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

2012 ◽  
Vol 442 (1) ◽  
pp. 171-180 ◽  
Author(s):  
Miyuki Kumano-Kuramochi ◽  
Yuuki Shimozu ◽  
Chika Wakita ◽  
Mayumi Ohnishi-Kameyama ◽  
Takahiro Shibata ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Chinese Hamster Ovary Cells ◽  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Low Density ◽  
Dependent Manner ◽  
Oxidized Low Density Lipoprotein

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.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1): a crucial driver of atherosclerotic cardiovascular disease

2020 ◽  
Author(s):  
Alexander Akhmedov ◽  
Tatsuya Sawamura ◽  
Chu-Huang Chen ◽  
Simon Kraler ◽  
Daria Vdovenko ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Basic Research ◽  
Plaque Formation ◽  
Atherosclerotic Cardiovascular Disease ◽  
Low Density ◽  
Oxidized Low Density Lipoprotein ◽  
Atheromatous Plaques

Abstract Cardiovascular diseases (CVDs), specifically lipid-driven atherosclerotic CVDs, remain the number one cause of death worldwide. The lectin-like oxidized low-density lipoprotein (LDL) receptor-1 (LOX-1), a scavenger receptor that promotes endothelial dysfunction by inducing pro-atherogenic signalling and plaque formation via the endothelial uptake of oxidized LDL (oxLDL) and electronegative LDL, contributes to the initiation, progression, and destabilization of atheromatous plaques, eventually leading to the development of myocardial infarction and certain forms of stroke. In addition to its expression in endothelial cells, LOX-1 is expressed in macrophages, cardiomyocytes, fibroblasts, dendritic cells, lymphocytes, and neutrophils, further implicating this receptor in multiple aspects of atherosclerotic plaque formation. LOX-1 holds promise as a novel diagnostic and therapeutic target for certain CVDs; therefore, understanding the molecular structure and function of LOX-1 is of critical importance. In this review, we highlight the latest scientific findings related to LOX-1, its ligands, and their roles in the broad spectrum of CVDs. We describe recent findings from basic research, delineate their translational value, and discuss the potential of LOX-1 as a novel target for the prevention, diagnosis, and treatment of related CVDs.

scholarly journals Unusual forms of low density lipoprotein receptors in hamster cell mutants with defects in the receptor structural gene.

1986 ◽  
Vol 102 (5) ◽  
pp. 1567-1575 ◽  
Author(s):  
K F Kozarsky ◽  
H A Brush ◽  
M Krieger
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Low Density ◽  
Wild Type ◽  
Ovary Cells ◽  
Ldl Receptors

The structure and processing of low density lipoprotein (LDL) receptors in wild-type and LDL receptor-deficient mutant Chinese hamster ovary cells was examined using polyclonal anti-receptor antibodies. As previously reported for human LDL receptors, the LDL receptors in wild-type Chinese hamster ovary cells were synthesized as precursors which were extensively processed by glycosylation to a mature form. In the course of normal receptor turnover, an apparently unglycosylated portion of the cysteine-rich N-terminal LDL binding domain of the receptor is proteolytically removed. The LDL receptor-deficient mutants fall into four complementation groups, ldlA, ldlB, ldlC, and ldlD; results of the analysis of ldlB, ldlC, and ldlD mutants are described in the accompanying paper (Kingsley, D. M., K. F. Kozarsky, M. Segal, and M. Krieger, 1986, J. Cell. Biol, 102:1576-1585). Analysis of ldlA cells has identified three classes of mutant alleles at the ldlA locus: null alleles, alleles that code for normally processed receptors that cannot bind LDL, and alleles that code for abnormally processed receptors. The abnormally processed receptors were continually converted to novel unstable intracellular intermediates. We also identified a compound-heterozygous mutant and a heterozygous revertant which indicate that the ldlA locus is diploid. In conjunction with other genetic and biochemical data, the finding of multiple mutant forms of the LDL receptor in ldlA mutants, some of which appeared together in the same cell, confirm that the ldlA locus is the structural gene for the LDL receptor.

scholarly journals Oxidized low density lipoprotein inhibits the migration of aortic endothelial cells in vitro.

1993 ◽  
Vol 120 (4) ◽  
pp. 1011-1019 ◽  
Author(s):  
G Murugesan ◽  
G M Chisolm ◽  
P L Fox
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Lipid Hydroperoxide ◽  
Density Lipoprotein ◽  
Low Density ◽  
Dependent Manner ◽  
Oxidized Low Density Lipoprotein ◽  
Inhibitor Molecule ◽  
Healing Response

Endothelial cell (EC) migration is a critical and initiating event in the formation of new blood vessels and in the repair of injured vessels. Compelling evidence suggests that oxidized low density lipoprotein (LDL) is present in atherosclerotic lesions, but its role in lesion formation has not been defined. We have examined the role of oxidized LDL in regulating the wound-healing response of vascular EC in vitro. Confluent cultures of bovine aortic EC were "wounded" with a razor, and migration was measured after 18 to 24 h as the number of cells moving into the wounded area and the mean distance of cells from the wound edge. Oxidized LDL markedly reduced migration in a concentration- and oxidation-dependent manner. Native LDL or oxidized LDL with a thiobarbituric acid (TBA) reactivity < 5 nmol malondialdehyde equivalents/mg cholesterol was not inhibitory; however, oxidized LDL with a TBA reactivity of 8-12 inhibited migration by 75-100%. Inhibition was half-maximal at 250-300 micrograms cholesterol/ml and nearly complete at 350-400 micrograms/ml. The antimigratory activity was not due to cell death since it was completely reversed 16 h after removal of the lipoprotein. The inhibitor molecule was shown to be a lipid; organic solvent extracts of oxidized LDL inhibited migration to nearly the same extent as the intact particle. When LDL was variably oxidized by dialysis against FeSO4 or CuSO4, or by UV irradiation, the inhibitory activity correlated with TBA reactivity and total lipid peroxides, but not with electrophoretic mobility or fluorescence (360 ex/430 em). This indicates that a lipid hydroperoxide may be the active species. These results suggest the possibility that oxidized LDL may limit the healing response of the endothelium after injury.

scholarly journals Identification of the lectin-like receptor for oxidized low-density lipoprotein in human macrophages and its potential role as a scavenger receptor

1998 ◽  
Vol 334 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Hiroshi YOSHIDA ◽  
Nonna KONDRATENKO ◽  
Simone GREEN ◽  
Daniel STEINBERG ◽  
Oswald QUEHENBERGER
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Scavenger Receptor ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Human Monocyte ◽  
Binding Activity ◽  
Low Density ◽  
Blood Monocytes ◽  
Oxidized Low Density Lipoprotein

A new receptor for oxidized low-density lipoprotein (LDL), lectin-like oxidized LDL receptor-1 (LOX-1), has recently been cloned from bovine endothelial cells and human lung. A limited tissue-distribution study suggested that the protein was mainly produced by the vascular endothelium. In the present study we demonstrate that LOX-1 is also expressed in macrophages, where it may function as a scavenger receptor. LOX-1 was not detected in undifferentiated THP-1 cells or in freshly isolated human blood monocytes. However, mature human monocyte-derived macrophages and differentiated THP-1 cells showed high levels of LOX-1 transcripts. Consistent with these results, immunofluorescence staining and FACS analysis demonstrated that LOX-1 protein is expressed on the plasma membrane of macrophages. Western-blot analysis of membranes from macrophages (but not those from monocytes) identified a single band, with an apparent molecular mass of about 40 kDa, that displayed oxidized LDL-binding activity. These results suggest that differentiation induces the expression of LOX-1 in macrophages, where it may play a role as a scavenger receptor and/or a receptor for oxidized LDL.

scholarly journals The neurorepellent, Slit2, prevents macrophage lipid loading by inhibiting CD36-dependent binding and internalization of oxidized low-density lipoprotein

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bushra Yusuf ◽  
Ilya Mukovozov ◽  
Sajedabanu Patel ◽  
Yi-Wei Huang ◽  
Guang Ying Liu ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Super Resolution ◽  
Low Density ◽  
Dependent Manner ◽  
Oxidized Low Density Lipoprotein ◽  
Cortical Actin ◽  
Cytoskeletal Remodeling ◽  
Atherosclerotic Lesions ◽  
Modified Lipoproteins

AbstractAtherosclerosis is characterized by retention of modified lipoproteins, especially oxidized low density lipoprotein (oxLDL) within the sub-endothelial space of affected blood vessels. Recruited monocyte-derived and tissue-resident macrophages subsequently ingest oxLDL by binding and internalizing oxLDL via scavenger receptors, particularly CD36. The secreted neurorepellent, Slit2, acting through its transmembrane receptor, Roundabout-1 (Robo-1), was previously shown to inhibit recruitment of monocytes into nascent atherosclerotic lesions. The effects of Slit2 on oxLDL uptake by macrophages have not been explored. We report here that Slit2 inhibits uptake of oxLDL by human and murine macrophages, and the resulting formation of foam cells, in a Rac1-dependent and CD36-dependent manner. Exposure of macrophages to Slit2 prevented binding of oxLDL to the surface of cells. Using super-resolution microscopy, we observed that exposure of macrophages to Slit2 induced profound cytoskeletal remodeling with formation of a thick ring of cortical actin within which clusters of CD36 could not aggregate, thereby attenuating binding of oxLDL to the surface of cells. By inhibiting recruitment of monocytes into early atherosclerotic lesions, and the subsequent binding and internalization of oxLDL by macrophages, Slit2 could represent a potent new tool to combat individual steps that collectively result in progression of atherosclerosis.

Oxidative stress augments pulmonary hypertension in chronically hypoxic mice overexpressing the oxidized LDL receptor

2013 ◽  
Vol 305 (2) ◽  
pp. H155-H162 ◽  
Author(s):  
Sayoko Ogura ◽  
Tatsuo Shimosawa ◽  
ShengYu Mu ◽  
Takashi Sonobe ◽  
Fumiko Kawakami-Mori ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Chronic Hypoxia ◽  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Ros Generation ◽  
Low Density ◽  
Ros Production ◽  
Oxidized Low Density Lipoprotein

Chronic hypoxia is one of the main causes of pulmonary hypertension (PH) associated with ROS production. Lectin-like oxidized low-density lipoprotein receptor (LOX)-1 is known to be an endothelial receptor of oxidized low-density lipoprotein, which is assumed to play a role in the initiation of ROS generation. We investigated the role of LOX-1 and ROS generation in PH and vascular remodeling in LOX-1 transgenic (TG) mice. We maintained 8- to 10-wk-old male LOX-1 TG mice and wild-type (WT) mice in normoxia (room air) or hypoxia (10% O2 chambers) for 3 wk. Right ventricular (RV) systolic pressure (RVSP) was comparable between the two groups under normoxic conditions; however, chronic hypoxia significantly increased RVSP and RV hypertrophy in LOX-1 TG mice compared with WT mice. Medial wall thickness of the pulmonary arteries was significantly greater in LOX-1 TG mice than in WT mice. Furthermore, hypoxia enhanced ROS production and nitrotyrosine expression in LOX-1 TG mice, supporting the observed pathological changes. Administration of the NADPH oxidase inhibitor apocynin caused a significant reduction in PH and vascular remodeling in LOX-1 TG mice. Our results suggest that LOX-1-ROS generation induces the development and progression of PH.

Characterization of a family of gamma-ray-induced CHO mutants demonstrates that the ldlA locus is diploid and encodes the low-density lipoprotein receptor

1986 ◽  
Vol 6 (9) ◽  
pp. 3268-3277
Author(s):  
R D Sege ◽  
K F Kozarsky ◽  
M Krieger
Keyword(s):  
Gamma Irradiation ◽  
Cho Cells ◽  
Gamma Ray ◽  
Receptor Gene ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Low Density ◽  
Ldl Receptors

The ldlA locus is one of four Chinese hamster ovary (CHO) cell loci which are known to be required for the synthesis of functional low-density lipoprotein (LDL) receptors. Previous studies have suggested that the ldlA locus is diploid and encodes the LDL receptor. To confirm this assignment, we have isolated a partial genomic clone of the Chinese hamster LDL receptor gene and used this and other nucleic acid and antibody probes to study a family of ldlA mutants isolated after gamma-irradiation. Our analysis suggests that there are two LDL receptor alleles in wild-type CHO cells. Each of the three mutants isolated after gamma-irradiation had detectable deletions affecting one of the two LDL receptor alleles. One of the mutants also had a disruption of the remaining allele, resulting in the synthesis of an abnormal receptor precursor which was not subject to Golgi-associated posttranslational glycoprotein processing. The correlation of changes in the expression, structure, and function of LDL receptors with deletions in the LDL receptor genes in these mutants directly demonstrated that the ldlA locus in CHO cells is diploid and encodes the LDL receptor. In addition, our analysis suggests that CHO cells in culture may contain a partial LDL receptor pseudogene.

Isolation and characterization of an extragenic suppressor of the low-density lipoprotein receptor-deficient phenotype of a Chinese hamster ovary cell mutant

1989 ◽  
Vol 9 (11) ◽  
pp. 4799-4806
Author(s):  
P Reddy ◽  
M Krieger
Keyword(s):  
Structural Gene ◽  
Chinese Hamster Ovary ◽  
Low Density Lipoprotein ◽  
Chinese Hamster ◽  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Ovary Cell ◽  
Low Density ◽  
Extragenic Suppressor ◽  
Extragenic Suppression

ldlC cells are low-density lipoprotein (LDL) receptor-deficient Chinese hamster ovary cell mutants which express pleiotropic defects in Golgi-associated glycosylation reactions. The dramatically reduced stability of the abnormally glycosylated LDL receptors in ldlC cells was shown to be due, in part, to rapid proteolysis and release of a large extracellular fragment of the receptor into the medium. A set of spontaneously arising LDL receptor-positive revertants of ldlC cells has been isolated. One of these, RevC-13, exhibits the glycosylation defects characteristic of the original ldlC mutant, suggesting that restoration of receptor activity was due to extragenic suppression. This suppression was due to a dramatic increase in the rate of LDL receptor synthesis rather than to an increase in the stability of the abnormally glycosylated receptors. Increased receptor synthesis was not due to receptor gene amplification. The increased LDL receptor activity was subject to normal sterol regulation. Analysis of the RevC-13 extragenic suppressor activity in a series of hybrid cells showed that RevC-13 suppression was a codominant trait that acted in cis to the LDL receptor structural gene (ldlA). Thus, the extragenic suppression in RevC-13 cells has defined a genetic element which is either part of or linked to the LDL receptor structural gene and which can control LDL receptor expression.

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