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（由申请人提供）：人类牙菌斑生物膜是一种物理和化学复杂的环境，由许多细菌物种（包括链球菌突变）居住，被视为人类龋齿的主要病因。 S. mutans具有多种行为，引起其毒力，并且通过使用从其环境中获得的化学提示来调节和激活这些行为。然而，生物膜内不同位置的链球菌的局部环境在化学上可能是化学和物理上不同的，这会经过pH，氧浓度和养分的可用性的实质性变化，以及定植物种的不同平衡以及不同浓度的小分子，使细菌可以传达和调节病毒性行为。该项目旨在确定微环境的这种多样性如何影响中心重要的s。Mutans毒力行为，称为遗传能力。能力是占用细胞外DNA的能力，调节链球菌能力的遗传网络与几乎调节生物体的其他所有其他癌性特征的机制紧密相互交织。能力基因对环境条件和收到的化学信号的性质极为敏感。在细胞群中的能力基因的表达可能是统一的，也可能仅涉及细菌的一部分。因此，一个广泛的科学目标是了解S. mutans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该处理以及如何在整个口腔生物膜的细胞到细胞水平上激活能力基因。该项目将重点o识别和理解控制S. mutans能力的遗传“开关”，探索pH，氧浓度和碳水化合物的可用性如何影响肽信号的调节能力，并研究和建模能力受到肽信号S. Mutans Biofans内部肽信号调节的方式。该项目将通过一种新型的微流体单细胞方法来实现这些目标。该方法允许将多个定义明确的环境输入提供给链球菌细胞的亚群，而在这些亚群中的能力基因激活的特征进行了定量测量和建模。该项目将产生有关S. mutans能力如何在口服生物膜中分布的详细信息，以及哪种化学条件会触发这种和相关的毒力行为。实现这些目标的成功将通过提高对链球菌如何引起牙齿疾病的理解来提高人类口腔健康的研究。