Fig. 5.

IL-1β and TNFα activation of NF-κB is dose-dependent and downregulated by P2 receptor blockade.A, Astrocyte cultures were transiently transfected with a reporter construct for NF-κB activity. Cells were treated with either IL-1β (0.1, 1, or 10 ng/ml) or TNFα (1, 10, or 100 ng/ml), and luciferase activity was measured at 5 hr (A). Level of luciferase activity (expressed as RLU) in untreated cells is represented by the transverse line, and SDs of these background levels are demarcated by the dotted lines. NF-κB induction by both IL-1β and TNFα was dose-dependent. However, IL-1β treatment resulted in much higher levels of NF-κB activation. Data shown represent the mean and SD of three separate measurements and are representative of three separate experiments derived from cells from three different brains. B, Cells were transfected as above and treated with both IL-1 (10 ng/ml) and TNFα (100 ng/ml) in the presence or absence of pretreatment with oATP (300 μm). As before, IL-1 and TNFα resulted in induction of NF-κB (with IL-1 induction greater than TNFα induction), and this was downregulated by pretreatment using oATP blockade of P2 receptors, which had no effect on background levels of NF-κB activation. Data shown are the mean and SD of three separate measurements and are representative of three separate experiments with cells from three different brains.