HIGHLY SIALYLATED N-CAM IS EXPRESSED IN ADULT-MOUSE OPTIC-NERVE AND RETINA
HIGHLY SIALYLATED N-CAM IS EXPRESSED IN ADULT-MOUSE OPTIC-NERVE AND RETINA
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DOI：
10.1007/bf01257243
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发表时间：
1990-08-01
期刊：
影响因子：
--
通讯作者：
SCHACHNER, M
中科院分区：
文献类型：
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作者：
BARTSCH, U;KIRCHHOFF, F;SCHACHNER, M
神经细胞粘附分子（N-CAM）及其高度唾液酸化的形式，这是普遍存在于年轻的组织，因此被称为胚胎神经细胞粘附分子的本地化，在发育和成年小鼠视神经和视网膜免疫组织学和免疫化学研究。在胚胎和出生后早期，神经母细胞和年轻的有丝分裂后神经元。视网膜中的Muller细胞和星形胶质细胞，以及视网膜神经节细胞轴突和视神经中的所有胶质细胞表达高度唾液酸化的神经细胞粘附分子。从出生后第三周开始，高度唾液酸化的神经细胞粘附分子从视神经中的视网膜神经节细胞轴突和视网膜中的神经元细胞体和突起中消失。此外，在3周龄动物的少突胶质细胞上检测不到它。然而，高度唾液酸化的神经细胞粘附分子继续在成人视神经和视网膜中由星形胶质细胞和Muller细胞表达。在这些细胞上，它仅在与基膜接触的细胞膜上缺失。相比之下，弱唾液酸化神经细胞粘附分子在发育期间和成人中由视网膜和视神经的所有细胞类型表达。因此，神经元和少突胶质细胞中高度唾液酸化的神经细胞粘附分子的丢失必须被认为是所谓的胚胎形式的神经细胞粘附分子向成体形式的细胞类型特异性转化，而不是简单地反映神经细胞粘附分子从这些细胞中的消失。然而，弱唾液酸化的神经细胞粘附分子，是不存在的感光细胞的外节，是高度唾液酸化的形式的情况下，从神经胶质细胞表面接触基膜。因此，有丝分裂前和有丝分裂后神经元以及少突胶质细胞表达高度唾液酸化的神经细胞粘附分子主要限于视网膜和视神经中的组织发生事件，即细胞分裂、细胞迁移、树突和轴突生长以及突触发生。除了观察到这种形式的神经细胞粘附分子比弱唾液酸化的成体形式粘附性更低之外，很可能高度唾液酸化的神经细胞粘附分子在动态形态发生事件中起重要作用。此外，高度唾液酸化的神经细胞粘附分子的表达，星形胶质细胞和Muller细胞在成年视神经和视网膜表明这些细胞在成年小鼠视觉系统中的一些组织遗传可塑性功能。
The localization of the neural cell adhesion molecule (N-CAM) and its highly sialylated form, which is prevalent in young tissue and has therefore been called embryonic neural cell adhesion molecule, was studied in the developing and adult mouse optic nerve and retina immunohistologically and immunochemically. At embryonic and early postnatal ages, neuroblasts and young postmitotic neurons. Muller cells and astrocytes in the retina, and retinal ganglion cell axons and all glial cells in the optic nerve express highly sialylated neural cell adhesion molecule. Beginning with the third postnatal week, highly sialylated neural cell adhesion molecule disappears from retinal ganglion cell axons in the optic nerve and from neuronal cell bodies and processes in the retina. In addition, it is not detectable on oligodendrocytes in 3-week-old animals. However, highly sialylated neural cell adhesion molecule continues to be expressed in the adult optic nerve and retina by astrocytes and Muller cells. On these cells it is only absent from cell membranes contacting basal lamina. Weakly sialylated neural cell adhesion molecule, in contrast, is expressed by all cell types of retina and optic nerve during development and in the adult. The loss of highly sialylated neural cell adhesion molecule from neurons and oligodendrocytes must therefore be considered as a cell-type-specific conversion of the so-called embryonic to the adult form of neural cell adhesion molecule and does not simply reflect the disappearance of neural cell adhesion molecule from these cells. Weakly sialylated neural cell adhesion molecule, however, is absent from outer segments of photoreceptor cells and, as is the case for the highly sialylated form, from glial cell surfaces contacting basal lamina. Thus, the expression of highly sialylated neural cell adhesion molecule by pre- and postmitotic neurons and by oligodendrocytes is restricted mainly to the period of histogenetic events in retina and optic nerve, i.e. cell divisions, cell migration, dendritic and axonal growth and synaptogenesis. In addition to the observation that this form of neural cell adhesion molecule is less adhesive than the weakly sialylated, adult form, it is likely that highly sialyated neural cell adhesion molecule plays an important role during dynamic morphogenetic events. Furthermore, the expression of highly sialylated neural cell adhesion molecule by astrocytes and Muller cells in adult optic nerves and retinae suggests some histogenetically plastic functions for these cells in the adult mouse visual system.