Fig. 3.
Downregulation of CD38 expression and cyclase activity in astrocytes with RNAi. Primary human astrocytes transfected with siRNAs were analyzed for CD38 mRNA expression and CD38 ADP-ribosyl cyclase activity in the presence or absence of IL-1β (20 ng/ml). IL-1β led to a significant upregulation in CD38 mRNA that was significantly reduced by CD38 siRNA (P<0.001). However, cells transfected with three independent, non-specific siRNAs upon subsequent activation with IL-1β showed comparable increase in CD38 mRNA levels as IL-1β-activated, non-transfected astrocytes (P>0.05), thus confirming the specificity of CD38 siRNA (A). IL-1β-induced increase in CD38 ADP-ribosyl cyclase activity was reversed by CD38 siRNA (B). One-way ANOVA analyses were performed using GraphPad Prism 4.0 software. The data represents the mean ± SEM with two independent astrocyte donors each done in triplicate