Slo-1K channels, TRP-2 channels, emodepside and diethylcarbamazine in Filaria

丝虫中的 Slo-1K 通道、TRP-2 通道、艾默德苷和二乙基卡马嗪

• 批准号: 10089614
• 负责人: Richard John Martin
• 金额: $ 46.45万
• 依托单位: IOWA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-16 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10089614
• 关键词: Adult; Adverse effects; African; Anthelmintics; Arachidonic Acids; Area; Basic Science; Blindness; Brugia; Brugia malayi; Calcium; Combined Modality Therapy; Detection; Development; Diethylcarbamazine; Disease; Disputes; Dopachrome isomerase; Evolution; Exposure to; Eye; Female; Filarial Elephantiases; Homologous Gene; Human; In Situ; In Vitro; Infection; Insecta; Intestinal Volvulus; Ion Channel; Knowledge; Larva; Life Cycle Stages; Loa; Loa loa; Loiasis; Mediating; Messenger RNA; Microfilaria; Molecular; Muscle; Nematoda; Nematode infections; Ocular Onchocerciasis; Onchocerca; Onchocerca volvulus; Onchocerciasis; Oocytes; Parasites; Parasitic nematode; Pathway interactions; Pharmaceutical Preparations; Pharmacology; Pharmacotherapy; Potassium Channel; Prevention; Prophylactic treatment; RNA Splicing; Recovery; Research; Resistance; Risk; Services; Site; Surgical Flaps; Techniques; Testing; Toxic effect; Vaccines; Variant; cell motility; comparative; desensitization; design; differential expression; drug action; filaria; gastrointestinal; human model; innovation; knock-down; male; mortality; neglected tropical diseases; novel therapeutics; patch clamp; phase II trial; programs; response; sex; success

Project Summary Filariases are a group of neglected tropical diseases produced by infection with microfilaria of Clade III parasitic nematodes that are transmitted by biting insects. One example is the lymphatic filariasis produced by Brugia malayi. Lymphatic filariasis is a debilitating and disfiguring disease which occurs in 120 million people worldwide. Other filarial diseases are River Blindness produced by Onchocerca volvulus and loiasis produced by Loa loa. Prevention and treatment of these nematode parasite diseases relies on the use of anthelmintic drugs because no effective vaccines are available. Prophylaxis using Mass Drug Administration [MDA] programs are limited by the efficacy of existing anthelmintics. Diethylcarbamazine is a mainstay for the treatment of lymphatic filariasis and loiasis in most parts of the world, except in areas where onchocerciasis is present because it is contra-indicated by risks of blindness. Diethylcarbamazine produces rapid clearance of microfilaria and causes ~40% mortality of adult parasites (macrofilaricide). A number of studies have suggested that diethylcarbamazine has an indirect host- mediated mode of action and that diethylcarbamazine acts by changing host arachidonic acid pathways. We have observed that diethylcarbamazine has direct effects on filarial nematodes. We present preliminary observations that show that diethylcarbamazine increases the opening of TRP-2 channels in Brugia malayi, and opening of calcium-activated SLO-1 K channels. The effect is a rapid, transient inhibition of motility followed by recovery: the response accommodates. Emodepside is an emerging and important cyclooctadepsipeptide class of anthelmintic that also has effects on microfilaria and adult filaria. 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 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 compare effects on filarial SLO- 1 K channels from Brugia, Onchocerca and Loa and to examine actions and interactions of these two drugs to explore their mode of action. We have 3 aims: Aim #1: Characterize, in vitro, the concentration motility-inhibition-response relationships of diethylcarbamazine and emodepside and their combination on: A) Brugia microfilaria; B) Brugia adult females; C) Brugia adult males. We will test the hypothesis that effects of diethylcarbamazine and emodepside are additive, synergistic or antagonistic and dependent of life-cycle stage and sex. Aim #2 Characterize the SLO-1 K channel current responses to diethylcarbamazine and emodepside in isolated Brugia malayi muscle flaps under patch-clamp We will test the hypotheses: a) that the effects of emodepside and diethylcarbamazine interact; b) that the interactions of diethylcarbamazine and emodepside are dependent on the presence of TRP-2 by knockdown of TRP-2 channels; and c) that TRP-2 and SLO-1 channel message & channel opening accommodates during prolonged exposure to diethylcarbamazine or emodepside. Aim #3: Characterize the comparative molecular pharmacology of: a) different SLO-1 K channels of Brugia malayi, Onchocerca volvulus and Loa loa and; b) TRP-2 channels of Brugia malayi and Loa loa expressed in oocytes. We will test the hypothesis that the pharmacology and potencies of emodepside and diethylcarbamazine on SLO-1 K channels and TRP-2 channels of, Brugia, Onchocerca and Loa are different and also different to a human channel homologue. We will examine channel desensitization. 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 our mixture of techniques, will be discovery and comparison of effects of diethylcarbamazine and emodepside on different species of filarial TRP-2 channels and SLO-1 K channels. Knowledge of the molecular actions of these drugs is required for: a) molecular detection of sensitivity of different filarial species and resistance; b) designing new drugs and combination therapies; c) predicting and understanding sensitivities of different nematode parasite species; and d) predicting possible host toxicity.

项目摘要 丝虫病是一组被忽视的热带疾病，由感染第三分支微丝虫病引起 通过咬人的昆虫传播的寄生线虫。淋巴丝虫病就是一个例子。 由Brugia Malayi制作。淋巴丝虫病是一种衰弱和毁容的疾病，发生在 全球有1.2亿人。其他丝虫病是由丝虫引起的河盲症 由Loa Loa引起的扭转和钩虫病。这些线虫寄生虫病的防治 依赖于驱虫药的使用，因为没有有效的疫苗可用。预防使用 大众药物管理局[MDA]计划受到现有驱虫药疗效的限制。 乙基卡马津是治疗淋巴丝虫病和线虫病的主要药物，在中国大部分地区 在世界范围内，除在存在盘尾丝虫病的地区外，这种疾病的发病率很高，因为有致盲的风险。 乙基乙胺嘧啶能迅速清除微丝虫病，并导致约40%的成虫死亡 (大杀丝剂)。多项研究表明，乙基卡马津具有间接宿主-- 通过改变宿主花生四烯酸途径发挥作用。 我们观察到乙基乙胺嘧啶对丝虫有直接作用。我们呈现的是 初步观察表明，乙基卡马津可增加心肌细胞Trp-2通道的开放。 和开放钙激活的SLO-1 K通道。这种影响是迅速的、短暂的。 运动抑制后恢复：反应适应。 依莫地平是一种新兴的重要的环八肽类驱虫药，它还具有 对微丝虫和成虫的影响。依莫地平治疗可以比现有的治疗方法有更大的进步 大规模药物管理(MDA)计划，需要定期治疗以杀死成虫。一 表情素的作用部位在线虫SLO-1 K通道上，其中通道开放 抑制运动，但并不是对所有丝虫都有效。在这里，我们建议比较对丝虫病SLO的影响- 来自Brugia、Onchocerca和LoA的1 K通道，并检查这两种通道的作用和相互作用 探索药物的作用模式。 我们有三个目标： 目的#1：体外表征药物的浓度、运动-抑制-反应关系 乙基卡马津和情绪苷及其联合治疗：A)微丝虫；B)丝虫 成年雌性；C)布氏丝虫成年雄性。 我们将检验这一假说，二乙基卡马津的作用 与情绪化是相加的、协同的或拮抗的，且依赖于生命周期阶段和性别。 目的#2研究SLO-1钾通道电流对乙基卡马津和 膜片钳下马来丝虫肌瓣的情绪化 我们将检验这些假设： A)情绪苷和二乙基乙胺嘧啶的作用是相互作用的；b) 乙基卡马津和情绪苷依赖于Trp-2的存在，通过敲除Trp-2 通道；以及c)TRP-2和SLO-1通道消息和通道开放在 长期接触乙基卡马津或情绪化药物。 目的#3：比较分子药理学：a)不同的SLO-1K通道 马来丝虫、螺旋体丝虫和Loa Loa的；b)马来丝虫和 LoA LoA在卵母细胞中表达。 我们将测试这一假设，即药物的药理和效力 莫地平和乙基乙胺嘧啶对丝虫、丝虫SLO-1 K通道和Trp-2通道的影响 和LOA是不同的，也不同于人类通道同源物。我们会研究一下频道 脱敏。 这项提议是创新的，使用一系列技术组合来测试二乙基卡马津的效果 并对其可能的靶点SLO-1丝虫K通道进行了表达。使用的总体影响 我们的混合技术，将是发现和比较乙基乙胺嘧啶和 表达于不同种类的丝虫Trp-2通道和SLO-1 K通道。了解以下内容 这些药物的分子作用需要：a)不同丝虫的敏感性的分子检测 品种和抗药性；b)设计新药和联合疗法；c)预测和 了解不同线虫寄生虫物种的敏感性；以及d)预测可能的宿主毒性。