L-精氨酸抑制内皮细胞粘附分子-1表达与氧化型低密度脂蛋白促单核细胞粘附作用下降有关

用经型低密度脂蛋白处理培养的猪主动脉内皮细胞，以Ｆｉｃｏｌｌ－Ｈａｐａｑｕｅ分离浓密度梯度离心分离人外周血单核细胞，观察Ｌ－精氨酸对内皮细胞－单核细胞粘附率的影响，采用反转录－多聚酶链反应技术检测氧化型低密度脂蛋白和Ｌ－精氨酸对内皮细胞血管细胞粘附分子－１表达的影响。结果显示：Ｌ－精氨酸具有剂量和时间依赖性地抑制氧化型低密度脂白促内皮细胞－单核细胞粘附作用，结果提示Ｌ－精氨酸可能通过抑制血管细胞粘     

氧化型低密度脂蛋白促进单核细胞－内皮细胞体外粘附反应

体外培养猪胸主动脉内皮细胞，观察氧化型低密度脂蛋白对内皮细胞－单核细胞体外粘附反应的影响，同时观察氧化型低密庆脂蛋白对内皮细胞表面粘附分子颗粒膜蛋白－１４０及内皮细胞分泌前列环素的影响。结果发现氧化型低密度脂蛋白（０、５０、１００和２００ｍｇ／Ｌ）增加内皮细胞－单核细胞粘附率并呈剂量依赖性，其中以１００ｍｇ／Ｌ作用最强；氧化型低密度脂蛋白（１００ｍｇ／Ｌ）与内皮细胞孵育０．５ｈ，粘附率上升但无显著性，１ｈ后显著升高，３ｈ达高峰，４８ｈ回复接近正常水平。同时发现１００ｍｇ／Ｌ氧化型低密度脂蛋白使内皮细胞表面颗粒膜蛋白－１４０含量从９２．８±４７．６上升到２９３．０±１４０．７μｇ／Ｌ（Ｐ＜０．０５），内皮细胞分泌前列环素量从８４．６±１８．７降低到６．０±３．１ｎｇ／Ｌ（Ｐ＜０．０１）．结果表明氧化型低密度脂蛋白可显著促进单核细胞－内皮细胞粘附，其作用机制可能同内皮细胞表面粘附分子颗粒膜蛋白－１４０增加有关。关键词     

动脉粥样硬化的发生与细胞间粘附分子

动脉粥样硬化的发生与单核细胞和血管内皮细胞的粘附密切相关。单核细胞产生自由基等，使低密度脂蛋白氧化，导致动脉粥样硬化，细胞间粘附分子与配体在单核细胞与血管内皮细胞的粘附中起重要作用。ＩＬ－１、ＴＮＦ等细胞因子可能是通过细胞间粘附分子来促使动脉粥样硬化的发生和发展。核因子ｋＢ在转录水平调节细胞站粘附分子的表达、也在动脉粥样硬化的发生发展中起调节作用。     

氧化型低密度脂蛋白介导单核细胞与血管内皮细胞粘附的单细胞定量研究

利用细胞微管吸吮技术对单核细胞与血管内皮细胞间的粘附力行单细胞定量测量，以两种细胞间的临界分离应力Ｓｃ来表示细胞的粘附性。观察氧化型低密度脂蛋白对单核细胞与培养人脐静脉内皮细胞粘附的影响。结果显示：氧化型低密度脂蛋白可使内皮细胞对正常单核细胞的粘附性明显增大，其发生较缓慢，４ｈ达峰值并维持至２４ｈ以后。经氧化型低密度脂蛋白处理的内皮细胞对中性粒细胞的粘附性无明显提高。单核细胞和中性粒细胞经氧化型低密度脂蛋白处理后，对内皮细胞的粘附性均有迅速提高，１ｈ达峰值，２４ｈ内逐渐减弱。实验结果提示氧化型低密度脂蛋白可选择性地提高单核细胞与内皮细胞相互粘附性，这种选择性的促粘附作用进一步证明它在动脉粥样硬化发生、发展中起重要作用。     

川芎嗪对血管壁细胞血管细胞粘附分子1和单核细胞趋化蛋白1表达的作用及可能机制

目的观察川芎嗪对血管内皮细胞和平滑肌细胞表达血管细胞粘附分子1、单核细胞趋化蛋白1和核因子κB的影响,探讨川芎嗪抗动脉粥样硬化分子机制。方法体外培养人脐静脉内皮细胞和大鼠胸主动脉平滑肌细胞。用氧化型低密度脂蛋白、氧化型极低密度脂蛋白、血管紧张素Ⅱ和(或)川芎嗪作用于细胞后,采用免疫细胞化学和原位分子杂交检测各组细胞血管细胞粘附分子1、单核细胞趋化蛋白1和核因子κB的表达情况。用单核细胞粘附试验检测川芎嗪对单核细胞粘附于内皮细胞的影响。结果氧化型低密度脂蛋白、氧化型极低密度脂蛋白或血管紧张素Ⅱ诱导内皮细胞血管细胞粘附分子1蛋白相对表达量分别为0.552±0.008、0.460±0.006和0.486±0.025,明显高于对照组的0.365±0.019(P<0.01);诱导平滑肌细胞血管细胞粘附分子1蛋白相对表达量分别为0.564±0.007、0.513±0.021和0.524±0.008,明显高于对照组(0.416±0.013,P<0.01)。氧化型低密度脂蛋白、氧化型极低密度脂蛋白或血管紧张素Ⅱ诱导内皮细胞单核细胞趋化蛋白1蛋白相对表达量分别为0.962±0.051、0.878±0.014和0.824±0.006,明显高于对照组的0.303±0.008(P<0.01);诱导平滑肌细胞单核细胞趋化蛋白1蛋白相对表达量分别为0.877±0.011、0.845±0.023和0.881±0.009,明显高于对照组的0.362±0.018(P<0.01)。氧化型低密度脂蛋白、氧化型极低密度脂蛋白或血管紧张素Ⅱ诱导组血管细胞粘附分子1和单核细胞趋化蛋白1的mRNA表达明显高于对照组(P<0.01)。同时加入川芎嗪后血管细胞粘附分子1和单核细胞趋化蛋白1蛋白和mRNA表达明显低于相应诱导组(P<0.01)。氧化型低密度脂蛋白、氧化型极低密度脂蛋白或血管紧张素Ⅱ诱导核因子κB在核内表达,同时加入川芎嗪后核因子κB表达于胞浆,核内阴性。与氧化型低密度脂蛋白或氧化型极低密度脂蛋白诱导组(2.047±0.011和1.936±0.014)比较,加入川芎嗪后,粘附于内皮细胞的单核细胞明显减少(1.282±0.020和1.265±0.016,P<0.01)。结论川芎嗪通过抑制或阻断动脉粥硬化危险因素氧化型低密度脂蛋白、氧化型极低密度脂蛋白和血管紧张素Ⅱ诱导的核因子κB活化及核内移位,抑制血管壁细胞血管细胞粘附分子1和单核细胞趋化蛋白1表达,抑制单核细胞粘附于内皮,而发挥其抗动脉粥样硬化作用。     

巨噬细胞与动脉粥样硬化斑块稳定性

为探讨抗氧化剂维生素Ｅ和元素硒对脂质过氧化诱导内此细胞表达细胞粘附分子及单核细胞粘附的影响产胺诱发培养内皮细胞脂质过氧化,检测维生素Ｅ和元素硒对单核细胞会的影响,用免疫组化及共焦显微镜观察维生素Ｅ和元素硒对内此表达血管细胞粘附分子－１及内此细胞白细胞粘附分子－１的影响。结果显示抗氧化剂维生素Ｅ和元素硒可抑制内此脂质过氧化,抑制血管细胞粘附分子－１及内此占附分子－１表达,减少单核细胞粘附。提示抗氧化     

氧化型低密度脂蛋白和普伐他汀对人脐静脉内皮细胞细胞间粘附分子-1表达的影响

观察氧化型低密度脂蛋白对人脐静脉内皮细胞细胞间粘附分子－１表达的诱导及普伐他汀对它的抑制影响,以期氧化型低密度脂蛋白致动脉粥样硬化的机制及普伐他汀可能的非调脂抗动脉粥样硬化作用。体外培养人脐静脉内皮细胞,分别加氧化型低密度脂蛋白５０ｍｇ／Ｌ、１００ｍｇ／Ｌ、２００ｍｇ／Ｌ及氧化型低密度旨蛋白（１００ｍｇ／Ｌ）＋普伐他汀（１０＾－４－－６ｍｏｌ／Ｌ）,孵育１２ｈ、２４ｈ和３６ｈ,采用细胞酶联免疫吸附     

内皮细胞形态和排列与血液动力学关系的探讨

丙丁酚阻抑氧化低密度脂蛋白介导的内皮细胞－单核细胞粘附作用李立新，陈剑雄，余麟，廖端芳，黄红林（衡阳医学院心肺药理研究室，衡阳４２１００１）用氧化低密度脂蛋白处理培养的猪胸主动脉内皮细胞，观察内皮细胞表面颗粒膜蛋白－１４０、内皮细胞－单核细胞粘附率、...     

丙丁酚对氧化型低密度脂蛋白和氧自由基促血管平滑肌细胞增殖的影响

本文用细胞计数和ＭＴＴ快速比色计量法观察到体外培养的半主动脉平滑肌细胞分别与氧化型低密度脂蛋白和黄嘌呤－黄嘌呤氧化酶共厕培养后，前者明显增殖（Ｐ＜０．０１）。抗氧化剂丙丁酚（１００μｍｏｌ·Ｌ－１）能抑制氧化型低密度脂蛋白和黄嘌呤－黄嘌呤氧化酶促平滑肌细胞增殖作用；一氧化氮合成酶抑制剂ＮＧ－硝基－Ｌ－精氨酸对两者促平滑肌细胞增殖的作用无影响，同时也不能阻断丙丁酚的抑制两者促细胞增殖作用．这一结果提示，丙丁酚能抑制氧化型低密度脂蛋白和外源性氧自由基促平滑肌细胞增殖，这一作用可能与血管平滑肌细胞中一氧化氮的合成及释放无关。     

氧化型低密度脂蛋白促进单核细胞-内皮细胞体外粘附反应

体外培养猪胸主动脉内皮细胞，观察氧化型低密度脂蛋白对内皮细胞－单核细胞体外粘附反应的影响同时观察氧化型低密度脂蛋白对内皮细胞表面粘附分子颗粒膜蛋白－１４０及内皮细胞分泌前列环素的影响。     

脂质过氧化对培养的内皮细胞表达细胞粘附分子的影响

为观察脂质过氧化损伤对细胞粘附分子表达的影响，用联胺诱发培养的人血管内皮细胞脂质过氧化后，检测其丙二醛含量及单核细胞粘附率，并用激光共聚焦显微镜观察细胞粘附分子表达的情况。结果发现，实验组较对照组内皮细胞丙二醛含量升高，单核细胞粘附率显著增加（P＜0．01），内皮细胞上有血管细胞粘附分子－1及内皮细胞白细胞粘附分子－1的表达，且其表达量均随时间增多。提示内皮细胞粘附分子的表达增加可能是脂质过氧化损伤导致单核细胞粘附增多的重要机制。     

抗氧化剂对脂质过氧化内皮细胞表达细胞粘附分子的影响

为研究一氧化氮合酶抑制剂左旋硝基精氨酸诱导的肺动脉高压大鼠各部位离体血管环对多巴胺－ １ 受体反应性的影响，采用大鼠肺动脉、肠系膜动脉和肾动脉离体血管标本，在去甲肾上腺素收缩血管后，用多巴胺－ １ 受体选择性激动剂非诺多泮使血管舒张，所有实验在吲哚美辛（１０ μｍｏｌＬ） 和普萘洛尔（３ μｍｏｌＬ） 存在下进行。左旋硝基精氨酸组大鼠各动脉对非诺多泮的反应性均有不同程度的降低，以肺动脉最明显，最大舒张占预收缩的百分比为４５．５％ ±４．１％ ，低于对照组的９７．３ ％ ±１０ ．６ ％（ Ｐ＜ ０．０１）；亲合常数为２０４２ ±２２１，低于对照组的４２７４ ．２±５１２（Ｐ＜ ０．０１） ，接近对照组的去内皮水平。肠系膜动脉和肾动脉对非诺多泮的反应性亦有下降，但下降程度明显低于肺动脉。结果提示，内皮依赖性受体介导多巴胺－ １ 的舒张效应降低是左旋硝基精氨酸形成肺动脉高压的因素之一。     

Monocytes initiate a cycle of leukocyte recruitment when cocultured with endothelial cells

During the development of atherosclerotic plaque, monocytes and T-lymphocytes are recruited to the arterial intima by endothelial cells (EC) lining the vessel. This process is associated with chronic arterial inflammation and requires the activation-dependent expression of adhesion receptors and chemokines on EC. Here we show that monocytes can activate cocultured EC so that they support the adhesion, activation and transmigration of a secondary bolus of flowing peripheral blood monocytes or lymphocytes. The number of adherent leukocytes and their behaviour was comparable to that seen on EC activated with tumour necrosis factor-alpha (TNF-alpha). Depending upon the duration of endothelial cell/monocyte coculture different patterns of adhesion receptors were utilised by leukocytes. After 4 h coculture, antibodies against E-selectin, P-selectin and vascular cell adhesion molecule-1 (VCAM-1) reduced mononuclear leukocyte adhesion. After 24 h coculture, antibodies against E-selectin and VCAM-1 but not P-selectin were effective. Immunofluorescence analysis confirmed that monocyte coculture induced endothelial expression of E-selectin and VCAM-1, while P-selectin was at the limit of detection. We conclude that EC stimulated by monocytes can support the adhesion of flowing mononuclear leukocytes. We hypothesise that this mode of EC activation and leukocyte recruitment could initiate a self-perpetuating cycle of inflammation that could be relevant to atherogenesis and other chronic inflammatory disease states.     

Dihydrotestosterone promotes vascular cell adhesion molecule-1 expression in male human endothelial cells via a nuclear factor-kappaB-dependent pathway

There exists a striking gender difference in atherosclerotic vascular disease. For decades, estrogen was considered atheroprotective; however, an alternative is that androgen exposure in early life may predispose men to earlier atherosclerosis. We recently demonstrated that the potent androgen, dihydrotestosterone (DHT), enhanced the binding of monocytes to the endothelium, a key early event in atherosclerosis, via increased expression of vascular cell adhesion molecule-1 (VCAM-1). We now show that DHT mediates its effects on VCAM-1 expression at the promoter level through a novel androgen receptor (AR)/nuclear factor-kappaB (NF-kappaB) mechanism. Human umbilical vein endothelial cells were exposed to 4-400 nm DHT. DHT increased VCAM-1 mRNA in a dose- and time-dependent manner. The DHT effect could be blocked by the AR antagonist, hydroxyflutamide. DHT increased VCAM-1 promoter activity via NF-kappaB activation without affecting VCAM-1 mRNA stability. Using 5' deletion analysis, it was determined that the NF-kappaB sites within the VCAM-1 promoter region were responsible for the DHT-mediated increase in VCAM-1 expression; however, coimmunoprecipitation studies suggested there is no direct interaction between AR and NF-kappaB. Instead, DHT treatment decreased the level of the NF-kappaB inhibitory protein. DHT did not affect VCAM-1 protein expression and monocyte adhesion when female endothelial cells were tested. AR expression was higher in male, relative to female, endothelial cells, associated with increased VCAM-1 levels. These findings highlight a novel AR/NF-kappaB mediated mechanism for VCAM-1 expression and monocyte adhesion operating in male endothelial cells that may represent an important unrecognized mechanism for the male predisposition to atherosclerosis.     

Membrane type 1-matrix metalloproteinase is involved in migration of human monocytes and is regulated through their interaction with fibronectin or endothelium

Membrane type 1-matrix metalloproteinase (MT1-MMP) is involved in endothelial and tumor-cell migration, but its putative role in leukocyte migration has not been characterized yet. Here, we demonstrate that anti-MT1-MMP monoclonal antibody (mAb) impaired monocyte chemotactic protein-1 (MCP-1)-stimulated monocyte migration on fibronectin (FN), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). In addition, monocyte transmigration through tumor necrosis factor-alpha (TNF-alpha)-activated endothelium is also inhibited by anti-MT1-MMP mAb. Therefore, regulation of MT1-MMP in human peripheral blood monocytes was investigated. First, MT1-MMP clustering was observed at motility-associated membrane protrusions of MCP-1-stimulated monocytes migrating on FN, VCAM-1, or ICAM-1 and at the leading edge, together with profilin, of monocytes transmigrating through activated endothelial cells. In addition, up-regulation of MT1-MMP expression was induced in human monocytes upon attachment to FN in a manner dependent on alpha4beta1 and alpha5beta1 integrins. Binding of monocytes to TNF-alpha-activated human endothelial cells as well as to VCAM-1 or ICAM-1 also resulted in an increase of MT1-MMP expression. These findings correlated with an enhancement of MT1-MMP fibrinolytic activity in monocytes bound to FN, VCAM-1, or ICAM-1. Our data show that MT1-MMP is required during human monocyte migration and endothelial transmigration and that MT1-MMP localization, expression, and activity are regulated in monocytes upon contact with FN or endothelial ligands, pointing to a key role of MT1-MMP in monocyte recruitment during inflammation.     

Apurinic/apyrimidinic endonuclease1/redox factor-1 inhibits monocyte adhesion in endothelial cells

OBJECTIVE: Expression of adhesion molecules on endothelial cells and subsequent monocyte adhesion are initial events in the development of atherosclerosis. The purpose of this study was to investigate the role of apurinic/apyrmidinic endonuclease1/redox factor-1 (APE1/ref-1) in the interaction of monocytes with vascular endothelial cells. METHODS: Human umbilical vein endothelial cells (HUVECs) were transfected with an adenovirus encoding human APE1/ref-1. The effect of APE1/ref-1 overexpression on monocyte adhesion, vascular cell adhesion molecule-1 (VCAM-1) protein expression, and intracellular superoxide production in tumor necrosis factor (TNF)-alpha-activated HUVECs was examined. RESULTS: Adhesion of the monocytic cell line U937 to TNF-alpha-stimulated HUVECs in which APE1/ref-1 was overexpressed was suppressed. APE1/ref-1 overexpression also suppressed expression of VCAM-1 induced by TNF-alpha. APE1/ref-1-mediated suppression of VCAM-1 was blocked by pretreatment with the nitric oxide synthase (NOS) inhibitor l-nitroarginine methyl ester. Furthermore, APE1/ref-1 overexpression inhibited the TNF-alpha-induced increase in intracellular superoxide and p38 MAPK phosphorylation. CONCLUSIONS: These data provide evidence that APE1/ref-1 in endothelial cells mitigates TNF-alpha-induced monocyte adhesion and expression of vascular cell adhesion molecules, and this anti-adhesive property of APE1/ref-1 is primarily mediated by a NOS-dependent mechanism. Furthermore, APE1/ref-1 may inhibit VCAM-1 expression by inhibiting superoxide production and p38 MAPK activation.     

Intercellular adhesion molecule-1 (ICAM-1) expression is necessary for monocyte adhesion to the placental bed endothelium and is increased in type 1 diabetic human pregnancy

BACKGROUND: That adhesion molecule expression is upregulated in endothelial cells of the placental bed in pregnancies complicated by type 1 diabetes mellitus, and that this is associated with increased adherence of peripheral blood monocytes, which can be reversed by reduction in activity or expression of relevant adhesion molecules. Specific aims were to compare the adherence of monocytes from normal pregnancies to decidual endothelial cells from both normal and diabetic pregnancies, and to examine the involvement of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in regulation of such adhesion. METHODS: We examined adhesion of peripheral blood monocytes (isolated by density gradient centrifugation) of normal third trimester pregnant women, to cultured endothelial cells (isolated from decidual biopsies collected at elective caesarean section) from both normal women and those with type 1 diabetes. Adhesion molecule expression was determined by flow cytometry. The role of ICAM-1 was further investigated by monoclonal antibody-blocking experiments and gene-silencing methodology. RESULTS: There was a significant increase in monocyte adhesion to decidual endothelial cells from diabetic pregnancies, associated with increased endothelial cell expression of ICAM-1, but not VCAM-1. ICAM-1 expression in normal decidual endothelial cells was stimulated by pro-atherogenic and pro-inflammatory stimuli. Following ICAM-1 antibody blockade, monocyte adhesion was decreased by > 70%. ICAM-1 silencing by small interfering RNAs also inhibited monocyte adhesion and ICAM-1 expression. CONCLUSIONS: These findings implicate upregulation of ICAM-1 in decidual endothelial cells in the development of placental bed vascular pathology in diabetic pregnancy.     

蚤休皂苷对氧化损伤的脐静脉内皮细胞间细胞粘附分子1和血管细胞粘附分子1表达的影响

目的研究中药蚤休皂苷对H2O2诱导的脐静脉内皮细胞ECV304损伤的保护作用及其机制。方法体外培养ECV304,建立氧化损伤细胞模型,然后分为五个实验处理组:正常对照组、氧化损伤组、高浓度蚤休皂苷组、中浓度蚤休皂苷组和低浓度蚤休皂苷组,采用四甲基偶氮唑盐比色法检测蚤休皂苷对H2O2诱导的内皮细胞氧化损伤的影响,逆转录聚合酶链反应检测细胞间细胞粘附分子1和血管细胞粘附分子1mRNA的表达水平,流式细胞术定量检测细胞间细胞粘附分子1和血管细胞粘附分子1的表达。结果损伤后细胞吸光度值低于正常对照组(P<0.01),药物预处理后吸光度值增加,高浓度蚤休皂苷组吸光度值与正常组相比差异无显著性;药物预处理氧化损伤后,细胞间细胞粘附分子1和血管细胞粘附分子1mRNA的表达水平与损伤组相比明显减弱(P<0.01);损伤组中与内参照的灰度值之比最大,与正常组相比差异显著(P<0.01);损伤组中表达细胞间细胞粘附分子1和血管细胞粘附分子1的阳性细胞数增多,与正常组相比差异显著(P<0.01);药物预处理氧化损伤后,阳性细胞数明显减少,且此效应呈剂量依赖性(P<0.01)。结论蚤休皂苷可以保护H2O2造成的人脐静脉内皮细胞的氧化损伤,是通过抑制内皮细胞粘附分子的表达从而抑制炎症性损伤,达到保护内皮细胞、抗动脉粥样硬化的目的。