欧芹素乙对人脐静脉内皮细胞的保护作用及对血管内皮生长因子表达的影响

目的:研究欧芹素乙对内皮细胞的保护作用;溶血磷脂酰胆碱(LPC)对人脐静脉内皮细胞株HUVEC细胞中血管内皮生长因子(VEGF)表达的影响以及欧芹素乙的影响.方法:应用四唑盐(MTT)法检测溶血磷脂酰胆碱对HUVEC细胞的毒性作用及欧芹素乙的保护作用;应用基础酶联免疫吸附试验(ELISA)检测各组条件培养基中VEGF蛋白含量;采用RT-PCR法及Reahime PCR方法检测溶血磷脂酰胆碱对VEGF mRNA的表达及欧芹素乙的影响.结果:MTT检测结果显示,溶血磷脂酰胆碱对HUVEC细胞具有较强的生长抑制作用,而欧芹素乙对溶血磷脂酰胆碱所致的细胞增殖抑制具有较好的保护作用.ELISA结果显示,HUVEC细胞暴露于溶血磷脂酰胆碱后,VEGF蛋白含量明显升高;加入欧芹素乙后剂量依赖性地降低VEGF蛋白的表达.RT-PCR结果显示,溶血磷脂酰胆碱可以增加3种VEGF异构体的转录水平,其中VEGF165的表达显著增加,欧芹素乙可剂量依赖性地抑制溶血磷脂酰胆碱引起的VEGF mRNA的高表达.结论:欧芹素乙对溶血磷脂酰胆碱引起的细胞损伤有明显的保护作用;欧芹素乙可抑制溶血磷脂酰胆碱所诱导的HUVEC细胞中VEGF蛋白及VEGF mRNA的高表达,对内皮细胞起到保护作用.     

Effect of vascular endothelial growth factor and epidermal growth factor on iatrogenic apoptosis in human endothelial cells

To study the effect of growth factors on iatrogenic apoptosis, we examined the influence of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) on staurosporine-induced apoptosis in primary cultures of human umbilical vein endothelial cells (HUVEC). Apoptosis was evaluated by a cell viability test, the TUNEL-POD assay and the activation of the pro-apoptotic caspase-3. Staurosporine (10-100nM) caused the activation of caspase-3. This effect was manifest after 2hr of incubation and reached its maximum after 5hr. Severe loss of viability followed within 18hr. VEGF or EGF (10-100ng/mL) added together with staurosporine decreased the activation of caspase-3. The loss of viability was 24hr delayed. The action of growth factors was observed at 1% serum concentration but also at concentration optimal for HUVEC survival (10%, v/v). Furthermore, the inhibition of PI-3 kinase (PI-3K) by wortmannin or LY294002 as well as the inhibition of MEK by PD098059 or U0126 prevented the protective effect of VEGF and EGF. Western blotting analysis showed that after 3hr of incubation with staurosporine the level of the anti-apoptotic protein Mcl-1 decreased and this effect was reverted by VEGF. It is concluded that VEGF and EGF antagonize the pro-apoptotic action of staurosporine by the combined signalling of PI-3K and ERKs pathways.     

Inhibition of vascular endothelial growth factor (VEGF)-induced endothelial proliferation, arterial relaxation, vascular permeability and angiogenesis by dobesilate

Vascular endothelial growth factor (VEGF) is a key factor in angiogenesis and vascular permeability which is associated with many pathological processes. 2,5-hydroxybenzene sulfonate (DHBS; dobesilate) is a small molecule with anti-angiogenic activity that has been described as an inhibitor of fibroblast growth factors (FGF). The aim of the present study was to evaluate the effects of DHBS on VEGF-induced actions. The effects of DHBS were evaluated on VEGF-induced proliferation in human umbilical vein endothelial cells (HUVEC) and rat aorta relaxation, as well as on in vivo VEGF-induced skin vascular permeability and neovascularization in rats. DHBS at 50 and 100 μM concentration significantly inhibited the proliferation of HUVEC induced by VEGF (10 ng/ml), without significantly affecting HUVEC proliferation in the absence of VEGF. Rapid VEGF-induced activation of Akt in HUVEC was also prevented by DHBS (100 μM). Additionally, DHBS (2 μM) specifically inhibited the relaxation of rat aorta induced by VEGF (0.1 to 30 ng/ml), but not endothelium-dependent relaxation to acetylcholine (1 nM to 10 μM). The in vivo enhancement of vascular permeability caused by VEGF injection (50 μl at 10 ng/ml) in rat skin was also inhibited by DHBS co-administration (200 μM) (74.8±3.8% inhibition of dye extravasation). Administration of DHBS (200 mg/kg/day; i.p.) also reduced VEGF-induced angiogenesis in vivo. DHBS inhibits main responses elicited in vitro and in vivo by VEGF. As a dual antagonist of VEGF and FGF activities, DHBS could be of therapeutic interest in the treatment of diseases related to VEGF/FGF overproduction and excessive angiogenesis.     

壳聚糖抑制高糖诱导的脂质过氧化及血管内皮细胞与单核细胞黏附

目的研究壳聚糖(chitosan)对高糖诱导细胞产生脂质过氧化及血管内皮细胞与单核细胞黏附的抑制作用。方法建立人脐静脉血管内皮细胞(HUVEC)高糖培养模型,实验分空白对照组、高糖模型组、高糖+壳聚糖组,测定细胞产生羟自由基(OH.)及脂质过氧化产物丙二醛(MDA)量;同时取单核巨噬细胞系Raw264.7,以荧光染料Rhodamin123孵育后加入以上各组,荧光摄像及比色检测单核细胞黏附数量;RT-PCR法检测血管细胞黏附分子(VCAM-1)mRNA变化。结果与空白对照组比较,高糖引起HUVEC产生OH.及MDA含量增加,黏附于HUVEC的Raw264.7数量以及VCAM-1表达升高;壳聚糖可呈浓度依赖性地抑制上述现象,但对细胞存活无明显影响。结论壳聚糖可能通过减轻自由基与脂质过氧化损伤,下调血管内皮细胞VCAM-1的表达,从而抑制高糖诱导的单核细胞与内皮细胞黏附。     

高糖对人脐静脉内皮细胞凋亡及bcl-x、bax和 eNOS表达的影响

目的:探讨高糖对人脐静脉内皮细胞(HUVEC)凋亡的影响,及其与bcl-x、bax和eNOS表达的相关性。方法:将培养成功的HUVEC以不同浓度的葡萄糖孵育72h,提取细胞总RNA。采用半定量逆转录聚合酶链反应(SQ-RT-PCR)法检测内皮细胞bcl-x、bax以及eNOS表达。用吖啶橙/溴乙锭(AO/EB)荧光染色法进行内皮细胞凋亡定性。结果:高浓度葡萄糖(33.3mmol)可诱导HUVEC凋亡增加(P<0.01),eNOS及bcl-x表达减弱。HUVEC凋亡与eNOS表达呈负相关。结论:糖尿病状态下高血糖诱导内皮细胞凋亡,可能与bcl-x及eNOS表达减弱有关。     

槲皮素抑制血管生成作用的实验研究

目的　研究槲皮素 (Quercetin)对血管生成和培养的人脐静脉内皮细胞 (HUVEC)的影响。方法　采用生长因子 (血管内皮细胞生长因子VEGF、碱性成纤维细胞生长因子bFGF)诱导的鸡胚绒毛尿囊膜 (CAM)血管增生模型观察槲皮素对血管生成的影响 ;利用培养的HUVEC ,用MTT法观察槲皮素抑制内皮细胞增殖的作用 ;流式细胞仪观察槲皮素对HUVEC细胞周期的影响。结果　槲皮素 (0 1、0 0 5和 0 0 2 5mmol·L-1)能明显抑制VEGF诱导的CAM小血管生成 ;槲皮素 (0 1和 0 0 5mmol·L-1)能明显抑制bFGF诱导的CAM小血管生成 ;槲皮素 (2 4 0、12 0 μmol·L-1和 6 0 μmol·L-1)对内皮细胞增殖有抑制作用 ,抑制率分别为 6 7 0 %、5 8 1%和39 7% ;槲皮素 (2 4 0、12 0 μmol·L-1)能显著导致HUVEC的S、G2 期阻滞。结论　槲皮素能抑制VEGF和bFGF诱导的血管生成 ,且对内皮细胞增殖具有抑制作用。     

川芎嗪对高糖诱导的人视网膜血管内皮细胞增殖的影响

目的 观察川芎嗪对高糖诱导的人视网膜血管内皮细胞（HRCECs）增殖的影响。方法 将HRCECs细胞分为对照（生理盐水）组、模型（25 mmol/L葡萄糖）组和川芎嗪低、中、高浓度（50、100、200 μmol/L）组,培养48 h后,MTT细胞毒实验检测细胞增殖变化,流式细胞技术检测细胞周期,ELISA法检测血管内皮生长因子（VEGF）表达。结果 与对照组比较,高糖对HRCECs细胞增殖、分裂（M）期比例、上清VEGF浓度均具有显著促进作用（P<0.05、0.01）;与模型组比较,低、中、高浓度川芎嗪对高糖诱导的HRCECs细胞增殖、分裂（M）期比例、上清VEGF浓度均发挥显著抑制作用（P<0.05、0.01）,且呈浓度相关性。结论 川芎嗪可能通过抑制高糖诱导的HRCECs细胞VEGF高表达,阻滞细胞周期,发挥抑制HRCECs细胞增殖的作用。     

Morroniside protects cultured human umbilical vein endothelial cells from damage by high ambient glucose

AIM: To determine whether morroniside, a compound in Cornus officinalis Sieb et Zucc can prevent cultured human umbilical vein endothelial cells (HUVEC) from damage by high ambient glucose. METHODS: HUVEC was incubated in glucose, 5 or 30 mmol/L, either alone or in the presence of morroniside (final concentration 100, 10, and 1 μmol/L, respectively) for 48 h. The proliferation of HUVEC was quantified by MTT method; its cycle was analyzed by flow cytometry; morphological change…     

Caveolin-1 is important for nitric oxide-mediated angiogenesis in fibrin gels with human umbilical vein endothelial cells

AIM: The role of caveolin-1 (Cav-1) in angiogenesis remains poorly understood. The endothelial nitric oxide (NO) synthase (eNOS), a caveolin-interacting protein, was demonstrated to play a predominant role in vascular endothelial growth factor (VEGF) -induced angiogenesis. The purpose of our study was to examine the role of Cav-1 and the eNOS complex in NO-mediated angiogenesis. METHODS: Human umbilical vein endothelial cells (HUVEC) were isolated and cultured in 3-D fibrin gels to form capillary-like tubules by VEGF stimulation. The expression of Cav-1 and eNOS was detected by semiquantitative RT-PCR. The HUVEC were treated with antisense oligonucleotides to downregulate Cav-1 expression. Both transduced and non-infected HUVEC were cultured in fibrin gels in the presence or absence of VEGF (20 ng/mL) and NG-nitro-L-arginine methyl ester (L-NAME; 5 mmol/L). NO was measured using a NO assay kit and capillary-like tubules were quantified by tubule formation index using the Image J program. RESULTS: RT-PCR analysis revealed that Cav-1 levels steadily increased in a time-dependent manner and reached their maximum after 5 d of incubation, but there were no obvious changes in eNOS mRNA expression in response to VEGF in the fibrin gel model. VEGF (20 ng/mL) can promote NO production and the formation of capillary-like tubules, and this promoting effect of VEGF was blocked by the addition of L-NAME (5 mmol/L). When transduced HUVEC with the antisense Cav-1 oligonucleotides were plated in the fibrin gels, the capillary-like tubules were significantly fewer than those of the non-infected cells. The capillary-like tubules formation and NO production of transduced HUVEC with the antisense Cav-1 oligonucleotides cultured in fibrin gels showed no responses to the addition of VEGF (20 ng/mL) and L-NAME (5.0 mmol/L). CONCLUSION: NO was a critical angiogenic mediator in this model. Cav-1 was essential for NO-mediated angiogenesis and may be an important target of anti-angiogenesis therapy.     

3,4,5,6-Tetrahydroxyxanthone prevents vascular endothelial cell apoptosis induced by high glucose

Apoptosis of endothelial cells may be an important risk factor contributing to the incidence of vascular complications in diabetes. In the present study, we tested the effect of 3,4,5,6-tetrahydroxyxanthone, a synthetic xanthone derivative, on apoptosis induced in human umbilical vein endothelial cells (HUVEC) by a high glucose concentration. Cell apoptosis was detected using DNA ladder formation and flow cytometric techniques. The expression of Bcl-2 protein was analysed using flow cytometric techniques. Lactate dehydrogenase (LDH) activity and malonyldialdehyde (MDA) content in the medium were measured. Cell viability was assayed by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method. Exposure of HUVEC to a high glucose concentration (30 mM) for 48 h markedly increased LDH release and MDA content in the medium and induced apoptosis and Bcl-2 protein expression in HUVEC. Pretreatment with 3,4,5,6-tetrahydroxyxanthone (1, 3 or 10 M) or probucol (10 M) significantly decreased the level of LDH and MDA in the medium, reduced apoptosis and increased the expression of Bcl-2 protein in HUVEC. These results suggest that 3,4,5,6-tetrahydroxyxanthone inhibits high-glucose-induced endothelial cell apoptosis by increasing Bcl-2 protein expression in HUVEC.     

舒脉汤对血管内皮细胞VEGF、bFGF表达的影响及其信号通路

目的研究舒脉汤对血管内皮细胞生成因子（VEGF）、碱性成纤维细胞生成因子（bFGF）的影响及其可能参与的信号通路。方法原代培养人脐静脉内皮细胞,以舒脉汤刺激内皮细胞,部分给予PI3K抑制剂,LY294002预处理,收集细胞测定VEGF、bFGF基因表达,收集上清液测定VEGF、bFGF蛋白表达。结果舒脉汤可以明显增加人脐静脉内皮细胞VEGF、bFGF基因及蛋白表达,且这一过程可被LY294002所阻断。结论舒脉汤通过上调内皮细胞VEGF、bFGF表达来发挥促血管新生作用,PI3K信号通路参与此过程。     

Insulinotropic activity of chromonyl-2,4-thiazolidinediones

Numerous compounds have been prepared in order to improve the pharmacological profile of insulinotropic activities. In the present paper, series of chromonyl-2,4-thiazolidinediones (Ia–e, IIa–e, and IIIa–e) were tested for their insulinotropic activities in INS-1 cells. Compounds IIb–d and IIId were very active even at a low concentration of 0.001 mg/ml. Compounds IIIa–c were active only at higher concentration (0.01 mg/ml). Increase of insulin release was observed in the presence of 5.6 mmol/l glucose.     

新藤黄酸干预肺腺癌血管生成的细胞学研究

目的 通过对人脐静脉内皮细胞HUVEC和人肺腺癌A549的培养,检测含新藤黄酸(GNA)条件培养基对血管内皮细胞存活率、成管和生长的影响.方法 采用甲基噻唑基四唑(MTT)法和平板克隆实验法研究GNA对HUVEC存活率和克隆形成率的影响;应用薄层胶原建立血管内皮细胞的二维培养模型,观察GN A对于血管内皮细胞成管现象的影响;采用细胞划痕愈合和小室迁移实验考察GNA对HUVEC的迁移能力影响;Westernblot检测血管内皮生长因子(VEGF)和缺氧诱导因子(HIF-1α)蛋白的表达.结果 MTT检测结果显示,HUVEC细胞存活率和克隆形成率随GNA剂量增加而降低.GNA可抑制HUVEC细胞的迁移.还可抑制HUVEC管腔样结构形成.此外,GNA可下调HUVEC中VEGF和HIF-1α蛋白的表达.结论GNA可在体外抑制血管生成,其作用机制可能与抑制肿瘤细胞分泌的HIF-1α和VEGF有关.     

The angiosuppressive effects of 20(R)- ginsenoside Rg3

Aberrant angiogenesis is an essential step for the progression of solid tumors. Thus anti-angiogenic therapy is one of the most promising approaches to control tumor growth. In this study, we examined the ability of 20(R)-ginsenoside Rg3 (Rg3), one of the active compounds present in ginseng root, to interfere with the various steps of angiogenesis. Rg3 was found to inhibit the proliferation of human umbilical vein endothelial cells (HUVEC) with an IC50 of 10 nM in Trypan blue exclusion assay. Rg3 (1-10(3) nM) also dose dependently suppressed the capillary tube formation of HUVEC on the Matrigel in the presence or absence of 20 ng/ml vascular endothelial growth factor (VEGF). The VEGF-induced chemoinvasion of HUVEC and ex vivo microvascular sprouting in rat aortic ring assay were both significantly attenuated by Rg3. In addition, Rg3 (150 and 600 nM) remarkably abolished the basic fibroblast growth factor (bFGF)-induced angiogenesis in an in vivo Matrigel plug assay. The Matrix metalloproteinases (MMPs), such as MMP-2 and MMP-9, which play an important role in the degradation of basement membrane in angiogenesis and tumor metastasis present in the culture supernatant of Rg3-treated aortic ring culture were found to decrease in their gelatinolytic activities. Taken together, these data underpin the anti-tumor property of Rg3 through its angiosuppressive activity.     

高血糖、高胰岛素对内皮细胞凋亡及Mn-SOD表达的研究

目的：了解糖尿病高胰岛素及高血糖的改变对内皮细胞凋亡及Mn-SOD表达的影响。方法：在高糖、高胰岛素及对照培养环境,分别孵育内皮细胞72h测定细胞凋亡情况并检测Mn-SOD的表达水平。结果：内皮细胞在高糖、高胰岛素条件下凋亡显著增加（P〈0.05）,同时Mn-SOD表达下降（P〈0.05）。结论：在高胰岛素血症而血糖没有升高到糖尿病标准的阶段,就会有内皮细胞凋亡显著增加,从而促进动脉粥样硬化形成,同时还有Mn-SOD表达水平的下降,病损持续存在于2型糖尿病进展的各个阶段。     

重组VEGF165基因腺相关病毒的包装和鉴定

目的包装重组VEGF165基因的无致病性腺相关病毒,以其作为基因载体感染HUVEC细胞并检测其表达,并在体外检测病毒生物学活性。方法从含有VEGF165基因的pET-32a（＋）-VEGF165原核表达载体中扩增出VEGF165片段,构建重组骨架质粒pAAV-VEGF165。将此质粒和对照质粒pAAV-GFP分别与腺相关病毒包装质粒pAAV-RC、辅助质粒pAAV-Helper用钙-磷共转法转染HEK293细胞,通过同源重组分别产生rAAV-VEGF165和rAAV-GFP重组腺相关病毒。通过real-timePCR法测定病毒滴度后,转染HUVEC细胞并检测其表达,并通过感染HUVEC来检测其促增殖作用。结果扩增出的VEGF165片段成功构建至重组骨架质粒中,pAAV-VEGF165经双酶切和测序鉴定正确。病毒包装效率达90%以上,收获纯化rAAV-VEGF165病毒滴度达6.0×1010pfu/mL。重组腺病毒rAAV-VEGF165能够感染HUVEC细胞并得到显著性表达;与未转染组和GFP组相比,能够显著促进HUVEC细胞的增殖。结论我们成功包装了重组腺相关病毒rAAV-VEGF165,它能够感染HUVEC细胞并高表达VEGF165蛋白,并具有促增殖作用,这为进一步开展VEGF165基因的基因靶向治疗奠定了基础。     

Mechanism of vascular endothelial growth factor on the prevention of restenosis after angioplasty

To evaluate the mechanism of vascular endothelial growth factor (VEGF) on the prevention of restenosis after angioplasty, the recombinant adenovirus vector containing hVEGF₁₆₅ cDNA was constructed and transfected into vascular smooth muscle cells (VSMC) in vitro. The conditioned medium containing VEGF was collected 72 h after the infection. Then, the VSMC and human umbilical vein endothelial cells (HUVEC) were divided into control group, H₂O₂-treated group and H₂O₂+ VEGF-treated group to observe the proliferation and apoptosis by water soluble tetrazolium (WST-1) method, in situ nick end labeling (TUNEL) and flow cytometry (FCM). Compared with the control and H₂O₂+ VEGF-treated groups, the absorbance (A) value of HUVEC was decreased, and apoptosis of HUVEC was significantly increased in H₂O₂-treated group. The changes of A value and apoptosis of VSMC were contrary to those of HUVEC. H₂O₂ could stimulate the proliferation of VSMC and induce the apoptosis of HUVEC, inhibit the proliferation of HUVEC and the apoptosis of VSMC and induce restenosis. VEGF could inhibit the effect of H₂O₂ on HUVEC and VSMC and prevent restenosis. These results offered further theoretical evidence for VEGF on the prevention of restenosis after angioplasty.     

Effect of an oversulfated exopolysaccharide on angiogenesis induced by fibroblast growth factor-2 or vascular endothelial growth factor in vitro

The aim of this study was to determine the angiogenic properties of an oversulfated exopolysaccharide (OS-EPS) derived from a polysaccharide secreted by the mesophilic bacterium Alteromonas infernus. We compared the effect of this OS-EPS with that of a non-oversulfated exopolysaccharide (EPS) on human umbilical vein endothelial cell (HUVEC) proliferation, migration and differentiation induced by basic fibroblast growth factor (FGF-2) or vascular endothelial growth factor (VEGF). OS-EPS enhanced HUVEC proliferation by 58% when used alone, and by respectively 30% and 70% in the presence of FGF-2 and VEGF. OS-EPS also increased the density of tubular structures on Matrigel in the presence of FGF-2 or VEGF. Vascular tube formation was related to alpha(6) integrin subunit expression, which was enhanced by 50% in the presence of the growth factors. Indeed, a monoclonal anti-alpha(6) blocking antibody abolished this vascular tube formation. EPS had no effect in any of the experimental conditions, underlying the importance of sulfation in the angiogenic effects of exopolysaccharide. By potentiating the angiogenic activity of FGF-2 and/or VEGF, OS-EPS, which possesses low anticoagulant activity and thus a low hemorrhagic risk, could potentially be used to accelerate vascular wound healing or to promote the growth of collateral blood vessels in ischemic tissues.     

Tirofiban induces VEGF production and stimulates migration and proliferation of endothelial cells

Tirofiban is a fibrinogen receptor antagonist, generated using the tripeptide Arg-Gly-Asp (RGD) as a template. RGD activates integrin receptors and integrin-mediated signals are necessary for normal cells to promote survival and stimulate cell cycle progression. We investigated whether tirofiban activated growth-stimulatory signals in endothelium. For this study human umbilical vein endothelial cells (HUVEC) and human aortic endothelial cells (HAEC) were used. Analysis of cell proliferation, by cell counts, showed that the number of endothelial cells doubled after 72 h of culture in the absence of tirofiban, while they were tripled and even quadrupled, in the presence of increasing doses of the drug. Moreover, tirofiban-stimulated cells had a greater ability to migrate through the transwell filters of Boyden chamber, compared to unstimulated cells. The scratch assay, which mimics cell migration during wound healing, showed that tirofiban stimulated HUVECs to migrate into the leading hedge of the scratch. Western blot showed that tirofiban increased the expression levels of VEGF and the downstream effectors Erk and cyclin D. An inhibitor of VEGFR2 counteracted tirofiban-induced-proliferation, suggesting a role for VEGF in such effect. Our study shows that tirofiban stimulates the migration and proliferation of endothelial cells suggesting that it can promote endothelial repair. Ex vivo cultures of arterial rings confirmed the growth stimulatory effect of tirofiban on endothelium. Thus, the benefits of tirofiban in those with acute coronary syndromes undergoing PTCA may be due to rapid endothelization of damaged vessel, besides antiplatelet effects.     

波动性高糖对血管内皮细胞生存及凋亡的影响

目的探讨波动性与持续性高糖对血管内皮细胞生存及凋亡的影响。方法以人脐静脉内皮细胞为研究对象,通过MTT,AnnxenV-FITC检测细胞生存率及凋亡率观察,探讨波动性高糖（5.5或25mmol/L）及持续性高浓度葡萄糖（25mmol/L）对血管内皮细胞存活率及凋亡率的作用。结果持续高葡萄糖条件下细胞生存率低于正常浓度,而波动性高糖条件下细胞生存率又低于持续高糖,凋亡率则相反。结论波动性高糖较持续性高糖对血管内皮细胞具有更强的损伤效应,且是独立于持续性高糖之外的血管内皮细胞伤害因素。