Cecal Ligation And Puncture Surgery Research Articles

Flavanones and Chromones from Salicornia herbacea Mitigate Septic Lethality via Restoration of Vascular Barrier Integrity.

Salicornia herbacea is an annual halophytic glasswort that has been employed as a culinary vegetable, salad, and traditional medicinal resource. Chemical investigation of the aerial parts of S. herbacea led to the isolation of two new (1, 2) and known (3) flavanones as well as a new nature-derived (4) and two known chromone derivatives (5, 6). These purified compounds were evaluated for their suppressive potentials against the release of high-mobility group box 1 protein (HMGB1), which has captured attention as a viable target for alleviating serious septic manifestations or septicemia. The phenolic compounds improved the survival rates of cecal ligation and puncture operation (CLP) in murine models, simulating severe septic shock and its related complications, to 40-60%. These results collectively validate that flavanone- and chromone-based secondary metabolites may serve as prospective prodrugs or food additives that may be commercialized for the control of septic complications and lethality.

Polydatin Inhibits Mitochondrial Dysfunction in the Renal Tubular Epithelial Cells of a Rat Model of Sepsis-Induced Acute Kidney Injury.

Mitochondrial injury is a major cause of sepsis-induced organ failure. Polydatin (PD), a natural polyphenol, demonstrates protective mitochondrial effects in neurons and arteriolar smooth muscle cells during severe shock. In this study, we investigated the effects of PD on renal tubular epithelial cell (RTEC) mitochondria in a rat model of sepsis-induced acute kidney injury. Rats underwent cecal ligation and puncture (CLP) to mimic sepsis-induced acute kidney injury. Rats were randomly divided into sham, CLP + normal saline, CLP + vehicle, and CLP + PD groups. Normal saline, vehicle, and 30 mg/kg PD were administered at 6, 12, and 18 hours after CLP or sham surgery via the tail vein. Mitochondrial morphology, metabolism, and function in RTECs were then assessed. Serum cytokines, renal function, survival, and histologic changes in the kidney were also evaluated. CLP increased lipid peroxide content, lysosomal instability, and opening of the mitochondrial permeability transition pore and caused mitochondrial swelling. Moreover, mitochondrial membrane potential (ΔΨm) was decreased and ATP levels reduced after CLP. PD inhibited all the above effects. It also inhibited the inflammatory response, improved renal function, attenuated histologic indicators of kidney damage, and prolonged survival. PD protects RTECs against mitochondrial dysfunction and prolongs survival in a rat model of sepsis-induced acute kidney injury. These effects may partially result from reductions in interleukin-6 and oxidative stress.

Prognosis of sepsis induced by cecal ligation and puncture in mice improved by anti-Clonorchis Sinensis cyclopholin a antibodies.

BackgroundCyclophilin A (CyPA), a ubiquitously distributed intracellular protein, is thought to be one of the important inflammatory factors and plays a significant role in the development process of sepsis. In the form of cytokine, CyPA deteriorates sepsis by promoting intercellular communication, apoptosis of endothelial cells and chemotactic effect on inflammatory cells. In our previous study, cyclophilin A of Clonorchis sinensis (CsCyPA), a type of excretory-secretory antigen, could induce the patients infected with Clonorchis sinensis to produce specific anti-CsCyPA antibodies. In this study, we investigated whether anti-CsCyPA antibodies could cross-react with CyPA and then play a protective role against sepsis, just like other anti-cytokine antagonists.MethodsThe mice model with sepsis was established with cecal ligation and puncture (CLP). Fifty mg/kg purified anti-CsCyPA antibodies were injected via the caudal vein 6 h after the CLP operation, and persistent observation was performed for 72 h. Blood samples and tissues were collected at 6 h, 12 h, 24 h, 48 h and 72 h after CLP. Cytokines in serum were measured by ELISA. Lung and mesentery tissues were stained with hematoxylin-eosin. Endothelial cells (ECs) isolated from murine aorta were co-cultured with CyPA of mice (MuCyPA) and anti-CsCyPAs for 24 h, then, viability was measured by Cell Counting Kit-8.ResultsAnti-CsCyPA antibodies could combine with MuCyPA and inhibite its peptidyl prolyl isomerase (PPIase) activity. In the antibodies treatment group, blood coagulation indicators including PT, aPTT, D-dimer and platelet count were obviously more ameliorative, the proinflammary factors like IL-6, TNF-α, IL-1β were significantly lower at 12 h and 24 h after surgery and the viability of ECs was significantly improved compared to those in the control group. Furthermore, the survival rate was elevated, ranging from 10.0 % to 45.0 % compared to the control group.ConclusionsThese antibodies may have a favorable effect on sepsis via inhibition of enzymic activity or protection of endothelial cells.

Exogenous Carbon Monoxide Decreases Sepsis-Induced Acute Kidney Injury and Inhibits NLRP3 Inflammasome Activation in Rats.

Carbon monoxide (CO) has shown various physiological effects including anti-inflammatory activity in several diseases, whereas the therapeutic efficacy of CO on sepsis-induced acute kidney injury (AKI) has not been reported as of yet. The purpose of the present study was to explore the effects of exogenous CO on sepsis-induced AKI and nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome activation in rats. Male rats were subjected to cecal ligation and puncture (CLP) to induce sepsis and AKI. Exogenous CO delivered from CO-releasing molecule 2 (CORM-2) was used intraperitoneally as intervention after CLP surgery. Therapeutic effects of CORM-2 on sepsis-induced AKI were assessed by measuring serum creatinine (Scr) and blood urea nitrogen (BUN), kidney histology scores, apoptotic cell scores, oxidative stress, levels of cytokines TNF-α and IL-1β, and NLRP3 inflammasome expression. CORM-2 treatment protected against the sepsis-induced AKI as evidenced by reducing serum Scr/BUN levels, apoptotic cells scores, increasing survival rates, and decreasing renal histology scores. Furthermore, treatment with CORM-2 significantly reduced TNF-α and IL-1β levels and oxidative stress. Moreover, CORM-2 treatment significantly decreased NLRP3 inflammasome protein expressions. Our study provided evidence that CORM-2 treatment protected against sepsis-induced AKI and inhibited NLRP3 inflammasome activation, and suggested that CORM-2 could be a potential therapeutic candidate for treating sepsis-induced AKI.

Sodium tanshinone II A sulfonate ameliorates microcirculatory disturbance of small intestine by attenuating the production of reactie oxygen species in rats with sepsis.

To examine whether sodium tanshinone II A sulfonate (STS), the main effective component of Salvia miltiorrhiza is effective in relieving the microcirculatory disturbance of small intestine by suppressing the production of reactive oxygen species (ROS) in rats with sepsis. A rat model of sepsis was induced by cecal ligation and puncture (CLP). Rats (n =40) were randomly divided into 4 groups: sham-operated group (sham, n =10), sepsis group (CLP, n =10), STS treatment group (STS, n =10) and ROS scavenger dimethylthiourea (DMTU, n =10) group. Animals in the STS group were injected with STS (1 mg/kg) for 10 min through the right external jugular vein after the CLP operation, and animals in the CLP group were given the same volume of normal saline after the CLP operation. Animals in the DMTU group were intraperitoneally injected with 5 mL/kg of 20% DMTU 1 h before CLP. The histopathologic changes in the intestinal tissues and changes of mesenteric microcirculation were observed. The levels of ROS in intestinal tissues from each group were qualitatively evaluated using a fluorescent microscope. The expressions of apoptosis signal-regulating kinase (ASK1), phosphorylated ASK1 (phospho-ASK1), p38 mitogen-activated protein kinases (p38 MAPK), phosphorylated p38 MAPK (phospho-p38 MAPK) and tissue factor (TF) were determined by Western blotting. It was shown that there were obvious microcirculatory disturbance (P <0.05) and tissue injuries in intestinal tissues after CLP operation. The levels of ROS production, phospho-ASK1, phospho-p38 MAPK and TF were increased. Both STS and DMTU suppressed ROS, phospho-ASK1, phospho-p38 MAPK and TF production, and ameliorated the microcirculatory disturbance and tissues injury (P <0.01). STS can ameliorate the microcirculatory disturbance of the small intestine by attenuating the production of ROS in rats with sepsis.

Astragaloside IV protects against polymicrobial sepsis through inhibiting inflammatory response and apoptosis of lymphocytes

BackgroundSepsis is a major clinical challenge in modern medicine, representing one of the leading causes of death in developed countries. The syndrome is a consequence of a dysregulated immune response, including early uncontrolled systemic inflammation and prolonged immunosuppression in the late phase. The present study was conducted to investigate the therapeutic effects of astragaloside IV (ASI-IV) on the cecal ligation and puncture (CLP)-induced sepsis in mice. Materials and methodsC57BL/6 mice were randomly divided into sham control + vehicle, CLP + vehicle, and CLP + ASI-IV groups. ASI-IV (3 mg/kg) was intravenously injected 1 h after CLP surgery. Survival rate, bacterial clearance, inflammatory mediators, phagocytes emigration, histopathology, and lymphocyte apoptosis were examined. The effects of ASI-IV on peritoneal macrophage activation and its underlying mechanisms were also evaluated. ResultsWe reported that treatment with ASI-IV significantly improved survival in septic mice. In agreement with this protective effect, the pathologic damage that was typically seen in lung and spleen was ameliorated; the level of bacterial burden was lessened; inflammatory cytokines and chemokines in circulation were profoundly reduced; lymphocyte apoptosis was inhibited. ASI-IV suppressed LPS-induced macrophage activation through inhibiting NF-κB and ERK1/2 signaling pathways. ConclusionsASI-IV protected mice against polymicrobial sepsis by inhibiting inflammatory response and lymphocyte apoptosis. Therefore, ASI-IV might provide a novel therapeutic approach for septic patients.

Biodistribution and Efficacy of Targeted Pulmonary Delivery of a Protein Kinase C-δ Inhibitory Peptide: Impact on Indirect Lung Injury.

Sepsis and sepsis-induced lung injury remain a leading cause of death in intensive care units. We identified protein kinase C-δ (PKCδ) as a critical regulator of the acute inflammatory response and demonstrated that PKCδ inhibition was lung-protective in a rodent sepsis model, suggesting that targeting PKCδ is a potential strategy for preserving pulmonary function in the setting of indirect lung injury. In this study, whole-body organ biodistribution and pulmonary cellular distribution of a transactivator of transcription (TAT)-conjugated PKCδ inhibitory peptide (PKCδ-TAT) was determined following intratracheal (IT) delivery in control and septic [cecal ligation and puncture (CLP)] rats to ascertain the impact of disease pathology on biodistribution and efficacy. There was negligible lung uptake of radiolabeled peptide upon intravenous delivery [<1% initial dose (ID)], whereas IT administration resulted in lung retention of >65% ID with minimal uptake in liver or kidney (<2% ID). IT delivery of a fluorescent-tagged (tetramethylrhodamine-PKCδ-TAT) peptide demonstrated uniform spatial distribution and cellular uptake throughout the peripheral lung. IT delivery of PKCδ-TAT at the time of CLP surgery significantly reduced PKCδ activation (tyrosine phosphorylation, nuclear translocation and cleavage) and acute lung inflammation, resulting in improved lung function and gas exchange. Importantly, peptide efficacy was similar when delivered at 4 hours post-CLP, demonstrating therapeutic relevance. Conversely, spatial lung distribution and efficacy were significantly impaired at 8 hours post-CLP, which corresponded to marked histopathological progression of lung injury. These studies establish a functional connection between peptide spatial distribution, inflammatory histopathology in the lung, and efficacy of this anti-inflammatory peptide.

Hydrogen Gas Alleviates the Intestinal Injury Caused by Severe Sepsis in Mice by Increasing the Expression of Heme Oxygenase-1.

Hydrogen gas (H2) has antioxidative, anti-inflammatory, and antiapoptotic effects and may have beneficial effects in severe sepsis. The purpose of this study was to investigate the mechanisms underlying these protective effects. Male Institute for Cancer Research mice were randomized into 6 groups: sham; sham + H2; severe sepsis; severe sepsis + H2; severe sepsis + zinc protoporphyrin IX (ZnPPIX), a heme oxygenase-1 (HO-1) inhibitor; and severe sepsis + H2 + ZnPPIX. Cecal ligation and puncture (CLP) was used to induce sepsis. Mice in the H2 groups received inhaled 2% H2 for 1 h at 1 h and 6 h after CLP or sham operation. Mice in the ZnPPIX groups received 40-mg/kg ZnPPIX by intraperitoneal injection 1 h before CLP. Tin protoporphyrin IX (TinPPIX), another HO-1 inhibitor, was also used in part for this study. Mice in the TinPPIX groups received 50-mg/kg TinPPIX through subcutaneous injection 6 h before CLP. The levels of biochemical markers, oxidative products, inflammatory mediator, the number of intestinal apoptotic cells, and the colony-forming unit numbers in the peritoneal lavage fluid were much higher in the severe sepsis group compared with the sham group. Intestinal injury in animals with severe sepsis was worse than that in animals in the sham group. H2 therapy in the animals with severe sepsis was associated with reduced intestinal injury, decreased numbers of colony-forming unit and apoptotic cells, reduced levels of biochemical markers, oxidative products, and high-mobility group box 1 protein. The protective effects of H2 were reversed by ZnPPIX and TinPPIX. Protein and messenger RNA expressions of HO-1 and nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) in the intestine were increased in the severe sepsis group compared to the sham group, and H2 further increased their expressions in the severe septic mice. Zinc protoporphyrin IX and TinPPIX inhibited the expression of HO-1 protein. Hydrogen has the capacity to protect mice from organ injury in severe sepsis through a mechanism involving HO-1.

Saikosaponin A protects against experimental sepsis via inhibition of NOD2-mediated NF-κB activation.

The excessive production of inflammatory cytokines during invasive infection primarily mediates the pathophysiology of sepsis. To improve the survival of septic patients, many selective or mediator-specific anti-inflammatory agents have been developed. Saikosaponin A (SsA), a triterpenoid saponin isolated from Radix Bupleuri, inhibits the production of proinflammatory mediators in several cell types and protects against CCl4-induced liver injury in rats. However, whether SsA treatment provides protective effects against sepsis remains unknown. The aim of the present study was to investigate the anti-inflammatory role of SsA in septic rats and the possible involvement of the nucleotide-binding oligomerization domain 2 (NOD2)/NF-κB signaling pathway in the regulation of inflammatory cytokine expression. Sixty male Wistar rats were randomly divided into six groups (10 rats per group): Sham surgery, cecal ligation and puncture (CLP), CLP plus SsA (1.0 mg/kg), CLP plus SsA (2.5 mg/kg), CLP plus SsA (5.0 mg/kg) and sham surgery plus SsA (2.5 mg/kg) groups. Rats in the SsA groups were intraperitoneally (i.p.) injected with different doses of SsA following the CLP surgery. Tissues from the ileum were harvested 8 h after CLP or sham surgery and the levels of inflammatory cytokines and NOD2 mRNA, and the activation of NF-κB were measured. The concentrations of the cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-6, as well as the NOD2 mRNA expression levels and NF-κB activation in the intestinal tissues were significantly increased in the septic rats of the CLP group compared with those in the sham group. SsA administration effectively suppressed the increase in the levels of TNF-α and IL-6. Moreover, the upregulation of NOD2 mRNA expression and phospho-NF-κB p65 levels was significantly inhibited following the administration of SsA. SsA may exert a protective role in the septic process by suppressing TNF-α and IL-6 concentrations in the intestines of septic rats and these effects appear to be mediated, at least partly, via inhibition of the NOD2/NF-κB signaling pathway.

Effects of hydrogen inhalation on serum pro-inflammatory factors and intestinal injury in mice with severe sepsis

To investigate the effects and mechanisms of hydrogen inhalation on serum levels of pro-inflammatory factors and intestinal injury in severe septic mice. 176 male ICR mice were randomly divided into four groups: sham operation group, hydrogen control group (sham+hydrogen inhalation), model group (severe sepsis model) and hydrogen treatment group (severe sepsis model+hydrogen inhalation), with 44 mice in each group. Severe sepsis model was reproduced by cecal ligation and puncture (CLP). 2% hydrogen inhalation was given for 1 hour at 1 hour and 6 hours after sham or CLP operation. Twenty animals in each group were selected and observed for 7-day survival rate. Six animals in each group were selected and sacrificed at 6, 12, 24 and 48 hours after sham or CLP, the concentrations of tumor necrosis factor-α (TNF-α), interleukins (IL-6, IL-10) and high mobility group box 1 (HMGB1) in serum were determined, the intestinal histopathological changes and scores were evaluated by light microscopy, and the activities of myeloperoxidase (MPO) and caspase-3 were determined. The 7-day survival rate of severe sepsis mice was 0; the 7-day survival rate was increased to 60% in hydrogen treatment group, with statistical significance in variables compared with model group (P<0.05). Compared with sham operation group, the serum concentrations of TNF-α, IL-6, IL-10 and HMGB1 were obviously increased, the intestine were heavily injured along with higher histopathological scores, and the intestinal MPO and caspase-3 activities were significantly enhanced at different time points after CLP in model group (all P<0.05). Compared with model group, the serum concentrations of TNF-α, IL-6 and HMGB1 were significantly decreased [ TNF-α (ng/L): 6 hours: 110.34±9.28 vs. 440.55±25.78, 12 hours: 82.29±8.43 vs. 448.36±32.54, 24 hours: 79.68±9.04 vs. 346.42±22.24, 48 hours: 80.79±10.06 vs. 368.94±31.58; IL-6 (ng/L): 12 hours: 58.68±8.55 vs. 158.28±16.73, 24 hours: 46.98±7.58 vs. 146.74±18.02, 48 hours: 38.67±8.22 vs. 136.45±15.45; HMGB1 (μg/L): 6 hours: 15.75±4.32 vs. 55.56±10.04, 12 hours: 32.02±9.33 vs. 89.65±15.65, 24 hours: 35.87±8.54 vs. 86.44±20.33, 48 hours: 23.85±9.83 vs. 98.33±18.88, all P<0.05], the serum concentrations of IL-10 (ng/L) at 24 hours and 48 hours after CLP were obviously increased (24 hours: 135.44±16.43 vs. 79.22±12.03, 48 hours: 110.92±12.54 vs. 74.47±11.18, both P<0.05), the intestinal injury were ameliorated with decreased histopathological scores (12 hours: 1.70±0.06 vs. 3.23±0.44, 24 hours: 2.12±0.31 vs. 4.51±0.58, 48 hours: 2.03±0.42 vs. 4.27±0.58, all P<0.05), and the intestinal MPO and caspase-3 activities were significantly decreased [MPO (U/g): 6 hours: 13.75±4.21 vs. 25.56±5.34, 12 hours: 14.72±4.22 vs. 30.53±6.87, 24 hours: 11.62±3.14 vs. 33.58±7.24, 48 hours: 11.33±4.03 vs. 38.57±8.12; caspase-3 (fluorescence intensity): 6 hours: 0.37±0.07 vs. 0.69±0.23, 12 hours: 0.42±0.07 vs. 0.86±0.13, 24 hours: 0.53±0.11 vs. 1.36±0.23, 48 hours: 0.50±0.08 vs. 1.48±0.15, all P<0.05] in hydrogen treatment group. Hydrogen inhalation can down-regulate the systemic inflammatory response to ameliorate the intestinal injury, and it may improve the septic process and increase the survival rate of mice with severe sepsis.

Effect of γ-Irradiation on the Antibacterial Activities of Cuminum cyminum L. Essential Oils In Vitro and In Vivo Systems

The present study was carried out to investigate the effect of γ-irradiation at two irradiation doses of 10 and 25 kGy, on the antibacterial activities of cumin essential oils (E.Os) in vitro and in vivo systems. For this purpose, the cumin seeds were irradiated with Co60 source (0, 10 and 25 kGy) and subjected to Clevenger extraction to obtain E.Os. In vitro antibacterial activities of cumin E.Os was determined on Gram-negative and Gram-positive bacterial strains including E. coli, P. aeroginosa, B. cereus and S. aureus using agar well diffusion method, disk diffusion method and, MIC and MBC determinations. In vivo antibacterial activity was performed on polymicrobial infection induced by cecal ligation and puncture (CLP) in rat through blood colony forming units (CFUs) determination. The results showed that CLP operation caused a marked increase in bacterial load of blood which was reduced in rats treated with fresh and irradiated cumin oils. In vitro results also showed the sensitivity of all tested bacterial strains against the fresh and irradiated cumin E.Os. These data may suggest that cumin E.O has potential antibacterial activity both in vivo and in vitro systems. Also, γ-irradiation to cumin seeds at 10 and 25 kGy has no significant effects on the antibacterial properties of cumin E.Os.

Abstract 659: Inhibition of vWF Secretion with Novel G alpha12 N-terminal alpha-SNAP Binding Domain Peptide Increases Survival in Septic Rodents

Severe sepsis is associated with disseminated intravascular coagulation (DIC) as a result of interdependent mechanisms of systemic intravascular inflammation, microvascular thrombosis, and thrombocytopenia. Currently, no drug is available to concomitantly treat these events in sepsis. A poorly understood mechanism and yet critical determinant of sepsis-induced microvascular thrombosis is von Willebrand Factor (vWF) secretion by activated endothelial cells. We recently discovered that heterotrimeric G protein alpha subunit G alpha 12 plays a critical role in basal and evoked vWF secretion by endothelial cells by promoting Weibel-Palade body (WPB) exocytosis. Based on the observed interaction of G alpha 12 with alpaSNAP, a critical member of the exocyst complex required for plasma membrane fusion and exocytosis of WPB contents, we generated a myristoylated Galpha12 N-terminal alphaSNAP Binding Domain (Myr-SBD) blocking peptide and tested the hypothesis that this would selectively and potently inhibit Galpha12 interaction with alphaSNAP and thereby block vWF secretion, limit platelet adhesion and prevent microvascular thrombosis associated with cecal ligation and puncture (CLP) induced sepsis. CLP-induced fulminant sepsis in rats and mice was associated with a 2-3-fold increase in plasma vWF within first 24 hrs. Importantly, we observed reduced plasma vWF levels 24 hrs after CLP surgery in mice given a one-time i.v. bolus (2 μmol/kg) of micellar Myr-SBD at the time of surgery as compared to Myr-scrambled peptide or vehicle only group. Strikingly, this was associated with increased survival without adversely inducing hemorrhage and vascular leakage. Furthermore, and consistent with the hypothesis that Gα12-dependent increase in vWF secretion during sepsis leads to poor outcome, control WT mice succumbed to sepsis in less than 96 hrs whereas 80% of Gα12-/- mice shown previously to have significantly reduced plasma vWF levels survived. Inhibition of Galpha12/alphaSNAP dependent vWF secretion may therefore be an effective strategy for blocking microvascular thrombosis, disseminated intravascular coagulation, and death due to sepsis.

Preclinical evaluation of the mitochondria‐targeted antioxidant MitoTEMPO on the renal microcirculation in a pediatric model of sepsis‐induced renal injury

Microcirculatory failure, mitochondrial dysfunction and oxidant generation are thought to be key events during sepsis that lead to multi-organ failure. Acute kidney injury is a leading cause of mortality in septic children. We developed a clinically relevant cecal ligation and puncture (CLP) sepsis model in rat pups 17-19 days old to identify and evaluate new therapeutic approaches. Analysis of the renal microcirculation using intravital video microscopy at 18 h post CLP or sham surgery showed a significant decrease in the percentage of continuously flowing capillaries (from 75% to 40%) and an increase in capillaries with no flow (from 5% to 30%). Microcirculatory failure was associated with a 2-fold increase in mitochondrial superoxide generation in renal tubules. We then performed dose-response studies to evaluate the effectiveness of the mitochondria-targeted antioxidant MitoTEMPO to reduce mitochondria superoxide and to improve renal microcirculation. MitoTEMPO was administered at doses of 1, 3, or 10 mg/kg (ip) at the time of CLP or sham surgery. Superoxide and perfusion were measured at 18 h. MitoTEMPO produced dose-dependent decreases in mitochondrial superoxide and increases in microcirculatory perfusion with 3 mg/kg being the lowest most efficacious dose to preserve the renal microcirculation. These findings suggest a previously unrecognized link between mitochondrial oxidants in the renal tubule epithelium and the regulation of microvascular perfusion. The protective effect of MitoTEMPO in the kidney suggests that agents like it should be evaluated further for their effectiveness at reducing sepsis-induced multi-organ failure. Supported by T32 GM106999 and AHA PRE20450050.

Hydrogen gas inhibits high-mobility group box 1 release in septic mice by upregulation of heme oxygenase 1

BackgroundSepsis is a potentially fatal whole-body inflammation caused by severe infection. Hydrogen gas (H2) is effective for treating sepsis. In this study, we hypothesized that the protective function of H2 in mice with septic lung injury occurred through the activation of heme oxygenase 1 (HO-1) and its upstream regulator nuclear factor-erythroid 2 p45-related factor 2 (Nrf2). Materials and methodsMale institute of cancer research mice were subjected to sepsis by cecal ligation and puncture (CLP) with the presence or absence of H2. Beginning at 1 and 6 h after CLP or sham operation, respectively, 2% H2 was inhaled for 1 h. We intraperitoneally injected the HO-1 inhibitor zinc protoporphyrin IX (40 mg/kg) 1 h before CLP. To assess the severity of septic lung injury, we observed the 7-d survival rate, wet/dry weight ratio of lung, lung histopathologic score, oxygenation index, and so forth. Serum and homogenates from the lung, liver, and kidney were acquired for measuring the levels of high-mobility group box 1 (HMGB1) at 6, 12, and 24 h after CLP or sham operation. Furthermore, the protein and messenger RNA expression of Nrf2, HO-1, and HMGB1 was measured at 6, 12, and 24 h. ResultsSeptic mice had a lower survival rate and more severe lung injury compared with the sham group. However, therapy with H2 increased the survival rate and alleviated the severity of lung injury, reduced the HMGB1 level, and increased the HO-1 and Nrf2 levels in septic mice. Moreover, the HO-1 inhibitor zinc protoporphyrin IX significantly eliminated the protective effect of H2 on septic lung injury. ConclusionsH2 plays a significant role in regulating the release of the inflammatory cytokine HMGB1 in septic mice, which is partially mediated through the activation of HO-1 as a downstream molecule of Nrf2.

Blockade of the JNK signalling as a rational therapeutic approach to modulate the early and late steps of the inflammatory cascade in polymicrobial sepsis.

Cecal ligation and puncture (CLP) is an experimental polymicrobial sepsis induced systemic inflammation that leads to acute organ failure. Aim of our study was to evaluate the effects of SP600125, a specific c-Jun NH2-terminal kinase (JNK) inhibitor, to modulate the early and late steps of the inflammatory cascade in a murine model of CLP-induced sepsis. CB57BL/6J mice were subjected to CLP or sham operation. Animals were randomized to receive either SP600125 (15 mg/kg) or its vehicle intraperitoneally 1 hour after surgery and repeat treatment every 24 hours. To evaluate survival, a group of animals was monitored every 24 hours for 120 hours. Two other animals were sacrificed 4 or 18 hours after surgical procedures; lung and liver samples were collected for biomolecular and histopathologic analysis. The expression of p-JNK, p-ERK, TNF-α, HMGB-1, NF-κB, Ras, Rho, Caspase 3, Bcl-2, and Bax was evaluated in lung and liver samples; SP600125 improved survival, reduced CLP induced activation of JNK, NF-κB, TNF-α, and HMGB-1, inhibited proapoptotic pathway, preserved Bcl-2 expression, and reduced histologic damage in both lung and liver of septic mice. SP600125 protects against CLP induced sepsis by blocking JNK signalling; therefore, it can be considered a therapeutic approach in human sepsis.

Cecal ligation and puncture accelerates development of ventilator-induced lung injury.

Sepsis is a leading cause of respiratory failure requiring mechanical ventilation, but the interaction between sepsis and ventilation is unclear. While prior studies demonstrated a priming role with endotoxin, actual septic animal models have yielded conflicting results regarding the role of preceding sepsis on development of subsequent ventilator-induced lung injury (VILI). Using a rat cecal ligation and puncture (CLP) model of sepsis and subsequent injurious ventilation, we sought to determine if sepsis affects development of VILI. Adult male Sprague-Dawley rats were subject to CLP or sham operation and, after 12 h, underwent injurious mechanical ventilation (tidal volume 30 ml/kg, positive end-expiratory pressure 0 cmH2O) for either 0, 60, or 120 min. Biochemical and physiological measurements, as well as computed tomography, were used to assess injury at 0, 60, and 120 min of ventilation. Before ventilation, CLP rats had higher levels of alveolar neutrophils and interleukin-1β. After 60 min of ventilation, CLP rats had worse injury as evidenced by increased alveolar inflammation, permeability, respiratory static compliance, edema, oxygenation, and computed tomography. By 120 min, CLP and sham rats had comparable levels of lung injury as assessed by many, but not all, of these metrics. CLP rats had an accelerated and worse loss of end-expiratory lung volume relative to sham, and consistently higher levels of alveolar interleukin-1β. Loss of aeration and progression of edema was more pronounced in dependent lung regions. We conclude that CLP initiated pulmonary inflammation in rats, and accelerated the development of subsequent VILI.

Low molecular weight heparin may prevent acute lung injury induced by sepsis in rats

The purpose of this study was to assess the protective effect of low molecular weight heparin (LMWH) on acute lung injury (ALI) in rats induced by sepsis. Rat ALI model was reproduced by cecal ligation and puncture (CLP). All rats were randomly divided into three groups (n=50): control group (A), ALI group (B), and LMWH-treated group (C). Group A received a sham operation and the other groups underwent CLP operation. Groups A and B accepted intraperitoneal injection (i.p.) of normal saline (NS) at a dose of 2.0mlkg−1 and ceftriaxone (30mgkg−1), group C was intraperitoneally injected with additional LMWH (150Ukg−1) except saline and ceftriaxone. Blood was collected and lung tissue was harvested at the designated time points for analysis. The lung specimens were harvested for morphological studies, immunohistochemistry examination. Lung tissue edema was evaluated by tissue water content. The levels of lung tissue myeloperoxidase (MPO) were determined. Meanwhile, the nuclear factor-kappa B (NF-κB) activation, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels, high mobility group box 1 (HMGB1) and intercellular adhesion molecule-1 (ICAM-1) protein levels in the lung were studied. There was a significant difference in each index between groups A and B (P<0.05). Treatment with LMWH significantly decreased the expression of TNF-α, IL-1β, HMGB1 and ICAM-1 in the lungs of ALI rats. Similarly, treatment with LMWH dramatically diminished sepsis-induced neutrophil sequestration and markedly reduced the enhanced lung permeability. In the present study, LMWH administration inhibited the nuclear translocation of NF-κB in the lungs. These data suggest that LMWH attenuates inflammation and ameliorates lung pathology in CLP-induced sepsis in a rat model.

Von Willebrand Factor-Dependent Inflammatory Responses in Mouse Septic Model By Cecal Ligation and Puncture

Sepsis is a serious inflammatory response syndrome, in which systemic activation of both inflammatory and coagulation pathways are provoked by severe microbial infection. In addition to the known hemostatic functions, von Willebrand factor (VWF) is recently assumed to participate in a cross-talk between inflammation and thrombosis. Indeed, recent mouse model studies demonstrated that proper functional regulation of VWF-dependent inflammatory responses by ADAMTS13 considerably improved the disease progression of brain stroke or myocardial infarction. However, little is known about the detailed mechanisms or relevant role of VWF functions in inflammation. We therefore studied the physiologic relevance of VWF-dependent inflammatory responses in a mouse model of experimental sepsis by cecal ligation and puncture (CLP). The mouse CLP was performed according to the established standard protocol (Rittirsch D, et al., Nat Protoc, 2009). Briefly, mouse cecum was ligated distal to the ileocecal valve under laparotomy, punctured with 18 gauge needle and gently pressed until a small drop of stool appeared. The cecum was returned to the peritoneal cavity and 200 μL of saline was injected into the cavity to avoid dehydration before body wall and skin incision were closed with a 4-0 Sofsilk. We compared 17 wild-type (WT) and 17 VWF-gene deleted (knock-out; KO) mice (from The Jackson Laboratory, Bar Harbor, ME), all of which were 10-12 weeks of age, healthy and fertile. Excess blood loss was not observed in all (WT or KO) mice during the CLP operation. Kaplan-Meier analysis revealed the significantly (p < 0.05) lower survival rate of KO mice than that of WT (KO; 23.5% vs. WT; 58.8% at the Day 7 of CLP). The impaired survival rate of KO mice was restored by the bolus administration of human VWF (n=21, 2.5 U/mouse) to an extent comparable to that of WT. Peripheral blood analysis of KO mice at 24 hours after CLP showed the severe leukocytopenia with sharp decrease of neutrophils in blood, as compared to WT. In addition, formation of walled-off abscess was confirmed at the peri-cecal space in all the WT and KO mice alive even at the Day 7 of CLP, while such focal abscess formation was not found in mice died before the Day 3 of CLP. Thus, our results altogether indicate that VWF could play a role on the recruitment or accumulation of neutrophils for microbial killing at the local inflammatory focus. VWF-mediated platelet aggregate formation in peripheral capillary vessels then could shut down the local microcirculation, thereby blocking systemic microbial expansion as a crucial biological defense mechanism. DisclosuresShima:Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity’s Board of Directors or advisory committees, Research Funding.

Inhalation of hydrogen gas attenuates brain injury in mice with cecal ligation and puncture via inhibiting neuroinflammation, oxidative stress and neuronal apoptosis

During the development of sepsis, the complication in central nervous system (CNS), appearing early and frequently relative to other systems, can obviously increase the mortality of sepsis. Moreover, sepsis survivors also accompany long-term cognitive dysfunction, while the ultimate causes and effective therapeutic strategies of brain injury in sepsis are still not fully clear. We designed this study to investigate the effects of 2% hydrogen gas (H2) on brain injury in a mouse model of sepsis. Male ICR mice were underwent cecal ligation and puncture (CLP) or sham operation. 2% H2 was inhaled for 60min beginning at both 1 and 6h after sham or CLP operation, respectively. H2 concentration in arterial blood, venous blood and brain tissue was detected after H2 inhalation separately. The survival rate was observed and recorded within 7 days after sham or CLP operation. The histopathologic changes and neuronal apoptosis were observed in hippocampus by Nissl staining and TUNEL assay. The permeability of brain–blood barrier (BBB), brain water content, inflammatory cytokines, activities of antioxidant enzymes (SOD and CAT) and oxidative products (MDA and 8-iso-PGF2α) in serum and hippocampus were detected at 24h after sham or CLP operation. The expressions of nucleus and total nuclear factor erythroid 2-related factor 2 (Nrf2) and cytoplasmic heme oxygenase-1(HO-1) in hippocampus were measured at 24h after sham or CLP operation. We assessed their cognitive function via Y-maze and Fear Conditioning test on day 3, 5, 7 and 14 after operation. H2 treatment markedly improved the survival rate and cognitive dysfunction of septic mice. CLP mice showed obvious brain injury characterized by aggravated pathological damage, BBB disruption and brain edema at 24h after CLP operation, which was markedly alleviated by 2% H2 treatment. Furthermore, we found that the beneficial effects of H2 on brain injury in septic mice were linked to the decreased levels of inflammatory cytokines and oxidative products and the increased activities of antioxidant enzymes in serum and hippocampus. In addition, 2% H2 inhalation promoted the expression and transposition of Nrf2 and the expression of HO-1 to mitigate brain injury in sepsis. Thus, the inhalation of hydrogen gas may be a promising therapeutic strategy to relieve brain injury in sepsis.

Effects of intra-abdominal sepsis on atherosclerosis in mice.

IntroductionSepsis and other infections are associated with late cardiovascular events. Although persistent inflammation is implicated, a causal relationship has not been established. We tested whether sepsis causes vascular inflammation and accelerates atherosclerosis.MethodsWe performed prospective, randomized animal studies at a university research laboratory involving adult male ApoE-deficient (ApoE−/−) and young C57B/L6 wild-type (WT) mice. In the primary study conducted to determine whether sepsis accelerates atherosclerosis, we fed ApoE−/− mice (N = 46) an atherogenic diet for 4 months and then performed cecal ligation and puncture (CLP), followed by antibiotic therapy and fluid resuscitation or a sham operation. We followed mice for up to an additional 5 months and assessed atheroma in the descending aorta and root of the aorta. We also exposed 32 young WT mice to CLP or sham operation and followed them for 5 days to determine the effects of sepsis on vascular inflammation.ResultsApoE−/− mice that underwent CLP had reduced activity during the first 14 days (38% reduction compared to sham; P < 0.001) and sustained weight loss compared to the sham-operated mice (−6% versus +9% change in weight after CLP or sham surgery to 5 months; P < 0.001). Despite their weight loss, CLP mice had increased atheroma (46% by 3 months and 41% increase in aortic surface area by 5 months; P = 0.03 and P = 0.004, respectively) with increased macrophage infiltration into atheroma as assessed by immunofluorescence microscopy (0.52 relative fluorescence units (rfu) versus 0.97 rfu; P = 0.04). At 5 months, peritoneal cultures were negative; however, CLP mice had elevated serum levels of interleukin 6 (IL-6) and IL-10 (each at P < 0.05). WT mice that underwent CLP had increased expression of intercellular adhesion molecule 1 in the aortic lumen versus sham at 24 hours (P = 0.01) that persisted at 120 hours (P = 0.006). Inflammatory and adhesion genes (tumor necrosis factor α, chemokine (C-C motif) ligand 2 and vascular cell adhesion molecule 1) and the adhesion assay, a functional measure of endothelial activation, were elevated at 72 hours and 120 hours in mice that underwent CLP versus sham-operations (all at P <0.05).ConclusionsUsing a combination of existing murine models for atherosclerosis and sepsis, we found that CLP, a model of intra-abdominal sepsis, accelerates atheroma development. Accelerated atheroma burden was associated with prolonged systemic, endothelial and intimal inflammation and was not explained by ongoing infection. These findings support observations in humans and demonstrate the feasibility of a long-term follow-up murine model of sepsis.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0469-1) contains supplementary material, which is available to authorized users.