The study on the role of heat shock protein (Hsp) 25 during dental and periodontal regeneration after tooth replantation

成牙本质细胞层在牙齿损伤后的再生过程尚未完全清楚。本研究的目的是阐明的命运和再生过程中的成牙本质细胞牙髓愈合后的牙齿再植在大鼠磨牙的免疫细胞化学使用的抗体热休克蛋白（Hsp）25，免疫活性细胞和蛋白基因产物（PGP）9.5，以及组织化学高碘酸希夫（PAS）反应。在未处理的对照牙中，在成牙本质细胞的细胞体中发现强烈的Hsp 25免疫反应性。再植牙术后第1 ~ 3天牙髓组织中Hsp 25免疫反应消失。术后第3天，许多免疫活性细胞沿着牙髓-牙本质边界聚集，随后Hsp 25免疫反应阳性细胞取代它们，同时伴有神经再支配。这些结果表明，热休克蛋白25-免疫反应性的表达的变化的时间过程中反映的成牙本质细胞的变性/再生过程。此外，免疫活性细胞的时间外观可能参与成牙本质细胞分化以及在初始防御反应。14天后，再植牙髓表现出两种再生模式：修复性牙本质和骨样组织形成。PAS反应细胞在牙髓间隙中的出现和Hsp 25免疫阳性细胞在牙髓-牙本质边缘的缺乏表明，牙囊来源的细胞迁移到牙髓间隙和随后的原始牙髓细胞的完全死亡是引起骨样组织在再植牙髓中形成的决定性因素。再植牙牙髓中骨样组织形成的机制尚需进一步研究。

The regeneration process of the odontoblast cell layer incident to tooth injury has not been fully understood. The purpose of the present study was to clarify the fate and regeneration process of odontoblasts during the pulpal healing following tooth replantation in rat molars by immunocytochemistry using antibodies to heat shock protein (Hsp) 25, immunocompetent cells and protein gene product (PGP) 9.5, as well as by histochemical periodic acid-Schiff (PAS) reaction. In untreated control teeth, intense Hsp 25-immunoreactivity was found in the cell bodies of odontoblasts. Tooth replantation caused loss of Hsp 25-immunoreactions in the coronal dental pulp during postoperative days 1-3. At postoperative 3 days, many immunocompetent cells accumulated along the pulp-dentin border, and subsequently Hsp 25-immunoreactive cells replaced them, concomitant with re-innervation. These findings indicate that the time course of changes in the expression of Hsp 25-immunoreactivity reflects the degeneration/regeneration process of odontoblasts. Furthermore, the temporal appearance of the immunocompetent cells might participate in odontoblast differentiation as well as in the initial defense reaction. After 14 days, the replanted pulp showed two regeneration patterns; reparative dentin and bone-like tissue formation. The occurrence of PAS-reactive cells in the pulp space and the absence of Hsp 25-immunopositive cells at the pulp-dentin border suggested that the migration of the dental follicle-derived cells into the pulp space and the subsequent total death of the original pulpal cells are decisive factors to elicit bone-like tissue formation in the replanted pulp. Further studies are needed to clarify the mechanisms of bone-like tissue formation in the dental pulp following tooth replantation.