血管内皮生长因子与脑梗死

血管内皮生长因子(vascular endothelial growth factor,VEGF)是血管内皮细胞的一种特异性促分裂原,是最重要的促血管新生因子.VEGF在脑梗死后高度表达,在血管新生和神经保护中起着重要作用;同时,其过度表达也会使血管通透性增加,进而可能加重脑水肿.文章对VEGF及其受体与脑梗死的研究进展进行了综述.     

血管内皮生长因子在脑缺血中的作用

血管内皮生长因子(vascular endothelial growth factor,VEGF)是一种重要的调节多种内皮功能的血管生长因子.脑缺血后,VEGF不仪能促进血管内皮细胞增殖和迁移,参与血管生成,增加血管通透性,而且在神经保护和神经发生等方面也起着重要作用.文章就VEGF在缺血性脑损伤中的作用进行了综述.     

Vascular endothelial growth factor

An understanding of the mechanisms regulating growth and differentiation of vascular endothelial cells is very important for cardiovascular biology and medicine. Several potential regulators of angiogenesis have been identified, including acidic and basic fibroblast growth factors, epidermal growth factor, platelet-derived endothelial cell growth factor, transforming growth factors and β, and tumor necrosis factor (TNF-). Vascular endothelial growth factor (VEGF) is unique among these agents by virtue of its direct and specific mitogenic effects on endothelial cells combined with the fact that it is a secreted polypeptide. By alternative splicing of mRNA, VEGF may exist in four different isoforms that have similar biologic activities but differ markedly in their secretion pattern. VEGF is emerging as an important regulator of developmental and ovarian angiogenesis. Its action is purely paracrine as it is produced by a variety of cell types, but its receptors are only in endothelial cells. There is no evidence that endothelial cells in vivo produce VEGF. The VEGF mRNA is expressed at high level by a variety of human tumors, suggesting that VEGF may be a tumor angiogenesis factor. This hypothesis is supported by the finding that monoclonal antibodies specific for VEGF are able to suppress tumor growth in vivo. Therefore, VEGF antagonists may be used for the treatment of malignancies and, possibly, other angiogenic diseases. The VEGF protein has therapeutic potential as an inducer of neovascularization in conditions characterized by impaired tissue perfusion like obstructive atherosclerosis.     

Vascular endothelial growth factor: direct neuroprotective effect in in vitro ischemia

Vascular endothelial growth factor (VEGF) is a hypoxia-inducible angiogenic peptide with recently identified neurotrophic effects. Because some neurotrophic factors can protect neurons from hypoxic or ischemic injury, we investigated the possibility that VEGF has similar neuroprotective properties. In HN33, an immortalized hippocampal neuronal cell line, VEGF reduced cell death associated with an in vitro model of cerebral ischemia: at a maximally effective concentration of 50 ng/ml, VEGF approximately doubled the number of cells surviving after 24 h of hypoxia and glucose deprivation. To investigate the mechanism of neuroprotection by VEGF, the expression of known target receptors for VEGF was measured by Western blotting, which showed that HN33 cells expressed VEGFR-2 receptors and neuropilin-1, but not VEGFR-1 receptors. The neuropilin-1 ligand placenta growth factor-2 failed to reproduce the protective effect of VEGF, pointing to VEGFR-2 as the site of VEGF's neuroprotective action. Two phosphatidylinositol 3'-kinase inhibitors, wortmannin and LY294002, reversed the neuroprotective effect of VEGF, implicating the phosphatidylinositol 3'-kinase/Akt signal transduction system in VEGF-mediated neuroprotection. VEGF also protected primary cultures of rat cerebral cortical neurons from hypoxia and glucose deprivation. We conclude that in addition to its known role as an angiogenic factor, VEGF may exert a direct neuroprotective effect in hypoxic-ischemic injury.     

血管内皮生长因子对脑缺血的保护作用

血管内皮生长因子(vascular endothelial growth factor,VEGF)是一种内皮细胞特异性分裂原.研究表明,VEGF与缺血性卒中密切相关,这使得从VEGF及其受体水平干预缺血性卒中成为可能.文章对VEGF及其受体的生物学作用、参与缺血性卒中各阶段的作用机制以及治疗前景进行了综述.     

Vascular endothelial growth factor in patients with critical limb ischemia before and after amputation.

BACKGROUND: It is known that levels of vascular endothelial growth factor (VEGF) in biological fluids increase with inflammation and vascular proliferation. Theraputic angiogenesis by injection of VEGF or genes encoding for it may be a promising strategy for treatment of critical limb ischemia. However growth factors are also implicated in the development of vascular disease by smooth muscle cell proliferation. METHODS: We have previously shown VEGF levels to be increased in juvenile diabetic subjects with no clinical evidence of vascular disease. We have measured serum VEGF using an enzyme linked immunosorbent assay and cellular VEGF expression using flow cytometry in patients with critical limb ischemia prior to and 6 months postamputation to determine whether removal of the ischemic limb leads to changes in systemic endothelial cell function. RESULTS: Baseline VEGF levels were significantly increased in the patient group compared to controls with levels returning to control levels at 6 months postsurgery. Monocyte and neutrophil VEGF expression was significantly reduced in the patient group. Platelet expression of VEGF was also reduced but this failed to reach statistical significance. CONCLUSIONS: The results suggest that it may be useful to determine the balance between VEGF production and cellular receptor expression prior to treatment.     

Vascular endothelial growth factor and diabetic nephropathy

The field of vascular endothelial growth factor (VEGF) has recently witnessed a surge of research into its role in diabetic kidney disease. Based on its credentials as a potent inducer of vasopermeability and angiogenesis, podocyte-derived VEGF is believed to participate in the glomerular capillary hyperpermeability of macromolecules that potentially underlies the pathogenesis of diabetic albuminuria. The evidence for VEGF’s role is relatively straightforward in animal models of diabetes, establishing that VEGF is upregulated in the diabetic kidney, that VEGF alone reproduces some aspects of diabetic glomerulopathy, and that antagonism of VEGF attenuates diabetic albuminuria and other associated features of the podocytopathy. However, the promise shown in the animal studies has not carried over as convincingly into the realm of human studies, as some investigators find a negative or no relationship between VEGF and diabetic nephropathy, whereas others find a positive correlation between the two. If VEGF does play a role in diabetic renal disease, its observed effects and known mechanisms seem to point squarely at the podocyte as a central target of the maladaptive VEGF overactivity.     

Vascular endothelial growth factor and vascular homeostasis

Vascular endothelial growth factor (VEGF) is the angiogenic factor promoting and orchestrating most, if not all, processes of neovascularization taking place in the embryo and the adult. VEGF is also required to sustain newly formed vessels and plays additional multiple roles in the maintenance and function of certain mature vascular beds. Correspondingly, perturbations in VEGF signaling may impact organ homeostasis in multiple ways. Here we briefly review potential consequences of VEGF loss of function in adult organs. Different vascular beds display highly variable dependencies on VEGF for survival, and its loss of function may trigger the regression of many VEGF-dependent vasculatures. Normal turnover of blood vessels, in conjunction with the fact that VEGF is indispensable for compensatory angiogenesis to restore adequate perfusion, accounts for progressive vascular rarefaction under conditions of chronic VEGF inhibition of even vasculatures that are not intrinsically dependent on VEGF. Because blood vessels may have paracrine functions other than their traditional role in tissue perfusion, vascular regression resulting from VEGF withdrawal may cause substantial collateral tissue damage. VEGF may also impact tissue homeostasis via acting directly on nonvascular cells expressing cognate receptors. In the particular case of the lung, constitutive abundant expression of VEGF together with the fact that its receptors are distributed on both endothelial and epithelial cells is compatible with multiple homeostatic VEGF functions in the adult lung. Indeed, experimental inhibition of VEGF in the mature lung produces lesions resembling common lung pathologies, including emphysema and respiratory distress syndrome.     

Vascular endothelial growth factor in colorectal cancer

Background Angiogenesis plays an important role in colorectal cancer progression. Evidence from preclinical and clinical studies indicates that vascular endothelial growth factor (VEGF) is the predominant angiogenic factor in human colorectal cancer and is associated with formation of metastases and poor prognosis. Based on these results it was hypothesized that attacking one or more of the VEGF-mediated mechanisms may be promising in the treatment of colorectal cancer.Aims This article reviews the role of VEGF in colon cancer and summarizes recent advances in the treatment of colorectal cancer by anti-VEGF strategies.M. Guba and H. Seeliger contributed equally to this paper     

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。     

Vascular endothelial growth factor and hypertrophic osteoarthropathy

OBJECTIVE: Hypertrophic osteoarthropathy (HOA) is characterized by the coexistence of digital clubbing and periosteal proliferation of the tubular bones. Localized vascular proliferation associated with platelet/endothelial cell activation are recognized features of this syndrome. Current knowledge suggests that HOA develops from the presence in the systemic circulation of one or more growth factors that are normally inactivated in the lungs. The nature of these purported growth factors has not yet been identified. Vascular endothelial growth factor (VEGF) has several features that may fit in with the pathogenesis of HOA. The objective of our study was to measure serum and plasma levels of VEGF in different groups of patients with HOA. METHODS: We studied 24 patients with HOA; of these, in 12 the HOA was secondary to cyanotic congenital heart disease and in 7 to lung cancer, while 5 represented primary cases. As controls we studied 28 individuals without HOA; of these, 12 were apparently healthy individuals, 7 had cyanosis secondary to chronic obstructive pulmonary disease, and 9 had lung cancer. ELISA was used to measure serum and plasma levels of VEGF. RESULTS: Plasma levels of VEGF were significantly higher in the patients with primary HOA (median 46.2; range 19.4-398.8 pg/ml) and in those with lung cancer-HOA (median 75.5; range 24.6-166.7), compared to healthy controls (median 7.4; range: 0-26.1), p < 0.05. Serum VEGF levels were higher in patients with lung cancer and HOA (median 411.4; range 164.2-959.5 pg/ml) compared with lung cancer patients without HOA (median 74.5; range 13.2-205.4), p < 0.001. CONCLUSIONS: Patients with primary HOA and those with HOA and lung cancer have increased circulating levels of VEGF. This cytokine may play a role in the pathogenesis of HOA.     

血管内皮生长因子与支气管哮喘

血管内皮生长因子(VEGF),又称血管渗透因子(VPF),是一种广泛存在于机体组织的细胞因子,参与体内多种疾病过程,本文就VEGF的生物学特性及其与支气管哮喘的关系进行综述。     

山茱萸环烯醚萜苷对局灶性脑缺血大鼠血管内皮生长因子及其受体表达的影响

目的研究山茱萸环烯醚萜苷（CIG）对局灶性脑缺血大鼠神经功能和血管内皮细胞生长因子（VEGF）及其受体FLK-1表达的影响。方法取成年雄性SD大鼠115只,随机分为假手术组、模型组及CIG治疗组。治疗组又分为20、60和180mg／kg剂量组,每组23只大鼠。采用大脑中动脉线栓法制作大鼠局灶性脑缺血模型,造模后3h开始灌胃给药。造模后7、14和28d,采用改良神经功能缺损评分（mNSS）评价大鼠的神经功能,用免疫组化法和Western Blot法检测VEGF蛋白表达。用RT—PCR方法检测VEGF及其受体FLK-1的mRNA表达。结果①造模后7、14和28d,与模型组相比,CIG 60和180mg／kg组大鼠mNSS均显著降低（F=2．832,F=4．970,F=2．661,均P〈0．05）;②造模后7d,模型组大鼠大脑皮质VEGF蛋白与假手术组相比无明显变化,14和28d时,VEGF蛋白表达降低;与模型组相比,7、14和28d时,CIG 60和180mg／kg组VEGF蛋白表达显著增加（F=1．202,F=1．705,F=2．189,均P〈0．05）;③造模后28d,CIG 60和180mg／kg组大鼠VEGF阳性细胞染色面积显著增加（F=13．249,均P〈0．05）;④造模后7d,与模型组相比,CIG 60和180mg／kg组大鼠大脑皮质VEGF-mRNA表达亦显著增加（F=2．389,均P〈0．05）;CIG 60和180mg／kg组FLK-1 mRNA的表达也显著增加（F=3．657,均P〈0．05）。结论CIG能明显改善局灶性脑缺血大鼠的神经功能,其机制可能与CIG促进VEGF蛋白的表达有关。     

Vascular endothelial growth factor in inflammatory bowel disease

BACKGROUND AND AIMS: Angiogenesis is an important component of tissue regeneration. As Inflammatory bowel disease (IBD) involves inflammation, ulceration, and regeneration of the intestinal mucosa, angiogenesis may be an integral part of IBD pathology. This study investigated the role of vascular endothelial growth factor in IBD. PATIENTS AND METHODS: The VEGF plasma (pVEGF) and serum (sVEGF) levels were assessed in patients with ulcerative colitis (UC; n=50) or Crohn's disease (CD; n=44) and in healthy controls (n=23). The immunohistochemical expression of VEGF was also assessed in surgical material from 11 patients with active IBD. RESULTS. Overall the sVEGF levels ranged from 30-899 pg/ml (median 200 pg/ml) and were significantly higher than the pVEGF levels (range 20-80 pg/ml, median 30 pg/ml). pVEGF levels were significantly lower in patients with active and quiescent CD than in healthy controls. Despite the lower pVEGF levels noted also for patients with UC, the difference was not significant. sVEGF levels were also reduced in patients with IBD, but the difference was not significant. No association of pEGF/sVEGF with beta-thromboglobulin and platelet factor 4 levels (markers of platelet activation) was noted. On immunohistochemistry VEGF was not expressed in the inflammatory component (lymphocytes and macrophages), the fibroblasts, or the muscular layer of the intestinal wall. The intestinal epithelium was negative in CD, while a cytoplasmic reactivity was noted in UC and normal controls. CONCLUSION. As VEGF is a vascular and epithelial cell survival factor, the defective VEGF response ability, confirmed here for patients with CD, may be a key element in the pathology of the disease. The pathology of UC, however, seems not to be VEGF dependent.     

Vascular endothelial growth factor in pleural fluid.

STUDY OBJECTIVES: The purpose of this study was to analyze the relationship of the pleural fluid vascular endothelial growth factor (VEGF) level with the diagnostic category and with the pleural fluid characteristics in a group of 70 patients. DESIGN: The VEGF levels of consecutive patients undergoing therapeutic thoracentesis were determined with an enzyme-linked immunosorbent assay. SETTING: University-affiliated tertiary care center. RESULTS: The median level of pleural fluid VEGF in the patients with congestive heart failure (150 pg/mL) was significantly (p < 0.05) lower than the median level in the patients with coronary artery bypass grafting (357 pg/mL), which in turn was significantly lower (p < 0.05) than the median levels in the patients with malignancy (1,097 pg/mL). The overlap between groups, however, limits the diagnostic usefulness of pleural fluid VEGF levels. The VEGF level was most closely correlated with the lactate dehydrogenase level (r = 0.42, p < 0.001) and was also significantly correlated with the total pleural fluid protein level. The median VEGF levels in the pleural fluid of patients with breast cancer were significantly lower (p = 0.017) than in those with lung cancer. The VEGF level was very high (3,294 pg/mL) in the one patient with pulmonary embolism. CONCLUSIONS: We conclude that the VEGF levels in pleural fluid differ significantly from one diagnostic category to another with the highest median levels occurring in patients with malignant pleural effusions. We speculate that VEGF may be responsible for the pleural fluid accumulation in at least some situations.     

Vascular endothelial growth factor in Henoch-Schonlein purpura.

OBJECTIVE: To investigate the possible role of vascular endothelial growth factor (VEGF) in the pathogenesis of Henoch-Schonlein purpura (IHSP). METHODS: Plasma VEGF levels were determined in 22 children by ELISA. Ten age matched healthy children served as controls. VEGF expression was evaluated by immunohistochemistry within the cutaneous vasculitic lesion as well as the nonaffected skin and in the skin specimens during the resolution of the disease. RESULTS. Plasma VEGF levels in pg/ml (mean +/- SE) were significantly higher during the acute phase (407.8 +/- 64.92) when compared with the levels seen during the resolution phase (202.17 +/- 26.6; p < 0.002) and in healthy controls (135 +/- 22.8; p < 0.001). Analysis showed that there was a correlation with erythrocyte sedimentation rate. C-reactive protein, white blood cell and platelet count. In all skin specimens, the intensity of the staining of VEGF in the epidermis, dermis, and vascular endothelial bed were evaluated and scored from (+) to (++++). VEGF expression in the epidermis and the vascular bed was more intense in resolving lesions compared with acute vasculitic lesions (p < 0.05). CONCLUSION: Our results suggest that as a potent permeability, chemotactic, and migratory factor, VEGF may play a crucial role in the morphological and functional changes of the vascular bed and inflammatory reaction in HSP.     

Vascular endothelial growth factor in human lung transplantation

STUDY OBJECTIVES: To determine levels of the vascular endothelial growth factor (VEGF) isoform consisting of 165 amino acids (VEGF(165)) in BAL fluid (BALF) from lung transplant recipients (LTXs). DESIGN: Bronchoscopy with BAL was performed on LTXs and normal volunteers (NVs). SETTING: University hospital. PARTICIPANTS: LTXs (n = 57) and NVs (n = 15). MEASUREMENTS AND RESULT: VEGF(165) concentrations in BALF were higher (mean +/- SEM, 240 +/- 32 pg/mL) for NVs (n = 15) vs 133 +/- 14 pg/mL for LTXs (n = 37) who were stable without evidence of significant rejection or infection at 6 months after transplantation (p < 0.0001). BALF VEGF concentrations sampled at 24 to 48 h, 2 weeks, 4 weeks, and 6 months after transplantation for 11 LTXs who lacked rejection or infection at any time point were 71 +/- 8 pg/mL, 80 +/- 20 pg/mL, 82 +/- 13 pg/mL, and 167 +/- 31 pg/mL, respectively. VEGF concentrations in BALF for LTXs with cytomegalovirus (CMV) pneumonia were 55 +/- 12 pg/mL (n = 10), 117 +/- 33 pg/mL for grade A3 acute rejection (n = 9), and 82 +/- 17 pg/mL (n = 14) for active bronchiolitis obliterans syndrome (BOS). Concentrations of VEGF in BALF at 6 months for the 32 stable recipients with bilateral lung transplantation were significantly higher for those with higher values for FEV(1), and BALF VEGF concentrations were significantly lower in BALF at 6 months for those recipients who subsequently went on to develop BOS (86 +/- 19 pg/mL) vs those who did not (158 +/- 18 pg/mL; p = 0.03). Serum concentrations of VEGF did not correlate with VEGF concentrations in BALF, but serum VEGF was 291 +/- 62 pg/mL at 10 to 14 days after transplantation vs 130 +/- 20 pg/mL at 4 weeks for nine LTXs with paired samples (p < 0.02). Serum VEGF concentrations for NVs (n = 15) were 102 +/- 15 pg/mL vs 94 +/- 17 for stable LTXs (n = 12) at 24 weeks after transplantation and 123 +/- 33 pg/mL for LTXs with active BOS (n = 10). CONCLUSIONS: BALF VEGF concentrations are particularly depressed at early time points following lung transplantation, gradually improve in the absence of significant rejection or infection, and are lower with active rejection or CMV pneumonia.