Effects of overexpression of miR-33a-5P and Anti-miR-33a-5P on the expression of miR-33a-5P, ABCA1 and ABCG1 in THP-1 macrophages in the absence or presence of LDL.

THP-1 macrophages were infected using Con-miR, miR-33a-5P, Con-Anti-miR, and Anti-miR-33a-5P, respectively, after 24 h PMA stimulation. After 48 h infection, THP-1 macrophages were incubated in serum-free medium at 37°C for 24 h. The medium was then respectively replaced by fresh serum-free medium (0.2% BSA) containing (A) blank control, blank control, 40 ng/ml IL-6, or 40 ng/ml IL-6, (B) 25 µg/ml LDL, 25 µg/ml LDL, 25 µg/ml LDL plus 40 ng/ml IL-6, or 25 µg/ml LDL plus 40 ng/ml IL-6, followed by incubation at 37°C for 24 h. mRNA levels of miR-33a-5P, ABCA1 and ABCG1 were determined using RT-PCR. U6 or β-actin served as a reference gene. Data are means ± SD from 6 experiments. (C and D) Protein levels of ABCA1 and ABCG1 determined by Western blotting. (E and F) Quantification of densitometric values of ABCA1 and ABCG1 protein bands from four experiments, which were normalized to β-actin and expressed as a percentage of control. Data are means ± SD from 4 experiments. *, P