Inhibition or knockdown of ABC transporters enhances susceptibility of adult and juvenile schistosomes to Praziquantel.
Inhibition or knockdown of ABC transporters enhances susceptibility of adult and juvenile schistosomes to Praziquantel.
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DOI：
10.1371/journal.pntd.0003265
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发表时间：
2014-10
影响因子：
3.8
通讯作者：
Greenberg RM
中科院分区：
文献类型：
--
作者：
Kasinathan RS;Sharma LK;Cunningham C;Webb TR;Greenberg RM
血吸虫属寄生扁虫会引起血吸虫病，这是一种被忽视的热带疾病，影响着数亿人。血吸虫病的治疗几乎完全依赖药物吡喹酮（PZQ）。尽管 PZQ 对于治疗和控制血吸虫病至关重要，但其主要局限性在于它对未成熟哺乳动物阶段的血吸虫没有活性。此外，有报道称现场分离株的 PZQ 敏感性可遗传降低，研究人员已在实验室中筛选出抗 PZQ 的血吸虫。 P-糖蛋白（Pgp；ABCB1）和其他 ATP 结合盒（ABC）转运蛋白可清除细胞中的多种毒素和异生物质，并与多药耐药性（MDR）有关。 ABC 转运蛋白结构或表达水平的变化也与寄生蠕虫（包括血吸虫）的药物敏感性降低有关。在这里，我们表明，通过同时施用高效 Pgp 抑制剂 Tariquidar 或针对多种 ABC 多药转运蛋白的抑制剂组合，可增强 PZQ 对离体血吸虫成虫和幼虫的活性。暴露于亚致死浓度 PZQ 的成虫仍保持活跃，但同时施用 ABC 转运蛋白抑制剂会导致运动性完全丧失和外皮破坏。值得注意的是，通常对 2 µM PZQ 耐药的幼年血吸虫（感染后 3-4 周）在与 PZQ 联合添加转运蛋白抑制剂时会变得瘫痪。使用荧光 PZQ 衍生物 (R)-PZQ-BODIPY 的实验与转运蛋白抑制剂增加 PZQ 蠕虫内有效浓度的结果一致。 ABC转运蛋白表达被RNA干扰抑制的成虫表现出对PZQ的反应性增加和(R)-PZQ-BODIPY的保留增加，这与这些蛋白质在设定PZQ敏感性水平中的重要作用一致。这些结果表明寄生虫 ABC 多药转运蛋白可能作为增强 PZQ 作用的重要靶标。他们还提出了一种潜在新颖且易于使用的策略来克服血吸虫 PZQ 敏感性降低的问题。血吸虫是引起血吸虫病的寄生扁虫，血吸虫病是一种影响全世界数亿人的热带疾病。吡喹酮 (PZQ) 是目前抗血吸虫病的首选药物，而且事实上，它是世界大部分地区唯一获得批准的抗血吸虫治疗药物。虽然总体上有效，但 PZQ 也有局限性，包括缺乏针对未成熟血吸虫的活性。此外，据报道，该领域的治愈率往往低于最佳水平，并且越来越多的证据表明血吸虫会对药物产生耐药性。 ABC 转运蛋白（例如 P-糖蛋白）是外排转运蛋白，通过去除毒素和异生物质（包括药物）来介导细胞解毒。它们是哺乳动物细胞多重耐药性的基础，也与包括血吸虫在内的寄生虫的耐药性有关。在这里，我们发现抑制这些外排转运蛋白的化合物可以增强 PZQ 对抗血吸虫的活性，包括通常对 PZQ 不敏感的幼虫。同样，抑制这些转运蛋白的表达也会增加成虫对 PZQ 的反应。我们的实验可以深入了解这些药物转运蛋白在 PZQ 作用中的作用，并且还可以转化为增强血吸虫感染治疗和克服耐药性的新治疗策略。
Parasitic flatworms of the genus Schistosoma cause schistosomiasis, a neglected tropical disease that affects hundreds of millions. Treatment of schistosomiasis depends almost entirely on the drug praziquantel (PZQ). Though essential to treating and controlling schistosomiasis, a major limitation of PZQ is that it is not active against immature mammalian-stage schistosomes. Furthermore, there are reports of field isolates with heritable reductions in PZQ susceptibility, and researchers have selected for PZQ-resistant schistosomes in the laboratory. P-glycoprotein (Pgp; ABCB1) and other ATP binding cassette (ABC) transporters remove a wide variety of toxins and xenobiotics from cells, and have been implicated in multidrug resistance (MDR). Changes in ABC transporter structure or expression levels are also associated with reduced drug susceptibility in parasitic helminths, including schistosomes. Here, we show that the activity of PZQ against schistosome adults and juveniles ex vivo is potentiated by co-administration of either the highly potent Pgp inhibitor tariquidar or combinations of inhibitors targeting multiple ABC multidrug transporters. Adult worms exposed to sublethal PZQ concentrations remain active, but co-administration of ABC transporter inhibitors results in complete loss of motility and disruption of the tegument. Notably, juvenile schistosomes (3–4 weeks post infection), normally refractory to 2 µM PZQ, become paralyzed when transporter inhibitors are added in combination with the PZQ. Experiments using the fluorescent PZQ derivative (R)-PZQ-BODIPY are consistent with the transporter inhibitors increasing effective intraworm concentrations of PZQ. Adult worms in which expression of ABC transporters has been suppressed by RNA interference show increased responsiveness to PZQ and increased retention of (R)-PZQ-BODIPY consistent with an important role for these proteins in setting levels of PZQ susceptibility. These results indicate that parasite ABC multidrug transporters might serve as important targets for enhancing the action of PZQ. They also suggest a potentially novel and readily-available strategy for overcoming reduced PZQ susceptibility of schistosomes. Schistosomes are parasitic flatworms that cause schistosomiasis, a tropical disease affecting hundreds of millions worldwide. Praziquantel (PZQ) is the current drug of choice against schistosomiasis, and, indeed, is the only approved antischistosomal treatment available in most parts of the world. Though effective overall, PZQ has limitations, including its lack of activity against immature schistosomes. Furthermore, reported cure rates in the field are often below optimal levels, and there is increasing evidence that schistosomes can become resistant to the drug. ABC transporters such as P-glycoprotein are efflux transporters that mediate detoxification of cells via removal of toxins and xenobiotics, including drugs. They underlie multidrug resistance in mammalian cells, and are also associated with drug resistance in parasitic worms, including schistosomes. Here, we show that compounds that inhibit these efflux transporters potentiate the activity of PZQ against schistosomes, including normally PZQ-insensitive juvenile worms. Similarly, suppressing expression of these transporters also increases adult worm responsiveness to PZQ. Our experiments may provide insights into the role of these drug transporters in PZQ action, and could also translate into new therapeutic strategies for augmenting treatment of schistosome infections and overcoming drug resistance.
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DOI：
10.1590/s0074-02762011000200006
发表时间：
2011-03-01
期刊：
Memórias do Instituto Oswaldo Cruz
影响因子：
--
作者：
Couto, Flávia FB;Coelho, Paulo Marcos Z;Mattos, Ana Carolina A
通讯作者：
Mattos, Ana Carolina A
影响因子：
9.7
作者：
de Bruin, M;Miyake, K;Bates, SE
通讯作者：
Bates, SE
影响因子：
56.3
作者：
Gray, Darren J.;McManus, Donald P.;Ross, Allen G.
通讯作者：
Ross, Allen G.
影响因子：
13.8
作者：
HIGGINS, CF;GOTTESMAN, MM
通讯作者：
GOTTESMAN, MM
影响因子：
2.4
作者：
Greenberg RM
通讯作者：
Greenberg RM