Effect of apoA-I on PLTP derived from macrophage foam cells. Panel A, PLTP gene expression was analyzed by real-time PCR in untreated cells (Control) and cells treated with 10 μg/ml apoA-I for 24 h (apoA-I). As a positive control induction of PLTP gene expression was measured after all-trans retinoic acid (ATRA) addition. To normalize the data we used as control two housekeeping genes, GAPDH and 18s rRNA. Panel B, PLTP was detected by Western blot in media and cell lysates from cells incubated in the presence (10 μg/ml) or in the absence (Control) of apoA-I. Actin was used as a reference. Panel C, PLTP activity measured in media from cells incubated in the presence (10 μg/ml) or in the absence (Control) of apoA-I in the media. Bands represent the mean ± SD calculated from triplicates. Figures are representative for at least two independent experiments. ** P < 0.01.