Shaulov Yana, Sarid Lotem, Trebicz-Geffen Meirav, Ankri Serge
Department of Molecular Microbiology, Ruth and Bruce Rappaport Faculty of Medicine, Technion, 31096 Haifa, Israel.
Antioxidants (Basel). 2021 Aug 2;10(8):1240. doi: 10.3390/antiox10081240.
Auranofin (AF), an antirheumatic agent, targets mammalian thioredoxin reductase (TrxR), an important enzyme controlling redox homeostasis. AF is also highly effective against a diversity of pathogenic bacteria and protozoan parasites. Here, we report on the resistance of the parasite to 2 µM of AF that was acquired by gradual exposure of the parasite to an increasing amount of the drug. AF-adapted trophozoites (AFAT) have impaired growth and cytopathic activity, and are more sensitive to oxidative stress (OS), nitrosative stress (NS), and metronidazole (MNZ) than wild type (WT) trophozoites. Integrated transcriptomics and redoxomics analyses showed that many upregulated genes in AFAT, including genes encoding for dehydrogenase and cytoskeletal proteins, have their product oxidized in wild type trophozoites exposed to AF (acute AF trophozoites) but not in AFAT. We also showed that the level of reactive oxygen species (ROS) and oxidized proteins (OXs) in AFAT is lower than that in acute AF trophozoites. Overexpression of TrxR (EhTrxR) did not protect the parasite against AF, which suggests that EhTrxR is not central to the mechanism of adaptation to AF.
金诺芬（AF）是一种抗风湿药物，作用于哺乳动物硫氧还蛋白还原酶（TrxR），这是一种控制氧化还原稳态的重要酶。AF对多种病原菌和原生动物寄生虫也具有高效性。在此，我们报告了寄生虫对2μM AF产生的抗性，这种抗性是通过让寄生虫逐渐接触越来越多的该药物而获得的。适应AF的滋养体（AFAT）生长和细胞病变活性受损，并且比野生型（WT）滋养体对氧化应激（OS）、亚硝化应激（NS）和甲硝唑（MNZ）更敏感。整合转录组学和氧化还原组学分析表明，AFAT中许多上调基因，包括编码脱氢酶和细胞骨架蛋白的基因，其产物在暴露于AF的野生型滋养体（急性AF滋养体）中被氧化，但在AFAT中未被氧化。我们还表明，AFAT中的活性氧（ROS）水平和氧化蛋白（OXs）水平低于急性AF滋养体。硫氧还蛋白还原酶（EhTrxR）的过表达并不能保护寄生虫免受AF侵害，这表明EhTrxR并非寄生虫适应AF机制的核心。
