Figure 1

ASB activity declines following exposure to chloroquine (CQ). ASB activity declined in the placental fibroblasts following chloroquine exposure (Panel A; p = 0.02, unpaired t-test, two-tailed). ASB activity was significantly higher in the C38 than in the IB3-1 cells. Following exposure to increasing concentrations of chloroquine, the ASB activity declined linearly in both cell lines (Panel B; p < 0.0001, 1-way ANOVA for linear trend; r² = 0.89 for C38 and r² = 0.86 for IB3-1). In the CVC, chloroquine exposure produced significant reduction in ASB activity (Panel C; p < 0.001, 1-way ANOVA with Tukey-Kramer post-test). Following ASB silencing by siRNA, the ASB activity was reduced more than by chloroquine. The extent of reduction in ASB activity is less when the baseline ASB activity is less, as demonstrated by the direct correlation between the change in ASB activity and the baseline ASB activity (Panel D; r = 0.91). [con si = control siRNA; ASB si = ASB siRNA; CVC = cerebrovascular cells; PC = placental cells; ASB = arylsulphatase B].