bFGF基因转染对血管内皮细胞迁移的影响及机制

目的研究碱性成纤维细胞生长因子（bFGF）基因转染对人脐静脉内皮细胞（HUVECs）迁移能力的影响,并探讨其可能机制。方法通过基因亚克隆构建真核表达载体pcDNA3．1-bFGF,利用脂质体介导将bFGF基因导入HUVECs内,通过RT-PCR和ELISA法检测基因的表达;bFGF基因转染后的HUVECs通过Transwell小室法检测其迁移能力的变化;Western blot法检测转染后的细胞Raf-1、细胞外调节蛋白激酶2（ERK2）和黏着斑激酶（FAK）蛋白表达变化。结果成功构建了表达载体pcDNA3．1-bFGF,该载体转染HUVECs后,bFGFmRNA和蛋白均显著增加。转染bFGF基因可使HUVECs的体外迁移能力增强,上调ERK2和FAK蛋白的表达,但对Raf-1蛋白表达无影响。结论bFGF基因转染能促进血管内皮细胞的迁移,其作用机制可能与上调ERK2和FAK蛋白表达有关。     

β-神经生长因子基因转染对人脐静脉内皮细胞功能的影响

目的研究β-神经生长因子(β-NGF)基因转染人脐静脉内皮细胞(HUVEC)对细胞增殖、单克隆形成、细胞周期、细胞凋亡、细胞迁移相关功能的影响。方法将人源β-NGF基因重组的真核表达质粒(p EGFP-N1/β-NGF)转染至HUVEC,同时设置p EGFP-N1空载组、正常组(未转染质粒)、酪氨酸激酶受体A(Trk A)抑制剂组(β-NGF基因转染组加入1∶1000的K252a)。观察转染前后细胞形态学变化,利用real-time PCR和Western blot检测β-NGF基因转染表达效果,MTT法检测β-NGF基因转染对细胞增殖的影响,平板单克隆实验检测β-NGF基因转染对细胞单克隆形成能力的变化,流式细胞术检测β-NGF基因转染对细胞周期和细胞凋亡率的影响,Transwell方法检测转染前后细胞迁移能力的变化,Western blot检测β-NGF基因转染前后Trk A和血管内皮生长因子(VEGF)的表达变化。结果β-NGF基因成功转染HUVEC 48 h后能够显著提高β-NGF mRNA和蛋白的表达水平(P0.05),同时促进细胞增殖、单克隆形成、细胞迁移能力,并影响细胞周期抑制细胞凋亡率(P0.05)。β-NGF基因转染HUVEC后Trk A和VEGF表达水平也随之显著上升(P0.05),但受到Trk A抑制剂的抑制。结论β-NGF基因能够成功转染HUVEC并显著表达,进而促进细胞增殖、单克隆形成、细胞迁移能力,并影响细胞周期抑制细胞凋亡率,而其发挥作用与Trk A结合诱导VEGF表达上调有关。     

迁移侵袭抑制蛋白对人脐静脉内皮细胞生物学行为的作用

目的:研究迁移侵袭抑制蛋白(migration and invasion inhibitory protein, MIIP)对人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)增殖能力、迁移侵袭能力等生物学行为的影响。方法:采用瞬时转染的方式在HUVEC中过表达MIIP,经蛋白质印迹(Western-blot)实验鉴定MIIP和VEGFR2的表达水平;采用5-乙炔基-2-脱氧尿苷(5-ethyny-2'-deoxyuridine,EdU)法检测MIIP对HUVEC增殖能力的影响,采用划痕愈合实验和穿透小室实验检测MIIP对HUVEC迁移侵袭能力的影响,采用小管形成实验检测HUVEC体外成管能力的变化,采用基质胶栓实验观察MIIP对HUVEC体内血管新生能力的影响。结果:通过瞬时转染可使MIIP在HUVEC中的表达上调2.8倍。与空载体转染的细胞相比,过表达MIIP的HUVEC的划痕愈合能力减弱;空载体转染组及MIIP过表达组的HUVEC在迁移实验中的穿膜细胞数分别为(350±24)个和(167±29)个(P0.01),在侵袭实验中的穿膜细胞数分别为(434±12)个和(286±8)个。在体外小管形成实验中形成的小管数分别为(27±4)个和(13±2)个。EdU阳性标记的细胞比例在2组分别为63%±4%和61%±2%。基质胶栓实验显示,过表达MIIP后,HUVEC的体内血管新生能力下降。蛋白质印迹结果显示,MIIP能够下调HUVEC中血管内皮细胞生长因子受体2(vascular endothelial growth factor receptor 2,VEGFR2)的表达。结论:MIIP能够抑制HUVEC的迁移侵袭能力、体外成管能力及体内血管新生能力。     

慢性粒细胞白血病血管新生的体外研究

目的：探讨K562细胞上清液对人脐静脉内皮细胞（HuVEc）增殖、迁移、体外小管形成的作用。方法：运用MTT法、Transwell室及体外小管形成实验观察K562细胞上清液对HUVEC增殖、迁移及体外分化的影响。Westernblot、ELISA法检测K562细胞血管内皮生长因子（VEGF）、碱性成纤维细胞生长因子（bFGF）的表达。结果：K562细胞系表达和分泌VEGF和bFGF。细胞培养上清液能明显促进HUVEC的增殖、迁移、体外小管形成,其作用随着细胞培养上清液浓度的增加而增强。结论：体外实验表明慢性粒细胞白血病患者存在血管新生,通过分泌血管新生正调控因子VEGF和bFGF,促进HUVEC的增殖、迁移、分化。     

腺病毒介导反义AT1R转染对大鼠血管平滑肌细胞增殖的抑制作用

目的观察腺病毒介导反义AT1基因转染对培养的大鼠动脉平滑肌细胞(VSMCs)增殖的影响.方法用定向克隆和同源重组方法构建携带人反义AT1基因的复制-缺陷型重组腺病毒(Ad/CMV*ahAT1),转染体外培养的 VSMCs,用RT-PCR半定量法和免疫组化法检测AT1R的表达,用3H-TdR掺入实验和流式细胞仪检测VSMCs的DNA合成和增殖指数.结果与对照组相比,转染Ad/CMV*ahAT1后48 h的VSMCs,AT1R 的mRNA表达低50%,蛋白表达也显著低于对照组(P<0.01).给予Ang Ⅱ刺激的VSMCs的3H-TdR掺入量和增殖指数明显高于空白对照组(分别为P<0.05和P<0.01);转染Ad/CMV*ahAT1组3H-TdR掺入量和增殖指数则显著降低(与DMEM组比P<0.05,与Ang Ⅱ对照组比P<0.01).结论腺病毒介导的反义AT1R转染,通过抑制AT1R的表达,明显抑制VSMCs的增殖和Ang Ⅱ刺激的VSMCs增殖.     

血管内皮生长因子基因修饰对内皮细胞前列腺环素合成影响的研究

目的 :观察血管内皮生长因子 (VEGF)基因转染对内皮细胞前列腺环素 (PGI2 )合成的影响 ,了解VEGF基因修饰对内皮细胞抗凝作用的影响。方法 :用脂质体转染的方法 ,将含有人VEGF基因的真核表达质粒pCD -hVEGF16 5体外转染人脐静脉内皮细胞。原位杂交、免疫组化法检测VEGF基因的表达 ,Elisa法检测培养上清液中VEGF及 6 -keto -PGF1α的含量。应用细胞计数法观察VEGF基因对内皮细胞生长的影响。结果 :外源性VEGF基因能被脂质体有效的导入内皮细胞并呈稳定表达。在高表达VEGF的同时 ,对PGI2 的合成和分泌较对照组明显增高 (p <0 .0 5 )。导入VEGF基因明显促进内皮细胞的分裂增殖。结论 :VEGF的高表达可显著提高内皮细胞对PGI2 的释放 ,可能增强内皮细胞的抗凝功能。     

血管内皮生长因子对培养内皮细胞增殖和移行的影响

目的　研究低氧培养心肌细胞分泌出的血管内皮生长因子 (VEGF)蛋白对培养内皮细胞增殖和移行的影响。方法　将培养的人脐静脉内皮细胞 (HUVECs)分为 4组 :正常对照组 ,低氧培养组 ,含VEGF的低氧培养心肌细胞分泌液组 (分泌液组 ) ,分泌液 +低氧培养组。分别采用流式细胞仪、免疫组织化学等方法检测VEGF对HUVECs细胞周期、增殖细胞核抗原表达、氚一亮氨酸掺入量及HUVECs移行的影响。结果　VEGF增加正常培养和低氧培养HUVECs由静止期 DNA合成前期向DNA合成期的转换 ,使DNA合成期及DNA合成后期 分裂期细胞数增加 ,从而促进HUVECs增殖 ,并使常氧和低氧培养HUVECs增殖细胞核抗原的表达、氚一亮氨酸掺入量及移行细胞数目增加。低氧抑制HUVECs的增殖和移行 ,VEGF可拮抗低氧对HUVECs增殖、移行的抑制作用。结论　低氧培养心肌细胞分泌出的VEGF蛋白不仅增加常氧培养HUVECs增殖、移行 ,而且能够拮抗低氧的抑制作用     

MicroRNA-181b 对衰老内皮细胞血管新生功能的影响

目的研究microRNA-181b（miR-181b）对衰老内皮细胞增殖、迁移和管腔形成等血管新生功能的影响。方法原代培养人脐静脉内皮细胞（Human umbilical vein endothelial cells,HUVECs）,通过传代培养计算细胞群体倍增水平（Population doublings,PDL）,建立HUVECs衰老模型（PDL44）。在PDL44HUVECs中过表达或抑制miR-181b,分刖用MTS法、划痕实验及成管实验检测内皮细胞增殖、迁移和成管功能,结果过表达miR-181b可抑制PDL44内皮细胞的增殖功能18％（P〈O．001）,减少内皮细胞迁移率40％（P=O．032）;反之,给于miR-181b抑制刹可硅著改善PDL44内皮细胞的迁移和增殖：给了血管内皮生长因子（Vascular endothelial growth factor,VEGF）刺激,术观察到miR-181b对PDL44内皮细胞成管功能的调控作用。结论抑制miR＋181b可提高衰老内皮细胞的增殖和迁移能力,提示它可作为一个新的靶点,调节内皮细胞的损伤修复和血管新生。     

内含子源性miRNA通过转录因子AP1调节内皮型一氧化氮合酶表达及血管内皮细胞增殖作用

目的　前期工作发现,内皮型一氧化氮合酶（eNOS）第4内含子的27碱基重复子产生相应27-nt　miRNA,并对eNOS的转录和表达有负反馈调节作用。进一步探讨该内含子源性27-nt　miRNA对内皮型一氧化氮合酶基因调节的分子机制及血管内皮细胞增殖相关转录因子AP1的作用机制。方法　应用MTT法检测人脐静脉内皮细胞（HUVEC）的增殖抑制率;细胞划痕实验检测HUVEC迁移能力;免疫组织化学方法检测内皮细胞中eNOS和AP1蛋白表达水平;进一步用Western　Blot检测27-nt　miRNA表达相关情况及细胞核转录因子eNOS表达情况。结果　27-nt　miRNA对HUVEC增殖具有强烈抑制作用　（P<0.05）;27-nt　miRNA对HUVEC迁移具有显著抑制作用（P<0.05）;27-nt　miRNA显著降低eNOS和AP1蛋白表达（P<0.05）;27-nt　miRNA通过负调控AP1降低eNOS蛋白表达（P<0.05）。结论　27-nt　miRNA显著抑制eNOS和AP1蛋白表达,AP1在27-nt　miRNA对eNOS表达调节中起重要作用。     

分化拮抗非编码RNA-201对人脐静脉内皮细胞增殖的影响

目的 探讨分化拮抗非编码RNA(DANCR)-201对人脐静脉内皮细胞（HUVECs）增殖的影响。方法 分离培养HUVECs后,构建过表达或敲低DANCR-201的细胞模型,采用长时间动态活细胞成像方法和细胞划痕实验检测HUVECs增殖和迁移能力。采用实时荧光定量PCR和蛋白质印迹法检测细胞增殖相关蛋白Phospho-c-Raf和细胞周期蛋白p16、p53的表达。结果 过表达DANCR-201可促进HUVECs增殖[（67.1±5.4）%比（90.4±3.5）%,P <0.01]和迁移[（64.2±1.5）%比（88.6±3.1）%,P <0.05],同时细胞增殖相关蛋白Phospho-c-Raf表达水平升高（P <0.01）,细胞周期蛋白p16、p53表达水平均降低（P <0.01或0.05）。敲低DANCR-201对HUVECs增殖和迁移无影响,但细胞周期蛋白p16、p53表达水平均升高（P <0.01或0.05）。结论 DANCR-201促进HUVECs增殖,但其在动脉粥样硬化斑块形成中的作用机制仍需深入研究。     

Kinetics of placenta growth factor/vascular endothelial growth factor synergy in endothelial hydraulic conductivity and proliferation

Vascular endothelial growth factor (VEGF) was originally discovered as vascular permeability factor because of its ability to increase microvascular permeability to plasma proteins. Since then, it has been shown to induce proliferation and migration in endothelial cells. Placenta growth factor (PlGF) is a member of the VEGF family of growth factors, but has little or undetectable mitogenic activity on endothelial cells. Intriguingly, however, PlGF was able to potentiate the action of low concentrations of VEGF on endothelial cell growth and macromolecule permeability in vitro. Here we show that PlGF can potentiate the effects of VEGF on the hydraulic conductivity of certain endothelial cells and that the duration of pretreatment with PlGF determines the resulting response. Hydraulic conductivity (Lp) was calculated from the water flux across the monolayer of human umbilical vein endothelial cells (HUVECs) or bovine aortic endothelial cells (BAECs). After 2 h of exposure to VEGF(165), the Lp of BAEC monolayers increased threefold, but the Lp of HUVEC monolayers did not increase. PlGF alone induced a small (63%) increase in Lp in BAECs, but not in HUVECs. BAEC, but not HUVEC, monolayers exposed first to PlGF and then to VEGF exhibited a seven- to eightfold increase in Lp. This enhancement in BAEC Lp could be observed for 4 h after the administration of PlGF. PlGF also potentiated the effect of VEGF on BAEC proliferation. Thus, augmentation of VEGF action by PlGF depends on the duration of PlGF exposure and on the origin of endothelial cells.     

Melatonin prevents human pancreatic carcinoma cell PANC-1-induced human umbilical vein endothelial cell proliferation and migration by inhibiting vascular endothelial growth factor expression

Abstract: Melatonin is an important natural oncostatic agent, and our previous studies have found its inhibitory action on tumor angiogenesis, but the mechanism remains unclear. It is well known that vascular endothelial growth factor (VEGF) plays key roles in tumor angiogenesis and has become an important target for antitumor therapy. Pancreatic cancer is a representative of the most highly vascularized and angiogenic solid tumors, which responds poorly to chemotherapy and radiation. Thus, seeking new treatment strategies targeting which have anti‐angiogenic capability is urgent in clinical practice. In this study, a co‐culture system between human umbilical vein endothelial cells (HUVECs) and pancreatic carcinoma cells (PANC‐1) was used to investigate the direct effect of melatonin on the tumor angiogenesis and its possible action on VEGF expression. We found HUVECs exhibited an increased cell proliferation and cell migration when co‐cultured with PANC‐1 cells, but the process was prevented when melatonin added to the incubation medium. Melatonin at concentrations of 1 μm and 1 mm inhibited the cell proliferation and migration of HUVECs and also decreased both the VEGF protein secreted to the cultured medium and the protein produced by the PANC‐1 cells. In addition, the VEGF mRNA expression was also down‐regulated by melatonin. Taken together, our present study shows that melatonin at pharmacological concentrations inhibited the elevated cell proliferation and cell migration of HUVECs stimulated by co‐culturing them with PANC‐1 cells; this was associated with a suppression of VEGF expression in PANC‐1 cells.     

Regulation of vascular endothelial growth factor by melatonin in human breast cancer cells

Melatonin exerts oncostatic effects on breast cancer by interfering with the estrogen‐signaling pathways. Melatonin reduces estrogen biosynthesis in human breast cancer cells, surrounding fibroblasts and peritumoral endothelial cells by regulating cytokines that influence tumor microenvironment. This hormone also exerts antiangiogenic activity in tumoral tissue. In this work, our objective was to study the role of melatonin on the regulation of the vascular endothelial growth factor (VEGF) in breast cancer cells. To accomplish this, we cocultured human breast cancer cells (MCF‐7) with human umbilical vein endothelial cells (HUVECs). VEGF added to the cultures stimulated the proliferation of HUVECs and melatonin (1 mm ) counteracted this effect. Melatonin reduced VEGF production and VEGF mRNA expression in MCF‐7 cells. MCF‐7 cells cocultured with HUVECs stimulated the endothelial cells proliferation and increased VEGF levels in the culture media. Melatonin counteracted both stimulatory effects on HUVECs proliferation and on VEGF protein levels in the coculture media. Conditioned media from MCF‐7 cells increased HUVECs proliferation, and this effect was significantly counteracted by anti‐VEGF and 1 mm melatonin. All these findings suggest that melatonin may play a role in the paracrine interactions between malignant epithelial cells and proximal endothelial cells through a downregulatory action on VEGF expression in human breast cancer cells, which decrease the levels of VEGF around endothelial cells. Lower levels of VEGF could be important in reducing the number of estrogen‐producing cells proximal to malignant cells as well as decreasing tumoral angiogenesis.     

Effect of Src kinase inhibition on metastasis and tumor angiogenesis in human pancreatic cancer

Tumor angiogenesis is a process that requires migration, proliferation, and differentiation of endothelial cells. We hypothesized that decrease in pancreatic tumor growth due to inhibition of Src activity is associated with the inability of Src kinase to trigger a network of such signaling processes, which finally leads to endothelial cell death and angiogenesis-restricted tumor dormancy. The therapeutic efficacy of Src kinase inhibitor AZM475271 was tested in nude mice orthotopically xenografted with L3.6pl pancreatic carcinoma cells. No liver metastases and peritoneal carcinosis were detected and a significant effect on the average pancreatic tumor burden was observed following treatment with AZM475271, which in turn correlated with a decrease in cell proliferation and an increase in apoptotic endothelial cells. AZM475271 was shown to significantly inhibit migration of human umbilical vein endothelial cells in an in vitro Boyden Chamber cell migration assay. In a rat aortic ring assay we could demonstrate as well inhibition of endothelial cell migration and sprouting following therapy with Src kinase inhibitor at similar doses. The most conclusive anti-angiogenic activity of AZM475271 was demonstrated in vivo (mouse corneal micropocket assay) by showing a marked inhibition of basic fibroblast growth factor-induced neovascularization in response to systemic administration of AZM475271. Furthermore, we could show reduced proliferation of HUVECs determined with the TACS MTT Cell Viability Assay Kit. The blockade of Src kinase significantly reduced the level of VEGF in L3.6pl medium, the effect which was found also in the cell culture supernate from HUVECs. Inhibition of Src kinase by AZM475271 also showed prevention of survival signaling from VEGF and EGF receptors. Treatment with AZM475271 resulted in VEGF - dependent inhibition of tyrosine phosphorylation of FAK. HUVECs were also examined using propidium iodide staining for cell cycle analysis by FACS. Inhibition of Src kinase promoted HUVEC apoptosis in a dose-dependent manner. Taken together, our results suggest that the Src kinase inhibitor AZM475271, in addition to its effects on tumor cells, suppresses tumor growth and metastasis in vitro and in vivo potentially also by anti-angiogenic mechanisms.     

Aggretin, a snake venom-derived endothelial integrin alpha 2 beta 1 agonist, induces angiogenesis via expression of vascular endothelial growth factor

Aggretin, a collagen-like alpha 2 beta 1 agonist purified from Calloselasma rhodostoma venom, was shown to increase human umbilical vein endothelial cell (HUVEC) proliferation and HUVEC migration toward immobilized aggretin was also increased. These effects were blocked by A2-IIE10, an antibody raised against integrin alpha 2. Aggretin bound to HUVECs in a dose-dependent and saturable manner, which was specifically inhibited by A2-IIE10, as examined by flow cytometry. Aggretin elicited significant angiogenic effects in both in vivo and in vitro angiogenesis assays, and incubation of HUVECs with aggretin activated phosphatidylinositol 3-kinase (PI3K), Akt, and extracellular-regulated kinase 1/2 (ERK1/2); these effects were blocked by A2-IIE10 or vascular endothelial growth factor (VEGF) monoclonal antibody (mAb). The angiogenic effect induced by aggretin may be via the production of VEGF because the VEGF level was elevated and VEGF mAb pretreatment inhibited Akt/ERK1/2 activation as well as the in vivo angiogenesis induced by aggretin. The VEGF production induced by aggretin can be blocked by A2-IIE10 mAb pretreatment. In conclusion, aggretin induces endothelial cell proliferation, migration, and angiogenesis by interacting with integrin alpha 2 beta 1 leading to activation of PI3K, Akt, and ERK1/2 pathways, and the increased expression of VEGF may be responsible for its angiogenic activity.     

Cigarette smoke exposure impairs VEGF-induced endothelial cell migration: role of NO and reactive oxygen species

Endothelial dysfunction is one of the earliest pathological effects of cigarette smoking. Vascular endothelial growth factor (VEGF) has been shown to be an important regulator of endothelial healing and growth. Accordingly, we tested the hypothesis that cigarette smoke exposure impairs VEGF actions in endothelial cells. In human umbilical vein endothelial cells (HUVECs), cigarette smoke extracts (CSE) inhibited VEGF-induced tube formation in the matrigel assay. CSE did not affect HUVECs proliferation, but significantly reduced cellular migration in response to VEGF. This impaired migratory activity was associated with a reduced expression of alpha(v)beta(3), alpha(v)beta(5), alpha(5)beta(1) and alpha(2)beta(1) integrins. The Akt/eNOS/NO pathway has been shown to be important for VEGF-induced endothelial cell migration. We found that CSE inhibited Akt/eNOS phosphorylation and NO release in VEGF-stimulated HUVECs. This was associated with an increased generation of reactive oxygen species (ROS). Importantly, in HUVECs exposed to CSE, treatment with antioxidants (NAC, vitamin C) reduced ROS formation and rescued VEGF-induced NO release, cellular migration and tube formation. Moreover, treatment with NO donors (SNAP, SNP) or a cGMP analog (8-Br-cGMP) rescued integrin expression, cellular migration and tube formation in endothelial cells exposed to CSE. (1) Cigarette smoke exposure impairs VEGF-induced endothelial cell migration and tube formation. (2) The mechanism involves increased generation of ROS, decreased expression of surface integrins together with a blockade of the Akt/eNOS/NO pathway. (3) These findings could contribute to explain the negative effect of cigarette smoking on endothelial function and vessel growth.     

血管内皮生长因子对内皮生长晕细胞冻存后复苏率及增殖、迁移能力的影响

目的研究血管内皮生长因子对冻存后内皮生长晕细胞复苏率及其增殖、迁移能力的影响。方法密度梯度离心法分离脐带血中单个核细胞,体外扩增培养内皮生长晕细胞,免疫组织化学法、荧光染色法鉴定内皮细胞特性。分别采用不含血管内皮生长因子和含50μg/L血管内皮生长因子的冻存液对内皮生长晕细胞进行冻存,分为正常组、对照组、50μg/L血管内皮生长因子组,24 h后复苏并观察细胞的复苏率及其增殖、迁移能力。结果50μg/L血管内皮生长因子组可提高冻存复苏后内皮生长晕细胞的复苏率。24 h内两组细胞增殖、迁移能力均较正常组减弱(P<0.01),但50μg/L血管内皮生长因子组显示对内皮生长晕细胞增殖、迁移能力的保护作用。48 h后50μg/L血管内皮生长因子组细胞迁移能力较正常组增强(P<0.01),增殖能力接近正常组(P>0.05),但对照组在观察期间内细胞增殖和迁移能力均较正常组与50μg/L血管内皮生长因子组减弱(P<0.01)。结论血管内皮生长因子可以提高冻存后内皮生长晕细胞的复苏率以及复苏后细胞的增殖、迁移能力。     

Platelet-activating factor enhances vascular endothelial growth factor-induced endothelial cell motility and neoangiogenesis in a murine matrigel model

We previously reported that platelet-activating factor (PAF) enhances the angiogenic activity of certain polypeptide mediators such as tumor necrosis factor and hepatocyte growth factor by promoting endothelial cell motility. The purpose of the present study was to evaluate whether the synthesis of PAF induced by vascular endothelial growth factor (VEGF) might affect endothelial cell motility, microvascular permeability, and angiogenesis. The neoangiogenesis and synthesis of PAF induced by VEGF were studied in vivo in a murine Matrigel model. Dermal permeability was studied in mice by injection of (125)I-albumin. The synthesis of PAF, cell motility, and the increased (125)I-albumin transfer across endothelial monolayers were studied in vitro by using cultures of human umbilical cord vein-derived endothelial cells (HUVECs). The results obtained demonstrate that the neoangiogenesis induced by VEGF in vivo was associated with a local synthesis of PAF and was inhibited by WEB2170 and CV3988, 2 chemically unrelated, specific PAF-receptor antagonists. In contrast, WEB2170 did not inhibit VEGF-enhanced dermal permeability, suggesting that the latter was independent of the synthesis of PAF. In vitro, it was found that VEGF induced the synthesis of PAF by HUVECs in a dose- and time-dependent manner. The cell motility induced by VEGF was inhibited by PAF-receptor antagonists. In contrast, VEGF-induced proliferation of HUVECs and albumin transfer through HUVEC monolayer were unaffected by PAF-receptor antagonists. These results suggest that the synthesis of PAF induced by VEGF enhances endothelial cell migration and contributes to the angiogenic effect of VEGF in the in vivo Matrigel model.