The Role of Heme and the Mitochondrion in the Chemical and Molecular Mechanisms of Mammalian Cell Death Induced by the Artemisinin Antimalarials
The Role of Heme and the Mitochondrion in the Chemical and Molecular Mechanisms of Mammalian Cell Death Induced by the Artemisinin Antimalarials
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DOI：
10.1074/jbc.m110.144188
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发表时间：
2011-01-14
影响因子：
4.8
通讯作者：
Park, B. Kevin
中科院分区：
文献类型：
--
作者：
Mercer, Amy E.;Copple, Ian M.;Park, B. Kevin
青蒿素类化合物是治疗耐药性疟疾的一线药物。它们对哺乳动物癌细胞系具有选择性细胞毒性，并且在动物研究中被认为具有神经毒性和胚胎毒性。内过氧化物官能团既是药效团又是毒效团，但所提出的化学机制和细胞毒性靶标仍不清楚。在这项研究中，我们使用细胞模型和定量药物代谢物分析来定义线粒体和细胞血红素在青蒿素化合物诱导的细胞死亡的化学和分子机制中的作用。 HeLa rho(0) 细胞缺乏功能电子传递链，用于证明活跃呼吸的线粒体通过产生活性氧和诱导线粒体功能障碍和细胞凋亡，在内过氧化物诱导的细胞毒性中发挥重要作用（青蒿琥酯 IC50 值，48 小时：HeLa 细胞，6 +/- 3 μM；HeLa rho(0) 细胞，34 +/- 5 μM）。内过氧化物还原激活细胞毒性碳中心自由基。然而，使用血红素合成的化学调节剂（琥珀酰丙酮和原卟啉 IX）和细胞铁含量（全转铁蛋白），我们明确证明游离或蛋白质结合的血红素负责细胞内内过氧化物基团的活化，并且这是细胞毒性的化学基础（IC50值和生物活化水平的生物标志物，分别为：单独的10β-（对氟苯氧基）二氢青蒿素， 0.36 +/- 0.20 μM 和 11 +/- 5%；对于琥珀酰丙酮，> 100 μM 和 2 +/- 5%。
The artemisinin compounds are the frontline drugs for the treatment of drug-resistant malaria. They are selectively cytotoxic to mammalian cancer cell lines and have been implicated as neurotoxic and embryotoxic in animal studies. The endoperoxide functional group is both the pharmacophore and toxicophore, but the proposed chemical mechanisms and targets of cytotoxicity remain unclear. In this study we have used cell models and quantitative drug metabolite analysis to define the role of the mitochondrion and cellular heme in the chemical and molecular mechanisms of cell death induced by artemisinin compounds. HeLa rho(0) cells, which are devoid of a functioning electron transport chain, were used to demonstrate that actively respiring mitochondria play an essential role in endoperoxide-induced cytotoxicity (artesunate IC50 values, 48 h: HeLa cells, 6 +/- 3 mu M; and HeLa rho(0) cells, 34 +/- 5 mu M) via the generation of reactive oxygen species and the induction of mitochondrial dysfunction and apoptosis but do not have any role in the reductive activation of the endoperoxide to cytotoxic carbon-centered radicals. However, using chemical modulators of heme synthesis (succinylacetone and protoporphyrin IX) and cellular iron content (holotransferrin), we have demonstrated definitively that free or protein-bound heme is responsible for intracellular activation of the endoperoxide group and that this is the chemical basis of cytotoxicity (IC50 value and biomarker of bioactivation levels, respectively: 10 beta-(p-fluorophenoxy)dihydroartemisinin alone, 0.36 +/- 0.20 mu M and 11 +/- 5%; and with succinylacetone, > 100 mu M and 2 +/- 5%).