Objective To explore the expression pattern and possible role of hypoxia inducible factor-1α （ HIF-1α ） in fetal vertebrae development of mouse. Methods The developmental stages of mice fetal vertebrae were obser...Objective To explore the expression pattern and possible role of hypoxia inducible factor-1α （ HIF-1α ） in fetal vertebrae development of mouse. Methods The developmental stages of mice fetal vertebrae were observed from embryonic days 13. 5 to 18. 5 （ E13. 5 to E18. 5 ） by stereoscopic and light microscopes respectively, and the expressions of HIF-1α at various times were also detected at levels of mRNA and protein by using methods of RT-PCR and Western blotting. Distribution of HIF-1α in the vertebrae was examined by immunohistochemical assay. Vascular endothelia growth factor （VEGF） mRNA and other chondro-osteoblast marker genes as type II collagen al （ Coll2al ） and osteocalcin （OCN） were detected by RT-PCR too. Results The cartilaginous spine column began to form at E13. 5, followed by the arising of the primary ossification center in vertebrae at E15. 5, then the osteogenesis expanded and extended to both sides of the vertebrae. HIF-1α mRNA began to express at E13. 5, and showed significantly higher level at E14. 5 （ P 〈 O. 05 ）, then declined to a low level. VEGF mRNA expressed coincidently with HIF-1α. While HIF-1α protein expression was observed at E14. 5 and lasted at low level till to birth. The expression pattern of Coll2al and OCN elucidated the cell evolution from chondrocyte to osteoblast. Conclusion The developmental pattern of vertebrae appears to be an endochondral osteogenesis process. Existed hypoxia microenviroment in the vertebrae may increase HIF-1α mRNA and protein contents thus activate VEGF expression, as may be related to the activation of other downstream genes of hypoxia inducible factor-1α and initiate the cascade of endochondral osteogenesis.展开更多
Objective:: To investigate the effects of recombinant human basic fibroblast growth factor (rhbFGF) on the cell proliferation during mandibular fracture healing in rabbits. Methods: The complex of rhbFGF and bovine ty...Objective:: To investigate the effects of recombinant human basic fibroblast growth factor (rhbFGF) on the cell proliferation during mandibular fracture healing in rabbits. Methods: The complex of rhbFGF and bovine type I collagen was implanted into the mandibular fracture site under periosteum of the animal. The whole mandible was harvested at 7, 14, 28, 56 and 84 days respectively after operation. The expression of proliferating cell nuclear antigen (PCNA) in callus was examined with immunohistochemical staining. Results: PCNA-positive cells in callus in the rhbFGF-treated group on days 7 and 14 were more than that in the control group (P< 0.01 ). Conclusions: It indicates that rhbFGF can stimulate cell proliferation during mandibular fracture healing in rabbits.展开更多
Objective: To elucidate the effects of exogenous basic fibroblast growth factor ( bFGF ) on biological characteristics of rat osteoblasts cultured in vitro.Methods: The osteoblasts isolated from a Sprague-Dawley rat a...Objective: To elucidate the effects of exogenous basic fibroblast growth factor ( bFGF ) on biological characteristics of rat osteoblasts cultured in vitro.Methods: The osteoblasts isolated from a Sprague-Dawley rat and cultured in vitro were treated with different concentrations of bFGF (5-50 ng/ml) respectively. At 24 hours after treatment, the proliferating cell nuclear antigen was measured with immunocytochemistry, alkaline phosphatase ( ALP) activity was determined and the expression of transforming growth factor beta 1 (TGF-β1) was detected to observe the effects of bFGF on growth and differentiation of osteoblasts. Results: bFGF ( 5-50 ng/ml ) could obviously promote the growth of osteoblasts. The intracellular expression of TGF-β, mRNA increased significantly, but the intracellular ALP content decreased.Conclusions: bFGF can obviously stimulate the proliferation of osteoblasts and promote the synthesis of TGF-β1, but cannot promote the differentiation of osteoblasts.展开更多
Objective:Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques.The aim of this study is to ...Objective:Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques.The aim of this study is to investigate the effect of connective tissue growth factor(CTGF) on the proliferation and osteogenic differentiation of the bone marrow mesenchymal stem cells(MSCs).Methods:A CTGF-expressing plasmid(pCTGF) was constructed and transfected into MSCs.Then expressions of bone morphogenesis-related genes,proliferation rate,alkaline phosphatase activity,and mineralization were examined to evaluate the osteogenic potential of the CTGF gene-modified MSCs.Results:Overexpression of CTGF was confirmed in pCTGF-MSCs.pCTGF transfection significantly enhanced the proliferation rates of pCTGF-MSCs(P<0.05).CTGF induced a 7.5-fold increase in cell migration over control(P<0.05).pCTGF transfection enhanced the expression of bone matrix proteins,such as bone sialo-protein,osteocalcin,and collagen type I in MSCs.The levels of alkaline phosphatase(ALP) activities of pCTGF-MSCs at the 1st and 2nd weeks were 4.0-and 3.0-fold higher than those of MSCs cultured in OS-medium,significantly higher than those of mock-MSCs and normal control MSCs(P<0.05).Overexpression of CTGF in MSCs enhanced the capability to form mineralized nodules.Conclusion:Overexpression of CTGF could improve the osteogenic differentiation ability of MSCs,and the CTGF gene-modified MSCs are potential as novel cell resources of bone tissue engineering.展开更多
基金Supported by Anhui Provincial Natural Science Foundation (No. 070413097)the Special Funds for Major State Basic Research Project of Shanghai (No. 04DZ05606)
文摘Objective To explore the expression pattern and possible role of hypoxia inducible factor-1α （ HIF-1α ） in fetal vertebrae development of mouse. Methods The developmental stages of mice fetal vertebrae were observed from embryonic days 13. 5 to 18. 5 （ E13. 5 to E18. 5 ） by stereoscopic and light microscopes respectively, and the expressions of HIF-1α at various times were also detected at levels of mRNA and protein by using methods of RT-PCR and Western blotting. Distribution of HIF-1α in the vertebrae was examined by immunohistochemical assay. Vascular endothelia growth factor （VEGF） mRNA and other chondro-osteoblast marker genes as type II collagen al （ Coll2al ） and osteocalcin （OCN） were detected by RT-PCR too. Results The cartilaginous spine column began to form at E13. 5, followed by the arising of the primary ossification center in vertebrae at E15. 5, then the osteogenesis expanded and extended to both sides of the vertebrae. HIF-1α mRNA began to express at E13. 5, and showed significantly higher level at E14. 5 （ P 〈 O. 05 ）, then declined to a low level. VEGF mRNA expressed coincidently with HIF-1α. While HIF-1α protein expression was observed at E14. 5 and lasted at low level till to birth. The expression pattern of Coll2al and OCN elucidated the cell evolution from chondrocyte to osteoblast. Conclusion The developmental pattern of vertebrae appears to be an endochondral osteogenesis process. Existed hypoxia microenviroment in the vertebrae may increase HIF-1α mRNA and protein contents thus activate VEGF expression, as may be related to the activation of other downstream genes of hypoxia inducible factor-1α and initiate the cascade of endochondral osteogenesis.
文摘Objective:: To investigate the effects of recombinant human basic fibroblast growth factor (rhbFGF) on the cell proliferation during mandibular fracture healing in rabbits. Methods: The complex of rhbFGF and bovine type I collagen was implanted into the mandibular fracture site under periosteum of the animal. The whole mandible was harvested at 7, 14, 28, 56 and 84 days respectively after operation. The expression of proliferating cell nuclear antigen (PCNA) in callus was examined with immunohistochemical staining. Results: PCNA-positive cells in callus in the rhbFGF-treated group on days 7 and 14 were more than that in the control group (P< 0.01 ). Conclusions: It indicates that rhbFGF can stimulate cell proliferation during mandibular fracture healing in rabbits.
文摘Objective: To elucidate the effects of exogenous basic fibroblast growth factor ( bFGF ) on biological characteristics of rat osteoblasts cultured in vitro.Methods: The osteoblasts isolated from a Sprague-Dawley rat and cultured in vitro were treated with different concentrations of bFGF (5-50 ng/ml) respectively. At 24 hours after treatment, the proliferating cell nuclear antigen was measured with immunocytochemistry, alkaline phosphatase ( ALP) activity was determined and the expression of transforming growth factor beta 1 (TGF-β1) was detected to observe the effects of bFGF on growth and differentiation of osteoblasts. Results: bFGF ( 5-50 ng/ml ) could obviously promote the growth of osteoblasts. The intracellular expression of TGF-β, mRNA increased significantly, but the intracellular ALP content decreased.Conclusions: bFGF can obviously stimulate the proliferation of osteoblasts and promote the synthesis of TGF-β1, but cannot promote the differentiation of osteoblasts.
基金supported by the National Basic Research Program (973) of China(No.2005CB623900)
文摘Objective:Large segmental bone defect repair remains a clinical and scientific challenge with increasing interest focusing on combining gene transfection with tissue engineering techniques.The aim of this study is to investigate the effect of connective tissue growth factor(CTGF) on the proliferation and osteogenic differentiation of the bone marrow mesenchymal stem cells(MSCs).Methods:A CTGF-expressing plasmid(pCTGF) was constructed and transfected into MSCs.Then expressions of bone morphogenesis-related genes,proliferation rate,alkaline phosphatase activity,and mineralization were examined to evaluate the osteogenic potential of the CTGF gene-modified MSCs.Results:Overexpression of CTGF was confirmed in pCTGF-MSCs.pCTGF transfection significantly enhanced the proliferation rates of pCTGF-MSCs(P<0.05).CTGF induced a 7.5-fold increase in cell migration over control(P<0.05).pCTGF transfection enhanced the expression of bone matrix proteins,such as bone sialo-protein,osteocalcin,and collagen type I in MSCs.The levels of alkaline phosphatase(ALP) activities of pCTGF-MSCs at the 1st and 2nd weeks were 4.0-and 3.0-fold higher than those of MSCs cultured in OS-medium,significantly higher than those of mock-MSCs and normal control MSCs(P<0.05).Overexpression of CTGF in MSCs enhanced the capability to form mineralized nodules.Conclusion:Overexpression of CTGF could improve the osteogenic differentiation ability of MSCs,and the CTGF gene-modified MSCs are potential as novel cell resources of bone tissue engineering.
