Identification of 4-hydroxy-2-nonenal-histidine adducts that serve as ligands for human lectin-like oxidized LDL receptor-1

• Published in: Biochemical journal Vol. 442; no. 1; p. 171
• Main Authors: Kumano-Kuramochi, Miyuki, Shimozu, Yuuki, Wakita, Chika, Ohnishi-Kameyama, Mayumi, Shibata, Takahiro, Matsunaga, Shigeru, Takano-Ishikawa, Yuko, Watanabe, Jun, Goto, Masao, Xie, Qiuhong, Komba, Shiro, Uchida, Koji, Machida, Sachiko
• Format: Journal Article
• Language: English
• Published: England 15.02.2012
• Subjects: Aldehydes - metabolism; Aldehydes - pharmacology; Animals; Aorta - metabolism; CHO Cells; Cricetinae; Endothelium, Vascular - cytology; Histidine - analogs & derivatives; Histidine - metabolism; Histidine - pharmacology; Humans; Ligands; Lipoproteins, LDL - metabolism; Reactive Oxygen Species - metabolism; Scavenger Receptors, Class E - metabolism
• ISSN: 1470-8728
• DOI: 10.1042/BJ20111029

LOX-1 (lectin-like oxidized low-density lipoprotein receptor-1) is an endothelial scavenger receptor that is important for the uptake of OxLDL (oxidized low-density lipoprotein) and contributes to the pathogenesis of atherosclerosis. However, the precise structural motifs of OxLDL that are recognized by LOX-1 are unknown. In the present study, we have identified products of lipid peroxidation of OxLDL that serve as ligands for LOX-1. We used CHO (Chinese-hamster ovary) cells that stably express LOX-1 to evaluate the ability of BSA modified by lipid peroxidation to compete with AcLDL (acetylated low-density lipoprotein). We found that HNE (4-hydroxy-2-nonenal)-modified proteins most potently inhibited the uptake of AcLDL. On the basis of the findings that HNE-modified BSA and oxidation of LDL resulted in the formation of HNE-histidine Michael adducts, we examined whether the HNE-histidine adducts could serve as ligands for LOX-1. The authentic HNE-histidine adduct inhibited the uptake of AcLDL in a dose-dependent manner. Furthermore, we found the interaction of LOX-1 with the HNE-histidine adduct to have a dissociation constant of 1.22×10(-8) M using a surface plasmon resonance assay. Finally, we showed that the HNE-histidine adduct stimulated the formation of reactive oxygen species and activated extracellular-signal-regulated kinase 1/2 and NF-κB (nuclear factor κB) in HAECs (human aortic endothelial cells); these signals initiate endothelial dysfunction and lead to atherosclerosis. The present study provides intriguing insights into the molecular details of LOX-1 recognition of OxLDL.