Evidence for up-regulation of epidermal growth-factor receptors on rat periodontal ligament fibroblastic cells associated with stabilization of phenotype in vitro

A cell line with characteristics of the periodontal ligament fibroblasts is negatively regulated for mineralization and Runx2/Cbfa1/Osf2 activity, part of which can be overcome by bone morphogenetic protein-2

“…1, clearly demonstrate that the established cell line PDL-L2 shares identical expression of the genes examined. Furthermore, PDL-L2 expressed the EGFR genes (data not shown), which have previously been shown to be present in the PDL (Matsuda et al, 1993;Cho and Garant, 1996). Since Runx2/Cbfa1/Osf2 is a transcription factor that is specifically expressed and functions in osteogenic cells, western blot analysis was also performed to examine whether or not this protein is produced in PDL-L2 cells.…”

Expression and role of epidermal growth factor receptors during differentiation of cementoblasts, osteoblasts, and periodontal ligament fibroblasts in the rat

“…These observations indicate that EGF is able to decrease spontaneous ALP activity as well as Dex-induced activity of the enzyme, suggesting the role of EGF-R may be to act as negative regulator of PDL fibroblast differentiation into mineralized tissue-forming cells (Matsuda et al, 1993).…”

“…To determine whether the decreased EGF binding capacity of Dex-treated PDL cells was due to decreased EGF-R synthesis, newly synthesized EGF-R protein' was immunoprecipitated after metabolic labeling with 35S-methionine, separated by SDS-PAGE, and exposed to XAR film (Matsuda et al, 1993). Radioautography of the gel containing the immunoprecipitated EGF-R protein from untreated PDL cells revealed a major band at a 170 kDa position with high intensity but a much less intense band in the Dex-treated cells (Fig.…”

“…Because ALP activity has been measured as a marker for early differentiation of mineralized tissueforming cells, we monitored ALP activity as a function of PDL fibroblastic cell differentiation (Matsuda et al, 1993) according to the procedures of Lowry et al (1954). Confluent PDL cells were cultured for 2,4, and 7 days in DMEM supplemented with 10% FBS, ascorbic acid (50 pg), and P-glycerophosphate (10 mM).…”

“…The binding capacity of EGF to Dex-treated PDL fibroblastic cells, untreated PDL fibroblastic cells, and rat osteosarcoma cells (ROD 17/2.8) was compared by an lZ5I-EGF binding assay according to the procedures of Carpenter (1985) with some modification (Matsuda et al, 1993). Semiconfluent (80-90%) cells cultured in 24-multiwell dishes were treated for 2 days with or without Dex.…”