[Effects of high-density lipoprotein 1 on the formation of foam cells from human monocyte-derived macrophages].

OBJECTIVE: To investigate effects of serum HDL(1) on the formation of foam cells from human peripheral blood monocyte-derived macrophages. METHODS: Sectie density polyacrylamide gel electrophoresis (sd-PAGE) was applied for isolation and preparation of HDL(1) simultaneously. Monocytes were isolated from human peripheral blood by Ficoll-Hypaque density gradient centrifugation and plastic adsorptive process. The isolated monocytes were stimulated by phorbol 12-myristate 13-acetate (PMA) at a concentration of 50 nmol/L for 48 h and transferred to macrophages. The monocyte-derived macrophages were then coincubated with 80 mg/L ox-LDL and HDL(1) (0, 0.1, 1.0 and 10.0 mg/L) for 6, 12 and 24 h, respectively. The formation of foam cells was identified by transmission electron microscope (TEM), total cholesterol (TC), free cholesterol (FC) and protein (Pro) in cultured cells were quantitatively analyzed by high performance chromatography (HPLC) and modified lowry protein assay, respectively. RESULTS: HDL(1) isolated from human serum by sd-PAGE could significantly decrease TC/Pro ratio in foam cells in a concentration-dependent (0 mg/L: 36.9 +/- 1.1, 10.0 mg/L: 6.2 +/- 0.4, P < 0.01) and time-dependent (10.0 mg/L HDL(1) 6 h: 16.9 +/- 0.9, 24 h: 6.4 +/- 0.6, P < 0.01) manner. CONCLUSION: HDL(1) is capable of inhibiting and attenuating the formation of foam cells by decreasing cellular TC, therefore, might play an important role in attenuating atherosclerosis.