Saito Kotaro, Nakatomi Mitsushiro, Kenmotsu Shinichi, Ohshima Hayato
Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata, 951-8514, Japan.
Cell Tissue Res. 2014 May;356(2):357-67. doi: 10.1007/s00441-014-1818-8. Epub 2014 Mar 27.
Our recent study suggested that allogenic tooth transplantation may affect the maintenance of dental pulp stem/progenitor cells. This study aims to elucidate the influence of allograft on the maintenance of dental pulp stem/progenitor cells following tooth replantation and allo- or auto-genic tooth transplantation in mice using BrdU chasing, immunohistochemistry for BrdU, nestin and Ki67, in situ hybridization for Dspp, transmission electron microscopy and TUNEL assay. Following extraction of the maxillary first molar in BrdU-labeled animals, the tooth was immediately repositioned in the original socket, or the roots were resected and immediately allo- or auto-grafted into the sublingual region in non-labeled or the same animals. In the control group, two types of BrdU label-retaining cells (LRCs) were distributed throughout the dental pulp: those with dense or those with granular reaction for BrdU. In the replants and autogenic transplants, dense LRCs remained in the center of dental pulp associating with the perivascular environment throughout the experimental period and possessed a proliferative capacity and maintained the differentiation capacity into the odontoblast-like cells or fibroblasts. In contrast, LRCs disappeared in the center of the pulp tissue by postoperative week 4 in the allografts. The disappearance of LRCs was attributed to the extensive apoptosis occurring significantly in LRCs except for the newly-differentiated odontoblast-like cells even in cases without immunological rejection. The results suggest that the host and recipient interaction in the allografts disturbs the maintenance of dense LRCs, presumably stem/progenitor cells, resulting in the disappearance of these cell types.
我们最近的研究表明，同种异体牙移植可能会影响牙髓干细胞/祖细胞的维持。本研究旨在通过BrdU追踪、BrdU、巢蛋白和Ki67免疫组化、Dspp原位杂交、透射电子显微镜和TUNEL检测，阐明同种异体移植对小鼠牙齿再植及同种或自体牙移植后牙髓干细胞/祖细胞维持的影响。在对用BrdU标记的动物拔除上颌第一磨牙后，将牙齿立即复位到原牙槽窝，或将牙根切除后立即同种或自体移植到未标记或同一动物的舌下区域。在对照组中，两种类型的BrdU标记保留细胞（LRCs）分布于整个牙髓：对BrdU呈密集反应或颗粒反应的细胞。在再植牙和自体移植牙中，密集的LRCs在整个实验期间一直存在于牙髓中央，与血管周围环境相关联，具有增殖能力，并维持向成牙本质细胞样细胞或成纤维细胞的分化能力。相比之下，在同种异体移植中，术后第4周牙髓组织中央的LRCs消失。LRCs的消失归因于即使在没有免疫排斥的情况下，除新分化的成牙本质细胞样细胞外，LRCs中也发生了大量凋亡。结果表明，同种异体移植中宿主与受体的相互作用干扰了密集LRCs（可能是干细胞/祖细胞）的维持，导致这些细胞类型消失。
