喉癌组织内皮素-1和血管内皮生长因子-C的表达与预后的关系

目的：探讨喉癌组织内皮素-1（ET-1）和血管内皮生长因子-C（VEGF-C）的表达与预后的关系。方法：采用免疫组织化学方法检测80例喉癌组织及62例喉良性组织ET-1和VEGF．C的表达,探讨二者与喉癌患者预后的关系。结果：喉癌组织ET-1及VEGF-C阳性率分别为56．3％和57．5％,喉良性组织分别为19．4％和21．0％,差别具有统计学意义（P〈0．05）;ET-1及VEGF-C与喉癌患者TNM分期、淋巴转移显著相关（P〈0．05）,与组织学分级、年龄及性别无关（P〉0．05）。结论：ET-1与VEGF-C参与喉癌的发生机制,且与肿瘤的转移侵袭等生物学行为显著相关。     

胰岛素受体及其底物与血管内皮生长因子

VEGF参与肿瘤发生与发展、缺血性血管病变、糖尿病小血管异常增生等多个病理生理过程,胰岛素受体及其底物作为VEGF的调节因素之一可通过多种途径影响VEGF的表达。文章综述了在糖尿病视网膜病变、肿瘤、缺血性血管病等不同病理生理条件下胰岛素受体及其底物对VEGF表达的影响,推测两者之间可能存在的调节机制。     

胰岛素样生长因子结合蛋白-1启动子的克隆与序列分析

用酚氯仿抽提法提取SD大鼠的肝脏基因组DNA,PCR扩增胰岛素样生长因子结合蛋白-1（IGFBP-1）启动子并克隆至pUC118载体。从含IGFBP-1启动子的质粒中酶切分离出IGFBP-1启动子并测序。PCR扩增出420bp的目的DNA片段,与文献报道的IGFBP-1启动子DNA大小一致。经正、反两方向序列分析显示,克隆的基因序列和GenBank数据库中的IGFBP-1启动子基因序列一致。以上结果表明克隆成功了IGFBP-1启动子基因,为构建具双向调节的胰岛素分泌调控基因质粒奠定了基础。     

乳腺癌组织中转化生长因子-beta1 和血管内皮生长因子的表达 及其与血管生成的关系

目的:研究转化生长因子-β1(transforming growth factor-β1,TGF-β1)和血管内皮生长因子(vascular endothelial cell growth factor,VEGF)在乳腺癌组织中的表达及其与血管生成的关系。方法:选取65例手术切除乳腺癌蜡块标本及其周围正常乳腺组织,分为两组:A组为对照组,检测标本为乳腺癌癌旁正常乳腺组织;B组为实验组,检测标本为乳腺癌组织,采用免疫组织化学染色和形态计量检测TGF-β1和VEGF在乳腺癌组织中的表达。利用CD34相关抗原标记血管内皮细胞,计数微血管密度(intratumoral mier oveseulardensity,MVD),并分析其与TGF-β1和VEGF表达的关系。结果:65例乳腺癌组织中,TGF-β1的阳性表达率为69.23%(45/65),TGF-β1阳性表达者MVD值(25.31±4.05)显著高于TGF-β1阴性表达者(21.23±4.29);VEGF的阳性表达率为78.46%(51/65),VEGF阳性表达者MVD值(26.62±3.41)亦明显显著高于VEGF阴性表达者(18.95±6.52)(均P<0.05)。不同病理类型的乳腺癌组织中TGF-β1、VEGF的阳性表达率比较差异无统计学意义(P>0.05),但TGF-β1、VEGF的阳性表达与乳腺癌的组织分级、淋巴结转移呈显著正相关(均P<0.05),且组织学分级越高、淋巴结转移越多,MVD值越大。结论:TGF-β1与VEGF在乳腺癌组织的表达高于正常乳腺组织,并与乳腺癌肿瘤血管的生成有关,二者有望作为乳腺癌恶性程度、浸润转移等生物学行为的评估指标。     

胰岛素样生长因子-1对血管平滑肌细胞PI3K/PTEN信号通路的影响

目的:探讨胰岛素样生长因子-1(IGF-1)促血管平滑肌细胞(VSMC)增殖的细胞内信号转导机制.方法:体外培养的兔血管平滑肌细胞分3组处理,以细胞计数、噻唑盐比色法测定细胞增殖能力,以磷脂酰肌醇-3激酶(PI3K)特异性抑制剂渥漫青霉素(WT)孵育细胞间接反映PI3K作用.Western Blot定量磷酸酶PTEN表达水平,免疫沉淀、特异底物diC16PIP3绿色试剂法测定PTEN脂质磷酸酶活性.结果:IGF-1(100 μg/L)使细胞计数及MTT 比色A值分别增加至对照组的2.8倍和3.8倍,WT抑制VSMC增殖,并完全逆转IGF-1的作用(均P<0.01).各浓度IGF-1对PTEN蛋白表达水平无明显影响,其对PTEN活性的抑制呈浓度(10～100 μg/L)及时间(3 min～24 h)依赖性(均P<0.01).结论:IGF-1促VSMC增殖作用与活化PI3K蛋白激酶的促生长活性及抑制PTEN脂质磷酸酶的负性调节细胞生长作用有关.     

胰岛素样生长因子-1与代谢性疾病及运动干预的研究进展

胰岛素样生长因子-1 (insulin-like growth factor-1,IGF-1)是分子结构与胰岛素类似的多肽类物质.IGF-1在组织生长发育、细胞代谢、增殖、分化和凋亡中发挥关键作用.IGF-1主要由肝脏分泌,其分泌量占总体的75％,剩余25％由骨骼肌、心、肾和脾等器官分泌.IGF-1可靶向心脏、血管、肝...     

生长激素/胰岛素样生长因子1与阿尔茨海默病

生长激素／胰岛素样生长因子-1（GH／IGF-1）轴的合成、分泌、调节及生物学活性与阿尔茨海默病（AD）有密切关系。生长激素（GH）的合成和分泌受生长激素释放激素（GHRH）正向调节。GH／IGF-1轴活性下降导致一系列生理功能变化。GH／IGF-1缺乏可引起衰老及神经退行性变（AD）而导致认知功能的下降,相应激素的补给可以抑制或逆转这种认知障碍。越来越多的证据表明：GH／IGF-1参与AD型痴呆病理过程,对AD有很好的治疗应用前景。本文就生长激素／胰岛素样生长因子1在AD发病中的机理和药理学研究做一综述。     

胰岛素样生长因子1及其在组织和器官生长发育中的作用

胰岛素样生长因子1(IGF1),具有调节组织细胞增殖、分化、有丝分裂等功能。研究表明IGF1不仅参与众多疾病的发生,还参与了不同组织和器官的发育过程。对IGF1信号通路及其在机体发育中的作用进行了综述。     

胰岛素样生长因子Ⅰ与生长激素的关系

胰岛素样生长因子Ⅰ与生长激素的关系邹仕庚盛爱武高峰（南京农业大学动物科技学院,２１００９５）１９５７年,Ｓａｌｍａｎ和Ｄａｕｇｈａｄａｙ发现正常大鼠血清能促进３５Ｓ进入培养的软骨细胞,而切除垂体的大鼠血清缺乏对这种硫化过程的促进作用。给切除垂体的大鼠...     

重组类胰岛素样生长因子-Ⅰ的纯化与复性

目的 获得高纯度和高活性的胰岛素样生长因子（Insulin-like growth factor, IGF-1）;方法 构建好的BL21大肠杆菌工程菌经IPTG诱导,以融合一段截短型半乳糖苷酶及His-tag形式表达IGF-1融合蛋白(约15,000Da),超声破碎,提取包涵体经镍柱亲和层析后, 用羟氨切割纯化的融合蛋白,纯化后的蛋白质在小分子保护剂及GSH/GSSG的存在下复性。结果 经Ni2＋柱亲和层析, IGF-1纯度达90％以上,复性后得到有较高生物活性的IGF-1。结论 IGF-1发酵及纯化和复性方法的建立为大量生产IGF-1打下了基础。     

缺氧诱导因子1α、血管内皮生长因子和成纤维细胞生长因子在胰腺癌中的表达及意义

目的：研究胰腺癌组织中缺氧诱导因子1alpha（Hypoxia-inducible factor-1alpha,HIF-1α）、血管内皮生长因子（vascular endothelial growth factor,VEGF）和成纤维细胞生长因子（fibroblast growth factor,FGF）的表达并探讨其意义。方法：Western blot法检测22例胰腺癌及癌旁组织中HIF-1α、VEGF和FGF蛋白的表达,分析HIF-1α与VEGF、FGF之间的相关性以及与性别、年龄、肿瘤大小、淋巴结转移和TNM分期之间的关系。结果：HIF-1α、VEGF和FGF在胰腺癌组织中的蛋白表达水平明显高于胰腺癌周组织（P〈0.01）,HIF-1α与VEGF、FGF之间的表达具有显著相关性（P〈0.01）。HIF-1α的表达与胰腺癌的TNM分期、肿瘤大小和淋巴结转移有关（P〈0.01）,VEGF和FGF的表达与胰腺癌的肿瘤大小和淋巴结转移有关（P〈0.05）。结论：HIF-1α可以上调VEGF和FGF的表达,在胰腺癌的发生、发展中起着重要作用。     

缺氧诱导因子1 α、血管内皮生长因子和成纤维细胞生长因子在胰腺癌中的表达及意义

目的:研究胰腺癌组织中缺氧诱导因子la|pha(Hypoxia-inducible factor-laipha,HIF-1α)、血管内皮生长因子(vascular endothelial growth factor,VEGF)和成纤维细胞生长因子(fibroblast growth factor,FGF)的表达并探讨其意义.方法:Western blot法检测22例胰腺癌及癌旁组织中HIF-1α、VEGF和FGF蛋白的表达,分析HIF-1α与VEGF、FGF之间的相关性以及与性别、年龄、肿瘤大小、淋巴结转移和TNM分期之间的关系.结果:HIF-1α、VEGF和FGF在胰腺癌组织中的蛋白表达水平明显高于胰腺癌周组织(P＜0.01),HIF-1α与VEGF、FGF之间的表达具有显著相关性(P＜0.01).HIF-1α的表达与胰腺癌的TNM分期、肿瘤大小和淋巴结转移有关(P＜0.01),VEGF和FGF的表达与胰腺癌的肿瘤大小和淋巴结转移有关(P＜0.05).结论:HIF-1α可以上调VEGF和FGF的表达,在胰腺癌的发生、发展中起着重要作用.     

血管内皮生长因子与肿瘤

血管内皮生长因子是新近确定的一种具有旁分泌机制的生长因子,能特异作用于血管内皮细胞,促进其增殖及新生血管的形成,同时还有增加血管通透性的作用．由于其生物学活性与实体瘤的生长密切相关,因此对它的研究倍受关注,进展非常迅速．     

血管内皮细胞生长因子研究进展

从不同侧面阐述了血管内皮细胞生长因子（VEGF）在新生血管形成中的作用.VEGF诱导新生血管形成,具有血管渗透性,是新生血管形成的主要调控者之一.VEGF mRNA不同剪接,形成5种VEGF变异体(isoform)即VEGF121-206.VEGF诱导新生血管的调控过程、拮抗VEGF成为大家竞相研究的领域.     

Vascular Endothelial Growth Factor Induces Endothelial Fenestrations In Vitro

Abstract. Vascular endothelial growth factor (VEGF) is an important regulator of vasculogenesis, angiogenesis, and vascular permeability. In contrast to its transient expression during the formation of new blood vessels, VEGF and its receptors are continuously and highly expressed in some adult tissues, such as the kidney glomerulus and choroid plexus. This suggests that VEGF produced by the epithelial cells of these tissues might be involved in the induction or maintenance of fenestrations in adjacent endothelial cells expressing the VEGF receptors. Here we describe a defined in vitro culture system where fenestrae formation was induced in adrenal cortex capillary endothelial cells by VEGF, but not by fibroblast growth factor. A strong induction of endothelial fenestrations was observed in cocultures of endothelial cells with choroid plexus epithelial cells, or mammary epithelial cells stably transfected with cDNAs for VEGF 120 or 164, but not with untransfected cells. These results demonstrate that, in these cocultures, VEGF is sufficient to induce fenestrations in vitro. Identical results were achieved when the epithelial cells were replaced by an epithelial-derived basal lamina-type extracellular matrix, but not with collagen alone. In this defined system, VEGF-mediated induction of fenestrae was always accompanied by an increase in the number of fused diaphragmed caveolae-like vesicles. Caveolae, but not fenestrae, were labeled with a caveolin-1–specific antibody both in vivo and in vitro. VEGF stimulation led to VEGF receptor tyrosine phosphorylation, but no change in the distribution, phosphorylation, or protein level of caveolin-1 was observed. We conclude that VEGF in the presence of a basal lamina-type extracellular matrix specifically induces fenestrations in endothelial cells. This defined in vitro system will allow further study of the signaling mechanisms involved in fenestrae formation, modification of caveolae, and vascular permeability.     

Regulation of Vascular Endothelial Growth Factor Receptor-2 (Flk-1) Expression in Vascular Endothelial Cells

We have previously reported the existence of a synergistic interaction between vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in the induction of angiogenesisin vitro.Here we demonstrate that bFGF increases VEGF receptor-2 (VEGFR-2/Flk-1) expression: mRNA levels were increased by 4.5- to 8.0-fold and total protein by 2.0- to 3.5-fold, in bovine microvascular endothelial (BME), aortic endothelial (BAE), and transformed fetal aortic (GM7373) endothelial cells. VEGF itself did not affect VEGFR-2 expression, and neither bFGF nor VEGF altered expression of FGF receptor-1. We also show that synergism occurs at the level of proliferation when this is measured in a three-dimensional but not in a conventional two-dimensional assay. Differences in the level of VEGFR-2 expression were also observed when cells were grown on or within collagen gels under different conditions: mRNA levels were lowest under sparse conditions, increased 20- to 26-fold at confluence, and increased even further (57-fold) when cells were cultured in suspension in three-dimensional collagen gels. Finally, a synergistic increase was seen in the level of expression of urokinase and urokinase receptor mRNAs when cells were exposed to bFGF and VEGF for 4 days. These findings demonstrate that the level of VEGFR-2 expression can be modulated by environmental factors including cytokines and the geometry of the culture conditions and provide some insight into the mechanisms of synergism between bFGF and VEGF in the induction of angiogenesisin vitro.     

牛初乳IGF-1的研究进展

牛初乳IGF-1是从牛初乳中提取制备的单链多肽蛋白质.氨基酸序列与其他物种同源性很高,其中与人类的IGF-1完全一致.在制备牛初乳IGF-1方面上,国内外的传统方法都是通过制备型色谱柱小剂量制备;而检测方面,国外早期是通过放射性免疫法(HAI)来测定,近几年也发展了一些新的技术,国内则大多数利用电泳、HPLC和Western blot.IGF-1具有促进细胞生长、增强机体免疫机制、促进骨骼生长、维持神经系统、调节心脏机能等功效,巳被广泛用于临床、生物学作用等研究领域.牛初乳IGF-1的大量制备具有相当广阔的前景,为牛初乳功能性食品的研制与开发带来新的方向.     

Vascular Endothelial Growth Factor Isoform-B Stimulates Neurovascular Repair After Ischemic Stroke by Promoting the Function of Pericytes via Vascular Endothelial Growth Factor Receptor-1

Ischemic stroke triggers endogenous angiogenic mechanisms, which correlates with longer survival in patients. As such, promoting angiogenesis appears to be a promising approach. Experimental studies investigated mostly the potent angiogenic factor vascular endothelial growth factor isoform-A (VEGF-A). However, VEGF-A increases the risk of destabilizing the brain microvasculature, thus hindering the translation of its usage in clinics. An attractive alternative VEGF isoform-B (VEGF-B) was recently reported to act as a survival factor rather than a potent angiogenic factor. In this study, we investigated the therapeutic potential of VEGF-B in ischemic stroke using different in vivo and in vitro approaches. We showed that the delayed intranasal administration of VEGF-B reduced neuronal damage and inflammation. Unexpectedly, VEGF-B stimulated the formation of stable brain microvasculature within the injured region by promoting the interaction between endothelial cells and pericytes. Our data indicate that the effects of VEGF-B were mediated via its specific receptor VEGF receptor-1 (VEGFR-1) that is predominately expressed in brain pericytes. Importantly, VEGF-B promoted the survival of pericytes, and not brain endothelial cells, by inducing expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) and the main protein involved in energy homeostasis AMP-activated protein kinase α (AMPKα). Moreover, we showed that VEGF-B stimulated the pericytic release of factors stimulating a “reparative angiogenesis” that does not compromise microvasculature stability. Our study unraveled hitherto unknown role of VEGF-B/VEGFR-1 signaling in regulating the function of pericytes. Furthermore, our findings suggest that brain microvasculature stabilization via VEGF-B constitutes a safe therapeutic approach for ischemic stroke.