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.

项目摘要/摘要 阴茎寄生虫感染了2亿人，导致大量发病率和超过200,000 每年死亡。血吸虫病控制策略几乎完全依赖于化学疗法和数十个 数以百万计的人接受了唯一可用的药物Praziquantel（PZQ）的治疗。没有新药 临床管道。大众药物管理运动中获得的PZQ治疗率通常小于50％。 此外，随着PZQ的预计水平，不可避免的是PZQ抗性寄生虫会发展。 因此，必须确定新的药物靶标和血吸虫病治疗的药物。 已经鉴定出许多具有抗肌体活动的高度有希望的化合物。但是，进一步 这些化合物将这些化合物的进步受到阻碍，因为它们的靶标是未知的。在这方面， 苯二氮卓类衍生物Meclonazepam（RO11-3128）已被确定为主要候选人。 Meclonazepam对S. Mansoni的成熟和未成熟阶段表现出强大的治疗活性 和人类的S. haematobium。不幸的是，由于缺乏选择性，该药物后来停产 在治疗剂量时导致不可接受的副作用。 meclonazepam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 在基因组数据库中已经确定了蠕虫。最接近的匹配（谷氨酸门控转运蛋白）具有 被调查，未被麦克洛齐ep抑制。这表明Meclonazepam的目标 血吸虫不是已知的苯二氮卓受体，并且未被发现。 该修订后的R21提案旨在检验中心假设，即meclonazepam通过 与蠕虫特异性和未知目标的相互作用。我们建议确定Meclonazepam的目标 血吸虫寄生虫使用正交和互补方法（1）新颖的设计和合成， 基于药物的麦伦西eepam的光电反应性探针，以及（2）蛋白质的生物物理变化 抑制剂。我们预计通过这些分析可以识别多种蛋白质。如果 （1）仅在对麦伦西ep敏感的物种中发现它们，而不是在那些不敏感的物种中，（2）它们是 在用meclonazepam或活性类似物处理的蠕虫中鉴定出来，而不是在没有活性治疗的蠕虫中 类似物，（3）麦伦辛ep竞争探针与蛋白质的结合。蛋白质符合这些严格 标准将被选为进一步调查。分析潜在功能，重组表达和 生化分析和基因沉默将用于确认靶标。鉴定分子 蠕虫中的目标是开发新型治疗靶标并在临床上产生的必要第一步 血吸虫病的相关治疗方法。