Santos Benedito M, Dias Bárbara K M, Nakabashi Myna, Garcia Celia R S
Department of Clinical and Toxicological Analysis, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil.
Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Front Microbiol. 2021 Mar 15;12:638869. doi: 10.3389/fmicb.2021.638869. eCollection 2021.
Previously we have reported that the G protein-coupled receptor (GPCR)-like PfSR25 in is a potassium (K) sensor linked to intracellular calcium signaling and that knockout parasites (PfSR25-) are more susceptible to oxidative stress and antimalarial compounds. Here, we explore the potential role of PfSR25 in susceptibility to the antimalarial compounds atovaquone, chloroquine, dihydroartemisinin, lumefantrine, mefloquine, piperaquine, primaquine, and pyrimethamine and the Medicine for Malaria Venture (MMV) compounds previously described to act on egress/invasion (MMV006429, MMV396715, MMV019127, MMV665874, MMV665878, MMV665785, and MMV66583) through comparative assays with PfSR25- and 3D7 parasite strains, using flow cytometry assays. The IC and IC results show that lumefantrine and piperaquine have greater activity on the PfSR25- parasite strain when compared to 3D7. For MMV compounds, we found no differences between the strains except for the compound MMV665831, which we used to investigate the store-operated calcium entry (SOCE) mechanism. The results suggest that PfSR25 may be involved in the mechanism of action of the antimalarials lumefantrine and piperaquine. Our data clearly show that MMV665831 does not affect calcium entry in parasites after we depleted their internal calcium pools with thapsigargin. The results demonstrated here shed light on new possibilities on the antimalarial mechanism, bringing evidence of the involvement of the GPCR-like PfSR25.
此前我们曾报道，疟原虫中的G蛋白偶联受体（GPCR）样蛋白PfSR25是一种与细胞内钙信号传导相关的钾（K）传感器，敲除该蛋白的寄生虫（PfSR25-）对氧化应激和抗疟化合物更敏感。在此，我们通过使用流式细胞术检测，对PfSR25-和3D7寄生虫株进行比较分析，探究PfSR25在抗疟化合物阿托伐醌、氯喹、双氢青蒿素、本芴醇、甲氟喹、哌喹、伯氨喹和乙胺嘧啶以及先前描述的作用于逸出/入侵的疟疾药物风险投资公司（MMV）化合物（MMV006429、MMV396715、MMV019127、MMV665874、MMV665878、MMV665785和MMV66583）敏感性方面的潜在作用。IC和IC结果表明，与3D7相比，本芴醇和哌喹对PfSR25-寄生虫株具有更强的活性。对于MMV化合物，除了用于研究储存性钙内流（SOCE）机制的化合物MMV665831外，我们未发现各菌株之间存在差异。结果表明，PfSR25可能参与了抗疟药本芴醇和哌喹的作用机制。我们的数据清楚地表明，在用毒胡萝卜素耗尽寄生虫内部钙库后，MMV665831不会影响寄生虫的钙内流。此处展示的结果为抗疟机制的新可能性提供了线索，证明了GPCR样蛋白PfSR25的参与。
