Morphological characteristics of p75 neurotrophin receptor-positive cells define a new type of glial cell in the rat dorsal root ganglia
Morphological characteristics of p75 neurotrophin receptor-positive cells define a new type of glial cell in the rat dorsal root ganglia
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DOI：
10.1002/cne.24667
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发表时间：
2019-08-15
影响因子：
2.5
通讯作者：
Yamada, Hisao
中科院分区：
文献类型：
--
作者：
Koike, Taro;Tanaka, Susumu;Yamada, Hisao
在背根神经节（DRG）中，根据细胞形态和特异性标志物的表达，鉴定出两种类型的胶质细胞（雪旺细胞和卫星胶质细胞）。在本研究中，我们观察到p75神经营养因子受体（p75NTR）阳性的未知胶质细胞，因此首次进行了免疫组织化学和超微结构表征。这些细胞比DRG神经元（以下称为p75ntr++细胞）对抗p75NTR抗体表现出更强的免疫反应性。此外，这些细胞覆盖了大直径DRG神经元近端突起周围的胶质细胞。近端过程称为树突-轴突。p75ntr++细胞主要分布在第一批髓鞘雪旺细胞出现的地方。p75ntr++细胞对泛胶质细胞标志物S100、巢蛋白和Sox10也呈阳性，但对成纤维细胞和巨噬细胞标志物呈阴性。此外，它们的卫星胶质细胞标记物Kir4.1和非髓鞘雪旺细胞标记物胶质纤维酸性蛋白均呈阴性。此外，它们的形态特征与有髓鞘的雪旺细胞不同。为了研究p75ntr++细胞的三维超微结构，我们采用阵列层析技术结合相关的光镜和电镜观察。三维超微结构观察显示，p75ntr++细胞松散地覆盖在树突-轴突周围的胶质细胞上，具有高度分叉的突起。具有这些形态特征的神经胶质细胞此前未见报道，提示p75ntr++神经胶质细胞是DRG中一种新的神经胶质细胞类型。我们的研究结果将为细胞-细胞关系提供新的见解。
In the dorsal root ganglia (DRG), two types of glial cells (Schwann cells and satellite glial cells) have been identified based on cell morphology and expression of specific markers. In the present study, we observed unknown glial cells that were positive for p75 neurotrophin receptor (p75NTR), and therefore were immunohistochemically and ultrastructurally characterized for the first time. These cells exhibited stronger immunoreactivity against an anti-p75NTR antibody than the DRG neurons (hereafter referred to as p75NTR++ cells). Moreover, these cells covered the glial cells surrounding proximal process of the large-diameter DRG neurons. The proximal process is called dendro-axon. The p75NTR++ cells were predominantly distributed where the first myelinating Schwann cells appear. The p75NTR++ cells were also positive for the pan-glial cell markers S100, nestin, and Sox10, but negative for fibroblast and macrophage markers. Moreover, they were negative for a satellite glial cell marker, inwardly rectifying potassium channel Kir4.1, as well as a nonmyelinating Schwann cell marker, glial fibrillary acidic protein. In addition, their morphological features were distinct from those of the myelinating Schwann cells. To investigate the three-dimensional ultrastructure of the p75NTR++ cells, we used array tomography combined with correlative light and electron microscopic observation. Three-dimensional ultrastructural observation revealed that the p75NTR++ cells loosely covered glial cells around the dendro-axons with highly ramified processes. Glial cells with these morphological features have not been reported before, indicating that the p75NTR++ glial cells are a new glial cell type in the DRG. Our results will give new insights into cell-cell relationships.