Syndecan-3 and syndecan-4 are enriched in Schwann cell perinodal processes
Syndecan-3 and syndecan-4 are enriched in Schwann cell perinodal processes
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DOI：
10.1186/1471-2202-4-29
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发表时间：
2003-11-18
期刊：
影响因子：
2.4
通讯作者：
Girault, JA
中科院分区：
文献类型：
--
作者：
Goutebroze, L;Carnaud, M;Girault, JA
背景：Ranvier 节点对应于电压门控钠通道高度集中的特殊轴突域。在周围神经系统中，它们被雪旺细胞微绒毛覆盖，其中发现富集了三种同源细胞骨架相关蛋白：埃兹蛋白、根蛋白和莫斯蛋白（ERM 蛋白）。这些神经胶质过程被认为在发育过程中组织轴突节点域中发挥着至关重要的作用。然而，人们对雪旺细胞过程中存在的可介导轴突胶质细胞相互作用的分子知之甚少。本研究的目的是通过免疫细胞化学鉴定富集在雪旺细胞突中的跨膜蛋白，这些蛋白可以直接或间接与轴突蛋白相互作用。结果：我们发现，雪旺细胞中表达的两种蛋白多糖 syndecan-3 (S3) 和 syndecan-4 (S4) 在大鼠坐骨神经的突周突中富集。早在出生后第 2 天，S3 标记就定位在钠通道附近，并高度集中在成人的 Ranvier 结处。 S4 免疫反应性随后在结节处积累，并且在有髓纤维的结间区域也很突出。 S3 和 S4 均与埃兹蛋白在节周过程中共定位。结论：我们的数据将 S3 和 S4 鉴定为在雪旺细胞节周过程中特异性富集的跨膜蛋白，并表明 S3 可能参与发育过程中的早期轴突相互作用。
Background: Nodes of Ranvier correspond to specialized axonal domains where voltage-gated sodium channels are highly concentrated. In the peripheral nervous system, they are covered by Schwann cells microvilli, where three homologous cytoskeletal-associated proteins, ezrin, radixin and moesin (ERM proteins) have been found, to be enriched. These glial processes are thought to play a crucial role in organizing axonal nodal domains during development. However, little is known about the molecules present in Schwann cell processes that could mediate axoglial interactions. The aim of this study is to identify by immunocytochemistry transmembrane proteins enriched in Schwann cells processes that could interact, directly or indirectly, with axonal proteins.Results: We show that syndecan-3 (S3) and syndecan-4 (S4), two proteoglycans expressed in Schwann cells, are enriched in perinodal processes in rat sciatic nerves. S3 labeling was localized in close vicinity of sodium channels as early as post-natal day 2, and highly concentrated at nodes of Ranvier in the adult. S4 immunoreactivity accumulated at nodes later, and was also prominent in internodal regions of myelinated fibers. Both S3 and S4 were co-localized with ezrin in perinodal processes.Conclusions: Our data identify S3 and S4 as transmembrane proteins specifically enriched in Schwann cell perinodal processes, and suggest that S3 may be involved in early axoglial interactions during development.