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: 10468815
• 负责人: Richard John Martin
• 金额: $ 46.91万
• 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/10468815
• 关键词: Adult; Adverse effects; African; Anthelmintics; Arachidonic Acids; Area; Basic Science; Blindness; Brugia; Brugia malayi; Calcium; Combined Modality Therapy; 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; Persons; Pharmaceutical Preparations; Pharmacology; Pharmacotherapy; Potassium Channel; Prevention; Prophylactic treatment; RNA Splicing; Recovery; Research; Resistance; Risk; Services; Site; Surgical Flaps; Techniques; Testing; Toxic effect; Variant; cell motility; comparative; desensitization; design; detection sensitivity; 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; vaccine access

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 丝虫是一组被忽视的热带疾病，该疾病是由枝条III的微丝菌感染产生的 通过咬昆虫传播的寄生线虫。一个例子是淋巴丝虫病 由Brugia Malayi生产。淋巴丝虫病是一种令人衰弱和毁容的疾病，发生在 全球1.2亿人。其他丝状疾病是OnChocerca产生的河流失明 LOA LOA产生的Volvulus和loiasis。这些线虫寄生虫疾病的预防和治疗 由于没有有效的疫苗，因此依赖于使用驱虫药。使用预防 大众药物管理局[MDA]计划受到现有驱虫药的功效的限制。 二乙基卡马嗪是在大多数部位治疗淋巴丝虫病和loiasis的中流 除了存在chocerceriasis的地区，世界除外，由于失明的风险与之相遇。 二乙基卡马嗪产生微丝菌的快速清除率，并导致约40％的成年寄生虫死亡率 （大紫杉醇）。许多研究表明，二乙基甘巴嗪具有间接的宿主 - 介导的作用方式和二乙基甘巴氨氮通过改变宿主蛛网膜酸途径而起作用。 我们已经观察到，二乙基甘巴嗪对丝状线虫有直接影响。我们在场 初步观察结果表明，二乙基卡马嗪增加了TRP-2通道的开放 Brugia Malayi和钙激活的SLO-1 K通道的开放。效果是快速，短暂的 抑制运动，然后恢复：响应可容纳。 Emodepside是一种新兴而重要的环链脱皮细胞肽类，也有 对微丝虫和成年丝状的影响。 Emodepside治疗可以使现有的重大进步 大众药物管理局（MDA）计划，需要定期治疗以杀死成人寄生虫。一 emodepside的作用部位的位于线虫slo-1 k通道上 抑制运动能力，但对所有丝状易于有效。在这里，我们建议比较对丝状slo-的影响 来自Brugia，Onchocerca和Loa的1个k频道，并检查这两个的动作和相互作用 药物探索其作用方式。 我们有3个目标： 目的＃1：在体外表征浓度抑制运动响应关系的关系 二乙基卡马嗪和Emodepside及其组合：a）Brugia微丝菌； b）布鲁吉亚 成年女性； c）布鲁吉亚成年男性。 我们将检验以下假设，即二乙基甘巴马嗪的影响 Emodepside是添加剂，协同或对抗的，以及生命周期阶段和性别的依赖。 AIM＃2表征SLO-1 K通道当前对二乙基卡马嗪的反应和 在斑块钳下的孤立的brugia malayi肌肉襟翼中的Emodepside 我们将检验这些假设： a）emodepside和二乙基甘巴马嗪的作用相互作用； b）相互作用 二乙基卡马嗪和emodepside取决于TRP-2的trp-2的存在 频道； c）TRP-2和SLO-1频道消息和频道打开可容纳 长时间暴露于二乙基卡马嗪或Emodepside。 AIM＃3：表征：A）不同的SLO-1 K通道的比较分子药理学 Brugia Malayi，OnChocerca Volvulus和Loa Loa和； B）Brugia Malayi的TRP-2通道和 LOA LOA在卵母细胞中表达。 我们将检验以下假设 slo-1 k通道和trp-2通道上的Emodepside和Diethylcarbamazine，brugia，onChocerca LOA与人类通道同源物不同，也不同。我们将检查频道 脱敏。 该提案是创新的，结合了技术来测试二乙基卡马嗪的影响 以及在其推定的目标位点上的Emodepside，即SLO-1 K丝状渠道。使用的总体影响 我们的技术混合物将是发现和比较二乙基瓜胺和 在不同种类的丝状TRP-2通道和SLO-1 K通道上的Emodepside。了解 这些药物的分子作用是：a）分子检测不同丝的敏感性 物种和抗性； b）设计新药和组合疗法； c）预测和 了解不同线虫寄生虫物种的敏感性； d）预测可能的宿主毒性。