The role of cell adhesion molecules and neurotrophic factros in reconstruction of nociceptive pathways in spinal cord and spinal nerve

钙依赖细胞黏附分子E-钙粘附素在轴突切断后特定感觉神经纤维的束状化、轴突-雪旺细胞接触和髓鞘形成过程中起重要作用。本研究采用免疫印迹和免疫组织化学方法检测E-钙粘蛋白、α和β-连环素以及肌动蛋白在小鼠神经组织中的表达和定位，以阐明钙粘附素-连环素复合体在神经系统的建立和维持中的作用。免疫印迹分析显示，E-钙粘蛋白在三叉神经、脊髓、背根、背根节和坐骨神经中均有表达。α-连环蛋白在大脑皮层、小脑、脑干、脊髓和背根神经节均有表达。抗E-钙粘蛋白抗体免疫沉淀结果显示，在三叉神经、背根神经节和坐骨神经中，α-E-连环素与E-钙粘附素形成复合体，但在脊髓中不形成复合体。E-钙粘附素-α…未检测到较多的N-连环蛋白复合体。免疫组织化学染色显示，E-钙粘蛋白表达于脊髓背根、腹根和板层II、背根节卫星细胞和小神经元胞体、无髓纤维亚群和雪旺细胞。部分神经元、脊髓中央管室管膜细胞、卫星细胞、部分神经元胞体和雪旺细胞表达αE-连环蛋白。脊髓灰质弥漫性表达N-连环蛋白，II层和中央管内免疫反应增强。卫星细胞和一些神经元胞体也呈阳性。此外，NGF的应用挽救了外周神经切断后消失的板层中P物质的免疫反应，但不影响E-钙粘蛋白或α-N-连环蛋白的免疫反应。这些结果表明钙粘附素-连环蛋白复合体以不同的方式调节细胞接触。此外，在背根节、三叉神经和坐骨神经中，αE-catenin与E-cadherin形成复合体，在周围神经(包括雪旺细胞和卫星细胞)的神经胶质接触中发挥作用。较少

Calcium dependent cell adhesion molecule, E-cadherin, plays important roles in fasciculation of a particular subset of sensory fibers, axon-Schwann cell contact and myelination after axotomy. The present study was performed to examine the expressions and localizations of E-cadherin, alpha and BETA -catenins, and actin in mouse neural tissues by immunoblot and immunohistochemical analyses, to elucidate roles of cadherin-catenin complex in establishment and maintenance of nervous system. In immunoblot analysis, E-cadherin was expressed in trigeminal nerves, spinal cords, dorsal roots, DRG, and sciatic nerves. alpha N-catenin was expressed in cerebral cortex, cerebellum, brain stem, spinal cord, and DRG.alpha E-catenin, beta -catenin and actin were expressed in all tissues that were examined. Immunoprecipitation using anti-E-cadherin antibody resulted that alpha E-catenin formed complex with E-cadherin in trigeminal nerve, DRG, and sciatic nerve, but not in spinal cord. E-cadherin- alpha … More N-catenin complex was not detected. In immunohistochemistry, E-cadherin was expressed in the dorsal and ventral root and the lamina II of the spinal cord, satellite cells and small sized neuronal cell bodies of DRG, subpopulation of unmyelinated fibers, and Schwann cells. alpha E-catenin was expressed in some of neurons, ependymal cells of central canal in spinal cord, satellite cells, some neuronal cell bodies, and Schwann cells. a N-catenin was diffusely expressed in gray matter in the spinal cord with enhanced immunoreactivity in lamina II and central canal. Satellite cells and some neuronal cell bodies were also positive. Furthermore, administration of NGF rescued the immunoreactivity of substance-P in lamina II, which is known to disappear after peripheral axotomy, but not influence that of both E-cadherin or alpha N-catenin. These results suggested that cadherin-catenin complexes regulate cell contact in various manner. Furthermore, alpha E-catenin form complex with E-cadherin in DRG, trigeminal nerves, and sciatic nerves, which plays a role in glial contact in peripheral nerves, including Schwann cells and satellite cells. Less