Fig. 9. Col2a1-ICAT transgenic mice have reduced angiogenesis. (A) PECAM-1 was detected by immunostaining using an anti-PECAM-1 antibody in tissue sections from 2-week-old mice. PECAM-1 expression was significantly decreased in Col2a1-ICAT transgenic mice at the secondary ossification center area of the femoral epiphysis compared with WT mice. (B,C) Microfil perfusion was performed using 2-week-old Col2a1-ICAT transgenic mice and their WT littermates. Femurs (B) and liver (C) were imaged using microCT after decalcification of femurs. The images of vessel structure showed a reduced vessel networks in the cartilage tissue (B) but not liver (C) in Col2a1-ICAT transgenic mice. The results indicate that inhibition of Wnt signaling by ICAT leads to reduced angiogenesis during endochondral bone formation.