The role of cell adhesion molecules in reconstruction of neural network in spinal cord and spinal nerves with special attention paid to E-cadherin and its associated protein catenin

越来越多的细胞粘附蛋白被鉴定为参与细胞-细胞和细胞-细胞外基质相互作用。神经系统发育和再生过程中的L1、N-CAM、MAG等分子成员的作用已被广泛研究。我们最近发现，钙离子依赖性细胞粘附分子E-钙粘蛋白起着重要的作用，在一个特定的子集的无髓感觉纤维的选择性成束和E-钙粘蛋白是专门表达在层II的Rexed在脊髓背角。在这项研究中，E-cadherin和钙粘蛋白相关蛋白α-N-连环蛋白的细胞和亚细胞表达的时间分布在脊髓的脊神经和椎板II进行了检查后，粉碎，横断或结扎小鼠坐骨神经。周围神经损伤导致神经元和胶质细胞的组织学和组织化学变化。雪旺细胞增殖迁移形成雪旺细胞 ...更多信息 细胞柱（Bungner带）作为对去神经支配的初始反应，并在其相互接触的部位表达E-钙粘蛋白，随后与出芽轴突接触。在髓鞘形成的初始阶段，单个雪旺氏细胞的细长突起与轴突相互交错并包裹轴突，并在单个雪旺氏细胞所阐述的接触部位表达E-cadherin。在第二层的E-钙粘蛋白的表达消失后7天轴突切断和神经结扎（部分轴突再生模型）后63天再次出现。相反，在神经夹闭后，其保持在降低的水平（轴突旁变性模型）。α-N-连环蛋白免疫反应性的变化也显示了类似的模式。提示E-cadherin可能参与周围神经胶质网络的稳定，为轴突的出芽和髓鞘形成提供指导，E-cadherin-alpha N-catenin复合物可能对周围神经切断后脊髓后角的可塑性起重要作用。少

An increasing number of cell adhesive proteins is being identified as involved in cell-cell and cell-extracellular matrix interactions. Extensive studies have focused on several members of molecules including L1, N-CAM,MAG during the development and regeneration of the nervous system. We have recently found that Ca2+-dependent cell adhesion molecule E-cadherin plays an important role in the selective fasciculation of a particular subset of unmyelinated sensory fibers and that E-cadherin is exclusively expressed in lamina II of Rexed in the spinal cord dorsal horn. In this study, the temporal profile of the cellular and subcellular expression of E-cadherin and cadherin-associated protein alpha N-catenin in both spinal nerves and lamina II of the spinal cord was examined after crushing, transecting or ligaturing the sciatic nerve in mice. Peripheral nerve injury results in histological and histochemical changes in neurons and glia. Schwann cells proliferated and migrated to form Schwann … More cell columns (Bungner's bands) as initial responses to denervation, and expressed E-cadherin at their site of contact with each other and later with sprouting axons. At the initial stage of myelin formation, slender processes of a single Schwann cell interdigitated with and enveloped axons, and expressed E-cadherin at the contact site elaborated by a single Schwann cell. The expression of E-cadherin in lamina II disappeared by day 7 after axotomy and reappeared following nerve ligature (partial axonal regeneration model) on day 63. In contrast, it remained at the reduced level after nerve clipping (parmanent axonal degeneration model). The alteration of alpha N-catenin immunoreactivity showed the similar pattern. On the basis of present data, it is suggested that E-cadherin might be involved in the stabilization of peripheral glial network which provides the guidance of sprouting axons and myelination, and that E-cadherin-alpha N-catenin complex might be crucial for plasticity of the spinal cord dorsal horn after peripheral axotomy. Less