Figure 6

NF-κB regulates CD38 in IL-1β-activated astrocytes. Cultured human astrocytes were activated with and without IL-1β in the presence or absence of NF-κB inhibitors, SN50 or IκBαM. CD38 mRNA expression was measured using real-time PCR while CD38 activity was measured using cADPR cyclase assay. (A) Pre-treatment of IL-1β-activated astrocytes with NF-κB blocker, SN50, showed significantly lower CD38 mRNA levels as compared to IL-1β-activated astrocytes (p < 0.001). SN50M treatment, however, did not affect IL-1β-responses in astrocytes. (B) IκBαM-transfection abrogated the IL-1β-mediated increase in CD38 mRNA levels (p < 0.001) without affecting basal CD38 levels in untreated astrocytes (p > 0.05). (C) IκBαM-transfected, IL-1β-activated astrocytes showed a significant reduction (p < 0.001) in CD38 cyclase activity compared to mock-transfected, IL-1β-activated astrocytes.