Laywell E D, Dörries U, Bartsch U, Faissner A, Schachner M, Steindler D A
Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163.
Proc Natl Acad Sci U S A. 1992 Apr 1;89(7):2634-8. doi: 10.1073/pnas.89.7.2634.
Tenascin is an extracellular matrix molecule synthesized and released by young astrocytes during embryonic and early postnatal development of the nervous system, and it is concentrated in boundaries around emerging functional neuronal units. In the adult nervous system, tenascin can be detected only in very low levels. Distinct spatial and temporal distributions of tenascin during developmental events suggest a role in the guidance and/or segregation of neurons and their processes within incipient functional patterns. We show here, using in situ hybridization and immunocytochemistry, that stab wounds of the adult mouse cerebellar and cerebral cortices result in an enhanced expression of tenascin in a discrete region around the lesion site that is associated with a subset of glial fibrillary acidic protein-positive astrocytes. Tenascin up-regulation in the lesioned adult brain may be directly involved in failed regeneration or indirectly involved through its interactions with other glycoconjugates that either inhibit or facilitate neurite growth.
腱生蛋白是一种细胞外基质分子，在神经系统胚胎期和出生后早期发育过程中由年轻的星形胶质细胞合成并释放，且集中于新出现的功能性神经元单元周围的边界处。在成体神经系统中，只能检测到极低水平的腱生蛋白。腱生蛋白在发育过程中独特的空间和时间分布表明其在神经元及其突起在初始功能模式中的导向和/或分离中发挥作用。我们在此利用原位杂交和免疫细胞化学方法表明，成年小鼠小脑和大脑皮质的刺伤会导致损伤部位周围离散区域腱生蛋白表达增强，该区域与一部分胶质纤维酸性蛋白阳性星形胶质细胞相关。成年脑损伤后腱生蛋白的上调可能直接参与再生失败，或通过其与其他抑制或促进神经突生长的糖缀合物的相互作用间接参与。
