Cholinergic receptors on the nematode pharynx: an unexploited drug target

线虫咽部的胆碱能受体：一个未开发的药物靶点

• 批准号: 8191307
• 负责人: Alan P Robertson
• 金额: $ 23.2万
• 依托单位: IOWA STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-17 至 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8191307
• 关键词: Adult; Affect; Age; Animals; Anthelmintics; Ascariasis; Ascaris; Ascaris suum; Child; Cholinergic Receptors; Development; Disease; Drosophila acetylcholine receptor alpha-subunit; Drug Delivery Systems; Drug resistance; Drug usage; Genes; Goals; Growth; Helminthiasis; Hookworms; Hour; Human; Infant; Infection; Integral Membrane Protein; Intestines; Ion Channel; Lead; Levamisole; Libraries; Life; Methods; Muscle; Nematoda; Nicotinic Receptors; Oocytes; Paralysed; Parasite Control; Parasites; Parasitic infection; Parasitic nematode; Patch-Clamp Techniques; Pharmaceutical Preparations; Pharmacology; Pharyngeal structure; Population; Property; Protein Subunits; Pyrantel; Reporting; Research; Resistance; Resistance development; Screening procedure; Site; Soil; Testing; Trichuris; Trichuris trichiura infection; Tropical Disease; Veterinary Medicine; Work; Xenopus laevis; Xenopus oocyte; avermectin; chemotherapy; cholinergic; drug discovery; in vivo; interest; man; neglect; novel; novel therapeutic intervention; receptor; receptor function; reconstitution; response; spastic paralysis; voltage/patch clamp

DESCRIPTION (provided by applicant): The Neglected Tropical Diseases (NTDs) include the soil-transmitted helminthiases (STHs) which are caused by diverse groups of intestinal nematodes. The parasites include Ascaris, Trichuris and hookworms. These infections are common. Ascariasis for example, affects 1.4 billion people worldwide and is most common in children between the ages of 3 and 8. Control of these nematode parasites relies on an effective supply of anthelmintics. Taking veterinary medicine as an example, we know that continued use of anthelmintic compounds for mass chemotherapy will lead to drug resistance. There is a need to identify novel target sites for anthelmintic development. Once such site is the nicotinic acetylcholine receptor on the nematode pharynx. We have discovered this receptor does not respond to currently used anrthelmintic drugs. Approach: The specific aims of this application are: 1. Characterize nAChR responses in A. suum pharynx: using current-, voltage- & patch- clamp techniques. We will test the hypothesis that the A. suum pharynx nAChRs are pharmacologically distinct from the muscle nAChRs activated by cholinergic anthelmintics. 2. Identify & clone pharyngeal specific nicotinic acetylcholine receptor subunits. We will identify the nAChR subunit genes present in the pharynx required to produce functional receptors. 3. Characterize the pharyngeal cholinergic receptors in Xenopus laevis oocytes using voltage- & patch-clamp techniques. We will test the hypothesis that expression of pharyngeal nAChR subunits results in functioning receptors that are pharmacologically similar to those found in vivo. On completion of this project we will have characterized the pharmacology of an important new potential drug target in a parasitic nematode. We will have identified the genes that encode these receptors. Finally, we will have reconstituted the receptors in an accessible platform suitable for screening potential new anthelmintics. The longer term goal of this research is provide ion- channel drug targets from a range of important parasite species in a platform (Xenopus oocytes) suitable for drug discovery screening. PUBLIC HEALTH RELEVANCE: The Neglected Tropical Diseases (NTDs) include soil transmitted nematode parasites like ascariasis, trichuriasis and hookworm. Ascariasis, for example, is one of the most common human parasitic infections. 1.5 billion people worldwide have ascariasis, and the disease is most common in children between the ages of 3 and 8. Treatment of helminthiasis includes use of nicotinic anthelmintics like pyrantel and oxantel which selectively paralyze nematodes by activating cholinergic ion-channels (nAChRs) on their muscle. However, resistance to anthelmintics drugs is a real concern. We have identified a novel potential target site for new anthelmintics, the nAChR on the nematode pharynx, which is not sensitive to currently used drugs. We propose to characterize the pharmacological properties of this receptor, clone the component subunit genes and express the functional receptor in Xenopus oocytes. On completion of the project we will have characterized a potential new drug target (the pharynx nAChR) and reconstituted it in a platform (Xenopus laevis oocytes) suitable for screening compound libraries to identify new anthelmintic compounds.

描述（由申请人提供）：被忽视的热带疾病（NTD）包括由多种肠道线虫群引起的土壤传播的蠕虫（STH）。这些寄生虫包括ass虫，trichuris和钩虫。这些感染很常见。例如，as虫病影响着全球14亿人，在3至8岁的儿童中最常见。对这些线虫寄生虫的控制依赖于有效的驱虫药。以兽医为例，我们知道继续使用驱虫化合物进行大规模化学疗法会导致耐药性。有必要确定新的目标地点以进行驱虫发育。一旦这种位点是线虫咽部上的烟碱乙酰胆碱受体。我们发现该受体对当前使用的脂肪抗性药物没有反应。方法：本应用程序的具体目的是：1。表征拟南芥中的NACHR响应：使用电流，电压和斑块夹技术。我们将检验以下假设：源自胆碱能驱虫药激活的肌肉NACHR在药理学上与肌肉NACHR不同。 2。识别和克隆咽特异性烟碱乙酰胆碱受体亚基。我们将确定产生功能受体所需的咽部中存在的NACHR亚基基因。 3。使用电压和斑块钳技术来表征爪蟾laevis卵母细胞中的咽胆碱能受体。我们将检验以下假设：咽NACHR亚基的表达会导致在药理学上与体内发现的受体相似的受体。该项目完成后，我们将表征寄生虫中重要的新潜在药物靶标的药理学。我们将确定编码这些受体的基因。最后，我们将在适合筛选潜在的新驱虫药的可访问平台中重构受体。这项研究的长期目标是提供适用于药物发现筛查的平台（Xenopus卵母细胞）中一系列重要的寄生虫物种的离子通道药物靶标。 公共卫生相关性：被忽视的热带疾病（NTD）包括土壤传播的线虫寄生虫，例如ass虫病，尿布病和钩虫。例如，as虫病是人类最常见的寄生虫感染之一。全世界有15亿人患有癌症，这种疾病在3至8岁的儿童中最常见。呼离性心灵症的治疗包括使用烟碱驱虫药（如吡喃氏菌和oxentel），可在其肌肉上通过激活胆碱能离子 - 振动器（Nachrs）来选择性地瘫痪。但是，对驱虫药物的抵抗是一个真正的问题。我们已经确定了一种新的潜在目标位点，用于新的驱虫药，即线虫咽的NACHR，该NACHR对当前使用的药物不敏感。我们建议表征该受体的药理特性，克隆组分亚基基因，并在爪蟾卵母细胞中表达功能受体。该项目完成后，我们将表征一个潜在的新药靶标（咽NACHR），并将其重新组装在适合筛选化合物库以识别新的驱虫化合物的平台（Xenopus laevis卵母细胞）中。