cyclic-gmp and Vasculitis

To demonstrate that nitroglycerin improves biological markers of arterial inflammation in patients with peripheral vascular disease.. Atherosclerosis is an inflammatory disease in which there is an increase in active inflammation markers such as C-reactive protein and other factors released by endothelial cells. Nitroglycerin acts by a chemical liberation of nitric oxide. We have previously published the results from several controlled clinical trials confirming an anti-inflammatory action of nitroglycerin.. Forty patients with peripheral vascular disease entered a randomized, double-blind, placebo-controlled pilot study for 6 weeks. Twenty-one patients were treated with continuous application of a transdermal nitroglycerin patch (15 mg/24 hours) on the anterior face of the thigh. Venous blood samples were obtained before treatment and 2 and 6 weeks after. We measured plasma levels of C-reactive protein, cGMP (also intraplatelet cGMP), E-selectin, ICAM, VCAM-1, IL-6, and nitrites/nitrates.. No biological parameter was modified in the placebo group. On the contrary, nitroglycerin significantly reduced plasma levels of C-reactive protein and sE-selectin and increased the levels of intraplatelet cGMP.. The results of this preliminary study show that nitroglycerin has an anti-inflammatory action in patients with peripheral vascular disease. This may provide a new therapeutic approach to understanding the efficacy of nitrovasodilators in the improvement of atherosclerotic syndromes.

Topics: Administration, Cutaneous; Adult; Aged; Anti-Inflammatory Agents; Arteriosclerosis; Biomarkers; C-Reactive Protein; Cyclic GMP; Double-Blind Method; E-Selectin; Female; Humans; Intercellular Adhesion Molecule-1; Interleukin-6; Male; Middle Aged; Nitrates; Nitrites; Nitroglycerin; Peripheral Vascular Diseases; Pilot Projects; Statistics, Nonparametric; Vascular Cell Adhesion Molecule-1; Vasculitis; Vasodilator Agents

To study the role of endogenous proinflammatory cytokines in endothelial dysfunction in diabetes, we administered semapimod, an inhibitor of proinflammatory cytokine production, to obese Zucker (OZ) rats, and examined its effect on endothelium-dependent vasorelaxation. Endothelium-dependent vasorelaxation induced by acetylcholine and adrenomedullin (AM) was significantly reduced in OZ rats compared to a control group of lean Zucker rats. Semapimod significantly restored endothelium-dependent vasorelaxation in OZ rats. This effect of semapimod was well correlated with the reduction in the serum concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin-6, and C-reactive protein, as well as with the recovery of AM-induced Akt phosphorylation and cGMP production. Furthermore, acute administration of TNF-alpha significantly suppressed endothelium-dependent vasorelaxation and AM-induced cGMP production. These results implicate endogenous proinflammatory cytokines, especially TNF-alpha, in endothelial dysfunction in diabetes, and indicate that blockade of these cytokines will be a promising strategy for inhibiting the progression of vascular inflammation.

Topics: Adrenomedullin; Animals; Biomarkers; C-Reactive Protein; Cyclic GMP; Endothelium, Vascular; Hydrazones; Hypertension; Immunosuppressive Agents; Interleukin-6; Male; Obesity; Phosphorylation; Proto-Oncogene Proteins c-akt; Rats; Rats, Zucker; Tumor Necrosis Factor-alpha; Vasculitis; Vasodilation

Neovascularization is an important physiological repair mechanism in response to ischemic injury, and its process is dependent on reactive oxygen species (ROS). Overproduction of superoxide anion (O2-) rather contributes to various cardiovascular diseases. The extracellular superoxide dismutase (ecSOD) is one of the major antioxidant enzymes against O2- in blood vessels; however, its role in neovascularization induced by tissue ischemia is unknown. Here we show that hindlimb ischemia of mice stimulates a significant increase in ecSOD activity in ischemic tissues where ecSOD protein is highly expressed at arterioles. In mice lacking ecSOD, ischemia-induced increase in blood flow recovery, collateral vessel formation, and capillary density are significantly inhibited. Impaired neovascularization in ecSOD(-/-) mice is associated with enhanced O2- production, TUNEL-positive apoptotic cells and decreased levels of NO2-/NO3- and cGMP in ischemic tissues as compared with wild-type mice, and it is rescued by infusion of the SOD mimetic tempol. Recruitment of inflammatory cells into ischemic tissues as well as numbers of inflammatory cells and endothelial progenitor cells (c-kit+/CD31+ cells) in both peripheral blood and bone marrow (BM) are significantly reduced in these knockout mice. Of note, ecSOD expression is markedly increased in BM after ischemia. NO2-/NO3- and cGMP levels are decreased in ecSOD(-/-) BM. Transplantation of wild-type BM into ecSOD(-/-) mice rescues the defective neovascularization. Thus, ecSOD in BM and ischemic tissues induced by hindlimb ischemia may represent an important compensatory mechanism that blunts the overproduction of O2-, which may contribute to reparative neovascularization in response to ischemic injury.

Topics: Animals; Antioxidants; Apoptosis; Bone Marrow Cells; Bone Marrow Transplantation; Cell Differentiation; Cells, Cultured; Cyclic GMP; Cyclic N-Oxides; Endothelium, Vascular; Extracellular Space; Hindlimb; Ischemia; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Neovascularization, Physiologic; Nitrates; Nitrites; Reactive Oxygen Species; Spin Labels; Stem Cells; Superoxide Dismutase; Vasculitis

We have previously shown that reoxygenation of hypoxic human umbilical vein endothelial cells (HUVECs) leads to the activation and deposition of complement. In the present study, we investigated whether the terminal complement complex (C5b-9) influences HUVEC nuclear factor-kappaB (NF-kappaB) translocation and vascular cell adhesion molecule-1 (VCAM-1) protein expression after hypoxia/reoxygenation by decreasing endothelial cGMP. Additionally, we investigated the action of anti-human C5 therapy on endothelial cGMP, NF-kappaB translocation, and VCAM-1 protein expression. Reoxygenation (0.5 to 3 hours, 21% O(2)) of hypoxic (12 hours, 1% O(2)) HUVECs in human serum (HS) significantly increased C5b-9 deposition, VCAM-1 expression, and NF-kappaB translocation compared with hypoxic/reoxygenated HUVECs treated with the recombinant human C5 inhibitor h5G1.1-scFv. Acetylcholine (ACh)-induced cGMP synthesis was significantly higher in normoxic HUVECs compared with hypoxic HUVECs reoxygenated in HS but did not differ from hypoxic HUVECs reoxygenated in buffer or HS treated with h5G1.1-scFv. Treatment of hypoxic/reoxygenated HUVECs with h5G1.1-scFv or cGMP analogues significantly attenuated NF-kappaB translocation and VCAM-1 protein expression. Treatment with NO analogues, but not a cAMP analogue, cGMP antagonists, or an NO antagonist, also significantly attenuated VCAM-1 expression. We conclude that (1) C5b-9 deposition, NF-kappaB translocation, and VCAM-1 protein expression are increased in hypoxic HUVECs reoxygenated in HS; (2) reoxygenation of hypoxic HUVECs in HS, but not buffer alone, attenuates ACh-induced cGMP synthesis; and (3) treatment of hypoxic/reoxygenated HUVECs with h5G1.1-scFv attenuates C5b-9 deposition, NF-kappaB translocation, and VCAM-1 expression while preserving ACh-induced cGMP synthesis. C5b-9-induced VCAM-1 expression may thus involve an NO/cGMP-regulated NF-kappaB translocation mechanism.

Topics: Aminoquinolines; Antibodies, Monoclonal; Blotting, Western; Bucladesine; Cell Hypoxia; Cells, Cultured; Complement Membrane Attack Complex; Cyclic GMP; Dibutyryl Cyclic GMP; Endothelium, Vascular; Enzyme Inhibitors; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Glutathione; Humans; Immunotherapy; Intercellular Adhesion Molecule-1; NF-kappa B; NG-Nitroarginine Methyl Ester; Nitric Oxide Donors; Nitroso Compounds; Oxygen; Penicillamine; S-Nitrosoglutathione; Umbilical Veins; Vasculitis; Vasodilation