Zhao Chen, Hosoya Akihiro, Kurita Hiroshi, Hu Tao, Hiraga Toru, Ninomiya Tadashi, Yoshiba Kunihiko, Yoshiba Nagako, Takahashi Masafumi, Kurashina Kenji, Ozawa Hidehiro, Nakamura Hiroaki
Department of Dental and Oral Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
Arch Oral Biol. 2007 Oct;52(10):945-53. doi: 10.1016/j.archoralbio.2007.04.015. Epub 2007 Jun 13.
While mineralized tissue is formed in the pulp cavity after tooth replantation or transplantation, little is known of this hard tissue formation. Therefore, we conducted histological and immunohistochemical evaluations of hard tissue formed in the pulp of rat maxillary molars after tooth replantation. At 5 days after replantation, degenerated odontoblasts were lining the pulp cavity. At 14 days, dentin- or bone-like tissue was present in the pulp cavity. Immunoreactivity for osteopontin (OPN) and bone sialoprotein (BSP) was strong in the bone-like tissue, but weak in the dentin-like tissue. Conversely, dentin sialoprotein (DSP) was localized in the dentin-like tissue, but not in the bone-like tissue. Cells positive for BMP4, Smad4, Runx2, and Osterix were found around the blood vessels of the root apex at 5 days. At 14 days, these cells were also localized around the bone-like tissue. Cells expressing alpha-smooth muscle actin (SMA) were seen around the newly formed bone-like tissue, whereas no such cells were found around the newly formed dentin-like tissue. In an experiment involving the transplantation of a green fluorescent protein (GFP)-transgenic rat tooth into a wild-type rat tooth socket, GFP-positive cells were detected on the surface of the bone-like tissue and over all dentin-like tissue. These results indicate that the original pulp cells had the ability to differentiate into osteoblast-like cells as well as into odontoblast-like cells.
虽然牙齿再植或移植后矿化组织在牙髓腔中形成，但对这种硬组织形成的了解甚少。因此，我们对大鼠上颌磨牙再植后牙髓中形成的硬组织进行了组织学和免疫组织化学评估。再植后5天，退变的成牙本质细胞排列在牙髓腔周围。14天时，牙髓腔中出现牙本质样或骨样组织。骨桥蛋白（OPN）和骨涎蛋白（BSP）在骨样组织中的免疫反应性强，而在牙本质样组织中弱。相反，牙本质涎蛋白（DSP）定位于牙本质样组织中，而不在骨样组织中。在5天时，在根尖血管周围发现了BMP4、Smad4、Runx2和Osterix阳性的细胞。14天时，这些细胞也定位于骨样组织周围。在新形成的骨样组织周围可见表达α-平滑肌肌动蛋白（SMA）的细胞，而在新形成的牙本质样组织周围未发现此类细胞。在将绿色荧光蛋白（GFP）转基因大鼠牙齿移植到野生型大鼠牙槽窝的实验中，可以在骨样组织表面和所有牙本质样组织上检测到GFP阳性细胞。这些结果表明，原来的牙髓细胞具有分化为成骨样细胞以及成牙本质样细胞的能力。
