Regulation of NFIL-6 and IL-6 expression by basic fibroblast growth factor in osteoblasts.
We determined whether basic fibroblast growth factor (bFGF) regulated the expression of IL-6 and NFIL-6 in osteoblasts. In mouse osteoblastic MC3T3-E1 cells, bFGF (10(-8) M) increased NFIL-6 mRNA 2-fold at 30 minutes and 3-fold at 2 h. IL-6 mRNA was increased by bFGF 10(-8) M after 1 h. IL-6 protein was detectable in control cultures but was significantly increased by bFGF (10(-8) M) at 4 h. Immunofluorescence analysis of MC3T3-E1 cells showed primarily cytoplasmic and perinuclear NFIL-6 staining in control cultures while bFGF-treated cells showed increased NFIL-6 staining at 2 and 4 h. Western blotting revealed that bFGF increased NFIL-6 protein at 2 h. In calvarial mouse osteoblasts, bFGF 10(-8) M induced IL-6 mRNA as early as 1 h and significantly increased IL-6 protein levels as early as 2 h. In conclusion, bFGF stimulates IL-6 and NFIL-6 mRNA in osteoblasts. The increase in NFIL-6 mRNA was associated with increased NFIL-6 protein. The increase in IL-6 mRNA was also associated with increased IL-6 protein. We propose that activations of NFIL-6 and IL-6 may be important mediators of the effects of bFGF on bone cells.
Hurley
M M
MM
Department of Medicine, University of Connecticut Health Center, Farmington, USA.
Abreu
C
C
Marcello
K
K
Kawaguchi
H
H
Lorenzo
J
J
Kalinowski
J
J
Ray
A
A
Gronowicz
G
G
D000818:Animals; D015153:Blotting, Western; D022762:CCAAT-Enhancer-Binding Proteins; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D010006:Osteoblasts / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis / Q000187:drug effects; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D015850:Interleukin-6; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D016222:Fibroblast Growth Factor 2; D003513:Cycloheximide