Environmental regulation of gene expression dissected by microfluidics

微流体剖析基因表达的环境调控

• 批准号: 8786073
• 负责人: Robert A Burne
• 金额: $ 37.5万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-12-13 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8786073
• 关键词: Acids; Adhesions; Affect; Bacteria; Behavior; Behavior Control; Carbohydrates; Catabolism; Cells; Chemicals; Communicable Diseases; Communities; Competence; Complex; Cues; DNA; Data; Dental Enamel; Dental Plaque; Dental caries; Dietary Carbohydrates; Diffusion; Environment; Equilibrium; Feedback; Fermentation; Gene Activation; Gene Expression; Gene Expression Regulation; Gene Fusion; Genes; Genetic; Goals; Health; Human; In Vitro; Individual; Laser Scanning Confocal Microscopy; Light; Link; Location; Measures; Methods; Microbial Biofilms; Microfluidic Microchips; Microfluidics; Modeling; Mouth Diseases; Nature; Nutrient; Oral health; Organism; Output; Oxygen; Pattern; Peptide Signal Sequences; Peptide Transport; Peptides; Population; Process; Property; Reading; Regulation; Regulon; Reporter Genes; Research; Role; Shapes; Signal Pathway; Signal Transduction; Streptococcus mutans; Structure; Study models; System; Testing; Tissues; Tooth Diseases; Variant; Virulence; extracellular; improved; intercellular communication; novel; oral biofilm; pathogen; response; small molecule; success; trait

DESCRIPTION (provided by applicant): The human dental plaque biofilm is a physically and chemically complex environment that is inhabited by a many bacterial species, including Streptococcus mutans, which is regarded as the primary etiological cause of human dental caries. S. mutans has a number of behaviors that give rise to its virulence, and it regulates and activates these behaviors through the use of chemical cues received from its environment. However, the local environment of S. mutans at different locations within a biofilm may be chemically and physically different, subject to substantial variation in pH, oxygen concentration and nutrient availability, as well as different balances of colonizing species and different concentrations of the small molecules that allow the bacteria to communicate and regulate virulence behaviors. This project seeks to determine how this diversity of microenvironments affects the centrally important S. mutans virulence behavior known as genetic competence. Competence is the ability to take up extracellular DNA, and the genetic network that regulates competence in S. mutans is closely intertwined with the mechanisms that regulate virtually every other cariogenic trait of the organism. The competence genes are extremely sensitive to environmental conditions and to the nature of the chemical signals received. Expression of competence genes across a population of cells can be uniform or can involve activation of only a subset of the bacteria. Therefore a broad scientific goal is to understand how S. mutans processes or interprets environmental signals to regulate competence and other virulence behaviors, how microenvironments in the biofilm affect this processing, and how competence genes are activated at the cell-to-cell level throughout an oral biofilm. This project will focus o identifying and understanding the genetic "switches" that control S. mutans competence, exploring how pH, oxygen concentration, and carbohydrate availability affect the regulation of competence by peptide signals, and studying and modeling the ways that competence is regulated by peptide signals inside an S. mutans biofilm. The project will accomplish these goals through a novel microfluidic, single-cell approach. This method allows multiple, well-defined environmental inputs to be supplied to subpopulations of S. mutans cells while the profile of competence gene activation across those subpopulations is measured and modeled quantitatively. The project will yield detailed information about how S. mutans competence is spatially distributed in an oral biofilm and what kinds of chemical conditions trigger this and related virulence behaviors. Success in achieving these objectives will advance research in human oral health by improving the understanding of how Streptococcus mutans causes dental disease.

描述（申请人提供）：人类牙菌斑生物膜是一个物理和化学复杂的环境，栖息着许多细菌种类，包括变形链球菌，它被认为是人类龋齿的主要原因。变形链球菌有许多导致其毒力的行为，并且它通过使用从环境中接收的化学信号来调节和激活这些行为。然而，生物膜内不同位置的变形链球菌的局部环境可能在化学和物理上有所不同，受到pH值、氧气浓度和养分可用性的显着变化，以及定殖物种的不同平衡和允许细菌交流和调节毒力行为的小分子的不同浓度的影响。该项目旨在确定微环境的多样性如何影响变异链球菌最重要的毒力行为，即遗传能力。能力是吸收细胞外DNA的能力，而调节变形链球菌能力的遗传网络与调节该生物体几乎所有其他致龋性状的机制密切相关。能力基因对环境条件和接收到的化学信号的性质极其敏感。细胞群中能力基因的表达可以是一致的，也可以仅涉及细菌子集的激活。因此，一个广泛的科学目标是了解变形链球菌如何处理或解释环境信号以调节能力和其他毒力行为，生物膜中的微环境如何影响这种处理，以及能力基因如何在整个口腔生物膜的细胞间水平上被激活。该项目将重点识别和理解控制变形链球菌能力的遗传“开关”，探索 pH、氧气浓度和碳水化合物可用性如何影响肽信号对能力的调节，以及研究和模拟变形链球菌生物膜内肽信号调节能力的方式。该项目将通过一种新颖的微流体、单细胞方法来实现这些目标。该方法允许向变形链球菌细胞亚群提供多个明确的环境输入，同时对这些亚群的能力基因激活谱进行定量测量和建模。该项目将产生有关变形链球菌能力如何在口腔生物膜中空间分布以及哪种化学条件触发这种能力和相关毒力行为的详细信息。成功实现这些目标将通过增进对变形链球菌如何引起牙科疾病的了解来推进人类口腔健康的研究。