Mechanisms for adaptation to oxidative stress in Porphyromonas gingivalis

描述（由申请人提供）：牙龈卟啉单胞菌适应氧化应激的机制牙龈卟啉单胞菌是一种黑色革兰氏阴性厌氧菌，是牙周病的重要病原体。牙周袋的炎症环境表明，这种生物体具有促进其在氧化环境中生存的能力的特性。我们对牙龈卟啉单胞菌和其他牙周病原体抗氧化应激机制的认识存在空白。我们的假设是，在牙龈卟啉单胞菌中，多种协调调节机制对于保护免受氧化应激至关重要，并且在生物体的致病性中具有重要意义。在初步研究中，我们使用了一种全球方法来评估牙龈卟啉单胞菌同基因突变体在牙周袋典型氧化应激环境中细胞反应的转录谱。对过氧化氢（H2 O2）诱导的氧化应激的反应确定了几个基因的诱导表达，包括一些已知参与氧化应激抗性。氧化应激的持续时间显示出差异调节转录，其中DNA修复/修饰基因的上调主要见于较短的暴露时间。在较长时间暴露于氧化应激期间，已知参与蛋白质修复的几个基因被上调。在暴露时间的范围内，有一个上调的几个假设的基因，以前没有被表征。我们以前的报告也表明，与其他生物体相比，涉及8-氧代-7，8-二氢鸟嘌呤（8-oxoG）的氧化应激诱导的DNA损伤的修复可能通过尚未描述的机制在牙龈卟啉单胞菌中发生。在这个项目中，我们希望全面了解牙龈卟啉单胞菌如何适应牙周袋典型的氧化条件，并评估它是否有助于其致病性。具体目标是：1。表征氧化应激诱导基因在牙龈卟啉单胞菌存活/致病性中的特定作用。2.鉴定和表征参与grpE基因座表达的调节序列和蛋白质。3.研究氧化应激条件下牙龈卟啉单胞菌同基因突变体的DNA损伤和修复机制。总的来说，这些信息可以提供重要的线索，允许开发新的治疗干预措施，以帮助控制和预防牙周病和其他牙龈卟啉单胞菌相关疾病。 公共卫生相关性：本研究的目的是表征牙周病原体牙龈卟啉单胞菌在牙周袋炎症环境中生存的重要因素。因为这种环境可能会对生物体造成严重损害，并且鉴于其作为牙龈疾病的重要原因的成功，表明牙龈卟啉单胞菌具有促进其在压力环境中生存的能力的特性。对于生存至关重要的重要因素是开发对人类健康产生积极影响的新型疗法的主要目标。

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.