Heme, Iron and Oxidative Stress: Regulation of Iron Homeostasis in H. Influenzae

血红素、铁和氧化应激：流感嗜血杆菌铁稳态的调节

基本信息

批准号：
7895756
负责人：
ROBERT S. MUNSON
金额：
$ 35.64万
依托单位：
RESEARCH INST NATIONWIDE CHILDREN'S HOSP
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-20 至 2014-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7895756
关键词：
5 year old Affect Albumins Avidity Bacteremia Bacteria Bioinformatics Biological Bronchitis Cells Child Chronic Chronic Obstructive Airway Disease Clinical Code Complement Complex Data Degradation Pathway Diagnosis Disease Drug Metabolic Detoxication Environment Enzymes Epithelial Cells Facilities and Administrative Costs Gene Expression Gene Expression Profile Gene Expression Regulation Gene Targeting Genes Genetic Transcription Genome Goals Growth Haemophilus influenzae Haptoglobins Heat shock proteins Heme Heme Iron Hemoglobin Hemopexin Hemophilus Homeostasis Homologous Gene Human Hydrogen Peroxide Hydroxyl Radical Individual Infant Infection Iron Lead Link Metabolism Microarray Analysis Modeling Mutagenesis Mutation Nasopharynx Neisseria gonorrhoeae Nontypable Haemophilus influenza Open Reading Frames Organism Otitis Media Oxidative Stress Oxygenases PAWR protein Pathogenicity Pattern Physiological Play Production Proteins Rattus Reaction Reactive Oxygen Species Regulation Regulator Genes Regulon Resistance Respiratory Tract Diseases Role Serotyping Serous otitis media Signal Transduction Sinusitis Site Small RNA Solubility Solutions Source Specificity Surface System Testing Therapeutic Intervention Toxic effect United States Upper respiratory tract Vaccine Design alkalinity base biological adaptation to stress cDNA Arrays cell growth combat design effusion extracellular ferrochelatase heme a improved in vivo insight member mucoid mutant novel novel strategies oxidation pathogen prevent protein expression protoporphyrin IX public health relevance research study response stress protein uptake

项目摘要

DESCRIPTION (provided by applicant): Nontypeable Haemophilus influenzae (NTHi) is a significant human pathogen as it is a major cause of otitis media (OM), sinusitis, exacerbations of chronic obstructive pulmonary disease (COPD) and bronchitis. Illness due to NTHi is thus a major societal burden, and an aggressive approach is needed to determine novel ways of combating diseases caused by NTHi. In all aspects of NTHi disease, the organism moves from being a passive member of the upper respiratory tract flora to an opportunistic pathogen in the site of infection. Although iron and heme uptake systems have been identified in NTHi, little is known about how iron and heme uptake is regulated. Also, NTHi is protected from the damage caused by excess iron or heme that is extremely toxic, primarily through production of toxic reactive oxygen species via the Fenton reaction. The mechanisms involved in this protection are unknown. We have used cDNA microarrays to interrogate the transcriptome of strain 86-028NP, an NTHi strain whose genome we have sequenced. We also have constructed mutants in strain 86-028NP that are deficient in the expression of the oxyR gene as well as the fur (ferric uptake regulator) gene and identified the genes in the OxyR and Fur regulons. We propose to further characterize the response of NTHi strain 86-028NP to oxidative stress. Emphasis will be placed on the interrelationship between oxidative stress and control of iron and heme uptake and usage. The fur regulon will be further characterized. Experiments are proposed to identify and characterize Fur- and oxidative stress- regulated small RNAs. Mutants deficient in the expression of both Fur- and sRNA-regulated genes of unknown or poorly defined function as well as genes encoding proteins involved in resistance to oxidative stress will be constructed and characterized. The NTHi strain 86-028NP heme oxygenase will be identified and characterized. These experiments will lead to an improved understanding of how NTHi regulates its iron and heme metabolism and will provide insight into previously uncharacterized iron-regulated genes, some of which may be involved in heme storage and/or heme degradation. The proposed studies will also provide data on the interplay between the oxidative stress response systems and the Fur system in NTHi thereby increasing our understanding of how NTHi responds to environmental signals and providing us with information that will be useful in the design of new approaches to prevent disease caused by NTHi. PUBLIC HEALTH RELEVANCE: Nontypeable Haemophilus influenzae (NTHi) is a common commensal that colonizes the nasopharynx of over 50% of individuals over 5 years of age and causes a number of respiratory tract diseases, including otitis media, sinusitis, exacerbations of chronic obstructive pulmonary disease, bronchitis and occasionally, invasive disease. The direct and indirect cost of diagnosing and managing otitis media exceeds $5 billion annually in the United States alone. Thus, defining how NTHi regulates the uptake of iron to both avoid potential iron toxicity and minimize oxidative stress will provide insight into how NTHi causes these diseases as well as novel ways to approach eradicating diseases caused by NTHi.

描述（由申请人提供）：不可用的流感嗜血杆菌（NTHI）是一种重要的人类病原体，因为它是中耳炎（OM），鼻窦炎，慢性阻塞性肺疾病（COPD）和支气管炎的主要原因。因此，由于nthi引起的疾病是一种重大的社会负担，需要一种积极的方法来确定新颖的抗击NTHI引起的疾病的方法。在NTHI疾病的各个方面，该生物从作为上呼吸道菌群的被动成员转变为感染部位的机会性病原体。尽管已经在NTHI中鉴定出铁和血红素摄取系统，但对铁和血红素的摄取如何受到调节知之甚少。同样，NTHI受到过多的铁或血红素造成的损害，这些损害主要是通过芬顿反应产生有毒的活性氧。该保护所涉及的机制尚不清楚。我们已经使用cDNA微阵列来询问菌株86-028NP的转录组，这是一种NTHI菌株，其基因组已测序。我们还构建了86-028NP菌株中的突变体，这些突变体在oxyr基因的表达以及毛皮（铁摄取调节剂）基因的表达不足，并鉴定了oxyr和fur rongulons中的基因。我们建议进一步表征NTHI菌株86-028NP对氧化应激的反应。重点将放在氧化应激与铁和血红素摄取和用法之间的相互关系上。毛皮法规将进一步表征。提出了实验来识别和表征脂肪应力调节的小RNA。将构建和表征与氧化应激抗性的蛋白质以及编码蛋白质的基因以及对氧化应激抗性的蛋白质的表达不足的突变体。 NTHI菌株86-028NP血红素加氧酶将被鉴定和表征。这些实验将使人们对NTHI如何调节其铁和血红素代谢有了深入的了解，并将提供对先前未表征的铁调节基因的见解，其中一些基因可能参与血红素储存和/或血红素降解。拟议的研究还将提供有关氧化应激反应系统与NTHI的皮毛系统之间相互作用的数据，从而增加了我们对NTHI如何响应环境信号的理解，并为我们提供有关预防NTHI引起疾病的新方法的信息。公共卫生相关性：不可抑制的流感嗜血杆菌（NTHI）是一种普遍的共同体，可在50岁以上的50％以上的鼻咽内分泌，并引起许多呼吸道疾病，包括耳炎媒体，鼻窦炎，慢性阻塞性肺部疾病，慢性阻塞性肺炎，造成病毒，有可能发生。仅在美国，诊断和管理中耳炎的直接和间接成本每年超过50亿美元。因此，定义NTHI如何调节铁的摄取以避免潜在的铁毒性并最大程度地减少氧化应激，将为NTHI如何引起这些疾病以及解决由NTHI引起的消除疾病的新方法提供深入的了解。