Streptococcal secretion of pyruvate - a novel antioxidant strategy in the oral biofilm

链球菌分泌丙酮酸——口腔生物膜中的一种新型抗氧化策略

• 批准号: 10264935
• 负责人: Jens Kreth
• 金额: $ 19.25万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-16 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10264935
• 关键词: Acetates; Anaerobic Bacteria; Antioxidants; Apoptosis; Area; Biological Assay; Carbon; Carbon Dioxide; Cell Survival; Cell physiology; ChIP-seq; Clinical; Communities; Competitive Behavior; Dental caries; Development; Diffuse; Disease; Drug Metabolic Detoxication; Ecology; Eligibility Determination; Enzymes; Equilibrium; Eukaryotic Cell; Gene Expression Regulation; Genetic; Genetic Screening; Growth; Homeostasis; Hydrogen Peroxide; Knowledge; Membrane; Metabolic; Metabolism; Microbial Biofilms; Minor; Molecular; Mutagenesis; Oral; Oral cavity; Oral health; Oxidative Stress; Pathway interactions; Periodontal Diseases; Peroxidases; Play; Process; Production; Prokaryotic Cells; Pyruvate; Pyruvate Oxidase; Regulation; Reporting; Repression; Role; Streptococcus; Stress; Transcript; alkyl hydroperoxide reductase; antimicrobial drug; base; biological adaptation to stress; catalase; disorder prevention; dysbiosis; extracellular; genetic manipulation; improved; microbial; microbiome components; novel; oral biofilm; oral commensal; oral microbiome; oral streptococci; pathobiont; polymicrobial biofilm; public health relevance; transcriptomics

Project Summary Commensal streptococci play an important role in oral biofilm homeostasis. Disturbance of biofilm homeostasis leads to dysbiosis and eventually disease development, including caries and periodontal disease. Several oral streptococci are producing significant amounts of H2O2 able to inhibit susceptible pathobionts involved in disease development. However, the production of H2O2 does not always correlate with the antagonistic ability of the producer. Our group recently identified the mechanism behind this observation: oral streptococci secrete the central metabolite pyruvate as potent H2O2 scavenger. The mechanism of pyruvate secretion as oxidative stress response has been reported for eukaryotic cells, but has not been investigated in prokaryotes and little is known about prokaryotic pyruvate transport in general. Our observation raises key ecological questions about the role of commensal streptococci in the oral cavity: why do some streptococcal H2O2 producers secrete protective amounts of pyruvate and others do not? What is the genetic basis for this ability? What are the implications for oral health? The following specific aims are proposed to identify and characterize the pyruvate secretion mechanism and its genetic control in oral streptococci: Aim I: Identify the pyruvate secretion mechanism and its specific regulation. We will identify the genetic components required for pyruvate secretion by combining transposon mutagenesis with an established genetic screening protocol. The regulation of these genes will be compared between species. Aim I will determine how different streptococci modulate the H2O2/pyruvate balance that is critical for oral microbial ecology. Aim II: Characterize the regulatory network that determines the H2O2/pyruvate balance. We will perform ChIP-seq (CCR+/-) under conditions of low and high pyruvate secretion to identify the key regulatory components of this pathway. This will also serve as independent approach to identify the pyruvate secretion mechanism. An improved understanding of how the streptococcal community regulates its H2O2/pyruvate balance will help to define the molecular determinates of disease development and provide a novel target for disease prevention.

项目摘要 共生链球菌在口服生物膜稳态中起重要作用。生物膜的干扰 稳态导致营养不良，最终导致疾病的发展，包括龋齿和 牙周疾病。几种口服链球菌正在产生大量的H2O2 抑制参与疾病发展的易感病原体。但是，H2O2的生产 并不总是与生产者的拮抗能力相关。我们的小组最近 确定了该观察结果背后的机制：口服链球菌分泌中央代谢物 丙酮酸作为有效的H2O2清道夫。丙酮酸分泌的机制作为氧化应激 已经报道了真核细胞的反应，但尚未在原核生物中进行研究 一般来说，对脑核丙酮酸的运输知之甚少。我们的观察提出了关键 关于共生链球菌在口腔中的作用的生态问题：为什么有些 链球菌H2O2生产商分泌丙酮酸的保护量，而其他人则没有？是什么 这种能力的遗传基础？对口腔健康有什么影响？以下特定 提出了旨在识别和表征丙酮酸分泌机制及其遗传的目的 口服链球菌中的控制： 目的I：确定丙酮酸分泌机制及其特定调节。我们将确定 丙酮酸分泌所需的遗传成分通过结合转座子诱变 具有建立的基因筛查方案。这些基因的调节将被比较 物种之间。目的我将确定不同的链球菌如何调节H2O2/丙酮酸 平衡对口腔微生物生态学至关重要。 AIM II：表征决定H2O2/丙酮酸平衡的调节网络。我们 将在低和高丙酮酸分泌条件下执行CHIP-SEQ（CCR +/-）以识别 该途径的关键调节组件。这也将作为独立方法 确定丙酮酸分泌机制。 对链球菌群落如何调节其H2O2/丙酮酸的改进了解 平衡将有助于定义疾病发展的分子确定，并提供 预防疾病的新目标。