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Endothelial Nitric Oxide (endothelial + nitric_oxide)
Terms modified by Endothelial Nitric Oxide Selected AbstractsIL-10 inhibits endothelium-dependent T cell costimulation by up-regulation of ILT3/4 in human vascular endothelial cellsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 1 2007Christian Abstract Effects of IL-10 on endothelium-dependent T cell activation have not been investigated in detail. We confirm expression of the IL-10 receptor and effective signaling via STAT-3 in human umbilical vein endothelial cells (HUVEC). In CD4 T cell cocultures with HUVEC, pretreatment of endothelial cells with IL-10 resulted in significant dose-dependent inhibition of CD4 T cell proliferation, which also occurred when IL-10 was removed after pretreatment before starting cocultures. Th1/Th2 polarization of proliferated T cells, endothelial nitric oxide (NO), or IL-12 production were unchanged. However, IL-10 stimulation resulted in up-regulation of SOCS-3, a negative regulator of cytokine secretion, and induction of the inhibitory surface molecules immunoglobulin-like transcript 3 and 4 (ILT3/ILT4) in EC, potentially involving glucocorticoid-induced leucine zipper (GILZ). Addition of blocking antibodies against ILT3/ILT4 to EC/T cell cocultures resulted in nearly complete reestablishment of T cell proliferation. In contrast, addition of soluble ILT3 or overexpression of ILT3 in cocultures significantly reduced T cell proliferation. No induction of foxp3+ regulatory T cells was seen. In conclusion, the T cell costimulatory potential of human EC is markedly suppressed by IL-10 due to up-regulation of ILT3/ILT4, obviously not involving generation of Treg. This identifies a novel action of IL-10 in EC and a potential therapeutical target for local immunomodulation. [source] Silent information regulator, Sirtuin 1, and age-related diseasesGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 1 2009Li Zeng Sirtuin 1 (SIRT1), a member of the silent information regulator 2 in mammals, has recently been found to be involved in age-related diseases, such as cancer, metabolic diseases, cardiovascular disease, neurodegenerative diseases, osteoporosis and chronic obstructive pulmonary disease (COPD), mainly through deacetylation of substrates such as p53, forkhead box class O, peroxisome proliferator activated receptor , co-activator 1,, and nuclear factor-,B. It is widely reported that SIRT1 can promote not only carcinogenesis but also metastasis and insulin resistance, andhave beneficial effects in metabolic diseases, mediate high-density lipoprotein synthesis and regulate endothelial nitric oxide to protect against cardiovascular disease, have a cardioprotective role in heart failure, protect against neurodegenerative pathological changes, promote osteoblast differentiation, and also play a pivotal role as an anti-inflammatory mediator in COPD. However, there are controversial results suggesting that SIRT1 has an effect in protecting against DNA damage and accumulation of mutations, and preventing tumorigenesis. In addition, a high level of SIRT1 can induce cardiomyopathy and even heart failure. This article reviews recent developments relating to these issues. [source] Induction of oxidative stress by homocyst(e)ine impairs endothelial function,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2001Vibhas S. Mujumdar Abstract Previous studies have demonstrated a relationship between hyperhomocysteinemia and endothelial dysfunction, reduced bioavailability of nitric oxide, elastinolysis and, vascular muscle cell proliferation. In vivo decreased nitric oxide production is associated with increased matrix metalloproteinase (MMP) activity and formation of nitrotyrosine. To test the hypothesis that homocysteine neutralizes vascular endothelial nitric oxide, activates metalloproteinase, causes elastinolysis and vascular hypertrophy, we isolated aortas from normotensive Wistar rats and cultured them in medium containing homocysteine, and calf serum for 14 days. Homocysteine-mediated impairment of endothelial-dependent vasodilatation was reversed by co-incubation of homocysteine with nicotinamide (an inhibitor of peroxinitrite and nitrotyrosine), suggesting a role of homocysteine in redox-mediating endothelial dysfunction and nitrotyrosine formation. The Western blot analysis, using anti-nitrotyrosine antibody, on aortic tissue homogeneates demonstrated decreased nitrotyrosine in hyperhomocysteinemic vessels treated with nicotinamide. Zymographic analysis revealed increased elastinolytic gelatinase A and B (MMP-2, -9) in homocysteine treated vessels and the treatment with nicotinamide decreases the homocysteine-induced MMP activation. Morphometric analyses revealed significant medial hypertrophic thickening (1.4,±,0.2-fold of control, P,=,0.03) and elastin disruption in homocysteine-treated vessels as compared to control. To determine whether homocysteine causes endothelial cell injury, cross-sections of aortas were analyzed for caspase activity by incubating with Ac-YVAD-AMC (substrate for apoptotic enzyme, caspase). The endothelium of homocysteine treated vessels, and endothelial cells treated with homocysteine, showed marked labeling for caspase. The length-tension relationship of homocysteine treated aortas was shifted to the left as compared to untreated aortas, indicating reduced vascular elastic compliance in homocysteine-treated vessels. Co-incubation of homocysteine and inhibitors of MMP, tissue inhibitor of metalloproteinase-4 (TIMP-4), and caspase, YVAD-CHO, improved vascular function. The results suggest that alteration in vascular elastin/collagen ratio and activation of MMP-2 are associated with decreased NO production in hyperhomocysteinemia. J. Cell. Biochem. 82:491,500, 2001. © 2001 Wiley-Liss, Inc. [source] ORIGINAL ARTICLE: Role of Inflammatory Cytokines and eNOS Gene Polymorphism in Pathophysiology of Pre-EclampsiaAMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2010Archana Singh Citation Singh A, Sharma D, Raghunandan C, Bhattacharjee J. Role of inflammatory cytokines and eNOS gene polymorphism in pathophysiology of pre-eclampsia. Am J Reprod Immunol 2010; 63: 244,251 Problem, Pre-eclampsia involves endothelial vascular dysfunction. The aim of this study was to test the hypothesis that (i) endothelial nitric oxide (NO) synthase Glu298Asp gene polymorphism limits constitutive NO production causing endothelial dysfunction and (ii) inflammatory cytokines impairs endothelium dependent relaxation in pre-eclampsia. Method of study, This cross-sectional study included 50 women with pre-eclampsia and 50 healthy pregnant women. Their blood samples were analyzed for NO, inflammatory cytokines and endothelial NO synthase (eNOS) gene polymorphism. Result, Decreased NO levels whereas increased tumor necrosis factor-,, interleukin (IL)-6 and interleukin-2 were found in pre-eclampsia (P < 0.001). No significant differences were found in genotype/allele distribution between two groups. Significant negative correlation was observed between NO and IL-6 in pre-eclamptic group (P = 0.001). Conclusion, An IL-6-mediated endothelium dependent NO-cyclic guanine monophosphate-mediated relaxation pathway may be inhibited in systemic vessels in pre-eclampsia. As observed in this study Glu298Asp eNOS gene polymorphism did not showed significant association with pre-eclampsia. [source] A VEGF Trap Inhibits the Beneficial Effect of bFGF on Vasoreactivity in Corporal Tissues of Hypercholesterolemic RabbitsTHE JOURNAL OF SEXUAL MEDICINE, Issue 9 2008Donghua Xie MD ABSTRACT Introduction., Hypercholesterolemia causes a decrease in normal corporal tissue vasoreactivity in a preclinical model of erectile dysfunction. Previous studies have shown that intracorporal injection (ICI) of basic fibroblast growth factor (bFGF) reverses some of the detrimental vasoreactivity effects of hypercholesterolemia and increases vascular endothelial growth factor (VEGF) expression. Aim., We sought to determine whether the beneficial effects of bFGF are VEGF-mediated. Methods., A total of 32 New Zealand white rabbits were fed a 1% cholesterol diet for 6 weeks and randomly divided into four groups (N = 8/group). Group 1 received a 2.5 µg bFGF ICI and 2.5 × 1011 viral particle unit (vpu) of adenovirus encoding ,-galactosidase (Ad,-gal) ICI, 10 days later. Group 2 received a 2.5 µg bFGF ICI and 2.5 × 1011 vpu of adenovirus encoding soluble VEGF receptor (VEGFR) (AdsVEGFR, a VEGF trap) ICI, 10 days later. Group 3 received phosphate buffered saline solution (PBS) ICI and 2.5 × 1011 vpu Ad,-gal ICI, 10 days later. Group 4 received PBS ICI and 2.5 × 1011 vpu AdsVEGFR ICI, 10 days later. Main Outcome Measures., The corpus cavernosum was harvested for vasoreactivity studies 10 days post viral injection. The effective dose of 50% maximum relaxation was determined. VEGF levels were assessed by enzyme-linked immunosorbent assay. Total and phoshorylated Akt and endothelial nitric oxide were analyzed by Western blot. Results., Endothelium-dependent vasoreactivity was significantly greater in Group 1 vs. all other groups. The VEGF trap eliminated the beneficial effects of bFGF on endothelium-dependent vasoreactivity and decreased Akt and nitric oxide phosphorylation. Conclusions., These data demonstrate that VEGF activity contributes much of the therapeutic modulation of bFGF-mediated vasoreactivity in corporal tissue. Xie D, Findley CM, Greenfield JM, Pippen AM, Kontos CD, Donatucci CF, and Annex BH. A VEGF trap inhibits the beneficial effect of bFGF on vasoreactivity in corporal tissues of hypercholesterolemic rabbits. J Sex Med 2008;5:2069,2078. [source] Long-term effects of losartan on structure and function of the thoracic aorta in a mouse model of Marfan syndromeBRITISH JOURNAL OF PHARMACOLOGY, Issue 6 2009HH Clarice Yang Background and purpose:, During development of thoracic aortic aneurysms in a mouse model of Marfan syndrome, upregulation of matrix metalloproteinase (MMP)-2 and -9 was accompanied by compromised aortic constriction and endothelium-dependent relaxation. Losartan has been proposed for the prevention of thoracic aortic aneurysm. We hypothesized that losartan would suppress MMP-2/-9 activation and improve aortic vasomotor function in this model. Experimental approach:, A well-characterized mouse model of Marfan syndrome (Fbn1C1039G/+) was used. Starting at 6 weeks old, Marfan mice were untreated or given losartan (0.6 g·L,1 in drinking water, n= 30). The littermate Fbn1+/+ mice served as control. Thoracic aortas were studied at 3, 6 and 9 months by histology and by contractility assays in isolated segments in vitro. Key results:, Losartan improved elastic fibre organization and increased aortic breaking stress. Losartan reduced the activity and protein expression of MMP-2 and MMP-9 at all ages. Aortic constriction in response to membrane depolarization or phenylephrine was increased by losartan at 3 and 9 months by 100,200%. Active force of aortic smooth muscle was also increased at 6 and 9 months. Acetylcholine-induced endothelium-dependent relaxation was improved by 30% after 3 months of losartan treatment, but such improvement disappeared with longer duration of treatment, accompanied by reduced phosphorylation of endothelial nitric oxide (NO) synthaseSer1177, AktThr308 and AktSer473, compared with the control. Conclusions and implications:, Losartan improved the contractile function of aorta and reduced MMP activation. However, the endothelial NO pathway remained suppressed in the thoracic aorta during losartan treatment, which might limit its long-term benefits in Marfan syndrome. [source] Tamoxifen dilates porcine coronary arteries: roles for nitric oxide and ouabain-sensitive mechanismsBRITISH JOURNAL OF PHARMACOLOGY, Issue 6 2006H S Leung Background and purpose: Experiments were designed to determine the mechanism of the relaxation induced by tamoxifen in porcine coronary arteries at the tissue, cellular and molecular levels. Experimental approach: Porcine left circumflex coronary arteries were isolated and isometric tension was measured. [Ca2+]i in native endothelial cells of intact arteries was determined by a calcium fluorescence imaging technique and eNOS ser1177 phosphorylation was assayed by Western blotting. Key results: Tamoxifen induced an endothelium-dependent relaxation that was antagonized by ICI 182,780 and abolished by NG -nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). L-Arginine reversed the effect of L-NAME while indomethacin was without effect. Tamoxifen-induced relaxation was attenuated by charybdotoxin (CTX) plus apamin, ouabain or by incubation in a K+ -free solution. Moreover, tamoxifen triggered extracellular Ca2+ -dependent increases in endothelial [Ca2+]i and this effect was abolished by ICI 182,780. Endothelium-independent relaxation to sodium nitroprusside was also inhibited by ouabain or in a K+ -free solution. Furthermore, tamoxifen increased endothelial nitric oxide synthase (eNOS) phosphorylation at Ser-1177 and ICI 182,780 prevented this effect. Conclusions and Implications: The present results suggest that tamoxifen mainly induces endothelium-dependent relaxation and that endothelial nitric oxide (NO) is the primary mediator of this effect. NO-dependent responses may result from elevated [Ca2+]i in endothelial cells; an effect abolished by ICI 182,780. NO activates Na+/K+ -ATPase in vascular smooth muscle, leading to relaxation. These results suggest that tamoxifen is able to modulate eNOS phosphorylation directly. British Journal of Pharmacology (2006) 149, 703,711. doi:10.1038/sj.bjp.0706921 [source] Lack of critical involvement of endothelial nitric oxide synthase in vascular nitrate tolerance in miceBRITISH JOURNAL OF PHARMACOLOGY, Issue 2 2002Ellen Q Wang We examined the direct involvement of endothelial nitric oxide (eNOS) in nitrate tolerance using eNOS knockout (eNOS (,/,)) and wild-type (eNOS (+/+)) mice. Animals were treated with either nitroglycerin (NTG, 20 mg kg,1s.c. 3×daily for 3 days) or vehicle (5% dextrose, D5W), and nitrate tolerance was assessed ex vivo in isolated aorta by vascular relaxation studies and cyclic GMP accumulation. Western blot was performed to determine NOS expression after NTG treatment. In both the eNOS (,/,) and (+/+) mice, the EC50 from NTG concentration-response curve was increased by ,3 fold, and vascular cyclic GMP accumulation was similarly decreased after NTG pretreatment. Vascular tolerance did not lead to changes in eNOS protein expression in eNOS (+/+) mice. These results indicate that vascular nitrate tolerance was similarly induced in eNOS (,/,) and (+/+) mice, suggesting that eNOS may not be critically involved in nitrate tolerance development in mice. British Journal of Pharmacology (2002) 135, 299,302; doi:10.1038/sj.bjp.0704532 [source] NANOMOLAR LEVEL OF OUABAIN INCREASES INTRACELLULAR CALCIUM TO PRODUCE NITRIC OXIDE IN RAT AORTIC ENDOTHELIAL CELLSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2004Xian Hui Dong Summary 1.,Changes in [Ca2+]i across the cell membrane and/or the sarcoplasmic reticulum regulate endothelial nitric oxide (NO) synthase activity. 2.,In the present study, we investigated the effect of ouabain, a specific inhibitor of Na+/K+ -ATPase, on NO release and [Ca2+]i movements in cultured rat aortic endothelial cells (RAEC) by monitoring NO production continuously using an NO-specific real-time sensor and by measuring the change in [Ca2+]i using a fluorescence microscopic imaging technique with high-speed wavelength switching. The t½ (half-time of the decline of [Ca2+]i to basal levels after stimulation with 10 µmol/L bradykinin) was used as an index of [Ca2+]i extrusion. 3.,A very low concentration of ouabain (10 nmol/L) did not increase the peak of NO production, but decreased the decay of NO release and, accordingly, increased integral NO production by the maximal dose,response concentration induced by bradykinin. The same dose of ouabain affected [Ca2+]i movements across the cell membrane and/or sarcoplasmic reticulum induced by bradykinin with a time-course similar to that of NO release. Moreover, the t½ was significantly increased. 4.,Pretreatment of RAEC with Na+ -free solution, an inhibitor of the Na+/Ca2+ exchanger, and nickel chloride hexahydrate prevented the effects induced by bradykinin and ouabain. 5.,These observations using real-time recording indicate that a small amount of ouabain contributes to the bradykinin-stimulated increase of NO production through inhibition of plasma membrane Na+/K+ -ATPase activity and an increase in intracellular Na+ concentrations. The membrane was then depolarized, leading to a decline in the bradykinin-stimulated increase in [Ca2+]i by forward mode Na+/Ca2+ exchange to prolong the Ca2+ signal time. 6.,From these results, we suggest that nanomolar levels of ouabain modulate [Ca2+]i movements and NO production in RAEC. [source] C-peptide: new findings and therapeutic implications in diabetesCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2004John Wahren Summary In contrast to earlier views, new data indicate that proinsulin C-peptide exerts important physiological effects and shows the characteristics of an endogenous peptide hormone. C-peptide in nanomolar concentrations binds specifically to cell membranes, probably to a G-protein coupled receptor. Ca2+ - and MAP-kinase dependent signalling pathways are activated, resulting in stimulation of Na+, K+ -ATPase and endothelial nitric oxide (NO) synthase, two enzyme systems known to be deficient in diabetes. C-peptide may also interact synergistically with insulin signal transduction. Studies in intact animals and in patients with type 1 diabetes have demonstrated multifaceted effects. Thus, C-peptide administration in streptozotocin-diabetic animals results in normalization of diabetes-induced glomerular hyperfiltration, reduction of urinary albumin excretion and diminished glomerular expansion. The former two effects have also been observed in type 1 diabetes patients given C-peptide in replacement dose for up to 3 months. Peripheral nerve function and structure are likewise influenced by C-peptide administration; sensory and motor nerve conduction velocities increase and nerve structural changes are diminished or reversed in diabetic rats. In patients with type 1 diabetes, beneficial effects have been demonstrated on sensory nerve conduction velocity, vibration perception and autonomic nerve function. C-peptide also augments blood flow in several tissues in type 1 diabetes via its stimulation of endothelial NO release, emphasizing a role for C-peptide in maintaining vascular homeostasis. Continued research is needed to establish whether, among the hormones from the islets of Langerhans, C-peptide is the ugly duckling that , nearly 40 years after its discovery , may prove to be an endogenous peptide hormone of importance in the treatment of diabetic long-term complications. [source] | ||||||||||||||||||||||