Gao W.-k.,The Fourth Hospital of Chinese PLA |
Wang D.-y.,The Fourth Hospital of Chinese PLA |
Li Z.-g.,The Fourth Hospital of Chinese PLA |
Yan Z.-q.,The Fourth Hospital of Chinese PLA |
And 2 more authors.
Journal of Clinical Rehabilitative Tissue Engineering Research | Year: 2011
BACKGROUND: Hypoxia influences bone metabolism by many means and exhibits negative effects on bone generation and bone healing. OBJECTIVE: To explore the effects of hypoxia on proliferation and differentiation of rat osteoblasts and investigate the underlying mechanisms. METHODS: Primary rat osteoblasts were isolated from excised calvarial bones of neonatal mice and cultured in vitro. The second passage of osteoblasts were cultured under hypoxic (3% O2) and normoxic (20% O2) conditions. RESULTS AND CONCLUSION: The proliferation levels, alkaline phosphatase activities, osteocalcin contents and the number ofcalcium nodules in the hypoxic group were significantly lower compared with the normoxic group (P < 0.05 or P < 0.01). It means that hypoxia inhibits the proliferation, differentiation and functions of rat osteoblasts. The mRNA expression of bone morphogenetic protein-2 and Runx2 in osteoblasts cultured in 3% O2 was lower than that cultured in 20% O2 (P < 0.05 or P < 0.01). It means that the mRNA expression of Runx2 and bone morphogenetic protein-2 was decreased in hypoxic conditions. These findings suggest that hypoxia can I nhibit the proliferation and differentiation of rat osteoblasts through inhibiting Runx2 and BMP-2 mRNA expression in vitro.