Distinct mechanism of helicobacter pylori-mediated NF-κB activation between gastric cancer cells and monocytic cells
Distinct mechanism of helicobacter pylori-mediated NF-κB activation between gastric cancer cells and monocytic cells
复制标题
DOI：
10.1074/jbc.m105381200
复制
发表时间：
2001-11-30
影响因子：
4.8
通讯作者：
Omata, M
中科院分区：
文献类型：
--
作者：
Maeda, S;Akanuma, M;Omata, M
NF-kappaB 是炎症相关基因的关键调节因子。胃上皮细胞和巨噬细胞被认为是促炎细胞因子的主要来源。我们研究了 MKN45 胃上皮细胞和 THP-1 单核细胞中幽门螺杆菌对 NF-kappaB 的激活作用。虽然，cag 致病性岛 (PAI) 阳性幽门螺杆菌（野生型）在两种细胞中均激活 NF-κB，但 cagE 的同基因突变体 (Delta cagE) 仅在 THP-1 细胞中激活它。野生型培养物的上清液可以激活 THP-1 细胞中的 NF-κB，但不能激活 MKN45 细胞中的 NF-κB。高密度 cDNA 阵列分析显示，两种细胞中野生型均显着上调 NF-κB 调节基因（如白细胞介素 (IL)-8、肿瘤坏死因子-α (TNF α) 和 IL-1 β）的 mRNA 表达，而仅在 THP-1 细胞中，Delta cagE 才上调该基因的 mRNA 表达。使用 CD14 中和抗体和 IL-1 受体相关激酶 (IRAK) 测定的实验表明，野生型和 Delta cagE 幽门螺杆菌均通过 THP-1 细胞中的 CD14 和 IRAK 激活 NF-κB，但在 MKN45 细胞中则不然。当用幽门螺杆菌处理时，与 C3H/HeN 小鼠巨噬细胞相比，来自携带 Toll 样受体 4 (TLR4) 基因点突变的 C3H/HeJ 小鼠的巨噬细胞显示出 NF-κB 激活和 TNFa 分泌减少。总之，上皮细胞中幽门螺杆菌诱导的 NF-κB 激活依赖于 cag PAI 和接触，但不涉及 CD14 和 IRAK，而在巨噬细胞/单核细胞中，它不依赖于 cag PAI 或接触，但涉及 CD14 和 TLR4。
NF-kappaB is a critical regulator of genes involved in inflammation. Gastric epithelial cells and macrophages are considered the main sources of pro-inflammatory cytokines. We investigated NF-kappaB activation by Helicobacter pylori in MKN45 gastric epithelial cells and THP-1 monocytic cells. Although, cag pathogenicity island (PAI)-positive H. pylori (wild type) activated NF-kappaB in both cells, isogenic mutant of cagE (Delta cagE) activated it only in THP-1 cells. Supernatant from the wild type culture could activate NF-kappaB in THP-1 cells but not in MKN45 cells. High density cDNA array analysis revealed that mRNA expression of NF-kappaB-regulated genes such as interleukin (IL)-8, tumor necrosis factor-alpha (TNF alpha), and IL-1 beta was significantly up-regulated by the wild type in both cells, whereas it was up-regulated by Delta cagE only in THP-1 cells. Experiments using CD14-neutralizing antibody and IL-1 receptor-associated kinase (IRAK) assay showed that both wild type and Delta cagE H. pylori activated NF-kappaB through CD14 and IRAK in THP-1 cells but not in MKN45 cells. Macrophages from C3H/HeJ mice carrying point mutation in the Toll-like receptor 4 (TLR4) gene showed decreased NF-kappaB activation and TNFa secretion compared with C3H/HeN mouse macrophage when treated with H. pylori. In conclusion, H. pylori-induced NF-kappaB activation in epithelial cells is dependent on cag PAI and contact but does not involve CD14 and IRAK, whereas in macrophage/monocytic cells it is independent of cag PAI or contact but involves CD14 and TLR4.