持续激活β-catenin对拔牙窝初期愈合的影响

Effect of constitutive activation of β-catenin on initial healing of extraction sockets

目的:探究持续激活β-连环蛋白(β-catenin)对拔牙后牙槽骨初期骨改建的影响。方法:构建Catnb lox(ex3)/+小鼠(对照组)和9.6 kb Dmp1-Cre+/-;Catnb lox(ex3)/+小鼠(实验组)。分别拔除两组小鼠右上颌第一磨牙,1周后收样,采用苏木精-伊红(HE)染色、Masson染色和抗酒石酸酸性磷酸酶(TRAP)染色观察两组小鼠拔牙窝愈合情况,免疫组织化学染色检测两组小鼠拔牙窝内成骨细胞特异性基质蛋白表达的差异。结果:成功构建9.6kb Dmp1-Cre+/-;Catnb lox(ex3)/+小鼠;与对照组相比,其拔牙窝内HE染色显示无新生骨质,Masson染色显示胶原矿化减少(P<0.001),TRAP染色显示破骨细胞数量减少(P<0.001),免疫组化染色显示成骨细胞的骨钙蛋白(OCN)、Ⅰ型胶原蛋白(COL1)和牙本质基质蛋白(DMP1)的特异性表达减少(P<0.01)。结论:9.6kb DMP1+细胞中持续激活β-catenin,延缓拔牙窝的初期愈合速率。

Objective:To investigate the effects of constitutive activation ofβ-catenin on the initial alveolar bone remodeling after tooth extraction.Methods:Catnb lox(ex3)/+mice(control group)and 9.6 kb Dmp1-Cre+/-;Catnb lox(ex3)/+mice(experimental group)were constructed.The right maxillary first molar was extracted and were collected 1 week later.Hematoxylin-eosin(HE)staining,Masson staining and tartrate resistant acid phosphatase(TRAP)staining were used to observe the healing of extraction sockets,and immunohistochemical staining was used to detect the differences in the expression of osteoblast-specific matrix proteins in the extraction sockets of the two groups of mice.Results:We successfully constructed 9.6kb Dmp1-Cre+/-;Catnb lox(ex3)/+mice(experimental group).Compared with the control group,HE staining of the experimental groupshowed no neoplastic bone,Masson staining showed decreased collagen mineralization(P<0.001),TRAP staining showed a decrease in the number of osteoclasts(P<0.001),and immunohistochemical staining showed reduced specific expression of osteocalcin(OCN),collagen typeⅠ(COL1),and dentin matrix protein(DMP1)in the cytoplasm of osteoblasts(P<0.01).Conclusion:Constitutive activation ofβ-catenin in 9.6kb DMP1+cells delayed the initial healing rate of extraction sockets.