晚期糖基化终产物通过其受体促进内皮细胞分泌IL-8的研究

探讨晚期糖基化终产物(AGE)修饰蛋白对内皮细胞生成白介素8(IL-8)的作用,及晚期糖基化终产物受体(RAGE)在此病理过程中的作用.内皮细胞来自培养的人脐静脉内皮细胞(HUVEC).将内皮细胞与不同浓度的AGE修饰人血清白蛋白(AGE-HSA)在体外共同培养,或以可溶性晚期糖基化终产物受体(sRAGE)对AGE-HSA进行预处理后再与HUVEC共同培养.用蛋白质液相芯片法检测HUVEC培养上清中IL-8水平,并提取细胞RNA,进行RT-PCR反应,检测细胞中IL-8 mRNA的表达水平.结果表明,AGE-HSA以时间和剂量依赖的方式刺激HUVEC生成IL-8,未经修饰的HSA无此作用.AGE-HSA用sRAGE预处理后,刺激HUVEC生成IL-8的作用被抑制,并且此抑制作用呈剂量依赖的方式.AGE-HSA刺激HUVEC使IL-8 mRNA表达增高,未经修饰的HSA无此作用.sRAGE能够阻断AGE-HSA诱导HUVEC表达IL-8mRNA的作用.整个变化趋势与蛋白质水平一致.研究首次证实,AGE-HSA与细胞表面受体RAGE相互作用可刺激内皮细胞分泌IL-8,并上调IL-8 mRNA的表达.这为研究加速型血管病变的发病机制提供了新视角,也为治疗由AGE增多和潴留所引起的病理损害提供了新靶点.

Advanced Glycation End Products Increase Secretion of IL-8 by Human Endothelial Cells Through RAGE

To investigate the effect of advanced glycation end products (AGE) modified protein on IL-8 secretion by human endothelial cells and the role of receptor for advanced glycation end products (RAGE) in this pathological procedure. Human umbilical vein endothelial cells (HUVEC) were cultured in vitro with different concentration AGE modified human serum albumin (AGE-HSA) which had been treated with soluble receptor for advanced glycation end products (sRAGE) or not. IL-8 levels in the supernatant were determined using Liquid Chip method. RNA was extracted from the cells and RT-PCR was performed to determine the mRNA expression levels of IL-8 in each group, and GAPDH levels were served as reference during this process. The results showed that AGE-HSA increased IL-8 secretion as a dose- and time- dependent manner. Unmodified HSA had no such effect. AGE-induced IL-8 secretion was significantly inhibited by sRAGE as a dose-dependent manner, and the decrease extent was 82.4% when the cells were incubated with 500 mg/L of sRAGE. AGE-RAGE interaction upregulated IL-8 mRNA expression in HUVEC, and this effect could be blocked by pretreatment of AGE-HSA with intact sRAGE. It was proved that AGE modified protein increases the secretion of IL-8 by endothelial cells through RAGE on protein and gene levels, which maybe provide a new aspect to study the machines and treatment methods of AGE-associated diseases.