Quantification of In Vitro Macrophage Cholesterol Efflux and In Vivo Macrophage-Specific Reverse Cholesterol Transport.

Promotion of reverse cholesterol transport (RCT) is thought to be a major HDL-mediated mechanism for protecting against atherosclerosis. Preclinical studies support the concept that increasing cholesterol efflux from macrophages may confer atheroprotective benefits independently of the plasma HDL-cholesterol concentration. The application of the macrophage-to-feces RCT method in genetically engineered mice has provided evidence that this major HDL property correlates closely with changes in atherosclerosis susceptibility. This chapter provides details on the methodologies currently used to measure in vitro cholesterol efflux from macrophages or in vivo macrophage-specific RCT. The general principles and techniques described herein may be applied to measure the in vitro cholesterol efflux capacity of human serum in macrophage cultures and to evaluate the effect of different experimental pathophysiological conditions or the efficacy of different therapeutic strategies on the modulation of in vivo macrophage-RCT in mice.