Insulin-like growth factor binding protein-1-6 expression in activated microglia.
In the CNS insulin-like growth factor-1 (IGF-1) enhances survival of neurons, promotes myelin synthesis and acts as a mitogen for microglia. The effects of IGF-1 are regulated by a family of 6 IGF binding proteins (IGFBPs). We investigated mRNA expression patterns of IGFBPs in primary rat microglia under basal conditions and after activation with lipopolysaccharide (LPS). Under basal conditions, microglia expressed IGFBP-2 to -6, whereas, IGFBP-1 could not be detected. Following 2 h treatment with LPS mRNA levels for IGFBP-4 and -6 displayed a down regulation, and IGFBP-5 became undetectable. Levels of IGFBP-2 and -3 remained unaltered. Expression patterns of IGFBPs might play an important role in regulating the autocrine/paracrine IGF-1 actions on microglia under inflammatory conditions.
Chesik
Daniel
D
Department of Neurology, University Hospital Groningen, Hanzeplein 1, 9700 RB Groningen, The Netherlands. d.chesik@med.rug.nl
Glazenburg
Koen
K
Wilczak
Nadine
N
Geeraedts
Felix
F
De Keyser
Jacques
J
D000818:Animals; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000096:biosynthesis / Q000235:genetics; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis / Q000235:genetics; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000096:biosynthesis / Q000235:genetics; D018974:Insulin-Like Growth Factor Binding Protein 4 / Q000096:biosynthesis / Q000235:genetics; D018975:Insulin-Like Growth Factor Binding Protein 5 / Q000096:biosynthesis / Q000235:genetics; D018976:Insulin-Like Growth Factor Binding Protein 6 / Q000096:biosynthesis / Q000235:genetics; D018969:Insulin-Like Growth Factor Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D017628:Microglia / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar
D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018972:Insulin-Like Growth Factor Binding Protein 3; D018974:Insulin-Like Growth Factor Binding Protein 4; D018975:Insulin-Like Growth Factor Binding Protein 5; D018976:Insulin-Like Growth Factor Binding Protein 6; D018969:Insulin-Like Growth Factor Binding Proteins; D008070:Lipopolysaccharides; D012333:RNA, Messenger