EMBO MOLECULAR MEDICINE, Issue 6 2010
Filipe Branco-Madeira
Abstract High mobility group box 1 (HMGB1) is a molecular alarm signal that triggers an immune response when released. It was assumed that the receptor for advanced glycation end-products (RAGE) would mediate the signal to the immune system. Recently pattern recognition receptors that are triggered by molecules of bacterial origin (the Toll-like receptor (TLR) family) were shown to also respond to HMGB1. Now two papers establish the TLR4,HMGB1 axis as proinflammatory, eventually leading to disparate conditions like seizures or skin cancer. These reports add a new twist to our understanding of the mode of action of the alarm signal HMGB1. [source]

Endothelin receptor selectivity in chronic kidney disease: rationale and review of recent evidence

EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 2009
W. Neuhofer
Abstract Endothelin (ET) is a potent vasoconstrictory peptide with proinflammatory and profibrotic properties that exerts its biological effects through two pharmacologically distinct receptor subtypes, namely ETA and ETB. In addition to its substantial contribution to normal renal function, a large body of evidence suggests that derangement of the renal ET system is involved in the initiation and progression of chronic kidney disease (CKD) in diabetes, hypertension and glomerulonephritis. Thus, the use of ET receptor antagonists (ERAs) may offer potential novel treatment strategies in CKD. Recent literature on the role of the renal ET system in the healthy kidney was reviewed. In addition, an unbiased PubMed search was performed for studies published during the last 5 years that addressed the effects of ERAs in CKD. A particular objective was to extract information regarding whether selective or nonselective ERAs may have therapeutic potential in humans. ET-1 acts primarily as an autocrine or paracrine factor in the kidney. In normal physiology, ET-1 promotes diuresis and natriuresis by local production and action through ETB receptors in the renal medulla. In pathology, ET-1 mediates vasoconstriction, mesangial-cell proliferation, extracellular matrix production and inflammation, effects that are primarily conveyed by ETA receptors. Results obtained in animal models and in humans with the use of ERAs in CKD are encouraging; nevertheless, it is still under debate which receptor subtype should be targeted. According to most studies, selective inhibition of ETA receptors appears superior compared with nonselective ERAs because this approach does not interfere with the natriuretic, antihypertensive and ET clearance effects of ETB receptors. Although preliminary data in humans are promising, the potential role of ERAs in patients with CKD and the question of which receptor subtype should be targeted can only be clarified in randomized clinical trials. [source]

T-cell-specific deletion of gp130 renders the highly susceptible IL-10-deficient mouse resistant to intestinal nematode infection

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 8 2009
Nicolas Fasnacht
Abstract Gp130 is the common receptor of the IL-6 family of cytokines and is involved in many biological processes, including acute phase response, inflammation and immune reactions. To investigate the role of gp130 under inflammatory conditions, T-cell-specific conditional gp130 mice were first bred to the IL-10-deficient background and were then infected with the gastrointestinal nematode Trichuris muris. While IL-10,/, mice were highly susceptible to T. muris, developed a mixed Th1/Th17 response and displayed severe inflammation of the caecum, infection of mice with an additional T-cell-specific deletion of gp130 signalling completely reversed the phenotype. These mice showed an accelerated worm expulsion that was associated with the rapid generation of a strong Th2 immune response and a significant increase in Foxp3-expressing Treg. Therefore, gp130 signalling in T cells regulates a switch between proinflammatory and pathogenic Th1/Th17 cells and regulatory Th2/Treg in vivo. Taken together, the data demonstrate that gp130 signalling in T cells is a positive regulator of inflammatory processes, favouring the Th1/Th17 axis. [source]

Transcriptional upregulation of inflammatory cytokines in human intestinal epithelial cells following Vibrio cholerae infection

FEBS JOURNAL, Issue 17 2007
Arunava Bandyopadhaya
Coordinated expression and upregulation of interleukin-1,, interleukin-1,, tumor necrosis factor-,, interleukin-6, granulocyte,macrophage colony-stimulating factor, interleukin-8, monocyte chemotactic protein-1 (MCP-1) and epithelial cell derived neutrophil activator-78, with chemoattractant and proinflammatory properties of various cytokine families, were obtained in the intestinal epithelial cell line Int407 upon Vibrio cholerae infection. These proinflammatory cytokines also showed increased expression in T84 cells, except for interleukin-6, whereas a striking dissimilarity in cytokine expression was observed in Caco-2 cells. Gene expression studies of MCP-1, granulocyte,macrophage colony-stimulating factor, interleukin-1,, interleukin-6 and the anti-inflammatory cytokine transforming growth factor-, in Int407 cells with V. cholerae culture supernatant, cholera toxin, lipopolysaccharide and ctxA mutant demonstrated that, apart from cholera toxin and lipopolysaccharide, V. cholerae culture supernatant harbors strong inducer(s) of interleukin-6 and MCP-1 and moderate inducer(s) of interleukin-1, and granulocyte,macrophage colony-stimulating factor. Cholera toxin- or lipopolysaccharide-induced cytokine expression is facilitated by activation of nuclear factor-,B (p65 and p50) and cAMP response element-binding protein in Int407 cells. Studies with ctxA mutants of V. cholerae revealed that the mutant activates the p65 subunit of nuclear factor-,B and cAMP response element-binding protein, and as such the activation is mediated by cholera toxin-independent factors as well. We conclude that V. cholerae elicits a proinflammatory response in Int407 cells that is mediated by activation of nuclear factor-,B and cAMP response element-binding protein by cholera toxin, lipopolysaccharide and/or other secreted products of V. cholerae. [source]

Minimizing the release of proinflammatory and toxic bacterial products within the host: A promising approach to improve outcome in life-threatening infections

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2005
Roland Nau
Abstract Various bacterial components (e.g., endotoxin, teichoic and lipoteichoic acids, peptidoglycans, DNA) induce or enhance inflammation by stimulating the innate immune system and/or are directly toxic in eukariotic cells (e.g., hemolysins). When antibiotics which inhibit bacterial protein synthesis kill bacteria, smaller quantities of proinflammatory or toxic compounds are released in vitro and in vivo than during killing of bacteria by ,-lactams and other cell-wall active drugs. In general, high antibiotic concentrations liberate lower quantities of bacterial proinflammatory or toxic compounds than concentrations close to the minimum inhibitory concentration. In animal models of Escherichia coli Pseudomonas aeruginosa and Staphylococcus aureus peritonitis/sepsis and of Streptococcus pneumoniae meningitis, a lower release of proinflammatory bacterial compounds was associated with a reduced mortality or neuronal injury. Pre-treatment with a bacterial protein synthesis inhibitor reduced the strong release of bacterial products usually observed during treatment with a ,-lactam antibiotic. Data available strongly encourage clinical trials comparing antibiotic regimens with different release of proinflammatory/toxic bacterial products. The benefit of the approach to reduce the liberation of bacterial products should be greatest in patients with a high bacterial load. [source]

Adenosine receptors: promising targets for the development of novel therapeutics and diagnostics for asthma

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 1 2006
Cristina Russo
Abstract Interest in the role of adenosine in asthma has escalated considerably since the early observation of its powerful bronchoconstrictor effects in asthmatic but not normal airways. A growing body of evidence has emerged in support of a proinflammatory and immunomodulatory role for the purine nucleoside adenosine in the pathogenic mechanisms of chronic inflammatory disorders of the airways such as asthma. The fact that adenosine enhances mast cell allergen-dependent activation, that elevated levels of adenosine are present in chronically inflamed airways, and that adenosine given by inhalation cause dose-dependent bronchoconstriction in subjects with asthma emphasizes the importance of adenosine in the initiation, persistence and progression of these common inflammatory disorders of the airways. These distinctive features of adenosine have been recently exploited in the clinical and research setting to identify innovative diagnostic applications for asthma. In addition, because adenosine exerts its multiple biological activities by interacting with four adenosine receptor subtypes, selective activation or blockade of these receptors may lead to the development of novel therapies for asthma. [source]

Hepatic recruitment of the inflammatory Gr1+ monocyte subset upon liver injury promotes hepatic fibrosis,

HEPATOLOGY, Issue 1 2009
Karlin Raja Karlmark
In addition to liver-resident Kupffer cells, infiltrating immune cells have recently been linked to the development of liver fibrosis. Blood monocytes are circulating precursors of tissue macrophages and can be divided into two functionally distinct subpopulations in mice: Gr1hi (Ly6Chi) and Gr1lo (Ly6Clo) monocytes. The role of these monocyte subsets in hepatic fibrosis and the mechanisms of their differential recruitment into the injured liver are unknown. We therefore characterized subpopulations of infiltrating monocytes in acute and chronic carbon tetrachloride (CCl4)-induced liver injury in mice using flow cytometry and immunohistochemistry. Inflammatory Gr1hi but not Gr1lo monocytes are massively recruited into the liver upon toxic injury constituting an up to 10-fold increase in CD11b+F4/80+ intrahepatic macrophages. Comparing wild-type with C-C chemokine receptor (CCR2)-deficient and CCR2/CCR6,deficient mice revealed that CCR2 critically controls intrahepatic Gr1hi monocyte accumulation by mediating their egress from bone marrow. During chronic liver damage, intrahepatic CD11b+F4/80+Gr1+ monocyte-derived cells differentiate preferentially into inducible nitric oxide synthase,producing macrophages exerting proinflammatory and profibrogenic actions, such as promoting hepatic stellate cell (HSC) activation, T helper 1,T cell differentiation and transforming growth factor , (TGF-,) release. Impaired monocyte subset recruitment in Ccr2,/, and Ccr2,/,Ccr6,/, mice results in reduced HSC activation and diminished liver fibrosis. Moreover, adoptively transferred Gr1hi monocytes traffic into the injured liver and promote fibrosis progression in wild-type and Ccr2,/,Ccr6,/, mice, which are otherwise protected from hepatic fibrosis. Intrahepatic CD11b+F4/80+Gr1+ monocyte-derived macrophages purified from CCl4 -treated animals, but not naïve bone marrow monocytes or control lymphocytes, directly activate HSCs in a TGF-,,dependent manner in vitro. Conclusion: Inflammatory Gr1+ monocytes, recruited into the injured liver via CCR2-dependent bone marrow egress, promote the progression of liver fibrosis. Thus, they may represent an interesting novel target for antifibrotic strategies. (HEPATOLOGY 2009;50:261,274.) [source]

IL-6 levels decrease with SSRI treatment in patients with major depression

HUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2005
Ayse Devrim Basterzi
Abstract Objective Some evidence indicates that an immune response with an increased production of proinflammatory cytokines often accompanies major depression. The objective of this study was to examine the serum levels of IL-6 in patients with major depression and the changes occurring in IL-6 levels during treatment with selective serotonin reuptake inhibitors (SSRI). Method Twenty-three patients with a DSM-IV diagnosis of major depressive disorder and 23 healthy matched controls were included in the study. The severity of depression was measured with the Hamilton rating scale for depression. Blood samples for IL-6 levels were obtained at baseline and at week 6 of treatment and IL-6 concentrations were evaluated using a solid phase sandwich enzyme immunoassay. All patients were treated with an SSRI. Results The IL-6 levels showed no statistically significant difference between the patients and the controls at baseline. However, IL-6 levels after treatment with SSRIs were significantly lower compared with the baseline IL-6 levels of both the patients and the controls. Conclusion The results of this study suggest that proinflammatory cytokines show some changes during the course of treatment of major depression. These findings might also be considered as supporting the hypothesis of a modulatory role of antidepressants on the immune system. Copyright © 2005 John Wiley & Sons, Ltd. [source]

The macrophage and the apoptotic cell: an innate immune interaction viewed simplistically?

IMMUNOLOGY, Issue 1 2004
Christopher D. Gregory
Summary Macrophages play important roles in the clearance of dying and dead cells. Typically, and perhaps simplistically, they are viewed as the professional phagocytes of apoptotic cells. Clearance by macrophages of cells undergoing apoptosis is a non-phlogistic phenomenon which is often associated with actively anti-inflammatory phagocyte responses. By contrast, macrophage responses to necrotic cells, including secondarily necrotic cells derived from uncleared apoptotic cells, are perceived as proinflammatory. Indeed, persistence of apoptotic cells as a result of defective apoptotic-cell clearance has been found to be associated with the pathogenesis of autoimmune disease. Here we review the mechanisms by which macrophages interact with, and respond to, apoptotic cells. We suggest that macrophages are especially important in clearing cells at sites of histologically visible, high-rate apoptosis and that, otherwise, apoptotic cells are removed largely by non-macrophage neighbours. We challenge the view that necrotic cells, including persistent apoptotic cells are, of necessity, proinflammatory and immunostimulatory and suggest that, under appropriate circumstances, persistent apoptotic cells can provide a prolonged anti-inflammatory stimulus. [source]

State of the art: IBD therapy and clinical trials in IBD

INFLAMMATORY BOWEL DISEASES, Issue S1 2005
Kim L Isaacs MD
Abstract Inflammatory bowel diseases (IBD) encompass Crohn's disease and ulcerative colitis, which are diseases characterized by chronic intestinal inflammation. IBD is believed to result from predisposing genetic and environmental factors (specific antigens and pathogen-associated molecular patterns) acting on the immunoregulatory system and causing inflammation of the gastrointestinal mucosa. IBD may be the result of an imbalance of effector (proinflammatory) and regulatory T-cell responses. Three scenarios indicative of the outcome of this balance exist in animal models: balanced effector and regulatory T cells resulting in a normal controlled inflammation; overactive effector T cells resulting in inflammation and disease; and an absence of regulatory T cells resulting in uncontrolled inflammation and severe, aggressive disease. The number of products under study for the treatment of IBD has increased from 3 products and 1 target in 1993 to more than 30 products and more than 10 targets in 2005. The number of products under development and continued investigations into the pathogenesis of IBD emphasize the need to expand clinical research efforts in IBD. [source]

Impact of elemental diet on mucosal inflammation in patients with active Crohn's disease: Cytokine production and endoscopic and histological findings

INFLAMMATORY BOWEL DISEASES, Issue 6 2005
Takayuki Yamamoto MD
Abstract Background: The aim of this study was to examine the impact of elemental diet on mucosal inflammation in Crohn's disease (CD), mainly by cytokine measurements. Methods: Twenty-eight consecutive patients with active CD were treated with an elemental diet (Elental) for 4 weeks. The mucosal biopsies were obtained from the terminal ileum and large bowel before and after treatment. As a control group, mucosal biopsies were obtained from 20 patients without inflammation. Mucosal cytokine concentrations were measured by enzyme-linked immunosorbent assay. Results: After treatment, clinical remission was achieved in 20 patients (71%). Endoscopic healing and improvement rates were 44% and 76% in the terminal ileum and 39% and 78% in the large bowel, respectively. Histologic healing and improvement rates were 19% and 54% in the terminal ileum and 20% and 55% in the large bowel, respectively. Before treatment, the mucosal concentrations of interleukin (IL)-1,, IL-1 receptor antagonist (IL-1ra), IL-6, IL-8, and tumor necrosis factor-, in the ileum and large bowel were significantly higher than in controls. These cytokine concentrations decreased to the levels of control after treatment. IL-1ra/IL-1, ratio in the ileum and large bowel was significantly lower than in controls before treatment. The ratio increased to the level of controls after treatment. The endoscopic and histologic healing of the mucosal inflammation was associated with a decline of the mucosal cytokines and an increase of the IL-1ra/IL-1, ratio. Conclusions: The elemental diet (Elental) reduced mucosal cytokine production and corrected an imbalance between proinflammatory and anti-inflammatory cytokines in CD. [source]

Association study of Wegener granulomatosis and the functionally relevant A645G polymorphism in the bactericidal/permeability increasing protein (BPI) gene

INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 1 2005
P. Jagiello
Summary In antineutrophil cytoplasmatic antibody (ANCA)-associated vasculitides (AAV), bactericidal/permeability increasing protein (BPI) ANCAs are detected. Recent observations suggest that BPI-ANCAs can potentially contribute to a proinflammatory setting in the absence of proteinase 3 (PRTN3) ANCAs during the development of a pulmonary relapse by impeding the elimination of Gram-negative bacteria (GNB). However, it is as yet not clear whether the genetic background contributes to the generation of BPI-ANCAs in Wegener granulomatosis (WG) or if BPI polymorphisms are associated with WG. In this study we genotyped the functionally relevant single nucleotide polymorphism (SNP) A645 (Glu216Lys) of the BPI gene in 201 WG patients and 608 healthy controls. To investigate whether further SNPs might be associated with WG, we also examined an intragenic microsatellite marker. No significant differences were found between patients and controls. Thus BPI polymorphisms do not appear to contribute to genetic predisposition to WG. Moreover, our data do not suggest a genetic background for the generation of BPI-ANCAs in WG. [source]

Atrial fibrillation and bisphosphonate therapy

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2010
Michael Pazianas
Abstract Bisphosphonates are the most commonly used treatment for osteoporosis and have proven efficacy in the reduction of vertebral and nonvertebral fractures. Recently, concerns have been raised about a possible association between bisphosphonate therapy and atrial fibrillation (AF) following the report of a significant increase in risk of serious AF in women treated with zoledronic acid in the HORIZON study. Subsequent studies have produced conflicting results but have not excluded the possibility of such an association. Currently there is no direct evidence that bisphosphonates exert either acute or chronic effects on cardiac electrophysiology. Nevertheless, altered intracellular electrolyte homeostasis and proinflammatory, profibrotic, and antiangiogenic effects provide potential mechanisms by which atrial conduction could be affected in patients treated with bisphosphonates. In studies in which an increase in risk of AF has been identified, there is no evidence that this translates into increased mortality or increased risk of stroke, and the risk-benefit balance of bisphosphonate therapy in patients with osteoporosis and other forms of metabolic bone disease remains strongly positive. © 2010 American Society for Bone and Mineral Research [source]

Immunomodulatory cytokines determine the outcome of Japanese encephalitis virus infection in mice

JOURNAL OF MEDICAL VIROLOGY, Issue 2 2010
S.M. Biswas
Abstract Japanese encephalitis virus (JEV) induces an acute infection of the central nervous system, the pathogenic mechanism of which is not fully understood. To investigate host response to JEV infection, 14-day-old mice were infected via the extraneural route, which resulted in encephalitis and death. Mice that received JEV immune splenocyte transfer were protected from extraneural JEV infection. Pathology and gene expression profiles were then compared in brains of mice that either succumbed to JEV infection or were protected from infection by JEV immune cell transfer. Mice undergoing progressive JEV infection had increased expression of proinflammatory cytokines, chemokines, and signal transducers associated with the interferon (IFN) pathway. In contrast, mice receiving immune cell transfer had increased production of the Th2 cytokine IL-4, and of IL-10, with subdued expression of IFN-,. We observed IL-10 to be an important factor in determining clinical outcome in JEV infection. Data obtained by microarray analysis were further confirmed by quantitative RT-PCR. Together, these data suggest that JEV infection causes an unregulated inflammatory response that can be countered by the expression of immunomodulatory cytokines in mice that survive lethal infection. J. Med. Virol. 82:304,310, 2010. © 2009 Wiley-Liss, Inc. [source]

Effects of statins on microglia

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 1 2005
Catharina Lindberg
Abstract High serum cholesterol level has been shown as one of the risk factors for Alzheimer's disease (AD), and epidemiological studies indicate that treatment with cholesterol-lowering substances, statins, may provide protection against AD. An acute-phase reaction and inflammation, with increased levels of proinflammatory cytokines, are well known in the AD brain. Notably, there is evidence for antiinflammatory activities of statins, such as reduction in proinflammatory cytokines. Consequently, it is of interest to analyze the effects of statins on microglia, the main source of inflammatory factors in the brain, such as in AD. The aims of this study were to determine the effects of statins (atorvastatin and simvastatin) on microglial cells with regard to the secretion of the inflammatory cytokine interleukin-6 (IL-6) and cell viability after activation of the cells with bacterial lipopolysaccharides (LPS) or ,-amyloid1,40 (A,1,40) and in unstimulated cells. Cells of the human microglial cell line CHME-3 and primary cultures of rat neonatal cortical microglia were used. Incubation with LPS or A,1,40 induced secretion of IL-6, and A,1,40, but not LPS, reduced cell viability. Both atorvastatin and simvastatin reduced the basal secretion of IL-6 and the cell viability of the microglia, but only atorvastatin reduced LPS- and A,1,40 -induced IL-6 secretion. Both statins potentiated the A,1,40 -induced reduction in cell viability. The data indicate the importance of also considering the microglial responses to statins in evaluation of their effects in AD and other neurodegenerative disorders with an inflammatory component. © 2005 Wiley-Liss, Inc. [source]

Immunohistochemical Characterization of Hepatic Malondialdehyde and 4-Hydroxynonenal Modified Proteins During Early Stages of Ethanol-Induced Liver Injury

ALCOHOLISM, Issue 6 2003
Brante P. Sampey
Background: Chronic ethanol consumption is associated with hepatic lipid peroxidation and the deposition or retention of aldehyde-adducted proteins postulated to be involved in alcohol-induced liver injury. The purpose of this study was to characterize hepatocellular formation of aldehyde-protein adducts during early stages of alcohol-induced liver injury. Methods: Female Sprague Dawley® rats were subjected to the intragastric administration of a low-carbohydrate/high-fat total enteral nutrition diet or a total enteral nutrition diet containing ethanol for a period of 36 days. Indexes of hepatic responses to ethanol were evaluated in terms of changes in plasma alanine aminotransferase activity, hepatic histopathologic analysis, and induction of cytochrome P-4502E1 (CYP2E1). Immunohistochemical methods were used to detect hepatic proteins modified with malondialdehyde (MDA) or 4-hydroxynonenal (4-HNE) for subsequent quantitative image analysis. Results: After 36 days of treatment, rats receiving the alcohol-containing diet displayed hepatic histopathologies characterized by marked micro- and macrosteatosis associated with only minor inflammation and necrosis. Alcohol administration resulted in a 3-fold elevation of plasma alanine aminotransferase activity and 3-fold increases (p < 0.01) in hepatic CYP2E1 apoprotein and activity. Quantitative immunohistochemical analysis revealed significant (p < 0.01) 5-fold increases in MDA- and 4-HNE modified proteins in liver sections prepared from rats treated with alcohol. The MDA- or 4-HNE modified proteins were contained in hepatocytes displaying intact morphology and were colocalized primarily with microvesicular deposits of lipid. Aldehyde-modified proteins were not prevalent in parenchymal or nonparenchymal cells associated with foci of necrosis or inflammation. Conclusions: These results suggest that alcohol-induced lipid peroxidation is an early event during alcohol-mediated liver injury and may be a sensitizing event resulting in the production of bioactive aldehydes that have the potential to initiate or propagate ensuing proinflammatory or profibrogenic cellular events. [source]

Platelet functions beyond hemostasis

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2009
S. S. SMYTH
Summary., Although their central role is in the prevention of bleeding, platelets probably contribute to diverse processes that extend beyond hemostasis and thrombosis. For example, platelets can recruit leukocytes and progenitor cells to sites of vascular injury and inflammation; they release proinflammatory and anti-inflammatory and angiogenic factors and microparticles into the circulation; and they spur thrombin generation. Data from animal models suggest that these functions may contribute to atherosclerosis, sepsis, hepatitis, vascular restenosis, acute lung injury, and transplant rejection. This article represents an integrated summary of presentations given at the Fourth Annual Platelet Colloquium in January 2009. The process of and factors mediating platelet,platelet and platelet,leukocyte interactions in inflammatory and immune responses are discussed, with the roles of P-selectin, chemokines and Src family kinases being highlighted. Also discussed are specific disorders characterized by local or systemic platelet activation, including coronary artery restenosis after percutaneous intervention, alloantibody-mediated transplant rejection, wound healing, and heparin-induced thrombocytopenia. [source]

Review article: anti-inflammatory mechanisms of action of Saccharomyces boulardii

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 8 2009
C. POTHOULAKIS
Aliment Pharmacol Ther,30, 826,833 Summary Background,Saccharomyces boulardii, a well-studied probiotic, can be effective in inflammatory gastrointestinal diseases with diverse pathophysiology, such as inflammatory bowel disease (IBD), and bacterially mediated or enterotoxin-mediated diarrhoea and inflammation. Aim, To discuss the mechanisms of action involved in the intestinal anti-inflammatory action of S. boulardii. Methods, Review of the literature related to the anti-inflammatory effects of this probiotic. Results, Several mechanisms of action have been identified directed against the host and pathogenic microorganisms. S. boulardii and S. boulardii secreted-protein(s) inhibit production of proinflammatory cytokines by interfering with the global mediator of inflammation nuclear factor ,B, and modulating the activity of the mitogen-activated protein kinases ERK1/2 and p38. S. boulardii activates expression of peroxisome proliferator-activated receptor-gamma (PPAR-,) that protects from gut inflammation and IBD. S. boulardii also suppresses ,bacteria overgrowth' and host cell adherence, releases a protease that cleaves C. difficile toxin A and its intestinal receptor and stimulates antibody production against toxin A. Recent results indicate that S. boulardii may interfere with IBD pathogenesis by trapping T cells in mesenteric lymph nodes. Conclusions, The multiple anti-inflammatory mechanisms exerted by S. boulardii provide molecular explanations supporting its effectiveness in intestinal inflammatory states. [source]

Controversies related to red blood cell transfusion in critically ill patients

JOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 2 2010
DACVECC, DACVIM, Jennifer E. Prittie DVM
Abstract Objective , To review the evolution of and controversies associated with allogenic blood transfusion in critically ill patients. Data sources , Veterinary and human literature review. Human Data Synthesis , RBC transfusion practices for ICU patients have come under scrutiny in the last 2 decades. Human trials have demonstrated relative tolerance to severe, euvolemic anemia and a significant outcome advantage following implementation of more restricted transfusion therapy. Investigators question the ability of RBCs stored longer than 2 weeks to improve tissue oxygenation, and theorize that both age and proinflammatory or immunomodulating effects of transfused cells may limit efficacy and contribute to increased patient morbidity and mortality. Also controversial is the ability of pre- and post-storage leukoreduction of RBCs to mitigate adverse transfusion-related events. Veterinary Data Synthesis , While there are several studies evaluating the transfusion trigger, the RBC storage lesion and transfusion-related immunomodulation in experimental animal models, there is little research pertaining to clinical veterinary patients. Conclusions , RBC transfusion is unequivocally indicated for treatment of anemic hypoxia. However, critical hemoglobin or Hct below which all critically ill patients require transfusion has not been established and there are inherent risks associated with allogenic blood transfusion. Clinical trials designed to evaluate the effects of RBC age and leukoreduction on veterinary patient outcome are warranted. Implementation of evidence-based transfusion guidelines and consideration of alternatives to allogenic blood transfusion are advisable. [source]

Quantitative Analysis of Inflammatory and Immune Responses in Dogs with Gastritis and Their Relationship to Helicobacter spp.

JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2005
Infection
The present study sought to quantitatively examine mucosal inflammatory and immune responses in dogs with gastritis and the relationship of these responses to infection with Helicobacter. Gastric biopsies from 30 dogs were evaluated for B- and T-lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. Mucosal atrophy, fibrosis, cellularity, and severity of gastritis were graded qualitatively. Messenger-RNA (mRNA) for actin, interleukin-1, (IL-1,), IL-4, IL-8, and IL-10, transforming growth factor beta (TGF-,), and interferon gamma (IFN-,) was quantified by polymerase chain reaction (PCR). The presence of Helicobacter spp. was determined by urease activity, histology, PCR, and enzyme-linked immunosorbent assay. mRNA for IL-1,, IL-8, IL-10, TGF-,, and IFN-, was detected in most dogs. IL-4 mRNA was detected in only 1 dog. Correlations were observed for IL-1, versus IL-8 and IL-10; IL-8 versus IL-10, IFN-,, and TGF-,; and IL-10 versus IFN-,. Mucosal pathology was related to cytokine mRNA expression (neutrophils to IL-8 and IFN-,, macrophages and lymphocytes to IFN-,, and fibrosis to IL-1,). Gastritis was categorized as lymphoplasmacytic in all dogs, and its histologic severity correlated with atrophy, infiltration with lymphocytes and macrophages, and expression of IL-10 and IFN-,. Of the dogs examined, 76.7% were infected with Helicobacter spp. Infection was associated with increased expression of TGF-, and fibrosis. Circulating anti- Helicobacter immunoglobulin G titers were higher in uninfected than infected dogs. We conclude that lymphoplasmacytic gastritis in dogs is characterized by concurrent activation of proinflammatory and immunomodulatory cytokines, with increased mRNA expression related to mucosal pathology. No significant associations between Helicobacter infection and proinflammatory cytokine expression, severity of gastritis, or differences in the pathogenicity of different Helicobacter spp. were found. [source]

Omega-3 fatty acids inhibit an increase of proinflammatory cytokines in patients with active Crohn's disease compared with omega-6 fatty acids

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 11-12 2005
A. A. NIELSEN
Summary Background :,Crohn's disease is a chronic inflammatory condition affecting the gastrointestinal tract. Polyunsaturated omega-3 fatty acids given orally may reduce the secretion of proinflammatory cytokines and hereby downregulate the inflammatory process. Aim :,To assess the effects of enteral fatty acids, in the form of Impact Powder (Novartis, Switzerland), as adjuvant therapy to corticosteroid treatment on the proinflammatory and anti-inflammatory cytokine profiles in patients with active Crohn's disease. Methods :,The proinflammatory and anti-inflammatory cytokines were measured in plasma from 31 patients with active Crohn's disease. Patients were randomized for oral intake of omega-3 fatty acid (3-Impact Powder) or omega-6 fatty acids (6-Impact Powder). Clinical and biochemical markers of inflammation were studied at baseline and after 5 and 9 weeks. Results :,Within the 3-Impact Powder group, no significant changes in concentrations of interleukin-6, interferon- ,, monocyte chemoattractant protein-1, interleukin-2, interleukin-5 and interleukin-10, whereas a significant differences in concentration of interleukin-1, and interleukin-4 were observed during therapy. Within the 6-Impact Powder group a significant changes in concentrations of interleukin-1,, interleukin-6, interferon- ,, monocyte chemoattractant protein-1, interleukin-2, interleukin-4, interleukin-5 and interleukin-10 were observed. Conclusions :,The 3-Impact Powder showed immunomodulatory properties and might inhibit an increase of proinflammatory cytokines in contrast to the 6-Impact Powder. [source]

Proliferative alloresponse of T-cytotoxic cells identifies rejection-prone children with steroid-free liver transplantation

LIVER TRANSPLANTATION, Issue 8 2009
Chethan Ashokkumar
Donor-induced and third-party,induced proliferation of T-helper and T-cytotoxic (Tc) cells and their naïve and memory subsets was evaluated simultaneously in single blood samples from 77 children who received steroid-free liver transplantation (LTx) after induction with rabbit anti-human thymocyte globulin. Proliferation was measured by dilution of the intravital dye carboxyfluorescein succinimidyl ester (CFSE) in a 3- to 4-day mixed lymphocyte response coculture. The ratio of donor/third-party,induced proliferated (CFSElow) T-cells was reported as the immunoreactivity index (IR) for each subset. Rejectors were defined as those who experienced biopsy-proven acute cellular rejection within 60 days of the assay. IR > 1 signified increased risk of rejection, and IR < 1 implied decreased risk. Demographics for 32 rejectors and 45 nonrejectors were similar. Proliferated CFSElow T-cells and subsets were significantly higher among rejectors compared with nonrejectors. In 33 of 77 randomly selected children, logistic regression, leave-one-out cross-validation, and receiver operating characteristic analyses showed that the IR of Tc cells was best associated with biopsy-proven rejection (sensitivity > 75%, specificity > 88%). Sensitivity and specificity were replicated in the remaining 44 children who composed the validation cohort. IR of CFSElow Tc cells correlated significantly with IR of proinflammatory, allospecific CD154+ Tc cells (r = 0.664, P = 0.0005) and inversely with IR of allospecific, anti-inflammatory, cytotoxic T lymphocyte antigen 4,positive Tc cells (r = ,0.630, P = 0.007). In conclusion, proliferative alloresponses of Tc cells can identify rejection-prone children receiving LTx. Liver Transpl 15:978,985, 2009. © 2009 AASLD. [source]

Iron and inflammatory bowel disease

ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2001
B. Oldenburg
Both anaemia of iron deficiency and anaemia of chronic disease are frequently encountered in inflammatory bowel disease. Anaemia of iron deficiency is mostly due to inadequate intake or loss of iron. Anaemia of chronic disease probably results from decreased erythropoiesis, secondary to increased levels of proinflammatory cytokines, reactive oxygen metabolites and nitric oxide. Assessment of the iron status in a condition associated with inflammation, such as inflammatory bowel disease, is difficult. The combination of serum transferrin receptor with ferritin concentrations, however, allows a reliable assessment of the iron deficit. The best treatment for anaemia of chronic disease is the cure of the underlying disease. Erythropoietin reportedly may increase haemoglobin levels in some of these patients. The anaemia of iron deficiency is usually treated with oral iron supplements. Iron supplementation may lead to an increased inflammatory activity through the generation of reactive oxygen species. To date, data from studies in animal models of inflammatory bowel disease support the theoretical disadvantage of iron supplementation in this respect. The results, however, cannot easily be extrapolated to the human situation, because the amount of supplemented iron in these experiments was much higher than the dose used in patients with iron deficiency. [source]

Mechanisms of virus-induced asthma exacerbations: state-of-the-art.

ALLERGY, Issue 5 2007
A GA2LEN, InterAirways document
Viral infections of the respiratory tract are the most common precipitants of acute asthma exacerbations. Exacerbations are only poorly responsive to current asthma therapies and new approaches to therapy are needed. Viruses, most frequently human rhinoviruses (RV), infect the airway epithelium, generate local and systemic immune responses, as well as neural responses, inducing inflammation and airway hyperresponsiveness. Using in vitro and in vivo experimental models the role of various proinflammatory or anti-inflammatory mediators, antiviral responses and molecular pathways that lead from infection to symptoms has been partly unravelled. In particular, mechanisms of susceptibility to viral infection have been identified and the bronchial epithelium appeared to be a key player. Nevertheless, additional understanding of the integration between the diverse elements of the antiviral response, especially in the context of allergic airway inflammation, as well as the interactions between viral infections and other stimuli that affect airway inflammation and responsiveness may lead to novel strategies in treating and/or preventing asthma exacerbations. This review presents the current knowledge and highlights areas in need of further research. [source]

Proinflammatory signalling stimulated by the type III translocation factor YopB is counteracted by multiple effectors in epithelial cells infected with Yersinia pseudotuberculosis

MOLECULAR MICROBIOLOGY, Issue 5 2003
Gloria I. Viboud
Summary Type III secretion systems are used by several pathogens to translocate effector proteins into host cells. Yersinia pseudotuberculosis delivers several Yop effectors (e.g. YopH, YopE and YopJ) to counteract signalling responses during infection. YopB, YopD and LcrV are components of the translocation machinery. Here, we demonstrate that a type III translocation protein stimulates proinflammatory signalling in host cells, and that multiple effector Yops counteract this response. To examine proinflammatory signalling by the type III translocation machinery, HeLa cells infected with wild-type or Yop,Y. pseudotuberculosis strains were assayed for interleukin (IL)-8 production. HeLa cells infected with a YopEHJ, triple mutant released significantly more IL-8 than HeLa cells infected with isogenic wild-type, YopE,, YopH, or YopJ, bacteria. Complementation analysis demonstrated that YopE, YopH or YopJ are sufficient to counteract IL-8 production. IL-8 production required YopB, but did not require YopD, pore formation or invasin-mediated adhesion. In addition, YopB was required for activation of nuclear factor kappa B, the mitogen-activated protein kinases ERK and JNK and the small GTPase Ras in HeLa cells infected with the YopEHJ, mutant. We conclude that interaction of the Yersinia type III translocator factor YopB with the host cell triggers a proinflammatory signalling response that is counteracted by multiple effectors in host cells. [source]

Molecular characterization of Treponema denticola infection-induced bone and soft tissue transcriptional profiles

MOLECULAR ORAL MICROBIOLOGY, Issue 4 2010
V. Bakthavatchalu
Summary Treponema denticola is associated with subgingival biofilms in adult periodontitis and with acute necrotizing ulcerative gingivitis. However, the molecular mechanisms by which T. denticola impacts periodontal inflammation and alveolar bone resorption remain unclear. Here, we examined changes in the host transcriptional profiles during a T. denticola infection using a murine calvarial model of inflammation and bone resorption. T. denticola was injected into the subcutaneous soft tissue over the calvaria of BALB/c mice for 3 days, after which the soft tissues and the calvarial bones were excised. RNA was isolated and analysed for transcript profiling using Murine GeneChip® arrays. Following T. denticola infection, 2905 and 1234 genes in the infected calvarial bones and soft tissues, respectively, were differentially expressed (P , 0.05). Biological pathways significantly impacted by T. denticola infection in calvarial bone and calvarial tissue included leukocyte transendothelial migration, cell adhesion (immune system) molecules, cell cycle, extracellular matrix,receptor interaction, focal adhesion, B-cell receptor signaling and transforming growth factor-, signaling pathways resulting in proinflammatory, chemotactic effects, and T-cell stimulation. In conclusion, localized T. denticola infection differentially induces transcription of a broad array of host genes, the profiles of which differed between inflamed calvarial bone and soft tissues. [source]

Cytokine profile of sickle cell disease in Oman

AMERICAN JOURNAL OF HEMATOLOGY, Issue 4 2004
Anil Pathare
Abstract The aim of our study was to assess the cytokine profile of sickle cell disease (SCD) patients in steady state and in vaso-occlusive crisis (VOC). VOC has a complex nature, involving interactions between sickle red blood cells (RBC), the endothelium, and leucocytes. Endothelial damage due to recurrent adhesion of sickle RBCs may disrupt endothelial function, leading to altered cytokine release. It is therefore pertinent to study the cytokine profile of SCD patients in steady state and in crisis prior to exploring its contribution to vaso-occlusive manifestations, since it is believed that an altered balance of proinflammatory and anti-inflammatory cytokines plays an important role in painful crisis. Cytokines including IL-1,, IL-2, IL-4, IL-6, IL-8, TNF-,, and IFN-, were measured by commercially available ELISA kits in SCD patients (n = 60); in steady state (n = 26) and in painful crisis (n = 34) and compared with nonanemic age- and sex-matched normal Omani controls (n = 20). SCD patients in crisis showed elevated levels of TNF-, (P < 0.092) and IL-6 (P < 0.024) when compared with steady state. It was also observed that SCD patients in steady state showed a significant elevation in IL-1, (P < 0.04), IL-6 (P < 0.0001), and IFN-, (P < 0.02) as compared to normal subjects. It is thus evident that both type I and type II cytokines are significantly altered in SCD patients. In steady state, type II proinflammatory cytokines are elevated, whereas in crisis, an additional augmentation of type I cytokines occurs, with persistent elevation of type II cytokines, emphasizing the role of perturbed endothelium and activated monocytes in the pathophysiology of vaso-occlusion in sickle cell crisis. Am. J. Hematol. 77:323,328, 2004 © 2004 Wiley-Liss, Inc. [source]

Downregulation of pro-inflammatory cytokines by lupeol measured using cytometric bead array immunoassay

PHYTOTHERAPY RESEARCH, Issue 1 2010
Sheikh Fayaz Ahmad
Abstract The objective of the study was to investigate the activity of Lupeol (LUP) on proinflammatory and anti-inflammatory cytokines in the pleural exudate from male swiss albino mice. We applied Cytometric bead array technology for simultaneously measurement of these cytokines in pleurisy induced mice treated with lupeol in graded oral doses. Cytometric bead array uses the sensitivity of amplified fluorescence detection by flowcytometer to measure soluble analytes in a particle based immune assay. This assay can accurately quantitate 5 cytokines in a 50 microlitre sample volume. Oral administration of LUP at doses of 25, 50, 100 and 200 mg/kg p.o. produced dose related inhibition of IL-2, IFN-gamma and TNF- , in the pleural exudate with the most significant effect at 100 mg/kg oral dose. LUP had a non significant inhibitory effect on the levels of IL-4 and IL-5. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Immunomodulatory effect of extracts of Hibiscus sabdariffa L. (Family Malvaceae) in a mouse model

PHYTOTHERAPY RESEARCH, Issue 5 2008
Titilayo O. Fakeye
Abstract The immunomodulatory activity of water and alcohol extracts (including its fractions) of the dried calyx of the plant was evaluated in mice. The ability of the extracts to inhibit or enhance the production of two cytokines, namely tumor necrosis factor-alpha (TNF- ,) and interleukin-10 (IL-10), respectively, implicated as proinflammatory and antiinflammatory interleukins were also evaluated. The extracts at doses of 50 mg/kg were found to possess higher immunostimulatory activities in comparison with levamisole (positive control), with significant effects when compared with the vehicle-treated group (p < 0.01). Increased activity was observed with increase in doses of the 50% ethanol and absolute ethanol extracts. The insoluble fraction exhibited a significant dose-dependent immunostimulatory activity (p < 0.05), while the residual water-soluble fraction exhibited activity at 100 mg/kg body weight. The production of tumor necrosis factor-alpha (TNF- ,), was low in all the extract groups tested, while the production of interleukin 10 (IL-10) was high compared with the control. The production of IL-10 was high in 300 mg/kg aqueous extract. The insoluble fraction exhibited a profound dose-dependent immunostimulatory activity higher than the positive control at 100 mg/kg. This study established the immunoenhancing properties of the extracts of this plant confirming that the immunomodulatory activity is cell mediated and humoral. The insoluble fraction could find use as an immunostimulatory agent in humans. Copyright © 2008 John Wiley & Sons, Ltd. [source]