Wintergerst E S, Bartsch U, Batini C, Schachner M
Department of Neurobiology, Swiss Federal Institute of Technology, Hönggerberg, Zürich, Switzerland.
Eur J Neurosci. 1997 Mar;9(3):424-34. doi: 10.1111/j.1460-9568.1997.tb01620.x.
In the central nervous system of rodents, the extracellular matrix glycoproteins tenascin-C and tenascin-R are expressed predominantly by astrocytes and oligodendrocytes respectively. Both molecules support neurite outgrowth from several neuronal cell types when presented as uniform substrates. When offered as a sharp boundary with a permissive substrate, however, both molecules prevent neurite elongation. On the basis of these observations it has been suggested that tenascin-C and tenascin-R may be relevant in determining the cellular response after injury in the adult rodent central nervous system. To investigate whether tenascin-C and tenascin-R may play important functional roles in the lesioned central nervous system, we have analysed their expression in the olivocerebellar system of the adult rat after 3-acetylpyridine-induced degeneration of nerve cells in the inferior olivary nucleus. Tenascin-C mRNA was not detectable at any time in the unlesioned or lesioned inferior olivary nucleus by in situ hybridization. In the cerebellar cortex, tenascin-C mRNA in Golgi epithelial cells was down-regulated 3 days after the lesion and returned to control values 80 days after the lesion. Tenascin-R mRNA was expressed by distinct neural cell types in the unlesioned olivocerebellar system. After a lesion, the density of cells containing tenascin-R transcripts increased significantly in the inferior olivary nucleus and in the white matter of the cerebellar cortex. Immunohistochemical and immunochemical investigations confirmed these observations at the protein level. Our data thus suggest differential functions of tenascin-C and tenascin-R in the injured central nervous system.
在啮齿动物的中枢神经系统中，细胞外基质糖蛋白腱生蛋白-C和腱生蛋白-R分别主要由星形胶质细胞和少突胶质细胞表达。当呈现为均匀底物时，这两种分子都能支持多种神经元细胞类型的神经突生长。然而，当作为与允许性底物的清晰边界提供时，这两种分子都会阻止神经突伸长。基于这些观察结果，有人提出腱生蛋白-C和腱生蛋白-R可能与确定成年啮齿动物中枢神经系统损伤后的细胞反应有关。为了研究腱生蛋白-C和腱生蛋白-R是否可能在受损的中枢神经系统中发挥重要的功能作用，我们分析了成年大鼠在3-乙酰吡啶诱导下橄榄核神经细胞变性后，其在橄榄小脑系统中的表达情况。通过原位杂交，在未损伤或损伤的下橄榄核中，任何时候都检测不到腱生蛋白-C mRNA。在小脑皮质中，损伤后3天，高尔基上皮细胞中的腱生蛋白-C mRNA下调，损伤后80天恢复到对照值。腱生蛋白-R mRNA在未损伤的橄榄小脑系统中由不同的神经细胞类型表达。损伤后，下橄榄核和小脑皮质白质中含有腱生蛋白-R转录本的细胞密度显著增加。免疫组织化学和免疫化学研究在蛋白质水平证实了这些观察结果。因此，我们的数据表明腱生蛋白-C和腱生蛋白-R在受损的中枢神经系统中具有不同的功能。
