MRNA expression of members of the IGF system in the organ of Corti, the modiolus and the stria vascularis of newborn rats.
We analyzed the mRNA expression of the insulin-like growth factor (IGF) family genes and of selected downstream pathway genes using the Affymetrix microarray system and confirmatory RT-PCR in the freshly prepared organ of Corti (OC), modiolus (MOD) and stria vascularis (SV) from neonatal rats (3-5 days old) and after 24h in culture. Among the seven members of the IGF family analyzed in this paper, IGF1, IGF2 and IGF-binding protein (IGFBP2) had the highest basal expression in all regions. Preparatory stress and culture increased the expression of IGF2, IGFBP2, IGFBP3, IGFBP5, glucose transporterl (GLUT1), signal transducer, and activator of transcription3 (STAT3), phosphoinositide-3-kinase regulatory subunit (Pik3r1), Jun oncogene (c-jun) and decreased that of mitogen-activated protein kinases MAPK3 and MAPK14 in all regions. Region-specific changes were observed in OC (GLUT1), MOD (IGFBP3 and c-jun) and SV (IGF2 and IGFBP2).
Molecular Biology Research Laboratory, Department of Otorhinolaryngology, Charité-Universitätsmedizin Berlin, Berlin, Germany. johann.gross@charite.de
Johann
J
Gross
Astrid
A
Machulik
Renate
R
Moller
Julia
J
Fuchs
Nyamaa
N
Amarjargal
Ute
U
Ungethüm
Ralf-Jürgen
RJ
Kuban
Agnieszka J
AJ
Szczepek
Heidemarie
H
Haupt
Birgit
B
Mazurek
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D003051:Cochlea / Q000737:chemistry / Q000378:metabolism*; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics / Q000378:metabolism*; D009924:Organ Culture Techniques; D009925:Organ of Corti / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013316:Stria Vascularis / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors
D018969:Insulin-Like Growth Factor Binding Proteins; D012333:RNA, Messenger