Diethylcarbamazine, Emodepside and SLO-1 K Channels of Filaria

二乙基卡马嗪、艾莫德苷和丝虫的 SLO-1 K 通道

• 批准号: 9807551
• 负责人: Richard John Martin
• 金额: $ 22.29万
• 依托单位: IOWA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-16 至 2021-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9807551
• 关键词: Adult; Affect; Agonist; Amino Acids; Animal Model; Animals; Anthelmintics; Arachidonic Acids; Area; Binding; Binding Sites; Biological Assay; Blindness; Brugia; Brugia malayi; Caenorhabditis elegans; Calcium; Cells; Central Africa; Chelating Agents; Cicatrix; Combined Modality Therapy; Cornea; Dermatitis; Detection; Diethylcarbamazine; Disease; Double-Stranded RNA; Drug Targeting; Drug effect disorder; Drug usage; Electrophysiology (science); Filarial Elephantiases; Filariasis; Helminths; Human; Infection; Insecta; Intestinal Volvulus; Investigation; Ion Channel; Knowledge; Larva; Mediating; Membrane; Metabolic Pathway; Microfilaria; Molecular; Molecular Target; Muscle; Muscle Cells; Nematoda; Nematode infections; Ocular Onchocerciasis; Onchocerca; Onchocerca volvulus; Onchocerciasis; Oocytes; Parasites; Parasitic nematode; Pharmaceutical Preparations; Pharmacology; Pharmacotherapy; Potassium Channel; Prevention; Property; Prophylactic treatment; Pruritus; Publishing; RNA Interference; RNA Splicing; Resistance; Resistance development; Risk; Services; Site; Slice; Structure; Techniques; Testing; Toxic effect; Vaccines; Variant; Visualization software; Xenopus; Xenopus oocyte; cell motility; chemotherapy; design; filaria; gastrointestinal; human model; iberiotoxin; improved; innovation; knock-down; large-conductance calcium-activated potassium channels; molecular site; mortality; neglected tropical diseases; novel therapeutics; patch clamp; programs; success; therapy development; voltage clamp

Project Summary Filariasis is a group of neglected tropical diseases produced by infection with microfilaria of Clade III parasitic nematodes that ae transmitted by biting insects. River Blindness caused by Onchocerca volvulus, and Lymphatic Filariasis produced by Brugia malayi are examples of these diseases. River Blindness is caused by parasites that produce scaring of the cornea as well as severe itching and dermatitis; it infects 17 million people in West and Central Africa. Lymphatic filariasis is a debilitating and disfiguring disease, which occurs in 120 million people worldwide. Control of these nematode parasites relies on a small number of anthelmintic drugs, which have a limited spectrum of action. There are no practical macrofilaricides, which kill the adult parasites in the host; and there are concerns that mass microfilaricide chemotherapy will lead to the development of resistance. Diethylcarbamazine is a mainstay for the treatment of lymphatic filariasis in most parts of the world, except in areas where onchocerciasis is present because it is contra-indicated by risks of blindness. It produces rapid clearance of microfilaria and causes ~40% mortality of adult parasites (macrofilaricide). It is striking however, that 68 years after its introduction, we have no proven understanding of the molecular mechanism of its action. Here, we propose to re-invigorate this investigation by studying its effects on filarial ion-channels, including effects on SLO-1 K channels. Emodepside is an emerging and important cyclooctadepsipeptide class of anthelmintic that also has effects on microfilaria and adult filaria. Single emodepside treatments could allow a major advance over existing mass drug administration (MDA) programs which require regular treatments to kill adult parasites. One of the putative sites of action of emodepside is on nematode SLO-1 K channels where opening of the channels inhibits motility, but it is not effective against all filaria. Here we propose to examine filarial SLO-1 K channels as sites of action of emodepside. Our approach will focus on Brugia malayi but we will also use include studies on Onchocerca and human channels. We will use patch-clamp, dsRNA knock down, Worminator motility assays and Xenopus expression to characterize the functional properties of innate SLO-1 K channels from Brugia malayi. In Aim #1, we will test the hypothesis that Brugia malayi SLO-1 K channels are the only target sites of diethylcarbamazine and emodepside. We will use patch-clamp recordings of SLO-1 K channels from Brugia muscle cells and examine effects of knock down of putative targets. We propose, in , to express Onchocerca, human and Brugia SLO-1 K channels splice variants in Xenopus oocytes to test the hypothesis that different species of filaria and human SLO-1 K channels are pharmacologically separable using emodepside and K channel agonists. Aim #2 The proposal is innovative, using a combination of techniques to test the effects of diethylcarbamazine and emodepside on their putative target sites, SLO-1 K channels of filarial. The overall impact of using this mixture of techniques, will be the discovery of effects of diethylcarbamazine and emodepside on filarial SLO-1 K channel splice variants, and an improved characterization of the modes of action of diethylcarbamazine and emodepside. Knowledge of the molecular sites of action of these drugs is required for: a) molecular detection of resistance; b) designing new drugs and combination therapies; c) predicting and understanding sensitivities of different nematode parasite species; and d) predicting host toxicity

项目摘要 丝虫病是一组被忽视的热带疾病，由微丝蚴感染引起 由叮咬昆虫传播的寄生线虫。河盲症由 盘尾丝虫和马来丝虫引起的淋巴丝虫病就是其中的例子 疾病河盲症是由寄生虫引起的，寄生虫会使角膜产生疤痕， 严重的瘙痒和皮炎;它感染了西非和中非的1700万人。淋巴 丝虫病是一种使人衰弱和毁容的疾病，全世界有1.2亿人感染。 控制这些线虫寄生虫依赖于少量的驱虫药， 有限的行动范围目前还没有实用的杀灭成虫的杀微丝蚴剂 在宿主中;并且有人担心大规模杀微丝蚴剂化疗将导致 发展抵抗力。 乙胺嗪是世界大部分地区治疗淋巴丝虫病的主要药物。 世界上，除了存在盘尾丝虫病的地区，因为它是禁忌的风险， 失明它能迅速清除微丝蚴，并导致约40%的成虫死亡 （macrofilaricide）。然而，令人惊讶的是，在其引入68年后，我们没有证明 了解其作用的分子机制。在这里，我们建议重新振兴这一点， 通过研究其对丝虫离子通道的影响，包括对SLO-1 K通道的影响，进行了研究。 苯缩酚酸是一种新兴的重要的环八缩酚肽类驱虫药， 对微丝蚴和成虫有作用。单一的emodepside治疗可以让一个主要的 先进的现有大规模药物管理（MDA）计划，需要定期 杀死成年寄生虫的方法推测的依莫得甙作用位点之一是线虫 SLO-1 K通道，其中通道的开放抑制运动性，但它不是对所有 丝虫。在这里，我们建议审查丝虫SLO-1 K通道的网站emodepside的行动。 我们的方法将集中在马来丝虫，但我们也将使用包括盘尾丝虫的研究 人的渠道。我们将使用膜片钳，dsRNA敲除，蠕虫运动分析 和非洲爪蟾表达来表征先天SLO-1 K通道的功能特性 来自马来丝虫。在 目标1， 我们将检验马来丝虫SLO-1 K 通道是乙胺嗪和依莫地昔单抗的唯一靶位点。我们将使用 膜片钳记录来自Brugia肌细胞的SLO-1 K通道，并检查 打击假想目标。我们建议，在，表达盘尾丝虫，人类和 在非洲爪蟾卵母细胞中Brugia SLO-1 K通道剪接变体，以检验以下假设： 不同种类的丝虫和人SLO-1 K通道是可分离的 使用依莫地昔和K通道激动剂。 目标2 该提案具有创新性，使用多种技术来测试 乙胺嗪和依莫地昔芬对丝虫SLO-1钾通道的作用。 使用这种混合技术的总体影响将是发现 乙胺嗪和emodepside对丝虫SLO-1 K通道剪接变异体的作用，以及一种改进的 乙胺嗪和依莫地昔的作用模式的表征。知识 需要这些药物的分子作用位点：a）耐药性的分子检测; B）设计新药和联合疗法; c）预测和了解敏感性 不同的线虫寄生虫物种;和d）预测宿主毒性