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.

淋病是由淋病奈瑟菌引起的一种性传播疾病，目前已成为一种性传播疾病。 被疾病预防控制中心列为四个“紧急级别”耐药菌之一 该疾病在现役军人中普遍存在，并且发病率似乎有所上升。 尽管从 1993 年开始常规使用喹诺酮类药物治疗淋病，但其使用 由于耐药性的高发生率，一线治疗于 2006 年停止。 喹诺酮类药物是细菌II型拓扑异构酶、旋转酶和IV型拓扑异构酶。 对抗这些经过充分验证的酶靶标的新型药物的表征，但克服了 相关的耐药性可能对淋病的临床治疗产生重要影响。 旋转酶和拓扑异构酶 IV 是调节 DNA 欠缠绕和过缠绕的必需酶。 通过在遗传物质中产生短暂的双链断裂来消除 DNA 结和缠结。 喹诺酮类药物通过增加这些旋转酶和拓扑异构酶 IV 生成的双链酶的水平来杀死细菌。 链状 DNA 断裂，将这些酶转化为致命的蛋白质，使基因组片段化。 酶是喹诺酮类药物的靶标，但它们对药物作用的重要性取决于物种和药物。 喹诺酮耐药性通常与旋转酶和/或拓扑异构酶 IV 的特定突变有关， 发生在高度保守的 Ser 残基或位于下游 4 个残基处的 Glu/Asp。 Osheroff 实验室的结构和一系列功能研究描述了之间的相互作用 来自炭疽杆菌、大肠杆菌和结核分枝杆菌的药物和酶，这些 残留物锚定了水-金属离子桥，作为喹诺酮类药物和类型之间的主要管道 通过表征喹诺酮-拓扑异构酶相互作用，PI 设计了新的药物 克服由于结核分枝杆菌促旋酶、炭疽芽孢杆菌促旋酶和拓扑异构酶 IV 突变而产生的耐药性。 最近，一类新的基于萘啶酮/氨基哌啶的药物“新型细菌拓扑异构酶” NBTI 以细菌 II 型拓扑异构酶为目标，但几乎没有交叉作用 对旋转酶或拓扑异构酶 IV 中临床相关的喹诺酮耐药突变的耐药性。 喹诺酮类药物，这些药物要么充当催化抑制剂，要么诱导酶介导的单链 DNA 然而，尚未报告该药物类别的任何成员的其他机制信息。 Gepotidacin 是一种 NBTI，正在进行针对淋病的临床试验，显示出针对野生型和 然而，它的作用以及任何其他 NBTI 的作用都没有。 淋病奈瑟菌旋转酶或拓扑异构酶 IV 已被描述。 迫切需要开发新药来治疗耐药性淋病（以及其他耐药性淋病） 细菌感染）。拟议研究的前提是了解药物如何作用。 与它们的酶靶标相互作用使我们能够更好地开发克服耐药性的药物。 因此，该提案的具体目标是 1) 确定喹诺酮类药物作用的机制基础 淋病奈瑟菌旋转酶和拓扑异构酶 IV，定义了靶标介导的喹诺酮耐药性的基础，以及 利用这些发现来识别能够克服最常见耐药形式的喹诺酮类药物；2) 确定 NBTI 对抗淋病奈瑟菌旋转酶和拓扑异构酶 IV 作用的机制基础。 尽管本研究的主要研究模型是淋病奈瑟菌旋转酶和拓扑异构酶 IV， 此外，一些拟议的研究可能会利用结核分枝杆菌、大肠杆菌、 最后，所提出的研究大大受益于以前的研究。 Osheroff 实验室关于细菌和真核 II 型拓扑异构酶机制的研究 这些酶与喹诺酮类药物和其他药物的相互作用。