Mechanism of Quinolone Resistance

喹诺酮类耐药机制

• 批准号: 10047688
• 负责人: NEIL OSHEROFF
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-10-01 至 2022-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10047688
• 关键词: Active Sites; Address; Bacillus anthracis; Bacteria; Bacterial Infections; Binding; Cell Death; Cells; Centers for Disease Control and Prevention (U.S.); Clinical Treatment; Clinical Trials; Complex; DNA; DNA Damage; DNA Double Strand Break; DNA Gyrase; DNA Single Strand Break; DNA Topoisomerase IV; Disease; Drug Interactions; Drug Targeting; Drug resistance; Drug usage; Enzyme Inhibition; Enzyme Interaction; Enzymes; Escherichia coli; General Population; Genetic Materials; Genome; Goals; Gonorrhea; Human; In Vitro; Incidence; Infection; Ions; LGLA; Laboratories; Lead; Ligation; Mediating; Metals; Military Personnel; Modeling; Monitor; Mutation; Mycobacterium tuberculosis; Neisseria gonorrhoeae; Neurofibrillary Tangles; Pharmaceutical Preparations; Positioning Attribute; Protein Fragment; Publishing; Quinolones; Relaxation; Reporting; Research; Resistance; Role; Series; Sexually Transmitted Diseases; Single-Stranded DNA; Stream; Structure; Structure-Activity Relationship; Study models; Superhelical DNA; System; Topoisomerase II; Topoisomerase Inhibitors; Topoisomerase Interaction; United States; Veterans; Water; bacterial resistance; base; cellular targeting; clinically relevant; comparative; design; drug action; drug structure; in vitro activity; inhibitor/antagonist; member; military veteran; mutant; novel; novel therapeutics; quinolone resistance; resistance mutation

Gonorrhea, which is caused by Neisseria gonorrhoeae, is a sexually transmitted disease that currently is categorized by the Centers for Disease Control and Prevention as one of the four “urgent level” drug-resistant threats to the United States. The disease is prevalent in active Military and rates appear to be elevated in Veteran populations. Although quinolones were used routinely to treat gonorrhea starting in 1993, their use as front-line therapy was discontinued in 2006 due to the high incidence of resistance. The cellular targets of quinolones are the bacterial type II topoisomerases, gyrase and topoisomerase IV. The identification and characterization of novel agents that act against these well-validated enzyme targets, but overcome the associated resistance, could have important ramifications for the clinical treatment of gonorrhea. Gyrase and topoisomerase IV are essential enzymes that regulate DNA under- and overwinding and remove DNA knots and tangles by generating transient double-stranded breaks in the genetic material. Quinolones kill bacteria by increasing the levels of these gyrase- and topoisomerase IV-generated double- stranded DNA breaks, which converts these enzymes into lethal proteins that fragment the genome. Both enzymes are targets for quinolones, but their importance to drug action is species- and drug-dependent. Initial quinolone resistance is most often associated with specific mutations in gyrase and/or topoisomerase IV that occur at a highly conserved Ser residue or a Glu/Asp located 4 residues downstream. Based on a published structure and a series of functional studies from the Osheroff laboratory that delineated interactions between drugs and the enzymes from Bacillus anthracis, Escherichia coli, and Mycobacterium tuberculosis, these residues anchor a water-metal ion bridge that serves as the primary conduit between quinolones and the type II enzymes. By characterizing quinolone-topoisomerase interactions, the PI has designed novel drugs that overcome resistance due to mutations in M. tuberculosis gyrase and B. anthracis gyrase and topoisomerase IV. Recently, a new class of naphthyridone/aminopiperidine-based agents, “novel bacterial topoisomerase inhibitors” (NBTIs), was reported. NBTIs target bacterial type II topoisomerases but display little or no cross- resistance to clinically relevant quinolone resistance mutations in gyrase or topoisomerase IV. Unlike the quinolones, these agents either act as catalytic inhibitors or induce enzyme-mediated single-stranded DNA breaks. However, no additional mechanistic information has been reported for any member of this drug class. Gepotidacin, an NBTI that is in clinical trials against gonorrhea, displays activity against wild-type and quinolone-resistant N. gonorrhoeae cultures. However, neither its actions, nor those of any other NBTI against N. gonorrhoeae gyrase or topoisomerase IV have been described. There is an urgent need to develop new drugs to treat resistant gonorrhea (as well as other resistant bacterial infections). The premise that underlies the proposed research is that understanding how drugs interact with their enzyme target places us in a far better position to develop drugs that overcome resistance. Thus, the specific aims of this proposal are to 1) determine the mechanistic basis for quinolone action against N. gonorrhoeae gyrase and topoisomerase IV, define the basis for target-mediated quinolone resistance, and utilize the findings to identify quinolones that overcome the most common forms of resistance; and 2) determine the mechanistic basis for the actions of NBTIs against N. gonorrhoeae gyrase and topoisomerase IV. Although the primary research models for this study will be N. gonorrhoeae gyrase and topoisomerase IV, cellular studies also are planned. In addition, some of the proposed studies may utilize M. tuberculosis, E. coli, or B. anthracis models for comparative purposes. Finally, the proposed research benefits greatly from previous studies from the Osheroff laboratory on the mechanism of bacterial and eukaryotic type II topoisomerases and the interaction of these enzymes with quinolones and other drugs.

淋病是由Neisseria Gonorrhoeae引起的，是一种性传播疾病，目前是 由疾病控制和预防中心归类为四个“紧急水平”耐药水平之一 对美国的威胁。该疾病在活跃的军队中普遍存在，率似乎升高 退伍军人人口。尽管从1993年开始使用奎诺酮通常用来治疗淋病，但它们用作 由于耐药性高，前线治疗在2006年停产。细胞靶 喹诺酮是细菌II型拓扑异构酶，回旋酶和拓扑异构酶IV。标识和 针对这些验证良好的酶靶标的新型药物的表征，但要克服 相关的耐药性可能对淋病的临床治疗产生重要的影响。 回旋酶和拓扑异构酶IV是调节DNA下和越来越多的DNA的必需酶 通过在遗传物质中产生瞬态双链断裂来消除DNA结和缠结。 喹诺酮通过增加这些回旋酶 - 和拓扑异构酶IV生成的双苯甲酸酶的水平来杀死细菌 滞留的DNA断裂，将这些酶转化为碎裂基因组的致命蛋白。两个都 酶是喹诺酮类药物的靶标，但它们对药物作用的重要性是物种和药物依赖性的。最初的 喹诺酮类抗性通常与回旋酶和/或拓扑异构酶IV中的特异性突变有关 发生在高度组成的SER住宅或位于4恢复下游的GLU/ASP。基于出版 Osheroff实验室的结构和一系列功能研究，这些研究描绘了相互作用 来自炭疽芽孢杆菌，大肠杆菌和结核分枝杆菌的药物和酶，这些 残留物锚定了一个水 - 金属桥，该桥是奎诺酮与类型之间的主要导管 II酶。通过表征奎诺酮 - 昆虫异构酶的相互作用，PI设计了新型药物 由于结核分枝杆菌的突变和炭疽芽孢杆菌和拓扑异构酶IV的突变而克服耐药性。 最近，一种新的萘甲苯酮/基于氨基哌啶的剂，“新型细菌拓扑异构酶 据报道抑制剂（NBTIS）。NBTIS靶标细菌II型拓扑异构酶，但几乎没有或没有交叉表现 在回旋酶或拓扑异构酶IV中对临床相关的奎诺酮抗性突变的抗性。不像 奎诺酮，这些药物要么充当催化抑制剂，要么诱导酶介导的单链DNA 休息。但是，尚未报告该药物类的任何成员的其他机械信息。 gepotidacin是一种针对淋病的临床试验中的NBTI，显示了针对野生型和 耐喹诺酮乳杆菌植物文化。但是，它的行动，也不是任何其他NBTI的行动 已经描述了淋病的旋转二和拓扑异构酶IV。 迫切需要开发新药物来治疗抗性淋病（以及其他抗药性 细菌感染）。拟议研究的基础的前提是了解毒品 与他们的酶目标相互作用使我们处于更好的位置，以开发克服抗药性的药物。 这是该提议的具体目的是1）确定喹诺酮类行动的机械基础 N.淋病旋转酶和拓扑异构酶IV，定义了靶介导的奎诺酮抗性的基础，并定义 利用这些发现来识别克服最常见形式的抗性形式的喹诺酮。和2） 确定NBTI对淋病链球菌和拓扑异构酶IV的作用的机械基础。 尽管这项研究的主要研究模型将是淋病二和拓扑异构酶IV，但 还计划了细胞研究。此外，一些提出的研究可能利用结核分枝杆菌，大肠杆菌， 或B.用于比较目的的炭疽模型。最后，拟议的研究受益于以前 Osheroff实验室的研究对细菌和真核II型拓扑异构酶的机制以及 这些酶与喹诺酮类和其他药物的相互作用。