Identification of the target of meclonazepam in schistosome worms

甲氯硝西泮在血吸虫中作用靶点的鉴定

• 批准号: 10357874
• 负责人: Pavel A Petukhov
• 金额: $ 19.7万
• 依托单位: RUSH UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-22 至 2023-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10357874
• 关键词: Anti-Anxiety Agents; Benzodiazepine Receptor; Benzodiazepines; Binding; Binding Proteins; Biochemical; Biochemistry; Biological Assay; Biological Process; Biology; Biophysics; Butyric Acids; Cessation of life; Chronic Disease; Clinical; Computer Analysis; Computer Assisted; Country; Coupled; Data Set; Disease; Dose; Drug Targeting; Drug resistance; Evolution; Exhibits; Foundations; Future; Gene Silencing; Genome; Glutamates; Goals; Homologous Gene; Human; Infection; Investigation; Label; Ligands; Mass Spectrum Analysis; Medical; Methods; Molecular; Molecular Target; Morbidity - disease rate; Parasite resistance; Parasites; Persons; Pharmaceutical Chemistry; Pharmaceutical Preparations; Phenotype; Praziquantel; Praziquantel resistance; Prevalence; Proteins; Proteome; Proteomics; RNA Interference; Recombinants; Research; Research Personnel; Schistosoma; Schistosoma mansoni; Schistosome Parasite; Schistosomiasis; Solubility; Techniques; Testing; Therapeutic; Validation; analog; base; chemotherapy; clinically relevant; design; disability; drug discovery; genome database; glutamate-gated chloride channel; inhibitor; insight; lead candidate; meetings; neglect; new therapeutic target; novel; novel therapeutics; prevent; protein expression; receptor; side effect; small molecule; transmission process

PROJECT SUMMARY/ABSTRACT Schistosome parasites infect 200 million people, resulting in significant morbidity and more than 200,000 deaths annually. Schistosomiasis control strategies rely almost exclusively on chemotherapy and tens of millions of people are treated with the only available drug, praziquantel (PZQ). There are no new drugs in the clinical pipeline. PZQ cure rates obtained in mass drug administration campaigns are typically less than 50%. Furthermore, with projected levels of PZQ use it is inevitable that PZQ-resistant parasites will evolve. Therefore, it is imperative to identify new drug targets and drugs for schistosomiasis treatment. A number of highly promising compounds with antischistosomal activity have been identified. However, further advancement of these compounds to drugs is impeded because their targets are unknown. In this regard, the benzodiazepine derivative meclonazepam (Ro11-3128) had been identified as a lead candidate. Meclonazepam exhibited potent therapeutic activity against both mature and immature stages of S. mansoni and S. haematobium in humans. Unfortunately, the drug was later discontinued due to its lack of selectivity resulting in unacceptable side effects at therapeutic doses. Meclonazepam is an anxiolytic benzodiazepine that is an allosteric modulator of mammalian gamma-amino butyric acid receptors. No homologues in Schistosoma worms have been identified in genome databases. The closest matches (glutamate-gated transporters) have been investigated and were not inhibited by meclonazepam. This indicates that the target of meclonazepam in schistosomes is not a known benzodiazepine receptor and remains undiscovered. This revised R21 proposal is designed to test the central hypothesis that meclonazepam kills worms through interaction with a worm-specific and unknown target. We propose to identify the target of meclonazepam in Schistosoma parasites using orthogonal and complementary approaches (1) design and synthesis of novel, drug-like meclonazepam-based photoreactive probes, and (2) biophysical changes in proteins bound to inhibitors. We anticipate multiple proteins being identified by these analyses. Proteins will be studied further if (1) they were identified only in species sensitive to meclonazepam and not in those insensitive, (2) they were identified in worms treated with meclonazepam or active analogs and not in worms treated with inactive analogs, and (3) meclonazepam competes with probe binding to the protein. Proteins meeting these strict criteria will be selected for further investigation. Analysis of potential function, recombinant expression and biochemical analysis, and gene silencing will be used to confirm the targets. Identification of the molecular target in the worm is the essential first step needed to develop novel therapeutic targets and produce clinically relevant treatments for schistosomiasis.

项目概要/摘要 血吸虫寄生虫感染 2 亿人，导致严重发病，超过 20 万人 每年死亡人数。血吸虫病控制策略几乎完全依赖于化疗和数十种 数百万人接受唯一可用的药物吡喹酮 (PZQ) 的治疗。国内尚无新药 临床管线。在大规模药物管理运动中获得的 PZQ 治愈率通常低于 50%。 此外，随着 PZQ 使用的预计水平，抗 PZQ 寄生虫将不可避免地进化。 因此，寻找新的治疗血吸虫病的药物靶点和药物势在必行。 已经鉴定出许多具有抗血吸虫活性的非常有前景的化合物。然而，进一步 这些化合物向药物的发展受到阻碍，因为它们的目标未知。对此， 苯二氮卓衍生物甲氯硝西泮 (Ro11-3128) 已被确定为主要候选药物。 甲氯硝西泮对成熟和未成熟阶段的曼氏沙门氏菌均表现出有效的治疗活性 和人类的埃及沙门氏菌。不幸的是，该药物后来因缺乏选择性而停产 导致治疗剂量下不可接受的副作用。甲氯硝西泮是一种抗焦虑苯二氮卓类药物， 是哺乳动物γ-氨基丁酸受体的变构调节剂。血吸虫中没有同源物 蠕虫已在基因组数据库中被识别。最接近的匹配（谷氨酸门控转运蛋白）有 已被研究并且不被甲氯硝西泮抑制。这表明甲氯西泮的目标 血吸虫不是已知的苯二氮卓类受体，并且尚未被发现。 修订后的 R21 提案旨在检验甲氯西泮通过以下方式杀死蠕虫的中心假设： 与蠕虫特定且未知的目标相互作用。我们建议确定甲氯西泮的靶点 使用正交和互补方法（1）设计和合成新型血吸虫寄生虫， 基于甲氯硝西泮的药物样光反应探针，以及 (2) 结合的蛋白质的生物物理变化 抑制剂。我们预计这些分析将鉴定出多种蛋白质。蛋白质将被进一步研究，如果 (1) 仅在对甲氯硝西泮敏感的物种中发现了它们，而在不敏感的物种中未发现它们，(2) 在用甲氯硝西泮或活性类似物处理的蠕虫中发现，而在用非活性类似物处理的蠕虫中则没有发现 类似物，(3)甲氯硝西泮与探针竞争与蛋白质的结合。满足这些严格要求的蛋白质 将选择标准进行进一步调查。潜在功能、重组表达和分析 将使用生化分析和基因沉默来确认目标。分子鉴定 蠕虫体内的靶点是开发新的治疗靶点并进行临床生产所需的重要的第一步 血吸虫病的相关治疗。