The molecular mechanism linking respiratory NADH oxidation and virulence in Staphylococcus aureus

金黄色葡萄球菌呼吸NADH氧化与毒力的分子机制

• 批准号: 10388212
• 负责人: ROBERT B GENNIS
• 金额: $ 51.92万
• 依托单位: UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-23 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10388212
• 关键词: Aerobic; Affect; Anaerobic Bacteria; Animals; Bacteria; Biochemical; Biochemistry; Bioenergetics; Cell physiology; Cells; Cytochrome c Reductase; Dangerousness; Data; Development; Disease; Elements; Environment; Enzymes; Evolution; Gene Expression Profiling; Generations; Genetic; Genus staphylococcus; Goals; Growth; Human body; In Vitro; Infection; Kinetics; Knock-out; Knowledge; Lead; Link; Longitudinal Studies; Membrane; Membrane Proteins; Metabolic; Metabolic Pathway; Metabolism; Methods; Microbial Biofilms; Molecular; Monitor; Morbidity - disease rate; Multi-Drug Resistance; NADH; Nebraska; Nitrates; Organ; Organism; Oxidation-Reduction; Oxygen; Pathogenesis; Pattern; Process; Production; Proteins; Proteomics; Regulation; Respiration; Respiratory Chain; Role; Signal Transduction; Signaling Molecule; Site; Staphylococcus aureus; Staphylococcus aureus infection; System; Techniques; Technology; Testing; United States; Universities; Variant; Virulence; Virulence Factors; Vitamin K 2; alpha Toxin; cost; detection of nutrient; differential expression; flexibility; interdisciplinary approach; metabolomics; microfluidic technology; mortality; new therapeutic target; oxidation; pathogen; pathogenic bacteria; promoter; respiratory; respiratory enzyme; sensor histidine kinase; therapeutically effective

ABSTRACT Staphylococcus aureus infections are a major cause of morbidity and mortality in the United States and across the globe. This is largely due to the evolution of multidrug-resistance and the ability of the bacterium to adapt its metabolism and bioenergetics to infect nearly every site of the human body. Thus, there is a significant need for the development of effective therapeutics against this organism. There are several critical gaps in our knowledge of how metabolic pathways used by S. aureus in different environments influence this pathogen virulence in vitro and inside the host. Therefore, our long-term goal is to elucidate how S. aureus receives signals from the environment in the host (e.g. oxygen concentration, nutrients), senses its own redox poise and energy status, and triggers metabolic changes, including the production of virulence factors. Our previous studies identified two respiratory enzymes in S. aureus called type 2 NADH dehydrogenases (NDH-2s: NdhC and NdhF) and revealed their importance for animal infection and organ colonization, and the production of virulence factors and biofilm formation in vitro. These results lead to our central hypothesis that the NADH-dependent respiratory chain is primarily responsible for controlling the NADH/NAD+ and MQH2/MQ (menaquinol/menaquinone) pools that are used by the cell to monitor its redox status and which we propose are major elements regulating virulence via specific global regulators. Guided by strong preliminary data, we propose to pursue three Specific Aims: (1) Determine the metabolic pathways utilized both in the presence and absence of each of the two NADH dehydrogenase enzymes, and the molecular mechanisms by which these enzymes modulate the production of α-toxin; (2) Determine why the presence of both NADH dehydrogenase enzymes is important for biofilm formation; (3) Determine if menaquinol is the signaling molecule that directly induces SrrB and SaeS autokinase activity in the SaeRS and SrrAB two-component systems, which are both critical for the regulation of virulence and biofilm formation. To accomplish these Aims, we have assembled a powerful team to employ a multidisciplinary approach that combines metabolomics, proteomics, genetics, microfluidics technology and biochemistry. Collectively, our proposed studies will have a broad impact on the field by uncovering the role of the respiratory chain in connecting environment signals with the intracellular redox poise that regulates S. aureus virulence. In the long term, these studies may reveal novel therapeutic targets to treat S. aureus-related diseases.

抽象的 金黄色葡萄球菌感染是美国及全世界发病率和死亡率的主要原因 地球仪。这很大程度上是由于多重耐药性的进化和细菌的适应能力 它的新陈代谢和生物能几乎感染人体的每个部位。因此，有一个显着的 需要开发针对这种生物体的有效疗法。我们的工作中存在几个关键差距 了解金黄色葡萄球菌在不同环境中使用的代谢途径如何影响该病原体 体外和宿主体内的毒力。因此，我们的长期目标是阐明金黄色葡萄球菌如何接受 来自宿主环境的信号（例如氧气浓度、营养物质），感知自身的氧化还原平衡并 能量状态，并引发代谢变化，包括毒力因子的产生。 我们之前的研究在金黄色葡萄球菌中发现了两种呼吸酶，称为 2 型 NADH 脱氢酶 （NDH-2s：NdhC 和 NdhF）并揭示了它们对动物感染和器官定植的重要性，以及 毒力因子的产生和体外生物膜的形成。这些结果引出了我们的中心假设： NADH 依赖性呼吸链主要负责控制 NADH/NAD+ 和 MQH2/MQ 我们建议细胞使用（甲基萘醌/甲基萘醌）池来监测其氧化还原状态 是通过特定的全球监管机构调节毒力的主要因素。在强有力的初步数据的指导下，我们 建议追求三个具体目标：（1）确定存在时所利用的代谢途径 以及两种 NADH 脱氢酶的缺失，以及其分子机制 这些酶调节 α-毒素的产生； (2)确定为什么同时存在NADH 脱氢酶对于生物膜的形成很重要； (3) 确定甲萘醌是否是信号传导 在 SaeRS 和 SrrAB 双组分中直接诱导 SrrB 和 SaeS 自激酶活性的分子 系统，这对于毒力和生物膜形成的调节都至关重要。为了实现这些目标， 我们组建了一支强大的团队，采用结合代谢组学的多学科方法， 蛋白质组学、遗传学、微流体技术和生物化学。 总的来说，我们提出的研究将通过揭示该领域的作用对该领域产生广泛的影响。 连接环境信号与调节金黄色葡萄球菌的细胞内氧化还原平衡的呼吸链 毒力。从长远来看，这些研究可能会揭示治疗金黄色葡萄球菌相关的新治疗靶点 疾病。