Fujie Tomoya, Murakami Masaki, Yoshida Eiko, Tachinami Tadashi, Shinkai Yasuhiro, Fujiwara Yasuyuki, Yamamoto Chika, Kumagai Yoshito, Naka Hiroshi, Kaji Toshiyuki
Department of Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, 2641 Yamazaki, Noda, 278-8510, Japan.
Graduate School of Science and Research Center for Materials Science, Nagoya University, Chikusa, Nagoya, 464-8602, Japan.
J Biol Inorg Chem. 2016 Apr;21(2):263-73. doi: 10.1007/s00775-016-1337-z. Epub 2016 Jan 29.
The interest in organic-inorganic hybrid molecules as molecular probes for biological systems has been growing rapidly. Such hybrid molecules exhibit unique biological activities. Herein, copper(II) bis(diethyldithiocarbamate) (Cu10) was found to activate the transcription factor NF-E2-related factor 2 (Nrf2), which is responsible for regulating antioxidant and phase II xenobiotic enzymes, in vascular endothelial cells. The copper complex rapidly accumulated within cells and induced nuclear translocation of Nrf2, leading to upregulation of the expression of downstream proteins without cytotoxic effects. However, while copper bis(2-hydroxyethyl)dithiocarbamate activated Nrf2, copper ion, diethyldithiocarbamate ligand with or without zinc or iron failed to exhibit this activity. Intracellular accumulation of Cu10 was higher than that of Cu(II) and Cu(I). While the accumulation of copper(II) bis(dimethyldithiocarbamate) was reduced by small interfering RNA (siRNA)-mediated knockdown of the copper transporter CTR1, the knockdown did not affect Cu10 accumulation, indicating that Cu10 rapidly enters vascular endothelial cells via CTR1-independent mechanisms. In addition, copper and iron complexes with other ligands tested could not activate Nrf2, suggesting that the intramolecular interaction between copper and dithiocarbamate ligand is important for the activation of the transcription factor. Cu10 induced the expression of heme oxygenase-1, NAD(P)H quinone oxidoreductase 1, and γ-glutamylcysteine synthetase, downstream proteins of Nrf2. It was suggested that Cu10-induced activation of Nrf2 was due to proteasome inhibition as well as binding to Kelch-like ECH-associated protein 1. Since the effects of Cu10 on vascular endothelial cells are unique and diverse, the copper complex may be a good molecular probe to analyze the functions of the cells.
将有机-无机杂化分子作为生物系统分子探针的研究兴趣一直在迅速增长。这类杂化分子表现出独特的生物活性。在此，发现双（二乙基二硫代氨基甲酸）铜（II）（Cu10）可激活血管内皮细胞中的转录因子NF-E2相关因子2（Nrf2），该因子负责调节抗氧化剂和II期外源性生物酶。铜络合物在细胞内迅速积累并诱导Nrf2的核转位，导致下游蛋白表达上调且无细胞毒性作用。然而，虽然双（2-羟乙基）二硫代氨基甲酸铜激活了Nrf2，但铜离子、有或没有锌或铁的二乙基二硫代氨基甲酸配体均未表现出这种活性。Cu10的细胞内积累高于铜（II）和铜（I）。虽然双（二甲基二硫代氨基甲酸）铜的积累通过小干扰RNA（siRNA）介导的铜转运蛋白CTR1敲低而减少，但敲低并不影响Cu10的积累，这表明Cu10通过不依赖CTR1的机制迅速进入血管内皮细胞。此外，测试的与其他配体形成的铜和铁络合物不能激活Nrf2，这表明铜和二硫代氨基甲酸配体之间的分子内相互作用对于转录因子的激活很重要。Cu10诱导了Nrf2下游蛋白血红素加氧酶-1、NAD（P）H醌氧化还原酶1和γ-谷氨酰半胱氨酸合成酶的表达。有人认为，Cu10诱导的Nrf2激活是由于蛋白酶体抑制以及与Kelch样ECH相关蛋白1的结合。由于Cu10对血管内皮细胞的作用独特且多样，该铜络合物可能是分析细胞功能的良好分子探针。
