Molecular determinants of oxidative stress in Salmonella pathogenesis

沙门氏菌发病机制中氧化应激的分子决定因素

基本信息

批准号：
10468719
负责人：
Andres Vazquez-Torres
金额：
$ 42.82万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-09-24 至 2024-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10468719
关键词：
ATP Synthesis Pathway Acetates Aging Animal Model Antibiotic Therapy Antioxidants Attenuated Bacteria Cancer Biology Carbon Cell membrane Cell model Cells Cessation of life Communicable Diseases Cysteine Cytochrome c Reductase DNA Double Strand Break Data Development Diabetes Mellitus Diarrhea Disease Disulfides Electron Transport Enzymes Equilibrium Face Fermentation Future Genes Glutathione Glycolysis HIV Host Defense Human Hydrogen Peroxide Individual Infection Investigation Knowledge Lead Learning Lesion Libraries Life Light Malignant Neoplasms Mass Spectrum Analysis Mediating Membrane Metabolic Metabolism Metals Modeling Molecular Mus Mutation NADH NADH dehydrogenase (ubiquinone)NADP NADPH Oxidase Oxidases Oxidation-Reduction Oxidative Stress Oxidoreductase Pathogenesis Pathogenicity Pathway interactions Pentosephosphate Pathway Periplasmic Proteins Persons Phagocytes Pharmaceutical Preparations Phosphoglycerate Mutase Phosphotransferases Play Process Proteins Reactive Oxygen Species Research Resistance Role Salmonella Salmonella enterica Salmonella infections Succinates TXN gene Testing Typhoid Fever Virulent antimicrobial cell envelope cofactor combat deep sequencing disulfide bond env Gene Products fighting genotoxicity in vivo innovation insight macrophage metabolomics microbial microorganism mutant novel oxidation oxidative damage pathogenic bacteria periplasm respiratory response single cell analysis

项目摘要

PROJECT SUMMARY/ ABSTRACT We have made the unexpected discovery that fermentation contributes to Salmonella's antioxidant defenses, an observation with wide ranging implications for defense against oxidative stress, well beyond bacteria. Infectious diarrhea afflicts a billion people a year and is responsible for 4% of all human deaths. Many of these infections are caused by one of the 2,500 serovars of nontyphoidal Salmonella enterica, which can inflict life- threatening systemic complications in the very young, very old, and HIV-infected individuals. Oxidative stress emanating from the enzymatic activity of the NADPH oxidase is one of the most potent host defenses Salmonella face during their associations with professional phagocytic cells. Genotoxicity that ensues from Fenton-mediated DNA double strand breaks together with cellular malfunctions associated with the oxidation of cysteine residues and metal cofactors in proteins constitute the paradigm for how oxidative stress kills Salmonella and numerous other bacterial pathogens. However, despite their central role in resistance to salmonellosis, the relative importance of the various mechanisms by which reactive oxygen species inflict anti- Salmonella activity is poorly understood. Our understanding of the adaptive responses that protect Salmonella against oxidative stress is similarly superficial. A screen of mutants in response to hydrogen peroxide, one of the most important effectors of the NADPH oxidase, revealed previously unanticipated roles for central metabolism and the electron transport chain in the hydrogen peroxide-mediated killing of Salmonella. Our preliminary data suggest oxidation of cell envelope proteins and plasmolysis-like lesions (i.e., separation of inner and outer membranes) as previously unsuspected steps in the killing of Salmonella during oxidative stress. These investigations offer an innovative framework for how NADPH oxidase inflicts potent anti-Salmonella activity during the innate response of macrophages. We will test the hypothesis that fermentation contributes to Salmonella's antioxidant defenses by assisting with ATP synthesis, balancing redox, and enabling disulfide bond formation in periplasmic proteins, thereby protecting the cell envelope from lethal damage by reactive oxygen species generated by the NADPH oxidase. Specifically, we will characterize the role fermentation plays in the antioxidant defenses of typhoidal and nontyphoidal Salmonella, elucidate the mechanism by which oxidative stress promotes fermentation, and determine how intracellular Salmonella is killed by the NADPH oxidase. Not only will this knowledge illuminate key aspects of Salmonella pathogenesis, but should also provide insights into unique and shared antioxidant defenses of various Salmonella serovars. Our research could ultimately have an impact on fields as diverse as microbial pathogenesis, aging, diabetes, or cancer biology for which oxidative stress is an intrinsic component. Drugs that specifically inhibit bacterial glycolytic enzymes and fermentative pathways may lead to the development of novel antibiotic treatments. Future Salmonella countermeasures could also explore strategies that increase respiratory activity as a means to foment oxidative killing.

项目概要/摘要我们意外地发现发酵有助于沙门氏菌的抗氧化防御，这一观察结果对于防御氧化应激具有广泛的影响，其影响远远超出了细菌的范围。传染性腹泻每年影响 10 亿人，占人类死亡人数的 4%。其中许多感染是由 2,500 种非伤寒沙门氏菌血清型中的一种引起的，可造成生命威胁年幼、年老和艾滋病毒感染者的全身并发症。氧化应激源自 NADPH 氧化酶的酶活性是最有效的宿主防御之一沙门氏菌在与专业吞噬细胞结合时面临的问题。产生的遗传毒性 Fenton 介导的 DNA 双链断裂以及与氧化相关的细胞功能障碍蛋白质中的半胱氨酸残基和金属辅助因子构成了氧化应激如何导致死亡的范例沙门氏菌和许多其他细菌病原体。然而，尽管它们在抵抗运动中发挥着核心作用沙门氏菌病，活性氧造成抗沙门氏菌病的各种机制的相对重要性人们对沙门氏菌的活性知之甚少。我们对保护沙门氏菌的适应性反应的理解对抗氧化应激同样是肤浅的。筛选响应过氧化氢的突变体，过氧化氢是 NADPH 氧化酶最重要的效应子，揭示了之前未预料到的中枢代谢作用以及过氧化氢介导的沙门氏菌杀灭过程中的电子传递链。我们的初步数据表明细胞包膜蛋白的氧化和质壁分离样病变（即内部和外部的分离）膜）作为氧化应激期间杀死沙门氏菌的先前未曾怀疑的步骤。这些研究为 NADPH 氧化酶如何产生有效的抗沙门氏菌活性提供了一个创新框架在巨噬细胞的先天反应期间。我们将检验发酵有助于的假设沙门氏菌通过协助 ATP 合成、平衡氧化还原和形成二硫键来进行抗氧化防御周质蛋白中的形成，从而保护细胞膜免受活性氧的致命损伤由 NADPH 氧化酶产生的物质。具体来说，我们将描述发酵在伤寒和非伤寒沙门氏菌的抗氧化防御，阐明氧化机制应激促进发酵，并确定 NADPH 氧化酶如何杀死细胞内沙门氏菌。不是这些知识不仅可以阐明沙门氏菌发病机制的关键方面，而且还应该提供以下见解：各种沙门氏菌血清型独特且共有的抗氧化防御。我们的研究最终可能会有一个对微生物发病机制、衰老、糖尿病或癌症生物学等各个领域的影响压力是一个内在的组成部分。特异性抑制细菌糖酵解酶和发酵酶的药物途径可能会导致新型抗生素治疗的发展。未来的沙门氏菌对策可能还探索增加呼吸活动的策略，作为引发氧化杀伤的手段。

项目成果

期刊论文数量（15）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Salmonella enterica Serovar Typhimurium 14028s Genomic Regions Required for Colonization of Lettuce Leaves.

肠沙门氏菌鼠伤寒血清型 14028s 生菜叶定植所需的基因组区域。

DOI：
发表时间：
2020
期刊：
影响因子：
0
作者：
Montano, Jeanine;Rossidivito, Gabrielle;Torreano, Joseph;Porwollik, Steffen;Sela Saldinger, Shlomo;McClelland, Michael;Melotto, Maeli
通讯作者：
Melotto, Maeli

Identification of Novel Genes Mediating Survival of Salmonella on Low-Moisture Foods via Transposon Sequencing Analysis.

通过转座子测序分析鉴定介导低水分食品中沙门氏菌存活的新基因。

DOI：
发表时间：
2020
期刊：
影响因子：
0
作者：
Jayeola, Victor;McClelland, Michael;Porwollik, Steffen;Chu, Weiping;Farber, Jeffrey;Kathariou, Sophia
通讯作者：
Kathariou, Sophia

Oxidative stress activates transcription of Salmonella pathogenicity island-2 genes in macrophages.

氧化应激激活巨噬细胞中沙门氏菌致病性 island-2 基因的转录。