Mechanism of glutamine-mediated amelioration of lipopolysaccharide-induced IL-8 production in Caco-2 cells
Mechanism of glutamine-mediated amelioration of lipopolysaccharide-induced IL-8 production in Caco-2 cells
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DOI：
10.1016/j.cyto.2003.12.008
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发表时间：
2004-04-21
期刊：
影响因子：
3.8
通讯作者：
Neu, J
中科院分区：
文献类型：
--
作者：
Liboni, K;Li, N;Neu, J
谷氨酰胺（Gln）介导的肠道炎症下调机制知之甚少。我们假设谷氨酰胺下调脂多糖（LPS）刺激的IL-8的生产在肠上皮细胞通过转录因子，抵消了LPS介导的IL-8的增加的影响。Caco-2细胞在LPS刺激（100 μ g/ml，24小时）之前，用不同剂量的Gln与或不与甲硫氨酸亚砜亚胺（MS）（谷氨酰胺合成酶的抑制剂）一起孵育24小时。在LPS刺激后，将有丝分裂原活化蛋白激酶（MAPK）家族的抑制剂添加到细胞中1.5小时。p38抑制剂SB 203580导致IL-8肽产生的显著降低（p < 0.01）。然而，p38 MAPK活性随着Gln而增加（p < 0.05），表明这与Gln介导的IL-8的下调无关。对54种转录因子的筛选表明，STAT-4是唯一的炎症相关转录因子，其通过Gln消耗而上调，并通过Gln补充而下调（2倍增加），与IL-8产生平行。EMSA分析证实了这些发现（增加3.5倍）。这些结果表明，Gln剥夺增强LPS刺激后Caco-2细胞的IL-8产生，并且Gln下调IL-8产生与STAT-4转录因子结合的改变相关。(C)2004 Elsevier Ltd.保留所有权利。
The mechanism of glutamine (Gln)-mediated down-regulation of inflammation in the intestine is poorly understood. We hypothesize that Gln down-regulates lipopolysaccharide (LPS)-stimulated IL-8 production in intestinal epithelial cells via transcription factors that counteract the effect of LPS-mediated increase in IL-8. Caco-2 cells were incubated with different doses of Gln with or without methionine sulfoximine (MS), an inhibitor of glutamine synthetase for 24 h before stimulation by LPS (100 mug/ml for 24 h). Inhibitors of the mitogen activated protein kinase (MAPK) family were added to cells for 1.5 h following stimulation by LPS. The p38 inhibitor SB 203580 resulted in a significant decrease in IL-8 peptide production (p < 0.01). However, p38 MAPK activity increased with Gln (p < 0.05), suggesting that this was not involved with Gln-mediated down-regulation of IL-8 screening of 54 transcription factors demonstrated that STAT-4 was the only inflammation-related transcription factor that was up-regulated by Gln depletion and down-regulated with Gln Supplementation (2-fold increase), paralleling IL-8 production. EMSA analysis confirmed these findings (3.5-fold increase). These results indicate that Gln deprivation enhances IL-8 production by Caco-2 cells after LPS stimulation and that down-regulation of IL-8 production wth Gln is associated with alterations in STAT-4 transcription factor binding. (C) 2004 Elsevier Ltd. All rights reserved.