Peripheral astrocyte processes: Monitoring by selective immunostaining for the actin-binding ERM proteins
Peripheral astrocyte processes: Monitoring by selective immunostaining for the actin-binding ERM proteins
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DOI：
10.1002/glia.1120
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发表时间：
2001-12-01
期刊：
影响因子：
6.2
通讯作者：
Frotscher, M
中科院分区：
文献类型：
--
作者：
Derouiche, A;Frotscher, M
星形胶质细胞在神经元中延伸薄的片状突起，特别是在突触周围，在那里它们可以调节突触功能或介导胶质细胞-神经元通信。以往的研究表明，这些层状突触周过程改变其形状，以响应神经元的活动，但其潜在的机制仍然不清楚。同样，这些细小的片状星形胶质细胞突起（通常为50-100纳米宽）的分子组成尚不清楚，但必须与其动态特性相关。为此，我们研究了ezrin，radixin，和膜突蛋白（ERM蛋白）在大鼠海马和原代培养的星形胶质细胞中的存在下，应用免疫过氧化物酶，免疫荧光，和免疫金技术。这三种ERM蛋白被称为肌动蛋白结合蛋白，其将细胞膜连接到肌动蛋白细胞骨架，特别是在微绒毛上皮细胞中。在细胞培养中，抗ezrin和antiradixin，但不antimoesin，抗体是特异性的星形胶质细胞，这往往显示选择性染色的丝状伪足和微绒毛。通过免疫细胞化学双标记ezrin和GFAP，分别获得星形胶质细胞外周和茎突的非重叠可视化。在大鼠海马的部分，均匀标记的神经元，但不是细胞层，导致精细的，外周星形胶质细胞的过程，免疫染色证实超微结构。我们的数据表明，星形胶质细胞，这也构成了突触周围的神经胶质鞘，精细的外周过程，是专门的，因为它们含有特征肌动蛋白相关的分子，可能有助于其动态特性。应用antiezrin和antiradixin作为选择性标记物，可以分析这些突触周围神经胶质过程的可塑性。(C)2001 Wiley-Liss，Inc.
Astrocytes extend thin lamellate processes in the neuropil, in particular around synapses, where they can modulate synaptic function or mediate glial-neuronal communication. Previous studies have shown that these lamellate perisynaptic processes change their shape in response to neuronal activity, but the underlying mechanisms have remained unclear. Similarly, the molecular composition of these fine, sheetlike astrocytic processes (often 50-100 nm wide) is not understood but has to be related to their dynamic properties. To this end, we have studied the presence of ezrin, radixin, and moesin (ERM proteins) in the rat hippocampus and in primary cultured astrocytes, applying immunoperoxidase, immunofluorescence, and immunogold techniques. These three ERM proteins are known as actin-binding proteins that link the cell membrane to the actin cytoskeleton, particularly in microvillus-bearing epithelial cells. In cell culture, anti-ezrin and antiradixin, but not antimoesin, antibodies were specific for astrocytes, which often displayed selective staining of filopodia and microvilli. Nonoverlapping visualization of astrocytic peripheral and stem processes was obtained by immunocytochemical double labeling for ezrin and GFAP, respectively. In sections of rat hippocampus, homogeneous labeling of the neuropil, but not of cell layers, resulted from immunostaining of fine, peripheral astrocyte processes, as confirmed ultrastructurally. Our data show that the fine peripheral processes of astrocytes, which also constitute the perisynaptic glial sheath, are specialized in that they contain characteristic actin-associated molecules, likely to contribute to their dynamic properties. Applying antiezrin and anti-radixin as selective markers, plasticity of these perisynaptic glial processes can be analyzed. (C) 2001 Wiley-Liss, Inc.