牛bFGF-pcDNA3在人脐静脉内皮细胞中的表达及鉴定

目的:研究牛bFGF-pcDNA₃在体外培养人脐静脉内皮细胞中的表达与活性,及对该细胞生物学特性的影响。方法:脂质体法将bFGF-pcDNA₃真核表达载体转染体外培养的人脐静脉内皮细胞,经G418筛选阳性克隆。通过免疫细胞化学法检测bFGF的表达部位及Ⅷ因子相关抗原的表达。应用化学发光Westernblotting法检测bFGF在转染细胞与未转染细胞中的表达。绘制细胞的生长曲线并计算倍增时间,采用MTT法对bFGF的生物活性进行估计。结果:bFGF-pcDNA₃转染人脐静脉内皮细胞后,细胞呈梭形者增多。免疫细胞化学证实转染前后细胞均为血管内皮来源细胞,转染与未转染细胞均在胞浆内表达bFGF。Westernblotting证实细胞转染前后均表达17kDbFGF,但转染后表达量增高,细胞生长曲线上移,倍增时间缩短。MTT法证实转染细胞产生的bFGF其生物学活性约相当于持续添加外源性bFGF5714ng/L。结论:转染bFGFcDNA的人脐静脉内皮细胞能在体外增殖,并具有表达与分泌活性bFGF的功能。bFGF-pcDNA₃可引起内源性bFGF表达增高,对血管内皮细胞产生相应的生物学活性。     

Cytokine-mediated induction of endothelial adhesion molecule and histocompatibility leukocyte antigen expression by cytomegalovirus-activated T cells.

Cytomegalovirus (CMV) has been associated with allograft rejection and transplantation-associated arteriosclerosis. CMV infects endothelium, the interface between allograft tissue and the host immune system; however, mechanisms by which such interaction might exacerbate the rejection process remain unresolved. Here we test the hypothesis that host immune activity, triggered by CMV-infected graft endothelial cells (ECs), can result in the production of cytokines capable of enhancing the alloimmunogenicity of nearby uninfected endothelia. To model these phenomena in vitro, confluent monolayers of ECs derived from human umbilical vein or adult gonadal vein were incubated 5 days beneath trans-well culture inserts containing CMV-seropositive or CMV-seronegative donor-derived CD3+ or CD4+ T cells alone or in combination with CMV-infected or uninfected allogeneic ECs. The extent of T cell proliferation was determined by [3H]thymidine labeling of trans-well contents after transfer to microtiter plates. Endothelial responses to soluble factors elaborated by CMV-activated T cells were determined by immunohistochemical staining and immunofluorescence flow cytometric analysis of underlying EC monolayers. Results of experiments with CMV-seropositive donor-derived CD4+ T cells demonstrated enhancement of ICAM-1 and histocompatibility leukocyte antigen class I, as well as induction of histocompatibility leukocyte antigen DR on ECs incubated beneath T cell/EC/CMV trans-well co-cultures. Total (CD3+) T cells co-cultured with EC/CMV induced VCAM-1 as well. Furthermore, [3H]thymidine incorporation by these T cells indicated a strong proliferative response. Endothelial responses to T cells alone or in combination with uninfected ECs were minimal, and T cells cultured under these conditions showed little proliferative activity. Similarly, little or no endothelial responses were apparent in monolayers beneath trans-wells containing T cells isolated from CMV-seronegative individuals regardless of the CMV status of stimulator ECs. Finally, experiments employing blocking antibodies identified interferon-gamma and tumor necrosis factor-alpha as inducing agents in this co-culture system. These findings suggest that allograft endothelium harboring CMV has the potential to activate host T cells and that the consequent release of cytokines shows potential to raise surrounding endothelia to a fully activated, highly immunogenic state. Results of these studies thus provide insight into mechanisms that help elucidate the association between CMV and transplantation-associated arteriosclerosis and/or allograft rejection.     

Inhibitory effects of nicotinamide on recombinant human interferon-gamma-induced intercellular adhesion molecule-1 (ICAM-1) and HLA-DR antigen expression on cultured human endothelial cells.

Intercellular adhesion molecule-1 (ICAM-1), HLA-A, B, C and HLA-DR antigen on endothelial cells (EC) play important roles in the development of inflammatory processes in autoimmune disorders. In the present study, we investigated the effect of nicotinamide, an inhibitor of poly(ADP ribose) synthetase, on interferon-gamma (IFN gamma)-induced ICAM-1 and HLA-DR antigen expression on the surface of cultured human umbilical vein endothelial cells, assessed by flow cytometry, and EC proliferation by counting cell numbers and [3H]thymidine incorporation assays. Nicotinamide dose-dependently inhibited the IFN-gamma-induced ICAM-1 and HLA-DR antigen expression, but not HLA-A, B, C antigen expression on cultured EC. Furthermore, nicotinamide significantly inhibited endothelial cell proliferation, as assessed by [3H]thymidine incorporation assay. Our findings suggest that nicotinamide may suppress mononuclear cell infiltration, antigen presentation and angiogenesis in the lesions of autoimmune disorders by reducing both IFN gamma-induced ICAM-1 and HLA-DR antigen expression on EC, and EC proliferation. Therefore, nicotinamide can be used for the treatment and prevention of the development of autoimmune disorders.     

The expression of E-selectin and chemokines in the cultured human lymphatic endothelium with lipopolysaccharides

This study investigated the expression of selectins and chemokines in cultured human lymphatic endothelial cells stimulated with lipopolysaccharides. In microarray, vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 gene expressions in the lymphatic endothelium with lipopolysaccharides did not change at 0.5 h but increased two- to three-fold at 12 h, whereas E-selectin increased 10-fold at 0.5 h and 68-fold at 12 h compared with untreated cells. The E-selectin mRNA and protein increased in the lymphatic endothelial cells with lipopolysaccharides at more than two-fold levels compared with human umbilical vein endothelial cells. Induction of Cys-Cys chemokine ligand 2, 3, 5, 7, 8 and 20 mRNAs in the lymphatic endothelial cells with lipopolysaccharides was detected in microarray and real-time PCR. The Cys-Cys chemokine ligand 2, 5 and 20 mRNA amounts in cells with high concentration lipopolysaccharides were larger in the lymphatic endothelial cells than in human umbilical vein endothelial cells. The Cys-Cys chemokine ligand 3 and 8 mRNAs were not detected in human umbilical vein endothelial cells. Induction of Cys-X-Cys chemokine ligand 1, 3, 5, 6 and 8 mRNAs was detected in the lymphatic endothelial cells with lipopolysaccharides. The Cys-X-Cys chemokine ligand 3, 5 and 8 mRNA amounts in cells with high concentration lipopolysaccharides were larger in the lymphatic endothelial cells than in human umbilical vein endothelial cells. In conclusion, it was demonstrated that the cultured human lymphatic endothelial cells express E-selectin and phagocyte-attractive chemokine genes.     

Expression of leukocyte adhesion molecules by endothelial cells seeded on various polymer surfaces

Although endothelial cell seeding in small-diameter vascular prostheses significantly improves graft survival, the detachment of adherent endothelial cells after the restoration of circulation remains one of the major obstacles. Because in vivo experiments indicate that leukocyte infiltration is involved in endothelial cell loss, we hypothesize that seeded endothelial cells become activated and express leukocyte adhesion molecules and cytokines because of an interaction with the underlying polymer surface. The aim of this study was to investigate the expression of the leukocyte adhesion molecules ICAM-1, VCAM-1, PECAM-1, and E-selectin by cultured human umbilical vein endothelial cells (HUVECs) and human adipose microvascular endothelial cells (HAMVECs). The cells were seeded on tissue culture poly(styrene) and the vascular graft materials Dacron and Teflon. The results of this study indicate that the expression of leukocyte adhesion molecules by cultured endothelial cells is mainly affected by the endothelial cell origin, that is, umbilical vein or adipose tissue. Expressions of both ICAM-1 and E-selectin by HUVECs and HAMVECs are characterized by the presence of two cell populations with distinct levels of expression. With respect to endothelial cell seeding in vascular prostheses, the increased expression of E-selectin by microvascular endothelial cells deserves further attention.     

Chemokines, chemokine receptors and adhesion molecules on different human endothelia: discriminating the tissue-specific functions that affect leucocyte migration

The selective accumulation of different leucocyte populations during inflammation is regulated by adhesion molecules and chemokines expressed by vascular endothelium. This study examined how chemokine production and the expression of adhesion molecules and chemokine receptors vary between endothelia from different vascular beds. Human saphenous vein endothelium was compared with lung and dermal microvascular endothelia and with umbilical vein endothelium and a bone-marrow endothelial cell line. All endothelia produced CCL2 and CXCL8 constitutively, whereas CXCL10 and CCL5 were only secreted after tumour necrosis factor (TNF)-alpha or interferon (IFN)-gamma stimulation. In combination with TNF-alpha, IFN-gamma suppressed CXCL8 but enhanced CCL5 and CXCL10, whereas transforming growth factor (TGF)-beta reduced secretion of all chemokines. Basal chemokine secretion was higher from umbilical vein than other endothelial cells. Chemokine receptors, CXCR1, CXCR3 and CCR3, were present on all endothelia but highest on saphenous vein. CCR4, CCR5, CCR6, CXCR2, CXCR4 and CXCR5 were also detected at variable levels on different endothelia. The variation between endothelia in chemokine secretion was much greater than the variations in adhesion molecules, both on resting cells and following cytokine stimulation. These results indicate that it is the tissue-specific variations in endothelial chemokine secretion rather than variations in adhesion molecules that can explain the different patterns of inflammation and leucocyte traffic seen in non-lymphoid tissues.     

Effect of cytokines on the expression of cell adhesion molecule and on the adhesion of melanoma cells to endothelial cells.

We examined the role of cell adhesion molecules (CAM) by which tumor cells bind to the endothelial cells using human umbilical vein endothelial cells (HUVEC) and cultured melanoma cells. Endothelial cells from human umbilical veins were isolated and examined for CAM expression and its modulation by tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-6 (IL-6) or interferon-gamma (IFN-gamma). The expression of intercellular adhesion molecule 1 (ICAM-1) on HUVEC was increased by TNF-alpha, IL-1 and IFN-gamma when measured by ELISA or flow cytometric (FACS) analysis. IL-6 did not increase ICAM-1 expression on HUVEC. Two melanoma cell lines, Malme-3M and SK-Mel-28, showed increased expression of ICAM-1 after treatment with TNF-alpha, IL-1 and IFN-gamma in FACS analysis. IFN-gamma induced increased expression of HLA-DR only in SK-Mel-28 melanoma cells, not in Malme-3M melanoma cells. Neither HUVEC nor melanoma cells expressed lymphocyte function-associated antigen 1 (LFA-1) in either the basal (i.e., cytokine untreated) condition or the cytokine treated condition. Melanoma cells showed minimal increment in adhesion to TNF-alpha or IL-1 treated HUVEC than to cytokine untreated HUVEC. HUVEC and melanoma cells did not express LFA-1 and increased ICAM-1 expression by TNF-alpha, IL-1 and IFN-gamma treatment in FACS analysis did not coincide with minimal increase of melanoma cells adhesion to cytokine treated HUVEC. These results suggest that adhesion between melanoma cells and HUVEC is probably mediated by molecular interaction other than ICAM-1/LFA-1.     

Expression patterns of leukocyte adhesion ligand molecules on human liver endothelia. Lack of ELAM-1 and CD62 inducibility on sinusoidal endothelia and distinct distribution of VCAM-1, ICAM-1, ICAM-2, and LFA-3.

Vascular expressed adhesion molecules mediate leukocyte reactivity and activation by receptor-ligand binding. A number of different ligand molecules have been identified to mediate the interaction between endothelial cells and leukocyte subpopulations. In this study, the tissue expression of ELAM-1, CD62 (PADGEM, GMP-140), VACM-1 (INCAM-110), ICAM-2, ICAM-1, and LFA-3 was analyzed on various liver endothelial cell types by immunohistology. The results reveal a differential expression of these molecules in normal liver and inflammation or rejection after liver transplantation. The selectins ELAM-1 and CD62 are basally expressed and inducible on portal tract endothelia (arterial and venous) and central vein endothelia with acute and chronic liver inflammation. Sinusoidal endothelia, however, lack this mechanism, even with severe inflammation, as in cases of irreversible rejection and sepsis. Portal and sinusoidal endothelia show a different expression and inducibility of VCAM-1, ICAM-1, ICAM-2, and LFA-3. The differences in expression of adhesion molecules on liver endothelial cell types may reflect their ability to regulate leukocyte trafficking and activation by means of the expression of specific ligand molecules. The inability of sinusoidal endothelia to express selectins may have implications for the pathophysiology of liver graft infiltration.     

Interferon-gamma stimulates the expression of galectin-9 in cultured human endothelial cells

Galectin-9 is a member of the galectin family and has been identified as an eosinophil chemoattractant produced by activated T lymphocytes. Vascular endothelial cells play an important role in the initial step of eosinophil recruitment and activation in immune and inflammatory responses. We have addressed the stimulation of galectin-9 expression in endothelial cells. Galectin-9 was detected in membrane and cytosolic fractions of human umbilical vein endothelial cells stimulated with interferon-gamma (IFN-gamma). IFN-gamma also enhanced the adhesion of human eosinophilic leukemia-1 cells to endothelial monolayers, and it was inhibited by the presence of lactose. Interleukin-4, which induces eotaxin expression, did not affect the expression of galectin-9. The in situ endothelium from patients with inflammatory diseases was found to express galectin-9. IFN-gamma-induced production of galectin-9 by endothelial cells may play an important role in immune responses by regulating interactions between the vascular wall and eosinophils.     

Expression of the CD40 antigen on normal endothelial cells and in benign and malignant tumours of vascular origin

CD40, a member of the nerve growth factor/tumour necrosis factor-receptor family, is expressed on endothelial cells in situ and in tissue culture. It is functionally involved in the regulation of the expression of adhesion molecules in these cells. In the current study we investigated the expression of CD40 on the endothelia of normal fetal and adult human tissues, as well as in the stroma of various neoplasms and in different inflammatory tissue reactions. By immunohistochemistry, endothelia were negative or only weakly positive for CD40 in all normal adult and most fetal organs studied. In contrast, endothelial cells of fetal and embryonic lungs, kidneys and larger vessels consistently expressed the CD40 antigen. Strong expression of CD40 on endothelial cells of blood vessels but not of lymphatic vessels was found in inflammatory reactions. In 65 tumours of vascular origin we found moderate to strong expression of CD40 in all of four juvenile proliferating capillary haemangiomas and 11 lobular capillary haemangiomas of adults. Senile and cavernous haemangiomas as well as lymphangiomas were negative or exhibited only weak CD40 reactivity. Weak to moderate CD40 expression was found in five of eight malignant neoplasms of endothelial origin. Our finding that the CD40 antigen is present on only a minority of normal endothelial cells, whereas strong staining can be detected on the majority of endothelial cells in inflammatory processes, complements previous reports which suggest that this surface receptor plays an important role in tissue inflammation. The heterogeneous pattern of expression in malignant endothelial neoplasms argues against a major role for CD40 in the pathogenesis of these tumours. Its consistent presence in juvenile and lobular capillary haemangiomas suggests rather the involvement of CD40 in the development and/or progression of these benign vascular proliferations.     

4A11, a monoclonal antibody recognizing a novel antigen expressed on aberrant vascular endothelium. Upregulation in an in vivo model of contact dermatitis.

We describe the production and characterization of a novel monoclonal antibody (MAb) that recognizes a human endothelial cell antigen expressed mainly in inflamed and malignant disease states. We have used immunohistochemistry to determine the spectrum of reactivity of this MAb compared with that of a MAb to factor VIII-related antigen (MAb FVIII). MAb 4A11 does not react with several myeloid or lymphoid cell lines or with peripheral blood cells. Unlike MAb FVIII, MAb 4A11 does not react with platelets. MAb 4A11 reacts with most vascular endothelial cells in lymphoid tissue but with few (< 10%) endothelial cells in thymus, spleen, liver, lung, adrenal gland, placenta, testes, and skin. MAb 4A11 detects endothelial cells in diseased tissues such as rheumatoid and osteoarthritic synovium and psoriatic skin. Vascular endothelial cells in both adrenal tumors and cutaneous Kaposi's sarcomas lesions are MAb 4A11 reactive. In vitro the 4A11 antigen is not detectable on cultured human umbilical vein endothelial cells and its expression is not induced on these cells by treatment with lipopolysaccharide, interferon-gamma, interleukin-1 and -6, or tumor necrosis factor-alpha. However, in an in vivo model of allergic contact dermatitis the 4A11 antigen is upregulated differentially from other endothelial markers such as E-selectin, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1. In this dermal model of inflammation, poison ivy extract is applied to the skin and biopsies taken at 0, 6, and 24 hours. In addition to focal keratinocyte expression, 4A11 antigen is found on 11% of dermal endothelial cells at time 0 and antigen expression increases with time until 24 hours, when 4A11 antigen is present on 63% of the endothelial cells. Using thin layer chromatography, MAb 4A11 reacts with the H-5-2 [Fuc alpha 2Gal beta 4GlcNAc beta 3Gal beta 4Glc beta 1Cer] and Lewis(y)-6 [Fuc alpha 2Gal beta 4(Fuc alpha 3)GlcNAc beta 3Gal beta 4-Glc beta 1Cer] blood group glycolipids. The presence of the novel 4A11 antigen in inflamed and malignant tissues containing many blood vessels and its differential upregulation in allergic contact dermatitis may signify an important function for this antigen in the inflammatory process.     

Shiga toxin-associated hemolytic uremic syndrome: effect of sodium butyrate on sensitivity of human umbilical vein endothelial cells to Shiga toxin.

Escherichia coli O157:H7-related vascular damage such as hemolytic uremic syndrome is believed to require the Shiga-like toxins. This study demonstrated that sodium butyrate sensitized human umbilical vein endothelial cells to Shiga toxin and increased the expression of Shiga toxin receptor, globotriaosylceramide (Gb3), on human umbilical vein endothelial cells.     

重组人促红细胞生成素对人脐静脉内皮细胞PCNA表达的影响

目的研究重组人促红细胞生成素（rHuEPO）对人脐静脉内皮细胞（HUVEC）增殖的影响。方法从脐静脉体外分离培养HUVEC，采用细胞培养及免疫组织化学方法检测不同剂量rHuEP0（10U／ml、20U／ml、40U／m1）对HUVEC增殖细胞核抗原（PCNA）表达的影响。结果对组照及10U／ml、20U／ml、40U／mlrHuEP0实验组内皮细胞PCNA阳性表达百分率分别为（31±3）％、（40±5）％、（68±6）％和（65±5）％，与对照组相比，rHuEPO作用后内皮细胞PCNA表达明显增强（P〈0．05），且随rHuEPO剂量提高作用增强，呈剂量效应关系。结论rHuEP0可促进体外培养内皮细胞增殖。     

siRNA沉默FOXO3a对三氧化二砷抑制内皮细胞增殖的影响

背景：课题组前期已证实As2O3可以促进乳腺癌细胞中FOXO3a因子的表达,并抑制肿瘤细胞中血管内皮生长因子的表达,但As2O3对血管内皮细胞增殖的影响,以及对血管内皮细胞中FOXO3a、血管内皮生长因子的影响尚未证实。 目的：观察siRNA沉默FOXO3a对As2O3抑制人脐静脉内皮细胞增殖及血管生成的影响。 方法：实验分为4组：①As2O3组：待人脐静脉内皮细胞贴壁,在含4 μmol/L As2O3的RPMI-1640培养基中培养。②control siRNA组：转染无关序列control siRNA后,细胞在含4 μmol/L As2O3的RPMI-1640培养基中培养。③FOXO3a siRNA组：转染FOXO3a siRNA后,细胞在含4 μmol/L As2O3的 RPMI-1640培养基中培养。④对照组：与实验药物等体积PBS作为对照,细胞在完全培养基条件下培养。应用CCK-8方法检测细胞增殖情况,采用免疫细胞化学方法观察人脐静脉内皮细胞中FOXO3a、血管内皮生长因子蛋白的表达情况。 结果与结论：与对照组相比,FOXO3a siRNA明显减弱了As2O3抑制人脐静脉内皮细胞增殖的作用,As2O3促进人脐静脉内皮细胞中FOXO3a蛋白的表达并抑制血管内皮生长因子蛋白的表达,FOXO3a siRNA处理后明显抑制FOXO3a蛋白表达且增加血管内皮生长因子蛋白表达。结果提示FOXO3a可能成为As2O3抑制肿瘤细胞增殖及血管生成治疗的重要靶点。     

CD40-CD40L共同表达于人内皮细胞及人动脉粥样斑块中

目的:探讨CD40和CD40L在人脐静脉内皮细胞及动脉粥样硬化斑块中是否可共同表达。方法:CD40及CD40L在内皮细胞表面的表达分别采用荧光技术、RT-PCR、流式细胞仪和Western blotting检测。人的动脉粥样硬化斑块中CD40及CD40L的表达采用免疫组化方法。结果:人内皮细胞能连续表达CD40及CD40LmRNA和蛋白, 并且细胞因子IL-1β、IL-6、TNF-α、INF-γ能明显刺激内皮细胞表达CD40、CD40L。人动脉粥样斑块中能共同表达CD40及CD40L, 而动脉壁的其它部分不表达。CD40L主要表达在斑块的肩部和底部, CD40在斑块中表达广泛。结论:人内皮细胞表面及粥样斑块中能共同高表达CD40和CD40L, 提示CD40及CD40L相互作用在动脉粥样硬化形成及发展中起重要作用。     

Endothelial heterogeneity and the acquired immunodeficiency syndrome: a paradigm for the pathogenesis of vascular disorders

Summary Vascular disorders comprise a wide range of diverse disease entities. Correspondingly, vessels, and even more so the endothelia which line them, show a remarkable extent of heterogeneous differentiation, e.g. between the blood vascular and lymphatic systems, along the length of the vascular trees, and in the microvascular beds of various organs. The most important morphologic criterion to discriminate between endothelia is continuity (continuous endothelial cell layer and well-formed basement membrane) versus discontinuity (intra- or intercellular gaps and/or reduced or missing basement membrane). Most blood vascular endothelia are of the continuous type, while most sinusoidal and lymphatic endothelia are discontinuous by these criteria. Antigen expression corroborates these morphologic data in that CD31, CD34, and 11710 antigen are exclusively expressed in continuous endothelia, while MS-1 antigen is preferentially expressed in non-continuous sinusoidal endothelia. In contrast, no specific marker has as yet been described for lymphatic endothelia. Endothelial heterogeneity substantially contributes to the pathogenesis of vascular disorders. For example, in patients with acquired immunodeficiency syndrome the same infectious agent may cause either bacillary angiomatosis (a lobular capillary proliferation) or peliosis (sinusoidal dilatation, endothelial denudation, and development of blood-filled cysts) depending on whether the affected organs have predominantly continuous endothelia or noncontinuous sinusoidal endothelia. Moreover, in Kaposi's sarcoma, it is still an open question of whether the lesion is derived from blood vascular or lymphatic endothelia (Kaposi's sarcoma cells in situ do not express the von Willebrand factor⁺, PAL-E⁺, 11710⁺ phenotype of mature, resting blood vascular endothelia). It is also unresolved how endothelia of either type may be differentially induced to dedifferentiate and how they are recruited into the lesion. Clearly, knowledge about endothelial heterogeneity is still too incomplete to identify the actual mechanisms and molecules that govern the pathogenesis of vascular disorders (including still others than those mentioned here such as atherosclerosis, diabetic angiopathy, and rheumatoid arthritis) affecting distinct endothelia. Further efforts in antigenic phenotyping and in cell and molecular biology of heterogeneously differentiated endothelia should be made to improve this state of affairs.Abbreviations vWF von Willebrand factor - PECAM-1 platelet-endothelial cell adhesion molecule-1 - CD cluster of differentiation - AIDS acquired immunodeficiency syndrome - HIV human immunodeficiency virus - ELAM-1 endothelialleukocyte adhesion molecule-1 - VCAM-1 vascular adhesion molecule-1 - MAb monoclonal antibody     

FasL/Fas pathway is involved in dengue virus induced apoptosis of the vascular endothelial cells

The hallmark of the dengue hemorrhagic fever/dengue shock syndrome is hematologic abnormality. The pathogenesis of dengue hemorrhagic fever/dengue shock syndrome remains unknown. Our work showed that the dengue virus serotype‐2 induced apoptosis in human umbilical vein endothelial cells. Fas (CD95), Tumor Necrosis Factor receptors, and Tumor Necrosis Factor‐related apoptosis‐inducing ligand receptors are the most common death receptors, which can induce apoptosis. Compared with the untreated human umbilical vein endothelial cells, Fas expression was increased both in the mRNA level and on the surface of infected human umbilical vein endothelial cells. FasL was expressed at similar levels on human umbilical vein endothelial cells over a course of dengue virus serotype‐2 infection, but the expression in mRNA level was increased in infected human umbilical vein endothelial cells. It is possible that there is soluble FasL secreted from human umbilical vein endothelial cells in the supernatant. Tumor Necrosis Factor‐related apoptosis‐inducing ligand receptor 1 and Tumor Necrosis Factor receptors 1–2 were constantly very low, whereas Tumor Necrosis Factor‐related apoptosis‐inducing ligand receptors 2–4 decreased after dengue virus serotype‐2 infection. This result suggested that dengue virus serotype‐2 may inhibit Tumor Necrosis Factor‐related apoptosis‐inducing ligand receptors‐induced apoptosis. The apoptotic rates in human umbilical vein endothelial cells were decreased upon the addition of caspase family inhibitors. In addition, activated caspase 8 and caspase 3 were also observed by Western blot following dengue virus serotype‐2 infection. Thus, it is shown that the Fas/FasL pathway may participate in dengue virus‐induced apoptosis of vascular endothelial cells in vitro. J. Med. Virol. 82:1392–1399, 2010. © 2010 Wiley‐Liss, Inc.     

Hepatocyte growth factor enhances vascular endothelial growth factor-induced angiogenesis in vitro and in vivo

Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis in both physiological and pathological processes. Hepatocyte growth factor (HGF) is a mesenchyme-derived mitogen that also stimulates cell migration, and branching and/or tubular morphogenesis of epithelial and endothelial cells. In the present study, we tested the hypothesis that simultaneous administration of HGF and VEGF would synergistically promote new blood vessel formation. HGF acted in concert with VEGF to promote human endothelial cell survival and tubulogenesis in 3-D type I collagen gels, a response that did not occur with either growth factor alone. The synergistic effects of VEGF and HGF on endothelial survival correlated with greatly augmented mRNA levels for the anti-apoptotic genes Bcl-2 and A1. Co-culture experiments with human neonatal dermal fibroblasts and human umbilical vein endothelial cells demonstrated that neonatal dermal fibroblasts, in combination with VEGF, stimulated human umbilical vein endothelial cells tubulogenesis through the paracrine secretion of HGF. Finally, in vivo experiments demonstrated that the combination of HGF and VEGF increased neovascularization in the rat corneal assay greater than either growth factor alone. We suggest that combination therapy using HGF and VEGF co-administration may provide a more effective strategy to achieve therapeutic angiogenesis.     

原代人脐静脉内皮细胞分离和培养方法的改进

目的建立一套高效、方便、可靠的脐静脉内皮细胞的体外分离和培养方法。方法取剖腹产新生婴儿脐带,加入Ⅰ型胶原酶消化分离人脐静脉内皮细胞,内皮专用培养基EGM-2培养传代。应用相差显微镜观察细胞形态。DiL-Ac-LDL染色证实细胞具有内皮功能。免疫荧光染色证明新分离细胞表达FⅧ相关抗原。流式细胞仪检测细胞表面表达CD31。结果原代培养细胞培养10～15d左右长成单层,细胞呈多角形,铺路石样排列。DiL-Ac-LDL染色阳性,证实细胞具内皮吞噬功能。免疫荧光检测证明细胞特异性表达FⅧ相关抗原。流式细胞仪检测证明细胞表面高表达CD31。结论通过酶灌注法消化脐静脉血管获得细胞,操作简便、高效,EGM-2培养基可保证内皮细胞具有较高纯度,细胞形态学观察和细胞生物学鉴定证明获得人脐静脉血管内皮细胞。     

Effects of extracellular matrix density and mesenchymal stem cells on neovascularization in vivo

Aberrant angiogenesis is common to a variety of diseases in which alterations in tissue mechanical properties also occur. A fundamental understanding of the interdependence of angiogenesis and tissue structural properties may enhance the development of therapeutic strategies. We previously established that increasing extracellular matrix density inhibits capillary morphogenesis in three-dimensional tissues in vitro, and that addition of human mesenchymal stem cells (MSCs) partially rescues a healthy angiogenic phenotype. This study's goal was to investigate if these effects can be recapitulated in vivo. Human umbilical vein endothelial cells, MSCs, or a mixture of both was suspended in fibrin gel precursor solutions of 5, 10, and 15?mg/mL concentrations and injected subcutaneously into SCID mice. Neovascularization was assessed in tissue constructs retrieved at 3, 7, and 21 days by quantifying vessel numbers, perfusion, thickness, maturity, and perivascular collagen deposition. The data show that changing extracellular matrix density inhibits capillary morphogenesis in vivo in a manner consistent with that observed in vitro. Delivery of both human umbilical vein endothelial cells and MSCs produced more robust and mature vessels than delivery of either cell type alone in all tissue concentrations.