Department of Oral Physiology, Matsumoto Dental University School of Dentistry, Shiojiri, Japan.
Int J Med Sci. 2013 Aug 9;10(10):1321-6. doi: 10.7150/ijms.6631. eCollection 2013.
Bone marrow-derived cells (BMCs) have abilities of cell migration and differentiation into tissues/organs in the body and related with the differentiation of teeth or periodontal tissue including fibroblasts. Then, we examined the effect of orthodontic mechanical stress to the transplanted BMC migration into periodontal tissues using BMC transplantation model.
BMC from green fluorescence protein (GFP) transgenic mice were transplanted into 8-week-old female C57BL/6 immunocompromised recipient mice, which had undergone 10 Gy of lethal whole-body-irradiation. Five mice as experimental group were received orthodontic mechanical stress using separator between first molar (M1) and second molar (M2) 1 time per week for 5 weeks and 5 mice as control group were not received mechanical stress. The maxilla with M1 and M2 was removed and was immunohistochemically analyzed using a Dako Envision + Kit-K4006 and a primary anti-GFP-polyclonal rabbit antibody. Immunohistochemically stained was defined as positive area and the pixel number of positive area in the periodontal tissue was compared with the previously calculated total pixel number of the periodontal tissue.
The immunohistochemistry revealed that GFP positive cells were detected in the periodontal tissues, both in the experimental and control specimens. The ratio of pixel number in the examination group showed 5.77 ± 3.24 % (mean ± SD); and that in the control group, 0.71 ± 0.45 % (mean ± SD). The examination group was significantly greater than that of control group (Mann-Whitney U test: p<0.001).
These results suggest that orthodontic mechanical stress accelerates transplanted BMC migration into periodontal tissues.
骨髓来源的细胞（BMC）具有细胞迁移的能力，并能分化为体内的组织/器官，与牙齿或牙周组织的分化有关，包括成纤维细胞。然后，我们使用 BMC 移植模型检查正畸机械应力对移植 BMC 向牙周组织迁移的影响。
从绿色荧光蛋白（GFP）转基因小鼠中分离出 BMC，移植到 8 周龄雌性 C57BL/6 免疫缺陷受体小鼠体内，这些小鼠接受了 10 Gy 的全身致死性照射。实验组的 5 只小鼠每周接受一次第一磨牙（M1）和第二磨牙（M2）之间的分离器的正畸机械力，共 5 周，对照组的 5 只小鼠不接受机械力。切除带有 M1 和 M2 的上颌骨，并使用 Dako Envision + Kit-K4006 和针对 GFP 的多克隆兔抗体进行免疫组织化学分析。免疫组织化学染色定义为阳性区域，并用牙周组织中阳性区域的像素数与之前计算的牙周组织的总像素数进行比较。
免疫组织化学显示，实验组和对照组的牙周组织中均检测到 GFP 阳性细胞。实验组的像素数比例为 5.77 ± 3.24%（平均值 ± 标准差）；对照组为 0.71 ± 0.45%（平均值 ± 标准差）。实验组明显大于对照组（Mann-Whitney U 检验：p<0.001）。
这些结果表明，正畸机械力加速了移植 BMC 向牙周组织的迁移。
