Thio-dependent Antioxidants: A Novel Drug Target for Toxoplasma Gondii

硫代依赖性抗氧化剂：弓形虫的新药物靶点

基本信息

批准号：
9057455
负责人：
Rosa M. Andrade
金额：
$ 18.87万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-05-15 至 2019-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9057455
关键词：
Acute Affect Antioxidants Auranofin Autophagocytosis Autophagosome Binding Biological Assay Biology Blood - brain barrier anatomy Brain Cell physiology Cells Central Nervous System Toxoplasmosis Cessation of life Chickens Chronic Clinical Trials Cloning Confocal Microscopy Data Drug Kinetics Drug Targeting Drug resistance Embryo Entamoeba histolytica Enzymes FDA approved Faculty Folic Acid Glutathione Goals Gold Health Hospitalization Immune response In Vitro Inductively Coupled Plasma Mass Spectrometry Infection Inflammation Inflammatory Knock-out Knowledge Leishmania infantum Ligation Literature Liver Location Long-Term Effects Mass Spectrum Analysis Measures Mentors Modeling Molecular Biology Molecular Immunology Mus Oxidoreductase Parasites Parasitic Diseases Parasitology Pathway interactions Pattern Penetration Permeability Peroxidases Pharmaceutical Preparations Pharmacotherapy Phase I Clinical Trials Proteins Public Health Reaction Reactive Oxygen Species Recombinants Reporting Resistance Rheumatoid Arthritis Role Safety Schistosoma mansoni Solid Speed Staging Sulfhydryl Compounds System Systems Biology TXN gene Testing Time Tissues Toxic effect Toxoplasma Toxoplasma gondii Toxoplasmosis Training Transmission Electron Microscopy United States National Institutes of Health Western Blotting XRCC5 gene antioxidant enzyme base career development chemotherapeutic agent drug development experience foodborne pathogen in vitro activity in vivo killings mouse model multidisciplinary new therapeutic target novel therapeutics parasite invasion prevent research study safety testing thioredoxin reductase trypanothione

项目摘要

DESCRIPTION (provided by applicant): Toxoplasmosis of the central nervous system can have potentially devastating long term effects. It is caused by Toxoplasma gondii and it is the second leading cause of hospitalizations (8%) and deaths (24%) among food borne pathogens in the US. Unfortunately, current available drugs have significant toxicity and have no effect over the bradyzoite/latent form while the impending threat of emergence of resistance to these drugs makes the discovery of new therapeutic targets a priority. In this proposal, we show that auranofin has in vitro activity against T. gondii and induces accumulation of reactive oxygen species in infected host cells while in vivo, it prevents death in 100% of chicken embryos (acute toxoplasmosis model) and modulates the host immune response preventing an overwhelming inflammatory reaction. Auranofin's likely target is the thiol-dependent anti-oxidant system as demonstrated by our own observations on Entamoeba histolytica (thioredoxin reductase), and on other parasites such as Leishmania infantum (trypanothione reductase), and Schistosoma mansoni (glutathione-thioredoxin reductase). The long term goal of this proposal is to elucidate the roles of the thiol-dependent antioxidant system in T. gondii biology which are largely unknown. The central hypothesis is that T. gondii thiol-dependent antioxidant system is essential for T. gondii biology, and is a viable drug target. Specific Aim 1 will determine that T. gondii thiol-dependent anti-oxidant enzymes (one thioredoxin reductase and two thioredoxin-dependent peroxidases) are auranofin targets. T. gondii knockout strains of these enzymes will be generated to corroborate these observations. Recombinant enzymes will be expressed and their pharmacokinetics of interaction with auranofin in vitro will be evaluated. Specific Aim 2 wil evaluate auranofin's in vivo activity in standard mouse models of acute and chronic toxoplasmosis and will measure auranofin concentrations in CNS by mass spectrometry to assess blood brain barrier penetration. Specific Aim 3 will evaluate the effect of auranofin on the host immune response given that it has an impressive effect on parasite clearance and decreasing host tissue inflammation in vivo chicken embryo model of acute toxoplasmosis. Tracking autophagy will be possible using GFP-LC3 mice which have been instrumental to study this cellular process. In vitro and in vivo assays will be conducted to determine autophagy activation and progression in the presence of auranofin and during T. gondii infection. This project has the potential of identifying a new anti-parasitic drug target, the T. gondii thiol-dependent anti-oxidant system, that can be exploited in drug development for the treatment of toxoplasma infection. Re-purposing of a FDA-approved drug with a proven safety profile can dramatically accelerate the time to clinical trials.

描述（由申请人提供）：中枢神经系统的弓形体病可能具有潜在的破坏性长期影响。它由弓形虫引起，是美国食源性病原体中导致住院 (8%) 和死亡 (24%) 的第二大原因。不幸的是，目前可用的药物具有显着的毒性并且对缓殖子/潜伏形式，而对这些药物产生耐药性的迫在眉睫的威胁使得发现新的治疗靶点成为当务之急。在该提案中，我们表明金诺芬具有抗弓形虫的体外活性，并诱导受感染宿主细胞中活性氧的积累，而在体内，它可以防止 100% 鸡胚胎死亡（急性弓形体病模型）并调节宿主免疫反应防止压倒性的炎症反应。金诺芬的可能目标是硫醇依赖性抗氧化系统，正如我们对溶组织内阿米巴（硫氧还蛋白还原酶）和其他寄生虫如婴儿利什曼原虫（锥硫酮还原酶）和曼氏血吸虫（谷胱甘肽硫氧还蛋白还原酶）的观察所证明的那样。该提案的长期目标是阐明硫醇依赖性抗氧化系统在弓形虫生物学中的作用，而这些作用在很大程度上是未知的。中心假设是弓形虫硫醇依赖性抗氧化系统对于弓形虫生物学至关重要，并且是可行的药物靶点。具体目标 1 将确定 T。弓形虫硫醇依赖性抗氧化酶（一种硫氧还蛋白还原酶和两种硫氧还蛋白依赖性过氧化物酶）是金诺芬的靶标。将产生这些酶的弓形虫敲除菌株来证实这些观察结果。将表达重组酶，并评估其与金诺芬体外相互作用的药代动力学。具体目标 2 将评估金诺芬在急性和慢性弓形虫病标准小鼠模型中的体内活性，并将通过质谱法测量中枢神经系统中金诺芬的浓度，以评估血脑屏障的渗透性。具体目标 3 将评估金诺芬对宿主免疫反应，因为它对急性弓形体病鸡胚模型中的寄生虫清除和减少宿主组织炎症具有显着的作用。使用 GFP-LC3 小鼠可以追踪自噬，该小鼠有助于研究这一细胞过程。将进行体外和体内测定，以确定金诺芬存在下和弓形虫感染期间的自噬激活和进展。该项目有潜力确定一种新的抗寄生虫药物靶点，即弓形虫硫醇依赖性抗氧化系统，可用于治疗弓形虫感染的药物开发。重新利用 FDA 批准的具有经过验证的安全性的药物可以大大加快临床试验的时间。