Comparison of developmental endothelial locus-1 angiogenic factor with vascular endothelial growth factor in a porcine model of cardiac ischemia

BACKGROUND: This study compared the angiogenic effects of developmental endothelial locus-1 (DEL-1), vascular endothelial growth factor (VEGF), as well as the negative control, beta-galactosidase (beta-gal), in a porcine model of cardiac ischemia. METHODS: Twenty pigs underwent left circumflex artery occlusions. After 3 weeks, the animals received myocardial injections of adenovirus expressing beta-gal (n=6), DEL-1 (n=7), or VEGF (n=7). At 7 weeks, animals were assessed for both function and coronary flow and compared with baseline measurements. RESULTS: Regional wall motion index and global ejection fraction showed deterioration in function in the beta-gal group and no change in the VEGF and DEL-1 groups between the treatment and harvest time points. Preload recruitable stroke work suggested functional improvement in the VEGF group (35.8 +/- 8.6 vs 56.4 +/- 17.8, p = 0.033). The increase in the DEL-1 group was not statistically significant (27.3 +/- 9.8 vs, 40.2 +/- 19.4, p = 0.067). The beta-gal group exhibited minimal change (30.7 +/- 14.8 vs 35.9 +/- 12.1, p = 0.96). Regional blood flow as assessed by fluorescent microspheres was improved under stress conditions in the VEGF group (1.00 +/- 0.15 vs 1.15 +/-0.22, p = 0.03). CONCLUSIONS: Treatment with VEGF led to a modest improvement in regional blood flow and cardiac function in previously ischemic myocardial tissue.     

Inhibition of vascular endothelial cell growth factor suppresses the in vivo growth of human prostate tumors

The LNCaP human prostate cancer cell line is androgenand stromal-dependent for in vivo growth. We co-inoculated LNCaP cells with human fetal fibroblasts, isolated from prostate, bone (male), and lung (male and female) derived from 18- to 22-week-old human fetal tissue, into non-castrate male nude mice. Co-inoculation of LNCaP with fetal prostatic fibroblasts resulted in high tumor take rates (27 of 30, or 90%) 6 to 8 weeks after subcutaneous co-inoculation. Serum prostate specific antigen (PSA) values correlated strongly with wet tumor weight (r=0.86). The fetal fibroblast enhancement of tumor take rates in vivo was neither gender- nor organ-specific. Fetal fibroblast-conditioned medium (CM) did not have a significant proliferative effect on LNCaP cell growth in vitro. Areas of angiogenesis were demonstrable in all tumors, with blood vessels arising at the interface between stromal and tumor cells. The fetal fibroblasts, but not the LNCaP cells, expressed significant amounts of the mRNA and protein for vascular endothelial cell growth factor (VEGF). Treatment of tumor-bearing animals with neutralizing antibodies to VEGF resulted in significant tumor growth suppression. These findings indicate that VEGF is an important mediator of stromal-induced enhancement of human prostate cancer cell growth in vivo.     

血管内皮生长因子在大鼠心脏移植急性排斥期的表达

目的　观察血管内皮生长因子(VEGF)在大鼠心脏移植急性排斥期中的表达及其和排斥的关系。方法　大鼠分对照组,CSA组,每组12只。分别静脉给予生理盐水及CSA干预,采用颈部心脏异位移植术式建立移植模型。常规监测排斥反应发生情况。每组5只用于观察移植物存活时间,7只用于动态切取标本。应用逆转录 聚合酶链反应(RT PCR)检测移植物局部VEGF的表达水平。结果　CSA组移植心存活时间(2 0 .4±5 .1)d显著长于对照组(8.6±1.5 )d ,CSA组VEGF的表达强度弱于对照组,其时间变化趋势和高峰时间较对照组推迟并和移植心存活延长时间有相关性。病理观察显示移植心局部的炎性细胞和淋巴细胞浸润和VEGF表达有关。结论　VEGF高表达促进排斥反应的发生缩短移植心存活时间,提示VEGF的表达和移植心的炎性浸润以及急性排斥有密切关系     

反义基因转染抑制骨肉瘤中血管内皮生长因子表达的研究

目的　观察以腺相关病毒 (rAAV)为载体的血管内皮生长因子 (VEGF)反义基因转染的骨肉瘤细胞中VEGF蛋白的表达。方法　用不同量 (0、2 0、5 0、10 0、2 0 0、2 40 μl)的以rAAV为载体包装的反义VEGF基因 (rAAV antiVEGF)转染人骨肉瘤细胞系MG 63细胞 ,收集转染前后的培养细胞及上清 ,用链霉素抗生素蛋白 过氧化酶连接法 (SP)和免疫印迹法 (Western blot)检测VEGF蛋白的表达 ;用逆转录聚合酶链式反应 (PCR)检测VEGFmRNA表达。结果　SP结果表明转染rAAV antiVEGF基因的量越多 ,显色越淡 ;Western Blot结果表明转染rAAV antiVEGF基因的量越多 ,其灰度越低。测得不同量 (0、2 0、5 0、10 0、2 0 0、2 40 μl)的转染基因其相应的吸光度值分别为 86614± 13 776、73 2 45± 15 414、610 78± 12 12 4、5 465 7± 10 95 3、3 980 2± 113 0 8、3 2 0 14±15 0 5 7,差异有显著性 (P <0 .0 5 ) ;PCR检测其灰度值分别为 0 .986、0 .913、0 .784、0 .60 6、0 .43 1、0 .40 8,差异有显著性 (P <0 .0 5 )。结论　rAAV antiVEGF可封闭VEGFmRNA ,使已转染rAAV antiVEGF的MG 63细胞表达的VEGF蛋白减少。     

Glucose-regulated protein 78 silencing down-regulates vascular endothelial growth factor/vascular endothelial growth factor receptor 2 pathway to suppress human colon cancer tumor growth

Background

Up to 20% of colorectal cancer (CRC) is diagnosed with distant metastasis. The combination of chemotherapy with anti-vascular endothelial growth factor (VEGF) antibody can improve patient survival. Glucose-regulated protein 78 (GRP78) has an important role in cancer progression, but little is known about its role in VEGF production in CRC. The aim of this study was to explore the mechanism of GRP78 in two human colon cancer cell lines.

Methods

We first checked the expression of GRP78 in human normal and colon cancer tissues and two colon cancer cell lines. Glucose-regulated protein 78 was knocked down using GRP78 small interfering RNA (siRNA) in HT29 and DLD-1 cells. We examined knockdown cells by the cell growth kinetics in vitro and tumor growth rate in vivo, respectively. We also investigated the effect of GRP78 siRNA on the expression of hypoxia inducible factor (HIF-1α), VEGF, and VEGF receptor 2 (VEGFR2).

Results

Compared with their adjacent normal tissue, we detected high expression levels of GRP78 of surgically removed colon cancer tissues. Using GRP78 siRNA, we reduced the expression of GRP78 in HT29 and DLD-1 cells. The GRP78 knockdown cells had a lower proliferation rate with fewer colony-forming units in vitro and produced smaller tumors in vivo. In dissecting the mechanism underlying the reduced cell growth, we found that the down-regulation of GRP78 decreased the production of HIF-1α, VEGF, and VEGFR2 and suppressed angiogenesis.

Conclusions

Silencing GRP78 not only inhibits tumor, but also decreases the expression of VEGF and VEGFR2. Collectively, therapy targeting for GRP78 may inhibit the formation of colon cancer tumors via the HIF-1α/VEGF/VEGFR2 pathway.     

血清血管内皮生长因子与肿瘤

肿瘤血管形成在实体肿瘤生长及转移过程中起重要作用。肿瘤血管形成是生长刺激因子 (如ＶＥＧＦ ,ｂＦＧＦ)与抑制因子 (ａｎｇｉｏｓｔａｔｉｎ ,ｅｎｄｏｓｔａｔｉｎ)相互作用的结果。测定肿瘤组织血管密度、ＶＥＧＦ、ｂＦＧＦ表达、血清或尿液中ＶＥＧＦ、ｂＦＧＦ浓度 ,有望成为判定肿瘤病期进展、转移及预后新的敏感指标[1] 。实体肿瘤生长在直径 >1ｍｍ时必须有ＶＥＧＦ等参与下的血管形成并网络化。目前 ,文献报道肿瘤组织ＶＥＧＦ、血管计数是肿瘤病期进展及预后的标志。血清ＶＥＧＦ(Ｓ ＶＥＧＦ)来源于肿瘤细胞。有资料报道Ｓ …     

血管内皮生长因子反义寡核苷酸抑制肝癌的血管形成

目的 研究血管内皮生长因子（VEGF）反义寡核苷酸（ODN）是否可以抑制人肝癌细胞系VEGF的蛋白表达,进而抑制肝癌的血管形成,探讨肝癌基因治疗的新方法。方法 人肝癌细胞系7721能表达VEGF,其培养上清液对牛主动脉内皮细胞（BAEC）的生长有促进作用。采用人工合成反义、正义ODN分别加入7721细胞培养液,比较7721细胞VEGF的表达以及各上清液刺激内皮细胞生长的受抑情况,即可了解ODN通过抑制VEGF的表达抑制肝癌的血管形成情况。结果 VEGF反义ODN明显抑制了人肝癌细胞VEGF的表达（灰度值：反义组122．6,正义组101．3,对照组106．3,P＜0．01）,且抑制率与剂量呈性关系（当剂量为1、2、5、10μmol/L时抑制率分别为：63．2％、82．4％、210．0％、287．5％）。结论 VEGF反义ODN能够抑制肝癌的血管形成,其有望成为抗肝癌的新一代基因治疗手段。     

High glucose blunts vascular endothelial growth factor response to hypoxia via the oxidative stress-regulated hypoxia-inducible factor/hypoxia-responsible element pathway

Vascular endothelial growth factor (VEGF) is an important survival factor for endothelial cells in hypoxic environments. High glucose regulates certain aspects of VEGF expression in various cell types, including proximal tubular cells. Thus, ambient glucose levels may modulate the progression of chronic kidney disease, especially diabetic nephropathy. Immortalized rat proximal tubular cells (IRPTC) were cultured for 24 h under hypoxic conditions (1% O(2)), with or without high d-glucose (25 mM), or with or without high l-glucose (25 mM). Controls included culture in normoxic conditions and normal d-glucose (5.5 mM). VEGF mRNA expression was assessed by real-time quantitative PCR, and VEGF protein in the supernatant was assessed by ELISA. Hypoxia increased VEGF expression. This response was significantly blunted by high d-glucose (1.98 +/- 0.11- versus 2.65 +/- 0.27-fold increase for VEGF mRNA expression, 252.8 +/- 14.7 versus 324.0 +/- 11.5 pg/10(5) cells for VEGF protein; P < 0.05 both) but not by high l-glucose. It is interesting that hydrogen peroxide also blunted this response, whereas alpha-tocopherol restored the VEGF response to hypoxia in the presence of high d-glucose. For determination of involvement of the hypoxia-inducible factor (HIF)/hypoxia-responsible element (HRE) pathway, IRPTC that were stably transfected with HRE-luciferase were cultured under the previous conditions. High d-glucose also reduced luciferase activity under hypoxia, whereas alpha-tocopherol restored activity. In vivo experiments using streptozotocin-induced diabetic rats confirmed that hyperglycemia blunted HIF-HRE pathway activation. Insulin treatment restored activation of the HIF-HRE pathway in streptozotocin-induced diabetic rats. In conclusion, high glucose blunts VEGF response to hypoxia in IRPTC. This effect is mediated by the oxidative stress-regulated HIF-HRE pathway.     

Inhibition of the stress response to breast cancer surgery by regional anesthesia and analgesia does not affect vascular endothelial growth factor and prostaglandin E2

Angiogenesis is essential for breast cancer metastases formation and is mediated by vascular endothelial growth factor (VEGF) and prostaglandin E2 (PGE2). We hypothesized that serum levels of VEGF and PGE2 are increased by the stress response to breast cancer surgery and attenuated by paravertebral anesthesia and analgesia (PVAA). Thirty women undergoing mastectomy were enrolled in this prospective, randomized study, to receive general anesthesia (GA) and postoperative opioid analgesia (morphine 0.1 mg/kg bolus and patient-controlled infusion) or GA and PVAA (72-h infusion). All patients received rectal diclofenac. Venous blood samples were taken preoperatively and at 4 and 24 h postoperatively for serum glucose, cortisol, C-reactive protein, VEGF, and PGE2. PVAA inhibited the surgical stress response, as indicated by significantly less plasma glucose, cortisol, and C-reactive protein. VEGF and PGE2 values did not differ significantly between the groups. Mean (SD) percentage change in VEGF at 4 and 24 h respectively were 3% +/- 44% versus 9% +/- 80%, P=0.29 and 5% +/- 43% versus -10% +/- 63%, P=0.41 for patients with combined general and PVAA and GA alone, respectively. Mean percentage change in postoperative PGE2 at 4 and 24 h respectively was 10% +/- 17% versus 11% +/- 69%, P=0.29 and 34% +/- 19% versus 47% +/- 18%, P=0.15. We conclude that despite inhibiting the surgical stress response, PVAA had no effect on serum levels of putative breast cancer angiogenic factors, VEGF and PGE2.     

低氧反应元件对缺血心肌转染人血管内皮生长因子165基因表达的调控作用

目的 观察低氧反应元件(HRE)对低氧、复氧心肌细胞及缺血心肌转染人血管内皮生长因子165(hVEGF165)基因表达的调控作用.方法 分离新生SD大鼠心肌细胞,采用不同氧条件进行培养;建立猪心肌缺血一复灌动物模型,将在HEK293T细胞包装后获得的rAW-9HRE.hVEGF165病毒分别转染心肌细胞及动物缺血心肌.取培养心肌细胞及培养液,另取缺血区心肌组织,采用细胞免疫荧光法、酶联免疫吸附试验(ELISA)及Western blot方法 分别测定hVEGF165蛋白表达;逆转录-聚合酶链反应(RT-PCR)测定hVEGF165 mRNA表达;Ⅷ因子染色,计数缺血心肌新生血管变化.结果 病毒转染率为87%;心肌细胞A、B及E组培养液中hVEGF165蛋白含量显著升高(P＜0.01),细胞免疫荧光hVEGF165蛋白染色呈阳性;RT-PCR检测显示,心肌细胞A、B及E组可见484 bp目的 条带;在动物整体水平,与转基因缺血组比较,转基因复灌组hVEGF165 mRNA及蛋白表达显著减弱(P＜0.01),心肌毛细血管密度亦减少.结论 HRE作为氧敏感基因调控开关能有效地调控缺血心肌转染hVEGF165基因的表达.     

Effects of finasteride on vascular endothelial growth factor

OBJECTIVE: Finasteride has been shown to reduce prostate bleeding in patients with benign prostatic hyperplasia (BPH). The mechanisms behind this are not known, but it has been suggested that finasteride reduces bleeding by inhibiting angiogenesis in the prostate. Studies in animals have shown that castration rapidly induces involution of the prostate vasculature, and androgen-stimulated prostate growth may be angiogenesis dependent. The objective of this study was to explore the response to finasteride on the vasculature and the expression of vascular endothelial growth factor (VEGF), a potent regulatory factor of angiogenesis in human prostate tissue. MATERIAL AND METHODS: Patients with BPH were randomly assigned to 3 months of treatment either with finasteride (5 mg/day) or placebo before undergoing transurethral resection of the prostate (TURP). Prostate tissue VEGF expression was quantified by Western blot and the vascular density determined in Factor VIII immunostained tissue sections. Serum concentrations of VEGF were measured with ELISA technique. RESULTS: Patients treated with finasteride (n = 15) showed a decrease in prostate tissue VEGF(165) expression compared with placebo (n = 13) treated patients (p < 0.05), but the vascular density and the serum VEGF levels were unaffected. CONCLUSIONS: This study shows that finasteride treatment decreases VEGF expression in the human prostate.     

血管内皮生长因子在脑胶质瘤中自分泌研究

目的 观察血管内皮生长因子(VEGF)在脑胶质瘤中自分泌现象.方法 采用免疫组织化学及图像分析方法 ,检测74例脑胶质瘤中肿瘤细胞上血管内皮生长因子受体VEGFR1和VEGFR2的表达,取其中42例检测VEGF的表达的情况.结果 VEGF在胶质瘤中表达强度与肿瘤病理级别明显相关(P＜0.05,r=0.331);VEGFR1、2在胶质瘤瘤细胞中表达强度吸光值分别为:正常组织(0.2104±0.0297)和(0.2100±0.0257);WHO I(0.2328±0.0194)和(0.2324±0.0186);WHOⅡ级(0.2533±0.0155)和(0.2514±0.0147);WHO Ⅲ级(0.2709±0.0203)和(0.2720±0.0149);WHOⅣ级(0.2906±0.0282)和(0.2834±0.0285);表达强度与胶质瘤病理级别明显相关(P＜0.01,r=0.748;P＜0.01,r=0.754).结论 在脑胶质瘤中存在VEGF的旁分泌和自分泌现象,并与病理级别有关.     

Expression patterns of vascular endothelial growth factor in human cardiac allografts: association with rejection

BACKGROUND: Vascular endothelial growth factor (VEGF), a major angiogenesis factor, has been found to have proinflammatory properties in vivo in several chronic inflammatory diseases. However, little is known of the expression or function of VEGF in acute and chronic allograft rejection. METHODS: In a cross-sectional analysis, we evaluated the expression of VEGF by immunohistochemistry in human endomyocardial biopsies (n=101) from 10 cardiac transplant patients. We correlated expression (scores from 0-4) with CD3+ T cell, CD68+ monocyte and macrophage infiltrates, or rejection (International Society of Heart and Lung Transplantation grades 0-4). In addition, we evaluated the temporal patterns of VEGF expression in consecutive biopsies from seven patients (total of 74 biopsies) who were assessed for the development of graft vascular disease (GVD) by intravascular ultrasonography at 1 year posttransplantation. RESULTS: VEGF is expressed in normal human endomyocardial biopsies at low levels and is induced (scores >1) in association with CD3+ T cells (odds ratio [OR], 19.90; P<0.001), CD68+ monocyte and macrophage infiltrates (OR, 8.49; P<0.001), and all grades of acute rejection (OR, 5.4; P<0.001). Increases in VEGF expression were persistent during the first posttransplant year in biopsies from four patients who demonstrated evidence of GVD (mean annual score of 2.3). In contrast, limited expression of VEGF was found in three patients without GVD (mean annual score 1.2). CONCLUSIONS: These findings define VEGF as an important proinflammatory cytokine after transplantation and indicate that its expression pattern might identify patients at risk for the development of GVD.