Axon-Schwann cell relationship in nerve regeneration and the mechanisms for the promotion of nerve

粘附分子和营养因子在神经再生中起重要作用。本研究考察了粘附分子中钙粘蛋白和α - n -连环蛋白的定位，以及碱性成纤维细胞生长因子（bFGF）对神经营养因子的作用。此外，还检测了蛋白激酶C （PKC）亚型的定位。钙粘蛋白存在于轴突与雪旺细胞或其他轴突接触的轴膜上。在轴质中，在不同大小的囊泡中检测到钙粘蛋白。α - n -连环蛋白在细胞质中弥散分布，与腋膜无明显关联。在雪旺细胞中未发现连环蛋白。在体内实验中，bFGF增强了大鼠坐骨神经再生轴突的延伸；其中雪旺细胞通过冷冻处理被杀死。在这个实验模型中，再生轴突生长锥体通过雪旺细胞基板管生长。雪旺细胞沿轴突向生长锥后迁移。结果表明，bFGF被困在基底层，并通过与基底层内表面接触的生长锥与轴膜上的受体结合而被吸收。经冷冻处理的犬腓总神经同种异体移植物实验表明，bFGF能在不使用免疫抑制剂的情况下促进再生轴突的生长。再生轴突细胞质中存在PKC亚型（delta, epsilon, zeta）。PKC被认为参与了再生轴突的延伸。结果表明，在突触中表达的神经素也存在于生长锥中。神经滨素是一种f -肌动蛋白结合蛋白，被认为与神经过程延伸有关。在脊髓背索处检查脱髓鞘和再髓鞘。

Adhesion molecules and trophic factors play important roles in nerve regeneration. The present study examined the localization of cadherin and alpha N-catenin for adhesion molecules, and the effects of basic fibroblast growth factors (bFGF) for nerve trophic factor. In addition the localization of subtypes of protein kinase C (PKC) was examined.Cadherin was present on the axolemma at which axons were in contact with Schwann cells or with the other axons. In the axoplasm cadherin was detected in various-sized vesicles. alpha N-catenin was distributed diffusely in the cytoplasm, with no distinct association with the axolemma. No catenin was found in the Schwann cell.bFGF enhanced the extension of the regenerating axons in the in vivo experiment using rat sciatic nerve ; in which Schwann cells had been killed by cryotreatment. In this experimental model growth cones of regenerating axons grew through the Schwann cell basal lamina tube. Schwann cells migrated behind growth cones-along axons. It was suggested that bFGF was trapped to the basal lamina, and took up through combining with the receptors on the axolemma by growth cones in contact with the inner surface of basal lamina.The allograft using the cryotreated dog common peroneal nerve revealed that the bFGF could promote the growth of regenerating axons without applying immunosuppressants.PKC subtypes (delta, epsilon, zeta) were present in the cytoplasm of the regenerating axons. PKC is considered to be involved in the extension of regenerating axons.It was revealed that the neurabin which is a molecule expressed in the synapse is also present in the growth cones. Neurabin is a F-actin binding protein and suggested to be involved in neural process extension.Demyelination and the remyelination were examined in the spinal cord dorsal funiculus.