Relationship between neuropeptide and bone remodeling during tooth movement.

本研究的目的是探讨神经肽（甘丙肽）在牙齿运动过程中骨重塑中的作用。在过去，我们报道了在牙齿运动过程中牙周韧带中丙氨酸的表达显著增加。我们分析了牙齿运动过程中三叉神经节甘丙肽阳性细胞的表达。在大鼠牙齿运动开始后，定量分析甘丙肽阳性细胞的数量和大小。此外，我们用甘丙肽和降钙素基因相关肽进行了双染色，并分析了共存率。结果表明，牙齿运动后三叉神经节中甘丙肽阳性细胞明显增多。甘丙肽阳性细胞的大小也发生了显著变化。此外，在牙齿运动后，甘丙肽和降钙素基因相关肽的共存率增加。因此，牙周韧带中甘丙氨酸增加的来源可能是在牙齿运动时疼痛传递中起重要作用的三叉神经节。这些研究结果发表在《牙科研究杂志》上。在存在或不存在丙氨酸的情况下，M-CSF和RANKL刺激小鼠骨髓培养形成破骨细胞。TRAP阳性的包括3个或更多核的多核细胞被定义为破骨细胞。RT-PCR检测mRNA表达。甘丙肽在小鼠骨髓培养中以剂量依赖的方式显著抑制破骨细胞的形成。我们还发现在小鼠骨髓细胞中有3种不同亚型的甘丙肽受体mRNA表达（1- 3型）。因此，丙氨酸可能在神经系统调节破骨细胞骨重塑中起关键作用。这一结果正准备提交给《华尔街日报》。

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.