Cecal Ligation And Puncture Surgery Research Articles

Effects of ghrelin on pulmonary NOD2 mRNA expression and NF-κB activation when protects against acute lung injury in rats challenged with cecal ligation and puncture

BackgroundMany studies have shown that ghrelin can down-regulate inflammatory cytokine expression via the inhibition of NF-κB activity and therefore, its administration to septic patients is considered beneficial. However, our knowledge of ghrelin's effects on the upstream activators of the NF-κB pathway, such as NOD2, is still limited. This study aimed to investigate the possible involvement of the NOD2 signaling pathway in the anti-inflammatory effects of ghrelin. MethodsTwenty-four male SD rats received cecal ligation and puncture (CLP) or sham operation, followed by infusion of saline or ghrelin. The lungs were harvested 6h after CLP or sham operation and analyzed for lung histopathology, neutrophil infiltration, inflammatory cytokines (TNF-α, and IL-6), NOD2 mRNA expression, and activation of NF-κB. Furthermore, survival was recorded for ten days in additional groups of rats. ResultsCompared with sham group, neutrophil infiltration, TNF-α and IL-6 levels, NOD2 mRNA expression, as well as NF-κB activation in lungs from rats undergoing CLP were significantly increased. After the administration of ghrelin, all inflammatory parameters analyzed were lower than those without ghrelin following CLP. In addition, ghrelin improved survival after CLP. ConclusionOur results indicate that in a CLP model of sepsis, the beneficial effects that ghrelin has on inflammatory outcomes are mediated at least in part through inhibition of NOD2 expression upstream of NF-κB.

Dual immuno-regulatory effects of Y-40138 in animal models of sepsis and aspiration pneumonitis

We evaluated the dual immuno-regulatory effects of Y-40138, inhibiting tumor necrosis factor (TNF)-α production and augmenting interleukin (IL)-10 productions, in animal models of organ dysfunction related to systemic inflammatory response syndrome. Male Sprague-Dawley rats received Y-40138 (1, 10 and 30 mg/kg) or saline subcutaneously, and were subjected to cecal ligation and puncture (CLP) surgery 15 min later. Male C57Bl/6 mice received Y-40138 (30 mg/kg) or saline intravenously and were subjected to intratracheal instillation of hydrochloric acid (0.1 N, pH = 1.0) 30 min later. Survival after CLP surgery was monitored for 10 days and compared by Kaplan-Meier analysis and log rank statistics. Neutrophil count and cytokine concentrations in bronchoalveolar lavage (BAL) fluid at 12 h after intratracheal instillation were analyzed by one-way ANOVA. After CLP surgery, while 1 mg/kg of Y-40138 increased survival, 30 mg/kg of Y-40138 decreased survival (p < 0.01). After acid aspiration, Y-40138 significantly inhibited neutrophil recruitment by decreasing TNF-α / IL-10 ratio in BAL fluid (p < 0.05). Although the down regulation of pro-inflammatory cytokines and augmentation of anti-inflammatory cytokines seems a rational approach for SIRS-related multiple organ failure, further studies are needed for future clinical application of Y-40138, especially in situations compromised with microorganisms infection. Key words: Immunomodulators, sepsis, aspiration pneumonitis.

Opioid analgesics in experimental sepsis: effects on physiological, biochemical, and haemodynamic parameters

Cecal ligation and puncture (CLP) is the sepsis model that more closely resembles the human pathology, but it is likely to cause suffering to experimental animals. However, it is not clear whether the use of analgesia may affect some parameters evaluated in experimental sepsis research. Therefore, we investigated the effects of fentanyl and tramadol in experimental sepsis in the rat. The following parameters were evaluated: body temperature, body weight, water and food ingestion, mortality, analgesia, blood leukocytes, mean arterial blood pressure, vascular reactivity to phenylephrine, lung myeloperoxidase activity, and plasma levels of IL1-β, glutamic-oxaloacetic, glutamic-pyruvic, lactate, creatinine and urea. While producing significant analgesia, the opioids modify minimally the parameters, with the exception of sepsis-induced hypotension and mortality. Although fentanyl and tramadol can minimize pain and the general suffering of animals submitted to CLP surgery, their effects on cardiovascular parameters as well as in the mortality indicate that their use in experimental sepsis must be done with caution and with all the proper control groups.

Effect of acute ethanol treatment on biochemical and histopathological factors in rat liver in an experimental sepsis model

The aim of this study was to investigate the contribution of acute alcohol in sepsis-related liver damages using a Cecal Ligation and Puncture (CLP) model. Rats were divided into 7 groups (5 rats/group): control (saline-injected), sham-operated, CLP, ethanol (1.0 and 2.0g/kg b.w) and CLP+ethanol. The CLP+ethanol group received a single dose of ethanol following sepsis induction. Sepsis induction caused early changes in lipid peroxidation products in liver, whereas ethanol alone (2.0g/kg b.w) resulted in a significant increase (∼21%) in lipid peroxidation, which was further increased (∼57%) in CLP rats treated with alcohol. CLP operation and alcohol treatment exhibited additive effects on plasma catalase, liver glutathione and glutathione S-transferase (GST), which were primarily suppressed due to ethanol. Hepatic cytochrome P4501A1, which was elevated in CLP rats, was reversed in the CLP+ethanol group. Plasma tumor necrosis factor-α was markedly elevated (∼85%) in septic rats, but was unaffected in septic rats having received ethanol. Histopathological observations revealed that inflammatory reactions in liver in response to CLP operation are not intensified by ethanol administration. On the basis of biochemical and histopathological results, it can be concluded that acute ethanol treatment is responsible for early changes in oxidative stress, which may lead to polymicrobial sepsis-related organ damage.

The Outcome of Polymicrobial Sepsis Is Independent of T and B CellS

The contribution of the adaptive and innate immune systems to the pathogenesis and outcome of sepsis remains a fundamental yet controversial question. Here, we use mice lacking the recombination activating gene 1 (Rag-1) to study the role of T and B cells in sepsis after cecal ligation and puncture (CLP). Spleens of Rag-1 mice were atrophic and completely devoid of CD3 T cells and CD19 B cells. Wild-type mice and Rag-1 mice (both on a C57BL/6J background) underwent CLP or sham surgery. Both wild-type and Rag-1 mice developed clinical signs of sepsis within the first day after CLP. This included severe hypothermia as measured by a decrease in body surface temperature and organ dysfunction as detected by plasma increases in blood urea nitrogen and lactate dehydrogenase levels. Survival curves of wild-type and Rag-1 mice after CLP were superimposable, with 35% survival in the wild-type group and 27% survival in the Rag-1 group, respectively (not significant, P = 0.875). Using multiplex bead-based assays, the mediator concentrations for 23 cytokines and chemokines were measured in plasma of wild-type and Rag-1 mice 8 h after CLP or sham surgery. Compared with sham surgery mice, the highest mediator levels were observed for granulocyte colony-stimulating factor, keratinocyte chemoattractant, IL-6, monocyte chemotactic protein 1, and IL-10. Levels for most mediators were unaffected by the absence of T and B lymphocytes. Only the concentrations of IL-6 and IL-17 were found to be significantly lower in Rag-1 mice compared with wild-type mice. In conclusion, the absence of T and B cells in the CLP model used does not appear to affect the acute outcome of severe sepsis.

Cecal Ligation and Puncture Sepsis Is Associated with Attenuated Expression of Adenylyl Cyclase 9 and Increased Mir142-3p

The host inflammatory response in sepsis may be resolved by endogenous anti-inflammatory immune cell responses, avoiding fatal pathogenesis, organ injury, and death. The intracellular signaling mediator cyclic 3'5'-adenosine monophosphate is a potent modulator of inflammatory responses and initiates the polarization of immune cells in a direction that suppresses inflammatory activation. Cyclic 3'5'-adenosine monophosphate is enzymatically produced by adenylyl cyclases (ACs). The expression of ACs is previously shown to be reduced in rat organs after in vivo endotoxemia, concurrent with the progressing systemic inflammation. In the present study, tissue AC gene expression and regulation are explored in a rat model of cecal ligation and puncture (CLP) sepsis. Eighteen hours after CLP operation, expression of several AC isoforms in the liver, spleen, and kidney was reduced, significantly so for AC9 in all tissues. AC9 expression is regulated by the microRNA miR142-3p in T cells. When microRNA was extracted and amplified for miR142-3p expression, it was increasingly expressed 18 h after CLP. A correlation between increased miR142-3p and decreased AC9 expression was found in the liver, kidney, and spleen, and when hepatocytes, Kupffer cells (KCs), and liver sinusoidal endothelial cells were isolated after CLP, reduced AC expression and increased miR142-3p expression were found in KCs and liver sinusoidal endothelial cells. Transfecting a miR142-3p inhibitor probe in rat KCs abolished LPS-mediated AC9 inhibition in vitro. These results indicate that CLP leads to miR142-3p-mediated AC9 reduction in liver macrophages, which may further limit cyclic 3'5'-adenosine monophosphate signaling and the ability of macrophages to resolve the proinflammatory response.

Sepsis-induced alterations in sleep of rats

Sepsis is a systemic immune response to infection that may result in multiple organ failure and death. Polymicrobial infections remain a serious clinical problem, and in the hospital, sepsis is the number-one noncardiac killer. Although the central nervous system may be one of the first systems affected, relatively little effort has been made to determine the impact of sepsis on the brain. In this study, we used the cecal ligation and puncture (CLP) model to determine the extent to which sepsis alters sleep, the EEG, and brain temperature (Tbr) of rats. Sepsis increases the amount of time rats spend in non-rapid eye movement sleep (NREMS) during the dark period, but not during the light period. Rapid eye movements sleep (REMS) of septic rats is suppressed for about 24 h following CLP surgery, after which REMS increases during dark periods for at least three nights. The EEG is dramatically altered shortly after sepsis induction, as evidenced by reductions in slow-frequency components. Furthermore, sleep is fragmented, indicating that the quality of sleep is diminished. Effects on sleep, the EEG, and Tbr persist for at least 84 h after sepsis induction, the duration of our recording period. Immunohistochemical assays focused on brain stem mechanisms responsible for alterations in REMS, as little information is available concerning infection-induced suppression of this sleep stage. Our immunohistochemical data suggest that REMS suppression after sepsis onset may be mediated, in part, by the brain stem GABAergic system. This study demonstrates for the first time that sleep and EEG patterns are altered during CLP-induced sepsis. These data suggest that the EEG may serve as a biomarker for sepsis onset. These data also contribute to our knowledge of potential mechanisms, whereby infections alter sleep and other central nervous system functions.

Complete Induction of Autophagy Is Essential for Cardioprotection in Sepsis

To investigate the entire process of autophagy in the left ventricle of septic mice, and the functional significance of autophagy by using pharmacological agents. Myocardial dysfunction is a common feature in sepsis and contributes to an increased risk of developing multiple organ failure. Autophagy functions predominantly as a prosurvival pathway in the heart during cellular stress. A dynamic process of autophagy that involves the complete activation of autophagy from autophagosome formation to fusion with lysosomes has driven the development of new approaches to detecting autophagy. Male mice were subjected to cecal ligation and puncture (CLP) or sham operation. At 1 hour after CLP operation, mice received either rapamycin (induction of autophagy), bafilomycin A1 (inhibition of autophagosomal degradation), or vehicle. The formation of autophagosomes was increased whereas the degradation of autophagosomes was decreased in the left ventricle at 24 hours after CLP. This was consistent with the morphologic finding that septic hearts revealed an increase in autophagosomes but few autolysosomes, indicating incompletion of the autophagic process. Rapamycin, which induced complete activation of autophagy, restored CLP-induced depressed cardiac performances. This cardioprotective effect was also seen in increased ATP levels, and decreased inflammatory responses. Bafiomycin A1, which resulted in incompletion of the autophagic process, did not show any above beneficial effects in CLP mice. Incompletion of the autophagic process may contribute to sepsis-induced cardiac dysfunction. Treatment with rapamycin may serve a cardioprotective role in sepsis, possibly through the effect of complete induction of autophagy.

Heart and kidney oxidative stress status in septic rats treated with caraway extracts

Context: Carum carvi L., (Umbelliferae) known as caraway, is a famous traditional herbal plant supposed to contain active components with pharmacological properties.Objective: In this study, the effects of caraway extracts on preventing sepsis induced by oxidative tissue injuries have been investigated by measuring heart and kidney oxidative stress parameters.Materials and methods: Sepsis was induced in rats (n = 6) by experimental cecal ligation and puncture (CLP) model. Then, either hydroalcoholic extract or essential oils (50 and 100 mg/kg body weight) were injected intraperitonially immediately after CLP operation. Twenty-four hours after CLP, the rats were anesthetized when kidney and heart tissues were removed to analyze the tissue oxidative stress parameters, that is, glutathione (GSH) and lipid peroxidation (LP).Results: Sepsis induction caused a significant increase in kidney but not heart LP, indicating that kidney was more affected by sepsis induction than heart. Kidney LP and plasma urea/creatinine ratio levels were readily reversed in rats treated with essential oils but not in those treated with hydroalcoholic extract. Unlike LP, the heart and kidney GSH levels were not affected in all treated groups.Discussion and conclusion: Our data imply that caraway oils probably have a protective role in kidney tissue against oxidative injury in advanced stages of sepsis.

Beneficial Effects of Hyperoncotic Albumin on Liver Injury and Survival in Peritonitis-Induced Sepsis Rats

Liver injury/dysfunction developing in patients with sepsis may lead to an increased risk of death. Small-volume resuscitation with hyperoncotic albumin (HA) has been proposed to restore physiologic hemodynamics in hemorrhagic and septic shock. We evaluated whether HA resuscitation could alleviate the development of liver injury/dysfunction in rats with polymicrobial sepsis induced by cecal ligation and puncture (CLP). The male Wistar rats received 0.9% saline or HA (25%, 3 mL/kg intravenously) at 3 h after CLP or sham operation. All hemodynamic and biochemical variables were measured during the 18-h observation. After 18 h of CLP, the septic rats developed circulatory failure (i.e., hypotension, tachycardia, and poor tissue perfusion), liver injury (examined by biochemical variables and histologic studies), and a higher mortality. Hyperoncotic albumin not only ameliorated the deterioration of hemodynamic changes but also attenuated neutrophil infiltration and cell death in the liver of septic animals. The septic rats treated with HA had a higher survival when compared with those with 0.9% saline treatment. Moreover, the increased plasma IL-1β, plasma IL-6, plasma nitrite/nitrate concentrations, liver iNOS expression, and liver superoxide levels in CLP rats were attenuated after administration of HA. Thus, HA may be regarded as a potential therapeutic agent in the early treatment of septic shock to prevent or reduce subsequent liver failure.

Effects of early administration of a novel anticholinergic drug on acute respiratory distress syndrome induced by sepsis

SummaryBackgroundAcute respiratory distress syndrome (ARDS) is the inflammatory disorder of the lung most commonly caused by sepsis. It was hypothesized that treating the lung with penehyclidine hydrochloride (PHC), a new type of hyoscyamus drug, early in the development of sepsis could diminish the lung dysfunction.Material/MethodsSprague-Dawley rats were divided into 4 groups: 1) a control group; 2) a sham-operated group; 3) a cecal ligation and puncture (CLP) group; 4) a PHC-treated group. One hour after CLP surgery, rats were either untreated or treated with PHC via intraperitoneal injection. Lung wet/dry weight ratio, bronchoalveolar lavage fluid (BALF), serum tumor necrosis factor (TNF-α), interleukin 6 (IL-6), interleukin 10 (IL-10), total nitrite/nitrate (NOx), superoxide dismutase (SOD), malondialdehyde (MDA) in lung tissues, and pulmonary functions were examined 24 hour after surgery. Another 60 rats were randomly assigned to 4 equal groups to observe survival status 96 hours after surgery.ResultsTreatment of PHC markedly decreased TNF-α, IL-6, NOx, SOD, MDA content, protein concentration in BALF, and lung wet/dry weight ratio and enhanced SOD activity (p<0.05), which are indicative of PHC-induced suppression in the pathogenesis of ARDS caused by sepsis. In comparison to group CLP/saline, plasma IL-10 level markedly increased in group CLP/PHC. In PHC-treated groups, the administered PHC had a significant protective effect on the lung dysfunction induced by sepsis.ConclusionsWe conclude that administration of PHC at the time of a systemic insult can protect the lung from the damaging effects of sepsis.

Interleukin-17A Plays a Pivotal Role in Polymicrobial Sepsis According to Studies Using IL-17A Knockout Mice

Interleukin (IL)-17A is a proinflammatory cytokine and plays an important role in neutrophil recruitment. We investigate the role of IL-17A in a mouse polymicrobial sepsis model. IL-17A knockout mice (KO) and wild-type (WT) mice were subjected the cecal ligation and puncture (CLP). Survival was assessed for the following 7 d after the CLP operation, and histopathologic findings were evaluated 12 h after CLP. Bacterial outgrowth in blood was assessed by blood culture 12 h after CLP. After CLP, expression of inflammatory mediators in serum was assessed by enzyme-linked immunosorbent assay (ELISA). Furthermore, expression of FOXP3 and IL-17A in the spleen was assessed by immunohistochemical staining and flow cytometry. Mortality was increased in KO mice compared with WT mice after CLP. Furthermore, bacterial outgrowth in blood and serum high mobility group box 1 (HMGB1) levels were also significantly greater in KO mice than WT mice. The expression of FOXP3 in the spleen was significantly greater in KO mice than WT mice. IL-17A play pivotal role in host defense during septic peritonitis.

Protective effect of Ulinastatin against murine models of sepsis: Inhibition of TNF-α and IL-6 and augmentation of IL-10 and IL-13

Excessive production of inflammatory mediators during invasive infection plays a key role in the pathogenesis of sepsis. In an attempt to improve survival of patients with this lethal syndrome, agents were developed to selectively inhibit mediators in this inflammatory response. Ulinastatin (UTI), a human protease inhibitor, inhibits the enhanced production of pro-inflammatory molecules. However, it is unknown if Ulinastatin treatment could result in protective effects for sepsis. The aim of this study was to investigate the role of Ulinastatin on septic rats. Sixty male Wistar rats were divided into six groups, 10 of each: sham-operation plus PBS (5 ml), cecal ligation and puncture (CLP) plus PBS (5 ml), CLP plus UTI (5000 U/kg), CLP plus UTI (10,000 U/kg), CLP plus UTI (20,000 U/kg) and sham-operation plus UTI (10,000 U/kg). Rats in the UTI groups after CLP operation were treated with Ulinastatin by intraperitoneal injection at different doses and then compared with untreated sepsis control animals. The intestinal concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and interleukin-13 (IL-13) were significantly higher in septic rats than those in normal rats. Ulinastatin administration effectively suppressed the levels of TNF-α and IL-6, whereas it markedly enhanced the levels of IL-10 and IL-13. Ulinastatin may possess a protective role in the septic process by inhibiting TNF-α and IL-6, and augmenting IL-10 and IL-13 concentrations in intestine of septic rats.

Loss of Suppression of Tumorigenicity 2 (ST2) Gene Reverses Sepsis-induced Inhibition of Lung Host Defense in Mice

After surviving the initial hyperinflammatory phase, patients with sepsis display features consistent with immunosuppression, which renders the host susceptible to nosocomial infections, in particular bacterial pneumonia. Suppression of tumorigenicity 2 (ST2) is a negative regulator of Toll-like receptor signaling implicated in endotoxin tolerance. The present study sought to determine the role of ST2 in modulating host defense in the lung during sepsis, using a murine model of cecal ligation and puncture (CLP)-induced sepsis followed by a secondary infection with Pseudomonas aeruginosa via the airways. CLP or sham surgery was performed on BALB/c wild-type (WT) and ST2 knockout (KO) mice, and 24 hours later animals were challenged with 10(8) live P. aeruginosa. CLP mice demonstrated impaired clearance of Pseudomonas from their lungs and reduced pulmonary levels of tumor necrosis factor-α and IL-6 compared with sham mice. After CLP, ST2KO mice with secondary pneumonia displayed a strongly improved survival and a better bacterial clearance compared with WT mice, which was accompanied by enhanced lung inflammation. CLP did not influence the responsiveness of alveolar macrophages toward P. aeruginosa ex vivo irrespective of the st2 genotype. In contrast, CLP resulted in a reduced capacity of WT CD4(+) and CD8(+) T cells to produce IFN-γ and tumor necrosis factor-α, an immune suppressive effect that was not seen in ST2KO mice. These findings indicate that gene products of ST2 contribute to the immune-compromised state during sepsis and the ensuing disturbed homeostasis of lung host defense.

Effects of hydrogen gas inhalation on serum high mobility group box 1 levels in severe septic mice

To investigate the effect of hydrogen gas inhalation on survival rate and serum high mobility group box 1 (HMGB1) levels in severe septic mice. Severe sepsis was induced by cecal ligation and puncture (CLP) operation in mice.A total of 248 mice were randomly divided into four groups: sham operation group (sham), sham operation with hydrogen gas inhalation group (sham+H2), severe CLP group (severe CLP) and severe CLP with hydrogen gas inhalation group (severe CLP+H2). Hydrogen gas inhalation was given for 1 h at 1st and 6th h after CLP or sham operation, respectively. The survival rates and serum HMGB1 levels of all groups at different time points were measured. The 7-d survival rates of severe CLP mice was 0 % (Compared with Sham group, P <0.05), and the serum HMBG1 levels from h2 to h32 after CLP operation were significantly increased in severe CLP mice (Compared with Sham group, P <0.05). Hydrogen gas treatment increased the 7-d survival rate of severe CLP mice to 60 % (Compared with severe sepsis group, P <0.05) and significantly reduced the serum HMGB1 levels at different time points (Compared with severe sepsis group, P <0.05). Hydrogen gas inhalation can decrease the serum HMGB1 levels and increase the survival rate of rats with severe sepsis.

Differential Involvement of Potassium Channel Subtypes in Early and Late Sepsis-induced Hyporesponsiveness to Vasoconstrictors

This study investigated the involvement of potassium channel subtypes in the hyporesponsiveness to vasoconstrictors of an experimental model of sepsis [cecal ligation and puncture (CLP)], at 2 time points, namely, 6 and 24 hours after sepsis onset. Wistar rats were submitted to CLP or sham surgery, and 6 and 24 hours later, responses to phenylephrine were obtained before and 30 minutes after injection of potassium channel blockers. The potassium channel blockers used were tetraethylammonium (TEA; a nonselective channel blocker), glibenclamide (GLB; an adenosine triphosphate -dependent channel blocker), 4-aminopyridine (4-AP; a voltage-dependent channel blocker), apamin (APA; a small-conductance calcium-dependent channel blocker), and iberiotoxin (IBTX; a large-conductance calcium-dependent channel blocker). It was found that (1) sepsis caused a severe vascular hyporesponsiveness to phenylephrine both 6 and 24 hours after CLP, (2) TEA partially reversed the hyporesponsiveness 6 hours after CLP and completely restored vascular response to phenylephrine 24 hours after CLP, (3) apamin reversed hyporesponsiveness 6 but not 24 hours after CLP, (4) GLB restored phenylephrine response only 24 hours after CLP, and (5) IBTX and 4-AP were ineffective in all periods studied. Our results suggest that potassium channels are important effectors of sepsis-induced vascular dysfunction in vivo and that different subtypes of potassium channels are involved in early (small-conductance calcium-dependent potassium channels) and late (adenosine triphosphate -dependent potassium channels) hyporesponsiveness to vasoconstrictors caused by sepsis.

PROTECTIVE EFFECTS OF HYDROGEN GAS ON MURINE POLYMICROBIAL SEPSIS VIA REDUCING OXIDATIVE STRESS AND HMGB1 RELEASE

Despite recent advances in antibiotic therapy and intensive care, sepsis is still considered to be the most common cause of death in intensive care units. Excessive production of reactive oxygen species plays an important role in the pathogenesis of sepsis. Recently, it has been suggested that molecular hydrogen (H2) exerts a therapeutic antioxidant activity by selectively reducing hydroxyl radicals (*OH, the most cytotoxic reactive oxygen species) and effectively protects against organ damage induced by I/R. Therefore, we hypothesized that H2 treatment had a beneficial effect on sepsis. In the present study, we found that H2 inhalation starting at 1 and 6 h after cecal ligation and puncture (CLP) or sham operation significantly improved the survival rate of septic mice with moderate or severe CLP in a concentration- and time-dependent manner. Furthermore, moderate or severe CLP mice showed significant multiple organ damage characterized by the increases of lung myeloperoxidase activity, wet-to-dry weight ratio, protein concentration in bronchoalveolar lavage, serum biochemical parameters, and organ histopathologic scores at 24 h after CLP operation, which was significantly attenuated by 2% H2 treatment. In addition, we found that the beneficial effects of H2 treatment on sepsis and sepsis-associated organ damage were associated with the decreased levels of oxidative product, increased activities of antioxidant enzymes, and reduced levels of high-mobility group box 1 in serum and tissue. Thus, H2 inhalation may be an effective therapeutic strategy for patients with sepsis.

The effects of polymicrobial sepsis with diabetes mellitus on kidney tissues in ovariectomized rats

Objectives: Sepsis model was used to understand the role of sustained hyperglycemia and ovariectomy, either separately or concomitantly, on the response of the activity of the nuclear factor kappa B (NF-κB) and the oxidative response in kidney. Subjects: Polymicrobial sepsis was induced by cecal ligation and puncture (CLP). Diabetes was induced in female rats using administration of alloxan. The rats were divided into five groups: sham control (group 1), ovariectomy (group 2), ovariectomy + sepsis (group 3), ovariectomy + diabetes (group 4), and ovariectomy + diabetic + sepsis (group 5). Results: In kidney tissues, the levels of lipid peroxidation (LPO) and glutathione (GSH) and the activity of catalase (CAT) were higher for groups 3, 4, 5 than the control groups. Superoxide dismutase (SOD) activity was lower for groups 3, 4, 5 than the control groups. We determined that CLP produced injury evident in the kidneys of rats when compared to the control group, whereas the severity of the injury was higher in the diabetes + ovariectomy + CLP group when compared to the CLP group. In immunohistochemical staining, we determined that CLP operation increased NF-κB activation. In the ovariectomized, septic, and diabetic group, NF-κB activation was significantly higher than other groups. Conclusions: Hyperglycemia and ovariectomy severely increased NF-κB activation and oxidant levels with the stages of our sepsis model. Ovariectomy resulted in general changes in metabolism, which are seen in the kidney with diabetes under sepsis conditions.

Effects of terbutaline on circulatory failure and organ dysfunction induced by peritonitis in rats

The pathogenesis of multiple organ dysfunction syndrome (MODS) in septic shock is mainly caused by maldistribution of tissue perfusion and the amplification of inflammatory responses, which may be modulated by beta(2)-adrenoceptor agonists. We evaluated and compared effects of terbutaline on MODS in a cecal ligation and puncture (CLP) model of sepsis. Prospective controlled animal study in a university laboratory. Male adult Wistar rats received CLP or sham operation followed by the administration of saline or terbutaline (0.3 mg/kg i.v. at 3 and 9 h after CLP). At 0, 9 and 18 h after CLP, the changes of hemodynamics, organ function indexes, as well as the plasma interleukin-1beta (IL-1beta) and nitrite/nitrate levels were examined. At 18 h after CLP, animals were killed and their lungs, livers and kidneys were immediately excised to analyze superoxide anion (O(2) (-)) levels and inducible nitric oxide synthase (iNOS) expression. These organs were also evaluated by pathological study. Terbutaline significantly (1) prevented delayed hypotension and reduced hepatic and renal dysfunction, (2) diminished plasma IL-1beta and nitrite/nitrate, lung iNOS expression, tissue O(2) (-) level and the infiltration of neutrophils in the lung and the liver, and (3) improved the 18-h survival rate. Terbutaline may be developed as an alternative treatment for severe sepsis-induced MODS. The protective effect of terbutaline seems to be through inhibition of proinflammatory mediators and attenuation of oxidant production.

PD-L1 blockade improves survival in experimental sepsis by inhibiting lymphocyte apoptosis and reversing monocyte dysfunction

IntroductionLymphocyte apoptosis and monocyte dysfunction play a pivotal role in sepsis-induced immunosuppression. Programmed death-1 (PD1) and its ligand programmed death ligand-1 (PD-L1) exert inhibitory function by regulating the balance among T cell activation, tolerance, and immunopathology. PD-1 deficiency or blockade has been shown to improve survival in murine sepsis. However, PD-L1 and PD-1 differ in their expression patterns and the role of PD-L1 in sepsis-induced immunosuppression is still unknown.MethodsSepsis was induced in adult C57BL/6 male mice via cecal ligation and puncture (CLP). The expression of PD-1 and PD-L1 expression on peripheral T cells, B cells and monocytes were measured 24 hours after CLP or sham surgery. Additionally, the effects of anti-PD-L1 antibody on lymphocyte number, apoptosis of spleen and thymus, activities of caspase-8 and caspase-9, cytokine production, bacterial clearance, and survival were determined.ResultsExpression of PD-1 on T cells, B cells and monocytes and PD-L1 on B cells and monocytes were up-regulated in septic animals compared to sham-operated controls. PD-L1 blockade significantly improved survival of CLP mice. Anti-PD-L1 antibody administration prevented sepsis-induced depletion of lymphocytes, increased tumor necrosis factor (TNF)-α and interleukin (IL)-6 production, decreased IL-10 production, and enhanced bacterial clearance.ConclusionsPD-L1 blockade exerts a protective effect on sepsis at least partly by inhibiting lymphocyte apoptosis and reversing monocyte dysfunction. Anti-PD-L1 antibody administration may be a promising therapeutic strategy for sepsis-induced immunosuppression.