Search results for "degranulation"
showing 10 items of 81 documents
The Inflammatory Feed-Forward Loop Triggered by the Complement Component C3 as a Potential Target in Endometriosis
2021
Copyright © 2021 Agostinis, Zorzet, Balduit, Zito, Mangogna, Macor, Romano, Toffoli, Belmonte, Morello, Martorana, Borelli, Ricci, Kishore and Bulla. The complement system is a major component of humoral innate immunity, acting as a first line of defense against microbes via opsonization and lysis of pathogens. However, novel roles of the complement system in inflammatory and immunological processes, including in cancer, are emerging. Endometriosis (EM), a benign disease characterized by ectopic endometrial implants, shows certain unique features of cancer, such as the capacity to invade surrounding tissues, and in severe cases, metastatic properties. A defective immune surveillance against…
Morelloflavone, a novel biflavonoid inhibitor of human secretory phospholipase A2 with anti-inflammatory activity
1997
Abstract The flavanonylflavone morelloflavone inhibited secretory phospholipase A 2 (PLA 2 ) in vitro , with a high potency on the human recombinant synovial and bee venom enzymes ( IC 50 = 0.9 and 0.6 μM, respectively). The inhibition was apparently irreversible. In contrast, the compound was inactive on cytosolic PLA 2 activity from human monocytes. Morelloflavone scavenged reactive oxygen species generated by human neutrophils ( IC 50 = 2.7 and 1.8 μM for luminol and lucigenin, respectively) but did not modify cellular responses such as degranulation or eicosanoid release. This biflavonoid exerted anti-inflammatory effects in animal models, with a potent inhibition of 12-O-tetradecanoylp…
A Mechanistic Approach to theIn VivoAnti-Inflammatory Activity of Sesquiterpenoid Compounds Isolated fromInula viscosa
2001
The present study was designed to examine the anti-inflammatory activity of the sesquiterpenoids ilicic acid and inuviscolide, isolated from Inula viscosa, on cell degranulation, leukotriene biosynthesis, neurogenic drive and glucocorticoid-like interactions. Swiss female mice were used to measure the ear oedema induced by phorbol esters or ethyl phenylpropiolate (EPP), and the paw oedema induced by phospholipase A(2) (PLA(2)) or serotonin. Drug treatment consisted of one topically-applied dose in the ear models and a subcutaneous or intraperitoneal injection in the paw models. Quantitative analysis of leukotriene B(4) (LTB(4)) formation was performed on rat peritoneal neutrophils by high p…
Dual specificity phosphatase 1 knockout mice show enhanced susceptibility to anaphylaxis but are sensitive to glucocorticoids.
2007
Dual specificity phosphatase DUSP1 (otherwise known as mitogen-activated phosphatase 1 or MKP-1) dephosphorylates MAPKs, particularly p38, and negatively regulates innate immunity. Recent studies have shown that the DUSP1 gene is transcriptionally up-regulated by glucocorticoids (GCs) and that the antiinflammatory action of GCs is impaired in DUSP1-/- mice. Here we show that GC-mediated dephosphorylation of ERK-1 and ERK-2 activated by IgE receptor cross-linking is unimpaired in bone marrow-derived mast cells (BMMCs) of DUSP1-/- mice. Dephosphorylation of phospho-p38 MAPK is impaired but only at early times of GC treatment. Proinflammatory cytokine and chemokine gene expression (CCL2, IL-6,…
Stabilization of Perivascular Mast Cells by Endothelial CNP (C-Type Natriuretic Peptide)
2020
Objective: Activated perivascular mast cells (MCs) participate in different cardiovascular diseases. Many factors provoking MC degranulation have been described, while physiological counterregulators are barely known. Endothelial CNP (C-type natriuretic peptide) participates in the maintenance of vascular barrier integrity, but the target cells and mechanisms are unclear. Here, we studied whether MCs are regulated by CNP. Approach and Results: In cultured human and murine MCs, CNP activated its specific GC (guanylyl cyclase)-B receptor and cyclic GMP signaling. This enhanced cyclic GMP–dependent phosphorylation of the cytoskeleton-associated VASP (vasodilator-stimulated phosphoprotein) and…
The Relationship Between Maximal Exercise-Induced Increases in Serum IL-6, MPO and MMP-9 Concentrations
2012
The aim of this study was to test the hypothesis that exercise would induce inflammatory response characterized by increased pro-inflammatory cytokines - interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α), adhesion molecule, matrix metalloprotease-9 (MMP-9) and myeloperoxidase (MPO) levels. Additional aim was to elucidate the possible source of maximal exercise-induced increase in MMP-9 concentration. To examine our hypothesis, 26 professional male ice hockey players [age 25 ± 1 (mean ± SEM) years; BMI 25.8 ± 0.4 kg/m(2) ] performed an incremental bicycle test until exhaustion, when maximal oxygen consumption was recorded. Venous blood samples were collected 30 min before and 2 min a…
Inter-relationship between platelet-derived microparticles and oxidative stress in patients with venous thromboembolism
2020
Background: Hypercoagulative conditions play a key role in venous thromboembolism (VTE). Inflammation is currently linked to VTE, but the potential role of circulating microparticles and oxidative stress (OxS) must be elucidated. The aim of this study was to evaluate platelet-derived microparticles and surrogate OxS biomarkers in patients diagnosed with VTE through a case&ndash
PEST-domain-enriched tyrosine phosphatase and glucocorticoids as regulators of anaphylaxis in mice
2011
To cite this article: Obiri DD, Flink N, Maier JV, Neeb A, Maddalo D, Thiele W, Menon A, Stassen M, Kulkarni RA, Garabedian MJ, Barrios AM, Cato ACB. PEST-domain-enriched tyrosine phosphatase and glucocorticoids as regulators of anaphylaxis in mice. Allergy 2012; 67: 175–182. Abstract Background: PEST-domain-enriched tyrosine phosphatase (PEP) is a protein tyrosine phosphatase exclusively expressed in hematopoietic cells. It is a potent negative regulator of T-cell receptor signalling that acts on receptor-coupled protein tyrosine kinases. PEST-domain-enriched tyrosine phosphatase is also expressed in mast cell and is positively regulated by glucocorticoids, but its function is unknown. In…
Variation of platelet function in clinical phenotypes of acute venous thromboembolism – Results from the GMP‐VTE project
2022
Background The role of platelets in the pathogenesis of venous thromboembolism (VTE) is receiving increasing attention; however, limited information is available on platelet function in the acute phase of the disease. Objective To characterize platelet function according to VTE phenotypes. Patients/Methods In total, 154 subjects (isolated pulmonary embolism [iPE], n = 28; isolated deep vein thrombosis [iDVT], n = 35; DVT+PE, n = 91) were included. In this study platelet function analyzer (PFA)-200, light transmission aggregometry (LTA), thrombin generation (TG) in presence (PRP) and absence (PFP) of platelets and platelet flow cytometry were investigated. LASSO regression was used to select…
Myeloperoxidase mediates neutrophil activation by association with CD11b/CD18 integrins.
2004
Recruitment and activation of polymorphonuclear neutrophils (PMNs) reflects a primary immunological response to invading pathogens and has also emerged as a hallmark of vascular inflammation. One of the principal enzymes released upon PMN activation is myeloperoxidase (MPO), a heme protein that not only generates cytotoxic oxidants but also impacts deleteriously on nitric oxide-dependent signaling cascades within the vasculature. Because MPO also associates with the membrane of PMN, we evaluated whether MPO could also function as an autocrine modulator of PMN activation. The extent of PMN membrane-associated MPO was elevated in patients with acute inflammatory vascular disease compared with…