Role of estrogen in the regulation of cholesteryl ester synthesis in macrophages: the interaction between native and modified low density lipoprotein and human monocyte-derived macrophages

Abstract

Objectives: To study the effects of estrogen on the changes in cholesterol esterification induced by native and modified low density lipoprotein (LDL) in macrophages. Design and methods: Human monocyte-derived macrophages (HMDM) were used, and the influence of the presence of 17β estradiol in the short term, and during the maturation of the cells, on the esterification of cholesterol from native (nLDL), acetylated (acLDL) and oxidized (oxLDL) LDL was determined. Results: In the short-term (6 h), 17β estradiol (1.5 × 10 −6M) did not affect the esterification of cholesterol from acLDL or oxLDL, but with native LDL (nLDL) a 1.5-fold increase was observed. In contrast, long-term exposure of HMDM during maturation to 17β-estradiol (1.5 × 10 −9M - 1.5 × 10 −5M) decreased cholesterol esterification in the presence of oxLDL and acLDL, but not nLDL. Conclusions: These results suggest that both the time of exposure and the concentration of estrogen used influence its effects on the interaction between HMDM and LDL, and thus on macrophage foam cell formation.