Usefulness of apolipoprotein B-depleted serum in cholesterol efflux capacity assays using immobilized liposome-bound gel beads.

Yuna Horiuchi,Ryunosuke Ohkawa,Shao-Jui Lai,Michio Hagihara,Shitsuko Shimano,Takahiro Kameda,Minoru Tozuka,Shuji Tohda

doi:10.1042/bsr20190213

Yuna Horiuchi, Ryunosuke Ohkawa + Show 6 more

Open Access

https://doi.org/10.1042/bsr20190213

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Abstract

Cholesterol efflux capacity (CEC) in atherosclerotic lesions is the main anti-atherosclerotic function of high-density lipoprotein (HDL). In recent studies, apolipoprotein (apo) B-depleted serum (BDS) obtained with the polyethylene glycol (PEG) precipitation method is used as a cholesterol acceptor (CA) substitution for HDL isolated by ultracentrifugation. However, the suitability of BDS as a CA is controversial. In the present study, CEC obtained from BDS (BDS-CEC) was evaluated based on a parameter, defined as whole-CEC, which was calculated by multiplying CEC obtained using fixed amounts of HDL by cholesterol concentration to HDL-cholesterol (HDL-C) levels in the serum. Significant correlation (r = 0.633) was observed between both CECs. To eliminate systematic errors from possible contamination with serum proteins and low-density lipoprotein (LDL) or very-LDL (VLDL) in BDS-CEC, the deviation of each CEC-BDS from the regression equation was compared with serum protein, LDL, and triglyceride (TG) levels. No correlation was observed between the deviation and the levels of each of these serum components, indicating that the deviations do not derive from systematic error. Further, to evaluate the effects of serum protein on the results, we measured BDS-CEC of reconstituted serum samples prepared using combinations of five levels of serum proteins with five levels of HDL-C. No significant change in BDS-CEC was observed in any combination. These results indicate that BDS-CEC reflects not only the function of HDL but also its concentration in serum.

Highlights

Cardiovascular disease (CVD) is one of the leading causes of death in developed countries [1]
A significant correlation was observed between high-density lipoprotein (HDL)-Cholesterol efflux capacity (CEC) (TP) and HDL-CEC (TC) (r = 0.897, P
Significant correlations were observed between HDL-C and whole-CEC (TP) (Figure 2B, r = 0.766, P

Summary

Introduction

Cardiovascular disease (CVD) is one of the leading causes of death in developed countries [1]. There are no symptoms until a crucial event occurs, indicating that the risk prediction for CVD events using regular blood tests is important. One of the blood biomarkers is high-density lipoprotein (HDL) because of its capacity to protect against atherosclerosis, the cause of CVD [2]. Serum HDL-cholesterol (HDL-C) levels have been shown to be a biomarker of CVD risk over a long period [3]. A recent epidemiological study showed that HDL-C does not always predict CVD risk because it indicates just the amount of HDL [4]. The need for evaluating the function as well as the amount of HDL has been emphasized

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