Intramyocardial Injection of DNA Encoding Vascular Endothelial Growth Factor in a Myocardial Infarction Model

In a previous study, we observed that one injection of 500g of DNA for the plasmid encoding for vascular endothelial growth factor (ph VEGF₁₆₅) into one site in a rat myocardial infarction model resulted in neovascularization confined to angiomatous structures that did not contribute to regional myocardial blood flow. The purpose of the present study was to determine whether a lower dose (125g DNA), which is the same as that being used in some clinical trials, injected into four separate sites could enhance collateral flow and vascularity to the ischemic bed without inducing angiomas. Rats received injections of 125g DNA of the plasmid encoding phVEGF₁₆₅ or control DNA at four separate sites within the anterior free wall of the left ventricle (LV) supplied by the left coronary artery. The left coronary artery was ligated and hearts analyzed at 4 weeks. In vitro studies confirmed that the phVEGF₁₆₅ used was capable of producing VEGF polypeptide in mammalian cells. The infarct size (percentage of endocardial circumference that infarcted) was similar in controls (42±6%) and treated hearts (39±7%); the LV cavity area did not differ between groups. The number of vascular structures per high-power field within the infarct scar was 10.50±0.68 in controls and 10.00±0.85 in phVEGF₁₆₅-treated rats. Relative regional myocardial blood flow determined by radioactive microspheres and expressed as a ratio of radioactive counts within the scar divided by radioactive counts in the noninfarcted ventricular septum was similar in control (0.74±0.25) and treated hearts (0.88±0.30) (p=not significant). No angiomatous structures were observed. Injections of 125g of DNA of phVEGF₁₆₅ into myocardium to become ischemic had no effect on infarct size or LV cavity size. Unlike higher doses of 500g of DNA, it did not cause gross angiomatous structures; however, it failed to improve neovascularization or regional myocardial blood flow in this rodent model of acute myocardial infarction.     

Shwachman-Diamond syndrome: an inherited model of aplastic anaemia with accelerated angiogenesis

Bone marrow angiogenesis is increased in myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML), but has not been studied in inherited or acquired marrow failure syndromes. Shwachman-Diamond syndrome (SDS) carries a high risk of MDS/AML and is characterised by marrow stromal dysfunction. Compared with controls, SDS patients without MDS/AML had higher marrow microvessel density. Stromal VEGF gene expression, stromal vascular endothelial growth factor (VEGF) secretion and VEGF levels in serum and marrow mononuclear cells were normal. Future studies should investigate the mechanism for increased angiogenesis in SDS, and whether SDS marrow, with its increased angiogenesis, promotes progression of malignant clones.     

动脉硬化闭塞症与血管新生

随着人们生活水平逐渐提高 ,动脉硬化闭塞症发病率相应升高 ,此类患者相当痛苦 ,但到目前为止没有理想的治疗方法。新近提出的治疗性血管新生为此类患者提供了美好前景。血管新生是指从原有血管床处以发芽方式内皮细胞和平滑肌细胞增生从而形成新的血管。可为患者提供一个治疗性“生物旁路”。 VEGF、FGF、HGF等能通过很多因素调节 ,其中低氧是很重要因素 ,从而促进血管新生起到治疗作用。这已经在动物及临床前期实验得以证实     

血管内皮细胞生长因子与治疗性血管新生

本文概述了血管内皮细胞生长因子(VEGF)家族及其受体的组成,介绍了调控VEGF表达的因素及VEGF信号传导途径。着重阐述了VEGF促血管新生的作用机制,以及VEGF在治疗性血管新生中的研究与应用现状、存在问题及未来发展前景。还简要介绍了VEGF其他的生物学作用。     

胰岛素经VEGF-A/VEGFR2途径促进恒河猴视网膜血管内皮细胞的血管新生

用人胰岛素处理恒河猴视网膜血管内皮细胞系RF/6A,测定其增殖、迁移、管腔形成情况和血管内皮生长因子A(VEGF-A)及其受体(VEGFR)的表达与磷酸化.与空白对照组相比,胰岛素促进RF/6A细胞增殖、迁移和管腔形成(均P＜0.01)、促进VEGF-A mRNA的表达和蛋白的活性(均P＜0.05);促进VEGFR2 mRNA的表达和蛋白的磷酸化(均P＜0.01),而对VEGFR1 mRNA的表达影响无统计学意义(P＞0.05)     

血管内皮细胞生长因子检测在重型肝炎患者中的应用

目的：探讨检测血管内皮细胞生长因子（VEGF）水平在重型肝炎患者中的临床应用，为其预后提供早期诊断依据。方法：采用双抗体夹心法定量检测80例重型肝炎患者血清VEGF水平。结果：急、慢性重型肝炎患者VEGF检出率分别为39．09％和81．36％。慢性期恢复率升高差异有显著性意义（P〈0．01），存活组和死亡组检出率分别高于正常组，存活组恢复期检出率达81．96％（P〈0．01），而死亡组恢复期检出率明显下降达21．05％（P〈0．05）。血清VEGF检测灵敏度为15pg／ml，特异性强，重复性好，板内板间变异系数均〈9．5％。结论：血清VEGF水平检测具有较好的特异性和敏感性，可反映重型肝炎患者肝细胞再生程度，是临床观察重型肝炎患者预后具有特征性的疗效指标。     

Manipulating angiogenesis in medicine

Blood vessels nourish organs with vital nutrients and oxygen and, thus, new vessels form when the embryo needs to grow or wounds are to heal. However, forming new blood vessels is a complex and delicate process, which, unfortunately, is often derailed. Thus, when insufficient vessels form, the tissue becomes ischaemic and stops to function adequately. Conversely, when vessels grow excessively, malignant and inflamed tissues grow faster. It is now becoming increasingly evident that abnormal vessel growth contributes to the pathogenesis of numerous malignant, ischaemic, inflammatory, infectious and immune disorders. With an in-depth molecular understanding, we should be better armamented to combat such angiogenic disorders in the future. That such therapeutic strategies might change the face of medicine is witnessed by initial evidence of success in the clinic.     

Angiogenesis in myocardial infarction. An acute or chronic process?

BACKGROUND: In the acute phase of myocardial infarction (acute MI) marked endothelial damage occurs within the first 24h following thrombolysis with streptokinase. We investigated whether this is associated with a change in levels of vascular endothelial growth factor (VEGF, possibly marking angiogenesis) in the first 24h post thrombolysis compared to chronic MI patients (defined as MI>3 months previously). METHODS: We recruited 15 patients (nine male, mean age 59+/-SD 10 years) with first-presentation acute MI, who were given 1.5 million U streptokinase over 1h and aspirin 300mg orally as standard treatment. Plasma samples were taken prior to the start of thrombolysis, followed every 15 min for 1h, at 3h and finally at 24h post-thrombolysis. Baseline levels of measured indices in the acute MI patients were compared to two control groups: (i) 26 chronic MI patients (18 male, mean age 59.9+/-7.0 years); and (ii) 26 apparently healthy controls (17 male, mean age 59.6+/-14.1 years). Plasma VEGF and the soluble form of its receptor Flt-1 (sFlt-1) were measured by ELISA. RESULTS: Plasma levels of VEGF were significantly higher in patients with a history of chronic MI compared to patients with acute MI (P=0.007) and healthy controls (P=0.002) with similar levels between acute MI patients and healthy controls (P=0.755). Levels of sFlt-1 in the acute (P=0.013) and chronic (P<0.001) MI groups were lower compared to healthy controls. In the first 24h post-thrombolysis in the acute MI group, levels of sFlt-1 changed significantly (P=0.039), but there was no change in levels of VEGF (P=0.207). CONCLUSION: In the first 24h of acute MI, significant changes in levels of VEGF receptor sFlt-1, but not VEGF, are seen. Plasma VEGF and sFlt-1 levels are markedly changed in chronic MI patients, suggesting that the activation of angiogenesis in MI patients may be a delayed response.     

干细胞联合血管内皮生长因子治疗缺血性脑损伤

最近的动物实验研究表明,神经发生和血管生成是卒中恢复的重要机制.干细胞移植能改善卒中后神经功能缺损,而血管内皮生长因子也可通过促进血管生成改善卒中后神经功能.文章综述了二者联合应用治疗缺血性脑损伤的研究进展.     

Decreased salivary vascular endothelial growth factor in elderly patients with pneumonia during the course of recovery

Background: Elderly individuals are known for their high risk of acquiring pneumonia. Poor oral hygiene and high incidence of gastro‐oesophageal reflux continue to cause persistent oropharyngeal mucosal injuries and results in overgrowth of bacterial population and alteration of bacterial flora to respiratory pathogens in the oropharyngeal cavity. Salivary secretion contributes in maintaining homeostasis of the oropharyngeal mucosal barrier. Vascular endothelial growth factor (VEGF) acts as an angiogenic and permeability‐enhancing cytokine but is normally secreted in saliva. It has been previously demonstrated that VEGF secreted in the airway functions in the restoration or repair of the injured tissue. We hypothesized that salivary VEGF is a candidate as a marker to evaluate the degree of oropharyngeal mucosal injury. Methods: We compared the volumes, protein contents, and the amount of VEGF secreted in the saliva of patients with pneumonia during the course of recovery (P; n = 7) and those without pneumonia (n = 10). Results: Volumes and protein contents within the secreted saliva were similar between the patients with P and the control subjects (0.60 ± 0.28 mL versus 0.41 ± 0.34 mL, P = 0.126, 7.12 ± 5.57 µg/mL versus 3.92 ± 3.58 µg/mL, P = 0.231, respectively). The concentrations of salivary VEGF were significantly lower in patients with P than those of the controls (0.71 ± 0.37 versus 2.66 ± 3.44 µg/µg protein, P = 0.032). Conclusion: Lower concentrations of salivary VEGF in patients with pneumonia during the course of recovery suggested the presence of persistent oropharyngeal mucosal injury even after normalization of systemic C‐reactive protein levels. The concentration of salivary VEGF is capable of being a marker for discriminating impaired oral mucosal barrier that precipitates in development of pneumonia in elderly individuals.     

血管内皮生长因子用于治疗性血管生成的问题及对策

生理和病理性血管生成中,血管内皮生长因子(vascularendothelialgrowthfactor,VEGF)是主要的血管生成因子。VEGF促血管生成的能力在动物和临床中已得到了广泛的研究。然而,越来越多的证据显示新生血管结构需要获得稳定,以避免水肿和形成血管瘤等不良反应。而且VEGF在促进血管生成的同时,也可能促进粥样斑块的生长。通过调节VEGF表达时间和表达量,或联合使用血小板衍生生长因子BB(plateletderivedgrowthfactorBB,PDGFBB)等“成熟”因子,有可能产生成熟的血管。导入不同基因到同一细胞以获得能同时表达“生长”和“成熟”因子的细胞,使细胞介导的基因转移在治疗性血管生成中具有独特价值。另一个可选择的策略是使用可调控多种血管生成因子表达的转录因子。     

胃癌组织血小板衍化内皮细胞生长因子的表达与血管生成和凋亡的关系

目的探讨血小板衍化内皮细胞生长因子（PD．ECGF）在胃癌组织中的表达及与血管生成和凋亡的关系。方法应用免疫组化技术对67例胃癌组织进行PD－ECGF表达、肿瘤组织微血管密度（MVD）检测，流式细胞技术检测胃癌组织细胞凋亡指数（川，凋亡百分率八结果＊r＊＊＊F的表达与胃癌淋巴结转移（P＜0．oj）。分化程度（P＜0．05）及组织分型（P＜0．05）显著相关，与＊V则尸＜001）和胃癌细胞凋亡指数（P＜001）显著相关。＊＊D和＊1与淋巳结转移（P＜001）显著相关。结论胃癌组织中P＊。 ECGF可促进血管生成，抑制胃癌细胞凋亡，促进胃癌的增殖与转移。     

Correlation between synovial blood flow signals and serum vascular endothelial growth factor levels in patients with refractory rheumatoid arthritis

The objective of the study is to examine the relationship between synovial blood flow signals and vascular endothelial growth factor (VEGF) involved in angiogenesis by Doppler ultrasound. Twenty-one patients meeting the diagnostic criteria of the American College of Rheumatology (ACR) were enrolled in this study. Doppler ultrasound signals of blood flow in the wrist synovial membrane were measured and classified into three grades: grade 1 = no flow; grade 2 = mild flow; grade 3 = intense flow. A significant correlation was observed between blood flow signals in the wrist synovial membrane and serum VEGF levels (r = 0.5681, P = 0.0072). These results suggest that the measurement of Doppler ultrasound signals of blood flow in the wrist synovial membrane is useful in the evaluation of angiogenesis.     

The importance of angiogenesis markers in the outcome of patients with diffuse large B cell lymphoma: a retrospective study of 97 patients

Purpose The role of angiogenesis has been extensively evaluated in solid tumors and more recently in hematologic malignancies. Several surrogate markers of angiogenesis including tumor VEGF, VEGF receptors, and microvessel density have correlated with outcome in some lymphoma studies. This is a single institution retrospective study evaluating the role of angiogenesis markers in the clinical outcome of patients with diffuse large B cell lymphoma (DLBCL). Patients and methods A total of 97 patients with DLBCL diagnosed and managed at Indiana University between 1993 and 2001 were included. Archived tumor samples were stained for VEGF-A, VEGF-C, VEGF-R1, and CD31 and graded as negative or positive (1+, 2+, 3+). The relationship between the expression of these markers and the international prognostic variables as well as the progression free survival (PFS) and the overall survival (OS) was evaluated. Results VEGF-A, VEGF-C, VEGF-R1 were expressed in 77, 98, and 18% of tumors, respectively. VEGF-A negative patients had an improved OS compared to VEGF-A (1+) (P = 0.0502). VEGF-C correlated with both LDH (r = 0.28, P = 0.0502) and IPI score (r = 0.25, P = 0.013). VEGF-R1 negative patients had a superior survival compared to those with VEGF-R1 (2+) (P = 0.0154). Conclusions The presence of tumor associated angiogenesis may alter the outcome of patients with DLBCL and could be a prognostic factor. Further clinical studies are needed to correlate the degree of angiogenesis with response to anti-angiogenesis agents. Supported in part by funds from Indiana University Cancer Center, Indianapolis, IN, USA.     

治疗性血管新生的临床研究进展

因冠状动脉狭窄而致的缺血性心脏病是世界范围内致死的首要原因。基于大量动物试验的成功,治疗性血管再生已经步入了临床阶段。现对这方面的一些临床研究进行了总结,虽然临床上对血管再生的安全性有较多的肯定,但是临床上血管再生的结果却远不如动物实验理想。为进一步阐明冠心病时血管再生的治疗方法,还需要有大规模的随机、双盲、安慰剂对照试验。     

血管内皮生长因子基因转染对犬肾动脉内膜损伤后的作用

目的:观察血管内皮生长因子(VEGF)基因转染肾动脉内膜后的表达,以及对肾动脉内膜损伤后的作用。方法:利用分子生物学技术,将pcD2/VEGF121真核表达质粒及pcD2空载质粒转化大肠杆菌XL1-Blue,大量提取质粒。试验犬14只采用自身对照方法将左右肾动脉随机分为治疗侧和对照侧。行双侧肾动脉造影,将PTCA球囊送入肾动脉中段加压并拉伤动脉内膜,再将涂布pcD2/VEGF121质粒及pcD2空载质粒的球囊分别导入治疗侧及对照侧损伤段动脉加压维持5min,以使基因转染动脉内膜。分别于术后1、6及10周行肾动脉造影后将犬处死,取损伤段肾动脉,制成病理切片进行HE染色及免疫组织化学染色,观察肾动脉内膜的变化和VEGF蛋白的表达,在电镜下观察动脉内膜的超微结构变化,以判断VEGF基因对犬肾动脉损伤后的作用。结果:肾动脉造影结果显示术后6周双侧肾动脉较术前均轻度狭窄,术后10周狭窄程度更明显,但治疗侧和对照侧之间狭窄程度差异无统计学意义;HE染色显示术后6周双侧肾动脉内膜较术前均轻度增生,10周时增生程度更明显,但治疗侧和对照侧肾动脉内膜增生程度均差异无统计学意义。免疫组织化学染色显示1周时,治疗侧肾动脉内膜及平滑肌的VEGF蛋白表达量明显高于对照侧,6周时仍有差异,但其差异减小;电镜显示:与对照侧比较,术后10周治疗侧动脉内膜覆盖较完全。结论:VEGF基因转染动脉壁后可以促进损伤动脉的内膜化,但不能阻止动脉内膜的过度增生及动脉损伤后形成的狭窄。     

Atherosclerosis in the back yard

The phenomenon of neovascularization in atherosclerosis has been widely recognized through "the eyes of novel imaging techniques" in recent years. Oxidative stress, inflammation, and hypoxia have been implied as the underlying mechanisms. The pathophysiologic consequences and therapeutic implications of this neovascularization process for atherosclerosis have, however, remained challenging and controversial. In the current focus issue of the Journal, 4 articles and this commentary are devoted to this topic.     

血管内皮生长因子及其受体与非小细胞肺癌血管新生

肿瘤生长和转移都依赖于新生血管的形成.血管内皮生长因子(vascular endothelial growth factor,VEGF)是血管新生最重要的诱导因子.不同VEGF及其受体的亚型功能相异.目前,对VEGF信号转导通路机制的研究取得了很大进展.通过阻断VEGF的某些环节来抑制血管新生的靶向治疗成为非小细胞肺癌的治疗热点.