Investigation of osteocalcin, osteonectin, and dentin sialophosphoprotein in developing human teeth
Investigation of osteocalcin, osteonectin, and dentin sialophosphoprotein in developing human teeth
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DOI：
10.1016/s8756-3282(01)00683-4
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发表时间：
2002-02-01
期刊：
影响因子：
4.1
通讯作者：
Macdougall, M
中科院分区：
文献类型：
--
作者：
Papagerakis, P;Berdal, A;Macdougall, M
啮齿类动物的生化研究表明，许多矿化基质蛋白在骨、牙本质和牙骨质中共享表达。关于这些蛋白质在人体组织中的表达模式，特别是在牙齿形成过程中的信息很少。本研究的目的是确定的表达模式的两个主要的非胶原蛋白的骨和牙本质，骨钙素（OC）和骨粘连蛋白（ON），在比较牙本质特异性蛋白，牙本质唾液磷蛋白（DSPP）。经国家伦理委员会批准，收集胎儿（5-26周）的下颌骨、新生儿尸检、10-12岁患者的牙齿形成、因正畸原因拔除的第三磨牙和骨肿瘤。通过逆转录-聚合酶链反应（RT-PCR）在胎儿下颌骨（5-11周）和牙髓原代细胞培养物中检测了人OC、ON和DSPP mRNA。此外，OC，ON和DSPP蛋白定位在形成人类矿化组织使用免疫组织化学。在体内，DSPP表达与牙齿末端上皮-间充质相互作用事件、釉质形成和牙本质形成相关。DSPP在分泌前的成釉细胞中呈短暂表达，在成牙本质细胞中呈持续表达。相反，成骨细胞和成牙本质细胞在早期发育中OC和ON表达之间存在时间间隔。ON在细胞分化的初始阶段表达，而OC仅在后期阶段表达，特别是在牙齿中。在釉质形成的成熟阶段，这两种蛋白在成牙本质细胞及其细胞外基质内的过程中被检测到。与骨相反，OC不位于富含胶原的牙本质基质（前牙本质或管间牙本质）的细胞外，但在成熟的釉质中发现。ON主要存在于非矿化前牙本质中。这些结果首次表明，OC和ON都是由人成牙本质细胞产生的，并决定了DSPP在人牙齿中的表达模式，并表明OC和ON通过成牙本质细胞突起在小管内移动，在牙本质和釉质形成过程中定位于特定的细胞外室。这些不同的细胞外模式可能与DSPP、OC和ON与其他基质特异性大分子（即，釉原蛋白、牙本质基质蛋白-1）和/或与成骨细胞相比与成牙本质细胞分泌的极化组织有关。(Bone 30：377-385; 2002）（C）2002由Elsevier Science Inc. All rights reserved.
Biochemical investigations in rodents have shown that numerous mineralized matrix proteins share expression in bone, dentin, and cementum. Little information is available regarding the expression pattern of these proteins in human tissues, particularly during tooth formation. The aim of this study was to identify the expression pattern of the two major noncollagenous proteins of bone and dentin, osteocalcin (OC) and osteonectin (ON), in comparison to the dentin-specific protein, dentin sialophosphoprotein (DSPP). Mandibles from fetuses (5-26 weeks), neonate autopsies, forming teeth from 10-12-year-old patients, third molars extracted for orthodontic reasons, and bone tumors were collected with approval from the National Ethics Committee. Human OC, ON, and DSPP mRNAs were detected by reverse transcription-polymerase chain reaction (RT-PCR) in fetal mandibles (5-11 weeks) and in primary cell cultures of dental pulp. In addition, OC, ON, and DSPP proteins were localized in forming human mineralized tissues using immunohistochemistry. In vivo, DSPP expression was associated with tooth terminal epithelial-mesenchymal interaction events, amelogenesis and dentinogenesis. Transient DSPP expression was seen in the presecretory ameloblasts with continuous expression in the odontoblasts. In contrast, both osteoblasts and odontoblasts showed a temporal gap between OC and ON expression in early development. ON was expressed in the initial stages of cytodifferentiation, whereas OC was expressed only during the later stages, especially in the teeth. At the maturation stage of enamel formation, both proteins were detected in odontoblasts and their processes within the extracellular matrix. In contrast to bone, OC was not localized extracellularly within the collagen-rich dentin matrix (predentin or intertubular dentin), but was found in the mature enamel. ON was present mostly in the nonmineralized predentin. These results demonstrate for the first time that both OC and ON are produced by human odontoblasts and determine the expression pattern of DSPP in human teeth, and suggest that OC and ON move inside the canalicule via odontoblast cell processes becoming localized to specific extracellular compartments during dentin and enamel formation. These distinct extracellular patterns may be related to the nature of DSPP, OC, and ON interactions with other matrix-specific macromolecules (i.e., amelogenin, dentin matrix protein-1) and/or to the polarized organization of odontoblast secretion as compared with osteoblasts. (Bone 30: 377-385; 2002) (C) 2002 by Elsevier Science Inc. All rights reserved.