卡维地洛对氧化低密度脂蛋白诱导血管内皮细胞ADMA-DDAH系统的影响

目的 观察卡维地洛对氧化低密度脂蛋白(ox-LDL)诱导的人脐静脉内皮细胞(HUVECs)二甲基精氨酸-二甲基赖氨酸水解酶(DDAH)活性及表达的影响,以探讨卡维地洛对内源性一氧化氮合酶抑制物不对称二甲精氨酸(ADMA)代谢机制的影响.方法 采用改良的Jaffe法培养原代人脐静脉内皮细胞(HUVECs),取生长良好的3～6代HUVECs用于实验,分为(1)空白对照组:加DMEM培养液;(2)ox-LDL组:加入ox-LDL(100 mg/L,150 mg/L);(3)ox-LDL 卡维地洛组:同时加入150 mg/L ox-LDL及卡维地洛(10 μmol/L)共孵24h后,检测上清液中NO、NOS活性、ADMA含量、L-胍氨酸(L-cit)浓度,采用Western blotting测定细胞裂解液中二甲基精氨酸-二甲基赖氨酸水解酶(DDAH)的蛋白表达.结果 ox-LDL条件培养下,内皮细胞的代谢产物ADMA、ET的量均较空白对照组高,而NO的量及NOS的活性减少;反应DDAH酶活性的L-cit浓度显著降低,且有浓度依赖性,而DDAH的表达无明显变化.卡维地洛干预后,ADMA、ET的量较ox-LDL组降低,NOS活性及NO增加,L-cit浓度明显升高.结论 ox-LDL诱导下,内皮损伤ADMA的增加与DDAH的活性减弱有关,而与DDAH的表达无关.卡维地洛通过增加DDAH活性促进ADMA代谢,使NOS活性增高,抑制ox-LDL对内皮功能的损伤.     

LOX-1对氧化低密度脂蛋白所诱导的PAI-1基因表达的影响

目的探讨血凝素样氧化型低密度脂蛋白受体(LOX)-1对氧化低密度脂蛋白(ox-LDL)所诱导1型纤溶酶原激活物抑制剂-1(PAI-1)表达的影响。方法不同浓度ox-LDL培养人脐静脉内皮细胞(HUVECs),采用倒置显微镜观察内皮细胞形态变化,通过反转录-聚合酶链反应(RT-PCR)测定LOX-1、PAI-1mRNA表达,Westernblot、酶联免疫吸附试验(ELISA)分别测定LOX-1、PAI-1蛋白的表达。结果不同浓度ox-LDL组,LOX-1和PAI-1mRNA和蛋白的表达明显增加,且呈浓度依赖性(P<0.01);用250μg/mLPoly(Ⅰ)与HUVECs预先作用2h后,再加入50μg/ml的ox-LDL培养24h,与未加Poly(Ⅰ)相比,LOX-1和PAI-1mRNA和蛋白的表达明显减少(P<0.05)。结论ox-LDL可以调节培养的脐静脉内皮细胞LOX-1和PAI-1表达;LOX-1作为ox-LDL特异性受体,介导了ox-LDL诱导脐静脉内皮细胞表达LOX-1。同时该实验提示了ox-LDL诱导脐静脉内皮细胞表达PAI-1是通过LOX-1介导的。     

西红花苷对氧化性低密度脂蛋白致内皮细胞损伤的保护作用

目的:探讨西红花苷对氧化性低密度脂蛋白(Ox-LDL)致内皮细胞损伤的保护作用.方法:在体外培养牛主动脉内皮细胞中,加入不同剂量的西红花苷培养12h后,再加入50μg·mL-1的Ox-LDL继续培养24h,测定培养液中乳酸脱氢酶(LDH)活性和一氧化氮(NO)的含量,测定细胞中一氧化氮合酶(NOS)的活性;利用流式细胞仪观察其对Ox-LDL诱导的内皮细胞凋亡的影响.结果:西红花苷(10,10-7,10-6mol·L-1)可剂量依赖性地抑制LDH活性及外漏(P＜0 01),提高细胞内NOS的活性(P＜0.01),使细胞分泌的NO含量升高(P＜0.01);西红花苷对Ox-LDL诱导的内皮细胞凋亡有抑制作用.结论:西红花苷对Ox-LDL致内皮细胞损伤有保护作用.     

3种中药成分对氧化型低密度脂蛋白诱导人主动脉内皮细胞损伤的影响

目的 探讨3种中药成分（姜黄素、连翘苷、白藜芦醇）对氧化型低密度脂蛋白（Ox-LDL）诱导的人主动脉内皮细胞（HAEC）损伤的影响。方法 实验设空白对照组（等体积基础培养液）,溶剂对照组[等体积含二甲基亚砜（DMSO）的基础培养液],Ox-LDL组（20μg/mL Ox-LDL）,姜黄素(1)(2)(3)(4)组（20μg/mL Ox-LDL+2.5μmol/L、5μmol/L、10μmol/L、20μmol/L姜黄素）,连翘苷(1)(2)(3)(4)组（20μg/mL Ox-LDL+10μmol/L、20μmol/L、40μmol/L、80μmol/L连翘苷）,白藜芦醇(1)(2)(3)组（20μg/mL OxLDL+20μmol/L、40μmol/L、80μmol/L白藜芦醇）,采用四甲基偶氮噻唑盐（MTT）法检测细胞活性,并计算细胞增殖率;采用实时荧光定量聚合酶链式反应（qPCR）法检测细胞微管相关蛋白1轻链3(LC3)和环氧合酶2(COX-2)mRNA的表达水平。结果 与Ox-LDL组比较,姜黄素、白藜芦醇各剂量组,连翘苷(4)组细胞增殖率均显著降低（P <0.01或P ...     

天然苯丙烷类化合物对氧化低密度脂蛋白诱导的内皮细胞毒性的抑制作用

氧化的低密度脂蛋白(Ox-LDL)可能是动脉粥样硬化致病因素之一。作者研究了5个苯丙烷类化合物毛蕊糖苷(acteoside,1)、悬垂连翘苷 B(forsythoside B,2)、arenario-side(3)、ballotetroside(4)和 I-咖啡酰-L-苹果酸(5)对最低氧化的低密度脂蛋白     

五味子酚对氧化低密度脂蛋白引起的血管内皮细胞及神经细胞损伤的保护作用

目的：氧化低密度脂蛋白（ox-LDL）对血管内皮细胞及神经细胞均有毒性作用，与动脉粥样硬化，神经退行性疾病的发展密切相关。本文探讨了具有很强抗氧化作用的五味子有效成分五味子酚（Sal）对ox-LDI。引起的牛主动脉内皮细胞及神经细胞NGl08-15的损伤和凋亡的保护作用及其初步的机制。方法：以细胞形态，MTT法，LDH释放检测ox-LDL对细胞的损伤及Sal的作用；DNA电泳，核染色质荧光染色观察细胞的凋亡，流式细胞术检测凋亡细胞的百分率；自由基（ROS）荧光探针DCF检测细胞内ROS变化，Western-blot法检测线粒体细胞色素C的释放。结果：ox-LDL可引起内皮细胞和NGl08-15细胞的损伤、凋亡，细胞形态发生明显变化，存活率降低，胞内LDH泄漏增加，出现核染色质聚集、DNA梯状条带，流式细胞术检测出现G1亚峰，凋亡细胞百分率显著增加，并可刺激细胞内ROS产生，促进NGl08-15细胞线粒体细胞色素C的释放增加。提前加入Sal对上述细胞损伤具有明显的保护作用，并能显著抑制细胞的凋亡，减少细胞内ROS产生，降低细胞色素C的表达。结论：Sal能抑制ox-LDL引起的血管内皮细胞及神经细胞的毒性损伤、凋亡，其机制可能与减少胞内自由基、抑制线粒体细胞色素C的释放有关。     

三七皂苷对氧化低密度脂蛋白损伤血管内皮细胞保护作用的研究

目的:研究三七皂苷(PNS)对氧化低密度脂蛋白(Ox-LDL)损伤血管内皮细胞的保护作用。方法:体外培养人脐静脉内皮细胞(HUVEC),加入100mg·L-1Ox-LDL造成细胞损伤,同时加入不同浓度PNS进行干预。观察形态学变化;采用MTT法测定细胞活性;比色法检测细胞上清液中乳酸脱氢酶(LDH)的释放量;硝酸还原法和放射免疫法分别测定HUVEC培养上清液中一氧化氮(NO)、内皮素(ET)含量。结果:各剂量PNS可使作用Ox-LDL的HUVEC形态趋于正常。与正常对照组比较,HU-VEC经Ox-LDL作用后,细胞活性显著下降,LDH的释放量显著升高;300、100、30mg·L-1PNS显著升高细胞活性,抑制LDH释放。HUVEC经Ox-LDL作用后,与正常对照组比较,培养上清液中NO含量显著降低,ET含量显著升高;300、100mg·L-1PNS显著升高NO含量,300mg·L-1PNS显著降低ET含量。结论:PNS对Ox-LDL损伤的血管内皮细胞具有一定的保护作用,可调节内皮细胞活性物质NO、ET的分泌。     

不对称二甲基精氨酸和内皮细胞功能紊乱及相关疾病的关系

在生理情况下,一氧化氮（nitric oxide,NO）是血管内皮细胞衍生的重要血管活性介质之一,具有保持静息血管张力、稳定血压、抑制血栓形成等重要生理功能。NO主要由一氧化氮合酶（nitric oxide synthase,NOS）家族催化左旋精氨酸（L-arginine,L-Arg）合成。NOS主要有三种亚型：神经型（nNOS）、诱导型（iNOS）和内皮型（eNOS）。NOS是钙和钙调素-依赖性的,可被乙酰胆碱、P物质、     

凝集素样氧化型低密度脂蛋白受体的病理作用和药物靶点研究

氧化型低密度脂蛋白(OxLDL)是动脉粥样硬化的主要致病因素，但是OxLDL必须通过其特异性受体，凝集素样氧化型低密度脂蛋白受体-1(LOX-1)的介导才能发挥作用。近来研究发现．众多因素能调控LDX-1的病理表达，内皮细胞吞噬与LDX-1结合OxLDL后触发一系列信息通路，调控转录因子的表达，使粘附分子、炎症因子等表达上调，活性氧表达降低，导致内皮损伤、动脉粥样硬化等疾病形成，LDX-1是众多事件的初始阶段，所以可能成为重要的药物作用靶点。     

溶血卵磷脂对血管内皮细胞增殖及凋亡的影响

目的观测溶血卵磷脂(LPC)对血管内皮细胞增殖及凋亡的影响,从而探讨动脉硬化发生的机制。方法取体外培养的人脐静脉内皮细胞(HUVECs),在含不同浓度LPC(5、10、20mg/L)的培养基中分别培养6、12、24、48h,用四甲基偶氮唑蓝(MTT)比色法、流式细胞仪、荧光显微镜观测血管内皮细胞增殖及凋亡的变化。结果与正常对照组比较,LPC抑制内皮细胞增殖,促进细胞凋亡,且其作用呈时间-效应、浓度-效应依赖关系,但随着LPC浓度增加,细胞凋亡增加的同时细胞死亡比例也增加。结论LPC抑制血管内皮细胞增殖,促进细胞凋亡,可能是其致动脉粥样硬化机制之一。     

Fluvastatin reduces endothelin secretion of cultured human umbilical vein endothelial cells

Objective: Fluvastatin is an agent of a new lipid lowering drug class, the 3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors, which seems to elicit direct effects on the vasculature. Methods: The effect of fluvastatin on endothelin secretion in endothelial cell cultures from human umbilical veins was investigated. Results: Fluvastatin significantly reduced endothelin secretion by 13% at a concentration of 10⁻⁸ M, by 41% at 10⁻⁷ M and by 62% at 10⁻⁶ M. Conclusion: Since endothelin is a potent vasoconstrictor which may be associated with the aetiology of cardiovascular diseases, the reduction of its synthesis by fluvastatin may contribute to the beneficial effects of this substance on the cardiovascular system. Received: 12 April 1999 / Accepted in revised form: 23 August 1999     

非诺贝特对溶血卵磷脂诱导的血管内皮细胞增生及凋亡的影响

目的:观察非诺贝特对溶血卵磷脂(LPC)诱导的血管内皮细胞增生、凋亡的影响并探讨其机制。方法:体外培养人脐静脉内皮细胞(HUVECs),分为正常对照组、LPC组、非诺贝特低浓度组(10μmol·L-1)、非诺贝特中浓度组(50μmol·L-1)及非诺贝特高浓度组(100μmol·L-1)。分别观测LPC对血管内皮细胞增生、凋亡及凋亡调控蛋白抑制X连锁凋亡抑制蛋白(XIAP)的影响,及非诺贝特干预后的变化。结果:与正常对照组比较,LPC抑制内皮细胞增生,促进内皮细胞凋亡,XIAP表达减弱。非诺贝特可干预LPC对内皮细胞的作用,使内皮细胞增生增强,凋亡减少,XIAP表达增强。结论:非诺贝特可通过促进XIAP表达干预LPC对HUVECs增生及凋亡的影响。     

吡格列酮对人脐静脉内皮细胞CD40/CD40L表达的影响

目的探讨吡格列酮对氧化低密度脂蛋白(oxLDL)刺激下的人脐静脉内皮细胞(HUVECs)CD40/CD40L表达的影响。方法原代培养人脐静脉内皮细胞,给予oxLDL刺激和不同浓度吡格列酮干预。采用流式细胞技术检测CD40/CD40L在细胞上的表达,采用反转录-聚合酶链反应(RT-PCR)检测LOX-1mRNA的表达。结果OxLDL以浓度和时间依赖的方式刺激HUVECs表达CD40/CD40L,吡格列酮以剂量依赖的方式减轻ox-LDL刺激HUVECs表达CD40/CD40L。同时我们还观察到oxLDL能刺激HUVECs上调LOX-1mRNA的表达,而吡格列酮能明显抑制这种作用。结论吡格列酮能减轻oxLDL刺激下的人脐静脉内皮细胞CD40/CD40L的表达,其作用的机制可能与其抑制了HUVECs的LOX-1受体表达有关。     

Effect of dietary phenolic compounds on apoptosis of human cultured endothelial cells induced by oxidized LDL

1. Oxidized low density lipoproteins (LDL) are toxic to cultured endothelial cells. Mildly oxidized LDL, characterized by relatively low levels of TBARS and only minor modifications of apoB, were obtained by using 2 experimental model systems of oxidation, namely oxidation by u.v. radiation or ferrylmyoglobin (a two electron oxidation product from the reaction of metmyoglobin with H₂O₂).
2. Toxic concentrations of mildly oxidized LDL induce apoptosis (programmed cell death) of cultured endothelial cells, as shown by typical morphological features, by the in situ TUNEL procedure and by DNA fragmentation revealed on gel electrophoresis. This apoptosis is calcium-dependent and subsequent to the intense and sustained cytosolic [Ca²⁺]_i peak elicited by oxidized LDL.
3. Five naturally occurring phenolic compounds present in food and beverages were able to prevent, in a concentration-dependent manner, the apoptosis of endothelial cells induced by oxidized LDL. Among the compounds tested, caffeic acid was the most effective. Under the conditions used, the protective effect of caffeic acid (IC₅₀ 8.3±2.1 μmol  l⁻¹) in the prevention of apoptosis induced by oxidized LDL was significantly higher than that of the other compounds tested (IC₅₀s were 12.4±3.2, 14.1±4.1, 20.4±4.4 and 72.6±9.2 μmol  l⁻¹ for ferulic, protocatechuic, ellagic and p-coumaric acids, respectively).
4. The anti-apoptotic effect of caffeic acid results from the addition of two effects, (i) the antioxidant effect which prevents LDL oxidation and subsequent toxicity (‘indirect'' protective effect); (ii) a ‘direct'' cytoprotective effect, acting at the cellular level.
5. Effective concentrations of caffeic acid acted at the cellular level by blocking the intense and sustained cytosolic [Ca²⁺]_i rise elicited by oxidized LDL.
6. In conclusion, phenolic acids (caffeic and ferulic acids being the most potent of the compounds tested under the conditions used) exhibit a potent cytoprotective effect of cultured endothelial cells against oxidized LDL. In addition to antioxidant effect delaying LDL oxidation, caffeic acid acts as a cytoprotective agent, probably by blocking the intracellular signalling triggered by oxidized LDL and culminating in the sustained calcium rise which is involved in oxidized LDL-induced apoptosis.

     

Genipin inhibits endothelial exocytosis via nitric oxide in cultured human umbilical vein endothelial cells

Aim： Exocytosis of endothelial Weibel-Palade bodies, which contain von Willebrand factor （VWF）, P-selectin and other modulators, plays an important role in both inflammation and thrombosis. The present study investigates whether genipin, an aglycon of geniposide, inhibits endothelial exocytosis. Methods： Human umbilical vein endothelial cells （HUVECs） were isolated from umbilical cords and cultured. The concentration of VWF in cell supernatants was measured using an ELISA Kit. P-selectin translocation on the cell surface was analyzed by cell surface ELISA. Cell viability was measured using a Cell Counting Kit-8. Mouse bleeding times were measured by amputating the tail tip. Western blot analysis was used to determine the amount of endothelial nitric oxide synthase （eNOS） and phospho-eNOS present. Nitric oxide （NO） was measured in the cell supernatants as nitrite using an NO Colorimetric Assay. Results： Genipin inhibited thrombin-induced VWF release and P-selectin translocation in HUVECs in a dose- and time- dependent manner. The drug had no cytotoxic effect on the cells at the same doses that were able to inhibit exocytosis. The functional study that demonstrated that genipin inhibited exocytosis in vivo also showed that genipin prolonged the mouse bleeding time. Furthermore, genipin activated eNOS phosphorylation, promoted enzyme activation and increased NO production. L-NAME, an inhibitor of NOS, reversed the inhibitory effects of genipin on endothelial exocytosis. Conclusion： Genipin inhibits endothelial exocytosis in HUVECs. The mechanism by which this compound inhibits exocytosis may be related to its ability to stimulate eNOS activation and NO production. Our findings suggest a novel antiinflammatory mechanism for genipin. This compound may represent a new treatment for inflammation and/or thrombosis in which excess endothelial exocytosis plays a pathophysiological role.     

阿托伐他汀对缺氧致人脐静脉内皮细胞损伤的保护作用

目的观察阿托伐他汀对缺氧导致人脐静脉内皮细胞(HUVECs)损伤的保护作用。方法体外培养HUVECs,建立缺氧模型,采用MTT法测定细胞增殖,透射电子显微镜技术观察细胞的微观结构;检测细胞培养液中LDH、NO、ET-1、Ang-Ⅱ及6-keto-PGF1α水平。结果阿托伐他汀能够促进缺氧HUVECs的增殖,稳定细胞的微观结构,显著降低细胞内LDH的释放及ET-1的分泌(P<0.01),提高NO、PGI2的分泌(P<0.01)。结论阿托伐他汀对缺氧导致HUVECs损伤具有明显的保护作用。     

氧化型低密度脂蛋白与血管紧张素II在脑梗死发病中的相关关系探讨

目的 :探讨氧化型低密度脂蛋白与血管紧张素II在急性脑梗死发病中的相关关系。方法 :对47例脑梗死患者、30例高血压病患者和48例健康人分别进行血浆ox LDL和AngII水平的测定。结果 :急性脑梗死组和高血压病组的血浆ox LDL、AngII水平均高于正常对照组 (P<0 01)。急性脑梗死组与高血压病组之间血浆ox LDL水平无显著性差异 (P>0 05) ,脑梗死组AngII水平高于高血压病组 (P<0 05)。急性脑梗死组血浆ox LDL水平与AngII水平呈正相关 (r=0 4765 ,P<0 01)。结论 :血浆ox LDL和AngII水平的升高可能参与动脉粥样硬化和脑梗死的发生和发展