Figure3

The proposed model of coordinated regulation of osteoblast differentiation and proliferation during bone formation by Osx and Wnt/β-catenin signaling. Ihh is the initiator of endochondral ossification. The Runx2-expressing biopotential progenitors can differentiate into either osteoblast or chondrocyte. Then cells differentiate into preosteoblasts, in which Runx2 play an essential role. In the next step, preosteoblasts differentiate into mature osteoblast, a process in which Osx plays a critical role. Wnt/β-catenin signaling has an essential role in osteoblast differentiation and osteoblast proliferation. The inhibition of Wnt/β-catenin signaling activity by Osx constitutes a possible mechanism for the inhibition by Osx of osteoblast proliferation.