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.

项目概要 土源性蠕虫感染是全球公共卫生问题，影响超过 10 亿人 世界各地的人们。由蛔虫、鞭虫和鞭虫引起的感染 十二指肠钩虫（钩虫）影响温暖潮湿气候中的人们，这些气候通常缺乏 卫生和环境卫生以及温暖月份的温带地区。受感染的儿童发育 严重营养不良，并表现出严重的身体和认知发育。控制这些寄生虫 取决于驱虫药的使用，如苯并咪唑类药物，如阿苯达唑， 大环内酯、伊维菌素和烟碱激动剂如左旋咪唑和噻嘧啶。这 对这些驱虫药的耐药性的发展对控制这些驱虫药提出了巨大的挑战 这些疾病的传播。寄生线虫是复杂的生物体，采用复杂的 抵抗接触驱虫药物的机制。我们已将快速耐受确定为一种 寄生虫在持续暴露于环境的情况下用来抵抗和恢复运动的机制 胆碱能驱虫左旋咪唑。内质网滞留蛋白 NRA-2 是一种 与调节雌性马来丝虫寄生虫的快速耐受有关的蛋白质。这 转录因子 DAF-12 在快速预防性蠕虫中表达上调，可能在 介导快速耐受。大环内酯阿维菌素本身对 马来芽孢杆菌成虫的运动能力，但与左旋咪唑联合使用时，可以防止 快速耐受和运动能力恢复。在此，我们建议， 目标#1：检验 DAF-12 介导马来芽孢杆菌快速耐受的假设。我们将 敲低马来芽孢杆菌成虫中的 daf-12，以确定其在介导快速耐受中的作用。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靶向 DAF-12，以预防 快速耐受。 目标#2：检验肌肉钙浓度和钙释放的假设 左旋咪唑产生的机制在大环化合物存在下发生改变 内酯。我们将研究大环内酯、阿维菌素、伊维菌素和 莫昔克汀可延长左旋咪唑引起的瘫痪。我们将评估变化 通过对兰尼碱进行 RNAi 来研究大环内酯引起的钙释放机制 以及 B. malayi 中的 IP3 受体 unc-68 和 itr-1，并使用 C.线虫。 在这些实验结束时，我们将把 DAF-12 定性为一种新型驱虫靶点 这可能有助于预防胆碱能快速耐受。我们将深入了解其效果 大环内酯对线虫肌肉中左旋咪唑钙释放机制的影响。这些 研究将为胆碱能快速耐受提供更好的机制见解，并提供合理的治疗方法 防止蠕虫恢复和抵抗的途径。