Objective To observe the influences of estradiol (E2), basic fibroblast growth factor (bFGF), and tamoxifen (TAM) on the proliferation of hemangioma vascular endothelial cell (HVEC). Methods Two strawberry hemangioma from 2 infants (case 1 and case 2) were prepared for HVEC culture. The HVEC on passage 3 were cultured in estrogenfree improved minimum essential medium (IMEM) and subjected to various treatments with 100 pg/ml 17-β-E2, 10 ng/ml bFGF, and 1×10-6 mol/L 4-OH-tamoxifen(4-OH-TAM). The experiment was divided into 5 groups: group 1(IMEM, control group), group 2(17-β-E2), group 3(bFGF), group 4(17-β-E2／bGFG) and group 5(17-β-E2／bGFG／4-OH-TAM). The cell count(CC) and DNA proliferation index (PI) were determined. Results Two cases of HVEC were successfully cultured in vitro. The HVEC showed cobblestoneslike under microscopy and factor Ⅷrelated antigen(also named as von Willebrand factor，vWF) was positive by immunochemical staining. At 9 days in case 1: CC and PI remained unchanged in the control group; CC and PI were slightly increased in group 2, being 1.4 and 1.6 times as much as those in the control group respectively (P＜0.05); CC and PI significantly increased in group 3, being2.6 and 2.3 times as much as those in the control group respectively (P＜0.01); CC and PI increased remarkably in group 4, being 3.7 and 2.9 times as much as those in thecontrol group respectively (P＜0.01); CC and PI were down to the levels of controls in group 5(P＞0.05). The results in case 2 were similar to those in case 1. Conclusion In vitro, the promoting effect of bFGF on HVEC proliferation is much ber than that of estrogen. Estrogen and bFGF enhance this proliferation in a synergistic manner, which can be inhibited by tamoxifen.
Objective To study the biological behavior of osteoblast and vascular endothelial cell culture. Methods The osteoblasts and vascular endothelial cells were obtained from calvarial bone and renal cortox of 2-week rabbits respectively. The experiment were divided into group A (osteoblasts), group B (vascular endothelial cells) and group C(co-cultured osteoblasts and vascular endothelial cells). The cells were identified with cytoimmunochemical staining. The cellular biological behavior and compatibilitywere observed under inverted phase contrast microscope and with histological staining. The cells viability and alkaline phosphatase(ALP) activity were measured. Results The cytoimmunochemical staining showed that the cultured cells were osteoblasts and vascular endothelial cells .The cellular compatibility of osteoblasts and vascular endothelial cells was good. The ALP activity was higher in group C than in group A and group B(P＜0.01), and it was higher in group A than in group B(P＜0.05). In group C, the cellproliferation were increased slowly early, but fast later. Conclusion Thecellular compatibility of osteoblasts and vascular endothelial cells were good. The vascular endothelial cells can significantly increased the osteoblast viability and ALP activity,and the combined cultured cells have greater proliferation ability.
Objective To establish a simple and efficient method to isolate and culture the umbilical vein vascular endothelial cells in canine. Methods Twelve umbilical cords [(13.0 ± 1.5) cm in length] were taken from 12 newborn pups of Beagles. And then the vascular endothelial cells were isolated from these umbilical cords digested by 1% collagenase type I for 5, 7, and 10 minutes respectively (4 umbilical cords in each group). After cultured, the vascular endothelial cells were identified by morphology, immunofluorescence, and flow cytometry. And the growth curvature of umbilical vein vascular endothelial cells was detected by MTT assay. Results Few vascular endothelial cells were collected at 5 and 10 minutes after digestion; many vascular endothelial cells were seen at 7 minutes, and became cobblestone with culture time, with a large nucleus; after passage, cell morphology had no obvious change. Fluorescence microscope results showed that positive von Willebrand factor (vWF) and CD31 cells were observed in most of cells. The flow cytometry test displayed that the positive cell rates of vWF and CD31 were 99.0% ± 0.7% and 98.0% ± 1.2%, respectively. The above results indicated that cultured cells were vascular endothelial cells. MTT assay showed that vascular endothelial cells proliferation increased significantly with culture time. Conclusion Enzyme digestion is a convenient method to isolate vascular endothelial cells from canine umbilical vein, and a large number of cells and high purity of cells can be obtained by the method.
Objective To develop a new method for a tissue engineered vascular graft by combining endothelial cells and an acelluarized allogenic matrix. Methods Acellularized matrix tubes were obtained by a 0.1% trypsin and 0 02% EDTA solution for 24 hours and 1% Triton X 100 for 176 hours, respectively. Endothelial cells were isolated from alloaorta and expanded in vitro. Finally, the inner surface of acellularized matrix was reseeded with endothelial cells. Acellularity and reseeding were analysed by light microscopy and scanning electron microscopy. Results The acellularization procedure resulted in an almost complete removal of the original cells and the loose three-dimensional (3D) matrix. The acellular matrix could be reseeded with expanded endothelial cells in vitro, and endothelial cells had the potential of spread and proliferation. Conclusion Acellular matrix produces by Tritoon X-100 and trypsin possesses satisfactory biocompatibility for allogenic endothelial cell. Vascular grafts can be generated in vitro by a combination of endothelial cells and allogenic acelluarized matrix.
Objective To compare the effects of flap delay and vascular endothelial growth factor (VEGF) on the viability of the rat dorsal flap. Methods Thirty rats were divided into 3 groups: saline group, flap delay group and VEGF group. The rats in flap delay group underwent flap delay by keeping bipedicle untouched, and the cranial pedicle was cut 7 days later. The rats in VEGF group were given VEGF solution locally when the flaps were elevated in the operation. The ratsin saline group were given saline solution in the same way. Five days after thesingle pedicle flaps were performed, the flap survival rate was measured. Theflap tissues were collected to measure and analyze the microvascular density, diameter and sectional area by immunochemical method. Results The flap survival rate of flap delay group was similar to that of VEGF group andthere is no statistically significant difference(Pgt;0.05). The vascular diameter of flap delay group was much larger than that of saline group and VEGF group, showing statistically significant difference (Plt;0.05). The vascular density of VEGF group was much higher than that of saline group and flap delay group, showing statistically significant difference (Plt;0.05). The vascular sectional area of flap delay group was similar to that of VEGF group(Pgt;0.05). Conclusion The change in the flap after flap delayis manifested as obvious dilatation of microvessels, while the change in the flap after the injection of VEGF is manifested as obvious vascular proliferation. Both flap delay and VEGF can increase the vascular sectional area and the viability of the flap, but the mechanism is different.
Objective To investigate the expression of transcription factors including nuclear factor-κB （NF-κB） and activator protein-1 （AP-1） in vascular endothelial cells （ECs） in different flow fields， and provide experimental evidence for mechanical signal effects on gene regulation pattern of ECs. Methods Cultured human umbilical vein ECs were loaded into steady flow chambers of laminar flow or turbulent flow and observed at 6 time points （0.5 h， 1 h， 2 h， 3 h， 4 h and 5 h） based on different load time. Spacial and temporal characteristics of NF-κB and AP-1 expression in ECs in different flow chambers were detected at a protein level by laser confocal microscope. Results In laminar flow， NF-κB expression rose to peak at 1 hour （26.49±1.63， P＜0.05）and then declined. In turbulent flow， NF-κB expression rose to peak at 3 hours （34.41±6.43， P＜0.05）. In laminar flow， c-Jun/AP-1 expression was transiently elevated， reached its peak at 0.5 hour （18.95±5.38，P＜0.05）and then fell to its baseline level. In turbulent flow， c-Jun/AP-1 expression rose slowly but steady to peak（P＜0.05） . Conclusion The effects of turbulent flow on NF-κB and AP-1 expression in ECs are different from those of laminar flow. Up-regulation and activation of NF-κB and AP-1 expression in ECs induced by turbulent flow may cause pathological changes in morphological structure and functional behavior of ECs.
Objective To study the differenation of adult marrow mesenchymal stem cells(MSCs) into vascular endothelial cells in vitro and to explore inducing conditions. Methods MSCs were isolated from adult marrow mononuclear cells by attaching growth. MSCs were divided into 4 groups to induce: the cells seeded at a density of 5×103/cm2 in 2% and 15% FCS LDMEM respectively (group1 and group 2)， at a density of 5×104/cm2 in 2% and 15% FCS LDMEM respectively (group 3 and group 4); vascular endothelial growth factor(VEGF) supplemented with Bovine pituitary extract was used to induce the cell differentiation. The differentiated cells were identified by measuring surfacemarks (CD34, VEGFR2, CD31 and vWF ) on the 14th day and 21st day and performed angiogenesis in vitroon the 21st day.The cell proliferation index（PI）of different inducing conditions were measured. Results After induced in VEGF supplemented with Bovine pituitary extract, the cells of group 3 expressed the surface marks CD34, VEGFR-2, CD31 and vWF on the 14th day, the positive rates were 8.5%, 12.0%, 40.0% and 30.0% respectively, and on the 21st day the positive ratesof CD34 and VEGFR2 increased to 15.5％ and 20.0％, while the other groups did not express these marks; the induced cells of group 3 showed low proliferating state(PI was 10.4%) and formed capillary-like structure in semisolid medium. Conclusion Adult MSCs can differentiate into vascular endothelial cellsafter induced by VEGF and Bovine pituitary extract at high cell densities and low proliferatingconditions，suggesting that adult MSCs will be ideal seed cells forthe therapeutic neovascularization and tissue engineering.
Objective To study the effect of vascular endothelial cell growth factor (VEGF) on repair of bone defect with cortical bone allograft. Methods Forty five New Zealand white rabbits, weighted 2.5-3.0 kg, were made bone defect model of 1.5 cm in length in the bilateral radii and then were randomly divided into 3groups. The defect was repaired with only cortical bone allograft in the control group, with the cortical bone allograft and local injection of human recombinantVEGF in the experimental group, and with the cortical bone allograft and abdominal injection of VEGF PAb3 in the antagonist group. Roentgenography, immunohistochemical staining and tetracycline labelling were carried out to evaluate the reparative results 1, 3, 5, 8 and 16 weeks after operation. Results Immunohistochemical staining results showed that a great deal of blood vessels formed in the experimental group, and the number of blood vessels increased gradually with the time and reached the highest value at the 8th week. Tetracyclinelabelling showed the same result.The best results in callus formation, ossification rate and count of microvascular density were shown in the experimental group, while those in the control group were significantly better than those in the antagonist group (Plt;0.05),but there was no significant difference between the experimental group and the control group at the 8th week and the 16th week (Pgt;0.05). Conclusion VEGF can accelerates the bone formation and angiogenesis in the bone allografts, thus it can promote the repair of bone defects.
ObjectiveTo investigate the role of protease-activated receptor-2 (PAR-2) activation on the expression of vascular endothelial growth factor (VEGF) in MKN28 gastric cancer cells. Methods①MKN28 cells were treated with increased concentrations of trypsin (0, 0.1, 1.0, 10.0, and 100.0 nmol/L respectively) for 6 hours, or treated with 10.0 nmol/L trypsin for 3, 6, 12, and 24 hours (blank control group was treated with PBS) respectively, then the expression levels of VEGF mRNA and its protein in MKN28 cells were detected by real-time reverse transcription polymerase chain reaction (qRT-PCR) and Western bolt method, with the concentration of VEGF protein in broth was detected by enzyme linked immunosorbent assay (ELISA) method.②MKN28 cells were divided into blank control group (treated with PBS), trypsin group, trypsin+PD98059 group, trypsin+SB203580 group, PD98059 group, and SB203580 group, then the expression levels of VEGF mRNA and its protein in MKN28 cells were detected by qRT-PCR method and Western bolt method respectively. Results①The effect of different concentration of trypsin. Compared with blank control group, the expression levels of VEGF mRNA and its protein in 0.1, 1.0, 10.0, and 100.0 nmol/L group were higher (P < 0.05); compared with 0.1 nmol/L group, the expression levels of VEGF mRNA and its protein in 1.0, 10.0, and 100.0 nmol/L group were higher (P < 0.05); compared with 1.0 nmol/L group, the expression levels of VEGF mRNA and its protein in 10.0 and 100.0 nmol/L group were higher (P < 0.05); but there was no significant difference between 10.0 nmol/L and 100.0 nmol/L group (P > 0.05). The broth concentration of VEGF protein in blank control group, 0.1, 1.0, 10.0, and 100.0 nmol/L group crept upward (P < 0.05).②The effect of different treated time of 10.0 nmol/L trypsin. The expression levels of VEGF mRNA in blank control group, 3, 6, 12, and 24 hours group crept upward, and there was significant difference between any 2 groups (P < 0.05). But the expression of VEGF protein was not similar with VEGF mRNA. Compared with blank control group, the expression levels of VEGF protein in 3, 6, 12, and 24 hours group were higher (P < 0.05); compared with 3 hours group, the expression levels of VEGF protein in 6, 12, and 24 hours group were higher (P < 0.05); but there was no significant difference among 6, 12, and 24 hours group (P > 0.05). The broth concentration of VEGF protein in blank control group, 3, 6, 12, and 24 hours group crept upward, and there was significant difference between any 2 groups (P < 0.05).③The effect of extracellular regulated protein kinase (ERK) inhibitor (PD98059) and p38 inhibitor (SB203580). The expression levels of VEGF mRNA and its protein in trypsin group were all higher than corresponding indexes of blank control group, trypsin+PD98059 group, trypsin+SB203580 group, PD98059 group, and SB203580 group (P < 0.01), but there was no significant difference among blank control group, trypsin+PD98059 group, trypsin+SB203580 group, PD98059 group, and SB203580 group (P > 0.05). ConclusionActivation of PAR-2 can induce the expressions of VEGF mRNA and its protein in MKN28 gastric cancer cells, that is mediated by ERK1/2-and p38-dependent pathway.
OBJECTIVE: To prepare the compound biodegradable matrices, polyglycolic acid (PGA), polylactic acid (PLA) mesh and poly-beta-hydroxybutyrate(PHB) which precoated with collagen, and to observe the growth and differentiation of bovine vascular endothelial cells on these scaffolds. METHODS: By enzymatic digestion methods, bovine vascular endothelial cell (VEC) were isolated from calf thoracic aorta, then cultured and purified. PGA, PLA, PHB meshes were dipped into cross-linked type I collagen solution, dried under vacuum frozen condition. VEC were seeded into these scaffolds. The growth of VEC on scaffolds was analyzed by MTT method. RESULTS: The collagen, PGA/collagen, PLA/collagen scaffolds were elasticity and tenacity. VEC grew better on collagen, PGA/collagen, and PLA/collagen membranes than on the PHB/collagen one. CONCLUSION: The PGA/collagen scaffold has elasticity, plasticity and tenacity. VEC grow best on it. It is an ideal scaffold for tissue engineered vessel reconstruction for it integrating both advantages of biomaterials and degradable materials.