Nitrosative stress defenses in periodontopathogen Porphyromonas gingivalis

牙周病原菌牙龈卟啉单胞菌的亚硝化应激防御

• 批准号: 8549467
• 负责人: Janina P Lewis
• 金额: $ 38.11万
• 依托单位: VIRGINIA COMMONWEALTH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-26 至 2018-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8549467
• 关键词: Adult; Anti-Bacterial Agents; Bacteria; Binding; Bioinformatics; Biological Process; Cells; Code; Complex; Crystallography; DNA; DNA Binding; DNA Sequence; Defense Mechanisms; Environment; Flavodoxin; Gene Expression Profile; Gene Targeting; Genes; Growth; Homeostasis; Human; Hydroxylamine; Invaded; Knowledge; Light; Mediating; Microarray Analysis; Molecular; Molecular Genetics; Molecular Structure; Nitric Oxide; Nitrite Reductase; Nitrites; Oral; Oral cavity; Organism; Oxidoreductase; Periodontal Diseases; Play; Porphyromonas gingivalis; Process; Property; Proteins; Proteome; Proteomics; Regulation; Regulon; Role; Signal Transduction; Structure; Therapeutic Agents; Tissues; Work; base; design; microorganism; mutant; nitrogen metabolism; nitrosative stress; novel; pathogen; periodontopathogen; prevent; public health relevance; tool; translational approach; weapons

DESCRIPTION (provided by applicant): Nitrite and nitric oxide are widespread and abundant in humans and are emerging as a potential new antibacterial therapeutic agents. The oral cavity has particularly high concentrations of nitrite, which can reach 1mM. Oral microorganisms have adapted to survive such high nitrosative stress exposure and disruption of these adaptation mechanisms would be expected to reduce growth and survival of bacteria in the oral environment. Porphyromonas gingivalis, a periodontopathogen, is well known for its high tolerance of nitrosative stress. However, the molecular basis of this tolerance is under-investigated. Using bioinformatics approaches and microarray analysis of P. gingivalis exposed to nitrite and nitric oxide, we identified several potential candidates that may play a role in nitrosative stress protection. The major upregulated gene was hcp, which codes for a putative hydroxylamine reductase. We have further identified a regulator, designated HcpR, which mediates expression of hcp and is required for growth of P. gingivalis in the presence of both nitrite and nitric oxide. We hypothesize that HcpR is a major player in adaptation of P. gingivalis to nitrosative stress. To determine its role in nitrosative stress protection, we will first definethe regulon of HcpR and the minimum DNA sequence required for its binding. Furthermore, we will carry out molecular structure studies of HcpR and of its complexes with DNA using NMR and crystallography. Since our study shows that the major regulated gene in P. gingivalis is hcp, we will determine the role of its gene product in adaptation of the bacterium to nitrosative stress an define its biological function in such adaptation. Also, P. gingivalis codes for multiple players that may be involved in nitrosative stress protection or nitrogen metabolism. We will characterize and determine the roles of those players in adaptation of P. gingivalis to nitrosative stress. Finally, we will investigate the role of nitrosative stress in host-pathogen interactions. The results of our study are expected to provide information regarding nitrosative stress homeostasis mechanisms in P. gingivalis at the regulatory and structural levels This knowledge will provide the tools to design agents that compromise the defense mechanisms of the periodontopathogen and turn endogenous human host nitrite and nitric oxide into a weapon that inhibits growth and ultimately can be exploited to treat periodontal disease. We predict that this work will shed light on nitrosative stress homeostasis mechanisms in a variety of other bacteria that carry similar nitrosative stress protection mechanisms to those in P. gingivalis.

描述（由申请人提供）：亚硝酸盐和一氧化氮在人类中广泛而丰富，并且正在成为一种潜在的新抗菌治疗剂。口腔具有特别高的亚硝酸盐，可以达到1mm。口服微生物已经适应了如此高的亚硝化应激暴露，这些适应机制的破坏将有望减少口腔环境中细菌的生长和存活。牙周病原（一种牙周病原）以其硝化应激的高耐受性而闻名。但是，这种公差的分子基础不足。使用暴露于亚硝酸盐和一氧化氮的生物信息学方法和微阵列分析，我们确定了可能在硝化应力保护中起作用的几个潜在候选者。主要上调的基因是HCP，它代码为推定的羟胺还原酶。我们进一步确定了一个指定的HCPR调节剂，该调节剂介导HCP的表达，并且在存在亚硝酸盐和一氧化氮的情况下是牙龈疟原虫生长所必需的。我们假设HCPR是适应牙龈疟原虫的主要参与者 硝化应激。为了确定其在硝化应力保护中的作用，我们将首先定义HCPR的调节量和其结合所需的最小DNA序列。此外，我们将使用NMR和晶体学对HCPR及其复合物进行分子结构研究。由于我们的研究表明，牙龈假单胞菌中的主要调节基因是HCP，因此我们将确定其基因产物在适应硝化胁迫的适应中的作用，从而定义了其在这种适应中的生物学功能。同样，牙龈疟原虫为可能涉及硝化应力保护或氮代谢的多个玩家编码。我们将表征并确定这些参与者在适应牙龈疟原虫中的作用 压力。最后，我们将研究亚硝化应激在宿主病原体相互作用中的作用。 The results of our study are expected to provide information regarding nitrosative stress homeostasis mechanisms in P. gingivalis at the regulatory and structural levels This knowledge will provide the tools to design agents that compromise the defense mechanisms of the periodontopathogen and turn endogenous human host nitrite and nitric oxide into a weapon that inhibits growth and ultimately can be exploited to treat periodontal disease.我们预测，这项工作将揭示出各种其他细菌中的硝化应激稳态机制，这些机制具有与牙龈疟原虫中的硝化应力保护机制相似的。