Objective       To determine the potential effect of EphrinB2 and EphB4 in the alveolar bone resorption and remodeling.       Methods       Mouse RAW264.7 cell line was induced to osteoclast

and mouse MC3T3-E1 cell line was treated with bone resorption supernatant

which was collected before

then the expression of EphrinB2 and EphB4 at mRNA and protein levels were detected in the cells. An experimental rat model with alveolar bone resorption was established. The effect of established model were estimated through

histological observation

tartrate resistant acid phosphatase (TRAP) staining

and TRAP stained osteoclast count of the tooth-periodontal samples. Expression of EphrinB2 and EphB4 were detected by immunohistochemical assay and immunofluorescent assay.       Results       Both EphrinB2 and EphB4 were expressed in the RAW264.7 and MC3T3-E1 cells

and the protein level of EphrinB2 in the MC3T3-E1 cells cultured with osteoclast bone absorbent supernatant was significantly higher than that in negative group (17.53±0.43 vs 15.67±0.45

P

<

0.01). There were obvious alveolar bone resorption and TRAP stained osteoclasts in the samples of E-LPS induced SD rat model

and the resorption was observed for at least 20 d. EphrinB2 were significantly noticed in the osteoblasts and osteoclasts

and more EphB4 was found in the osteogenic zone than the bone absorption area.       Conclusion       EphrinB2/EphB4 participates in the process of alveolar bone resorption and remodeling. Co-expression of EphrinB2 and EphB4 in mouse osteoclasts and osteoblast-like cells may promote the osteogenesis by potential EphrinB2-EphB4 comminication between osteoblasts.