title: High glutamate decreases S100B secretion stimulated by serum deprivation in astrocytes.
abstract: S100B is a calcium-binding protein expressed and secreted by astrocytes, playing a neurotrophic role in neighboring cells. A protective role of the S100B against glutamate-induced excitotoxicity has recently been proposed. We investigated S100B secretion in rat hippocampal astrocytes exposed to high concentrations of glutamate during serum deprivation (stimulated condition) or not (basal condition), for 30 min. Glutamate at 1 mM had no effect on basal secretion of S100B, but it decreased S100B secretion in serum-deprived astrocytes after 1 h. Secretion was inhibited by Rp-cAMPS or H89. In addition, serum deprivation was accompanied by a transitory increase of intracellular content of cAMP. Our results suggest that high levels of glutamate in a serum-deprived condition could impair S100B secretion from hippocampal astrocytes.
authors.affiliation: Departmento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos, Porto Alegre, Brazil.
authors.forename: Daniela
authors.initials: D
authors.lastname: Gonçalves
authors.forename: Juliana
authors.initials: J
authors.lastname: Karl
authors.forename: Marina
authors.initials: M
authors.lastname: Leite
authors.forename: Liane
authors.initials: L
authors.lastname: Rotta
authors.forename: Christianne
authors.initials: C
authors.lastname: Salbego
authors.forename: Elizabete
authors.initials: E
authors.lastname: Rocha
authors.forename: Susana
authors.initials: S
authors.lastname: Wofchuk
authors.forename: Carlos-Alberto
authors.initials: CA
authors.lastname: Gonçalves
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D016895:Culture Media, Serum-Free / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D018698:Glutamic Acid / Q000494:pharmacology*; D009414:Nerve Growth Factors / Q000378:metabolism*; D009498:Neurotoxins / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins
chemical_list: D002135:Calcium-Binding Proteins; D016895:Culture Media, Serum-Free; D009414:Nerve Growth Factors; D009498:Neurotoxins; D011500:Protein Synthesis Inhibitors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; C579158:S100b protein, rat; D018698:Glutamic Acid; D003513:Cycloheximide; D000242:Cyclic AMP