Lung overexpression of the vascular endothelial growth factor gene induces pulmonary edema

We hypothesized that the angiogenic mediator, vascular endothelial growth factor (VEGF), known to be expressed in the lung and to be capable of inducing local edema in skin, might evoke the development of lung edema if expressed in excess amounts. To test this hypothesis, we developed an in vivo model of VEGF overexpression in the lung on the basis of delivery to the respiratory epithelium of the VEGF165 complementary DNA by an E1(-) adenovirus vector (AdVEGF165). Administration of AdVEGF165 by the intratracheal route (10(9) plaque-forming units [pfu]) to C57Bl/6 mice showed increased expression of VEGF messenger RNA in lung tissue by Northern analysis. Overexpression of VEGF protein in the lung at Days 1 to 10 was confirmed by enzyme-linked immunosorbent assay. Intratracheal administration of AdVEGF165 resulted in a dose-dependent increase in lung wet/dry weight ratios over time, lung histology showed widespread intra- alveolar edema, and pulmonary capillary permeability was significantly increased as quantified by the Evans blue dye assay and [(131)I]albumin permeability. To confirm the specificity of these observations, mice were pretreated with intranasal administration of an adenovirus vector expressing a truncated soluble form of the VEGF receptor flt-1 (Adsflt). Adsflt (10(9) pfu) pretreatment completely abrogated the increased lung wet/dry weight ratio caused by AdVEGF165 administration, whereas an identical adenovirus vector with an irrelevant transgene had no effect upon subsequent AdVEGF165-induced pulmonary edema. Together, these data suggest that overexpression of VEGF in the lung may be one mechanism of increased pulmonary vascular permeability in the early stages of acute lung injury.     

Adenovirus-mediated lung vascular endothelial growth factor overexpression protects against hypoxic pulmonary hypertension in rats

Chronic hypoxic pulmonary hypertension (PH) is associated with vasoconstriction and structural remodeling of pulmonary vessels including narrowing of the arterial lumen and loss of distal functional arteries. To test whether lung overexpression of the angiogenic factor vascular endothelial growth factor (VEGF) is beneficial in hypoxic PH, recombinant adenovirus encoding the human VEGF 165 gene under the control of a cytomegalovirus promoter (Ad. VEGF) or control vector containing no gene in the expression cassette (Ad.Null) was administered intratracheally to rats. With Ad. VEGF (10(8) plaque-forming units [pfu]), VEGF protein was present in bronchoalveolar lavage fluid as early as 2 d and until 17 d after gene transfer, but was not detected in serum. Only small patchy areas of mononuclear cells without cell damage, edema, or hemorrhage were observed on lung histology with no significant change in lung permeability. In rats pretreated with Ad.VEGF (10(8) pfu) 2 d before a 2-wk exposure to hypoxia (10% O(2)), lower values versus Ad. Null-pretreated controls were found for pulmonary artery pressure (25 +/- 1 versus 30 +/- 2 mm Hg, P < 0.05), right ventricular over left ventricular-plus-septum weight (0.37 +/- 0.01 versus 0.47 +/- 0. 02, P < 0.001), normalized wall thickness of 50- to 200-microm vessels (P < 0.001), and muscularization of distal vessels (P < 0. 001). Pretreatment with Ad.VEGF (10(8) pfu) increased endothelial nitric oxide synthase activity in lung tissue and partially restored endothelium-dependent vasodilation in isolated lungs from chronically hypoxic rats, as assessed by improvement of ionophore A23187-induced vasodilation and attenuation of endothelin-1 (300 pmol)-induced vasoconstriction, an effect abolished in the presence of nitro-L-arginine methylester. We conclude that adenoviral-mediated VEGF overexpression in the lungs attenuates development of hypoxic PH, in part by protecting endothelium-dependent function.     

Expression of vascular endothelial growth factor receptor Flk-1 in canine mammary tumours

Vascular endothelial growth factor (VEGF) induces endothelial cell proliferation, and the beginning of angiogenesis, by interacting with specific endothelial receptors termed VEGFR-1 (Flt-1) and VEGFR-2 (Flk-1). In this study, Flk-1 expression was evaluated immunohistochemically in 10 benign and 40 malignant canine mammary tumours. There was immunolabelling of endothelial cells located within the neoplastic proliferation and at the infiltrating periphery, and also of neoplastic cells. The number of positive endothelial and neoplastic cells, was higher in malignant than in benign tumours. Moreover, in the malignant tumours, expression of Flk-1 increased from well to less differentiated phenotypes (grade 1-3). The presence of VEGF receptor on neoplastic cells suggests that VEGF has an autocrine function in which neoplastic cells act as both VEGF producers and target cells. Thus, in malignant tumours, VEGF may contribute to neoplastic growth by inducing angiogenesis and by stimulating the proliferation of neoplastic cells.     

Enhanced expression of vascular endothelial growth factor in pulmonary plexogenic arteriopathy due to congenital heart disease

Congenital heart disease (CHD) leading to increased pulmonary blood pressure and flow is an important cause of pulmonary plexogenic arteriopathy (PPA). This type of arteriopathy tends to progress to an irreversible stage, hallmarked histologically by the emergence of a number of characteristic lesions, which include concentric laminar intimal proliferation and fibrosis, and plexiform lesions. The pathogenesis of these lesions, which connote a very poor prognosis, is not well understood. Since endothelial cell proliferation has been demonstrated in these lesions, it was hypothesized that vascular endothelial growth factor (VEGF), a key mediator of angiogenesis, might play a role in their pathogenesis. Thirty-nine patients with various types of CHD, who underwent cardiac catheterization and subsequent cardiac surgery, were studied prospectively. On the basis of a detailed assessment of the type of cardiac defect, the haemodynamic abnormalities, and the histopathological features evident from open lung biopsies, taken in all instances, patients were histologically grouped into cases with moderate PPA (n=18), advanced PPA (n=7), pulmonary congestive vasculopathy (PCV, n=5), and controls lacking pulmonary hypertension or increased pulmonary blood flow (n=4). Five patients were excluded from analysis because of inadequate sample size or quality. The presence of VEGF was assessed immunohistochemically using standard procedures and was correlated with haemodynamic and histological data. Immunoreactive VEGF was detected in pulmonary arterial smooth muscle cells and endothelial cells in 13 out of 34 cases and was more frequent and more pronounced in patients with the histological lesions of advanced PPA than in those with moderate PPA (p<0.01). VEGF positivity was particularly prominent in the lesions characteristic of advanced PPA. No difference in VEGF expression was observed between controls, PVC, and moderate PPA cases. Measured haemodynamic parameters did not differ significantly between VEGF-positive and VEGF-negative cases. We conclude that VEGF may play a role in the angioproliferative changes of advanced PPA.     

Hepatocyte growth factor increases expression of vascular endothelial growth factor and plasminogen activator inhibitor-1 in human keratinocytes and the vascular endothelial growth factor receptor flk-1 in human endothelial cells

The pleiotropic growth factor hepatocyte growth factor/scatter factor (HGF/SF) has been implicated by clinical and experimental studies in repair mechanisms in different organs and tissues. However, no data on the impact of HGF/SF in wound healing in the skin are yet available. Proliferating and migrating keratinocytes play a major role in repair processes in the skin by closing the wound. Recent evidence gathered from studies that used gene-deficient mice has implicated the plasminogen activator (PA)/plasmin system in wound healing, which depends on controlled matrix degradation and deposition during cell migration and proliferation. Furthermore, keratinocytes are an important source of vascular endothelial growth factor (VEGF), which is a potent inducer of angiogenesis. In this study, we show that in human keratinocytes HGF/SF but not the related cytokine macrophage stimulating protein (MSP) significantly increases expression of VEGF and plasminogen activator inhibitor-1 (PAI-1) on the level of protein and mRNA. Furthermore, we demonstrate that HGF/SF increases the expression of the VEGF receptor flk-1 in human endothelial cells and that, in an angiogenesis co-culture assay of endothelial cells and keratinocytes, HGF/SF increases endothelial cell tube formation significantly. Therefore, we propose a role for HGF/SF in wound repair in the skin: HGF/SF--produced by activated fibroblasts--increases in keratinocytes the expression of PAI-1, which leads to increased matrix stability during the repair process and which could also limit activation of HGF/SF by proteases such as urokinase-type PA (u-PA) or tissue-type PA (t-PA). Furthermore HGF/SF also increases the expression of VEGF in these cells, thereby initiating angiogenesis in a paracrine manner. This effect would be enhanced by an increased responsiveness of endothelial cells toward VEGF, resulting from the HGF/SF-induced up-regulation of flk-1 on these cells.     

血管内皮生长因子与促血管生成素1对大鼠血管内皮细胞的作用

背景：血管内皮生长因子、促血管生成素1是血管形成过程中始动并且使之持续的重要因子,研究其对血管内皮细胞的作用具有重要的意义。 目的：观察血管内皮生长因子与促血管生成素1对培养血管内皮细胞迁移与增殖能力的影响,并探讨其在血管生成方面的作用机制。 方法：在大鼠脐静脉内皮细胞内单独或联合加入血管内皮生长因子、促血管生成素1后,划痕实验和MTT检测对细胞迁移与增殖的影响,观察内皮细胞形态、活性、迁移能力。 结果与结论：划痕实验显示单独血管内皮生长因子作用时,与空白对照组细胞迁移无明显差异,单独促血管生成素1作用时,不仅不能增加细胞的迁移作用,反较空白对照组有所减弱,当血管内皮生长因子与促血管生成素1联合作用时,细胞迁移较空白对照组明显增强;MTT实验结果表明：单纯加入血管内皮生长因子或促血管生成素1,均不能起到有效促进内皮细胞增殖的作用;联合应用血管内皮生长因子及促血管生成素1可有效促进增殖。结果可见当血管内皮生长因子与促血管生成素1联合应用时,才能有效促内皮细胞迁移与增殖,发挥促血管生成作用。     

Gene transfer of the vascular endothelial growth factor receptor flt-1 suppresses pulmonary metastasis associated with lung growth

Growth of solid tumor metastases is critically dependent on angiogenesis. We hypothesized that an "angiogenic-rich" milieu, as in pneumonectomy-induced lung growth, would be conducive to growth of pulmonary metastases, and that transfer of an antiangiogenic gene would suppress tumor growth. Two weeks after left pneumonectomy in BALB/c mice, right lung mass increased 1.5-fold compared with controls (P < 0.0001). Our pulmonary metastases model, intravenous administration of beta-galactosidase (betagal)-marked CT26.CL25 colon carcinoma cells, resulted in diffuse metastases at 12 d after administration. However, if left pneumonectomy was performed 1 d before tumor cell administration, right lung mass was increased 1.7-fold after 12 d (P < 0.001 compared with the right + left lung of controls), and betagal activity was greater (2.8-fold, P < 0.05). To assess antiangiogenesis therapy, tumor cells were administered 1 d after pneumonectomy and 1 d later, 5 x 10(8) plaque-forming units of Adsflt (an Ad vector expressing the extracellular portion of the flt-1 vascular endothelial growth factor [VEGF] receptor) was administered. Compared with controls, mice receiving Adsflt via intranasal or intravenous routes showed suppression of pneumonectomy-induced tumor growth (P < 0.01, both routes compared with controls). Postpneumonectomy lung growth enhances growth of lung metastases, but this can be suppressed with Adsflt antiangiogenesis therapy.     

Hypoxia-inducible factor-1alpha expression in experimental cirrhosis: correlation with vascular endothelial growth factor expression and angiogenesis

Angiogenesis progresses together with fibrogenesis during chronic liver injury. Hypoxia-inducible factor-1alpha (HIF-1alpha), a master regulator of homeostasis, plays a pivotal role in hypoxia-induced angiogenesis through its regulation of vascular endothelial growth factor (VEGF). The association between hypoxia, angiogenesis and VEGF expression has been demonstrated in experimental cirrhosis. However, expression of HIF-1alpha has yet to be reported. The aim of this study was to investigate the significance of HIF-1alpha expression during experimental liver fibrosis and the relationships between HIF-1alpha expression, VEGF expression and angiogenesis. Cirrhosis was induced in male Wistar rats by intraperitoneal administration of diethyl nitrosamine (DEN) (100 mg/kg, once a week). The serial sections from liver tissues were stained with anti-HIF-1alpha, anti-VEGF and anti-CD34 antibodies before being measured by light microscopy. Our results showed that HIF-1alpha expression gradually increases according to the severity of fibrosis (p<0.01). Moreover, its expression was found to be correlated with angiogenesis (r=0.916) and VEGF expression (r=0.969). The present study demonstrates that HIF-1alpha might have a role in the development of angiogenesis via regulation of VEGF during experimental liver fibrogenesis and suggests that this factor could be a potential target in the manipulation of angiogenesis in chronic inflammatory diseases of the liver.     

Placental expression of vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 correlates with severity of clinical preeclampsia and villous hypermaturity

Overexpression of soluble vascular endothelial growth factor receptor-1 has been linked to preeclampsia and is thought to be secondary to placental insufficiency caused by hypoxia. Villous hypermaturity, characterized by presence of increased syncytial knots, has been associated with syndromes of placental insufficiency, particularly when severe. This study was undertaken to determine whether there is a link between soluble vascular endothelial growth factor receptor-1 expression, villous hypermaturity, and clinical severity of preeclampsia. We conducted a retrospective cohort study in which 48 placentas were selected from pathology archives (hypertensive group). Of these, 6 had chronic hypertension, 15 had mild preeclampsia, 14 had severe preeclampsia, and 13 had hemolysis, elevated liver enzymes, and low platelets syndrome. These were compared with 55 placentas from normotensive patients (control group). One representative section of placental parenchyma from each case was stained with an antibody to vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 and given a score based on extent and intensity of staining, representing expression level. Assignment of staining score was done, blinded to clinical history and pathologic diagnosis. Vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 staining was seen in placental syncytiotrophoblasts and was particularly strong in syncytial knots. There was a positive association between vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 staining score and severity of clinical hypertensive state, small placental size, and villous hypermaturity. The association between vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 score and small placentas did not persist after controlling for hypermaturity. Vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 overexpression in the placenta strongly correlates with both severity of hypertensive disease and villous hypermaturity. The correlation with villous hypermaturity further links hypoxia to vascular endothelial growth factor receptor-1/soluble vascular endothelial growth factor receptor-1 production in the placenta.     

The secretion of endothelin-1 by microvascular endothelial cells from human benign prostatic hyperplasia is inhibited by vascular endothelial growth factor

Prostate growth seems to be influenced by paracrine factors like endothelin-1 (ET-1), originating from the microvascular endothelium. Recently, we reported on the first isolation and primary culture of microvascular endothelial cells (HPEC) derived from tissue of human benign prostatic hyperplasia (BPH). Therefore, direct investigation of growth factor secretion by HPEC is now possible. BPH tissue was cut into small cubes and gently squeezed after incubation with dispase. HPEC were cultured from the resulting cell suspension after a stepwise selection by use of superparamagnetic beads coated with antibodies against endothelial specific antigens. HPEC were characterized by flow cytometry. After the incubation of HPEC either with vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF-alpha), or adenosine triphosphate (ATP), the secretion of ET-1 was measured by ELISA. HPEC showed a typical endothelial morphology. They were positive for von Willebrand factor and CD31. The ET-1 secretion of HPEC was inhibited by VEGF, but was unaffected by TNF-alpha or ATP. Furthermore, histochemistry revealed that in vivo microvascular endothelial cells were negative for ET-1. Because of the suppression by the widespread VEGF, it is unlikely that ET-1 from the microvascular endothelium acts as a growth factor in human BPH.     

Early neutrophilic expression of vascular endothelial growth factor after traumatic brain injury

The formation of edema after traumatic brain injury (TBI) is in part associated with the disruption of the blood-brain barrier. However, the molecular and cellular mechanisms underlying these phenomena have not been fully understood. One possible factor involved in edema formation is vascular endothelial growth factor (VEGF). This growth factor has previously been demonstrated to increase the blood-brain barrier permeability to the low molecular weight markers and macromolecules. In this study, we analyzed the temporal changes in VEGF expression after TBI in rats. In the intact brain, VEGF was expressed at relatively low levels and was found in the cells located close to the cerebrospinal fluid space. These were the astrocytes located under the ependyma and the pia-glial lining, as well as the epithelial cells of the choroid plexus. In addition, several groups of neurons, including those located in the frontoparietal cortex and in all hippocampal regions, were VEGF-positive. The pattern of VEGF-immunopositive staining of neurons and choroidal epithelium suggested that in these cells, VEGF binds to the cell membrane-associated heparan sulfate proteoglycans. Following TBI, there was an early (within 4 h post-injury) increase in VEGF expression in the traumatized parenchyma associated with neutrophilic invasion. The ipsilateral choroid plexus appeared to play a role in facilitating the migration of neutrophils from blood into the cerebrospinal fluid space, from where many of these cells infiltrated the brain parenchyma. VEGF-immunopositive staining of neutrophils resembled haloes and was found ipsilaterally within the frontoparietal cortex and around the velum interpositum, a part of the subarachnoid space. These haloes likely represent the deposition of neutrophil-derived VEGF within the extracellular matrix, from where this growth factor may be gradually released during an early post-traumatic period. The maximum number of VEGF-secreting neutrophils was observed between 8 h and 1 day after TBI. In addition, from 4 h post-TBI, there was a progressive increase in the number of VEGF-immunoreactive astrocytes in the ipsilateral frontoparietal cortex. The maximum number of astrocytes expressing VEGF was observed 4 days after TBI, and then the levels of astroglial VEGF expression declined gradually. Early invasion of brain parenchyma by VEGF-secreting neutrophils together with a delayed increase in astrocytic synthesis of this growth factor correlate with the biphasic opening of the blood-brain barrier and formation of edema previously observed after TBI. Therefore, these findings suggest that VEGF plays an important role in promoting the formation of post-traumatic brain edema.     

Defective pulmonary development in the absence of heparin-binding vascular endothelial growth factor isoforms

Development of the airways, alveoli, and the pulmonary vasculature in the fetus is a process that is precisely controlled. One of the growth factors involved, vascular endothelial growth factor (VEGF), is so critical for embryonic development that in the mouse, elimination of just a single allele is lethal. In the early stages of lung development, the mouse VEGF gene expresses three isoforms (120, 164, and 188) in a distinct temporo-spatial pattern, suggesting a specific function for each. We engineered mice that express only VEGF 120, to study the role of VEGF isoforms in lung development. Lung vessel development in these mice was studied by scanning electron microscopy of Mercox casts of lung vasculature. Airway and air-blood barrier development was analyzed by light microscopy, transmission electron microscopy, immunohistochemistry, and morphometry. In all VEGF120/120 fetuses and pups, lung vascular casts were smaller and less dense compared with 120/+ and wild-type littermates. Although the generation count of pre-acinar vessels was similar in all three genotypes, the most peripheral vessels were dilated and were more widely separated in 120/120 fetuses of all ages, compared with 120/+ and wild-type littermates. In addition, 120/120 animals had fewer air-blood barriers and a decreased airspace-parenchyma ratio compared with 120/+ and wild-type littermates. We concluded that the absence of VEGF 164 and 188 isoforms impairs lung microvascular development and delays airspace maturation, indicating an essential role for heparin-binding VEGF isoforms in normal lung development.     

Expression of vascular endothelial growth factor and thrombospondin-1 in colorectal carcinoma

Solid tumors require neovascularization for growth and metastasis. Vascular endothelial growth factor (VEGF) is a well-characterized inducer of angiogenesis, while, thrombospondin-1 (TSP-1) is thought to be an antiangiogenic factor. In this study, we examined the expressions of these antigens and their relationship with microvessel density, and determined their prognostic significance. One hundred specimens resected from patients with colorectal adenocarcinoma were examined using immunohistochemical methods. Microvessel density, determined by immunostaining for factor VIII-related antigen, was significantly higher in tumors that were VEGF-positive and TSP-1-negative than in other tumors. Patients with VEGF-positive tumors had a significantly worse prognosis than did those with VEGF-negative tumors, and TSP-1 expression was inversely correlated with prognosis. The frequency of hepatic recurrence was significantly higher in patients with tumors that were VEGF-positive and TSP-1-negative than in all other patients. In conclusion, VEGF and TSP-1 are important regulators of tumor angiogenesis, and combined analysis of VEGF and TSP-1 may be useful for predicting recurrence in patients with colorectal adenocarcinoma.     

喉癌中血管内皮素-1的表达与血管内皮生长因子-C、淋巴管生成及预后的关系

目的:探讨血管内皮素-1(ET-1)在喉癌组织中的表达与血管内皮生长因子-C(VEGF-C)、淋巴管密度(LVD)、淋巴转移之间的关系及其在喉癌预后中的意义.方法:以45例经病理确诊的喉癌组织为实验组,20例喉良性病变组织为对照组,采用免疫组织化学SP法对上述组织中ET-1、VEGF-C蛋白的表达进行分析,同时采用5′-核苷酸酶-碱性磷酸酶双重染色法(5'-Nase-ALP)计数LVD,并结合临床病理特征和生存资料进行相关分析.结果:喉癌组织中ET-1和VEGF-C的表达均高于良性病变组织,且ET-1和VEGF-C的表达具有相关性;在喉癌组织中ET-1的表达与瘤内LVD和瘤周LVD、淋巴结转移、淋巴管浸润、TNM临床分期呈正相关,ET-1+/VEGF-C+、VEGF-C的表达与生存率呈负相关,其中ET-1+/VEGF-C+组具有高危死亡率.结论:ET-1促进喉癌淋巴管生成和淋巴管转移,ET-1信号途径和VEGF-C信号途径可能对喉癌淋巴管生成和转移有协同促进作用,联合检测ET-1和VEGF-C的表达可成为独立判断喉癌预后的新的生物学指标.     

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     

Expression of vascular endothelial growth factor and vascular endothelial growth factor receptors 1 and 2 in invasive breast carcinoma: prognostic significance and relationship with markers for aggressiveness

Dhakal H P, Naume B, Synnestvedt M, Borgen E, Kaaresen R, Schlichting E, Wiedswang G, Bassarova A, Holm R, Giercksky K‐E & Nesland J M
(2012) Histopathology  61, 350–364 Expression of vascular endothelial growth factor and vascular endothelial growth factor receptors 1 and 2 in invasive breast carcinoma: prognostic significance and relationship with markers for aggressiveness Aims: Vascular endothelial growth factor (VEGF), VEGF receptor 1 (VEGFR‐1) and VEGF receptor 2 (VEGFR‐2) play a role in breast cancer growth and angiogenesis. We examined the expression and relationship with clinical outcome and other prognostic factors. Methods and results: Tumour sections from 468 breast cancer patients were immunostained for VEGF, VEGFR‐1, and VEGFR‐2, and their relationships with tumour vascularity, disseminated tumour cells (DTCs) in bone marrow and other clinicopathological parameters were evaluated. VEGF, VEGFR‐1 and VEGFR‐2 immunoreactivities were observed in invasive breast carcinoma cells. VEGF expression was significantly associated with VEGFR‐1 and VEGFR‐2 expression (P < 0.001). High‐level cytoplasmic expression of VEGFR‐1 was associated with significantly reduced distant disease‐free survival (DDFS) (P = 0.017, log‐rank) and breast cancer‐specific survival (BCSS) (P = 0.005, log‐rank) for all patients, and for node‐negative patients without systemic treatment (DDFS, P = 0.03, log‐rank; BCSS, P = 0.009, log‐rank). VEGFR‐1 expression was significantly associated with histopathological markers of aggressiveness (P < 0.05). Significantly reduced survival was observed in DTC‐positive patients as compared with DTC‐negative patients in the combined moderate/high VEGFR‐1 group (P < 0.001 for DDFS and BCSS), and the same was true for DDFS in the moderate VEGFR‐2 group (P = 0.006). Conclusions: High‐level expression of VEGFR‐1 indicates reduced survival. Higher‐level expression of VEGFR‐1 or VEGFR‐2 in primary breast carcinomas combined with the presence of DTC selects a prognostically unfavourable patient group.     

Changes in circulating levels of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 after carotid endarterectomy

It has been shown that vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR-2) are upregulated in severe carotid stenosis. However, it is unknown whether carotid endarterectomy (CEA) affects serum level of these molecules. We investigated changes in concentration of VEGF and VEGFR-2 in patients undergoing carotid endarterectomy. Forty-three patients with extracranial carotid stenosis (>70%), were studied. Patients with severe vertebrobasilar stenosis, recent (<1 month) vascular event (stroke, coronary infarction, arterial thromboembolism), critical ischemia of lower extremity, recent infection, autoimmune disease or malignancy were excluded from the study. Blood samples were taken before CEA and on the second post-operative day. Thirty healthy blood donors served as a control group. We used enzyme linked immuno-absorbent assay as a method for the determination of VEGF and VEGFR-2. Pre-operative levels of VEGF (371+/-42 pg/ml) and VEGFR-2 (8424+/-356 pg/ml) were significantly elevated. There was significant decrease in both VEGF (152 pg/ml) and VEGFR-2 (1297 pg/ml) after CEA, without however reaching normal values. In asymptomatic patients and in patients with a contralateral carotid stenosis of >50%, however, the observed reduction of VEGF did not reach statistical significance. On the other hand, in the same subgroups, a major decrease of VEGFR-2 values was observed. VEGF and VEGFR-2 showed a very significant increase in serum of patients with severe carotid stenosis. These pre-operative levels decreased significantly after endarterectomy, and the changes emphasize the importance of these molecules in carotid disease progression.     

不同间期慢性低O2高CO2肺动脉高压大鼠血管内皮生长因子的变化

目的：观察不同间期低O2高CO2大鼠肺循环中血管内皮生长因子（VEGF）水平的变化。方法： 采用ELISA法、透射电镜、免疫组化和原位杂交等方法，观察低O2高CO22周组（T组）、低O2高CO24周组（F组）、低O2高CO28周组（E组）大鼠肺动脉平均压（mPAP）、右心室重量比（RV/LV+S）、血清和肺组织VEGF的含量、肺细小动脉的超微结构、肺组织VEGF及VEGF mRNA表达的变化。结果： T、F、E组大鼠的mPAP、RV/LV+S、血清和肺组织VEGF的含量以及VEGF及其mRNA的表达明显高于正常对照组。随低O2高CO2间期的延长，各组大鼠内皮细胞逐渐向管腔凸起，基底变窄，中膜平滑肌细胞、胶原纤维明显增多。结论：低O2高CO2刺激肺细小动脉壁VEGF mRNA表达增加，导致VEGF的合成和分泌增多，后者可能参与慢性低氧性肺动脉高压的形成和肺细小动脉壁的重建。