Regulation of NFIL-6 and IL-6 expression by basic fibroblast growth factor in osteoblasts

Open Access
Publisher Website
Google Scholar
Abstract
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.
Funding Information
  • Department of Veterans Affairs Merit Review Program. (AR42368, AR42362)