Molecular Pathways Targeted by Potent Antimalarial Pyrazole Compounds

描述（由申请人提供）：疟疾仍然是世界上最重要的寄生虫病，每年影响数亿人，造成近100万人死亡。抗疟药物是疟疾控制的主要手段，但寄生虫对大多数抗疟药物的耐药性的蔓延令人严重关切。为了解决这一问题，各方共同努力发现和开发新的抗疟疾药物，并取得了一些令人鼓舞的早期成果。然而，很明显，在可预见的未来，我们需要为抗疟疾药物的管道提供补给，因为对新药的耐药性肯定会出现。最近，我们发现了一系列以吡唑为核心的化合物，它们具有很强的抗疟疾活性。这些化合物正处于作为具有新结构的抗疟药物的开发过程中。我们的数据还表明，它们的作用模式可能针对疟疾寄生虫中一个至关重要且迄今未知的脆弱途径。通过应用各种方法，我们建议揭示这一途径的性质及其分子成分。我们在这里提出的目标将使用经验和假设驱动的方法来确定这一系列有前途的化合物的分子机制。我们将采用多种方法来评估恶性疟原虫血液阶段发生的变化，因为它们正在迅速被吡唑化合物杀死。这些将包括：磷蛋白谱、转录组变化、代谢物变化、钙稳态以及光镜和电镜水平上的形态变化。这些研究将为化合物影响的途径提供线索和证实。最近的研究表明，吡唑类药物和另一种强效抗疟药螺络酮可能通过共同途径起作用。我们将评估这两种化学性质不同的化合物在作用方式上的共同特征。我们将验证一个假设，即吡唑化合物靶向的途径类似于在植物中观察到的磷酸化调节机制。这一假设是基于我们通过对耐药寄生虫的全基因组测序发现的突变的初步观察，我们发现这些突变对赋予耐药表型很重要。总的来说，这些研究不仅有可能了解有前途的抗疟药物的作用机制，而且有可能为未来的研究揭示新的靶点。

DESCRIPTION (provided by applicant): Malaria remains the most important parasitic disease in the world, affecting hundreds of millions of people and killing almost a million every year. Antimalarial drugs are the mainstay of malaria control, but the spread of parasite resistance to most antimalarials is of grave concern. To address this concern, concerted efforts have been directed at discovering and developing new antimalarial drugs, with some encouraging early results. Yet, it is clear that for the foreseeable future we would need to feed the pipeline of antimalarials, because resistance to new drugs is sure to arise. Recently, we have discovered a series of compounds with a pyrazole core that demonstrate highly potent antimalarial activity. These compounds are undergoing the process of development as an antimalarial drug with a novel structure. Our data also suggest that their mode of action is likely to target a vital and a hitherto unknown vulnerable pathway in malaria parasites. By applying a variety of approaches, we propose to uncover the nature of this pathway and its molecular components. The aims we propose here will use both empirical and hypothesis-driven approaches to identify molecular mechanisms underlying this promising series of compounds. We will employ a variety of methods to assess changes occurring in P. falciparum blood stages as they are rapidly being killed by the pyrazole compounds. These will include: phosphoprotein profiling, transcriptome changes, changes in metabolites, calcium homeostasis, and morphological changes at both light and electron microscopic levels. These studies will provide clues, as well as confirmation, regarding the pathways affected by the compounds. Recent studies suggest that pyrazoles and another series of potent antimalarials, spiroindolones, may be working through a common pathway. We will assess common features in mode of action of these two chemically distinct compounds. We will test a hypothesis that the pyrazole compounds are targeting a pathway similar to phosphorylation regulatory mechanisms observed in plants. This hypothesis is based on our initial observation of mutations discovered through whole genome sequencing of resistant parasites that we found to be important in imparting the resistance phenotype. Overall, these studies has the potential not only to understand mechanism of action for promising antimalarials but also to reveal new targets for future investigations.)