title: beta-Amyloid increases enzyme activity and protein levels of glutamine synthetase in cultured astrocytes.
abstract: Previous studies have reported that beta-amyloid peptides induce properties of reactivity in cultured astrocytes. We report here that aggregated A beta peptides increase expression of the enzyme glutamine synthetase in cultured astrocytes, as assessed by enzyme assay, Western blot analysis, and immunocytochemistry. The enhanced enzyme levels occur gradually over a period of 4 days after A beta exposure and maintain peak values for at least several days thereafter. These data suggest that A beta-related reactive astrocytosis in Alzheimer's disease brain may benefit local neurons by enhancing glial capacity to regulate levels of the excitotoxin glutamate.
authors.affiliation: Institute for Brain Aging and Dementia, University of California, Irvine 92717-4540, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Pike
authors.forename: N
authors.initials: N
authors.lastname: Ramezan-Arab
authors.forename: S
authors.initials: S
authors.lastname: Miller
authors.forename: C W
authors.initials: CW
authors.lastname: Cotman
mesh_terms: D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000201:enzymology*; D002478:Cells, Cultured / Q000187:drug effects / Q000201:enzymology; D002540:Cerebral Cortex / Q000166:cytology; D004790:Enzyme Induction; D005974:Glutamate-Ammonia Ligase / Q000096:biosynthesis* / Q000378:metabolism; D051381:Rats
chemical_list: D016229:Amyloid beta-Peptides; D005974:Glutamate-Ammonia Ligase