DMP1、Runx2在小鼠下颌第一磨牙萌出过程中的免疫学定位

Immunolocalization of dental mineralization protein 1 and runt-related transcription factor 2 during mouse mandibular first molar eruption

目的研究小鼠下颌第一磨牙萌出过程中牙本质基质蛋白1(DMP1)和Runt相关转录因子2(RUNX2)的表达,并探索其表达与牙萌出之间的关系。方法分离出生后1 d至14 d小鼠的下颌骨,连续切片,偶氮卡红苯胺蓝染色显示磨牙萌出过程骨胶原形成情况,切片原位杂交法分析DMP1及RUNX2 mRNA在牙齿及周围组织的表达与分布,免疫组化法显示DMP1和RUNX2蛋白的表达与分布。结果冠方骨组织中骨胶原形成在P5 d出现高峰,以后呈逐渐减少的趋势;根方骨胶原形成在整个萌出过程中一直呈活跃状态,在P9 d出现高峰。DMP1表达越丰富,骨胶原形成越多,成骨活动越活跃。结论下颌第一磨牙萌出过程中,根方成骨活动一直很活跃,DMP1的表达与根方成骨活动参与了小鼠第一磨牙的萌出过程。

Objective To investigate the expression of dental mineralization protein 1 （ DMP1 ） and runt related transcription factor- 2 （RUNX2） in mouse mandibular first molar eruption and to explore the correlation between their expression and the process of the first mandibular molar eruption. Methods Mouse mandibles dissected from 1 ～ 14 day old mice were serially sectioned and stained respec- tively using Heidenhain Azan staining to observe collagen formation. Expression patterns and distribution of DMP1 and RUNX2 mRNA in teeth and surrouding tissue were analyzed by section in situ hybridization. The DMP1 and RUNX2 protein expression and distribution were examined by immunohistochemical staining method. Results The peak value of collagen in the occlusal region was observed on the PS,which reduced hereafter ;while the peak value in the basal region was observed on the P9. Collagen in the basal region was al- ways active during the whole eruption process. During the mouse molar eruption, the more DMP1 expressed, the more collagen formed and the more active osteogenesis was. Conclusions During the mouse first molar eruption, collagen in the basal region is always ac- tive. Expression of DMP1 and basal osteoblast activity take part in the process of the first molar eruption.