血管内皮生长因子与治疗性血管生成

近年来 ,由于分子生物学等基础学科的迅猛发展 ,缺血性及其相关疾病的治疗取得了长足的进步。其中 ,以增加新生血管、改善缺血为主要目的的治疗性血管形成 (ｔｈｅｒａｐｅｕｔｉ ｃａｌａｎｇｉｏｇｅｎｅｓｉｓ)广泛地应用在各类缺血及其相关性疾病的实验和临床研究中。血管形成 (ａｎｇｉｏｇｅｎｅｓｉｓ)在机体的生长发育、新陈代谢、脏器修复、创伤愈合和生殖过程中均起着重要作用[1] ,有很多因素与之有关 ,其中 ,血管内皮细胞生长因子(ｖａｓｃｕｌａｒｅｎｄｏｔｈｅｌｉａｌｇｒｏｗｔｈｆａｃｔｏｒ,ＶＥＧＦ)的作用最为突出 ,尤…     

Topical vascular endothelial growth factor reverses delayed wound healing secondary to angiogenesis inhibitor administration

The prevention of new blood vessel growth is an increasingly attractive strategy to limit tumor growth. However, it remains unclear whether anti-angiogenesis approaches will impair wound healing, a process thought to be angiogenesis dependent. Results of previous studies differ as to whether angiogenesis inhibitors delay wound healing. We evaluated whether endostatin at tumor-inhibiting doses delayed excisional wound closure. C57/BL6J mice were treated with endostatin or phosphate-buffered solution 3 days prior to the creation of two full-thickness wounds on the dorsum. Endostatin was administered daily until wound closure was complete. A third group received endostatin, but also had daily topical vascular endothelial growth factor applied locally to the wound. Wound area was measured daily and the wounds were analyzed for granulation tissue formation, epithelial gap, and wound vascularity. Endostatin-treated mice showed a significant delay in wound healing. Granulation tissue formation and wound vascularity were significantly decreased, but reepithelialization was not effected. Topical vascular endothelial growth factor application to wounds in endostatin-treated mice resulted in increased granulation tissue formation, increased wound vascularity, and wound closure approaching that of control mice. This study shows that the angiogenesis inhibitor endostatin delays wound healing and that topical vascular endothelial growth factor is effective in counteracting this effect.     

Up-regulation of vascular endothelial growth factor mRNA and angiogenesis after transmyocardial laser revascularization.

BACKGROUND: Angiogenesis has been proposed as a potential mechanism whereby transmyocardial laser revascularization (TMLR) has provided clinical relief of angina. Experimental work has found histologic evidence supporting this, as well as an improved response when angiogenic growth factors have been added to TMLR. The purpose of this study was to demonstrate that the molecular response to TMLR was an increase in the production of endogenous vascular endothelial growth factor to promote angiogenesis. METHODS: Ameroid constrictors were placed on the proximal circumflex artery in 12 domestic pigs. After a chronic ischemic zone was established the animals were randomly divided into two groups. In the TMLR group the ischemic zone was treated with carbon dioxide laser. In the control group the ischemic zone was untreated. Six weeks later the animals were sacrificed, and sections from the ischemic zone and the nonischemic zone were submitted for immunohistochemical, histologic, and molecular analysis. Messenger RNA was obtained from northern blot analysis after being probed with vascular endothelial growth factor. RESULTS: There was a twofold increase in the vascular endothelial growth factor messenger RNA in the ischemic zone of the TMLR group compared with the control group. Additionally, there was a threefold increase in the number of new blood vessels in the ischemic zone of the TMLR group compared with the control group. CONCLUSIONS: Transmyocardial laser revascularization promotes angiogenesis by upregulation of vascular endothelial growth factor. The resulting angiogenesis could be the principle mechanism for the clinical efficacy of TMLR.     

Tumor angiogenesis: the pivotal role of vascular endothelial growth factor

Summary There is considerable evidence that vascular endothelial growth factor is involved in the vascularization and growth of primary tumors and in the formation of metastases. The expression of vascular endothelial growth factor depends on activated oncogenes and inactivated tumor-suppressor genes as well as several other factors, e.g., growth factors, hypoxia, and tumor promoters. Substantial expression of vascular endothelial growth factor receptors is mainly restricted to tumor vessels. The causal involvement of this angiogenic factor in the progression of the disease has been successfully evaluated using monoclonal antibodies against vascular endothelial growth factor, dominant negative receptor mutants, and antisense oligonucleotides against the messenger RNA of vascular endothelial growth factor. Thus, the vascular endothelial growth factor-signaling system seems to be an appropriate target for inhibition of tumor angiogenesis and metastasis formation.     

Enhanced brain angiogenesis in chronic cerebral hypoperfusion after administration of plasmid human vascular endothelial growth factor in combination with indirect vasoreconstructive surgery

OBJECT: Vascular endothelial growth factor (VEGF) is a secreted mitogen associated with angiogenesis. The conceptual basis for therapeutic angiogenesis after plasmid human VEGF gene (phVEGF) transfer has been established in patients presenting with limb ischemia and myocardial infarction. The authors hypothesized that overexpression of VEGF using a gene transfer method combined with indirect vasoreconstruction might induce effective brain angiogenesis in chronic cerebral hypoperfusion, leading to prevention of ischemic attacks. METHODS: A chronic cerebral hypoperfusion model induced by permanent ligation of both common carotid arteries in rats was used in this investigation. Seven days after induction of cerebral hypoperfusion, encephalomyosynangiosis (EMS) and phVEGF administration in the temporal muscle were performed. Fourteen days after treatment, the VEGF gene therapy group displayed numbers and areas of capillary vessels in temporal muscles that were 2.2 and 2.5 times greater, respectively, in comparison with the control group. In the brain, the number and area of capillary vessels in the group treated with the VEGF gene were 1.5 and 1.8 times greater, respectively, relative to the control group. CONCLUSIONS: In rat models of chronic cerebral hypoperfusion, administration of phVEGF combined with indirect vasoreconstructive surgery significantly increased capillary density in the brain. The authors' results indicate that administration of phVEGF may be an effective therapy in patients with chronic cerebral hypoperfusion, such as those with moyamoya disease.     

Role of vascular endothelial growth factor in the regulation of angiogenesis.

Compelling evidence indicates that vascular endothelial growth factor (VEGF) is a fundamental regulator of normal and abnormal angiogenesis. The loss of a single VEGF allele results in defective vascularization and early embryonic lethality. VEGF plays also a critical role in kidney development, and its inactivation during early postnatal life results in the suppression of glomerular development and kidney failure. Recent evidence indicates that VEGF is also essential for angiogenesis in the female reproductive tract and for morphogenesis of the epiphyseal growth plate and endochondral bone formation. Substantial experimental evidence also implicates VEGF in pathological angiogenesis. Anti-VEGF monoclonal antibodies or other VEGF inhibitors block the growth of several human tumor cell lines in nude mice. Furthermore, the concentrations of VEGF are elevated in the aqueous and vitreous humors of patients with proliferative retinopathies such as the diabetic retinopathy. In addition, VEGF-induced angiogenesis results in a therapeutic benefit in several animal models of myocardial or limb ischemia. Currently, both therapeutic angiogenesis using recombinant VEGF or VEGF gene transfer and inhibition of VEGF-mediated pathological angiogenesis are being pursued clinically.     

Induction of pulmonary angiogenesis by adenoviral-mediated gene transfer of vascular endothelial growth factor

BACKGROUND: We hypothesized that gene transfer of vascular endothelial growth factor (VEGF) mediated by an adenovirus vector might induce pulmonary artery angiogenesis in a lamb model of pulmonary artery hypoplasia. METHODS: Thirteen fetal lambs had left pulmonary artery banding at 106 days of gestation. Following birth, 3 groups were divided: VEGF group (n = 5) and beta-GAL group (n = 4) received an adenoviral vector encoding respectively for human VEGF165 and for galactosidase A. A control group (n = 4) had neither gene nor virus. Viral suspensions were selectively instilled in the left bronchus 6.5 days after birth. Five nonoperated lambs constituted the normal group. Euthanasia was performed at 30 days of age. Gene transfer was confirmed by blue coloration of left lung obtained with Xgal solution in an additional experiment. Histomorphometric evaluation was performed. All groups were compared with ANOVA test and paired test was used to compare right and left lung in each animal. RESULTS: Left lung was similarly hypoplastic in all operated lambs. Left pulmonary artery hypoplasia present in all operated groups was significantly less pronounced in VEGF group. The number of pleural arteries was similarly increased in left lung of all operated lambs. Left lung arterial density was higher in VEGF group than in all other groups. The percentage of parenchyma of left lung was lower in beta-GAL group than in all others, partially returned to normal in VEGF group. CONCLUSIONS: In this model, transbronchial VEGF gene transfer induces pulmonary angiogenesis, proximal pulmonary artery growth and contributes to lung parenchyma recovery.     

Effects of inhaled fluticasone on angiogenesis and vascular endothelial growth factor in asthma

BACKGROUND: Subepithelial hypervascularity and angiogenesis in the airways are part of structural remodelling of the airway wall in asthma, but the effects of inhaled corticosteroids (ICS) on these have not been explored. Increased vascularity in asthma may contribute to a number of functional abnormalities. A study was undertaken to explore angiogenic modulation by ICS and its likely regulation via vascular endothelial growth factor (VEGF), its receptors and the angiopoietins. METHODS: A placebo-controlled intervention study with ICS in asthma was performed, examining vascularity, VEGF, its receptors (VEGFR1 and VEGFR2), and angiopoietin-1 (Ang1) to assess which of these factors were changed in the asthmatic airways after ICS treatment. Airway wall biopsy specimens, lavage fluid and cells were obtained from 35 patients with mild asthma randomised to receive ICS or placebo for 3 months, after which bronchoscopic examination and sample collection were repeated. Immunohistochemistry and image analysis were used to obtain quantitative measures of vessels, angiogenic sprouts, VEGF, VEGFR1, VEGFR2 and Ang1 staining in airway biopsy specimens. ELISA was used to assess VEGF concentrations in the lavage fluid. RESULTS: Vessel, VEGF and sprout staining were decreased after 3 months of ICS treatment. VEGF levels remained unchanged. VEGF receptors and Ang1 staining were not reduced after treatment. CONCLUSIONS: The findings of this study support an effect of ICS in downregulating angiogenic remodelling in the airways in asthma, associated with decreasing VEGF activity within the airway wall. The environment of the airways after treatment with ICS, with changes in the balance between VEGF, its receptors, Ang1 and sprouts, appears to be less angiogenic than in untreated asthma.     

Expression of vascular endothelial growth factor and angiogenesis in the diabetic frozen shoulder

The purpose of this study was to investigate neovascularization and the expression of vascular endothelial growth factor (VEGF) in patients with diabetic frozen shoulders. Eleven patients with diabetic frozen shoulders underwent arthroscopic lysis of adhesions, and we observed the reported findings. VEGF expression was determined by immunohistochemistry and Western blot analysis, and the density of vessels was evaluated based on CD34 immunoreactivity by use of samples of the synovial tissue. For the control group, we took 5 samples of synovium from patients undergoing shoulder arthroscopy. The arthroscopic findings showed hyperemia of the synovial tissue in all cases of diabetic frozen shoulder. This synovium showed stronger immunostaining to VEGF (P = .010) and CD34 (P = .011) than the control synovial tissue. Western blot analysis also showed a stronger VEGF intensity than in the control group. We postulate that VEGF is synthesized and secreted in the synovium of diabetic frozen shoulders and VEGF may have some role in the pathogenesis and neovascularization of frozen shoulders in diabetic patients.     

人血管内皮生长因子D表达载体促进大鼠肝脏血管形成的研究

目的　人血管内皮生长因子D表达载体 (PCHO/hVEGF D)肠系膜上静脉注射后大鼠肝脏表达的维持时间以及血管形成效果观察。方法　健康级S D大鼠实验组 (2 4只 ) ,肠系膜上静脉注射PCHO/hVEGF D 15 0 μg/只 ,对照组 (18只 )同法注射等量生理盐水 ,然后行门静脉部分结扎术 ,制成门静脉高压症模型。术后 8、14、2 1d处死大鼠 ,取下肝脏标本 ,原位杂交法检测人血管内皮生长因子D(hVEGF D)mRNA的表达水平 ;Ⅷ因子法计算肝脏的血管计数。结果　实验 1、2、3组的hVEGF D的mRNA表达平均积分和阳性率分别为 6.83± 1.72 ,5 /6;3 .71± 2 .14 ,2 /7;2 .5 7± 2 .0 7,1/7;对照组极弱或无表达。第 1组与第 2组、第 3组的差异均有非常显著性 (t1/ 2 =2 .86,t1/ 3 =3 .99,P <0 .0 1)。第 2组和第 3组之间 ,差异无显著性 (t =1.0 16,P >0 .0 5 )。对照组未检测到表达。实验 1、2、3组的血管计数分别为 :12 .83± 4.0 2、8.2 0± 1.92 ,t =2 .3 5 ,P <0 .0 5 ;12 .71± 3 .14、8.80± 1.79,t =2 .49,P <0 .0 5 ;12 .0 0± 3 .74、7.67± 2 .5 0 ,t =2 .41,P <0 .0 5。 3组均显著高于相应对照组 ;实验组 3组之间血管计数差异无显著性。结论　裸基因肠系膜静脉注射PCHO/hVEGF D可以在门静脉部分结扎大鼠得到高效表达hVEGF D     

Relaxin induces vascular endothelial growth factor expression and angiogenesis selectively at wound sites

Relaxin is a reproductive hormone that has historically been characterized as being responsible for pubic ligament loosening and cervical ripening. Recently, relaxin has been associated with neovascularization of the endometrial lining of the uterus, potentially via specific induction of vascular endothelial growth factor. Previously conducted clinical studies using partially purified porcine relaxin have described relaxin's ability to stimulate the healing of ischemic wounds, suggesting that relaxin may also have angiogenic effects at sites of ischemic wound healing. In the present study, relaxin's angiogenic effects in the context of wound repair were tested in rodent models of angiogenesis and wound healing. Relaxin showed an ability to stimulate new blood vessel formation, particularly at ischemic wound sites, and to induce both vascular endothelial growth factor and basic fibroblast growth factor specifically in cells, presumably including macrophages, collected from wound sites. Resident macrophages collected from nonwound sites, such as the lung, did not show altered expression of these cytokines following relaxin administration. Because angiogenic wound cells are frequently macrophages, THP-1 cells, a cell line of monocyte lineage that binds relaxin specifically, were tested for and shown to induce vascular endothelial growth factor and basic fibroblast growth factor in response to relaxin. In conclusion, relaxin may be useful in the treatment of ischemic wounds by stimulating angiogenesis via the induction of vascular endothelial growth factor and basic fibroblast growth factor in wound macrophages.     

血管内皮生长因子与治疗性血管生成研究进展

血管内皮生长因子(vascular endothelial growtll factor,VEGF)是内皮细胞特异的有丝分裂原,有促进内皮细胞增生、增强血管通透性、加速新血管形成的作用.血管生成是一个具有重要生理、病理意义的过程.在人体的创伤愈合、炎症反应、器官再生过程以及肿瘤生长转移、血管增生性疾病中,血管生成有重要作用.治疗性血管生成是指利用成血管诱导因子或内皮祖细胞,模拟体内血管生成机制,促进新生血管形成,改善侧支循环.本文就VEGF和治疗性血管生成研究进展做一综述.     

The effect of vascular endothelial growth factor on angiogenesis: an experimental study.

OBJECTIVE: to evaluate the effects of exogenous vascular endothelial growth factor (VEGF) on angiogenesis in a rabbit model of persistent hind limb ischaemia. MATERIALS AND METHODS: ischaemia was induced in the hind limbs of 42 New Zealand white rabbits divided into six groups, each of 7 animals. Group 1a and 1b received intramuscular injections of 1 and 2 mg VEGF/day, respectively, into the ischaemic hind limb for 10 days beginning on postoperative 11th day, and group 1c received IM injections of saline only. Group 2a and 2b received similar regimen of VEGF, but administered intra-arterially. Group 2c served as controls. Perfusion of the ischaemic limb was evaluated by thigh blood pressure and thigh circumference at 10, 25 and 40 days following limb ischaemia in all animals and by digital subtraction angiography, perfusion scans, histological examination of capillary density in 2 animals from each group. RESULTS: thigh pressure index and thigh circumference improved significantly in the VEGF treated animals (Groups 1a,b and 2a,b). Collateral formation, as assessed by angiography, scintigraphy and by histological examination, indicated marked formation of collaterals in the VEGF treated animals as compared with the controls. This was most pronounced in groups receiving the highest dose of VEGF. CONCLUSION: these data suggest that VEGF promotes angiogenesis, that the route of administration is unimportant, but that a dose-response relationship is present in this experimental ischaemic hind limb model.     

Intraventricular infusion of vascular endothelial growth factor promotes cerebral angiogenesis with minimal brain edema

OBJECTIVE: Therapeutic cerebral angiogenesis, i.e., using angiogenic factors to enhance collateral vessel formation within the central nervous system, is a potential method for cerebral revascularization. Vascular endothelial growth factor (VEGF) is a potent endothelial cell mitogen that also increases capillary permeability, particularly in ischemic tissue. The purpose of this study was to assess the angiogenic and capillary permeability effects of chronic intraventricular infusion of exogenous VEGF in nonischemic brain tissue, because many patients with impaired cerebrovascular reserve do not exhibit chronic cerebral ischemia. METHODS: Recombinant human VEGF(165) was infused into the right lateral ventricle of rats at a rate of 1 microl/h for 7 days, at concentrations of 1 to 25 microg/ml, with osmotic minipumps. Control animals received vehicle only. Vessels were identified in laminin immunohistochemical analyses. Capillary permeability and brain edema were assessed with Evans blue extravasation, [(3)H]inulin permeability, and brain water content measurements. RESULTS: Vessel density was dose-dependently increased by VEGF(165) infusions, with significant increases occurring in animals treated with 5 or 25 microg/ml, compared with control animals (P h 0.01). Significant enlargement of the lateral ventricles was observed for the highest-dose group but not for animals treated with other doses. Capillary permeability was assessed in animals treated with a dose of 5 microg/ml. An increase in capillary permeability in the diencephalon was identified with Evans blue extravasation and [(3)H]inulin permeability assessments; however, the brain water content was not significantly increased. CONCLUSION: Chronic intraventricular infusions of VEGF(165) increased vascular density in a dose-dependent manner. There seems to be a therapeutic window, because infusion of VEGF(165) at a concentration of 5 microg/ml resulted in a significant increase in vessel density with minimal associated brain edema and no ventriculomegaly.     

Salvage angiogenesis induced by adenovirus-mediated gene transfer of vascular endothelial growth factor protects against ischemic vascular occlusion

Purpose: Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis, and transgene expression from adenovirus vectors can provide in vivo delivery of proteins. On the basis of this knowledge, we hypothesized that local administration of a replication-deficient adenovirus vector expressing complementary DNA for VEGF (AdVEGF) would induce collateral vessel formation in the setting of ischemia that could protect against subsequent acute vascular occlusion. Methods: Hindlimb ischemia was induced in Sprague-Dawley rats by means of unilateral ligation of the common iliac artery immediately followed by administration of 4 × 10⁹plaque-forming units VEGF, the control vector AdNull, or phosphate-buffered saline solution into the iliofemoral adipose tissue and thigh muscles. Untreated rats with common iliac ligation were used as an additional control group. Results: Local VEGF expression was observed for 5 days in AdVEGF-treated rats but not in controls. Three weeks after ligation and vector administration, the ipsilateral femoral artery was ligated for a model of an acute vascular occlusion in the setting of preexisting ischemia. Blood flow to the ischemic hindlimb relative to the contralateral hindlimb evaluated with color microspheres demonstrated significantly increased blood flow in the AdVEGF-treated rats compared with each control group (p < 0.0001). Relative blood flow assessed by means of ^99mTc-sestamibi radionuclide scans also demonstrated increased blood flow to the ligated hindlimb of AdVEGF-treated rats compared with each control group (p < 0.002). AdVEGF-treated rats also demonstrated increased vascularity in the ligated limb compared with each control group as assessed by means of angiography (p < 0.0001) and histologic quantification of blood vessels less than 80 μm diameter in local adipose tissue and capillaries per muscle fiber (p < 0.0002). AdVEGF treatment prevented a rise in femoral venous lactate femoral venous concentrations 1 hour after femoral artery ligation in control rats (p < 0.04). Conclusions: An adenovirus vector expressing VEGF complementary DNA is capable of stimulating an angiogenic response that protects against acute vascular occlusion in the setting of preexisting ischemia, suggesting that in vivo gene transfer of VEGF complementary DNA might be useful in prophylaxis of advancing arterial occlusive disease. (J Vasc Surg 1998;27:699-709.)     

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。