Macrophage Inflammatory Protein-2 Levels Research Articles

Effects of Surfactant Protein‐A on the Interaction of Pneumocystis murina with its Host at Different Stages of the Infection in Mice

We examined the effects of surfactant protein A (SP-A), a collectin, on the interaction of Pneumocystis murina with its host at the beginning, early to middle, and late stages of infection. Pneumocystis murina from SP-A wild-type (WT) mice inoculated intractracheally into WT mice (WT(S)-WT(R)) adhered well to alveolar macrophages, whereas organisms from SP-A knockout (KO) mice inoculated into KO mice (KO(S)-KO(R)) did not. Substitution of WT mice as the source of organisms (WT(S)-KO(R)) or recipient host macrophages (KO(S)-WT(R)) restored adherence to that found with WT(S)-WT(R) mice. In contrast, when immunosuppressed KO and WT mice were inoculated with P. murina from a homologous source (KO(S)-KO(R), WT(S)-WT(R)) or heterologous source (WT(S)-KO(R), KO(S)-WT(R)) and followed sequentially, WT(S)-KO(R) mice had the highest levels of infection at weeks 3 and 4; these mice also had the highest levels of the chemokine macrophage inflammatory protein-2 and neutrophils in lavage fluid at week 3. Surfactant protein-A administered to immunosuppressed KO(S)-KO(R) mice with Pneumocystis pneumonia for 8 wk as a therapeutic agent failed to lower the organism burden. We conclude that SP-A can correct the host immune defect in the beginning of P. murina infection, but not in the middle or late stages of the infection.

Role of extracellular signal-regulated protein kinase (ERK) in 17β-estradiol-mediated attenuation of lung injury after trauma-hemorrhage

Extracellular signal-regulated protein kinase (ERK) is known to be involved in pro-inflammatory and chemotactic events in response to injury. The aim of this study is to elucidate whether ERK plays any role in 17beta-estradiol (E2)-mediated attenuation of lung injury and pro-inflammatory mediators after trauma-hemorrhage. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure approximately 40 mm Hg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle (cyclodextrin), E2 (1 mg/kg body weight [BW]), or the ERK inhibitor PD98059 (2 mg/kg BW). At 2 h after sham operation or trauma-hemorrhage, various parameters were measured. Trauma-hemorrhage led to a significant increase in lung ERK phosphorylation, which was associated with increased lung myeloperoxidase activity, wet-to-dry weight ratio, interleukin (IL)-6, tumor necrosis factor (TNF)-alpha, intercellular adhesion molecule (ICAM)-1, cytokine-induced neutrophil chemoattractant (CINC)-1, and macrophage inflammatory protein-2 levels. Circulatory IL-6, TNF-alpha, and lactate levels were also increased after trauma-hemorrhage compared with shams. Administration of E2 or ERK inhibitor PD98059 after trauma-hemorrhage attenuated the trauma-hemorrhage-induced increase in lung injury markers, ERK phosphorylation and cytokines/chemokines, ICAM-1 production, as well as circulatory cytokines and lactate levels. These results collectively suggest that the salutary effects of E2 on the lung after trauma-hemorrhage are mediated via an ERK pathway and subsequent downregulation of pro-inflammatory mediator production.

Abstract 559: Elevated Level of sCD40L During Acute Coronary Syndrome Leads to Systemic MIP-2 Release

Purpose: Acute coronary syndromes (ACS) have been associated with sCD40 Ligand (sCD40L) release. Endothial cells are located at the interface between the blood and parenchymal cells and take active part in many physiological and pathologic processes, including inflammation. It has been suggested that CD40L is a key player in the pathogenesis of atherosclerosis and ACS, originating from endothelial cells. When sCD40L is present in human plasma during ACS, it is mainly derived from activated platelets. This may lead to activation of endothelial cells resulting in atherosclerosis and eventually atherothrombosis. Therefore, the aim of the present study was to investigate differential gene expression profiles of endothelial cells after stimulation with sCD40L. Methods: Human endothelial cells (HUVEC) were stimulated with sCD40L for 2 hours. Differential gene expression patterns were evaluated with Oligonucleotide microarray hybridization (UG-U133A, Affymetrix Inc, Santa Clara, CA). Significantly up-regulated gene expression was confirmed and quantitated by Real-time-PCR as well as ELISA. In serum from ACS patients expression of sCD40L was correlated with these up-regulated genes products. Results: Stimulation of HUVEC with sCD40L leads to a profound release of proinflammatory mediators like IL-8, ICAM1, ISGF3 as well as MCP-1 on a transcriptional level. In addition, gene expression profiling revealed a highly significant increase in expression of the macrophage inflammatory protein 2 (MIP-2), also known as GRO-beta or CXCL2. This was quantitated as approximately 30 fold up-regulation by real-time-PCR as well as in ELISA analysis (8 fold at 8 to 24 hours) derived from supernations. In clinical serum samples from ACS patients there was a highly significant correlation between sCD40L and MIP-2 levels (r = 0.88, p < 0.01) Conclusion: Proinflammatory mediators as well as MIP-2 play an important role in the chemoattraction of macrophages, which underlines the key role of CD40L as a link between thrombotic events, e.g ACS, and inflammatory processes, e.g. atherosclerosis. Therefore targeting MIP-2 up-regulation might be a potential approach to prevent the progression of atherosclerotic diseases as well as a new therapeutic approach to treat ACS.

Effects of parenteral structured lipid emulsion on modulating the inflammatory response in rats undergoing a total gastrectomy

Objectives Structured lipid emulsion improves the nitrogen balance and is rapidly cleared from the blood of moderately catabolic patients. However, the effects of structured lipids on inflammatory reactions during major surgery are not clear. This study investigated the effect of a parenteral structured triacylglycerol emulsion on leukocyte adhesion molecule expression and inflammatory mediator production in rats undergoing a total gastrectomy. Methods Normal rats with internal jugular catheters were assigned to three experimental groups and received total parenteral nutrition. At the same time, a total gastrectomy was performed on the experimental groups. The total parenteral nutrition solutions were isonitrogenous and identical in nutrient compositions except for differences in the composition of the fat emulsion. Group 1 received a conventional fat emulsion with long-chain triacylglycerols (LCTs), group 2 received a physical mixture of medium-chain triacylglycerols (MCTs) and LCTs (MCT/LCT), and group 3 received structured lipids composed of MCTs and LCTs (STG). Half of the rats in each respective group were sacrificed 1 d and the other half 3 d after surgery to examine the analytical parameters. Results Plasma cholesterol and free fatty acid levels in the STG group were lower than those in the other groups after surgery. The STG group had lower leukocyte CD11a/CD18 expressions than the MCT/LCT group 3 d after surgery, and CD11b/CD18 expressions in the STG group were lower than those in the LCT group on postoperative days. The STG group had higher monocyte chemotactic protein-1 and macrophage inflammatory protein-2 levels in peritoneal lavage fluid than did the other two groups. Conclusion These results suggest that, compared with the LCT and MCT/LCT groups, rats administered STG had lower plasma lipid concentrations and leukocyte integrin expressions. In addition, STG administration may cause increased recruiting of neutrophils and monocytes at the site of injury and enhance antipathogenicity in rats undergoing a total gastrectomy.

Thrombin enhances the production of monocyte chemoattractant protein-1 and macrophage inflammatory protein-2 in cultured rat glomerular epithelial cells

Glomerular crescents play an important role in progressive glomerular injury. The lesions consist of epithelial cells, macrophages and deposits of fibrin and extracellular matrix. Monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) are members of chemokine subfamilies. MCP-1 and MIP-2 are potent chemoattractant leukocyte cytokines, and they may be involved in crescent formation. Thrombin participates in fibrin formation. We hypothesized that thrombin stimulates the production of MCP-1 and MIP-2 by glomerular epithelial cells (GECs). Cultured rat GECs from the 19th to the 24th passage were used. We incubated GECs with or without thrombin to examine the effect of thrombin on the production of MCP-1 and MIP-2. The levels of MCP-1 and MIP-2 were measured in the cell supernatants by enzyme-linked immunosorbent assay (ELISA). The mRNA expressions of MCP-1 and MIP-2 were analysed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). We also examined the inhibitory effect of argatroban, a synthetic thrombin inhibitor, and prednisolone in the production of MCP-1 and MIP-2 stimulated by thrombin. Thrombin stimulated the production of MCP-1 and MIP-2 in a dose- and time-dependent manner. Thrombin also enhanced the mRNA expressions of MCP-1 and MIP-2 in the GECs. The stimulating effect of thrombin on the production of MCP-1 and MIP-2 was inhibited by the addition of argatroban or prednisolone. We demonstrated a novel role of thrombin: it stimulates the production of MCP-1 and MIP-2 by GECs. It is clinically important that the inhibition of these chemokines leads to the improvement of crescentic glomerulonephritis. Anti-thrombin drugs and prednisolone may be useful in treating crescentic glomerulonephritis.

Apolipoprotein E –/– mice have delayed skeletal muscle healing after hind limb ischemia–reperfusion

Classic studies of limb ischemia-reperfusion injury have been performed using young healthy mice. However, patients with peripheral vascular disease are older and often exhibit metabolic derangements that may delay healing after revascularization. Mice with genetic deletion of apolipoprotein E (ApoE(-/-)) have been used as a model in various experimental scenarios of hypercholesterolemia. These experiments evaluated the inflammatory response and changes in skeletal muscle morphology during the acute and chronic phases of limb ischemia-reperfusion injury in aged ApoE(-/-) mice. Age-matched ApoE(-/-) and wild-type (Wt) mice underwent 1.5 hours of unilateral hind limb ischemia, followed by 1, 7, or 14 days of reperfusion (DR). Histologic analysis of skeletal muscle fiber injury was assessed at 1DR. Morphologic evidence of muscular fiber maturation was assessed at 14DR. Levels of MyoD and myogenin, markers of skeletal muscle differentiation, were assessed at 7 and 14DR using Western blots. Markers of inflammation, including myeloperoxidase, macrophage inflammatory protein-2 (MIP-2), monocyte chemotactic protein-1 (MCP-1), and osteopontin, were assayed using enzyme-linked immunosorbent assay and chemokine (C-C motif) receptor 2 (CCR2) using Western blots at 1, 7, and 14DR. After 1DR, tissue adenosine 5'-triphosphate (ATP) levels were measured to assess metabolic activity. Unpaired t test and Mann-Whitney test were used for comparisons. Histologic evaluation of skeletal muscle after 1DR showed no difference in the degree of injury between Wt and ApoE(-/-) mice. However, at 14DR, ApoE(-/-) mice had higher percentage of immature muscle fibers than Wt mice. Myogenin level was lower in the ApoE(-/-) mice at 7DR. Injured skeletal muscle of ApoE(-/-) mice had lower levels of myeloperoxidase than Wt mice at 7 DR and higher levels of MCP-1 at 14DR. There was no difference in the levels of tissue ATP, MIP-2, osteopontin, or CCR2 at all experimental intervals. Although there was no difference between the injured muscle of Wt and ApoE(-/-) mice during the acute phase of reperfusion, ApoE(-/-) mice showed delay in skeletal muscle healing during the chronic phase of reperfusion. This lag in muscle regeneration was associated with lower levels of myogenin at 7DR and an increased level of MCP-1 at 14DR in the ApoE(-/-) mice. The delay in skeletal muscle healing in the ApoE(-/-) mice may have broader implications for poor tissue healing and functional recovery in elderly patients who have vascular risk factors such as hypercholesterolemia.

Inhaled levosimendan reduces mortality and release of proinflammatory mediators in a rat model of experimental ventilator-induced lung injury*

Mechanical ventilation during critical care can cause structural and functional disturbances in the lung with subsequent release of proinflammatory mediators, termed ventilator-induced lung injury (VILI). VILI progressively provokes decreased efficiency of gas exchange with subsequent hypoxic pulmonary vasoconstriction leading to cardiopulmonary alterations, such as pulmonary hypertension and right heart failure. We therefore aimed to evaluate whether inhalation therapy with levosimendan, a calcium-sensitizer with pulmonary vasodilating properties, could attenuate VILI and improve short-term survival in a rat experimental model. Experimental animal model. University hospital. Forty male Sprague-Dawley rats. Rats were randomly treated as follows (n = 8, each group): 1) inhalation of the solvent only before induction of VILI, no further intervention; 2) inhalation of 240 microg of levosimendan before VILI induction; 3) inhalation of 24 microg of levosimendan before VILI induction; 4) intravenous administration of 24 microg/kg levosimendan before VILI induction; 5) control group with surgical preparation only. All groups were observed for 4 hrs. After 4 hrs following induction of VILI, levels of interleukin-1beta and macrophage inflammatory protein-2 in plasma and bronchoalveolar lavage fluid were analyzed by enzyme-linked immunosorbent assay. Nitric oxide release from alveolar macrophages was measured by Griess assay. Content of matrix metalloproteinase-2 and matrix metalloproteinase-9 in bronchoalveolar lavage fluid was analyzed by gelatin zymography. Inhalation of 240 microg of levosimendan significantly improved survival after 4 hrs and mean arterial blood pressure compared with VILI only. Additionally, inhalation of 240 microg and infusion of 24 microg/kg levosimendan significantly reduced the release of interleukin-1beta, the nitric oxide release from alveolar macrophages, macrophage inflammatory protein-2 in plasma, and the macrophage inflammatory protein-2 and matrix metalloproteinase-9 content in bronchoalveolar lavage fluid compared with VILI only. Our study demonstrates that prophylactic inhalation of 240 microg of levosimendan improves survival and reduces release of inflammatory mediators in our experimental model of VILI. This might affect the clinical prophylaxis and treatment of VILI.

Angiotensin II type 2 receptor antagonist reduces bleomycin-induced pulmonary fibrosis in mice

BackgroundThe role of angiotensin II type 2 receptor (AT2) in pulmonary fibrosis is unknown. To evaluate the influence of angiotensin II type 1 receptor (AT1) and AT2 antagonists in a mouse model of bleomycin (BLM)-induced pulmonary fibrosis.MethodsWe examined effects of the AT1 antagonist (AT1A) olmesartan medoxomil (olmesartan) and the AT2 antagonist (AT2A) PD-123319 on BLM-induced pulmonary fibrosis, which was evaluated by Ashcroft's pathological scoring and hydroxyproline content of lungs. We also analyzed the cellular composition and cytokine levels in bronchoalveolar lavage fluid (BALF).ResultsWith olmesartan, the lung fibrosis score and hydroxyproline level were significantly reduced, and lymphocyte and neutrophil counts and tumor necrosis factor (TNF)-α levels in BALF were reduced on day 7. On day 14, macrophage and lymphocyte counts in BALF were reduced, accompanied by a reduction in the level of transforming growth factor (TGF)-β1. With PD-123319, the lung fibrosis score and hydroxyproline level were reduced. On day 7, macrophage, lymphocyte, and neutrophil counts in BALF were reduced, accompanied by reductions in TNF-α and monocyte chemoattractant protein (MCP)-1 levels. On day 14, macrophage, lymphocyte, and neutrophil counts in BALF were also reduced, accompanied by a reduction in the level of macrophage inflammatory protein (MIP)-2 level but not TGF-β1.ConclusionBoth AT1 and AT2 are involved in promoting interstitial pneumonia and pulmonary fibrosis via different mechanisms of action.

Short-term exposure to high-pressure ventilation leads to pulmonary biotrauma and systemic inflammation in the rat

Though often lifesaving, mechanical ventilation itself bears the risk of lung damage [ventilator-induced lung injury (VILI)]. The underlying molecular mechanisms have not been fully elucidated, but stress-induced mediators seem to play an important role in biotrauma related to VILI. Our purpose was to evaluate an animal model of VILI that allows the observation of pathophysiologic changes along with parameters of biotrauma. For VILI induction, rats (n=16) were ventilated with a peak airway pressure (pmax) of 45 cm H2O and end-expiratory pressure (PEEP) of 0 for 20 min, followed by an observation time of 4 h. In the control group (n=8) the animals were ventilated with a pmax of 20 cm H2O and PEEP of 4. High-pressure ventilation resulted in an increase in paCO2 and a decrease in paO2 and mean arterial pressure. Only 4 animals out of 16 survived 4 h and VILI lungs showed severe macroscopic and microscopic damage, oedema and neutrophil influx. High-pressure ventilation increased the cytokine levels of macrophage inflammatory protein-2 and IL-1beta in bronchoalveolar lavage and plasma. VILI also induced pulmonary heat shock protein-70 expression and the activity of matrix metalloproteinases. The animal model used enabled us to observe the effect of high-pressure ventilation on mortality, lung damage/function and biotrauma. Thus, by combining barotrauma with biotrauma, this animal model may be suitable for studying therapeutical approaches to VILI.

Gabexate Mesilate Suppresses Influenza Pneumonia in Mice through Inhibition of Cytokines

Gabexate mesilate is a synthetic protease inhibitor that is effective for acute pancreatitis. The effect of gabexate mesilate in influenza pneumonia in mice was investigated by examining the changes in pulmonary inflammatory cytokines and chemokines. Pathological changes in the lungs of treated mice were extremely mild, compared with changes in infected, untreated mice. Intrapulmonary levels of interleukin-6 and macrophage inflammatory protein-2 decreased in treated mice compared with untreated mice, despite similar viral titres in the lungs. Survival terms for treated and untreated groups were similar. These data indicate that gabexate mesilate has beneficial effects on influenza pneumonia, which may be due to the modulation of inflammatory cytokine/chemokine responses.

Enhanced immediate inflammatory response to Streptococcus pneumoniae in the lungs of mice with pulmonary emphysema

Pulmonary emphysema is associated with frequent respiratory infections but little is known about the reasons for this susceptibility to bacterial infection. We previously demonstrated an impaired inflammatory response to Streptococcus pneumoniae in an experimental emphysema mouse model at 24 h, or longer following bacterial inoculation. Toll-like receptors (TLR) have been recognized as regulators in the inflammatory response. We examined the expression of TLR on alveolar macrophages in experimental emphysema mice and evaluated the immediate inflammatory response of the emphysematous lung to streptococcal infection. Elastase was administered once into mice trachea to induce pulmonary emphysema. Three weeks later, expression of TLR-2 and TLR-4 in the BAL cells was examined by immunostaining. Following the intratracheal inoculation of Streptococcus pneumoniae, pro-inflammatory cytokine concentrations were measured in the BAL fluids of the control and emphysema mice. The expression of TLR-2 and TLR-4 was significantly elevated in the alveolar macrophages of emphysema mice. Six hours after infection, neutrophils in the BAL fluid of emphysema mice were significantly increased, and the levels of tumour necrosis factor-alpha, IL-1beta and IL-6 were significantly elevated, compared with the control mice. At 3 h post inoculation, macrophage inflammatory protein-2 levels were significantly elevated. The immediate inflammatory response in the emphysematous lung is significantly enhanced in response to streptococcal infection. This may be partly attributed to the increased expression of TLR in the alveolar macrophages of emphysema mice.

Comparing the protective effects of ciprofloxacin, moxifloxacin and levofloxacin in mice with lipopolysaccharide‐induced acute lung injuries

Ciprofloxacin, moxifloxacin and levofloxacin are recognized immunomodulators. Their effects in acute lung injuries have not been tested. This study compared the immunoprotective effects of these agents in mice with lung injuries induced by LPS by measuring the cytokine profiles in the injured lung and the associated mortality. The development of lung injury and mortality was compared in mice pretreated with either ciprofloxacin, levofloxacin, moxifloxacin or saline (control group) after the intratracheal administration of LPS. BALF and serum were collected at 1, 3 and 6 h to measure the concentrations of tumour necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6, IL-10 and macrophage inflammatory protein-2 (MIP-2) using enzyme-linked immunoassay. Levels of TNF-alpha, IL-1beta and MIP-2 in the BAL of the ciprofloxacin group were significantly lower compared with those of controls (all P < 0.0083) at 3 and 6 h after LPS challenge. There were no significant differences in the levels of these cytokines in the moxifloxacin and levofloxacin groups compared with controls. Overall, the 96-h survival for the mice pretreated with ciprofloxacin, but not for those pretreated with moxifloxacin or levofloxacin, was significantly greater than that of the control animals (P = 0.019). In the setting of LPS-induced lung injuries, ciprofloxacin appears to provide better anti-inflammatory properties and survival benefits than the other fluoroquinolones tested.

Inflammation and ischemia-induced lung angiogenesis

A role for inflammation in modulating the extent of angiogenesis has been shown for a number of organs. The present study was undertaken to evaluate the importance of leukocyte subpopulations for systemic angiogenesis of the lung after left pulmonary artery ligation (LPAL) in a mouse model of chronic pulmonary thromboembolism. Since we (24) previously showed that depletion of neutrophils did not alter the angiogenic outcome, we focused on the effects of dexamethasone pretreatment (general anti-inflammatory) and gadolinium chloride treatment (macrophage inactivator) and studied Rag-1(-/-) mice (T/B lymphocyte deficient). We measured inflammatory cells in bronchoalveolar lavage fluid and lung homogenate macrophage inflammatory protein-2 (MIP-2) and IL-6 protein levels within 24 h after LPAL and systemic blood flow to the lung 14 days after LPAL with labeled microspheres as a measure of angiogenesis. Blood flow to the left lung was significantly reduced after dexamethasone treatment compared with untreated control LPAL mice (66% decrease; P < 0.05) and significantly increased in T/B lymphocyte-deficient mice (88% increase; P < 0.05). Adoptive transfer of splenocytes (T/B lymphocytes) significantly reversed the degree of angiogenesis observed in the Rag-1(-/-) mice back to the level of control LPAL. Average number of lavaged macrophages for each group significantly correlated with average blood flow in the study groups (r(2) = 0.9181; P = 0.01 different from 0). Despite differences in angiogenesis, left lung homogenate MIP-2 and IL-6 did not differ among study groups. We conclude that inflammatory cells modulate the degree of angiogenesis in this lung model where lymphocytes appear to limit the degree of neovascularization, whereas monocytes/macrophages likely promote angiogenesis.

Ursodeoxycholic acid protects concanavalin A-induced mouse liver injury through inhibition of intrahepatic tumor necrosis factor-α and macrophage inflammatory protein-2 production

Ursodeoxycholic acid (UDCA) is widely used for the therapy of liver dysfunction. In this study, we investigated the protective effect of UDCA in concanavalin A-induced mouse liver injury. The treatment with UDCA at oral doses of 50 and 150 mg/kg at 2 h before concanavalin A injection significantly reduced the elevated plasma levels of aminotransferases and the incidence of liver necrosis compared with concanavalin A-injected control group without affecting the concentrations of liver hydrophobic bile acids. UDCA significantly inhibited elevated levels of tumor necrosis factor-α (TNF-α), macrophage inflammatory protein-2 (MIP-2), and interleukin 6 (IL-6) in blood of concanavalin A-injected mice. To clarify the influence of UDCA on production of cytokines, we examined intrahepatic mRNA expressions and the protein levels of TNF-α, MIP-2, interferon-γ (IFN-γ), IL-4, IL-6, and IL-10 at 1 h after concanavalin A injection. The treatment with UDCA significantly decreased the intrahepatic levels of TNF- α and MIP-2, whereas this compound showed no clear effect on IFN-γ, IL-4, IL-6, or IL-10. Furthermore, UDCA significantly decreased myeloperoxidase activity as well as MIP-2 level in the liver and histological examination of liver tissue revealed that intrasinusoidal accumulation of neutrophils was decreased markedly by UDCA. In addition, UDCA significantly inhibited the production of TNF-α and MIP-2 when cultured with nonparenchymal and lymph node cells. In conclusion, these findings suggest that UDCA protects concanavalin A-induced liver injury in mice by inhibiting intrahepatic productions of TNF-α and MIP-2, and the infiltration of neutrophils into the liver.

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

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. 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. 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. 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.

Effect of Laparotomy on Clearance and Cytokine Induction inStaphylococcus aureus–infected Lungs

Staphylococcus aureus is a major pathogen complicating postsurgical care. To test the effect of sterile laparotomy (LAP) on pulmonary clearance of S. aureus in a murine model. Control and LAP mice were infected intranasally with 10(8) cfu of S. aureus. Microbial clearance, pulmonary leukocyte recruitment, and cytokine profiles were compared between the groups. Antibody neutralization or cytokine gene knockout mice were used to evaluate the role of cytokines. Laparotomy resulted in a 10-fold increase in S. aureus lung colony-forming units on Days 2 and 3 postinfection. Both groups cleared the infection by Day 4. No defect in leukocyte recruitment into the lungs was observed in infected LAP animals; however, an increase in the number of Mac-3-positive cells and a significant decrease of cells with high surface expression of Fc-gammaR suggest suboptimal activation of leukocytes in the lungs of infected LAP animals. Infected LAP mice had decreased expression of interferon (IFN)-gamma and increased expression of mRNA for IL-13 in the lungs on Day 1 postinfection and decreased levels of IL-6, keratinocyte-derived chemokine (KC), and macrophage inflammatory protein-2 (MIP-2) in bronchoalveolar lavage at Day 2 postinfection. Neutralization of IFN-gamma mimicked the effect of LAP with impaired clearance on Day 2. Sterile LAP induced temporary deactivation of innate immune responses to pulmonary S. aureus challenge. Impaired microbial clearance was accompanied by altered cytokine expression and suboptimal activation of pulmonary leukocytes. Lack of early IFN-gamma induction in the infected lungs of LAP animals is a likely mechanism contributing to the observed phenotype.

The adenosine A2A receptor agonist CGS 21680 fails to ameliorate the course of dextran sulphate-induced colitis in mice.

In this study we investigated the effect of CGS 21680 (2-p-(2-Carboxyethyl)phenethylamino-5-N-ethylcarboxamidoadenosine hydrochloride), an adenosine A2A receptor agonist, in a model of dextran sulphate sodium (DSS)-induced colitis. NMRI mice were fed 5 % (w/v) DSS, and were treated intraperitoneally with 0.5 mg/kg CGS 21680 or vehicle for 10 days. Changes of bodyweight, colon length, the incidence of rectal bleeding, levels of macrophage inflammatory protein (MIP)-1alpha, MIP-2, interferon gamma, interleukin (IL)-1beta, IL-12 and tumour necrosis factor-alpha from homogenates of colon biopsies, and the release of [3H]acetylcholine (ACh) from longitudinal muscle strip were determined. DSS significantly decreased bodyweight, colon length, and it increased the incidence of rectal bleeding and levels of MIP-1alpha, MIP-2 and IL-1beta compared to DSS-untreated animals. CGS 21680 had no effect on these changes. No change could be observed in release of ACh in DSS-induced colitis with or without CGS 21680. In summary, CGS 21680 is ineffective in ameliorating DSS-induced colitis in mice.

Green Tea Polyphenol Administration Partly Ameliorates Chemotherapy-Induced Side Effects in the Small Intestine of Mice

The chemotherapeutic agent irinotecan (IT) is highly effective against several types of cancer, although its use is limited due to severe intestinal toxicity. The aim of this study was to evaluate inflammatory and oxidative stress-related processes contributing to small intestinal mucosa damage and to determine the extent to which green tea polyphenols could ameliorate the detrimental effects induced by IT. In Expt. 1, mice were challenged intraperitoneally with IT or saline on 2 consecutive days. For time kinetic measurements, the IT-treated mice were killed at 3, 24, 48, 72, and 96 h after the 2nd dose of IT. Three hours after IT administration, the ileum glutathione concentration dropped significantly. Lipid peroxidation and inflammation, as measured by macrophage inflammatory protein-2 content, myeloperoxidase activity, and nuclear factor-κB translocation, were highest between 24 and 48 h after IT treatment. In Expt. 2, green tea polyphenols (1 g/L) were supplied via drinking water for 7 d before and 3 d after treatment with IT. Green tea polyphenols significantly affected the glutathione:glutathione disulfide ratio but not lipid peroxidation, macrophage inflammatory protein-2 levels, myeloperoxidase activity, or nuclear factor-κB activation. Our study reveals that IT administration is associated with oxidative stress and inflammation, both occurring simultaneously to IT-induced mucosal damage. The antioxidative defense is affected soon after IT administration. Green tea polyphenols supplied orally protected against oxidation in our experimental model and could be one approach to reducing the risk of IT-induced side effects in the clinical setting.

Role of mesothelial cell-derived granulocyte colony-stimulating factor in interleukin-17-induced neutrophil accumulation in the peritoneum

Recent studies suggest that peritoneal CD4(+) T lymphocytes may control recruitment of polymorphonuclear leukocytes (PMN) during peritonitis by an interleukin-17 (IL-17)-dependent mechanism. IL-17 and granulocyte colony-stimulating factor (G-CSF) have been proposed to form an axis that regulates PMN transmigration. Here we report on the role of G-CSF released by human peritoneal mesothelial cells (HPMCs) in IL-17A-mediated peritoneal PMN accumulation. In vitro exposure of HPMCs to IL-17A resulted in a time- and dose-dependent release of G-CSF. This effect was related to the induction of G-CSF mRNA and mediated through the nuclear factor-kappaB (NF-kappaB) pathway. The novel observation was that IL-17A-stimulated NF-kappaB activation in HPMCs followed a biphasic profile, with an early induction (45 min), followed by the return to basal levels (90 min), and a delayed induction (3 h). Tumor necrosis factor alpha synergistically amplified IL-17A-induced G-CSF production by enhanced NF-kappaB activation and through stabilization of G-CSF mRNA. Intraperitoneal (i.p.) administration of IL-17A in Balb/c mice resulted in increased local levels of G-CSF and selective PMN accumulation. Administration of anti-G-CSF blocking antibody before IL-17A injection significantly reduced the IL-17A-triggered PMN infiltration. This effect occurred despite increased i.p. levels of PMN-specific chemokines KC and macrophage inflammatory protein-2 seen in animals treated with anti-G-CSF antibody. These data demonstrate that the mesothelium-derived G-CSF plays an important role in IL-17A-induced PMN recruitment into the peritoneum.

Hydroxyethyl Starch, but Not Modified Fluid Gelatin, Affects Inflammatory Response in a Rat Model of Polymicrobial Sepsis with Capillary Leakage

Intravascular volume therapy is crucial in septic patients to improve tissue perfusion and maintain stable hemodynamics. Modified fluid gelatins (MFG) and medium weight hydroxyethyl starches (HES) are the most widely used synthetic colloids. Our aim in this study, performed in septic rats challenged by cecal ligation and puncture (CLP), was to investigate the effects of HES and MFG on pulmonary capillary leakage and to determine whether an antiinflammatory mechanism was involved. Animals were randomly allocated to eight groups: saline control; CLP and saline; CLP and HES (7.5, 15, and 30 mL/kg); CLP and MFG (7.5, 15, and 30 mL/kg). Each group had 20 rats, 10 of which were used for pulmonary capillary leakage and 10 for other measurements. Four hours after CLP, the specified doses of HES or MFG were infused. Six hours after surgery, pulmonary capillary leakage, levels of tumor necrosis factor-alpha, interleukin-1beta, and macrophage inflammatory protein-2, intercellular adhesion molecule-1 mRNA expression, myeloperoxidase activity, lung histological changes, and nuclear factor-kappaB activation were measured. HES and MFG significantly attenuated the increase in capillary leakage in a dose-dependent manner. In addition, HES could decrease tumor necrosis factor-alpha, interleukin-1beta, and macrophage inflammatory protein-2 expression, intercellular adhesion molecule-1 mRNA expression, myeloperoxidase activity, neutrophil infiltration, and nuclear factor-kappaB activation, whereas MFG could not. HES may attenuate capillary leakage by modulating an inflammatory response, whereas an antiinflammatory mechanism was not involved in the effects of MFG on capillary leakage.