Increased Vascular Endothelial Growth Factor Concentrations Research Articles

Visible Photoluminescence of Variable-Length Zinc Oxide Nanorods Embedded in Porous Anodic Alumina Template for Biosensor Applications

Zinc oxide (ZnO) and porous anodic aluminum oxide (PAAO) are technologically important materials, rich with features that are of interest in optical applications, for example, in light-emitting and sensing devices. Here, we present synthesis method of aligned ZnO nanorods (NR) with 40 nm diameter and variable length in 150 to 500 nm range obtained by atomic layer deposition (ALD) of ZnO in pores of continuously variable thickness PAAO. The relative intensity of yellow (1.99 eV), green (2.35 eV), and blue (2.82 eV) photoluminescence (PL) components originating from the different types of defects, varied with non-monotonic dependency on the composite film thickness with a Fabry–Pérot like modulation. The intensity variation of any individual PL component correlated well with anti-reflective properties of ZnO NR–PAAO composite film at the peak wavelength of the particular PL component. This provides a route for selective enhancement or suppression of color components of hybrid fluorescent emitters by tuning only geometric parameters, with potential use in imaging and other optical devices. As an application example we tested the composite film for sensing of vascular endothelial growth factor (VEGF) using a widely accessible fluorescence microscopy setup. The intensity of the yellow and green PL components reduced in response to increased VEGF concentrations, whereas blue component remained invariant.

Assessment of endothelial progenitor cells, VEGF-A and SDF-1α in Hodgkin's lymphoma.

Recently, there is great interest in vasculogenesis, a process of the formation of new blood vessels from progenitor cells or angioblasts, in the pathogenesis of cancer. To the best of our knowledge, the evaluation of endothelial progenitor cells (EPCs) in Hodgkin's lymphoma has not yet been reported. The aim of the present study was to assess the number of EPCs and selected cytokines, such as vascular endothelial growth factor (VEGF-A) and stromal cell-derived factor (SDF-1α) involved in vasculogenesis in Hodgkin's lymphoma patients. The study was conducted in a group of 42 patients with Hodgkin's lymphoma (eight patients with relapsed Hodgkin's lymphoma and 34 patients before the first treatment) and 30 healthy controls. The number of EPCs defined as CD31(+), CD34(+), CD45(-), CD133(+) was analysed on FacsCalibur flow cytometer and the concentration of VEGF-A and SDF-1α was assessed by ELISA. The study showed that there was a significantly higher EPCs number and VEGF-A concentration in the blood of Hodgkin's lymphoma patients compared to healthy individuals (8.20 vs. 0.55 cells/μl; P < 0.000001; 85.10 vs. 25.33 pg/ml, P = 0.000017; respectively). Detailed analysis revealed that there was elevated EPCs number in both study subgroups as compared to the control group. However, there was no difference in VEGF concentration between recurrent Hodgkin's lymphoma patients and the control group. A significant positive correlation was found between the number of EPCs and VEGF-A concentration (R = 0.31, P = 0.047). Significantly higher EPCs number combined with increased VEGF-A concentration, found in Hodgkin's lymphoma patients before the first treatment, suggest stimulation of new blood vessels formation, which may in turn contribute to tumour growth and metastasis in these patients.

PR1P Stabilizes VEGF and Upregulates Its Signaling to Reduce Elastase-induced Murine Emphysema.

Emphysema is a progressive and fatal lung disease with no cure that is characterized by thinning, enlargement, and destruction of alveoli, leading to impaired gas exchange. Disease progression is due in part to dysregulation of VEGF (vascular endothelial growth factor) signaling in the lungs and increased lung-cell apoptosis. Here we asked whether PR1P (Prominin-1-derived peptide), a novel short peptide we designed that increases VEGF binding to endothelial cells, could be used to improve outcome in in vitro and in vivo models of emphysema. We used computer simulation and in vitro and in vivo studies to show that PR1P upregulated endogenous VEGF receptor-2 signaling by binding VEGF and preventing its proteolytic degradation. In so doing, PR1P mitigated toxin-induced lung-cell apoptosis, including from cigarette-smoke extract in vitro and from LPS in vivo in mice. Remarkably, inhaled PR1P led to significantly increased VEGF concentrations in murine lungs within 30 minutes that remained greater than twofold above that of control animals 24 hours later. Finally, inhaled PR1P reduced acute lung injury in 4- and 21-day elastase-induced murine emphysema models. Taken together, these results highlight the potential of PR1P as a novel therapeutic agent for the treatment of emphysema or other lung diseases characterized by VEGF signaling dysregulation.

Balance of interstitial flow magnitude and vascular endothelial growth factor concentration modulates three-dimensional microvascular network formation.

Hemodynamic and biochemical factors play important roles in critical steps of angiogenesis. In particular, interstitial flow has attracted attention as an important hemodynamic factor controlling the angiogenic process. Here, we applied a wide range of interstitial flow magnitudes to an in vitro three-dimensional (3D) angiogenesis model in a microfluidic device. This study aimed to investigate the effect of interstitial flow magnitude in combination with the vascular endothelial growth factor (VEGF) concentration on 3D microvascular network formation. Human umbilical vein endothelial cells (HUVECs) were cultured in a series of interstitial flow generated by 2, 8, and 25 mmH2O. Our findings indicated that interstitial flow significantly enhanced vascular sprout formation, network extension, and the development of branching networks in a magnitude-dependent manner. Furthermore, we demonstrated that the proangiogenic effect of interstitial flow application could not be substituted by the increased VEGF concentration. In addition, we found that HUVECs near vascular sprouts significantly elongated in >8 mmH2O conditions, while activation of Src was detected even in 2 mmH2O conditions. Our results suggest that the balance between the interstitial flow magnitude and the VEGF concentration plays an important role in the regulation of 3D microvascular network formation in vitro.

Inhibition of soluble epoxide hydrolase augments astrocyte release of vascular endothelial growth factor and neuronal recovery after oxygen-glucose deprivation.

Epoxyeicosatrienoic acids (EETs) are synthesized in astrocytes, and inhibitors of soluble epoxide hydrolase (sEH), which hydrolyzes EETs, reduce infarct volume in ischemic stroke. Astrocytes can release protective neurotrophic factors, such as vascular endothelial growth factor (VEGF). We found that addition of sEH inhibitors to rat cultured astrocytes immediately after oxygen-glucose deprivation (OGD) markedly increased VEGF concentration in the medium 48h later and the effect was blocked by an EET antagonist. The sEH inhibitors increased EET concentrations to levels capable of increasing VEGF. When the sEH inhibitors were removed from the medium at 48h, the increase in VEGF persisted for an additional 48h. Neurons exposed to OGD and subsequently to astrocyte medium previously conditioned with OGD plus sEH inhibitors showed increased phosphorylation of their VEGF receptor-2, less TUNEL staining, and increased phosphorylation of Akt, which was blocked by a VEGF receptor-2 antagonist. Our findings indicate that sEH inhibitors, applied to cultured astrocytes after an ischemia-like insult, can increase VEGF secretion. The released VEGF then enhances Akt-enabled cell survival signaling in neurons through activation of VEGF receptor-2 leading to less neuronal cell death. These results suggest a new strategy by which astrocytes can be leveraged to support neuroprotection.

Increased plasma VEGF levels following ischemic preconditioning are associated with downregulation of miRNA-762 and miR-3072-5p.

Ischemic preconditioning (IPC) has protective effects against ischemia-perfusion injury of organs. In the present study, we investigated the associated mechanisms after performing remote IPC (rIPC) of lower limbs by clamping abdominal aorta in mice. Subsequent experiments showed decreased damage and paralysis of lower limbs following spinal cord injury (SCI). Concomitantly, plasma vascular endothelial growth factor (VEGF) levels were increased 24 h after rIPC compared with those in sham-operated animals. In subsequent microRNA analyses, thirteen microRNAs were downregulated in exosomes 24 h after rIPC. Further studies of femoral CD34-positive bone marrow (BM) cells confirmed downregulation of these seven microRNAs 24 h after rIPC compared with those in sham-operated controls. Subsequent algorithm-based database searches suggested that two of the seven microRNAs bind to the 3′ UTR of VEGF mRNA, and following transfection into CD34-positive BM cells, anti-miR-762, and anti-miR-3072-5p inhibitors led to increased VEGF concentrations. The present data suggest that rIPC transiently increases plasma VEGF levels by downregulating miR-762 and miR-3072-5p in CD34-positive BM cells, leading to protection against organ ischemia.

Antihypertensive drugs methyldopa, labetalol, hydralazine, and clonidine improve trophoblast interaction with endothelial cellular networks in vitro

The interaction between trophoblasts and maternal endothelium is important for placental vascular modeling. Failure of uterine spiral artery transformation is linked to the etiopathology of preeclampsia. Antihypertensive medications used to control hypertension in early pregnancy can alter placental and circulating cytokines. This study investigated whether selected antihypertensive drugs can modulate the interaction between trophoblast and endothelial cells. Human uterine myometrial microvascular endothelial cells were preincubated with (or without) low-dose tumor necrosis factor-α (TNF-α; 0.5 ng/ml) or TNF-α and soluble fms-like tyrosine kinase 1 (sFlt-1; 100 ng/ml). Red fluorescent-labeled endothelial cells were then cultured on Matrigel. After appearance of endothelial cellular networks, green fluorescent-labeled HTR-8/SVneo trophoblast cells were cocultured in the presence of pharmacological doses of methyldopa, labetalol, hydralazine, and clonidine. Images were captured after 24 h and drug effects on HTR-8/SVneo cell integration were quantified by Image Analysis software. The conditioned medium was collected to measure sFlt-1, vascular endothelial growth factor (VEGF), placental growth factor, interleukin-10, and interleukin-6 by ELISA. Methyldopa, labetalol, hydralazine, and clonidine increased trophoblast integration into TNF-α-preincubated endothelial cellular networks. In conditioned medium, sFlt-1 was reduced by methyldopa, hydralazine, and clonidine alone. VEGF was increased by methyldopa. A decrease in placental growth factor was seen by methyldopa and also in nontreated endothelial cell coculture of the other three drugs. Some antihypertensive drugs used in pregnancy may improve the cellular interaction between trophoblast and endothelial cells exposed to TNF-α. Methyldopa, hydralazine, and clonidine reduced sFlt-1 concentration in culture medium, whereas labetalol increased trophoblast integration independently of sFlt-1. Methyldopa increased VEGF concentration. Some pregnancy-related antihypertensives may affect placental vascularization.

The endothelium-protective effect of 3-methyl-1,2,4-triazolyl-5-thioacetate (S)-2,6-diaminohexanic acid (lysinium): Effects on the expression of vascular endothelial growth factor (VEGF) and the characteristics of the endotheliocytes of the cerebral vessels of animals with cerebral ischemia

We modeled acute disruption of the brain blood circulation (ADBC) by bilateral ligature of the common carotids in white outbred rats. This resulted in the formation of endothelial dysfunction of capillary network in the IV–V layers of the cortex and the vessels of the pia mater, choroids plexuses, and the branches of the middle cerebral and ophthalmic arteries, which was seen as a considerable decrease in the density of nuclei of endotheliocytes, a decrease in the RNA concentration in them, expression of vascular endothelial growth factor (VEGF), and a substantial decrease in the index of the proliferative activity of endotheliocytes. Intraperitoneal treatment of rats with ADBC with lysinium for 21 days at a dose of 50 mg/kg led on the 4th day to an increase in the density of endotheliocytes in the capillary network of the brain cortex and the walls of cerebral vessels and an increase in the RNA content in endothelial nuclei. At the end of the lysinium treatment, we observed an increase in the density of endotheliocytes in the capillary network of the brain cortex and the walls of cerebral vessels, an increase in the RNA content in nuclei of endotheliocytes, and an increase in the density of proliferating endotheliocytes in these vessels, which was associated with increased VEGF concentration. Administration of the control drug piracetam had no endothelium-protective effect.

Weight Reducing and Metabolic Effects of Topiramate in Patients with Migraine – an Observational Study

Topiramate is an anticonvulsant agent effective in the prophylaxis of migraine, which also induces weight reduction by an unknown mechanism. We investigated the effect of topiramate on metabolic and endocrine parameters in patients with migraine independently of any intention to lose body weight. Six patients (26-61 years old, body mass indices [BMI] 20.9-32.1 kg/m(2)) with migraine were treated with an average dose of 100 mg topiramate/day over a period of 20 weeks. The following parameters were measured every 4-8 weeks: BMI, body fat proportion, waist and hip circumference, HOMA insulin resistance, fasting serum-/plasma concentrations of adiponectin, leptin, ghrelin, vascular endothelial growth factor (VEGF), cortisol, interleukin-6 and tumor necrosis factor (TNF)-alpha. Profound metabolic changes were observed for the whole treatment period. Compared with the baseline value, 20 weeks of treatment reduced the BMI by 7.2+/-1.4%, body fat proportion by 11.6+/-3.6%, waist circumference by 4.2+/-1.2%, leptin by 39.2+/-6.5% and HOMA insulin resistance by 37.3+/-5%, while adiponectin was increased by 69.9+/-17.3% (P<0.05, respectively). VEGF concentrations increased during the week 2-4 by 177.4+/-39.4% (P<0.05) followed by a continuous decrease. There were trends for a reduction in ghrelin concentration, whereas cortisol, interleukin-6 and TNF-alpha values were unchanged. In summary, in this small sample of migraine patients topiramate treatment was associated with increased insulin sensitivity, increased adiponectin concentration and a reduction of body fat in all treated patients. The role of increased VEGF concentrations prior to these metabolic changes is not clear and might, hypothetically, involve a centrally mediated effect of topiramate on body weight regulation.

Molecular mechanisms of ovarian hyperstimulation syndrome: paracrine reduction of endothelial claudin 5 by hCG in vitro is associated with increased endothelial permeability

Ovarian hyperstimulation syndrome (OHSS) is a potentially life-threatening complication of ovarian stimulation associated with severe vascular hyperpermeability. Primary co-cultures of human luteinized granulosa cells (LGCs) and human umbilical vein endothelial cells (HUVECs) were used as a model of steroidgenic/endothelial cell interaction in OHSS. hCG and the vascular endothelial growth factor (VEGF) inhibitor, Flt-1Fc, were added to co-cultures of LGCs and HUVECs separated by a micropore membrane. Endothelial permeability to labeled bovine serum albumin was measured and the expression of the endothelial cell-specific adhesion protein claudin 5 was investigated using immunocytochemistry and western blotting. The addition of hCG increased HUVEC permeability in the presence of LGCs (P < 0.05). hCG increased VEGF concentrations in both chambers of the co-culture system (P < 0.05). The increased permeability in the presence of LGCs and hCG was inhibited when VEGF was blocked by Flt-1Fc (P < 0.05). Endothelial membrane claudin 5 protein was reduced in the presence of hCG and LGCs, as measured by immunocytochemistry (P < 0.05) and western blotting (P < 0.05) and this reduction was inhibited by Flt-1Fc. hCG had no direct effects on endothelial cell claudin 5. For OHSS, this novel paradigm suggests that hCG can increase endothelial permeability by up-regulating VEGF in LGCs which causes reduction in endothelial claudin 5 expression.

Vascular endothelial growth factor in thyroid cyst fluids

The pathogenesis of cystic thyroid nodules is incompletely understood. Based on the assumption that vascular endothelial growth factor (VEGF) may play an important role in the pathogenesis of thyroid cyst fluid, we investigated the VEGF concentration in cyst fluids of thyroid lesions. Cyst fluids from 24 patients (age 31-84 years) were obtained using ultrasound-guided fine-needle aspiration. The patients' cystic thyroid nodules were of different origins. Thyroid and cyst volumes were determined using high-resolution ultrasonography. VEGF concentrations were determined using a solid-phase enzyme-linked immunosorbent assay (ELISA). Differing elevated VEGF concentrations were demonstrated in cyst fluids of thyroid nodules of varied origins. The VEGF concentration in cyst fluid of patients with adenomatous goiter was significantly higher (P < 0.05) than that in thyroid nodules with cystic degeneration. The highest level of VEGF was found in bloody cyst fluid when compared with levels in other cyst fluids (P < 0.05). Interestingly, there was significant correlation (P < 0.01) between thyroid volume and VEGF concentration in cyst fluid, but no significant correlation (P = 0.20) between cyst volume and VEGF concentration. Significantly increased VEGF concentrations were found in bloody cyst fluid and in cyst fluid of thyroid adenomatous goiter, compared with VEGF concentrations in degenerative thyroid cysts. Our results suggest that VEGF may play an important role in the pathogenesis of thyroid cyst fluid.

Different effects of estradiol and various antiestrogens on TNF-α-induced changes of biochemical markers for growth and invasion of human breast cancer cells

In the field of estrogen therapy breast cancer risk is one of the most controversially discussed topic. Actually, the as yet largest placebo-controlled study, the Women's Health Initiative, rather showed a risk reduction, in contrast to observational studies. In the present study we have investigated the effect of estradiol on TNF-α-induced changes of various markers in human breast cancer cells and compare it with the effect of the antiestrogens tamoxifen and 2-methoxyestradiol. MCF-7 cells were used for the experiments, the incubation time was 96 h. TNF-α elicited a 3–4-fold increase of monocyte-attracting protein-1 (MCP-1) and interleukin-8 (IL-8) as compared to the control value, matrix metalloproteinase-9 (MMP-9) and vascular endothelial growth factor (VEGF) were enhanced by 30 to 40%. E2 alone had no effect on MCP-1, slightly reduced the synthesis of MMP-9 and increased VEGF concentrations by about 20%. In combination with TNF, E2 induced a further stimulation of MCP-1, IL-8 and VEGF, whereby the MMP-9 synthesis was not changed. Tamoxifen and the endogenous estradiol metabolite 2-methoxyestradiol seem to be able to partly inhibit the action of TNF-α and estradiol. Our results suggest that estrogens may slightly increase tumor growth and spreading beyond the effect of chemokines such as TNF-α. However, the magnitude of this E2 effect seems to be marginal as compared to the effect of TNF-α alone. The risk of recurrence of breast cancer in patients taking hormone therapy after breast cancer may be slightly enhanced by estrogens, but seems mainly to be driven by the potency of still existing tumor cells to secrete chemokines which can stimulate tumor growth and spreading.

TGF-beta1, IL-1beta, and Th2 cytokines stimulate vascular endothelial growth factor production from conjunctival fibroblasts

Giant papillary formation containing newly formed vessels is a major characteristic of severe allergic conjunctivitis, such as atopic keratoconjunctivitis (AKC) or vernal keratoconjunctivitis (VKC). We examined production of vascular endothelial growth factor (VEGF) from cultured conjunctival fibroblasts from normal volunteers under stimulation with type 1-, type 2-helper T cell derived and proinflammatory cytokines to investigate the mechanism of giant papillae formation in AKC/VKC. Primary cultured conjunctival fibroblasts were incubated with interleukin (IL)-4, IL-13, IL-1beta, IL-2, tumor necrotizing factor (TNF)-alpha, interferon (IFN)-gamma, or transforming growth factor (TGF)-beta1. Effects of cytokines on VEGF protein secretion in supernatant were assessed by ELISA, and VEGF mRNA expression in cultured cells were assessed by quantitative PCR. TGF-beta1 most effectively increased VEGF concentration with dose- and time-dependent manner IL-1beta, IL-4, and IL-13 significantly increased VEGF concentration. Though IL-2 also showed slight increase of VEGF concentration, it was not statistically significant. TNF-alpha and INF-gamma did not increase VEGF concentration. Quantitative PCR showed significant increase of VEGF mRNA in TGF-beta1, IL-1beta, and IL-4 stimulated fibroblasts. TGF-beta1, IL-1beta, and Th2 cytokines from allergic inflammatory cells induced VEGF production in conjunctival fibroblasts, and may play a crucial role in neovascularization and formation of giant papillae in AKC/VKC.

Circulating Vascular Endothelial Growth Factor Levels in Patients with Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is associated with intermittent hypoxia during sleep. Vascular endothelial growth factor (VEGF) has detectable levels in the circulation and its expression is highly regulated by oxygen tension. We therefore hypothesized that serum VEGF levels will be elevated in patients with OSA. Blood samples were collected at random times during the day from 68 adults and 41 children who were clinically suspected for the presence of OSA, and who underwent overnight polysomnography. University hospital sleep laboratory. N/A. N/A. For both children and adults, serum VEGF levels were significantly higher in polysomnographically confirmed OSA (AHI>15 and AI>5 in adults and children respectively) when compared to those with mild or no disease (p<0.0001). Furthermore, significant correlations were found between VEGF concentrations and respiratory disturbance index and sleep time spent at SpO2 <90%. In addition, VEGF levels in children were higher for any given duration of hypoxia during sleep (p<0.0001). No differences in VEGF emerged between evening and morning samples. However, temporal delays in blood sample processing were associated with spuriously increased VEGF concentrations. Exploratory analysis of the data revealed that serum VEGF concentrations of >150 pg/ml in adults and >100 pg/ml in children were predictive of OSA, when an apnea-hypopnea index >30 and an apnea index >5 were used as disease criteria in adults and children, respectively. We conclude that circulating VEGF levels are frequently elevated in OSA patients, and may play a role in the regulation of tissue oxygen delivery.

The splice variants VEGF121 and VEGF189 of the angiogenic peptide vascular endothelial growth factor are expressed in osteoarthritic cartilage.

Vascular endothelial growth factor (VEGF) has recently been shown to play an important role during endochondral bone formation in hypertrophic cartilage remodeling, ossification, and angiogenesis, but it is not expressed in normal adult cartilage. Since genes expressed during development often reappear in the disease state, we investigated whether VEGF and its receptors (VEGFRs) are expressed in osteoarthritic (OA) cartilage. VEGF production in OA cartilage from the tibial plateau was measured by enzyme-linked immunosorbent assay. Deposition of VEGF and VEGFR was determined by immunohistochemistry. Expression of messenger RNA for the different VEGF splice forms and for VEGFR was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). Increased VEGF concentrations were measured in OA cartilage from the tibial plateau, while VEGF was almost undetectable in normal cartilage but could be immunostained within the intracellular and pericellular matrices of OA chondrocytes. In analyses of cartilage samples from all 10 OA patients evaluated, VEGF121 and VEGF189 were identified as the only VEGF splice forms expressed. RT-PCR and immunohistochemistry for VEGF in normal hyaline cartilage yielded negative findings. In addition to VEGF, VEGFR-2 (kinase domain region/fetal liver kinase 1), but not VEGFR-1 (fms-like tyrosine kinase 1), could be detected by RT-PCR in OA cartilage and immunostained on OA chondrocytes. Apart from its production in hypertrophic chondrocytes, VEGF is also produced in chondrocytes of OA cartilage. While the splice variant VEGF189 binds to extracellular matrix proteoglycans, VEGF121 is diffused freely. Both proteins should contribute to the inflammatory process by autocrine/paracrine stimulation of chondrocytes, chemotaxis of macrophages, and promotion of angiogenesis.

Vascular endothelial growth factor (VEGF) in children, adolescents and young adults with Type 1 diabetes mellitus: relation to glycaemic control and microvascular complications.

To evaluate serum levels of vascular endothelial growth factor (VEGF) in a large group of children, adolescents and young adults with Type 1 diabetes mellitus to investigate whether increased VEGF concentrations are associated with long-term glycaemic control and microvascular complications. The study involved 196 patients with Type 1 diabetes mellitus (age range 2-24 years, onset of diabetes before the age of 12 years, duration of disease longer than 2 years), without clinical and laboratory signs of microvascular complications; they were divided into three groups (group 1 - n = 37, age < 6 years; group 2 - n = 71, age 6-12 years; group 3 - n = 88, age > 12 years). Fifty-three adolescents and young adults (age 16.1-29.7) with different grades of diabetic retinopathy and microalbuminuria were also selected (group 4). A total of 223 healthy controls were matched for age and sex with each group of patients with diabetes mellitus. VEGF serum levels were significantly increased in pre-school and pre-pubertal children with diabetes as well as in pubertal patients compared to controls. VEGF concentrations were markedly increased in adolescents and young adults with microvascular complications compared with both healthy controls and diabetic patients without retinopathy or nephropathy. Multivariate analysis showed that elevation of VEGF in serum was an independent correlate of complications. One-year mean HbA1c values were significantly correlated with VEGF concentrations (r = 0.372; P < 0.01). Children with HbA1c levels greater than 10% had significantly higher VEGF concentrations when compared with matched patients whose HbA1c levels were lower than 10%. In poorly controlled diabetic children (HbA1c > 10%), long-term (2 years) improvement of glycaemic control (aiming at HbA1c < 7%) resulted in a significant reduction of VEGF levels. VEGF serum concentrations are increased in prepubertal and pubertal children with diabetes. Glycaemic control influences VEGF serum levels. Severity of microvascular complications is associated with marked increase of VEGF concentrations in the serum of these patients.

Further evidence for oxidant-induced vascular endothelial growth factor up-regulation in the bronchoalveolar lavage fluid of lung cancer patients undergoing radio-chemotherapy.

Vascular endothelial growth factor (VEGF) is a potent inducer of physiological and neoplastic blood vessel growth. Moreover, in vitro studies have demonstrated that VEGF can be up-regulated by conditions associated with the generation of free radicals and reactive oxygen species. In a previous study we reported on strongly increased VEGF concentrations in the bronchoalveolar lavage fluid (BALF) of patients with lung cancer under therapy. In this study we aimed to reveal whether this increase was due to the therapy-associated intrapulmonary oxidative burden. A total of 103 BALF samples from 94 patients with lung cancer (82 patients with non-small-cell lung cancer, 12 patients with small-cell lung cancer) were studied at different times before, during or after cancer treatment. VEGF levels in the lavage fluid and ratios of oxidised methionine in proteins of epithelial lining fluid (ELF) were determined. As reported previously, strongly increased VEGF levels in the ELF were observed in patients undergoing chemotherapy when radiotherapy had been administered before. Increased levels of oxidised methionine indicated that these patients suffered from severe pulmonary oxidative stress that was significantly less in patients undergoing only chemotherapy. Similarly, VEGF concentrations in the ELF were significantly elevated in cancer patients at the time of diagnosis, but the oxidised methionine levels did not reveal significant oxidant/antioxidant imbalances in these patients. Systemic chemotherapy is associated with oxidative stress in vivo, which is more pronounced if patients are additionally treated with radiation. VEGF levels in the ELF are increased by this condition as well as by the activity of the tumour itself.

New advances in the therapy of allergic conjunctivitis

Giant papillary formation containing newly formed vessels is a major characteristic of severe allergic conjunctivitis, such as atopic keratoconjunctivitis (AKC) or vernal keratoconjunctivitis (VKC). We examined production of vascular endothelial growth factor (VEGF) from cultured conjunctival fibroblasts from normal volunteers under stimulation with type 1-, type 2-helper T cell derived and proinflammatory cytokines to investigate the mechanism of giant papillae formation in AKC/VKC. Primary cultured conjunctival fibroblasts were incubated with interleukin (IL)-4, IL-13, IL-1beta, IL-2, tumor necrotizing factor (TNF)-alpha, interferon (IFN)-gamma, or transforming growth factor (TGF)-beta1. Effects of cytokines on VEGF protein secretion in supernatant were assessed by ELISA, and VEGF mRNA expression in cultured cells were assessed by quantitative PCR. TGF-beta1 most effectively increased VEGF concentration with dose- and time-dependent manner IL-1beta, IL-4, and IL-13 significantly increased VEGF concentration. Though IL-2 also showed slight increase of VEGF concentration, it was not statistically significant. TNF-alpha and INF-gamma did not increase VEGF concentration. Quantitative PCR showed significant increase of VEGF mRNA in TGF-beta1, IL-1beta, and IL-4 stimulated fibroblasts. TGF-beta1, IL-1beta, and Th2 cytokines from allergic inflammatory cells induced VEGF production in conjunctival fibroblasts, and may play a crucial role in neovascularization and formation of giant papillae in AKC/VKC.