坏死性凋亡介导高糖引起的人脐静脉内皮细胞损伤

目的:研究坏死性凋亡是否介导高糖(HG)诱导的人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)损伤。方法:CCK-8法检测细胞存活率;Western blot法测定受体相互作用蛋白3(RIP3)、cleaved caspase-3的蛋白水平;罗丹明123染色荧光显微镜照相法检测线粒体膜电位(mitochondrial membrane potential,MMP);双氯荧光素(DCFH-DA)染色荧光显微镜照相法测定胞内活性氧簇(reactive oxygen species,ROS)的水平。结果:应用不同浓度葡萄糖(10、20和40 mmol/L)处理HUVECs 24 h,RIP3的蛋白水平随葡萄糖剂量增加而升高,40 mmol/L时达高峰;应用40 mmol/L葡萄糖处理HUVECs 3 h、6 h、9 h、12 h和24 h能上调RIP3的蛋白水平,于9 h达最高峰;应用20μmol/L凋亡蛋白酶抑制剂Z-VAD-FMK预处理HUVECs 30 min促进RIP3表达;应用100μmol/L坏死性凋亡抑制剂necrostatin-1预处理HUVECs 1 h能抑制HG诱导HUVECs的细胞存活率降低,ROS过度生成及MMP丢失,但能升高cleaved caspase-3的蛋白水平。结论:坏死性凋亡介导高糖引起的人脐静脉内皮细胞损伤,但与内皮细胞凋亡存在负相关。     

Astragaloside IV inhibits PMA-induced EPCR shedding through MAPKs and PKC pathway

Astragaloside IV (AS-IV), a main active substance isolated from Astragalus membranaceus Bunge, has been shown to have multiple pharmacological effects. Endothelial cell protein C receptor (EPCR) is a marker of inflammation, and is also a major member of protein C (PC) anti-coagulation system. EPCR can be cut off from the cell surface by tumor necrosis factor-α converting enzyme (TACE), which is controlled through mitogen-activated protein kinase (MAPK) and protein kinase C (PKC) pathways. To develop novel therapeutic drug for EPCR shedding, the effect of AS-IV was studied in phorbol-12-myristate 13-acetate (PMA)-induced human umbilical vein endothelial cells (HUVECs) and the potential molecular mechanism of AS-IV action was investigated. The results showed that AS-IV could significantly inhibit PMA-induced EPCR shedding. In further study, AS-IV suppressed the expression and activity of TACE. In addition, AS-IV could decrease the phosphorylation of MAPK such as janus kinase (JNK) and p38, and inhibit activation of PKC through the prevention of non-phosphorylation and phosphorylation of specific PKC isoforms in PMA-stimulated HUVECs. These findings indicate that AS-IV may be used as a natural medicine to treat EPCR-related systemic inflammation and cardiovascular diseases by targeting MAPK and PKC pathway.     

槲皮素对血管内皮细胞的作用及其机制研究

目的: 观察不同浓度槲皮素对人脐静脉血管内皮细胞（HUVECs）生物学特性的影响,探讨槲皮素抑制血管生成的机制。方法: 应用不同浓度槲皮素处理细胞,在不同时间点,采用CCK-8法检测槲皮素对HUVECs增殖能力的影响;采用细胞划痕实验、基质胶体外成管实验检测槲皮素对HUVECs迁移及形成管腔能力的影响;采用实时荧光定量PCR检测槲皮素对HUVECs中血管内皮细胞因子（VEGF）、碱性成纤维细胞生长因子（bFGF）mRNA表达的影响;采用Western免疫印迹法检测HUVECs中AKT信号通路相关蛋白表达的变化。采用 SPSS 17.0 软件包对数据进行单因素方差分析和Tukey post-hoc分析。结果: 槲皮素能抑制HUVECs的增殖;与对照组相比,槲皮素处理后,HUVECs细胞迁移及形成管腔结构的数量明显减少,抑制作用呈剂量依赖性。槲皮素能抑制HUVECs中VEGF、bFGF mRNA的表达,抑制HUVECs中AKT相关信号通路。结论: 槲皮素抑制HUVECs增殖及体外血管形成能力,其机制部分通过AKT相关信号通路介导。     

胶原海绵促进人脐静脉血管内皮细胞生长的体外实验研究

目的探讨胶原海绵促进人脐静脉血管内皮细胞生长的疗效与机制。方法实验组在细胞培养孔中加入含8 U胶原酶的0.2 ml PBS 2 mm×2 mm×2 mm正方体胶原海绵;对照组仅加入含8 U胶原酶的0.2 ml无菌的PBS液体。培养24 h后测血管内皮细胞增殖(MTT实验)、迁移(划痕实验)、及免疫蛋白印迹检测血管生成素1(Ang1)、血管内皮生长因子(VEGF)与整合素(Integraαv)。结果细胞培养后24 h,实验组可以显著促进HUVEC的增殖,增殖率达86%;实验组血管内皮细胞细胞迁移加快,12 h细胞迁移完成,显著高于对照组(P0.01);实验组VEGF、Ang1及Integraαv蛋白表达明显高于控制组,其中以整合素аv蛋白表达增加尤为显著,增加了80%。结论胶原海绵促进血管内皮细胞增殖与迁移,其中促进迁移的作用较强,机制之一为提高了血管内皮细胞中VEGF、ANG1、Integraαv蛋白表达。     

miR-21在山核桃叶总黄酮抑制人脐静脉内皮细胞增殖中的作用研究

[目的]探讨山核桃叶总黄酮对人脐静脉内皮细胞（HUVECs）增殖的作用,以及miR-21在山核桃叶总黄酮抑制HUVECs增殖中的作用,进一步探讨山核桃叶总黄酮抑制血管生成的作用机制.[方法]不同浓度山核桃叶总黄酮孵育HUVECs后,采用Cell Counting Kit （CCK-8）法检测HUVECs的生长情况;采用SYBR定量PCR检测miR-21的转录水平及Western blot法测定其靶基因PDCD4的蛋白表达水平.[结果]CCK-8法检测结果表明,山核桃叶总黄酮可以剂量依赖性地抑制HUVECs的增殖;SYBR定量PCR结果表明山核桃叶总黄酮孵育过的HUVECs中miR-21的表达量呈浓度依赖性降低,而PDCD4蛋白的表达量呈浓度依赖性升高.[结论]miR-21可能通过PDCD4参与了山核桃叶总黄酮抑制HUVECs增殖的过程.     

当归挥发油对人脐静脉内皮细胞增殖作用的谱效关系

目的:探讨不同产地当归挥发油与人脐静脉内皮细胞增殖作用的相关关系。方法:利用水蒸气蒸馏法提取当归挥发油,采用GC-MS联用分析技术建立44批不同产地当归药材挥发油指纹图谱,质谱检索库及保留指数法鉴定各色谱峰所示化学成分,用噻唑蓝染色(MTT)实验考察不同产地当归挥发油对HUVECs细胞的增值率,再通过线性回归分析方法,建立并分析当归挥发油促HUVECs细胞增殖作用的相关关系。结果:通过线性回归分析得色谱峰X_1,X_2与细胞增殖率呈负相关的关系,其余色谱峰与细胞增殖率均呈正相关的关系,且其中X_3,X_6,X_7号色谱峰回归系数较大,是当归挥发油促HUVECs细胞增殖的主要化学成分。结论:该方法能快速、有效地建立当归挥发油谱效相关关系,可为当归挥发油化学成分药理性质的研究提供参考依据。     

Asymmetric dimethylarginine impairs fibrinolytic activity in human umbilical vein endothelial cells via p38 MAPK and NF-κB pathways

Introduction

Asymmetric dimethylarginine (ADMA) is a potent endogenous inhibitor of nitric oxide (NO) synthase. An increased synthesis and/or a reduced catabolism of ADMA might contribute to the onset and progression of thrombosis. The present study was designed to evaluate the effect of ADMA on fibrinolytic factors in endothelial cells, and to investigate the cellular mechanisms.

Materials and Methods

Human umbilical vein endothelial cells (HUVECs) were treated with different concentrations of ADMA for various periods; Then HUVECs were preincubated with NO precursor (L-arginine), MAPK inhibitors, or NF-κB inhibitor (PDTC) before ADMA treatment to repeat the experiment. Protein levels of tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1), and NF-κB activity were measured by ELISA; mRNA levels of tPA and PAI-1 were assayed by qRT-PCR; The activation of MAPK was characterized by western blot analysis.

Results

(1) ADMA decreased tPA antigen levels in time- and concentration-dependent manners, with the maximum effect of 30 μmol/L ADMA for 48 h (control 109.01 ± 4.15 ng/ml vs ADMA 86.76 ± 5.95 ng/ml, p < 0.01); (2) 30 μmol/L ADMA elevated antigen levels of PAI-1 in a time-dependent manner, with the maximum effect of 30 μmol/L ADMA for 48 h (control 2721.12 ± 278.02 ng/ml vs ADMA 3435.78 ± 22.33 ng/ml, p < 0.05); (3) ADMA reduced tPA mRNA levels and increased PAI-1 mRNA levels; (4) L-arginine, SB203580 (p38 MAPK inhibitor) and PDTC attenuated the effects of ADMA on tPA and PAI-1 significantly. (5) ADMA induced a rapid phosphorylation of p38 MAPK, and stimulated NF-κB activity greatly.

Conclusions

ADMA may accelerate thrombosis development by impairing fibrinolytic activity in vascular via inhibiting nitric oxide production and then activating its downstream p38 MAPK and NF-κB pathways.     

C-reactive protein activates the nuclear factor-kappaB pathway and induces vascular cell adhesion molecule-1 expression through CD32 in human umbilical vein endothelial cells and aortic endothelial cells

C-reactive protein (CRP) contributes to the process of atherosclerosis by inducing pro-inflammatory changes in endothelial cells. However, the exact receptor involved in CRP-induced endothelial changes remains unclear. Human umbilical vein endothelial cells (HUVECs) and human aortic endothelial cells (HAECs) were used for the experiments. After incubation with CRP, immunoblotting showed a significant decrease of IkappaB protein and electrophoretic mobility shift assay showed a significant increase of nuclear NF-kappaB binding capacity. These changes were associated with a significant increase of vascular cell adhesion molecule-1 (VCAM-1) expression. The mRNA level of CD32, the major binding protein for CRP in endothelial cells, increased significantly as measured by Northern blot and Western blot. When these cells were transfected with siRNA directed against CD32, the mRNA of CD32 decreased significantly. The IkappaB degradation, NF-kappaB nuclear translocation and VCAM-1 up-regulation induced by CRP were all inhibited by treatment with siRNA against CD32. SB203580, a P38 inhibitor, significantly attenuated the CRP-induced responses while SP600125 (c-jun kinase inhibitor) did not. In conclusion, CRP-induced IkappaB degradation, NF-kappaB nuclear translocation and VCAM-1 protein expression in HUVECs and HAECs. CRP also increased the expression of CD32, which might serve as the receptor for CRP in endothelial cells and mediated the effects of CRP.