丝裂原活化的蛋白激酶在高迁移率族蛋白1诱导内皮细胞释放炎性细胞因子中的作用

目的 研究重组人高迁移率族蛋白1(HMGB1)诱导内皮细胞释放趋化因子白介素-8(IL-8)和单核细胞趋化蛋白-1(MCP-1)的规律及其与脂多糖(LPS)的协同作用;探讨丝裂原活化的蛋白激酶(MAPK)信号通路在上述作用中的地位.方法 用LiquiChip液相蛋白芯片系统检测不同浓度重组HMGB1(0～75 ng/ml),或者HMGB1(15 ng/ml)刺激后不同时间点人脐静脉内皮细胞(HUVEC)分泌IL-8、MCP-1的水平变化以及HMGB1(15 ng/ml)与LPS(10ng/ml)共同刺激后IL-8、MCP-1的水平变化;探讨MAPK信号通路在HMGB1诱导内皮细胞释放趋化因子中的作用时首先加入抑制剂SB203580(20 mol/L)、PD98059(20 mol/L)和JNK inhibitor Ⅱ(50 nmol/L)预处理细胞1 h,再加入HMGB1和LPS刺激.结果 在HMGB1蛋白刺激后3～6h,IL-8和MCP-1水平开始增加,12～24h持续增高(P<0.01);随着 HMGB1浓度的增加,IL-8和MCP-1水平也明显升高,与基础值相比差异有统计学意义(P<0.01).如果用LPS(10ng/ml)和HMGB1(15 ng/ml)共同刺激HUVEC,IL-8和MCP-1的生成量较单独刺激时大大增加(P<0.01),二者存在协同效应(P<0.01).SB203580、PD98059及JNK inhibitor Ⅱ对HMGB1和LPS协同诱导趋化因子的释放均有不同程度的抑制作用,其中以p38 MAPK抑制剂SB203580的抑制作用最为明显;同时用SB203580、PD98059和JNK inhibitor Ⅱ预处理细胞则完全抑制趋化因子的释放.结论 HMGB1蛋白以时间和剂量依赖方式诱导HUVEC表达趋化因子IL-8和MCP-1的上调;并协同LPS刺激HUVEC释放趋化因子IL-8和MCP-1从而加重炎症反应.MAPK信号通路在HMGB1与LPS协同诱导内皮细胞释放趋化因子的过程中发挥了重要作用.

Abstract：

Objective To examine the synergistic effect of recombinant human high mobility group box 1 (HMGB1) protein and lipopolysaccharides (LPS) on the release of interleukin-8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) in human umbilic vein endothelial cells (HUVECs), and explore the role of mitogen-activated protein kinases (MAPK) signal transduction in cytokine release. Methods HUVECs were incubated with recombinant HMGB1(0-75 ng/ml) for 24 h and the culture medium supernatant was harvested for detection of IL-8 and MCP-1 with LiquiChip system. At 0, 1, 3, 6, 12 and 24 h after stimulation with 15 ng/ml HMGB1 or 15 ng/ml HMGB1 plus 10 ng/ml LPS, the levels of IL-8 and MCP-1 in the HUVECs were examined, To test the effect of MAPK inhibitors, HUVCs were pretreated with the inhibitors SB203580 (20 mol/L), PD98059 (20 mol/L), and JNK inhibitor II (50 nmol/L) 1 h before HMGB1 and LPS stimulation. Results The levels of IL-8 and MCP-1 were significantly increased in the HUVECs stimulated with HMGB1 protein at the concentrations of 3, 15 and 75 ng/ml in comparison with the control levels (P<0.01). Since 3-6 h after the stimulation with HMGB1, the levels of IL-8 and MCP-1 began to increase gradually, and steadily increased at 12 and 24 h, all significantly higher than those of the control group (P<0.01). Stimulation of the HUVECs with LPS (10 ng/ml) or HMGB1 (15 ng/ml) alone resulted in significantly increased levels of IL-8 and MCP-1 (P<0.01), which were further increased after costimulation with LPS and HMGB1,suggesting a synergistic effect between HMGB1 and LPS (P<0.01). This synergistic effect was significantly inhibited by pretreatment with MAPK signaling kinases inhibitors, especially the p38 MAP kinase inhibitor SB203580, and the cocktail of MAP kinase inhibitors almost totally blocked the expression of these chemokines in HUVECs treated with HMGB1 and LPS. Conclusion HMGB1 protein can activate HUVECs to produce the chemokines IL-8 and MCP-1 in a dose-and time-dependent manner. HMGB1 also acts synergisrically with LPS to induce IL-8 and MCP-1 release, which might play an important role in the development of sepsis.MAPK signal transduction plays an important role in HMGB1 and LPS-induced IL-8 and MCP-1 release.

High mobility group box-1 stimulates proinflammatory cytokine production in endothelial cells via MAP kinases

Objective To examine the synergistic effect of recombinant human high mobility group box 1 (HMGB1) protein and lipopolysaccharides (LPS) on the release of interleukin-8 (IL-8) and monocyte chemotactic protein 1 (MCP-1) in human umbilic vein endothelial cells (HUVECs), and explore the role of mitogen-activated protein kinases (MAPK) signal transduction in cytokine release. Methods HUVECs were incubated with recombinant HMGB1 (0-75 ng/ml) for 24 h and the culture medium supernatant was harvested for detection...