Khan Saifur R, Baghdasarian Argishti, Nagar Prarthna H, Fahlman Richard, Jurasz Paul, Michail Karim, Aljuhani Naif, Siraki Arno G
Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton, AB T6G 2E1, Canada.
Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB T6G 2E1, Canada.
Chem Biol Interact. 2015 Sep 5;239:129-38. doi: 10.1016/j.cbi.2015.06.020. Epub 2015 Jun 20.
In this study, the cellular effects resulting from the metabolism of aminoglutethimide by myeloperoxidase were investigated. Human promyelocytic leukemia (HL-60) cells were treated with aminoglutethimide (AG), an arylamine drug that has a risk of adverse drug reactions, including drug-induced agranulocytosis. HL-60 cells contain abundant amounts of myeloperoxidase (MPO), a hemoprotein, which catalyzes one-electron oxidation of arylamines using H2O2 as a cofactor. Previous studies have shown that arylamine metabolism by MPO results in protein radical formation. The purpose of this study was to determine if pathways associated with a toxic response could be determined from conditions that produced protein radicals. Conditions for AG-induced protein radical formation (with minimal cytotoxicity) were optimized, and these conditions were used to carry out proteomic studies. We identified 43 proteins that were changed significantly upon AG treatment among which 18 were up-regulated and 25 were down-regulated. The quantitative proteomic data showed that AG peroxidative metabolism led to the down-regulation of critical anti-apoptotic proteins responsible for inhibiting the release of pro-apoptotic factors from the mitochondria as well as cytoskeletal proteins such as nuclear lamina. This overall pro-apoptotic response was confirmed with flow cytometry which demonstrated apoptosis to be the main mode of cell death, and this was attenuated by MPO inhibition. This response correlated with the intensity of AG-induced protein radical formation in HL-60 cells, which may play a role in cell death signaling mechanisms.
在本研究中，对髓过氧化物酶代谢氨鲁米特所产生的细胞效应进行了研究。用氨鲁米特（AG）处理人早幼粒细胞白血病（HL-60）细胞，AG是一种芳胺类药物，存在药物不良反应风险，包括药物性粒细胞缺乏症。HL-60细胞含有大量的髓过氧化物酶（MPO），这是一种血红素蛋白，它以H2O2作为辅因子催化芳胺的单电子氧化。先前的研究表明，MPO介导的芳胺代谢会导致蛋白质自由基的形成。本研究的目的是确定是否可以从产生蛋白质自由基的条件中确定与毒性反应相关的途径。优化了AG诱导蛋白质自由基形成（细胞毒性最小）的条件，并使用这些条件进行蛋白质组学研究。我们鉴定出43种在AG处理后发生显著变化的蛋白质，其中18种上调，25种下调。定量蛋白质组学数据表明，AG的过氧化代谢导致关键的抗凋亡蛋白下调，这些蛋白负责抑制线粒体中促凋亡因子的释放以及细胞骨架蛋白如核纤层蛋白。流式细胞术证实了这种整体促凋亡反应，表明凋亡是细胞死亡的主要方式，并且这种反应因MPO抑制而减弱。这种反应与HL-60细胞中AG诱导的蛋白质自由基形成的强度相关，这可能在细胞死亡信号机制中起作用。
