Figure 2

LPS increases the autophagic activity during the human macrophage foam cell formation. THP-1 macrophages were incubated in the absence (control) or presence of LPS (1 μg/ml), LPS plus rapamycin (Rap, an autophagy activator, 10 μM), Rap alone, LPS plus 3-methyladenine (3MA, an autophagy inhibitor, 10 μM) or 3MA alone as indicated (n = 3). (A) THP-1 human macrophages stably expressing GFP-LC3 were treated with LPS (1 μg/ml) for the indicated time points. (B) The levels of LC3II and LC3I were detected with specific antibodies by using immunoblotting and the percentage of cells with autophagosomes was calculated. (C) Representative immunofluorescence images with GFP-LC3⁺ in THP-1 human macrophages after exposure to 1 μg/ml LPS for the indicated time points (0, 8, 16, and 24 h) and the percentage of cells with autophagosomes were calculated. Data represent mean ± S.E. from 3 independent experiments. *significant difference from LPS treatment P < 0.05; **, P < 0.01.