Osteoblast and osteoclast behaviors in the turnover of attachment bones during medaka tooth replacement
Osteoblast and osteoclast behaviors in the turnover of attachment bones during medaka tooth replacement
复制标题
DOI：
10.1016/j.ydbio.2015.12.002
复制
发表时间：
2016-01-15
影响因子：
2.7
通讯作者：
Kudo, Akira
中科院分区：
文献类型：
--
作者：
Mantoku, Akiko;Chatani, Masahiro;Kudo, Akira
多形齿动物的牙齿替换是一个维持牙齿内环境稳定的有序系统，包括牙齿支撑元件附着骨等骨骼组织的动态结构变化。组织学分析揭示了牙齿替换的特征，然而，牙齿替换过程中骨骼组织如何改变的细胞机制在很大程度上是未知的。在这里，我们显示了成骨细胞的重要作用，控制破骨细胞修改附着骨在青鳉咽齿的牙齿替换过程中，再加上osterix-DsRed/TRAP-GFP转基因系可视化成骨细胞和破骨细胞。在附着骨排的翻转中，这些骨在最发达的功能牙齿所在的后侧被吸收，并在新萌出牙齿的前侧生成，从而导致连续的牙齿替换。在细胞分析中，破骨细胞和成骨细胞分别位于附着骨，因为成熟的破骨细胞位于吸收侧，而成骨细胞聚集在生成侧。为了证明破骨细胞在牙齿替换中的作用，我们通过TALEN建立了c-fms-a缺陷的青鳉。c-fms-a缺陷青鳉表现出附着骨的增生沿着骨吸收减少，伴有少量TRAP阳性破骨细胞，表明破骨细胞在附着骨的转换中起重要作用。此外，硝基还原酶介导的成骨细胞特异性消融可诱导破骨细胞消失，这表明成骨细胞对于维持破骨细胞的适当更新至关重要。总之，我们的研究结果表明，青鳉附着骨提供了模型，以了解牙齿替换的细胞机制，成骨细胞通过支持破骨细胞在骨形态的协调。(C)2015 Elsevier Inc. All rights reserved.
Tooth replacement in polyphyodont is a well-organized system for maintenance of homeostasis of teeth, containing the dynamic structural change in skeletal tissues such as the attachment bone, which is the supporting element of teeth. Histological analyses have revealed the character of tooth replacement, however, the cellular mechanism of how skeletal tissues are modified during tooth replacement is largely unknown. Here, we showed the important role of osteoblasts for controlling osteoclasts to modify the attachment bone during tooth replacement in medaka pharyngeal teeth, coupled with an osterix-DsRed/TRAP-GFP transgenic line to visualize osteoblasts and osteoclasts. In the turnover of the row of attachment bones, these bones were resorbed at the posterior side where most developed functional teeth were located, and generated at the anterior side where teeth were newly erupted, which caused continuous tooth replacement. In the cellular analysis, osteoclasts and osteoblasts were located at attachment bones separately, since mature osteoclasts were localized at the resorbing side and osteoblasts gathered at the generating side. To demonstrate the role of osteoclasts in tooth replacement, we established medaka made deficient in c-fms-a by TALEN. c-fms-a deficient medaka showed hyperplasia of attachment bones along with reduced bone resorption accompanied by a low number of TRAP-positive osteoclasts, indicating an important role of osteoclasts in the turnover of attachment bones. Furthermore, nitroreductase-mediated osteoblast-specific ablation induced disappearance of osteoclasts, indicating that osteoblasts were essential for maintenance of osteoclasts for the proper turnover. Taken together, our results suggested that the medaka attachment bone provides the model to understand the cellular mechanism for tooth replacement, and that osteoblasts act in the coordination of bone morphology by supporting osteoclasts. (C) 2015 Elsevier Inc. All rights reserved.