Oxidative stress-induced iron signaling is responsible for peroxide-dependent oxidation of dichlorodihydrofluorescein in endothelial cells - Role of transferrin receptor-dependent iron uptake in apoptosis
Oxidative stress-induced iron signaling is responsible for peroxide-dependent oxidation of dichlorodihydrofluorescein in endothelial cells - Role of transferrin receptor-dependent iron uptake in apoptosis
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DOI：
10.1161/01.res.0000048195.15637.ac
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发表时间：
2003-01-10
影响因子：
20.1
通讯作者：
Kalyanaraman, B
中科院分区：
文献类型：
--
作者：
Tampo, Y;Kotamraju, S;Kalyanaraman, B
二氯二氢荧光素(DCFH)是检测细胞内氧化应激反应最常用的探针之一。在这项研究中，我们报道了依赖于H_2O_2的DCFH在细胞内氧化成绿色荧光产物2‘，7’-二氯荧光素(DCF)，需要通过内皮细胞的转铁蛋白受体(TFR)摄取细胞外的铁。能阻断TFR内吞和铁摄取的抗TFR单抗(42/6)可抑制H_2O_2诱导的DCF荧光。H_2O_2介导的胞浆乌头酸酶失活导致铁调节蛋白-1的激活和TFR表达的增加，导致内皮细胞铁摄取增加。抗TFR抗体可抑制过氧化氢介导的caspase-3蛋白水解酶活性。在脂质过氧化氢存在的情况下，也得到了类似的结果。我们的结论是，过氧化氢诱导的DCFH氧化和内皮细胞的凋亡需要依赖于TFR的铁运输机制摄取细胞外的铁，一般来说，过氧化氢诱导的铁信号在氧化血管生物学中具有更广泛的意义。
Dichlorodihydrofluorescein (DCFH) is one of the most frequently used probes for detecting intracellular oxidative stress. In this study, we report that H2O2-dependent intracellular oxidation of DCFH to a green fluorescent product, 2',7'-dichlorofluorescein (DCF), required the uptake of extracellular iron transported through a transferrin receptor (TfR) in endothelial cells. H2O2-induced DCF fluorescence was inhibited by the monoclonal IgA-class anti-TfR antibody (42/6) that blocked TfR endocytosis and the iron uptake. H2O2-mediated inactivation of cytosolic aconitase was responsible for activation of iron regulatory protein-1 and increased expression of TfR, resulting in an increased iron uptake into endothelial cells. H2O2-mediated caspase-3 proteolytic activation was inhibited by anti-TfR antibody. Similar results were obtained in the presence of a lipid hydroperoxide. We conclude that hydroperoxide-induced DCFH oxidation and endothelial cell apoptosis required the uptake of extracellular iron by the TfR-dependent iron transport mechanism and that the peroxide-induced iron signaling, in general, has broader implications in oxidative vascular biology.