Divergent regulation of vascular endothelial growth factor and of erythropoietin gene expression in vivo

There is accumulating evidence from in vitro experiments that the gene expression of the vascular endothelial growth factor (VEGF) is, like that of the erythropoietin (EPO) gene, regulated by the oxygen tension and by divalent cations such as cobalt. Since the information about the regulation of VEGF gene expression in vivo is rather scarce, this study aimed to examine the influence of hypoxia and of cobalt on VEGF gene expression in different rat organs and to compare it with that on EPO gene expression. To this end male Sprague-Dawley rats were exposed to carbon monoxide (0.1% CO), hypoxia (8% O₂ ) or to cobalt chloride (12 and 60 mg/kg s.c.) for 6 h. mRNA levels for VEGF- 188, -164, and -120 amino acid isoforms in lungs, hearts, kidneys and livers were semiquantitated by RNase protection. For these organs we found a rank order of VEGF mRNA abundance of lung >> heart > kidney = liver. EPO mRNA levels were semiquantitated in kidneys and livers. Hypoxia, CO and cobalt increased EPO mRNA levels 60-fold, 140-fold and 5-fold, respectively, in the kidneys, and 11-fold, 11-fold and 3-fold, respectively, in the livers. None of these manoeuvres caused significant changes of VEGF mRNA in lung, heart or kidneys. Only in the livers did hypoxia lead to a significant (50%) increase of VEGF mRNA. These findings suggest that, in contrast to the in vitro situation, the expression of the VEGF gene in normal rat tissues is rather insensitive to hypoxia. In consequence, the in vivo regulation of the VEGF and the EPO genes appear to differ substantially, suggesting that the regulation of the VEGF and EPO genes may not follow the same essential mechanisms in vivo. Received: 31 July 1995/Received after revision: 20 November 1995/Accepted: 27 November 1995     

血管内皮生长因子及其受体在子宫内膜异位症中的表达和意义

目的:研究血管内皮生长因子(Vascular endothelial growth factor,VEGF)及其受体(Vascular endothelial growth factor receptor1,VEGFR1)在子宫内膜异位症(内异症)患者子宫在位内膜、异位内膜及正常对照组内膜组织中的表达,探讨其在子宫内膜异位症中的作用机制.方法:采用免疫组织化学及Western blot方法检测34例异位症患者在位内膜、异位内膜(内异症组)及34例正常内膜(对照组)组织中VEGF及其受体VEGFR1蛋白的定位及表达.结果:异症组在位及异位子宫内膜组织腺上皮细胞及间质细胞中均有VEGF及VEGFR1蛋白表达,且均高于同期对照组内膜,差异有统计学意义;对照组分泌期内膜VEGF及VEGFR1蛋白表达高于增生期,呈现周期性变化,而内异症组在位及异位内膜VEGF及VEGFR1蛋白表达失去周期性变化,分泌期与增生期均高表达,差异无统计学意义.Western blot检测结果与免疫组化结果一致.结论:内异症患者在位及异位内膜组织中VEGF、VEGFR1蛋白高表达可能与内异症的发生发展有关.     

Time-course expression of vascular endothelial growth factor as related to the development of the retinochoroidal vasculature in rats

Growth factors involved in angiogenesis are critical to both the normal and pathological vascular development in the retina and choroid. In the present experiment, the relationship between the vascular endothelial growth factor (VEGF) expression and the retinochoroidal vasculogenesis in Sprague-Dawley rats was investigated using in situ hybridization and immunohistochemistry. It was found that VEGF was produced mainly by astrocytes and Müller cells in the neural retina, and this was correlated temporally and spatially with the retinal vasculogenesis. In addition, it was observed that, although the VEGF expression in the retinal pigment epithelium (RPE) decreased with increasing age, it persisted from the embryonic stage to adulthood. These findings indicate that the VEGF expression in RPE may play a role in the development of the choroidal vessels as well as in the maintenance of the normal structure and permeability of the choriocapillaris in adults. Received: 12 August 1997 / Accepted: 11 July 1997     

Syk基因对乳腺癌血管内皮生长因子-C表达的调控作用

目的 研究Syk基因对乳腺癌血管内皮生长因子(VEGF)-C表达的调控机制.方法 采用免疫组织化学(EnVision法)检测乳腺癌组织中Syk、NFκB与VEGF-C的蛋白表达情况,分析三者的相关性及与淋巴转移的关系.转染pcDNA3.1(-)-Syk至乳腺癌MDA-MB-231细胞,检测对VEGF-C和NFκB表达的影响.结果 在淋巴转移组中,Syk蛋白阳性率低于非淋巴转移组,VEGF-C与NFκB阳性率在淋巴转移组高于非淋巴转移组.Syk蛋白表达与NFκB(r=-0.448,P=0.002)、VEGF-C(r=-0.620,P=0.000)蛋白表达呈负相关,VEGF-C与NFκB呈正相关(r =0.310,P=0.036).转染pcDNA3.1(-)-Syk重组质粒的乳腺癌细胞中VEGF-C的mRNA及蛋白表达水平均低于空白对照组,细胞核NFκB蛋白表达低于空白对照组(均P＜0.05).结论 Syk基因与乳腺癌转移相关,可能是通过抑制NFκB的活性而下调VEGF-C的表达,从而抑制乳腺癌的淋巴转移.     

Localization of vascular endothelial growth factor in synovial membrane mast cells: examination with ”multi-labelling subtraction immunostaining”

 Mast cells are believed to play a novel part in the development of destructive synovial pannus in rheumatoid arthritis (RA). This study was undertaken to investigate the localization of vascular endothelial growth factor (VEGF) in the synovial membrane using a unique immunostaining technique. Synovial specimens of RA patients were examined immunohistochemically and were compared with specimens from non-RA controls. Multi-labelling subtraction immunostaining, a modification of double- and triple-labelling immunostaining, revealed that the VEGF-positive cells were identical to tryptase-positive cells (mast cells). No other cell types were found to be positive for VEGF. The synovium of RA patients showed a larger number of VEGF-positive mast cells than that of non-RA controls (P<0.001). The study suggests that mast cell-derived VEGF may contribute to the development of synovial pannus in RA. Received: 1 April 1998 / Accepted: 13 July 1998     

血管内皮生长因子受体在膀胱癌中的表达及临床意义

目的：探讨血管内皮生长因子受体在膀胱癌中的表达及与临床病理因素的相关性。方法：免疫组化法采用链霉菌抗生物素一过氧化物酶连接法(SP法)对50例膀胱癌标本，20例正常膀胱组织标本中血管内皮生长因子受体的表达进行检测。结果：血管内皮生长因子受体在大多数膀胱癌组织中表达(74％)，而且其表达水平与病理分期及组织分级呈正相关。在正常膀胱组织中无1例表达(0％)。结论：膀胱癌组织中血管内皮生长因子受体阳性表达，提示其在膀胱癌的血管生成中起着重要作用。     

血管内皮生长因子的免疫学测定法

目的：检测肿瘤细胞条件培养液中ＶＥＧＦ的表达量。方法：在表达及分离纯化ＶＥＧＦ的基础上,成功地制备了ＶＥＧＦ抗体,以夹心法测定ＶＥＧＦ,ＶＥＧＦ测定范围为０．０２～２００．００ｎｇ／ｍｌ,灵敏度可达０．０２ｎｇ／ｍｌ,批内及批间变异均小于１０％,回收率平均为１０２．４％。其中人胃癌细胞ＭＧＣ８０３、ＢＧＣ８２３、乳癌ＮＭＣＦ－７及肝癌ＢＥＬ－７４０２分泌上清中ＶＥＧＦ的含量分别为６．５０、０．４５     

血管内皮生长因子及其可溶性血管内皮生长因子受体-1水平与胎儿出生体重

目的本研究通过对比血管内皮生长因子(VEGF)、可溶性血管内皮生长因子受体-1(sFlt-1)水平差异与新生儿出生体重的关系,以探讨其在胎儿出生体重发生中的作用。方法采用免疫组织化学法检测40例分娩正常出生体重儿组(AGA组)、30例高出生体重儿组(LGA组)及30例低出生体重儿组(SGA组)胎盘组织中VEGF、sFlt-1的表达水平。结果①LGA组胎盘组织中VEGF的表达高于AGA组,sFlt-1的表达水平低于AGA组,差异有统计学意义(χ2=21.17,P<0.01)。SGA组胎盘组织中VEGF的表达低于AGA组,sFlt-1的表达水平高于AGA组,差异有统计学意义(χ2=8.44,P=0.04)。②胎盘组织中VEGF的表达水平与胎儿出生体重呈正相关(r=0.427,P<0.01),胎盘组织中sFlt-1的表达水平与胎儿出生体重呈负相关(r=-0.569,P<0.01)。结论孕妇胎盘组织中VEGF及sFlt-1表达水平的变化可能与胎儿出生体重有关。     

多发性浅表膀胱移行细胞癌中VEGF的表达及意义

目的:探讨单发性和多发性浅表膀胱移行细胞癌组织中血管内皮生长因子(VEGF)的表达及意义。方法:采用免疫组化方法对60例浅表膀胱移行细胞癌组织及10例正常膀胱组织进行血管内皮生长因子(VEGF)的检测,观察单发性和多发性浅表膀胱移行细胞癌组织中VEGF表达的关系。结果:多发性浅表膀胱移行细胞癌VEGF的高表达明显高于单发者的高表达;VEGF高表达的浅表膀胱移行细胞癌的患者的复发率明显高于低表达者的复发率。结论:VEGF表达的高低与浅表膀胱移行细胞癌的生物学行为有关。     

The effect of epidermal growth factor on vascular endothelial growth factor secretion by endometrial stromal cells

Endometrial stromal cells undergo morphological and functional changes to facilitate oocyte implantation under regulation of various hormones and growth factors. We studied physiological induction by epidermal growth factor (EGF) of vascular endothelial growth factor (VEGF) in these cells. In human endometrial stromal cells, the effect of EGF, genistein, tryphostin AG1478 (a tyrosine kinase inhibitor), and wortmannin (a phosphatidylinositol 3-kinase inhibitor) on production of VEGF was examined: Total RNA was extracted and VEGF mRNA expression was quantified by Northern analysis. EGF induced production of VEGF by stromal cells in a time-dependent manner; the effect became significant after 12 h and increased further between 24 and 48 h (P<0.05). Dose dependency was also significant (P<0.01). Genistein, tryphostin AG1478, and wortmannin partially suppressed the increase in production induced by EGF (P<0.01, P< 0.01, P<0.01), respectively. Production of EGF by fertilized oocytes and trophoblasts has been reported in early pregnancy. VEGF is believed to be induced by EGF through mechanisms involving tyrosine kinase and phosphatidylinositol 3-kinase. The increase in VEGF may contribute to neovascularization that promotes proliferation of endometrium and placentation. Received: 6 September 2001 / Accepted: 21 May 2002     

Alterations in the immunohistochemical distribution patterns of vascular endothelial growth factor receptors Flk1 and Flt1 in bleomycin-induced rat lung fibrosis

To investigate the role of vascular endothelial growth factor (VEGF) in fibrogenesis, the distribution patterns of the VEGF receptors Flt1 and Flk1 were studied by immunohistochemistry, double immunofluorescence, and immunoelectron microscopy in normal (n=2) and bleomycin-treated (n=21) adult rats. Lungs were studied at 5, 24, 28, 35, and 42 days after treatment (p.t.). Flt1, Flk1, and VEGF immunoreactivity localised predominantly to the pulmonary epithelium. In control lungs, Flt1 immunoreactivity was present in ciliated bronchial epithelium and type 2 pneumocytes, Flk1 in Clara cells, and VEGF in Clara cells and type 2 pneumocytes. Flk1 localised to mast cells, present in the peribronchovascular and pleural interstitium only. Flt1- and Flk1-mRNAs were observed in Clara cells and type 2 pneumocytes. Bleomycin-induced fibrogenesis was characterised by a decrease in Flk1 immunoreactivity of Clara cells, and an increase in VEGF-immunoreactive myofibroblasts and type 2 pneumocytes by day 5 p.t., followed by a progressive accumulation of Flk1-immunoreactive mast cells by day 24 p.t. in fibrotic lesions containing VEGF-immunoreactive myofibroblasts. After 42 days, fibrotic regions were densely populated by mast cells. Since mast cells are known to be chemotactically attracted by VEGF, we suggest that VEGF/Flk1 represents the molecular link between proliferation of myofibroblasts, accumulation of mast cells, and the burst of fibrosis at sites of initial lesions in bleomycin-induced fibrosis. Received: 27 August 1998 / Accepted: 31 March 1999     

血管内皮生长因子基因多态性与克罗恩病的相关性CSCD

目的探讨血管内皮生长因子（vascular endothelial growth factor,VEGF）基因多态性与克罗恩病（Crohn’S disease,CD）易感性的关系。方法收集275例CD患者和495名性别、年龄相匹配的健康对照者,采用SNaPshot技术检测VEGF基因rs699947和rs3025039位点的等位基因和基因型频率。结果CD组与对照组之间整体比较,VEGF基因rs699947和rs3025039位点的变异等位基因和基因型频率差异无统计学意义（P均〉o．05）。分层分析发现,结肠型CD患者中rs699947的变异等位基因（A）和基因型（CA＋AA）频率显著高于对照组（P=0．006,95％CI：1．143～2．234;P=0．005,95％CI：1．203～2．900）。与对照组相比,回肠受累（回肠末段型＋回结肠型）的CD患者中,rs699947的变异等位基因（A）和基因型（CA4-AA）频率偏低（P=0．033,95％CI：0．524～0．974;P=0．043,95％CI：0．481～0．989）。此外,非狭窄非穿透型CD患者中rs3025039纯合子变异基因型（TT）频率低于对照组（0．62％vs．4．85％,P=0．036,95％CI：0．016～O．870）。结论VEGF基因rs699947位点基因变异可能增加结肠型CD的发病风险,但在回肠受累的CD患者中可能发挥保护作用。VEGF基因rs3025039位点的纯合子变异基因型（TT）携带者中非狭窄非穿透型CD的发病风险可能降低。     

The effect of epidermal growth factor on production of vascular endothelial growth factor by amnion-derived (WISH) cells

Our objective was to clarify the physiological role of vascular endothelial growth factor (VEGF) by amnion-derived (WISH) cells. WISH cells were cultured, and the effect of epidermal growth factor (EGF), mitogen-activated protein (MAP) kinase kinase or extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitors (U0126) or phosphatidylinositol (PI) 3-kinase on the production of VEGF was examined. VEGF was assayed by ELISA. The activation of MAP kinase and akt, which is phosphorylated by PI 3-kinase, were detected by Western blot analysis using anti-phosphorylated MAP kinase antibody and anti-phosphorylated akt antibody. In the time course of VEGF production following EGF treatment, VEGF production showed a significant increase only after 16 (p < 0.01)–32?h (p < 0.01). EGF increased the production of VEGF by WISH cells in a dose-dependent manner. The MAP kinase and akt activity were determined by treatment with EGF. VEGF production was significantly decreased following pretreatment with U0126 or wortmannin for two hours before treatment with EGF (p < 0.01, p < 0.01). WISH cells appeared to produce VEGF via a mechanism involving tyrosine kinase activation of EGF receptor and MAP kinase or PI 3-kinase. It is suggested that VEGF may contribute to the neovascularization and proliferation of the placenta and gestational tissue, and EGF may play an important role in regulation of VEGF production in the placenta.     

血管内皮生长因子、细胞间黏附分子1在糖尿病大鼠肾小球的表达

目的 探讨血管内皮生长因子(VEGF)和细胞间黏附分子1(1CAM-1)在糖尿病肾病(DN)发生机理中的作用。方法 采用链脲佐菌素(STZ)诱发糖尿病(DM)大鼠模型，观察大鼠肾小球肥大、肾功能和24h尿蛋白改变以及用免疫组织化学和计算机图像分析技术定位、半定量检测VEGF和ICAM—1在DM大鼠肾小球的表达。结果 VEGF和ICAM—1在糖尿病大鼠肾小球中均有不同程度表达，VEGF主要分布于肾小球脏层上皮细胞的脑浆之中，ICAM—1主要分布于肾小球内皮细胞和系膜细胞的脑浆中。VEGF、ICAM-1水平与蛋白尿和肾小球肥大呈正相关关系。结论 DM大鼠肾小球VEGF和ICAM-1的升高可能参与了DN的疾病发展过程，估计是糖尿病肾病发生机理之一。     

Effects of vascular endothelial growth factor released from cultured dermal substitute on proliferation of vascular endothelial cells in vitro

Allogeneic cultured dermal substitute (CDS) was prepared by culturing fibroblasts on a two-layered spongy matrix of hyaluronic acid and atelocollagen. CDS can be cryopreserved and transported to other hospitals in a frozen state. The present study was designed to analyze the amounts of vascular endothelial growth factor (VEGF) released from fibroblasts in fresh and cryopreserved CDS and to investigate the effects of this VEGF on proliferation of vascular endothelial cells in vitro. The culture medium used in preparing CDS (fresh CDS culture medium sample) was collected and stored at –30°C for the quantitative analysis of VEGF. After thawing cryopreserved CDS, it was recultured in a culture medium for 1 week. The culture medium used was collected and stored at –30°C for quantitative analysis of VEGF. The amounts of VEGF released from the fresh and cryopreserved CDS into the culture medium were about 610pg/ml and 640pg/ml, respectively. This finding suggests that the cryopreserved CDS retains its ability to release VEGF. Immunohistological analysis indicated that some of the VEGF adhered to the matrix. Human vascular endothelial cells were cultured in medium mixed with the fresh or cryopreserved CDS culture medium sample. Proliferation of vascular endothelial cells was enhanced by increasing the concentration of both CDS culture medium samples. When antihuman VEGF antibody was added to the culture medium, the proliferative activity of vascular endothelial cells was reduced. These findings confirm that VEGF released from CDS promotes proliferation of vascular endothelial cells.     

The roles of vascular endothelial growth factor gene polymorphisms in congenital heart diseases: a meta-analysis

We performed this study to better elucidate the correlations between vascular endothelial growth factor (VEGF) gene polymorphisms and congenital heart diseases (CHD). Eligible articles were searched in PubMed, Medline, Embase and CNKI. Eighteen studies were finally included in our meta-analysis. A significant association with the risk of CHD was detected for the rs1570360 polymorphism in additive comparison in overall analyses. Further subgroup analyses according to ethnicity of study participants and type of disease demonstrated that the rs833061 polymorphism was significantly correlated with the risk of CHD in Asians under additive genetic model, and the rs3025039 polymorphism was significantly correlated with the risk of Tetralogy of Fallot (TOF) in dominant, recessive and allele models. In conclusion, our findings indicated that rs1570360 and rs833061 polymorphisms may affect the risk of CHD. In addition, the rs3025039 polymorphism may serve as a genetic biomarker of TOF.     

低氧诱导体外培养大鼠星形胶质细胞VEGF的表达

目的　血管内皮细胞生长因子 (VEGF)是一种高度特异性的促血管内皮细胞生长的因子 ,探讨其在低氧情况下缺血组织血管形成的影响。方法　用免疫组织化学法和RT RCR法检测了正常培养和低氧复氧诱导情况下体外培养大鼠星形胶质细胞中VEGF蛋白及VEGFmRNA表达。结果　正常培养的大鼠星形胶质细胞中有VEGF表达 ,但表达量较低 ,低氧复氧诱导后星形胶质细胞中VEGF表达量会增加 ,且随着复氧时间延长表达量增加 ,6h到达高峰 ,以后又逐渐降低。结论　低氧复氧可能诱导大鼠星形胶质细胞代偿性增生 ,使VEGFmRNA表达上调而促进血管再生 ,这在一定程度上可减少缺血对神经元的影响。