Short-chain aldehyde-derived ligands for RAGE and their actions on endothelial cells.
The formation and accumulation of advanced glycation endproducts (AGE) have been implicated in the development of diabetic vascular complications. Their biological responses are known to be mediated by the receptor for AGE (RAGE). Recently, AGE have been proposed to be derived not only from the classical Maillard reaction but also from other pathways of sugar autoxidation and metabolism. Here, we report the identification of glyceraldehydes (Gcer)- and glycolaldehyde (Gcol)-derived AGE as RAGE ligands and their presence in vivo. The apparent dissociation constants assessed by surface-plasmon resonance (SPR) analysis with purified human RAGE proteins were 360 nM for Gcer-AGE and 1.35 microM for Gcol-AGE. The radiolabeled-ligand binding assay with RAGE-expressing COS-7 cells revealed similar association kinetics. Competitive SPR assay with antibodies specific to the respective AGE fractions demonstrated abundant existence of both Gcer- and Gcol-AGE in RAGE affinity-purified proteins from human sera. The serum contents of Gcer- and Gcol-AGE in a diabetic patient were about twice as high as those in a healthy control. Functionally, Gcer- and Gcol-AGE upregulated the endothelial cell levels of mRNA for vascular endothelial growth factor (VEGF) and the secretion of its protein product into the culture media and DNA synthesis in a dose-dependent manner. Further, these endothelial responses were augmented by RAGE overexpression. The results suggest that RAGE engagement of Gcer- and Gcol-AGE may elicit angiogenesis through the induction of autocrine VEGF, thereby contributing to the development and progression of diabetic angiopathies.
Yamamoto
Yasuhiko
Y
Department of Biochemistry and Molecular Vascular Biology, Kanazawa University Graduate School of Medical Science, 13-1 Takara-machi, Kanazawa 920-8640, Japan.
Yonekura
Hideto
H
Watanabe
Takuo
T
Sakurai
Shigeru
S
Li
Hui
H
Harashima
Ai
A
Myint
Khin Mar
KM
Osawa
Mari
M
Takeuchi
Akihiko
A
Takeuchi
Masayoshi
M
Yamamoto
Hiroshi
H
D000447:Aldehydes / Q000378:metabolism* / Q000494:pharmacology*; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004261:DNA Replication / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D000882:Haplorhini; D006801:Humans; D008024:Ligands; D012333:RNA, Messenger / Q000235:genetics; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020349:Surface Plasmon Resonance; D014471:Umbilical Veins
D000447:Aldehydes; D008024:Ligands; D012333:RNA, Messenger; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic