钮蛋白在神经生长锥的三维分布及其机能意义

目的　探索钮蛋白 (vinculin)在神经生长锥形态变化和神经生长过程中的作用机制。　方法　用免疫细胞化学方法 ,检测了初代培养鸡胚脊神经节细胞生长锥的细胞骨架蛋白vinculin的三维分布特征及其与纤维型肌动蛋白 (F actin)的相互关系。　结果　在三维的水平面上 ,vinculin与F actin的免疫反应活性在P领域和C领域的部分区域重合 ,在P领域伸展方向前端和丝状伪足内免疫反应活性最强。vinculin比F actin更接近细胞膜分布 ;在纵轴方向 ,vinculin主要分布在中部以上的表面游离侧 ,基质侧未见分布 ;F actin大部分与vinculin重叠 ,但比vinculin分布更广泛。　结论　vinculin是构成膜骨架蛋白成分之一 ,具有连接生长锥细胞膜和F actin的作用 ,参与生长锥形态变化、伪足伸缩 ,使神经突起生长。

THREE-DIMENSIONAL DISTRIBUTIONS AND SIGNIFICANCE OF VINCULIN IN NERVE GROWTH CONES

Objective To study the mechanism of vinculin in the process of nerve growing and morphologic changes of nerve growth cones. Methods Using immunocytochemistry(double immunofluorescent method and PAP method).We investigated the distributions of vinculin in nerve growth cones of primary culture of chicken embryo spinal ganglion cells.Meanwhile,we studied the interrelationship of vinculin and F-actin. Results In the horizontal direction,the immunoactivity of vinculin and F-actin partly overlapped in the C-domain and P-domain.The strongest immunologic reactions of them occurred in the head of P-domain stretching area and filopodia.Compared with F-actin,vinculin was closer to the membrane.In the longitudinal direction,vinculin mostly distributed in the free surface side,but not in the matrix side.Most of F-actin overlapped with vinculin,except the former distributed wider than the latter.Conclusion 1.Vinculin is one kind of the cytokeleton proteins which connect growth cone membrane with F-actin, and participates in morphologic alterations of nerve growth cone and filopodia action in making growth of nerve processes.2.Whether the developing nerve growth cones can temporarily gain the biological characteristics similar to that of tumor cells that make them possess brisk activities and some morphologic changes needs to be further investigated.;