Fig 4. Acrolein-HDL is unable to stimulate efflux of free cholesterol from primary macrophages.

Peritoneal macrophages harvested from C57BL6/J mice were pretreated with 50 μg/mL oxLDL for 24 hours at 37°C. Macrophages were then incubated with PBS or 50 μg/mL oxLDL, HDL or acrolein-modified HDL for an additional 24 hours at 37°C. Neutral lipids were visualized by Oil Red O staining (Panels A-D). Data are representative of 3 independent experiments. Percent foam cell formation was quantified by counting stained versus total cells in 7–8 fields. Cholesteryl ester (Panel E) and free cholesterol (Panel F) content were quantified using TLC. Values represent the mean ± SEM of three treatment replicates. Statistical analyses were determined by one-way ANOVA. *p<0.05, **p<0.01 and ***p<0.001