A Preliminary Study On The Regulation Of Osteoclast By Wnt5a/Ror2 In The Process Of Tooth Eruption

Objective:To study the expression of Wnt5a/Ror2 signal in the normal development SD rats dental follicle with time and to explore its relationship with the formation of mature osteoclasts and the eruption of the teeth.Methods:Isolated mandibular bone from 1-13 days old SD rats, to observe the mandibular and alveolar bone growth of SD rats by HE staining, and the expression of Wnt5 a and Ror2 in rat dental follicle by Immunohistochemistry. Isolated and cultured postnatal 5-6d SD rats first molar dental follicle cells, to observe the expression of Wnt5a/Ror2 in dental follicle cells by immunohistochemistry and Western blot methods; Build dental follicle cells and bone marrow macrophage co-culture system, to observe the number of mature osteoclasts by tartrate resistant acid phosphatase staining after the stimulation of exogenous Wnt5 a, determine Wnt5 a on bone marrow macrophages to the role of osteoclast differentiation. Results:HE staining showed SD rat’s dental follicle begin to differentiate into the periodontal tissue at the second days after birth, alveolar bone of 1-3d did not change significantly, the number of osteoclasts increased significantly since the fourth day. The results of immunohistochemistry showed that Wnt5 a was not expressed in 1-3th days, since the fourth day it began to appear positive expression and lasted for 13 days. Ror2 is expressed in 1-3th days after birth and expressed in 4-13 days not obviously. Western Blot showed that the expression intensity of Wnt5 a was different during the differentiation of osteoclast precursor cells into mature osteoclasts(P<0.01). Co-cultured dental follicle cells and bone marrow macrophages after mature osteoclast formation, after different concentrations of Wnt5 a after stimulation of mature osteoclast number(P<0.05).Conclusion:The expression of Wnt5a/Ror2 rat dental follicle is different at any time in vivo and vitro,the number of osteoclasts is changed with the expression of Wnt5 a and Ror2,exogenous Wnt5 a can promote the differentiation of osteoclast precursor cells into mature osteoclasts., all above suggesting that Wnt5a/Ror2 signaling pathway may be involved in the formation of mature osteoclasts, thereby affecting the eruption of teeth.