5 可能会进一步增强过氧化物酶体功能。为了测试这一点，LC-FAOD 小鼠模型将交叉到 Sirt5-/- 背景上。这些具体目标的完成将共同形成 操纵过氧化物酶体功能治疗 LC-FAOD 的关键新知识。这些机制也 与衰老、肾损伤、糖尿病、癌症和许多其他以受损为特征的疾病有关 过氧化物酶体功能和脂质代谢功能失调。