EphrinB2 Signalling in Osteoblast Differentiation, Bone Formation and Endochondral Ossification

Abstract

The main functions of the osteoblast lineage (pre-osteoblasts, osteoblasts and osteocytes) are the production of bone matrix (osteoid), its mineralisation and the support of osteoclast formation. EphrinB2 and its contact-dependent receptor, EphB4, are stably expressed through all these stages of the lineage, and their expression of ephrinB2 is stimulated by parathyroid hormone (PTH), an agent that stimulates bone formation. Recent work has shown that the ephrinB2/EphB4 interaction is required for late stages of osteoblast differentiation and PTH action. Furthermore, specific deletion of ephrinB2 within the osteoblast lineage delays the process of bone mineralisation resulting in impaired bon..