Effect of PTX2 and SR-AI on FX levels and clearance. Hydrodynamic gene delivery of anti-murine PTX2 shRNA in C57Bl/6 mice. Blood was taken by retro-orbital puncture 24 and 48 hours postinjection, and PTX2 antigen, FX and FIX activities, and VWF antigen were measured in the plasma (A). Control was performed using a scramble shRNA construct (red bars). Tissue cryosections of the liver were performed and immunostained for CD68 (B), and macrophages density was subsequently measured (C). Results are presented as the mean ± SD of 5 to 11 mice per condition in 3 different experiments. Representative images were acquired in widefield microscopy (B), objective 40×; bars represent 20 µm. (D) PTX2 antigen levels in plasma of SR-AI–deficient vs wt mice. Results are expressed in a whisker plot where boxes represent the median and 25th to 75th percentile, and bars represent the minimum and maximum of 7 mice per condition. (E) Correlation of PTX2 antigen level and FX activity in the plasma of wt and SR-AI–deficient mice. Spearman’s rank correlation coefficient was calculated to assess the statistical dependence of the 2 values. Dots represent each individual mice, and bars represent the mean ± SD. (F-G) C57Bl/6 (closed symbols) and SR-AI–deficient mice (open symbols) were injected in the caudal vein with 10 µg of FX (circles) or FX_N181A (triangles). Plasma was collected at different time point (5 minutes, 15 minutes, 1 hour, 4 hours, and 24 hours), and residual FX antigen was measured. Data are presented as percentage antigen relative to the amount injected (mean ± SD; 5 to 10 mice per group). Recoveries are presented separately in a whisker plot where boxes represent the median and 25th to 75th percentile, and bars represent the minimum and maximum (insert in G and F). *P < .05, **P <0.01, and ***P < 0.001, statistical difference in a Mann-Whitney nonparametric unpaired statistical test.