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

基本信息

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
项目类别：
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

项目摘要

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

项目概要丝虫病是由分支微丝蚴感染引起的一组被忽视的热带疾病 III 寄生线虫，通过昆虫叮咬传播。河盲症是由什么原因引起的盘尾丝虫和由马来丝虫产生的淋巴丝虫病就是这些例子疾病。河盲症是由寄生虫引起的，寄生虫会造成角膜疤痕以及严重瘙痒和皮炎；它感染了西非和中非的 1700 万人。淋巴管丝虫病是一种使人衰弱和毁容的疾病，全世界有 1.2 亿人患有该病。对这些线虫寄生虫的控制依赖于少量的驱虫药物，这些药物已有限的行动范围。没有实用的杀灭大丝虫剂，可以杀死成虫寄生虫在主机中；人们担心大规模杀微丝蚴化疗会导致抵抗力的发展。二乙基卡马嗪是大多数地区治疗淋巴丝虫病的主要药物世界各地，但存在盘尾丝虫病的地区除外，因为盘尾丝虫病的风险是禁忌的。失明。它能快速清除微丝蚴并导致约 40% 的成虫死亡率（杀大丝虫剂）。然而，令人惊讶的是，在其推出 68 年后，我们还没有证明了解其作用的分子机制。在此，我们建议重振这一活力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）进行调查。 Emodepside 是一种新兴且重要的环八缩酚肽类驱虫药，也对微丝蚴和成丝蚴有作用。单一艾默德赛治疗可以使主要优于现有的大规模药物管理 (MDA) 计划，该计划需要定期进行杀死成虫寄生虫的治疗。艾莫德苷的假定作用位点之一是在线虫上 SLO-1 K 通道，通道的开放会抑制运动，但并非对所有通道都有效丝虫。在这里，我们建议检查丝虫 SLO-1 K 通道作为 emodepside 的作用位点。我们的方法将重点关注马来丝虫，但我们也将使用包括盘尾丝虫的研究和人力渠道。我们将使用膜片钳、dsRNA 敲除、Worminator 运动测定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布鲁贾。在目标#1，我们将检验马来丝虫 SLO-1 K 的假设通道是二乙基卡马嗪和艾莫德苷的唯一靶位点。我们将使用来自布鲁吉亚肌细胞的 SLO-1 K 通道的膜片钳记录并检查击倒假定的目标。我们建议，在中表达 Onchocerca、人类和 Brugia SLO-1 K 通道爪蟾卵母细胞中的剪接变异体，以检验以下假设：不同种类的丝虫和人类 SLO-1 K 通道在药理学上是可分离的使用 emodepside 和 K 通道激动剂。目标#2 该提案具有创新性，使用多种技术组合来测试效果二乙基卡马嗪和艾默德苷位于丝虫的假定靶位点 SLO-1 K 通道上。使用这种技术组合的总体影响将是发现以下效果：二乙基卡马嗪和艾莫德苷对丝虫 SLO-1 K 通道剪接变体的影响，以及改进的二乙基卡马嗪和艾默德苷的作用方式的表征。知识这些药物的分子作用位点对于以下目的是必需的： a) 耐药性的分子检测； b) 设计新药和联合疗法； c) 预测和理解敏感性不同线虫寄生虫种类； d) 预测宿主毒性