We previously showed that the repair of bone defects is regulated by neural and vascular signals. In the present study, we examined the effect of topically applied β-nerve growth factor（β-NGF） on neurogenesis and ...We previously showed that the repair of bone defects is regulated by neural and vascular signals. In the present study, we examined the effect of topically applied β-nerve growth factor（β-NGF） on neurogenesis and angiogenesis in critical-sized bone defects filled with collagen bone substitute. We created two symmetrical defects, 2.5 mm in diameter, on either side of the parietal bone of the skull, and filled them with bone substitute. Subcutaneously implanted osmotic pumps were used to infuse 10 μgβ-NGF in PBS（β-NGF ＋ PBS） into the right-hand side defect, and PBS into the left（control） defect, over the 7 days following surgery. Immunohistochemical staining and hematoxylin-eosin staining were carried out at 3, 7, 14, 21 and 28 days postoperatively. On day 7, expression of β III-tubulin was lower on the β-NGF ＋ PBS side than on the control side, and that of neurofilament 160 was greater. On day 14, β III-tubulin and protein gene product 9.5 were greater on the β-NGF ＋ PBS side than on the control side. Vascular endothelial growth factor expression was greater on the experimental side than the control side at 7 days, and vascular endothelial growth factor receptor 2 expression was elevated on days 14 and 21, but lower than control levels on day 28. However, no difference in the number of blood vessels was observed between sides. Our results indicate that topical application of β-NGF promoted neurogenesis, and may modulate angiogenesis by promoting nerve regeneration in collagen bone substitute-filled defects.展开更多
The human immunodeficiency virus type 1 gag p20 gene fragment was clonedinto plasmid pBV220 to construct a recombinant expression plasmid pCY7.By induction,the p20 protein was expressed in E.coli,and it was confirmed ...The human immunodeficiency virus type 1 gag p20 gene fragment was clonedinto plasmid pBV220 to construct a recombinant expression plasmid pCY7.By induction,the p20 protein was expressed in E.coli,and it was confirmed by Western blotting thatthe expressed p20 protein could be specifically recognized by anti-p17 monoclonalantibodies.The recombinant bacteria was lysed and fractionated into snpernatant andprecipitate by centrifugation.It was found that the p20 protein was present chiefly inthe precipitate.After p20 protein being washed twice,its purity reached 27.4%.Then theprecipitate was washed with 1 mol/L urea solution and the purity of p20 protein wasraised to 58.1%.Finally,the precipitate was dissolved in 6mol/L of urea and appliedonto a heparin affinity column.Four peaks were obtained and the p20 protein wasfound mainly in peak 3.The purity of p20 protein at this step reached 84.2% as meas-ured by gel scanning.展开更多
基金supported by the Fujian Foundation for Distinguished Young Scientists in China,No.Grant#2060203the National Natural Science Foundation of China,No.31070838
文摘We previously showed that the repair of bone defects is regulated by neural and vascular signals. In the present study, we examined the effect of topically applied β-nerve growth factor（β-NGF） on neurogenesis and angiogenesis in critical-sized bone defects filled with collagen bone substitute. We created two symmetrical defects, 2.5 mm in diameter, on either side of the parietal bone of the skull, and filled them with bone substitute. Subcutaneously implanted osmotic pumps were used to infuse 10 μgβ-NGF in PBS（β-NGF ＋ PBS） into the right-hand side defect, and PBS into the left（control） defect, over the 7 days following surgery. Immunohistochemical staining and hematoxylin-eosin staining were carried out at 3, 7, 14, 21 and 28 days postoperatively. On day 7, expression of β III-tubulin was lower on the β-NGF ＋ PBS side than on the control side, and that of neurofilament 160 was greater. On day 14, β III-tubulin and protein gene product 9.5 were greater on the β-NGF ＋ PBS side than on the control side. Vascular endothelial growth factor expression was greater on the experimental side than the control side at 7 days, and vascular endothelial growth factor receptor 2 expression was elevated on days 14 and 21, but lower than control levels on day 28. However, no difference in the number of blood vessels was observed between sides. Our results indicate that topical application of β-NGF promoted neurogenesis, and may modulate angiogenesis by promoting nerve regeneration in collagen bone substitute-filled defects.
基金Supported by the National Science Foundation of China No.39100029
文摘The human immunodeficiency virus type 1 gag p20 gene fragment was clonedinto plasmid pBV220 to construct a recombinant expression plasmid pCY7.By induction,the p20 protein was expressed in E.coli,and it was confirmed by Western blotting thatthe expressed p20 protein could be specifically recognized by anti-p17 monoclonalantibodies.The recombinant bacteria was lysed and fractionated into snpernatant andprecipitate by centrifugation.It was found that the p20 protein was present chiefly inthe precipitate.After p20 protein being washed twice,its purity reached 27.4%.Then theprecipitate was washed with 1 mol/L urea solution and the purity of p20 protein wasraised to 58.1%.Finally,the precipitate was dissolved in 6mol/L of urea and appliedonto a heparin affinity column.Four peaks were obtained and the p20 protein wasfound mainly in peak 3.The purity of p20 protein at this step reached 84.2% as meas-ured by gel scanning.
