Interplay of Transition Metal Homeostasis and Reactive Sulfur Species in Bacterial Pathogens

细菌病原体中过渡金属稳态与活性硫的相互作用

• 批准号: 9071683
• 负责人: DAVID P. GIEDROC
• 金额: $ 57.92万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9071683
• 关键词: Acinetobacter baumannii; Anti-Bacterial Agents; Antibiotic Resistance; Area; Bacteria; Biological; Cells; Communicable Diseases; Communities; Copper; Cysteine; Development; Future; Goals; Health; Homeostasis; Human; Hydrogen Sulfide; Immunity; Investigation; Life; Link; Manganese; Mass Spectrum Analysis; Mediating; Metals; Microbial Biofilms; Microbial Physiology; Molecular; Morbidity - disease rate; Multi-Drug Resistance; Mycobacterium tuberculosis; Nitric Oxide; Nitrogen Oxides; Nosocomial Infections; Nutrient; Nutritional; Organism; Oxidative Stress; Pneumonia; Probability; Process; Proteome; Relaxation; Resistance; Site-Directed Mutagenesis; Staphylococcus aureus; Streptococcus pneumoniae; Stress; Sulfhydryl Compounds; Sulfides; Sulfur; Sulfur Metabolism Pathway; System; Toxic effect; Transcription Repressor/Corepressor; Transcriptional Regulation; Transition Elements; Vancomycin resistant enterococcus; Virulence; World Health Organization; Zinc; antimicrobial; base; biophysical chemistry; insight; interdisciplinary approach; interest; methicillin resistant Staphylococcus aureus; nitroxyl; novel; pathogen; protein transport; public health relevance; research study; respiratory; response; transcriptomics

 DESCRIPTION (provided by applicant): Infectious disease is a global threat to human health. The World Health Organization notes a pressing need to develop novel antimicrobial strategies that limit the impact of these life-threatening pathogens. These pathogens include the major causative agents of nosocomial infections, e.g., Staphylococcus aureus, and a major respiratory pathogen responsible for community-acquired pneumonia and morbidity world-wide, Streptococcus pneumoniae. Each is becoming increasingly multidrug-resistant severely complicating treatment options. In this proposal, we seek to integrate our fundamental studies of bacterial transition metal (manganese, copper and zinc) homeostasis, sulfur metabolism and sulfide homeostasis to accelerate the pace of discovery of novel antibacterial strategies. We have long-standing interests in the transcriptional repressors and more recently, metal trafficking proteins, that allow a bacterium to adapt to host-mediated "remodeling" of transition metal availability. We've discovered and structurally characterized new players in this process in M. tuberculosis, S. aureus and S. pneumoniae and have framed our quantitative investigations of these systems as "allosteric inorganic switches" that orchestrate metal homeostasis and resistance to toxicity in cells. These studies led directly to the discovery and ongoing elucidatio of what we anticipate represents a novel, highly specific regulatory response to reactive sulfur species (RSS) and potentially, reactive nitrogen oxide species (nitroxyl; HNO) in S. aureus. We hypothesize that this response impacts the ability of S. aureus and other pathogens to regulate colonization and nitric oxide (NO)-mediated dispersal of biofilms (biofilm dynamics) and resistance to antibiotic-induced oxidative stress. Future studies will be carried out in three general areas: 1) biological characterization and structural/dynamics studies, using state-of-the-art methyl-specific NMR relaxation experiments, of new allosteric systems involved in metalloregulation of transcription and regulation of RSS and RNOS; 2) obtaining new molecular-level insights into copper resistance and manganese homeostasis in S. pneumoniae, and mechanisms of adaptation to extreme zinc limitation induced by host-mediated "nutritional immunity" in Acinetobacter baumannii, and 3) holistically probe the cellular response to sulfide and RNOS stress using transcriptomic, mass spectrometry-based profiling of proteome cysteine thiol oxidative modifications, and targeted metabolite profiling approaches, with the goal to identity new players and mechanisms in this process. Our multidisciplinary approach, which seamlessly spans biophysical chemistry to microbial physiology, enhances the probability of transforming our understanding of fundamental features of transition metal homeostasis linked to virulence and a completely unexplored cellular response to RSS/RNOS in important human pathogens.

 描述(申请人提供)：传染病是对人类健康的全球性威胁。世界卫生组织指出，迫切需要开发新的抗菌素战略，以限制这些威胁生命的病原体的影响。这些病原体包括院内感染的主要病原体，如金黄色葡萄球菌，以及导致社区获得性肺炎和全球发病率的主要呼吸道病原体-肺炎链球菌。每一种都变得越来越多药耐药，使治疗选择严重复杂化。在这项建议中，我们寻求整合我们对细菌过渡金属(锰、铜和锌)稳态、硫代谢和硫化物稳态的基础研究，以加快发现新的抗菌策略的步伐。长期以来，我们一直对转录抑制因子和最近的金属运输蛋白感兴趣，这些蛋白质允许细菌适应宿主介导的过渡金属可获得性的“重塑”。我们已经在结核分枝杆菌、金黄色葡萄球菌和肺炎链球菌中发现了这一过程中的新角色，并对其进行了结构表征，并将我们对这些系统的定量研究框定为“变构无机开关”，它协调细胞中的金属动态平衡和抗毒性。这些研究直接导致了金黄色葡萄球菌对活性硫物种(RSS)和潜在的活性氮氧化物物种(Nitxyl；HNO)的一种新的、高度特异的调控反应的发现和正在进行的阐明。我们假设这种反应影响金黄色葡萄球菌和其他病原体调节生物膜的定植和一氧化氮(NO)介导的扩散的能力(生物膜动力学)和对抗生素诱导的氧化应激的抵抗力。未来的研究将主要在三个方面进行：1)利用最先进的甲基核磁共振弛豫实验，对参与转录金属调控和RSS和RNO调控的新变构系统的生物学特性和结构/动力学进行研究；2)在分子水平上深入了解肺炎链球菌对铜的抗性和锰的动态平衡，以及鲍曼不动杆菌对宿主介导的“营养免疫”所诱导的极端锌限制的适应机制；3)利用蛋白质组半胱氨酸硫醇氧化修饰的转录、质谱学和靶向代谢物分析方法，从整体上探索细胞对硫化物和RNO胁迫的响应，目的是确定这一过程中的新角色和新机制。我们的多学科方法无缝地跨越了生物物理化学和微生物生理学，提高了我们对过渡金属动态平衡的基本特征的理解与毒力有关的可能性，以及在重要的人类病原体中完全未知的细胞对RSS/RNO的反应。