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: 7381357
• 负责人: AVELINA ESPINOSA
• 金额: $ 10.14万
• 依托单位: UNIVERSITY OF RHODE ISLAND
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2007-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7381357
• 关键词: SEARCH; ANTI; AMOEBIC; DRUGS; LESS

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. The intestinal protozoan Entamoeba histolytica is a major cause of morbidity and mortality worldwide, causing fifty million cases of diarrhea and one hundred thousand deaths per year. Amoebiasis is primarily treated with metronidazole. Limitations of metronidazole include toxic side effects, neurological complications, and the appearance of metronidazole-resistant E. histolytica strains. These concerns have prompted the search for alternative therapeutic agents. One promising approach is the development of novel anti-metabolites. Entamoeba histolytica lacks mitochondria and obtains its energy from the fermentation of glucose. Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2), a bifunctional enzyme with both aldehyde dehydrogenase (ALDH) and alcohol dehydrogenase (ADH) activities, constitutes a key enzyme in this pathway. EhADH2 is required for the growth and survival of E. histolytica, suggesting this enzyme could be a target for new anti-amoebic drugs. 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 from aim 1 will be further analyzed in vivo for safety in animal models. 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 kinetic, spectrophotometric, computer modeling, and x-ray crystallography.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。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代表。列出的机构适用于该中心，这不一定是调查员的机构。肠道原生动物的肠胃溶组织是全球发病率和死亡率的主要原因，每年造成五千万例腹泻和十万人死亡。阿莫氏病主要用甲硝唑治疗。甲硝唑的局限性包括毒性副作用，神经系统并发症以及抗甲硝唑耐药性大肠杆菌菌株的出现。这些担忧促使人们寻找替代治疗剂。一种有希望的方法是新型​​抗代谢产物的发展。 Entamoeba Histolictica缺乏线粒体，并从葡萄糖的发酵中获得能量。 Entamoeba Histoltica醇脱氢酶2（EHADH2）是一种双功能酶，具有醛脱氢酶（ALDH）和酒精脱氢酶（ADH）活性，构成了该途径中的关键酶。 EHADH2对于溶组织溶液的生长和存活是必需的，这表明该酶可能是新型抗氨基药物的靶标。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。从AIM 1中选择的化学物质将在体内进一步分析动物模型的安全性。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。将使用动力学，分光光度法，计算机建模和X射线晶体学分析EHADH2（野生型，突变体）。