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（由申请人提供）：传染病是对人类健康的全球性威胁。世界卫生组织指出，迫切需要制定新的抗菌策略，限制这些威胁生命的病原体的影响。这些病原体包括医院感染的主要病原体，例如，金黄色葡萄球菌，和一种主要的呼吸道病原体，负责社区获得性肺炎和发病率在世界范围内，肺炎链球菌。每一种药物都变得越来越耐多药，使治疗方案变得严重复杂。在这个提议中，我们试图整合我们的细菌过渡金属（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。我们有长期的兴趣在转录抑制因子，最近，金属运输蛋白，使细菌适应宿主介导的“重塑”过渡金属的可用性。我们已经在M.结核S.金黄色葡萄球菌和pneumoniae，并将我们对这些系统的定量研究框架为“变构无机开关”，其协调细胞中的金属稳态和对毒性的抗性。这些研究直接导致了我们预期的对S中活性硫物质（RSS）和潜在的活性氮氧化物物质（硝酰基; HNO）的新型高度特异性调节反应的发现和正在进行的阐明。金黄色。我们假设这种反应影响了S.金黄色葡萄球菌和其它病原体调节生物膜的定殖和一氧化氮（NO）介导的分散（生物膜动力学）以及对抗生素诱导的氧化应激的抗性。未来的研究将在三个方面进行：1）生物学特性和结构/动力学研究，使用最先进的甲基特异性NMR弛豫实验，新的变构系统参与转录的金属调控和RSS和RNOS的调控; 2）获得新的分子水平上的见解在S.本发明的目的在于：（a）研究鲍曼不动杆菌中由宿主介导的“营养免疫”诱导的对极端锌限制的适应机制，以及（b）使用蛋白质组半胱氨酸巯基氧化修饰的基于转录组学、质谱分析和靶向代谢物分析方法来全面探测对硫化物和RNOS应激的细胞应答，目的在于鉴定该过程中的新参与者和机制。我们的多学科方法，无缝地跨越生物物理化学微生物生理学，提高了我们对过渡金属稳态的基本特征的理解的可能性，这些特征与毒性和对重要人类病原体中RSS/RNOS的完全未探索的细胞反应有关。