Influence of PRCP on angiogenesis. (A) Confluent BAEC transfected with Control or PRCP siRNA were “scratched” and images were obtained initially (“Time 0”) and after 5 hours. (B) The distance of cell migration from (A) as determined by MetaMorph analysis was obtained by subtracting 5-hour widths from Time 0 divided by 2 (n = 9 for both groups). (C) Endothelial sprouting of aortic segments from WT and PRCP^gt/gt mice were photographed on D3, D5, and D9. The red line indicates the leading edge of the sprout. The absence of a red line indicates the sprouting was beyond the field of view. (D) Morphometric analysis of images in (C) expressed as the mean ± SEM of the pixel area of sprouts per aortic perimeter. (E) A Matrigel plug containing no growth factors or with vascular endothelial growth factor and basic fibroblast growth factor were injected subcutaneously into WT or PRCP^gt/gt mice (n = 13-17 for all 4 groups). Gross Matrigel plug images were obtained using a Nikon SMZ-U dissecting microscope (original magnification ×1). (F) Hemoglobin content on homogenized Matrigel plugs from the 4 conditions in (E) harvested on D9. (G) Frozen sections of Matrigel plugs from WT or PRCP^gt/gt (gt/gt) mice were stained for the endothelial cell marker PECAM (red) and VSMC marker NG2 (green). The percent PECAM (CD31)-positive (H) or NG2 positive (I) area was assessed by morphometric analysis (n > 4 for all Matrigel stain analysis). (J) The ratios between NG2 and PECAM-positive stained areas within each image were obtained. Migration and sprout images were obtained using a Nikon TE200 microscope with a 10×/0.25 objective lens, 20×/0.45 for Matrigel plug staining images. *P < .05, **P < .01 of comparison between 2 groups.