RA increased ABCA1 and ABCG1 protein expression through the JAK/STAT3 signaling pathway in THP-1 macrophages. (A,B) THP-1 macrophages were pretreated with AG490 (a JAK2 inhibitor, 50 µM) for 1 h and then treated with RA (100 µM) for 24 h. ABCA1 (A) and ABCG1 (B) protein levels were analyzed by western blot analysis. Band densities were quantified, and relative protein levels are presented as the mean ± SD of five independent experiments. (C) THP-1 macrophages were treated with RA (100 µM) for various time durations, after which phospho-STAT3 protein levels were determined by western blotting. (D) Cells were pretreated with AG490 (50 µM) for 1 h and then treated with RA (100 µM) for 4 h. The phospho-STAT3 protein levels were determined by western blotting. The data are presented as the mean ± SD of five independent experiments. * p < 0.05, ** p < 0.01 compared to the control; ## p < 0.01 compared to the RA-treated group.