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Cancer metastases into the brain constitute one of the most severe, but not uncommon, manifestations of cancer progression. Several factors control how cancer cells interact with the brain to establish metastasis. These factors include mediators of signaling pathways participating in migration, infiltration of the blood–brain barrier, interaction with host cells (e.g., neurons, astrocytes), and the immune system. Development of novel therapies offers a glimpse of hope for increasing the diminutive life expectancy currently forecasted for patients suffering from brain metastasis. However, applying these treatment strategies has not been sufficiently effective. Therefore, there is a need for a better understanding of the metastasis process to uncover novel therapeutic targets. In this review, we follow the journey of various cancer cells from their primary location through the diverse processes that they undergo to colonize the brain. These processes include EMT, intravasation, extravasation, and infiltration of the blood–brain barrier, ending up with colonization and angiogenesis. In each phase, we focus on the pathways engaging molecules that potentially could be drug target candidates.

Cancer metastasis into the brain constitutes one of the most severe but not uncommon development of cancer growth. Several factors control how cancer types interact with the brain to establish metastasis These factors include system of migration, system of infiltration of the blood-brain barrier and the interaction with host cells (e.g., neurons, astrocytes) and the immune system fight against metastasis in the brain. Although, brain radiotherapy is the main treatment procedure carried out to treat, new therapies are emerging that constitute a glimpse of hope for increasing the diminutive life expectancy currently forecasted to cancer patients who are facing the prospectus of brain metastasis. However applying these therapeutic strategies has been has not been effective. Thus there is a need for better understanding of the metastasis process in order to suggest novel therapeutic targets. In this review, we follow the journey of various cancer cells from their primary location through the various process that they undergo including EMT, penetration of the ECM, intravasation, extravasation and infiltration of the blood brain barrier ending up with colonization and angiogenesis. In each phase, we focus on molecules that could potentially be drug target candidates.

Supplemental Digital Content is available in the text., Rationale: Despite increasing understanding of the prognostic importance of vascular stiffening linked to perivascular fibrosis in hypertension, the molecular and cellular regulation of this process is poorly understood. Objectives: To study the functional role of microRNA-214 (miR-214) in the induction of perivascular fibrosis and endothelial dysfunction driving vascular stiffening. Methods and Results: Out of 381 miRs screened in the perivascular tissues in response to Ang II (angiotensin II)-mediated hypertension, miR-214 showed the highest induction (8-fold, P=0.0001). MiR-214 induction was pronounced in perivascular and circulating T cells, but not in perivascular adipose tissue adipocytes. Global deletion of miR-214−/− prevented Ang II-induced periaortic fibrosis, Col1a1, Col3a1, Col5a1, and Tgfb1 expression, hydroxyproline accumulation, and vascular stiffening, without difference in blood pressure. Mechanistic studies revealed that miR-214−/− mice were protected against endothelial dysfunction, oxidative stress, and increased Nox2, all of which were induced by Ang II in WT mice. Ang II-induced recruitment of T cells into perivascular adipose tissue was abolished in miR-214−/− mice. Adoptive transfer of miR-214−/− T cells into RAG1−/− mice resulted in reduced perivascular fibrosis compared with the effect of WT T cells. Ang II induced hypertension caused significant change in the expression of 1380 T cell genes in WT, but only 51 in miR-214−/−. T cell activation, proliferation and chemotaxis pathways were differentially affected. MiR-214−/− prevented Ang II-induction of profibrotic T cell cytokines (IL-17, TNF-α, IL-9, and IFN-γ) and chemokine receptors (CCR1, CCR2, CCR4, CCR5, CCR6, and CXCR3). This manifested in reduced in vitro and in vivo T cell chemotaxis resulting in attenuation of profibrotic perivascular inflammation. Translationally, we show that miR-214 is increased in plasma of patients with hypertension and is directly correlated to pulse wave velocity as a measure of vascular stiffness. Conclusions: T-cell–derived miR-214 controls pathological perivascular fibrosis in hypertension mediated by T cell recruitment and local profibrotic cytokine release.

Supplemental Digital Content is available in the text., Combined inhibition of NEP (neutral endopeptidase) and ACE (angiotensin-converting enzyme), without unwanted effects, remains an attractive therapeutic strategy in cardiovascular medicine. Omapatrilat, a dual NEP inhibitor–ACE inhibitor, was a promising antihypertensive drug but failed in trials due to angioedema, an effect possibly caused by inhibition of both the N- and C-domains of ACE. Here, we aimed to determine whether lisinopril-tryptophan (lisW-S), a C-domain specific ACE inhibitor that preserves the N-domain catalytic activity, together with sacubitril (NEP inhibitor), differentially influences cardiovascular function and vascular permeability in hypertension compared with omapatrilat and lisinopril+sacubitril which inhibits both the ACE C- and N-domains. Ang II (angiotensin II)–dependent hypertensive mice (transgenic mice expressing active human renin in the liver [also known as LinA3]) received vehicle, sacubitril, lisW-S, lisinopril, lisinopril+sacubitril, or lisW-S+sacubitril for 4 weeks. Systolic blood pressure was increased in LinA3 mice, along with cardiac hypertrophy/dysfunction, impaired endothelium-dependent vasorelaxation, hypercontractile responses, vascular remodeling, and renal inflammation. LisW-S+sacubitril, lisinopril+sacubitril, and omapatrilat reduced systolic blood pressure and normalized cardiovascular remodeling and vascular hypercontractile responses in LinA3 mice. Although lisinopril+sacubitril and omapatrilat improved Ach-induced vasorelaxation, lisW-S+sacubitril had no effect. Endothelial permeability (Evans Blue assessment) was increased in omapatrilat but not in LisW-S+sacubitril–treated mice. In conclusion, lisW-S combined with sacubitril reduced systolic blood pressure and improved cardiac dysfunction in LinA3 mice, similar to omapatrilat but without effects on endothelium-dependent vasorelaxation. Moreover, increased vascular leakage (plasma extravasation) induced by omapatrilat was not evident in mice treated with lisW-S+sacubitril. Targeting ACE C-domain and NEP as a combination therapy may be as effective as omapatrilat in lowering systolic blood pressure, but without inducing vascular permeability and endothelial injury.

The perivascular adipose tissue (PVAT) differs from other fat depots and exerts a paracrine action on the vasculature. The spleen has an important role in the immune response, and it was observed to have either a protective role or a contribution to obesity-related diseases. However, the relation between spleen and PVAT is elusive in obesity. We investigated the role of spleen in the inflammatory profile of the mesenteric PVAT (mPVAT) from mice fed a high-fat diet (HFD) for 16 weeks. Male C57Bl/6 mice were sham-operated or splenectomized (SPX) and fed a HFD for 16 weeks. mPVAT morphology was evaluated by hematoxylin and eosin staining, infiltrated immune cells were evaluated by flow cytometry, inflammatory cytokines were evaluated by ELISA and the splenic cell chemotaxis mediated by mPVAT was evaluated using a transwell assay. In SPX mice, HFD induced adipocyte hypertrophy and increased immune cell infiltration and proinflammatory cytokine levels in mPVAT. However, none of these effects were observed in mPVAT from sham-operated mice. Spleen from HFD fed mice presented reduced total leukocytes and increased inflammatory markers when compared to the spleen from control mice. Chemotaxis of spleen cells mediated by mPVAT of HFD fed mice was reduced in relation to standard diet fed mice. The spleen protects mPVAT against the effects of 16-week HFD. This information was missing, and it is important because PVAT is different from other fat depots and data cannot be extrapolated from any type of adipose tissue to PVAT.

Background and Purpose: Inflammation plays a key role in atherosclerosis. The protective role of angiotensin 1–7 (Ang-(1–7)) in vascular pathologies suggested the therapeutic use of low MW, non-peptide Ang-(1–7) mimetics, such as AVE0991. The mechanisms underlying the vaso-protective effects of AVE0991, a Mas receptor agonist, remain to be explored. Experimental Approach: We investigated the effects of AVE0991 on the spontaneous atherosclerosis in apolipoprotein E (ApoE)−/− mice, in the context of vascular inflammation and plaque stability. Key Results: AVE0991 has significant anti-atherosclerotic properties in ApoE−/− mice and increases plaque stability, by reducing plaque macrophage content, without effects on collagen. Using the descending aorta of chow-fed ApoE−/− mice, before significant atherosclerotic plaque develops, we gained insight to early events in atherosclerosis. Interestingly, perivascular adipose tissue (PVAT) and adventitial infiltration with macrophages and T-cells precedes atherosclerotic plaque or the impairment of endothelium-dependent NO bioavailability (a measure of endothelial function). AVE0991 inhibited perivascular inflammation, by reducing chemokine expression in PVAT and through direct actions on monocytes/macrophages inhibiting their activation, characterized by production of IL-1β, TNF-α, CCL2 and CXCL10, and differentiation to M1 phenotype. Pretreatment with AVE0991 inhibited migration of THP-1 monocytes towards supernatants of activated adipocytes (SW872). Mas receptors were expressed in PVAT and in THP-1 cells in vitro, and the anti-inflammatory effects of AVE0991 were partly Mas dependent. Conclusions and Implications: The selective Mas receptor agonist AVE0991 exhibited anti-atherosclerotic and anti-inflammatory actions, affecting monocyte/macrophage differentiation and recruitment to the perivascular space during early stages of atherosclerosis in ApoE−/− mice. Linked Articles: This article is part of a themed section on Targeting Inflammation to Reduce Cardiovascular Disease Risk. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.22/issuetoc and http://onlinelibrary.wiley.com/doi/10.1111/bcp.v82.4/issuetoc

Background and purpose Hypertension is a multifactorial disease, manifested by vascular dysfunction, increased superoxide production, and perivascular inflammation. In this study, we have hypothesized that 1,2,3,4,6-penta-O-galloyl-β-d-glucose (PGG) would inhibit vascular inflammation and protect from vascular dysfunction in an experimental model of hypertension. Experimental approach PGG was administered to mice every 2 days at a dose of 10 mg·kg-1 i.p during 14 days of Ang II infusion. It was used at a final concentration of 20 μM for in vitro studies in cultured cells. Key results Ang II administration increased leukocyte and T-cell content in perivascular adipose tissue (pVAT), and administration of PGG significantly decreased total leukocyte and T-cell infiltration in pVAT. This effect was observed in relation to all T-cell subsets. PGG also decreased the content of T-cells bearing CD25, CCR5, and CD44 receptors and the expression of both monocyte chemoattractant protein 1 (CCL2) in aorta and RANTES (CCL5) in pVAT. PGG administration decreased the content of TNF+ and IFN-γ+ CD8 T-cells and IL-17A+ CD4+ and CD3+ CD4- CD8- cells. Importantly, these effects of PGG were associated with improved vascular function and decreased ROS production in the aortas of Ang II-infused animals independently of the BP increase. Mechanistically, PGG (20 μM) directly inhibited CD25 and CCR5 expression in cultured T-cells. It also decreased the content of IFN-γ+ CD8+ and CD3+ CD4- CD8- cells and IL-17A+ CD3+ CD4- CD8- cells. Conclusion and implication PGG may constitute an interesting immunomodulating strategy in the regulation of vascular dysfunction and hypertension. Linked articles This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Monocytes are pivotal cells in inflammatory joint diseases. We aimed to determine the effect of TNF-&alpha, inhibitors (TNFi) on peripheral blood monocyte subpopulations and their activation in ankylosing spondylitis (AS) and rheumatoid arthritis (RA) patients with high disease activity. To address this, we studied 50 (32 AS, 18 RA) patients with highly active disease with no prior history of TNFi use who were recruited and assigned to TNFi or placebo treatment for 12 weeks. Cytometric and clinical assessment was determined at baseline, four, and 12 weeks after initiation of TNFi treatment. We observed that treatment with TNFi led to a significant decrease in CD14hiCD16&minus, monocytes in comparison to placebo, while circulating CD14dimCD16+ monocytes significantly increased. The TNFi-induced monocyte subset shifts were similar in RA and AS patients. While the percentage of CD14dimCD16+ monocytes increased, expression of CD11b and CD11c integrins on their surface was significantly reduced by TNFi. Additionally, CD45RA+ cells were more frequent. The shift towards nonclassical CD14dimCD16+ monocytes in peripheral blood due to TNFi treatment was seen in both AS and RA. This may reflect reduced recruitment of these cells to sites of inflammation due to lower inflammatory burden, which is associated with decreased disease activity.

Recent studies have emphasized the role of perivascular inflammation in cardiovascular disease. We studied mechanisms of perivascular leukocyte infiltration in angiotensin II (Ang II)-induced hypertension and their links to vascular dysfunction. Chronic Ang II infusion in mice increased immune cell content of T cells (255 ± 130 to 1664 ± 349 cells/mg; P < 0.01), M1 and M2 macrophages, and dendritic cells in perivascular adipose tissue. In particular, the content of T lymphocytes bearing CC chemokine receptor (CCR) 1, CCR3, and CCR5 receptors for RANTES chemokine was increased by Ang II (CCR1, 15.6 ± 1.5% vs. 31 ± 5%; P < 0.01). Hypertension was associated with an increase in perivascular adipose tissue expression of the chemokine RANTES (relative quantification, 1.2 ± 0.2 vs. 3.5 ± 1.1; P < 0.05), which induced T-cell chemotaxis and vascular accumulation of T cells expressing the chemokine receptors CCR1, CCR3, and CCR5. Mechanistically, RANTES−/− knockout protected against vascular leukocyte, and in particular T lymphocyte infiltration (26 ± 5% in wild type Ang II vs. 15 ± 4% in RANTES−/−), which was associated with protection from endothelial dysfunction induced by Ang II. This effect was linked with diminished infiltration of IFN-γ-producing CD8+ and double-negative CD3+CD4−CD8− T cells in perivascular space and reduced vascular oxidative stress while FoxP3+ T-regulatory cells were unaltered. IFN-γ ex vivo caused significant endothelial dysfunction, which was reduced by superoxide anion scavenging. In a human cohort, a significant inverse correlation was observed between circulating RANTES levels as a biomarker and vascular function measured as flow-mediated dilatation (R = −0.3, P < 0.01) or endothelial injury marker von Willebrand factor (R = +0.3; P < 0.01). Thus, chemokine RANTES is important in the regulation of vascular dysfunction through modulation of perivascular inflammation.—Mikolajczyk, T. P., Nosalski, R., Szczepaniak, P., Budzyn, K., Osmenda, G., Skiba, D., Sagan, A., Wu, J., Vinh, A., Marvar, P. J., Guzik, B., Podolec, J., Drummond, G., Lob, H. E., Harrison, D. G., Guzik, T. J. Role of chemokine RANTES in the regulation of perivascular inflammation, T-cell accumulation, and vascular dysfunction in hypertension.

Objective: Hypertension (HT) is associated with perivascular inflammation and increased vascular fibrosis. MicroRNAs (miR) are a novel gene expression regulation mechanism and play a pivotal role in a range of pathological processes. The role and mechanism of miR214 in vascular fibrosis is unknown. Methods: 3-month-old C57BL/6, miR214KO and wild-type littermates were treated with angiotensin II (AngII, 490ng/kg/min; n=6-10) or control buffer for 14 days. PVATs from C57BL/6 animals were analysed using TaqMan_Rodent_microRNA_Arrays. Histological studies, wire myography, lucigenin-enhanced luminometry and cytometrical analysis was conducted, followed by statistical analysis with ANOVA or t-test. Data are expressed as a mean±SEM. Results: Out of 381 miRs, 16 were significantly overexpressed in C57BL/6 AngII animals, with only miR214 showing 8-fold induction (p Conclusions: MiR-214 plays a major role in modulation of aortic fibrosis, vascular function, oxidative stress and perivascular inflammation.

Free radicals present in coffee may be responsible for exerting toxic effects on an organism. The objectives of this work were to compare free radicals properties and concentrations in different commercially available coffees, in solid and liquid states, and to determine the effect of roasting on the formation of free radicals in coffee beans of various origins. The free radicals content of 15 commercially available coffees (solid and liquid) was compared and the impact of processing examined using electron paramagnetic resonance (EPR) spectroscopy at X-band (9.3 GHz). First derivative EPR spectra were measured at microwave power in the range of 0.7-70 mW. The following parameters were calculated for EPR spectra: amplitude (A), integral intensity (I), and line-width (ΔBpp); g-Factor was obtained from resonance condition. Our study showed that free radicals exist in green coffee beans (10(16) spin/g), roasted coffee beans (10(18) spin/g), and in commercially available coffee (10(17)-10(18) spin/g). Free radical concentrations were higher in solid ground coffee than in instant or lyophilised coffee. Continuous microwave saturation indicated homogeneous broadening of EPR lines from solid and liquid commercial coffee samples as well as green and roasted coffee beans. Slow spin-lattice relaxation processes were found to be present in all coffee samples tested, solid and liquid commercial coffees as well as green and roasted coffee beans. Higher free radicals concentrations were obtained for both the green and roasted at 240 °C coffee beans from Peru compared with those originating from Ethiopia, Brazil, India, or Colombia. Moreover, more free radicals occurred in Arabica coffee beans roasted at 240 °C than Robusta. EPR spectroscopy is a useful method of examining free radicals in different types of coffee.

Background Systemic lupus erythematosus (SLE) is characterized by increased cardiovascular morbidity and mortality. SLE patients have increased prevalence of subclinical atherosclerosis, although the mechanisms of this observation remain unclear. Considering the emerging role of monocytes in atherosclerosis, we aimed to investigate the relationship between subclinical atherosclerosis, endothelial dysfunction and the phenotype of peripheral blood monocytes in SLE patients. Methods We characterized the phenotype of monocyte subsets defined by the expression of CD14 and CD16 in 42 patients with SLE and 42 non-SLE controls. Using ultrasonography, intima-media thickness (IMT) of carotid arteries and brachial artery flow-mediated dilation (FMD) as well as nitroglycerin-induced dilation (NMD) were assessed. Results Patients with SLE had significantly, but only modestly, increased IMT when compared with non-SLE controls (median (25th/75th percentile) 0.65 (0.60/0.71) mm vs 0.60 (0.56/0.68) mm; p Conclusions Our observations suggest that CD14dimCD16+monocytes are associated with subclinical atherosclerosis in SLE, although the mechanism appears to be independent of endothelial dysfunction.

Background Cardiac dysfunction is one of the hallmarks of hypertension. It is characterised by cardiac fibrosis, diastolic dysfunction and development of heart failure. The mechanisms of hypertensive heart disease are not fully understood. Recent studies suggest a role of miR-214 in regulation of fibrosis. Thus, the aim of this work is to investigate the role miR-214 has in the cardiac sequelae of hypertension. Methods Hypertension was induced in three month old miR-214 knock out (KO) and wild type (WT) littermates using 490 ng/kg/min angiotensin II (Ang II) for 14 or 28 days (n=4–6). Blood pressure was monitored by tail cuff plethysmography. Cardiac fibrosis was assessed by picrosirius red and Massons trichrome staining. Mir214 expression was assessed by Taqman and in situ hybridisation (ISH). Cardiac function was assessed by echocardiography. Effects of Ang II on fibrosis genes was studied in primary cardiac fibroblasts. Results 14 day Ang II infusion caused 4-fold induction of miR-214 in the left ventricle of C57bl/6 mice (p COL1A1 mRNA compared with their WT littermates (p in vivo observations, in vitro fibroblast studies show that KO fibroblasts showed significantly reduced induction of COL1A1 (p COL3A1 (p Conclusions Cardiac fibrosis, hypertrophy and diastolic dysfunction are enhanced in miR-214 KO animals. The mechanisms of this observation are not caused by mir214 effects in cardiac fibroblasts, but through other mechanisms that need to be further addressed.

Angiotensin 1-7 (Ang 1-7) has anti-atherosclerotic effects, possibly through its anti-inflammatory properties. As perivascular inflammation is an important component of early atherosclerosis, we aimed to determine whether angiotensin-(1-7) non peptide mimetic (AVE0991) can modulate these inflammatory mechanisms in the early development of atherosclerosis. Twelve-week old ApoE-/- mice and controls (C57BL/6J) on chow diet were treated with placebo or AVE0991 (0.58μM/g/day, per os). Mice were analysed at 16, 20 and 24 weeks of age. The level of perivascular leukocyte and T cell infiltration was measured by flow cytometry. Atherosclerotic plaque area was assessed by Oil Red O staining of en-face aortic preparations. Endothelial dysfunction was measured by wire myography and ROS production in the aorta by lucigenin-enhanced chemiluminescence (5μM). RESULTS: Levels of endogenous Ang 1-7, measured by mass spectrometry in the perivascular adipose tissue were low in both WT and ApoE-/- (32.9±1.2 vs 31.1±1.1 pg/mg; p=0.1). AVE0991 significantly reduced plaque area in ApoE-/- mice at all time points (14.2±1.9% vs 7.25±1.3% at 24 weeks; p

Efficient removal of apoptotic polymorphonuclear leukocytes (PMNs) is an important step in the resolution of inflammation, which protects tissues from the noxious contents of dying cells. While the impairment of apoptotic PMNs removal has been demonstrated for macrophages in systemic lupus erythematosus (SLE), recent studies show that monocytes are also capable of such phagocytosis, although their involvement in SLE is not clear. Therefore, we characterized phagocytosis of apoptotic PMNs by monocytes in 22 patients with SLE and 22 healthy controls. Using flow cytometry we demonstrate that in SLE peripheral blood monocytes show impaired phagocytosis of autologous apoptotic PMNs, while they efficiently engulf apoptotic PMNs isolated from healthy subjects. Monocytes CD14highCD16+ and CD14dimCD16+ more efficiently interacted with apoptotic neutrophils than CD16– cells both in SLE and healthy subjects. Monocytes in SLE showed modestly decreased expression of CD35 and CD91 and increased expression of T Cell Ig- and mucin-domain-containing molecule-3 (TIM-3); however, these differences were evident mainly in selected subsets of monocytes (CD16+) while defects in phagocytosis were observed in all monocyte subsets. Apoptotic cell-dependent induction of lipopolysaccharide (LPS) stimulated production of anti-inflammatory cytokine IL-10 by peripheral blood mononuclear cells (PBMC) was blunted in SLE while the production of pro-inflammatory cytokine TNF-α was unchanged.

Hypertension is associated with perivascular inflammation and increased collagen deposition in adventitia. MicroRNAs (miR) are a novel mechanism for gene expression regulation and play a pivotal role in a wide range of pathological processes such as vascular fibrosis.The role and mechanism of miRs in this irreversible process are still unknown. 3-months-old C57BL/6, miR-214KO and wild type littermates were treated with angiotensin II (AngII, 490ng/kg/min; n = 6-10) or control buffer for 14 days. Perivascular adipose tissues (PVAT) from C57BL/6 animals were analysed using TaqMan_Rodent_microRNA_Arrays. Histological studies, wire myography, lucigenin enhanced luminometry and cytometrical analysis was conducted. Statistical analysis was performed using ANOVA or t-test. Data are expressed as a meanSEM. Out of 381 miRs, 16 were significantly overexpressed in C57BL/6 AngII animals after global normalisation. Mir-214 was the only significantly overexpressed miR with 8-fold induction (p

Nosocomial infections, despite the introduction of the numerous control systems, still constitute a considerable problem in hospitals. They are of great socio-economic importance due to the prolonged stay of patients in hospitals and high treatment costs. They also contribute to an increase in the death rate. For many years staphylococci have remained at the top of the list of microorganisms that cause infections in hospitals. The methicillin-resistant staphylococci (MRSA) strains that occur among both coagulase positive and coagulase negative (MRCNS) species are particularly dangerous. The aim of the presented paper was to determine the usefulness of the 16S rRNA gene sequence analysis and the region between the genes coding 16 S and 23 S rRNA for an examination of the diversity of Staphylococcus spp. isolated from a hospital environment and to perform a polymorphism analysis within and among the species. We also analyzed the polymorphism of 84 Staphylococcus strains and isolated from a hospital environment using PCR-RFLP and ITS PCR methods. A restriction enzyme analysis of the 16 S rRNA gene using TaqI enzyme did not show any considerable power of differentiation in relation to the Staphylococci strains examined. However, the variable region between genes 16 S and 23S rRNA showed a high degree of polymorphisms and allowed for the differentiation of the hospital strains examined. The results demonstrated the highest differentiation inStaphylococcus aureus strains. The examined strains originating from hospital environment are characterised by a high polymorphism. Key words: ITS-PCR, Staphylococcus spp., hospital infections, 16 S rRNA, 23 S rRNA.

INTRODUCTION Varicose vein disease is one of the most common morbidities in the developed countries. Recent studies have shown that oxidative stress is increased in varicose veins (VV) and venous insufficiency. However, the exact mechanisms of oxidative stress in VV remain unknown. OBJECTIVES The aim of the study was to measure superoxide anion production and analyze its enzymatic sources in VV in comparison with control human saphenous veins (HSV). Superoxide production was also compared between the proximal and distal segments of the veins. PATIENTS AND METHODS Proximal and distal segments of varicose veins (14 patients, aged 52 ±3.5 years) and control veins (15 patients, aged 56 ±4 years) were obtained during VV removal or elective coronary artery bypass graft surgery, respectively. Subjects were matched for age, sex, and the major risk factors for atherosclerosis. Superoxide was measured by lucigenin-enhanced chemiluminescence (5 μmol/l) in the presence and absence of oxidase inhibitors. RESULTS Superoxide production was increased in VV compared with control HSV. This increase was particularly evident in the distal segments of VV. There was a significant correlation between superoxide production in the proximal and distal segments of HSV but not of VV. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and uncoupled nitric oxide synthase (NOS) were the major sources of superoxide in VV, because their inhibitors greatly attenuated superoxide production in VV. CONCLUSIONS NADPH oxidases and NOS could represent valuable drug targets for pharmacological treatment and prevention of varicose vein disease. Oxidative stress may provide a link between endothelial dysfunction, inflammation, and immune activation and the development of chronic venous dysfunction.