Endogenous natural killer enhancing factor-B increases cellular resistance to oxidative stresses.
Endogenous natural killer enhancing factor-B increases cellular resistance to oxidative stresses.
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DOI：
10.1016/s0891-5849(96)00372-3
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发表时间：
1997
影响因子：
7.4
通讯作者：
H. Shau;A. Kim;C. Hedrick;A. J. Lusis;C. Tompkins;R. Finney;D. Leung;D. Paglia
中科院分区：
文献类型：
--
作者：
H. Shau;A. Kim;C. Hedrick;A. J. Lusis;C. Tompkins;R. Finney;D. Leung;D. Paglia
天然免疫增强因子（NKEF）的鉴定和克隆的基础上，它的能力，增加NK细胞的细胞毒性。两个基因，NKEF-A和-B，编码NKEF蛋白和序列分析表明，每个属于一个高度保守的抗氧化剂家族。为了研究NKEF的抗氧化潜力，我们将NKEF-B cDNA的编码区转染到人内皮细胞系ECV 304中。稳定的转染子B/1能过表达NKEF-B基因转录本和蛋白。我们使B/1经受氧化应激，通过用葡萄糖氧化酶（GO）培养它们，其连续产生过氧化氢，或者通过直接添加过氧化氢。我们发现B/1细胞比对照细胞系更耐药。对过氧化氢的抗性最初被认为主要由过氧化氢酶和谷胱甘肽循环介导。因此，我们使用抑制剂阻断这两种途径，发现当我们使用抑制剂预阻断任一途径时，B/1细胞比对照细胞更能抵抗氧化应激。我们还研究了细胞炎症反应，氧化低密度脂蛋白（LDL）和细菌脂多糖（LPS），通过测量单核细胞粘附内皮细胞在体外，发现B/1细胞抵抗这种反应。最后，我们发现B/1细胞对一种新的化疗剂CT-2584更具抗性，CT-2584似乎通过刺激线粒体中活性氧中间体的产生来杀死肿瘤细胞。这些结果表明，NKEF-B是一种抗氧化剂，可保护细胞免受氧化应激、化疗药物和炎症诱导的单核细胞粘附的影响。此外，其表达可介导细胞对促炎分子的反应。版权所有© 1996 Elsevier Science Inc.
Natural killer-enhancing factor (NKEF) was identified and cloned on the basis of its ability to increase NK cytotoxicity. Two genes, NKEF-A and -B, encode NKEF proteins and sequence analysis presented suggests that each belongs to a highly conserved family of antioxidants. To examine the antioxidant potential of NKEF, we transfected the coding region of NKEF-B cDNA into the human endothelial cell line ECV304. The stable transfectant, B/1, was found to overexpress NKEF-B gene transcript and protein. We subjected B/1 to oxidative stress by either culturing them with glucose oxidase (GO), which continuously generates hydrogen peroxide, or by direct addition of hydrogen peroxide. We found that B/1 cells were more resistant than control cell lines. Resistance to hydrogen peroxide was originally thought to be mediated mainly by catalase and the glutathione cycle. Therefore,we used inhibitors to block the two pathways and found that B/1 cells were more resistant to oxidative stress than control cells when we used inhibitors to preblock either pathway. We also examined the cellular inflammatory responses to oxidized low-density lipoprotein (LDL) and bacterial lipopolysaccharide (LPS) by measuring monocyte adhesion to endothelial cells in vitro and found that B/1 cells were resistant to such responses. Lastly, we found that B/1 cells were more resistant to a novel chemotherapeutic agent CT-2584, which appears to kill tumor cells by stimulating production of reactive oxygen intermediates in mitochondria. These results demonstrate that the NKEF-B is an antioxidant that protects cells from oxidative stress, chemotherapy agents, and inflammation-induced monocyte adhesion. Furthermore, its expression may mediate cellular responses to proinflammatory molecules.Copyright © 1996 Elsevier Science Inc.