Pyrrolidine dithiocarbamate up-regulates the expression of the genes encoding the catalytic and regulatory subunits of gamma-glutamylcysteine synthetase and increases intracellular glutathione levels.
Pyrrolidine dithiocarbamate up-regulates the expression of the genes encoding the catalytic and regulatory subunits of gamma-glutamylcysteine synthetase and increases intracellular glutathione levels.
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DOI：
10.1042/bj3380659
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发表时间：
1999-03
期刊：
影响因子：
--
通讯作者：
A. C. Wild;R. Mulcahy
中科院分区：
文献类型：
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作者：
A. C. Wild;R. Mulcahy
人肝癌细胞经吡咯烷二硫代氨基甲酸酯(PDTC)处理后，γ-谷氨酰半胱氨酸合成酶(GCS)催化亚单位和调节亚单位(GCS)基因的稳态mRNA水平呈时间和剂量依赖性增加。通过氧化还原敏感染料二氢罗丹明123的荧光减弱和谷胱甘肽的氧化，证实了PDTC在HepG2细胞中表现出抗氧化性和促氧化性。试图描述从PDTC暴露到GCS催化和调节亚单位基因表达增加的信号通路的尝试表明，PDTC的诱导可以通过硫醇试剂N-乙酰半胱氨酸和铜络合剂巴铜丙氨酸二磺酸部分阻断。这些发现表明，这两个基因的上调是PDTC诱导的促氧化信号的结果，这部分依赖于铜。综上所述，这些研究表明，PDTC暴露引起了HepG2细胞的细胞反应，其特征是诱导了编码GCS酶的两个亚单位的基因，并增加了细胞保护剂GSH的从头合成。
Time- and dose-dependent increases in the steady-state mRNA levels of the genes encoding the catalytic and regulatory subunits of the enzyme gamma-glutamylcysteine synthetase (GCS) were observed in HepG2 human hepatocarcinoma cells after exposure to pyrrolidine dithiocarbamate (PDTC). PDTC was demonstrated to manifest both antioxidant and pro-oxidant properties in HepG2 cells, as assessed by the decreased fluorescence of the redox-sensitive dye Dihydrorhodamine 123 and by the oxidation of glutathione respectively. Attempts to characterize the signalling pathway from PDTC exposure to increases in the expression of the GCS catalytic and regulatory subunit genes demonstrated that induction by PDTC could be partially blocked by treatment with the thiol agent N-acetylcysteine and by the copper chelator bathocuproine disulphonic acid. These findings suggested that the up-regulation of the two genes resulted from a PDTC-induced pro-oxidant signal, which was partially copper-dependent. In summary, these studies demonstrate that PDTC exposure elicits a cellular response in HepG2 cells, characterized by the induction of the genes encoding the two subunits of the enzyme GCS and increased de novo synthesis of the cellular protectant GSH.