Time course of PF4 activation of NF-κB. EMSA demonstrating the binding of nuclear proteins to an oligonucleotide containing the NF-κB–binding site. HUVECs were incubated in the absence (C) or presence of PF4 (20 μg/mL) for 1, 3, 8, or 24 hours prior to assay. NF-κB–complex denotes shifted band corresponding to the binding of NF-κB to the oligonucleotide; free oligo denotes unbound oligonucleotide. Data are representative of at least 3 independent experiments.