Résumé
PURPOSE: The development of a microvascularization is important for the homeostasis of normal bone. Vascular endothelial growth factor (VEGF) is one of the most important factors in vessel formation. The purpose of this study was to examine VEGF-related autocrine growth in periostealderived cells. MATERIALS AND METHODS: Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured for 21 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and beta-glycerophosphate. RESULTS: The expression of four VEGF isoforms and VEGFRs was observed in periosteal-derived cells. Treatment with cultures with VEGFR-1 and VEGFR-2 Kinase Inhibitor inhibited osteoblastic differentiation and alkaline phosphatase (ALP) activity of periosteal-derived cells. In addition, exogenous VEGF treatment increased calcium content in the periosteal-derived cells. CONCLUSION: These results suggest that VEGF might act as an autocrine growth molecule during osteoblastic differentiation of cultured human periosteal-derived cells.
Sujets)
Humains , Phosphatase alcaline , Acide ascorbique , Calcium , Techniques de culture cellulaire , Dexaméthasone , Durapatite , Glycosaminoglycanes , Homéostasie , Ostéoblastes , Périoste , Phosphotransferases , Isoformes de protéines , Facteur de croissance endothéliale vasculaire de type A , Récepteur-1 au facteur croissance endothéliale vasculaire , Récepteur-2 au facteur croissance endothéliale vasculaireRésumé
PURPOSE: The development of a microvascularization is important for the homeostasis of normal bone. Vascular endothelial growth factor (VEGF) is one of the most important factors in vessel formation. The purpose of this study was to examine VEGF-related autocrine growth in periostealderived cells. MATERIALS AND METHODS: Periosteal-derived cells were obtained from mandibular periosteums and introduced into the cell culture. After passage 3, the periosteal-derived cells were further cultured for 21 days in an osteogenic inductive culture medium containing dexamethasone, ascorbic acid, and beta-glycerophosphate. RESULTS: The expression of four VEGF isoforms and VEGFRs was observed in periosteal-derived cells. Treatment with cultures with VEGFR-1 and VEGFR-2 Kinase Inhibitor inhibited osteoblastic differentiation and alkaline phosphatase (ALP) activity of periosteal-derived cells. In addition, exogenous VEGF treatment increased calcium content in the periosteal-derived cells. CONCLUSION: These results suggest that VEGF might act as an autocrine growth molecule during osteoblastic differentiation of cultured human periosteal-derived cells.
Sujets)
Humains , Phosphatase alcaline , Acide ascorbique , Calcium , Techniques de culture cellulaire , Dexaméthasone , Durapatite , Glycosaminoglycanes , Homéostasie , Ostéoblastes , Périoste , Phosphotransferases , Isoformes de protéines , Facteur de croissance endothéliale vasculaire de type A , Récepteur-1 au facteur croissance endothéliale vasculaire , Récepteur-2 au facteur croissance endothéliale vasculaireRésumé
Sujets)
Humains , Acide ascorbique , Développement osseux , Moelle osseuse , Dexaméthasone , Durapatite , Fractures osseuses , Expression des gènes , Glycérophosphate , Neuropiline 1 , Ostéoblastes , Ostéocalcine , Ostéogenèse , Phénotype , Isoformes de protéines , Récepteurs aux facteurs de croissance endothéliale vasculaire , Cellules stromales , Facteur de croissance endothéliale vasculaire de type A , Récepteur-1 au facteur croissance endothéliale vasculaire , Récepteur-2 au facteur croissance endothéliale vasculaireRésumé
BACKGROUND: Distraction osteogenesis (DO) is a useful method for treating cases demanding the generation of new bone. During DO, the angiogenic activity is crucial factor in the new bone formation. The aim of this study was to detect the autocrine growth activity in the cellular components of the distracted bone with observation of the co-expression of vascular endothelial growth factor (VEGF) and its receptors following the mandibular DO. MATERIALS AND METHODS: Unilateral mandibular distraction (0.5 mm twice per day for 10 days) was performed in six mongrel dogs. Two animals were killed at 7, 14, and 28 days after completion of distraction, respectively. Immediately after the animals were killed, the right mandibles were harvested en block. Immunohistochemical staining was processed for observation of the VEGF expression, and double immunofluorescent staining was also processed for detection of the co-expression of osteocalcin and VEGF's two distinct receptors (VEGFR-1 and VEGFR-2). RESULTS: At 7 and 14 days after distraction, the expressions of VEGF were significantly increased in the osteogenic cells of the distracted bone. Up to 28 days after distraction, VEGF was still expressed moderate in the osteoblastic cells of distracted bone. The co-expressions of osteocalcin / VEGFR-1 and osteocalcin / VEGFR-2 were observed in the distracted bone at 7 and 14 days after distraction. In the double immunofluorescent staining, the co-expression's level of osteocalcin / VEGFR-1 was more than that of osteocalcin / VEGFR-2. Conclusion: Taken together, this study suggested that VEGF plays an important role in the osteogenesis, and these osteoblastic cell-derived VEGF might act as autocrine growth factor during distraction osteogenesis. In the other word, the cellular components, such as osteoblasts and immature fibroblast-like cellsor mesenchymal cells in the distracted bone, might have autocrine growth activity during distraction osteogenesis.
Sujets)
Animaux , Chiens , Mandibule , Ostéoblastes , Ostéocalcine , Ostéogenèse , Ostéogenèse par distraction , Facteur de croissance endothéliale vasculaire de type A , Récepteur-1 au facteur croissance endothéliale vasculaire , Récepteur-2 au facteur croissance endothéliale vasculaireRésumé