Schmidt A M, Yan S D, Brett J, Mora R, Nowygrod R, Stern D
Department of Physiology, Columbia University, College of Physicians and Surgeons, New York 10032.
J Clin Invest. 1993 May;91(5):2155-68. doi: 10.1172/JCI116442.
Nonenzymatic glycation of proteins occurs at an accelerated rate in diabetes and can lead to the formation of advanced glycation end products of proteins (AGEs), which bind to mononuclear phagocytes (MPs) and induce chemotaxis. We have isolated two cell surface-associated binding proteins that mediate the interaction of AGEs with bovine endothelial cells. One of these proteins is a new member of the immunoglobulin superfamily of receptors (termed receptor for AGEs or RAGE); and the second is a lactoferrin-like polypeptide (LF-L). Using monospecific antibodies to these two AGE-binding proteins, we detected immunoreactive material on Western blots of detergent extracts from human MPs. Radioligand-binding studies demonstrated that antibody to the binding proteins blocked 125I-AGE-albumin binding and endocytosis by MPs. Chemotaxis of human MPs induced by soluble AGE-albumin was prevented in a dose-dependent manner by intact antibodies raised to the AGE-binding proteins, F(ab')2 fragments of these antibodies and by soluble RAGE. When MP migration in response to N-formyl-Met-Leu-Phe was studied in a chemotaxis chamber with AGE-albumin adsorbed to the upper surface of the chamber membrane, movement of MPs to the lower compartment was decreased because of interaction of the glycated proteins with RAGE and LF-L on the cell surface. The capacity of AGEs to attract and retain MPs was shown by implanting polytetrafluoroethylene (PTFE) mesh impregnated with AGE-albumin into rats: within 4 d a florid mononuclear cell infiltrate was evident in contrast to the lack of a significant cellular response to PTFE with adsorbed native albumin. These data indicate that RAGE and LF-L have a central role in the interaction of AGEs with human mononuclear cells and that AGEs can serve as a nidus to attract MPs in vivo.
蛋白质的非酶糖基化在糖尿病中加速发生，并可导致蛋白质晚期糖基化终产物（AGEs）的形成，AGEs与单核吞噬细胞（MPs）结合并诱导趋化作用。我们分离出了两种细胞表面相关结合蛋白，它们介导AGEs与牛内皮细胞的相互作用。其中一种蛋白是免疫球蛋白超家族受体的新成员（称为AGEs受体或RAGE）；另一种是乳铁蛋白样多肽（LF-L）。使用针对这两种AGE结合蛋白的单特异性抗体，我们在人MPs去污剂提取物的蛋白质印迹上检测到了免疫反应性物质。放射性配体结合研究表明，针对结合蛋白的抗体可阻断MPs对125I-AGE-白蛋白的结合和内吞作用。针对AGE结合蛋白产生的完整抗体、这些抗体的F(ab')2片段以及可溶性RAGE，以剂量依赖的方式阻止了可溶性AGE-白蛋白诱导的人MPs趋化作用。当在趋化室中研究MPs对N-甲酰甲硫氨酰亮氨酰苯丙氨酸的迁移时，趋化室膜上表面吸附有AGE-白蛋白，由于糖化蛋白与细胞表面的RAGE和LF-L相互作用，MPs向下腔室的移动减少。通过将浸渍有AGE-白蛋白的聚四氟乙烯（PTFE）网植入大鼠体内，显示了AGEs吸引和保留MPs的能力：与吸附天然白蛋白的PTFE缺乏显著细胞反应形成对比，4天内可见大量单核细胞浸润。这些数据表明，RAGE和LF-L在AGEs与人单核细胞的相互作用中起核心作用，并且AGEs可作为体内吸引MPs的病灶。
