SEARCH FOR ANTI-AMOEBIC DRUGS WITH LESS TOXICITY IN HUMANS: ENTAMOEBA HISTOLYTI

寻找对人类毒性较小的抗阿米巴药物：ENTAMOEBA Histolyti

• 批准号: 7725146
• 负责人: AVELINA ESPINOSA
• 金额: $ 9.33万
• 依托单位: UNIVERSITY OF RHODE ISLAND
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7725146
• 关键词: Acetates; Affect; Amebiasis; Animal Model; Carbon Dioxide; Chemicals; Computer Retrieval of Information on Scientific Projects Database; Computer Simulation; Crystallography; Cultured Cells; Cyst; Disease; Drug toxicity; EhADH2 enzyme; Entamoeba; Entamoeba histolytica; Enzymes; Escherichia coli; Ethanol; Fermentation; Food; Funding; Glucose; Goals; Grant; Growth; Human; In Vitro; Ingestion; Institution; Kinetics; Large Intestine; Lethal Dose 50; Life Cycle Stages; Mitochondria; Pharmaceutical Preparations; Procedures; Research; Research Personnel; Resources; SCID Mice; Source; Staging; Standards of Weights and Measures; Study models; Techniques; Testing; Toxic effect; United States National Institutes of Health; Water; antimicrobial; design; in vivo; inhibitor/antagonist; killings; mutant; pathogen; trait

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Anaerobic pathogens have acquired traits to survive and thrive in host guts. As a model, we study the causative agent of human amebiasis, Entamoeba histolytica. This disease affects 50 million people yearly with 100 thousand fatalities worldwide. Entamoeba histolytica's life cycle consists of the disease-causing trophozoite stage and the infectious cyst stage. Cysts are acquired by ingestion of contaminated food or water, and multiplication and differentiation of the emergent trophozoites happen within the human's large intestine. Entamoeba histolytica lacks mitochondria and obtains its energy from the fermentation of glucose, producing carbon dioxide, acetate, and ethanol. The bifunctional Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), is essential for the growth and survival of E. histolytica trophozoites. A likely different evolutionary origin from vertebrate enzymes designates them as appealing antimicrobial targets. The goal of this study is to search for alternative non-toxic drugs that inhibit the growth of E. histolytica trophozoites, by specifically affecting the EhADH2 enzyme. Animal models will be used to determine the toxicity of these drugs in humans. Three specific aims will help achieve this goal: (1) Identify candidate chemicals that inhibit EhADH2. First, test potential inhibitors in vitro using an Escherichia coli AdhE deficient strain, and later in vivo using Entamoeba histolytica trophozoites. Useful candidates should inhibit the enzymatic activity of EhADH2, killing trophozoites with little or no effect to mammalian enzymes; (2) The selected chemicals will be further analyzed in cell cultures. To evaluate the toxicity of these drugs, various concentrations of drugs will be tested in animal models (SCID mice). LD50 standard procedures will be used; (3) Further analysis of EhADH2 will aid in designing anti-amoebic agents. EhADH2 (wild-type, mutants) will be analyzed with identified and designed inhibitors, using classical kinetics, spectrophotometer, computer modeling, and x-ray crystallography techniques.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此，可以在其他清晰的条目中表示。列出的机构是 对于中心，这不一定是调查员的机构。 厌氧病原体已经获得了在宿主胆量中生存和壮成长的特征。作为模型，我们研究了人amebiasis，entamoeba Histolictica的病因。这种疾病每年影响5000万人，全世界有1万人死亡。 Entamoeba Histolictica的生命周期由引起疾病的滋养体阶段和感染性囊肿阶段组成。囊肿是通过摄入受污染的食物或水的摄入而获取的，并且在人类的大肠中发生繁殖和分化。 Entamoeba Histolictica缺乏线粒体，并从葡萄糖的发酵，产生二氧化碳，乙酸和乙醇中获得能量。双功能的结构性溶质膜醇脱氢酶2（EHADH2）对于组织溶性性大肠杆菌滋养体的生长和存活至关重要。与脊椎动物酶的进化起源可能不同，将它们指定为有吸引力的抗菌靶标。这项研究的目的是通过专门影响EhADH2酶来寻找抑制组织溶血性大肠杆菌滋养体生长的替代性无毒药物。动物模型将用于确定这些药物在人类中的毒性。三个具体目标将有助于实现这一目标：（1）确定抑制Ehadh2的候选化学物质。首先，使用大肠杆菌ADHE菌株在体外测试潜在的抑制剂，然后使用Entamoeba Histolytictotica滋养体在体内进行体内测试。有用的候选者应抑制Ehadh2的酶活性，杀死滋养体，对哺乳动物酶几乎没有影响。 （2）选定的化学物质将在细胞培养物中进一步分析。为了评估这些药物的毒性，将在动物模型（SCID小鼠）中测试各种浓度的药物。将使用LD50标准程序； （3）对Ehadh2的进一步分析将有助于设计抗氨基剂。将使用经典动力学，分光光度计，计算机建模和X射线晶体学技术对EHADH2（野生型，突变体）进行分析和设计抑制剂。