Integrating Global Responses to Nutrient Limitation in Gram-positive Bacteria

整合全球对革兰氏阳性菌营养限制的反应

基本信息

批准号：
8382894
负责人：
Shaun R Brinsmade
金额：
$ 9万
依托单位：
TUFTS UNIVERSITY BOSTON
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-01 至 2013-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8382894
关键词：
Affect Amino Acids Award Bacillus subtilis Bacteria Bacterial Infections Bacterial Physiology Behavior Benign Binding Biochemical Biochemistry Branched-Chain Amino Acids Calculi Cells Development Disease Foundations Funding Gene Expression Gene Expression Profile Genes Genetic Goals Gram-Positive Bacteria Guanine Nucleotides Guanosine Triphosphate Health Heart Human Human body In Vitro Infection Isoleucine Knowledge Laboratories Lead Learning Leucine Life Life Style Maps Mass Spectrum Analysis Measures Mediating Mentors Metabolic Metabolism Methods Mission Modeling Monitor National Institute of General Medical Sciences Nosocomial Infections Nutrient Output Pathogenesis Pathway interactions Phase Physiological Physiology Process Public Health Regulation Regulon Research Research Personnel Resources Role Route Signal Transduction Soil Staphylococcus aureus System Systems Biology Techniques Therapeutic Time Training Universities Valine Variant Virulence antimicrobial base biological adaptation to stress career career development design environmental change exhaustion functional genomics genetic manipulation in vivo innovation medical schools metabolomics novel novel therapeutics nucleoside triphosphate pathogen prevent programs promoter research and development research study response tool transcription factor

项目摘要

DESCRIPTION (provided by applicant): Expression of bacterial virulence genes often correlates with the exhaustion of nutrients, but how the signaling of nutrient availability and the resulting physiological responses are co- ordinated is unclear. Until this gap in knowledge is closed, metabolically diverse bacteria like Staphylococcus aureus will continue to cause perilous hospital-acquired infections. The applicant's long-term goal is to lead an independent academic research group studying how bacteria integrate and respond to information provided by intracellular metabolites (the metabolome) to reconfigure metabolism to adapt to environmental changes and cause disease. The objective of this project is to augment existing genetic and biochemical expertise with high- throughput global techniques to analyze gene expression, intracellular metabolites and flux, and, in doing so, titrate the activity of the global regulator CodY and deduce its regulatory hierarchy in S. aureus. At the heart of this project is the hypothesis that fluctuations in the intracellular pools of branched-chain amino acids and GTP result in a spectrum of CodY activities that produce a graded response to nutrient limitation, culminating in metabolic adaptation and the development of virulence. This hypothesis is based on preliminary studies that identified the true intracellular metabolites that control CodY activit in living cells and revealed hierarchical organization for three genes. The rationale for this project is that comprehensive knowledge of the co-regulation of metabolism and virulence is essential if we are to understand the physiological origins of bacterial pathogenesis. During the mentored (K99) phase at Tufts University School of Medicine, massively parallel sequencing, mass spectrometry-based metabolomics and chemostat cultivation will be mastered to map intersecting metabolic and virulence gene expression patterns in S. aureus, while gaining critical scholarly training needed to launch a successful independent academic career with guidance from a mentoring committee composed of experts in bacterial physiology, biochemistry and systems biology. Mastering the cultivation and genetic manipulation of pathogenic S. aureus along with high-throughput methods will enable efforts during the R00 phase to quantify changes in the S. aureus CodY regulon upon induction of physiological stress response systems. The approach is innovative, because continuous bacterial cultures mimic nutrient-limiting bacterial niches in the human body and the experiments will place virulence gene expression in the context of the normal behavior of S. aureus under the nutrient-limiting conditions of the host. Furthermore, correlations between global metabolite pools and CodY activity will provide a previously unattainable linkage of the transcriptome to the metabolome. The project is significant because it will increase our understanding of how the genetic pro- grams of metabolic adaptation and virulence gene expression are interrelated and interdependent. A more thorough understanding of these connections may also offer potentially novel therapeutic strategies. The Pathway to Independence Award will provide the time and resources needed to achieve these goals. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because understanding how bacteria connect metabolism and disease-causing processes may reveal new ways to prevent the switch from harmless to harmful lifestyles that lead to potentially life-threatening infections. The research and career development proposed in this Pathway to Independence award application will unravel cellular mechanisms underlying bacterial disease while providing a stepping stone to an independent academic career - objectives that align with the mission of the National Institute of General Medical Sciences.

描述（由申请人提供）：细菌毒力基因的表达通常与养分的耗尽相关，但营养物的信号传导如何尚不清楚由此产生的生理反应。在知识上的差距封闭之前，如金黄色葡萄球菌等代谢多样的细菌将继续引起危险的医院获得感染。申请人的长期目标是领导一个独立的学术研究小组，研究细菌如何整合和响应细胞内代谢物（代谢组）提供的信息，以重新配置代谢，以适应环境变化并引起疾病。该项目的目的是使用高吞吐全球技术来扩大现有的遗传和生化专业知识，以分析基因表达，细胞内代谢物和通量，并在此过程中滴定全球调节剂Cody的活性并推导其在S中的监管等级体系。该项目的核心是一个假设，即分支链氨基酸和GTP的细胞内池的波动导致了多种Cody活性，这些谱系对营养限制，最终导致代谢适应和毒力的发展产生了分级反应。该假设基于初步研究，该研究确定了控制活细胞中Cody Activit的真正细胞内代谢产物，并揭示了三个基因的分层组织。该项目的理由是，如果我们要了解细菌发病机理的生理起源，那么对代谢和毒力的共同调节的综合知识至关重要。在Tufts大学医学院的指导阶段（K99）期间，将掌握基于质谱的代谢组学和化学固化培养的大规模平行测序，将掌握在S. aureus中与代谢基因表达模式相交，同时获得关键的学术训练，需要进行关键的学术训练由一个由细菌生理学，生物化学和系统生物学专家组成的指导委员会的指导，启动成功的独立学术职业。掌握致病金黄色葡萄球菌的培养和遗传操纵以及高通量方法将在R00期间努力在诱导生理压力反应系统后量化金黄色葡萄球菌Cody调节的变化。这种方法是创新的，因为连续细菌培养物模仿人体中限制营养的细菌壁ni，实验将在金黄色葡萄球菌在宿主的营养限制条件下的正常行为的背景下将毒力基因表达放置。此外，全球代谢物池与CODY活性之间的相关性将提供以前无法实现的转录组与代谢组的联系。该项目之所以重要，是因为它将增加我们对代谢适应和毒力基因表达的遗传学研究的理解是相互关联的和相互依存的。对这些联系的更透彻的了解也可能提供潜在的新型治疗策略。独立奖的途径将为实现这些目标提供所需的时间和资源。公共卫生相关性：拟议的研究与公共卫生有关，因为了解细菌如何连接代谢和引起疾病的过程可能会揭示新的方法，以防止从无害的生活方式转变为有害生活方式，从而导致潜在的威胁生命的感染。在这项通往独立奖项申请的途径中提出的研究和职业发展将揭示细菌疾病的细胞机制，同时为独立的学术职业提供垫脚石 - 与国家一般医学科学研究所的使命相吻合的目标。