Covalent Plasmodium falciparum-selective proteasome inhibitors exhibit a low propensity for generating resistance in vitro and synergize with multiple antimalarial agents
Covalent Plasmodium falciparum-selective proteasome inhibitors exhibit a low propensity for generating resistance in vitro and synergize with multiple antimalarial agents
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DOI：
10.1371/journal.ppat.1007722
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发表时间：
2019-06-01
期刊：
影响因子：
6.7
通讯作者：
Fidock, David A.
中科院分区：
文献类型：
--
作者：
Stokes, Barbara H.;Yoo, Euna;Fidock, David A.
迫切需要具有新的作用模式和产生耐药性风险低的治疗方法来防治耐药性恶性疟原虫疟疾。在这里，我们报告了肽乙烯基砜WLL-vs（WLL）和WLW-vs（WLW），恶性疟原虫蛋白酶体的高度选择性共价抑制剂，有效地消除遗传多样性的寄生虫，包括K13突变体，青蒿素耐药株系，并且对环期寄生虫特别有效。选择研究表明，寄生虫不容易获得对WLL或WLW的抗性，并且20 S蛋白酶体核心颗粒的β 2、β 5或β 6亚基或19 S蛋白酶体调节颗粒的组分中的突变仅使易感性降低100倍。我们观察到WLL和WLW之间没有交叉耐药性。此外，大多数突变，赋予一个抑制剂的寄生虫易感性的适度损失显着增加敏感性，以其他。这些抑制剂有效地协同多种化学不同类别的抗疟药，暗示了它们的作用模式中蛋白质稳态的共同破坏。这些结果强调了靶向疟原虫蛋白酶体与共价小分子抑制剂作为对抗多药耐药malaria.Author摘要青蒿素耐药恶性疟原虫疟疾在东南亚的传播创造了一个迫切需要开发新的治疗方案的化合物，是不受现有的抗疟药物耐药性机制。最近的工作已经确定恶性疟原虫蛋白酶体作为一个有前途的药物靶点。在这里，我们报告了高选择性乙烯砜结合肽蛋白酶体抑制剂的有效抗疟活性，包括对青蒿素耐药的恶性疟原虫早期环阶段的寄生虫，传统上难以治疗。与许多先进的抗疟候选药物，这些共价蛋白酶体抑制剂不容易选择耐药性。培养寄生虫的选择研究揭示了26 S蛋白酶体组分的点突变导致的易感性罕见和轻微降低，我们使用基于冷冻电子显微镜的结构数据进行建模。没有观察到寄生虫对两种化合物交叉耐药;事实上，对一种化合物的部分耐药通常会导致对另一种化合物的超敏反应。我们还记录了这些共价蛋白酶体抑制剂和多种抗疟药之间的有效协同作用，包括双氢青蒿素，临床候选药物OZ 439和寄生虫传播阻断剂亚甲蓝。蛋白酶体抑制剂作为治疗多药耐药疟疾的新型组合疗法的组分具有显著的前景。
Therapeutics with novel modes of action and a low risk of generating resistance are urgently needed to combat drug-resistant Plasmodium falciparum malaria. Here, we report that the peptide vinyl sulfones WLL-vs (WLL) and WLW-vs (WLW), highly selective covalent inhibitors of the P. falciparum proteasome, potently eliminate genetically diverse parasites, including K13-mutant, artemisinin-resistant lines, and are particularly active against ring-stage parasites. Selection studies reveal that parasites do not readily acquire resistance to WLL or WLW and that mutations in the beta 2, beta 5 or beta 6 subunits of the 20S proteasome core particle or in components of the 19S proteasome regulatory particle yield only hundred-fold decreases in susceptibility. We observed no cross-resistance between WLL and WLW. Moreover, most mutations that conferred a modest loss of parasite susceptibility to one inhibitor significantly increased sensitivity to the other. These inhibitors potently synergized multiple chemically diverse classes of antimalarial agents, implicating a shared disruption of proteostasis in their modes of action. These results underscore the potential of targeting the Plasmodium proteasome with covalent small molecule inhibitors as a means of combating multidrug-resistant malaria.Author summary The spread of artemisinin-resistant Plasmodium falciparum malaria across Southeast Asia creates an imperative to develop new treatment options with compounds that are not susceptible to existing mechanisms of antimalarial drug resistance. Recent work has identified the P. falciparum proteasome as a promising drug target. Here, we report potent antimalarial activity of highly selective vinyl sulfone-conjugated peptide proteasome inhibitors, including against artemisinin-resistant P. falciparum early ring-stage parasites that are traditionally difficult to treat. Unlike many advanced antimalarial candidates, these covalent proteasome inhibitors do not readily select for resistance. Selection studies with cultured parasites reveal infrequent and minor decreases in susceptibility resulting from point mutations in components of the 26S proteasome, which we model using cryo-electron microscopy-based structural data. No parasites were observed to be cross-resistant to both compounds; in fact, partial resistance to one compound often created hypersensitivity to the other. We also document potent synergy between these covalent proteasome inhibitors and multiple classes of antimalarial agents, including dihydroartemisinin, the clinical candidate OZ439, and the parasite transmission-blocking agent methylene blue. Proteasome inhibitors have significant promise as components of novel combination therapies to treat multidrug-resistant malaria.