A functional characterization of Brugia malayi GABA-gated chloride channels: an unexplored target for antifilarial therapeutics

马来丝虫 GABA 门控氯离子通道的功能表征：抗丝虫治疗的未探索靶点

基本信息

批准号：
10742453
负责人：
Shivani Choudhary
金额：
$ 21.67万
依托单位：
IOWA STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-08-21 至 2025-07-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10742453
关键词：
Adult Affect Africa South of the Sahara Agonist Albendazole Anthelmintics Antiparasitic Agents Appearance Biological Biological Process Biology Brugia malayi Caenorhabditis elegans Cell Line Characteristics Child Childhood Chloride Channels Chlorides Chronic Citrates Cloning Contralateral Country Culicidae Data Dedications Development Diethylcarbamazine Drug Targeting Drug resistance Economic Development Economics Electrophysiology (science)Elephantiasis Exhibits Filaria bancrofti Filarial Elephantiases Filariasis Future GABA Receptor GABA-A Receptor Genes Genital Genitalia Haemonchus Human Infection Infectious Skin Diseases Interruption Invertebrates Ion Channel Ion Channel Gating Ivermectin Ligands Limb structure Locomotion Lymphatic Lymphatic System Lymphedema Mediating Mediator Medicine Methods Molecular Movement Muscle Muscle Contraction Muscle relaxation phase Nematoda Neuromuscular Junction Neurotransmitters Obstruction Pain Paralysed Parasites Parasitic infection Parasitic nematode Pathologic Persons Pharmaceutical Preparations Pharmacology Pharmacotherapy Phenotype Physiological Piperazines Potassium Channel Poverty Productivity Property Protein Isoforms Psyche structure RNA Interference RNA Splicing Recommendation Research Role Side Southeastern Asia Stress Swelling System Techniques Testing Therapeutic Variant Xenopus oocyte antagonist behavioral study chemotherapeutic agent chemotherapy chronic infection disease transmission drug resistance development experimental study gamma-Aminobutyric Acid in vivo insight knock-down lymphadenopathy lymphatic drainage lymphatic dysfunction mosquito-borne neglected tropical diseases nerve supply new therapeutic target novel pharmacologic physically handicapped psychologic receptor response social therapeutic target transmission process vaccine access

项目摘要

Project summary Lymphatic filariasis is a mosquito-transmitted disease caused by filarial nematodes, including Brugia malayi, B. timori, and Wuchereria bancrofti, that affect millions of people in the poverty- stricken regions of Sub-Saharan Africa and Southeast Asia. The filarial worms are located in the host lymphatic system, blocking lymphatic drainage, resulting in gross swelling of the limbs (elephantiasis) and skin infections. These infections result in physical disability and disfigurement, mental stress, and reduced productivity, hampering social-economic development in endemic regions. Control and treatment of lymphatic filariasis rely on the mass drug administration (MDA) of antiparasitic drugs, ivermectin, diethylcarbamazine, and albendazole. This strategy has been successful to a certain extent, but the parasitic infections persist, mainly attributed to the limited adulticidal effect of current anti-filarial agents. Besides, there are no vaccines available for use, and concerns about developing drug resistance in humans. There is an accepted need to identify novel chemotherapeutic targets and macrofilaricidal therapeutics for more efficient control of filarial infections. Here we propose to investigate and characterize the pharmacological properties of UNC-49 γ- aminobutyric acid (GABA) channels in B. malayi to contribute to the search for novel drug targets. The majority of the commercially available anthelmintic drugs target cys-loop ligand-gated ion channels (LGICs), including the recently introduced emodepside (SLO potassium channels), monepantel (nAChRs), and derquantel (nAChRs). However, nematode ion channels are an underexploited chemotherapeutic target with a limited number already explored. Ionotropic GABA channels are the major inhibitory chloride-gated channels at the neuromuscular junction of invertebrates and are essential for coordinated movement. And yet, GABA receptors serve as the target of only one antiparasitic drug, piperazine. UNC-49 GABA channels have been characterized from Caenorhabditis elegans and Haemonchus contortus. These channels were distinct from the vertebrate receptors in subunit composition, in vivo function, and pharmacological properties and displayed species-based diversity. It is essential to gain insights into the molecular mechanisms of species-based diversity among nematode ion channels to understand drug targets better. We propose to perform cloning and heterologous expression of the previously uncharacterized UNC-49 GABA channels from B. malayi. We will use electrophysiological methods to conduct pharmacological characterization on the channels expressed in a heterologous system, Xenopus oocytes, and HEK293 cell lines. We will also use RNAi techniques on B. malayi worms to knock down GABA subunit encoding genes to validate GABA as a drug target. The results generated through these experiments will help develop preliminary data concerning the biology and pharmacology of GABA channels in the filarial nematode. Upon completing this project, we will have broadened our understanding of the filarial UNC-49 channels and identified the contribution of UNC-49 isoforms to the endogenous GABA function. The project has two specific aims: Aim 1: To study the role of UNC-49 channels' physiological function in adult B. malayi. Aim 2: Cloning of UNC-49 subunits from B. malayi and functional expression to characterize the channels' pharmacology.

项目概要淋巴丝虫病是一种由丝虫线虫引起的蚊媒疾病，包括马来丝虫、帝摩丝虫和班氏丝虫影响着数百万贫困人口—— 丝虫分布于撒哈拉以南非洲和东南亚地区。宿主淋巴系统，阻塞淋巴引流，导致四肢严重肿胀（象皮病）和皮肤感染这些感染会导致身体残疾和毁容，精神压力和生产力下降，阻碍了流行病的社会经济发展淋巴丝虫病的控制和治疗依赖于大规模的药物管理。 (MDA) 抗寄生虫药、伊维菌素、二乙基卡马嗪和阿苯达唑。策略在一定程度上取得了成功，但寄生虫感染仍然存在，主要是归因于目前的抗丝虫药物的杀成虫作用有限。可用的疫苗，以及对人类产生耐药性的担忧。确定新的化疗靶点和杀丝虫疗法的公认需求更有效地控制丝虫感染。在这里，我们建议研究和表征 UNC-49 γ- 的药理学特性 B. malayi 中的氨基丁酸 (GABA) 通道有助于寻找新的药物靶点。大多数市售驱虫药以 cys 环配体门控离子为靶点通道（LGIC），包括最近推出的 emodepside（SLO 钾通道），然而，线虫离子通道是一种通道。尚未开发的化疗靶点，已探索的数量有限。 GABA 通道是神经肌肉接头处主要的抑制性氯门控通道 GABA 受体对于无脊椎动物的协调运动至关重要。只有一种抗寄生虫药物哌嗪 UNC-49 GABA 通道是其靶标。这些通道的特征是秀丽隐杆线虫和捻转血矛线虫。在亚基组成、体内功能和功能上与脊椎动物受体不同药理学特性和显示的基于物种的多样性至关重要。研究线虫离子通道基于物种多样性的分子机制我们建议进行克隆和异源表达。我们将使用来自 B. malayi 的先前未表征的 UNC-49 GABA 通道。对通道进行药理学表征的电生理学方法我们还将使用在异源系统、爪蟾卵母细胞和 HEK293 细胞系中表达。 RNAi 技术对马来芽孢杆菌敲低 GABA 亚基编码基因进行验证通过这些实验产生的结果将有助于 GABA 作为药物靶标的开发。有关丝虫 GABA 通道生物学和药理学的初步数据完成这个项目后，我们将拓宽对线虫的了解。丝虫UNC-49通道并确定了UNC-49亚型对丝虫UNC-49通道的贡献该项目有两个具体目标：目的1：研究UNC-49通道在马来芽孢杆菌成虫中生理功能的作用。目标 2：从 B. malayi 克隆 UNC-49 亚基并进行功能表达表征通道的药理学。