Miltefosine induces apoptosis-like death in Leishmania donovani promastigotes
Miltefosine induces apoptosis-like death in Leishmania donovani promastigotes
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DOI：
10.1128/aac.48.3.852-859.2004
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发表时间：
2004-03-01
影响因子：
4.9
通讯作者：
Bréard, J
中科院分区：
文献类型：
--
作者：
Paris, C;Loiseau, PM;Bréard, J
米替磷脂(十六烷基磷胆碱[HEPC])已被证明是治疗由杜氏利什曼原虫引起的人类内脏利什曼病的有效口服药物。其抗利什曼活性的分子机制尚不清楚。我们报道，在杜氏利什曼原虫的野生型前鞭毛体中，HepC能够诱导细胞死亡过程，具有大量的细胞质、核和膜特征的后生动物凋亡，包括细胞收缩、DNA片断成寡核小体大小的片段和磷脂酰丝氨酸暴露。在用相同药物浓度处理的抗HepC克隆中，没有检测到这些变化。因此，丙型肝炎病毒似乎不是通过直接毒性机制杀死杜氏乳杆菌前鞭毛体，而是通过间接机制杀死前鞭毛虫。在药物暴露前用两种广谱caspase抑制剂z-Val-Ala-DL-Asp(甲氧基)-氟甲基酮和Boc-Asp(甲氧基)氟甲酮以及一种广谱蛋白酶抑制剂Calain抑制剂1预处理野生型前鞭毛体可以干扰DNA片段化，但不能防止细胞收缩或磷脂酰丝氨酸外化。这些数据表明，在野生型前鞭毛体中，至少部分的凋亡机制涉及到蛋白酶。识别在HEPC敏感寄生虫中激活的死亡信号通路对于更好地理解这些寄生虫的作用和抗性的分子机制似乎是至关重要的。
Miltefosine (hexadecylphosphocholine [HePC]) has proved to be a potent oral treatment for human visceral leishmaniasis due to Leishmania donovani. The molecular mechanisms that contribute to the antileishmanial activity of HePC are still unknown. We report that in wild-type promastigotes of Leishmania donovani HePC is able to induce a cell death process with numerous cytoplasmic, nuclear, and membrane features of metazoan apoptosis, including cell shrinkage, DNA fragmentation into oligonucleosome-sized fragments, and phosphatidylserine exposure. None of these changes were detected in an HePC-resistant clone treated with the same drug concentration. Therefore, HePC does not appear to kill L. donovani promastigotes by a direct toxic mechanism but, rather, kills the promastigotes by an indirect one. Pretreatment of wild-type promastigotes with two broad caspase inhibitors, z-Val-Ala-DL-Asp(methoxy)-fluoromethylketone and Boc-Asp(methoxy)fluoromethylketone, as well as a broad protease inhibitor, calpain inhibitor 1, prior to drug exposure interfered with DNA fragmentation but did not prevent cell shrinkage or phosphatidylserine externalization. These data suggest that at least part of the apoptotic machinery operating in wild-type promastigotes involves proteases. Identification of the death-signaling pathways activated in HePC-sensitive parasites appears to be essential for a better understanding of the molecular mechanisms of action and resistance in these parasites.