Mechanisms involved in Helicobacter pylori-induced interleukin-8 production by a gastric cancer cell line, MKN45
Mechanisms involved in Helicobacter pylori-induced interleukin-8 production by a gastric cancer cell line, MKN45
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DOI：
10.1128/iai.65.8.3218-3224.1997
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发表时间：
1997-08-01
影响因子：
3.1
通讯作者：
Matsushima, K
中科院分区：
文献类型：
--
作者：
Aihara, M;Tsuchimoto, D;Matsushima, K
白细胞介素-8（IL-8）在幽门螺杆菌（Helicobacter pylori，Hp）感染相关的慢性萎缩性胃炎和消化性溃疡中起重要作用。pylori感染，而对灭活H.幽门螺杆菌、H. pylori培养上清液或活H. pylori中的细胞被渗透膜隔开，表明IL-8的产生需要细胞和活细菌之间的直接接触。此外，酪氨酸激酶抑制剂除莠霉素而不是蛋白激酶C抑制剂，（staurosporine）和蛋白激酶A抑制剂（H89）均抑制与活细菌共培养的MKN 45细胞产生IL-8，表明酪氨酸激酶参与幽门螺杆菌诱导的IL-8产生。pylori诱导MKN 45细胞中IL-8 mRNA的表达，以及用与IL-8基因5 ′-侧翼区连接的荧光素酶表达载体转染的细胞中荧光素酶活性的增加（bp-133至+44），表明IL-8产生的诱导发生在转录水平。该区域含有对诱导IL-8基因表达重要的三个顺式元件：AP-1（-126至-120 bp），NF-IL 6（-91至-81 bp）和NF-κ B NF-κ B结合位点的突变完全消除了荧光素酶活性的诱导，而AP-1位点的突变部分降低了荧光素酶活性的诱导，但NF-IL 6结合位点的突变并不导致荧光素酶活性的降低。幽门。总的来说，这些结果表明H。pylori诱导NF-κ B B和AP-1的活化，导致IL-8基因转录。
Accumulating evidence suggests an important role of interleukin-8 (IL-8) in Helicobacter pylori infection-associated chronic atrophic gastritis and peptic ulcer, We observed in this study that a gastric cancer-derived cell line, MKN45, produced a massive amount of IL-8 upon coculture with live H. pylori but not with killed H. pylori, H. pylori culture supernatants, or live H. pylori separated by a permeable membrane, indicating that IL-8 production requires a direct contact between the cells and live bacteria. Moreover, the tyrosine kinase inhibitor herbimycin but neither a protein kinase C inhibitor (staurosporine) nor a protein kinase A inhibitor (H89) inhibited IL-8 production by MKN45 cells cocultured with live bacteria, suggesting the involvement of a tyrosine kinase(s) in H, pylori-induced IL-8 production, In addition, coculture of H, pylori induced IL-8 mRNA expression in MKN45 cells and an increase in luciferase activity in cells which were transfected with a luciferase expression vector linked with a 5'-flanking region of the IL-8 gene (bp -133 to +44), indicating that the induction of IL-8 production occurred at the transcriptional level, This region contain three cis elements important for induction of IL-8 gene expression: AP-1 (-126 to -120 bp), NF-IL6 (-91 to -81 bp), and NF-kappa B (-80 to -70 bp) binding sites, Mutation of the NF-kappa B binding site abrogated completely the induction of luciferase activity, whereas that of the AP-1 site partially reduced the induction, However mutation of the NF-IL6 binding site resulted in no decrease in the induction of luciferase activity, Moreover, specific NF-kappa B complexes were detected in the nuclear proteins extracted from MKN45 cells which were infected with H. pylori. Collectively, these results suggest that H. pylori induced the activation of NF-kappa B as well as AP-1, leading to IL-8 gene transcription.