Protective effects of timosaponin B-II on high glucose-induced apoptosis in human umbilical vein endothelial cells

This study was designed to investigate the action of timosaponin B-II, a main bioactive compound in Anemarrhena asphodeloides Bunge, on the prevention from high glucose-induced cytotoxicity and apoptosis in human umbilical vein endothelial cells (HUVECs) and the potential mechanisms involved. The results showed that compared with the normal control group, exposure of HUVECs to high glucose media for 72 h resulted in a significant increase in lactates dehydrogenise release, reactive oxygen species production, Caspase-3 activity and the percentage of apoptotic cells (p < 0.01). However, pretreatment with timosaponin B-II significantly increased the viability of HUVECs and decreased lactates dehydrogenise release, Caspase-3 activity and the apoptosis rate in a concentration-dependent manner (p < 0.05). In addition, timosaponin B-II notably decreased the amount of reactive oxygen species and malondialdehyde, as well as promoted glutathione peroxidase activity, endothelial nitric oxide synthase activity and nitric oxide release (p < 0.05). These results suggest that timosaponin B-II has the antiapoptotic effect in endothelial cells through inhibition of high glucose-induced oxidative stress and has the potential for preventing diabetic cardiovascular complications.     

灵芝多糖对血管紧张素Ⅱ诱导的血管内皮细胞衰老的干预研究

目的探讨灵芝多糖保护血管内皮细胞、抑制血管内皮细胞衰老的作用。方法采用血管紧张素Ⅱ(AngⅡ)诱导的人脐静脉内皮细胞(HUVECs)建立衰老模型,分为对照组、AngⅡ诱导组和灵芝多糖组(给予AngⅡ刺激前1 h先给予100 mg/L灵芝多糖)。采用CCK-8法检测细胞存活率,采用免疫化学染色方法检测衰老相关β-半乳糖苷酶活性,流式细胞术检测细胞周期来反映细胞的增殖能力。结果与对照组比较,AngⅡ诱导组细胞存活率明显下降,β-半乳糖苷酶阳性染色率明显增多,细胞周期多停滞于G0/G1期,S期细胞逐渐减少,表明AngⅡ成功诱导了HUVECs衰老,而给予灵芝多糖干预后上述变化改善。结论灵芝多糖具有抑制内皮细胞衰老、保护血管内皮功能的作用。     

蛋白激酶C-胞外信号调节激酶1/2信号通路在尼古丁诱导的血管内皮细胞表达纤维溶解酶原激活物抑制物-1中的作用

目的 探讨蛋白激酶C(PKC)-胞外信号调节激酶(ERK)1/2信号通路在尼古丁诱导人脐静脉内皮细胞(HUVECs)表达纤维溶解酶原激活物抑制物-1(PAI-1)中的作用.方法 体外培养HUVECs,采用不同实验条件尼古丁进行干预,ELISA法测定细胞上清液中PAI-1的浓度,观察尼古丁作用的最佳浓度和时间.进一步分别用PKC的抑制剂星型胞菌素staurosporine (STS)和ERK的抑制剂PD98059干预HUVECs,观察PKC或ERK被阻断后对尼古丁诱导的HUVECs 表达PAI-1的影响,ELISA测定各组细胞上清液中PAI-1蛋白的表达水平,RT-PCR检测各组细胞PAI-1 mRNA的表达.结果 100 μmol/L尼古丁组PAI-1蛋白水平[(22.6 ± 1.1)μg/L]明显高于对照组[(14.2± 2.8)μg/L,q=5.64,P＜0.05];以100 μmol/L 尼古丁分别与HUVECs孵育0、4、6、8、12及24 h,各组PAI-1蛋白表达呈时间依赖性升高,并在12 h达到高峰(F=32.063,P＜0.05);尼古丁组PAI-1 mRNA及蛋白含量[(1.32±0.20),(21.08±0.83)μg/L]明显高于对照组[(0.73±0.10),(13.39± 0.93)μg/L,q=8.43、11.97,均P＜0.05];尼古丁+STS组PAI-1 mRNA及蛋白含量[(1.07±0.10),(16.19±2.15)μg/L]较尼古丁组降低(q=5.61、7.61,均P＜0.05),但仍高于对照组(q=7.84、4.36,均P＜0.05);尼古丁+ PD98059组PAI-1 mRNA及蛋白表达[(1.12±0.11),(17.52±1.72)μg/L]低于尼古丁组(q=4.68、5.54,均P＜0.05),仍高于对照组(q=8.77、6.43,均P＜0.05).结论 PKC-ERK1/2信号通路在尼古丁诱导的血管内皮细胞PAI-1表达上调中发挥一定作用.

Abstract：

Objective To explore the role of protein kinase C (PKC)- extracellular signal-regulated kinase (ERK)1/2 signal pathway in the process of plasminogen activator inhibitor-1(PAI-1) protein and mRNA expression in cultured human umbilical vein endothelial cells(HUVECs) induced by nicotine. Methods HUVECs were cultured to examine the effect of nicotine on the expression of secreting PAI-1 in HUVECs on different experimental conditions. The expression of PAI-1 protein was measured by ELISA. PKC inhibitor staurosporine (STS)and ERK1/2 inhibitor PD98059 were used to detect PKC or ERK1/2 function on the expression of PAI-1 in HUVECs induced by nicotine. The PAI-1 mRNA expression was determined by RT-PCR. Results The expression level of PAI-1 protein in 100 μmol/L nicotine treated group [(22.6±1.1) μg/L] increased significantly compared to the control group [(14.2±2.8) μg/L; q=5.64,P<0.05]. After stimulation with 100 μmol/L nicotine for 0,4,6,8,12 and 24 h, the levels of PAI-1 protein increased over time and reached the peak at 12 h (F=32.063,P<0.05).The PAI-1 mRNA and protein expression in nicotine treated group [(1.32±0.20), (21.08 ± 0.83) μg/L] increased significantly compared to the control group [(0.73±0.10), (13.39±0.93) μg/L; q=8.43,11.97,all P<0.05].Compared with nicotine treated group , the PAI-1 mRNA and protein expression in nicotine and STS treated group [(1.07±0.10),(16.19±2.15) μg/L] decreased significantly(q=5.61,7.61, all P<0.05), but still higher than the control group (q=7.84,4.36, all P<0.05). In nicotine and PD98059 treated group, the PAI-1 mRNA and protein expression [(1.12±0.11),(17.52±1.72) μg/L] decreased significantly compared to the nicotine treated group(q= 4.68,5.54, all P<0.05), still higher than the control group (q=8.77,6.43, all P<0.05). Conclusion PKC-ERK1/2 signal pathway may play a partial role in the up-regulation of PAI-1 induced by nicotine in HUVECs.     

整合素αvβ3在血管紧张素Ⅱ诱导人脐静脉内皮细胞衰老中的变化

目的观察整合素αvβ3在血管紧张素Ⅱ(AngⅡ)诱导的人脐静脉内皮细胞(HUVECs)衰老中的变化。方法体外培养HUVECs,采用CCK-8法检测细胞存活率,用AngⅡ(终浓度10-6mol/L)干预,分为实验对照组、AngⅡ诱导组。以衰老相关β-半乳糖苷酶活性和细胞增殖能力两种衰老标志物为主要观察指标。其中衰老相关β-半乳糖苷酶活性采用免疫化学染色方法,流式细胞术检测细胞周期来反应细胞的增殖能力;利用Western印迹法分析AngⅡ诱导HUVECs 0、12、24、36、48 h的整合素αvβ3表达的时间效应关系。结果与对照组相比,10-6 mol/L AngⅡ诱导组存活的细胞数为对照组的(77.15±6.83)%;(81.80±0.92)%的细胞呈现β-半乳糖苷酶阳性染色,流式细胞仪检测细胞周期停滞于G0～G1,证实细胞衰老;AngⅡ呈时间依赖性上调整合素αvβ3表达。结论 AngⅡ可以诱导HUVECs衰老,其机制可能与上调衰老细胞整合素αvβ3表达有关。     

金属硫蛋白2A重组质粒的构建及其在血管内皮细胞中的表达

目的 建立人血管内皮细胞金属硫蛋白2A(MT2A)上调表达细胞模型.方法 构建重组质粒pEGFP-N1-MT2A,转染至人脐静脉内皮细胞(HUVECs),荧光显微镜观察转染效果,RT-PCR及蛋白印迹法测定细胞MT2A表达水平.结果 测序证实pEGFP-N1-MT2A重组质粒构建正确,转染至HUVECs后,通过RT-PCR蛋白印迹实验证实细胞MT2A表达水平升高.结论 成功构建了重组质粒pEGFP-N1-MT2A,转染至HUVECs可使MT2A表达水平升高.     

Antiangiogenic Effect of Bile Acid Acylated Heparin Derivative

Purpose Chemically modified heparin–DOCA was prepared and found to have markedly lower anticoagulant activity than heparin. In the present study, we elucidated the antiangiogenic and antitumoral activities of heparin–DOCA derivative.Methods To evaluate the antiangiogenic and antitumoral effects of heparin–DOCA, capillary-like tube formation assay, Matrigel plug assay in vivo, western blotting for FGFR phosphorylation, ERK and p38 MAPK activities, tumor growth of SCC in vivo and immunostaining of blood vessels in tumor tissues were performed.Results Heparin–DOCA inhibited capillary-like tubular structures of endothelial cells and bFGF-induced neovascularizations in Matrigel plug assays. Signaling experiments showed that heparin–DOCA significantly inhibited angiogenesis by suppressing the phosphorylation of FGFR and its downstream signal pathways (ERK and p38 MAPK activities). The antiangiogenic activity of this heparin derivative was found to be closely associated with antitumoral activity in a mouse model. In addition, histological evaluations supported the inhibitory effect of heparin–DOCA on blood vessel formation in tumor tissues.Conclusion Heparin–DOCA derivative exerted a significant antitumoral effect by inhibiting angiogenesis resulting from the disruption of FGF/FGFR and its downstream signal pathways, and could be applied to treat various angiogenic diseases.     

益气活血复方含药血清对人脐静脉内皮细胞TLR4／NF—KB信号通路及TNF—a ICAM-1 mRNA表达的影响

目的：研究益气活血复方含药血清对脂多糖（LPS）诱导的人脐静脉内皮细胞（HUVECs）Toll样受体4（TLR4）／NF—KB及肿瘤坏死因子-a（TNF—a）、细胞间黏附分子（ICAM-1）mRNA表达的影响,探讨益气活血复方含药血清防治动脉粥样硬化（AS）的机制。方法：（1）选择新西兰大耳白兔20只,随机分为4组,即正常组、中药高浓度组、中药中浓度组、中药低浓度组,每组5只。以上各组白兔分别以生理盐水和高、中、低浓度益气活血复方连续灌胃7天。末次灌胃给药2h后,心脏采血,离心后分离血清。（2）体外培养人脐静脉内皮细胞,用LPS刺激后,分别加入高、中、低浓度益气活血复方含药血清干预24h,收集细胞,用荧光定量PCR方法测定TLR4、NF—KB、TNF—a及ICAM-1mRNA的表达。结果：用LPS刺激人脐静脉内皮细胞后,引起TLR4、NF-KB、TNF-a及ICAM-1 mRNA的高表达（与空白对照组比较P〈0．01）,用益气活血复方含药血清干预以后显著抑制TLR4、NF-KB、TNF-a及ICAM-1 mRNA的高表达（与模型组比较P〈0．01或P〈0．05）。结论：益气活血复方可阻断TLR4／NF—KB信号通路的高表达,同时抑制TNF—a及ICAM-1的表达,这可能是其发挥抗动脉粥样硬化作用的机制之一。     

Ang1、Ang2及Tie2在脐静脉内皮细胞的体外三维培养中的表达及意义

目的 探讨促血管生成素1、2及其受体(Ang1、Ang2及Tie2)在人脐静脉内皮细胞(HUVECs)体外三维培养的血管生成中的作用.方法 采用逆转录-聚合酶链式反应(RT-PCR)的方法检测10例体内HVUECs、体外二维培养的HVUECs和三维培养的血管样结构中Ang1、Ang2及Tie2的mRNA表达水平.结果 体外三维培养的血管样结构中Ang2、Tie2的mRNA表达水平均高于体内HVUECs和体外二维培养的HVUECs,差异有显著性(P<0.05);各组中Ang1的mRNA表达水平相比差异无显著性(P>0.05).结论 Ang/Tie2体系在体外血管生成中可能起重要的作用.     

DAPT在ox-LDL损伤HUVECs过程中的细胞保护作用

目的:探究γ-分泌酶抑制剂N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester(DAPT)在氧化低密度脂蛋白(oxidized low-density lipoprotein,ox-LDL)损伤人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)模型中的细胞保护作用及其对Notch信号通路的调控。方法:体外培养HUVECs,用oxLDL处理HUVECs构建细胞损伤模型。实验分为对照组、ox-LDL处理组、DAPT处理组和DAPT+ox-LDL处理组。用倒置相差显微镜观察不同处理方法下细胞的形态变化;CCK-8法检测细胞存活率;Western blot法检测蛋白Notch1、Notch4和Jagged1的表达情况。结果:体外培养HUVECs,倒置相差显微镜下发现ox-LDL处理组细胞死亡和碎片增多,经DAPT预处理后,ox-LDL作用造成的细胞损伤死亡较少,细胞碎片较少。通过CCK-8法检测发现ox-LDL处理组细胞存活率降低,DAPT处理组细胞存活率升高,DAPT预处理后ox-LDL造成存活率降低的幅度变小。在ox-LDL作用下,Notch1和Jagged1蛋白表达量降低,Notch4表达量升高;而DAPT作用下Notch1和Jagged1表达量升高,Notch4表达量降低;ox-LDL与DAPT共同作用时蛋白接近正常水平。结论:ox-LDL对HUVECs具有损伤作用;DAPT减轻ox-LDL对HUVECs造成的损伤;DAPT保护HUVECs免受ox-LDL损伤的作用与Notch信号通路有关。