L-Arg availability affects the physiological state of porphyromonas gingivalis

L-精氨酸的可用性影响牙龈卟啉单胞菌的生理状态

• 批准号: 10316786
• 负责人: Mary Ellen Davey
• 金额: $ 36.22万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10316786
• 关键词: Adult; Affect; Affinity; Agar; Alzheimer' s Disease; Amino Acids; Anabolism; Anaerobic Bacteria; Arginine; Arginine deiminase; Bacteria; Biochemical; Biogenesis; Biological Assay; Carboxypeptidase; Cardiovascular Diseases; Caspase; Cells; ChIP-seq; Clinical; Communities; Complex; Cues; Data; Development; Disease; Disease Progression; Epithelial; Equilibrium; Excision; Genes; Germ-Free; Gingival Crevicular Fluid; Goals; Growth; Homeostasis; Human; Hydration status; Image; Immune response; Indigenous; Infection; Inflammatory; Knowledge; Laboratories; Larva; Lead; Life; Life Style; Link; Lipoproteins; Mediating; Membrane; Metabolism; Methods; Microbial Biofilms; Modeling; Molecular; Monitor; Moths; Movement; Mus; Nutritional; Oral cavity; Pathogenicity; Pathology; Peptide Hydrolases; Peptides; Periodontal Diseases; Periodontal Infection; Periodontitis; Phenotype; Physiological; Physiology; Pilum; Play; Polyamines; Population; Porphyromonas gingivalis; Prevention; Proliferating; Protocols documentation; Regulation; Regulon; Reporting; Research; Rheumatoid Arthritis; Role; Signal Transduction; Slide; Surface; Surface Tension; System; Systemic disease; Testing; Time; United States; Urocanate Hydratase; Vesicle; Virulence; Waxes; appendage; base; cell motility; chronic inflammatory disease; cost; differential expression; dysbiosis; extracellular; genetic regulatory protein; gingipain; host microbiome; host-associated microbial communities; immunoregulation; inflammatory bone loss; metabolomics; microbial community; microbiome; microbiota; migration; mutant; oral anaerobes; oral microbiome; oral pathogen; pathogen; pathogenic bacteria; programs; response; sensor; subgingival biofilm; targeted treatment; therapeutic development; transcriptome sequencing; transcriptomics; uptake

Project Summary/Abstract Many chronic inflammatory diseases, including periodontal infections, are biofilm-based pathologies mediated by indigenous microbiota persisting within complex host-associated microbial communities. Determining the environmental cues that direct the physiological state (commensal versus pathogenic state) of oral anaerobes, is fundamental to development of therapeutic strategies for periodontal diseases. Recent studies indicate that the pathogenic potential of the anaerobic bacterium Porphyromonas gingivalis is not solely dependent on its ability to colonize and proliferate within the subgingival biofilm; its physiological state and its associations within the microbial consortium are fundamental to development of pathology. The central hypothesis for this application is that the availability of L-arginine is a key signal/substrate that impacts P. gingivalis surface translocation, expression of virulence determinants, and biofilm formation. Studies have reported that the levels of arginine increase 2-fold (from ~5µM to 10µM) in gingival crevicular fluid during periodontal disease. The reason for this increase is not known but may reflect a decrease in metabolism by the microbial community, a decrease in uptake by host cells, or an increase in bacterial arginine biosynthesis. One known factor is the activity of the arginine - specific cysteine proteases (Arg-gingipains) produced by P. gingivalis, along with its carboxypeptidase that releases the terminal arginine residues from peptides produced by Arg- gingipains. Our analysis shows that both intracellular and extracellular accumulation of L-arginine has a negative impact on P. gingivalis physiology, confirming that the levels of L-arginine are monitored and controlled. Our studies have shown that under L-arginine deplete conditions, P. gingivalis down regulates expression of fimbriae, inhibiting biofilm formation; and, in contrast, addition of L-arginine boosts fimbrial expression and surface colonization. Thus, P. gingivalis adjusts its lifestyle in response to changes in extracellular L-arginine. What remains unclear is the sensing and regulatory mechanisms that control this change in physiology. The goal of this application is to determine how P. gingivalis controls extracellular and intracellular arginine concentrations and in particular the effect of changes in arginine concentration on its ability to surface translocate. Importantly, L-arginine is known to be an important modulator of the host immune response to pathogens, so we posit that there is a delicate balance between host and pathogen responses to arginine during disease progression and that P. gingivalis has evolved with the ability to sense and respond to this key amino acid as a fundamental strategy for persistence. The rationale for these studies is that identifying the signals that control colonization and the physiological state of oral pathogens will provide prime targets for the development of therapeutic strategies. Thus, the long-term objective is to determine if this mechanism of signaling can be targeted for treatment and prevention of biofilm-induced diseases in humans.

项目摘要/摘要 许多慢性炎症性疾病，包括牙周感染，都是以生物膜为基础的病理机制。 通过在复杂的寄主相关微生物群落中持续存在的本土微生物群。确定 指示口腔厌氧菌生理状态(共生状态与致病状态)的环境线索， 是牙周疾病治疗策略发展的基础。最近的研究表明， 厌氧菌牙龈卟啉单胞菌的致病潜力并不完全依赖于它的 在龈下生物膜内定植和增殖的能力；其生理状态及其与 微生物群体是病理学发展的基础。关于这一点的中心假设 应用是L-精氨酸的可用性是影响牙龈假单胞菌表面的关键信号/底物 转位，毒力决定因素的表达，以及生物膜的形成。研究报告称， 牙周病期间，龈沟液中的精氨酸水平增加了2倍(从~5微米增加到10微米)。 这种增加的原因尚不清楚，但可能反映了微生物新陈代谢的减少 宿主细胞对精氨酸的摄取减少，或细菌精氨酸生物合成增加。已知的一个 因子是牙龈假单胞菌产生的精氨酸特异性半胱氨酸蛋白酶(精氨酸-牙龈痛)的活性。 与其羧肽酶一起，从Arg-2产生的多肽中释放末端精氨酸残基。 牙龈痛。我们的分析表明，L精氨酸在细胞内和细胞外的积累都有一个 对牙龈假单胞菌生理的负面影响，证实了L-精氨酸水平受到监测和 控制住了。我们的研究表明，在L精氨酸耗竭的条件下，牙龈假单胞菌下调表达。 菌毛的表达，抑制生物膜的形成；相反，L精氨酸的加入促进了菌毛的形成 表达和表面定植。因此，牙龈假单胞菌会调整自己的生活方式，以适应 胞外L-精氨酸。目前尚不清楚的是控制这一现象的感知和调控机制。 生理上的变化。这个应用程序的目标是确定牙龈假单胞菌是如何控制细胞外和 细胞内精氨酸浓度，特别是精氨酸浓度变化对其影响 表面移位的能力。重要的是，L精氨酸被认为是宿主免疫的重要调节剂。 对病原体的反应，所以我们假设在宿主和病原体对 精氨酸在疾病发展过程中的作用，牙龈假单胞菌已经进化出感知和反应的能力 这一关键氨基酸是持之以恒的基本策略。这些研究的基本原理是 识别控制口腔病原体定植和生理状态的信号将提供最好的 制定治疗策略的目标。因此，长期目标是确定这一点是否 信号转导机制可作为治疗和预防生物被膜引起疾病的靶点。