Effects of overexpression of miR-33a-5P and anti-miR-33a-5P on apoA-I mediated cholesterol efflux 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 18 h. Next, the cells were cultured in serum-free medium containing treatment factors and 10 µg/ml apoA-I for 4 h. ApoA-I-mediated cholesterol efflux was assayed as described in the Materials and Methods section. Data are means ± SD of duplicate wells from 6 experiments. *, P