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 共生链球菌在口腔生物膜动态平衡中起着重要作用。生物膜的干扰 动态平衡导致生物失调，最终导致疾病发展，包括龋齿和 牙周病。几种口腔链球菌产生大量的过氧化氢，能够 抑制参与疾病发展的易感病原体。然而，过氧化氢的产生 并不总是与制作人的对抗能力相关。我们的小组最近 确定了这一观察背后的机制：口腔链球菌分泌中枢代谢物 丙酮酸是一种有效的过氧化氢清除剂。丙酮酸分泌作为氧化应激的机制 已经报道了真核细胞的反应，但还没有在原核生物和 人们对原核生物丙酮酸转运知之甚少。我们的观察提出了关键 口腔共生链球菌作用的生态学问题：为什么会有一些 链球菌产过氧化氢能分泌保护量的丙酮酸，而其他产生者不能吗？是什么 这种能力的遗传基础是什么？这对口腔健康有什么影响？以下是具体的 目的是鉴定和表征丙酮酸的分泌机制及其遗传 口腔链球菌的控制： 目的I：明确丙酮酸的分泌机制及其特异性调节。我们将确定 转座子联合诱变分泌丙酮酸所需的遗传成分 有一套既定的基因筛查方案。我们将比较这些基因的调控情况。 在物种之间。目的研究不同链球菌对过氧化氢/丙酮酸的调节作用。 对口腔微生物生态至关重要的平衡。 目的II：描述决定过氧化氢/丙酮酸平衡的调控网络。我们 将在低丙酮酸分泌和高丙酮酸分泌条件下进行CHIP-SEQ(Ccr+/-)鉴定 这一途径的关键调控成分。这也将作为独立的方法来实现 确定丙酮酸的分泌机制。 更好地理解链球菌群落如何调节其过氧化氢/丙酮酸 BALANCE将有助于定义疾病发展的分子决定因素并提供 疾病预防的新目标。