KERATINOCYTE GROWTH-FACTOR MESSENGER-RNA EXPRESSION IN PERIODONTAL-LIGAMENT FIBROBLASTS

Keratinocyte growth factor (KGF) is a fibroblast growth factor-which m ediates epithelial growth and differentiation. KGF is expressed in sub epithelial fibroblasts, but generally not in fibroblasts of deep conne ctive tissue, such as fascia and ligaments. Here we demonstrate that K GF mRNA is expressed in periodontal ligament fibroblasts, and that the expression is increased upon serum stimulation. Fibroblasts from huma n periodontal ligament, from buccal mucosa, from gingiva, and from ski n were established from explants. Alkaline phosphatase activity was us ed as an indicator of the periodontal nature of fibroblasts. Cells wer e first cultured in DMEM with 0.5% fetal calf serum (FCS) and then inc ubated for 8 h, and 72 h in fresh DMEM with 10% FCS. Total RNA was iso lated and used for Northern blotting with a P-32-labeled KGF cDNA prob e. Total RNA from cultured keratinocytes was used as negative controls . KGF mRNA was found in all cultured fibroblasts. Upon addition of 10% FCS to the cell cultures, an increase in KGF mRNA levels was noticed especially after 72 h. Furthermore, RT-PCR analysis of material scrape d from the tooth root surface indicated the presence of KGF mRNA even in noncultured periodontal ligament cells.