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The Role of Galectin-3 in Endocytosis of Advanced Glycation End Products and Modified Low Density Lipoproteins

2001; Elsevier BV; Volume: 280; Issue: 4 Linguagem: Inglês

10.1006/bbrc.2001.4256

1090-2104

Wenqin Zhu, Hiroyuki Sano, Ryoji Nagai, Kaori Fukuhara, Akira Miyazaki, Seikoh Horiuchi,

Studies on Chitinases and Chitosanases

Galectin-3, a member of beta-galactoside-binding lectin family, is suggested to be an AGE-receptor. To examine this possibility, we prepared CHO cells overexpressing human galectin-3 (galectin-3-CHO cells). Galectin-3-CHO cells showed a specific and saturable binding to (125)I-AGE-BSA with Kd of 3.1 microg/ml. (125)I-AGE-BSA was endocytosed by galectin-3-CHO cells and underwent lysosomal degradation. The endocytosis of (125)I-AGE-BSA was inhibited not only by unlabeled AGE-BSA but also by acetylated LDL and oxidized LDL, ligands for the scavenger receptor family. Furthermore, (125)I-oxidized LDL and (125)I-acetylated LDL were actively endocytosed by galectin-3-CHO cells and the incubation with acetyl-LDL led to intracellular accumulation of cholesteryl esters, indicating the role of galectin-3 in endocytosis of AGE-proteins and modified LDLs. Since galectin-3 was localized and up-regulated in foam cells at human atherosclerotic lesions, the present results suggest that galectin-3 plays an important role in formation of atherosclerotic lesions in vivo, by modulating endocytic uptake of AGE-proteins and modified LDLs.