晚期糖基化终产物诱导单核细胞产生细胞因子的细胞内信号传导机制

Advanced glycation end products-induced inflammatory reaction in human monocytes:cellular receptor pathway & intracellular signaling

目的 探讨晚期糖基化终产物 (AGE)诱导单核细胞产生白细胞介素 1β(IL 1β)和肿瘤坏死因子 浕(TNF 浕)的细胞内信号传导机制。方法 采用密度梯度离心法分离健康成人外周血单核细胞 ,经AGE修饰的人血清白蛋白 (AGE HSA)刺激后 ,用ELISA法检测培养上清中IL 1β、TNF 浕水平 ,用化学发光法测定活性氧的生成 ;免疫细胞化学染色及凝胶迁移电泳 (EMSA)法观察核因子 κB(NF κB/p6 5 )的激活。分别用抗AGE受体 (RAGE)抗体、NADPH氧化酶特异性抑制剂apocynin和p38通路抑制剂SB 2 0 35 80预处理单核细胞 ,观察对AGE HSA诱导细胞因子和活性氧产生的影响。结果 AGE HSA与单核细胞在体外共同培养后 ,细胞内NF κB激活 ,培养上清中IL 1β、TNF 浕水平明显增高 ,活性氧生成增加 ;用抗RAGE抗血清或apocynin预处理细胞可阻断AGE HSA诱导的活性氧生成 (P <0 0 1) ,抑制NF κB的活化并使培养上清IL 1β、TNF 浕显著降低 (P <0 0 1)。用SB 2 0 35 80预处理细胞也可抑制AGE HSA诱导的NF κB激活及IL 1β、TNF 浕的产生 ,但对活性氧的产生无明显影响 (P >0 0 5 )。结论 AGE通过RAGE介导的途径刺激单核细胞生成IL 1β、TNF 浕和活性氧 ,NADPH氧化酶途径可能是RAGE细胞内信号途径的上游 。

Objective To investigate the cellular receptor pathway and the intracellular signaling of advanced glycation end products(AGE)-induced inflammatory reaction in monocytes. Methods Human peripheral monocytes were isolated from healthy volunteers. Cells were incubated with AGE modified by the addition of human serum albumin (AGE-HSA) either with pretreatment or no pretreatment of anti-AGE receptor (RAGE) IgG, NADPH oxidase inhibitor (apocynin)or a specific inhibitor of p38(SB 203580). The levels of interleukin-1β(IL-1β)and tumor necrosis factor-α(TNF-α) in the supernatants were assayed with enzyme-linked immunoadsorbent assay (ELISA). Reactive oxygen species (ROS) production was determined by MCLA chemiluminescence. Nuclear factor-κB translocation was assayed by immunochemical staining with anti-NF-κB/p65 and electrophoretic mobility shift assay(EMSA). Results AGE-HSA was found to induce activation of NF-κB, increase levels of IL-1β and TNF-α in the supernatants, and enhance production of ROS by monocytes. Pre-treatment of cells with anti-RAGE IgG or apocynin inhibited AGE-HSA to induce NF-κB translocation and IL-1β or TNF-α production. AGE stimulated ROS production could also be blocked by pre-treatment of cultured cells with anti-RAGE IgG or apocynin. Pre-treatment of cultured cells with SB 203580 inhibited both NF-κB activation and cytokines production, but showed no significant effect the cells to produce ROS. Conclusion AGE-HSA could induce IL-1β and TNF-α release as well as ROS production in human monocytes via a pathway mediated by RAGE. Activation of NADPH oxidase may be the upstream of the intracellular pathway. AGE-induced cytokines production was p38 pathway-dependent.