title: SC1/hevin and reactive gliosis after transient ischemic stroke in young and aged rats.
abstract: SC1 is a member of the SPARC family of glycoproteins that regulate cell-matrix interactions in the developing brain. SC1 is expressed in astrocytes, but nothing is known about the expression in the aged or after stroke. We found that after focal striatal ischemic infarction in adult rats, SC1 increased in astrocytes surrounding the infarct and in the glial scar, but in aged rats, SC1 was lower at the lesion edge. Glial fibrillary acidic protein (GFAP) also increased, but it was less prominent in reactive astrocytes further from the lesion in the aged rats. On the basis of their differential expression of several molecules, 2 types of reactive astrocytes with differing spatiotemporal distributions were identified. On Days 3 and 7, SC1 was prevalent in cells expressing markers of classic reactive astrocytes (GFAP, vimentin, nestin, S100β), as well as apoliprotein E (ApoE), interleukin 1β, aggrecanase 1 (ADAMTS4), and heat shock protein 25 (Hsp25). Adjacent to the lesion on Days 1 and 3, astrocytes with low GFAP levels and a "starburst" SC1 pattern expressed S100β, ApoE, and Hsp32 but not vimentin, nestin, interleukin 1β, ADAMTS4, or Hsp25. Neither cell type was immunoreactive for NG2,CC-1, CD11b, or ionized calcium-binding adapter-1. Their differing expression of inflammation-related and putatively protective molecules suggests different roles for starburst and classic reactive astrocytes in the early glial responses to ischemia.
authors.affiliation: Toronto Western Research Institute, University Health Network, Toronto, Canada.
authors.forename: Starlee
authors.initials: S
authors.lastname: Lively
authors.forename: Iska
authors.initials: I
authors.lastname: Moxon-Emre
authors.forename: Lyanne C
authors.initials: LC
authors.lastname: Schlichter
mesh_terms: D051722:ADAM Proteins / Q000378:metabolism; D000071116:ADAMTS5 Protein; D025601:Adenomatous Polyposis Coli Protein / Q000378:metabolism; D000375:Aging / Q000473:pathology*; D000818:Animals; D000831:Animals, Newborn; D053327:Apolipoprotein E4 / Q000378:metabolism; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D001921:Brain / Q000166:cytology; D039481:CD11b Antigen / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000633:toxicity; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D007839:Functional Laterality; D005786:Gene Expression Regulation / Q000502:physiology*; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000209:etiology* / Q000378:metabolism*; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020521:Stroke / Q000139:chemically induced / Q000150:complications*; D013997:Time Factors; D014746:Vimentin / Q000378:metabolism
chemical_list: D025601:Adenomatous Polyposis Coli Protein; D053327:Apolipoprotein E4; D039481:CD11b Antigen; D002135:Calcium-Binding Proteins; D019332:Endothelin-1; D016326:Extracellular Matrix Proteins; D005904:Glial Fibrillary Acidic Protein; D053583:Interleukin-1beta; D009419:Nerve Tissue Proteins; C503128:Sparcl1 protein, rat; D014746:Vimentin; D006419:Heme Oxygenase (Decyclizing); C491523:Hmox1 protein, rat; D051722:ADAM Proteins; D000071116:ADAMTS5 Protein; C518696:Adamts5 protein, rat