Role of low-density lipoproteins in atherogenesis and development of coronary heart disease

1995 ◽  
Vol 41 (1) ◽  
pp. 139-146 ◽  
Author(s):  
S M Grundy

Abstract There is a strong association between increased blood concentrations of low-density lipoprotein (LDL) and severity of coronary atherosclerosis. Multiple mechanisms affect hypercholesterolemia, e.g., diet, aging, hormones, and genetics. LDL receptors apparently are also important--through down-regulation, defects in structure, or decreased numbers--as are changes in LDL binding characteristics caused by alterations in apolipoprotein B content or structure. Current concepts of LDL metabolism are extensively reviewed, including the role of modified or oxidized LDL in atherogenesis.

1979 ◽  
Vol 83 (3) ◽  
pp. 588-594 ◽  
Author(s):  
H S Kruth ◽  
J Avigan ◽  
W Gamble ◽  
M Vaughan

The effect of cell density on low density lipoprotein (LDL) binding by cultured human skin fibroblasts was investigated. Bound LDL was visualized by indirect immunofluorescence. Cellular lipid and cholesterol were monitored by fluorescence in cells stained with phosphine 3R and filipin, respectively. LDL binding and lipid accumulation were compared in cells in stationary and exponentially growing cultures, in sparsely and densely plated cultures, in wounded and non-wounded areas of stationary cultures, and in stationary cultures with and without the addition of lipoprotein-deficient serum. We conclude that LDL binding and cholesterol accumulation induced by LDL are influenced by cell density. It appears that, compared to rapidly growing cells, quiescent (noncycling) human fibroblasts exhibit fewer functional LDL receptors.


Biologia ◽  
2017 ◽  
Vol 72 (2) ◽  
Author(s):  
Panit Yamchuen ◽  
Rattima Jeenapongsa ◽  
Sutisa Nudmamud-Thanoi ◽  
Nanteetip Limpeanchob

AbstractHypercholesterolemia has been considered as a risk factor for Alzheimer’s disease (AD). In addition to low density lipoprotein (LDL), oxidized LDL plays some roles in AD pathology. Neurodegenerative effect of oxidized LDL was supported by the increased oxidative stress in neurons. To further investigate the role of oxidized LDL, the present study aimed to test its effect on amyloid precursor protein (APP) processing. The release of soluble APP (sAPP) was evaluated in differentiated SH-SY5Y neuroblastoma cells exposed to native (non-oxidized) or oxidized human LDL including mildly and fully oxidized LDL (mox- and fox-LDL). Non-amyloidogenic and amyloidogenic pathways were investigated using specific antibody against sAPP


2005 ◽  
Vol 35 (3) ◽  
pp. 531-545 ◽  
Author(s):  
B Löhrke ◽  
T Viergutz ◽  
B Krüger

The role of endogenously oxidized low density lipoprotein (oxLDL) in follicular steroidogenic regulation is unknown. Information may be important in order to elucidate ovulatory dysregulation in disordered lipid metabolism. To obtain specific data, we studied the effect of polar phospholipids (PL) isolated from oxLDL with different endogenous levels of lipohydroperoxides (LHP) on the thecal expression of mRNA encoding steroidogenic enzymes and cyclooxygenase 2 (COX-2), and on the thecal production of superoxide and progesterone. Large (preovulatory) bovine follicles were used and analyses of thecal fragments from single follicles were performed by radioimmunoassays, chemiluminescence assays and quantitative RT-PCR. Basal concentration of mRNA for several lipoprotein receptors exceeded by about 10-times the basal level of mRNA encoding steroidogenic enzymes, suggesting that preovulatory theca receptors may favour uptake of oxLDL. PL (5–11 pmol phosphorus/ml) decreased (up to 0.5-times the control) progesterone synthesis, production of superoxide and levels of P450 cholesterol side chain cleavage (P450 scc), 3β-hydroxysteroid dehydrogenase and COX-2 mRNA. Abundance of COX-2 transcripts in thecal tissue incubated with forskolin depended on the progesterone/17β-oestradiol ratio of the follicle fluid, i.e. the previous microenvironment in vivo. PL effects were mimicked by the platelet-activating factor (PAF). WEB 2086, a PAF receptor blocker, did not always abolish these responses, suggesting that the effects were not mediated solely by this receptor. PAF interfered dose-dependently with LH-induced responses, indicating interference with LH signalling. PL from mildly oxidized LDL (0.5 nmol/ml LHP) tended to exert greater effects than PL from oxLDL containing 1.5 nmol/ml LHP. In consideration of the known physiologic role of progesterone, COX-2 and possibly superoxide, these results provide evidence for a potential of PL from oxLDL to induce ovulatory dysregulation and suggest that the extent of the LDL oxidation seems to be important for interfering with thecal responses to the preovulatory LH surge.


2015 ◽  
Vol 129 (12) ◽  
pp. 1195-1206 ◽  
Author(s):  
H.K. Irundika Dias ◽  
Caroline L.R. Brown ◽  
M. Cristina Polidori ◽  
Gregory Y.H. Lip ◽  
Helen R. Griffiths

We have established a novel anti-inflammatory and antioxidant role of statins towards oxidized fats in the “bad” cholesterol low density lipoprotein (LDL) particle from the blood of mid-life adults with high cholesterol. Oxidized LDL-fat levels were also higher in the blood of patients with dementia and caused inflammatory damage to cells that line blood vessels.


Author(s):  
Joaquim Barreto ◽  
Sotirios K. Karathanasis ◽  
Alan Remaley ◽  
Andrei C. Sposito

Atherosclerosis, the underlying cause of cardiovascular disease (CVD), is a worldwide cause of morbidity and mortality. Reducing ApoB-containing lipoproteins—chiefly, LDL (low-density lipoprotein)—has been the main strategy for reducing CVD risk. Although supported by large randomized clinical trials, the persistence of residual cardiovascular risk after effective LDL reduction has sparked an intense search for other novel CVD biomarkers and therapeutic targets. Recently, Lox-1 (lectin-type oxidized LDL receptor 1), an innate immune scavenger receptor, has emerged as a promising target for early diagnosis and CV risk prediction and is also being considered as a treatment target. Lox-1 was first described as a 50 kDa transmembrane protein in endothelial cells responsible for oxLDL (oxidized LDL) recognition, triggering downstream pathways that intensify atherosclerosis via endothelial dysfunction, oxLDL uptake, and apoptosis. Lox-1 is also expressed in platelets, where it enhances platelet activation, adhesion to endothelial cells, and ADP-mediated aggregation, thereby favoring thrombus formation. Lox-1 was also identified in cardiomyocytes, where it was implicated in the development of cardiac fibrosis and myocyte apoptosis, the main determinants of cardiac recovery following an ischemic insult. Together, these findings have revealed that Lox-1 is implicated in all the main steps of atherosclerosis and has encouraged the development of immunoassays for measurement of sLox-1 (serum levels of soluble Lox-1) to be used as a potential CVD biomarker. Finally, the recent development of synthetic Lox-1 inhibitors and neutralizing antibodies with promising results in animal models has made Lox-1 a target for drug development. In this review, we discuss the main findings regarding the role of Lox-1 in the development, diagnosis, and therapeutic strategies for CVD prevention and treatment.


2019 ◽  
Vol 26 (9) ◽  
pp. 1512-1524 ◽  
Author(s):  
Alexander N. Orekhov ◽  
Igor A. Sobenin

Atherosclerotic diseases are the leading cause of mortality in industrialized countries. Correspondingly, studying the pathogenesis of atherosclerosis and developing new methods for its diagnostic and treatment remain in the focus of current medicine and health care. This review aims to discuss the mechanistic role of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) in atherogenesis. In particular, the generally accepted hypothesis about the key role of oxidized LDL in atherogenesis is questioned, and an alternative concept of multiple modification of LDL is presented. The fundamental question discussed in this review is whether LDL and HDL are effectors or biomarkers, or both. This is important for understanding whether lipoproteins are a therapeutic target or just diagnostic indicators.


2005 ◽  
Vol 12 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Gabriel Virella ◽  
M. Brooks Derrick ◽  
Virginia Pate ◽  
Charlyne Chassereau ◽  
Suzanne R. Thorpe ◽  
...  

ABSTRACT Antibodies to malondialdehyde (MDA)-modified low-density lipoprotein (LDL), copper-oxidized LDL (oxLDL), N ε(carboxymethyl) lysine (CML)-modified LDL, and advanced glycosylation end product (AGE)-modified LDL were obtained by immunization of rabbits with in vitro-modified human LDL preparations. After absorption of apolipoprotein B (ApoB) antibodies, we obtained antibodies specific for each modified lipoprotein with unique patterns of reactivity. MDA-LDL antibodies reacted strongly with MDA-LDL and also with oxLDL. CML-LDL antibodies reacted strongly with CML-LDL and also AGE-LDL. oxLDL antibodies reacted with oxLDL but not with MDA-LDL, and AGE-LDL antibodies reacted with AGE-LDL but not with CML-LDL. Capture assays were set with each antiserum, and we tested their ability to capture ApoB-containing lipoproteins isolated from precipitated immune complexes (IC) and from the supernatants remaining after IC precipitation (free lipoproteins). All antibodies captured lipoproteins contained in IC more effectively than free lipoproteins. Analysis of lipoproteins in IC by gas chromatography-mass spectrometry showed that they contained MDA-LDL and CML-LDL in significantly higher concentrations than free lipoproteins. A significant correlation (r = 0.706, P < 0.019) was obtained between the MDA concentrations determined by chemical analysis and by the capture assay of lipoproteins present in IC. In conclusion, we have developed capture assays for different LDL modifications in human ApoB/E lipoprotein-rich fractions isolated from precipitated IC. This approach obviates the interference of IC in previously reported modified LDL assays and allows determination of the degree of modification of LDL with greater accuracy.


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