内皮细胞药理学在心血管药物研究中的应用

心 血管药理学是一门兴起不久但发展十分迅速的一个研究领域 ,而内皮细胞药理学又是一门从中分离出来的新分支。因为血管内皮细胞不仅是血液与血管平滑肌之间的生理屏障 ,而且是高度活跃的代谢库。它能合成多种血管活性物质包括自分泌、旁分泌和内分泌性物质 ,小分子的NO ,到肽     

血管内皮细胞在生物材料引起血栓形成过程中的作用

血管内皮细胞——这一铺展于血管内腔、包绕着循环血的细胞，可合成和释放多种活性物质调节血液的凝血与抗凝平衡，在生物材料引起血栓形成的过程中起着重要的作用。同时它促栓和抗栓功能的异常改变也是衡量生物材料血液相容性优劣的灵敏指标。本就近年来对内皮细胞对凝血-抗凝系统的调节及其在生物材料引起血栓形成中的作用等方面的研究以及尚待解决的一些问题作一综述。     

血管内皮细胞在生物材料引起血栓形成过程中的作用

血管内皮细胞——这一铺展于血管内腔、包绕着循环血的细胞,可合成和释放多种活性物质调节血液的凝血与抗凝平衡,在生物材料引起血栓形成的过程中起着重要的作用。同时它促栓和抗栓功能的异常改变也是衡量生物材料血液相容性优劣的灵敏指标。本文就近年来对内皮细胞对凝血—抗凝系统的调节及其在生物材料引起血栓形成中的作用等方面的研究以及尚待解决的一些问题作一综述。     

血管内皮细胞释放的血管活性物质之间的相互作用

血管内皮细胞释放多种血管活性物质，它们的活性特别是它们之间的相互作用决定血管口径的变化。本文综述血管内皮细胞释放的血管活性物质之间的相互关系，探讨不同血管活性物质对血管口径及血管阻力的影响。     

血管内皮细胞NO合成与释放的信号转导

在血管内皮细胞的功能活动中,G蛋白在其信号转导过程中起着重要作用.多种自身活性物质、循环激素均能通过激活血管内皮细胞膜上的G蛋白控制内皮细胞合成与释放NO进而调控血管平滑肌细胞的各种功能.G蛋白表达量及功能的异常与动脉粥样硬化、高脂血症等心血管疾病有着密切的关系.     

内皮细胞抗凝及纤溶功能障碍和动脉粥样硬化

介于组织与血液之间的内皮细胞具有多种功能，在保护血管完整性和维持血液流动性方面起到关键性作用[1,2]。自本世纪80年代，人们才认识到纤维蛋白原、其它凝血因子、纤维蛋白形成与溶解等都参与动脉粥样硬化的发生发展[3]。现今内皮细胞损伤在动脉粥样硬化发生发展中的重...     

β-NGF减轻H_2O_2对HUVECs的损伤

<正>血管内皮细胞损伤被认为是导致动脉粥样硬化的重要病理原因之一,且多与氧化应激损伤有关。因此,如何保护氧化损伤后血管内皮细胞功能对于防治动脉粥样硬化等心血管疾病具有重要意义。神经生长因子β-NGF是一种多功能性神经营养因子,可以促进血管新生且与血管内皮功能密切相关,但其对氧化损伤后血管内皮细胞的作用及其机制尚未知[1]。因此本研究以人脐静脉血管内皮细胞(human umbilical vein endothelial cells,HUVECs)为研究对象,利用     

p38MAPK与内皮细胞损伤的关系

p3 8MAPK通过磷酸化转录因子引起多种相关基因转录 ,调控活性物质的表达 ,参与血管内皮细胞氧化应激损伤甚至凋亡等过程。在信号通路水平阻断和调控p3 8MAPK的表达和活性 ,可以达到控制和减轻内皮细胞损伤或凋亡的目的。这为临床心血管疾病的防治提供了新的理论依据     

miR-21对血管内皮功能及血管生成调节作用的研究进展

<正>血管内皮细胞作为血管的内衬,一方面参与构成血管的通透性屏障,调节液体、气体及生物大分子物质的选择性通透;另一方面可分泌大量血管活性因子,参与对凝血与抗凝功能、纤溶系统和炎症发生发展等的调控,与血管功能和循环系统的稳定密切相关。研究表明,血管内皮细胞功能激活是血管生成的先决条件~([1])。血管内皮细胞在多种细胞因子的诱导下增殖迁移,为血管管腔形成提供内皮细胞数量的积累。血管生成因子与内皮细胞受体结合可激     

系统性自身免疫性疾病的血管内皮损伤机制

<正>系统性自身免疫性疾病是免疫调节机制异常而出现的一系列临床疾病谱,可引起全身多器官和组织的病理损伤。近年来研究表明,血管内皮作为人类最大的器官,已成为自身免疫性疾病危及的部位。血管内皮细胞(En-dothelialCells,ECs)不仅是血管壁的衬里,还具有多种生理功能,除血管的保护和物质转运作用外,还参与机体的凝血、纤溶、免疫、血管的生长和血管运动的调节,并能产生和释放多种活性物质。血管内皮损伤与功能障碍可导致多种疾病的产生,特别是心血管疾病。     

How endothelial cell organo-specificity mediates circulating cell homing

Normal and transformed cells home into tissues from the circulation in a very selective way thanks to highly complex molecular mechanisms that govern cell-to-cell interactions and drive the homing of circulating cells so that it is achieved properly. Because this is characterized by a resulting high selectivity, it constitutes a template for targeted drug-, gene- or cell-therapy strategies. Designing a mimetic-based therapy requires the identification of the responsible selective molecules, but also their mechanisms of action and interactions with their ligands together with their biological modulation and regulation. This homing/invasion event is decisive at the level of the endothelium that lines the vessel walls. Since cell-to-cell interactions mean a double recognition process, this review will illustrate the part played by the endothelial cells (ECs) and their adhesion molecules: the protein as well as the glycan point of view, the chronology, and the environmental modulation of EC adhesion molecule expression. These characteristics should provide keys to understanding the resulting overall specificity of cell localization. Taking into account the cytokine microenvironment, a fundamental role was recently documented for locally secreted chemokines which act through their restricted presentation by endothelial cells. As such, chemokines contribute to illustrating the concept of endothelial organo-specificity which is approached here, uncovering the role of glycoconjugate signaling as the hallmark of refined cellular recognition, and discussed in the context of potential drug design against site-directed diseases such as metastases, inflammatory leukocyte recruitment, and tumor/inflammation-induced angiogenesis.     

Platelet adhesion and fusion to endothelial cell facilitate the metastasis of tumor cell in hypoxia-reoxygenation condition

To investigate the relevant molecular mechanisms of platelet in promoting metastasis of tumor cell. The adhesion of fluorescence dye labeled-platelet to human liver sinusoidal endothelial cell (LSEC) line and tumor cell lines were detected by fluorescence microscope and fluorescence plate reader or laser scanning confocal microscope. The relevant adhesion molecules were analyzed by the antibody blockage experiment. The immune colloidal gold transmission electron microscope (TEM), flow cytometry and dye transfer were used to decipher the adhesion and fusion of platelet and LSEC. The tumor cells adhesion to vessels in ischemia condition was analyzed on mouse mesenteric vessels and the metastasis and neovascularization of metastatic foci in pulmonary tissue were also detected after tumor cells injected into nude mice via tail veil. After hypoxia-reoxygenation, tumor cell or LSEC markedly increased its adhesion with platelet, which could be blocked by different antibodies to platelet adhesion molecules. Platelet increased adhesion of tumor cell to LSEC in dose-dependent manner. The fusion of platelet and LSEC was demonstrated by translocation of fluorescent dye from platelet into the adherent LSEC; gpIIb emerged on the LSEC; and confirmed by TEM. The morphological examination found platelet presented between tumor cell and LSEC. Animal experiment indicated that the tumor adhesion to vessels was seldom in normal condition, but increased in ischemia-reperfusion condition, and further significantly enhanced by platelets. The number of tumor metastatic foci and the density of blood vessels within metastatic foci in lung were markedly increased by tumor cell pre-adhered with platelet. The adhesion or fusion of platelet to endothelial cell mediated by platelet surface adhesion molecules, which could promote the adhesion of tumor cell with endothelial cells and the tumor metastasis.     

Leukocyte-mediated endothelial cell injury and death in the diabetic retina

Endothelial cell death is a hallmark of diabetic retinopathy. Its occurrence is required for the formation of acellular (devitalized) capillaries, lesions that produce irreversible retinal ischemia through their inability to support blood flow. The mechanisms underlying diabetic retinal endothelial cell injury and death remain largely unknown. The current study demonstrates that adherent leukocytes are temporally and spatially associated with retinal endothelial cell injury and death within 1 week of streptozotocin-induced experimental diabetes in rats. Moreover, the antibody-based neutralization of intercellular adhesion molecule-1 and CD18 is shown to prevent both leukocyte adhesion and retinal endothelial cell injury and death. These data highlight the central and causal role of adherent leukocytes in the pathogenesis of diabetic retinopathy. They also underscore the potential utility of anti-intercellular adhesion molecule1- and anti-CD18-based therapies in the treatment of diabetic retinopathy, a newly recognized inflammatory disease.     

Anti-endothelial cell antibodies from patients with thrombotic thrombocytopenic purpura specifically activate small vessel endothelial cells

Thrombotic thrombocytopenic purpura (TTP) is an uncommon disease of an unknown etiology, characterized by consumptive thrombocytopenia, microangiopathic hemolytic anemia, fever and acute thrombotic complications, especially within the cerebral circulation. Although anti-endothelial cell antibodies (AECA) have occasionally been shown to be present in TTP, their role in the pathogenesis of the disease has never been ascertained. In the current study we demonstrated the pathogenic activity of affinity-purified anti-endothelial cell F(ab)2 antibodies (AECA/TTP) from four consecutive patients with active TTP. These AECA/TTP bound to and activated only microvascular endothelial cells (EC) and not large vessel EC. The specificity of AECA/TTP binding to microvascular EC was confirmed by competition assay employing membranes derived from small and large vessels EC. Activation included enhanced IL-6 and von Willebrand factor release from the EC followed by increased expression of adhesion molecules P-selectin, E-selectin and vascular cell adhesion molecule-1 on the EC, as evaluated by ELISA. Increased expression of adhesion molecules was followed by an increase in monocyte adhesion to EC. The level of soluble thrombomodulin (TM) also increased in the culture medium of activated microvascular EC upon exposure to AECA/TTP antibodies and was directly correlated to a decrease in cell-associated TM. Our data suggest that AECA/TTP directed against microvascular EC could play a pathogenic role in the development of endothelial injury in TTP that leads to thrombosis.     

Fibronectin expression correlates with U937 cell adhesion to migrating bovine aortic endothelial cells in vitro.

A blood vessel's response to denudation injury will determine its final luminal diameter as well as its function. The synthesis, deposition, and remodeling of extracellular matrix components and migration by vascular endothelial cells are major factors in determining luminal diameter, cellular proliferative and migratory responses, and mononuclear cell adhesion at sites of injury. Previously, we have shown that after in vivo and in vitro denudation injury, endothelial cell migration is dramatically influenced by the amount of fibronectin synthesized and deposited by the responding endothelial cell population. The aim of this study was to elucidate the roles of fibronectin in modulating mononuclear cell adhesion to the endothelial cell population during in vitro migration. In this report we demonstrate that U937 cell binding to the migrating fronts of endothelial cell monolayers is modulated by the amount of fibronectin synthesized and deposited by the endothelial cells. Agents which increase fibronectin deposition, such as transforming growth factor-beta 1, elicit greater U937 cell adhesion. Manipulations that decrease fibronectin deposition, such as transfection and overexpression of pp60c-src proto-oncogene in endothelial cells, reduce U937 cell adhesion. These results suggest that changes in endothelial cell extracellular matrix synthesis and deposition modulate, in part, the adhesive properties of the vessel wall after injury. In turn, the intensity and duration of mononuclear cell adhesion at sites of vessel wall injury determines, in part, the vessel wall response.     

Up-regulation of the endothelial cell adhesion molecule intercellular adhesion molecule-1 (ICAM-1) by autoantibodies in autoimmune vasculitis

Autoimmune vasculitis is characterized by the presence of autoantibodies, particularly anti-neutrophil cytoplasmic antibodies (ANCA) and anti-nuclear antibodies (ANA), in patient sera. These autoantibodies have an incompletely understood role in development of vascular injury. The expression or up-regulation of cell adhesion molecules is an early phase in the development of an inflammatory vascular lesion. Autoantibody-positive sera from patients with vasculitis were assessed for their ability to modulate adhesion molecule expression by human umbilical vein endothelial cells (HUVEC). Autoantibody-positive serum samples from 11 out of 21 patients with primary vasculitis produced substantial up-regulation of ICAM-1 on HUVEC. Autoantibody-negative samples did not produce adhesion molecule up-regulation. Up-regulation of adhesion molecules on HUVEC was observed with samples positive for ANA, a phenomenon not previously reported. Preincubation of the sera with purified antigens recognized by ANCA failed to block this activation. In addition, MoAbs to ANCA antigens were ineffective at inducing ICAM-1 up-regulation, suggesting that activation is independent of the molecular specificity of the antibody. This capacity of ANCA- and ANA-positive sera to up-regulate adhesion molecules on endothelial cells may be a factor in the vessel wall inflammation seen in ANCA-associated vasculitis.     

Distinct molecular composition of blood and lymphatic vascular endothelial cell junctions establishes specific functional barriers within the peripheral lymph node

Lymph nodes are strategically localized at the interfaces between the blood and lymphatic vascular system, delivering immune cells and antigens to the lymph node. As cellular junctions of endothelial cells actively regulate vascular permeability and cell traffic, we have investigated their molecular composition by performing an extensive immunofluorescence study for adherens and tight junction molecules, including vascular endothelium (VE)-cadherin, the vascular claudins 1, 3, 5 and 12, occludin, members of the junctional adhesion molecule family plus endothelial cell-selective adhesion molecule (ESAM)-1, platelet endothelial cell adhesion molecule-1, ZO-1 and ZO-2. We found that junctions of high endothelial venules (HEV), which serve as entry site for naive lymphocytes, are unique due to their lack of the endothelial cell-specific claudin-5. LYVE-1(+) sinus-lining endothelial cells form a diffusion barrier for soluble molecules that arrive at the afferent lymph and use claudin-5 and ESAM-1 to establish characteristic tight junctions. Analysis of the spatial relationship between the different vascular compartments revealed that HEV extend beyond the paracortex into the medullary sinuses, where they are protected from direct contact with the lymph by sinus-lining endothelial cells. The specific molecular architecture of cellular junctions present in blood and lymphatic vessel endothelium in peripheral lymph nodes establishes distinct barriers controlling the distribution of antigens and immune cells within this tissue.     

Mechanics of endothelial cell architecture and vascular permeability.

Blood vessel walls form a selective barrier to the transport of materials between blood and tissue, and the endothelium contributes significantly to this barrier function. The role of the endothelium is particularly important in thin-walled vessels, such as venules, because during tissue inflammation the endothelial junctions widen in localized areas and gaps form, thus compromising the barrier function. The mechanisms of endothelial gap formation are still under question. In this review we describe what is known about the structure of endothelial cell-cell junctions and how this structure can change during inflammation. We then consider two possible mechanisms by which endothelial gaps are formed: active endothelial cell contraction or breakdown of the junctional complex, followed by passive recoil. Using measured values of the mechanical properties of endothelial cells, and the forces to which they are subjected, we calculate that gap formation by breakdown of cellular adhesion, followed by passive recoil, is a feasible mechanism. Finally, since endothelial cell surfaces, including junctions, are coated with a glycocalyx, we consider the question of whether changes in the glycocalyx can markedly increase endothelial permeability. We conclude that gap formation can occur by active contraction or by breakdown of adhesion, depending on the inflammatory mediator, and that the responses of the glycocalyx may also play an important role in the regulation of microvascular permeability.     

Selenium-dependent enzymes in endothelial cell function

Glutathione peroxidases and thioredoxin reductases are the main selenoproteins expressed by endothelial cells. These enzymes reduce hydroperoxides, their role in endothelial cell physiology, however, by far exceeds prevention of oxidative damage. Reactive oxygen and nitrogen species, especially superoxide, hydroperoxides, and nitric oxide, are crucial signaling molecules in endothelial cells. Their production is regulated by vascular NAD(P)H oxidases and the endothelial nitric oxide synthase. Their metabolism and physiological functions are coordinated by glutathione peroxidases and the thioredoxin/thioredoxin reductase system. Endothelial selenoproteins are involved in the regulation of the vascular tone by maintaining the superoxide anion/nitric oxide balance, of cell adhesion by controlling cell adhesion molecule expression, of apoptosis via inhibition/activation of apoptosis signal-regulating kinase-1, and of eicosanoid production by controlling the activity of cyclooxygenases and lipoxygenases. Accordingly, they regulate inflammatory processes and atherogenesis. The underlying mechanisms are various and differ between individual selenoproteins. Scavenging of hydroperoxides not only prevents oxidative damage, but also interferes with signaling cascades and enzymes involved. Modulation of proteins by hydroperoxide-driven thiol/disulfide exchange is a novel mechanism that needs to be further investigated. A better understanding of the complex interplay of selenoproteins in regulating endothelial cell functions will help to develop a rationale for an improvement of health by an optimum selenium supply.     

Globotriaosylceramide induces oxidative stress and up-regulates cell adhesion molecule expression in Fabry disease endothelial cells

Fabry disease, an X-linked systemic vasculopathy, is caused by a deficiency of alpha-galactosidase A resulting in globotriaosylceramide (Gb(3)) storage in cells. The pathogenic role of Gb(3) in the disease is not known. Based on previous work, we tested the hypothesis that accumulation of Gb(3) in the vascular endothelium of Fabry disease is associated with increased production of reactive oxygen species (ROS) and increased expression of cell adhesion molecules. Gb(3)-loading resulted in increased intracellular ROS production in cultured vascular endothelial cells in a dose-dependent manner. Increased Gb(3) also induced expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin. Reduction of endogenous Gb(3) by treatment of the cells with an inhibitor of glycosphingolipid synthase or alpha-galactosidase A led to decreased expression of adhesion molecules. Plasma from Fabry patients significantly increased ROS generation in endothelial cells when compared with plasma from non-Fabry controls. This effect was not influenced by reduction of intracellular Gb(3). This study provided direct evidence that excess intracellular Gb(3) induces oxidative stress and up-regulates the expression of cellular adhesion molecules in vascular endothelial cells. In addition, other factors in patient's plasma may also contribute to oxidative stress in Fabry vascular endothelial cells.