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Background Disseminated intravascular coagulation (DIC), a severe complication of sepsis, promotes multiple organ dysfunctions and lethality. Bacterial infection is the most common cause of sepsis. We previously show an important role of bacteria-released outer membrane vesicles (OMVs) in bacterial infection-induced DIC. In the light of recent advance that activation of caspase-11 and its enzymatic substrate gasdermin D (GSDMD) is able to trigger coagulation, we postulate that OMVs might induce DIC through the caspase-11-GSDMD pathway. Methods Caspase-11- or GSDMD-deficient mice and their wild-type (WT) controls were injected with purified Escherichia coli-derived OMVs. Blood samples were then collected. The development of DIC was assessed in terms of the occurrence of coagulopathy, the organ injuries and the lethality. Peritoneal macrophages derived from WT, Caspase-11- or GSDMD-deficient mice were stimulated with OMVs. Then the cell surface tissue factor (TF) activity and thrombin generation were assessed. Results Genetic deletion of Caspase-11 or GSDMD or pharmacological inhibition of caspase-11 markedly attenuated OMVs-induced coagulopathy, multiple organ injuries and mortality. Caspase-11- or GSDMD-deficient macrophages exhibited markedly reduced TF activity after OMVs stimulation. Conclusion OMVs induce DIC through the caspase-11-GSDMD pathway. These findings might open a new avenue to prevent or treat bacterial infection-induced DIC.

In this work, both the density functional theory (DFT) calculation and X-ray photoelectron spectroscopy (XPS) were conducted to investigate the depression mechanisms of cyanide on the flotation performance of chalcopyrite. The density functional theory calculation results showed that cyanide could be adsorbed on a chalcopyrite (112) surface spontaneously, which preferably occurred on the surface Fe–Fe hollow site. Both C and N atoms of cyanide could bond with Fe atoms of the chalcopyrite (112) surface, while the interaction of Fe–C bond was more intense, where the Fe 3d orbital donated electrons to the hybrid sp orbital of a C atom forming a back-donating bond. XPS analysis indicated that the chemical interaction between cyanide and surface Fe atoms occurred, resulting in the generation of a hydrophilic iron–cyanide complex on the chalcopyrite surface, which deteriorated the flotation performance of chalcopyrite.

Background: Interruption of hepatic blood inflow to reduce intraoperative blood loss during liver surgery such as elective liver surgical procedures and organ transplantation causes hepatic ischemia and subsequent reperfusion that leads to liver damage and dysfunction. Double-stranded RNA dependent protein kinase (PKR) is an important regulator of immune responses in the settings of infection and tissue injury. However, little is known about the function of PKR in liver ischemia/reperfusion (I/R) injury. Methods: Wild-type (WT) and PKR knockout (PKR-/-) mice were subjected to partial (70%) hepatic I/R injury. In another set of experiments, mice were pretreated intraperitoneally with C16, a specific PKR inhibitor, or fludarabine, a specific inhibitor of STAT1 (signal transducer and activator of transcription 1), then subjected to I/R in-vivo. In-vitro investigations were conducted by subjecting primary mouse hepatocytes with hypoxia. The role of PKR in I/R-induced liver injury and the potential underlying molecular mechanisms were clarified through biological and phenotypic analyses. Results: Liver PKR protein levels were increased during the ischemic and reperfusion stages in both the mouse liver I/R model and the livers of humans who were subjected to liver resection. PKR inactivation by genetic deletion or pharmacological inhibition exhibited less liver damage than their respective control. PKR deficiency was also associated with lower levels of inflammatory cytokines and less apoptotic cell death. Mechanistically, STAT1 signaling was inhibited in livers of PKR-/- mice but was activated in WT mice. Most importantly, WT mice treated with STAT1 specific inhibitor fludarabine were protected from hepatic I/R injury. PKR also regulated the release of HMGB1 in hepatic I/R injury.Conclusions: Our novel findings document PKR is a modulator in I/R-induced liver damage. Inhibition of PKR by using the specific inhibitor, C16, may represent a promising therapeutic target for the management of I/R injury-related diseases.

Bacterial infection not only stimulates innate immune responses but also activates coagulation cascades. Overactivation of the coagulation system in bacterial sepsis leads to disseminated intravascular coagulation (DIC), a life-threatening condition. However, the mechanisms by which bacterial infection activates the coagulation cascade are not fully understood. Here we show that type 1 interferons (IFNs), a widely expressed family of cytokines that orchestrate innate antiviral and antibacterial immunity, mediate bacterial infection-induced DIC by amplifying the release of high-mobility group box 1 (HMGB1) into the bloodstream. Inhibition of the expression of type 1 IFNs and disruption of their receptor IFN-α/βR or downstream effector (eg, HMGB1) uniformly decreased gram-negative bacteria-induced DIC. Mechanistically, extracellular HMGB1 markedly increased the procoagulant activity of tissue factor by promoting the externalization of phosphatidylserine to the outer cell surface, where phosphatidylserine assembles a complex of cofactor-proteases of the coagulation cascades. These findings not only provide novel insights into the link between innate immune responses and coagulation, but they also open a new avenue for developing novel therapeutic strategies to prevent DIC in sepsis.

A systematic first-principles model study of La(III) adsorption on kaolinite (0 0 1) surface was studied using periodic DFT calculations. The effective coordination number, coordination geometry, preferred adsorption position and adsorption type were examined. Based on the binding energy, the form of [La(OH)(H2O)8]2+ would be more stable than [La(H2O)10]3+ in a high pH solution system. Outer-layer and inner-layer adsorption models were applied to account for the different bonding between La and the kaolinite surface. The inner-layer adsorption model was dominated by coordination bonds between La and surface oxygen, while the outer-layer adsorption model was related to hydrogen bonds. The inner-layer adsorption at the Ou site was the optimal adsorption site. The PDOS projections and Mulliken bond populations suggest that the bonding orbital combination of La 5d and Ou 2p was the dominant orbital contribution of La-Ou. Contrary to the stability of La ions in aqueous systems, [La(H2O)10]3+ would be more stable than [La(OH)(H2O)8]2+ after adsorption on the kaolinite (0 0 1) surface, which was verified by microcalorimetry experiments.

Bacterial infection not only stimulates innate immune responses but also activates the coagulation cascades. Over-activation of the coagulation system in bacterial sepsis leads to disseminated intravascular coagulation (DIC), a life-threatening condition. However, the mechanisms by which bacterial infection activates the coagulation cascade are not fully understood. Here we show that type 1 interferons (IFNs), widely expressed family of cytokines that orchestrate innate antiviral and antibacterial immunity, mediate bacterial infection-induced DIC through amplifying the release of high mobility box group box 1 (HMGB1) into the blood stream. Inhibition of the expression of type 1 IFNs, disruption of their receptor IFN-α/βR or downstream effector (e.g., HMGB1) uniformly decreased Gram-negative bacteria-induced DIC. Mechanistically, extracellular HMGB1 markedly increased the pro-coagulant activity of tissue factor (TF) by promoting the externalization of phosphatidylserine (PS) to the outer cell surface, where PS assembles a complex of cofactor-proteases of the coagulation cascades. These findings not only provide novel insights into the link between innate immune responses and coagulation, but also open a new avenue for developing novel therapeutic strategies to prevent DIC in sepsis.

Summary Excessive activation of the coagulation system leads to life-threatening disseminated intravascular coagulation (DIC). Here, we examined the mechanisms underlying the activation of coagulation by lipopolysaccharide (LPS), the major cell-wall component of Gram-negative bacteria. We found that caspase-11, a cytosolic LPS receptor, activated the coagulation cascade. Caspase-11 enhanced the activation of tissue factor (TF), an initiator of coagulation, through triggering the formation of gasdermin D (GSDMD) pores and subsequent phosphatidylserine exposure, in a manner independent of cell death. GSDMD pores mediated calcium influx, which induced phosphatidylserine exposure through transmembrane protein 16F, a calcium-dependent phospholipid scramblase. Deletion of Casp11, ablation of Gsdmd, or neutralization of phosphatidylserine or TF prevented LPS-induced DIC. In septic patients, plasma concentrations of interleukin (IL)-1α and IL-1β, biomarkers of GSDMD activation, correlated with phosphatidylserine exposure in peripheral leukocytes and DIC scores. Our findings mechanistically link immune recognition of LPS to coagulation, with implications for the treatment of DIC.

Density functional theory calculations, flotation behavior, X-ray photoelectron spectroscopy, and infrared spectra were combined to reveal the Cu2+ activation mechanism on a cyanide (CN−)-leached sphalerite surface. Low CN− adsorption enhanced the activation capability of Cu2+ on the sphalerite surface, whereas the hydrophilicity of the sphalerite increased with increasing CN− coverage, which hindered Cu2+ adsorption. As the amount of chemically adsorbed Cu2+ on the sphalerite surface increased, Cu2+ began to desorb CN−, leading to the same result, which is consistent with the low CN− coverage.

Excessive activation of the coagulation system by endotoxin (lipopolysaccharide: LPS), the major cell-wall component of Gram-negative bacteria, leads to life-threatening disseminated intravascular coagulation (DIC). However, the underlying mechanisms remain largely unknown. Here, we show that caspase-11, a cytosolic LPS receptor, activates the coagulation cascade through gasdermin D (GSDMD) and tissue factor (TF), an initiator of coagulation cascades. Upon activation by caspase-11, GSDMD-mediated phosphatidylserine exposure markedly enhances the activation of TF. Genetic deletion or pharmacological inhibition of caspase-11, ablation of GSDMD or neutralization of phosphatidylserine or TF uniformly prevents LPS-induced DIC. Further, plasma concentrations of interleukin (IL)-1α and IL-1β, biomarkers of GSDMD activation, correlated with phosphatidylserine exposure in peripheral leukocytes and DIC scores in septic patients. These findings not only identify molecular links between innate immunity and coagulation, but also could open a new avenue to prevent infection-induced DIC.

Introduction Sepsis is frequently complicated by disseminated intravascular coagulation (DIC), which promotes multiple organ dysfunctions and significantly increase the mortality of patients with sepsis. How bacteria cause DIC is not fully understood. Outer membrane vesicles (OMVs) are membrane-enclosed microvesicles released by variety of bacteria. The aim of this study is to determine whether OMVs contribute to the pathogenesis of DIC during bacterial infection. Methods Wild-type (WT) or Toll-like receptor 4 (TLR4) knock-out mice were intraperitoneally injected with purified Escherichia coli (E.coli) derived OMVs, or with either wild type E.coli or E.coli with genetic deletion of ypjA, which is critical for OMV's production. Blood samples, liver and lung tissues were collected. The development of DIC was assessed in terms of the occurrence of coagulopathy, the thrombi deposition in livers and lungs, the multiple organ injuries, and the lethality. Results Genetic deletion of ypjA significantly attenuated E.coli-induced coagulopathy, intravascular thrombi deposition, multiple organ injuries and mortality, whereas injection of purified E.coli-derived OMVs resulted in the development of DIC in a TLR4-dependent manner. Conclusions OMVs importantly contribute to the pathogenesis of DIC during Gram-negative bacterial infection. These findings might open a new avenue to prevent infection-associated coagulopathy by targeting OMVs production.

Ethyl pyruvate exertsa special protectiveeffecton endotoxin-induced endotoxemia and experimental sepsis, but the underlying mechanism remains elusive. Werecently demonstrated that ethyl pyruvate inhibited caspase-11-mediated macrophage pyroptotic cell death. GasderminDis akeymolecule incaspase-11 mediated non-canonical inflammasome-inducedpyroptosis. We proved that ethyl pyruvate significantly decreased caspase-11 and gasdermin D-mediated pyroptosis induced by cytoplasmic lipopolysaccharide (LPS) and bacterial outer membrane vesicles (OMVs). Ethyl pyruvate treatment offered effective protection against lethal endotoxemia and reduced the release of IL-1α and IL-1β. Similarresults were observed in the mousececal ligation and puncture (CLP)peritonitissepsismodel. These findings identified ethyl pyruvate as an inhibitor against LPS-mediated activation of cytoplasmic caspase-11 and gasdermin D. This mechanism is believed to contribute tothe further explanation of theprotectiveactionof ethyl pyruvate in experimental sepsis and endotoxemia and the potential application of ethyl pyruvate for rescuing sepsis.