Egawa K, Yoshiwara M, Nose K
Department of Microbiology, Showa University School of Pharmaceutical Sciences, Tokyo, Japan.
Experientia. 1994 Oct 15;50(10):958-62. doi: 10.1007/BF01923487.
Active oxygen, produced by cultured cells following stimulation with various growth factors, seems to be involved in signal transduction leading to cellular responses such as gene expression and growth modulation. In the present study, the intracellular oxidation state was measured in immortalized human endothelial cells (ECV304) after treatment with tumor necrosis factor (TNF) alpha, using a fluorescent dye and a laser-scanning confocal microscope. The intracellular oxidation state was increased 60 min after the addition of TNF alpha, and this increase was abolished by a radical scavenger, N-acetylcysteine (NAC), which is also a precursor of glutathione, and by pyrrolidine dithiocarbamate (PDTC). TNF alpha increased the steady state level of urokinase-type plasminogen activator (uPA), and NAC inhibited this increase at a dose that also inhibited the increase in the intracellular oxidation state. PDTC, on the other hand, did not affect the induction of the uPA gene by TNF alpha. These results suggest that intracellular glutathione level rather than the oxidation state is necessary for the induction of the uPA gene by TNF alpha.
培养细胞在受到各种生长因子刺激后产生的活性氧似乎参与了导致细胞反应（如基因表达和生长调节）的信号转导过程。在本研究中，使用荧光染料和激光扫描共聚焦显微镜，对用肿瘤坏死因子（TNF）α处理后的永生化人内皮细胞（ECV304）的细胞内氧化状态进行了测量。添加TNFα后60分钟，细胞内氧化状态增加，这种增加被自由基清除剂N-乙酰半胱氨酸（NAC，它也是谷胱甘肽的前体）和吡咯烷二硫代氨基甲酸盐（PDTC）消除。TNFα增加了尿激酶型纤溶酶原激活剂（uPA）的稳态水平，NAC以一种也能抑制细胞内氧化状态增加的剂量抑制了这种增加。另一方面，PDTC并不影响TNFα对uPA基因的诱导。这些结果表明，TNFα诱导uPA基因需要细胞内谷胱甘肽水平而非氧化状态。
