Figure 1

Characterization of cholesterol and PC release from cultured neurons in the presence of apoE3-HDL or apoE4-HDL. Neurons labeled with 37 Bq/ml [¹⁴C] acetate were cultured for 3 days at 37°C. These neurons were washed in DMEM three times and incubated in DMEM for 1 h in the presence of apoE3-HDL or apoE4-HDL at various ApoE or HDL cholesterol concentrations, and the amounts of released [¹⁴C]-labeled cholesterol and PC were determined. A) The amounts of cholesterol and PC released, as induced by apoE3-HDL (○), were significantly greater than those of cholesterol and PC released, as induced by apoE4-HDL (●). B) The amounts of cholesterol and PC are plotted against the concentrations of apoE associated with HDL. Data are means ± S.E. of four samples. *p < 0.05 and **p < 0.001 vs apoE4-HDL at various cholesterol concentrations. Six independent experiments show similar results.