Velcade诱导多发性骨髓瘤细胞株U266细胞凋亡研究

为了研究velcade诱导多发性骨髓瘤细胞株U266细胞凋亡效应及机制，采用台盼蓝拒染法检测2、10、50和100nmol／L velcade处理U266细胞活率，用流式细胞术分析Annexin—V、线粒体跨膜电位（△ψm）和氧自由基（ROS），用半定量RT—PCR法检测bcl-2 mRNA的表达。结果表明：velcade抑制U266细胞增殖；诱导U266细胞凋亡，24小时Annexin—V阳性细胞比例增高，△ψm降低；12小时时活性氧明显增高，荧光强度增强；抗凋亡基因bcl-2表达降低。结论：velcade对U266细胞具有增殖抑制和杀伤作用。其可通过内源性细胞凋亡信号通路诱导U266细胞凋亡。     

细胞色素C对HL-60细胞凋亡作用及其与相关bcl-2、bax基因的关系

为了探讨细胞色素C在体外作用于HL-60细胞时细胞发生的变化及其相关凋亡基因的bcl-2、bax表达变化的机制，用不同浓度的细胞色素C作用于HL-60细胞24小时，然后分别用肌检测细胞色素C对HL-60细胞的抑制率；应用光学显微镜、荧光显微镜观察HL-60细胞形态的变化；用流式细胞术检测细胞凋亡率和细胞周期的变化；用DNA凝胶电泳检测HL-60细胞的凋亡；用RT—PCR检测bcl-2、bax基因的表达的变化。结果表明：在细胞色素C浓度为0—150mg／L时，细胞抑制率随着浓度的增加而增加；当细胞色素C浓度在0—37．5mg／L时，细胞凋亡率逐渐增加，可见典型的凋亡细胞和明显DNA梯形条带，同时，在该浓度范围内bcl-2表达逐渐减少，而bax表达逐渐增加；当细胞色素C浓度大于37．5mg／L时，细胞凋亡率增加不明显，但细胞出现坏死。结论：细胞色素C能诱导HL-60细胞发生凋亡，细胞色素C对细胞周期的作用是将细胞阻滞于G1期，并且细胞凋亡率、bcl-2、bax基因的表达的变化与细胞色素C浓度呈一定的量效依赖关系，细胞色素C诱导HL-60凋亡可能与bax的激活和bcl-2的抑制有关。     

bcl-2在HL-60细胞分化和凋亡过程中的表达

细胞凋亡抑制基因bcl-2在髓系造血细胞中的表达与细胞分化程度有关。本研究证实全反式维甲酸(ATRA)可诱导HL-60细胞凋亡。流式细胞仪分析表明,在HL-60细胞分化凋亡过程中bcl-2表达逐渐下降,凋亡细胞bcl-2表达水平较低,而未凋亡细胞bcl-2仍维持在高水平。上述结果提示:经ATRA诱导分化成熟的HL-60细胞与正常粒细胞相似,最终走向凋亡;bcl-2表达降低可能对终末分化细胞凋亡有易化作用;未凋亡细胞bcl-2高表达可能是肿瘤细胞耐药和白血病复发的重要因素。     

三氧化二砷诱导MUTZ-1细胞凋亡的端粒酶调控研究

为了研究三氧化二砷（As2O3）诱导人类骨髓增生异常综合征难治性贫血伴原始细胞过多型（MDS—RAEB）细胞株MUTZ-1细胞凋亡的端粒酶调控机制，采用端粒重复序列扩增-酶联免疫吸附试验（TRAP—ELISA）检测端粒酶活性；RT—PCR法检测端粒酶逆转录酶（hTERT）、TRF1（TTAGGG repeat binding factor 1）、TRF2（TTAGGG repeat binding factor 2）、bcl-2、bax等基因mRNA水平的表达；磷脂酰丝氨酸（PS）转位等方法检测细胞凋亡，结果表明：1—8μmol／L As2O3诱导MUTZ-1细胞凋亡呈时间、浓度依赖关系。在该浓度范围内，As2O3可下调细胞端粒酶活性。且端粒酶活性下调与凋亡细胞阳性率呈明显负相关（r=一0．938，P=0．018）。MUTZ-1细胞经As，01作用后，hTERT基因mRNA表达下调，并与端粒酶活性变化呈正相关（r=0．783，P=0.022），但As2O3对TRF1及TRF2基因mRNA表达没有明显影响.MUTZ-1细胞端粒酶活性受抑制同时，伴有bcl-2 mRNA表达下调及bcl-2／bax比值下降结论：As2O3可能通过抑制细胞端粒酶活性及hTERT表达，诱导MUTZ-1细胞凋亡。As2O3抑制MUTZ-1细胞端粒酶活性可能是诱导该凋亡机制之一。     

凋亡抑制基因survivin反义寡核苷酸联合bcl-2反义寡核苷酸诱导肺癌细胞株凋亡的实验观察

目的：探讨凋亡：抑制基因survivin反义寡核苷酸单用或联用bcl-2反义寡核苷酸对肺癌细胞株的作用，探讨其在抗癌方面的作用。方法：①实验于2002-08／2003-04在蚌埠医学院免疫学实验室完成。将对数生长期NCI—H446细胞分为6组：空白对照组，脂质体10mg／L组（仅加空脂质体），NSODN 500nmol／L组（该3组均为对照组），survivin反义寡核苷酸500nmol／L组，bcl-2反义寡核苷酸5μmol／L，survivin反义寡核苷酸500nmol／L＋bcl-2反义寡核苷酸5μmol／L组（分别在脂质体介导下转染不同寡核苷酸，48h后收取细胞进行以下检测）。②在脂质体介导下，以survivin的反义寡核苷酸作用于肺癌细胞株NCI-H446和SPC—A1，于72h用反转录聚合酶链反应检测survivin mRNA表达。凋亡指数：（静止期／DNA合成前期）占整个细胞周期的百分比；增殖指数=（DNA复制期＋合成后期／有丝分裂期）占整个细胞周期的百分比。②survivin反义寡核苷酸单独或联合bcl-2反义寡核苷酸作用NCI—H446后，用四甲基偶氮唑盐法检测细胞生长抑制率并计算两药相互作用指数，锥虫蓝拒染实验检测细胞死亡率。（3）计量资料差异性比较采用方差分析和q检验。结果：①两种肺癌细胞株皆表达survivin基因。survivin反义寡核苷酸作用细胞株后，出现生长抑制和细胞凋亡，细胞survivin mRNA明显下调，反义寡核苷酸500nmol／L作用72h后NCI—H446和SPC—A1细胞survivin mRNA抑制率分别达62．72％和67．43％。②四甲基偶氮唑盐法检测结果显示，survivin反义寡核苷酸和bcl-2反义寡核苷酸单独应用对NCI—H446细胞均有生长抑制作用；联合应用survivin反义寡核苷酸和bcl-2反义寡核苷酸的细胞生长抑制率为64．9％，优于单独应用（单用bcl-2反义寡核苷酸为34．2％）（P〈0．01），两药相互作用指数为0．708。锥虫蓝拒染实验显示，survivin反义寡核苷酸500nmol／L＋bcl-2反义寡核苷酸5μmol／L组细胞死亡率为62．1％，高于两药单用时的31．4％和41．4％。流式细胞仪检测凋亡显示，与各对照组相比，survivin反义寡核苷酸和bcl-2反义寡核苷酸均可诱导细胞凋亡，凋亡率分别为43．6％和30．7％，两者联用凋亡率提高到58．6％（p〈0．01）。结论：①survivin反义寡核苷酸能抑制肺癌细胞株survivin基因表达，并诱导细胞凋亡和抑制生长。②survivin反义寡核苷酸联合bcl-2反义寡核苷酸具有显著协同抗癌作用。     

bcl-2硫代反义寡核苷酸对Raji细胞增殖和凋亡的影响

研究bcl-2硫代反义寡核苷酸(bcl-2 ASODN)对淋巴系统恶性肿瘤的作用及机制。将bcl-2 ASODN与Raji细胞共孵育，应用MTT检测，电镜超微结构，流式细胞仪（FCM）分析和RT-PCR方法，观察bcl-2 ASODN对Raji细胞增殖及凋亡的影响，以及bcl-2蛋白及mRNA水平的变化。MTT检测显示bcl-2 ASODN可以部分抑制Raji细胞增殖；经ASODN作用48h，电镜超微细胞观察细胞呈现典型凋亡特征，包括胞膜出芽，异染色质核膜下浓聚形成凋亡小体及胞核破裂；FCM检测Annexin V^ /PI^-的凋亡细胞比例升高，20μmol/L bcl-2 ASODN处理Raji细胞72h，细胞凋亡率达43.86%，比对照组（10.05%）明显增高。bcl-2阳性细胞率逐渐下降，于72h达低谷为0.88%，明显低于对照组（79.54%）。bcl-2 mRNA水平亦显下降。结论 bcl-2 ASODN通过下调bcl-2蛋白表达水平，诱导Raji细胞凋亡。     

右旋柠烯对HL-60、K562白血病细胞体外作用的研究

本研究观察右旋柠烯（d-limonene，D-L）对HL-60和K562白血病细胞增殖凋亡的影响，并进一步探讨其作用机制。首先采用碘化丙锭染色法观察右旋柠烯对HL-60、K562细胞增殖的影响，再通过细胞形态学观察、流式细胞术分析、免疫细胞化学半定量测定突变型p53、bcl-2、bax基因的表达水平，系统观察D-L对HL-60、K562细胞体外诱导凋亡的情况。结果表明：D-L抑制HL-60和K562细胞的增殖，IC50均为0．75mmol／L，呈剂量时间依赖关系；D-L诱导HL-60、K562细胞凋亡；D-L在诱导HL-60细胞凋亡过程中随作用浓度增加，bcl-2的表达下降；D-L在诱导K562细胞凋亡过程中随作用浓度增加，突变型p53及bcl-2的表达下调，而bax的表达上调。结论：D-L抑制HL-60和K562细胞增值并诱导其凋亡；突变型p53，bcl-2，bax参与了D-L诱导凋亡的基因调控，     

血管内皮生长因子和血管生成素—1抑制心脏成肌细胞凋亡研究

目的：探讨血管内皮生长因子（VEGF165)和血管生成素－1（angiopoietin-1)抑制心肌细胞凋亡的作用机制。方法：将编码人VEGF165或angiopoietin-1的复制缺陷型腺病毒载体（Ad-VEGF165或Ad-Ang1)转染大鼠心脏成肌细胞（H9C2），24h后以H2O2诱导细胞凋亡，分析VEGF165和angiopoietin-1的抗凋亡作用。腺病毒转染24h后检测细胞中三磷酸肌醇激酶（phosphatidylinositol-3 kinase)活性和bcl-2表达水平。结果：VEGF165和angiopoietin-1可不同程度抑制H9C2细胞凋亡。VEGF165和Ang1作用下细胞内三磷酸肌醇激酶活性和bcl-2表达水平增高。结论：VEGF165和／或Ang1可抑制心脏成肌细胞凋亡，这种保护作用与其激活细胞内三磷酸肌醇激醇途径和促进抗凋亡分子bcl-2的表达相关，血管生长因子VEGF165和angiopoietin-1的心脏成肌细胞保护作用为其功能学研究和临床应用开辟了新的方向。     

一定浓度下三氧化二砷对T细胞淋巴瘤Hut-78细胞株增殖的影响

背景:近年来有将三氧化二砷试用于T细胞肿瘤的有效报道,但未见其治疗机制的相关研究.目的:检测三氧化二砷对人皮肤T细胞淋巴瘤Hut-78细胞的抑制增殖、诱导凋亡及细胞周期的影响.方法:分别采用MTT、PI单标记流式细胞术和TUNEL法检测2,5,10 μmol/L的三氧化二砷干预24,48,72 h,对人皮肤T细胞淋巴瘤Hut-78细胞株抑制增殖、诱导凋亡和细胞周期的影响,及其凋亡相关基因bcl-2及血管内皮细胞生长因子基因表达的变化.结果与结论:在一定的浓度范围内,三氧化二砷对Hut-78细胞存在增殖抑制作用,其增殖抑制作用在一定程度上可能与下调血管内皮细胞生长因子基因的表达有关,同时还存在一定的细胞毒作用;三氧化二砷可诱导Hut-78细胞发生凋亡,凋亡机制主要发生在G2~M期,其凋亡作用可能与下调bcl-2基因表达有关.三氧化二砷对Hut-78细胞的增殖抑制及诱导凋亡作用呈时间剂量依赖性.     

预防性干预脑缺血损伤与bcl-2基因家族对凋亡调控的作用

目的：bcl-2基因家族成员在脑缺血损伤机制所发挥的作用已被证实，结合凋亡的发生机制来阐明bcl-2基因家族对凋亡的调节作用，近而追求对脑缺血性损伤的早期预防性干预措施。资料来源：应用计算机检索Medline数据库1990—01／2004-10期间的相关献，检索词为“bcl-2”和“cerebml ischemia”，分别组合进行检索。限定章语言种类为英。同时计算机检索中国期刊全数据库1990-01／2004-10期间的相关献，检索词为“bcl-2，脑缺血，凋亡”，限定章语言种类为中。资料选择：对资料进行初审，选取实验包括上述干预组和对照组的献，然后排除非随机实验的研究，对剩余献开始查找全。资料提炼：共收集到51篇关于bcl-2家族成员及对脑缺血凋亡影响的随机与未随机献，23个试验符合纳入标准。资料综合：23个试验中有15个研究了脑缺血时bcl-2家族成员的表达水平，8篇采用转基因手法来观测bcl-2家族成员对脑缺血凋亡的调节作用。结论：Bcl-2蛋白家族具有调控细胞色素C，调控凋亡诱导因子释放的功能。凋亡作为一系列精确控制的基因表达和蛋白激活决定它是可干预的，未来的药物将从分子水平防止和减少凋亡，为脑血管疾病的一、二级康复预防提供可行性措施。     

Anti-proliferative effects of oridonin on SPC-A-1 cells and its mechanism of action

Oridonin, an extract from the Chinese herb Rabdosia rubescens, is currently one of the most important traditional Chinese herbal medicines. We investigated the anti-proliferative effect of oridonin on the lung cancer cell line SPC-A-1 and its mechanism of action. Growth inhibition was measured using a microculture tetrazolium assay and apoptosis was measured by several standard methods. Western blot analysis measured the expression of bcl-2 and bax proteins. Oridonin (> 28 micromol/l) inhibited the growth of SPC-A-1 cells and induced apoptosis. Marked morphological changes indicative of apoptosis were observed, especially in cells treated with oridonin for 48 - 60 h. Western blot analysis revealed downregulation of bcl-2 and upregulation of bax proteins following treatment with oridonin for 48 h. We conclude that oridonin demonstrated anti-proliferative and apoptosis-inducing effects on SPC-A-1 cells in vitro, and that changes in bcl-2 and bax protein levels may play an important role in its mechanism of action.     

腺病毒载体介导肝细胞生长因子基因对血管内皮细胞的作用

目的：研究腺病毒载体介导肝细胞生长因子（HGF）基因感染血管内皮细胞后在正常供氧、缺氧及缺氧后复氧的情况下细胞的凋亡情况。方法：将分离、培养的内皮细胞分为3组，分别给予M199（对照组）、HGF（HGF组）和HGF基因腺病毒载体（Ad-HGF组），分别在正常供氧、缺氧及缺氧后复氧3种情况下观察细胞的凋亡情况。结果：Ad-HGF组及HGF组细胞凋亡数均低于对照组（P〈0．01），Ad-HGF组与HGF组细胞凋亡数差异无显著性意义。结论：腺病毒载体介导HGF基因感染内皮细胞后能在缺氧情况下有效地阻止细胞凋亡。     

浙江蝮蛇蛇毒诱导人白血病K562细胞凋亡

目的研究浙江蝮蛇毒诱导人白血病K562细胞凋亡的作用及机制。方法MTT法测IC50值及细胞毒作用,Hoechest33258荧光染色法观察凋亡小体形成,流式细胞仪PI染色法检测凋亡峰和细胞周期,同时FCM及Westernblot法检测Bcl2蛋白表达。结果浙江蝮蛇毒能抑制细胞生长且呈剂量依赖关系,并能诱导人白血病K562细胞凋亡,Bcl2蛋白表达下降。结论浙江蝮蛇毒能诱导人白血病K562细胞凋亡且呈剂量依赖关系,此作用与Bcl2蛋白表达下调有关。     

缺氧预适应对缺氧复氧诱导内皮细胞-中性粒细胞黏附的影响

目的：观察缺氧预适应对缺氧／复氧后血管内皮细胞表面黏附分子的表达以及中性粒细胞－内皮细胞黏附的影响。方法：采用β－N－乙酰氨基己糖苷酶比色法检测黏附率;流式细胞术检测内皮细胞表面黏附分子E－选择素、细胞间黏附分子－1（ICAM－1）的表达;苔盼蓝摄取法检测细胞存活率;常规生化法检测乳酸脱氢酶活性。结果：血管内皮细胞经缺氧／复氧处理后,苔盼蓝摄取率,乳酸脱氢酶活性均明显增高,E－选择素、ICAM－1表达明显上调,其表面中性粒细胞的黏附增加,缺氧预适应显著抑制缺氧／复氧的上述作用。结论：缺氧预适应通过调节内皮细胞表面黏附分子的表达,抑制缺氧／复氧诱导的内皮细胞－中性粒细胞黏附。     

Intravenous liposomal delivery of the snake venom disintegrin contortrostatin limits breast cancer progression

Despite significant research in this area, metastatic breast cancer remains a disease with a poor prognosis. Until an effective therapy is developed, it is imperative that new treatment modalities be investigated. In this report, we describe an effective method for delivery of a novel snake venom disintegrin, contortrostatin (CN), in an orthotopic, xenograft model of human mammary cancer in immunodeficient mice. CN (Mr 13,500) is a homodimeric disintegrin isolated from venom of the Southern Copperhead snake. The homodimer possesses two Arg-Gly-Asp sites, which modulate its interaction with integrins on tumor cells and angiogenic vascular endothelial cells. Although our laboratory has previously described the antitumor activity of CN in a mouse model of human mammary cancer, the method of delivery, daily intratumor injection, was not translatable to clinical application. We now describe a clinically relevant method of administering CN, liposomal delivery (LCN). A unique liposomal system has been designed for i.v. administration of a biologically active protein with full retention of biological activity. Pharmacokinetics, biodistribution, platelet reactivity, and immunogenicity of LCN were determined and compared with similar characteristics of native, unencapsulated CN. There are several advantages to liposomal delivery of CN: (1) LCN has a significantly prolonged circulatory half-life compared with native CN; (2) LCN is passively accumulated in the tumor; (3) LCN has no platelet reactivity; and (4) LCN is not recognized by the immune system. Finally, antiangiogenic activity is an important component of CN's mechanism of antitumor action. We have demonstrated that i.v. delivery of LCN leads to potent antiangiogenic activity in the orthotopic, xenograft human mammary tumor model.     

Combination therapy with IFN-alpha plus bortezomib induces apoptosis and inhibits angiogenesis in human bladder cancer cells

In a recent study, we showed that the proteasome inhibitor bortezomib sensitizes human bladder cancer cells to IFN-induced cell death. Here, we characterized the molecular mechanisms underlying the antitumoral effects of the combination in more detail. Bortezomib synergized with IFN-alpha to promote apoptosis via a tumor necrosis factor-related apoptosis-inducing ligand-associated mechanism but did not inhibit production of proangiogenic factors (vascular endothelial growth factor, basic fibroblast growth factor, and interleukin-8) in human UM-UC-5 cells. In contrast, exposure to the combination did not increase the levels of apoptosis in human UM-UC-3 cells but did inhibit the production of basic fibroblast growth factor and vascular endothelial growth factor. Studies with tumor xenografts confirmed that combination therapy with bortezomib plus IFN-alpha was effective in both models but that the effects were associated with differential effects on tumor necrosis factor-related apoptosis-inducing ligand-associated apoptosis (predominant in UM-UC-5) versus inhibition of angiogenesis (predominant in UM-UC-3). Together, our results show that combination therapy with IFN-alpha plus bortezomib is effective but can work via different mechanisms (apoptosis versus angiogenesis inhibition) in preclinical models of human bladder cancer.     

The vascular endothelial growth factor (VEGF)/VEGF receptor system and its role under physiological and pathological conditions

The VEGF (vascular endothelial growth factor) family and its receptors are essential regulators of angiogenesis and vascular permeability. Currently, the VEGF family consists of VEGF-A, PlGF (placenta growth factor), VEGF-B, VEGF-C, VEGF-D, VEGF-E and snake venom VEGF. VEGF-A has at least nine subtypes due to the alternative splicing of a single gene. Although the VEGF165 isoform plays a central role in vascular development, recent studies have demonstrated that each VEGF isoform plays distinct roles in vascular patterning and arterial development. VEGF-A binds to and activates two tyrosine kinase receptors, VEGFR (VEGF receptor)-1 and VEGFR-2. VEGFR-2 mediates most of the endothelial growth and survival signals, but VEGFR-1-mediated signalling plays important roles in pathological conditions such as cancer, ischaemia and inflammation. In solid tumours, VEGF-A and its receptor are involved in carcinogenesis, invasion and distant metastasis as well as tumour angiogenesis. VEGF-A also has a neuroprotective effect on hypoxic motor neurons, and is a modifier of ALS (amyotrophic lateral sclerosis). Recent progress in the molecular and biological understanding of the VEGF/VEGFR system provides us with novel and promising therapeutic strategies and target proteins for overcoming a variety of diseases.     

In vitro Bartonella quintana infection modulates the programmed cell death and inflammatory reaction of endothelial cells

Bartonella quintana is an epicellular bacterium, which in vivo as well as in vitro, invades endothelial cells and develops within them inducing proliferative effects that play a pivotal role in neovascular manifestation of this disease. We investigated the effect of live Bartonella quintana and its LPS on apoptosis and inflammatory response in HUVEC-C, an endothelial cell line. The kinetics of the programmed cell death of Bartonella quintana-infected HUVEC-C showed a peculiar course. Even if early during infection apoptosis reached a peak after 6 h, later on apoptosis was inhibited. Such apoptosis inhibition was not observed during Bartonella quintana lipopolysaccharide treatment because LPS-stimulated HUVEC-C did progress to cell death. Evaluation of multiple cell signal transduction pathways revealed an overexpression of Apaf 1 and caspase 8 in HUVEC-C after 2 h of infection, and of bcl-2 starting from 10 h post Bartonella quintana infection. Moreover, Bartonella quintana and its LPS showed a different effect on the activation of genes involved in inflammatory response as revealed by molecular analysis of host cells. Bartonella quintana appears to be able to inhibit programmed cell death, inducing intracellular signals leading to survival and proliferation through the bcl-2 gene, despite the early increase of inflammatory status induced in endothelial cells. This mechanism, together with a poor endotoxin ability to stimulate strong inflammatory response, could contribute to the capability of the bacteria to persist intracellularly, causing chronic disease and producing neovascular manifestations.     

Vascular endothelial growth factor confers endothelial resistance to apoptosis through poly(ADP‐ribose) polymerase

Summary. Background: Vascular endothelial growth factor (VEGF) inhibits the endothelial apoptosis that is induced by caspases during vascular remodeling; however, the underlying mechanisms have not been completely elucidated. Objectives: We hypothesized that VEGF upregulates poly(ADP‐ribose) polymerase‐1 (PARP) as a caspase mediator, and sought to investigate the link between apoptosis inhibition by VEGF and PARP regulation in the human vasculature. Methods: Human endothelial cells (primary cells, macrovascular/microvascular lines) were incubated with 100 pg mL^?1 to 1 μg mL^?1 VEGF‐A(165) in the absence or presence of PARP small interfering RNA (siRNA). Apoptosis induced by integrin inhibition was measured by flow cytometry, trypan blue exclusion, and nuclear morphology. PARP expression and activity were determined by real‐time RT‐PCR, Western blot, and ribosylation assay. VEGF receptors and signal transduction were analyzed by inhibitor experiments, enzyme assays, western blot, and immunofluorescence microscopy. Immunohistochemistry was applied to a vascular culture model and to 24 atherosclerotic and 10 normal human arteries. Results: VEGF‐A(165) induced resistance to apoptosis caused by caspase activation in endothelial cells in a time‐dependent manner. VEGF, but not fibroblast growth factor‐2 or transforming growth factor‐β, time‐dependently and dose‐dependently induced PARP expression and activity, involving VEGF receptor‐2 colocalized with neuropilin‐1 as well as the signal transduction molecules c‐Jun N‐terminal kinase and Akt. The antiapoptotic effect of VEGF was abrogated by PARP siRNA. The relationship between local VEGF influence and endothelial PARP expression was confirmed in human arteries and the vascular culture model. Conclusions: VEGF exerts its antiapoptotic effect on the endothelium through the regulation of PARP expression. PARP has been attributed an ambiguous role in apoptosis; here, we show that PARP promotes vascular endothelial integrity in VEGF‐associated processes.     

γ-干扰素对过氧化氢诱导血管内皮氧化应激损伤的作用研究

目的 观察γ-干扰素(IFN-γ)对血管内皮氧化应激损伤的保护作用,并评价26S蛋白酶体在其中的作用.方法 建立由过氧化氢(H2O2)诱导的血管内皮氧化应激损伤细胞及离体器官模型,以细胞培养上清液中乳酸脱氢酶(LDH)及丙二醛(MDA)浓度评价血管内皮细胞(VEC)的损伤程度,以内皮依赖性血管松弛反应评价离体器官水平VEC的损伤程度.结果 H2O2可呈剂量依赖性和时间依赖性引起VEC损伤,表现为细胞培养上清液中LDH及MDA浓度增加(P<0.05或P<0.01),由乙酰胆碱(Ach)诱导的血管内皮依赖性松弛反应明显降低,表现为10-5 mol/L Ach引起血管最大舒张反应由(95.82±9.25)%降至(12.61±2.96)%(P<0.01);采用20 μg/L IFN-γ预孵育VEC 48 h后可明显降低由H2O2引起的LDH及MDA生成(P均<0.05),改善内皮依赖性血管松弛反应,由Ach诱导的血管最大舒张反应增至(72.68±18.82)%(P<0.01);26S蛋白酶体抑制剂lactacystin可取消由IFN-γ诱导的内皮抗氧化保护作用.结论 IFN-γ可诱导血管内皮对氧化应激的保护,其机制与26S蛋白酶体有关.