Figure 6

(A) Oil red O staining of macrophages. PMA differentiated macrophages were incubated with 50 µl of oxLDL (1 mg/ml), 50 µl of rHDL (1.4 mg/ml), and 400 µl of RPMI1640 media. The extent of cellular uptake of lipids or LDL in macrophages was then compared by oil red O staining as described in the text. The cells were then photographed using a Nikon Eclipse TE2000 microscope (Tokyo, Japan) at 600× magnification. (B) The cell media was analyzed by TBARS assay and the LPO assay kit (Calbiochem) to determine production of oxidized species. Malondialdehyde (MDA) was used as a standard and the extent of oxidation was expressed as MDA concentration (arbitrary unit, AU). The LPO level in 0.1 ml of culture media was decreased in media that contained rHDL treated cells when compared to media that contained PBS treated cells. In addition, media that was used to culture cells treated with V156K-rHDL or R173C-rHDL contained less MDA and LPO than that of media that was used to culture WT-rHDL treated cells.