EphB4-EphrinB2双向信号传导在骨重建中的作用

Eph-Ephrin双向信号传导机制是近年来细胞间的通讯机制的研究热点，在神经系统、血管内皮系统及肿瘤形成和转移方面发挥着重要的作用。研究发现该信号传导系统在骨重建中发挥重要作用。破骨细胞上存在EphrinB2配体，成骨细胞前体上存在EphB4受体，以细胞直接接触的方式，通过胞内酪氨酸激酶信号系统，在成骨细胞和破骨细胞内分别产生正向和反向信号，促进成骨细胞前体分化成熟，同时抑制破骨细胞功能，并促进其凋亡。

Effects of bidirectional EphB4-EphrinB2 signaling on bone remodeling

Bidirectional Eph-Ephrin signaling as a focal point of research in cell-cell communications is critical for generation of nerves and vesssels as well as invation and metastasis of tumor cells. The roles for Ephrin-Eph bidirectional signaling in bone remodeling were important. EphrinB2 is expressed on osteoblasts and EphB4 is expressed on osteoclasts. Forward signaling through the EphB4 receptor into mesenchymal precursors promotes osteoblast differentiation,while reverse signaling through the EphrinB2 ligand into osteoclast suppresses differentiation. Signaling between the ligand EphrinB2 and the receptors EphB4 explains bidirectional signaling between osteoblasts and osteoclasts,bone absorption and remodeling,which may lay a theoretical foundation for identifying drug targeting and preventing and treating bone loss.