抗内皮细胞抗体介导的内皮细胞损伤机制

目的探讨抗内皮细胞抗体（antiendothelial cell antibody，AECA）对内皮细胞凋亡的影响及重组α-烯醇化酶对内皮细胞凋亡的阻断作用。方法以EA．hy926细胞（内皮细胞永生细胞）提取物蛋白为抗原，采用免疫印迹法检测并筛选47000-AECA阳性患者血清，用蛋白G亲和层析法纯化IgG，在体外诱导内皮细胞凋亡，观察重组α-烯醇化酶对凋亡的阻断作用。结果含47000-AECA IgG在体外可诱导内皮细胞凋亡，荧光染色可见明显的核形态变化及典型的凋亡小体；含47000-AECA系统性红斑狼疮患者的IgG作用于EA．hy926细胞24、48和72小时后，凋亡率均明显高于相同剂量正常人kG作用EA．hy926细胞的凋亡率；而经重组α-烯醇化酶预处理后EA．hy926细胞凋亡率则明显降低。含47000-AECA IgG作用于EA．hy926细胞8小时后，AnnexinV^＋细胞数明显增加，并随IgG作用时间和浓度的增加而升高；而经重组α-烯醇化酶预处理的含47000-AECA IgG作用于EA．hy926细胞后，AnnexinV^＋细胞有所减少。结论AECA在体外可诱导内皮细胞凋亡，引起内皮细胞损伤；重组α-烯醇化酶可部分阻断47000-AECA体外诱导内皮细胞凋亡的作用，α-烯醇化酶是AECA识别的自身抗原之一。     

替罗非班通过上调miR-22保护ox-LDL诱导的脐静脉内皮细胞损伤

目的探讨替罗非班对氧化型低密度脂蛋白(ox-LDL)诱导的脐静脉内皮细胞(EA.hy926)损伤的影响和可能机制。方法采用低、中、高剂量的替罗非班作用于ox-LDL诱导的EA.hy926细胞,采用细胞计数法(CCK-8)、流式细胞术分别检测细胞活力和凋亡。实时荧光定量PCR(qRT-PCR)检测miR-22表达水平。酶联免疫吸附法(ELISA)检测细胞培养上清液中肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)水平。转染miR-22模拟物上调EA.hy926细胞中miR-22表达水平,采用上述方法检测上调miR-22对ox-LDL诱导的EA.hy926细胞损伤的影响。结果替罗非班作用于ox-LDL诱导的EA.hy926细胞后,细胞存活率显著升高,凋亡率显著降低,细胞培养上清液中TNF-α和IL-6含量显著降低,miR-22表达显著升高(P0.05)。上调miR-22表达后,ox-LDL诱导的EA.hy926细胞培养上清液中TNF-α和IL-6含量显著降低,细胞存活率显著升高,凋亡率显著降低(P0.05)。结论替罗非班能够减轻ox-LDL诱导的脐静脉内皮细胞凋亡和炎症反应,其机制可能与上调miR-22表达有关。     

汉滩病毒感染EA.hy926细胞上调固有免疫相关分子表达的研究

目的　探讨汉滩病毒（hantaan virus, HTNV）感染EA.hy926细胞诱导抗病毒固有免疫相关分子的表达,为建立HTNV感染的细胞模型提供依据。方法　将HTNV感染EA.hy926细胞,利用间接免疫荧光和实时荧光定量PCR技术于不同感染时间段,检测EA.hy926细胞中模式识别受体、细胞因子及抗病毒相关分子的mRNA表达水平。结果　HTNV感染EA.hy926细胞后,随着感染时间的持续,核蛋白mRNA相对表达倍数显著上调,且不同感染时间段差异具有统计学意义（P＜0.05）;与未处理组相比,HTNV感染EA.hy926后,Toll样受体3、RIG-I和MDA5模式识别受体mRNA相对表达倍数均显著上调（P均＜0.05）,IL-6、IL-10、IFN-β和CCL5细胞因子mRNA相对表达倍数均显著上调（P均＜0.05）,ISG15、MxA、OAS1、IFITM1和IFITM3抗病毒相关分子mRNA相对表达倍数均显著上调（P均＜0.05）。结论　HTNV感染EA.hy926细胞后,可上调抗病毒固有免疫相关分子的表达,该细胞可以作为体外HTNV感染的细胞模型。     

苦荞麦总黄酮对软脂酸诱导的EA.hy926细胞Bcl-2表达的影响

目的研究苦荞麦总黄酮对软脂酸诱导的人脐静脉血管内皮细胞株(EA.hy926)Bcl-2表达的影响。方法苦荞麦总黄酮作用于高浓度软脂酸刺激下的EA.hy926细胞,RT-PCR技术检测Bcl-2 mRNA表达水平,免疫组织化学方法检测Bcl-2蛋白的表达情况。结果与对照组相比,模型组细胞Bcl-2 mRNA及蛋白表达显著降低(P<0.01);与模型组相比较,苦荞麦总黄酮组与二甲双胍组细胞Bcl-2 mRNA和蛋白表达水平明显升高(P<0.01);苦荞麦总黄酮组与二甲双胍组之间无显著差异(P>0.05)。结论苦荞麦总黄酮可以促进EA.hy926细胞Bcl-2基因及蛋白的表达发挥抑制凋亡的作用。     

MIF促进新生微血管生成及其相关基因表达的研究

目的探讨巨噬细胞移动抑制因子(macrophage migration inhibitory factor,MIF)对新生微血管生成及血管内皮生长因子(VEGF)、Smadl 基因表达的影响。方法以体外培养的人血管内皮细胞株 EA.hy926为研究对象,分别用体外血管生成分析试剂盒及免疫组织化学染色法观察 MIF 在体内外对新生微血管生成的作用。通过基因芯片实验检测 MIF 对内皮细胞血管生成相关基因表达的影响,并通过 RT-PCR 检测 MIF 对 VEGF_(165)、Smadl 基因表达的影响。结果 MIF 可以促进人血管内皮细胞在体外形成血管腔,在小鼠体内也能促进新生微血管生成。MIF 可以显著上调血管内皮细胞血管生成基因21个,其中上调 VEGF_(165)、Smadl 基因表达呈剂量依赖性。结论MIF 有促进新生微血管生成的作用,并能促进人血管内皮细胞中 VEGF_(165)、Smadl 基因表达。     

不同浓度TGF-β对内皮细胞锌指基因ZNF580表达的影响

目的探讨不同浓度转化生长因子(TGF-β)对内皮细胞锌指基因ZNF580表达的影响。方法以不同浓度(0.25⁴ ng/ml)的TGF-β刺激EA.hy926内皮细胞12 h,提取细胞总RNA,通过半定量逆转录聚合酶链反应(RT-PCR)分析ZNF580基因在内皮细胞中的表达情况。结果成功提取内皮细胞总RNA并进行RT-PCR反应;当TGF-β浓度从0.254 ng/ml)的TGF-β刺激EA.hy926内皮细胞12 h,提取细胞总RNA,通过半定量逆转录聚合酶链反应(RT-PCR)分析ZNF580基因在内皮细胞中的表达情况。结果成功提取内皮细胞总RNA并进行RT-PCR反应;当TGF-β浓度从0.25² ng/ml逐渐增加时,ZNF580的表达呈逐渐下降趋势(P<0.05,P>0.01);但继续增加TGF-β刺激浓度至4 ng/ml,ZNF580的表达又有所回升(P<0.05)。结论随TGF-β刺激浓度逐渐升高,EA.hy926内皮细胞中ZNF580基因表达呈先降低后升高变化,表明ZNF580很可能是受TGF-β信号转导通路调控的核转录因子,ZNF580和Smad2间的相互作用及ZNF580转录活性的改变可能进一步影响下游相应靶基因的转录,进而影响内皮细胞的功能。     

磷酯酰肌醇3-激酶/蛋白激酶B信号通路介导葛根素改善缺氧复氧损伤的作用及机制

目的:探讨磷酯酰肌醇3-激酶(PI3K)/蛋白激酶B(Akt)信号通路介导葛根素改善缺氧复氧损伤的作用及机制。方法:应用噻唑蓝法筛选出合适的葛根素以及PI3K抑制剂LY294002干预人脐静脉内皮细胞EA.hy926的浓度。分为对照组、缺氧复氧组、缺氧复氧+葛根素组(葛根素组),缺氧复氧+葛根素+LY294002处理组(葛根素+抑制剂组),每组均设3个复孔。应用蛋白免疫印迹法(Western blot)检测葛根素预处理细胞后以及葛根素预处理细胞的同时加入LY294002后对B细胞淋巴瘤/白血病-(2Bcl-2)、Bcl-2相关X蛋白(Bax)、活化天冬氨酸蛋白水解酶-(3cleaved caspase-3)、活化天冬氨酸蛋白水解酶-9(cleaved caspase-9)、磷酸化的蛋白激酶B(p-Akt)、Akt蛋白表达的影响。应用实时荧光定量PCR检测葛根素预处理对EA.hy926细胞缺氧复氧后天冬氨酸蛋白水解酶-3(caspase-3)和Bcl-2信使核糖核酸(m RNA)表达的影响。应用Hoechest染色检测葛根素预处理对EA.hy926细胞凋亡的影响。结果:葛根素(10-7mol/L)明显升高缺氧复氧后EA.hy926细胞活力(P0.001),并显著上调Bcl-2蛋白水平的表达,下调Bax、cleaved caspase-9、cleaved caspase-3蛋白水平的表达(P均0.01)。与缺氧复氧组相比,葛根素预处理后,p-Akt蛋白表达水平明显升高(P0.01)。加入LY294002(10μmol/L)后p-Akt蛋白表达水平下降,且抗凋亡蛋白Bcl-2的表达水平下降,促凋亡蛋白cleaved caspase-3、cleaved caspase-9、Bax的表达水平升高(P均0.01)。结论:葛根素对缺氧复氧诱导的EA.hy926细胞凋亡具有抑制作用,其抑制作用可能与其对PI3K/Akt信号通路的调控有关。     

棕榈酸对EA.hy926细胞胆固醇代谢相关基因表达的影响及机制

目的研究棕榈酸(PA)对内皮细胞株EA.hy926胆固醇代谢的影响,检测胆固醇流出、胆固醇胞内转化、脂蛋白摄入以及信号通路相关基因表达的变化。方法体外培养内皮细胞株EA.hy926,分为白蛋白(ALB)对照组和PA处理组。采用实时荧光定量PCR法检测ATP结合盒转运体A1(ABCA1)、ABCG1、27-羟化酶、清道夫受体A1(SR-A1)、SR-B1、CD36、凝集素样氧化低密度脂蛋白受体1(LOX-1)、肝X受体α(LXRα)、过氧化物酶体增殖物激活受体γ(PPARγ)的表达变化。结果和ALB对照组相比,10、20、30μmol/L PA处理组ABCG1 mRNA水平显著下降(P0.01),20、30μmol/L PA处理组CD36、LOX-1 mRNA水平显著升高(P0.05)。与ALB对照组相比,10、20、30μmol/L PA处理组LXRαmRNA水平显著下降(P0.001、P0.05、P0.001),10μmol/L PA处理组PPARγmRNA水平显著下降(P0.05)。而10、20、30μmol/L PA处理EA.hy926细胞未显著影响ABCA1、SR-A1、SR-B1、27-羟化酶的表达。结论 PA能够改变内皮细胞EA.hy926细胞胆固醇流出和脂蛋白摄入相关基因的表达,其机制与LXRα和PPARγ信号途径有关。     

槲皮素对软脂酸诱导的EA.hy926细胞eNOS合成的影响

目的研究槲皮素对软脂酸诱导EA.hy926细胞e NOS合成的影响。方法体外培养EA.hy926细胞,分正常对照组、模型组、槲皮素组、二甲双胍组,采用RT-PCR法及免疫组化法,测定各组细胞e NOS m RNA和蛋白表达。结果模型组细胞e NOS m RNA和蛋白表达显著低于正常对照组(P0.05),药物组与模型组相比e NOS m RNA及蛋白表达显著增加(P0.05),药物组间差异无统计学意义(P0.05)。结论槲皮素对软脂酸诱导EA.hy926细胞e NOS合成具有显著促进作用。     

颈动脉斑块与斑块旁组织基因差异表达和信号通路分析

目的基于颈动脉粥样硬化斑块中基因芯片数据分析差异性基因表达、信号传导通路及蛋白质网络分析。方法从基因表达数据库(GEO)下载GSE43292基因芯片数据,数据预处理后,使用在线R软件分析颈动脉斑块和斑块旁组织中差异表达的基因,运用生物医学信息学GSEA方法进行富集GO分析和Pathway分析,并对差异性基因行蛋白质网络分析。结果芯片数据分析显示,颈动脉斑块和斑块旁组织中表达水平显著上调的有87个基因,表达水平显著下调的有60个基因(P均0.01),并绘制成热图。GSEA的GO功能富集分析发现,差异表达多与抗原结合、丝氨酸水解酶活性、趋化因子受体结合相关。GSEA的Pathway富集分析显示,差异表达上调基因与造血干细胞系、溶酶体、细胞因子受体相互作用等通路中富集。STRING分析筛选出IL-8、CXCL-10、SELE、MMP-9、IL-18共5个核心基因。结论通过生物信息学方法对GEO基因芯片数据分析,发现了动脉粥样硬化斑块中差异性基因的相关信号传导通路及蛋白质的核心基因,为动脉粥样硬化研究提供基础资料。     

Comparative expression profiling in primary and immortalized endothelial cells: changes in gene expression in response to hydroxy methylglutaryl-coenzyme A reductase inhibition.

Immortalized cell lines offer significant logistical advantages over primary cells when used for in-vitro studies. Immortalized cells may, however, exhibit important differences relative to their primary cell counterparts. In this study, microarrays were used to make a genome-wide comparison between primary human umbilical vein endothelial cells (HUVECs) and EA.hy926, an immortalized HUVEC cell line, in their baseline properties and in their response to inhibition of the mevalonate pathway with an inhibitor of hydroxy methylglutaryl-coenzyme A reductase (statin). HUVECs and EA.hy926 were incubated with control medium, atorvastatin, mevalonate, or a combination of atorvastatin and mevalonate for 24 h. Gene expression profiles were obtained in duplicates using Affymetrix Human Genome U133A 2.0 arrays (Santa Clara, California, USA). Probe-sets were selected according to the following criteria: a twofold or greater increase/decrease in atorvastatin-treated cells compared with untreated cells; a twofold or greater reversal of the effect of atorvastatin by combined treatment with atorvastatin and mevalonate; no significant change in gene expression in cells treated with mevalonate alone compared with untreated cells. Most genes that were expressed by untreated HUVECs, were also expressed by untreated EA.hy926 cells. EA.hy926 cells, however, constitutively expressed a large number of additional genes, many of which were related to cell cycle control and apoptosis. Atorvastatin induced differential expression (> or = twofold) of 103 genes in HUVECs (10 up, 93 down) and 466 genes in EA.hy926 cells (198 up, 268 down). Applying the above selection criteria, thrombomodulin and tissue plasminogen activator were up-regulated in both cell types, whereas, connective tissue growth factor, thrombospondin-1, and cysteine-rich angiogenic inducer 61 were down-regulated. In conclusion, EA.hy926 cells retain most of the characteristics of endothelial cells under baseline conditions as well as after treatment with atorvastatin. It is necessary, however, to carefully select and validate changes in genes that are the focus of studies when using EA.hy926 cells. While this cell line is highly useful in studies on some genes, including genes encoding molecules involved in regulating thrombohemorrhagic homeostasis, they appear to be less suited for studies focused on other genes, particularly those involved in the regulation of cell proliferation and apoptosis.     

登革2型病毒与整合素β3相互作用机制的研究

目的 观察登革2型病毒(dengue virus+etotype 2,DV2)感染后及转染DV2病毒蛋白的质粒后,EA.hy926细胞中整合素β3表达规律及表达量的变化,以初步明确DV2与整合素β3的相互作用的可能机制.方法　经噬斑法测定DV2在EA.hy926中的增殖规律,并通过间接免疫荧光染色检测DV2感染后及病毒...     

Expression of ryanodine receptor type 3 and TRP channels in endothelial cells: comparison of in situ and cultured human endothelial cells

OBJECTIVE: Ca(2+) mobilization plays an important role in endothelial function by stimulating Ca(2+)-dependent synthesis of vasodilating factors. In addition to inositol-1,4,5-trisphosphate (InsP(3)) mediated Ca(2+) mobilization, Ca(2+) release from ryanodine-sensitive pools and Ca(2+)-influx through TRP channels have been suggested to be important in endothelial Ca(2+)-signaling. However, the function and molecular identity of TRP channels and ryanodine receptors in human endothelium in situ are still elusive. We hypothesized that expression of ryanodine-receptors (RyR) and TRP channels differs between human endothelium in situ and in cultured cells. METHODS: By combining single-cell RT-PCR and patch-clamp techniques, expression of RyR and TRP channels was determined in situ in endothelial cells of human mesenteric artery (HMAECs) obtained from patients undergoing bowel resection and in the endothelial cell line EA.hy926. RESULTS: At the single cell level, expression of RyR 3 was detected in 25 and 5% of HMAECs and EA.hy926 samples, respectively. Expression of the RyR 1 and 2 was not detected in either HMAECs or EA.hy926. In patch-clamp experiments in HMAECs, applications of caffeine (0.5 mM) induced sustained hyperpolarization mediated by activation of Ca(2+)-activated K channels. In EA.hy926, caffeine-induced hyperpolarization was not detected. Single HMAECs expressed the TRP genes, TRP1 and TRP3, but not TRP 4 and 6. The TRP1 was the predominantly expressed TRP gene in HMAECs in situ whereas TRP3 expression was rarely detected. EA.hy926 expressed only TRP1. In patch clamp experiments in HMAECs, Ca(2+)-store depletion activated non-selective cation currents leading to Ca(2+) entry. CONCLUSIONS: Our findings suggest that, in addition to InsP(3) mediated Ca(2+) release, Ca(2+) release from ryanodine-sensitive stores mediated by RyR3 and Ca(2+) entry through TRP1 might represent important components of endothelial Ca(2+) signaling in situ and thereby of endothelial function in intact human blood vessels.     

阿妥伐他汀对人结肠癌细胞基因表达谱的影响

目的 研究阿妥伐他汀对人结肠腺癌colo-320细胞的反式调节基因,并对结果进行验证.方法 以阿妥伐他汀作用于人结肠腺癌细胞株colo-320为实验组,对照组加入PBS,提取总mRNA,逆转录为cDNA,进行基因芯片技术分析;采用Western Blot方法检测阿妥伐他汀对细胞中热休克蛋白70(HSPTO)表达的影响.结果 实验组细胞19种基因的表达水平上调,24种基因的表达水平下调;实验组HSP70表达水平高于对照组.结论 阿妥伐他汀可使人结肠癌细胞的基因表达谱发生改变,可能是他汀类药物防治结肠癌的重要分子机制之一.     

Increased expression of endothelin-converting enzyme-1c isoform in response to high glucose levels in endothelial cells

Endothelin-1 (ET-1) is both a potent vasoconstrictor and mitogenic factor that has been implicated as a cause of the micro- and macrovascular complications of diabetes mellitus. The pathway by which the high-glucose environment of diabetes mediates increased levels of endothelins has not been completely elucidated but appears to involve endothelin-converting enzyme (ECE-1), which converts inactive big ET-1 to active ET-1 peptide. To determine the effect of high glucose concentrations on the expression of ECE-1, hybrid endothelial cells (EA.hy926) and human umbilical vein endothelial cells (HUVEC) were both grown in various glucose concentrations. There was a 2-fold increase in ECE-1 immunoreactivity in the EA.hy926 cell line growing in medium containing 22.2 versus 5.5 mmol/l glucose after 24 h, which rose to greater than 20-fold after 5 days. Similar results were seen with HUVEC. Bradykinin or NG-nitro-L-arginine methyl ester did not change the effect of high glucose on ECE-1 protein expression. High glucose induced a 72 and 41% increase in total protein kinase C (PKC) activity in both EA.hy926 cells and HUVEC, respectively, and a 39, 49 and 109% elevation in PKC beta1, beta2 and delta expression, respectively, in EA.hy926 cells. The increase in ECE-1 expression was inhibited in both cell cultures by GF109203X (5 micromol/l), a general PKC inhibitor, while addition of 10 nmol/l phorbol myristic acid to EA.hy926 cells or HUVEC growing on medium containing 5.5 mmol/l glucose increased ECE-1 expression to a level similar to that of cells conditioned in high glucose. Human ECE-1 protein exists in four different isoforms, termed 1a, 1b, 1c and 1d. Northern blot analysis revealed that only ECE-1c isoform mRNA levels increased. Immunohistochemical staining of EA.hy926 cells grown in high glucose concentrations demonstrated an increase in the ECE-1c isoform, which occurred mainly in the plasma membrane. These results showed that the PKC pathway may play an important role in the glucose-mediated induction of ECE-1 expression. The main isoform to increase in response to high glucose was ECE-1c. This enzyme may be one of the factors contributing to the elevated ET-1 peptide levels observed in diabetes.     

不稳定冠心病循环microRNA表达谱特点及功能分析

目的 明确不稳定冠心病患者循环microRNA（miRNA）表达谱,并对差异表达miRNA在细胞增殖中的调控作用进行探讨。方法 （1）分别收集不稳定冠心病患者（试验组）及疑似心绞痛的非冠心病患者（对照组）血浆,通过miRNA芯片检测,得到试验组患者循环miRNA表达谱。（2）分别在3个不同的生物信息学数据库——TargetScan、miRanda和DIANAmT,对miRNA靶基因进行预测,得到在3个数据库均有预测的miRNA靶基因。（3）通过DAVID数据库,对上述靶基因在细胞增殖方面的功能进行聚类及信号通路分析。（4）通过实时（real time,RT）-PCR实验,进一步验证循环miRNA-19b（miR-19b）在两组中的表达水平。（5）结合功能聚类分析结果,对差异表达最明显的（miR-19b）在细胞增殖中的调控作用进行验证。结果 （1）与对照组相比,试验组存在39个差异表达miRNAs,其中miR-19b差异表达最明显。（2）通过对miRNA靶基因的预测,发现有14个miRNAs与细胞增殖关系密切,其中miR-19b调控的细胞增殖相关基因最多。（3）RT-PCR检测证实不稳定冠心病患者血浆miR-19b水平较对照组明显增高。（4）细胞增殖实验表明,miR-19b明显抑制血管内皮细胞（EA.hy926细胞）增殖。结论 不稳定冠心病患者具有特定的循环miRNA表达谱,这些miRNAs可能是不稳定冠心病的潜在生物标志物。miR-19b可能通过抑制内皮细胞增殖,发挥稳定动脉粥样硬化斑块的保护作用。     

系统性血管炎抗内皮细胞抗体与抗中性粒细胞胞质抗体的相关性初探

目的以来源于大小血管内皮细胞的两种永生细胞株为底物,检测系统性血管炎血清中抗内皮细胞抗体(AECA),分析其与抗中性粒细胞胞质抗体(ANCA)的相关性。方法细胞酶联免疫吸附试验(Cyto-ELISA)法检测血清中AECA;间接免疫荧光法(IIF)及抗抗体结合内皮细胞表面的蛋白酶3(PR3)、抗MPO-ELISA检测血清中ANCA;IIF及抗PR3、抗MPO-ELISA检测细胞株中PR3及MPO;反转录—聚合酶链反应(RT-PCR)法检测细胞株中PR3及MPOmRNA。结果AECAEA(EA.hy926为底物所测AECA)阳性率33.6%(41/122),AECAHMEC(HMEC-1为底物所测AECA)37.7%(46/122),ANCA35.3%(43/122),AECAEA或AECAHMEC与ANCA串联诊断系统性血管炎敏感性分别为59.8%(73/122)或60.7%(74/122)。AECAEA与ANCA,AECAHMEC与ANCA分别行配对字2检验,差异均无显著性(P>0.05),符合率仅分别为49.2%及51.6%。EA.hy926和HMEC-1中蛋白水平及mRNA水平均无PR3和MPO的表达。结论EA.hy926与HMEC-1中无PR3、MPO蛋白水平的表达,ANCA与AECA可能是两种相互独立的抗体,串联检测可提高诊断敏感性。     

Drug Resistance of Endocardial Endothelial Cells is Related to Higher Endogenous ABCG2

Endocardial endothelial cells (EECs), when compared with endothelial cells of arteries and veins, possess higher resistance to apoptosis-inducing anticancer agents. The mechanism of this resistance property is unknown. We have investigated the molecular mechanism, which contributes to increased cell survival capacity in EECs. We explored whether the resistance to apoptosis is associated with the cellular expression of ATP-binding cassette transporters such as P-glycoprotein, MRP-1, and ABCG2. We used primary and immortalized porcine endocardial endothelial cells (PEECs and hTERT PEECs) and compared the results with that in porcine aortic endothelial cells (PAECs), left atrioventricular valve endothelial cells (PVECs), and human umbilical vein endothelial cell line (EA.hy926). FACS and immunoblot analysis revealed a significantly higher expression of ABCG2 in PEECs and hTERT PEECs compared to PAECs, PVECs, and EA.hy926. Using apoptosis-inducing anticancer agents such as doxorubicin and camptothecin, through chromatin condensation assay and immunoblot analysis, we demonstrated a higher resistance to apoptosis in EECs compared to PAECs, PVECs, and EA.hy926. Interestingly, resistance in EECs reversed in presence of ABCG2 specific inhibitor, fumitremorgin C. Our observations suggest that an inherently high expression of ABCG2 in EECs protects them against apoptosis in presence of anticancer agents.