Effects of dapagliflozin on the serum levels of fibroblast growth factor 21 and myokines and muscle mass in Japanese patients with type 2 diabetes: A randomized, controlled trial

AIMS/INTRODUCTION

Our aims were to examine the add-on effects of a sodium-glucose cotransporter 2 inhibitor, dapagliflozin, compared with existing antidiabetes treatments, on anthropometric/metabolic parameters, the levels of an endocrine regulator, fibroblast growth factor 21 (FGF21); a skeletal muscle mass (SMM) negative regulator, myostatin; and a metabolic regulator, irisin, in patients with type 2 diabetes.

MATERIALS AND METHODS

A total of 54 patients with type 2 diabetes were randomly divided into dapagliflozin and control groups. The dapagliflozin group received dapagliflozin 5 mg/day in addition to conventional therapy for 24 weeks. The primary outcome was the change in the level of serum FGF21 from baseline. The secondary outcomes included changes from baseline in anthropometric/metabolic parameters and serum levels of myostatin and irisin.

RESULTS

Bodyweight decreased in the dapagliflozin group compared with the control group (P < 0.001), but the changes in SMM were not significant between the groups (P = 0.611), thereby elevating the ratio of SMM-to-bodyweight in the dapagliflozin group (P = 0.028). Myostatin levels were significantly decreased (P = 0.010), and irisin levels showed a nearly significant reduction (P = 0.052) in the dapagliflozin group compared with the control group, whereas FGF21 levels did not change significantly from baseline to the end of the intervention in both the dapagliflozin (P = 0.673) and the control (P = 0.823) groups.

CONCLUSIONS

Dapagliflozin add-on therapy in patients with type 2 diabetes reduced myostatin levels significantly and maintained SMM, without significant changes in FGF21 levels.

Pulmonary Exposure to Diesel Exhaust Particle Components Enhances Circulatory Chemokines during Lung Inflammation

This study examines the effects of DEP components on circulatory CC and CXC chemokines, potent activators and chemoattractants for macrophage and leukocyte subpopulations, in a murine model of lung inflammation. 1CR mice were divided into six experimental groups which received intratracheal inoculation of vehicle, LPS alone (2.5 mg/kg), organic chemicals in DEP (DEP-OC: 4 mg/kg) extracted with dichloromethane, residual carbonaceous nuclei after the extraction (washed DEP: 4 mg/kg), DEP-OC + LPS, or washed DEP + LPS. Intratracheal instillation of each DEP component alone did not significantly change the circulatory level of macrophage inflammatory protein (MIP)-1α, MIP-2, and macrophage chemoattractant protein-1 (MCP-1) 24 h after the exposure as compared with vehicle instilled alone. In the LPS group, MCP-1, but not MIP-1α or MIP-2, was significantly greater than in the vehicle group. The combined administration of LPS and washed DEP caused a further three to five-fold increase in MIP-1α, MIP-2, and MCP-1 proteins in the serum as compared with LPS administered alone. No significant difference between the LPS + DEP-OC group and the LPS group was observed. These results indicate that pulmonary exposure to washed DEP enhances circulatory level of chemokines during lung inflammation. The enhancement may be important in the aggravations of systemic inflammatory responses and ischemic cardiovascular conditions associated with air pollution.

A whole blood monokine-based reporter assay provides a sensitive and robust measurement of the antigen-specific T cell response

BACKGROUND

The ability to measure T-cell responses to antigens is proving critical in the field of vaccine development and for understanding immunity to pathogens, allergens and self-antigens. Although a variety of technologies exist for this purpose IFNγ-ELISpot assays are widely used because of their sensitivity and simplicity. However, ELISpots cannot be performed on whole blood, and require relatively large volumes of blood to yield sufficient numbers of peripheral blood mononuclear cells. To address these deficiencies, we describe an assay that measures antigen-specific T cell responses through changes in monokine gene transcription. The biological amplification of the IFNγ signal generated by this assay provides sensitivity comparable to ELISpot, but with the advantage that responses can be quantified using small volumes of whole blood.

METHODS

Whole blood or peripheral blood mononuclear cells (PBMCs) from healthy controls and immunosuppressed recipients of solid organ transplants were incubated with peptide pools covering viral and control antigens or mitogen for 20 hours. Total RNA was extracted and reverse transcribed before amplification in a TaqMan qPCR reaction using primers and probes specific for MIG (CXCL9), IP-10 (CXCL10) and HPRT. The induction of MIG and IP-10 in response to stimuli was analysed and the results were compared with those obtained by ELISpot.

RESULTS

Antigen-specific T cell responses can be measured through the induction of MIG or IP-10 gene expression in PBMCs or whole blood with results comparable to those achieved in ELISpot assays. The biological amplification generated by IFNγ-R signaling allows responses to be detected in as little as 25 uL of whole blood and enables the assay to retain sensitivity despite storage of samples for up to 48 hours prior to processing.

CONCLUSIONS

A monokine-based reporter assay provides a sensitive measure of antigen-specific T cell activation. Assays can be performed on small volumes of whole blood and remain accurate despite delays in processing. This assay may be a useful tool for studying T cell responses, particularly when samples are limited in quantity or when storage or transportation are required before processing.

Effects of the Antimicrobial Peptide LL-37 and Hyperthermic Preconditioning in Septic Rats

Background

The authors tested the effects of LL-37 prophylaxis or therapy on the outcome after intraabdominal sepsis and examined whether hyperthermic preconditioning plus LL-37 therapy augments host immune response and improves survival.

Methods

A rat model of peritoneal contamination and infection (PCI) with human stool was used to simulate clinical conditions. In trial 1, the authors compared (1) PCI, (2) LL-37 prophylaxis (0.5 mg/kg, 12 h before PCI), and (3) LL-37 therapy (0.5 mg/kg, 1 h after PCI). In trial 2, the authors compared (1) PCI, (2) LL-37 therapy, (3) hyperthermic preconditioning (41 degrees C for 1 h, 24 h before PCI), and (4) LL-37 therapy and hyperthermic preconditioning. The primary endpoint was mortality at 120 h. In trial 2, secondary endpoints were systemic levels of tumor necrosis factor alpha, interleukin 6, macrophage inflammatory protein 2, and heat shock protein 70; leukocyte counts; and neutrophil granulocyte phagocytosis.

Results

In trial 1, 30% of the control group compared with 70% of the LL-37 therapy group survived, but 55% after LL-37 prophylaxis survived (P = 0.038). In trial 2, 38% of the controls, 67% of the LL-37 therapy, 59% of the hyperthermic preconditioned, and 90% of the hyperthermic preconditioned plus LL-37 therapy group survived (P = 0.01). LL-37 therapy plus hyperthermic preconditioning reduced proinflammatory cytokine concentrations after sepsis; specifically compared with controls, macrophage inflammatory protein-2 and interleukin-6 levels were 1.5 +/- 1.5 versus 11 +/- 6 pg/ml (P = 0.028) and 13 +/- 8 versus 86 +/- 31 pg/ml, (P = 0.015), respectively.

Conclusions

In this model of intraabdominal sepsis, LL-37 therapy improved outcome. Hyperthermic preconditioning per se was not successful, but in combination with LL-37 therapy, the survival rate after sepsis was increased and the proinflammatory cytokine response was downgraded.

Treatment with anti-factor VIIa in acute pancreatitis in rats: blocking both coagulation and inflammation?

OBJECTIVE

Acute pancreatitis starts as an autodigestive process restricted to the pancreas and progresses to a systemic inflammation via cytokine release into the blood stream. Several inhibitors of the coagulation cascade, including active-site-inactivated factor VIIa, have shown anti-inflammatory properties in other inflammatory models than acute pancreatitis. Free radical scavengers have proven useful in reducing the oxidative damage during hyperinflammatory conditions. The aim of this study was to investigate whether pretreatment with FVIIai would have any effect on the multiple organ dysfunction syndrome (MODS) in severe acute pancreatitis.

MATERIAL AND METHODS

Experimental acute pancreatitis was induced by intraductal infusion of taurodeoxycholate in the pancreatic duct. The animals were pretreated with N-acetyl-cysteine and active-site-inactivated factor VIIa. Neutrophil infiltration in the lungs, ileum and colon was quantified by myeloperoxidase activity. Inflammatory markers, IL-6 and MIP-2, were measured using ELISA.

RESULTS

Tissue infiltration of neutrophils in the lungs, ileum and colon significantly increased during acute pancreatitis as compared to sham operation. These levels were reduced by pretreatment with N-acetylcysteine and active-site-inactivated factor VIIa. Levels of interleukin-6 and macrophage inflammatory protein-2 increased significantly during acute pancreatitis. Pretreatment with NAC and FVIIai reduced these levels.

CONCLUSIONS

Both N-acetylcysteine and active-site-inactivated factor VIIa showed powerful anti-inflammatory properties in experimental acute pancreatitis. As they exert their effects through different physiological mechanisms, they represent potential candidates for future multimodal treatment of acute pancreatitis.

An inflammatory pathway of IFN-gamma production in coronary atherosclerosis

Inflammation is associated with the pathogenesis of coronary atherosclerosis, although the mechanisms remain unclear. We investigated whether cytokine secretion by innate immune responses could contribute to the production of proarteriosclerotic Th1-type cytokines in human coronary atherosclerosis. Cytokines were measured by ELISA in the plasma of patients with coronary atherosclerosis undergoing cardiac catheterization. IL-18 was detected in all subjects, whereas a subset of patients demonstrated a coordinated induction of other IFN-gamma-related cytokines. Specifically, elevated plasma levels of IL-12 correlated with that of IFN-gamma and IFN-gamma-inducible chemokines, defining an IFN-gamma axis that was activated independently of IL-6 or C-reactive protein. Systemic inflammation triggered by cardiopulmonary bypass increased plasma levels of the IFN-gamma axis, but not that of IL-18. Activation of the IFN-gamma axis was not associated with acute coronary syndromes, but portended increased morbidity and mortality after 1-year follow-up. IL-12 and IL-18, but not other monokines, elicited secretion of IFN-gamma and IFN-gamma-inducible chemokines in human atherosclerotic coronary arteries maintained in organ culture. T cells were the principal source of IFN-gamma in response to IL-12/IL-18 within the arterial wall. This inflammatory response did not require, but was synergistic with and primed for TCR signals. IL-12/IL-18-stimulated T cells displayed a cytokine-producing, nonproliferating, and noncytolytic phenotype, consistent with previous descriptions of lymphocytes in stable plaques. In contrast to cognate stimuli, IL-12/IL-18-dependent IFN-gamma secretion was prevented by a p38 MAPK inhibitor and not by cyclosporine. In conclusion, circulating IL-12 may provide a mechanistic link between inflammation and Th1-type cytokine production in coronary atherosclerosis.

17Beta-estradiol downregulates Kupffer cell TLR4-dependent p38 MAPK pathway and normalizes inflammatory cytokine production following trauma-hemorrhage

Although studies have shown that 17beta-estradiol (estradiol) normalized Kupffer cell function following trauma-hemorrhage, the mechanism by which E2 maintains immune function remains unclear. Activation of Toll-like receptor 4 (TLR4) initiates an inflammatory cascade, involving activation of p38 mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K), and nuclear factor-kappaB (NF-kappaB). This leads to the release of proinflammatory cytokines. Thus, we hypothesized that the salutary effects of estradiol on Kupffer cell function following trauma-hemorrhage are mediated via negative regulation of TLR4-dependent p38 MAPK and NF-kappaB. TLR4 mutant (C3H/HeJ) and wild type (C3H/HeOuJ) mice were subjected to trauma-hemorrhage (mean BP 35+/-5 mmHg approximately 90 min, then resuscitation) or sham operation. Administration of estradiol following trauma-hemorrhage in wild type mice decreased Kupffer cell TLR4 expression as well as prevented the phosphorylation of p38 MAPK and NF-kappaB. This was accompanied by normalization of Kupffer cell production capacities of IL-6, TNF-alpha, macrophage inflammatory protein (MIP)-1alpha, and MIP-2 and the decrease in plasma cytokine levels. In contrast, TLR4 mutant mice did not exhibit the increase in Kupffer cell p38 MAPK and NF-kappaB activation, cytokine production, or the increase in circulating cytokine levels following trauma-hemorrhage. No difference was observed in activation of PI3K among groups. These results suggest that the protective effect of estradiol on Kupffer cell function is mediated via downregulation of TLR4-dependent p38 MAPK and NF-kappaB signaling following trauma-hemorrhage, which prevents the systemic release of cytokines.

Modest Inflammation Enhances Diclofenac Hepatotoxicity in Rats: Role of Neutrophils and Bacterial Translocation

Idiosyncratic adverse drug reactions (IADRs) represent an important human health problem, yet animal models for preclinical prediction of these reactions are lacking. Recent evidence in animals suggests that some IADRs arise from drug interaction with an inflammatory episode that renders the liver sensitive to injury. Diclofenac (DCLF) is one of those drugs for which the clinical use is limited by idiosyncratic liver injury. We tested the hypothesis that modest inflammation triggered in rats by a small dose of lipopolysaccharide (LPS) renders a nonhepatotoxic dose of DCLF injurious to liver. Cotreatment of rats with nonhepatotoxic doses of LPS and DCLF resulted in elevated serum alanine aminotransferase activity and liver histopathologic changes 6 h after DCLF administration. Neither LPS nor DCLF alone had such an effect. Gene array analysis of livers revealed a unique gene expression pattern in the LPS/DCLF-cotreated group compared with groups given either agent alone. Antiserum-induced neutrophil (PMN) depletion in LPS/DCLF-cotreated rats protected against liver injury, demonstrating a role for PMNs in the pathogenesis of this LPS/DCLF interaction. Gut sterilization of LPS/DCLF-treated rats did not protect against liver injury. In contrast, gut sterilization did attenuate liver injury caused by a large, hepatotoxic dose of DCLF, suggesting that hepatotoxicity induced by large doses of DCLF is caused in part by its ability to increase intestinal permeability to endotoxin or other bacterial products. These results demonstrate that inflammation-DCLF interaction precipitates hepatotoxicity in rats and raise the possibility of creating animal models that predict human IADRs.

Increase of expression and activation of chemokine CCL15 in chronic renal failure

Chemokines are believed to be involved in the pathogenesis of chronic renal failure (CRF). In CRF, significantly increased CCL15-IR plasma concentrations were detected. Whereas in plasma of healthy individuals one predominant CCL15-IR molecule with a M(w) of 15kDa [high molecular weight (HMW-CCL15-IR)] was identified, CRF plasma contains increased concentrations of truncated CCL15-IR molecules [intermediate molecular weight (IMW-CCL15-IR)]. HMW-CCL15-IR isolated from hemofiltrate revealed an M(w) of 10141.3, corresponding to deglycosylated CCL15(1-92) carrying a N-terminal pyrrolidone carboxylic acid. CCL15(12-92) was identified as a major component of IMW-CCL15-IR in CRF plasma. Compared to CCL15(1-92), in monocytes CCL15(12-92) causes stronger induction of intracellular calcium flux, chemotactic activity, and adhesion to fibronectin. Intracellular calcium flux assays revealed that, in comparison to peripheral blood mononuclear cells (PBMC) of healthy donors, PBMCs of CRF patients demonstrated an increased sensitivity to CCL15. Our results point to an involvement of the CCL15-CCR1 axis in the pathophysiology of CRF.

Quantum proteolytic activation of chemokine CCL15 by neutrophil granulocytes modulates mononuclear cell adhesiveness

Monocyte infiltration into inflammatory sites is generally preceded by neutrophils. We show here that neutrophils may support this process by activation of CCL15, a human chemokine circulating in blood plasma. Neutrophils were found to release CCL15 proteolytic activity in the course of hemofiltration of blood from renal insufficiency patients. Processing of CCL15 immunoreactivity (IR) in the pericellular space is suggested by a lack of proteolytic activity in blood and blood filtrate, but a shift of the retention time (t(R)) of CCL15-IR, detected by chromatographic separation of CCL15-IR in blood and hemofiltrate. CCL15 molecules with N-terminal deletions of 23 (delta23) and 26 (delta26) aa were identified as main proteolytic products in hemofiltrate. Neutrophil cathepsin G was identified as the principal protease to produce delta23 and delta26 CCL15. Also, elastase displays CCL15 proteolytic activity and produces a delta21 isoform. Compared with full-length CCL15, delta23 and delta26 isoforms displayed a significantly increased potency to induce calcium fluxes and chemotactic activity on monocytes and to induce adhesiveness of mononuclear cells to fibronectin. Thus, our findings indicate that activation of monocytes by neutrophils is at least in part induced by quantum proteolytic processing of circulating or endothelium-bound CCL15 by neutrophil cathepsin G.

The synthetic pentasaccharide fondaparinux reduces coagulation, inflammation and neutrophil accumulation in kidney ischemia-reperfusion injury

Ischemia-reperfusion (I/R) injury is associated with activation of coagulation and inflammation. Interestingly, various anticoagulants have been shown to reduce both coagulation and inflammation in animal models of kidney I/R injury. Fondaparinux is a synthetic pentasaccharide that selectively inhibits factor Xa (FXa) in the coagulation cascade. The aim of this study was to investigate the effect of fondaparinux in a lethal murine model of kidney I/R injury. A murine model of kidney I/R was established. In this model, we measured activation of the coagulation cascade and induction of inflammation. Administration of fondaparinux to I/R-injured mice reduced fibrin deposition in the kidney, reduced serum creatinine levels and increased survival from 0 to 44% compared with saline-treated control mice. Fondaparinux also reduced interleukin-6 and macrophage inflammatory protein-2 expression and decreased neutrophil accumulation in the injured kidneys. Finally, we showed that fondaparinux reduced thioglycollate-induced recruitment of neutrophils into the peritoneum and inhibited the binding of U937 cells to P-selectin in vitro. Our data suggest that fondaparinux reduces kidney I/R injury primarily by inhibiting the recruitment of neutrophils.

Trypanosoma congolenseinfections: antibody-mediated phagocytosis by Kupffer cells

Immunohistochemical double-label technique was used to detect trypanosomal antigen in macrophages. Immunoglobulin (Ig)M as well as IgG2a monoclonal antibodies (mAb) specific for the variant surface glycoprotein (VSG) mediated phagocytosis of Trypanosoma congolense variant antigenic type (VAT) TC13 by macrophages [bone marrow-derived macrophage cell line from BALB/c (BALB.BM)] in vitro. Administration of these IgM or IgG2a antibodies to BALB/c mice 30 min after injection of 3 x 10(8) T. congolense mediated phagocytosis of trypanosomes by Kupffer cells of the liver within 1 h. Plasma levels of the monokines interleukin (IL)-1beta, IL-10, and IL-12p40 were significantly increased 6-48 h after phagocytosis. In BALB/c mice infected with 10(3) T. congolense, a small degree of phagocytosis of trypanosomes by Kupffer cells, mediated by actively synthesized antibodies, was detected as early as 5 days after infection. Phagocytosis of trypanosomes was dramatically enhanced on day 6. Concomitantly, the Kupffer cells trippled in size. In BALB/c mice infected for 6 days, treatment with IgM or IgG2a mAb specific for T. congolense VSG led to clearance of VAT TC13 parasitemia but did not prevent death at the second parasitemia of a different VAT. We conclude that IgM as well as IgG antibody mediate phagocytosis of trypanosomes by Kupffer cells.

Monokine levels in cancer and infection

The levels of monocyte intracellular monokines (TNFalpha, MIP, and MIG) in patients with cancer or bacterial infection were studied by multiparameter flow cytometry and comparative fluorescence analysis. TNFalpha, MIP, and MIG levels in peripheral blood of patients with cancer or bacterial infection were higher than in normal controls (p < 0.005). In normal controls, no significant relationships were found among TNFalpha, MIG, MIP levels, monocyte count, and lymphocyte count in peripheral blood. In cancer patients, TNFalpha was strongly related to MIP (r = 0.809, p < 0.001) and MIG (r = 0.773, p < 0.001). Of the 3 monokines, TNFalpha and MIG levels were related to monocyte count, but none showed correlation with lymphocyte count in cancer patients. In patients with bacterial infection, TNFalpha was not significantly related to MIP (r = 0.423, p = 0.051), but it was related to MIG (r = 0.457; p = 0.033). None of the monokines (TNFalpha, MIP, MIG) was related to the monocyte count, but the MIP level was related to the peripheral blood lymphocyte count in patients with bacterial infection (r = 0.559, p = 0.008). These results suggest that circulating monocytes may play an important role in both cancer and bacterial infection through increased production of monokines. Moreover, correlations of the monokine levels with each other and their relationships to the monocyte count differ in patients with cancer and bacterial infection.

Inflammatory cytokine profile in children with severe acute respiratory syndrome

OBJECTIVE

To study the inflammatory cytokine profile in children with severe acute respiratory syndrome (SARS) and to investigate whether monoclonal antibody to tumor necrosis factor-alpha (TNF-alpha) could be considered for treatment of these patients.

METHODS

Plasma inflammatory cytokine concentrations (interleukin [IL]-1beta, IL-6, IL-8, IL-10, IL-12p70, and TNF-alpha) were monitored longitudinally on admission, immediately before corticosteroids, and 1 to 2 days and 7 to 10 days after the drug treatment in a cohort of pediatric patients (n = 8) with virologic confirmed SARS-associated coronavirus infection. None of the patients required mechanical ventilation or intensive care treatment. All children except 1 (patient 3) received corticosteroids.

RESULTS

Plasma IL-1beta levels (excluding patient 3) were substantially elevated immediately before (range: 7-721 ng/L) and 7 to 10 days after (range: 7-664 ng/L) corticosteroid treatment. In contrast, the plasma concentrations of other key proinflammatory cytokines, including IL-6 and TNF-alpha, were not overtly increased in any of the patients throughout the course of illness. In addition, plasma IL-10 concentration was significantly lower 1 to 2 days and 7 to 10 days after corticosteroid treatment, compared with the immediate pretreatment level. Similarly, plasma IL-6 and IL-8 concentrations were significantly decreased 7 to 10 days after the drug treatment.

CONCLUSIONS

Pediatric SARS patients have markedly elevated circulating IL-1beta levels, which suggests selective activation of the caspase-1-dependent pathway. Other key proinflammatory cytokines, IL-6 and TNF-alpha, showed only mildly elevated levels at the initial phase of the illness. The current evidence does not support the use of TNF-alpha monoclonal antibody in this group of children.

Effects of albumin and Ringer's lactate on production of lung cytokines and hydrogen peroxide after resuscitated hemorrhage and endotoxemia in rats

RATIONALE AND HYPOTHESIS

Acute lung injury is a frequent complication of severe sepsis or blood loss and is often associated with an excessive inflammatory response requiring mechanical ventilation. We tested the hypothesis that the types of fluids used during early resuscitation have an important effect on the evolution of lung injury.

METHODS

Rats were subjected to either hemorrhage or endotoxemia for 1 hr, followed by resuscitation to a controlled mean blood pressure with Ringer's lactate, 5% albumin, or 25% albumin for 1 hr. After resuscitation, blood cytokine levels were measured. The lung was then excised and ventilated with a tidal volume of 30 mL/kg for 2 hrs.

RESULTS

The volume of fluids required was significantly smaller in the albumin-treated groups than in the Ringer's lactate groups. In the hemorrhagic shock model, plasma concentrations of tumor necrosis factor-alpha, interleukin-6, and macrophage inflammatory protein-2 were significantly lower and interleukin-10 was significantly higher in the albumin-treated groups compared with the Ringer's lactate-treated group. The levels of tumor necrosis factor-alpha and macrophage inflammatory protein-2 in bronchoalveolar lavage fluid were lower and interleukin-10 was higher in the albumin-treated groups than in the Ringer's lactate group. The decreased cytokine production was associated with a reduction of hydrogen peroxide formation with albumin resuscitation. The lung wet/dry ratio was lower in the 5% albumin (0.54 +/- 0.01) and 25% albumin (0.55 +/- 0.02) groups than in the Ringer's lactate group (0.62 +/- 0.02; both p <.05). These effects of albumin seen in the hemorrhagic shock model were not observed in the endotoxic shock model.

CONCLUSIONS

We conclude that resuscitation with albumin may have utility in reducing ventilator-induced lung injury after hemorrhagic shock, but not after endotoxic shock. These findings suggest that the mechanisms leading to ventilator-induced lung injury after hemorrhage differ from those after endotoxemia.

Mechanical ventilation may increase susceptibility to the development of bacteremia

OBJECTIVE

We examined the hypothesis that mechanical ventilation with a potentially injurious strategy would predispose animals to the detrimental effects of subsequent instillation of bacteria.

DESIGN

Interventional animal study.

SETTING

A university hospital research laboratory.

SUBJECTS

Fifty Sprague-Dawley male rats.

INTERVENTIONS

Rats were anesthetized and randomized to receive a protective (tidal volume 7 mL/kg, positive end-expiratory pressure 5 cm H(2)O, n = 25) or an injurious ventilatory strategy (tidal volume 21 mL/kg, zero positive end-expiratory pressure, n = 25). Hemodynamics were similar during the 1-hr ventilation period in the two groups. Animals were then disconnected from the ventilator and Pseudomonas aeruginosa was instilled intratracheally before extubation. Thereafter, animals breathed spontaneously; mortality rate was assessed up to 48 hrs, at which time the animals were killed.

MEASUREMENTS AND MAIN RESULTS

The 48-hr mortality rate was 28% in the protective group and 40% in the injurious group (p = not significant). A positive bacterial culture from the lung was obtained in 56% of the surviving rats in the low tidal volume group and 67% in the high tidal volume group (p =.059). A positive blood bacterial culture was found in 11% of the low tidal volume group and 33% in the high tidal volume group (p <.05). The absolute bacterial count in the blood was lower in the low tidal volume group compared with the high tidal volume group (p <.05). Concentrations of blood tumor necrosis factor-alpha and macrophage inflammatory protein-2, and lung macrophage inflammatory protein-2 at 48 hrs were significantly higher in the low tidal volume group than in the high tidal volume group.

CONCLUSIONS

An injurious ventilatory strategy predisposes animals to subsequent bacteremia associated with an impaired host defense reflected by cytokine response.

Regulation of pro-inflammatory and anti-inflammatory cytokine responses by Kupffer cells in endotoxin-enhanced reperfusion injury after total hepatic ischemia

The effects of Kupffer cells on cytokine responses in endotoxin-enhanced reperfusion injury after total hepatic ischemia were investigated in this study. Male rats pretreated with either normal saline solution (NS group) or gadolinium chloride (GdCl(3)) to inhibit Kupffer cell function (GC group) were subjected to 60 min of hepatic ischemia. These animals received either normal saline solution or sublethal doses of endotoxin (1 mg/kg) at reperfusion. In the NS group, endotoxin administration induced an enhanced tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 production 1 h after reperfusion with a subsequent peak of macrophage inflammatory protein-2 (MIP-2) levels, which resulted in a 7-day survival rate of 30%. Despite endotoxin administration, GdCl(3) pretreatment significantly suppressed TNF-alpha and increased interleukin-10 production 1 h after reperfusion, which led to a decline in MIP-2 production and amelioration of functional and structural liver damage with a 7-day survival rate of 80%. Augmented pro-inflammatory and anti-inflammatory cytokine responses by Kupffer cells were associated with endotoxin-enhanced reperfusion injury after hepatic ischemia. Kupffer cell blockade has a potential to attenuate the insult via modulation of cytokine responses.

Aromatic trap analysis of free radicals production in experimental collagen-induced arthritis in the rat: protective effect of glycosaminoglycans treatment

Many findings demonstrated that Glycosaminoglycans (GAGs) and Proteoglycans (PGs) possess antioxidant activity. Collagen-induced arthritis (CIA) is an experimental animal model similar to human rheumatoid arthritis (RA) in which free radicals are involved. Sodium salicylate can be used as a chemical trap for hydroxyl radicals (OH*), the most damaging reactive oxygen species (ROS), yielding 2,5-dihydroxybenzoic acid), (2,5-DHBA) and 2,3-dihydroxybenzoic acid (2,3-DHBA). The measurement of these two acids in the plasma allows to indirectly assess the production of OH* radicals. The aim of the study was to investigate the effect of hyaluronic acid (HYA) (30 mg/kg i.p.) or chondroitin-4-sulphate (C4S) (30 mg/kg i.p.), on free radical production in Lewis rats subjected to CIA. After the immunization with bovine collagen type II in complete Freund's adjuvant, rats developed an erosive hind paw arthritis, that produced high plasma OH* levels assayed as 2,3-DHBA and 2,5-DHBA, primed lipid peroxidation, evaluated by analyzing conjugated dienes (CD) in the articular cartilage; decreased the concentration of endogenous vitamin E (VE) and catalase (CA) in the joint cartilage; enhanced macrophage inflammatory protein-2 (MIP-2) serum levels and increased elastase (ELA) evaluated as an index of activated leukocyte polymophonuclear (PMNs) accumulation in the articular joints. The administration of HYA and C4S starting at the onset of arthritis (day 11) for 20 days, limited inflammation and the clinical signs in the knee and paw, reduced OH* production, decreased CD levels, partially restored the endogenous antioxidants VE and CA, reduced MIP-2 serum levels and limited PMNs infiltration. The results indicate that the GAGs HYA and C4S significantly reduce free radical production in CIA and could be used as a tool to investigate the role of antioxidants in RA.

Flagellin from gram-negative bacteria is a potent mediator of acute pulmonary inflammation in sepsis

Flagellin is a recently identified bacterial product that elicits immune response via toll-like receptor 5. Here, we demonstrate that flagellin is an extraordinarily potent proinflammatory stimulus in the lung during sepsis. In vitro, flagellin triggers the production of interleukin (IL)-8 by human lung epithelial (A549) cells, with 50% of the maximal response obtained at a concentration of 2 x 10(-14) M. Flagellin also induces the expression of ICAM-1 in vitro. Intravenous administration of flagellin to mice elicited a severe acute lung inflammation that was significantly more pronounced than following lipopolysaccharide (LPS) administration. Flagellin induced a local release of proinflammatory cytokines, the accumulation of inflammatory cells, and the development of pulmonary hyperpermeability. These effects were associated with the nuclear translocation of the transcription NF-kappaB in the lung. Flagellin remained active in inducing pulmonary inflammation at doses as low as 10 ng/mouse. In the plasma of patients with sepsis, flagellin levels amounted to 7.1 +/- 0.1 ng/mL. Plasma flagellin levels showed a significant positive correlation with the lung injury score, with the alveolar-arterial oxygen difference as well as with the duration of the sepsis. Flagellin emerges as a potent trigger of acute respiratory complications in gram-negative bacterial sepsis.

Hypercholesterolaemia and circulating levels of CXC chemokines in apoE*3 Leiden mice

Hyperlipidaemia may accelerate the development of atherosclerosis by enhancing the expression of chemokines by cells within the arterial wall. Chemokines of the CC subfamily are clearly implicated in atherogenesis; however, recent reports suggest that CXC chemokines may play a hitherto unrecognised role in monocyte recruitment into atheromatous lesions expressing these molecules. Here, we examine whether circulating levels of CXC chemokines may reflect the pathogenic changes occurring during early atherogenesis. ApoE*3 Leiden mice developed marked hypercholesterolaemia, and early Type I 'fatty streak' lesions, following consumption of an atherogenic diet high in saturated fat and cholesterol, and containing sodium cholate, for up to 4 weeks. By contrast, their non-transgenic littermates (C57BL/6J) exhibited a much less pronounced hypercholesterolaemia and did not develop fatty streak lesions, when fed the same diet. Under these conditions, serum concentrations of CXC chemokines, KC and Macrophage Inflammatory Protein-2 (MIP-2) were significantly (P<or=0.0005) elevated in apoE*3 Leiden mice consuming HFC/C diet, compared with apoE*3 Leiden mice consuming a chow diet. Further, serum concentrations of KC were significantly (P<0.02) higher at 4 weeks in apoE*3 Leiden mice fed HFC/C diet compared with their non-transgenic littermates consuming the same diet. Expression of KC mRNA was detected in both aortic and hepatic tissues of apoE*3 Leiden mice, and the non-transgenic controls. Thus, hypercholesterolaemia is associated with elevated serum concentrations of CXC chemokines, KC and MIP-2 that probably reflect chronic inflammation during atherogenesis.

Expression of interleukin-18 and its monokine-directed function in rheumatoid arthritis

OBJECTIVES

To investigate the expression of and monokine induction by interleukin 18 (IL-18; also called interferon-gamma inducing factor, IGIF), in peripheral blood mononuclear cells (PBMC) and cultured synoviocytes from rheumatoid arthritis (RA) patients.

METHODS

We carried out IL-18 Western blotting and semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) of cytokines in PBMC [IL-18, IL-1beta and tumour necrosis factor alpha (TNF-alpha)] and long-term cultured fibroblast-like synoviocytes (FLS) [IL-18, IL-1beta, TNF-alpha, IL-6, interferon gamma (INF-gamma) and [granulocyte-macrophage colony stimulating factor (GM-CSF)] from RA patients and controls. FLS were isolated from RA synovial membranes (FLS(SM)) and RA synovial fluids (FLS(SF)), osteoarthritis (OA) FLS(SM) and FLS(SF) from spondyloarthropathy patients. FLS were characterized by fluorescence-activated cell sorting of the FLS. PBMC and FLS from RA patients and control subjects were stimulated with recombinant human IL-18 and IL-1beta (rHuIL-18/rHuIL-1beta), and TNF-alpha, IL-1beta and MMP-1 were measured by ELISA in supernatants.

RESULTS

Constitutive expression of IL-18 mRNA was significantly reduced whereas that of TNF-alpha was enhanced in RA PBMC. Persistent low expression of IL-18, TNF-alpha, GM-CSF and IL-1beta was observed in RA and OA FLS(SM) as well as spondyloarthropathy FLS(SF). In contrast, high constitutive expression of IL-18 in FLS (CD90/Thy-1- and CD54-positive, CD14- and CD86-negative), accompanied by persistent high levels of TNF-alpha, GM-CSF and IL-1beta expression, was restricted to synovial fluid-derived FLS obtained from RA patients. IFN-gamma was not detectable in any culture, but IL-6 mRNA was equally expressed in all FLS cultures. rHuIL-18 was effective in stimulating TNF-alpha and IL-1beta secretion in PBMC from healthy controls, but failed to stimulate TNF-alpha and IL-1beta secretion from PBMC in 11 of 12 RA patients, and all FLS cultures. rHu-IL-1beta, but not rHu-IL-18, induced interstitial collagenase (MMP-1) in FLS.

CONCLUSIONS

Persistent high production of proinflammatory cytokines in RA-FLS(SF) may be relevant for chronic progression in RA synovitis. Levels of TNF-alpha and IL-1beta expression are increased in RA-FLS(SF), but are independent of IL-18. The pathological function of enhanced IL-18 expression in RA-FLS(SF) remains to be further elucidated.

Intracellular cytokine profile of CD14 positive cells in patients with hematologic malignancies and solid tumors during hematologic recovery phase after intensive chemotherapy designed to mobilize peripheral blood stem cells

We studied intracellular cytokines in monocytes by flow cytometry from 28 patients with hematologic malignancies and solid tumors to analyze the role of monokines in the hematologic recovery phase for peripheral blood stem cell harvest. The patients were divided into three groups: the first group, A, had a documented infection; the second group, B, had fever of unknown origin; and the third group, C, was afebrile. We found an increase in intracellular IL-1alpha, IL-6, IL-8 and TNF-alpha positive monocytes as CD14 positive gated cells cultured with lipopolysaccharide in all groups, but no increase was found with medium only when cultured for 4 h. We also found an increase in intracellular IL-1a, IL-6, IL-8 and TNF-alpha positive monocytes cultured with autologous serum for 4 h, but only in group A. The rate of intracellular cytokine positive cells was higher in monocytes cultured with only autologous serum from group A patients compared to those cells from the other groups; the data concerning IL-1a, IL-6 and TNF-alpha reached statistical significance (P < 0.05). However, increasing intracellular cytokine levels in the control group of patients exhibiting only infectious disease were observed. Thus, it appear that pro-inflammatory intracellular cytokine levels in monocytes are only related to microbial infections.

Hepatic cryoablation, but not radiofrequency ablation, results in lung inflammation

OBJECTIVE

To compare the effects of 35% hepatic cryoablation with a similar degree of radiofrequency ablation (RFA) on lung inflammation, nuclear factor kappaB (NF-kappaB) activation, and production of NF-kappaB dependent cytokines.

SUMMARY BACKGROUND DATA

Multisystem injury, including acute lung injury, is a severe complication associated with hepatic cryoablation of 30% to 35% or more of liver parenchyma, but this complication has not been reported with RFA.

METHODS

Sprague-Dawley rats underwent 35% hepatic cryoablation or RFA and were killed at 1, 2, and 6 hours. Liver and lung tissue were freeze-clamped for measurement of NF-kappaB activation, which was detected by electrophoretic mobility shift assay. Serum concentrations of tumor necrosis factor alpha and macrophage inflammatory protein 2 were measured by enzyme-linked immunosorbent assay. Histologic studies of pulmonary tissue and electron microscopy of ablated liver tissue were compared among treatment groups.

RESULTS

Histologic lung sections after cryoablation showed multiple foci of perivenular inflammation, with activated lymphocytes, foamy macrophages, and neutrophils. In animals undergoing RFA, inflammatory foci were not present. NF-kappaB activation was detected at 1 hour in both liver and lung tissue samples of animals undergoing cryoablation but not after RFA, and serum cytokine levels were significantly elevated in cryoablation versus RFA animals. Electron microscopy of cryoablation-treated liver tissue demonstrated disruption of the hepatocyte plasma membrane with extension of intact hepatocyte organelles into the space of Disse; RFA-treated liver tissue demonstrated coagulative destruction of hepatocyte organelles within an intact plasma membrane. To determine the stimulus for systemic inflammation, rats treated with cryoablation had either immediate resection of the ablated segment or delayed resection after a 15-minute thawing interval. Immediate resection of the cryoablated liver tissue prevented NF-kappaB activation and lung injury; however, pulmonary inflammatory changes were present when as little as a 15-minute thaw interval preceded hepatic resection.

CONCLUSIONS

Hepatic cryoablation, but not RFA, induces NF-kappaB activation in the nonablated liver and lung and is associated with acute lung injury. Lung inflammation is associated with the thawing phase of cryoablation and may be related to soluble mediator(s) released from the cryoablated tissue. These findings correlate the clinical observation of an increased incidence of multisystem injury, including adult respiratory distress syndrome (ARDS), after cryoablation but not RFA.

The dynamic responses of pro-inflammatory and anti-inflammatory cytokines of human mononuclear cells induced by uromodulin

This study was undertaken to examine the dynamic response of human peripheral blood mononuclear cells (PBMC) in the secretion of proinflammatory and anti-inflammatory cytokines induced by uromodulin (URO). Levels of tumor necrosis factor-alpha (TNFalpha), TNF soluble receptor (sTNFRI and II), interleukin 1-beta (IL-1beta), and IL-1 receptor antagonist (IL-1Ra) in the supernatants of URO-stimulated PBMC were measured by ELISA. URO stimulated the secretion of all these cytokines in a dose dependent manner except sTNFRI. Peak levels of TNFalpha and IL-1beta were reached at 6-12 h, while 5-10 fold higher in sTNFR II and IL-1Ra levels were observed at 24-48 h after URO stimulation. URO-induced secretion of TNFalpha, IL-1beta, sTNFRII and IL-1Ra could be enhanced by human plasma. Specifically, serum proteins including C3, sCD14 and IgG not only bound to URO but also enhanced URO-induced TNFalpha secretion of PBMC. Collectively, our data suggest that URO might have dual immunomodulating effect through regulating the secretion of proinflammatory and anti-inflammatory cytokines, and that serum binding proteins might enhance this activity.

Human monocytes express functional receptors for granulocyte colony-stimulating factor that mediate suppression of monokines and interferon-gamma

In a double-blind, placebo-controlled, randomized study, 10 healthy men received either a single dose of 480 microg granulocyte colony-stimulating factor (G-CSF) or saline. Blood taken from the volunteers was stimulated with 10 microg/mL endotoxin and released cytokines were measured by enzyme-linked immunosorbent assay. Expression of G-CSF receptors on leukocytes was examined by flow cytometry and reverse transcriptase-polymerase chain reaction. Functional activity of these receptors was tested by challenging isolated leukocyte populations to release cytokines with endotoxin in the presence of G-CSF. The G-CSF treatment attenuated the release of the proinflammatory cytokines tumor necrosis factor (TNF)-alpha, interleukin (IL)-12, IL-1beta, and interferon (IFN)-gamma in ex vivo lipopolysaccharide (LPS)-stimulated whole blood. In blood from untreated volunteers the presence of G-CSF in vitro also attenuated the LPS-stimulated release of these cytokines. G-CSF in vitro also attenuated TNF-alpha release from elutriation-purified monocytes. In the presence of 10 ng/mL recombinant TNF-alpha, the attenuation of LPS-inducible IFN-gamma release by G-CSF was blunted in whole blood. However, G-CSF had no such effect on IFN-gamma release from isolated lymphocytes stimulated with anti-CD3 or a combination of TNF-alpha and IL-12. G-CSF receptor expression was detected in human neutrophils and monocytes but not in lymphocytes by means of RT-PCR as well as flow cytometry. These results indicate that G-CSF receptors expressed on monocytes are functional in modulating monokine release. We conclude that the attenuation of IFN-gamma release from lymphocytes is not a direct effect of G-CSF on these cells but is rather due to the inhibition of monocytic IL-12 and TNF-alpha release by G-CSF. (Blood. 2000;95:270-276)

IL-13 activates STAT6 and inhibits liver injury induced by ischemia/reperfusion

Hepatic ischemia/reperfusion injury is initiated by the activation of Kupffer cells and their subsequent release of proinflammatory mediators, including tumor necrosis factor-alpha (TNFalpha). These mediators stimulate a cascade of events including up-regulation of CXC chemokines and vascular endothelial adhesion molecules, leading to hepatic neutrophil recruitment and tissue injury. Interleukin-13 (IL-13) is a cytokine that has been shown to suppress macrophage production of proinflammatory mediators. The objective of the current study was to determine whether IL-13 could regulate the liver inflammatory injury induced by ischemia and reperfusion. C57BL/6 mice underwent 90 minutes of partial hepatic ischemia followed by reperfusion with or without intravenous administration of recombinant murine IL-13. Hepatic ischemia/reperfusion increased expression of TNFalpha and macrophage inflammatory protein-2 (MIP-2), leading to hepatic neutrophil recruitment, hepatocellular injury, and liver edema. Administration of IL-13 reduced the production of TNFalpha and MIP-2 mRNA and protein. IL-13 suppressed liver neutrophil recruitment by up to 72% and hepatocellular injury and liver edema were each reduced by >60%. Administration of IL-13 had no effect on liver NFkappaB activation, but greatly increased the activation of STAT6. The data suggest that the hepatoprotective effects of IL-13 may be a result of STAT6 activation.

Acute lung injury after hepatic cryoablation: correlation with NF-kappa B activation and cytokine production

BACKGROUND

Previous clinical reports have documented multisystem organ injury after hepatic cryoablation. We hypothesized that hepatic cryosurgery, but not partial hepatectomy, induces a systemic inflammatory response characterized by distant organ injury and overproduction of nuclear factor kappa B (NF-kappa B)-dependent, proinflammatory cytokines.

METHODS

In this study, rats underwent either cryoablation of 35% of liver parenchyma or a similar resection of left hepatic tissue. Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels and NF-kappa B activation were assessed by electrophoretic mobility shift assay at 30 minutes 1, 2, 6, and 24 hours after either procedure.

RESULTS

Cryoablation of 35% of liver (n = 22 rats) resulted in lung injury and a 45% mortality rate within 24 hours of surgery, whereas 7% treated with 35% hepatectomy (n = 15 rats) died during the 24 hours after surgery (P < .05, cryoablation vs hepatectomy). Serum tumor necrosis factor-alpha and macrophage inflammatory protein-2 levels were markedly increased in rats (n = 10 rats) 1 hour after hepatic cryoablation compared with rats that underwent partial hepatectomy (P < .005). We evaluated NF-kappa B activation by electrophoretic mobility shift assay in nuclear extracts of liver and lung after cryosurgery and found that NF-kappa B activation was strikingly increased in the liver but not the lung at 30 minutes and in both organs 1 hour after cryosurgery, and returned to baseline in both organs by 2 hours. In rats undergoing 35% hepatectomy, no increase in NF-kappa B activation was detected in nuclear extracts of either liver or lung at any time point.

CONCLUSIONS

These data show that hepatic cryosurgery results in systemic inflammation with activation of NF-kappa B and increased production of NF-kappa B-dependent cytokines. Our data suggest that lung injury and death in this animal model is mediated by an exaggerated inflammatory response to cryosurgery.

A common functional polymorphism (C-->A substitution at position -863) in the promoter region of the tumour necrosis factor-alpha (TNF-alpha) gene associated with reduced circulating levels of TNF-alpha

Tumour necrosis factor-alpha (TNF-alpha) plays a key role in orchestrating the complex events involved in inflammation and immunity. Accordingly, TNF-alpha has been implicated in a wide range of autoimmune and infectious diseases, but also in conditions such as obesity and insulin resistance. The regulation of TNF-alpha expression in man is indicated to be partly genetically determined. We therefore screened a 1263 bp section of the proximal promoter of the TNF-alpha gene for common genetic variants affecting the transcriptional activity of the gene. Here we report the characterization of a common functional polymorphism in the promoter region of the TNF-alpha gene, a C-->A substitution at position -863. Electromobility shift assays provided evidence for a distinct difference in the binding of monocytic and hepatic nuclear factors to the -863C and -863A alleles. The rare -863A allele was associated with 31% lower transcriptional activity ( P < 0.001) in chloramphenicol acetyltransferase (CAT) reporter gene studies in human hepatoblastoma (HepG2) cells, indicating that the-863C/A polymorphism influences the basal rate of transcription of the TNF-alpha gene in vitro. Allele frequencies were 0.83/0.17 amongst 254 apparently healthy men of Swedish origin, aged 35-50 years. In 156 men, the -863C/A polymorphism was associated with the serum TNF-alpha concentration, carriers of the rare A allele having a significantly lower TNF-alpha level ( P < 0.05). It is concluded that the common-863C/A polymorphism in the promoter region of the TNF-alpha gene is functional in vitro in monocytic and hepatic cells and influences the serum TNF-alpha concentration in vivo in healthy middle-aged men.

Mechanical ventilation affects local and systemic cytokines in an animal model of acute respiratory distress syndrome

We examined the hypothesis that injurious ventilatory strategies (large tidal volume [VT] and/or low positive end-expiratory pressure [PEEP]) would increase release of inflammatory mediators into the lung and into the systemic circulation in a lung injury model. Lung injury was induced in 40 anesthetized paralyzed Sprague-Dawley rats (350 +/- 2 g) by hydrochloric acid instillation (pH 1.5, 2.5 ml/kg). Rats were then randomized into five groups (n = 8): (1) high-volume zero PEEP (HVZP): VT, 16 ml/ kg; (2) high-volume PEEP (HVP): VT, 16 ml/kg, PEEP, 5 cm H2O; (3) low-volume zero PEEP (LVZP): VT, 9 ml/kg; (4) low-volume PEEP (LVP): VT, 9 ml/kg, PEEP, 5 cm H2O; (5) same settings as (4) plus a recruitment maneuver performed every hour (LVPR). Respiratory rate was adjusted to maintain normocapnia and fraction of inspired oxygen (FIO2) was 1. Cytokine concentrations (tumor necrosis factor-alpha [TNF-alpha] and macrophage inflammatory protein-2 [MIP-2]) were measured by ELISA. All animals in the LVZP group died before the end of the experiment. After 4 h of ventilation, the HVZP group had similar lung fluid TNF-alpha concentrations compared with the HVP group: 1,861 +/- 333 pg/ml versus 1,259 +/- 189 pg/ml; and much higher serum concentrations: 692 +/- 74 pg/ml versus 102 +/- 31 pg/ml (p < 0.05). An identical pattern was found for MIP-2. These results suggest that the particular ventilatory strategy can affect the release of cytokines into the systemic circulation, a finding that may have relevance for the development of multisystem organ failure.

Macrophage inflammatory protein-2 predicts acute lung injury in endotoxemia

BACKGROUND

Proinflammatory mediators that include tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-2 (MIP-2) and anti-inflammatory mediators such as interleukin-10 (IL-10) modulate the immune response to endotoxemia. IL-10 downregulates the production of TNF-alpha and MIP-2. Acute lung injury may occur secondary to neutrophil chemotaxis mediated by chemokine MIP-2. We studied the temporal relationship of TNF-alpha, MIP-2, and IL-10 in rat endotoxemia and correlation of MIP-2 concentrations with acute lung injury.

METHODS

Ten ventilated rats were randomized to receive an intravenous infusion of 2 mg/kg Escherichia coli lipopolysaccharide (n = 6) or saline placebo (n = 4). Blood pressure was continuously monitored and arterial blood was obtained for lactate, blood gas, TNF-alpha, IL-10, and MIP-2 measurements at baseline, 2, 4, and 5.5 hours after LPS or saline infusion.

RESULTS

Endotoxemia resulted in hypotension, lactic acidemia, and increased alveolar-arterial oxygen gradient (A-a O2 gradient) compared with the placebo group. TNF-alpha, MIP-2, and IL-10 levels were increased 2 hours after endotoxemia. Subsequently, TNF-alpha levels declined while IL-10 and MIP-2 levels remained elevated. Control rats had no significant increase in cytokine production at any time point. MIP-2 concentrations correlated with A-a O2 gradient, an indicator of lung injury (r = 0.56, p < 0.001).

CONCLUSIONS

MIP-2, possibly released by TNF-alpha stimulation of macrophages, is associated with acute lung injury possibly by inducing neutrophil chemotaxis. IL-10 may exert its counter-inflammatory response by inhibiting the release of TNF-alpha in endotoxemia.

The effect of LPS on cytokine synthesis and lung neutrophil influx after hepatic ischemia/reperfusion injury in the rat

OBJECTIVE

To determine if cytokine responses and lung injury induced by intravenous (i.v.) lipopolysaccharide (LPS) at 4 hr were enhanced in rats that had been previously subjected to 30 min of total liver ischemia (Pringle's maneuver) followed by 24 hr or 3 days of reperfusion.

BACKGROUND

Many patients with liver trauma require occlusion of hepatic blood flow to control hemorrhage and facilitate repair. A significant number of these patients subsequently develop the systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction (MOD) characterized by the release of cytokines and tissue neutrophil influx. Macrophages, including Kupffer cells, may be activated by ischemic injury and dysregulation of their response to LPS may contribute to the development of SIRS and acute respiratory distress syndrome.

METHODS

Adult male Sprague-Dawley rats were randomly divided into six groups: three groups received total hepatic ischemia for 30 min and three groups had a sham procedure. Twenty-four hours or 3 days after hepatic ischemia/reperfusion injury, rats were treated with LPS (5 mg/kg) or saline and monitored for 4 hr. We collected serum, bronchoalveolar lavage (BAL) fluid, and lung tissue.

RESULTS

Serum and BAL cytokine concentrations were significantly increased by i.v. LPS; however, hepatic ischemia/reperfusion injury 24 hr or 3 days before iv LPS ameliorated this cytokine response. The LPS-induced pulmonary neutrophil influx and histopathological changes were similar in sham and hepatic ischemia/reperfusion-injured groups.

CONCLUSIONS

Hepatic ischemia/reperfusion injury significantly attenuated the serum and BAL cytokine concentrations, but did not change pulmonary neutrophil influx or histopathological alterations in response to i.v. LPS.

Enhanced immune responses in females, as opposed to decreased responses in males following haemorrhagic shock and resuscitation

Although haemorrhagic shock produces immunodepression in both humans and experimental animals, no information is available concerning gender differences in the immune and endocrine response to shock. To study this, male and female (proestrus and diestrus) C3H/HeN mice (25 g body weight) were bled and maintained at a mean arterial blood pressure of 35 +/- 5 mmHg for 1 h and then adequately resuscitated. The animals were killed at 2 h after resuscitation to obtain splenocytes, macrophages (M phi, peritoneal and splenic), as well as whole blood. IL-1 release by M phi, splenocyte proliferative capacity and splenocyte IL-3 release in female mice was significantly increased. Male mice, however, showed decreased release of all interleukins (IL-1, 2, 3, 6) as well as splenocyte proliferative capacity after shock. Plasma corticosterone levels decreased in proestrus female mice, as opposed to increased levels in males following shock. Corticosterone may therefore, be in part responsible for the observed gender differences. To the authors' knowledge, this is the first study which shows that immune responsiveness in female mice is enhanced after haemorrhagic shock, as opposed to decreased responsiveness in males. Thus, unlike males which exhibit increased susceptibility to sepsis/infections, females should be able to better tolerate the deleterious effects of shock.

Immune function is more compromised after closed bone fracture and hemorrhagic shock than hemorrhage alone

OBJECTIVE

To determine whether closed bone fracture in conjunction with hemorrhagic shock compromises immune functions more severely than hemorrhagic shock alone.

DESIGN

In a randomized, controlled trial, closed bone fracture of the right lower leg and/or hemorrhagic shock (mean +/- SEM arterial blood pressure, 35 +/- 5 mm Hg for 90 minutes) were induced in male C3H/HeN mice (weight, 25 g). Animals subjected to hemorrhage were resuscitated with the shed blood and lactated Ringer solution. At 72 hours after the experiment, all animals were killed to obtain whole blood, splenocytes, and splenic and peritoneal macrophages. Macrophage interleukin-1 and splenocyte interleukin-2 and interleukin-3 release were determined by bioassay, and splenocyte proliferation was measured by tritiated thymidine incorporation.

RESULTS

Closed bone fracture alone did not affect immune functions 72 hours after the trauma. Hemorrhagic shock, however, induced a significant depression of splenocyte and macrophage functions. Bone fracture followed by hemorrhagic shock further depressed splenocyte proliferation and splenocyte interleukin-2 and interleukin-3 release as well as interleukin-1 release.

CONCLUSION

Since bone injury coupled with hemorrhagic shock produces more severe depression of immune functions than hemorrhage alone, bone injury appears to play a contributory role in further depressing immune functions in trauma patients who experience major blood loss.

Serglycin-binding proteins in activated macrophages and platelets

The major proteoglycan in macrophages and platelets is the chondroitin sulphate proteoglycan serglycin. To study the biological role of serglycin, its binding to secreted and cell-associated proteins from macrophages and blood platelets was examined. Affinity chromatography with serglycin-Sepharose and chondroitin sulphate-Sepharose was used to isolate proteoglycin-binding proteins from macrophages and platelets. Antibodies against human macrophage inflammatory protein-1 alpha (MIP-1 alpha) precipitated a 14-kDa 35S-methionine-labeled protein among the chondroitin sulfate binding proteins secreted from the macrophage-like U937 cells after stimulation. Two proteins from murine macrophage J774 cells with molecular masses of approximately 10 and 14 kDa were precipitated by an antiserum against the murine MIP-1 alpha. Protein sequencing of fragments obtained by trypsin digestion of a 14-kDa chondroitin sulfate-binding protein from cell extracts of stimulated U937 cells revealed 100% homology with lysozyme, a bacteriolytic enzyme. Fragment of one other protein with approximate molecular mass of 8 kDa showed high homology with bone morphogenetic protein. Inhibition studies showed that chondroitin 6-sulfate inhibited the bacteriolytic activity of lysozyme in a competitive manner more efficiently than heparin and chondroitin 4-sulphate. Amino-terminal sequencing of two proteins from platelet extracts that bound to serglycin-Sepharose revealed that they corresponded to multimeric forms of human platelet factor 4 (PE4). Chondroitin sulfate-Sepharose was shown to be equally efficient in retaining PF4 from platelet extracts as serglycin-Sepharose indicating that the glycosaminoglycan chains mediate the binding to PF4 in the intact proteoglycan molecule. Competition experiments showed that serglycin was as efficient as heparin sulfate in blocking the binding of [3H] chondrotin sulfate to PF4, whereas heparin was one order of magnitude more efficient. Affinity measurements using fluoresceinamine-labeled glycosaminoglycans showed that the affinity of heparin for PF4 is on the order of 30 nM, whereas chondroitin sulfate has an affinity of 260 nM. Both PF4, MIP-1 alpha, and lysozyme play important role in different types of inflammatory reactions. The interaction with serglycin may indicate that this proteoglycan is involved in the regulation of the inflammatory response.

Tumour necrosis factor, interleukin-1 and adenosine deaminase in tuberculous pleural effusion

Tumour necrosis factor (TNF) and interleukin-1 (IL-1) are powerful mediators with a key role in inflammation. This study was undertaken to study the presence of TNF and IL-1 in tuberculous effusion where there is marked inflammation and where examination of the pleural fluid may give information about the local inflammatory reaction. Adenosine deaminase activity (ADA, a marker of TB pleurisy) was also tested. Tumour necrosis factor, IL-1 and ADA levels were measured in the pleural fluid and serum of 97 patients; 33 with tuberculous effusion, 33 with malignant effusion, and 31 patients with benign non-tuberculous effusion. Pleural fluid TNF and ADA levels were higher in tuberculous (TB) patients than in patients with benign disorders or cancer (P < 0.01). Serum TNF levels were also higher in TB patients than other benign (P < 0.01) or malignant (P < 0.05) effusions. There was a positive correlation between serum and pleural fluid values (r = 0.998-0.999, P < 0.001) although pleural fluid concentration was higher (P < 0.001), possibly suggesting local production in the pleural cavity. Pleural fluid IL-1 levels were not raised in any patient group but there was a positive correlation between TNF and IL-1. In addition, a positive correlation was found between TNF and ADA levels, probably indicating some common production mechanism. Furthermore, ADA sensitivity in the diagnosis of tuberculous effusion was augmented by the combined use of TNF and ADA. The use of both these markers may prove useful in the differential diagnosis of TBC pleurisy.

Macrophage inflammatory protein-1 beta: a C-C chemokine in osteoarthritis

The aim of this study was to determine whether the cytokine macrophage inflammatory protein-1 beta (MIP-1 beta) is present and functionally active in the arthritic joint. We used immunoassays and bioassays to assess the presence and function of MIP-1 beta using samples obtained from 62 arthritic patients. MIP-1 beta levels were increased in synovial fluids (SFs) from patients with osteoarthritis (OA) (18.0 +/- 8.9 ng/ml) (SD) compared to patients with rheumatoid arthritis (RA) 6.1 +/- 2.9 ng/ml) or other forms of arthritis (10.4 +/- 7.0 ng/ml) (P < 0.05). Levels of OA SF MIP-1 beta were significantly greater than OA or normal serum levels of MIP-1 beta. Anti-MIP-1 beta neutralized 28% of the chemotactic activity for monocytes found in OA SFs. Isolated OA synovial tissue fibroblasts did not constitutively produce MIP-1 beta but could be induced to express this chemokine upon exposure to tumor necrosis factor-alpha, interleukin-1 beta, or lipopolysaccharide. Synovial tissue immunohistochemical staining revealed that the main immunopositive cells in OA were the lining cells as well as vascular smooth muscle and endothelial cells. A minority of macrophages were immunopositive as well. In this study, we identify MIP-1 beta as a unique cytokine increased in OA compared to RA SF. We conclude that MIP-1 beta may play a role in the ingress of monocytes into the OA joint.

Monokine production by peripheral whole blood in chronic hepatitis C patients treated with interferon

Using our scoring system, we studied the production of monokines (interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6) by lipopolysaccharide-stimulated peripheral whole blood in 34 patients with chronic hepatitis C during the interferon-alpha/beta therapy. It decreased in 25.7% (9/35 group A), fluctuated in 60.0% (21/35, group B), and increased in 14.3% (5/35, group C). The patients in group A were younger than those in group B (P < 0.05). The histological grade of injury was milder in group A than in group B or C. The rate of sustained response was 66.7% (6/9) in group A, 19.0% (4/21) in group B, and 40.0% (2/5) in group C(P = 0.0184, group A versus group B). In summary, monokine production by peripheral whole blood varied during interferon therapy for chronic hepatitis C patients. No significant change was noted in 60% of the patients. However, patients with decreased monokine production were younger, with a mild histological grade, and likely to respond to the interferon therapy.

LPS-induced release of EGF, GM-CSF, GRO alpha, LIF, MIP-1 alpha and PDGF-AB in PBMC from persons with high or low levels of HDL lipoprotein

We have examined basal and lipopolysaccharide (LPS)-induced release of epidermal growth factor (EGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), growth-regulated peptide alpha (GRO alpha), leukaemia inhibitory factor (LIF), macrophage inflammatory protein-1a (MIP-1 alpha) and platelet-derived growth factor-AB (PDGF-AB) in peripheral blood mononuclear cells (PBMC) from 20 persons with either high (n = 10) or low (n = 10) levels of high-density lipoprotein (HDL). PBMC were incubated with 100 ng LPS/ml for up to 160 h, and showed a significantly higher release of the chemokines GRO alpha (P = 0.04) and MIP-1 alpha (P < 0.01) in persons with high HDL, whereas levels of GM-CSF were similar. Levels of EGF, LIF and PDGF-AB were always low, and remained unaltered during 160 h of incubation. These findings indicate that PBMC from persons with high or low levels of HDL have different functional properties, of importance in cell recruitment and activation.

Immunocytochemical localization of the chemokines RANTES and MIP-1 alpha within human platelets and their release during storage

The cytokines RANTES and MIP-1 alpha are 8-kD peptides which belong to the C-C subfamily of chemokines. They are both potent chemotactic factors for basophils and eosinophils. Apart from lymphocytes, the RANTES peptides was recently shown to be released from human platelets stimulated with thrombin [Kameyoshi et al: J Exp Med 1992;176:587-592]. Employing postembedding immunocytochemistry, we could detect RANTES and for the first time also MIP-1 alpha within the alpha-granules of human platelets. To date, MIP-1 alpha was not reported to occur in platelets. In slightly activated platelets, as found in stored platelet concentrates (PC), label for RANTES and MIP-1 alpha could also be observed within cisterns of the open canalicular system and on the plasma membrane, indicating a release of both peptides. These findings were confirmed by in vitro studies in PC, by investigation of RANTES and MIP-1 alpha release into the suspending medium. Over a period of 8 days, RANTES was steadily released in relatively high amounts, whereas MIP-1 alpha was measured in rather small amounts in the suspending medium. As RANTES and MIP-1 alpha, besides their chemotactic activity on eosinophils and basophils, are able to mediate the release of histamine, it is tempting to speculate about a participation of platelets in inflammatory reactions in which eosinophils and basophils are involved.

Serum concentrations of MIP-1 alpha and interleukin-8 in patients suffering from acute Plasmodium falciparum malaria

The chemokines are a superfamily of small proteins secreted primarily by leukocytes and related by a conserved four-cystein motif. In the present study we investigated the serum levels of macrophage inflammatory protein 1 alpha (MIP-1 alpha) and interleukin-8 (IL-8). MIP-1 alpha is a neutrophil chemotactic protein important in acute and chronic inflammation. Recent studies demonstrated that MIP-1 alpha may also act as potent inhibitor of hemopoetic stem cell proliferation, which may be important in the development of prolonged anemia in patients suffering from Plasmodium falciparum malaria. IL-8 serum concentrations correlate with severity and outcome of infectious diseases. Moreover, recent reports indicate that IL-8 plays a major role in fatal gram-negative sepsis. It was the aim of this study to investigate the time course of MIP-1 alpha and IL-8 concentrations in patients suffering from acute P. falciparum infection. Blood samples of 20 patients suffering from severe P. falciparum malaria were investigated. MIP-1 alpha and IL-8 concentrations were determined using ELISA technique at admission, on Days 7, 14, 21, and 28. Maximal concentrations of MIP-1 alpha and IL-8 were found on Day 14, at a time when parasites were not detected in the smears. The serum levels of IL-8 on the day of admission were correlated to the parasite count. No correlation was seen between the hematokrit values and the MIP-1 alpha concentrations at any time.

A system for assessment of monokine gene expression using human whole blood

Monocyte derived cytokines (monokines) are important mediators in inflammatory diseases and cancer. Control of monokine expression is also a major therapeutic target in autoimmune inflammation. Whole blood cultures permit examination of monokine expression under conditions which emulate the in-vivo environment whilst avoiding many of the artefacts associated with monocyte separation and culture. Here we describe a system for measuring interleukin-1 beta, interleukin-1 alpha, interleukin-6 and tumour necrosis factor-alpha mRNA in stimulated human whole blood ex-vivo, which can be applied to specimens from treated patients. Oligodeoxyribonucleotide probes are designed to allow standardisation of hybridisation and washing procedures. Washing and reprobing of membranes in appropriate sequence permits measurement of each monokine mRNA and mRNA for glyceraldehyde-3-phosphate dehydrogenase in only 7 ml of lipopolysaccharide-stimulated human blood. The method has been used successfully in studies of dexamethasone and methotrexate action on lipopolysaccharide stimulated IL-beta gene expression.

CT-1501R selectively inhibits induced inflammatory monokines in human whole blood ex vivo

The effect of (R)-1-(5-hydroxyhexyl)-3,7-dimethylxanthine (CT-1501R; the nonproprietary name for CT-1501R approved by the United States Name Council is lisofylline), an inhibitor of second messenger signaling through phosphatidic acid, on release of endogenous mediators important in the systemic inflammatory response syndrome (SIRS) was studied using the human whole blood ex vivo assay system. Human blood was stimulated with various endotoxin preparations, zymosan, or protein A, and the levels of secreted monokines were measured by enzyme-linked immunosorbent assay. CT-1501R inhibited tumor necrosis factor alpha (TNF-alpha), interleukin 1 beta (IL-1 beta), and IL-6 release in a dose-dependent manner and was active with all stimuli tested including Salmonella and Escherichia coli-derived endotoxin, endotoxin from both rough and smooth E. coli strains, as well as zymosan and protein A. CT-1501R inhibited monokine release by approximately 50% at 200 microM and 30% at 50 microM and was independent of the relative potency of stimulus. CT-1501R also inhibited IL-1 alpha or IL-1 beta induction of either TNF-alpha or IL-1 beta and inhibited the synergistic effects of stimulation with both human IL-1 beta and murine TNF-alpha on release of human TNF-alpha. Inhibition of monokine release following stimulation with monokine(s) was, in general, greater than that achieved with lipopolysaccharide (LPS) stimulation. Northern blot analysis showed decreased mRNA accumulation of TNF-alpha and IL-1 beta in CT-1501R-treated samples following LPS stimulation suggesting that CT-1501R acts at least in part, at the pretranslational level. In contrast, CT-1501R does not inhibit LPS-stimulated IL-8 or IL-1 receptor antagonist (IL-1ra) release in human whole blood or IL-1 alpha-induced release of PGE2 in human foreskin fibroblast cells. These data suggest that CT-1501R may be of use for clinical intervention in SIRS.

Biomaterial-induced macrophage activation and monokine release

This study quantifies macrophage acid phosphatase release as a marker of cell activation when cultured with or without biomaterials. Peritoneal macrophages were harvested from six New Zealand White rabbits and cultured in minimum essential media with 10% equine serum. After cell identification by morphology, nonspecific esterase, and RAM 11 immunoperoxidase, cells were passaged twice, and second-passage macrophages were seeded in 96-well plates (5,000 cells/well) and grown to confluence. After collection of day zero media, circular disks of polyglactin 910 and two types of commercially available polyethylene terephthalate with different construction and sterilization characteristics were placed on the cell monolayer. Controls without biomaterials were also established. Media was collected and pooled for each group and time point beginning on day 2 and continuing every other day for 22 days. Conditioned media were quantitatively assayed for acid phosphatase colorimetrically at 402 nm using p-nitrophenylphosphate as the substrate. Acid phosphatase activity increased progressively at late time points for each group but no difference was noted between groups at any time point. These data show that the activation of cultured macrophages with time is not altered differentially by the presence of biomaterials. The previously demonstrated monokine release following biomaterial exposure is therefore a specific event and not simply part of the generalized activation phenomenon.

Intraoperative cytokines production during orthotopic liver transplantation

In summary, we established that a significant production of the monokines interleukin-6, tumor necrosis factor apha, and interleukin-1 occurred during orthotopic liver transplantation whereas the lymphokines interferon gamma and interleukin-2 were not detected. Levels of interleukin-6 reached their maximum values before and especially at the end of the anhepatic phase. They remained high after the anhepatic phase, i. e. after reperfusion of the new livers. Tumor necrosis factor alpha and interleukin-1 reached their maximum values after the anhepatic phase. Not only were interleukin-6, tumor necrosis factor alpha, and interleukin-1 present in the serum but they could also be detected in the bile produced by these new livers. Mechanisms of monokine production during orthotopic liver transplantation is multifactorial in origin and further studies will have to evaluate the relative contribution of the various factors involved. The possibility of an association between peroperative monokines and transplant outcome and their potential clinical implication will have to be elucidated.

Phase I study of liposomal MTP-PE-activated autologous monocytes administered intraperitoneally to patients with peritoneal carcinomatosis

We have conducted a phase I study with autologous monocytes activated ex vivo and administered intraperitoneally in nine patients with peritoneal carcinomatosis. Blood monocytes were collected by leukapheresis and then purified by counterflow elutriation (up to 10(9) cells, with a purity of greater than 90%). Ex vivo activation was obtained by incubating these cells with 1 micrograms liposomal MTP-PE/10(6) monocytes for 18 hours in hydrophobic culture bags at 37 degrees C in 5% carbon dioxide humidified air. The activated monocytes were then infused in the peritoneal cavity once a week for 5 consecutive weeks through an implanted peritoneal infusion system, Port-A-Cath (Pharmacia Deltec, St Paul, MN), on an intrapatient dose-escalating schedule (10(7) to 10(9) monocytes). No severe adverse reactions occurred. Toxicity was mild, the chief acute reactions being fever (27%), chills (13%), and abdominal pain (25%). None of the side effects led to dose reduction. No consistent change in hemostatic function, liver function, or renal function was observed. Significant increases in granulocyte counts, neopterine, and acute phase reactants (fibrinogen, C-reactive protein) occurred in the peripheral blood. In vitro monocyte activation was demonstrated by the relapse of procoagulant activity and monokines (interleukin-1 [IL-1], IL-6, and tumor necrosis factor-alpha [TNF alpha]) in the supernatants of cultured monocytes. Evidence for in vivo monocyte activation was provided by the increase of these monokines in the peritoneal fluids. Kinetic studies with indium-111 (111In)-labeled activated autologous monocytes in five patients suggest that these infused monocytes may remain in the peritoneal cavity for up to 7 days. This locoregional immunotherapeutic approach seems to be encouraging in view of adjuvant therapeutic modality in ovarian cancer patients with minimal residual intraabdominal disease following second-look laparotomy.