Effects of vascular endothelial growth factor and danshen on osteoblastic cell activities

Abstract

AIM: The search for an ideal bone grafting material remains a challenge in modern surgery. Sufficient bone support is essential for effective orthodontic tooth movement. Osteogenesis and angiogenesis are closely correlated. This study aimed to investigate the effects of vascular endothelial growth factor (VEGF) and the medicinal herb, Danshen, on osteoblastic cell activities. MATERIALS AND METHOD: An osteoblastic cell line, MC3T3-E1, was cultured in vitro with or without VEGF and Danshen. The cells in both control and test groups were collected at different culture time points of 24, 48 and 72 hours. Real-time polymerase chain reaction was carried out to quantify the expression of VEGF, alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OCN), osteoprotegerin (OPG) and the receptor activator of nuclear factor kappa B ligand (RANKL) at the mRNA level. RESULTS: The expression of VEGF was down-regulated by extrinsic VEGF (P < 0.05), while upregulated by extrinsic Danshen (P < 0.05). The expression of ALP was upregulated by both VEGF and Danshen (P < 0.05), but Danshen showed a more continuous effect. Both VEGF and Danshen upregulated the expression of OPN and OCN (P < 0.05), but the effect of Danshen appeared earlier than that of VEGF. Both VEGF and Danshen regulated the expression of OPG, while only Danshen regulated the expression of RANKL. CONCLUSION: Danshen enhances expression of VEGF in osteoblastic cells, but VEGF shows negative feedback of autoregulation. Both VEGF and Danshen promote bone remodelling by direct effects on osteoblastic cells via regulating gene expression of ALP, OPN, OCN and OPG. Supported by Seed Funding Programme for Basic Research HKU 200803159006.