Role of interleukin-6 in a non-septic shock model induced by zymosan.

In the present study, we used IL-6 knock-out mice (IL-6KO) to evaluate a possible role of IL-6 in the pathogenesis of non-septic shock induced by peritoneal injection of zymosan. A severe inflammatory response characterized by peritoneal exudation, high peritoneal levels of nitrate/nitrite, and leukocyte infiltration into peritoneal exudate was induced by zymosan administration in wild-type control (WT) mice. This inflammatory process coincided with the damage to the lung and small intestine, as assessed by histological examination. Lung, small intestine and liver myeloperoxidase (MPO) activity, indicative of neutrophil infiltration and lipid peroxidation, were significantly increased in zymosan-treated WT mice. Peritoneal administration of zymosan in the WT mice also induced a significant increase in the plasma levels of nitrite/nitrate and in the levels of peroxynitrite, 18 hours after zymosan challenge. Immunohistochemical examination demonstrated a marked increase in the immunoreactivity to nitrotyrosine in the lung of zymosan-treated WT mice. Zymosan-treated IL-6KO showed significantly decreased mortality and inhibition of the development of peritonitis. In addition, IL-6KO mice showed significant protection from the development of organ failure, since tissue injury and MPO was reduced in the lung, small intestine and liver. Furthermore, a significant reduction of suppression of mitochondrial respiration, DNA strand breakage and reduction of cellular levels of NAD+ was observed in ex vivo macrophages harvested from the peritoneal cavity of IL-6KO mice subjected to zymosan-induced non-septic shock. In vivo treatment with anti-IL-6 (5,000 ng/day per mouse, 24 and 1 hour before zymosan administration) significantly reduced the inflammatory process. Taken together, the present study clearly demonstrates that IL-6 exerts a role in zymosan-induced non-septic shock.     

Role of substance P in hydrogen sulfide-induced pulmonary inflammation in mice

We have shown earlier that H(2)S acts as a mediator of inflammation. In this study, we have investigated the involvement of substance P and neurogenic inflammation in H(2)S-induced lung inflammation. Intraperitoneal administration of NaHS (1-10 mg/kg), an H(2)S donor, to mice caused a significant increase in circulating levels of substance P in a dose-dependent manner. H(2)S alone could also cause lung inflammation, as evidenced by a significant increase in lung myeloperoxidase activity and histological evidence of lung injury. The maximum effect of H(2)S on substance P levels and on lung inflammation was observed 1 h after NaHS administration. At this time, a significant increase in lung levels of TNF-alpha and IL-1beta was also observed. In substance P-deficient mice, the preprotachykinin-A knockout mice, H(2)S did not cause any lung inflammation. Furthermore, pretreatment of mice with CP-96345 (2.5 mg/kg ip), an antagonist of the neurokinin-1 (NK(1)) receptor, protected mice against lung inflammation caused by H(2)S. However, treatment with antagonists of NK(2), NK(3), and CGRP receptors did not have any effect on H(2)S-induced lung inflammation. Depleting neuropeptide from sensory neurons by capsaicin (50 mg/kg sc) significantly reduced the lung inflammation caused by H(2)S. In addition, pretreatment of mice with capsazepine (15 mg/kg sc), an antagonist of the transient receptor potential vanilloid-1, protected mice against H(2)S-induced lung inflammation. These results demonstrate a key role of substance P and neurogenic inflammation in H(2)S-induced lung injury in mice.     

CD36, but not G2A,modulates efferocytosis,inflammation, and fibrosis following bleomycin-induced lung injury

Macrophage G2A and CD36 lipid receptors are thought to mediate efferocytosis following tissue injury and thereby prevent excessive inflammation that could compromise tissue repair. To test this, we subjected mice lacking G2A or CD36 receptor to bleomycin-induced lung injury and measured efferocytosis, inflammation, and fibrosis. Loss of CD36 (but not G2A) delayed clearance of apoptotic alveolar cells (mean 78% increase in apoptotic cells 7 days postinjury), potentiated inflammation (mean 56% increase in lung neutrophils and 75% increase in lung KC levels 7 days postinjury, 51% increase in lung macrophages 14 days postinjury), and reduced lung fibrosis (mean 41% and 29% reduction 14 and 21 days postinjury, respectively). Reduced fibrosis in CD36^−/− mice was associated with lower levels of profibrotic TH2 cytokines (IL-9, IL-13, IL-4), decreased expression of the M2 macrophage marker Arginase-1, and reduced interstitial myofibroblasts. G2A, on the other hand, was required for optimal clearance of apoptotic neutrophils during zymosan-induced peritoneal inflammation (50.3% increase in apoptotic neutrophils and 30.6% increase in total neutrophils 24 h following zymosan administration in G2A^−/− mice). Thus, CD36 is required for timely removal of apoptotic cells in the context of lung injury and modulates subsequent inflammatory and fibrotic processes relevant to fibrotic lung disease.     

Lung injury during LPS-induced inflammation occurs independently of the receptor P2Y<Subscript>1</Subscript>

Disruption of the lung endothelial and epithelial barriers during acute inflammation leads to excessive neutrophil migration. It is likely that activated platelets promote pulmonary recruitment of neutrophils during inflammation, and previous studies have found that anti-platelet therapy and depletion of circulating platelets have lung-protective effects in different models of inflammation. Because ADP signaling is important for platelet activation, I investigated the role of the ADP-receptor P2Y₁, a G protein-coupled receptor expressed on the surface of circulating platelets, during lipopolysaccharide (LPS)-induced inflammation and lung injury in P2Y₁-null and wild-type mice. Systemic inflammation was induced by a single intraperitoneal dose of LPS (3 mg/kg), and the mice were analyzed 24 h posttreatment. The data show that the LPS-induced inflammation levels were comparable in the P2Y₁-null and wild-type mice. Specifically, splenomegaly, counts of circulating platelets and white blood cells (lymphocytes and neutrophils), and assessments of lung injury (tissue architecture and cell infiltration) were similar in the P2Y₁-null and wild-type mice. Based on my results, I conclude that lung injury during LPS-induced inflammation in mice is independent of P2Y₁ signaling. I propose that if a blockade of purinergic signaling in platelets is a potential lung-protective strategy in the treatment of acute inflammation, then it is more likely to be a result of the disruption of the signaling pathway mediated by P2Y₁₂, another G protein-coupled receptor that mediates platelet responses to ADP.     

The effect of cholesterol on macrophage-foam-cell generation upon zymosan-induced inflammation in mice

It has been shown that a significant number (about 40% of the total population) of macrophage-foam cells (MFCs) are formed during the early period (24 h) of zymosan-induced peritonitis resolution. Agonists of peroxisome proliferator-activated receptors α, γ (PPAR-α, γ) exert an anti-inflammatory effect, preventing its formation (Dushkin et al., 2007). The work is devoted to the influence of cholesterol-containing liposomes (CHLs) on the dynamics of zymosan-induced peritonitis in C57Bl/6 mice. Cholesterol accumulation, cytokine production, PPAR-γ activity, and cholesterol efflux in macrophages have been assayed. Infiltration of neutrophils, mononuclears, and increased MFC number in the peritonel cavity of zymosan-induced mice enhanced the inflammation process and MFC resolution period. Macrophages obtained after zymosan injection preferentially accumulated triglycerides (TGs) incorporated into TG, whereas CHLs at zymosan-induced inflammation promoted utilization of the [1-¹⁴C]oleate pool in cholesterol ethers (maximum after 2 days) and reduction of fluorescent NBD-cholesterol efflux from macrophages during the whole inflammation period. Cholesterol efflux after zymosan exposure was inhibited for 1–2 days, restored after 3 days, and enhanced at the fifth day. CHLs stimulated TNF-α and TGF-β1 production but inhibited IL-10 production and PPAR-γ DNA-binding activity in macrophages at early stages of zymosan-induced peritonitis. Thus, accumulation of cholesterol in inflammatory macrophages and MFC generation prolong the resolution of acute inflammation changing the balance of pro- and anti-inflammatory cytokins and inhibiting PPAR-γ activity and cholesterol efflux.     

Effect of Methylguanidine in a Model of Septic Shock Induced by LPS

Septic shock, a severe form of sepsis, is characterized by cardiovascular collapse following microbial invasion of the body. The progressive hypotension, hyporeactivity to vasopressor agents and vascular leak leads to circulatory failure with multiple organ dysfunction and death. Many inflammatory mediators (e.g. TNF-α, IL-1 and IL-6) are involved in the pathogenesis of shock and, among them, nitric oxide (NO). The overproduction of NO during septic shock has been demonstrated to contribute to circulatory failure, myocardial dysfunction, organ injury and multiple organ failure. We have previously demonstrated with in vitro and in vivo studies that methylguanidine (MG), a guanidine compound deriving from protein catabolism, significantly inhibits iNOS activity, TNF-α release and carrageenan-induced acute inflammation in rats. The aim of the present study was to evaluate the possible anti-inflammatory activity of MG in a model of septic shock induced by lipopolysaccharide (LPS) in mice. MG was administered intraperitoneally (i.p.) at the dose of 30 mg/kg 1 h before and at 1 and 6 h after LPS-induced shock. LPS injection (10 mg/kg in 0.9% NaCl; 0.1 ml/mouse; i.p.) in mouse developed a shock syndrome with enhanced NO release and liver, kidney and pancreatic damage 18 h later. NO_x levels, evaluated as nitrite/nitrate serum levels, was significantly reduced in MG-treated rats (78.6%, [Formula: See Text]). Immunohistochemistry revealed, in the lung tissue of LPS-treated group, a positive staining for nitrotyrosine and poly(adenosine diphosphate [ADP] ribose) synthase, both of which were reduced in MG-treated mice. Furthermore, enzymatic evaluation revealed a significant reduction in liver, renal and pancreatic tissue damage and MG treatment also improved significantly the survival rate. This study provides evidence that MG attenuates the degree of inflammation and tissue damage associated with endotoxic shock in mice. The mechanisms of the anti-inflammatory effect of MG is, at least in part, dependent on the inhibition of NO formation.     

CCR2 and CXCR3 agonistic chemokines are differently expressed and regulated in human alveolar epithelial cells type II

Background

In the present study, by comparing the responses in wild-type mice (WT) and mice lacking (KO) the inducible (or type 2) nitric oxide synthase (iNOS), we investigated the role played by iNOS in the development of on the lung injury caused by bleomycin administration. When compared to bleomycin-treated iNOSWT mice, iNOSKO mice, which had received bleomycin, exhibited a reduced degree of the (i) lost of body weight, (ii) mortality rate, (iii) infiltration of the lung with polymorphonuclear neutrophils (MPO activity), (iv) edema formation, (v) histological evidence of lung injury, (vi) lung collagen deposition and (vii) lung Transforming Growth Factor beta1 (TGF-β1) expression.

Methods

Mice subjected to intratracheal administration of bleomycin developed a significant lung injury. Immunohistochemical analysis for nitrotyrosine revealed a positive staining in lungs from bleomycin-treated iNOSWT mice.

Results

The intensity and degree of nitrotyrosine staining was markedly reduced in tissue section from bleomycin-iNOSKO mice. Treatment of iNOSWT mice with of GW274150, a novel, potent and selective inhibitor of iNOS activity (5 mg/kg i.p.) also significantly attenuated all of the above indicators of lung damage and inflammation.

Conclusion

Taken together, our results clearly demonstrate that iNOS plays an important role in the lung injury induced by bleomycin in the mice.     

Effect of methylguanidine in a model of septic shock induced by LPS

Septic shock, a severe form of sepsis, is characterized by cardiovascular collapse following microbial invasion of the body. The progressive hypotension, hyporeactivity to vasopressor agents and vascular leak leads to circulatory failure with multiple organ dysfunction and death. Many inflammatory mediators (e.g. TNF-alpha, IL-1 and IL-6) are involved in the pathogenesis of shock and, among them, nitric oxide (NO). The overproduction of NO during septic shock has been demonstrated to contribute to circulatory failure, myocardial dysfunction, organ injury and multiple organ failure. We have previously demonstrated with in vitro and in vivo studies that methylguanidine (MG), a guanidine compound deriving from protein catabolism, significantly inhibits iNOS activity, TNF-alpha release and carrageenan-induced acute inflammation in rats. The aim of the present study was to evaluate the possible anti-inflammatory activity of MG in a model of septic shock induced by lipopolysaccharide (LPS) in mice. MG was administered intraperitoneally (i.p.) at the dose of 30 mg/kg 1 h before and at 1 and 6 h after LPS-induced shock. LPS injection (10 mg/kg in 0.9% NaCl; 0.1 ml/mouse; i.p.) in mouse developed a shock syndrome with enhanced NO release and liver, kidney and pancreatic damage 18 h later. NOx levels, evaluated as nitrite/nitrate serum levels, was significantly reduced in MG-treated rats (78.6%, p < 0.0001; n = 10). Immunohistochemistry revealed, in the lung tissue of LPS-treated group, a positive staining for nitrotyrosine and poly(adenosine diphosphate [ADP] ribose) synthase, both of which were reduced in MG-treated mice. Furthermore, enzymatic evaluation revealed a significant reduction in liver, renal and pancreatic tissue damage and MG treatment also improved significantly the survival rate. This study provides evidence that MG attenuates the degree of inflammation and tissue damage associated with endotoxic shock in mice. The mechanisms of the anti-inflammatory effect of MG is, at least in part, dependent on the inhibition of NO formation.     

Neurokinin-1 receptor agonists are involved in mediating neutrophil accumulation in the inflamed, but not normal, cutaneous microvasculature: an in vivo study using neurokinin-1 receptor knockout mice

We have used tachykinin neurokinin-1 receptor (NK1 receptor) knockout mice to learn of the link between NK1 receptors and neutrophil accumulation in normal naive skin, as compared with inflamed skin. Intradermal substance P (300 pmol) induced edema formation in wild-type mice, but not in NK1 knockout mice, as expected. However, in contrast to IL-1beta (0.3 pmol), substance P did not induce neutrophil accumulation in wild-type mice. IL-1beta-induced neutrophil accumulation was similar in wild-type and knockout mice, but a significant (p < 0.05) contributory effect of added NK1 agonists, which by themselves have no effect on neutrophil accumulation in normal skin, was observed. The results support the concept that NK1 agonists such as substance P cannot act on their own to mediate neutrophil accumulation in naive skin and provide direct evidence that in inflamed skin, under certain circumstances, the NK1 receptor can play a pivotal role in modulating neutrophil accumulation during the ongoing inflammatory process. We investigated responses to two inflammatory stimuli (carrageenin and zymosan). Neutrophil accumulation was significantly attenuated (p < 0.001) in carrageenin- but not zymosan-induced inflammation in NK1 knockout mice. The carrageenin (500 microg)-induced response was inhibited (p < 0.05) by a NK1 receptor antagonist, SR140333 (480 nmol/kg i.v. at -5 min), in the wild-type group. The bradykinin B1 and B2 receptor antagonists (desArg9[Leu8]bradykinin and HOE 140) each reduced neutrophil accumulation to carrageenin in wild-type animals (p < 0.05), but did not cause further reduction of the suppressed response of knockout mice. The results provide evidence that kinin receptors participate in NK1 receptor-dependent neutrophil accumulation in inflamed mouse skin.     

Adrenalectomy in mice does not prevent loss of intestinal lymphocytes after exercise.

Exhaustive exercise is associated with an increase in circulating glucocorticoids (GCs), lymphocyte apoptosis, and a reduction in intestinal lymphocyte number. The present study examined the role of GCs on the numerical changes seen in intestinal lymphocytes after exercise. Female C57BL/6 mice were bilaterally adrenalectomized (ADX; n = 18) or given sham surgery (Sham; n = 18) and assigned to one of three exercise conditions: treadmill running (28 m/min, 90 min, 2 degrees slope) and killed immediately or after 24 h recovery, or not exercised and killed immediately after 90-min exposure to the treadmill environment. Lymphocytes were isolated from the intestines with CD45(+) cells collected by positive selection using magnetic bead separation columns, and lymphocyte subpopulations were analyzed by flow cytometry for CD45(+), CD3alphabeta(+), CD3gammadelta(+), CD8beta(+), CD8alpha(+), CD4(+), and NK(+) phenotypic markers. ADX mice had significantly more intestinal CD45(+) leukocytes (P < 0.05) and CD3alphabeta(+) (P < 0.05), CD3gammadelta(+) (P < 0.01), CD8alpha(+) (P < 0.001), and NK(+) (P < 0.05) intestinal lymphocytes than Sham mice. There was a significant effect of exercise condition on total intestinal CD45(+) leukocytes (P < 0.01) and CD3alphabeta(+) (P < 0.05), CD8alpha(+) (P < 0.001), and CD4(+) (P < 0.05) intestinal lymphocytes, with fewer cells at 24 h postexercise compared with the other treatment conditions. There were no surgical x exercise interaction effects on the CD3 and CD8 phenotype numbers. Plasma corticosterone was virtually nil in ADX mice regardless of exercise condition but was significantly elevated in Sham mice immediately postexercise (P < 0.001). The data indicate that ADX does not prevent the loss of lymphocytes from the intestinal mucosa 24 h after strenuous exercise and GCs are not directly causal in the leukopenia of exercise.     

Effects of neutrophil elastase inhibitor (ONO-5046) on lung injury after intestinal ischemia-reperfusion.

The underlying mechanisms of lung endothelial injury after intestinal ischemia-reperfusion (I/R) injury are not fully known. Here we investigated the effects of posttreatment with a neutrophil elastase inhibitor (NEI; ONO-5046) on lung injury after intestinal I/R injury in a rat model. Intestinal I/R was produced by 90 min of ischemia followed by either 60 or 240 min of reperfusion. For all experimental groups, the endothelial permeability index increased, neutrophil H(2)O(2) production increased in the pulmonary vasculature blood, neutrophil counts increased in bronchoalveolar lavage fluid (BALF), and the cytokine-induced neutrophil chemoattractant (CINC)-1 and CINC-3 levels were increased in BALF after 240 min (P < 0.01). In rats treated with NEI from 60 min after reperfusion, the lung endothelial permeability index was significantly reduced (P < 0.05), whereas neutrophil H(2)O(2) production in pulmonary vasculature blood and neutrophil count in BALF were significantly suppressed by NEI (P < 0.05 and P < 0.01, respectively). In addition, NEI significantly suppressed the increase of CINC-1 and CINC-3 levels in BALF (P < 0.05). Our study clearly indicates that posttreatment with NEI reduces neutrophil activation in the pulmonary vessels and neutrophil accumulation in the lungs and suggests that ONO-5046, even when administered after the primary intestinal insult, can prevent the progression of lung injury associated with intestinal I/R.     

Protective effect of Hypericum perforatum in zymosan-induced multiple organ dysfunction syndrome: relationship to its inhibitory effect on nitric oxide production and its peroxynitrite scavenging activity.

Hypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Since polyphenolic compounds have high antioxidant potential, we have investigated the effects of H. perforatum extract on the development of multiple organ dysfunction syndrome caused by zymosan (500 mg/kg, administered i.p. as a suspension in saline) in mice. Organ failure and systemic inflammation in rats was assessed 18 h after administration of zymosan and/or H. perforatum extract and monitored for 12 days (for loss of body weight and mortality). Treatment of mice with H. perforatum extract (30 mg/kg i.p., 1 and 6h after zymosan) attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan, pulmonary, intestinal and pancreatic injury, and renal dysfunction as well as the increase in myeloperoxidase in the lung and intestine. Immunohistochemical analysis for inducible nitric oxide synthase (iNOS), nitrotyrosine, and poly(ADP-ribose) (PAR) revealed positive staining in lung and intestine tissues obtained from zymosan-injected mice. The degree of staining for nitrotyrosine, iNOS, and PAR was markedly reduced in tissue sections obtained from zymosan-treated mice, which received H. perforatum extract. In conclusion, this study provides evidence, for the first time, that H. perforatum extract attenuates the degree of zymosan-induced multiple organ dysfunction syndrome in mice.     

P2X7 Receptor Modulates Inflammatory and Functional Pulmonary Changes Induced by Silica

Silicosis is an occupational lung disease, characterized by irreversible and progressive fibrosis. Silica exposure leads to intense lung inflammation, reactive oxygen production, and extracellular ATP (eATP) release by macrophages. The P2X7 purinergic receptor is thought to be an important immunomodulator that responds to eATP in sites of inflammation and tissue damage. The present study investigates the role of P2X7 receptor in a murine model of silicosis. To that end wild-type (C57BL/6) and P2X7 receptor knockout mice received intratracheal injection of saline or silica particles. After 14 days, changes in lung mechanics were determined by the end-inflation occlusion method. Bronchoalveolar lavage and flow cytometry analyzes were performed. Lungs were harvested for histological and immunochemistry analysis of fibers content, inflammatory infiltration, apoptosis, as well as cytokine and oxidative stress expression. Silica particle effects on lung alveolar macrophages and fibroblasts were also evaluated in cell line cultures. Phagocytosis assay was performed in peritoneal macrophages. Silica exposure increased lung mechanical parameters in wild-type but not in P2X7 knockout mice. Inflammatory cell infiltration and collagen deposition in lung parenchyma, apoptosis, TGF-β and NF-κB activation, as well as nitric oxide, reactive oxygen species (ROS) and IL-1β secretion were higher in wild-type than knockout silica-exposed mice. In vitro studies suggested that P2X7 receptor participates in silica particle phagocytosis, IL-1β secretion, as well as reactive oxygen species and nitric oxide production. In conclusion, our data showed a significant role for P2X7 receptor in silica-induced lung changes, modulating lung inflammatory, fibrotic, and functional changes.     

TLR2 modulates inflammation in zymosan-induced arthritis in mice

The interplay between the innate and acquired immune systems in chronic inflammation is not well documented. We have investigated the mechanisms of inflammation in murine zymosan-induced arthritis (ZIA) in the light of recent data on the roles of Toll-like receptor 2 (TLR2) and Dectin-1 in the activation of monocyte/macrophages by zymosan. The severity of inflammation, joint histology, lymphocyte proliferation and antibody production in response to zymosan were analyzed in mice deficient in TLR2 and complement C3, and the effects of Dectin-1 inhibition by laminarin were studied. In comparison with wild-type animals, TLR2-deficient mice showed a significant decrease in the early (day 1) and late phases (day 24) of joint inflammation. C3-deficient mice showed no differences in technetium uptake or histological scoring. TLR2-deficient mice also showed a significant decrease in lymph node cell proliferation in response to zymosan and a lower IgG antibody response to zymosan at day 25 in comparison with wild-type controls, indicating that TLR2 signalling has a role in the development of acquired immune responses to zymosan. Although laminarin, a soluble β-glucan, was able to significantly inhibit zymosan uptake by macrophages in vitro, it had no effect on ZIA in vivo. These results show that ZIA is more prolonged than was originally described and involves both the innate and acquired immune pathways. C3 does not seem to have a major role in this model of joint inflammation.     

Analysis of sphingolipid and prostaglandin synthesis during zymosan-induced inflammation

Sphingosine-1-phosphate (S1P) is generated through phosphorylation of sphingosine by two sphingosine kinases (SPHK-1 and -2). As extra- and intracellular messenger S1P fulfils multiple roles in inflammation such as mediating proinflammatory inputs or acting as chemoattractant. In addition, S1P induces cyclooxygenase-2 (COX-2) expression and the synthesis of proinflammatory prostanoids in several cell types. Here, we analysed in vivo the regulation of S1P level as well as potential interactions between S1P and COX-dependent prostaglandin synthesis during zymosan-induced inflammation. S1P and prostanoid levels were determined in the blood and at the site of inflammation under basal conditions and during zymosan-induced inflammation using wild type and SPHK-1 and -2 knockout mice. We found that alterations in S1P levels did not correlate with changes in plasma- or tissue-concentrations of the prostanoids as well as COX-2 expression. In the inflamed tissue S1P and prostanoid concentrations were reciprocally regulated. Prostaglandin levels increased over 6h, while S1P and sphingosine level decreased during the same time, which makes an induction of prostanoid synthesis by S1P in zymosan-induced inflammation unlikely. Additionally, despite altered S1P levels wild type and SPHK knockout mice showed similar behavioural nociceptive responses and oedema sizes suggesting minor functions of S1P in this inflammatory model.     

IL-10 deficiency augments acute lung but not liver injury in hemorrhagic shock

In hemorrhagic shock and trauma, patients are prone to develop systemic inflammation with remote organ dysfunction, which is thought to be caused by pro-inflammatory mediators. This study investigates the role of the immuno-modulatory cytokine IL-10 in the development of organ dysfunction following hemorrhagic shock. Male C57/BL6 and IL-10 KO mice were subjected to volume controlled hemorrhagic shock for 3 h followed by resuscitation. Animals were either sacrificed 3 or 24 h after resuscitation. To assess systemic inflammation, serum IL-6, IL-10, KC, and MCP-1 concentrations were measured with the Luminex? multiplexing platform; acute lung injury (ALI) was assessed by pulmonary myeloperoxidase (MPO) activity and lung histology and acute liver injury was assessed by hepatic MPO activity, hepatic IL-6 levels, and serum ALT levels. There was a trend towards increased IL-6 and KC serum levels 3 h after resuscitation in IL-10 KO as compared to C57/BL6 mice; however this did not reach statistical significance. Serum MCP-1 levels were significantly increased in IL-10 KO mice 3 and 24 h following resuscitation as compared to C57/BL6 mice. In IL-10 KO mice, pulmonary MPO activity was significantly increased 3 h following resuscitation and after 24 h histological signs of acute lung injury were more apparent than in C57/BL6 mice. In contrast, no significant differences in any liver parameters were detected between IL-10 KO and C57/BL6 mice. Our data indicate that an endogenous IL-10 deficiency augments acute lung but not liver injury following hemorrhagic shock.     

Dyospiros kaki phenolics inhibit colitis and colon cancer cell proliferation,but not gelatinase activities

Polyphenols from persimmon (Diospyros kaki) have demonstrated radical-scavenging and antiinflammatory activities; however, little is known about the effects of persimmon phenolics on inflammatory bowel diseases (IBD) and colorectal cancer (CRC). Therefore, we aimed in this work to characterize the antiinflammatory and antiproliferative effects of a persimmon phenolic extract (80% acetone in water), using an in vivo model of experimental colitis and a model of cancer cell invasion. Our results show, for the first time, a beneficial effect of a persimmon phenolic extract in the attenuation of experimental colitis and a potential antiproliferative effect on cultured colon cancer cells. Administration of persimmon phenolic extract to mice with TNBS-induced colitis led to a reduction in several functional and histological markers of colon inflammation, namely: attenuation of colon length decrease, reduction of the extent of visible injury (ulcer formation), decrease in diarrhea severity, reduced mortality rate, reduction of mucosal hemorrhage and reduction of general histological features of colon inflammation. In vitro studies also showed that persimmon phenolic extract successfully impaired cell proliferation and invasion in HT-29 cells. Further investigation showed a decreased expression of COX-2 and iNOS in the colonic tissue of colitis mice, two important mediators of intestinal inflammation, but there was no inhibition of the gelatinase MMP-9 and MMP-2 activities. Given the role of inflammatory processes in the progression of CRC and the important link between inflammation and cancer, our results highlight the potential of persimmon polyphenols as a pharmacological tool in the treatment of patients with IBD.     

Extended high-frequency partial liquid ventilation in lung injury: gas exchange, injury quantification, and vapor loss.

High-frequency oscillatory ventilation with perflubron (PFB) reportedly improves pulmonary mechanics and gas exchange and attenuates lung injury. We explored PFB evaporative loss kinetics, intrapulmonary PFB distribution, and dosing strategies during 15 h of high-frequency oscillation (HFO)-partial liquid ventilation (PLV). After saline lavage lung injury, 15 swine were rescued with high-frequency oscillatory ventilation (n = 5), or in addition received 10 ml/kg PFB delivered to dependent lung [n = 5, PLV-compartmented (PLV(C))] or 10 ml/kg distributed uniformly within the lung [n = 5, PLV(U)]. In the PLV(C) group, PFB vapor loss was replaced. ANOVA revealed an unsustained improvement in oxygenation index in the PLV(U) group (P = 0.04); the reduction in oxygenation index correlated with PFB losses. Although tissue myeloperoxidase activity was reduced globally by HFO-PLV (P < 0.01) and regional lung injury scores (lung injury scores) in dependent lung were improved (P = 0.05), global lung injury scores were improved by HFO-PLV (P < 0.05) only in atelectasis, edema, and alveolar distension but not in cumulative score. In our model, markers of inflammation and lung injury were attenuated by HFO-PLV, and it appears that uniform intrapulmonary PFB distribution optimized gas exchange during HFO-PLV; additionally, monitoring PFB evaporative loss appears necessary to stabilize intrapulmonary PFB volume.     

MG53 attenuates nitrogen mustard‐induced acute lung injury

Nitrogen mustard (NM) is an alkylating vesicant that causes severe pulmonary injury. Currently, there are no effective means to counteract vesicant‐induced lung injury. MG53 is a vital component of cell membrane repair and lung protection. Here, we show that mice with ablation of MG53 are more susceptible to NM‐induced lung injury than the wild‐type mice. Treatment of wild‐type mice with exogenous recombinant human MG53 (rhMG53) protein ameliorates NM‐induced lung injury by restoring arterial blood oxygen level, by improving dynamic lung compliance and by reducing airway resistance. Exposure of lung epithelial and endothelial cells to NM leads to intracellular oxidative stress that compromises the intrinsic cell membrane repair function of MG53. Exogenous rhMG53 protein applied to the culture medium protects lung epithelial and endothelial cells from NM‐induced membrane injury and oxidative stress, and enhances survival of the cells. Additionally, we show that loss of MG53 leads to increased vulnerability of macrophages to vesicant‐induced cell death. Overall, these findings support the therapeutic potential of rhMG53 to counteract vesicant‐induced lung injury.