Discovery of New Anti-amoeba Therapeutics

新抗阿米巴疗法的发现

• 批准号: 9094675
• 负责人: William David Nes
• 金额: $ 23.81万
• 依托单位: TEXAS TECH UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-22 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9094675
• 关键词: ADME Study; Acanthamoeba; Acanthamoeba Keratitis; Active Sites; Amebiasis; Amino Acid Sequence; Amoeba genus; Amphotericin B; Anabolism; Animals; Antifungal Agents; Azoles; Binding; Binding Sites; Biochemical; Biological Availability; Catalysis; Characteristics; Cholesterol; Collaborations; Combined Modality Therapy; Complex; Cornea; Cultured Cells; Cyst; Disease; Drug Targeting; Drug usage; Effectiveness; Electronics; Enzymes; Ergosterol; Genome; Goals; Growth; Growth Inhibitors; Health; Health Sciences; Healthcare; Human; In Vitro; Incubated; Infection; Ketoconazole; Lanosterol; Lead; Life; Medical; Medical center; Metabolic Control; Metabolism; Methyltransferase; Mus; Naegleria; Naegleria fowleri; Orthologous Gene; Outcome; Parasites; Pathway interactions; Pharmaceutical Preparations; Pharmacotherapy; Phase; Process; Property; Protein Isoforms; Protozoa; Reaction; Recombinant Proteins; Research; Research Personnel; Rodent Model; Roentgen Rays; Series; Side; Specificity; Sterols; Structure; Testing; Texas; Therapeutic; Toxic effect; Universities; Use Effectiveness; Vision; analog; base; cholesterol biosynthesis; design; drug candidate; enzyme biosynthesis; feeding; fungus; improved; in vitro testing; in vivo; inhibitor/antagonist; interest; medical schools; methyl group; molecular recognition; mouse model; novel; pathogen; preference; primary amebic meningoencephalitis

 DESCRIPTION (provided by applicant): Amebiasis and related vision-threatening infections caused by amoebae is a major contributor to diarrheal diseases, primary amoebic meningoencephalitis and cornea problems. Sequencing of amoeba genomes has evoked a broad search for new, pathogen-specific drug targets, of which the sterol C24-methyltransferase (24-SMT) is a clear candidate since it is synthesized in protozoa but not in animals. Notably, 24-SMT is responsible for the introduction of the methyl group at C24 into the ergosterol side chain. The cholesterol side chain is missing this structural feature which is crucial to ergosterol function. In the R21 phase, we will incubate a series of mechanism-based inhibitors of 24-SMT that differ in the sterol frame and electronics of the side chain with cultured cells of Acanthamoeba and Naegleria and determine which compounds are the most potent inhibitors of ergosterol biosynthesis, trophozoites growth and cyst formation. Additionally, to make improvements to existing drug therapy for treating amoeba infections we will further evaluate in vitro representative anti-fungal azoles that target sterol 14-demethylase (14-SDM; CYP51). Therefore, we will characterize the substrate preference and product outcome of cloned enzymes and use these enzymes to determine inhibitor specificity, binding and covalent inactivation properties. The R33 phase will be undertaken with the proof-of-concept demonstrated. We will test in vitro whether our lead molecules that inhibit 24-SMT in combination with traditional chemotherapeutics have synergistic activities. Additionally, in collaboration with investigators at Meharry Medical College and UTSouthwestern Medical Center, we will evaluate our lead candidate drugs in a mouse model of Acanthamoeba keratitis or primary amebic meningoencephalitis due to Naegleri fowleri. With the aid of a collaborator at Texas Tech University Health Sciences Center, crystal structures of 24-SMT and 14- SDM complexed with relevant inhibitors will be generated to identify binding sites with certainty and should reveal interactions involved with catalysis. ADME/toxicity properties will be evaluated by the bioavailability and metabolism of 3H-inhibitor fed to healthy mice. The overall goal of these studies is to establish mechanism-based inhibitors as a novel class of anti- amoeba agents and to develop synergistic partners of steroidal inhibitors and antifungal agents (medical azole or amphotericin B) that target ergosterol biosynthesis and processing. Specific therapeutic combinations of these compounds could achieve optimal amebacidal effectiveness that thereby, provide for better healthcare.

 描述（由适用提供）：由变形虫引起的amebiasis和相关视力威胁感染是腹泻疾病，原发性四向脑膜脑膜炎和角膜问题的主要因素。 Amoeba基因组的测序引起了人们对新的病原体特异性药物靶标的广泛搜索，其中固醇C24-甲基转移酶（24-SMT）是一个明显的候选者，因为它是在原生动物中合成的，但在动物中没有合成。值得注意的是，24-SMT负责将C24的甲基引入到麦角固醇侧链中。胆固醇侧链缺少这种结构特征，这对于麦角固醇功能至关重要。在R21阶段，我们将与24-SMT的一系列基于机制的基于机制的抑制剂，这些抑制剂在固醇框架和侧链的电子学上与Acanthamoeba和Naegleria的培养细胞不同，并确定哪些化合物是麦角糖素生物合成，滋养剂的生长和基因生长和基因生长和基因生物最有效的抑制剂。此外，为了改善现有药物治疗的药物治疗变形虫感染，我们将进一步评估代表抗真菌偶氮的体外，该甲唑以乙醇14-二甲基酶（14-SDM； CYP51）。因此，我们将表征克隆酶的底物偏好和产物结果，并使用这些酶来确定抑制剂特异性，结合和共价灭活特性。 R33阶段将在概念验证证明中进行。我们将在体外测试我们的铅分子是否与传统化学治疗剂结合使用24-SMT具有协同活性。此外，与Meharry医学院和Utsouth -Western医学中心的研究人员合作，我们将通过Naegleri Fowleri导致的Acanthamoeba角膜炎或原发性amebic脑膜炎的小鼠模型来评估主要候选药物。在德克萨斯理工大学健康科学中心的合作者的帮助下，将生成24-SMT和14-SDM与相关抑制剂复合的晶体结构，以确定具有确定性的结合位点，并应揭示与催化有关的相互作用。 ADME/毒性特性将通过饲喂健康小鼠的3H抑制剂的生物利用度和代谢进行评估。这些研究的总体目的是建立基于机制的抑制剂作为一种新型的抗Amoeba剂，并开发类固醇抑制剂和抗真菌剂（医用硫唑或两性霉素B）的协同伴侣，以靶向麦芽糖素的生物合成和加工。这些化合物的特定治疗组合可以实现最佳的amebacidal有效性，从而提供更好的医疗保健。

项目成果

Steroidal Antimetabolites Protect Mice against Trypanosoma brucei.

• DOI: 10.3390/molecules27134088
• 发表时间: 2022-06-25
• 期刊: MOLECULES
• 影响因子: 4.6
• 作者: Chaudhuri, Minu;Singha, Ujjal K.;Vanderloop, Boden H.;Tripathi, Anuj;Nes, W. David
• 通讯作者: Nes, W. David

Steroidal antibiotics are antimetabolites of Acanthamoeba steroidogenesis with phylogenetic implications.

类固醇抗生素是具有系统发育意义的棘阿米巴类固醇生成的抗代谢物。

• DOI: 10.1194/jlr.m091587
• 发表时间: 2019
• 期刊: Journal of lipid research
• 影响因子: 6.5
• 作者: Zhou,Wenxu;Ramos,Emilio;Zhu,Xunlu;Fisher,PaxtynM;Kidane,MedhanieE;Vanderloop,BodenH;Thomas,CristaD;Yan,Juqiang;Singha,Ujjal;Chaudhuri,Minu;Nagel,MichaelT;Nes,WDavid
• 通讯作者: Nes,WDavid