Fig. 6.
Bidirectional cholesterol exchange occurs at the PM. A: Total cellular cholesterol in U2OS-SRAshNPC1 cells treated for 6 h with CD or vehicle quantified by LC/MS/MS. B: Cellular uptake of diI-labeled LDL or HDL after 6 h with CD or vehicle and in the presence or absence of DYN to inhibit dynamin activity. Data expressed by the ratio of cell-associated fluorescence relative to fluorescence in the media at baseline per milligram of total protein. C: Cells were incubated with d7 cholesterol-loaded LDL or HDL for 6 h in the presence or absence of CD and in the presence or absence of DYN. The graph on the left reports the ratio of cell-associated d7 cholesterol relative to d7 cholesterol in the media at baseline. The graph on the right reports cell-associated cholesterol for each lipoprotein incubation in the presence of CD relative to vehicle (no DYN). Means ± SEs (n = 3–5). *P < 0.05 by unpaired t-test or two-way ANOVA for comparisons indicated. V, vehicle.