Nitrosative Stress and Oral Bacteria

亚硝化应激和口腔细菌

• 批准号: 10440244
• 负责人: Janina P Lewis
• 金额: $ 36.12万
• 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 2026-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10440244
• 关键词: Accounting; Adult; Anti-Bacterial Agents; Bacteria; Biochemical; Cells; Characteristics; Complex; DNA; Data; Defense Mechanisms; Detoxification Process; Environment; Genes; Growth; Heme; Hemin; Human; Knowledge; Length; Light; Mediating; Molecular; Molecular Genetics; Nitric Oxide; Nitrites; Oral; Oral cavity; Organism; Periodontal Diseases; Play; Porphyromonas gingivalis; Proteins; Proteomics; Regulation; Role; Sigma Factor; Signal Pathway; Signal Transduction; Structure; System; Therapeutic Agents; Tissues; Toxic effect; Work; biological adaptation to stress; convict; design; flexibility; insight; microorganism; nitric oxide reductase; nitrosative stress; novel; oral bacteria; pathogen; periodontopathogen; prevent; response; structural biology; tool; translational approach; weapons; whole genome

Summary Nitrite and nitric oxide are widespread and robust signaling modulators that are emerging as 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, we expect, that disruption of these adaptation mechanisms will reduce growth and survival of bacteria in the oral environment. We know that Porphyromonas gingivalis, a periodontopathogen, has high tolerance of nitrosative stress. However, the complex signaling pathways setting the basis of this tolerance are yet to be determined in in this bacterium as well as in other oral bacteria. Using whole genome expression analysis we have identified hcp encoding newly re-designated S-nitrosylase as the most dramatically upregulated gene under nitrosative stress. Furthermore, we demonstrated that regulation of Hcp is dependent on an FNR- like regulator, HcpR, that employs novel hemin-dependent mechanism to sense nitrosative stress. We hypothesize that the HcpR-Hcp system is central for adaptation of P. gingivalis to nitrosative stress. Thus, we will first define the molecular mechanisms of P. gingivalis sensing nitrosative stress through determination of the structural and biochemical characteristics of HcpR. Since adaptation to nitrosative stress involves a novel enzymatic activity mediated by Hcp, we will characterize the Hcp-mediated S-nitrosylome using proteomic approaches. In addition, we will characterize the mechanism P. gingivalis Hcp employs to mediate protection against nitrosative stress. Finally, we will investigate the contribution of other putative regulatory and effector proteins in nitrosative stress defense in P. gingivalis. It is noteworthy, that we will verify the contribution of the mechanisms under host-pathogen setting. This knowledge will provide the tools to design agents that can compromise the defense mechanisms of the periodontopathogen and turn endogenous human host nitrite and nitric oxide into a weapon that inhibits growth of the bacterium and, ultimately, we can exploit it to treat periodontal disease. We predict that this work will shed light on nitrosative stress signaling mechanisms in a variety of other bacteria that carry similar nitrosative stress protection mechanisms to those in P. gingivalis.

总结 亚硝酸盐和一氧化氮是广泛而强大的信号调节剂， 潜在的新型抗菌治疗剂。口腔中有特别高的浓度 亚硝酸盐，可达1 mM。口腔微生物已经适应了在如此高的温度下生存 亚硝化应激暴露，我们预计，这些适应机制的破坏将 减少口腔环境中细菌的生长和存活。我们知道卟啉单胞菌 牙龈炎菌是牙周病病原体，对亚硝化应激具有高耐受性。然而，复杂的 在这种细菌中，建立这种耐受性基础的信号通路还有待确定 以及其他口腔细菌。利用全基因组表达分析，我们鉴定了hcp 编码新重新命名的S-亚硝基酶作为最显着上调的基因， 亚硝化胁迫此外，我们证明了HCP的调节依赖于FNR- 如调节剂HcpR，其采用新颖的氯化血红素依赖性机制来感知亚硝化应激。 我们假设HcpR-HCP系统是牙龈卟啉单胞菌适应亚硝化的中心 应力因此，我们将首先确定牙龈卟啉单胞菌感受亚硝化的分子机制， 通过测定HcpR的结构和生物化学特性来研究胁迫。以来 对亚硝化胁迫的适应涉及由HCP介导的新的酶活性，我们将 使用蛋白质组学方法表征HCP介导的S-亚硝基体。此外，我们将 表征牙龈卟啉单胞菌HCP介导抗亚硝化保护的机制 应力最后，我们将研究其他假定的调节和效应因子的贡献。 牙龈卟啉单胞菌中的亚硝化应激防御蛋白。值得注意的是，我们将核实 在宿主-病原体环境下的机制的贡献。这些知识将提供工具， 设计能够破坏牙周病原体防御机制的药剂， 将内源性的人类宿主亚硝酸盐和一氧化氮转化为抑制生长的武器， 最终，我们可以利用它来治疗牙周病。我们预测这项工作 将揭示亚硝化应激信号机制在各种其他细菌携带， 类似于牙龈卟啉单胞菌的亚硝化应激保护机制。