可溶性血管内皮生长因子受体1真核克隆表达及其对血管内皮细胞增殖的影响

本研究旨在构建可溶性血管内皮生长因子(vascular endothelial growth factor,VEGF)受体1(soluble fmslike tyosine kinase-1,sFlt-1)的真核表达质粒pcDNA3.1-sFlt-1,并观察sFlt-1对血管内皮细胞增殖的影响。提取人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)总RNA,扩增Flt-1基因胞外1-3结构域,构建真核表达质粒pcDNA3.1-sFlt-1,测序鉴定基因序列。将重组质粒转染Lewis肺癌细胞,采用RT-PCR和SDS-PAGE检测sFlt-1在基因及蛋白水平的表达情况。MTT法检测sFlt-1对VEGF诱导的HUVECs生长的影响。结果显示:①插入片段序列正确;②sFlt-1在基因水平成功表达且转染后的Lewis肺癌细胞能分泌表达sFlt-1;③含sFlt-1的细胞上清液可明显抑制VEGF诱导的HUVECs增殖。本研究成功构建了真核表达质粒pcDNA3.1-sFlt-1,sFlt-1,在基因和蛋白水平均获得有效表达,且表达的蛋白可明显抑制由VEGF诱导...     

血管内皮细胞生长因子基因转染骨髓基质细胞的瞬时表达与稳定表达

目的探讨血管内皮细胞生长因子（VEGF）基因修饰的大鼠骨髓基质细胞（BMCS）的表达能力及表达活性。方法取6周龄SD大鼠BMCS传代培养后以3μl阳离子脂质体（Lipofectamine）：1μg pc DNA3．1-VEGF165的比例转染，通过RT—PCR技术、免疫组织化学S—P法检测转染细胞中外源性VEGF165基因的转录及瞬时表达和稳定表达，用血管内皮细胞（VEC）增殖试验测定转染细胞培养上清中VEGF的生物活性。结果VEGF基因转染的大鼠骨髓基质细胞可有效转录VEGF165，其分泌培养上清液中的表达产物可促进血管内皮细胞增殖，具有很强的生物活性。结论采用基因转染技术可将VEGF转染至BMCS中，并可有效表达具有生物活性的VEGF。     

Immunohistochemical Expression of Vascular Endothelial Growth Factor and Vascular Endothelial Growth Factor Receptor in Canine Cutaneous Fibrosarcomas

The expression of five markers associated with tumour angiogenesis, proliferation and apoptosis was studied in 24 canine cutaneous fibrosarcomas. Tumours were assigned histological grades and were immunohistochemically evaluated for the expression of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR-2). Additionally, intra-tumour microvessel density (iMVD) was assessed by immunohistochemical labelling for expression of von Willebrand factor (vWf) and tumour proliferation index (PI) was measured following labelling of Ki-67 antigen. Finally, tumour apoptotic index (AI) was determined by application of the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP end-labelling method (TUNEL). VEGF and VEGFR-2 expression were detected in 22/24 (92%) and 24/24 (100%) of fibrosarcomas, respectively. There was correlation between VEGF and VEGFR-2 expression (r = 0.51) and between histological grade and PI (r = 0.82). A significant difference in PI between tumours of different histological grade was found (P < 0.05). The median PI in grade 2 and 3 tumours (30.6 and 54.7, respectively) was significantly higher than in grade 1 tumours (6.4). Therefore, only PI correlates significantly with the histological grade of canine cutaneous fibrosarcomas. The potential for autocrine activity for VEGF exists in canine cutaneous fibrosarcomas, as VEGF and VEGFR-2 expression was found in most tumours.     

Study on Tumor Microvasculature Damage Induced by Alternate Cooling and Heating

Tumor vasculature damage induced by various thermal treatments has been studied in vivo via laser confocal microscopy. Murine mammary carcinoma 4T1 was implanted in the nude mice dorsal skin fold window chamber. The implanted tumor was treated by alternate cooling and heating. Results showed that the treatment was much more effective as compared with that of cooling or heating alone, especially in damaging the tumor vasculature. In general, tumor vascular response to thermal stimuli was heterogeneous. All the treatments of hyperthermia at 42 °C (for 1 h), alternate cooling at 1 °C and heating at 42 °C (for 1/2 h each) and that of −10 °C/42 °C (for 1/2 h each) enhanced liposome extravasation. Pre-cooling tumor at 1 °C preserved most of the vascular integrity but partially inhibited the effect of post-hyperthermia at 42 °C. On the other hand, cooling at −10 °C for 1/2 h before heating at 42 °C caused severe vessel damage. Histo-pathological analyses further confirmed the effect as rare tumor vessel recurrence and large necrotic tumor tissue areas shown on the 7th day after the treatment.     

Resveratrol Inhibits Hypoxia-Induced Vascular Endothelial Growth Factor Expression and Pathological Neovascularization

Purpose

To investigate the effects of resveratrol on the expression of hypoxia-inducible factor 1α (HIF-1α) and vascular endothelial growth factor (VEGF) in human adult retinal pigment epithelial (ARPE-19) cells, and on experimental choroidal neovascularization (CNV) in mice.

Materials and Methods

ARPE-19 cells were treated with different concentrations of resveratrol and then incubated under hypoxic conditions with subsequent evaluation of cell viability, expression of HIF-1α, and expression of VEGF. The effects of resveratrol on the synthesis and degradation of hypoxia-induced HIF-1α were evaluated using inhibitors of the PI3K/Akt/mTOR and the ubiquitin proteasome pathways. In animal studies, CNV lesions were induced in C57BL/6 mice by laser photocoagulation. After 7 days of oral administration of resveratrol or vehicle, which began one day after CNV induction, image analysis was used to measure CNV areas on choroidal flat mounts stained with isolectin IB4.

Results

In ARPE-19 cells, resveratrol significantly inhibited HIF-1α and VEGF in a dose-dependent manner, by blocking the PI3K/Akt/mTOR signaling pathway and by promoting proteasomal HIF-1α degradation. In mice experiments, orally administered resveratrol significantly inhibited CNV growth in a dose-dependent manner.

Conclusion

Resveratrol may have therapeutic value in the management of diseases involving pathological neovascularization.     

湍流流动对血管内皮细胞黏附分子表达的影响

本研究考察了ECs在不同流场中的血管细胞黏附分子(VCAM-1)和胞间黏附分子(ICAM—1)表达，揭示了湍流流体力学信号影响黏附分子表达和ECs功能状态。构建了层流和湍流的离体流室模型，运用共聚焦显微镜，从蛋白水平考察培养的人脐静脉ECs中VCAM-1和ICAM-1在不同流室中的表达。发现层流中VCAM-1表达显著增强，而ICAM-1表达只一过性增加，随即回落。湍流中VCAM-1表达下降，而ICAM-1表达持续缓慢上升。由此表明：湍流流场对血管ECs黏附特性的影响不同于层流，而且不同的黏附分子对流动具有不同的响应性；湍流是引起ECs形态结构和功能行为的病理学改变的重要原因。     

血管内皮生长因子分子多样性及其与肿瘤的关系

血管内皮生长因子是肿瘤发生发展过程中起重要作用的一类糖蛋白,其在基因水平存在较多的SNP位点以及在RNA剪切水平上存在选择性剪切.研究表明,这些变异与各种肿瘤的发生、发展、恶性程度有着密切的关系.     

脂质体介导的VEGF_(165)基因转染对内皮细胞生长的作用

构建血管内皮细胞生长因子基因VEGF165真核表达载体pcDNA3 VEGF165,以阳离子脂质体介导的基因转染技术 ,将基因转入原代培养的人脐静脉内皮细胞中。结果表明 ,基因转染 1h后细胞内就有VEGFDNA存在 ,VEGFmRNA水平显著上升 ;基因转染 2d后培养液上清VEGF蛋白表达显著上升 (135 5 12± 6 2 34)pg/ml和 (19 2 7± 2 96 )pg/ml,P <0 0 1。转染VEGF165基因 2d的内皮细胞再经程序降温冷冻保存复苏后 ,其存活率显著高于对照组 (pcDNA3 组 ) (90 13%± 2 84 %和81 5 2 %± 2 15 % ,P <0 0 5 ) ,凋亡率显著低于对照组 (7 15 %± 0 4 2 %和 17 6 1%± 1 5 6 % ,P <0 0 5 )。MTT法显示转染VEGF165基因能促进内皮细胞VEGF蛋白的表达 ,促进细胞增殖 ,抑制细胞凋亡。在治疗心脏及下肢动脉缺血性疾病中 ,VEGF165基因治疗可能具有重要的意义。     

Vascular Endothelial Growth Factor Gene Polymorphisms May Predict the Risk of Acute Graft-versus-Host Disease following Allogeneic Transplantation: Preventive Effect of Vascular Endothelial Growth Factor Gene on Acute Graft-versus-Host Disease

Microvessel injury is associated with the development of graft-versus-host disease (GVHD), whereas high levels of posttransplantation vascular endothelial growth factor (VEGF) have a protective effect on severe acute GVHD (aGVHD) and transplantation-related mortality. The current study aimed to determine the impact of VEGFA gene single-nucleotide polymorphisms (SNPs) on the risk of aGVHD after allogeneic stem cell transplantation (SCT). Using polymerase chain reaction and restriction fragment length polymorphism, 4 VEGFA SNPs— -2578 C>A (rs699947), -460 T>C (rs833061), +405 G>C (rs2010963), and +936 C>T (rs3025039)—were analyzed in 98 recipients. Strong linkage disequilibrium was noted among loci -2578, -460, and +405, but not among these loci and locus +936. Accordingly, 4 haplotypes were generated based on the genotypes of -2578, -460, and +405: CTC (47.9%), CTG (26.7%), ACG (24.2%), and CCC (1.0%). The group with low VEGF production (ie, +936CT genotype and 2 copies of the ACG haplotype) had a higher incidence of aGVHD. Significant associations were found between the risk of grade 2-4 aGVHD and the +936 CT (P = .006), -2578 AA (P = .003), and -460 CC (P = .002) genotypes and the ACG haplotype (P = .003). No association between the VEGFA SNPs and chronic GVHD was observed. The VEGFA SNPs might predict a lower risk of aGVHD. Our findings suggest that VEGF may have a protective role in the pathogenesis of aGVHD.     

血管内皮生长因子(VEGF)对培养内皮细胞VEGF受体表达的影响

目的 :为探讨VEGF对培养内皮细胞 (EC)VEGF受体表达的影响。方法 :将培养的人脐静脉内皮细胞 (HUVEC)随机分为 4组 :( 1)正常对照组 ;( 2 )低氧培养组 ;( 3)VEGF 10ng/ml组 ;( 4)低氧 +VEGF10ng/ml组。HUVEC低氧培养参照Kuwara等介绍的方法并加以改进。HUVECVEGF受体的检测采用免疫组织化学方法。结果 :采用简易低氧培养法 ,48h内培养液氧分压维持在 5 8mmHg ;与对照组相比 ,低氧培养组、VEGF组和低氧 +VEGF组HUVECVEGF受体Flk 1/KDR阳性细胞数增多 ,强度增加 ;但未检测到VEGF受体Flt 1表达。结论 :低氧可使HUVEC表面的VEGF受体Flk 1/KDR表达增加 ,VEGF同源上调其受体Flk 1/KDR ,低氧和VEGF在调节VEGF受体Flk 1/KDR方面有协调作用。     

Immunohistochemical Expression of Vascular Endothelial Growth Factor in Canine Mammary Tumours

The histopathological and clinical aspects of canine mammary tumours (CMTs) have been widely studied, but the variation in the biological behaviour of these neoplasms hampers the identification of prognostic factors. Sustained angiogenesis has been suggested to be one of the most important factors underlying tumour growth and invasion. This process involves the action of several growth factors including vascular endothelial growth factor (VEGF). The present study characterizes the relationship between immunohistochemical expression of VEGF and gross (e.g. size and tissue fixation) and microscopical (e.g. type, growth, necrosis, lymphoid infiltration, lymph node metastasis, histological grade and proliferation index) features of CMTs. Forty-eight benign and 64 malignant CMTs were evaluated. Statistical analysis failed to show a significant relationship between VEGF expression and the pathological features, suggesting that VEGF expression occurs in both benign and malignant tumours and is independent of histological type, proliferation, tissue invasion or local metastatic capacity.     

血管内皮细胞和动脉粥样硬化

作 为心脑血管病的病理基础动脉粥样硬化 (ＡＳ) ,其病变发生于动脉壁内层 ,ＡＳ的发病机制一直受到关注 ,百年来提出了种种学说 :如脂质浸润学说、血栓形成学说、平滑肌细胞克隆生长学说等 ,这意味着ＡＳ发病机理的复杂性 ,1990年代以来 ,提出了损伤反应学说 ,认为ＡＳ是一种慢性炎性疾病 ,表现为在致病因素作用下 ,动脉壁内由内皮细胞、平滑肌细胞、单核细胞和Ｔ淋巴细胞参与的细胞间相互作用 ,在ＡＳ发病机理中起着极其重要的意义。这种相互作用通过这些细胞分泌的趋化因子、生长因子和细胞因子实现调控。ＡＳ发生发展过程中包括许多病理…     

Angiogenesis and the Expression of Vascular Endothelial Growth Factor in Endometrium and Placenta

PROBLEM: The demand for increased angiogenesis and microvascular permeability during cyclical changes in the endometrium and during placentation raises the possibility that aberrations in these events could lead to suboptimal reproductive performance. However, relatively little is presently known regarding the regulation of vascular growth and permeability in these tissues. METHOD OF STUDY: This review of current literature focuses on the expression, regulation, and potential physiological effects of vascular endothelial growth factor (VEGF) within endometrial and placental tissue. RESULTS: Spatial and temporal expression of VEGF as well as its restricted specificity, essential role in vasculogenesis/angiogenesis, and ability to induce vascular permeability makes VEGF an attractive regulator of vascular growth and permeability in the endometrium and placenta. CONCLUSION: A better understanding of the production, regulation, and physiological responses of the vasculature to angiogenic growth factors may lead to new therapeutic strategies for reproductive disturbances secondary to vascular insufficiencies within the female reproductive tract.     

血管内皮细胞糖萼与脂蛋白

血管内皮细胞糖萼是位于内皮细胞表面的一层多糖蛋白复合结构,在内皮细胞表面形成选择性通透屏障。在对糖萼进行概述后,主要针对在流动剪切力作用下,糖萼与物质传输,尤其是与大分子物质如低密度脂蛋白(low density lipoprotein,LDL)的关系展开论述。其关系体现为:一方面,糖萼的厚度和完整性影响LDL的浓度极化及跨内膜输运;糖萼中的硫酸肝素蛋白聚糖参与残余脂蛋白代谢的全过程。另一方面,LDL的氧化产物ox-LDL会破坏内皮细胞糖萼层的主要成分硫酸肝素。研究糖萼与脂蛋白的关系,将为阐明动脉粥样硬化的发病机理提供新的线索,并为将糖萼作为新的防治靶点提供更多依据。     

Fogarty球囊导管取栓对兔静脉内皮形态及血管性血友病因子表达的影响

目的：观察Fogarty球囊导管取栓治疗兔急性静脉血栓后，兔病变段静脉内皮细胞形态及血管性血友病因子（vWF）的变化情况。方法：家兔95只，70只建血栓模型，并分为取栓（thrombectomy，TX）组、非取栓（non-thrombectomy，N-TX）组各35只；另25只为假手术组（shamoperation，SH）。于取栓后不同时段，获取病变段血管。扫描电镜观察内皮细胞形态学变化，免疫组化观察vWF的改变情况。结果：TX组术后1天内皮损伤为Ⅰ～Ⅱ级，4、7天时Ⅲ～Ⅳ级，14～28天Ⅱ～Ⅲ级，与N-TX和SH组比较，内皮细胞损伤重（P〈0．05）；vWF表达在取栓后7天时最强，14～28天有所降低。结论：急性深静脉血栓取栓后早期（7天内），静脉内皮形态学上损伤较为严重，促血小板聚集增强；取栓后期（14～28天）内皮形态部分修复，促血小板聚集有所减弱，但均未恢复到正常水平。     

从肿瘤基因表达数据挖掘分类规则的研究

基于肿瘤基因表达数据,利用信息科学的方法和技术建立肿瘤预测分类模型,对肿瘤基因表达模式研究和肿瘤的诊断识别具有重要意义.本研究提出一种从肿瘤基因表达数据中直接挖掘分类规则建立肿瘤预测分类器的方法.该方法首先抽取实验样本集,分别找出标记肿瘤和正常组织样本的分类特征,由此生成可预测样本类别的分类规则,对每个未知类别样本,按照置信度最高原则,选择一个分类规则作为预测结构.本研究的实验数据来自Broad Institute的前列腺癌基因表达数据,实验结果显示该方法的预测精度在90%以上,且同时获得了大量结构透明的分类预测规则,表明本研究的方法是可行的和有效的.     

脑血管内皮细胞ICAM-1的表达对T淋巴细胞与内皮细胞粘附的影响

为研究血脑屏障内皮细胞ICAM 1的表达对T淋巴细胞与内皮细胞粘附的影响 ,本实验采用液氮冷冻Wistar大鼠脑组织制成血管源性脑水肿模型 ,将脑组织制成冰冻切片 ,与大鼠T淋巴细胞悬液共温后 ,常规HE染色和显微镜观察 ,求出T淋巴细胞与脑血管壁的特异性粘附率。结果发现事先未滴加抗ICAM 1单抗组 ,T淋巴细胞的特异性粘附率 (均值 :6 2 % )较高 ,而事先滴加抗ICAM 1单抗组 ,T淋巴细胞的特异性粘附率 (均值 :30 % )明显下降 (P <0 0 0 0 1) ,但并未被完全抑制 ,说明ICAM 1是介导T淋巴细胞粘附的重要的粘附分子之一。     

血管内皮细胞生长因子对内皮细胞凋亡拮抗作用的研究

目的 :初步探讨缺氧对培养人脐静脉内皮细胞凋亡的影响及血管内皮生长因子的干预性影响。方法 :( 1)人脐静脉内皮细胞的培养及鉴定。 ( 2 )建立人脐静脉内皮细胞缺氧模型 ,TUNEL法观测不同缺氧时间 ( 0、12、2 4、48h)对内皮细胞凋亡的影响及不同剂量血管内皮生长因子的拮抗作用。结果 :随缺氧时间延长 ,HUVECs凋亡率显著升高 ,呈时间相关性 ;血管内皮生长因子显著抑制缺氧导致的内皮细胞凋亡 ,呈剂量相关性。结论 :缺氧作为一种致病因素 ,对内皮细胞凋亡的促发作用是随缺氧时间的延长而加重的。内皮细胞的过度凋亡是引起内皮功能障碍的一个重要因素 ,血管内皮生长因子通过抑制内皮细胞凋亡 ,而具有内皮细胞保护作用。