scholarly journals Assessment of Vascular Endothelial Growth Factor in Fresh versus Frozen Platelet Rich Plasma

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Nada Hosny ◽  
Fikry Goubran ◽  
Basma BadrEldin Hasan ◽  
Noha Kamel
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Calcium Gluconate ◽  
Platelet Rich Plasma ◽  
Vascular Endothelial ◽  
High Concentration ◽  
Significant Difference ◽  
Growth Factor Release ◽  
Endothelial Growth Factor ◽  
Vegf Release

Platelet rich plasma (PRP) is hemoconcentration with platelets concentration above baseline values and high concentration of many growth factors. The aim of this study was to assess freezing effect on vascular endothelial growth factor (VEGF) release from PRP using two different activation methods to simplify its use in different clinical applications. PRP was prepared using two-centrifugation steps method from 12 qualified blood donors. VEGF concentrations were measured in fresh PRP and after freezing/thawing for one and three weeks with two methods of activation using (i) calcium gluconate and (ii) calcium gluconate and thrombin. Platelets count was significantly increased compared to baseline whole blood values in all fresh and frozen PRP samples (p value was <0.05). No significant difference was found between VEGF concentrations after activating fresh and frozen-thawed PRP samples for one and three weeks by calcium alone or calcium with thrombin, and also no significant difference was found when freezing period was extended from one to three weeks. Our results showed that platelets count does not correlate with variable levels of VEGF. PRP could be prepared once and preserved frozen for at least three weeks for the next treatment sessions and activation with thrombin addition to calcium will not augment the growth factor release.

scholarly journals HSP22 (HSPB8) positively regulates PGF2α-induced synthesis of interleukin-6 and vascular endothelial growth factor in osteoblasts

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Gen Kuroyanagi ◽  
Go Sakai ◽  
Takanobu Otsuka ◽  
Naohiro Yamamoto ◽  
Kazuhiko Fujita ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Map Kinase ◽  
Interleukin 6 ◽  
Prostaglandin F2α ◽  
P38 Map Kinase ◽  
Vascular Endothelial ◽  
Mitogen Activated Protein ◽  
Endothelial Growth Factor ◽  
Vegf Release

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.

scholarly journals The VAD Scheme versus Thalidomide plus VAD for Reduction of Vascular Endothelial Growth Factor in Multiple Myeloma: A Meta-Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-8
Author(s):  
Gan-Lin He ◽  
Duo-Rong Xu ◽  
Wai-Yi Zou ◽  
Sui-Zhi He ◽  
Juan Li
Keyword(s):  
Multiple Myeloma ◽  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Meta Analysis ◽  
Biomedical Literature ◽  
Cochrane Library ◽  
Vascular Endothelial ◽  
China National Knowledge Infrastructure ◽  
Significant Difference ◽  
Endothelial Growth Factor

The VAD (vincristine-doxorubicin-dexamethasone) regimen has been used for decades to treat multiple myeloma (MM). Based on reports that vascular endothelial growth factor- (VEGF-) mediated angiogenesis is critical for MM pathogenesis, the antiangiogenic compound thalidomide has been added to VAD (T-VAD). However, it remains unclear whether T-VAD is more efficacious than VAD for serum VEGF reduction or if the difference influences clinical outcome. Pubmed, Cochrane library, China Biomedical Literature (CBM) database, China National Knowledge Infrastructure (CNKI) database, Vip database, and Wanfang database were searched for relevant studies published up to June 2017. RevMan5.2 was used for methodological quality evaluation and data extraction. Thirteen trials (five randomized, seven nonrandomized, and one historically controlled) involving 815 cases were included. Serum VEGF was significantly higher in MM cases than non-MM controls (MD=353.01, [95%CI 187.52–518.51], P<0.01), and the overall efficacy of T-VAD was higher than that of VAD (RR=1.36, [1.21–1.53], P <0.01). Further, T-VAD reduced VEGF to a greater extent than VAD does ([MD=-49.85, [-66.28− -33.42], P<0.01). The T-VAD regimen also reduced VEGF to a greater extent in newly diagnosed MM patients than it did in recurrent patients ([MD=-120.20, [-164.60–-39.80], P<0.01). There was no significant difference in VEGF between T-VAD patients (2 courses) and nontumor controls (MD=175.94, [-26.08–377.95], P=0.09). Greater serum VEGF reduction may be responsible for the superior efficacy of T-VAD compared to VAD.

Abstract 326: Granzyme B Releases Vascular Endothelial Growth Factor from Extracellular Matrix Stores and Induces Vascular Permeability in vivo

2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Alon Hendel ◽  
David J Granville
Keyword(s):  
Extracellular Matrix ◽  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Vascular Permeability ◽  
Chronic Inflammation ◽  
Granzyme B ◽  
Vascular Endothelial ◽  
Endothelial Growth Factor ◽  
Vegf Release

Introduction The formation of unstable and leaky neovessels underlies the pathogenesis of a large number of chronic inflammatory diseases. Granzyme B (GZMB) is a serine protease that is expressed and released by a variety of immune cells and accumulates in the extracellular matrix (ECM) during chronic inflammation where it cleaves a number of ECM proteins, including fibronectin (FN). Vascular endothelial growth factor (VEGF) is a potent vascular permeabilizing agent that is sequestered in the ECM by binding FN in both normal and diseased tissue. We hypothesize that GZMB cleavage of FN will release VEGF from its extracellular stores and promote vascular permeability as a mechanism that contributes to neovessel leakage during chronic inflammation. Methods GZMB-mediated VEGF release from either FN coated wells or endogenously produce endothelial cell (EC) matrix was measured by VEGF ELISA. VEGF-release supernatants were used to treat EC and VEGF receptor 2 (VEGFR2) activation was evaluated by immunoblotting for phosphorylated VEGFR2. Evan’s blue was injected intravenously to CD1 mice followed by ear injection of either mouse GZMB, saline control, GZMB + neutralizing mouse VEGF antibody or GZMB+ IgG control (n=5 for each experimental group). Vascular leakage was evaluated by Evan’s blue dye extraction. Results GZMB effectively releases VEGF from both FN and from EC matrix, while inhibition of GZMB prevented VEGF release. GZMB-mediated VEGF release resulted in significant activation of VEGFR2 in EC monolayer signified by increased VEGFR2 phosphorylation. GZMB ear injection resulted in a significant increase in vascular permeability in vivo. Importantly, co-injection of GZMB and neutralizing mouse VEGF antibody significantly reduced vascular leakage compared to co-injection of GZMB and matching IgG control. Conclusions and Impact GZMB increases VEGF bioavailability by releasing it from the ECM leading to VEGFR2 activation and increased vascular permeability in vivo. These findings present a novel role for GZMB as a modulator of vascular response during chronic inflammation.

In vitro release of vascular endothelial growth factor during platelet aggregation

1998 ◽  
Vol 275 (3) ◽  
pp. H1054-H1061 ◽  
Author(s):  
James P. Maloney ◽  
Christopher C. Silliman ◽  
Daniel R. Ambruso ◽  
Jun Wang ◽  
Rubin M. Tuder ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Platelet Aggregation ◽  
Growth Factor ◽  
Platelet Rich Plasma ◽  
In Vitro Release ◽  
Endothelial Permeability ◽  
Vascular Endothelial ◽  
Vessel Injury ◽  
Endothelial Growth Factor

Platelet aggregation is a cardinal feature of both vascular repair and vascular disease. During aggregation platelets release a variety of vasoactive substances; some of these promote angiogenesis, endothelial permeability, and endothelial growth, actions shared by vascular endothelial growth factor (VEGF). This study was undertaken to investigate the hypothesis that VEGF is released by aggregating platelets. We found that VEGF was secreted during the in vitro aggregation of platelet-rich plasma induced by thrombin, collagen, epinephrine, and ADP (range 23–518 pg VEGF/ml). Furthermore, serum VEGF levels were elevated compared with plasma (230 ± 63 vs. 38 ± 8 pg VEGF/ml), indicative of VEGF release during whole blood coagulation. Lysates of apheresed, leukocyte-poor platelet units contained significant amounts of VEGF (2.4 ± 0.8 pg VEGF/mg protein). VEGF message and protein were also present in a megakaryocytic cell line (Dami cell). These results suggest constitutive roles for platelet VEGF in the repair of intimal vessel injury and in the altered permeability and intimal proliferation seen at sites of platelet aggregation and thrombosis.

Measurement of free and complexed soluble vascular endothelial growth factor receptor, Flt-1, in fluid samples: development and application of two new immunoassays

2001 ◽  
Vol 100 (5) ◽  
pp. 567-575 ◽  
Author(s):  
Funmi M. BELGORE ◽  
Andrew D. BLANN ◽  
Gregory Y. LIP
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Endothelial Cell ◽  
Growth Factor ◽  
Plasma Levels ◽  
Biological Significance ◽  
Growth Factor Receptor ◽  
Soluble Form ◽  
Vascular Endothelial ◽  
Significant Difference ◽  
Endothelial Growth Factor

Vascular endothelial growth factor (VEGF) mediates endothelial cell mitogenesis and enhances vascular permeability. VEGF interacts with the endothelium via two membrane-spanning receptors, fms-like tyrosine kinase (Flt)-1 and kinase domain receptor. A soluble form of Flt-1 (sFlt-1) was isolated from endothelial cell media; however, its biological significance is still unknown, with limited data on plasma sFlt-1 levels in disease states. We have developed two new ELISAs for detecting free and VEGF-complexed sFlt-1, which were tested in accordance with standard validation and assessment methodologies employed in commercial settings. The intra-and inter-assay coefficients of variation are < 5% and 10% respectively, and results are highly reproducible. Applying these ELISAs in a clinical setting, we measured levels of VEGF, free and complexed sFlt-1 in citrated plasma from 40 patients with cardiovascular disease and 40 healthy controls. Median (interquartile range) plasma levels of VEGF in patients were significantly greater than controls [403 pg/ml (158–925 pg/ml) versus 113 pg/ml (33–231 pg/ml), P ⩽ 0.05]. Free sFlt-1 was significantly lower in patients compared with controls [8 ng/ml (2–22 ng/ml) versus 21 ng/ml (10–73 ng/ml), P ⩽ 0.05]. There was no significant difference in the levels of complexed sFlt-1 between the two groups. Plasma levels of VEGF-complexed sFlt-1 are minimal, despite the presence of excess free sFlt-1. Thus unbound plasma VEGF detected by ELISA may represent the majority of circulating VEGF, and justifies the measurement of plasma VEGF as an indicator of circulating VEGF levels. Furthermore, these results suggest that circulating sFlt-1 may serve as a selective inhibitor of VEGF activity, and that this regulatory mechanism may be altered by pathological conditions.

scholarly journals Sublytic Membrane-Attack-Complex (MAC) Activation Alters Regulated Rather than Constitutive Vascular Endothelial Growth Factor (VEGF) Secretion in Retinal Pigment Epithelium Monolayers

2011 ◽  
Vol 286 (27) ◽  
pp. 23717-23724 ◽  
Author(s):  
Kannan Kunchithapautham ◽  
Bärbel Rohrer
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Complement Activation ◽  
Retinal Pigment ◽  
Age Related Macular Degeneration ◽  
Vascular Endothelial ◽  
Vegf Expression ◽  
Age Related ◽  
Endothelial Growth Factor ◽  
Vegf Release

Uncontrolled activation of the alternative complement pathway and secretion of vascular endothelial growth factor (VEGF) are thought to be associated with age-related macular degeneration (AMD). Previously, we have shown that in RPE monolayers, oxidative-stress reduced complement inhibition on the cell surface. The resulting increased level of sublytic complement activation resulted in VEGF release, which disrupted the barrier facility of these cells as determined by transepithelial resistance (TER) measurements. Induced rather than basal VEGF release in RPE is thought to be controlled by different mechanisms, including voltage-dependent calcium channel (VDCC) activation and mitogen-activated protein kinases. Here we examined the potential intracellular links between sublytic complement activation and VEGF release in RPE cells challenged with H2O2 and complement-sufficient normal human serum (NHS). Disruption of barrier function by H2O2 + NHS rapidly increased Ras expression and Erk and Src phosphorylation, but had no effect on P38 phosphorylation. Either treatment alone had little effect. TER reduction could be attenuated by inhibiting Ras, Erk and Src activation, or blocking VDCC or VEGF-R2 activation, but not by inhibiting P38. Combinatorial analysis of inhibitor effects demonstrated that sublytic complement activation triggers VEGF secretion via two pathways, Src and Ras-Erk, with the latter being amplified by VEGF-R2 activation, but has no effect on constitutive VEGF secretion mediated via P38. Finally, effects on TER were directly correlated with release of VEGF; and sublytic MAC activation decreased levels of zfp36, a negative modulator of VEGF transcription, resulting in increased VEGF expression. Taken together, identifying how sublytic MAC induces VEGF expression and secretion might offer opportunities to selectively inhibit pathological VEGF release only.

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