Activation of Nuclear Factor-B by Depolarization and

The purpose of the current study was to determine whether nuclear factor-B (NF-B) activation is a com-ponent of the depolarization/Ca2-dependent signaling in -cells. MIN6 cells were transfected with a plasmid containing five tandem repeats of NF-B binding sites linked to a luciferase reporter. The results of these experiments showed that KCl induced depolarization-activated NF-B–dependent transcription (3.8-fold at 45 mmol/l, P < 0.01) in a concentration-dependent manner. Tumor necrosis factor- (TNF-), a known inducer of NF-B signaling, activated this construct by 3.4-fold (P < 0.01). The response of NF-B to depolar-ization was inhibited by the Ca2-channel blocker vera-pamil and by the mitogen-activated protein kinase kinase (MEK) inhibitor PD98059 (70 and 62%, respec