A novel biological activity of praziquantel requiring voltage-operated Ca2+ channel beta subunits: subversion of flatworm regenerative polarity.
A novel biological activity of praziquantel requiring voltage-operated Ca2+ channel beta subunits: subversion of flatworm regenerative polarity.
复制标题
DOI：
10.1371/journal.pntd.0000464
复制
发表时间：
2009-06-23
影响因子：
3.8
通讯作者：
Marchant JS
中科院分区：
文献类型：
--
作者：
Nogi T;Zhang D;Chan JD;Marchant JS
全世界约有2亿人感染寄生性扁形虫，导致血吸虫病。自20世纪80年代以来，一种单一的药物-吡喹酮（PZQ）-一直是治疗难治性感染的主要药物。然而，吡喹酮的相关体内靶点仍未确定。在这里，我们提供了新的视角吡喹酮疗效在体内的分子基础上，随后发现一个显着的行动PZQ再生的一个物种的自由生活的扁形虫（三角洲）。具体来说，PZQ引起了一个强大的（100%的重复率）和完整的复制整个前后轴扁形虫再生产生双头生物体复制，集成的中枢神经和器官系统。利用这种表型作为影响吡喹酮疗效的蛋白质的读数，我们证明了PZQ诱发的双极性被电压操纵钙通道（VOCC）β亚基的体内RNAi选择性消融，但不是通过敲低VOCC α亚基。在较高剂量的PZQ下，VOCC β亚基的敲低也在致死性测定中赋予对PZQ的抗性。这项研究确定了抗血吸虫药物吡喹酮对自由生活的扁形虫物种再生极性的新生物活性。通过体内VOCC β亚基的RNAi消除PZQ诱发的双极再生表型提供了第一个遗传证据，暗示了对体内PZQ活性至关重要的分子靶标，并支持PZQ功效的“VOCC假说”。此外，在再生生物学和Ca 2+信号传导方面，这些数据突出了电压操作的Ca 2+进入在调节体内干细胞分化和再生模式中的新作用。吡喹酮是用于治疗感染寄生虫的人的主要药物，寄生虫导致被忽视的热带疾病血吸虫病。尽管吡喹酮在临床上被广泛使用，但令人惊讶的是，科学家们还没有确定吡喹酮如何杀死致病性染色体。这种缺乏病理生物学洞察力是治疗血吸虫病的新药定向设计的主要障碍，因为吡喹酮的相关体内靶分子/途径仍然不确定。在本报告中，我们发现了吡喹酮的一种新的生物活性，使我们能够从独特的化学遗传学角度来识别吡喹酮体内功效所需的分子。具体来说，我们表明，吡喹酮miscues再生模式的一种自由生活的扁形虫产生双极（双头）生物。通过使用这种表型来筛选支持这种活性的分子，我们为PZQ功效的“Ca 2+通道假说”提供了体内支持，并表明操纵电压门控Ca 2+通道的特定亚基可以防止这种效应，并减轻吡喹酮介导的毒性。这些数据为研究这些蛋白质在药物治疗中的作用提供了进一步的动力。
Approximately 200 million people worldwide harbour parasitic flatworm infections that cause schistosomiasis. A single drug—praziquantel (PZQ)—has served as the mainstay pharmacotherapy for schistosome infections since the 1980s. However, the relevant in vivo target(s) of praziquantel remain undefined. Here, we provide fresh perspective on the molecular basis of praziquantel efficacy in vivo consequent to the discovery of a remarkable action of PZQ on regeneration in a species of free-living flatworm (Dugesia japonica). Specifically, PZQ caused a robust (100% penetrance) and complete duplication of the entire anterior-posterior axis during flatworm regeneration to yield two-headed organisms with duplicated, integrated central nervous and organ systems. Exploiting this phenotype as a readout for proteins impacting praziquantel efficacy, we demonstrate that PZQ-evoked bipolarity was selectively ablated by in vivo RNAi of voltage-operated calcium channel (VOCC) β subunits, but not by knockdown of a VOCC α subunit. At higher doses of PZQ, knockdown of VOCC β subunits also conferred resistance to PZQ in lethality assays. This study identifies a new biological activity of the antischistosomal drug praziquantel on regenerative polarity in a species of free-living flatworm. Ablation of the bipolar regenerative phenotype evoked by PZQ via in vivo RNAi of VOCC β subunits provides the first genetic evidence implicating a molecular target crucial for in vivo PZQ activity and supports the ‘VOCC hypothesis’ of PZQ efficacy. Further, in terms of regenerative biology and Ca2+ signaling, these data highlight a novel role for voltage-operated Ca2+ entry in regulating in vivo stem cell differentiation and regenerative patterning. Praziquantel is the major drug used to treat people infected with parasitic worms that cause the neglected tropical disease schistosomiasis. Despite being in widespread clinical use, it is surprising that scientists have not identified how praziquantel works to kill pathogenic schistosomes. This lack of pathobiological insight is a major roadblock to the directed design of new drugs to treat schistosomiasis, as the relevant in vivo target molecule/pathway of praziquantel remains undefined. In this report, we have discovered a new biological activity of praziquantel that enables us to bring a unique chemical genetic perspective to the problem of identifying molecules needed for in vivo praziquantel efficacy. Specifically, we show that praziquantel miscues regenerative patterning in a species of free-living flatworm to yield bipolar (two-headed) organisms. By using this phenotype to screen for molecules underpinning this activity, we provide in vivo support for the ‘Ca2+ channel hypothesis’ of PZQ efficacy, and show that manipulation of specific subunits of voltage-gated Ca2+ channels prevent this effect, and lessen praziquantel-mediated toxicity. These data provide further impetus to studying the role of these proteins in schistosome pharmacotherapy.
登录
查看更多内容
影响因子：
2.4
作者：
Angelucci, F.;Basso, A.;Valle, C.
通讯作者：
Valle, C.
影响因子：
4
作者：
Jeziorski, Michael C.;Greenberg, Robert M.
通讯作者：
Greenberg, Robert M.
影响因子：
2.4
作者：
Mendonca-Silva, D. L.;Novozhilova, E.;Day, T. A.
通讯作者：
Day, T. A.
影响因子：
4.9
作者：
Gnanasekar, Munirathinam;Salunkhe, Ashok M.;Kalyanasundaram, Ramaswamy
通讯作者：
Kalyanasundaram, Ramaswamy
影响因子：
2.7
作者：
Mannini, L;Rossi, L;Batistoni, R
通讯作者：
Batistoni, R