阿托伐他汀钙调节人脐静脉内皮细胞E-选择素和细胞间黏附分子1表达的浓度依赖性

目的:观察具有调脂作用的阿托伐他汀钙在不同浓度下对肿瘤坏死因子诱导体外培养的人脐静脉内皮细胞表达E-选择素和细胞间黏附分子1的影响。方法:①实验于2002-05/2003-12在大连医科大学附属第二医院实验室完成。将健康婴儿脐带进行无菌处理,用D-Hank’s液冲洗脐静脉,1g/L胶原酶消化、离心,置于37℃、体积分数0.05CO2培养箱中培养,选择第2,3代细胞作为实验用。②用肿瘤坏死因子40μg/L、不同浓度(0.005～10μmol/L)的阿托伐他汀钙与体外培养的人脐静脉内皮细胞共同孵育24h后,提取细胞的总RNA,采用半定量反转录聚合酶链反应在mRNA水平进行分析。③用曲线图表示E-选择素和细胞间黏附分子1表达在不同浓度阿托伐他汀钙影响下的变化趋势。结果:①在mRNA水平,阿托伐他汀钙对肿瘤坏死因子诱导的人脐静脉内皮细胞所表达的E-选择素与细胞黏附分子1均具有浓度依赖性。②阿托伐他汀钙对肿瘤坏死因子诱导人脐静脉内皮细胞表达E-选择素mRNA呈促进作用,即阿托伐他汀钙在0～10μmol/L的浓度区间内,随着其浓度由0,0.005,0.01μmol/L渐升至10μmol/L,E-选择素mRNA的表达呈逐渐升高的趋势。③阿托伐他汀钙对肿瘤坏死因子诱导人脐静脉内皮细胞表达细胞间黏附分子1的影响呈双向性,具有浓度差异性。即随着阿托伐他汀钙浓度由0,0.005,0.01μmol/L升至0.05μmol/L,细胞间黏附分子1mRNA表达呈逐渐下降趋势,而在高浓度(0.05～10μmol/L)区间,随着阿托伐他汀钙浓度0.05,0.1μmol/L渐升至10μmol/L,细胞间黏附分子1mRNA的量呈逐渐升高的趋势。结论:在基因水平,阿托伐他汀钙对肿瘤坏死因子诱导血管内皮细胞黏附分子的表达有着确切的调节作用,且存在着浓度依赖性,并在不同的浓度区间,对不同的黏附分子作用不同。     

阿托伐他汀钙调节人脐静脉内皮细胞E-选择素和细胞间黏附分子1表达的浓度依赖性

目的：观察具有调脂作用的阿托伐他汀钙在不同浓度下对肿瘤坏死因子诱导体外培养的人脐静脉内皮细胞表达E-选择素和细胞间黏附分子1的影响。 方法：①实验于2002-05／2003-12在大连医科大学附属第二医院实验室完成。将健康婴儿脐带进行无菌处理，用D-Hank’s液冲洗脐静脉，1g/L胶原酶消化、离心，置于37℃、体积分数0．05 CO2培养箱中培养，选择第2,3代细胞作为实验用。②用肿瘤坏死因子40μg／L、不同浓度（0．005～10μmol／L）的阿托伐他汀钙与体外培养的人脐静脉内皮细胞共同孵育24h后，提取细胞的总RNA，采用半定量反转录聚合酶链反应在mRNA水平进行分析。③用曲线图表示E-选择素和细胞间黏附分子1表达在不同浓度阿托伐他汀钙影响下的变化趋势。 结果：①在mRNA水平，阿托伐他汀钙对肿瘤坏死因子诱导的人脐静脉内皮细胞所表达的E-选择素与细胞黏附分子1均具有浓度依赖性。②阿托伐他汀钙对肿瘤坏死因子诱导人脐静脉内皮细胞表达E-选择素mRNA呈促进作用，即阿托伐他汀钙在0～10μmol／L的浓度区间内，随着其浓度由0，0．005,0．01μmol／L渐升至10μmol／L，E-选择素mRNA的表达呈逐渐升高的趋势。③阿托伐他汀钙对肿瘤坏死因子诱导人脐静脉内皮细胞表达细胞间黏附分子1的影响呈双向性，具有浓度差异性。即随着阿托伐他汀钙浓度由0,0．005,0．01μmol／L升至0．05μmol／L，细胞间黏附分子1 mRNA表达呈逐渐下降趋势，而在高浓度（0．05-10μmol／L）区间，随着阿托伐他汀钙浓度0．05，0．1μmol／L渐升至10μmol／L，细胞间黏附分子1 mRNA的量呈逐渐升高的趋势。 结论：在基因水平，阿托伐他汀钙对肿瘤坏死因子诱导血管内皮细胞黏附分子的表达有着确切的调节作用，且存在着浓度依赖性，并在不同的浓度区间，对不同的黏附分子作用不同。     

Shear stress selectively upregulates intercellular adhesion molecule-1 expression in cultured human vascular endothelial cells.

Disseminated Mycobacterium avium infection in AIDS is associated with high tissue burdens (10(9)-10(10) mycobacteria/g tissue) of organism. The basis for the extraordinary susceptibility of AIDS to M. avium infection is unclear. HIV or its constituents may alter mononuclear phagocyte functions resulting in enhanced intracellular M. avium growth. The effects of an envelope glycoprotein (gp120), a transmembrane protein (p121), and core proteins of HIV-1 on M. avium infection of human monocytes were examined. Preculturing monocytes with gp120 inhibited M. avium phagocytosis and consistently enhanced intracellular growth of six M. avium strains. Pretreatment with p121, gag5, or p24 did not inhibit phagocytosis nor enhance intracellular growth of M. avium. Incubation of gp120 with soluble CD4 before addition to monocyte cultures or pretreatment of monocytes with OKT4A abrogated gp120 effects on M. avium phagocytosis and intracellular growth. gp120 also augmented cytokine production by infected monocytes. These results suggest that gp120, but not p121 or core proteins, modulate monocyte phagocytosis and enhance intracellular growth of M. avium at least in part through monocyte CD4 receptors. Direct effects of HIV-1 products may, therefore, contribute to the diathesis of AIDS to develop disseminated M. avium infection and to the extensive replication of the organisms within tissue macrophages.     

Effect of high and low density lipoproteins on proliferation of cultured bovine vascular endothelial cells.

Bovine vascular endothelial cells maintained on dishes coated with an extracellular matrix and exposedto medium supplemented with lipoprotein-deficient serum (LPDS) require the presence of lipoprotein to proliferate optimally. High density lipoprotein (HDL) seems to be the major factor involved in the proliferation of vascular endothelial cells. This is mostly due to its lack of toxicity when added at high concentration, as well as to its nondependence on LPDS to exhibit its mitogenic properties. Therefore, HDL at physiological concentrations (1,000--1,500 microgram protein/ml) can fully replace serum. Low density lipoprotein, unlike HDL, has a biphasic effect. Although mitogenic for vascular endothelial cells when added at low concentration, once physiological concentrations are reached it becomes toxic for the cells. Moreover, and in contrast with HDL, the mitogenic effect of low density lipoprotein was found to be a function of the LPDS concentration to which cultures were exposed. The substrate upon which cultures are maintained has been found to be an important factor if a mitogenic effect of HDL is to be observed. When maintained on plastic, cells proliferate poorly in response to HDL unless fibroblast growth factor is added to the medium. In contrast, when maintained on extracellular matrix, an optimal growth rate is induced by HDL, even in the absence of fibroblast growth factor. This suggests that, in vivo, the integrity of the basement membrane upon which endothelial cells rest and migrate is an important factor in determining the cells response to lipoproteins present in plasma.     

Intermittent high glucose enhances ICAM-1, VCAM-1, E-selectin and interleukin-6 expression in human umbilical endothelial cells in culture: the role of poly(ADP-ribose) polymerase.

It has been previously reported that endothelial cells exposed to constant high concentrations of glucose upregulate the expression of adhesion molecules. Moreover, it has been suggested that this phenomenon is related to generation of oxidative stress. It has also been suggested that oxidative injuries, related to high glucose, induce the activation of the enzyme poly ADP ribose polymerase (PARP), which can promote the expression of adhesion molecules and the generation of inflammation. Recent in-vivo and in-vitro evidence suggests that oscillation of glucose may play an autonomous and direct role in favoring the development of cardiovascular complications in diabetes. In this study we have investigated the effects of constantly high and intermittently high glucose on nitrotyrosine formation (a marker of nitrosative stress) and adhesion molecule (ICAM-1, VCAM-1 and E-selectin), as well as on interleukin (IL)-6 expression in human umbilical vein endothelial cells, either in the presence or in the absence of PJ34, a potent inhibitor of PARP. We found that oscillating glucose was more effective in triggering the generation of nitrotyrosine and inducing the expression of adhesion molecules and IL-6 than stable high glucose. Pharmacological inhibition of PARP suppressed both nitrotyrosine formation, adhesion molecule expression and IL-6 to the levels seen in the normal glucose conditions. Thus, PARP activation appears to be involved in both promoting nitrosative stress and upregulating adhesion molecules and inflammation in endothelial cells exposed to oscillating high glucose conditions.     

氧化低密度脂蛋白刺激内皮细胞程序性死亡配体-1的表达

目的:研究氧化低密度脂蛋白(ox-LDL)对人脐静脉内皮细胞的负性共刺激分子程序性死亡因子配体-1(PD-L1)袁达的影响,探讨动脉粥样硬化发病的免疫机制.方法:体外培养人脐静脉内皮细胞,并分别与不同浓度(10、50、100 mg/L)ox-LDL温育24 h,以PBS作阴性对照,采用逆转录聚合酶链反应、流式细胞技术分别检测人脐静脉内皮细胞PD-L1的mRNA及蛋白表达水平.结果:随着ox-LDL浓度的增加,人脐静脉内皮细胞的PD-L1表达逐步升高,低浓度(10 mg/L)OX-LDL与对照组比较差异无统计学意义,中浓度(50 mg/L)及高浓度(100 mg/L)ox-LDL组较对照组PD-L1表达显著升高,差异有统计学意义(P＜0.05).结论:公认有致慢性炎症作用的ox-LDL刺激人脐静脉内皮细胞炎症反应时,上调负性共刺激分子PD-L1的表达,这种负反馈调节可能是抑制动脉粥样硬化的一种免疫机制.     

Injury to cultured endothelial cells induced by low density lipoproteins: protection by high density lipoproteins.

Cultured human endothelial cells derived from umbilical cord veins were injured when exposed to low density lipoproteins (LDL). Addition of high density lipoproteins (HDL), together with LDL, inhibited the cellular injury induced by LDL as demonstrated by lowered 51Cr release and prevention of morphological changes. Serum albumin had a similar, but far weaker effect. Preincubation of the cells with HDL did not reduce injury inflicted during a subsequent incubation with LDL, while preincubation with LDL aggravated later damage. The protective effect of HDL could be overcome by increasing the DLD concentration.     

Injury to human endothelial cells in culture induced by low density lipoproteins.

Low density lipoproteins (LDL) have been shown to injure culture endothelial cells derived from the human umbilical cord. During a 48 h incubation period LDL significantly increased 51Cr release from prelabelled cells and induced marked cellular injury if the ratio between the LDL cholesterol and the infranatant proteins was kept above 0.1-0.12 mmol/g protein. Actually, an injurious effect of a fixed concentration of LDL could be completely prevented by increasing the concentration of infranatant proteins. High density lipoproteins within physiological concentration ranges had no effect when tested in the presence of infranatant proteins. The effects of LDL were not cell specific because normal as well as LDL receptor negative human skin fibroblasts were injured by LDL.     

Insulin attenuates vasopressin-induced calcium transients and a voltage-dependent calcium response in rat vascular smooth muscle cells.

Insulin attenuates the contractile responses of vascular smooth muscle (VSM) to various agonists. Insulinopenic and insulin-resistant rats lack this normal attenuation of vascular contractile responses. To study this attenuating mechanism, the effects of insulin on calcium (Ca2+) responses of cultured VSM cells (a7r5) to arginine vasopressin (AVP) and membrane potential were investigated. Insulin (1 and 100 mU/ml) shifted AVP dose-response curves to the right, reducing relative potency of AVP by 16-fold and 220-fold, respectively. Responses to AVP were significantly attenuated within 30 min of insulin application. The AVP-elicited rise in [Ca2+]i was partially dependent upon extracellular Ca2+. AVP-elicited inward current was reduced by 90 min of insulin treatment (100 mU/ml), from a peak current of -103 +/- 27 pA (normal) to -37 +/- 15 pA (insulin treated). Peak voltage-dependent Ca(2+)-dependent inward current was unaffected by insulin; however, the current-voltage curve was shifted 16 +/-3 mV to the right by insulin. Thus, insulin may reduce VSM contractile responses by attenuating agonist-mediated rises in [Ca2+]i mediated, in part, by reductions in Ca2+ influx through both receptor- and voltage-operated channels.     

三七总皂苷对氧化型低密度脂蛋白诱导的人脐静脉内皮细胞血管细胞黏附分子1表达的影响水

背景:氧化低密度脂蛋白能诱导血管内皮细胞活化和黏附分子表达,在动脉粥样硬化形成早期起重要作用.三七总皂苷在心血管系统方面具有保护血管内皮细胞、显著改善动脉粥样硬化病变程度的药理作用.目的:验证三七总皂苷对氧化型低密度脂蛋白损伤内皮细胞后血管细胞黏附分子1的表达及与人单核细胞黏附的影响.设计、时间及地点:体外实验,分组对照,于2007-03/2008-05在北京中医药大学东直门医院中医内科学教育部重点实验室完成.材料:原代人脐静脉内皮细胞为美国Cascade Biologics公司产品;三七总皂苷(血塞通冻干粉针)为黑龙江珍宝岛制药有限公司产品,成分为三七总皂苷,批号:20040207.方法:以培养原代人脐静脉内皮细胞作为靶细胞.用氧化型低密度脂蛋白造成人脐静脉内皮细胞损伤模型.将培养的人脐静脉内皮细胞分为5组:氧化型低密度脂蛋白组(100 mg/L)、氧化型低密度脂蛋白+三七总皂苷组(终浓度分别为200,100,50 mg/L)、正常对照组.主要观察指标:光镜下观察细胞形态变化,四甲基偶氮唑盐法检测细胞活性;采用蛋白定量法检测人脐静脉内皮细胞与单核细胞的黏附率;用流式细胞仪测定人脐静脉内皮细胞的血管细胞黏附分子1的蛋白表达.结果:氧化型低密度脂蛋白作用人脐静脉内皮细胞后12,24 h时,人脐静脉内皮细胞损伤明显,细胞活性显著降低,人单核细胞与人脐静脉内皮细胞的黏附率显著升高,人脐静脉内皮细胞的血管细胞黏附分了1的蛋白表达水平也均明显升高,均明显高于正常对照组(P<0.05,P<0.01),而三七总皂苷能使氧化型低密度脂蛋白损伤的人脐静脉内皮细胞形态趋于正常,活性增强,并明显降低人单核细胞与人脐静脉内皮细胞的黏附率,以及显著降低血管细胞黏附分子1的蛋白的表达水平,与氧化型低密度脂蛋白组相比均有显著性差异(P<0.05,P<0.01),这种作用随着剂量的增加而增强.结论:三七总皂苷能通过下调血管细胞黏附分子1的表达抑制单核-血管内皮细胞黏附,从而发挥对血管内皮细胞的保护作用,这可能是其治疗动脉硬化闭塞症的机制之一.     

Telmisartan-enhanced hypercholesterolaemic serum-induced vascular endothelial growth factor expression in immortalized human umbilical vascular endothelial cells

OBJECTIVE: To clarify whether hypercholesterolaemia can increase vascular endothelial growth factor (VEGF) expression in human umbilical vascular endothelial cells (HUVECs) through the phosphatidylinositol 3-kinase (PI3K) pathway, and whether a special angiotensin II receptor blocker, telmisartan, can attenuate VEGF expression induced by hypercholesterolaemia. METHODS: Levels of VEGF expression, PI3K activity and angiogenesis in vitro were determined by various methods after HUVECs were incubated with hypercholesterolaemic serum or combined with telmisartan and/or wortmannin. RESULTS: We found that hypercholesterolaemic serum (cholesterol > or = 0.08 mmol/L) can increase VEGF expression in HUVECs and that telmisartan cooperates with hypercholesterolaemic serum in promoting VEGF expression. The increased VEGF expression was associated with enhanced PI3K activity and could be significantly inhibited by wortmannin, a potent PI3K inhibitor. Likewise, hypercholesterolaemic serum significantly promoted angiogenesis in vitro, which could be inhibited when PI3K activity was suppressed. CONCLUSIONS: Our study suggests that hypercholesterolaemic serum induces VEGF expression through PI3K in HUVECs and that telmisartan cooperates with hypercholesterolaemia in promoting VEGF expression.     

Interleukin 1 stimulates platelet-activating factor production in cultured human endothelial cells.

Monocyte-derived interleukin 1 (IL-1) was found to be a potent inducer of platelet-activating factor (PAF) in cultured human vascular endothelial cells (HEC). The product was identified as PAF by its behavior in chromatographic systems, its recovery of biological activity, and its physico-chemical properties and susceptibility to lipases. The response of HEC to IL-1 was concentration-dependent, took more than 2 h to become apparent, and decreased after 18 h of incubation. Most of the PAF produced was cell-associated and only a small amount (about 25% of the total) was released in the culture medium. To study the mechanism of IL-1-induced HEC-PAF production we tested the activity of 1-O-alkyl-sn-glycero-3-phosphocholine:acetyl/coenzyme A acetyltransferase in HEC. Acetyltransferase activity measured in IL-1-stimulated HEC lysates showed a three to five times greater maximum velocity, but the same Michaelis constant, as untreated cells. The regulation of PAF generation in HEC by IL-1 may be an important aspect of the two-way interaction between immunocompetent cells and vascular tissue.     

Increased expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured endothelial cells exposed to serum from type 1 diabetic patients: no effects of high glucose concentrations

Activation of the arterial endothelium may play an important role in the development of an atherosclerosis-prone vascular wall in diabetes. The induction of the adhesion molecules VCAM-1 and E-selectin on activated endothelial cells is crucial in monocyte recruitment during the atherogenic process. In the present study, we investigated whether sera from type 1 diabetic patients and non-diabetic persons are capable of inducing expression of VCAM-1 and E-selectin in human endothelial cells cultured in vitro. First, it was found that the addition of serum from non-diabetics to the cultures resulted in expression of adhesion molecules above basal level and also increased the cellular response to the cytokine tumor necrosis factor-alpha (TNF-alpha), a strong inducer of both adhesion molecules. Moreover, it was found that, on average, sera from 17 diabetic males induced a higher expression of VCAM-1 in the endothelial cells after 6 h of incubation than samples from 20 non-diabetic age-matched males (p < 0.05). No difference between the diabetic and non-diabetic group was seen in the expression of E-selectin. Likewise, no differences were observed between the effects of the sera to induce TNF-alpha responsivity. A series of experiments showed that alterations in the glucose concentrations of the growth medium (5.5-13.5 mmol/L) did not change the cellular content of either VCAM-1 or E-selectin before and after TNF-alpha treatment. In conclusion, it has been shown that sera from diabetic patients contain component(s), capable of inducing VCAM-1 expression in endothelial cells independent of hyperglycemia. Augmented induction of endothelial VCAM-1 expression by circulating factor(s) may play a role in the development of atherosclerosis in diabetes.     

Increased expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured endothelial cells exposed to serum from type 1 diabetic patients: no effects of high glucose concentrations

Activation of the arterial endothelium may play an important role in the development of an atherosclerosis-prone vascular wall in diabetes. The induction of the adhesion molecules VCAM-1 and E-selectin on activated endothelial cells is crucial in monocyte recruitment during the atherogenic process. In the present study, we investigated whether sera from type 1 diabetic patients and non-diabetic persons are capable of inducing expression of VCAM-1 and E-selectin in human endothelial cells cultured in vitro . First, it was found that the addition of serum from non-diabetics to the cultures resulted in expression of adhesion molecules above basal level and also increased the cellular response to the cytokine tumor necrosis factor-alpha (TNF- &#102 ), a strong inducer of both adhesion molecules. Moreover, it was found that, on average, sera from 17 diabetic males induced a higher expression of VCAM-1 in the endothelial cells after 6 h of incubation than samples from 20 non-diabetic age-matched males (p<0.05). No difference between the diabetic and non-diabetic group was seen in the expression of E-selectin. Likewise, no differences were observed between the effects of the sera to induce TNF- &#102 responsivity. A series of experiments showed that alterations in the glucose concentrations of the growth medium (5.5 - 13.5 mmol/L) did not change the cellular content of either VCAM-1 or E-selectin before and after TNF- &#102 treatment. In conclusion, it has been shown that sera from diabetic patients contain component(s), capable of inducing VCAM-1 expression in endothelial cells independent of hyperglycemia. Augmented induction of endothelial VCAM-1 expression by circulating factor(s) may play a role in the development of atherosclerosis in diabetes.