Identification of 4-hydroxy-2-nonenal-histidine adducts that serve as ligands for human lectin-like oxidized LDL receptor-1
Identification of 4-hydroxy-2-nonenal-histidine adducts that serve as ligands for human lectin-like oxidized LDL receptor-1
复制标题
鉴定作为人凝集素样氧化 LDL 受体 1 配体的 4-羟基-2-壬烯醛-组氨酸加合物。
DOI：
10.1042/bj20111029
复制
发表时间：
2012-02-15
影响因子：
4.1
通讯作者：
Machida, Sachiko
中科院分区：
文献类型：
--
作者：
Kumano-Kuramochi, Miyuki;Shimozu, Yuuki;Machida, Sachiko
LOX-1（凝集素样氧化低密度脂蛋白受体-1）是一种内皮清除率受体，对OxLDL（氧化低密度脂蛋白）的摄取很重要，并参与动脉粥样硬化的发病机制。然而，OxLDL被LOX-1识别的精确结构基序尚不清楚。在目前的研究中，我们已经确定了OxLDL的脂质过氧化产物作为LOX-1的配体。我们使用稳定表达LOX-1的CHO（中国仓鼠卵巢）细胞来评估脂质过氧化修饰的BSA与AcLDL（乙酰化低密度脂蛋白）竞争的能力。我们发现HNE（4-羟基-2-壬烯醛）修饰的蛋白最有效地抑制AcLDL的摄取。基于hne修饰的BSA和LDL氧化导致hne -组氨酸Michael加合物的形成的发现，我们研究了hne -组氨酸加合物是否可以作为LOX-1的配体。真正的hne -组氨酸加合物以剂量依赖的方式抑制AcLDL的摄取。此外，我们发现LOX-1与hne -组氨酸加合物的相互作用具有1.22x10(-8) M的解离常数。最后，我们发现，在人主动脉内皮细胞中，组氨酸加合物刺激活性氧的形成，激活细胞外信号调节激酶1/2和nf - κ B（核因子κ B）；这些信号引发内皮功能障碍并导致动脉粥样硬化。本研究为LOX-1识别OxLDL的分子细节提供了有趣的见解。
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 1.22x10(-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-kappa B (nuclear factor kappa B) 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.