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Publication
Journal: Biomaterials
October/23/2006
Abstract
The pro-angiogenic cytokine <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) has been implicated in periprosthetic osteolysis and subsequent aseptic loosening of implants following total hip arthroplasty (THA). The goal of this study was to investigate whether increased VEGF at the bone-implant interface is secondary to a greater number of VEGF-producing cells or to increased VEGF production by individual cells. Real time polymerase chain reaction (RT-PCR) techniques were used to assess the expression of VEGF mRNA (isoforms <em>121</em>, 165, 189) in periprosthetic tissues from revision THAs. Immunofluorescence was used to determine both differences in overall cellularity and in VEGF-producing cell type (macrophages, fibroblasts, <em>endothelial</em> cells) between patients with periprosthetic osteolysis (OL) and a control group undergoing primary THA for osteoarthritis (OA). Quantitative analysis of VEGF release in periprosthetic membranes via RT-PCR demonstrated no significant difference in the per-cell mRNA production of VEGF isoforms <em>121</em> 165, or 189 between OL and OA patient groups. Immunofluorescence showed both higher cellularity and higher overall VEGF expression in the OL group. Immunofluorescence also showed a significant increase in macrophages in the OL group, but no significant difference in the proportion of fibroblasts or <em>endothelial</em> cells between the OL and OA groups. Co-localization of CD68+ and CD11b+ macrophage fluorescent signals with VEGF signal was greater in the OL group than in the OA group. Our results demonstrate that increased VEGF in OL periprosthetic tissue compared to OA synovium is correlated to increased numbers of VEGF-producing CD68+ and CD11b+ macrophages. Impact statement: Aseptic loosening, caused in large part by OL, remains the major cause of failed THAs leading to revision surgery. At the bone-implant interface, we found increased numbers of macrophages-cellular mediators of OL-and increased VEGF expression. VEGF may be a possible target for therapeutic intervention in mitigating OL.
Publication
Journal: American Journal of Physiology - Renal Physiology
January/4/2007
Abstract
Renal micro<em>vascular</em> injury and tubulointerstitial inflammation may provide a potential mechanism for the development of salt-sensitive hypertension. Therefore, we hypothesized that <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) administration would prevent the development of salt-sensitive hypertension induced by ANG II. Infusion of ANG II in rats for 2 wk led to an elevation in blood pressure and an increase in blood urea nitrogen. Prominent tubular injury, focal areas of peritubular capillary loss accompanied by a decrease in urinary nitrites, thickening of the afferent arteriole, and an elevation in systemic and renal VEGF protein levels also occurred. In separate studies, animals were infused with ANG II and then placed on a low-salt diet for 1 wk. At this point, the animals were paired on the basis of weight and blood pressure and treated with either VEGF(<em>121</em>) or vehicle subcutaneously for 8 wk while being fed a high-salt diet. During the treatment period, a spontaneous improvement in many parameters, including both renal function and healing of the peritubular capillaries, occurred to the same degree in both vehicle- and VEGF(<em>121</em>)-treated rats. VEGF(<em>121</em>) significantly reduced blood pressure and accelerated the recovery of tubular injury. In contrast, vehicle-treated rats demonstrated a persistent increase in afferent arteriolar media-to-lumen ratio, which was further enhanced in rats treated with VEGF(<em>121</em>). Therefore, VEGF therapy has only limited benefits on the healing of renal lesions in the salt-dependent phase of post-ANG II-mediated hypertension.
Publication
Journal: Growth Factors
November/27/2003
Abstract
The oxygen status of the placenta during pregnancy is unclear although it has been hypothesised that in pre-eclampsia large regions of the placenta are hypoxic. Circulating levels of <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) are increased in women with pre-eclampsia, while circulating placental <em>growth</em> <em>factor</em> (PlGF) levels are decreased. We hypothesise that secreted levels of VEGF are increased in cultures of trophoblast cells under lowered oxygen conditions while secreted levels of PlGFare alternatively regulated. Primary isolates of first trimester and term cytotrophoblasts cells were cultured in 20 and 5% oxygen for 24h. There was a significant increase in the levels of VEGF secreted fromfirst trimester and term cytotrophoblast cells cultured under lowered oxygen conditions compared to the controls while there was a significant decrease in the secreted levels of PIGF in the same cell populations (as measured by ELISA). In first trimester and term trophoblast cells the presence of VEGF (<em>121</em>, 165 and 189) and PlGF (132 and 152) mRNA were demonstrated in both groups by reverse transcription-polymerase chain reaction (RT-PCR). These altered levels of secreted VEGF andPIGF may be released as compensatory molecules in the pathogenesis of diseases such as pre-eclampsia and intrauterine <em>growth</em> restriction.
Publication
Journal: Journal of Cellular Physiology
March/28/2000
Abstract
Human neonatal fibroblasts were cultured on a lactate-glycollate copolymer scaffold for 12-16 days to form a three-dimensional dermal equivalent tissue. The cellular content of <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) mRNA in these three-dimensional cultures was 22-fold greater than that observed in the same fibroblasts grown as monolayers. No induction was shown by hepatocyte <em>growth</em> <em>factor</em> (HGF) or angiopoietin 1 indicating that the effect was specific to VEGF. The predominant VEGF splice variant, detected by RT-PCR corresponded to the <em>121</em> amino acid form, with less of the 165 amino acid form. The cell-associated forms (189 and 206 amino acids) comprised less than 1% of the total VEGF mRNA. VEGF and HGF proteins, determined by ELISA, were secreted in physiologically significant amounts, 0.5-4 ng per 24 h/10(6) cells. Conditioned medium from the three-dimensional cultures stimulated proliferation of <em>endothelial</em> cells in a dose-dependent manner and induced cellular expression of integrin alpha(v)beta(3). Conditioned medium from the same dermal fibroblasts cultured in monolayer showed little angiogenic activity in any of these assays. Using the chorioallantoic membrane (CAM) angiogenesis assay, the cultures stimulated blood vessel production 2.8-fold over scaffold alone. VEGF-neutralizing antibody reduced the vessel development in the CAM to the level in the scaffold control. Anti-HGF antibody had no significant effect. In conclusion, three-dimensional cultures of dermal equivalent tissue express angiogenic activity to a greater extent than monolayer cultures, some of which can be assigned to VEGF.
Publication
Journal: Journal of Vascular Research
March/4/2009
Abstract
OBJECTIVE
Exercise training enhances vasodilatation to vascular endothelial growth factor (VEGF(165)) in collateral-dependent coronary arterioles. Interaction of VEGF receptor 2 (VEGFR-2) and the non-tyrosine-kinase receptor, neuropilin-1 has been reported to potentiate VEGF(165)-mediated signaling. In the current study, we tested the hypotheses that neuropilin-1 mediates the exercise-enhanced VEGF(165)-mediated vasodilatation in collateral-dependent arterioles and that neuropilin-1 and/or VEGFR-2 protein levels are increased in these arterioles.
METHODS
Ameroid occluders were surgically placed around the proximal left circumflex coronary artery of miniature swine. Eight weeks after surgery, the animals were randomized into sedentary or exercise training (treadmill run; 5 days/week; 14 weeks) protocols. Coronary arterioles (approximately 100 microm diameter) were isolated from both collateral-dependent and control (left anterior descending) myocardial regions and studied by in vitro videomicroscopy or frozen for immunoblot analysis.
RESULTS
Exercise-enhanced VEGF(165)-mediated vasodilatation in collateral-dependent arterioles was reversed by inhibition of the VEGF(165)-neuropilin-1 interaction. VEGF(121), which does not interact with neuropilin-1, induced similar vasodilatation in arterioles from all treatment groups. Immunoblot revealed significantly elevated VEGFR-1, VEGFR-2 and neuropilin-1 protein levels in collateral-dependent arterioles of exercise-trained pigs.
CONCLUSIONS
Neuropilin-1 plays a vital role in the exercise-enhanced VEGF(165)-mediated vasodilatation of collateral-dependent coronary arterioles and is associated with increased neuropilin-1 receptor protein levels.
Publication
Journal: Cancer Biotherapy and Radiopharmaceuticals
August/5/2009
Abstract
OBJECTIVE
Vascular endothelial growth factor-A (VEGF-A) is one of the most important factors inducing angiogenesis in tumors. Nine splice-variant isoforms of VEGF-A have been identified, each having different properties. Recently, we showed that radiolabeled anti-VEGF monoclonal antibody, bevacizumab, accumulates specifically in VEGF-A expressing tumors. In this study, we investigated in a nude mouse model which VEGF-isoforms are responsible for tumor accretion.
METHODS
The humanized anti-VEGF-A antibody, A.4.6.1. (bevacizumab), was radiolabeled with In-111. The originally VEGF-negative Mel57 tumor was transfected with different VEGF isoforms (VEGF-121, VEGF-165, and VEGF-189). The obtained melanoma xenografts specifically expressing different VEGF-isoforms were used in mice. The bevacizumab uptake was examined in biodistribution studies and by gamma-camera imaging.
RESULTS
The tumor cell line expressing VEGF-121 did not show specific uptake, most likely as a result of the fact that this isoform is freely diffusible. Tumors expressing VEGF-165 and -189 were clearly visualized by using gamma-camera imaging.
CONCLUSIONS
The accumulation of radiolabeled bevacizumab in the tumor is due to interaction with VEGF-A isoforms that are associated with the tumor cell surface and/or the extracellular matrix. Scintigraphic imaging of the expression of these VEGF isoforms may thus be useful to predict response to angiogenic therapy.
Publication
Journal: American Journal of Hypertension
August/14/2011
Abstract
BACKGROUND
Pre-eclampsia (PE) is a serious hypertensive disorder of pregnancy characterized by excessive production of a soluble form of the <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) receptor-1, termed soluble fms-like tyrosine kinase-1 (sFlt-1). This placental-derived <em>factor</em> is believed to be a key contributor to the clinical features of PE. Women with PE are also characterized by the presence of autoantibodies, termed angiotensin type 1 receptor activating autoantibody (AT(1)-AA), that activate the major angiotensin receptor, AT(1). These autoantibodies cause clinical features of PE and elevated sFlt-1 when injected into pregnant mice. The research reported here used this autoantibody-injection model of PE to assess the therapeutic potential of recombinant VEGF(<em>121</em>), a relatively stable form of the natural ligand.
METHODS
Immunoglobulin G (IgG) from women with PE was injected into pregnant mice with or without continuous infusion of recombinant VEGF(<em>121</em>). Injected mice were monitored for symptoms of PE.
RESULTS
As a result of infusion of recombinant VEGF(<em>121</em>) autoantibody-induced hypertension (systolic blood pressure) was reduced from 159 ± 5 to 124 ± 5 mm Hg, proteinuria from 111 ± 16 to 40 ± 5 mg protein/mg creatinine and blood urea nitrogen levels from 31 ± 1 mg/dl to 18 ± 2 mg/dl, P < 0.05. Histological analysis revealed that autoantibody-induced glomerular damage including the narrowing of Bowman's space and occlusion of capillary loop spaces was largely prevented by VEGF(<em>121</em>) infusion. Finally, impaired placental angiogenesis resulting from AT(1)-AA injection was significantly improved by VEGF(<em>121</em>) infusion.
CONCLUSIONS
The infusion of recombinant VEGF(<em>121</em>) significantly attenuated autoantibody-induced features of PE.
Publication
Journal: Fertility and Sterility
December/26/2005
Abstract
OBJECTIVE
To determine the effect of 17beta-estradiol, progesterone, medroxyprogesterone acetate, levonorgestrel, norethindrone, tibolone, and tibolone metabolites on <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) isoforms <em>121</em> and 165 mRNA in two breast cancer cell lines, MCF-7 (estrogen receptor rich) and T47-D (progesterone receptor rich), in vitro.
METHODS
Prospective basic research study.
METHODS
Basic research laboratory.
METHODS
None.
METHODS
MCF-7 and T47-D cells were cultured to 80% confluence in vitro. After 24 hours' incubation in serum-free media, 1.0, 0.1, and 0.01 microM of 17beta-estradiol, tibolone, 3alpha-hydroxytibolone and 3beta-hydroxytibolone were added to MCF-7 cells. Progesterone, medroxyprogesterone acetate, levonorgestrel, norethindrone, and Delta4 tibolone at 1.0, 0.1, and 0.01 microM were added to T47-D cells. The cells plus steroids were incubated for a further 24 hours.
METHODS
Isolation and identification of VEGF isoforms <em>121</em> and 165 using semiquantitative polymerase chain reaction, gel electrophoresis, with cyclophilin as an internal control.
RESULTS
17beta-estradiol, tibolone, 3alpha-hydroxytibolone, and 3beta-hydroxytibolone had no effect on VEGF mRNA in MCF-7 cells. Progesterone, medroxyprogesterone acetate, levonorgestrel, and norethindrone increased VEGF mRNA in T47-D cells. Delta4-Tibolone also increased VEGF mRNA but to a lesser extent than the progestogens.
CONCLUSIONS
17beta-estradiol, tibolone, and tibolone hydroxy-metabolites had no effect on VEGF mRNA in MCF-7 cells. Progesterone and progestins increased VEGF mRNA in T47-D breast cancer cells, but Delta4-tibolone was less effective than progestogens on this angiogenic gene in the T-47 D cells. This differential effect may be related to breast cancer growth.
Publication
Journal: Journal of Virology
December/5/2004
Abstract
Recombinant green fluorescent protein encoding Kaposi's sarcoma-associated herpesvirus (rKSHV.152) infection of beta-estradiol stimulated human foreskin fibroblasts (HFF) or HFF/DeltaB-Raf([FF]):ER (expressing a weaker form of B-Raf) could be enhanced to levels comparable to that of HFF/DeltaB-Raf([DD]):ER cells by pretreating cells with soluble <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF). Conversely, VEGF expression and infection efficiency typically observed in beta-estradiol stimulated HFF/DeltaB-Raf([DD]):ER cells could be lowered significantly by treating with VEGF small interfering RNA. In addition, we observed enhancement of the KSHV infection in HFF cells transfected with human VEGF(<em>121</em>). These results confirm the ability of Raf-induced VEGF to augment KSHV infection of cells.
Publication
Journal: Ophthalmology
June/29/2017
Abstract
To investigate the role of baseline demographics, disease characteristics, and treatment responses to ranibizumab during RIDE/RISE in predicting long-term treatment frequency with a criteria-based pro re nata (PRN) regimen during the open-label extension (OLE).
Pooled, retrospective, post hoc analysis from the phase III, randomized RIDE/RISE studies and subsequent OLE.
Five hundred patients enrolled in the OLE after completion of the 36-month RIDE/RISE studies.
Summary statistics of RIDE/RISE baseline characteristics and treatment responses were generated by PRN ranibizumab 0.5 mg annualized injection frequency in the OLE (0 and >7 annualized injections). Univariable regression and analysis of variance, and multivariable analysis of covariance were performed on the annualized number of ranibizumab injections administered during the OLE versus baseline characteristics and response to treatment during the RIDE/RISE studies.
Association of patient characteristics and responses to treatment during RIDE/RISE with the observed ranibizumab treatment burden during the OLE.
During the OLE, <em>121</em> patients required no treatment, 132 required >0 to ≤3 annualized injections, 159 required >3 to ≤7 annualized injections, and 88 required >7 annualized injections. Parameters identified in the multivariable analysis as related to the annualized number of injections included the total number of rescue focal macular lasers received during the core studies (P = 0.0203), central foveal thickness at baseline (P = 0.0002) and month 36 (P < 0.0001), fluorescein leakage area at month 36 (P = 0.0137), and glycated hemoglobin (HbA1c) levels at month 36 (P = 0.0054). Patients receiving 0 versus >7 annualized injections during the OLE had, on average, a shorter duration of diabetes and diabetic macular edema (DME) at baseline, were less likely to have proliferative diabetic retinopathy at baseline, received fewer rescue focal macular laser treatments, and were more likely to experience diabetic retinopathy severity scale improvement of ≥2 steps.
Patients who received less frequent injections during the RIDE/RISE OLE tended to have less advanced disease at baseline and responded better to initial ranibizumab treatment, suggesting that earlier anti-vascular endothelial growth factor treatment of center-involving DME with visual acuity loss may decrease long-term treatment burden.
Publication
Journal: Eye
May/12/2017
Abstract
PurposeTo report the 12-months visual and anatomical outcomes of chronic diabetic macular oedema (DMO) treated with ILUVIEN in a real-world clinical practice in a single tertiary referral centre.MethodRetrospective data collection and analysis of consecutive 28 eyes of 23 diabetic patients received ILUVIEN implant for refractory DMO. Standard assessment included visual acuity (VA), central retinal thickness (CRT), slit-lamp biomicroscopy, and Goldmann tonometry for intraocular pressure (IOP) at 1, 6, and 12 months.ResultsBaseline mean VA was 47 (SD 18) letters improved to 55 (SD 17) letters (P=0.004) at 12 months. VA was improved in 16 eyes (57%), stabilised in 9 eyes (32%), and decreased in 3 eyes (11%). Seven eyes (25%) gained ≥15 letters, and 10 eyes (36%) gained >10 letters from baseline. The percentage of eyes achieved driving vision (≥70 Early Treatment Diabetic Retinopathy Study letters) was doubled from baseline 18 to 36% at 6 months and 32% at 12 months. Mean CRT decreased by 198 μm from baseline 494 μm (SD 191) to 296 μm (SD <em>121</em>) at 12 months (P<0.001). Two eyes received additional anti-<em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> injections after 10 months.
RESULTS
Raised IOP in three eyes (11%) controlled with IOP-lowering drops, vitreous haemorrhage in one eye and one endophthalmitis (1 year vision improved to 6/24).ConclusionOur real-world results show that the visual and the anatomical improvements achieved by a single ILUVIEN implant injection were maintained up to 12 months with minimal adjunctive therapy. IOP monitoring remains essential in ILUVIEN patients, although our study shows a relatively low risk of IOP elevation post ILUVIEN injection, even in existing controlled ocular hypertension. Our results demonstrate that ILUVIEN is an effective long-term option in treating chronic refractory DMO.
Publication
Journal: Cancer Research
April/28/2002
Abstract
<em>Vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) is a multifunctional cytokine with important roles in angiogenesis. VEGF is overexpressed in human cancers, including highly vascularized and infiltrative brain tumors. In our previous study of seven glioma cell lines, VEGF expression levels correlated with blood vessel density and tumorigenicity, and U251 MG and NG-1 cells were recognized as low-tumorigenic glioma cell lines. We hypothesized that low-tumorigenic cells can become highly tumorigenic when high levels of VEGF are expressed. To test this hypothesis, we constructed VEGF expression vectors containing 564 bp or 696 bp of VEGF(<em>121</em>) or VEGF(165) cDNA, respectively, and transfected them into U251 MG and NG-1 cells. In comparison to parental cells, the 20 VEGF-expressing clones examined had on average 8-10-fold more VEGF mRNA and 12-88-fold more secreted VEGF proteins. Four VEGF-overexpressing clones (U251 MG/V<em>121</em>-C2, U251 MG/V165-C3, NG-1/V<em>121</em>-C6, and NG-1/V165-C3) were selected for additional study. As VEGF production increased with population <em>growth</em>, U251 MG/V<em>121</em>-C2 and U251 MG/V165-C3 cells accumulated 47.9 and 22.0 ng of VEGF during a 5-day culture of 10(4) cells, a 313- and 144-fold overexpression when compared with that in parental U251 MG cells. NG-1/V<em>121</em>-C6 and NG-1/V165-C3 cells secreted 30.4 and 9.4 ng of VEGF, respectively, or 138- and 43-fold more than did the parental NG-1 cells. Subcutaneous implantation of the VEGF-overexpressing U251 MG cells into nude mice caused huge, soft hemorrhagic tumors to form, whereas controls maintained very small tumors. Intracranial implantation of the VEGF-overexpressing cell lines significantly shortened survival of the mice when compared with controls, and it caused formation of solid brain tumors with variable sized hemorrhages, whereas the controls had no apparent brain tumors. Tumorigenicity of U251 MG cells was synergized by co-overexpression of VEGF(<em>121</em>) and VEGF(165). In addition, VEGF(165) seemed to be more potent to the brain endothelium than was VEGF(<em>121</em>). More interestingly, except when an admixture of cells was implanted s.c., VEGF overexpression in NG-1 cells did not promote hemorrhagic tumor formation. These data suggested that a switch from a phenotype of low tumorigenicity to one of high tumorigenicity is possible when VEGF overexpression occurs, although other <em>factors</em> may also be required.
Publication
Journal: Cochrane Database of Systematic Reviews
April/6/2016
Abstract
BACKGROUND
Sickle cell disease includes a group of inherited haemoglobinopathies affecting multiple organs including the eyes. Some people with the disease develop ocular manifestations due to vaso-occlusion. Vision-threatening complications of sickle cell disease are mainly due to proliferative sickle retinopathy which is characterized by proliferation of new blood vessels. Laser photocoagulation is widely applicable in proliferative retinopathies such as proliferative sickle retinopathy and proliferative diabetic retinopathy. It is important to evaluate the efficacy and safety of laser photocoagulation in the treatment of proliferative sickle retinopathy to prevent sight-threatening complications.
OBJECTIVE
To evaluate the effectiveness of various techniques of laser photocoagulation therapy in sickle cell disease-related retinopathy.
METHODS
We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. Date of last search: 21 September 2015.We also searched the following resources (24 March 2015): Latin American and Carribean Health Science Literature Database (LILACS); WHO International Clinical Trials Registry Platforms (ICTRP); and ClinicalTrials.gov.
METHODS
Randomised controlled trials comparing laser photocoagulation to no treatment in children and adults.
METHODS
Two authors independently assessed trial eligibility, the risk of bias of the included trials and extracted and analysed data. We contacted the trial authors for additional information.
RESULTS
Two trials (341 eyes of 238 children and adults) were included comparing efficacy and safety of laser photocoagulation to no therapy in people with proliferative sickle retinopathy. There were <em>121</em> males and 117 females with an age range from 13 to 67 years. The laser photocoagulation technique used was different in the two trials; one single-centre trial employed sectoral scatter laser photocoagulation using an argon laser; and the second, two-centre trial, employed feeder vessel coagulation using argon laser in one centre and xenon arc in the second centre. The follow-up period ranged from a mean of 21 to 32 months in one trial and 42 to 47 months in the second. Both trials were at risk of selection bias (random sequence generation) because of the randomisation method employed for participants with bilateral disease. One study was considered to be at risk of reporting bias.Using sectoral scatter laser photocoagulation, one trial (174 eyes) reported that complete regression of proliferative sickle retinopathy was seen in 30.2% in the laser group and 22.4% in the control group (no difference between groups). The same trial reported the development of new proliferative sickle retinopathy in 34.3% of laser-treated eyes and in 41.3% of eyes given no treatment; again, there was no difference between treatment groups. The second trial, using feeder vessel coagulation, did not present full data for either treatment group for these outcomes.There was evidence from both trials (341 eyes) that laser photocoagulation using scatter laser or feeder vessel coagulation may prevent the loss of vision in eyes with proliferative sickle retinopathy (at median follow up of 21 to 47 months). Data from both trials indicated that laser treatment prevented the occurrence of vitreous haemorrhage with both argon and xenon laser; with the protective effect being greater with feeder vessel laser treatment compared to scatter photocoagulation.Regarding adverse effects, the incidence of retinal tear was minimal, with only one event reported. Combined data from both trials were available for 341 eyes; there was no difference between the laser and control arms for retinal detachment. In relation to choroidal neovascularization, treatment with xenon arc was found to be associated with a significantly higher risk, but visual loss related to this complication is uncommon with long-term follow up of three years or more.Data regarding quality of life and other adverse effects were not reported in the included trials.
CONCLUSIONS
Our conclusions are based on the data from two trials conducted over 20 years ago. In the absence of further evidence, laser treatment for sickle cell disease-related retinopathy should be considered as a one of therapeutic options for preventing visual loss and vitreous haemorrhage. However, it does not appear to have a significant different effect on other clinical outcomes such as regression of proliferative sickle retinopathy and development of new ones. No evidence is available assessing efficacy in relation to patient-important outcomes (such as quality of life or the loss of a driving licence). There is limited evidence on safety, overall, scatter argon laser photocoagulation is superior in terms of adverse effects, although feeder vessel coagulation has a better effect in preventing vitreous haemorrhage. Further research is needed to examine the safety of laser treatment compared to other interventions such as intravitreal injection of anti-vascular endothelial growth factors. In addition, patient-important outcomes as well as cost-effectiveness should be addressed.
Publication
Journal: Neoplasma
July/22/2013
Abstract
Maspin is a serine protease which belongs to the serpin family and seems to play an important role in inhibiting angiogenesis and tumor proliferation. The significance of its expression in colorectal cancer (CRC) has not been elucidated so far. In our study, we tried to identify, based on Maspin expression, four groups of CRC, with possible prognostic impact. In <em>121</em> CRC, we analyzed the Maspin expression in correlation with the clinico-pathological features, microsatellite status and other markers such as p53, bax, bcl-2, VEGF (<em>Vascular</em> <em>Endothelial</em> <em>Growth</em> <em>Factor</em>) and CD31. Based on the percentage and intensity of Maspin expression in the tumor cells, the cases were grouped in four classes: negative, with cytoplasmic predominance, nuclear predominated, and cases with mixed (cytoplasmic-nuclear) expression. 9% of the cases were negative, 44% presented cytoplasmic predominance, the nuclear predominance was revealed in 24% of the cases, and the other 23% of CRC having a mixed Maspin positivity. The cytoplasmic predominance was correlated with a better prognosis, p53 negativity, bax positivity, and lack of tumor budding. Forty percent of microsatellite instable (MSI) cases presented mixed expression, this pattern being also related to a lower angiogenesis. Nuclear predominance was associated with p53 positivity, the lowest survival rate and intense VEGF expression. In conclusion, CRC with cytoplasmic predominance and mixed Maspin expression seems to present better prognosis whereas nuclear predominance is connected with high aggressivity.
Publication
Journal: Journal of Neurochemistry
May/15/2005
Abstract
beta-amyloid (Abeta) is a major component of senile plaques that is commonly found in the brain of Alzheimer's disease (AD) patient. In the previous report, we showed that an important angiogenic <em>factor</em>, <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) interacts with Abeta and is accumulated in the senile plaques of AD patients' brains. Here we show that Abeta interacts with VEGF(165) isoform, but not with VEGF(<em>121</em>). Abeta binds to the heparin-binding domain (HBD) of VEGF(165) with similar affinity as that of intact VEGF(165). Abeta binds mostly to the C-terminal subdomain of HBD, but with greatly reduced affinity than HBD. Therefore, the full length of HBD appears to be required for maximal binding of Abeta. Although Abeta binds to heparin-binding sequence of VEGF, it does not bind to other heparin-binding <em>growth</em> <em>factors</em> except midkine. Thus it seems that Abeta recognizes unique structural features of VEGF HBD. VEGF(165) prevents aggregation of Abeta through its HBD. We localized the core VEGF binding site of Abeta at around 26-35 region of the peptide. VEGF(165) and HBD protect PC12 cells from the Abeta-induced cytotoxicity. The mechanism of protection appears to be inhibition of both Abeta-induced formation of reactive oxygen species and Abeta aggregation.
Publication
Journal: Journal of Pharmacology and Experimental Therapeutics
July/13/2000
Abstract
<em>Vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) is an <em>endothelial</em> cell mitogen that promotes angiogenesis during embryonic development and the progression of certain pathologies. This study examined the regulation of VEGF expression by adenosine receptor (AR) activation in PC12 rat pheochromocytoma cells. Treatment of cells with the AR agonist CGS21680 reduced the VEGF mRNA level to approximately 20% of that in control cells with an EC(50) value of 0.47 nM, indicative of mediation by the A(2A)AR. Down-regulation of VEGF mRNA by CGS21680 was abolished by pretreatment of cells with the AR antagonist ZM241385. Additionally, ZM241385 alone increased VEGF mRNA by 2.8-fold above basal. RNase protection assays indicated that CGS21680 down-regulated VEGF(<em>121</em>), VEGF(165), and VEGF(189) transcripts. VEGF protein secretion was similarly decreased by CGS21680. Under hypoxic conditions, VEGF mRNA expression was reduced by 85.7% after pretreatment with CGS21680. The down-regulation response appears to be mediated predominately by coupling of the A(2A)AR to G(s) because cholera toxin treatment also reduced VEGF expression. The decrease in VEGF mRNA steady-state levels after A(2A)AR activation is apparently due to a decrease in the VEGF gene transcription rate and not to a decrease in mRNA stability. Thus, depending on the cell type, adenosine may have an inhibitory effect on VEGF production, which may have implications in blood vessel development.
Publication
Journal: Journal of Clinical Endocrinology and Metabolism
October/2/2002
Abstract
Ovarian steroids and/or premenstrual endometrial hypoxia are thought to restore the endometrial vasculature shed during menstruation by elevating endometrial <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF) levels. During the luteal phase, VEGF levels peak, progesterone induces estradiol (E(2))-primed human endometrial stromal cells (HESCs) to decidualize and express tissue <em>factor</em> (TF), and endometrial <em>vascular</em> permeability is enhanced. The latter would present circulating clotting <em>factors</em> to decidual cell-expressed TF to form local thrombin. HESCs were incubated in serum-supplemented medium containing vehicle (control) or 10(-8) M E(2) or 10(-7) M medroxyprogesterone acetate (MPA) or E(2) + MPA for 7 d to induce decidualization, while monolayers of human endometrial glandular epithelial cells (HEGECs) formed during 4-d incubation of glands. The medium was exchanged for a defined medium containing corresponding vehicle or steroids +/- thrombin under normoxia or hypoxia (0-1% O(2)). Hypoxia enhanced secreted immunoreactive VEGF levels by severalfold in HESCs and HEGECs, but the steroids did not affect VEGF output in either cell type under normoxia or hypoxia. In E(2) + MPA-decidualized HESCs, VEGF levels were elevated by 0.1 U/ml of thrombin, and 0.5-2.5 U/ml of thrombin elicited maximum effects. The addition of 0.5 U/ml of thrombin evoked a time-dependent enhancement of VEGF levels and about an 8-fold increase at 48 h (P < 0.02; n = 6). Northern blotting indicated that E(2) + MPA-decidualized HESCs expressed VEGF(<em>121</em>), VEGF(165), and VEGF(189) mRNA, which were enhanced severalfold during 5- to 20-h incubation with thrombin. Moreover, TRAP, a synthetic peptide activator of the constitutively expressed protease activated receptor-1 thrombin receptor in decidualized HESCs, also elevated secreted VEGF levels. By contrast, HEGECs were unresponsive to thrombin added alone or with ovarian steroids. These results suggest that thrombin formed by progestin-augmented TF levels acts as an autocrine enhancer of VEGF expression in decidualized HESCs. Because angiogenesis occurs in a matrix of decidualized HESCs, these in vitro results provide a novel mechanism to account for both the peak in VEGF and angiogenesis in luteal phase human endometrium.
Publication
Journal: Journal of Gastroenterology and Hepatology
April/3/2011
Abstract
OBJECTIVE
In animal models for acute liver injury, the administration of some angiogenic factors such as vascular endothelial growth factor (VEGF) and granulocyte-colony stimulating factor (G-CSF) are shown to reduce liver injury and improve liver proliferative capacity. The aim of the present study was to assess the role of angiogenic factors in fulminant hepatic failure (FHF).
METHODS
Serum levels of nine angiogenic factors (angiopoietin-2, follistatin, G-CSF, hepatocyte growth factor [HGF], interleukin-8, leptin, platelet-derived growth factor [PDGF]-BB, platelet endothelial cell adhesion molecule-1 and VEGF) were measured using the Bio-Plex Protein Array System in 30 patients, 17 of whom were diagnosed with FHF, 13 with acute hepatitis (AH), and 20 controls.
RESULTS
Serum levels of PDGF-BB and VEGF were lower in FHF patients than AH patients and controls (PDGF-BB; 2050±1572 pg/mL vs 4521±2419 pg/mL vs 8506±5500 pg/mL, VEGF; 39±38 pg/mL vs 144±122 pg/mL vs 205±121 pg/mL). By using univariate logistic regression models, serum levels of PDGF-BB and VEGF were associated with poor outcomes. Serum PDGF-BB levels were strongly correlated with serum VEGF levels (r=0.70). Furthermore, serum PDGF-BB levels were significantly correlated with platelet counts (r=0.79), PT activity (r=0.37) and D.Bil/T.Bil ratio (r=0.50), while serum VEGF levels were significantly correlated with platelet counts (r=0.68) and PT activity (r=0.38).
CONCLUSIONS
We consider that serum levels of PDGF-BB and VEGF are worth investigating as biomarkers for predicting outcomes of FHF patients.
Publication
Journal: Advanced Pharmaceutical Bulletin
November/30/2014
Abstract
OBJECTIVE
Angiogenesis or formation of new blood vessels is an essential process for tumor <em>growth</em>, invasion and metastasis. <em>Vascular</em> <em>Endothelial</em> <em>Growth</em> <em>Factor</em> (VEGF) and its receptors play an important role in angiogenesis-dependent tumors. VEGF-A is the most important <em>factor</em> in angiogenesis process. Human VEGF-A gene consists of eight exons that undergoes alternative exon splicing and produce five different proteins consisting of <em>121</em>, 145, 165, 189 and 206 amino acids (named VEGF<em>121</em>, VEGF145, VEGF165, VEGF189, and VEGF206).
METHODS
In this study, VEGF<em>121</em> gene synthesized and cloned into the pET-26b plasmid. The recombinant plasmid was transferred into appropriate expression strain of BL-21. Expression of VEGF<em>121</em> induced by IPTG (Isopropyl β-D-1-thiogalactopyranoside) and confirmed by SDS-PAGE and Western-Blotting. Recombinant VEGF<em>121</em> was purified by nickel affinity chromatography. HUVECs (Human Umbilical Vein Endothelia Cells) cells were isolated from umbilical vein and the effect of VEGF<em>121</em> on tube formation of endothelial cells was investigated.
RESULTS
SDS-PAGE and Western-Blotting results verified the purification of VEGF<em>121</em>. The final yield of recombinant protein was about 5mg per liter. <em>Endothelial</em> cell tube formation assay results showed that VEGF<em>121</em> leads to tube formation of endothelial cell on matrix and induces angiogenesis in vitro.
CONCLUSIONS
Recombinant VEGF<em>121</em> is important <em>factor</em> in tube formation of endothelial cell, so it could be used in different cancer researches and angiogenesis assay.
Publication
Journal: Journal of Biotechnology
December/6/2005
Abstract
We present a novel set of autoregulated, bidirectional and multicistronic mammalian as well as lentiviral expression vectors which enable transgene expression fine-tuning by gaseous acetaldehyde. The acetaldehyde-inducible regulation (AIR) technology capitalizes on Aspergillus nidulans components evolved to convert ethanol into metabolic energy. AIR is based on functional interaction of the fungal transactivator AlcR and AlcR-specific chimeric promoters (P(AIR)) which drive desired transgene expression in mammalian cells only in the presence of gaseous acetaldehyde. We have engineered AIR technology into a variety of different mammalian and lentiviral expression vector systems including (i) a most compact autoregulated expression format harboring alcR and the transgene in a single P(AIR)-driven transcription unit, (ii) a bidirectional P(AIR) derivative supporting expression of two transgenes with strict 1:1 transcription stoichiometry and (iii) a multicistronic expression arrangement providing simultaneous translation of three independent transgenes from a single P(AIR)-controlled transcript. All expression vectors have been validated in Chinese hamster ovary (CHO-K1), baby hamster kidney (BHK-21) and human HeLa cells for gas-inducible (co-)expression of the reporter transgenes such as Bacillus stearothermophilus-derived secreted alpha-amylase (SAMY), human <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> <em>121</em> (VEGF<em>121</em>), human placental-secreted alkaline phosphatase (SEAP) and Escherichia coli-derived chloramphenicol acetyl-transferase (CAT). The panoply of mammalian/lentiviral vectors presented here provides a robust and versatile expression platform for the first gas-inducible transgene control system which we expect to foster future advances in gene therapy, tissue engineering as well as biopharmaceutical manufacturing.
Publication
Journal: Reproduction, Fertility and Development
May/12/2008
Abstract
The aim of the present study was to evaluate the pattern of regulation of <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF)-A (isoforms <em>121</em>, 165, 189), VEGF receptor tyrosine kinases (VEGF-R1 and VEGF-R2), matrix metalloproteinase (MMP)-1, MMP-2, MMP-14, MMP-19, tissue-specific inhibitor of metalloproteinases (TIMP)-1, TIMP-2, tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) in time-defined follicle classes before (0 h) and after the application of gonadotrophin-releasing hormone (GnRH). Bovine ovaries containing periovulatory follicles or new corpora lutea (CL; Days 1-2) were collected 0, 4, 10, 20 and 25 h (follicles) or 60 h (CL) after the injection of GnRH. Transcripts of VEGF isoforms (VEGF(<em>121</em>), VEGF(165), VEGF(189)) were upregulated 4 h after GnRH injection (during the luteinising hormone (LH) surge) and decreased thereafter to lowest levels around ovulation. All VEGF isoforms and their receptors were upregulated again after ovulation. The VEGF peptide concentration in follicular fluid decreased 20 h after GnRH injection, followed by an increase in follicles 25 h after GnRH. Expression of MMP-1 mRNA increased rapidly 4 h after GnRH injection and remained high during the entire experimental period. In contrast, MMP-19 mRNA increased significantly only after ovulation. Expression of TIMP-1 mRNA increased 4 h after GnRH and again after ovulation. Expression of tPA mRNA increased 4 h after GnRH and remained high during the entire experimental period, whereas expression of uPA transcripts increased significantly only after ovulation. Both uPAR and PAI-1 mRNA levels increased in follicles 4 h after GnRH and again after ovulation. The amount of MMP-1 protein (immunolocalisation) increased in follicles 10 h after GnRH: additional staining was observed in the granulosa cell layer. In conclusion, the temporal and spatial pattern of regulation of VEGF and extracellular matrix-degrading proteinases during periovulation suggests they are important mediators of the LH-dependent rupture of bovine follicles and for early CL formation (angiogenesis).
Publication
Journal: Chinese Medical Journal
February/22/2006
Abstract
BACKGROUND
To better understand the possibilities of antiangiogenic tumor therapy and to assess possible side effects, we investigated the effect of tumour necrosis factor (TNF)-alpha and curcumin on the expression of vascular endothelial growth factor (VEGF) in U937 and Raji cell lines and their effect on angiogenesis in a human umbilical vein endothelial cell (HUVECs)-derived cell line (ECV304), and also the relationship between Notch1 and VEGF. The aim of this study was to elucidate potential mechanisms controlling tumor neovascularization.
METHODS
VEGF secreted by U937 and Raji cell lines was determined by ELISA. Angiogenesis was tested by network formation of endothelial cells on Matrigel. Levels of VEGF mRNA in U937 and Raji cells and Notch1 mRNA levels in EV304 cells were determined by RT-PCR.
RESULTS
Secretion of VEGF by U937 and Raji cells was increased by TNF-alpha treatment and suppressed by curcumin (P < 0.01). The mRNA expression of VEGF165 and VEGF121 (containing 165 and 121 amino acid residues, respectively) were detected in any fractions. TNF-alpha augmented the expression of VEGF165 and VEGF121 mRNA and curcumin reduced the expression (P < 0.01). No networks or cords formed in control and curcumin groups. There was tube formation on matrigel in the supernatants of the Raji culture group and the supernatants groups treated by VEGF group and TNF-alpha in Raji cell. Notch1 mRNA was detected but there was no significant change in the VEGF group compared with control (P>> 0.05).
CONCLUSIONS
Expressions of VEGF mRNA in U937 and Raji cells were increased by TNF-alpha and suppressed by curcumin. VEGF and TNF-alpha can induce angiogenesis, and curcumin can inhibit angiogenesis in ECV304 cells.
Publication
Journal: Cochrane Database of Systematic Reviews
February/12/2017
Abstract
Choroidal neovascularisation (CNV) is a common complication of pathological myopia. Once developed, most eyes with myopic CNV (mCNV) experience a progression to macular atrophy, which leads to irreversible vision loss. Anti-vascular endothelial growth factor (anti-VEGF) therapy is used to treat diseases characterised by neovascularisation and is increasingly used to treat mCNV.
To assess the effects of anti-vascular endothelial growth factor (anti-VEGF) therapy for choroidal neovascularisation (CNV), compared with other treatments, sham treatment or no treatment, in people with pathological myopia.
We searched a number of electronic databases including CENTRAL and Ovid MEDLINE, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform ICTRP). We did not use any date or language restrictions in the electronic searches for trials. Electronic databases were last searched on 16 June 2016.
We included randomised controlled trials (RCTs) and quasi-RCTs comparing anti-VEGF therapy with another treatment (e.g. photodynamic therapy (PDT) with verteporfin, laser photocoagulation, macular surgery, another anti-VEGF), sham treatment or no treatment in participants with mCNV.
We used standard methodological procedures expected by Cochrane. Two authors independently screened records, extracted data, and assessed risk of bias. We contacted trial authors for additional data. We analysed outcomes as risk ratios (RRs) or mean differences (MDs). We graded the certainty of the evidence using GRADE.
The present review included six studies which provided data on the comparison between anti-VEGF with PDT, laser, sham treatment and another anti-VEGF treatment, with 594 participants with mCNV. Three trials compared bevacizumab or ranibizumab with PDT, one trial compared bevacizumab with laser, one trial compared aflibercept with sham treatment, and two trials compared bevacizumab with ranibizumab. Pharmaceutical companies conducted two trials. The trials were conducted at multiple clinical centres across three continents (Europe, Asia and North America). In all these six trials, one eye for each participant was included in the study.When compared with PDT, people treated with anti-VEGF agents (ranibizumab (one RCT), bevacizumab (two RCTs)), were more likely to regain vision. At one year of follow-up, the mean visual acuity (VA) in participants treated with anti-VEGFs was -0.14 logMAR better, equivalent of seven Early Treatment Diabetic Retinopathy Study (ETDRS) letters, compared with people treated with PDT (95% confidence interval (CI) -0.20 to -0.08, 3 RCTs, 263 people, low-certainty evidence). The RR for proportion of participants gaining 3+ lines of VA was 1.86 (95% CI 1.27 to 2.73, 2 RCTs, 226 people, moderate-certainty evidence). At two years, the mean VA in people treated with anti-VEGFs was -0.26 logMAR better, equivalent of 13 ETDRS letters, compared with people treated with PDT (95% CI -0.38 to -0.14, 2 RCTs, 92 people, low-certainty evidence). The RR for proportion of people gaining 3+ lines of VA at two years was 3.43 (95% CI 1.37 to 8.56, 2 RCTs, 92 people, low-certainty evidence). People treated with anti-VEGFs showed no obvious reduction (improvement) in central retinal thickness at one year compared with people treated with PDT (MD -17.84 μm, 95% CI -41.98 to 6.30, 2 RCTs, 226 people, moderate-certainty evidence). There was low-certainty evidence that people treated with anti-VEGF were more likely to have CNV angiographic closure at 1 year (RR 1.24, 95% CI 0.99 to 1.54, 2 RCTs, 208 people). One study allowed ranibizumab treatment as of month 3 in participants randomised to PDT, which may have led to an underestimate of the benefits of anti-VEGF treatment.When compared with laser photocoagulation, there was more improvement in VA among bevacizumab-treated people than among laser-treated people after one year (MD -0.22 logMAR, equivalent of 11 ETDRS letters, 95% CI -0.43 to -0.01, 1 RCT, 36 people, low-certainty evidence) and after two years (MD -0.29 logMAR, equivalent of 14 ETDRS letters, 95% CI -0.50 to -0.08, 1 RCT, 36 people, low-certainty evidence).When compared with sham treatment, people treated with aflibercept had better vision at one year (MD -0.19 logMAR, equivalent of 9 ETDRS letters, 95% CI -0.27 to -0.12, 1 RCT, 121 people, moderate-certainty evidence). The fact that this study allowed for aflibercept treatment at 6 months in the control group might cause an underestimation of the benefit with anti-VEGF.People treated with ranibizumab had similar improvement in VA recovery compared with people treated with bevacizumab after one year (MD -0.02 logMAR, equivalent of 1 ETDRS letter, 95% CI -0.11 to 0.06, 2 RCTs, 80 people, moderate-certainty evidence).Of the included six studies, two studies reported no adverse events in either group and two industry-sponsored studies reported both systemic and ocular adverse events. In the control group, there were no systemic or ocular adverse events reported in 149 participants. Fifteen people reported systemic serious adverse events among 359 people treated with anti-VEGF agents (15/359, 4.2%). Five people reported ocular adverse events among 359 people treated with anti-VEGF agents (5/359, 1.4%). The number of adverse events was low, and the estimate of RR was uncertain regarding systemic serious adverse events (4 RCTs, 15 events in 508 people, RR 4.50, 95% CI 0.60 to 33.99, very low-certainty evidence) and serious ocular adverse events (4 RCTs, 5 events in 508 people, RR 1.82, 95% CI 0.23 to 14.71, very low-certainty evidence). There were no reports of mortality or cases of endophthalmitis or retinal detachment.There was sparse reporting of data for vision-related quality of life (in favour of anti-VEGF) in only one trial at one year of follow-up. The studies did not report data for other outcomes, such as percentage of participants with newly developed chorioretinal atrophy.
There is low to moderate-certainty evidence from RCTs for the efficacy of anti-VEGF agents to treat mCNV at one year and two years. Moderate-certainty evidence suggests ranibizumab and bevacizumab are equivalent in terms of efficacy. Adverse effects occurred rarely and the trials included here were underpowered to assess these. Future research should be focused on the efficacy and safety of different drugs and treatment regimens, the efficacy on different location of mCNV, as well as the effects on practice in the real world.
Publication
Journal: Human Gene Therapy
September/9/2013
Abstract
On the basis of studies in experimental animals demonstrating that AdVEGF<em>121</em>, an E1(-)E3(-) serotype 5 adenovirus coding the <em>121</em> isoform of <em>vascular</em> <em>endothelial</em> <em>growth</em> <em>factor</em> (VEGF), could mediate the generation of new blood vessels and reverse coronary ischemia, a clinical study of direct myocardial administration of AdVEGF<em>121</em> was initiated in patients with late-stage, diffuse coronary artery disease. This study provides long-term (median, 11.8 years) follow-up on these patients. From 1997 to 1999, AdVEGF<em>121</em> was administered by direct myocardial injection to an area of reversible ischemia in 31 patients with severe coronary disease, either as an adjunct to conventional coronary artery bypass grafting (group A) or as minimally invasive sole (MIS) therapy, using a minithoracotomy (group B). There was no control group; the study participants served as the control subjects. The 5- and 10-year survival was 10 of 15 (67%) and 6 of 15 (40%) for the group A patients, and 11 of 16 (69%) and 5 of 16 (31%) for group B sole therapy patients, respectively. In comparison, maximal medical therapy in comparable groups in the literature have a 3- to 5-year survival rate of 52 to 59%. For the survivors, the angina score for group A was 3.4±0.5 at time 0 and 1.9±1.0 at last follow-up, and for group B it was 3.4±0.6 and 2.0±1.1, respectively. The incidences of malignancy and retinopathy were no greater than that expected for the age-matched general population. We conclude that adenovirus-mediated VEGF direct myocardial administration to patients with severe coronary artery disease is safe, and future larger trials are warranted to assess efficacy.
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