Metabolic basis of the NADPH-independent disulfide reductase system in mouse liver

小鼠肝脏中不依赖 NADPH 的二硫键还原酶系统的代谢基础

• 批准号: 10005545
• 负责人: Gina Marie DeNicola
• 金额: $ 46.39万
• 依托单位: MONTANA STATE UNIVERSITY - BOZEMAN
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-12 至 2020-09-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10005545
• 关键词: Active Sites; Adenosine; Anabolism; Biliary; Biology; Bypass; Carbon; Catabolism; Cells; Coenzyme A; Consumption; Creatine; Cultured Cells; Cysteine; DNA; DNA Methylation; Dependence; Disease; Disulfides; Enzymes; Excretory function; Folic Acid; Future; Generations; Glutamates; Glutathione; Glutathione Disulfide; Glutathione Reductase; Glycine; Health; Hepatic; Hepatocyte; Homeostasis; Inflammatory; Investigation; Knowledge; Lead; Lecithin; Lipids; Liver; Malignant Neoplasms; Mammalian Cell; Metabolic; Metabolic Pathway; Metabolism; Methionine; Methylation; Methyltransferase; Microbe; Modeling; Mus; NADP; Natural regeneration; Nerve Degeneration; Normal Cell; Nutrient; Organoids; Outcome; Oxidants; Oxidation-Reduction; Oxidative Stress; Oxidoreductase; Pathogenicity; Pathway interactions; Patients; Peripheral; Physiological; Positioning Attribute; Predisposition; Process; Production; Proteins; RNA; Reaction; Regulation; Resources; Role; Route; S-Adenosylhomocysteine; Serine; Source; Stress; Sulfur; Sulfur Amino Acids; Sulfur Metabolism Pathway; System; Taurine; Testing; Tissues; Toxin; Translations; Vision; Work; amino acid metabolism; base; carbon skeleton; clinical application; combat; histone methylation; liver metabolism; metabolomics; methyl group; mouse model; novel therapeutic intervention; oxidation; oxidative damage; pathogen; prevent; reaction rate; regenerative; response; therapeutic target; thioredoxin reductase; thioredoxin reductase 1; uptake

What is known: Disulfide reduction-fueled enzymes s!upport homeostasis and combat oxidative damage that contributes to neurodegeneration, inflammatory diseases, and cancer. NADPH provides the reducing power for most anabolic and cytoprotective reduction reactions, yet only two enzymes can use NADPH to reduce cytosolic disulfides: thioredoxin reductase-1 (TrxR1) and glutathione reductase (Gsr) 1. Both TrxR1 and Gsr have active sites that are dominantly inhibited by electrophilic toxins and oxidants 2, 3. In Co-PI Schmidt's lab, mice with TrxR1/Gsr-null livers uncovered unexpected robustness in the disulfide reductase systems, including an NADPH-independent pathway that uses catabolism of methionine (Met) to sustain redox homeostasis 4. Importantly, this pathway is also thought to sustain normal cells under oxidative or electrophilic stress 5. Met and Cys are the 2 sulfur (S)-amino acids found in proteins, but S-containing molecules synthesized from Met or Cys, including S-adenosyl-Met (SAM), glutathione (GSH), CoA, and others, are also important in redox, detox, energetics, biosynthesis, regulation, and other processes. Co-PI DeNicola has been studying the roles of altered S-amino acid metabolism in sustaining some cancers 6. These studies are revealing how some cancers use altered S-amino acid redox metabolism, which could uncover targetable cancer-specific susceptibilities. Unresolved questions: It remains unknown how other metabolic activities, including those that directly utilize Met or Cys, as well as more peripheral systems that either (i) supply resources to these pathways; (ii) depend upon these pathways; or (iii) might, in some conditions, compete with these pathways for substrates, are realigned to help cells survive stress. We hypothesize that conversion to Met-dependence involves realignment of diverse metabolic pathways. A better understanding of these processes will uncover processes that can be therapeutically targeted to either specifically increase the robustness of critical cells under oxidative or toxic stress, or specifically increase the vulnerability of pathogenic cells in cancer or inflammatory diseases. What is proposed: In this collaborative project, we will define the metabolic pathway realignments that occur when hepatocytes switch from NADPH-dependent to -independent disulfide reduction. We propose 3 Specific Aims: Aim 1, Define how NADPH- versus Met-fueled disulfide reductase homeostasis influences S-metabolism prioritization. Aim 2, Define how re-wiring of serine metabolism supports Met-fueled disulfide reductase homeostasis. Aim 3, Test whether Met-dependent survival increases the activity and dependence on liver methyltransferases. Anticipated outcomes, value: This project will help us understand how global shifts in hepatic metabolism occurs in response to severe oxidative or electrophilic stress in liver, and how this helps sustain health.

什么是已知的：二硫化物还原燃料酶！支持体内平衡和对抗氧化损伤， 导致神经退化、炎性疾病和癌症。NADPH提供还原力， 大多数合成代谢和细胞保护还原反应，但只有两种酶可以使用NADPH来还原 胞质二硫化物：硫氧还蛋白还原酶-1（TrxR 1）和谷胱甘肽还原酶（Gsr）1。TrxR 1和Gsr 有活性位点，主要是抑制亲电毒素和氧化剂2，3。在合作PI施密特的实验室里， TrxR 1/Gsr缺失肝脏的小鼠在二硫还原酶系统中发现了意想不到的稳健性，包括 一种NADPH非依赖性途径，使用蛋氨酸（Met）的催化剂来维持氧化还原稳态4。 重要的是，这种途径也被认为是在氧化或亲电应激下维持正常细胞5。遇到 和Cys是在蛋白质中发现的2种硫（S）-氨基酸，但是从Met或Cys合成的含S分子是 Cys，包括S-腺苷-Met（SAM）、谷胱甘肽（GSH）、CoA等，在氧化还原、排毒、 能量学、生物合成、调节和其他过程。Co-PI DeNicola一直在研究 改变S-氨基酸代谢在维持某些癌症6.这些研究揭示了一些癌症 使用改变的S-氨基酸氧化还原代谢，这可以揭示靶向癌症特异性的敏感性。 未解决的问题：目前还不清楚其他代谢活动，包括那些直接利用 Met或Cys，以及更多的外周系统，其（i）为这些途径提供资源;（ii）依赖于 或（iii）在某些条件下可能与这些途径竞争底物， 帮助细胞在压力下存活我们假设向大都会依赖的转化涉及 多种代谢途径的重新排列。更好地理解这些过程将揭示过程 其可以在治疗上靶向于特异性地增加关键细胞在氧化应激下的鲁棒性， 或毒性应激，或特别是增加癌症或炎性疾病中致病细胞的脆弱性。 建议内容：在这个合作项目中，我们将定义发生的代谢途径重组 当肝细胞从依赖NADPH的二硫键还原转变为不依赖NADPH的二硫键还原时。我们提出3个具体的 目的：目的1，定义NADPH与Met燃料二硫还原酶稳态如何影响S代谢 优先化。目的2，确定丝氨酸代谢的重新布线如何支持Met-燃料二硫键还原酶 体内平衡目的3、检测Met依赖性存活是否增加了肝细胞的活性和依赖性 甲基转移酶 预期结果，价值：该项目将帮助我们了解肝脏代谢的全球变化 发生在对肝脏严重氧化或亲电应激的反应中，以及这如何有助于维持健康。