bFGF单抗的抗血管新生作用

目的在人脐静脉内皮细胞(HUVECs)以及鸡胚中来研究抗碱性成纤维细胞生长因子(bFGF)单抗对血管新生的作用。方法制备3种腹水型bFGF单抗MabF7,MabF10,MabF12。CCK-8法检测bFGF单抗对HUVECs细胞增殖的影响;Transwell小室研究bFGF单抗对HUVECs迁移的影响;ECM gel检测其对HUVEC体外成管的影响;并研究其体内对鸡胚尿囊膜(CAM)血管新生作用。结果 MabF7,MabF10,MabF12均可中和bFGF的活性;3株单抗均可抑制内皮细胞迁移过程,无抗体组,对照抗体组,MabF7,MabF10,MabF12组细胞迁移率分别为100%,106.25%±7.89%,69.50%±6.86%,74.00%±4.16%,67.75%±3.30%;3株单抗均可抑制内皮细胞成管过程,无抗体组,对照抗体组,MabF7,MabF10,MabF12组管状结构形成率分别为:100%,105.93%±3.85%,56.53%±4.35%,29.23%±6.45%,12.77%±2.67%;计数尿囊膜上加药滤纸周围呈放射状的血管条数,bFGF组,bFGF+MabF7组,bFGF+MabF10组,bFGF+MabF12呈放射状的血管条数分别为15±0.82,7.5±1.29,13.5±3.10,8.5±0.58。结论 bFGF单抗对HUVECs的增殖、迁移、成管以及鸡胚尿囊膜血管新生均有抑制作用,从而为具有抗肿瘤作用的抗体药物的研发奠定基础。     

Effect of Brazilian propolis on human umbilical vein endothelial cell apoptosis

Brazilian propolis has been widely studied in recent years. Considering the lack of data concerning the effects of Brazilian propolis on human umbilical vein endothelial cells (HUVECs), we examined the effects of ethanol-extracted Brazilian propolis (EEBP) at 12.5, 25 and 50 μg/ml on apoptosis of HUVECs deprived of basic fibroblast growth factor (FGF-2) and serum. A high concentration of the extract induced HUVEC apoptosis at 24 h. Furthermore, we investigated the molecular mechanisms of HUVEC apoptosis induced by EEBP by testing the levels of integrin β4, p53, reactive oxygen species (ROS) and mitochondrial membrane potential. A low concentration of EEBP (12.5 μg/ml) could decrease the expression of integrin β4, p53 and ROS levels, whereas high concentrations (25 and 50 μg/ml) could increase the levels of integrin β4, p53 and ROS at 24 h and depress mitochondrial membrane potential level at all times. Considering the doses and the results obtained in this study, Brazilian propolis at high concentrations may be an apoptosis-inducing agent associated with the signal pathway mediated by integrin β4, p53, ROS and mitochondrial membrane potential, thus, propolis should be used in safer levels for human health.     

酸敏感离子通道在过敏性紫癜血管内皮细胞中的表达

目的观察酸敏感离子通道(ASICs)在过敏性紫癜(HSP)患儿血管内皮细胞中的表达并探讨其在血管炎性损伤中的作用及可能的调节机制。方法①采用免疫组化法观察HSP患儿及正常儿童皮肤血管内皮细胞胞浆ASIC1a、ASIC2a、ASIC3的表达情况;②培养人脐静脉内皮细胞(HU-VECs),分为空白对照组(不含血清的1640培养)、正常血清组、HSP血清组、甲泼尼龙干预组,采用半定量RT-PCR法检测HUVECs ASIC1a、ASIC2a、ASIC3 mRNA表达,Western blot检测其蛋白表达及甲泼尼龙干预对ASICs表达的影响。结果①免疫组化显示HSP患儿皮肤血管内皮细胞胞浆ASIC1a、ASIC3表达较正常对照组显著增多(P<0.05),ASIC2a少量表达与正常对照组差异无统计学意义;②HSP血清组ASIC1a、ASIC3 mRNA及蛋白表达较空白对照组、正常血清组明显增高(P<0.01),而甲泼尼龙干预组明显低于HSP血清组(P<0.01),且与正常血清组比较差异无统计学意义;③ASIC1a、ASIC3蛋白表达正常血清组较空白对照组增高(P<0.05),但正常血清组和空白对照组比较,mRNA表达差异无显著性;④ASIC2a mRNA及蛋白表达各组差异均无统计学意义。结论 HSP患儿血清刺激可使HUVECsASIC1a及ASIC3表达增高,ASICs可能参与了过敏性紫癜皮肤血管的损伤过程。甲泼尼龙可能通过抑制体内ASICs的高表达而缓解血管损伤。     

异丙酚在第三丁基过氧化氢诱导脐静脉内皮细胞氧化应激中的保护作用

目的:研究异丙酚对第三丁基过氧化氢(t-BHP)诱导的脐静脉内皮细胞(HUVECs)氧化应激的保护作用和机制。方法:体外培养的HUVECs分为对照组、异丙酚组、t-BHP组、异丙酚预处理+t-BHP组,给予相应处理后,Westernblot检测p38MAPK磷酸化水平变化,RT-PCR检测iNOS、eNOS表达。结果:t-BHP处理后,能显著诱导p38MAPK磷酸化,激活iNOS、eNOS表达,而异丙酚预处理后能减轻这些变化。结论:异丙酚通过抑制p38MAPK,减少iNOS、eNOS表达,减轻氧化应激从而起到保护HUVECs的作用。     

Conversion of biliverdin to bilirubin by biliverdin reductase contributes to endothelial cell protection by heme oxygenase-1—evidence for direct and indirect antioxidant actions of bilirubin

Heme oxygenase-1 (HO-1) is highly protective in various pathophysiological states such as cardiovascular and neurodegenerative diseases. HO-1-derived bilirubin is an efficient scavenger of reactive oxygen and nitrogen species (RONS). It remains to determine whether conversion of biliverdin to bilirubin is an essential step for HO-1-conferred protection of endothelial cells. RONS scavenging activities of biliverdin versus bilirubin were assessed by different RONS generating systems and detection techniques. We also silenced the biliverdin reductase (BVR) or HO-1 gene in cultured primary human endothelial cells (HUVECs) and measured the effect on RONS formation upon stimulation with lipopolysaccharide (LPS). In addition, effects of bilirubin and biliverdin on expression of GTP-cyclohydrolase were assessed in an endothelial cell line (EA.hy 926). HO-1- and BVR-silenced cells have increased levels of oxidative stress and bilirubin but not biliverdin increased expression of the protective protein GTP-cyclohydrolase. Moreover, protection by hemin-induced HO-1 expression or biliverdin-triggered bilirubin formation was impaired upon silencing of the HO-1 or BVR gene, respectively. Since bilirubin significantly scavenged RONS but chronic treatment was even more protective our observations support direct and indirect antioxidant properties of BVR and bilirubin and an important role for BVR and bilirubin in HO-1 conferred protection of endothelial cells.     

Participation of cyclin D1 deregulation in TNP-470-mediated cytostatic effect: involvement of senescence

Inhibition of angiogenesis is becoming one promising, alternative approach to stop tumor from growth and spreading to distant organs. TNP-470, an analog of fumagillin, possesses potent anti-angiogenic effects with minimal toxicity in animal tumor models and is now in the phase III of human cancer trial. Although TNP-470 induced endothelial cell cycle arrest at G1 phase via p53 and p21(Cip1), the underlying mechanism of the cytostatic effect of TNP-470 on endothelial cells remains limited. We have found that TNP-470 did not only induce p53 and p21(Cip1) but also cyclin D1 in the basic fibroblast growth factors (bFGF)-treated endothelial cells. The TNP-470-mediated increase of cyclin D1 protein was due to the enhanced expression of mRNA. The induced cyclin D1 formed a complex with cyclin-dependent kinase4 (CDK4) and p21(Cip1). The ability of cyclin D1-associated CDK4 to phosphorylate retinoblastoma (Rb) protein was, however, reduced in the same cells. TNP-470 also significantly increased senescence-associated-beta-galactosidase activity (SA-gal), hallmark of cells undergoing senescence. Interestingly, the effect of increased cyclin D1 protein mimicked by overexpression of cyclin D1 increased the sensitivity of human umbilical vein endothelial cells (HUVECs) to TNP-470. In summary, the cytostatic effect of TNP-470 on endothelial cells is in part mediated by induction of senescence and cyclin D1 is a key molecule participating in this event.     

Andrographolide suppresses endothelial cell apoptosis via activation of phosphatidyl inositol-3-kinase/Akt pathway

Andrographolide (Andro), an active component isolated from the Chinese official herbal Andrographis paniculata, which has been reported to prevent oxygen radical production and thus prevent inflammatory diseases. In this study, we investigated the molecular mechanisms and signaling pathways by which Andro protects human umbilical vein endothelial cells (HUVECs) from growth factor (GF) deprivation-induced apoptosis. Results demonstrated that HUVECs undergo apoptosis after 18 hr of GF deprivation but that this cell death was suppressed by the addition of Andro in a concentration-dependent manner (1-100 microM). Andro suppresses the mitochondrial pathway of apoptosis by inhibiting release of cytochrome c into the cytoplasm and dissipation of mitochondrial potential (Deltapsi(m)), as a consequence, prevented caspase-3 and -9 activation. Treatment of endothelial cells with Andro-induced activation of the protein kinase Akt, an anti-apoptotic signal, and phosphorylation of BAD, a down-stream target of Akt. Suppression of Akt activity by wortmannin, by LY-294002 and by using a dominant negative Akt mutant abolished the anti-apoptotic effect of Andro. In contrast, the ERK1/2 activities were not affected by Andro. The ERK1/2 inhibitor, PD98059 failed to antagonize the protective effect of Andro. In conclusion, Andro exerts its anti-apoptotic potential via activation of the Akt-BAD pathway in HUVECs and thus may represent a candidate of therapeutic agent for atherosclerosis.     

High precision measurement of electrical resistance across endothelial cell monolayers

Effects of vasoactive agonists on endothelial permeability was assessed by measurement of transendothelial electrical resistance (TEER) of human umbilical vein endothelial cells (HUVECs) grown on porous polycarbonate supports. Because of the low values of TEER obtained in this preparation (< 5 cm²) a design of an Ussing type recording chamber was chosen that provided for a homogeneous electric Held across the monolayer and for proper correction of series resistances. Precision current pulses and appropriate rates of sampling and averaging of the voltage signal allowed for measurement of < 0.1 resistance changes of the endothelium on top of a 21 series resistance of the support and bathing fluid layers. Histamine (10 M) and thrombin (10 U/ml) induced an abrupt and substantial decrease of TEER, bradykinin (1 M) was less effective, PAF (380 nM) and LTC₄ (1 M) had no effect TEER was also reduced by the calcium ionophore A-23187 (10 M). The technique allows for measurements of TEER in low resistance monolayer cultures with high precision and time resolution. The results obtained extend previous observations in providing quantitative data on the increase of permeability of HUVECs in response to vasoactive agonists.Supported by grant P-10435-M from the Austrian Science Foundation to BRB.     

PEDF对人脐静脉内皮细胞和肺癌SK-MES-1细胞增殖的影响及作用机制

目的 探讨色素上皮衍生因子(PEDF)对SK-MES-1细胞和人脐静脉内皮细胞(HUVECs)增殖的影响及可能的机制.方法 CCK-8法检测不同浓度PEDF在不同作用时间条件下对HUVECs和SK-MES-1细胞增殖的影响;流式细胞仪检测不同浓度PEDF对此两种细胞凋亡的影响;qRT-PCR检测PEDF对此两种细胞中血管内皮生长因子(VEGF)基因表达水平的影响.结果 CCK-8结果显示,PEDF对HUVECs和SK-MES-1细胞具有增殖抑制作用,呈一定浓度和时间依赖性(P<0.05);流式细胞术结果表明,实验组细胞的凋亡率高于对照组(P<0.05),高浓度用药组凋亡率高于低浓度用药组(P<0.05);qRT-PCR结果表明,与对照组相比,PEDF能抑制HUVECs和SK-MES-1细胞中VEGF mRNA水平的表达(P<0.05).结论 PEDF的抗肿瘤作用主要包括抑制肿瘤血管生成和直接作用于肿瘤细胞两方面,PEDF对HUVECs和SK-MES-1细胞增殖的影响可能与降低VEGF表达水平有关.