FXII-mediated contact system activation in AD mouse plasma. AD mice and their WT littermate controls were treated with FXII-ASO or CTL-ASO for 4 months. Blood was collected at the end of the treatment, and FXII, PPK, and HK levels were determined by western blot. Transferrin was used to normalize the samples. (A) Representative western blots (2 samples per group). (B) Plasma FXII level in CTL-ASO-treated AD mice was significantly lower when compared to that of CTL-ASO–treated WT mice (Student t test, n = 10 mice per group). Values are presented as mean ± SEM. Results are from 3 independent experiments. (C) HKi levels in WT mouse plasma were similar between groups, and HKi levels in CTL-ASO–treated AD mice were significantly lower than those in CTL-ASO–treated WT mice. In FXII-ASO–treated AD mice, HKi levels were significantly higher compared to CTL-ASO–treated AD mice, but similar to FXII-ASO–treated WT mice. (D) PPK levels were similar in WT mice between groups, but PPK levels in FXII-ASO–treated AD mice were significantly higher than those in CTL-ASO–treated AD mice. For (C) and (D), one-way analysis of variance, (ANOVA), n = 9-14 mice per group; all values presented as mean ± SEM. Results are from 3 independent experiments.