scholarly journals Cholesterol efflux capacity assay using immobilized liposomes and apolipoprotein B-depleted serum

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Hima Rani Sapa

Abstract Cholesterol efflux capacity (CEC), an important functional step in reverse cholesterol transport, is the main anti-atherosclerotic function of high-density lipoprotein (HDL). Assays that improve the determination of CEC ex vivo for clinical applications are constantly explored. In the accompanying article, Horiuchi et al. (Biosci. Rep. (2019) 39(4), BSR20190213) evaluate the availability of apolipoprotein B-depleted serum for CEC assays. Using their recently developed immobilized liposome-bound gel beads (ILG) method, Horiuchi et al. demonstrate that apolipoprotein B-depleted serum obtained with poly ethylene glycol precipitation enables CEC assays to be easily and accurately introduced into laboratory medicine.

2014 ◽  
Vol 34 (4) ◽  
pp. 921-926 ◽  
Author(s):  
R.J. Doonan ◽  
A. Hafiane ◽  
C. Lai ◽  
J.P. Veinot ◽  
J. Genest ◽  
...  

Objective— To investigate the association of cholesterol efflux capacity with carotid atherosclerosis and cerebrovascular disease. Approach and Results— Patients with high-grade carotid stenosis (n=154) were recruited from Vascular Surgery clinics and 9 healthy controls from the McGill University Health Network, Montreal, Canada. Cerebrovascular symptomatology history was obtained. Stenosis was assessed by carotid ultrasound. Fasting blood samples were collected and depleted of apolipoprotein B particles by polyethylene glycol precipitation from serum. Cholesterol efflux was determined by incubating apolipoprotein B–depleted serum in cAMP-stimulated J774 cells for 6 hours. Carotid specimens were classified by 2 vascular pathologists using the American Heart Association atheromatous plaque classification. Differences in efflux were assessed according to (1) stenosis, (2) American Heart Association classification, and (3) cerebrovascular symptomatology. Normalized efflux was significantly lower in patients with carotid atherosclerosis compared with controls (0.97±0.16 versus 1.5±0.46; P <0.0001). Efflux was inversely associated with stenosis; the odds ratio for 80% to 99% versus 50% to 79% stenosis of tertile 1 (lowest) versus tertile 3 (highest) of efflux was 3.78 (95% confidence interval, 1.18–12.06) after adjusting for age, sex, low-density lipoprotein, and high-density lipoprotein. There were significant differences in cholesterol efflux between American Heart Association fibroatheroma (Va, 0.91±0.13), mainly calcific (Vb, 0.97±0.15), and mainly fibrotic (Vc, 1.03±0.21; P =0.05). There were no significant differences in efflux according to symptomatology. Conclusions— Cholesterol efflux capacity is inversely associated with increasing carotid stenosis and is associated with more advanced carotid plaque morphology, suggesting that cholesterol efflux capacity may be a biomarker for severity of carotid atherosclerotic burden. Whether therapies targeting high-density lipoprotein quality could be useful for stabilizing carotid atherosclerosis needs to be assessed.


2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Yuna Horiuchi ◽  
Shao-Jui Lai ◽  
Azusa Yamazaki ◽  
Ayaka Nakamura ◽  
Ryunosuke Ohkawa ◽  
...  

Estimation of the function as well as the amount of high-density lipoprotein (HDL) is required to predict the risk of cardiovascular disease development. Cholesterol efflux capacity (CEC) is the key metric for determining the antiatherosclerotic function of HDL. However, the assay methods currently used to calculate CEC are not ideal for clinical use as they require the culture of cells. In the present study, we developed a novel CEC assay using immobilized liposome-bound gel beads (ILGs), containing fluorescently labeled cholesterol, as a substitute for cultured cells. When apolipoprotein B-100 depleted serum, obtained by polyethylene glycol precipitation, was used as the cholesterol acceptors, the basic properties of this method, such as the available range of HDL-cholesterol, efflux temperature and time, and normalization parameters, indicate that this method is sufficient to estimate CEC. Furthermore, the CEC values obtained with this ILG method were also correlated with those obtained with a conventional method using THP-1 macrophages derived foam cells and 3H-cholesterol as a tracer (r = 0.932). Overall, this novel cholesterol efflux assay method is a realistic and effective alternative to current methods in the field while also being easier to use in clinical laboratories as neither cell culture, radioisotope nor ultracentrifugation is required.


2014 ◽  
Vol 1 (3) ◽  
Author(s):  
Janet Lo ◽  
Eric S. Rosenberg ◽  
Michael L. Fitzgerald ◽  
Suzane B. Bazner ◽  
Ezinne J. Ihenachor ◽  
...  

Abstract Background.  Individuals infected with human immunodeficiency virus (HIV) have decreased high-density lipoprotein (HDL)-cholesterol and increased cardiovascular disease (CVD). Reverse cholesterol transport from macrophages may be inhibited by HIV and contribute to increased CVD. Human studies have not investigated longitudinal effects of HIV and antiretroviral therapy (ART) on cholesterol efflux. Methods.  Subjects with acute HIV infection were randomized to ART or not. Cholesterol efflux capacity was determined ex vivo after exposure of murine macrophages to apolipoprotein B-depleted patient sera obtained at baseline and after 12 weeks. Results.  After 12 weeks, HIV RNA decreased most in subjects randomized to ART. Available data on cholesterol demonstrated that efflux capacity from Abca1+/+ macrophages was increased most by sera obtained from ART-treated subjects (20.5% ± 5.0% to 24.3 % ± 6.9%, baseline to 12 weeks, P = .007; ART group [n = 6] vs 18.0 % ± 3.9% to 19.1 % ± 2.9%, baseline to 12 weeks, P = .30; untreated group [n = 6] [P = .04 ART vs untreated group]). Change in HIV RNA was negatively associated with change in Abca1+/+ macrophage cholesterol efflux (r = − 0.62, P = .03), and this finding remained significant (P = .03) after controlling for changes in HDL-cholesterol, CD4+ cells, and markers of monocyte or macrophage activation. Conclusions.  In subjects acutely infected with HIV, ATP-binding cassette transporter A1-mediated cholesterol efflux was stimulated to a greater degree over time by apolipoprotein B-depleted serum from subjects randomized to ART. The improvement in cholesterol efflux capacity is independently related to reduction in viral load.


Author(s):  
Yuna Horiuchi ◽  
Shao-Jui Lai ◽  
Takahiro Kameda ◽  
Minoru Tozuka ◽  
Ryunosuke Ohkawa

Objectives Cholesterol efflux capacity (CEC), an atheroprotective function of high-density lipoprotein, is expected to be a potential biomarker for cardiovascular disease. However, CEC has not been widely introduced for application in clinical laboratories because of the complexity of the conventional CEC assay using cells and radioactive materials. Previously, we developed a novel CEC assay using immobilized liposome-bound gel beads (ILG), which solves these issues. We aimed to confirm the validation and further improve the ILG method for application in the clinical setting. Methods Cholesterol efflux capacity values by the ILG method assayed for shorter incubation time (4 h) were compared to those assayed for 16 h (our previous ILG method). To investigate a reference material that can correct the variation between ILG manufacturing lots, bovine serum albumin, human gamma-globulins, and globulin complexes were evaluated. CEC values were also estimated in plasmas obtained with different anticoagulants, serum treated with freeze-thaw cycles, and serum mixed with several interference substances. Results The CEC of 4- and 16-h incubation times were well correlated. Globulin complexes may be used as a reference material. Plasma can be used as the specimen. The serum and stored temperature of the specimen did not largely affect CEC. Hemoglobin and chyle did not have an effect on CEC, whereas high-bilirubin serum showed elevated CEC. The effect of bilirubin was nearly canceled by subtracting basal fluorescence intensity. Conclusions Present ILG method further fulfills some requirements for application in clinical laboratory. Using this reliable simple method, evaluation for clinical significance of CEC is expected.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 574
Author(s):  
Maria Pia Adorni ◽  
Nicoletta Ronda ◽  
Franco Bernini ◽  
Francesca Zimetti

Over the years, the relationship between high-density lipoprotein (HDL) and atherosclerosis, initially highlighted by the Framingham study, has been revealed to be extremely complex, due to the multiple HDL functions involved in atheroprotection. Among them, HDL cholesterol efflux capacity (CEC), the ability of HDL to promote cell cholesterol efflux from cells, has emerged as a better predictor of cardiovascular (CV) risk compared to merely plasma HDL-cholesterol (HDL-C) levels. HDL CEC is impaired in many genetic and pathological conditions associated to high CV risk such as dyslipidemia, chronic kidney disease, diabetes, inflammatory and autoimmune diseases, endocrine disorders, etc. The present review describes the current knowledge on HDL CEC modifications in these conditions, focusing on the most recent human studies and on genetic and pathophysiologic aspects. In addition, the most relevant strategies possibly modulating HDL CEC, including lifestyle modifications, as well as nutraceutical and pharmacological interventions, will be discussed. The objective of this review is to help understanding whether, from the current evidence, HDL CEC may be considered as a valid biomarker of CV risk and a potential pharmacological target for novel therapeutic approaches.


2019 ◽  
Vol 20 (3) ◽  
pp. 732 ◽  
Author(s):  
Robin Dullaart ◽  
Sabrina Pagano ◽  
Frank Perton ◽  
Nicolas Vuilleumier

Background: We determined relationships of cholesterol efflux capacity (CEC), plasma cholesterol esterification (EST) and cholesteryl ester transfer (CET) with anti-c-terminus apoA-1 (Ac-terAA1) and anti-apolipoprotein (apo)-1 (AAA1) autoantibodies in subjects with and without Type 2 diabetes mellitus (T2D). Methods: In 75 T2D subjects and 75 nondiabetic subjects, Ac-terAA1 and AAA1 plasma levels were measured by enzyme-linked immunosorbent assay. CEC was measured as [3H]-cholesterol efflux from human cultured fibroblasts to diluted individual subject plasma. Plasma EST and CET were assayed by isotope methods. Results: Ac-terAA1 and AAA1 levels and were similar between T2D and control subjects. Univariate regression analysis (n = 150) demonstrated that Ac-terAA1 levels were inversely correlated with CEC, EST, CET, total cholesterol, non-HDL cholesterol, triglycerides and apolipoprotein B, (p < 0.05 to p < 0.01), but not with glucose and HbA1c. In separate multivariable linear regression models, CEC, EST and CET were inversely associated with Ac-terAA1 levels independently of age, sex, T2D and drug use (β = −0.186, p = 0.026; β = −0.261, p < 0.001; and β = −0.321, p < 0.001; respectively). These associations were lost after additional adjustment for non-HDL cholesterol and triglycerides. No associations were observed for AAA1. Conclusions: CEC, plasma EST and CET are inversely associated with Ac-terAA1 autoantibodies, conceivably attributable to an inverse relationship of these autoantibodies with apolipoprotein B-containing lipoproteins.


2018 ◽  
Vol 103 (9) ◽  
pp. 3430-3438 ◽  
Author(s):  
Huicui Meng ◽  
Nirupa R Matthan ◽  
Susan K Fried ◽  
Silvia Berciano ◽  
Maura E Walker ◽  
...  

Abstract Context and Objective Direct comparisons between types of dietary carbohydrate in terms of cardiometabolic risk indicators are limited. This study was designed to compare the effects of an isocaloric exchange of simple, refined, and unrefined carbohydrates on serum cardiometabolic risk indicators, adipose tissue inflammatory markers, and peripheral blood mononuclear cell (PBMC) fractional cholesterol efflux. Design, Participants, and Measures Participants [postmenopausal women and men (N = 11), 65 ± 8 years, body mass index 29.8 ± 3.2 kg/m2, low-density lipoprotein (LDL) cholesterol ≥2.6 mmol/L] were provided with diets (60% energy from total carbohydrate, 15% from protein, 25% from fat) for 4.5 weeks in a randomized crossover design, with 2-week washout periods. The variable component was an isocaloric exchange of simple, refined, or unrefined carbohydrate–containing foods. Serum lipoprotein, glucose, insulin, and inflammatory marker concentrations were measured. Abdominal subcutaneous adipose tissue was aspirated to assess macrophage and inflammatory marker gene expression and ex vivo cytokine secretion, and PBMCs were isolated to assess ex vivo fractional cholesterol efflux. Results Fasting serum LDL and non–high-density lipoprotein (HDL) cholesterol concentrations were higher after the refined compared with simple or unrefined carbohydrate–enriched diets (P &lt; 0.01). Other serum measures, ex vivo fractional cholesterol efflux and adipose tissue gene expression and ex vivo cytokine secretion, were similar between diets. Conclusions Diets enriched in refined compared with simple or unrefined carbohydrate resulted in higher fasting serum LDL and non-HDL cholesterol concentrations but had little effect on other cardiometabolic risk indicators. This small study raises the intriguing possibility that refined carbohydrate may have unique adverse effects on cardiometabolic risk indicators distinct from simple and unrefined carbohydrate.


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