Reduction Of Vascular Endothelial Growth Factor Research Articles

Cell-Cell Junctions and Vascular Endothelial Growth Factor in Rat Lung as Affected by Ischemia/Reperfusion and Preconditioning With Inhaled Nitric Oxide

Previous investigations have shown that short term inhalation of nitric oxide (NO) before ischemia and reperfusion (I/R) prevents I/R-related consequences on lung function. Here we correlate effects of NO-induced preconditioning, especially on the lung permeability barrier, with analysis of cell junction proteins and the level of vascular endothelial growth factor (VEGF). A rat model of left lung in situ I/R was used. After left lateral thoracotomy, left lung ischemia was maintained for 60 min, followed by 30 min or 4 h (h) reperfusion (I/R groups). In the NO groups, inhalation of NO (10 min, 15 ppm) preceded I/R. Animals in control groups underwent sham surgery without NO inhalation and ischemia. The extent of I/R injury was assessed in terms of oxygenation (arterial PO(2)) and lung permeability (Evans blue extravasation). Expression of junctional proteins and phosphorylation was determined in complete protein extracts from lung tissue, whereas the adherens junction (AJ) core complex was analyzed in Triton extracts by co-immunoprecipitation using antibodies against E-cadherin and VE-cadherin. The inhalation of NO prevented the I/R-induced increase of permeability at 30 min reperfusion, and the PO(2) increased from 27% of controls in the I/R group to 77% in the NO group. Left lung I/R correlated with a progressive loss of cadherins (VE-cadherin, E-cadherin, desmoglein 1) during reperfusion, whereas AJ catenins were largely preserved. Preconditioning with NO resulted in an increased ratio of catenins (alpha- and beta-catenin) to E-cadherin in immunoprecipitates and in reduced phosphorylation of beta-catenin. A reduction of VEGF in left lung lavage fluid was observed at 4 h but not at 30 min reperfusion. The NO-induced changes of the AJ complex may have contributed to the stabilization of the lung permeability barrier during reperfusion.

MicroRNAs Regulate Ocular Neovascularization

In this study, we used ischemia-induced retinal neovascularization (NV) as a model to investigate the possible role of microRNAs in a clinically important disease process. Microarray analysis demonstrated seven microRNAs (miR-106a, -146, -181, -199a, -214, -424, and -451) that were substantially increased and three microRNAs (miR-31, -150, and -184) that were substantially decreased in ischemic retina. Potential targets for the upregulated microRNAs were not identified, but bioinformatic analysis suggested target genes for the downregulated microRNAs, and these were confirmed using a luciferase reporter assay. Real-time reverse transcriptase PCR confirmed that the substantial levels of miR-31, -150, and -184 present in normal retina were significantly reduced in ischemic retina. Interestingly, constitutive levels of miR-31 and -184 are high in the cornea and lens, two avascular tissues. Intraocular injection of pre-miR-31, -150, or -184 significantly reduced ischemia-induced retinal NV, and injection of pre-miR-31 or -150 also significantly reduced choroidal NV. These data suggest that alteration of microRNA levels contributes to two types of ocular NV, and that injection or enhanced expression of microRNAs is a potential therapeutic strategy.

VEGF Inhibition and Renal Thrombotic Microangiopathy

The glomerular microvasculature is particularly susceptible to injury in thrombotic microangiopathy, but the mechanisms by which this occurs are unclear. We report the cases of six patients who were treated with bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), in whom glomerular disease characteristic of thrombotic microangiopathy developed. To show that local reduction of VEGF within the kidney is sufficient to trigger the pathogenesis of thrombotic microangiopathy, we used conditional gene targeting to delete VEGF from renal podocytes in adult mice; this resulted in a profound thrombotic glomerular injury. These observations provide evidence that glomerular injury in patients who are treated with bevacizumab is probably due to direct targeting of VEGF by antiangiogenic therapy.

1α,25‐dihydroxyvitamin D regulates vascular endothelial growth factor and hypoxia‐inducible factor‐1α in breast epithelial cells

The angiogenic vascular endothelial growth factor (VEGF) has been shown to be differentially regulated by 1α, 25‐dihydroxyvitamin D (1,25(OH)2D) in untransformed cells and cancer cells, but the effect at different stages of cancer progression has not been investigated in breast epithelial cells. Evidence also suggests that 1,25(OH)2D reduces VEGF expression through stabilization of hypoxia‐inducible factor (HIF)‐1α, a direct transcriptional regulator of VEGF. The purpose of this study was to determine the impact of 1,25(OH)2D on VEGF expression in untransformed and H‐ras transfected MCF10A breast epithelial cells. Compared to vehicle, 1,25(OH)2D treatment (24 hrs) significantly reduced VEGF mRNA expression in a dose‐dependent manner, with significance achieved at 1 nM (25%) in untransformed cells. Similarly, with 1,25(OH)2D (1 nM) treatment, mRNA expression of HIF‐1α was also significantly decreased by 32% compared to vehicle in untransformed cells. In ras‐transfected MCF10A cells, 1,25(OH)2D‐mediated reduction of VEGF (28%) and HIF‐1α (34%) mRNA was achieved only at a higher dose (10 nM and 100nM, respectively) compared to vehicle. These results suggest that in breast cells, 1,25(OH)2D‐induced suppression of VEGF may occur through the transcriptional regulation of HIF‐1α, and the effect may be reduced in the presence of the H‐ras oncogene. Supported by NIH DK069965.

In vivo platelet activation is responsible for enhanced vascular endothelial growth factor levels in hypertensive patients

Background Essential hypertension may be a consequence of an abnormal regulation of vascular endothelial growth factor (VEGF). In vivo activation of platelets does result in the release of VEGF. Thus, we investigated whether VEGF production in hypertensive patients is related to in vivo platelet activation, and whether it may be modified by aspirin treatment. Methods Plasma VEGF, soluble (s)P-selectin and thrombin–anti-thrombin complex (TATc) were analyzed in 80 patients with therapeutically controlled essential hypertension and 40 age and sex-matched healthy normotensive controls. The effects of a 6-month treatment with aspirin 100 mg/day on VEGF levels of 20 hypertensive patients were also studied. Results Plasma VEGF ( p < 0.0001), sP-selectin ( p = 0.01) and TATc ( p = 0.02) levels were higher in hypertensives compared to controls. Multivariate analysis including age, sex, risk factors, cardiovascular disease, anti-hypertensive treatment, sP-selectin and TATc showed that only sP-selectin was an independent predictor of VEGF (beta = 0.40, p < 0.03). Aspirin treated hypertensives showed a significant reduction of sP-selectin (− 26%, p < 0.01) and VEGF (− 33%, p < 0.01) levels. Moreover, the reduction of plasma VEGF levels directly correlated with that of sP-selectin (Rho = 0.46, p = 0.04). Conclusions In vivo activation of platelets in hypertensive patients is responsible for enhanced circulating VEGF levels, which are significantly lowered by aspirin treatment.

Lowering Homocysteine Decreases Levels and Expression of VEGF 165 and Endostatin

Homocysteine, vascular endothelial growth factor (VEGF), and endostatin have been implicated in angiogenesis and in the development and progression of atherothrombotic vascular disease. We sought to determine whether homocysteine modulates plasma levels of VEGF and endostatin and their expression in leukocytes in patients with peripheral arterial disease (PAD) or diabetes mellitus (DM). Ten patients with PAD and 15 patients with type 2 DM were evaluated before and 6 wk after oral administration of folic acid and B vitamins. Evaluation included measurements of plasma levels of homocysteine, VEGF, and endostatin by enzyme-linked immunosorbent assay and the expression of VEGF and endostatin mRNAs in leukocytes using RT-PCR. The measurements were compared with baseline findings in 12 healthy subjects. Basal homocysteine (P < 0.001) and VEGF (P < 0.01) levels were elevated in all patients versus healthy subjects. Basal endostatin levels were lower in patients with PAD but were higher in patients with DM compared with healthy subjects (P < 0.001). In patients with PAD or DM, folic acid and B vitamins administration resulted in significant reduction (P < 0.001) of plasma levels of homocysteine (20.9% and 26.2%), VEGF (29.7% and 40.4%) and endostatin (9.4% and 5.7%), respectively. Moreover, VEGF and endostatin mRNA expression in leukocytes was down-regulated in all patients after B vitamins and folate treatment. These findings demonstrate that lowering of homocysteine with B vitamins and folic acid resulted in substantial reduction of plasma levels of VEGF but minimal reduction of endostatin and in down-regulation of their expression in leukocytes in patients with PAD or DM.

Dietary Influence on Pancreatic Cancer Growth by Catechin and Inositol Hexaphosphate

Pancreatic cancer is an extremely virulent form of cancer with few effective treatments. Catechin and inositol hexaphosphate (IP6), two naturally occurring molecules found in green tea and high-fiber foods, respectively, are compounds that have been shown to demonstrate anti-proliferative effects when administered as single therapeutic agents against a number of cancers. We hypothesized that, alone and in combination, IP6 and catechin would be effective against pancreatic cancer. Pancreatic (PANC-1 and MIAPACA) cancer cell lines were cultured and treated with IP6 (0.8 mM/well), catechin (100 microM/well), and the combination of the two. Cell viability was measured by 3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide (MTT) at 24, 48, and 72 h. Vascular endothelial growth factor (VEGF) was measured in the cell supernatants by ELISA. Apoptosis was evaluated by Annexin V-fluorescein isothiocyanate (FITC). The combination of catechin and IP6 significantly inhibited proliferation in the PANC-1 cell line at 24, 48, and 72 h compared to single agents (P < 0.001). Growth of the MIAPACA cell line was inhibited (P < 0.01) by each agent alone, but additive inhibitory effects were not seen. An increase in early apoptosis was attributed to catechin therapy in both cell lines (P < 0.01). The combination of these agents also increased early apoptotic activity when compared to the control (P < 0.001). IP6 reduced VEGF in both cell lines (P < 0.01). In combination, catechin and IP6 amplified VEGF reduction compared to each agent in MIAPACA and control (P < 0.002). These results, combined with the prevalence of these compounds in safe, naturally occurring foods, make catechin and IP6 attractive therapies for treatment, and possibly in preventative trials, of pancreatic cancer.

Impaired integration of endothelial progenitor cells in capillaries of diabetic wounds is reversible with vascular endothelial growth factor infusion

To understand impaired angiogenesis in diabetic wounds, polyvinyl tubes were implanted subcutaneously in rats to form a granulation tissue for 2 weeks and the granulation tissue was studied after inducing diabetes with streptozotocin. By 1 week of diabetes, the granulation tissue was bloody and thinner than controls, its medial layer was depleted of microvessels, and the surviving vessels appeared dehisced. Vascular endothelial growth factor (VEGF) in the diabetic granulation tissue was reduced by 50% compared with control granulation tissue. After 3 days of diabetes, the diabetic tissue showed a greater degree of apoptosis in the microvessels. Chemotactic factors [stromal cell-derived factor-1alpha and chemokine receptor-4 (CXCR-4)], responsible for attracting bone marrow cells, showed equal intensity in control and diabetic tissues. As expected, progenitor endothelial CD-34 cells were observed in abundance in both the control and the diabetic granulation tissues. However, although the CD-34-positive cells appeared mostly to be integrated in the blood vessels of the control tissue, fewer such cells were present in the blood vessels of the diabetic tissues, suggesting that CD-34 failed to integrate into new blood vessels. Infusion of VEGF in the granulation tissue of diabetic rats for 1 week resulted in complete prevention of the microvascular defect compared with the contralateral granulation tissue that showed the typical diabetic changes. It was concluded that diabetes causes reduction of VEGF in the wound, resulting in loss of blood vessels by apoptosis and possible failure of CD-34 cells to integrate into the vessel structure.

Circulating VEGF Reduction, Response and Outcome in Advanced Colorectal Cancer Patients Treated with Cetuximab Plus Irinotecan

We designed this trial to investigate if modifications in levels of circulating vascular endothelial growth factor (VEGF) may be related to clinical response and outcome in advanced colorectal cancer patients during treatment with a weekly combination of cetuximab plus irinotecan. A total of 45 heavily pretreated metastatic colorectal cancer patients were prospectively evaluated for circulating levels of VEGF during the treatment with cetuximab plus weekly irinotecan. VEGF circulating levels were assessed at the following time points: just before and at 1, 21, 50 and 92 days after the start of cetuximab plus irinotecan treatment. Basal VEGF median levels were significantly decreased just 1 day after the first anticancer infusion (p = 0.016) and reached the highest statistical significance 92 days after the first infusion (p < 0.0001). A total of 22 patients showed a reduction in median VEGF circulating levels of at least 50% 92 days after the first infusion with respect to the basal time point. For patients with at least a 50% reduction in VEGF levels, the response rate was 45.5% compared with 8.7% in the nonreduced VEGF group (p = 0.014). The median time to progression was 6 months in the reduced VEGF group versus 3.9 months in the other patients (p < 0.0001). In addition, overall survival was longer in patients with VEGF reduction (11.0 months) than in patients without (9.6 months; p = 0.01). These data represent the first evidence that suggests a role of VEGF reduction in the prediction of efficacy of treatment with cetuximab plus weekly irinotecan in heavily pretreated advanced colorectal cancer patients.

Elevated vascular endothelial growth factor levels in Coats disease: rapid response to pegaptanib sodium

The purpose was to report a case of elevated intraocular vascular endothelial growth factor (VEGF) levels in a 2-year-old boy with stage 4 Coats disease. Interventional case report. A 2-year-old boy with severe Coats disease and complex retinal detachment refractory to surgical intervention underwent two injections of intravitreal pegaptanib sodium in his right eye 8 weeks apart. After intravitreal injection there was a marked reduction in VEGF (908 to 167 pg/ml) levels and improvement of exudation, hemorrhage, and nearly complete reattachment of his retina within 3 weeks of treatment. The patient remains stable 6 months post-treatment. Coats disease may have a component of dysregulation of VEGF-mediated angiogenesis as evidenced by elevated levels in this patient.

Poly(ADP-ribose)polymerase inhibition decreases angiogenesis

Inhibitors of poly(ADP-ribose)polymerase (PARP), a nuclear enzyme involved in regulating cell death and cellular responses to DNA repair, show considerable promise in the treatment of cancer both in monotherapy as well as in combination with chemotherapeutic agents and radiation. We have recently demonstrated that PARP inhibition with 3-aminobenzamide or PJ-34 reduced vascular endothelial growth factor (VEGF)-induced proliferation, migration, and tube formation of human umbilical vein endothelial cells (HUVECs) in vitro. Here, we show dose-dependent reduction of VEGF- and basic fibroblast growth factor (bFGF)-induced proliferation, migration, and tube formation of HUVECs in vitro by two potent PARP inhibitors 5-aminoisoquinolinone-hydrochloride (5-AIQ) and 1,5-isoquinolinediol (IQD). Moreover, PARP inhibitors prevented the sprouting of rat aortic ring explants in an ex vivo assay of angiogenesis. These results establish the novel concept that PARP inhibitors have antiangiogenic effects, which may have tremendous clinical implications for the treatment of various cancers, tumor metastases, and certain retinopathies.

Apoptotic effect of EGCG in HT-29 colon cancer cells via AMPK signal pathway

EGCG [(−)epigallocatechin-3-gallate], a green tea-derived polyphenol, has been shown to suppress cancer cell proliferation, and interfere with the several signaling pathways and induce apoptosis. Practically, there is emerging evidence that EGCG has a potential to increase the efficacy of chemotherapy in patients. We hypothesized that EGCG may exert cell cytotoxicity through modulating AMPK (AMP-activated protein kinase) followed by the decrease in COX-2 expression. EGCG treatment to colon cancer cells resulted in a strong activation of AMPK and an inhibition of COX-2 expression. The decreased COX-2 expression as well as prostaglandin E 2 secretion by EGCG was completely abolished by inhibiting AMPK by an AMPK inhibitor, Compound C. Also, the activation of AMPK was accompanied with the reduction of VEGF (vascular endothelial growth factor) and glucose transporter, Glut-1 in EGCG-treated cancer cells. These findings support the regulatory role of AMPK in COX-2 expression in EGCG-treated cancer cells. Furthermore, we have found that reactive oxygen species (ROS) is an upstream signal of AMPK, and the combined treatment of EGCG and chemotherapeutic agents, 5-FU or Etoposide, exert a novel therapeutic effect on chemo-resistant colon cancer cells. AMPK, a molecule of newly defined cancer target, was shown to control COX-2 in EGCG-treated colon cancer cells.

Angiogenesis modifications are predictive of response and outcome in heavily pretreated advanced colorectal cancer patients during therapy with cetuximab plus irinotecan

3562 Background: Angiogenesis has been correlated with increased invasion and metastases in a variety of human neoplasms. Inadequate inhibition of the growth of tumor microvessels by anticancer agents may result in treatment failure, rated clinically as progressive or stable disease. We designed this trial to investigate if Vascular Endothelial Growth Factor (VEGF) circulating levels modifications may be related with clinical response and outcome in advanced colorectal cancer patients during treatment with a weekly combination of cetuximab plus irinotecan. Methods: 45 heavily pretreated metastatic colorectal cancer patients were prospectively evaluated for circulating levels of VEGF during the treatment with cetuximab (initial dose of 400 mg per square meter, followed by weekly infusions of 250 mg per square meter) plus weekly irinotecan (90 mg per square meter). VEGF circulating levels were assessed at the following time-points: just before and at 1, 21, 50 and 92 days after the start of cetuximab plus irinotecan treatment. Results: Basal serum VEGF median levels were significantly decreased just at the first day (after the first treatment infusion (P=0.016). The VEGF persisted at the following time points reaching the highest statistical significance 92 days after the first infusion (P&lt;0.0001). Twenty-two patients showed a reduction in median VEGF circulating levels of at least 50% 92 days after the first infusion respect to the basal time point. In the group of patients with at least 50% reduction of VEGF levels the response rate was 59.1% vs 21.7% in the non reduced VEGF group (P=0.024). Moreover, the median time to progression was 6.12 months (95% C.I.: 3.9 - 7.1) in the reduced VEGF group vs 2.3 months (95% C.I.: 1.6 - 3.5) in the other patients (P=0.001). Finally, also overall survival was longer in patients who developed VEGF reduction (12.3 months; 95% C.I.: 8.65 - 15.9) than this recorded in patients without the reduction (6.4 months; 95% C.I.: 5.6 - 8.4) (P=0.05). Conclusions: The present data represent the first evidence that suggest a role of VEGF reduction in the prediction of efficacy of treatment with cetuximab plus weekly irinotecan in heavily pretreated advanced colorectal cancer patients. No significant financial relationships to disclose.

The Role of PDGF Receptor Inhibitors and PI3-Kinase Signaling in the Pathogenesis of Corneal Neovascularization

Corneal neovascularization remains an unsolved therapeutic problem. Platelet-derived growth factor (PDGF) is directly linked to vessel formation and stabilization. This study was undertaken to elucidate the mechanisms by which PDGF exerts its effects on corneal angiogenesis. Corneal neovascularization was induced in C57 mice by removal of the limbal epithelium. When mature vessels appeared after 7 days, mice were treated with the PDGF receptor-beta inhibitor AG 1296 or the phosphatidylinositol 3-kinase (PI3-K)-inhibitors wortmannin and LY294002, respectively, using an intraperitoneally implanted miniosmotic pump. At day 14 after scraping, corneas of treated and untreated (control) mice were dissected and immunostained with FITC-CD31 antibody for endothelial cells and with Cy3-SMA (smooth muscle actin) for pericytes. VEGF (vascular endothelial growth factor), ang1/2 (angiopoietin 1 and 2), and PDGF mRNA levels of treated and untreated corneas were determined by real-time RT-PCR. Mice treated with the PDGF inhibitor AG 1296 showed an inhibition of corneal neovascularization of 21.1% and a reduction of pericytes of 52% in the newly formed vessels compared with untreated animals. VEGF, ang1, ang2, and PDGF mRNA expression was reduced in the corneas of AG 1296-treated mice compared with the respective control. Treatment with the PI3-K inhibitors wortmannin and LY29002 had similar effects, inducing a decrease in corneal neovascularization and a reduction of VEGF, ang1, ang2, and PDGF mRNA levels. Inhibition of the PDGF signal pathway results in loss of pericytes and a reduction in vessel density in the neovascularized cornea that correlates with reduced expression of PDGF, ang1/2, and VEGF mRNA. Furthermore, PI3-K was shown to be involved in the regulation of VEGF, ang1, and PDGF, as the PI3-K inhibitors wortmannin or LY294002 had similar effects. Because PDGF is a known stimulus for PI3-K activation, it can be postulated that the observed decrease in VEGF, ang1/2, and PDGF mRNA levels on administration of the PDGF inhibitor is caused by the decreased activation of the PI3-K signaling cascade.

Changes in bone resorption and vascular endothelial growth factor after a single zoledronic acid infusion in cancer patients with bone metastases from solid tumours

Zoledronic acid (Zometa, ZOL) is increasingly used to treat tumour-induced bone disease, and is also reported to have antiangiogenic properties in vivo. In this study, we have investigated the correlations between changes in the proangiogenic cytokine, vascular endothelial growth factor (VEGF), and markers of bone resorption in a cohort of patients with metastatic bone disease, following a single infusion of ZOL. Twenty-four consecutive selected cancer patients with scintigraphic and radiographic evidence of bone metastases were treated for the first time with a single infusion of 4 mg ZOL. Patients were considered ineligible if they had received any steroid therapy, radiotherapy, chemotherapy, immunotherapy or haemopoietic growth factors in the 4 weeks before or during the study period. Circulating levels of VEGF and beta crosslinked type I collagen C-telopeptide (betaCTX) were measured at base-line and at 1, 2, 7 and 21 days following ZOL infusion. The majority of our patients (23/24) developed a significant reduction in circulating levels of betaCTX at just 1 day after the single zoledronic acid infusion, median percentage decrease 67.05% (95% CI, 52.39%; 76.27%). This reduction persisted at all following time points in almost all subjects in our patient population (day 2, 95.8%; day 7, 100%; day 21, 91.7%). The median decrease at day 2 was 85.67% (95% CI, 78.23%; 90.16%); at day 7, 67.38% (95% CI, 67.38%; 86.98); and at day 21, 76.89% (95% CI, 35.00%; 83.16%). Moreover, a linear regression model with variance analysis demonstrated a statistically significant correlation between median VEGF and betaCTX circulating levels at each of the time points (1, 2, 7 and 21 days after ZOL infusion). The present work demonstrates that a single infusion of ZOL was able to induce a rapid and long lasting decrease of betaCTX plasma levels in the majority (23/24) of the included cancer patients. Furthermore, we found that there is a correlation between the levels of VEGF and betaCTX following ZOL treatment. Future clinical trials should be designed to prospectively evaluate the prognostic role of reduction of betaCTX and VEGF in response to ZOL to predict clinical and skeletal outcome.

Vascular endothelial growth factor serum concentrations in hypercholesterolemic patients

Objective. Vascular endothelial growth factor (VEGF) promotes normal and pathological angiogenesis. VEGF is a chemotactic factor for macrophages and vascular smooth muscle cells, and induces synthesis of metalloproteinases and adhesion molecules. VEGF expression is regulated by hypoxia, cytokines, oncogenes, and oxidized low‐density lipoprotein (LDL). The purpose of this study was to determine the relationship between levels of lipid parameters and VEGF, to investigate whether pravastatin treatment influences VEGF serum concentrations, and to examine the relationship between VEGF and the variations in post‐treatment lipid and inflammatory parameters. Material and methods. Eighteen patients aged 48±6.8 years with total cholesterol (TC) >6.1 mmol/L comprised the hypercholesterolemic group. The controls included 12 individuals aged 50±7.4 years with TC <5.1 mmol/L. TC, high‐density lipoprotein cholesterol (HDLC), triglycerides, LDLC, C‐reactive protein (CRP), and VEGF were determined in both groups at baseline, and in the hypercholesterolemic group after 4 months of treatment with 20 mg/day pravastatin. Results. A significant correlation was observed between concentrations of VEGF and TC, LDLC and TG, and a significant difference in VEGF concentration was observed between the control group (mean 142 ng/L) and the hypercholesterolemic group (mean 272.9 ng/L). A significant decrease was observed in TC (14.7 %), LDLC (21.5 %), CRP (22.7 %), and VEGF (14.8 %) after 4 months of treatment with pravastatin. Conclusions. A relationship was found between serum levels of VEGF and most atherogenic lipoproteins. In patients with hypercholesterolemia treated with pravastatin, a reduction in VEGF and CRP was seen in addition to lipid decreases.

Renal Effects of HMG-CoA Reductase Inhibition in a Rat Model of Chronic Inhibition of Nitric Oxide Synthesis

Background/Aims: In addition to their lipid-lowering effects, HMG-CoA reductase inhibitors (statins) induce a variety of pleiotropic actions that have been recently studied in the area of cardiovascular and renal protection. In the present studies we sought to determine whether statins retain beneficial effects in the experimental model of NO deficiency achieved by chronic administration of a pressor dose of L-arginine analogue N-nitro-L-arginine-methyl ester (L-NAME). Methods: To address this issue, blood pressure (BP), renal function (GFR), and albuminuria were determined in rats treated for 4 weeks with L-NAME, L-NAME + atorvastatin (ATO), and in untreated controls. In addition, renal cortical protein expression of caveolin 1 (CAV1), vascular endothelial growth factor (VEGF), and activity of RhoA were also determined. Results:L-NAME administration resulted in sustained elevation of BP, decreased GFR, and in higher albuminuria as compared to control animals. Co-administration of ATO with L-NAME normalized albuminuria and prevented decreases in GFR in L-NAME rats without having an impact on pressor effects of L-NAME. CAV1 protein expression was similar in all groups of rats. In contrast, VEGF expression and RhoA activity was increased in L-NAME-treated animals, and normalized with co-administration of ATO. Conclusion: Treatment with ATO exerts early nephroprotective effects in the NO-deficient model of hypertension. These effects could be mediated by amelioration of VEGF expression and reduction of RhoA activity.

Zoledronic-Acid-Induced Circulating Level Modifications of Angiogenic Factors, Metalloproteinases and Proinflammatory Cytokines in Metastatic Breast Cancer Patients

Background: To evaluate the modifications of circulating angiogenic factors, metalloproteinases and acute-phase cytokines after the first single zoledronic acid (ZA) intravenous infusion. Experimental Design:Eighteen consecutive breast cancer patients with bone metastases were evaluated for circulating levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), metalloproteinase 1 (MMP-1), metalloproteinase 2 (MMP-2), interleukins 1β, 6 and 8 (IL-1β, IL-6, IL-8), interferon γ, tumor necrosis factor α (TNF-α) and transforming growth factor β₁ just before and 2 and 7 days after ZA infusion. Results: The MMP-2 basal value showed a statisticallysignificant decrease 48 h after ZA (p = 0.01), being at 7 days higher than the day 2 value (p = 0.03). The VEGF basal value showed a statisticallysignificant decrease 48 h after ZA infusion (p = 0.03), increasing above the basal level at 7 days (p = 0.07). The bFGF basal level almost significantly decreased 2 days after infusion (p = 0.06), being at 7 days higher than the basal value (p = 0.09). Comparing the day 2 values with basal ones, the linear regression model showed a significantpositive correlation between IL-8 and bFGF (p = 0.02), IL-8 and TNF-α (p < 0.0001), bFGF and TNF-α (p = 0.01), MMP-1 and TNF-α (p = 0.02). Conclusions: ZA could exert an antiangiogenic activity and inhibition of tumor cell bone invasiveness by a transient reduction of VEGF, bFGF and MMP-2 circulating levels after infusion.

Inhaled Nitric Oxide Enhances Distal Lung Growth after Exposure to Hyperoxia in Neonatal Rats

Exposure of newborn rats to hyperoxia impairs alveolarization and vessel growth, causing abnormal lung structure that persists during infancy. Recent studies have shown that impaired angiogenesis due to inhibition of vascular endothelial growth factor (VEGF) signaling decreases alveolar and vessel growth in the developing lung, and that nitric oxide (NO) mediates VEGF-dependent angiogenesis. The purpose of this study was to determine whether hyperoxia causes sustained reduction of lung VEGF, VEGF receptor, or endothelial NO synthase (eNOS) expression during recovery, and whether inhaled NO improves lung structure in infant rats after neonatal exposure to hyperoxia. Newborn rat pups were randomized to hyperoxia [fraction of inspired oxygen (Fio(2)), 1.00] or room air exposure for 6 d, and then placed in room air with or without inhaled NO (10 ppm) for 2 wk. Rats were then killed for studies, which included measurements of body weight, lung weight, right ventricular hypertrophy (RVH), morphometric analysis of alveolarization (by mean linear intercept (MLI), radial alveolar counts (RAC), and vascular volume (Vv), and immunostaining and Western blot analysis. In comparison with controls, neonatal hyperoxia reduced body weight, increased MLI, and reduced RAC in infant rats. Lung VEGF, VEGFR-2, and eNOS protein expression were reduced after hyperoxia. Inhaled NO treatment after hyperoxia increased body weight and improved distal lung growth, as demonstrated by increased RAC and Vv and decreased MLI. We conclude that neonatal hyperoxia reduced lung VEGF expression, which persisted during recovery in room air, and that inhaled NO restored distal lung growth in infant rats after neonatal hyperoxia.

Impact of surgery and chemotherapy on von Willebrand factor and vascular endothelial growth factor levels in colorectal cancer

von Willebrand factor (vWf) is thought to mediate binding of tumour cells to platelets and to favour their systemic spreading capacity. Platelets involved in tumour angiogenesis are capable of releasing vascular endothelial growth factor (VEGF). Hence, levels of vWf and VEGF may correlate with cancer stage. The objectives are determine the impact of surgery and chemotherapy on vWf and VEGF in colorectal cancer (CRC) patients. Twenty healthy volunteers (group 1), 14 patients with locally advanced CRC (group 2) and 12 patients with metastatic CRC (group 3) were enrolled. Blood samples were taken at recruitment in group 1, and before and after surgery and chemotherapy in groups 2 and 3, respectively. Blood levels of vWf, VEGF, platelet count, C-reactive protein (CRP), ceruloplasmin and carcinoembrionary antigen (CEA) were measured. At baseline, group 3 showed higher concentrations of vWf than the other groups (p<0.05). In group 2, vWf became elevated 40% post-surgery (p=0.016), independently of changes in CRP or ceruloplasmin. In group 3, chemotherapy caused a 42% reduction in VEGF (p=0.015). There was a strong correlation between higher vWf levels and more advanced CRC stage at diagnosis. These levels were elevated post-surgery in patients with locally advanced CRC. Chemotherapy significantly decreased VEGF in metastatic CRC patients before CEA showed any significant change.