scholarly journals Soluble Lectin-Like Oxidized LDL Receptor 1 as a Possible Mediator of Endothelial Dysfunction in Patients With Metabolic Syndrome

2014 ◽  
Vol 29 (3) ◽  
pp. 184-190 ◽  
Author(s):  
S. Civelek ◽  
M. Kutnu ◽  
H. Uzun ◽  
F. Erdenen ◽  
E. Altunoglu ◽  
...  
2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Felipe A. Zuniga ◽  
Valeska Ormazabal ◽  
Nicolas Gutierrez ◽  
Valeria Aguilera ◽  
Claudia Radojkovic ◽  
...  

The bioavailability of nitric oxide (NO) represents a key marker in vascular health. A decrease in NO induces a pathological condition denominated endothelial dysfunction, syndrome observed in different pathologies, such as obesity, diabetes, kidney disease, cardiovascular disease, and preeclampsia (PE). PE is one of the major risks for maternal death and fetal loss. Recent studies suggest that the placenta of pregnant women with PE express high levels of lectin-like oxidized LDL receptor-1 (LOX-1), which induces endothelial dysfunction by increasing reactive oxygen species (ROS) and decreasing intracellular NO. Besides LOX-1 activation induces changes in migration and apoptosis of syncytiotrophoblast cells. However, the role of this receptor in placental tissue is still unknown. In this review we will describes the physiological roles of LOX-1 in normal placenta development and the potential involvement of this receptor in the pathophysiology of PE.


1970 ◽  
Vol 3 (2) ◽  
pp. 169-177
Author(s):  
MSA Sheikh ◽  
T Yang ◽  
U Salma ◽  
M Ali

Lectin-like oxidized LDL receptor-1 (LOX-1), a lectin-like 50-kD receptor for oxidized low-density lipoproteins (ox-LDL), is present primarily on endothelial cells. Oxidatively modified low-density lipoprotein (oxLDL) is implicated in the pathogenesis of atherosclerosis. Endothelial dysfunction is the initial change in the vascular wall that induces morphological changes for atheroma-formation. LOX-1 was identified as the receptor for oxLDL that was thought to be a major cause of endothelial dysfunction. LOX-1 has been demonstrated to contribute not only to endothelial dysfunction, but also to atherosclerotic-plaque formation, hypertension, myocardial infarction and intimal thickening after balloon injury. Studies with transgenic and knockout mouse models have elucidated in part the role of LOX-1 in the pathogenesis of atherosclerosis and cardiac remodeling. Recently, a circulating soluble form of LOX-1(sLOx-1), corresponding solely to its extracellular domain, has been identified in human serum. Circulating levels of sLOX-1 are increased in inflammatory and atherosclerotic conditions and are associated with acute coronary syndrome, with the severity of coronary artery disease, and with serum biomarkers for oxidative stress and inflammation, suggesting that they could be useful marker for vascular injury. Identification and regulation of this receptor and understanding of signal transduction pathways might open new gateways from diagnosis to therapeutics for cardiovascular diseases. Keywords: Atherosclerosis; Endothelial dysfunction; LOX-1; ox-LDL; Signal transduction. DOI: http://dx.doi.org/10.3329/cardio.v3i2.9187 Cardiovasc. J. 2011; 3(2): 169-177


2006 ◽  
Vol 290 (3) ◽  
pp. R601-R608 ◽  
Author(s):  
Fruzsina K. Johnson ◽  
Robert A. Johnson ◽  
William Durante ◽  
Keith E. Jackson ◽  
Blake K. Stevenson ◽  
...  

Vascular heme oxygenase (HO) metabolizes heme to form carbon monoxide (CO). Increased heme-derived CO inhibits nitric oxide synthase and can contribute to hypertension via endothelial dysfunction in Dahl salt-sensitive rats. Obese Zucker rats (ZR) are models of metabolic syndrome. This study tests the hypothesis that endogenous CO formation is increased and contributes to hypertension and endothelial dysfunction in obese ZR. Awake obese ZR showed increased respiratory CO excretion, which was lowered by HO inhibitor administration [zinc deuteroporphyrin 2,4-bis glycol (ZnDPBG) 25 μmol·kg−1·24 h−1 ip]. In awake obese ZR, chronically instrumented with femoral arterial catheters, blood pressure was elevated but was decreased by the HO inhibitor ZnDPBG. Body weight, blood glucose, glycated hemoglobin, plasma insulin, total and LDL cholesterol, oxidized LDL, and triglyceride levels were elevated in obese ZR, and, except for LDL cholesterol, were unchanged by HO inhibition. Total HO-1 protein levels were not different between lean and obese ZR aortas. In vitro experiments used isolated skeletal muscle arterioles with constant pressure and no flow, or constant midpoint, but altered endpoint pressures to establish graded levels of luminal flow. In obese ZR arterioles, responses to ACh and flow were attenuated. Acute in vitro pretreatment with an HO inhibitor, chromium mesoporphyrin, enhanced ACh and flow-induced dilation and abolished the differences between groups. Furthermore, exogenous CO prevented the restoration of flow-induced dilation by the HO inhibitor in obese ZR arterioles. These results suggest that HO-derived CO production is increased and promotes hypertension and arteriolar endothelial dysfunction in obese ZR with metabolic syndrome independent of affecting metabolic parameters.


2012 ◽  
Vol 43 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Vincenzo O. Palmieri ◽  
Brigida Coppola ◽  
Ignazio Grattagliano ◽  
Valentina Casieri ◽  
Giovanna Cardinale ◽  
...  

2009 ◽  
Vol 296 (5) ◽  
pp. H1643-H1650 ◽  
Author(s):  
Heather H. Shih ◽  
Songwen Zhang ◽  
Wei Cao ◽  
Ashleigh Hahn ◽  
Juan Wang ◽  
...  

C-reactive protein (CRP) is a risk factor for cardiovascular events and functions to amplify vascular inflammation through promoting endothelial dysfunction. Lectin-like oxidized low-density lipoprotein (oxLDL) receptor-1 (LOX-1) is the primary endothelial receptor for oxLDL, and both its expression and function are associated with vascular inflammation. As a scavenger receptor, LOX-1 is capable of binding to a variety of structurally unrelated ligands. Evidence is provided that demonstrates that CRP can act as a novel ligand for LOX-1. The direct interaction between these two proteins was demonstrated with purified protein in both ELISA and AlphaScreen assays. This interaction could be disrupted with known LOX-1 ligands, such as oxLDL and carrageenan. Moreover, the CRP interaction with cell surface-expressed LOX-1 was confirmed in cell-based immunofluorescent-binding studies. Mutagenesis studies demonstrated that the arginine residues forming the basic spine structure on the LOX-1 ligand-binding interface were dispensable for CRP binding, suggesting a novel ligand-binding mechanism for LOX-1, distinct from that used for oxLDL binding. The treatment of human endothelial cells with CRP led to the activation of proinflammatory genes including IL-8, ICAM-1, and VCAM-1. The inductions of these genes by CRP were LOX-1 dependent, as demonstrated by their attenuation in cells transfected with LOX-1 small-interfering RNA. Our study identifies and characterizes the direct interaction between LOX-1 and CRP and suggests that this interaction may mediate CRP-induced endothelial dysfunction.


2016 ◽  
Vol 62 (2) ◽  
pp. 320-327 ◽  
Author(s):  
Nicole Stancel ◽  
Chih-Chieh Chen ◽  
Liang-Yin Ke ◽  
Chih-Sheng Chu ◽  
Jonathan Lu ◽  
...  

Abstract BACKGROUND Studies have shown that the classic acute-phase protein C-reactive protein (CRP) has proinflammatory effects on vascular cells and may play a causal role in the pathogenesis of coronary artery disease. A growing body of evidence has suggested that interplay between CRP, lectin-like oxidized LDL receptor-1 (LOX-1), and atherogenic LDL may underlie the mechanism of endothelial dysfunction that leads to atherosclerosis. CONTENT We review the biochemical evidence for an association of CRP, LOX-1, and either oxidized LDL (OxLDL) or electronegative L5 LDL with the pathogenesis of coronary artery disease. Artificially oxidized OxLDL has been studied extensively for its role in atherogenesis, as has electronegative L5 LDL, which is present at increased levels in patients with increased cardiovascular risks. OxLDL and L5 have been shown to stimulate human aortic endothelial cells to produce CRP, indicating that CRP is synthesized locally in the endothelium. The ligand-binding face (B-face) of CRP has been shown to bind the LOX-1 scavenger receptor and increase LOX-1 expression in endothelial cells, thereby promoting the uptake of OxLDL or L5 by LOX-1 into endothelial cells to induce endothelial dysfunction. SUMMARY CRP and LOX-1 may form a positive feedback loop with OxLDL or L5 in atherogenesis, whereby increased levels of atherogenic LDL in patients with cardiovascular risks induce endothelial cells to express CRP, which may in turn increase the expression of LOX-1 to promote the uptake of atherogenic LDL into endothelial cells. Further research is needed to confirm a causal role for CRP in atherogenesis.


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