interleukin-8 and Endotoxemia

Continuous hemofiltration currently represents standard renal replacement therapy in critically ill patients. Because higher ultrafiltration rates are related to better survival rates in experimental and clinical studies and hemofiltration results in fewer cardiovascular side effects than does conventional hemodialysis, the use of inflammatory mediator removal by this extracorporeal procedure has emerged. This article reviews clinically relevant principles of compound transport and the experimental and clinical effects of hemofiltration during sepsis. Hemofiltration did not have a major impact on plasma concentrations of prominent inflammatory cytokines (tumor necrosis factor-a and interleukins 1b, 6, and 8) and seems therefore not to be able to counterbalance endogenous cytokine production despite considerable cytokine removal in the filtrate. Contradictory results in the literature are discussed under the viewpoint of membrane-related sieving coefficients and plasma cytokine measurement. A significant reduction in plasma anaphylatoxin concentrations by hemofiltration is associated with impressive immunomodulatory and cardiodepressive ultrafiltrate effects. Thus far, however, the use of hemofiltration for nonrenal indications remains experimental and is not supported by controlled clinical trials. Modern strategies of blood purification that may be associated with a high degree of effectiveness for mediator removal (high-volume hemofiltration and heparin-induced extracorporeal lipoprotein-fibrinogen precipitation) are discussed.

Topics: Anaphylatoxins; Animals; Blood Component Removal; Endotoxemia; Hemofiltration; Humans; Inflammation Mediators; Interleukin-1; Interleukin-6; Interleukin-8; Multiple Organ Failure; Sepsis; Tumor Necrosis Factor-alpha

Diabetes mellitus is a systemic disease with several major complications affecting both the quality and length of life. One of these complications is periodontal disease (periodontitis). Periodontitis is much more than a localized oral infection. Recent data indicate that periodontitis may cause changes in systemic physiology. The interrelationships between periodontitis and diabetes provide an example of systemic disease predisposing to oral infection, and once that infection is established, the oral infection exacerbates systemic disease. In this case, it may also be possible for the oral infection to predispose to systemic disease. In order to understand the cellular/molecular mechanisms responsible for such a cyclical association, one must identify common physiological changes associated with diabetes and periodontitis that produce a synergy when the conditions coexist. A potential mechanistic link involves the broad axis of inflammation, specifically immune cell phenotype, serum lipid levels, and tissue homeostasis. Diabetes-induced changes in immune cell function produce an inflammatory immune cell phenotype (upregulation of proinflammatory cytokines from monocytes/polymorphonuclear leukocytes and downregulation of growth factors from macrophages). This predisposes to chronic inflammation, progressive tissue breakdown, and diminished tissue repair capacity. Periodontal tissues frequently manifest these changes because they are constantly wounded by substances emanating from bacterial biofilms. Diabetic patients are prone to elevated low density lipoprotein cholesterol and triglycerides (LDL/TRG) even when blood glucose levels are well controlled. This is significant, as recent studies demonstrate that hyperlipidemia may be one of the factors associated with diabetes-induced immune cell alterations. Recent human studies have established a relationship between high serum lipid levels and periodontitis. Some evidence now suggests that periodontitis itself may lead to elevated LDL/TRG. Periodontitis-induced bacteremia/endotoxemia has been shown to cause elevations of serum proinflammatory cytokines such as interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha), which have been demonstrated to produce alterations in lipid metabolism leading to hyperlipidemia. Within this context, periodontitis may contribute to elevated proinflammatory cytokines/serum lipids and potentially to systemic disease arising from chronic hyperlipidemia and/o

Topics: Bacteremia; Bacterial Infections; Biofilms; Blood Glucose; Cholesterol, LDL; Diabetes Complications; Diabetes Mellitus; Disease Susceptibility; Down-Regulation; Endotoxemia; Growth Substances; Homeostasis; Humans; Hyperlipidemias; Inflammation; Inflammation Mediators; Insulin Resistance; Interleukin-8; Islets of Langerhans; Periodontitis; Phenotype; Risk Factors; Triglycerides; Tumor Necrosis Factor-alpha; Up-Regulation; Wound Healing

Topics: Animals; Chemokine CCL2; Clinical Trials as Topic; Colony-Stimulating Factors; Cytokines; Endotoxemia; Humans; Inflammation; Interleukin 1 Receptor Antagonist Protein; Interleukin-1; Interleukin-6; Interleukin-8; Sepsis; Sialoglycoproteins; Tumor Necrosis Factor-alpha

Expectancies play a major role for the treatment outcome of a broad variety of immune-mediated conditions and may strengthen or mimic the effects of regular long-term therapies. This study adds to a recently published study of Kox et al. (PNAS 111:7379-7384, 2014) on the ability to voluntarily influence the physiological stress response in healthy men after a training program consisting of meditation, breathing techniques, and exposure to cold, which found highly promising results on the clinical, autonomic, and immune response to experimentally induced inflammation (using the experimental human endotoxemia model). Within this project, a number of variables were included to assess the role of generalized (optimism, neuroticism) and specific outcome expectancies (related to the effects of the training on health) on the response to endotoxin administration after training. Indications were found that especially the generalized outcome expectancy optimism is a potential determinant of the autonomic (epinephrine: rho = 0.76, p < .01) and immune response (interleukin-10: rho = 0.60, p < .05) to induced inflammation after training, whereas more specific expectations with regard to the effects of the training could be especially relevant for the clinical symptom report (flu-like symptoms: rho = -0.71, p < .01). This proof-of-principle study provides first indications for potential innovative treatments to change immune-modulating responses by means of psychological mechanisms. If replicated, these findings may be used for predicting training responses and potentiate their effects by means of optimism-inducing interventions in patients with immune-mediated rheumatic conditions.

Topics: Adult; Anticipation, Psychological; Autonomic Nervous System; Cold Temperature; Endotoxemia; Endotoxins; Healthy Volunteers; Humans; Immune System; Inflammation; Interleukin-10; Interleukin-6; Interleukin-8; Male; Meditation; Optimism; Research Design; Respiration; Treatment Outcome; Tumor Necrosis Factor-alpha; Young Adult

Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, and has been proposed to be central in clinical pain conditions. Women are overrepresented in many chronic pain conditions, but experimental studies on sex differences in pain regulation during systemic inflammation are still scarce. In two randomized and double blind placebo controlled experiments, we used low doses of lipopolysaccharide (LPS) as an experimental model of systemic inflammation. The first study employed 0.8ng/kg LPS in a within-subject design of 8 individuals (1 woman), and the second study 0.6ng/kg LPS in a between-subject design of 52 participants (29 women). We investigated the effect on (a) pressure, heat, and cold pain thresholds, (b) suprathreshold noxious heat and cold sensitivity, and (c) conditioned pain modulation (CPM), and differences between men and women. LPS induced significantly lower pressure pain thresholds as compared to placebo (mean change with the 0.8ng/kg dose being -64±30kPa P=.04; with the 0.6ng/kg dose -58±55kPa, P<.01, compared to before injection), whereas heat and cold pain thresholds remained unaffected (P's>.70). Suprathreshold noxious pain was not affected by LPS in men (P's⩾.15). However, LPS made women rated suprathreshold noxious heat stimuli as more painful (P=.01), and showed a tendency to rate noxious cold pain as more painful (P=.06) as compared to placebo. Furthermore, LPS impaired conditioned pain modulation, a measure of endogenous pain inhibition, but this effect was also restricted to women (P<.01, for men P=.27). Pain sensitivity correlated positively with plasma IL-6 and IL-8 levels. The results show that inflammation more strongly affects deep pain, rather than cutaneous pain, and suggest that women's pain perception and modulation is more sensitive to immune activation than men's.

Topics: Adult; Cold Temperature; Double-Blind Method; Endotoxemia; Female; Hot Temperature; Humans; Inflammation; Interleukin-6; Interleukin-8; Male; Pain; Pain Measurement; Pain Threshold; Pressure; Sex Characteristics; Young Adult

The purpose of this study was to investigate whether an age-associated impaired acute-phase response exists. Nine healthy elderly volunteers (median, 66 years; range, 61 to 69 years) and eight young controls (median, 24 years; range, 20 to 27 years) were given an intravenous bolus of endotoxin (2 ng/kg). The rectal temperature was monitored continuously, and blood samples for cytokine measurements were obtained before endotoxin administration as well as 0.5, 1, 1.5, 2, 3, 4, 8, 12, and 24 h after the injection. The elderly subjects showed a more prolonged fever response compared to the young controls. Levels of tumor necrosis factor alpha (TNF-alpha), soluble TNF receptors (sTNFR-I), interleukin-6 (IL-6), IL-8, IL-10, and IL-1 receptor antagonist (IL-1ra) in plasma increased markedly following endotoxin administration in both groups. The elderly group showed larger initial increases in TNF-alpha and sTNFR-I levels and prolonged increased levels of sTNFR-I. Monocyte concentrations decreased in both groups, with the elderly group showing a more rapid decrease and a slower subsequent increase than did the young group. Furthermore, the elderly group had a more rapid increase in C-reactive protein levels than did the young group. In conclusion, ageing is associated with an altered acute-phase response including initial hyperreactivity, prolonged inflammatory activity, and prolonged fever response.

Topics: Acute-Phase Reaction; Adult; Aged; Aging; Body Temperature; C-Reactive Protein; Endotoxemia; Endotoxins; Female; Fever; Humans; Interleukin 1 Receptor Antagonist Protein; Interleukin-10; Interleukin-6; Interleukin-8; Male; Middle Aged; Monocytes; Receptors, Tumor Necrosis Factor; Sialoglycoproteins; Tumor Necrosis Factor-alpha

Sepsis resulting in multiorgan failure and death is still a major problem in intensive care medicine, despite extensive attempts to interfere in the supposed underlying mechanism of a deranged immune system. This is not only due to the persistent lacunae in knowledge about the immune system in sepsis but also due to the lack of sufficient instruments for intervention. Inhibitors of the p38 mitogen-activated protein kinase (p38MAPK) have been used to study the signalling pathway of the immune response. In vitro and animal studies have demonstrated that blocking p38MAPK could mitigate the pro-inflammatory response and improve survival after endotoxaemia. Using an endotoxaemia model in healthy human volunteers we evaluated the attenuation of clinical and cytokine response to endotoxin after inhibition of p38MAPK by an oral dose of RWJ-67657, a pyrindinyl imidazole. We measured the clinical parameters temperature, blood pressure and heart rate. The proinflammatory cytokines tumour necrosis factor-alpha, interleukin-6 and interleukin-8 were measured by ELISA at various points during a 24-h period. Drug toxicity was evaluated by routine clinical and laboratory examinations. After a single dose dose of RWJ-67657 the temperature and blood pressure response remained at the basal level. The inhibition of TNF-alpha, IL-6 and IL-8 response was a dose dependent. With the maximum dosage, reduction in peak serum levels of the proinflammatory cytokines was greater than 90%. There was no drug-related toxicity.. We conclude that inhibition of p38MAPK by RWJ-67657 might be a tool to intervene in the deranged immune response in sepsis and other inflammatory diseases.

Topics: Adult; Cytokines; Dose-Response Relationship, Drug; Endotoxemia; Endotoxins; Enzyme Inhibitors; Fever; Humans; Hypotension; Imidazoles; Interleukin-6; Interleukin-8; Male; MAP Kinase Signaling System; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Pyridines; Tumor Necrosis Factor-alpha

Pretreatment with interleukin (IL)-10 inhibited the release of growth-related oncogene GRO-alpha but not of epithelial-cell derived neutrophil activating protein (ENA)-78, after injection of lipopolysaccharide (LPS) into healthy humans. In vitro, IL-10 dose-dependently attenuated LPS-induced release of both GRO-alpha and ENA-78 in whole blood and in cultures of isolated polymorphonuclear and mononuclear cells.

Topics: Adult; Chemokine CXCL1; Chemokine CXCL5; Chemokines, CXC; Chemotactic Factors; Double-Blind Method; Endotoxemia; Growth Substances; Humans; Injections, Intravenous; Intercellular Signaling Peptides and Proteins; Interleukin-10; Interleukin-8; Leukocytes, Mononuclear; Lipopolysaccharides; Male; Neutrophils

High-density lipoprotein (HDL) has been found to neutralize LPS activity in vitro and in animals in vivo. We sought to determine the effects of reconstituted HDL (rHDL) on LPS responsiveness in humans in a double-blind, randomized, placebo-controlled, cross-over study. rHDL, given as a 4-h infusion at 40 mg/kg starting 3.5 h before endotoxin challenge (4 ng/kg), reduced flu-like symptoms during endotoxemia, but did not influence the febrile response. rHDL potently reduced the endotoxin-induced release of TNF, IL-6, and IL-8, while only modestly attenuating the secretion of proinflammatory cytokine inhibitors IL-1ra, soluble TNF receptors and IL-10. In addition, rHDL attenuated LPS-induced changes in leukocyte counts and the enhanced expression of CD11b/CD18 on granulocytes. Importantly, rHDL infusion per se, before LPS administration, was associated with a downregulation of CD14, the main LPS receptor, on monocytes. This effect was biologically relevant, since monocytes isolated from rHDL-treated whole blood showed reduced expression of CD14 and diminished TNF production upon stimulation with LPS. These results suggest that rHDL may inhibit LPS effects in humans in vivo not only by binding and neutralizing LPS but also by reducing CD14 expression on monocytes.

Topics: Adult; Antigens, CD; Apolipoprotein A-I; Cholesterol; Cross-Over Studies; Double-Blind Method; Endotoxemia; Endotoxins; Granulocytes; Humans; Inflammation; Infusions, Intravenous; Interleukin-6; Interleukin-8; Leukocyte Count; Lipopolysaccharides; Lipoproteins, HDL; Male; Monocytes; Nausea; Pain; Phosphatidylcholines; Placebos; Shivering; Time Factors; Tumor Necrosis Factor-alpha; Vomiting

Endotoxin as the inciting agent of cytokines and other mediators, whose high level expression correlates with the septic shock and MOF, has been the one of leading causes of death in ICU.. For treating sepsis and MOF caused by endotoxin, the anti-lipid A of LPS antibody was used, 19 burned patients whose TBSA varied from 50% to 100% were divided into anti-LPS treatment group and nontreated group.. The levels of serum endotoxin, IL-6, IL-8, TNF and soluble IL-2R were lower obviously in patients of anti-LPS group than those of nontreated group (P < 0.05).. Clinical study surggests that anti-lipid A of LPS antibody can act as an therapeutic agent against gram-negative bacterin infection in burned patients.

Topics: Adult; Antibodies; Antitoxins; Burns; Cytokines; Endotoxemia; Endotoxins; Female; Humans; Interleukin-6; Interleukin-8; Lipid A; Male; Tumor Necrosis Factor-alpha

Animal models of endotoxemia are frequently used to understand the pathophysiology of sepsis and test new therapies. However, important differences exist between commonly used experimental models of endotoxemia and clinical sepsis. Animal models of endotoxemia frequently produce hypodynamic shock in contrast to clinical hyperdynamic shock. This difference may exaggerate the importance of hypoperfusion as a causative factor in organ dysfunction. This study sought to develop an ovine model of hyperdynamic endotoxemia and assess if there is evidence of impaired oxidative metabolism in the vital organs.. Eight sheep had microdialysis catheters implanted into the brain, heart, liver, kidney, and arterial circulation. Shock was induced with a 4 h escalating dose infusion of endotoxin. After 3 h vasopressor support was initiated with noradrenaline and vasopressin. Animals were monitored for 12 h after endotoxemia. Blood samples were recovered for hemoglobin, white blood cell count, creatinine, and proinflammatory cytokines (IL-1Beta, IL-6, and IL-8).. The endotoxin infusion was successful in producing distributive shock with the mean arterial pressure decreasing from 84.5 ± 12.8 mm Hg to 49 ± 8.03 mm Hg (P < 0.001). Cardiac index remained within the normal range decreasing from 3.33 ± 0.56 L/min/m to 2.89l ± 0.36 L/min/m (P = 0.0845). Lactate/pyruvate ratios were not significantly abnormal in the heart, brain, kidney, or arterial circulation. Liver microdialysis samples demonstrated persistently high lactate/pyruvate ratios (mean 37.9 ± 3.3).. An escalating dose endotoxin infusion was successful in producing hyperdynamic shock. There was evidence of impaired oxidative metabolism in the liver suggesting impaired splanchnic perfusion. This may be a modifiable factor in the progression to multiple organ dysfunction and death.

Topics: Animals; Blood Pressure; Disease Models, Animal; Endotoxemia; Endotoxins; Female; Hemodynamics; Interleukin-1beta; Interleukin-6; Interleukin-8; Sheep; Vasoconstrictor Agents; Vasopressins

Human monocytes are a heterogeneous cell population, which can be divided into a classical (CD14++CD16-), a non-classical (CD14+CD16+), and an intermediate (CD14++CD16+) subset. We hypothesized that low-grade inflammation may differentially affect monocyte subsets. We used a human lipopolysaccharide (LPS) infusion model to mimic low-grade inflammation to identify, which monocyte subsets are preferentially activated under these conditions. Monocyte subsets were identified by staining for CD14 and CD16, activation status of monocytes was analyzed by staining for CD11b and a novel in situ mRNA hybridization approach to detect IL-6 and IL-8 specific mRNA at the single-cell level by flow cytometry. After LPS challenge, cell numbers of monocyte subsets dropped after 2 h with cell numbers recovering after 6 h. Distribution of monocyte subsets was skewed dramatically towards the intermediate subset after 24 h. Furthermore, intermediate monocytes displayed the largest increase of CD11b expression after 2 h. Finally, IL-6 and IL-8 mRNA levels increased in intermediate and non-classical monocytes after 6 h whereas these mRNA levels in classical monocytes changed only marginally. In conclusion, our data indicates that the main responding subset of monocytes to standardized low-grade inflammation induced by LPS in humans is the CD14++CD16+ intermediate subset followed by the CD14+CD16+ non-classical monocyte subset. Circulating classical monocytes showed comparably less reaction to LPS challenge in vivo.

Topics: Cell Count; Endotoxemia; Humans; Inflammation; Interleukin-6; Interleukin-8; Lipopolysaccharide Receptors; Lipopolysaccharides; Monocytes; Receptors, IgG; RNA, Messenger

Lipopolysaccharide (LPS)-induced endotoxemia can cause serious organ damage such as acute lung injury and death by triggering the secretion of proinflammatory cytokines and acute-phase reactants. The goal of this study was to evaluate the effects of β-glucan on inflammatory mediator levels and histopathological changes in LPS-induced endotoxemia.. Forty-seven male Wistar albino rats were randomly allocated into four groups as follows: control group, LPS group (10 mg/kg LPS), LPS + β-glucan group (100 mg/kg β-glucan before LPS administration), and β-glucan group. Twelve hours after LPS administration, lung and serum samples were collected. Concentrations of IL-6, IL-8, C-reactive protein (CRP), and procalcitonin were measured in the serum at hours 0 (basal) and 12. The severity of lung damage was assessed by an appropriate histopathological scoring system.. Serum levels of CRP in the LPS group at 12 h were significantly higher than in the other groups, whereas serum IL-6 levels in the LPS and LPS + β-glucan groups at 12 h were significantly decreased. The mean histopathological damage score of the LPS group was slightly higher than that of the LPS + β-glucan group. Moreover, mortality rate was significantly decreased in the LPS + β-glucan group versus the LPS group.. β-glucan reduces endotoxemia-induced mortality and might be protective against endotoxemia-induced lung damage.

Topics: Acute Lung Injury; Acute-Phase Proteins; Animals; beta-Glucans; Biological Factors; C-Reactive Protein; Endotoxemia; Interleukin-6; Interleukin-8; Lipopolysaccharides; Lung; Male; Protective Agents; Rats; Rats, Wistar

Clinical studies have reported associations between MMP-8 genotypes and clinical outcomes without exploring underlying mechanisms. This study aims to understand the influence of the rs1940475 SNP on downstream chemokine and cytokine response in human endotoxemia. Rs1940475 was genotyped in 44 healthy Caucasian males, who were challenged with an intravenous bolus of 2 ng/kg lipopolysaccharide (LPS). Plasma levels of tumor necrosis factor (TNF), interleukin (IL)-6, IL-8, and macrophage inflammatory protein (MIP)-1α were measured at baseline and 2, 4, 6, and 24 h after LPS infusion with high-sensitivity enzyme immunoassays. Peak TNF levels at 2 h after LPS infusion were significantly higher in subjects with AA genotype compared to subjects with AG or GG genotypes (185 pg/mL [IQR, 154-234] vs. 94 pg/mL [IQR, 65-125] vs. 107 pg/mL [IQR, 80-241], respectively; p = 0.03 between groups). Peak IL-6 levels were trend-wise higher in subjects with AA genotype compared to those with AG or GG genotypes (566 pg/mL [IQR, 294-644] vs. 278 pg/mL [IQR, 184-539] and 329 pg/mL [IQR, 240-492], respectively; p = 0.15 between groups). In contrast, peak MIP-1α at 2 h was highest in GG genotype carriers compared to those with AG or AA genotypes (602 pg/mL [IQR, 449-727] vs. 389 pg/mL [IQR, 375-490] and 510 pg/mL [425-813], respectively; p < 0.03 between groups). AA genotype carriers had highest peak TNF and IL-6 levels after LPS challenge, whereas peak MIP-1α levels were highest in GG carriers. This indicates that the rs1940475 SNP modifies the host response to inflammatory stimuli, which may in part explain previously shown associations with clinical outcomes.

Topics: Administration, Intravenous; Adult; Biomarkers; Blood Coagulation; Chemokine CCL3; Endotoxemia; Endotoxins; Gene Frequency; Genetic Predisposition to Disease; Healthy Volunteers; Humans; Inflammation Mediators; Interleukin-6; Interleukin-8; Male; Matrix Metalloproteinase 8; Neutrophils; Phenotype; Polymorphism, Single Nucleotide; Time Factors; Tumor Necrosis Factor-alpha; White People; Young Adult

To investigate the effects of the commonly-used immunomodulators l-glutamine, l-alanine, and the combination of both l-alanyl-l-glutamine (Dipeptamin(®)) on intracellular expression of IL-6, IL-8, and TNF-α during endotoxemia, lipopolysaccharide (LPS)-stimulated human monocytes in a whole blood system were investigated by flow cytometry. Whole blood of twenty-seven healthy volunteers was stimulated with LPS and incubated with three different amino acid solutions (1. l-glutamine, 2. l-alanine, 3. l-alanyl-l-glutamine, each concentration 2 mM, 5 mM, incubation time 3 h). CD14(+) monocytes were phenotyped in whole-blood and intracellular expression of cytokines was assessed by flow cytometry. Our investigations showed for the first time in whole blood probes, imitating best physiologically present cellular interactions, that l-glutamine caused a dose-independent inhibitory effect on IL-6 and TNF-α production in human monocytes stimulated with LPS. However, l-alanine had contrary effects on IL-6 expression, significantly upregulating expression of IL-6 in LPS-treated monocytes. The impact of l-alanine on the expression of TNF-α was comparable with glutamine. Neither amino acid was able to affect IL-8 production in LPS-stimulated monocytes. The combination of both did not influence significantly IL-6 and IL-8 expression in monocytes during endotoxemia, however strongly reduced TNF-α production. For the regulation of TNF-α, l-glutamine, l-alanine and the combination of both show a congruent and exponentiated downregulating effect during endotoxemia, for the modulation of IL-6, l-glutamine and l-alanine featured opposite regulation leading to a canceling impact of each other when recombining both amino acids.

Topics: Adult; Alanine; Dipeptides; Endotoxemia; Flow Cytometry; Glutamine; Humans; Interleukin-6; Interleukin-8; Intracellular Space; Lipopolysaccharides; Monocytes; Tumor Necrosis Factor-alpha

To gain insights into individual variations in acute inflammation and physiology.. Large-animal study combined with mathematical modeling.. Academic large-animal and computational laboratories.. Outbred juvenile swine.. Four swine were instrumented and subjected to endotoxemia (100 µg/kg), followed by serial plasma sampling.. Swine exhibited various degrees of inflammation and acute lung injury, including one death with severe acute lung injury (PaO(2)/FIO(2) ratio μ200 and static compliance μ10 L/cm H(2)O). Plasma interleukin-1β, interleukin-4, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor-α, high mobility group box-1, and NO(2)/NO(3) were significantly (p μ .05) elevated over the course of the experiment. Principal component analysis was used to suggest principal drivers of inflammation. Based in part on principal component analysis, an ordinary differential equation model was constructed, consisting of the lung and the blood (as a surrogate for the rest of the body), in which endotoxin induces tumor necrosis factor-α in monocytes in the blood, followed by the trafficking of these cells into the lung leading to the release of high mobility group box-1, which in turn stimulates the release of interleukin-1β from resident macrophages. The ordinary differential equation model also included blood pressure, PaO(2), and FIO(2), and a damage variable that summarizes the health of the animal. This ordinary differential equation model could be fit to both inflammatory and physiologic data in the individual swine. The predicted time course of damage could be matched to the oxygen index in three of the four swine.. The approach described herein may aid in predicting inflammation and physiologic dysfunction in small cohorts of subjects with diverse phenotypes and outcomes.

Topics: Acute Lung Injury; Animals; Endotoxemia; Endotoxins; Female; Hemodynamics; HMGB1 Protein; Inflammation; Interleukin-10; Interleukin-1beta; Interleukin-4; Interleukin-6; Interleukin-8; Models, Biological; Principal Component Analysis; Respiratory Physiological Phenomena; Swine; Tumor Necrosis Factor-alpha

To determine whether the method of lipopolysaccharide (LPS) administration (intermittent vs continuous) affects the magnitude and duration of the systemic inflammatory response in horses and whether prolonged (48 hours) endotoxemia induces laminitis.. 12 healthy adult horses (10 mares and 2 geldings).. Horses were randomly assigned to receive LPS (total dose, 80 μg; n = 4) or saline (0.9% NaCl) solution (80 mL/h; 4) via constant rate infusion or 8 bolus IV injections of LPS (10 μg, q 6 h;4) during a 48-hour period. Physical examinations were performed every 4 hours, inflammatory cytokine gene expression was determined for blood samples obtained every 8 hours, and IV glucose tolerance tests were performed.. All LPS-treated horses had signs of depression and mild colic; those signs abated as the study progressed. Administration of LPS increased expression of interleukin-1β, interleukin-6, and interleukin-8, but results were not significantly different between LPS treatment groups. Cytokine expression was significantly higher on the first day versus the second day of LPS treatment. Interleukin-1β expression was positively correlated with rectal temperature and expression of other cytokines. Glucose and insulin dynamics for both LPS groups combined did not differ significantly from those of the saline solution group. Signs of laminitis were not detected in any of the horses.. Horses developed LPS tolerance within approximately 24 hours after administration was started, and the method of LPS administration did not affect the magnitude or duration of systemic inflammation. Laminitis was not induced in horses.

Topics: Animals; Area Under Curve; Blood Glucose; Endotoxemia; Female; Foot Diseases; Glucose Tolerance Test; Horse Diseases; Horses; Inflammation; Insulin; Interleukin-1beta; Interleukin-6; Interleukin-8; Lipopolysaccharides; Male; Random Allocation

The ELR-CXC chemokines play important roles in neutrophilic inflammation. We report in this study that a fully human ELR-CXC chemokine antagonist that we have generated, CXCL8((3-72))K11R/G31P (G31P), has potent anti-inflammatory effects that arise through its actions at multiple levels. G31P inhibited CXCL8-induced chemotactic responses and intracellular Ca(2+) flux in CXCR1-transfected HEK cells and neutrophils, and responses of neutrophils to CXCR2-exclusive ligands. G31P desensitized heterologous G protein-coupled receptors on neutrophils, 52-86% reducing their Ca(2+) flux and chemotactic responses to leukotriene B(4), C5a, and the bacterial tripeptide fMLP. G31P also 60-90% blocked neutrophil chemotactic responses to mediators present in 10 of 12 sputum samples from cystic fibrosis or bronchiectasis subjects with bacterial pneumonia. Moreover, whereas A549 bronchial epithelial cells (which expressed CXCR1) secreted approximately 29,000 pg/ml CXCL8 in response to in vitro endotoxin challenge, G31P reduced this response by up to 98%, presumably by interrupting an autocrine inflammatory loop. The anti-inflammatory effects of G31P extended also to reversing the antiapoptotic influence of ELR-CXC chemokines on neutrophils. That these effects were relevant in vivo was confirmed in a guinea pig model of airway endotoxemia, wherein the human form of G31P >95% blocked neutrophil infiltration into and activation within the airways, as determined by airway levels of the neutrophil primary, secondary, and tertiary granule markers myeloperoxidase, lactoferrin, and matrix metalloproteinase-9, respectively, and the epithelial cell marker matrix metalloproteinase-2. These data suggest that the beneficial effects of ELR-CXC chemokine antagonism arise through effects that occur at multiple levels, including epithelial cells, neutrophils, and alternate G protein-coupled receptors.

Topics: Amino Acid Motifs; Animals; Arginine; Cattle; Cell Line; Chemotaxis, Leukocyte; Endotoxemia; Glutamic Acid; Guinea Pigs; Humans; Inflammation; Inflammation Mediators; Interleukin-8; Leucine; Ligands; Neutrophil Activation; Neutrophils; Pneumonia, Bacterial; Receptors, Interleukin-8A; Receptors, Interleukin-8B; Respiratory Mucosa

ERG (Ets-related gene) is an ETS transcription factor that has recently been shown to regulate a number of endothelial cell (EC)-restricted genes including VE-cadherin, von Willebrand factor, endoglin, and intercellular adhesion molecule-2. Our preliminary data demonstrate that unlike other ETS factors, ERG exhibits a highly EC-restricted pattern of expression in cultured primary cells and several adult mouse tissues including the heart, lung, and brain. In response to inflammatory stimuli, such as tumor necrosis factor-alpha, we observed a marked reduction of ERG expression in ECs. To further define the role of ERG in the regulation of normal EC function, we used RNA interference to knock down ERG. Microarray analysis of RNA derived from ERG small interfering RNA- or tumor necrosis factor-alpha-treated human umbilical vein (HUV)ECs revealed significant overlap (P<0.01) in the genes that are up- or downregulated. Of particular interest to us was a significant change in expression of interleukin (IL)-8 at both protein and RNA levels. Exposure of ECs to tumor necrosis factor-alpha is known to be associated with increased neutrophil attachment. We observed that knockdown of ERG in HUVECs is similarly associated with increased neutrophil attachment compared to control small interfering RNA-treated cells. This enhanced adhesion could be blocked with IL-8 neutralizing or IL-8 receptor blocking antibodies. ERG can inhibit the activity of the IL-8 promoter in a dose dependent manner. Direct binding of ERG to the IL-8 promoter in ECs was confirmed by chromatin immunoprecipitation. In summary, our findings support a role for ERG in promoting antiinflammatory effects in ECs through repression of inflammatory genes such as IL-8.

Topics: Animals; Cell Adhesion; Cells, Cultured; Coculture Techniques; Disease Models, Animal; Down-Regulation; Endothelial Cells; Endotoxemia; Humans; Inflammation; Interleukin-8; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Neutrophils; Oncogene Proteins; Promoter Regions, Genetic; RNA Interference; RNA, Messenger; RNA, Small Interfering; Time Factors; Trans-Activators; Transcription Factors; Transcription, Genetic; Transcriptional Regulator ERG; Tumor Necrosis Factor-alpha

Intensive insulin therapy, aiming for strict normoglycaemia, is associated with increased survival in critically ill patients. Insulin therapy concomitantly reduces plasma-free fatty acids. Recent studies indicate that free fatty acids mediate inflammation. In addition to plasma glucose and free fatty acid-lowering effects, insulin also has anti-inflammatory properties. This study was designed to study the pro-inflammatory effects of two free fatty acid concentrations during acute endotoxaemia and controlled comparable levels of plasma glucose and insulin. Twenty pigs were anaesthetized and mechanically ventilated. Pigs were randomized to two different, constant Intralipid infusion rates, throughout observation. All pigs were administered continuous intravenous infusion of endotoxin and subjected to controlled levels of p-glucose (4.5 mmol/l) and insulin by use of a hyperinsulinaemic euglycaemic clamp. Changes in circulating tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-6, leucocytes, insulin, glucose, free fatty acids, triglycerides, albumin, blood gases, temperature, and, haemodynamic function were monitored. Immediately following killing, biopsies were taken from heart and kidney. Biopsies were analysed for protein content of TNF-alpha, IL-6, IL-8 and IL-10. Sustained elevated and significantly different plasma levels of free fatty acids were demonstrated between groups (mean free fatty acid concentrations, 1.62 mM versus 0.58 mM, p < 0.0002). Endotoxaemia induced a steep increase in plasma TNF-alpha, IL-6 and leucocytes, however, without differences between the low- and high-free fatty acid groups. Cytokine content in heart and kidney tissue was not modified by free fatty acids. Compared with the response obtained at lower free fatty acid levels, high free fatty acid levels did not exacerbate the inflammatory response to acute endotoxaemia. Our results do not support the role of free fatty acids as a significant pro-inflammatory mediator.

Topics: Acute Disease; Animals; Blood Glucose; Cytokines; Endotoxemia; Endotoxins; Fat Emulsions, Intravenous; Fatty Acids, Nonesterified; Female; Infusions, Intravenous; Insulin; Interleukin-10; Interleukin-6; Interleukin-8; Kidney; Lipopolysaccharides; Myocardium; Swine; Systemic Inflammatory Response Syndrome; Tumor Necrosis Factor-alpha

Cardiac surgery using cardiopulmonary bypass (CPB) is performed widely, given the progress in cardioprotective methods. However, endotoxemia caused by CPB leads to systemic inflammatory response syndrome and deterioration of organ function. We evaluated the effectiveness of endotoxin removal with a polymyxin B-immobilized hemoperfusion cartridge (PMX) in CPB.. Pigs weighing about 25 kg were divided into control (n = 5) and PMX (n = 5) groups. Normothermic CPB was performed in the control group, while endotoxin was removed with PMX under normothermic CPB in the PMX group. Endotoxin removal was performed from the start to end of CPB. The end-systolic pressure-volume ratio (E(max)), left ventricular pressure (LVP), maximum and minimum rates of increase in LVP (+/-LVdp/dt), and cardiac output (CO) were measured 2 h after CPB, and the recovery rates of the parameters were compared between the two groups. A histopathological study was also conducted.. The recovery rates of E(max), CO, and LVP were significantly better (P < 0.05) in the PMX group than in the control group. The PaO(2) 2 h after CPB was significantly higher (P < 0.05) in the PMX group than in the control group. The interleukin (IL)-8 level 2 h after CPB was significantly lower (P < 0.05) in the PMX group. Histopathologically, the heart and pulmonary tissues were better preserved in the PMX group.. The PMX treatment reduced the inflammatory reaction caused by CPB, and cardiac and pulmonary functions after normothermic CPB were well preserved.

Topics: Animals; Cardiac Output; Cardiopulmonary Bypass; Endotoxemia; Endotoxins; Heart; Hemoperfusion; Interleukin-6; Interleukin-8; Liver; Lung; Male; Models, Animal; Myocardial Ischemia; Myocardium; Polymyxin B; Swine; Ventricular Function, Left; Warm Ischemia

To define the importance of leukocyte recruitment in endotoxin-induced gut permeability.. 31 male C57BL/6 mice were challenged with lipopolysaccharide (LPS). Ileal permeability was measured in Ussing chambers and leukocyte-endothelium interactions studied with intravital fluorescence microscopy after 18 h.. LPS caused a clear-cut increase in leukocyte accumulation and intestinal permeability. Immunoneutralisation of P-selectin not only reduced leukocyte recruitment significantly (54 % reduction) but also abolished endotoxin-induced intestinal leakage. Intestinal levels of pro-inflammatory chemokines increased markedly in response to LPS but were not influenced by inhibition of P-selectin in vivo.. The present study shows not only that endotoxin-induced leukocyte recruitment is mediated by P-selectin but also that sepsis-associated intestinal leakage in the gut is largely regulated by leukocyte accumulation. Thus, our novel data demonstrate a critical link between P-selectin-dependent leukocyte recruitment and gut barrier failure in endotoxemia.

Topics: Animals; Cell Membrane Permeability; Cell Movement; Chemokine CXCL2; Chemokines; Endotoxemia; Endotoxins; Ileum; Interleukin-8; Intestinal Absorption; Leukocytes; Male; Mice; Mice, Inbred C57BL; P-Selectin

Glu-Leu-Arg (ELR)-CXC chemokines are important in acute responses to bacterial infections, wherein neutrophils are often critical to pathogen clearance. However, excessive neutrophil recruitment augments the pathology of many diseases. We have shown that bovine CXCL8((3-74))K11R/G31P (bG31P) is a highly effective ELR-CXC chemokine and neutrophil antagonist in cattle, but herein we wished to determine whether humanized forms of this antagonist would be similarly effective. We thus examined the independent contributions of the bovine-human-discrepant amino acids within CXCL8 to the biological activity of bG31P. We first examined the effect of wholesale ligation of the carboxy half of hCXCL8 onto the amino half of bG31P, and found that this human-bovine chaemeric G31P (hbG31P; i.e., bCXCL8((3-44))K11R/G31P-hCXCL8((45-72))) fully retained the ELR-CXC chemokine antagonist activity of bG31P. Thus, hbG31P blocked the abilities of human CXCL8 to chemoattract human neutrophil or induce reactive oxygen intermediate (ROI) release. It was also a highly effective antagonist in vivo in a guinea pig model of airway endotoxemia. We next methodically moved through the 5' half of the hbG31P cDNA, using site-directed mutagenesis to one-by-one make substitutions at each remaining discrepant amino acid (i.e., T3K, H13Y, T15K, E35A, and S37T). We generated and tested the agonist and antagonist activities of each analogue using human neutrophils and human CXCL8. We found that none of these possessed better antagonist activities than hbG31P. Our data thus suggests that partially humanized analogues of bG31P display significant potential as antagonists of human ELR-CXC chemokines.

Topics: Amino Acid Sequence; Animals; Calcium; Cattle; Chemokine CXCL1; Chemotaxis; Endotoxemia; Guinea Pigs; Humans; Interleukin-8; Lung; Molecular Sequence Data; Neutrophils; Peptide Fragments; Reactive Oxygen Species; Receptors, Interleukin-8A; Receptors, Interleukin-8B

Tissue factor (TF) is a transmembrane glycoprotein that binds its zymogen cofactor, Factor VIIa (FVIIa) on the cell surface. Together (TF/FVIIa) they activate Factor X (FX) and Factor IX (FIX) and start the extrinsic pathway of blood coagulation. As such, the TF/FVIIa complex plays an important role in normal physiology as well as in thrombotic diseases such as unstable angina (UA), disseminated intravascular coagulation (DIC), and deep vein thrombosis (DVT). In addition to its function as an initiator of coagulation, TF/FVIIa plays an important role in inflammation. Expression of TF on the cell surface and its appearance as a soluble molecule are characteristic features of acute and chronic inflammation in conditions such as sepsis and atherosclerosis. Here we demonstrate that BCX-3607, a small molecule potent inhibitor of TF/FVIIa, reduces thrombus weight in an animal model of DVT. BCX-3607 also decreases the level of interleukin-6 (IL-6) in a LPS-stimulated mouse model of endotoxemia. Additionally, in vitro studies indicate that BCX-3607 blocks the generation of TF/FVIIa-induced IL-8 mRNA in human keratinocytes and reduces the TF/FVIIa-mediated generation of IL-6 and IL-8 in human umbilical vein endothelial cells (HUVEC). Therefore, BCX-3607 might block the TF/FVIIa-mediated coagulation and inflammation associated with pathological conditions.

Topics: Animals; Anti-Inflammatory Agents; Atherosclerosis; Blotting, Northern; Cells, Cultured; Disease Models, Animal; Dose-Response Relationship, Drug; Endothelium, Vascular; Endotoxemia; Factor VIIa; Fibrinolytic Agents; Humans; Inflammation; Interleukin-6; Interleukin-8; Keratinocytes; Lipopolysaccharides; Male; Mice; Models, Biological; Models, Chemical; Prothrombin Time; Pyridines; Rats; Rats, Sprague-Dawley; RNA, Messenger; Sepsis; Thromboplastin; Time Factors

Acute endotoxemia is characterized by an enhanced inflammatory response. Pentoxifylline (PTX), a phosphodiesterase inhibitor, has been shown to decrease TNF-alpha levels and to down-regulate neutrophil activation, likely because of increases in intracellular cyclic AMP. Its effects on lipopolysaccharide (LPS) induced lung injury, more specifically on tissue neutrophil infiltration and degranulation, adhesion molecule expression, and transcriptional factor activation, have not been fully investigated. We postulated that PTX treatment in acute endotoxemia downregulates the inflammatory response and may decrease lung injury.. Male Sprague-Dawley rats were randomized into three groups: Sham (saline i.v.), LPS (5 mg/kg i.v.), and PTX + LPS (25 mg/kg and 5 mg/kg i.v., respectively; concomitant injection). After 4 hours, bronchoalveolar lavage fluid (BAL), plasma, and lungs were sampled. BAL IL-8 (ELISA), BAL MMP-2, plasma MMP-9, and BAL MMP-9 (Zymography) were measured. Lung histology (H&E), in addition to lung MPO, ICAM-1, and NF-kappaB expression evaluated by immunohistochemistry were analyzed. Lung NF-kappaB DNA binding was evaluated by electrophoretic mobility shift assay.. PTX treatment decreased BAL IL-8 levels, BAL MMP-2, and plasma MMP-9 activity. Lung neutrophil infiltration (MPO), ICAM-1 expression and NF-kappaB activation were decreased by PTX. In addition, PTX treatment caused a marked attenuation of LPS-induced lung injury.. Phosphodiesterase inhibition by PTX attenuates LPS-induced end-organ injury. In addition, proinflammatory cytokine production is also downregulated, likely because of the marked attenuation of NF-kappaB DNA binding and activation.

Topics: Animals; Disease Models, Animal; Endotoxemia; Escherichia coli Infections; Intercellular Adhesion Molecule-1; Interleukin-8; Lipopolysaccharides; Lung; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; NF-kappa B; Pentoxifylline; Peroxidase; Phosphodiesterase Inhibitors; Rats; Rats, Sprague-Dawley; Respiratory Distress Syndrome

Studies in vitro reveal that endothelin-1 (ET-1) activates the alpha isoform of protein kinase C (PKC-alpha) in cultures of endothelial cells, thereby deranging cellular integrity. Sepsis and endotoxemia are associated with increased plasma concentrations of ET-1 that induce acute lung injury (ALI). We recently reported that non-selective ET-1 receptor blockade attenuates ALI in sheep by reducing the endotoxin-induced increase in extravascular lung water index (EVLWI). The aim of this study was to find out whether this attenuation is associated with reduced translocation of PKC-alpha from the cytosolic to the membrane fraction of lung tissue homogenate.. Seventeen awake, instrumented sheep were randomly assigned to a sham-operated group (n = 3), a lipopolysaccharide (LPS) group (n = 7) receiving an intravenous infusion of Escherichia coli 15 ng/kg per min for 24 hours, and a tezosentan group (n = 7) subjected to LPS and, from 4 hours, an intravenous injection of tezosentan 3 mg/kg followed by infusion at 1 mg/kg per hour for the reminder of the experiment. Pulmonary micro-occlusion pressure (Pmo), EVLWI, plasma concentrations of ET-1, tumor necrosis factor-a (TNF-a), and interleukin-8 (IL-8) were determined every 4 hours. Western blotting was used to assess PKC-alpha.. In non-treated sheep a positive correlation was found between the plasma concentration of ET-1 and Pmo in the late phase of endotoxemia (12 to 24 hours). A positive correlation was also noticed between Pmo and EVLWI in the LPS and the LPS plus tezosentan groups, although the latter was significantly reduced in comparison with LPS alone. In both endotoxemic groups, plasma concentrations of ET-1, TNF-alpha, and IL-8 increased. In the LPS group, the cytosolic fraction of PKC-alpha decreased by 75% whereas the membrane fraction increased by 40% in comparison with the sham-operated animals. Tezosentan completely prevented the changes in PKC-alpha in both the cytosolic and the membrane fractions, concomitantly causing a further increase in the plasma concentrations of ET-1, TNF-alpha, and IL-8.. In endotoxemic sheep, ET-1 receptor blockade alleviates lung injury as assessed by a decrease in EVLWI paralleled by a reduction in Pmo and the prevention of activation of PKC-alpha.

Topics: Animals; Endothelin A Receptor Antagonists; Endothelin-1; Endotoxemia; Enzyme Activation; Escherichia coli Infections; Interleukin-8; Protein Kinase C; Pyridines; Respiratory Distress Syndrome; Sheep; Tetrazoles; Tumor Necrosis Factor-alpha; Vasodilator Agents

CXC chemokine receptor 2 (CXCR2) antagonism alone can reduce neutrophil infiltration of some inflammatory sites, but the CXCR1 and CXCR2 critically regulate neutrophil responses to Glu-Leu-Arg-CXC chemokines. Herein, we assessed a combined CXCR1/CXCR2 antagonist, CXC chemokine ligand 8(3-74) [CXCL8(3-74)]K11R/G31P, for its ability to blunt neutrophil-influx and ancillary pathology in severe endotoxemia. Guinea pigs challenged via the airways with Escherichia coli lipopolysaccharide (LPS; 5 microg/kg) were given CXCL8(3-74)K11R/G31P (subcutaneously) before or after the onset of symptoms. The airways of the LPS-challenged animals contained high levels of endogenous pyrogens interleukin (IL)-1 and tumor necrosis factor (TNF) at 2-4 h, and the animals developed pyrexia, which peaked at approximately 6 h; strong pulmonary, neutrophilic inflammation; and marked pleural hemorrhagic consolidation, as assessed at approximately 15 h. CXCL8(3-74)K11R/G31P treatment before LPS challenge reduced lung pleural hemorrhagic consolidation and airway neutrophilia by >90% and essentially abrogated the IL-1, TNF, and fever responses. When given 3 or 6 h after LPS, CXCL8(3-74)K11R/G31P reduced pulmonary neutrophilia by up to 85% and pleural hemorrhagic consolidation by 50-85%. The 3-h treatment reduced the 6- to 24-h fever response to background. Delays of 6 or 9 h in beginning treatment had significant effects on the fever decay curve, but only the 6-h treatment had a significant effect on the 24-h fever. These results indicate that combined CXCR1/CXCR2 antagonism can have significant therapeutic effects on pulmonary inflammation and hemorrhage, as well as pyrexia in endotoxemic animals.

Topics: Animals; Chemokines, CXC; Chemotaxis, Leukocyte; Disease Models, Animal; Dose-Response Relationship, Drug; Endotoxemia; Female; Fever; Guinea Pigs; Hemorrhage; Interleukin-8; Lipopolysaccharides; Lung; Neutrophil Infiltration; Neutrophils; Peptide Fragments; Pneumonia; Pulmonary Artery; Receptors, Interleukin-8A; Receptors, Interleukin-8B; Time Factors; Treatment Outcome

Chemokine receptors CXC receptor (CXCR) 1 and 2, and their ligands interleukin (IL)-8 and growth-related oncogene alpha (GRO alpha), are principal regulators of neutrophil activation and migration. To investigate the role of p38 mitogen activated protein kinase (MAPK) in the regulation of CXCR expression during an inflammatory response in vivo, 24 healthy volunteers received an intravenous injection with lipopolysaccharide (LPS) preceded (-3 hr) by a specific p38 MAPK inhibitor (BIRB 796 BS) at a high dose (600 mg) or a low dose (50 mg) or a placebo. The LPS-induced reduction of neutrophil CXCR 1 and 2 expression, as determined by fluorescence-activated cell sorter analysis, was inhibited in volunteers receiving the high dose of the p38 MAPK inhibitor. The kinase inhibitor also dose dependently diminished the LPS-induced rises in plasma IL-8 and GRO alpha levels. These results indicate a principal role for p38 MAPK in regulating factors essential for neutrophil activation and chemotaxis in vivo.

Topics: Chemokine CXCL1; Chemokines, CXC; Down-Regulation; Endotoxemia; Humans; Intercellular Signaling Peptides and Proteins; Interleukin-8; Mitogen-Activated Protein Kinases; Neutrophils; p38 Mitogen-Activated Protein Kinases; Receptors, Interleukin-8A; Receptors, Interleukin-8B

s: The impairment of cardiac contractility during endotoxemia involves induction of nitric oxide formation through a cascade of events initiated by overexpression of proinflammatory cytokines. We previously showed that hypothermia attenuates endotoxin-induced overexpression of nitric oxide in rat lungs. In the present study, we tested the hypothesis that hypothermia protects against endotoxin-induced myocardial inflammation by changing the balance of pro- and anti-inflammatory cytokines, inhibiting myeloperoxidase, an indicator of neutrophil activity, and inhibiting nitric oxide-mediated protein damage.. Rats were randomized to treatment with either hypothermia (n = 6; 18 to 24 degrees C) or normothermia (n = 6; 36 to 38 degrees C). Endotoxin (15 mg/kg) was administered intravascularly to anesthetized animals, and heart tissue was harvested 150 min later.. Using enzyme-linked immunosorbent assays (ELISAs), we found that hypothermia induced myocardial expression of the anti-inflammatory cytokines interleukin (IL)-4 and IL-10, while decreasing concentrations of the pro-inflammatory cytokines IL-1beta and growth-related oncogene/cytokine-induced neutrophil chemoattractant (rat homolog of IL-8). Electromobility shift assay revealed that hypothermia inhibited the nuclear translocation of nuclear factor-kappaB. Reverse transcriptase-polymerase chain reaction and Western blot assays revealed that hypothermia attenuated the endotoxin-induced overexpression of both inducible nitric oxide synthase (iNOS) messenger RNA and iNOS protein, respectively. Hypothermia also attenuated nitric oxide-mediated myocardial protein damage, as determined by a nitrotyrosine ELISA. Myocardial myeloperoxidase content, an indicator of neutrophil accumulation and oxidative activity, was also inhibited by hypothermia in endotoxemic rats.. These data demonstrate that hypothermia induces an anti-inflammatory cytokine profile, inhibits neutrophil aggregation, and inhibits the formation of nitric oxide during endotoxemia in the rat.

Topics: Animals; Cytokines; Endotoxemia; Enzyme-Linked Immunosorbent Assay; Hypothermia, Induced; Inflammation; Interleukin-1; Interleukin-10; Interleukin-4; Interleukin-8; Male; Myocardium; NF-kappa B; Nitric Oxide; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Peroxidase; Random Allocation; Rats; Rats, Sprague-Dawley

Ghrelin is a novel growth hormone-releasing peptide that has been shown to improve cachexia in heart failure and cancer and to ameliorate the hemodynamic and metabolic disturbances in septic shock. Because cytokine-induced inflammation is critical in these pathological states and because the growth hormone secretagogue receptor has been identified in blood vessels, we examined whether ghrelin inhibits proinflammatory responses in human endothelial cells in vitro and after administration of endotoxin to rats in vivo.. Human umbilical vein endothelial cells (HUVECs) were treated with or without tumor necrosis factor-alpha (TNF-alpha), and induction of proinflammatory cytokines and mononuclear cell adhesion were determined. Ghrelin (0.1 to 1000 ng/mL) inhibited both basal and TNF-alpha-induced cytokine release and mononuclear cell binding. Intravenous administration of ghrelin also inhibited endotoxin-induced proinflammatory cytokine production in rats in vivo. Ghrelin inhibited H2O2-induced cytokine release in HUVECs, suggesting that the peptide blocks redox-mediated cellular signaling. Moreover, ghrelin inhibited basal and TNF-alpha-induced activation of nuclear factor-kappaB. Des-acyl ghrelin had no effect on TNF-alpha-induced cytokine production in HUVECs, suggesting that the antiinflammatory effects of ghrelin require interaction with endothelial growth hormone secretagogue receptors.. Ghrelin inhibits proinflammatory cytokine production, mononuclear cell binding, and nuclear factor-kappaB activation in human endothelial cells in vitro and endotoxin-induced cytokine production in vivo. These novel antiinflammatory actions of ghrelin suggest that the peptide could play a modulatory role in atherosclerosis, especially in obese patients, in whom ghrelin levels are reduced.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arteriosclerosis; Cell Adhesion; Cells, Cultured; Chemokine CCL2; Depression, Chemical; Endothelial Cells; Endothelium, Vascular; Endotoxemia; Gene Expression Regulation; Genes, Reporter; Ghrelin; Humans; Hydrogen Peroxide; Interleukin-8; NF-kappa B; Peptide Hormones; Random Allocation; Rats; Rats, Sprague-Dawley; Signal Transduction; Tumor Necrosis Factor-alpha; U937 Cells; Umbilical Veins

The present study investigates the modulating effects of nicotinamide on the cytokine response to endotoxin. In an in vitro model of endotoxaemia, human whole blood was stimulated for two hours with endotoxin at 1 ng/ml, achieving high levels of the proinflammatory cytokines IL-1 beta, IL-6, IL-8 and TNF alpha. When coincubating whole blood, endotoxin and the vitamin B3 derivative nicotinamide, all four cytokines measured were inhibited in a dose dependent manner. Inhibition was observed already at a nicotinamide concentration of 2 mmol/l. At a concentration of 40 mmol/l, the IL-1 beta, IL-6 and TNF alpha responses were reduced by more than 95% and the IL-8 levels reduced by 85%. Endotoxin stimulation activates poly(ADP-ribose)polymerase (PARP), a nuclear DNA repair enzyme. It has been hypothesized that the anti-inflammatory properties of nicotinamide are due to PARP inhibition. In the present study, the endotoxin induced PARP activation was dose dependently decreased with 4-40 mmol/l nicotinamide or 4-100 micro mol/l 6(5H) phenanthridinone, a specific PARP inhibitor. 6(5H)phenanthridinone however, failed to inhibit the proinflammatory cytokines. Thus, the mechanism behind the cytokine inhibition in our model seems not to be due to PARP inhibition. In conclusion, the present study could not only confirm previous reports of a down-regulatory effect on TNFalpha, but demonstrates that nicotinamide is a potent modulator of several proinflammatory cytokines. These findings demonstrate that nicotinamide has a potent immunomodulatory effect in vitro, and may have great potential for treatment of human inflammatory disease.

Topics: Adjuvants, Immunologic; Cells, Cultured; Cytokines; Depression, Chemical; Dose-Response Relationship, Drug; Endotoxemia; Enzyme Inhibitors; Humans; Interleukin-1; Interleukin-6; Interleukin-8; Niacinamide; Phenanthrenes; Poly Adenosine Diphosphate Ribose; Tumor Necrosis Factor-alpha

This study was carried out to study the prophylactic effects of inhalation of nitric oxide (NO) before and during the induction of endotoxic shock.. Eighteen anaesthetized pigs received an infusion of 10-20 microg kg(-1) endotoxin during 2 h after pre-treatment with the cortisol-synthesis inhibitor metyrapone. Three groups were tested (n = 6 each) and received 0, 0.2 or 20 ppm inhaled NO from 30 min before start of endotoxin infusion until 4 h after start of endotoxin. Both 0.2 and 20 ppm NO were able to improve blood gas values.. Area above curve values of arterial P2/FiO2 from 0 to 4 h were 0.83 +/- 0.09 kPa h (control), 0.78 +/- 0.22 (0.2 ppm NO, non-significant) and 0.31 +/- 0.06 (20 ppm NO, P < 0.01, Mann-Whitney U-test, compared to control). Area under curve values of PCO2 from 0 to 4 h were 3.96 +/- 0.66 kPa h (control), 1.20 +/- 0.46 (0.2 ppm NO, P < 0.05, Mann-Whitney U-test, compared to control) and 2.78 +/- 1.06 (20 ppm NO group, non-significant). The increase in pulmonary arterial pressure (PAP) was partly prevented by 20 ppm NO, but not by 0.2 ppm NO at 4 h. Inhaled NO did not affect the levels of BAL fluid total protein, tumour necrosis factor-alpha, interleukin-8 and neutrophil counts.. The addition of a high (20 ppm), but not a low (0.2 ppm), concentration of NO to the inhaled air during endotoxin shock improves arterial oxygen tension and reduces pulmonary artery pressure. Neither dose affects lung mechanics or inflammatory indices, in spite of being given prophylactically.

Topics: Airway Resistance; Animals; Antimetabolites; Area Under Curve; Blood Pressure; Bronchoalveolar Lavage Fluid; Endotoxemia; Endotoxins; Female; Hemodynamics; Interleukin-8; Leukocyte Count; Lipopolysaccharides; Lung Compliance; Metyrapone; Nitric Oxide; Proteins; Rats; Swine; Tumor Necrosis Factor-alpha

A lipopolysaccharide (LPS) dose-response study in an experimental baboon endotoxemia model is presented to define the relevance of this model compared with human endotoxemia. We describe acute and subacute endotoxemic models in baboons, the first evoked by bolus injection of LPS (1 mg, 0.1 mg, or 4 ng per kg of Escherichia coli LPS), and the second evoked by infusion of 1.5 mg/kg of E. coli LPS over 30 min. We report the analysis of LPS clearance, the kinetics of tumor necrosis factor, interleukin (IL) 6, and IL-8 expression on the protein as well as on the mRNA level, change in blood counts (white and red blood cells and circulating platelets), and several hemodynamic parameters such as temperature, cardiac index, heart rate, and mean arterial pressure via multiple sampling. The resulting data are compared with previously published human data. Our results show that the LPS-induced kinetics of cytokine release, as well as of hemodynamic and hematologic changes in baboons, were similar to those observed in humans, even though baboons required a approximately 104-fold higher initial LPS dose to develop these manifestations. Hence, we demonstrate that endotoxemia in baboons qualitatively, yet not quantitatively, resembles endotoxemia in humans and, therefore, proves to constitute a useful model for studying the pathogenic mechanisms of sepsis in relation to humans.

Topics: Animals; Blood Cell Count; Blood Pressure; Body Temperature; Cardiac Output; Disease Models, Animal; Dose-Response Relationship, Drug; Endotoxemia; Gene Expression; Heart Rate; Interleukin-6; Interleukin-8; Kinetics; Lipopolysaccharides; Male; Papio; Platelet Count; Time Factors; Tumor Necrosis Factor-alpha; Up-Regulation

Pentoxifylline (PTX) attenuates end-organ injury in models of sepsis and hemorrhage. PTX is thought to act by inhibiting phosphodiesterase, thus increasing cAMP and decreasing tumor necrosis factor-alpha (TNF-alpha) synthesis. The effects of PTX on neutrophil and endothelial cell adhesion molecules and, ultimately, organ injury in a chronic endotoxemia model have not been studied. We hypothesized that continuous infusion of PTX reduces acute lung injury (ALI) caused by chronic lipopolysaccharide (LPS) exposure.. Male Sprague-Dawley rats were given continuous infusion of LPS, PTX + LPS combined, or saline (sham) by implantable pumps. Neutrophil CD11b expression, lung histopathology, lung intercellular adhesion molecule-1 (ICAM-1) expression assessed by immune staining, serum TNF-alpha, serum interleukin-6 (IL-6), and bronchoalveolar lavage (BAL) IL-8 were evaluated at different time points. Lung injury was graded in a blinded fashion from 0 (normal) to 4 (severe) for interstitial inflammation, neutrophil infiltration, congestion, and edema. Total lung injury score (TLIS) was calculated by adding listed categories. White cell count in the peripheral blood and in the BAL was also performed.. Animals treated with PTX + LPS showed a significant reduction in lung injury score, a marked decrease in ICAM-1 expression, and a significant decrease in IL-8 levels in the BAL and serum IL-6 levels when compared with LPS-treated animals.. Continuous infusion of PTX reduces ALI caused by chronic endotoxemia. The effect seems to be a result of decreased expression of endothelial and epithelial ICAM-1 and modulation of proinflammatory cytokine synthesis.

Topics: Animals; Bronchoalveolar Lavage Fluid; CD11b Antigen; Chronic Disease; Edema; Endotoxemia; Intercellular Adhesion Molecule-1; Interleukin-6; Interleukin-8; Leukocyte Count; Lipopolysaccharides; Lung; Lung Diseases; Male; Neutrophils; Pentoxifylline; Rats; Rats, Sprague-Dawley; Tumor Necrosis Factor-alpha

To analyze the effect of cytokines generated in sepsis and endotoxemia (tumor necrosis factor [TNF]-alpha and interleukins [IL]-1beta, -6, and -8) on activation of human platelets and to study the effect of cytokines on platelet activation in the presence of alpha-thrombin, a potent inducer of coagulation and platelet activation generated in sepsis and endotoxemia.. flow cytometric study of platelet activation induced by cytokines and/or thrombin in the whole blood and platelet-rich plasma (PRP) of healthy volunteers.. Research laboratory in a Canadian hospital.. Nine healthy volunteers recruited from laboratory staff.. Venous blood samples were obtained into acid-citrate-dextrose anticoagulant. Whole blood and PRP were diluted with appropriate buffer optimized for analyzing platelet activation by flow cytometry. TNF-alpha, IL-1beta, IL-6, and IL-8 were added to blood or PRP in concentrations ranging from 1 to 100 ng/mL and incubated for 15 mins at 37 degrees C in the presence or absence of a submaximal concentration of human alpha-thrombin (0.025 units/mL). Samples were stained with fluorescent antibodies against markers of platelet activation (P-selectin [CD62], lysosomal protein [CD63], and fibrinogen and von Willebrand factor receptors [CD41 and CD42b, respectively]) and analyzed by flow cytometry. The data obtained show that none of these cytokines trigger activation of resting platelets in whole blood or PRP and do not modulate the effect of thrombin on platelet activation as measured by quantitation of CD62, CD63, and CD42b markers on the platelet surface.. Cytokines TNF-alpha, IL-1beta, IL-6, and IL-8, which are extensively produced in sepsis and endotoxemia, do not trigger activation of resting human platelets directly or indirectly by mediating processes in white or red blood cells. The cytokines did not affect thrombin-induced platelet activation.

Topics: Cytokines; Endotoxemia; Flow Cytometry; Humans; In Vitro Techniques; Interleukin-1; Interleukin-6; Interleukin-8; Platelet Activation; Sepsis; Statistics, Nonparametric; Tumor Necrosis Factor-alpha

FR167653 inhibits the production of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, powerful inducers of CXC chemokines IL-8 and growth related oncogene (GRO)-alpha. The production of IL-8 and GRO-alpha was investigated and the effects of FR167653 were examined in a rabbit model of endotoxin shock. Male New Zealand rabbits were given endotoxin at a dose sufficient to induce DIC. Three groups of rabbits received FR167653 at different doses. TNF-alpha, IL-1beta, IL-8, and GRO-alpha levels were measured, several pathologic features were evaluated, and the results were compared with those obtained in control rabbits, which received only endotoxin. Endotoxin increased serum levels of IL-8 and GRO-alpha, which were associated with hypotension, renal dysfunction, and mortality, peaking at 4 h. FR167653 improved mortality, an event that was associated with decreased levels of not only TNF-alpha and IL-1beta but also IL-8 and GRO-alpha. TNF-alpha peaked at 2 h, at a time point before IL-8 and GRO-alpha reached their peak, and the TNF-alpha level was tightly correlated with that of IL-8 and GRO-alpha. Altogether, these data suggest the possible involvement of IL-8 and GRO-alpha in endotoxin shock, and FR167653 may foster a beneficial outcome in part by modulating the chemokines level by inhibiting TNF-alpha and IL-1beta.

Topics: Animals; Chemokines; Chemokines, CXC; Chemotactic Factors; Endotoxemia; Growth Inhibitors; Intercellular Signaling Peptides and Proteins; Interleukin-1; Interleukin-8; Leukocytes; Lipopolysaccharides; Male; Neoplasm Proteins; Nitric Oxide; Pyrazoles; Pyridines; Rabbits; Statistics as Topic; Tumor Necrosis Factor-alpha

We investigated whether pulsatile flow in cardiopulmonary bypass (CPB), which has been shown to improve intestinal perfusion, reduces endotoxin translocation from the gut and, in consequence, decreases cytokine generation. The study population consisted of 48 adult patients who underwent elective CPB surgery. Pulsatile flow was used during aortic cross-clamping in 24 patients and nonpulsatile flow in 24 patients. Plasma endotoxin concentration increased in all patients during CPB. Significantly (P < 0.05) lower peak levels of 8.25 +/- 1.17 (SEM) pg/mL were reached 30 min after CPB in patients with pulsatile flow in contrast to 11.26 +/- 1.42 pg/mL in patients with nonpulsatile flow. The extent of endotoxemia was not related to the duration of CPB. Following the increase of plasma endotoxin, the concentrations of IL-6 and IL-8 increased with delay of approximately 1 h. The peak levels of these cytokines corresponded significantly (P < 0.005 and P < 0.01, respectively) with duration of CPB, but not with flow mode. Thus, in patients with CPB of more than 97 min (median), IL-6 reached a peak of 335.5 +/- 48.87 pg/mL and IL-8 of 64.86 +/- 24.79 pg/mL in contrast to 210.9 +/- 18.45 pg/mL and 21.2 +/- 10.19 pg/mL, respectively, with bypass times of less than 97 min. The degree of endotoxemia in CPB mainly depends on the quality of tissue perfusion. Cytokine generation, however, is not triggered exclusively by endotoxin, but rather by the trauma of CPB and surgery.

Topics: Aged; Aged, 80 and over; Cardiac Surgical Procedures; Cardiopulmonary Bypass; Cytokines; Endotoxemia; Endotoxins; Female; Humans; Interleukin-6; Interleukin-8; Male; Middle Aged; Pulsatile Flow; Time Factors

To investigate the effects of lidocaine administration on hemodynamics and cytokine concentrations in Escherichia coli endotoxemia in rabbits.. Randomized, prospective laboratory study.. University laboratory.. Thirty-two Japanese rabbits anesthetized with urethane and ventilated mechanically.. Animals were randomly assigned to one of four groups: endotoxemic controls (n = 8), receiving intravenous E. coli endotoxin (0.5 mg/kg bolus) via the mesenteric vein; laparotomy controls (n = 8), treated identically to the endotoxemic controls except for the substitution of 0.9% saline for endotoxin; lidocaine controls (n = 8), treated identically to the laparotomy controls with the addition of intravenous lidocaine (3 mg/kg bolus followed by infusion at 2 mg/kg/hr) administered immediately after the injection of 0.9% saline; and lidocaine-treated rabbits (n = 8), treated identically to the endotoxemic controls with the addition of intravenous lidocaine (3 mg/kg bolus followed by infusion at 2 mg/kg/hr) administered immediately after the injection of endotoxin.. We compared the cardiac output, systemic vascular resistance, blood gases, and plasma cytokine concentrations (tumor necrosis factor, interleukin [IL]-6, and IL-8) for each group. After endotoxin injection, the mean arterial pressure, cardiac output, and systemic vascular resistance decreased progressively in the endotoxemic controls. At 4 hrs after injection, all of the variables except the heart rate and central venous pressure were lower in the endotoxemic controls than in the other groups. At 4 hrs after endotoxin injection, both IL-6 and IL-8 concentrations increased in all groups. However, the mean concentrations of IL-6 and IL-8 in the endotoxemic controls significantly exceeded those in the other groups. No significant differences existed between the laparotomy controls and lidocaine-treated rabbits.. Lidocaine had a profound inhibitory effect on the hemodynamic and cytokine responses to endotoxemia when it was administered immediately after exposure to endotoxin. Our results demonstrate the potential usefulness of lidocaine as an anti-inflammatory agent in endotoxemia.

Topics: Animals; Blood Gas Analysis; Cytokines; Endotoxemia; Escherichia coli Infections; Hemodynamics; Interleukin-6; Interleukin-8; Lidocaine; Prospective Studies; Rabbits; Random Allocation; Time Factors

Altered transendothelial migration and delayed apoptosis of neutrophils (PMN) have been implicated as contributing to infection in patients with gram-negative sepsis. Macrophage inflammatory protein 2 (MIP-2) signals PMN immigration and may alter other PMN functions. We tested the hypothesis that sequential endotoxin challenge in vivo alters PMN apoptosis and chemotactic responses.. Endotoxemia was induced in male Wistar rats (250 g) via intraperitoneal (IP) administration of LPS (4 mg/kg). After 18 h, intratracheal (IT) injection of LPS (400 microg/kg) was performed. Control animals received saline injections. Four hours after IT-LPS, circulating and bronchoalveolar lavage (BAL) PMN were isolated. PMN yields were calculated, and apoptosis was quantified after 18 h in culture by annexin V-fluorescein isothiocyanate FACS analysis. BAL MIP-2 concentrations were determined by ELISA. PMN chemotaxis to MIP-2 and IL-8 was determined using a fluorescent in vitro migration assay.. Endotoxemia (IP-LPS) significantly decreases BAL PMN yield in response to an in vivo IT-LPS challenge. IT-LPS inhibits BAL PMN apoptosis to the same extent as sequential IP/IT-LPS. Alveolar MIP-2 concentrations are similar in the two groups. In vitro migration to IL-8 and MIP-2 was inhibited in PMN from endotoxemic versus control animals.. These data demonstrate that endotoxemia inhibits PMN migration despite similar MIP-2 concentrations in the alveolus. Sequential insults do not affect the inhibition of apoptosis. In vitro, PMN from endotoxemic animals display impaired chemotaxis to MIP-2 and interleukin-8. This may result in an inadequate host defense that contributes to increased ICU-acquired pneumonia in septic patients.

Topics: Animals; Antigens, CD; Apoptosis; Cell Movement; Chemokine CXCL2; Endotoxemia; Interleukin-8; Lipopolysaccharides; Male; Monokines; Neutrophils; Pulmonary Alveoli; Rats; Rats, Wistar; Receptors, Chemokine; Receptors, Interleukin; Receptors, Interleukin-8A; Receptors, Interleukin-8B

Neonates with septicemia tend to develop granulocytopenia, which may, in part, be due to septic mediators such as oxygen free radicals and tumor necrosis factor alpha (TNF-alpha). Granulocytopenia may be caused by a decrease in granulocyte growth and/or an increase in granulocyte destruction. In the present study, we investigated antioxidant regulation of endotoxin-modulated neonatal granulopoiesis and granulocyte apoptosis. Using human umbilical cord blood (HUCB), we found that simulating endotoxemia in vitro elicited significant superoxide production within a few minutes. Endotoxin exposure suppressed colony-forming unit-granulocyte and monocyte formation in a dose-dependent fashion. Addition of antioxidants such as N-acetyl-cysteine could reverse the endotoxin suppression of colony-forming unit-granulocyte and monocyte formation (13 +/- 5 versus 75 +/- 5 colony-forming units/mL). Spontaneous in vitro granulocyte apoptosis in 6 h, as reflected by phosphatidylserine expression on the cell surface, was higher in granulocytes from HUCB than in those from adult blood (10.8 +/- 1.0% versus 5.6 +/- 1.2%). The addition of endotoxin or IL-8 to the cells in the in vitro model did not promote granulocyte apoptosis, but TNF-alpha, a major mediator of the effects of endotoxin, significantly induced granulocyte apoptosis in HUCB (control versus TNF-alpha: 8.9 +/- 1.2% versus 35.9 +/- 2.9%). Addition of the antioxidant N-acetyl-cysteine effectively blocked TNF-alpha-induced granulocyte apoptosis as demonstrated by DNA fragmentation. Results from these studies indicate that oxygen radicals are directly involved in endotoxin suppression of granulopoiesis, and indirectly promote granulocyte apoptosis, presumably through TNF-alpha-mediated action. Thus, under certain conditions, modulation of oxygen radical production in the blood may benefit neonates with granulocytopenia.

Topics: Acetylcysteine; Adult; Antioxidants; Apoptosis; Cells, Cultured; DNA Fragmentation; Endotoxemia; Endotoxins; Fetal Blood; Granulocytes; Hematopoiesis; Humans; Infant, Newborn; Interleukin-8; Oxidative Stress; Reactive Oxygen Species; Tumor Necrosis Factor-alpha

Bacterial sepsis is characterized by a systemic inflammatory state, with activation of numerous cell types. Phagocytes participate in this phenomenon by secreting various proinflammatory cytokines and enzymes. Matrix metalloproteinases (MMPs) such as gelatinases are produced by phagocytes and are thought to play an important role in processes of cell transmigration and tissue remodeling. In this work, we show that endotoxin (lipopolysaccharide [LPS]) and other inflammatory mediators, such as tumor necrosis factor (TNF), interleukin-8, and granulocyte colony-stimulating factor, induce a rapid (within 20 min) release of gelatinase-B (MMP-9) zymogen in whole human blood, as determined by gelatin zymography. The polymorphonuclear neutrophil was identified as the cell responsible for this rapid secretion, as a result of the release of preformed enzymes stored in granules. Normal human subjects given LPS intravenously showed a similar pattern of proMMP-9 secretion, with maximum plasma levels reached 1.5 to 3 h after LPS administration (P = 0.0009). Prior administration of TNF receptor:Fc, a potent TNF antagonist, to subjects given LPS, only partially blunted the release of proMMP-9 (P = 0.033). Ibuprofen, a cyclooxygenase inhibitor, did not alter this pattern of release. Increased levels of proMMP-9 and proMMP-2, as well as activated forms of MMP-9, were found in plasma from two patients with gram-negative sepsis. The levels of MMPs paralleled the severity of clinical condition and a marker of the severity of sepsis, plasma procalcitonin. These data indicate that MMPs are released in whole blood in response to various inflammatory mediators and that they could serve as sensitive and early markers for cell activation during the course of bacterial sepsis.

Topics: Aged; Bacteremia; Endotoxemia; Enzyme Precursors; Female; Gelatinases; Gram-Negative Bacterial Infections; Granulocyte Colony-Stimulating Factor; Humans; Inflammation Mediators; Interleukin-8; Lipopolysaccharides; Male; Metalloendopeptidases; Neutrophils; Tumor Necrosis Factor-alpha

Chemokines are a family of cytokines regulating the migration and functions of leukocytes in a cell-type specific manner. A prototype of C-X-C chemokines, interleukin-8 (IL-8), chemoattracts and activates neutrophils in vitro, and IL-8 concentrations in body fluids are markedly increased in several neutrophil-mediated acute inflammation. Moreover, we previously reported that the administration of a neutralizing antibody to IL-8 prevented neutrophil-mediated tissue injury, as well as neutrophil infiltration, in several animal disease models. These observations implicate IL-8 as a major mediator of neutrophil-mediated tissue injury. Furthermore, we recently showed that an anti-IL-8 antibody effectively prevented two models that are very relevant to clinical situations; endotoxemia-induced acute respiratory distress syndrome (ARDS)-like lung injury and cerebral reperfusion injury. These results raise the possibility that IL-8 is a novel target for therapeutic intervention in neutrophil-mediated acute inflammation.

Topics: Animals; Antibodies, Monoclonal; Brain Ischemia; Chemokines; Endotoxemia; Female; Immunization, Passive; Inflammation; Interleukin-8; Macrophages; Mice; Neutrophils; Rabbits; Reactive Oxygen Species; Reperfusion Injury; Respiratory Distress Syndrome

We have herein established an endotoxemia-induced acute respiratory distress syndrome (ARDS)-like lung injury administered a sublethal dose of lipopolysaccharide (LPS) intravenously 36 hours after the intratracheal instillation of heat-killed Streptococcus pyogenes (OK-432). At 36 hours after OK-432 priming, a mild infiltration into the lungs, consisting of a small number of neutrophils and macrophages, was observed without destruction of pulmonary architecture. A subsequent challenge with a sublethal dose of LPS induced pathologic changes characteristic of ARDS--such as extensive edema in alveolar lumina, marked infiltration composed of a large number of neutrophils and a few macrophages, fibrin deposit in alveolar space, and destruction of pulmonary architecture--resulting in severe hypoxemia. Concomitantly, LPS challenge after priming with OK-432 induced a marked elevation of IL-8 levels in serum and bronchoalveolar lavage fluid with local IL-8 production in lungs, as revealed by immunohistochemical analysis. An anti-IL-8 antibody treatment almost completely prevented pulmonary edema, destruction of pulmonary architecture, and impairment in gas exchange as well as neutrophil infiltration in lungs; there was also a significant reduction in the rate of acute lethality. These results provide evidence that IL-8 has a pivotal role in the induction of ARDS associated with endotoxemia, probably by recruiting and activating neutrophils locally.

Topics: Animals; Antibodies, Monoclonal; Biomarkers; Edema; Endotoxemia; Female; Humans; Immunoglobulin G; Immunoglobulin kappa-Chains; Interleukin-8; Lipopolysaccharides; Lung; Mice; Neutrophils; Peroxidase; Pulmonary Alveoli; Rabbits; Respiratory Distress Syndrome

In 17 patients plasma TNF-alpha and IL-8 were assayed with enzyme-linked immunosorbent assay. IL-6 activity in plasma was determined by bioassay with IL-6-dependent cell line 7TD1. The limulus amoebocyte lysate chromogenic test was used for plasma endotoxin assay. Plasma cytokine levels in injured patients were significantly increased. Plasma TNF-alpha was shown to be increased earlier, while an increase in plasma IL-6 and IL-8 levels occurred late, all of which were shown to be significantly positively correlated with ISS, cardiac and hepatic enzyme activities, and index of renal function. In addition, obvious endotoxaemia occurred at an early stage of injuries, which was respectively significantly correlated with ISS and plasma TNF-alpha, IL-6 and IL-8 levels. Severe injuries could induce increased successive release of TNF-alpha, IL-6 and IL-8, and obvious endotoxaemia. The post injury release of cytokines might be related to endotoxaemia, and may play an important role in the development of organ damage after injury.

Topics: Adolescent; Adult; Aged; Cytokines; Endotoxemia; Endotoxins; Enzymes; Female; Humans; Interleukin-6; Interleukin-8; Male; Middle Aged; Multiple Organ Failure; Tumor Necrosis Factor-alpha; Wounds and Injuries

To examine the kinetics of plasma tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6) and interleukin-8 (IL-8) in patients with severe trauma and to discuss their relationship with organ damage and endotoxemia.. Seventeen patients (10 men and 7 women) with severe trauma were selected in this study. Their mean age was 37.9 +/- 11.9 years. All patients were divided into two groups according to injury severity score (ISS): group I with ISS from 16-25 (18.8 +/- 2.9, n = 10) and group II with ISS more than 25 (34.3 +/- 8.3, n = 7). Ten young healthy volunteers (6 men and 4 women) were used as controls. Plasma TNF alpha and IL-8 levels were assayed with enzyme-linked immunosorbent assay. IL-6 activity in the plasma was determined by bioassay with IL-6-dependent cell-line 7TD1. Limulus amebocyte lysate chromogenic test was used for plasma endotoxin assay.. Plasma cytokine levels in patients with trauma had a successively significant increase. Plasma TNF level increased earlier. Increases in plasma IL-6 and IL-8 occurred later. All the increases were significantly correlated with the severity of trauma and organ damage after trauma. In addition, obvious endotoxemia occurred at the early stage of trauma and was significantly correlated with the severity of trauma and the levels of plasma TNF alpha, IL-6 and IL-8.. Release of TNF alpha, IL-6 and IL-8 can be significantly increased in patients with severe trauma. The increase may be related to massive endotoxin translocation and may play an important role in the development of organ damage after trauma.

Topics: Adolescent; Adult; Aged; Brain Injuries; Endotoxemia; Female; Fractures, Bone; Humans; Injury Severity Score; Interleukin-6; Interleukin-8; Liver; Male; Middle Aged; Pelvic Bones; Tumor Necrosis Factor-alpha