NF-κB p65 activation in NZB/W mesangial cells with lipopolysaccharide treatment. Growth-arrested (under 2% fetal bovine serum (FBS)) mesangial cells (MCs) were incubated with 10 μg/ml lipopolysaccharide (LPS) for different periods of time, and then the distribution of NF-κB p65 was examined. (a) Immunofluorescence: images a–d, NZB/W MCs; images e–h, DBA/W MCs (nonimmune strain, served as control) incubated for 0–12 hours with LPS; and image i, semiquantitative data. (b) Electrophoresis mobility-shift assay performed using a DIG-labeled synthetic oligonucleotide and nuclear extract from MCs. The competition assay used the same unlabeled oligonucleotide at a 10-fold higher concentration. Arrow, NF-κB p65 binding bands. Comp., the abbreviation of competition. (c) ELISA performed using the TransAM NF-κB p65 kit. The NF-κB p65 expression levels at various time points were normalized to nuclear protein (ng/mg). The experiment was performed in triplicate, and results are expressed as the mean ± standard error, n = 6. The last time point without LPS stimulation (unstimulated) was presented as the negative control. ***P < 0.005 versus DBA/W MC controls.