Fig. 2.

The effect of overexpression of ABCG1 on ABCG1 abundance in RAW 264.7 cells (A) and cholesterol efflux to HDL from HeLa cells (B), THP-1 macroophages (C), and 3T3 fibroblasts (D). A: RAW 264.7 cells were transiently transfected with ABCG1-GFP and the abundance of ABCG1 was assessed by Western blot. B–D: HeLa cells (B), THP-1 human macrophages (C), or 3T3 murine fibroblasts (D) were transfected as indicated and labeled with [³H]cholesterol, and cholesterol efflux to HDL (final concentration 30 μg/ml) was assessed as described in Materials and Methods. Cholesterol efflux was expressed as a proportion of [³H]cholesterol transferred from cells to medium. Means ± SEM of quadruplicate determinations are shown. * P < 0.05 versus mock-transfected cells.