thromboplastin and Acute-Lung-Injury

The pathophysiology of acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), is characterized by increased vascular and epithelial permeability, hypercoagulation and hypofibrinolysis, inflammation, and immune modulation. These detrimental changes are orchestrated by cross talk between a complex network of cells, mediators, and signaling pathways. A rapidly growing number of studies have reported the appearance of distinct populations of microparticles (MPs) in both the vascular and alveolar compartments in animal models of ALI/ARDS or respective patient populations, where they may serve as diagnostic and prognostic biomarkers. MPs are small cytosolic vesicles with an intact lipid bilayer that can be released by a variety of vascular, parenchymal, or blood cells and that contain membrane and cytosolic proteins, organelles, lipids, and RNA supplied from and characteristic for their respective parental cells. Owing to this endowment, MPs can effectively interact with other cell types via fusion, receptor-mediated interaction, uptake, or mediator release, thereby acting as intrinsic stimulators, modulators, or even attenuators in a variety of disease processes. This review summarizes current knowledge on the formation and potential functional role of different MPs in inflammatory diseases with a specific focus on ALI/ARDS. ALI has been associated with the formation of MPs from such diverse cellular origins as platelets, neutrophils, monocytes, lymphocytes, red blood cells, and endothelial and epithelial cells. Because of their considerable heterogeneity in terms of origin and functional properties, MPs may contribute via both harmful and beneficial effects to the characteristic pathological features of ALI/ARDS. A better understanding of the formation, function, and relevance of MPs may give rise to new promising therapeutic strategies to modulate coagulation, inflammation, endothelial function, and permeability either through removal or inhibition of "detrimental" MPs or through administration or stimulation of "favorable" MPs.

Topics: Acute Lung Injury; Biological Transport; Capillary Permeability; Cell Communication; Cell-Derived Microparticles; Endothelium; Immunomodulation; Inflammation; Respiratory Distress Syndrome; Thromboplastin; Thrombosis

Acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) are characterized by excessive intraalveolar fibrin deposition, driven, at least in part by inflammation. The imbalance between activation of coagulation and inhibition of fibrinolysis in patients with ALI/ARDS favors fibrin formation and appears to occur both systemically and in the lung and airspace. Tissue factor (TF), a key mediator of the activation of coagulation in the lung, has been implicated in the pathogenesis of ALI/ARDS. As such, there have been numerous investigations modulating TF activity in a variety of experimental systems in order to develop new therapeutic strategies for ALI/ARDS. This review will summarize current understanding of the role of TF and other proteins of the coagulation cascade as well the fibrinolysis pathway in the development of ALI/ARDS with an emphasis on the pathways that are potential therapeutic targets. These include the TF inhibitor pathway, the protein C pathway, antithrombin, heparin, and modulation of fibrinolysis through plasminogen activator- 1 (PAI-1) or plasminogen activators (PA). Although experimental studies show promising results, clinical trials to date have proven unsuccessful in improving patient outcomes. Modulation of coagulation and fibrinolysis has complex effects on both hemostasis and inflammatory pathways and further studies are needed to develop new treatment strategies for patients with ALI/ARDS.

Topics: Acute Lung Injury; Animals; Antithrombins; Blood Coagulation; Factor VIIa; Heparin; Humans; Inflammation; Protein C; Recombinant Proteins; Respiratory Distress Syndrome; Thromboplastin

Acute lung injury (ALI) is a disease marked by diffuse endothelial injury and increased capillary permeability. The coagulation system is a major participant in ALI and activation of coagulation is both a consequence and contributor to ongoing lung injury. Increased coagulation and depressed fibrinolysis result in diffuse alveolar fibrin deposition which serves to amplify pulmonary inflammation. In addition, existing evidence demonstrates a direct role for different components of coagulation on vascular endothelial barrier function. In particular, the pro-coagulant protein thrombin disrupts the endothelial actin cytoskeleton resulting in increased endothelial leak. In contrast, the anti-coagulant activated protein C (APC) confers a barrier-protective actin configuration and enhances the vascular barrier in vitro and in vivo. However, recent studies suggest a complex landscape with receptor cross-talk, temporal heterogeneity and pro-coagulant/anti-coagulant protein interactions. In this article, the major signaling pathways governing endothelial permeability in lung injury are reviewed with a particular focus on the role that endothelial proteins, such as thrombin and APC, which play on the vascular barrier function.

Topics: Acute Lung Injury; Animals; Blood Coagulation; Capillary Permeability; Endothelium, Vascular; Humans; Lung; Protein C; Signal Transduction; Thromboplastin

Patients with severe infections almost invariably exhibit evidence of activation of the coagulation system. The lungs are amongst the most frequently affected organs during severe infection and sepsis. The abundant presence of intravascular and extravascular fibrin appears to be a specific hallmark of acute lung injury after sepsis. Tissue factor (TF) is regarded to be the primary initiator of coagulation in severe infection. Effective blockade of the TF pathway, either by recombinant TF pathway inhibitor or by anti-TF antibodies in experimental sepsis, attenuates lung injury and partially prevents pulmonary dysfunction. In addition, inhibition of the activity of TF prevents local activation of coagulation in models of pneumonia. The TF pathway can influence inflammatory signaling by activation of protease activated receptor-1 and -2. This review presents the most recent data on the crosstalk between TF-mediated coagulation and inflammation, with a specific emphasis on these processes in the lung.

Topics: Acute Lung Injury; Animals; Blood Coagulation; Humans; Inflammation Mediators; Respiratory Tract Infections; Thromboplastin

The tissue factor (TF)-dependent extrinsic pathway has been suggested to be a central mechanism by which the coagulation cascade is locally activated in the lungs of patients with acute lung injury and acute respiratory distress syndrome (ALI/ARDS) and thus represents an attractive target for therapeutic intervention. This study was designed to determine the pharmacokinetic and safety profiles of ALT-836, an anti-TF antibody, in patients with ALI/ARDS.. This was a prospective, randomized, placebo-controlled, dose-escalation Phase I clinical trial in adult patients who had suspected or proven infection, were receiving mechanical ventilation and had ALI/ARDS (PaO(2)/FiO(2) ≤ 300 mm). Eighteen patients (6 per cohort) were randomized in a 5:1 ratio to receive ALT-836 or placebo, and were treated within 48 hours after meeting screening criteria. Cohorts of patients were administered a single intravenously dose of 0.06, 0.08 or 0.1 mg/kg ALT-836 or placebo. Blood samples were taken for pharmacokinetic and immunogenicity measurements. Safety was assessed by adverse events, vital signs, ECGs, laboratory, coagulation and pulmonary function parameters.. Pharmacokinetic analysis showed a dose dependent exposure to ALT-836 across the infusion range of 0.06 to 0.1 mg/kg. No anti-ALT-836 antibody response was observed in the study population during the trial. No major bleeding episodes were reported in the ALT-836 treated patients. The most frequent adverse events were anemia, observed in both placebo and ALT-836 treated patients, and ALT-836 dose dependent, self-resolved hematuria, which suggested 0.08 mg/kg as an acceptable dose level of ALT-836 in this patient population.. Overall, this study showed that ALT-836 could be safely administered to patients with sepsis-induced ALI/ARDS.. ClinicalTrials.gov: NCT01438853.

Topics: Acute Lung Injury; Adult; Aged; Anemia; Antibodies; Biological Products; Cohort Studies; Female; Hematuria; Humans; Immunoglobulin G; Male; Middle Aged; Prospective Studies; Recombinant Fusion Proteins; Recombinant Proteins; Respiration, Artificial; Respiratory Distress Syndrome; Thromboplastin

Background: Monocytes and monocyte-derived tissue factor (TF) promote the development of sepsis-induced acute lung injury (ALI). Classical monocytes (C-Mcs) can be induced to express TF. Valproic acid (VPA) alleviates hemorrhagic shock (HS)-induced ALI (HS/ALI) and inhibits TF expression in monocytes. We hypothesized that C-Mcs and C-Mc-derived TF promoted HS/ALI and that VPA could inhibit C-Mc-derived TF expression and attenuate HS/ALI. Methods: Wistar rats and THP-1 cells were used to evaluate our hypothesis. Monocyte subtypes were analyzed by flow cytometry; mRNA expression was measured by fluorescence quantitative polymerase chain reaction; protein expression was measured by Western blotting, immunofluorescence, or immunohistology; inflammatory cytokines levels were measured by enzyme-linked immunosorbent assay; and ALI scores were used to determine the degree of ALI. Results: The blood %C-Mcs and C-Mcs/non-C-Mcs ratios, monocyte TF levels, serum and/or lung inflammatory cytokine levels, and ALI scores of HS rats were significantly increased ( P < 0.05). After monocyte depletion and thrombin inhibition, the inflammatory cytokine levels and ALI scores were significantly decreased ( P < 0.05). VPA reduced the %C-Mcs and C-Mc/non-C-Mc ratios, TF expression, inflammatory cytokine levels, and ALI scores during HS ( P < 0.05) and inhibited HS-induced monocyte Egr-1 and p-ERK1/2 expression ( P < 0.05). VPA inhibited hypoxia-induced TF expression in THP-1 cells by regulating the p-ERK1/2-Egr-1 axis. Conclusion: C-Mcs and C-Mc-derived TF accelerate the development of HS/ALI by increasing thrombin production. VPA inhibits HS-induced C-Mc production of TF by regulating the p-ERK1/2-Egr-1 axis and alleviates HS/ALI.

Topics: Acute Lung Injury; Animals; Cytokines; Lung; Monocytes; Rats; Rats, Wistar; Shock, Hemorrhagic; Thrombin; Thromboplastin; Valproic Acid

Topics: Acute Lung Injury; Animals; Gene Expression Regulation; Lidocaine; Lipopolysaccharides; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Sepsis; Thromboplastin; Voltage-Gated Sodium Channel Blockers

Endotoxin-induced lung injury is one of the major causes of death induced by endotoxemia, however, few effective therapeutic options exist. Hydrogen inhalation has recently been shown to be an effective treatment for inflammatory lung injury, but the underlying mechanism is unknown. In the current study we aim to investigate how hydrogen attenuates endotoxin-induced lung injury and provide reference values for the clinical application of hydrogen. LPS was used to establish an endotoxin-induced lung injury mouse model. The survival rate and pulmonary pathologic changes were evaluated. THP-1 and HUVECC cells were cultured

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Coculture Techniques; Disease Models, Animal; Down-Regulation; Human Umbilical Vein Endothelial Cells; Humans; Hydrogen; Interleukin-6; Lipopolysaccharides; Lung; Macrophages; Male; Matrix Metalloproteinase 9; Mice, Inbred ICR; Neutrophil Infiltration; Pulmonary Edema; Signal Transduction; Thioredoxins; THP-1 Cells; Thromboplastin

Sepsis is a systemic inflammatory disease causing life-threatening multi-organ dysfunction. Accumulating evidences suggest that two forms of programmed necrosis, necroptosis and pyroptosis triggered by the pathogen component lipopolysaccharide (LPS) and inflammatory cytokines, play important roles in the development of bacterial sepsis-induced shock and tissue injury. Sepsis-induced shock and tissue injury required receptor-interacting protein kinase-3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL) phosphorylation, caspase11 activation and gasdermin D (GSDMD) cleavage. However, the synergistic effect of necroptosis and pyroptosis in the pathological progress of sepsis remains elusive. In this study, we found that blockage of both necroptosis and pyroptosis (double deletion of Ripk3/Gsdmd or Mlkl/Gsdmd) resulted in accumulative protection against septic shock, systemic blood clotting and multi-organ injury in mice. Bone marrow transplantation confirmed that necroptosis and pyroptosis in both myeloid and nonmyeloid cells are indispensable in the progression of sepsis-induced multi-organ injury. Both RIPK3 and GSDMD signaling collaborated to amplify necroinflammation and tissue factor release in macrophages and endothelial cells, which led to tissue injury. Furthermore, cell death induced by inflammatory cytokines and high-mobility group box 1 could be prevented by double ablation of Ripk3/Gsdmd or Mlkl/Gsdmd, suggesting that a positive feedback loop interconnecting RIPK3/MLKL and GSDMD machinery and inflammation facilitated sepsis progression. Collectively, our findings demonstrated that RIPK3-mediated necroptosis and GSDMD-mediated pyroptosis collaborated to amply inflammatory signaling and enhance tissue injury in the process of sepsis, which may shed new light on two potential targets of combined therapeutic interventions for this highly lethal disorder.

Topics: Acute Lung Injury; Animals; Blood Coagulation; Cecum; Cell Movement; Endothelial Cells; Gene Deletion; Inflammation; Interleukin-1beta; Intestines; Intracellular Signaling Peptides and Proteins; Ligation; Mice, Inbred C57BL; Mice, Knockout; Monocytes; Myeloid Cells; Necroptosis; Neutrophils; Organ Specificity; Phosphate-Binding Proteins; Punctures; Pyroptosis; Receptor-Interacting Protein Serine-Threonine Kinases; Sepsis; Signal Transduction; Thromboplastin

Topics: Acute Lung Injury; Animals; Biomarkers; Biopsy; Cysteine Endopeptidases; Disease Models, Animal; Immunophenotyping; JNK Mitogen-Activated Protein Kinases; Lipopolysaccharides; Macrophages; Mice; Mice, Knockout; Monocytes; Phosphorylation; Protein Kinase Inhibitors; Reactive Oxygen Species; Thromboplastin

Acute lung injury (ALI) caused by gas explosion is common, and warrants research on the underlying mechanisms. Specifically, the role of abnormalities of coagulation and fibrinolysis in this process has not been defined. It was hypothesized that the abnormal coagulation and fibrinolysis promoted ALI caused by gas explosion. Based on the presence of ALI, 74 cases of gas explosion injury were divided into the ALI and non-ALI groups. The results of prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), and platelet count (PLT) were collected within 24 hours and compared between the groups. ALI models caused by gas explosion were established in Sprague Dawley rats, and injuries were evaluated using hematoxylin and eosin (HE) staining and histopathological scoring. Moreover, the bronchoalveolar lavage fluid (BALF) was collected to examine thrombin-antithrombin complex (TAT), tissue factor (TF), tissue factor pathway inhibitor (TFPI), and plasminogen activator inhibitor-1 (PAI-1) levels by enzyme-linked immunosorbent assay (ELISA). The patients in ALI group had shorter PT and longer APTT, raised concentration of FIB and decreased number of PLT, as compared to the non-ALI group. In ALI rats, the HE staining revealed red blood cells in alveoli and interstitial thickening within 2 hours which peaked at 72 hours. The levels of TAT/TF in the BALF increased continually until the seventh day, while the PAI-1 was raised after 24 hours and 7 days. The TFPI was elevated after 2 hours and 24 hours, and then decreased after 72 hours. Abnormalities in coagulation and fibrinolysis in lung tissues play a role in ALI caused by gas explosion.

Topics: Acute Lung Injury; Animals; Antithrombin III; Blast Injuries; Blood Platelets; Bronchoalveolar Lavage Fluid; Explosions; Fibrinogen; Fibrinolysis; Gases; Humans; Lipoproteins; Lung; Partial Thromboplastin Time; Peptide Hydrolases; Plasminogen Activator Inhibitor 1; Platelet Count; Prothrombin Time; Rats; Rats, Sprague-Dawley; Thromboplastin

Tissue factor (TF)-dependent coagulation contributes to lung inflammation and the pathogenesis of acute lung injury (ALI). In this study, we explored the roles of targeted endothelial anticoagulation in ALI using two strains of transgenic mice expressing either a membrane-tethered human tissue factor pathway inhibitor (hTFPI) or hirudin fusion protein on CD31

Topics: Acute Lung Injury; Animals; Blood Coagulation; Chemokines; Chemotaxis, Leukocyte; Endothelial Cells; Hirudins; Humans; Inflammation; Leeches; Lipopolysaccharides; Lipoproteins; Lung; Mice, Inbred C57BL; Mice, Transgenic; Platelet Endothelial Cell Adhesion Molecule-1; Pseudomonas aeruginosa; Receptors, Proteinase-Activated; Recombinant Fusion Proteins; Thrombin; Thromboplastin

Essentials Tissue factor (TF) represents a central link between hemostasis and inflammation. We studied the roles of myeloid and airway epithelial TF in acid-caused acute lung injury (ALI). TF on myeloid cells displays a non-coagulatory role regulating the inflammatory response in ALI. Airway epithelial TF contributes to hemostatic functions, but is dispensable in ALI pathogenesis.. Introduction Acute lung injury (ALI) is a life-threatening condition characterized by damaged alveolar-capillary structures and activation of inflammatory and hemostatic processes. Tissue factor (TF) represents a crucial link between inflammation and coagulation, as inflammatory mediators induce myeloid TF expression, and TF initiates extrinsic coagulation. Objective As pulmonary inflammation stimulates TF expression and TF modulates immune responses, we aimed to elucidate its impact on ALI. In particular, we wanted to distinguish the contributions of TF expressed on airway epithelial cells and TF expressed on myeloid cells. Methods Mice with different cell type-specific TF deficiency and wild-type littermates were intratracheally treated with hydrochloric acid, and leukocyte recruitment, cytokine levels, thrombin-antithrombin (TAT) complexes and pulmonary protein-rich infiltrates were analyzed. Results Our data demonstrate that a lack of epithelial TF did not influence acute responses, as bronchoalveolar neutrophil accumulation 8 h after ALI induction was unaltered. However, it led to mild, prolonged inflammation, as pulmonary leukocyte and erythrocyte numbers were still increased after 24 h, whereas those in wild-type mice had returned to basal levels. In contrast, myeloid TF was primarily involved in regulating the acute phase of ALI without affecting local coagulation, as indicated by increased bronchoalveolar neutrophil infiltration, pulmonary interleukin-6 levels, and edema formation, but equal TAT complex formation, 8 h after ALI induction. This augmented inflammatory response associated with myeloid TF deficiency was confirmed in vitro, as lipopolysaccharide-stimulated TF-deficient alveolar macrophages released increased levels of chemokine (C-X-C motif) ligand 1 and tumor necrosis factor-α as compared with wild-type macrophages. Conclusion We conclude that myeloid TF dampens inflammation in acid-induced ALI.

Topics: Acute Lung Injury; Animals; Antithrombin III; Blood Coagulation; Cells, Cultured; Chemotaxis, Leukocyte; Cytokines; Disease Models, Animal; Epithelial Cells; Genetic Predisposition to Disease; Hydrochloric Acid; Inflammation Mediators; Lung; Macrophages, Alveolar; Mice, Inbred C57BL; Mice, Knockout; Neutrophil Infiltration; Peptide Hydrolases; Phenotype; Pneumonia; Pulmonary Edema; Thromboplastin; Time Factors

It is generally regarded that Sirtuin 1 (SIRT1), a longevity factor in mammals, acts as a negative regulator of inflammation. However, recent studies also found that SIRT1 might be a detrimental factor under certain inflammatory circumstance. In this study, the potential pathophysiological roles and the underlying mechanisms of SIRT1 in a mouse model with endotoxemia-associated acute lung injury were investigated. The results indicated that treatment with the selective SIRT1 inhibitor EX-527 suppressed LPS-induced elevation of TNF-α and IL-6 in plasma. Treatment with EX-527 attenuated LPS-induced histological abnormalities in lung tissue, which was accompanied with decreased myeloperoxidase level and suppressed induction of tissue factor and plasminogen activator inhibitor-1. Treatment with EX-527 also suppressed LPS-induced phosphorylation of eukaryotic translation initiation factor-binding protein 1 (4E-BP1). Co-administration of a mammalian target of rapamycin (mTOR) activator 3-benzyl-5-[(2-nitrophenoxy) methyl]-dihydrofuran-2 (3H)-one (3BDO) abolished the inhibitory effects of EX-527 on 4E-BP1 phosphorylation. Meanwhile, the inhibitory effects of EX-527 on IL-6 induction and the beneficial effects of EX-527 on lung injury were partially reversed by 3BDO. This study suggests that selective inhibition of SIRT1 by EX-527 might alleviate endotoxemia-associated acute lung injury partially via suppression of mTOR, which implies that SIRT1 selective inhibitors might have potential value for the pharmacological intervention of inflammatory lung injury.

Topics: 4-Butyrolactone; Acute Lung Injury; Adaptor Proteins, Signal Transducing; Animals; Carbazoles; Carrier Proteins; Cell Cycle Proteins; Endotoxemia; Eukaryotic Initiation Factors; Interleukin-6; Lipopolysaccharides; Lung; Male; Mice; Mice, Inbred BALB C; Phosphoproteins; Phosphorylation; Plasminogen Activator Inhibitor 1; Sirtuin 1; Thromboplastin; TOR Serine-Threonine Kinases; Tumor Necrosis Factor-alpha

For the purposes of the present study, the protective effect of prostaglandin E1 (PGE1) on lung injury following renal ischemia-reperfusion (RIR) was investigated. Adult male rats were divided into four groups, namely, (I) control rats given physiological saline; (II) rats given PGE1 (20 μg/kg, intravenously); (III) rats subjected to RIR; and (IV) rats subjected to RIR given PGE1 30 min prior to ischemia and just before reperfusion. The right nephrectomy was performed in the RIR model. The left renal pedicle was occluded for 60 min to induce ischemia and then the left kidney was subjected to reperfusion for 60 min. The lungs of rats were used for microscopic and biochemical analyses. Although rats subjected to RIR did not exhibit heavy degenerative alterations in the lung structure, they possessed pulmonary interstitial edema. Lung glutathione levels and catalase, superoxide dismutase, glutathione peroxidase, and tissue factor (TF) activities were decreased in rats subjected to RIR, while lung lipid peroxidation, myeloperoxidase (MPO), xanthine oxidase and serum lactate dehydrogenase (LDH) activities, and blood urea and serum creatinine levels were increased in these rats when compared with the control group. PGE1 treatments resulted in the regression of oxidative stress via induction of antioxidant system, the decreased MPO and LDH activities, the reduced urea and creatinine levels, and the induced TF activity in rats subjected to RIR, while edema still remained permanent. We conclude that PGE1 may be useful in preventing lung injury with the exception of edema that occurred as a result of RIR in rats.

Topics: Acute Lung Injury; Alprostadil; Animals; Biomarkers; Glutathione; Immunohistochemistry; Infusions, Intravenous; Ischemia; Kidney; Lipid Peroxidation; Lung; Male; Nephrectomy; Oxidative Stress; Oxidoreductases; Protective Agents; Pulmonary Edema; Rats, Sprague-Dawley; Reperfusion Injury; Thromboplastin

Sepsis-induced acute lung injury (ALI) is characterized by fibrin deposition, which indicates the local activation of coagulation. Tissue factor (TF), expressed in the pulmonary microvasculature, acts as a critical initiator of blood coagulation and ALI in sepsis. The molecular mechanism of lipopolysaccharide (LPS)-induced TF expression in endothelial cells (ECs), however, has not been determined. In this study, we implicate the Rho-associated protein kinase (ROCK)/Yes associated protein (YAP)/early growth response (Egr-1) signaling pathway in LPS-induced TF expression in vitro and in sepsis-induced ALI in vivo.. Human umbilical vein ECs incubated with LPS were pretreated with or without the ROCK inhibitor Y-27632, a YAP small, interfering RNA (siRNA) and an Egr-1 siRNA. ROCK, YAP and Egr-1 signaling-induced protein expression was investigated by Western blot. The LPS-induced activation of YAP was analyzed by an immunofluorescent assay. Furthermore, we intratracheally injected YAP siRNA to assess septic ALI in mice by hematoxylin and eosin staining.. LPS rapidly induced ROCK activation and increased TF expression in ECs. LPS caused YAP shuttling into the nuclei of ECs and combined with Egr-1 via the activation of ROCK. Furthermore, the LPS-mediated TF expression increase was prevented by ROCK inactivation, YAP knockdown and Egr-1 depletion, suggesting that LPS-induced TF expression is closely associated with the ROCK/YAP/Egr-1 signaling pathway in ECs. Finally, an intratracheal injection of YAP siRNA relieved lung injury in septic mice.. This study not only suggests that ROCK/YAP/Egr-1 signaling regulates TF expression after stimulation with LPS in ECs, but it also indicates that LPS-induced activation of YAP signaling plays an important role in septic ALI in mice. Our findings provide a new insight into the pathogenic mechanism of TF expression, which is closely linked to septic ALI, and YAP signaling is considered to be a novel target for therapeutic intervention under septic conditions.

Topics: Acute Lung Injury; Adaptor Proteins, Signal Transducing; Animals; Biomarkers; Blotting, Western; Cell Cycle Proteins; Early Growth Response Protein 1; Human Umbilical Vein Endothelial Cells; Humans; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Phosphoproteins; rho-Associated Kinases; Sepsis; Signal Transduction; Thromboplastin; Transcription Factors; YAP-Signaling Proteins

Tissue factor (TF) is a critical mediator of direct acute lung injury (ALI) with global TF deficiency resulting in increased airspace inflammation, alveolar-capillary permeability, and alveolar hemorrhage after intra-tracheal lipopolysaccharide (LPS). In the lung, TF is expressed diffusely on the lung epithelium and intensely on cells of the myeloid lineage. We recently reported that TF on the lung epithelium, but not on myeloid cells, was the major source of TF during intra-tracheal LPS-induced ALI. Because of a growing body of literature demonstrating important pathophysiologic differences between ALI caused by different etiologies, we hypothesized that TF on myeloid cells may have distinct contributions to airspace inflammation and permeability between direct and indirect causes of ALI. To test this, we compared mice lacking TF on myeloid cells (TF(∆mye), LysM.Cre(+/-)TF(flox/flox)) to littermate controls during direct (bacterial pneumonia, ventilator-induced ALI, bleomycin-induced ALI) and indirect ALI (systemic LPS, cecal ligation and puncture). ALI was quantified by weight loss, bronchoalveolar lavage (BAL) inflammatory cell number, cytokine concentration, protein concentration, and BAL procoagulant activity. There was no significant contribution of TF on myeloid cells in multiple models of experimental ALI, leading to the conclusion that TF in myeloid cells is not a major contributor to experimental ALI.

Topics: Acute Lung Injury; Animals; Cytokines; Disease Models, Animal; Female; Lipopolysaccharides; Macrophages; Male; Mice; Mice, Transgenic; Myeloid Cells; Permeability; Phagocytosis; Pneumonia; Respiratory Distress Syndrome; Thromboplastin

Tissue factor (TF) initiates the extrinsic coagulation cascade in response to tissue injury, leading to local fibrin deposition. Low levels of TF in mice are associated with increased severity of acute lung injury (ALI) after intratracheal LPS administration. However, the cellular sources of the TF required for protection from LPS-induced ALI remain unknown. In the current study, transgenic mice with cell-specific deletions of TF in the lung epithelium or myeloid cells were treated with intratracheal LPS to determine the cellular sources of TF important in direct ALI. Cell-specific deletion of TF in the lung epithelium reduced total lung TF expression to 39% of wild-type (WT) levels at baseline and to 29% of WT levels after intratracheal LPS. In contrast, there was no reduction of TF with myeloid cell TF deletion. Mice lacking myeloid cell TF did not differ from WT mice in coagulation, inflammation, permeability, or hemorrhage. However, mice lacking lung epithelial TF had increased tissue injury, impaired activation of coagulation in the airspace, disrupted alveolar permeability, and increased alveolar hemorrhage after intratracheal LPS. Deletion of epithelial TF did not affect alveolar permeability in an indirect model of ALI caused by systemic LPS infusion. These studies demonstrate that the lung epithelium is the primary source of TF in the lung, contributing 60-70% of total lung TF, and that lung epithelial, but not myeloid, TF may be protective in direct ALI.

Topics: Acute Lung Injury; Animals; Blood Coagulation; Capillary Permeability; Disease Models, Animal; Epithelial Cells; Gene Expression; Hemorrhage; Lipopolysaccharides; Mice; Mice, Knockout; Myeloid Cells; Pulmonary Alveoli; Respiratory Distress Syndrome; Respiratory Mucosa; Thromboplastin

Tissue factor (TF) and tissue factor pathway inhibitor (TFPI) play a central role in the endothelial permeability regulation and dysfunction, which is associated with the development of sepsis and acute lung injury/acute respiratory distress syndrome (ALI/ARDS). The aim of this study is to assess the diagnostic and prognostic values of TF and TFPI in patients with sepsis and sepsis-induced ARDS.. A total of 62 patients with sepsis, 167 patients with severe sepsis and 32 healthy volunteers were enrolled in this prospective observational study. TF and TFPI levels were measured by enzyme-linked immunosorbent assay (ELISA).. Patients with sepsis-induced ARDS showed significantly higher median levels of TF compared with patients without ARDS (1425.5 (1019.9 to 2595.2) pg/ml vs 916.2 (724.1 to 1618.2) pg/ml, P < 0.001), and compared with sepsis patients (943.5 (786.4 to 992.4) pg/ml, P < 0.001) on the day of admission. However, there was no significant difference between sepsis patients and healthy subjects, or between septic shock and non-septic shock patients (P > 0.05). The AUC of TF for the diagnosis of sepsis-induced ARDS was 0.749 (95% confidence interval (CI) 0.675-0.822). Plasma TF levels in the non-survivors of severe sepsis were significantly higher than those of survivors (1618.6 (1017.1 to 2900.8) pg/ml vs. 979.9 (757.2 to 1645.5) pg/ml, P < 0.001), and multivariate logistic regression showed the plasma value of TF was the independent predictor for 30-day mortality in patients with severe sepsis (P = 0.0022, odds ratio (OR) = 1.41, 95% CI 1.24-1.69). The AUC of TF for predicting 30-day mortality in severe sepsis patients was 0.718 (95% CI 0.641-0.794). However, there was no significant difference in the plasma TFPI values among the healthy control, sepsis and severe sepsis groups (P > 0.05).. Our data showed that tissue factor is a valuable diagnostic biomarker for the diagnosis of sepsis-induced ARDS. Moreover, tissue factor is a strong prognostic marker for short-term mortality in severe sepsis and sepsis-induced ARDS patients.

Topics: Acute Lung Injury; Aged; Case-Control Studies; Female; Humans; Male; Middle Aged; Prognosis; Respiratory Distress Syndrome; ROC Curve; Sepsis; Survival Analysis; Thromboplastin; Treatment Outcome

Acute lung injury is still a significant clinical problem with a high mortality rate and there are few effective therapies in clinic. Here, we studied the inhibitory effect of ruscogenin, an anti-inflammatory and anti-thrombotic natural product, on lipopolysaccharide (LPS)-induced acute lung injury in mice basing on our previous studies. The results showed that a single oral administration of ruscogenin significantly decreased lung wet to dry weight (W/D) ratio at doses of 0.3, 1.0 and 3.0 mg/kg 1 h prior to LPS challenge (30 mg/kg, intravenous injection). Histopathological changes such as pulmonary edema, coagulation and infiltration of inflammatory cells were also attenuated by ruscogenin. In addition, ruscogenin markedly decreased LPS-induced myeloperoxidase (MPO) activity and nitrate/nitrite content, and also downregulated expression of tissue factor (TF), inducible NO synthase (iNOS) and nuclear factor (NF)-κB p-p65 (Ser 536) in the lung tissue at three doses. Furthermore, ruscogenin reduced plasma TF procoagulant activity and nitrate/nitrite content in LPS-induced ALI mice. These findings confirmed that ruscogenin significantly attenuate LPS-induced acute lung injury via inhibiting expressions of TF and iNOS and NF-κB p65 activation, indicating it as a potential therapeutic agent for ALI or sepsis.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Disease Models, Animal; Lipopolysaccharides; Male; Mice; Mice, Inbred ICR; NF-kappa B; Nitrates; Nitric Oxide Synthase Type II; Nitrites; Peroxidase; Spirostans; Thromboplastin

Although the lung expresses procoagulant proteins under inflammatory conditions, underlying mechanisms remain unclear. Here, we addressed lung endothelial expression of tissue factor (TF), which initiates the coagulation cascade and expression of which signifies development of a procoagulant phenotype in the vasculature. To establish the model of acid-induced acute lung injury (ALI), we intranasally instilled anesthetized mice with saline or acid. Then 2 h later, we isolated pulmonary vascular cells for flow cytometry and confocal microscopy to detect the leukocyte antigen, CD45 and the endothelial markers VE-cadherin and von Willebrand factor (vWf). Acid increased both the number of vWf-expressing cells as well as TF and P-selectin expressions on these cells. All of these effects were markedly inhibited by treating mice with antiplatelet serum, suggesting the involvement of platelets. The increased expressions of TF, vWf, and P-selectin in response to acid also occurred in platelets. Moreover, the effects were replicated in endothelial cells derived from isolated, blood-perfused lungs. However, the effect was inhibited completely in lungs perfused with platelet-depleted and, to a lesser extent, with leukocyte-depleted blood. Acid injury increased endothelial expressions of the platelet proteins, CD41 and CD42b, providing evidence that platelet proteins were transferred to the vascular surface. Reactive oxygen species (ROS) were implicated in these responses, in that the endothelial and platelet protein expressions were inhibited. We conclude that acid-induced ALI causes NOX2-mediated ROS generation that activates platelets, which then generate a procoagulant endothelial surface.

Topics: Acute Lung Injury; Animals; Antigens, CD; Blood Coagulation; Blood Platelets; Cadherins; Disease Models, Animal; Endothelial Cells; Endothelium, Vascular; Hydrochloric Acid; Leukocyte Common Antigens; Lung; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; NADPH Oxidase 2; NADPH Oxidases; P-Selectin; Platelet Activation; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIb-IX Complex; Platelet Membrane Glycoprotein IIb; Reactive Oxygen Species; Thromboplastin; von Willebrand Factor

Systemic blockade of tissue factor (TF) attenuates acute lung injury (ALI) in animal models of sepsis but the effects of global TF deficiency are unknown. We used mice with complete knockout of mouse TF and low levels (∼1%) of human TF (LTF mice) to test the hypothesis that global TF deficiency attenuates lung inflammation in direct lung injury.. LTF mice were treated with 10 μg of lipopolysaccharide (LPS) or vehicle administered by direct intratracheal injection and studied at 24 h.. Contrary to our hypothesis, LTF mice had increased lung inflammation and injury as measured by bronchoalveolar lavage cell count (3.4×10(5) wild-type (WT) LPS vs 3.3×10(5) LTF LPS, p=0.947) and protein (493 μg/ml WT LPS vs 1014 μg/ml LTF LPS, p=0.006), proinflammatory cytokines (TNF-α, IL-10, IL-12, p<0.035 WT LPS vs LTF LPS) and histology compared with WT mice. LTF mice also had increased haemorrhage and free haemoglobin in the airspace accompanied by increased oxidant stress as measured by lipid peroxidation products (F(2) isoprostanes and isofurans).. These findings indicate that global TF deficiency does not confer protection in a direct lung injury model. Rather, TF deficiency causes increased intra-alveolar haemorrhage following LPS leading to increased lipid peroxidation. Strategies to globally inhibit TF may be deleterious in patients with ALI.

Topics: Acute Lung Injury; Analysis of Variance; Animals; Blotting, Western; Bronchoalveolar Lavage; Cytokines; Electrophoresis, Polyacrylamide Gel; Furans; Hemoglobins; Hemorrhage; Inflammation; Isoprostanes; Lipopolysaccharides; Mice; Mice, Knockout; Oxidative Stress; Pulmonary Alveoli; Real-Time Polymerase Chain Reaction; Statistics, Nonparametric; Thromboplastin

To determine if neurally adjusted ventilatory assist (NAVA) that delivers pressure in proportion to diaphragm electrical activity is as protective to acutely injured lungs (ALI) and non-pulmonary organs as volume controlled (VC), low tidal volume (Vt), high positive end-expiratory pressure (PEEP) ventilation.. Prospective, randomized, laboratory animal study.. Twenty-seven male New Zealand white rabbits.. Anesthetized rabbits with hydrochloric acid-induced ALI were randomized (n = 9 per group) to 5.5 h NAVA (non-paralyzed), VC (paralyzed; Vt 6-ml/kg), or VC (paralyzed; Vt 15-ml/kg). PEEP was adjusted to hemodynamic goals in NAVA and VC6-ml/kg, and was 1 cmH2O in VC15-ml/kg.. PaO2/FiO2; lung wet-to-dry ratio; lung histology; interleukin-8 (IL-8) concentrations in broncho-alveolar-lavage (BAL) fluid, plasma, and non-pulmonary organs; plasminogen activator inhibitor type-1 and tissue factor in BAL fluid and plasma; non-pulmonary organ apoptosis rate; creatinine clearance; echocardiography. PEEP was similar in NAVA and VC6-ml/kg. During NAVA, Vt was lower (3.1 +/- 0.9 ml/kg), whereas PaO2/ FiO2, respiratory rate, and PaCO2 were higher compared to VC6-ml/kg (p<0.05 for all). Variables assessing ventilator-induced lung injury (VILI), IL-8 levels, non-pulmonary organ apoptosis rate, and kidney as well as cardiac performance were similar in NAVA compared to VC6-ml/kg. VILI and non-pulmonary organ dysfunction was attenuated in both groups compared to VC15-ml/kg.. In anesthetized rabbits with early experimental ALI, NAVA is as effective as VC6-ml/kg in preventing VILI, in attenuating excessive systemic and remote organ inflammation, and in preserving cardiac and kidney function.

Topics: Acute Lung Injury; Analysis of Variance; Animals; Bronchoalveolar Lavage Fluid; Diaphragm; Disease Models, Animal; Electrophysiological Phenomena; Feedback, Physiological; Interleukin-8; Male; Multiple Organ Failure; Plasminogen Activator Inhibitor 1; Positive-Pressure Respiration; Prospective Studies; Rabbits; Random Allocation; Respiration, Artificial; Statistics, Nonparametric; Thromboplastin; Tidal Volume; Ventilator-Induced Lung Injury