Figure 4

The baseline levels of cholesterol efflux depend on LXRα, but not LXRβ. in human macrophages. After labeled with [³H]-cholesterol for 24 h, human macrophages were transfected with non-targeting control, LXRα , or LXRβ siRNA, and incubated in DMEM containing 0.2% BSA for 72 h. The media were then replaced with DMEM containing 0.2% BSA in the presence of apoA-I (10 μg/mL) (A) or HDL (50 μg/mL) (B) for 24 h, a ssayed for cholesterol efflux in triplicate as described under the Methods. Data are presented as Mean ± SEM, *P < 0.05 (vs non-targeting control).