Enhanced expression of the developmentally regulated extracellular matrix molecule tenascin following adult brain injury.
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.
Department of Anatomy and Neurobiology, University of Tennessee, Memphis 38163.
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Laywell
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Dörries
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Bartsch
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Faissner
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Schachner
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Steindler
D000367:Age Factors; D000818:Animals; D001930:Brain Injuries / Q000503:physiopathology*; D015816:Cell Adhesion Molecules, Neuronal / Q000378:metabolism*; D002525:Cerebellar Cortex / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D015870:Gene Expression; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007124:Immunoenzyme Techniques; D051379:Mice; D008815:Mice, Inbred Strains; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics; D019063:Tenascin
D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D005904:Glial Fibrillary Acidic Protein; D012333:RNA, Messenger; D019063:Tenascin