scholarly journals Modified LDL Particles Activate Inflammatory Pathways in Monocyte-derived Macrophages: Transcriptome Analysis

2018 ◽  
Vol 24 (26) ◽  
pp. 3143-3151 ◽  
Author(s):  
Alexander N. Orekhov ◽  
Yumiko Oishi ◽  
Nikita G. Nikiforov ◽  
Andrey V. Zhelankin ◽  
Larisa Dubrovsky ◽  
...  
Keyword(s):  
Cholesterol Metabolism ◽  
Low Density Lipoprotein ◽  
Atherosclerotic Lesion ◽  
Density Lipoprotein ◽  
Primary Response ◽  
Secondary Response ◽  
Modified Ldl ◽  
Ldl Particles ◽  
Regulator Genes ◽  
Lipid Metabolism Genes

Background: A hallmark of atherosclerosis is its complex pathogenesis, which is dependent on altered cholesterol metabolism and inflammation. Both arms of pathogenesis involve myeloid cells. Monocytes migrating into the arterial walls interact with modified low-density lipoprotein (LDL) particles, accumulate cholesterol and convert into foam cells, which promote plaque formation and also contribute to inflammation by producing proinflammatory cytokines. A number of studies characterized transcriptomics of macrophages following interaction with modified LDL, and revealed alteration of the expression of genes responsible for inflammatory response and cholesterol metabolism. However, it is still unclear how these two processes are related to each other to contribute to atherosclerotic lesion formation. Methods: We attempted to identify the main mater regulator genes in macrophages treated with atherogenic modified LDL using a bioinformatics approach. Results: We found that most of the identified genes were involved in inflammation, and none of them was implicated in cholesterol metabolism. Among the key identified genes were interleukin (IL)-7, IL-7 receptor, IL- 15 and CXCL8. Conclusion: Our results indicate that activation of the inflammatory pathway is the primary response of the immune cells to modified LDL, while the lipid metabolism genes may be a secondary response triggered by inflammatory signalling.

scholarly journals The Atherogenic Role of Circulating Modified Lipids in Atherosclerosis

2019 ◽  
Vol 20 (14) ◽  
pp. 3561 ◽  
Author(s):  
Summerhill ◽  
Grechko ◽  
Yet ◽  
Sobenin ◽  
Orekhov
Keyword(s):  
Immune Complexes ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Diagnostic Biomarkers ◽  
Modified Ldl ◽  
Atherosclerotic Lesions ◽  
Ldl Particles ◽  
Atherosclerosis Development ◽  
Accumulation Of Lipids

Lipid accumulation in the arterial wall is a crucial event in the development of atherosclerotic lesions. Circulating low-density lipoprotein (LDL) is the major source of lipids that accumulate in the atherosclerotic plaques. It was discovered that not all LDL is atherogenic. In the blood plasma of atherosclerotic patients, LDL particles are the subject of multiple enzymatic and non-enzymatic modifications that determine their atherogenicity. Desialylation is the primary and the most important atherogenic LDL modification followed by a cascade of other modifications that also increase blood atherogenicity. The enzyme trans-sialidase is responsible for the desialylation of LDL, therefore, its activity plays an important role in atherosclerosis development. Moreover, circulating modified LDL is associated with immune complexes that also have a strong atherogenic potential. Moreover, it was shown that antibodies to modified LDL are also atherogenic. The properties of modified LDL were described, and the strong evidence indicating that it is capable of inducing intracellular accumulation of lipids was presented. The accumulated evidence indicated that the molecular properties of modified LDL, including LDL-containing immune complexes can serve as the prognostic/diagnostic biomarkers and molecular targets for the development of anti-atherosclerotic drugs.

Intralysosomal Accumulation of Colloidal Gold-Low Density Lipoprotein Conjugates in Chloroquine-Treated Fibroblasts

1985 ◽  
Vol 43 ◽  
pp. 546-547 ◽  
Author(s):  
Dean A. Handley ◽  
Cynthia M. Arbeeny ◽  
Larry D. Witte
Keyword(s):  
Colloidal Gold ◽  
Cultured Cells ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Coated Vesicle ◽  
Low Density ◽  
Cholesterol Esters ◽  
Cultured Fibroblasts ◽  
Surface Receptors ◽  
Ldl Particles

Low density lipoproteins (LDL) are the major cholesterol carrying particles in the blood. Using cultured cells, it has been shown that LDL particles interact with specific surface receptors and are internalized via a coated pit-coated vesicle pathway for lysosomal catabolism. This (Pathway has been visualized using LDL labeled to ferritin or colloidal gold. It is now recognized that certain lysomotropic agents, such as chloroquine, inhibit lysosomal enzymes that degrade protein and cholesterol esters. By interrupting cholesterol ester hydrolysis, chloroquine treatment results in lysosomal accumulation of cholesterol esters from internalized LDL. Using LDL conjugated to colloidal gold, we have examined the ultrastructural effects of chloroquine on lipoprotein uptake by normal cultured fibroblasts.

Do mitochondrial DNA mutations play the key role in chronification of sterile inflammation? Special focus on atherosclerosis

2020 ◽  
Vol 26 ◽  
Author(s):  
Alexander N. Orekhov ◽  
Elena V. Gerasimova ◽  
Vasily N. Sukhorukov ◽  
Anastasia V. Poznyak ◽  
Nikita G. Nikiforov
Keyword(s):  
Innate Immunity ◽  
Mitochondrial Dna ◽  
Low Density Lipoprotein ◽  
Atherosclerotic Lesion ◽  
Density Lipoprotein ◽  
Sterile Inflammation ◽  
Special Focus ◽  
Mitochondrial Dysfunctions ◽  
Mtdna Mutations ◽  
Dna Mutations

Background: The elucidation of mechanisms implicated in the chronification of inflammation is able to shed the light on the pathogenesis of disorders that are responsible for the majority of the incidence of disease and deaths, and also causes of ageing. Atherosclerosis is an example of the most significant inflammatory pathology. The inflammatory response of innate immunity is implicated in the development of atherosclerosis arising locally or focally. Modified low-density lipoprotein (LDL) was regarded as the trigger for this response. No atherosclerotic changes in the arterial wall occur due to the quick decrease in inflammation rate. Nonetheless, the atherosclerotic lesion formation can be a result of the chronification of local inflammation, which, in turn, is caused by alteration of the response of innate immunity. Objective: In this review, we discussed potential mechanisms of the altered response of the immunity in atherosclerosis with a particular emphasis on mitochondrial dysfunctions. Conclusion: A few mitochondrial dysfunctions can be caused by the mitochondrial DNA (mtDNA) mutations. Moreover, mtDNA mutations were found to affect the development of defective mitophagy. Modern investigations have demonstrated the controlling mitophagy function in the response of the immune system. Therefore, we hypothesized that impaired mitophagy, as a consequence of mutations in mtDNA, can raise a disturbed innate immunity response resulting in the chronification of inflammation in atherosclerosis.

Non-Traditional Cardiovascular Risk Markers in the Era of Established Major Risk Factors and Multiple Guidelines

2019 ◽  
Vol 17 (3) ◽  
pp. 270-277 ◽  
Author(s):  
Thomas F. Whayne
Keyword(s):  
Risk Factors ◽  
Interleukin 1 ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
High Sensitivity ◽  
Arterial Disease ◽  
Good Evidence ◽  
Ldl Particles ◽  
Cv Disease ◽  
Peripheral Arterial

The non-traditional cardiovascular (CV) risk factors that appear to be of most clinical interest include: apolipoprotein A (ApoA), apolipoprotein B (ApoB), high-sensitivity C-Reactive protein (hsCRP), homocysteine, interleukin 1 (IL1), lipoprotein (a) [Lp(a)], the density of low-density lipoprotein (LDL) particles, the LDL particle number, tissue/tumor necrosis factor-α (TNF-α) and uric acid. These non-traditional risk factors may be of value in adding further confirmation and attention to suspected significant CV risk. They can also provide a better understanding of current concepts of atherogenesis (e.g. various potential mechanisms associated with inflammation) as an etiology and in guiding current plus future therapies. In the mid-20th century, atherosclerosis and CV disease were considered mechanistic occurrences with essentially no attention to possible metabolic and molecular etiologies. Therefore, the only treatments then centered around mainly surgical procedures to try to improve blood flow, first with peripheral arterial disease (PAD) and later coronary artery disease (CAD). Now, failure to treat CV risk factors, especially where there is good evidence-based medicine, as in the case of statins for high CV risk patients, is considered medical negligence. Nevertheless, many problems remain to be solved regarding atherosclerosis prevention and treatment.

scholarly journals Aggregation Susceptibility of Low-Density Lipoproteins—A Novel Modifiable Biomarker of Cardiovascular Risk

2021 ◽  
Vol 10 (8) ◽  
pp. 1769
Author(s):  
Katariina Öörni ◽  
Petri T. Kovanen
Keyword(s):  
Ex Vivo ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Atherosclerotic Cardiovascular Disease ◽  
Low Density ◽  
Cholesterol Crystals ◽  
Ldl Particles ◽  
Arterial Intima ◽  
Matrix Bound ◽  
Atherosclerotic Cardiovascular Diseases

Circulating low-density lipoprotein (LDL) particles enter the arterial intima where they bind to the extracellular matrix and become modified by lipases, proteases, and oxidizing enzymes and agents. The modified LDL particles aggregate and fuse into larger matrix-bound lipid droplets and, upon generation of unesterified cholesterol, cholesterol crystals are also formed. Uptake of the aggregated/fused particles and cholesterol crystals by macrophages and smooth muscle cells induces their inflammatory activation and conversion into foam cells. In this review, we summarize the causes and consequences of LDL aggregation and describe the development and applications of an assay capable of determining the susceptibility of isolated LDL particles to aggregate when exposed to human recombinant sphingomyelinase enzyme ex vivo. Significant person-to-person differences in the aggregation susceptibility of LDL particles were observed, and such individual differences largely depended on particle lipid composition. The presence of aggregation-prone LDL in the circulation predicted future cardiovascular events in patients with atherosclerotic cardiovascular disease. We also discuss means capable of reducing LDL particles’ aggregation susceptibility that could potentially inhibit LDL aggregation in the arterial wall. Whether reductions in LDL aggregation susceptibility are associated with attenuated atherogenesis and a reduced risk of atherosclerotic cardiovascular diseases remains to be studied.

scholarly journals Efficacy of Bilberry and Grape Seed Extract Supplement Interventions to Improve Glucose and Cholesterol Metabolism and Blood Pressure in Different Populations—A Systematic Review of the Literature

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1692
Author(s):  
Teresa Grohmann ◽  
Caroline Litts ◽  
Graham Horgan ◽  
Xuguang Zhang ◽  
Nigel Hoggard ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Metabolic Syndrome ◽  
Ldl Cholesterol ◽  
Cholesterol Metabolism ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Grape Seed Extract ◽  
Grape Seed ◽  
Good Evidence ◽  
Seed Extract

Intervention with fruit extracts may lower glucose and lipid levels, as well as blood pressure. We reviewed the efficacy of bilberry and grape seed extracts to affect these outcomes across populations with varying health status, age and ethnicity, across intervention doses and durations, in 24 intervention studies with bilberry and blackcurrant (n = 4) and grape seed extract (n = 20). Bilberry and blackcurrant extract lowered average levels of glycated hemoglobin (HbA1c), at least in Chinese subjects, especially in those who were older, who were diagnosed with Type 2 Diabetes Mellitus (T2DM) and who were participating in longer-term studies. We also found good evidence that across studies and in subjects with hypercholesterolemia, T2DM or metabolic syndrome, intervention with bilberry and blackcurrant extract, and to some extent grape seed extract, significantly lowered total and low density lipoprotein (LDL) cholesterol levels after four weeks. Intervention with grape seed extract may reduce systolic and diastolic blood pressure in subjects with hypertension or metabolic syndrome. Differential responsiveness in cholesterol and blood pressure outcomes between stratified populations could not be explained by age, dose or study duration. In conclusion, bilberry and blackcurrant extract appears effective in lowering HbA1c and total and LDL cholesterol, whereas grape seed extract may lower total and LDL cholesterol, and blood pressure, in specific population groups.

scholarly journals Long-term fasting improves lipoprotein-associated atherogenic risk in humans

2021 ◽  
Author(s):  
Franziska Grundler ◽  
Dietmar Plonné ◽  
Robin Mesnage ◽  
Diethard Müller ◽  
Cesare R. Sirtori ◽  
...  
Keyword(s):  
Low Density Lipoprotein ◽  
Plasma Lipid ◽  
Density Lipoprotein ◽  
Apolipoprotein A1 ◽  
Health Concern ◽  
Low Density ◽  
Lipoprotein Subclasses ◽  
Ldl Particles ◽  
Increased Risk

Abstract Purpose Dyslipidemia is a major health concern associated with an increased risk of cardiovascular mortality. Long-term fasting (LF) has been shown to improve plasma lipid profile. We performed an in-depth investigation of lipoprotein composition. Methods This observational study included 40 volunteers (50% men, aged 32–65 years), who underwent a medically supervised fast of 14 days (250 kcal/day). Changes in lipid and lipoprotein levels, as well as in lipoprotein subclasses and particles, were measured by ultracentrifugation and nuclear magnetic resonance (NMR) at baseline, and after 7 and 14 fasting days. Results The largest changes were found after 14 fasting days. There were significant reductions in triglycerides (TG, − 0.35 ± 0.1 mmol/L), very low-density lipoprotein (VLDL)-TG (− 0.46 ± 0.08 mmol/L), VLDL-cholesterol (VLDL-C, − 0.16 ± 0.03 mmol/L) and low-density lipoprotein (LDL)-C (− 0.72 ± 0.14 mmol/L). Analysis of LDL subclasses showed a significant decrease in LDL1-C (− 0.16 ± 0.05 mmol/L), LDL2-C (− 0.30 ± 0.06 mmol/L) and LDL3-C (− 0.27 ± 0.05 mmol/L). NMR spectroscopy showed a significant reduction in large VLDL particles (− 5.18 ± 1.26 nmol/L), as well as large (− 244.13 ± 39.45 nmol/L) and small LDL particles (− 38.45 ± 44.04 nmol/L). A significant decrease in high-density lipoprotein (HDL)-C (− 0.16 ± 0.04 mmol/L) was observed. By contrast, the concentration in large HDL particles was significantly raised. Apolipoprotein A1 decreased significantly whereas apolipoprotein B, lipoprotein(a), fibrinogen and high-sensitivity C-reactive protein were unchanged. Conclusion Our results suggest that LF improves lipoprotein levels and lipoprotein subclasses and ameliorates the lipoprotein-associated atherogenic risk profile, suggesting a reduction in the cardiovascular risk linked to dyslipidemia. Trial Registration Study registration number: DRKS-ID: DRKS00010111 Date of registration: 03/06/2016 “retrospectively registered”.

scholarly journals Development of Capture Assays for Different Modifications of Human Low-Density Lipoprotein

2005 ◽  
Vol 12 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Gabriel Virella ◽  
M. Brooks Derrick ◽  
Virginia Pate ◽  
Charlyne Chassereau ◽  
Suzanne R. Thorpe ◽  
...  
Keyword(s):  
Oxidized Ldl ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Gas Chromatography Mass Spectrometry ◽  
Low Density ◽  
Modified Ldl ◽  
Capture Assay ◽  
Carboxymethyl Lysine

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.

Abstract 5293: A New Animal Model of Hypercholesterolemia and Atherosclerosis: Mice Deficient in All Nitric Oxide Synthases

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Masato Tsutsui ◽  
Yasuko Yatera ◽  
Hiroaki Shimokawa ◽  
Sei Nakata ◽  
Kiyoko Shibata ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Low Density Lipoprotein ◽  
Atherosclerotic Lesion ◽  
Density Lipoprotein ◽  
Serum Levels ◽  
Vascular Lesion ◽  
Lesion Formation ◽  
Regular Diet ◽  
Oxide Synthase ◽  
Nos Isoforms

We have recently developed mice lacking all three nitric oxide synthase (NOS) isoforms: nNOS, iNOS, and eNOS ( PNAS 2005). In this study, we examined the effects of a high-cholesterol (HC) diet on lipid metabolism and vascular lesion formation in those mice. Experiments were performed in 2-month-old male wild-type (WT) and singly, doubly, and triply NOS −/− mice (n=6–9). They were maintained on either a regular diet or a HC diet for 3 months. The HC feeding significantly increased plasma levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL) in all the genotypes studied as compared on the regular diet (all P <0.05). These serum levels of TC and LDL on the HC diet (mg/dl) were both significantly higher in all the singly, doubly, and triply NOS −/− genotypes as compared with the WT genotype (singly nNOS −/− [371±61 and 205±65], iNOS −/− [559±62 and 350±62], eNOS −/− [619±22 and 395±25], doubly n/iNOS −/− [518±77 and 328±72], n/eNOS −/− [635±56 and 458.8±42], e/iNOS −/− [480±38 and 260±40], triply n/i/eNOS −/− [2316±704 and 1588±715], and WT [326±43 and 244±54]) (all P <0.05). Notably, the extent of the dyslipidemia was by far severest in the triply n/i/eNOS −/− genotype among the NOS −/− genotypes, and intriguingly, the serum levels of TC and LDL in the triply n/i/eNOS −/− genotype were equivalent to those in apolipoprotein E −/− mice that exhibit severe hypercholesterolemia. Lipid accumulation in the aorta on the HC diet (lipid area, %, oil red O staining) was also significantly more accelerated in all the NOS −/− genotypes than in the WT genotype (singly nNOS −/− [6.6±1.5], iNOS −/− [6.7±2.2], eNOS −/− [5.5±2.3], doubly n/iNOS −/− [4.7±1.7], n/eNOS −/− [6.4±1.4], i/eNOS −/− [6.8±1.3], triply n/i/eNOS −/− [20.6±1.0], and WT [3.6±1.2]), while the extent of the aortic atherosclerosis was again by far severest in the triply n/i/eNOS −/− genotype (all P <0.05). These results demonstrate that mice deficient in all NOSs manifest severe hypercholesterolemia and lipid-rich atherosclerotic lesion formation in response to a HC diet, indicating a pivotal role of the whole NOS system in preventing those disorders. Our triply NOS −/− mouse is a new experimental model of human hypercholesterolemia and atherosclerosis.

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