• Journal of Chest Surgery
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• v.30 no.6
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• pp.553-558
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• 1997

Arterial allografts have known advantages over prosthetic vascular conduit for treatment of heart valvular disease, congenital heart disease and aortic disease. Cell viability may play a role in determining the longterm outcome of allografts. Endothelial cell is one important part in determining the allograft viability. To evaluate the viability of endothelial cells using current allograft preservation technique, porcine heart valve leaflets and arterial wall were subjected to collagenase digestion. Single endothelial cell suspension was labeled with GSA-PITC(Griffonia simplicifolia agglutininfluorescein isothiocyan te), a vascular, endothelial cell specific marker. The cell suspension was washed and incubated with Pl(Propidium iodide), which does not bind with viable cells, Endothelial cell viability was evaluated by calculating the percentage of GSA-FITC(+) and Pl(-) group using flowcytometric analysis. Allografts were treated with $4^{\circ}C$ antibiotic solo!ion for 24 hours for sterilization. After this, half of allografts were stored in $4^{\circ}C$ RPMI 1640 with HEPES buffer culture medium with 10% fetal bovine serum for 1 to 14 days(Group I). Another half of allografts were cryopreserved with a currently used technique (Group II). During the procurement and sterilization of arterial allografts, 22.8% and 24.4% of endothelial cell viability declined, respectively. In Group I, 11.9% of endothelial cell viability declined further steadily during 14 days of storage. In Group II, 13.7% of endothelial cell viability declined. These results show that largest loss of endothelial cell viability occurs during the nitial process. After 14 days of arterial allograft storage under $4^{\circ}C$ nutrient medium or cryopreservation, about 40% of endothelial cell viability is maintained. There were no differences between the endothelial cell viability from aortic valve leaflet, pulmonic valve leaflets, aortic wall and pulmonic wall.

• Journal of Yeungnam Medical Science
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• v.27 no.2
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• pp.91-97
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• 2010

Endothelial cells play a key role in pathological processes such as cancer cell metastasis, atherosclerosis, and diabetic retinopathy. Vascular smooth muscle cells directly involve in the formation of atheroma in atherosclerosis. Some kinds of the endothelial cells are simply harvested from the umbilical veins, the tunica intima of aortic walls, the retina using various enzymes solutions. Those purely isolated cells provide a powerful tool in vitro studies of the endothelial cell related diseases. In this context, the cultured smooth muscle cells after the isolation from the tunica media of aortic walls are also used for elucidating the pathogenesis of atherosclerosis. Here, I briefly introduce articles that include the isolation of human umbilical vein endothelial cells(HUVEC), aortic endothelial and smooth muscle cells, retinal microvascular endothelial cells(RMEC), as well as the diseases' applications of these cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.117-128
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• 2006

Free flap transplantation with microvascular anastomosis has been successfully performed by development of surgical technique, materials and postoperative monitoring equipments of flap. But success rate of microvascular anastomosis is influenced by various factors, and failure rate is about 5-10%. The most influential factor for success rate is surgical technique and other factors that influence failure of microvascular anastomosis are ischemic time of free flap, thrombus formation of anastomosis region and vascular spasm. Many studies has been published in microvascular anastomosis with histologic effect for irrigating solution. But local irrigation solution has been used clinically in microvascular anastomosis, the comparison with each solution, microhistological study for endothelial cell repair and vascular patency has not been reported. The heparin which is anti-thrombotic agent, and urokinase which is fibrinolytic agent are used for this study. Vascular patency and thrombus formation in experimental micro-arterial anastomosis, and endothelial repair were observed with histologic analysis, scanning electron microscopy, transmission electron microscopic examination. The results were obtained as follows: 1. In vascular patency test in 30 minute and 7 days after micro-arterial anastomosis, equal effects of good vascular patency were obtained in group of local irrigation with heparin and urokinase. 2. In thrombus formation in 7 days after micro-arterial anastomosis, equal effects of minimal thrombus formation were obtained in group of local irrigation with heparin and urokinase. 3. In toluidin blue staining in 7 days after micro-arterial anastomosis, local destruction of endothelial cell and inner elastic lamina were seen and endothelial repair was not seen. 4. In scanning electron microscope examination in 7 days after micro-arterial anastomosis, endothelial cell was not seen in peripheral to suture materials, thrombus associated fibrin network was observed. 5. In transmission electron microscope examination in 7 days after micro-arterial anastomosis, inflammatory cell was seen within smooth muscle cells in site of endothelial cell destruction, smooth muscle cell around suture material were arranged irregularly, some collagenous change were seen. From the results obtained in this study, same results of good vascular patency and anti-thrombotic effect of heparin and urokinase were obtained as a local irrigation solution, and repair of endothelial cell was not seen in 7 days after micro-arterial anastomosis.

• Journal of Nutrition and Health
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• v.31 no.8
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• pp.1235-1243
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• 1998

Although an elevated plasma level of high density lipoprotein (HDL) is known as a protective component against the development of atherosclerosis and ensuing coronary heart diseases, the related mechanisms are still not established . It has been clearly demonstrated in the early stages of atherogenesis that adhesion of monocytes and lymphocytes to the vascular endothelium is enhanced via adhesion molecules, and that monocytes and macrophages accumulate in the subendothelial space. The present study has investigated whether isolated plasma HDL plays a role in protection against atherogenesis by inhibiting the expression of vascular cell adhesioin molecule-1(VCAM-1) on the endothelial cells. Effects of plasma native low density lipoprotein (LDL) and ac ethylated LDL(AcLDL) on VCAM-1 expression were also examined by using an immunocytochemical technique. While plasma HDL did not alter the basal expression of VCAM-1 , lipopolysaccharide(LPS) induction of this adhesion modlecule was markedly inhibited at a phyaiological concentration of HDL. In contrast, 30$\mu\textrm{g}$ protein/ml AcLDL increased sifnificantly both basal VCAM-1 expression and its LPD induction , suggesting that this modified LDL enhances leukocyte adhesiion to endothelial cells. Unlike AcLDL , plasma native LDL inhibited significantly VCAM-1 expression. This indicates that LDL did not undergo oxidative modificantion while incubated with endothelial cells. These results suggest that plasam HDL may inhibit atherogenesis by reducing the expression of adhesion molecules, which is a protective mechanism independent of tis reverse cholesterol transport function . Modified LDL is a potent iducer for adhesion molecules in vascular endothelical cells and could play a role in the pathogenesis of atherosclerosis by adhering to blood cells.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.474-480
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• 2018

Most angiogenesis assays are performed using endothelial cells. However, blood vessels are composed of two cell types: endothelial cells and pericytes. Thus, co-culture of two vascular cells should be employed to evaluate angiogenic properties. Here, we developed an in vitro 3-dimensional angiogenesis assay system using spheroids formed by two human vascular precursors: endothelial colony forming cells (ECFCs) and mesenchymal stem cells (MSCs). ECFCs, MSCs, or ECFCs+MSCs were cultured to form spheroids. Sprout formation from each spheroid was observed for 24 h by real-time cell recorder. Sprout number and length were higher in ECFC+MSC spheroids than ECFC-only spheroids. No sprouts were observed in MSC-only spheroids. Sprout formation by ECFC spheroids was increased by treatment with vascular endothelial growth factor (VEGF) or combination of VEGF and fibroblast growth factor-2 (FGF-2). Interestingly, there was no further increase in sprout formation by ECFC+MSC spheroids in response to VEGF or VEGF+FGF-2, suggesting that MSCs stimulate sprout formation by ECFCs. Immuno-fluorescent labeling technique revealed that MSCs surrounded ECFC-mediated sprout structures. We tested vatalanib, VEGF inhibitor, using ECFC and ECFC+MSC spheroids. Vatalanib significantly inhibited sprout formation in both spheroids. Of note, the $IC_{50}$ of vatalanib in ECFC+MSC spheroids at 24 h was $4.0{\pm}0.40{\mu}M$, which are more correlated with the data of previous animal studies when compared with ECFC spheroids ($0.2{\pm}0.03{\mu}M$). These results suggest that ECFC+MSC spheroids generate physiologically relevant sprout structures composed of two types of vascular cells, and will be an effective pre-clinical in vitro assay model to evaluate pro- or anti-angiogenic property.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.4
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• pp.980-984
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• 2006

In order to examine the effect of oxygen free radicals on the vascular endothelial cells, cell viability was measured by XTT assay after bovine pulmonary vascular endothelial cell line(BPVEC) was treated only with hydrogen peroxide. In addition, the antioxidant effect of allopurinol on cells treated with hydrogen peroxide was examined by colormetric assay. in this study, the BPVEC treated with hydrogen peroxide showed the significantly decreased cell viability compared with control. Whereas, the viability of cells treated with hydrogen peroxide and allopurinol has significantly increased when compared with that of cells treated only with hydrogen peroxide. These results suggested that hydrogen peroxide, one of the oxygen free radicals showed cytotoxic effect and allopurinol has protective effect on oxygen free radical-induced cytotoxicity.

• Journal of Biomedical Engineering Research
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• v.17 no.2
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• pp.255-262
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• 1996

Antithrombogenic surFace is one of the most important things to the artificial vascular prostheses. This problem will be solved if the surface of prosthesis is covered with endothelial cells. The attachment and the growth of endothelial cells onto vascular prosthesis are very difficult. So many studies have been concentrated on the attachement of endothelial cell. But no good performance of the in uiwo experiments has been shown until now. In this study, we used the whole extracellular matrix (ECM) excreted from fibroblasts as an underlying matrix, and the endothelial cells were seeded to obtain the long term patency of vascular graft(i.e., for the patent 8 week implanted wafts in the animal model of rat). In order to study the antithrombogenic functions of cultured endothelial cells, prostaglandin(PGF 1 a) synthesis and platelet adhesion were assayed. The concentration of PGF a of stimulated group was sisnificantly higher than that of control group(21.97 $\pm$ 3.45 vs 4.93 $\pm$0.71 pg/1000 cells). The platelet adhesion of the polyurethane sheet covered with endothelial cells was lower than that of polyurethane sheet or sheet covered with ECM(1.04$\pm$0.28, 2.87$\pm$0.77, 2.89$\pm$0.70, % radioactivities, respectively). Endothelial cells grew well on polyurethane coated with ECM, synthesized the prostacyclin and functioned well as antithrombogenic. Therefore the endothelialization onto the ECM excreted from fibroblasts may be a good method for the vfudig prosthesis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.10a
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• pp.645-646
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• 2009

• Animal Bioscience
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• v.34 no.4
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• pp.533-538
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• 2021

Objective: Pluripotent stem cell-derived lymphatic endothelial cells (LECs) show great promise in their therapeutic application in the field of regenerative medicine related to lymphatic vessels. We tested the approach of forced differentiation of mouse embryonal stem cells into LECs using biodegradable poly lactic-co-glycolic acid (PLGA) nanospheres in conjugation with growth factors (vascular endothelial growth factors [VEGF-A and VEGF-C]). Methods: We evaluated the practical use of heparin-conjugated PLGA nanoparticles (molecular weight ~15,000) in conjugation with VEGF-A/C, embryoid body (EB) formation, and LEC differentiation using immunofluorescence staining followed by quantification and quantitative real-time polymerase chain reaction analysis. Results: We showed that formation and differentiation of EB with VEGF-A/C-conjugated PLGA nanospheres, compared to direct supplementation of VEGF-A/C to the EB differentiation media, greatly improved yield of LYVE1(+) LECs. Our analyses revealed that the enhanced potential of LEC differentiation using VEGF-A/C-conjugated PLGA nanospheres was mediated by elevation of expression of the genes that are important for lymphatic vessel formation. Conclusion: Together, we not only established an improved protocol for LEC differentiation using PLGA nanospheres but also provided a platform technology for the mechanistic study of LEC development in mammals.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.149-154
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• 2008

Porphyromonas gingivalis, a major periodontal pathogen, has been implicated in the initiation and progression of periodontal disease. Endothelial dysfunction (Editor note: Aberrant and dysfunction are somewhat redundant. The authors may want to choose one or the other.) contributes to chronic periodontal inflammation. Using cDNA-representational difference analysis, we found that P.gingivalis lipopolysaccharide differentially induces a number of genes in human microvascular endothelial cells. Among these upregulated genes, we focused on intercellular adhesion molecule-1 (VCAM-1), which is crucial for leukocyte recruitment during vascular inflammation. P. gingivalis LPS significantly increased the expression of vascular cell adhesion molecule-1 (VCAM-1) as well as ICAM-1. Promoter assays revealed that the transcription of these cell adhesion molecules was mainly regulated by nuclear factor-${\kappa}B$ (NF-${\kappa}B$) in endothelial cells. Furthermore, P. gingivalis LPS significantly increased leukocyte adhesiveness to microvascular endothelial cells and to aortic endothelium. Taken together, our results demonstrate that P. gingivalis LPS activates microvascular endothelial cells through NF-${\kappa}B$-dependent expression of cell adhesion molecules.