Hattori Hiroyuki, Imai Hirotaka, Furuhama Kazuhisa, Sato Osamu, Nakagawa Yasuhito
School of Pharmaceutical Sciences, Kitasato University, Minato-ku, Tokyo, Japan.
Biochem Biophys Res Commun. 2005 Nov 18;337(2):464-73. doi: 10.1016/j.bbrc.2005.09.076. Epub 2005 Sep 21.
Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is characterized as an important enzyme for protecting cells from oxidative stress-induced apoptosis and regulating the production of leukotrienes and prostanoids in cells overexpressing PHGPx. We studied whether the expression level of PHGPx fluctuates in polymorphonuclear leukocytes (PMNs) which were exposed to reactive oxygen species (ROS) and inflammatory cytokines at an inflammation site. Human peripheral PMNs up-regulated the expression level of PHGPx following culture with TNF-alpha, but not with IL-1beta, IL-8, and GRO. The up-regulated PHGPx expression was also observed in neutrophil-like cells that differentiated from the human leukemia cell line HL60 only after stimulation with TNF-alpha. However, macrophage-like differentiated HL60 cells and other cell lines, A498, ECV304, HeLa, U937, and HEK293, showed no increase in the PHGPx expression. This up-regulation of PHGPx was inhibited by treatment with the anti-oxidants, pyrrolidine dithiocarbamate, and N-acetyl-L-cysteine, and by inhibitors of NFkappaB and Src kinases. The stimulation of neutrophil-like differentiated HL60 cells with TNF-alpha induced activation of NFkappaB and c-Src kinase, and the activation was attenuated by treatment with the anti-oxidants. Up-regulation in neutrophil-like HL60 cells was also observed following exposure to H(2)O(2). These results indicate that activation of NFkappaB and/or Src kinases through ROS signaling may be involved in the up-regulation of the PHGPx in human PMNs stimulated by TNF-alpha.
磷脂氢过氧化物谷胱甘肽过氧化物酶（PHGPx）是一种重要的酶，可保护细胞免受氧化应激诱导的凋亡，并调节过表达PHGPx的细胞中白三烯和前列腺素的产生。我们研究了在炎症部位暴露于活性氧（ROS）和炎性细胞因子的多形核白细胞（PMN）中，PHGPx的表达水平是否会波动。人外周血PMN在与TNF-α共培养后上调了PHGPx的表达水平，但与IL-1β、IL-8和GRO共培养时则没有。仅在用TNF-α刺激后，从人白血病细胞系HL60分化而来的中性粒细胞样细胞中也观察到了PHGPx表达的上调。然而，巨噬细胞样分化的HL60细胞和其他细胞系A498、ECV304、HeLa、U937和HEK293中PHGPx的表达没有增加。用抗氧化剂吡咯烷二硫代氨基甲酸盐和N-乙酰-L-半胱氨酸以及NFκB和Src激酶抑制剂处理可抑制PHGPx的这种上调。用TNF-α刺激中性粒细胞样分化的HL60细胞可诱导NFκB和c-Src激酶的激活，而抗氧化剂处理可减弱这种激活。暴露于H(2)O(2)后，中性粒细胞样HL60细胞中也观察到了上调。这些结果表明，通过ROS信号激活NFκB和/或Src激酶可能参与了TNF-α刺激的人PMN中PHGPx的上调。
