Immunohistochemical detection of ENaCβ in the terminal Schwann cells associated with the periodontal Ruffini endings of the rat incisor
Immunohistochemical detection of ENaCβ in the terminal Schwann cells associated with the periodontal Ruffini endings of the rat incisor
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DOI：
10.2220/biomedres.30.113
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发表时间：
2009-04-01
影响因子：
1.2
通讯作者：
Maeda, Takeyasu
中科院分区：
文献类型：
--
作者：
Hitomi, Yasumasa;Suzuki, Akiko;Maeda, Takeyasu
上皮钠通道（ENaCs）是退变蛋白/ENaC（DEG/ENaC）超家族中的离子通道亚家族。先前的研究已经表明ENaC在皮肤机械感受器以及背根和三叉神经节神经元的神经元件中的免疫定位，表明该分子参与机械转导。本研究通过免疫组织化学方法检测了大鼠切牙牙周膜中机械感受性Ruffini末梢中ENaC β（ENaC蛋白的主要成分）的表达。ENaC β在三叉神经节中的表达也在mRNA和蛋白质水平上进行了研究，三叉神经节支配牙周Ruffini末梢。此外，双重染色和神经损伤实验，以阐明其在牙周Ruffini终末的详细定位。三叉神经节中的ENaC β免疫反应在被认为介导机械转导的相对较大的神经元中是可识别的。ENaC β的免疫组化显示了Ruffini末端的树突分支以及牙周膜中的圆形细胞。ENaC β和PGP9.5或S-100蛋白的双重染色显示ENaC β在牙周膜中的轴突和神经胶质成分中的免疫反应。一些圆形轮廓的ENaC β阳性细胞对非特异性胆碱酯酶活性有反应。此外，切断下牙槽神经未能消除ENaC β反应的圆形细胞，表明它们是与牙周Ruffini终末相关的终末Schwann细胞。这些发现表明ENaC β是牙周Ruffini末梢中的关键机械转导通道。可能是终末雪旺氏细胞与轴突终末共同调节牙周终末的力学传导。
Epithelial sodium channels (ENaCs) are a subfamily of ion channels within the degenerin/ENaC (DEG/ENaC) superfamily. Previous studies have shown the immunolocalization of ENaC in the neural elements of the Cutaneous mechanoreceptors as well as dorsal root and trigeminal ganglion neurons, indicating the involvement of this molecule in mechanotransduction. The present study examined the expression of ENaC beta, a major component of ENaC protein, in the mechanoreceptive Ruffini endings in the periodontal ligament of the rat incisors by immunohistochemistry. The expression of ENaC beta in the trigeminal ganglion-which innervates the periodontal Ruffini endings-was also investigated at the mRNA and protein levels. Furthermore, double staining and a nerve injury experiment were applied to clarify its detailed localization in the periodontal Ruffini endings. ENaC beta immunoreaction in the trigeminal ganglion was recognizable in the comparatively large neurons which have been considered to mediate mechanotransduction. Immunohistochemistry for ENaC beta demonstrated dendritic ramifications of the Ruffini endings as well as the rounded cells in the periodontal ligament. Double staining with ENaC beta and either PGP9.5 or S-100 protein showed immunoreaction for ENaC beta in both the axonal and glial elements in the periodontal ligament. Some ENaC beta positive cells with rounded profiles were reactive to non-specific cholinesterase activity. Furthermore, a transection of the inferior alveolar nerve failed to eliminate the rounded cells with ENaC beta reaction, indicating that they were the terminal Schwann cells associated with the periodontal Ruffini endings. These findings suggest that ENaC beta is a key mechanotransducing channel in the periodontal Ruffini endings. Probably, the terminal Schwann cells together with the axon terminals regulate mechanotransduction in the periodontal endings.