Mechanisms for adaptation to oxidative stress in Porphyromonas gingivalis

牙龈卟啉单胞菌适应氧化应激的机制

• 批准号: 7741803
• 负责人: Hansel M. Fletcher
• 金额: $ 36.13万
• 依托单位: LOMA LINDA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-06-08 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7741803
• 关键词: 8-hydroxyguanosine; Affinity; Amino Acid Sequence; Anaerobic Bacteria; Base Excision Repairs; Binding; Binding Sites; Cleaved cell; DNA; DNA Damage; DNA Repair; Development; Disease; Environment; Exposure to; Fractionation; Gene Expression; Genes; Genetic Transcription; Genome; Goals; Health; Human; Hydrogen Peroxide; Inflammatory; Knowledge; Lesion; Life; Modification; Mutagenesis; Mutation; Nucleotide Excision Repair; Oligonucleotides; Operon; Organism; Oxidation-Reduction; Oxidative Stress; PAWR protein; Pathogenicity; Pathway interactions; Peptide Sequence Determination; Periodontal Diseases; Periodontal Pocket; Pigments; Play; Porphyromonas gingivalis; Prevention; Promoter Regions; Property; Proteins; Reaction; Reporting; Research; Resistance; Role; Stress; Structure; Testing; Time; Up-Regulation; UvrC protein; Virulence; design; mouse model; mutant; novel therapeutic intervention; novel therapeutics; pathogen; public health relevance; repaired; resistance mechanism; response; sensor; success

DESCRIPTION (provided by applicant): Mechanisms for adaptation to oxidative stress in Porphyromonas gingivalis Porphyromonas gingivalis, a black-pigmented, Gram-negative anaerobe, is an important etiologic agent of periodontal disease. The inflammatory environment of the periodontal pocket suggests that this organism has properties that will facilitate its ability live in an oxidative environment. There is a gap in our knowledge of mechanism(s) of oxidative stress resistance in P. gingivalis and other periodontal pathogens. It is our hypothesis that in P. gingivalis multiple coordinately regulated mechanisms are vital for protection against oxidative stress and are significant in the pathogenicity of the organism. In preliminary studies, we have used a global approach to assess the transcription profile of the cellular response of isogenic mutants of P. gingivalis in an environment of oxidative stress typical of the periodontal pocket. The response to hydrogen peroxide (H2O2)-induced oxidative stress identified the induced expression of several genes including some known to be involved in oxidative stress resistance. The duration of oxidative stress was shown to differentially modulate transcription with the up-regulation of DNA repair/modification genes mostly seen at a shorter exposure time. During a longer exposure to oxidative stress, several genes known to be involved in protein repair were up-regulated. Over the range of exposure times, there was an up-regulation of several hypothetical genes which have not been previously characterized. Our previous report has also demonstrated that, in contrast to other organisms, the repair of oxidative stress-induced DNA damage involving 8-oxo-7,8-dihydroguanine (8-oxoG) may occur by a yet-to-be described mechanism in P. gingivalis. In this project, we wish to gain a comprehensive understanding of how P. gingivalis adapts to the oxidative conditions typical of the periodontal pocket and evaluate whether it contributes to its pathogenicity. The Specific Aims are: 1. To characterize the specific role(s) of oxidative stress-induced genes in the survival/pathogenicity of P. gingivalis. 2. To identify and characterize the regulatory sequences and protein(s) involved in the expression of the grpE locus. 3. To characterize the DNA damage and mechanism(s) of repair in isogenic mutants of P. gingivalis under conditions of oxidative stress. Collectively, this information could provide important clues that would allow the development of novel therapeutic interventions to aid in the control and prevention of periodontal disease and other P. gingivalis-associated diseases. PUBLIC HEALTH RELEVANCE: The goal of this research is to characterize important factors that will facilitate the survival of the periodontal pathogen Porphyromonas gingivalis in the inflammatory environment of the periodontal pocket. Because this environment may cause severe damage to the organism and given its success as important cause of gum disease suggests that P. gingivalis has properties that will facilitate its ability live in a stress environment. Important factors that are essential for survival are prime targets for the development of novel therapeutics that will have a positive impact on human health.

描述（由申请人提供）：适应卟啉念珠菌的氧化应激的机制是牙周疾病的重要病因学药物。牙周口袋的炎症环境表明，该生物具有促进其能力在氧化环境中的能力。我们对牙龈疟原虫和其他牙周病原体中氧化应激抗性机制的了解存在差距。我们的假设是，在牙龈疟原虫中，多个协同调节的机制对于防止氧化应激至关重要，并且对生物体的致病性很重要。在初步研究中，我们使用了一种全局方法来评估牙龈疟原虫的等源性突变体在牙周口袋典型的氧化应激环境中的细胞反应。对过氧化氢（H2O2）诱导的氧化应激的反应确定了几种基因的诱导表达，包括已知的一些基因参与氧化应激抗性。氧化应激的持续时间显示为差异调节转录，而DNA修复/修饰基因的上调主要在较短的暴露时间出现。在更长的氧化应激暴露期间，已知已知参与蛋白质修复的几个基因被上调。在暴露时间范围内，几种假设基因的上调以前尚未表征。我们先前的报告还表明，与其他生物相反，氧化应激诱导的DNA损伤涉及8-oxo-7,8-二氢甘氨酸（8-oxog），可能会通过牙龈疟原虫假单胞菌中尚未描述的机制发生。在这个项目中，我们希望对牙龈疟原虫如何适应牙周口袋的氧化条件有一个全面的了解，并评估其是否有助于其致病性。具体目的是：1。表征氧化应激诱导基因在牙龈疟原虫的存活/致病性中的特定作用。 2。识别和表征与GRPE基因座表达相关的调节序列和蛋白质。 3。表征在氧化应激条件下，牙龈疟原虫的同源性突变体中修复的DNA损伤和机制。总的来说，这些信息可以提供重要的线索，从而允许开发新的治疗干预措施，以帮助控制和预防牙周疾病和其他与牙龈疟原虫相关的疾病。 公共卫生相关性：这项研究的目的是表征重要因素，以促进牙周口袋炎症环境中牙周病原体卟啉单胞菌的生存。因为这种环境可能会对生物体造成严重损害，并作为牙龈疾病的重要原因表明，牙龈疟原虫具有促进其能力在压力环境中的能力。生存至关重要的重要因素是开发新型治疗剂的主要目标，这些疗法将对人类健康产生积极影响。