Comparison of the effects of different lipoproteins on AP-1. Macrophages were cultured for 48 h in serum-free medium (SF, lanes 2–3) or in the presence of 5% LPDS ± 50 μg/mL LDL or 50 μg/mL ac-LDL. Half of the dishes were then stimulated with TNF (10 ng/mL) for 2 h. Some dishes were treated for 2 h with ox-LDL (100 μg/mL) before addition of TNF. EMSA was performed as described in methods. The arrowhead indicates the position of AP-1 specific complexes. Lanes: 1, probe only; 2, SF; 3, SF + TNF; 4, Control (5% LPDS); 5, TNF; 6, LDL; 7, LDL + TNF; 8, ac-LDL; 9, ac-LDL + TNF; 10, ox-LDL; 11, ox-LDL + TNF. Data are representative of three independent experiments.