title: SPARC, an extracellular matrix glycoprotein containing the follistatin module, is expressed by astrocytes in synaptic enriched regions of the adult brain.
abstract: Although extracellular matrix (ECM) glycoproteins play important roles in neural development, their levels are generally believed to decrease in the adult brain. Immunohistochemical analysis indicates that the anti-adhesive ECM glycoprotein SPARC/osteonectin, which contains a follistatin 'module,' is expressed in the adult rabbit nervous system. In the cerebellum, SPARC is present in Bergmann glia, with a strong signal along their radial fibres. SPARC, while enriched in membrane fractions, is not a transmembrane protein. In the hippocampus, colocalization of SPARC is observed in cells which express the astrocytic marker GFAP. The expression of SPARC by a subset of astrocytes, particularly in synaptic enriched areas, suggests a continuing role for the ECM in the adult brain.
authors.affiliation: Department of Zoology, University of Toronto, Ont., Canada.
authors.forename: D B
authors.initials: DB
authors.lastname: Mendis
authors.forename: L
authors.initials: L
authors.lastname: Malaval
authors.forename: I R
authors.initials: IR
authors.lastname: Brown
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000737:chemistry / Q000378:metabolism*; D015153:Blotting, Western; D001921:Brain / Q000276:immunology / Q000378:metabolism*; D002531:Cerebellum / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D038681:Follistatin; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D006624:Hippocampus / Q000276:immunology / Q000378:metabolism; D007150:Immunohistochemistry; D015676:Osteonectin / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D013569:Synapses / Q000737:chemistry / Q000378:metabolism
chemical_list: D038681:Follistatin; D006023:Glycoproteins; D015676:Osteonectin