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.
【摘要】 目的 通过比较两种原代人脐静脉内皮细胞的分离培养方法并对细胞特异性抗原进行鉴定,探索提高原代内皮细胞体外培养存活率及纯化率的方法。 方法 采用一次性无菌注射器向人脐静脉灌注消化液,消化液的浓度和消化时间分别025%(质量体积比)胰蛋白酶,10 min和01%(质量体积比)胶原酶Ⅱ,15 min。通过在倒置显微镜下观察细胞的形态特点和用免疫荧光染色的方法对细胞进行鉴定,比较两种消化方法的优劣。 结果 01%胶原酶Ⅱ,15 min的消化方法较025%胰蛋白酶,10 min对原代人脐静脉内皮细胞有更好的分离效果,活细胞数量多且细胞纯度较高。免疫荧光染色结果表明细胞内有Ⅷ因子相关抗原表达。结论 胶原酶Ⅱ可以有效分离脐静脉内皮细胞,最佳消化条件是01%胶原酶Ⅱ,37℃,15 min。【Abstract】 Objective To explore the optimal method for primary culture of human umbilical vein endothelial cells (HUVECs). Methods HUVECs were prepared from human umbilical cords by 01% collagenase Ⅱ digestion for 15 minutes and 025 trypsinase digestion for 10 minutes,respectively. HUVECs were observed under inverted microscope and identified by immunofluorescence.The two methods of digestion were compared. Results More HUVECs were harvested through the method of 01% collagenase Ⅱ for 15 minutes,which expressed Ⅷ related antigen. Conclusion The method of 0.1% collagenase Ⅱ digestion for 15 minutes is a better choice to isolate HUVECs.
In order to study the effect of vascular endothelial cell growth factor (VEGF) on the survival of skin flap 30 SD rats were used. A randomized flap measuring 7.5 cm x 3.0 cm was created on the back of each SD rat. The treatment group (n = 10) received VEGF 40 ng/flap by subcutaneous injection with microinjector during and 24 hours after operation. The control groups received heparin 16 U/flap (n = 10) or normal saline 800 microliters/flap (n = 10). After operation, on the 3rd and 11th day, the survival rate of the skin flaps and the dermovascular density of each flap were investigated by histological and histo-morphometrical examination. The results showed that there was no significant difference in the survival rate between the treatment group and the controls on the 3rd day after operation, while on the 11th day, there was a significant difference between them, and the survival rate was much higher in the treatment group. Besides, dermovascular density was much more increased in the treatment group than that in the controls, especially in the distal 1/3 of the flap (P lt; 0.02). The conclusion was that VEGF could .
Objective To investigate the role of vascular endothelial growth factor-C (VEGF-C) and its receptors in the formation of lymphatic vessels and lymphatic metastasis in gastric cancer. Methods By the domestic and overseas literatures review, the expressions of VEGF-C and its receptors in gastric cancer, their role in tumor lymphatic metastasis and prospect in treatment of gastric cancer were summarized.Results There was a significant correlation between VEGF-C and its receptors and the formation of lymphatic vessels and lymphatic metastasis in gastric cancer. VEGF-C high expression might be an early event in lymphatic metastasis and could be considered as an independent predictive factor of lymphaticmicrometastasis. By inhibition of gastric cancer cell from secrete VEGF-C or blockage of the interaction of VEGF-C with VEGFR3, it was possible to inhibit tumor angiogenesis and the invasion and distant spread of cancer cells, thereby decreased mortality and improve survival. ConclusionVEGF-C and its receptors may promote the formation of lymphatic vessels and lymphatic metastasis in gastric cancer. It may be an effective way to gastric cancer for the treatments against VEGF-C and its receptors.
ObjectiveTo explore the effect of Kaempferol on bone microvascular endothelial cells (BMECs) in glucocorticoid induced osteonecrosis of the femoral head (GIONFH) in vitro. MethodsBMECs were isolated from cancellous bone of femoral head or femoral neck donated voluntarily by patients with femoral neck fracture. BMECs were identified by von Willebrand factor and CD31 immunofluorescence staining and tube formation assay. The cell counting kit 8 (CCK-8) assay was used to screen the optimal concentration and the time point of dexamethasone (Dex) to inhibit the cell activity and the optimal concentration of Kaempferol to improve the inhibition of Dex. Then the BMECs were divided into 4 groups, namely, the cell group (group A), the cells treated with optimal concentration of Dex group (group B), the cells treated with optimal concentration of Dex+1 μmol/L Kaempferol group (group C), and the cells treated with optimal concentration of Dex+5 μmol/L Kaempferol group (group D). EdU assay, in vitro tube formation assay, TUNEL staining assay, Annexin Ⅴ/propidium iodide (PI) staining assay, Transwell migration assay, scratch healing assay, and Western blot assay were used to detect the effect of Kaempferol on the proliferation, tube formation, apoptosis, migration, and protein expression of BMECs treated with Dex. ResultsThe cultured cells were identified as BMECs. CCK-8 assay showed that the optimal concentration and the time point of Dex to inhibit cell activity was 300 μmol/L for 24 hours, and the optimal concentration of Kaempferol to improve the inhibitory activity of Dex was 1 μmol/L. EdU and tube formation assays showed that the cell proliferation rate, tube length, and number of branch points were significantly lower in groups B-D than in group A, and in groups B and D than in group C (P<0.05). TUNEL and Annexin V/PI staining assays showed that the rates of TUNEL positive cells and apoptotic cells were significantly higher in groups B-D than in group A, and in groups B and D than in group C (P<0.05). Scratch healing assay and Transwell migration assay showed that the scratch healing rate and the number of migration cells were significantly lower in groups B-D than in group A, and in groups B and D than in group C (P<0.05). Western blot assay demonstrated that the relative expressions of Cleaved Caspase-3 and Bax proteins were significantly higher in groups B-D than in group A, and in groups B and D than in group C (P<0.05); the relative expressions of matrix metalloproteinase 2, Cyclin D1, Cyclin E1, VEGFA, and Bcl2 proteins were significantly lower in groups B-D than in group A, and in groups B and D than in group C (P<0.05). Conclusion Kaempferol can alleviate the damage and dysfunction of BMECs in GIONFH.
After escaping from the hyperacute rejection (HAR), the xenograft has to be faced the challenge of acute vascular, acute cellular and even chronic rejection. Endothelial cells have been confirmed as a kind of antigen processing cell (APC) in allo-rejection. The porcine aortic endothelial cell (PAEC) expressed SLA-II and B7 which are the characteristics of professional APC. PAEC also has plenty of alpha-Gal residues, whether the antigen play any role in the post-HAR is still unknown. Human and porcine peripheral blood lymphocyte (PBLC) were isolated and divided into two parts, one for the effectors and the another were incubated with mitomycin C (MMC) as stimulators. The two kinds of PBLC were mixed-cultured within five days. Cultured PAEC from NJZ Pig was incubated with MMC and divided into two: One digested with alpha-galactosidase. The two kinds of PAEC were taken as stimulators to mixed-culture with human PBLC for five days. All the proliferation was detected with 3H-TdR intermingled in the system. The results showed that allo-MLR was ber than xeno-MLR in the cases. The proliferation was much ber when PAEC was used as the stimulator than that of porcine PBLC. However, the response was remarkably decreased after the digestion of alpha-Gal with alpha-galactosidase. The conclusion was that the low response of porcine-to-human MLR in vitro might be related to the predominant indirect pathway of antigen recognition in this system. While PAEC was used as the stimulator the proliferation in MLR was ber which might be concerned that PAEC itself was an APC as well as xeno-antigen sources, thus the direct pathway was predominant and worked more efficiently. The alpha-Gal might induce T cell proliferation through the linkage with the biological big molecules working as a complete antigen. The other post-HAR antigen might also exist in PAEC such as SLA-II, etc.
Objective To investigate the molecular signal mechanism of transform growth factor (TGF)-β induced arterial endothelial-mesenchymal transition. Methods Rat arterial endothelial cells were primarily cultured by ex-transplant method. The endothelial cells were incubated by combinant TGF-β (10 ng/mL) for 48 hours and then were detected by immunofluorescence staining and western blotting to observe the cell surface marker expression profile and Akt/mTOR signal activation. On the other hand, the endothelial cells were preincubated by Ly294002 (20 μmol/L) and rapamycin (10 nmol/L) to inhibit the Akt/mTOR signal, and then the cells were further treated with TGF-β (10 ng/mL) for 48 hours to observe the cell surface marker expression profile without Akt/mTOR signal activation. Results Rat artery endothelial cells by TGF-β after incubation, the expressions of smooth muscle cell markers α-smooth muscle actin (α-SMA) and smooth muscle-22α (SM-22α) were up-regulated, and the endothelial cell markers CD31 and vW factor were significantly down-regulated, at the same time, the expressions of phosphorylated Akt and mTOR were also up-regulated. However, after preincubation of Ly294002 (20 μmol/L) and rapamycin (10 nmol/L) to inhibit the phosphorylation of Akt and mTOR signal, above TGF-β-induced expressions of α-SMA and SM-22α in arterial endothelial cells were significantly suppressed and the expressions of CD31 and vWF were preserved. Conclusion TGF-β-induced arterial endothelial-mesenchymal transition is dependent on activation of Akt/mTOR signal, suggesting that Akt/mTOR-dependent arterial endothelial-mesenchymal transition would be one of the mechanisms for intima hyperplasia in transplant arteriosclerosis.
【Abstract】Objective To investigate the effects of human interlukin-13 (hIL-13) on the expression of E-selectin and intercellular adhesion molecule-1(ICAM-1) on bovine aortic endothelial cells(BAECs) stimulated by tumor necrosis factor alpha(TNF-α), and to provide experimental basis for hIL-13 inducing immunity endure and relieving the repulsion reaction of xenograft. Methods BAECs were co-cultured with different concentrations of hIL-13 for 2 h and followed by co-cultured with 4 ng/ml TNF-α for 6 h or 18 h. The expressions of E-selectin and ICAM-1 on BAECs were detected by Cell-ELISA. The effect of hIL-13 on activity of BAECs was detected by MTT colorimetry.Results BAECs pretreateded with hIL-13 could inhibit the expression of E-selectin and ICAM-1 induced by TNF-α, and showed a doesdependent manner from 5 ng/ml to 20 ng/ml of hIL-13 (P＜0.01). The experimental result of BAECs activity measured by MTT proved no significant difference in the activities of BAECs in every experimental groups compared with control group’s. Conclusion hIL-13 could inhibit the expression of E-selectin and ICAM-1 on BAECs induced by TNF-α, which may contribute to the xenotransplant immune tolerance.
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.
ObjectiveTo observe the effects of p21 activated kinase 4 (PAK4) on the mitochondrial function and biological behavior in retinal vascular endothelial cells. MethodsThe experimental study was divided into two parts: in vivo animal experiment and in vitro cell experiment. In vivo animal experiments: 12 healthy C57BL/6J male mice were randomly divided into normal control group and diabetes group, with 6 mice in each group. Diabetes mice were induced by streptozotocin to establish diabetes model. Eight weeks after modeling, quantitative real-time polymerase chain reaction and Western blots were performed to detect the expression of PAK4 in diabetic retinas. In vitro cell experiments: the human retinal microvascular endothelial cells (hRMEC) were divided into three groups: conventional cultured cells group (N group), empty vector transfected (Vector group); pcDNA-PAK4 eukaryotic expression plasmid transfected group (PAK4 group). WB and qPCR were used to detect transfection efficiency, while scratching assay, cell scratch test was used to detect cell migration in hRMEC of each group. In vitro white blood cell adhesion experiment combined with 4 ', 6-diamino-2-phenylindole staining was used to detect the number of white blood cells adhering to hRMEC in each group. The Seahorse XFe96 cell energy metabolism analyzer measures intracellular mitochondrial basal respiration, adenosine triphosphate (ATP) production, maximum respiration, and reserve respiration capacity. The t-test was used for comparison between the two groups. Single factor analysis of variance was used for comparison among the three groups. ResultsIn vivo animal experiments: compared with normal control group, the relative expression levels of PAK4 mRNA and protein in retina of diabetic mice were significantly increased, with statistical significance (t=25.372, 22.419, 25.372; P＜0.05). In vitro cell experiment: compared with the N group and Vector group, the PAK4 protein, mRNA relative expression and cell mobility in the hRMEC of PAK4 group were significantly increased, with statistical significance (F=36.821, 38.692, 29.421; P＜0.05). Flow cytometry showed that the adhesion number of leukocytes on hRMEC in PAK4 group was significantly increased, and the difference was statistically significant (F=39.649, P＜0.01). Mitochondrial pressure measurement results showed that the capacity of mitochondrial basic respiration, ATP production, maximum respiration and reserve respiration in hRMEC in PAK4 group was significantly decreased, with statistical significance (F=27.472, 22.315, 31.147, 27.472; P＜0.05). ConclusionOver-expression of PAK4 impairs mitochondrial function and significantly promotes leukocyte adhesion and migration in retinal vascular endothelial cells.