Trypanosoma cruzi response to sterol biosynthesis inhibitors: morphophysiological alterations leading to cell death.
Trypanosoma cruzi response to sterol biosynthesis inhibitors: morphophysiological alterations leading to cell death.
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DOI：
10.1371/journal.pone.0055497
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Krieger MA
中科院分区：
文献类型：
--
作者：
Kessler RL;Soares MJ;Probst CM;Krieger MA
原生动物寄生虫克氏锥虫（Trypanosoma cruzi）在其固醇脂质生物合成方面与真菌相似，因为麦角固醇和其他24-烷基化固醇是其主要的内源性固醇。因此，甾醇途径是治疗恰加斯病的潜在药物靶点。本文对导致嗜热链球菌死亡的生长抑制、超微结构和生理变化进行了比较研究。在用固醇生物合成抑制剂（SBIs）酮康唑和洛伐他汀处理后的cruzi细胞中。我们首先计算了抑制上鞭毛体生长50%（EC 50/72 h）或在24小时内杀死所有细胞（EC 100/24 h）的药物浓度。在EC 50/72 h与抑制剂孵育导致有趣的形态学变化：线粒体内膜的强烈增殖，这是通过流式细胞术和罗丹明123染色的寄生虫的共聚焦显微镜证实的，以及吖啶橙子染色证实的线粒体的强烈肿胀。线粒体和储泡体的这些变化可能反映了这些细胞器参与麦角固醇生物合成或在EC 50/72 h下用SBI处理6至7天后最终导致细胞溶解的进行性自噬过程。相比之下，在EC 100/24 h下用SBIs处理导致具有坏死表型的快速细胞死亡：时间依赖性细胞溶质钙超载、线粒体去极化和线粒体膜透化（RMP），在药物暴露数小时后细胞溶解达到顶峰。我们提供了第一个证明，RMP构成了细胞死亡级联的“不归点”，并提出了一个模型的坏死细胞死亡的T。克鲁兹因此，在T.克鲁兹这些发现为麦角固醇的生物合成和这种古老的原生动物寄生虫的程序性细胞死亡机制提供了新的线索。
The protozoan parasite Trypanosoma cruzi displays similarities to fungi in terms of its sterol lipid biosynthesis, as ergosterol and other 24-alkylated sterols are its principal endogenous sterols. The sterol pathway is thus a potential drug target for the treatment of Chagas disease. We describe here a comparative study of the growth inhibition, ultrastructural and physiological changes leading to the death of T. cruzi cells following treatment with the sterol biosynthesis inhibitors (SBIs) ketoconazole and lovastatin. We first calculated the drug concentration inhibiting epimastigote growth by 50% (EC50/72 h) or killing all cells within 24 hours (EC100/24 h). Incubation with inhibitors at the EC50/72 h resulted in interesting morphological changes: intense proliferation of the inner mitochondrial membrane, which was corroborated by flow cytometry and confocal microscopy of the parasites stained with rhodamine 123, and strong swelling of the reservosomes, which was confirmed by acridine orange staining. These changes to the mitochondria and reservosomes may reflect the involvement of these organelles in ergosterol biosynthesis or the progressive autophagic process culminating in cell lysis after 6 to 7 days of treatment with SBIs at the EC50/72 h. By contrast, treatment with SBIs at the EC100/24 h resulted in rapid cell death with a necrotic phenotype: time-dependent cytosolic calcium overload, mitochondrial depolarization and reservosome membrane permeabilization (RMP), culminating in cell lysis after a few hours of drug exposure. We provide the first demonstration that RMP constitutes the “point of no return” in the cell death cascade, and propose a model for the necrotic cell death of T. cruzi. Thus, SBIs trigger cell death by different mechanisms, depending on the dose used, in T. cruzi. These findings shed new light on ergosterol biosynthesis and the mechanisms of programmed cell death in this ancient protozoan parasite.
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影响因子：
5.8
作者：
Contreras, LM;Vivas, J;Urbina, JA
通讯作者：
Urbina, JA
DOI：
10.1590/s0074-02762009000900036
发表时间：
2009-07-01
期刊：
Memórias do Instituto Oswaldo Cruz
影响因子：
--
作者：
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通讯作者：
Camargo, Erney Plessmann
影响因子：
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作者：
de Souza, Wanderley;Rodrigues, Juliany Cola Fernandes
通讯作者：
Rodrigues, Juliany Cola Fernandes
影响因子：
2.9
作者：
Grijalba, MT;Vercesi, AE;Schreier, S
通讯作者：
Schreier, S
DOI：
10.1016/0006-291x(86)90410-9
发表时间：
1986-05-14
影响因子：
3.1
作者：
BEACH, DH;GOAD, LJ;HOLZ, GG
通讯作者：
HOLZ, GG