Fig. 4.

Cholesterol efflux capacity of WT and Cys-mutant rHDL particles. RAW mouse macrophages were exchange labeled with [³H]free cholesterol and incubated with rHDL generated with WT or Cys-mutant APOA1. Ten micrograms per milliliter (protein) of the various rHDL particles were incubated with the cells for 6 h at 37°C. The cells were treated in the presence or absence cAMP to distinguish between ABCA1-mediated (with cAMP, white bar) and aqueous diffusion (without cAMP, gray bar) cholesterol efflux. Experiments were performed in triplicate and bars represent mean ± SD. The mean was normalized to the medium alone control condition. A two-way ANOVA and Holm-Sidak post hoc test were used to determine cholesterol efflux differences between samples and within treatments with or without cAMP (K133C + cAMP vs. K133C − cAMP; *P < 0.001, t = 6.818).