Induced Sepsis Mouse Research Articles

Suppressive activity of RGX-365 on HMGB1-mediated septic responses

RGX-365 is the main fraction of black ginseng conmprising protopanaxatriol (PPT)-type rare ginsenosides (ginsenosides Rg4, Rg6, Rh4, Rh1, and Rg2). No studies on the antiseptic activity of RGX-365 have been reported. High mobility group box 1 (HMGB1) is recognized as a late mediator of sepsis, and the inhibition of HMGB1 release and recovery of vascular barrier integrity have emerged as attractive therapeutic strategies for the management of sepsis. In this study, we examined the effects of RGX-365 on HMGB1-mediated septic responses and survival rate in a mouse sepsis model. RGX-365 was administered to the mice after HMGB1 challenge. The antiseptic activity of RGX-365 was assessed based on the production of HMGB1, measurement of permeability, and septic mouse mortality using a cecal ligation and puncture (CLP)-induced sepsis mouse model and HMGB1-activated human umbilical vein endothelial cells (HUVECs). We found that RGX-365 significantly reduced HMGB1 release from LPS- activated HUVECs and CLP-induced release of HMGB1 in mice. RGX-365 also restored HMGB1-mediated vascular disruption and inhibited hyperpermeability in the mice. In addition, treatment with RGX-365 reduced sepsis-related mortality in vivo. Our results suggest that RGX- 365 reduces HMGB1 release and septic mortality in vivo, indicating that it is useful in the treatment of sepsis.

Exosome-Mediated eCIRP Release From Macrophages to Induce Inflammation in Sepsis.

Extracellular cold-inducible RNA-binding protein (eCIRP) is an important damage-associated molecular pattern (DAMP). Despite our understanding of the potentially harmful effects of eCIRP in sepsis, how eCIRP is released from cells remains elusive. Exosomes are endosome-derived extracellular vesicles, which carry proteins, lipids, and nucleic acids to facilitate intercellular communication and several extracellular functions. We hypothesized that eCIRP is released via exosomes to induce inflammation in sepsis. Exosomes isolated from the supernatants of LPS-treated macrophage culture and serum of endotoxemia and polymicrobial sepsis mice showed high purity, as revealed by their unique median sizes ranging between 70 and 126 nm in diameter. eCIRP levels of the exosomes were significantly increased after LPS treatment in the supernatants of macrophage culture, mouse serum, and cecal ligation and puncture (CLP)-induced sepsis mouse serum. Protease protection assay demonstrated the majority of eCIRP was present on the surface of exosomes. Treatment of WT macrophages and mice with exosomes isolated from LPS-treated WT mice serum increased TNFα and IL-6 production. However, treatment with CIRP−/- mice serum exosomes significantly decreased these levels compared with WT exosome-treated conditions. CIRP−/- mice serum exosomes significantly decreased neutrophil migration in vitro compared with WT exosomes. Treatment of mice with serum exosomes isolated from CIRP−/- mice significantly reduced neutrophil infiltration into the peritoneal cavity. Our data suggest that eCIRP can be released via exosomes to induce cytokine production and neutrophil migration. Thus, exosomal eCIRP could be a potential target to inhibit inflammation.

Functional delivery of lncRNA TUG1 by endothelial progenitor cells derived extracellular vesicles confers anti-inflammatory macrophage polarization in sepsis via impairing miR-9-5p-targeted SIRT1 inhibition

The delivery of biomolecules by extracellular vesicles (EVs) derived from endothelial progenitor cells (EPCs) has been proven to ameliorate sepsis, yet the therapeutic mechanism remains to be elucidated. Taurine upregulated gene 1 (TUG1) is a long noncoding RNA (lncRNA) that is downregulated in sepsis. The current study was designed to explore the role of EPCs derived EVs transmitting TUG1 in macrophage polarization and macrophage-mediated inflammation in a cecal ligation and puncture (CLP)-induced sepsis mouse model. TUG1 was underexpressed in CLP-induced sepsis, and its reexpression induced anti-inflammatory macrophage polarization and suppressed macrophage-medicated inflammatory injury to the pulmonary vascular endothelium. EPCs derived EVs transmitted TUG1 to promote M2 macrophage polarization. Luciferase, RIP, and RNA pull-down assays showed that TUG1 could competitively bind to microRNA-9-5p (miR-9-5p) to upregulate the expression of sirtuin 1 (SIRT1). Furthermore, EPCs derived EVs transmitted TUG1 to promote M2 macrophage polarization through the impairment of miR-9-5p-dependent SIRT1 inhibition. Finally, EPCs derived EVs carrying TUG1 were verified to ameliorate sepsis-induced organ damage in the murine model. In summary, EPCs derived EVs transmit TUG1 to attenuate sepsis via macrophage M2 polarization. This study also highlights the proinflammatory mechanism associated with miR-9-5p-mediated inhibition of SIRT1, which contributes to a more comprehensive understanding of the pathogenesis of sepsis.

Alamandine, a derivative of angiotensin-(1-7), alleviates sepsis-associated renal inflammation and apoptosis by inhibiting the PI3K/Ak and MAPK pathways

Sepsis is a frequent cause of kidney injury. The present study investigated whether Alamandine (Ala) could alleviate sepsis-associated renal injury by reducing inflammation and apoptosis. In addition, we investigated downstream signaling pathways modulated by Ala. Studies were performed in mice treated with lipopolysaccharide (LPS) and in the human proximal tubular epithelial cell line HK-2. The increase in serum creatinine, blood urea nitrogen, cystatin C and Fg, and neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 in the kidneys of mice treated with LPS were reduced after administration of Ala. Exposure to LPS increased interleukin-1 beta (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) in mice and HK-2 cells, but were reduced after Ala treatment. Furthermore, increased levels of cleaved caspase 3, cleaved caspase 7, cleaved caspase 9, cleaved poly (ADP-ribose) polymerase (PARP) and Bax and reduced levels of Bcl2 in LPS-treated mice and HK-2 cells were reversed after Ala administration. In addition, LPS increased the levels of p-PI3K/PI3K, p-Akt/Akt, p-ERK/ERK, p-JNK/JNK, p-p38/p38 and p-FoxO1 in HK-2 cells, and all were reversed after Ala administration. These results indicate that Ala could improve renal function and inhibit inflammation and apoptosis in LPS induced sepsis mouse models. We demonstrated that Ala attenuated LPS induced sepsis by inhibiting the PI3K/Akt and MAPK signaling pathways.

Cecal Ligation and Puncture-Induced Sepsis Promotes Brown Adipose Tissue Inflammation Without Any Impact on Expression of Thermogenic-Related Genes.

Background and Aims: The negative effects of chronic low-level inflammation on adipose tissue physiology have been extensively demonstrated, whereas the effects of acute inflammation are less studied. Here, we aimed to investigate the effects of sepsis-induced acute inflammation on gene expression markers of brown and white adipose tissue functionality.Methods: Brown adipose tissue (BAT) and perirenal white adipose tissue (prWAT) gene expression markers were analyzed in cecal ligation and puncture (CLP)-induced sepsis mice model.Results: CLP-induced sepsis attenuated expression of adipogenesis-related genes, in parallel to increased Tnf, Il6, and Ltf gene expression in prWAT. In contrast, CLP-induced sepsis resulted in increased expression of pro-inflammatory genes (Il6, Ltf, and Lbp) in BAT, without affecting expression of genes encoding for thermogenic activity.Conclusion: Sepsis promotes both prWAT and BAT inflammation, associated with reduced adipogenesis-related gene expression in prWAT, without significant effects on BAT thermogenic genes.

Imipenem alters systemic and liver inflammatory responses in CLP- induced sepsis mice in a dose-dependent manner

BackgroundConsidering the role of inflammation in the outcome of sepsis and the widespread use of imipenem in the disease, this study was designed to assess the effect of imipenem on the dynamics of inflammatory responses in the sepsis mouse model. MethodsCecal Ligation and Puncture (CLP) model was used to induce sepsis in mice. C57BL/6 mice were divided into sham, CLP-induced sepsis mice, CLP-induced sepsis mice receiving 25 mg/kg, and 125 mg/kg imipenem. Blood and liver samples were obtained and bacterial load, endotoxin level, and liver enzymes were evaluated. The concentration and mRNA expression of cytokines were also determined. ResultsSepsis mice treated with a high dose (125 mg/kg) of imipenem showed a significant reduction in bacterial load, while increased liver enzymes, endotoxin level, and inflammatory cytokine production in plasma and liver. In contrast, significant reduction in the liver enzymes, bacterial load, endotoxin levels, and inflammatory cytokine levels was observed in the mice treated with a low dose (25 mg/kg) of imipenem compared with other mice groups. Liver tissue pathology of mice indicated little tissue destruction in the sepsis mice treated with 25 mg/kg of imipenem compared to other groups. Mice receiving 25 mg/kg of imipenem had better survival rate. ConclusionsOur results demonstrated the dose-dependent effect of subcutaneous administration of imipenem on the inflammatory responses in sepsis mice. A dose of 25 mg/kg imipenem resulted in better pathology, lower inflammatory mediators, and increased survival rate in sepsis mice.

Biapenem reduces sepsis mortality via barrier protective pathways against HMGB1-mediated septic responses.

As a late mediator of sepsis, the role of high mobility group box 1 (HMGB1) has been recognized as important, and suppression of HMGB1 release and restoration of vascular barrier integrity are regarded as potentially promising therapeutic strategies for sepsis. For repositioning of previously FDA-approved drugs to develop new therapies for human diseases, screening of chemical compound libraries, biological active, is an efficient method. Our study illustrates an example of drug repositioning of Biapenem (BIPM), a carbapenem antibiotic, for the modulation of HMGB1-induced septic responses. We tested our hypothesis that BIPM inhibits HMGB1-induced vascular hyperpermeability and thereby increases the survival of septic mouse model from suppression of HMGB1 release upon lipopolysaccharide (LPS)-stimulation. In LPS-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model, antiseptic activity of BIPM was investigated from suppression of vascular permeability, pro-inflammatory proteins, and markers for tissue injury. BIPM significantly suppressed release of HMGB1 both in LPS-activated HUVECs (upto 60%) and the CLP-induced sepsis mouse model (upto 54%). BIPM inhibited hyperpermeability (upto 59%) and reduced HMGB1-mediated vascular disruptions (upto 62%), mortality (upto 50%), and also tissue injury including lung, liver, and kidney in mice. Reduction of HMGB1 release and septic mortality by BIPM (in vitro, from 5 to 15μM for 6h; in vivo, from 0.37 to 1.1mg/kg, 24h) indicate a possibility of successful repositioning of BIPM for the treatment of sepsis.

Acute lung injury inhibition by juglone in LPS induced sepsis mouse model involves Sirt1 activation

Purpose: To investigate the effect of juglone on LPS induced lung injury in a mouse model and in TC 1cell line.Methods: Edema formation in lungs were measured by determination of lung wet/dry weight. Expressions of various proteins were assessed by western blot assay, while Sirt1 level was assessed using immunohistochemistry. Mice were randomly assigned to nine groups of 10 mice each: normal control, untreated and seven juglone treatment groups. Acute lung injury was induced in mice by injecting LPS (10 mg/kg) via intraperitoneal route (ip). The treatment groups were given 10, 20, 30, 40, 50, 60 and 100 μM of juglone, ip, respectively.Results: The levels of MMP-9, IL-6, IL-1β and iNOS were significantly higher in acute lung injury induced mice compared than the control group (p < 0.05). Treatment of the mice with juglone significantly decreased LPS-induced up-regulation of inflammatory cytokines in a dose-dependentmanner. The production of inflammatory cytokines was almost completely inhibited in the mice treated with 100 mg/kg dose of juglone, while treatment of the LPS-stimulated TC 1 cells with juglone upregulated the expression of Sirt1 mRNA. Down-regulation of Sirt1 expression by siRNA inhibited the effect of juglone on LPS-induced increase in inflammatory cytokine production.Conclusion: Juglone prevents lung injury in mice via up-regulation of Sirt1 expression. Therefore, juglone might be useful for the development of a treatment strategy for lung injury.
 Keywords: Inflammatory, Sirtuin, Edema, Cytokines, Lung injury, TC 1 lung alveolar epithelial cells, Sirt1

Effect of growth differentiation factor 15 (GDF-15) inhibition on energy balance in cancer cachexia and in lipopolysaccharide (LPS)-induced sepsis mouse models.

e24153 Background: Growth differentiation factor 15 (GDF-15) is a cytokine that induces anorexia, weight loss and has been reported to be associated with cachexia and poor survival in illnesses characterized by inflammation such as cancer cachexia and heart failure. In preclinical cancer cachexia models, GDF-15 inhibition has been demonstrated to reverse cachexia and improve survival. Circulating GDF-15 is also elevated in patients with sepsis and is associated with increased complications and poor survival. However, the role of infection- and sepsis-induced GDF-15 in mouse models is controversial based on published reports. Methods: In this study, we examined the effect of GDF-15 inhibition on tumor and lipopolysaccharide (LPS)-induced anorexia, weight loss, and survival using a GDF-15 neutralizing antibody (mAB2) and GDF-15 knockout mice. Results: mAB2 efficacy was confirmed by reversing AAV-GDF-15-induced weight loss in wildtype mice. A cachectic (anorexia and weight loss) mouse tumor model was established with subcutaneous implantation of mouse renal cell carcinoma (RENCA) cells. The chemotherapy sorafenib was administered to slow tumor progression. Plasma GDF-15 was increased to ~2 ng/mL, similar to levels in cancer patients. Treatment with mAB2 rapidly reversed both anorexia and weight loss in the tumor-bearing mice. LPS injection (intraperitoneal, 5 mg/kg) increased circulating GDF-15 in wildtype mice reaching concentrations like that reported in septic patients within 90 minutes and remaining elevated after 48 hours (~1 ng/mL). LPS decreased food intake, body weight, and increased mortality (~20%). Different from the tumor model, GDF-15 neutralization with mAB2 did not prevent or exacerbate any of the effects of LPS. There were no observed detrimental effects of mAB2 treatment in either model. Similarly, in GDF-15 knockout mice the LPS effect on energy balance and survival was comparable to that observed in wildtype controls. Plasma GDF-15 was undetectable in the GDF-15 knockout mice. Conclusions: Taken together, these data suggest that GDF-15 is a critical regulator of energy balance and survival in selective pathophysiological states associated with weight loss.

Antibacterial Fusion Protein BPI21/LL-37 Modification Enhances the Therapeutic Efficacy of hUC-MSCs in Sepsis

Sepsis, which is characterized by multiple organ dysfunctions as a result of an unbalanced host-inflammatory response to pathogens, is potentially a life-threatening condition and a major cause of death in the intensive care units (ICUs). However, effective treatment or intervention to prevent sepsis-associated lethality is still lacking. Human umbilical cord mesenchymal stem cell (hUC-MSC) transplantation has been shown to have potent immunomodulatory properties and improve tissue repair yet lacks direct antibacterial and endotoxin clearance activities. In this study, we engineered hUC-MSCs to express a broad-spectrum antibacterial fusion peptide containing BPI21 and LL-37 (named BPI21/LL-37) and confirmed that the BPI21/LL-37 modification did not affect the stemness and immunoregulatory capacities of hUC-MSCs but remarkably, enhanced its antibacterial and toxin-neutralizing activities invitro. Furthermore, we showed that administration of BPI21/LL-37-engineered hUC-MSCs significantly reduces serum levels of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6, whereas increases that of IL-10 in cecal ligation and puncture (CLP)-induced sepsis mouse model. Administration of BPI21/LL-37-engineered hUC-MSCs significantly reduced systemic endotoxin (lipopolysaccharide [LPS]) levels and organ bacterial load, ameliorated damage to multiple organs, and improved survival. Taken together, our study demonstrates that BPI21/LL-37-engineered hUC-MSCs might offer a novel therapeutic strategy to prevent or treat sepsis via enhanced antimicrobial and anti-inflammatory properties to preserve organ functions better.

Inhibitory functions of maslinic acid, a natural triterpene, on HMGB1-mediated septic responses

BackgroundMaslinic acid (MA), a natural triterpenoid from Olea europaea, prevents oxidative stress and pro-inflammatory cytokine generation. High mobility group box 1 (HMGB1) has been recognized as a late mediator of sepsis, and the inhibition of the release of HMGB1 and the recovery of vascular barrier integrity have emerged as attractive therapeutic strategies for the management of sepsis. MethodsWe tested the hypothesis that MA induces sirtuin 1 and heme oxygenase-1, which inhibit the release of HMGB1 in lipopolysaccharide (LPS)-stimulated cells, thus inhibiting HMGB1-induced hyperpermeability and increasing the survival of septic mice. MA was administered after LPS or HMGB1 challenge, and the antiseptic activity of MA was determined based on permeability, the activation of pro-inflammatory proteins, and the production of markers for tissue injury in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model. ResultsMA significantly reduced the release of HMGB1 in LPS-activated HUVECs and attenuated the CLP-induced release of HMGB1. Additionally, MA alleviated HMGB1-mediated vascular disruption and inhibited hyperpermeability in mice, and in vivo analysis revealed that MA reduced sepsis-related mortality and tissue injury. ConclusionTaken together, the present results suggest that MA reduced HMGB1 release and septic mortality and thus may be useful in the treatment of sepsis.

Imaging of the ex vivo transglutaminase activity in liver macrophages of sepsis mice

Sepsis is the leading cause of death in hospitalized patients and is characterized by a dysregulated inflammatory response to infection and multiple organ failure, including the liver. Transglutaminase 2 (TG2) is a multifunctional enzyme that exhibits transamidase, GTPase, and integrin-binding activities and has opposing roles in the regulation of cell growth, differentiation, and apoptosis. TG2 plays both pathogenic and protective roles in liver diseases, revealing the need to examine the activities of TG2. Here, we introduced an ex vivo imaging approach to examine the in vivo transamidase activity of TG2 based on the combination of intraperitoneal injection of 5-biotinamidopentylamine (5BAPA), a biotinylated substrate for TG2, and fluorescent streptavidin staining in frozen liver sections. Increased 5BAPA signals was observed in the livers of lipopolysaccharide (LPS) and cecal ligation and puncture (CLP)-induced sepsis mice. Pharmacological inhibition of TG2 activity ameliorated LPS-induced liver injury. 5BAPA signals were observed in TG2-expressing and F4/80-positive midzonal macrophages, providing direct evidence that activated macrophages are the major cellular source of active TG2 in the livers of sepsis mice. Further studies focusing on the activation of 5BAPA-stained midzonal macrophages may improve understanding of the molecular pathophysiology and the development of therapeutic strategies for sepsis.

Borneol alleviates brain injury in sepsis mice by blocking neuronal effect of endotoxin

AimBrain injury after sepsis leads to high mortality and long-term brain dysfunction in patients. Previous studies revealed that borneol has a protective effect on the brain, but its function on sepsis associated encephalopathy (SAE) remains unknown. Herein, we investigated the protective effect of borneol against sepsis-related brain injury. Main methodsLipopolysaccharide (LPS)-induced sepsis mice and cells were treated with borneol at the dose of 100 mg/kg by gavage or 10 μg/ml in culture, respectively. The protective effect of borneol on neurons and the microglia were assessed in vivo and in vitro. Key findingsWe observed that borneol attenuated brain neuronal and microglial inflammation in LPS-induced sepsis mice with a suppression of p-p65 and p38 signaling that were initially activated by LPS in the brain. In vitro examination confirmed that the protective effect of borneol on both neurons and microglia, and its suppressive effect on p-p65 and p38 pathways were, at least in part, direct. SignificanceAn early protection of neurons and microglia from bacterial endotoxin during sepsis is beneficial, and borneol has the potential to protect these cells.

Inactivation of the tyrosine phosphatase SHP-2 drives vascular dysfunction in Sepsis.

BackgroundSepsis, the most severe form of infection, involves endothelial dysfunction which contributes to organ failure. To improve therapeutic prospects, elucidation of molecular mechanisms underlying endothelial vascular failure is of essence.MethodsPolymicrobial contamination induced sepsis mouse model and primary endothelial cells incubated with sepsis serum were used to study SHP-2 in sepsis-induced endothelial inflammation. SHP-2 activity was assessed by dephosphorylation of pNPP, ROS production was measured by DCF oxidation and protein interactions were assessed by proximity ligation assay. Vascular inflammation was studied in the mouse cremaster model and in an in vitro flow assay.FindingsWe identified ROS-dependent inactivation of the tyrosine phosphatase SHP-2 to be decisive for endothelial activation in sepsis. Using in vivo and in vitro sepsis models, we observed a significant reduction of endothelial SHP-2 activity, accompanied by enhanced adhesion molecule expression. The impaired SHP-2 activity was restored by ROS inhibitors and an IL-1 receptor antagonist. SHP-2 activity inversely correlated with the adhesive phenotype of endothelial cells exposed to IL-1β as well as sepsis serum via p38 MAPK and NF-κB. In vivo, SHP-2 inhibition accelerated IL-1β-induced leukocyte adhesion, extravasation and vascular permeability. Mechanistically, SHP-2 directly interacts with the IL-1R1 adaptor protein MyD88 via its tyrosine 257, resulting in reduced binding of p85/PI3-K to MyD88.InterpretationOur data show that SHP-2 inactivation by ROS in sepsis releases a protective break, resulting in endothelial activation.FundGerman Research Foundation, LMU Mentoring excellence and FöFoLe Programme, Verein zur Förderung von Wissenschaft und Forschung, German Ministry of Education and Research.

Aloin Reduces HMGB1-Mediated Septic Responses and Improves Survival in Septic Mice by Activation of the SIRT1 and PI3K/Nrf2/HO-1 Signaling Axis.

High mobility group box 1 (HMGB1) is recognized as a late mediator of sepsis, and the inhibition of HMGB1 release and recovery of vascular barrier integrity have emerged as attractive therapeutic strategies for the management of sepsis. We tested the hypothesis that aloin induces sirtuin 1 (SIRT1) and heme oxygenase (HO)-1, which inhibit HMGB1 release in lipopolysaccharide (LPS)-stimulated cells, thereby inhibiting HMGB1-induced hyperpermeability and increasing the survival of septic mice. Aloin was administered after LPS or HMGB1 challenge, and the antiseptic activity of aloin was determined from measurements of permeability, activation of pro-inflammatory proteins and production of markers for tissue injury in HMGB1-activated human umbilical vein endothelial cells (HUVECs) and a cecal ligation and puncture (CLP)-induced sepsis mouse model. Aloin significantly reduced HMGB1 release in LPS-activated HUVECs via SIRT1-mediated HMGB1 deacetylation and the PI3K/Nrf2/heme oxygenase (HO)-1 signaling axis. Aloin also suppressed the production of tumor necrosis factor (TNF)- and interleukin (IL)-6, as well as the activation of nuclear factor (NF)- B and extracellular signal-regulated kinase 1/2 (ERK 1/2) by HMGB1. Moreover, aloin restored HMGB1-mediated vascular disruption and inhibited vascular hyperpermeability in mice. In addition, treatment with aloin reduced the CLP-induced release of HMGB1, sepsis-related mortality and tissue injury in vivo. Our results suggest that aloin reduces HMGB1 release and sepsis-related mortality by activating SIRT1 and PI3K/Nrf2/HO-1 signals, indicating that aloin has potential for the treatment of sepsis.

Glucosamine improves survival in a mouse model of sepsis and attenuates sepsis-induced lung injury and inflammation

The aim of the current study was to investigate the effects of glucosamine (GlcN) on septic lethality and sepsis-induced inflammation using animal models of mice and zebrafish. GlcN pretreatment improved survival in the cecal ligation and puncture (CLP)-induced sepsis mouse model and attenuated lipopolysaccharide (LPS)-induced septic lung injury and systemic inflammation. GlcN suppressed LPS-induced M1-specific but not M2-specific gene expression. Furthermore, increased expressions of inflammatory genes in visceral tissue of LPS-injected zebrafish were suppressed by GlcN. GlcN suppressed LPS-induced activation of mitogen-activated protein kinase (MAPK) and NF-κB in lung tissue. LPS triggered a reduction in O-GlcNAc levels in nucleocytoplasmic proteins of lung, liver, and spleen after 1 day, which returned to normal levels at day 3. GlcN inhibited LPS-induced O-GlcNAc down-regulation in mouse lung and visceral tissue of zebrafish. Furthermore, the O-GlcNAcase (OGA) level was increased by LPS, which were suppressed by GlcN in mouse and zebrafish. OGA inhibitors suppressed LPS-induced expression of inflammatory genes in RAW264.7 cells and the visceral tissue of zebrafish. Stable knockdown of Oga via short hairpin RNA led to increased inducible nitric oxide synthase (iNOS) expression in response to LPS with or without GlcN in RAW264.7 cells. Overall, our results demonstrate a protective effect of GlcN on sepsis potentially through modulation of O-GlcNAcylation of nucleocytoplasmic proteins.

Ulinastatin attenuates liver injury and inflammation in a cecal ligation and puncture induced sepsis mouse model.

Sepsis is a syndrome of life-threatening multiorgan dysfunction caused by host response dysregulation to infection. Ulinastatin (UTI), a serine protease inhibitor, possesses anti-inflammatory properties and has been suggested to modulate lipopolysaccharide-induced sepsis. However, little is known about the mechanism underlying its effects on sepsis. In the current study, we investigated the protective effect of UTI on liver injury in a cecal ligation and puncture (CLP)-induced sepsis of C57BL/6 mouse model and explored the possible mechanisms. Mice underwent CLP as sepsis models and were randomized into five groups including the sham group, UTI group, CLP group, UTI-L group, and UTI-H group. UTI was intraperitoneally administered at doses of UTI 1500 U/100 g (UTI-L group) or 3000 U/100 g (UTI-H group), before CLP. The mice were killed, and immunohistochemical changes, cytokine levels, and antioxidant enzyme activities were detected. Our results showed that UTI ameliorated CLP-mediated increases in serum aspartate aminotransferase and alanine aminotransferase activities, histological activity index, degenerative region ratio, and infiltrated inflammatory cell numbers. Moreover, UTI also decreased nitrotyrosine and 4-hydroxynonenal, activated caspase-3, and activated poly (ADP-ribose) polymerase (PARP) levels and inhibited the mitogen-activated protein kinase pathway activation in liver tissues. Our results indicated that UTI could inhibit CLP-induced liver injury by suppressing inflammation and oxidation. Our results indicated that UTI may serve as a potential therapeutic agent for sepsis.

Protective effects of Cinnamomum cassia (Lamaceae) against gout and septic responses via attenuation of inflammasome activation in experimental models

Ethnopharmacological relevanceCinnamomum cassia (C. cassia, Lauraceae family), commonly used for treating dyspepsia, gastritis, blood circulation, and inflammatory diseases is considered as one of the 50 fundamental herbs in traditional Chinese medicine. Aim of the studyThe anti-inflammatory action of an ethanol extract of C. cassia (CA), and its underlying mechanisms were explored in both in vitro cellular and in vivo murine models. Materials and methodsBone marrow-derived macrophages (BMDMs) were used to study the regulatory effect of CA on inflammasome activation. A lipopolysaccharide (LPS)-induced sepsis mouse model and a monosodium urate (MSU)-induced gout model were employed to study the effect of CA on in vivo efficacy. ResultsCA improved the survival rate in the LPS-induced septic shock mouse model and inhibited inflammasome activation including NLRP3, NLRC4, and AIM2, leading to suppression of interleukin-1β secretion. Further, ASC oligomerization and its speck formation in cytosol were attenuated by CA treatment. Furthermore, CA improved both survival rate of LPS-induced septic shock and gout murine model. ConclusionsCA treatment significantly attenuated danger signals-induced inflammatory responses via regulation of inflammasome activation, substantiating the traditional claims of its use in the treatment of inflammation-related disorders.

Impact of Pioglitazone on Macrophage Dynamics in Adipose Tissues of Cecal Ligation and Puncture-Treated Mice.

Pioglitazone improves sepsis-induced organ injury accompanied with anti-inflammatory effects on visceral adipose tissue. However, its action in adipose immune cells remains to be ascertained. We investigated the effects of pioglitazone on visceral adipose macrophage population and polarisation in cecal ligation and puncture (CLP)-induced sepsis mice. Eight-week-old male mice were assigned to 3 groups: 1) sham-operated group, 2) CLP group, or 3) pioglitazone-treated CLP group. Pioglitazone (10 mg/kg) was injected intraperitonally for 7 d and CLP surgery was performed. Visceral adipose tissues were collected 24 h after the surgery. mRNA expression of several macrophage markers (inducible nitric oxide synthase (iNOS) for M1, arginase1 (Arg1) and interleukin (IL)-10 for M2, CD163 and F4/80 for mature macrophages) and inflammatory adipokines (IL-6, monocyte chemoattractant protein-1: MCP-1) was quantified by real-time RT-PCR. Tissue sections were subjected to the immunohistochemical analysis and the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. CLP significantly enhanced Arg1, IL-10 and iNOS mRNA expressions as compared with the sham group, and pioglitazone significantly increased the mRNA level of CD163 and F4/80 in CLP mice. Expression of IL-6 and MCP-1 stimulated by CLP was reduced by pioglitazone treatment. Increased CD11b/c- and CD163-positive cells as well as apoptotic cells were observed in the CLP group and the pioglitazone-treated group. The data indicate that M1/M2 macrophage activation of visceral adipose tissues is induced in CLP-induced mice, and the function of macrophages recruited from surrounding organs may be modulated by pioglitazone treatment.

Molecular hydrogen protects mice against polymicrobial sepsis by ameliorating endothelial dysfunction via an Nrf2/HO-1 signaling pathway

Endothelial injury is a primary cause of sepsis and sepsis-induced organ damage. Heme oxygenase-1 (HO-1) plays an essential role in endothelial cellular defenses against inflammation by activating nuclear factor E2-related factor-2 (Nrf2). We found that molecular hydrogen (H2) exerts an anti-inflammatory effect. Here, we hypothesized that H2 attenuates endothelial injury and inflammation via an Nrf2-mediated HO-1 pathway during sepsis. First, we detected the effects of H2 on cell viability and cell apoptosis in human umbilical vein endothelial cells (HUVECs) stimulated by LPS. Then, we measured cell adhesion molecules and inflammatory factors in HUVECs stimulated by LPS and in a cecal ligation and puncture (CLP)-induced sepsis mouse model. Next, the role of Nrf2/HO-1 was investigated in activated HUVECs, as well as in wild-type and Nrf−/− mice with sepsis. We found that both 0.3mmol/L and 0.6mmol/L (i.e., saturated) H2-rich media improved cell viability and cell apoptosis in LPS-activated HUVECs and that 0.6mmol/L (i.e., saturated) H2-rich medium exerted an optimal effect. H2 could suppress the release of cell adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1), and pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β and high-mobility group box 1 protein (HMGB1). Furthermore, H2 could elevate anti-inflammatory cytokine IL-10 levels in LPS-stimulated HUVECs and in lung tissue from CLP mice. H2 enhanced HO-1 expression and activity in vitro and in vivo. HO-1 inhibition reversed the regulatory effects of H2 on cell adhesion molecules and inflammatory factors. H2 regulated endothelial injury and the inflammatory response via Nrf2-mediated HO-1 levels. These results suggest that H2 could suppress excessive inflammatory responses and endothelial injury via an Nrf2/HO-1 pathway.