Objective: We aim to identify the impact of endogenous cholesteryl ester transfer protein (CETP) activity on plasma capacity to mediate free cholesterol efflux from human macrophages.
Methods and results: Endogenous plasma CETP activity was measured in a population of 348 women. We defined a low CETP group corresponding to subjects displaying an endogenous plasma CETP activity within the first tertile and a high CETP group corresponding to subjects with an endogenous plasma CETP activity within the third tertile. Subjects from the high CETP activity group displayed a significant increase in the capacity of their plasma (+8.2%; P=0.001) to mediate cholesterol efflux from human acute monocytic leukemia cell line human macrophages and from ATP-binding cassette transporter A1-dependent pathway (+23.4%; P=0.0001) as compared with those from the low CETP activity group. Multivariate analyses revealed that the impact of CETP activity was independent of plasma lipids levels. Pre-β1-high-density lipoprotein concentrations were significantly elevated (+29.6%; P=0.01) in the high CETP activity group as compared with the low CETP activity group. A positive correlation between pre-β1-high-density lipoprotein levels and plasma efflux efficiency from human acute monocytic leukemia cell line human macrophages was observed (r=0.29, P=0.02).
Conclusions: CETP leading to the improvement of plasma efflux capacity, as a result of efficient pre-β-high-density lipoprotein formation and ATP-binding cassette transporter A1 efflux, should be preserved to prevent lipid accumulation in human macrophages.