Vascular Endothelial Growth Factor (VEGF) is Released from Platelets during Blood Clotting: Implications for Measurement of Circulating VEGF Levels in Clinical Disease

1998 ◽  
Vol 94 (4) ◽  
pp. 395-404 ◽  
Author(s):  
Nicholas J. A. Webb ◽  
Martyn J. Bottomley ◽  
Carolyn J. Watson ◽  
Paul E. C. Brenchley

1. Dysregulated vascular endothelial growth factor (VEGF) expression has been reported in several pathological states based upon evidence of elevated serum VEGF levels. Using two immunoassays for VEGF, this study determines normal plasma and serum VEGF ranges, determines which are more likely to reflect circulating VEGF levels and investigates a potential contribution of VEGF from platelets to VEGF levels detected in serum. 2. The presence of soluble VEGF receptor, sflt-1, at a molar excess of 7:1 significantly reduced measured VEGF levels in both assays. Serum VEGF levels were higher than plasma levels in children [(mean ± S.E.M.) 306.1 ± 39.4 versus 107.4 ± 24.9 pg/ml, P < 0.0001] and adults (249.4 ± 46.4 versus 76.1 ± 10.7 pg/ml, P < 0.0001). Serum VEGF increased with clotting time (P = 0.0005 t0 compared with 2 h samples); plasma VEGF levels were not affected by time between sampling and centrifugation. 3. Calcium-induced clotting of platelet-rich but not platelet-poor plasma induced VEGF release with a proportional response between platelet count and VEGF level and isolated platelets released significant quantities of VEGF upon incubation with thrombin. Reverse transcriptase—PCR studies confirmed that platelets express VEGF121 and VEGF165 mRNA. 4. These data suggest that plasma is the preferred medium to measure VEGF levels; a significant and highly variable platelet-mediated secretion of VEGF during the clotting process invalidates the use of serum as an indicator of circulating VEGF levels in disease states.

2013 ◽  
Vol 5 (1) ◽  
pp. e2013044 ◽  
Author(s):  
Sameh Samir Fahmey ◽  
Hassan Naguib ◽  
Sanna Abdelshafy ◽  
Rasha Alashry

Background: The β-Thalassemia syndromes are the most common hereditary chronic hemolytic anemia due to impaired globin chain synthesis.  Vascular endothelial growth factor (VEGF) plays several roles in angiogenesis which is a crucial process in the pathogenesis of several inflammatory, autoimmune and malignant diseases .Endothelial damage and inflammation make a significant contribution to the pathophysiology of β-thalassemia. Purpose: The aim of the study was to assess serum VEGF level in children with beta-thalassemia major as a marker of angiogenesis. Methods: Blood samples were collected from 40 patients with thalassemia major and 10 healthy controls and assayed for VEGF by enzyme-linked immunosorbent assay. Results: VEGF level was significantly higher in patients with β-Thalassemia major than healthy controls (p=0.001).In addition, VEGF level was higher in splenectomised thalassemic patients than non splenectomised ones (p=0.001) .However, there were a positive correlation between VEGF and chelation starting age (p=0.008) and a negative correlation between VEGF and frequency of blood transfusion (p=0.002). Conclusion: thalassemia patients, especially splenectomized, have elevated serum levels of VEGF. Early chelation and regular blood transfusion help to decrease serum VEGF and the risk of angiogenesis.  


2017 ◽  
Vol 40 (2) ◽  
pp. 40 ◽  
Author(s):  
Hongliang Shen ◽  
Qingjun Liu ◽  
Mingyi Li ◽  
Peiqian Yang

Objective: Vascular endothelial growth factor (VEGF) serum level or tumor expression may be prognostic in renal cell carcinoma (RCC). The purpose of this meta-analysis was to examine the prognostic value of serum VEGF level and tumor expression in patients with RCC. Methods: PubMed and EMBASE databases were searched until September 26, 2016. Prospective and retrospective studies of RCC patients that had VEGF levels measured were included. Outcome measures were overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS). Results: A total of 14 studies were included in the meta-analysis. In patients with RCC, elevated serum VEGF level was not associated with OS (pooled hazard ratio [HR] = 1.16; 95% confidence interval [CI]: 0.52 to 2.60; p = 0.716), but was associated with poor DSS (pooled HR = 4.22; 95% CI: 2.02 to 8.79; p < 0.001) and PFS (pooled HR = 1.50; 95% CI: 1.22 to 1.85; p < 0.001). Removal of one study, however, resulted in elevated serum level being associated with poorer OS. Tumor VEGF expression was not associated with OS (pooled HR = 1.48; 95% CI: 0.74 to 2.95; p = 0.263), but was associated with worse DSS (pooled HR = 1.83; 95% CI: 1.24 to 2.71; p = 0.003). Conclusion: In patients with RCC, elevated serum VEGF level is associated with worse OS, DSS, and PFS, while tumor expression is only associated with worse DSS. The number of studies, however, was limited and the results should be interpreted with caution.


2014 ◽  
Vol 99 (3) ◽  
pp. 978-987 ◽  
Author(s):  
Tracey L. Weissgerber ◽  
Augustine Rajakumar ◽  
Ashley C. Myerski ◽  
Lia R. Edmunds ◽  
Robert W. Powers ◽  
...  

Context: Research examining the source of excess soluble fms-like tyrosine kinase 1 (sFLT1) in preeclampsia has focused on the placenta. The potential contribution of the releasable store of sFLT1 in the systemic vasculature is unknown. Objective: We asked whether the nonplacental releasable store of sFLT1 is larger in women with previous preeclampsia than in women with a previous uncomplicated pregnancy. Design: We administered heparin to nulligravid women and to women with previous preeclampsia or a previous uncomplicated pregnancy. We compared post-heparin sFLT1 concentrations with those observed in uncomplicated pregnancy and preeclampsia. Setting: The study was performed at Magee-Womens Hospital. Patients: Participants included nulligravidas (n = 8), women 6–24 months postpartum (previous uncomplicated pregnancy, n = 16; previous preeclampsia, n = 15), and pregnant women (uncomplicated pregnancy, n = 30; preeclampsia, n = 25). Intervention: Nonpregnant women received an unfractionated heparin bolus. Main Outcome Measures: Pre- and post-heparin plasma sFLT1, placental growth factor, and vascular endothelial growth factor were measured. Results: In nonpregnant women, heparin increased plasma sFLT1 by 250-fold (P &lt; .01), increased placental growth factor by 7-fold (P &lt; .01), and decreased free vascular endothelial growth factor (P &lt; .01). These changes did not differ between nulligravidas, women with previous preeclampsia, and women with a previous uncomplicated pregnancy. Post-heparin sFLT1 in nonpregnant women was higher than sFLT1 in uncomplicated pregnancy, but lower than sFLT1 in preeclampsia. Baseline and post-heparin sFLT1 were positively correlated (r2 = 0.19; P &lt; .01). Heparin increased the concentration of the 100-kDa sFLT1 isoform. Adding heparin to whole blood or plasma did not increase sFLT1. Conclusions: Nonpregnant women have a significant vascular store of releasable sFLT1. The size of this store does not differ between women with previous preeclampsia vs women with previous uncomplicated pregnancy.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Gen Kuroyanagi ◽  
Go Sakai ◽  
Takanobu Otsuka ◽  
Naohiro Yamamoto ◽  
Kazuhiko Fujita ◽  
...  

Abstract Background Heat shock protein 22 (HSP22) belongs to class I of the small HSP family that displays ubiquitous expression in osteoblasts. We previously demonstrated that prostaglandin F2α (PGF2α), a potent bone remodeling factor, induces the synthesis of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) via p44/p42 mitogen-activated protein (MAP) kinase and p38 MAP kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated whether HSP22 is implicated in the PGF2α-induced synthesis of IL-6 and VEGF and the mechanism of MC3T3-E1 cells. Methods MC3T3-E1 cells were transfected with HSP22-siRNA. IL-6 and VEGF release was assessed by ELISA. Phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was detected by Western blotting. Results The PGF2α-induced release of IL-6 in HSP22 knockdown cells was significantly suppressed compared with that in the control cells. HSP22 knockdown also reduced the VEGF release by PGF2α. Phosphorylation of p44/p42 MAP kinase and p38 MAP kinase was attenuated by HSP22 downregulation. Conclusions Our results strongly suggest that HSP22 acts as a positive regulator in the PGF2α-induced synthesis of IL-6 and VEGF in osteoblasts.


2004 ◽  
Vol 286 (3) ◽  
pp. L539-L545 ◽  
Author(s):  
Altaf S. Kazi ◽  
Shidan Lotfi ◽  
Elena A. Goncharova ◽  
Omar Tliba ◽  
Yassine Amrani ◽  
...  

In severe asthma, cytokines and growth factors contribute to the proliferation of smooth muscle cells and blood vessels, and to the increased extracellular matrix deposition that constitutes the process of airway remodeling. Vascular endothelial growth factor (VEGF), which regulates vascular permeability and angiogenesis, also modulates the function of nonendothelial cell types. In this study, we demonstrate that VEGF induces fibronectin secretion by human airway smooth muscle (ASM) cells. In addition, stimulation of ASM with VEGF activates ERK, but not p38MAPK, and fibronectin secretion is ERK dependent. Both ERK activation and fibronectin secretion appear to be mediated through the VEGF receptor flt-1, as evidenced by the effects of the flt-1-specific ligand placenta growth factor. Finally, we demonstrate that ASM cells constitutively secrete VEGF, which is increased in response to PDGF, transforming growth factor-β, IL-1β, and PGE2. We conclude that ASM-derived VEGF, through modulation of the extracellular matrix, may play an important role in airway remodeling seen in asthma.


2011 ◽  
Vol 4 ◽  
pp. CGM.S7113 ◽  
Author(s):  
Ozgur Kemik ◽  
Ahu Sarbay Kemik ◽  
Aziz Sümer ◽  
Sevim Purisa ◽  
A. Cumhur Dulger ◽  
...  

Background The aim of the present study was to determine whether serum vascular endothelial growth factor (VEGF) can provide prognostic information independent of carcinoembryonic antigen levels in patients undergoing curative surgery. Methods Serum samples were collected from 158 patients with colorectal cancer and from 100 controls. Serum and tissue levels of VEGF were measured by enzyme-linked immunosorbent assay. Serum VEGF levels in colorectal cancer patients were compared with those in healthy controls, and we retrospectively assessed the association between serum VEGF levels and clinicopathologic findings and survival. Results VEGF expression was significantly higher in colorectal cancer tissue compared with nontumor tissue. Mean serum VEGF levels in patients were significantly higher than those in controls, and significantly higher in patients with large tumors, lymph node involvement, and distant metastases. Conclusion Elevated serum VEGF was significantly associated with poor survival, but was only an independent risk factor for poor survival in Stage II and/or III disease. Elevated serum VEGF is significantly associated with development of colorectal cancer, and lymph or distant invasive phenotypes and survival, especially in Stage II and III patients.


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