Endothelial cell apoptosis is accelerated by inorganic iron and heat via an oxygen radical dependent mechanism
Endothelial cell apoptosis is accelerated by inorganic iron and heat via an oxygen radical dependent mechanism
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DOI：
10.1016/s0039-6060(97)90015-5
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发表时间：
1997-08-01
期刊：
影响因子：
3.8
通讯作者：
Buchman, TG
中科院分区：
文献类型：
--
作者：
Jacob, AK;Hotchkiss, RS;Buchman, TG
背景铁通过催化活性氧（ROS）形成的芬顿反应参与多种病理过程。为了检验这一反应加速细胞凋亡的假设，我们使用人脐静脉内皮细胞（HUVECs）作为体内微血管系统的替代物。HUVECs负载Fe [III]（氯化铁和柠檬酸铁铵）与8-羟基喹啉作为载体，然后用两种刺激的热休克反应，真正的热或亚砷酸钠的挑战。铁的依赖性进行了测试，两个螯合剂，膜不渗透性去铁胺和膜渗透性邻菲咯啉。超氧化物歧化酶，过氧化氢酶和报告化合物二氯荧光素二乙酸酯的ROS的作用进行了评估。用三种互补技术评估细胞死亡的机制。Annexin V/碘化丙啶标记、TUNEL染色和电子显微镜检查。热休克刺激后，载铁HUVECs发生凋亡。铁催化ROS的形成似乎是一个关键的机制，因为铁的螯合和ROS的酶促解毒都减弱了这种抑制作用。无机铁，与热休克反应的化学和物理诱导剂，可能会触发细胞凋亡。罗恩在受损组织中的积累可能因此倾向于加速细胞凋亡，并且部分地导致伤口愈合不良和器官衰竭。
Background. Iron participates in diverse pathologic processes by way of the Fenton reaction, which catalyzes the formation of reactive oxygen species (ROS). To test the hypothesis that this reaction accelerates apoptosis, we used human umbilical vein endothelial cells (HUVECs) as surrogates for the microvasculature in vivo.Methods. HUVECs were loaded with Fe [III](ferric chloride and ferric ammonium citrate) with 8-hydroxyquinoline as carrier and were then challenged with two stimuli of the heat shock response, authentic heat or sodium arsenite. Iron dependence was tested with two chelators, membrane-impermeable deferoxamine and membrane-permeable o-phenanthroline. The role of ROS was assessed with superoxide dismutase, catalase, and the reporter compound dichlorofluorescein diacetate. The mechanism of cell death was assessed with three complementary techniques. Annexin V/propidium iodide labeling, the TUNEL stain, and electron microscopy.Results. Iron-loaded HUVECs executed apoptosis after a heat shock stimulus. Iron-catalyzed formation of ROS appeared to be a critical mechanism, because both chelation of iron anal enzymatic detoxification of ROS attenuated this apoptosis.Conclusions. Inorganic iron, in concert with chemical and physical inducers of the heat shock response, may trigger apoptosis. The accumulation of ron in injured tissue may thereby predispose to accelerated apoptosis and account, in part, for poor wound healing and organ failure.