Accumulated caveolae constitute subcellular compartments for glial calcium signaling in lanceolate sensory endings innervating rat vibrissae
Accumulated caveolae constitute subcellular compartments for glial calcium signaling in lanceolate sensory endings innervating rat vibrissae
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DOI：
10.1002/cne.23028
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发表时间：
2012-06-15
影响因子：
2.5
通讯作者：
Iwanaga，Toshihiko
中科院分区：
文献类型：
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作者：
Takahashi-Iwanaga，Hiromi;Iwanaga，Toshihiko
已知大鼠触毛毛囊中伴随披针形感觉末梢的末端雪旺细胞显示出称为小窝的小质膜内陷，其集中了 Ca2+ 信号分子。我们之前已经表明，这些细胞通过激活代谢型嘌呤受体 P2Y2 在覆盖受体轴突的层状突起处产生 Ca2+ 信号。为了研究小窝在 Ca2+ 信号时空组织中的作用，通过免疫组织化学方法以及透射和扫描电子显微镜观察了终末雪旺细胞的小窝蛋白 Caveolin-1。此外，在用小凹消除剂甲基-β-环糊精处理或未处理的分离组织制剂中，对 P2Y2 及其偶联伴侣 Gq/11 进行免疫组织化学检测，并对嘌呤能诱导的神经胶质 Ca2+ 反应进行共聚焦图像分析。结果显示，雪旺片层的特征是存在致密的小凹，伴随着内质网 Ca2+ 储存的细管状网络，以及信号分子 P2Y2 和 Gq/11 的强烈表达。小凹的丢失使这些分子在整个细胞中广泛重新分布，并损害了层状 Ca2+ 信号，无论是在时间顺序优先级（先于整体细胞反应）还是在空间完整性（涉及过程的整个长度）方面。据我们所知，这是第一份关于区室化胶质细胞 Ca2+ 信号下的小凹的亚细胞积累的报告，这些信号可以与伴随的轴突末端的局部效应相结合。 J.Comp。内罗尔。 520:2053–2066, 2012。© 2011 Wiley periodicals, Inc.
The terminal Schwann cells that accompany lanceolate sensory endings in the rat vibrissal follicle are known to display the small plasma membrane invaginations termed caveolae, which concentrate Ca2+signaling molecules. We have previously shown that these cells generate Ca2+signals at the lamellar processes covering the receptor axons through activation of the metabotropic purinoceptor P2Y2. To investigate the roles of caveolae in the spatiotemporal organization of Ca2+signals, terminal Schwann cells were observed by immunohistochemistry for the caveola protein caveolin‐1, and by transmission and scanning electron microscopy. In addition, immunohistochemical detection of P2Y2and its coupling partner Gq/11along with confocal image analysis of the purinergically induced glial Ca2+responses was performed in isolated tissue preparations either treated or untreated with the caveolae eliminator methyl‐β‐cyclodextrin. Results showed the Schwann lamellae to be characterized by the presence of dense caveolae accompanying a fine tubular network of the endoplasmic reticulum Ca2+store and by intense expression of the signaling molecules P2Y2and Gq/11. Loss of caveolae diffusely redistributed these molecules throughout the entire cell and impaired the lamellar Ca2+signals, both in chronological priority (preceding the global cell response) and in spatial integrity (involving the entire length of the processes). To our knowledge, this is the first report of a subcellular accumulation of caveolae underlying compartmentalized glial Ca2+signals that can couple with local effects on the accompanying axon terminals. J. Comp. Neurol. 520:2053–2066, 2012. © 2011 Wiley Periodicals, Inc.