and stained with Memcode Reversible Protein Stain Kit (Pierce, Rockford, USA). Densitometry values of protein load were used for normalization of Western blot data. After destaining, membranes were incubated with stripping buffer (62.5 mM Tris-HCl, 2% SDS, 100 mM β-mercaptoethanol, pH 6.7) for 20 min at 55°C, blocked for 30 min with 5% non-fat dry milk in 50 mM Tris-HCl, 0.15 M NaCl, 0.05% Tween 20 buffer and probed with rabbit polyclonal antibodies against the human NF-κB p50 or p65 subunits (PC136, 1∶2000; PC137, 1∶2000; Calbiochem, San Diego, CA, USA), or goat polyclonal antibodies against the C-terminus of human IKKβ (sc-7329; 1∶500; Santa Cruz, California, USA). Goat anti-rabbit (Bio Rad) or rabbit anti-goat (Sigma) antibodies all conjugated with horseradish peroxidase (HRP) were used as secondary antibodies. Membranes were developed with the ECL detection system (Amersham, Little Chalfont, UK). Fuji Film Image Gauge software was used for densitometric analysis.
