Asurvey of new factors which involve in development and regeneration process of the periodontal Ruffini endings

我们先前的研究显示，牙周膜中有高亲和力神经营养因子受体trk B的免疫表达。此外，我们已经表明参与BDNF和NT-4/5，配体trkB，在牙周Ruffini末梢的发展/再生。然而，迄今为止，没有关于参与其成熟过程的分子的信息。因此，本研究进行调查GDNF（胶质细胞系衍生的神经营养因子）和半乳糖凝集素在大鼠切牙牙周Ruffini终末的表达。本研究的主要结果如下：1. APCR检测到三叉神经节内GDNF、GFRα 1和Ret mRNA的强信号。免疫细胞化学分析显示，约30%的三叉神经元表达GFRα 1和Ret，图像分析显示这些神经元大多数为介导机械力信号转导的中型神经元。GDNF免疫反应主要集中在卫星细胞内 ...更多信息 ，神经元中从未出现。成熟的牙周Ruffini终末在终末雪旺氏细胞中表达GDNF、GFRα 1和Ret。而轴突终末缺乏GDNF免疫反应。牙周膜Ruffini终末未见免疫反应.生后3天牙周Ruffini终末缺乏各种免疫反应。在出生后第1周，终末Schwarm细胞对GFRα 1呈阳性。第2周部分轴突终末出现Ret-I免疫反应，在增厚的轴突终末附近出现少量GDNF阳性终末Schwann细胞。此后，GDNF阳性终末雪旺细胞数量增加。切除下牙槽神经的实验显示，GDNF阳性的终末雪旺细胞，梭形，在术后2周首次出现。术后3周，缅因州终末雪旺细胞呈圆形，GDNF免疫阳性。这些阶段特异性表达模式可能与牙周Ruffini终末的成熟和维持有关。少

Our previous studies haw revealed an immuno-expression of trk B, a high affinity neurotrophin receptor in the periodontal ligament. Furthermore, we have shown the involvement of BDNF and NT-4/5, ligands for trkB, in the development/regeneration of the periodontal Ruffini endings. However, no information available for the molecules involved in their maturation process to date. Thus, the present study was undertaken to investigate expression of GDNF (glial-cell line derived neutrotrophic factor) and galectin in the periodontal Ruffini endings of the rat incisors. The main results obtained from this study are as follows.1. APCR analysis detected intense signals far GDNF, GFRαl and Ret mRNAs in the trigeminal ganglion. Immunocytochemical analysis demonstrated positive reaction for GFRαl and Ret in about 30% trigeminral neurons, almost which were categorized in medium-sized neurons that mediate mechanotransduction by an image analysis. GDNF-immunoreaction was localized infix satellite cells … More , never in the neurons.2. The mature periodontal Ruffini endings exhibited GDNF, GFRαl and Ret-immunoreactions in the terminal Schwann cells. However, their axon terminals were devoid of GDNF-immunoreaclion. Furthermore, no immunoreaction existed in the periodontal Ruffini endings.3. The periodontal Ruffini endings lacked all kinds of immunoreaction at postnatal 3 days. At postnatal week 1, the terminal Schwarm cells became positive for GFRαl. Apart of the axon terminals showed Ret-immunoreaction at week 2, and a few GDNF-reactive terminal Schwann cells occurred near the thickening axon terminals. Thereafter, the GDNF-positive terminal Schwann cells increase in number.4. An experiment to resect inferior alveolar nerve showed first appearance of the GDNF-positivity in the terminal Schwann cells, spindle-in shape, at postoperative 2 weeks. Maine terminal Schwann cells which had round profile were detectable as GDNF-immunopositive after postoperative 3 weeks. These stage-specific expression patterns might be related to the maturation and maintenance of the periodontal Ruffini endings. Less