Cholinergic anthelmintics: Tachyphylaxis mechanisms and control in a parasitic nematode model,Brugia malayi

胆碱能驱虫药：马来丝虫寄生线虫模型的快速耐受机制和控制

• 批准号: 10742175
• 负责人: Sudhanva Srinivas Kashyap
• 金额: $ 2.51万
• 依托单位: IOWA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10742175
• 关键词: Abdominal Pain; Adopted; Adult; Affect; Age; Agonist; Albendazole; Anthelmintics; Ascaris lumbricoides; Biological Assay; Brugia malayi; Caenorhabditis elegans; Calcium; Child; Climate; Cognitive; Complex; Developing Countries; Diarrhea; Down-Regulation; Drosophila acetylcholine receptor alpha-subunit; Endoplasmic Reticulum; Excretory function; Exposure to; Female; Growth; Health; Helminths; Hookworms; Hygiene; Image; Immobilization; Individual; Infection; Ion Channel; Ivermectin; Kinetics; Lactones; Levamisole; Malnutrition; Measures; Mediating; Membrane; Modeling; Muscle; Mutation; Nematoda; Nematode infections; Nicotinic Agonists; Old World Hookworm; Organism; Paralysed; Parasite Control; Parasites; Parasitic nematode; Persons; Pharmaceutical Preparations; Play; Prevention; Proteins; Public Health; Pyrantel; RNA Interference; Recovery; Rectal Prolapse; Reporting; Resistance; Resistance development; Role; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sanitation; Sex Differences; Soil; Tachyphylaxis; Testing; Transcript; Treatment Protocols; Trichocephalus trichiura; benzimidazole; cell motility; cholinergic; desensitization; disease transmission; drug metabolism; experimental study; filaria; helminth infection; improved; in vivo; in vivo calcium imaging; insight; knock-down; male; moxidectin; nicotine exposure; nicotine use; novel; prevent; public health relevance; receptor; synergism; transcription factor; transmission process

Project Summary Soil-transmitted helminth infections are a global concern for public health and affect over 1 billion people worldwide. Infections caused by Ascaris lumbricoides, Trichuris trichiura (whipworms), and Ancylostoma duodenale (hookworms) affect people in warm and moist climates often lacking in hygiene and sanitation and in temperate zones during warmer months. Infected children develop severe malnutrition and show severe physical and cognitive growth. Control of these parasites depends on the administration of anthelmintic drugs like benzimidazoles like albendazole, macrocyclic lactone, ivermectin, and nicotinic agonists like levamisole and pyrantel. The development of resistance to these anthelmintics poses a great challenge in controlling the transmission of these diseases. Parasitic nematodes are complex organisms that adopt complex mechanisms to resist exposure to anthelmintic drugs. We have identified tachyphylaxis as one mechanism the parasite utilizes to resist and recover motility in the continued exposure to the cholinergic anthelmintic levamisole. The endoplasmic reticulum retention protein, NRA-2, is one of the proteins implicated in modulating tachyphylaxis in the female Brugia malayi parasites. The transcription factor, DAF-12 is upregulated in tachyphylactic worms and could play a key role in mediating tachyphylaxis. Macrocyclic lactone, abamectin, has limited effect on its own on the motility of adult B. malayi but, when applied in combination with levamisole, prevents tachyphylaxis and recovery of motility. Here, we propose, Aim #1: To test the hypothesis that DAF-12 mediates tachyphylaxis in B. malayi. We will knockdown daf-12 in adult B. malayi to determine its role in mediating tachyphylaxis. We will measure transcript levels of nra-2 in daf-12 knockdown worms to determine the role of DAF-12 in regulating the expression of nra-2. We will also target DAF-12 using agonists to prevent tachyphylaxis. Aim #2: To test the hypothesis that muscle calcium concentrations & calcium release mechanisms produced by levamisole are changed in the presence of macrocyclic lactones. We will investigate the effects of macrocyclic lactones, abamectin, ivermectin, and moxidectin in prolonging the paralysis induced by levamisole. We will evaluate the change in calcium release mechanisms due to macrocyclic lactones by performing RNAi of the ryanodine and the IP3 receptors, unc-68 and itr-1 in B. malayi, and performing in vivo calcium imaging using C. elegans. At the end of these experiments, we will have characterized DAF-12 as a novel anthelmintic target that could help prevent cholinergic tachyphylaxis. We would have an insight into the effect of macrocyclic lactones on levamisole calcium release mechanisms in nematode muscle. These studies will provide an improved mechanistic insight into cholinergic tachyphylaxis and a rational avenue to prevent worm recovery and resistance.

项目摘要 土壤传播的蠕虫感染是全球关注的公共卫生，影响超过10亿 全球人。阿斯卡里斯·朗布雷德（Ascaris lumbricoides），trichuris trichiura（鞭子）和 Ancylostoma duodeNale（钩虫）在温暖而潮湿的气候下通常缺乏 卫生和卫生以及温暖的月份在温带地区。受感染的儿童发展 严重的营养不良并显示出严重的身体和认知生长。控制这些寄生虫 取决于诸如Albendazole这样的苯咪唑类药物药物的给药， 大环内酯，伊维菌素和烟碱激动剂（如左旋甲虫和吡喃烷）。这 对这些驱虫药的抵抗的发展在控制该驱动器方面构成了巨大的挑战 这些疾病的传播。寄生线虫是采用复杂的复杂生物 抵抗暴露于驱虫药物的机制。我们已经确定速度为一个 寄生虫用来抵抗和恢复运动性的机制。 胆碱能驱虫剂量左右。内质网保留蛋白NRA-2是一个 与在雌性Brugia Malayi寄生虫中调节速度的蛋白质有关的蛋白质。这 转录因子，DAF-12在速度蠕虫中上调，并且可能在 介导速度。大环内酯Abamectin对其自身的影响有限 成人马来语的运动性，但与左旋硅唑结合使用时，可防止 速度和运动的恢复。在这里，我们建议 目的＃1：测试DAF-12介导Malayi中旋转的假设。我们将 成年马来语中敲低的DAF-12，以确定其在介导速度的作用。我们将 测量DAF-12敲低蠕虫中NRA-2的转录水平，以确定DAF-12在 调节NRA-2的表达。我们还将使用激动剂来瞄准DAF-12 速度。 目标＃2：测试肌肉钙浓度和钙释放的假设 在大环存在的情况下，左旋唑产生的机制改变了 内酯。我们将研究大环内酯，腹膜蛋白，ivermectin和 在延长左旋甲唑诱导的瘫痪的过程中。我们将评估更改 通过大环内酯引起的钙释放机制，通过ryanodine进行RNAi 以及Malayi中的IP3受体UNC-68和ITR-1，并在体内钙成像进行 秀丽隐杆线。 在这些实验结束时，我们将以DAF-12的形式将DAF-12描述为一种新的驱虫目标 这可以有助于预防胆碱能的速度。我们会深入了解 在线虫肌肉中的levamisole钙释放机制上的大环内酯。这些 研究将提供改进的机械性洞察力，对胆碱能的速度和理性 防止蠕虫恢复和阻力的途径。