3,850 research outputs found
Vitamins C and E prevent endothelial VEGF and VEGFR-2 overexpression induced by porcine hypercholesterolemic LDL
OBJECTIVE: Vascular endothelial growth factor (VEGF) is believed to play a role in the development of atherosclerosis and has been found to be increased in hypercholesterolemia. We examined the hypothesis that endothelial VEGF and VEGF receptor-2 (VEGFR-2) expression is upregulated by hypercholesterolemic low-density lipoprotein (LDL) and, because it could be driven by oxidative stress, we tested whether vitamin C and E supplementation could modulate it.
METHODS: Native LDL were characterized after isolation from adult normal (C-LDL), hypercholesterolemic (HC-LDL) and hypercholesterolemic mini-pigs receiving vitamins C and E (HCV-LDL). VEGF, VEGFR-2, HIF-1 alpha and superoxide anion (O(2)(-)) productions were measured in porcine coronary endothelial cells (ECs) incubated for 48 h with native LDL. The effect of exogenous ascorbic acid and alpha- or beta-tocopherol was also studied.
RESULTS: HC-LDL, with high cholesterol (P<0.05) and reduced tocopherol/cholesterol ratio (P<0.05), increased significantly VEGF and VEGFR-2 (p<0.001) in EC, associated with higher O(2)(-) and HIF-1 alpha expression, in comparison with C-LDL and HCV-LDL. The addition of vitamin C and alpha- or beta-tocopherol to the culture medium prevented the induction of VEGF and VEGFR-2 expression by HC-LDL, both at mRNA and protein levels.
CONCLUSIONS: Our data suggest HC-LDL induce endothelial VEGF and VEGFR-2 overexpression at least by increasing oxidative stress, and HIF-1 alpha is one of the signaling mechanisms involved. Prevention of VEGF and VEGFR-2 upregulation could help explain the beneficial effects of vitamins C and E in hypercholesterolemia-induced experimental atherosclerosis
Integrated soil degradation analysis of tierra de Barros region (Badajoz, Spain).
This study assesses the soil degradalion in Tierra de Barros region (Badajoz province, Spain (280.900 ha). The sludy emphasizes on lhe soil susceptibilily to sealing and crusting, compactation and soilloss by water erosion
Electronic and Geometric Corrugation of Periodically Rippled, Self-nanostructured Graphene Epitaxially Grown on Ru(0001)
Graphene epitaxially grown on Ru(0001) displays a remarkably ordered pattern
of hills and valleys in Scanning Tunneling Microscopy (STM) images. To which
extent the observed "ripples" are structural or electronic in origin have been
much disputed recently. A combination of ultrahigh resolution STM images and
Helium Atom diffraction data shows that i) the graphene lattice is rotated with
respect to the lattice of Ru and ii) the structural corrugation as determined
from He diffraction is substantially smaller (0.015 nm) than predicted (0.15
nm) or reported from X-Ray Diffraction or Low Energy Electron Diffraction. The
electronic corrugation, on the contrary, is strong enough to invert the
contrast between hills and valleys above +2.6 V as new, spatially localized
electronic states enter the energy window of the STM. The large electronic
corrugation results in a nanostructured periodic landscape of electron and
holes pockets.Comment: 16 pages, 6 figure
Vitamins C and E downregulate vascular VEGF and VEGFR-2 expression in apolipoprotein-E-deficient mice
Anti-angiogenic therapy reduces both plaque growth and intimal neovascularization in apolipoprotein-E-deficient mice (apoE-/-). Vascular endothelial growth factor (VEGF) has been suggested as playing a role in the development of atherosclerosis. We examined the hypothesis that VEGF and VEGF receptor-2 (VEGFR-2) expression is upregulated in apoE-/- and, since it could be driven by oxidative stress, tested whether dietary supplementation with vitamins C and E could downregulate it.Two-month-old apoE-/- received vitamin C combined with alpha- or beta-tocopherol for 4 weeks. Aortic VEGF and VEGFR-2 expression were measured by RT-qPCR and western blot.ApoE-/- showed significantly higher expression of aortic VEGF and VEGFR-2 mRNA (P<0.001) and protein (P<0.001) than wild-type mice, as well as increased plasma VEGF (P<0.001). Vitamin C and alpha-tocopherol significantly reduced aortic VEGF and VEGFR-2 expression in apoE-/- (P<0.001), circulating VEGF (P<0.01) and plasma lipid peroxidation (P<0.01). apoE-/- receiving vitamin C and beta-tocopherol showed diminished lipid peroxidation and VEGFR-2, but only partial reduction of VEGF expression. These data demonstrate that augmented VEGF and VEGFR-2 expression in apoE-/- vasculature can be downregulated by vitamins C and E, at least partially through oxidative stress reduction. This novel mechanism could contribute to explaining the beneficial effects of antioxidant vitamins in experimental atherosclerosis
Recommendations for myeloid-derived suppressor cell nomenclature and characterization standards
Myeloid-derived suppressor cells (MDSCs) have emerged as major regulators of immune responses in cancer and other pathological conditions. In recent years, ample evidence supports key contributions of MDSC to tumour progression through both immune-mediated mechanisms and those not directly associated with immune suppression. MDSC are the subject of intensive research with >500 papers published in 2015 alone. However, the phenotypic, morphological and functional heterogeneity of these cells generates confusion in investigation and analysis of their roles in inflammatory responses. The purpose of this communication is to suggest characterization standards in the burgeoning field of MDSC research
Il-15 enhances the persistence and function of bcma-targeting car-t cells compared to il-2 or il-15/il-7 by limiting car-t cell dysfunction and differentiation
Chimeric antigen receptor (CAR)-T cell immunotherapy has revolutionized the treatment of B-lymphoid malignancies. For multiple myeloma (MM), B-cell maturation antigen (BCMA)-targeted CAR-T cells have achieved outstanding complete response rates, but unfortunately, patients often relapse within a year of receiving the therapy. Increased persistence and reduced dysfunction are crucial features that enhance the durability of CAR-T cell responses. One of the factors that influence CAR-T cell in vivo longevity and loss of function, but which has not yet been extensively studied for BCMA-directed CAR-T cells, are the cytokines used during their production. We here compared the impact of IL-2, IL-15 and a combination of IL-15/IL-7 on the phenotype and function of ARI2h, an academic BCMA-directed CAR-T cell that is currently being administered to MM patients. For this study, flow cytometry, in vitro cytotoxicity assays and analysis of cytokine release were performed. In addition, ARI2h cells expanded with IL-2, IL-15, or IL-15/IL-7 were injected into MM tumor-bearing mice to assess their in vivo efficacy. We demonstrated that each of the cytokine conditions was suitable for the expansion of ARI2h cells, with clear in vitro activity. Strikingly, however, IL-15-produced ARI2h cells had improved in vivo efficacy and persistence. When explored further, it was found that IL-15 drove a less-differentiated ARI2h phenotype, ameliorated parameters related to CAR-T cell dysfunction, and lowered the release of cytokines potentially involved in cytokine release syndrome and MM progression. Moreover, we observed that IL-15 was less potent in inducing T cell senescence and DNA damage accumulation, both of which may contribute to an unfavorable CAR-T cell phenotype. These findings show the superiority of IL-15 to IL-2 and IL-15/IL-7 in the quality of anti-BCMA CAR-T cells, particularly their efficacy and persistence, and as such, could improve the duration of responses if applied to the clinical production of CAR-T cells for patients
Inflammatory biomarkers and brain health indicators in children with overweight and obesity: The ActiveBrains project
INTRODUCTION: Chronic inflammation plays an important role on the pathogenesis of several cardiovascular and metabolic diseases, as well as on brain function and behaviour. The aim of the present study was to examine the associations between inflammatory biomarkers and a wide range of brain health indicators (i.e., academic performance, executive function, behavioural and emotional functioning, and brain volume) in children with overweight/obesity.
METHODS: A total of 107 children (10.0 ± 1.1 years, 41% girls) from the ActiveBrains project were included in the analysis. Five inflammatory biomarkers were analysed in plasma: white blood cell (WBC) count, interleukin-6 (IL-6), interleukin-1beta, tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP). Academic performance was assessed by Woodcock-Munoz Tests of Achievement. Executive function was assessed through the Design Fluency Test for cognitive flexibility, the Stroop test for cognitive inhibition, and the Delayed Non-Match-to-Sample task for working memory. Behavioural and emotional functioning was evaluated through the Behavior Assessment System for Children (BASC) questionnaire. Total and regional brain volume was assessed by magnetic resonance imaging.
RESULTS: IL-6 was inversely associated with adaptive skills (beta = -0.228; p = 0.030), while TNF-alpha was related to mathematics (beta = -0.198; p = 0.034). In addition, CRP was positively associated with externalizing (beta = 0.246; p = 0.046) and internalizing problems (beta = 0.234; p = 0.039), as well as the behavioural symptoms index (beta = 0.236; p = 0.047). However, these significant associations disappeared after multiple comparisons correction. Inflammatory biomarkers were not associated with executive function and total brain volumes. Regarding regional brain analyses, WBC was positively associated with gray matter volume in the left middle temporal gyrus (beta = 0.387; p < 0.001, k = 44), and CRP was positively associated with gray matter volume in the right superior temporal gyrus (beta = 0.439; p < 0.001, k = 29). Additionally, when adjusting by total brain volume, CRP was positively associated with gray matter volume in the right supplementary motor cortex (beta = 0.453; p < 0.001, k = 51). Moreover, both, IL-6 (beta = 0.366; p < 0.001, k = 81) and TNF-alpha (beta = 0.368; p < 0.001, k = 62) were positively associated with white matter volume around the right inferior frontal gyrus pars opercularis, while CRP was inversely associated with white matter volume around the left superior frontal gyrus (beta = -0.482; p < 0.001, k = 82). After adjusting by total brain volume, CRP was also inversely associated with white matter volume in 3 additional clusters (beta ranging from -0.473 to -0.404; p < 0.001, k = 87).
CONCLUSIONS: Inflammation was slightly associated with brain health (i.e., academic performance, behavioural and emotional functioning and regional brain volume) in children with overweight or obesity. Further larger longitudinal and interventional studies are warranted to elucidate the short-term and long-term effect of systemic low-grade inflammation on children's brain health
Some Problems in Density Functional Theory
Though calculations based on density functional theory (DFT) are used
remarkably widely in chemistry, physics, materials science, and biomolecular
research and though the modern form of DFT has been studied for almost 60
years, some mathematical problems remain. For context, we provide an outline of
the basic structure of DFT, then pose several questions regarding both its
time-independent and time-dependent forms. Progress on any of these would aid
in development of better approximate functionals and in interpretation
Antioxidant vitamins increase the collagen content and reduce MMP-1 in a porcine model of atherosclerosis: implications for plaque stabilization
Degradation of extracellular matrix, particularly interstitial collagen, promotes plaque instability and contributes to restenosis after vascular injury. We have explored the effects of vitamins C and E on the collagen content and metalloproteinase-1 (MMP-1) expression after angioplasty in hypercholesterolemic pigs. Iliac angioplasty was performed on 18 minipigs divided into three diet groups: a normal-cholesterol (NC), a high-cholesterol (HC) and a high-cholesterol plus vitamins C+E (HCV). Four weeks later, after sacrifice, the vascular collagen content and MMP-1 protein expression, along with the plasma caseinolytic activity and lipid peroxidation, were measured. MMP-1 was also determined in arterial rings stimulated with native low-density lipoproteins (LDL) isolated from experimental groups. Cholesterol-rich diet augmented plasma lipid peroxidation (P<0.05), reduced the collagen content and increased vascular MMP-1 expression after injury (P<0.05). Enhanced caseinolytic activity (identified as MMP-1) was also observed in HC plasma samples and in supernatants from arterial rings incubated with HC-LDL. Vitamins C and E markedly increased neointimal collagen content (P<0.01), reduced the hypercholesterolemia-induced changes in vascular MMP-1 (P<0.05) and diminished plasma and ex vivo caseinolytic activity. Vitamins C and E may help stabilize atherosclerotic plaque after angioplasty and favor vascular remodeling by increasing collagen content and reducing vascular MMP-1 expression in porcine hypercholesterolemia
Dietary supplementation with vitamins C and E prevents downregulation of endothelial NOS expression in hypercholesterolemia in vivo and in vitro
Impaired endothelium-dependent vasodilation has been associated with decreased NO bioavailability in hypercholesterolemia. This study aimed to determine whether antioxidant vitamins C and E could improve hypercholesterolemia-derived endothelial dysfunction in the porcine model, and whether observed in vivo results could be reproduced in vitro by incubation of coronary endothelial cells (EC) in the presence of native low-density lipoproteins (LDL). Adult mini-pigs were fed standard (C), cholesterol rich (HC) or cholesterol rich diet supplemented with vitamins C and E (HCV). Endothelium-dependent blood flow increase in response to acetylcholine was determined. Endothelial nitric oxide synthase (eNOS) expression was measured in arterial samples and in EC incubated with LDL isolated from porcine plasma. Vasomotor response to acetylcholine in HC was significantly lower (P<0.05) than control and HCV. There was a significant (P<0.05) decrease in eNOS immunoreactivity in HC, compared with HCV and control. Native LDL from HC, but not from HCV, induced a significant decrease in eNOS expression. Vitamins C and E treatment improved the endothelium-dependent vasomotor capacity and prevented decreased expression of eNOS in hypercholesterolemic pigs. A similar effect could be demonstrated in vitro, by incubation of EC with native LDL, suggesting that the effect of physiologically-modified LDL on eNOS could have a role in recovering vascular function
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