出生后小鼠牙不同发育期DKK1表达的形态学特点及其意义  

Morphological characteristics of expressions of DKK1 in different periods of tooth development in postnatal mice and their significances

作　　者：郭小凯[1,2] 包幸福[1] 杨军星[1] 王玉琢[1] 李雨桐[1] 胡敏[1] GUO Xiaokai BAO Xingfu YANG Junxing WANG Yuzhuo LI Yutong HU Min(Department of Orthodontics, Stomatology Hospital, Jilin University, Changchun 130021, China Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Changchun 130021, China)

机构地区：[1]吉林大学口腔医院正畸科,吉林长春130021 [2]吉林省牙发育及颌骨重塑与再生重点实验室,吉林长春130021

出　　处：《吉林大学学报（医学版）》2017年第2期241-244,I0002,共5页Journal of Jilin University：Medicine Edition

基　　金：国家自然科学基金资助课题(81470764);吉林省卫计委青年科研基金资助课题(2015Q003);吉林大学白求恩计划项目资助课题(2015321);吉林省科技厅科技发展计划项目资助课题(20160520156JH)

摘　　要：目的:探讨Wnt通路抑制因子Dickkopf1(DKK1)在出生后小鼠牙发育各阶段的时空表达特点,为阐明Wnt信号通路调控牙发育机制提供理论依据。方法:选择出生后第0.5、6.5、12.5、18.5、24.5和30.5天的昆明小鼠并按时间分组,每组3只。颈椎脱臼法处死小鼠,分离包含第一磨牙的下颌骨组织后进行固定、脱钙处理,制作厚度为5μm的下颌第一磨牙牙体-牙周组织联合切片。采用苏木素-伊红(HE)染色观察下颌第一磨牙的发育状态,应用免疫组织化学染色方法观察小鼠牙体组织和牙周组织中DKK1的表达特点。结果:小鼠出生后第0.5天时,下颌第一磨牙牙胚处于钟状晚期;第6.5天时,下颌第一磨牙牙釉质发育基本完成,可见上皮根鞘向根方延伸;第12.5天时,冠部牙本质发育完成,牙根形成约1/3;第18.5天时,牙根形成约2/3;第24.5天时牙根发育达到全长;第30.5天时根尖孔缩窄,牙根发育基本完成。小鼠出生后第0.5天时,牙胚中无DKK1阳性表达;第6.5天时,成牙本质细胞中DKK1呈弱表达;从第12.5天到30.5天,成牙本质细胞中DKK1仍呈阳性表达,而牙周膜中开始出现DKK1表达,且随时间延长表达逐渐增强,牙槽骨和细胞性牙骨质中也出现DKK1的阳性表达,牙髓组织中始终呈阴性表达。结论:出生后小鼠牙不同发育期DKK1呈规律性表达,提示其可能参与了牙本质和牙周组织的发育过程。Objective：To study the expression characteristics of Dickkopf1（DKK1）in different time and space during tooth development of the postnatal mice,and to provide the theoretical basis for clarifying the mechanism of Wnt signaling pathway in regulating the tooth development.Methods：The postnatal Kunming mice at days 0.5,6.5,12.5,18.5,24.5,and 30.5respectively after birth were selected and divided into various groups by time,three in each group.The mice in each group were sacrificed and the paraffin sections of mandibular bone including the first molar were prepared at the thickness of 5μm,followed by HE staining and immunohistochemical staining in order to detect the expressions of DKK1 in tooth tissue and periodontal tissue.Results：At 0.5dafter birth,the mandibular first molar tooth germ was in the bell stage.At 6.5dthe enamel development of mandibular first molar was almost completed,and the epithelium root sheath extended to the root direction.At 12.5 dthe dentin development of crown was completed,with the root formatted about 1/3.At 18.5dthe root had formatted about2/3.At 24.5dthe root had reached the full length.At 30.5dthe apical foramen was narrow,and the root development was basically completed.There was no DKK1 expression at 0.5d,but it expressed in the odontoblasts and predentin at 6.5d.From days 12.5to 30.5,the expressions of DKK1 were positive in periodontal ligament,alveolar bone,and cellular cementum as odontoblasts,which were gradually increased with the prolongation of time.However,no expression of DKK1 was detected in the pulp.Conclusion：DKK1shows regular expressions at different tooth developmental stages after birth,suggesting its potential role in the growth of dentin and periodontal tissues.

关 键 词：DKK1 牙发育 牙周组织 免疫组化染色 苏木素-伊红染色 

分 类 号：R78[医药卫生—口腔医学] R-332[医药卫生—临床医学]