Characterization of the modes of action of deoxynivalenol (DON) in the human Jurkat T-cell line
Characterization of the modes of action of deoxynivalenol (DON) in the human Jurkat T-cell line
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DOI：
10.3109/1547691x.2014.925995
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发表时间：
2015-07-01
影响因子：
3.3
通讯作者：
Peijnenburg, Ad A. C. M.
中科院分区：
文献类型：
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作者：
Katika, Madhumohan R.;Hendriksen, Peter J. M.;Peijnenburg, Ad A. C. M.
脱氧雪腐镰刀菌烯醇 (DON) 是全世界最丰富的霉菌毒素之一，主要存在于谷物中。因此，呕吐毒素对人类和动物的健康造成许多不利影响。特别是，免疫细胞对 DON 非常敏感，导致毒性的起始步骤是与真核 60S 核糖体亚基结合并诱导核糖毒性应激。本研究旨在：（1）深入了解DON在免疫细胞中的作用机制（MOA）； (2) 了解为什么免疫细胞比大多数其他细胞类型对 DON 更敏感。先前发表的微阵列研究描述了 DON 对免疫细胞的影响。为了以这些发现为基础，本文使用暴露于 0.5 μM DON 3 小时的人 T 淋巴细胞 Jurkat 细胞进行了免疫细胞学和生化研究。免疫细胞学证实 DON 诱导 ER 应激，表明两种主要 ER 应激标记物 ATF3 和 DDIT3 的蛋白表达增加。通过诱导蛋白激酶 JNK 和 AKT 磷酸化、激活 NF-kappa B (p65) 以及 NFAT 靶基因 NUR77 表达增加，证实了 T 细胞激活；其中每一种都是已知的 T 细胞激活反应诱导剂。通过监测主要氧化应激标记物 NRF2 和 KEAP1 的核转位以及还原型谷胱甘肽的细胞水平的变化（即降低）也证实了氧化应激反应的诱导。最后，这项研究表明 DON 诱导 caspase-3 裂解，这是一种已知介导细胞凋亡的事件。总而言之，这些结果使我们能够制定 DON 在免疫细胞中的潜在作用机制，即与真核 60S 核糖体亚基结合 -> 核糖毒性应激 -> 内质网应激 -> 钙从内质网释放到细胞质 -> T 细胞激活和氧化应激 -> 细胞凋亡。有人提出，由于细胞内钙水平增加会诱导 T 细胞激活反应，因此免疫细胞比其他细胞类型对 DON 更敏感。
Deoxynivalenol (DON) is one of the most abundant mycotoxins worldwide and mostly detected in cereals and grains. As such, DON poses a risk for many adverse health effects to human and animals. In particular, immune cells are very sensitive to DON, with the initiating step leading to toxicity being a binding to the eukaryotic 60S ribosomal subunit and induction of ribotoxic stress. The present study aimed to: (1) extend insight into the mechanism of action (MOA) of DON in immune cells; and (2) understand why immune cells are more sensitive to DON than most other cell types. Previously published microarray studies have described the effects of DON on immune cells. To build upon these findings, here, immunocytological and biochemical studies were performed using human T-lymphocyte Jurkat cells that were exposed for 3 h to 0.5 mu M DON. Induction of ER stress by DON was confirmed by immunocytology demonstrating increased protein expression of two major ER stress markers ATF3 and DDIT3. T-cell activation was confirmed by induction of phosphorylation of protein kinases JNK and AKT, activation of NF-kappa B (p65), and increased expression of NFAT target gene NUR77; each of these are known inducers of the T-cell activation response. Induction of an oxidative stress response was also confirmed by monitoring the nuclear translocation of major oxidative stress markers NRF2 and KEAP1, as well as by changes (i.e. decreases) in cell levels of reduced glutathione. Lastly, this study showed that DON induced cleavage of caspase-3, an event known to mediate apoptosis. Taken together, these results allowed us to formulate a potential mechanism of action of DON in immune cells, i.e. binding to eukaryotic 60S ribosomal subunit -> ribotoxic stress -> ER stress -> calcium release from the ER into cytoplasm -> T-cell activation and oxidative stress -> apoptosis. It is proposed that immune cells are more sensitive to DON than other cell types due to the induction of a T-cell activation response by increased intracellular calcium levels.