Dexamethasone and Basic-Fibroblast Growth Factor Regulate Markers of Mineralization in Cementoblasts In Vitro
- Autores: Dr. Sema S. Hakki, Rahime M. Nohutcu, Erdogan E. Hakki, Janice E. Berry, Mahinur S. Akkaya, Martha J. Somerman
- Localización: Journal of periodontology, ISSN 0022-3492, Vol. 76, Nº. 9, 2005, págs. 1550-1558
- Idioma: inglés
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Resumen
Background: The aim of this study was to determine the effects of basic-fibroblast growth factor (b-FGF) and/or dexamethasone (Dex) on cementoblasts in vitro.
Methods: Murine cementoblasts were treated as follows: 1) 5% FBS (fetal bovine serum) + ascorbic acid (AA, 50 µg/ml, control); 2) 5% FBS+Dex (10–7M)+AA; 3) 5% FBS+b-FGF (50 ng/ml)+AA; or 4) 5% FBS+Dex (10–7 M)+b-FGF (50 ng/ml)+AA and then evaluated by Northern analysis for changes in specific genes and by von Kossa stain for changes in mineral nodule formation.
Results: Mitotic activity: b-FGF stimulated DNA synthesis significantly versus negative control. Gene expression: osteocalcin (OCN): Dex or b-FGF or the combination resulted in a decrease in expression versus control. Bone sialoprotein (BSP): Dex increased expression of BSP mRNA levels, b-FGF decreased transcript for BSP at 6 and 24 hours. Long-term (8 days) Dex, b-FGF, or Dex plus b-FGF caused a decrease in BSP expression versus control; osteopontin (OPN): both Dex and b-FGF increased transcripts for OPN seen by 6 hours, with a greater increase noted with b-FGF versus Dex. No apparent additive effect of Dex with b-FGF was noted; matrix gamma-carboxyglutamic acid protein (MGP): b-FGF induced transcripts for MGP and addition of Dex increased this effect, while Dex alone had no effect on expression. Biomineralization: Dex increased cementoblast- mediated biomineralization, while b-FGF blocked this activity, and addition of Dex to b-FGF did not alter FGF associated inhibition.
Conclusion: Dex and FGF alone and in combination alter cementoblast behavior, but additional studies are required to determine whether these factors have beneficial effects at the clinical level. J Periodontol 2005;76:1550-1558.
