Relationship between neuropeptide and bone remodeling during tooth movement.

本研究旨在探讨神经肽甘丙肽在牙齿移动过程中骨改建中的作用。过去，我们报道了在牙齿移动过程中，牙周膜中甘丙肽的表达显著增加。我们分析了在牙齿移动过程中甘丙肽阳性细胞在三叉神经节中的表达。在大鼠牙齿移动开始后，定量分析甘丙肽阳性细胞的数量和大小。此外，我们还用甘丙肽和降钙素基因相关肽进行了双重染色，并分析了共存率。结果表明，牙齿移动后三叉神经节内甘丙肽阳性细胞明显增多。还观察到甘丙肽阳性细胞大小的显著变化。此外，在牙齿移动后，甘丙肽和降钙素基因相关肽的共存率增加。因此，牙周膜中甘丙肽增加的起源被认为是三叉神经节，在牙齿移动过程中疼痛的传递中起着重要作用。这些结果发表在Journal of Dental Research上。在甘丙肽存在或不存在的情况下，用M-CSF和RANKL刺激小鼠骨髓培养物形成破骨细胞。TRAP阳性的多核细胞包括3个或更多的细胞核被定义为破骨细胞。RT-PCR检测mRNA表达。甘丙肽以剂量依赖性方式显著抑制小鼠骨髓培养中破骨细胞的形成。我们还发现甘丙肽受体的3种不同亚型（1型-3型）mRNA在小鼠骨髓细胞中表达。因此，甘丙肽可能通过神经系统调节骨细胞的骨重建。这一结果正在准备中，将在《日刊》上提交。

The purpose of this study was to investigate the role of neuropeptide (galanin) in bone remodeling during tooth movement. In the past, we reported a significant increase of the expression of galanin in periodontal ligament during tooth movement. We analyzed the expression of galanin positive cell in the trigeminal ganglion during tooth movement. After the initiation of tooth movement in rats, the number of galanin positive cells and size were quantitatively analyzed. Furthermore, we performed a double stain with galanin and calcitonin gene-related peptide and analyzed the rate of the coexistence. As a result, in trigeminal ganglion, galanin positive cell were remarkably increased after tooth movement. Significant change in the size of galanin-positive cells was also observed. Furthermore, the coexistence rate of galanin and calcitonin gene-related peptide was increased after tooth movement. Therefore, the origin of the increased galanin in the periodontal ligament is suggested to be the trigeminal ganglion that plays an important role on transmission of pain during tooth movement. These results were published in Journal of Dental Research. The murine bone marrow culture was stimulated by M-CSF and RANKL to form osteoclast formation in the presence or absence of galanin. TRAP positive multinucleated cells including 3 or more nuclei were defined as osteoclasts. mRNA expression was detected by RT-PCR. Galanin significantly inhibited osteoclast formation in murine bone marrow culture in a dose-dependent fashion. We also found that 3 distinct subtypes mRNA of galanin receptor (type 1-type 3) was expressed in murine bone marrow cells. Therefore, It is possible that galanin plays a critical role in regulating osteoclastic bone remodeling by neural systems. This result is in preparation to be submitted in the Journal.