Hijacking Plasmodium ubiquitin-proteasome system to defeat drug resistance

劫持疟原虫泛素蛋白酶体系统以击败耐药性

• 批准号: 10719157
• 负责人: Gang Lin
• 金额: $ 75.27万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10719157
• 关键词: Active Sites; Africa; African; Antimalarials; Artemisinins; Binding; Binding Proteins; Biochemical; Biological; Biological Assay; Biological Availability; Cells; Cessation of life; Chemicals; Child; Clinical; Combined Modality Therapy; Communicable Diseases; Distal; Drug Combinations; Drug Kinetics; Drug resistance; Exposure to; Frequencies; Goals; HIV; Hemin; Hybrids; In Vitro; Infection; Investigation; Life Cycle Stages; Lipids; Malaria; Malignant Neoplasms; Modeling; Multienzyme Complexes; Mus; Mutation; Oligopeptides; Oral; Organism; Parasite resistance; Parasites; Penetration; Peptides; Pharmaceutical Preparations; Plasmodium; Plasmodium falciparum; Point Mutation; Prevention; Process; Prodrugs; Property; Proteasome Inhibitor; Proteins; Recrudescences; Reporting; Resistance; Resistance development; Site; Southeastern Asia; Structure-Activity Relationship; System; Testing; Therapeutic; Time; Tissues; Toxic effect; Ubiquitin; Vertebral column; analog; cytotoxicity; detection limit; efficacy study; efficacy testing; global health; high risk; humanized mouse; improved; in vivo; inhibitor; lead optimization; mouse model; multicatalytic endopeptidase complex; multidrug tolerance; mutant; novel; oxidative damage; pharmacophore; prevent; resistance mechanism; resistance mutation; standard care; success; synergism; tuberculosis treatment

Project Summary/Abstract In 2020, with over 250 million debilitating cases and over half a million deaths, mostly in young children, malaria is a persistent global health crisis. The malaria-causing parasite Plasmodium falciparum (Pf) has developed resistance to most antimalarial drug deployed, including the backbone artemisinins (ARTs). ART and its semi-synthetic analogs are considered essential for malaria treatment. ARTs are prodrugs that are activated within the parasites to form a reactive radical that covalently attacks proteins, lipids and other cellular constituents. ART resistance is widespread in Southeast Asia and has been reported in Africa. ART combination therapy (ACT) is a mainstay for treatment of malaria, but its efficacy can be derailed when a two-drug combination becomes de facto monotherapy. Moreover, extended exposure of Pf to ACTs induces multidrug tolerance. We recently showed that inhibitors specific for the Pf proteasome (Pf20S) kill Pf in each stage of its life cycle and synergize with ART, overcoming ART resistance. This proposal builds on our discovery that a covalent hybrid of an ART analogue and a Pf20S inhibitor that we call an artezomib (ATZ) can enhance ART action and overcome resistance to each of its components. We have synthesized ATZs that are more potent Pf20S inhibitors than their component Pf20S inhibitor. They not only kill wild type and ART-resistant (K13 mutant) Pf, Pf with proteasome mutations that confer resistance to the Pf20S inhibitor, but also kill Pf that expresses both ART-resistant and PI-resistant mutations. We propose the following mechanism by which ATZs overcome resistance to the Pf20S inhibitor within them: We found that upon activation of ATZ in the parasites, the ART component binds Pf proteins, like activated ART itself. The Pf ubiquitin proteasome system digests ATZ-bound proteins into oligopeptides, some of which display the Pf inhibitor component of the ATZ. We hypothesize that extended contact of ATZ-bearing peptides within the Pf20S active site augments the binding of the Pf20S inhibitor component of the ATZ, overcoming the decreased binding otherwise conferred by Pf20S point mutations. Thus, an ATZ can overcome resistance to each of its components. In mouse models of malaria, an ATZ drove P. berghei below the limit of detection and suppressed recrudescence of a P. berghei ART-resistant K13 mutant and doing so better than ART. In Aim 1 of this proposal, we will conduct lead optimization to improve ATZs' potency, selectivity and ATZs' pharmacokinetic properties. In Aim 2, we will explore ATZs' mechanism of action; attempt to select for ATZ-resistant parasites; determine the frequency and mechanism of resistance, if any; and study antimalarial activity of ATZs in stages of the Pf life cycle when ART alone is ineffective. Aim 3 will test the efficacy of ATZs in mice, including humanized mice infected with Pf. .

项目概要/摘要 2020 年，将有超过 2.5 亿例使人衰弱的病例，超过 50 万人死亡，其中大部分是幼儿， 疟疾是一场持续存在的全球健康危机。引起疟疾的寄生虫恶性疟原虫 (Pf) 对大多数已使用的抗疟药物（包括主干青蒿素）产生了耐药性 （艺术）。 ART 及其半合成类似物被认为对于疟疾治疗至关重要。艺术是 在寄生虫内被激活形成共价攻击反应性自由基的前药 蛋白质、脂质和其他细胞成分。抗逆转录病毒疗法在东南亚普遍存在， 非洲已有报道。 ART 联合疗法 (ACT) 是治疗疟疾的支柱，但其 当两种药物组合成为事实上的单一疗法时，疗效可能会脱轨。而且， Pf 长时间暴露于 ACT 会诱导多药耐受。我们最近表明抑制剂 特异性针对 Pf 蛋白酶体 (Pf20S) 在其生命周期的每个阶段杀死 Pf 并与 ART 协同作用， 克服抗逆转录病毒疗法。该提案基于我们的发现，即 ART 的共价杂合体 类似物和我们称为阿替佐米 (ATZ) 的 Pf20S 抑制剂可以增强 ART 作用并克服 对其每个组件的电阻。我们合成了更有效的 Pf20S 抑制剂 ATZ 比其组分 Pf20S 抑制剂。它们不仅杀死野生型和抗 ART（K13 突变体）Pf、Pf 蛋白酶体突变赋予对 Pf20S 抑制剂的抗性，但也会杀死表达 Pf20S 的 Pf ART 抗性和 PI 抗性突变。我们提出以下机制，ATZ 可以通过以下机制 克服它们内部对 Pf20S 抑制剂的耐药性：我们发现，在激活 ATZ 后， 在寄生虫中，ART 成分与 Pf 蛋白结合，就像激活的 ART 本身一样。 Pf 泛素蛋白酶体 系统将 ATZ 结合蛋白消化成寡肽，其中一些显示 Pf 抑制剂 ATZ 的组成部分。我们假设携带 ATZ 的肽在 Pf20S 活性位点增强了 ATZ 的 Pf20S 抑制剂成分的结合，克服了 Pf20S 点突变导致的结合减少。因此，ATZ 可以克服 对其每个组件的电阻。在疟疾小鼠模型中，ATZ 将伯氏疟原虫驱至低于 伯氏疟原虫抗 ART K13 突变体的检测限和抑制复发 比艺术更好。在该提案的目标 1 中，我们将进行先导化合物优化以提高 ATZ 的 效力、选择性和 ATZ 的药代动力学特性。在目标2中，我们将探索ATZ的机制 行动的；尝试选择 ATZ 抗性寄生虫；确定频率和机制 阻力，如果有的话；并研究单独使用 ART 时 ATZ 在 Pf 生命周期阶段的抗疟活性 是无效的。目标 3 将测试 ATZ 在小鼠中的功效，包括感染 Pf 的人源化小鼠。 。