Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0034063 (pulmonary edema)
 10,665 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Urokinase plasminogen activator (uPA) plays a major role in fibrinolytic processes and also can potentiate LPS-induced neutrophil activation through interactions with its kringle domain (KD). To investigate the role of the uPA KD in modulating acute inflammatory processes in vivo, we cloned and then developed Abs to the murine uPA KD. Increased pulmonary expression of uPA and the uPA KD was present in the lungs after LPS exposure. Administration of anti-kringle Abs diminished LPS-induced up-regulation of uPA and uPA KD in the lungs, and also decreased the severity of LPS-induced acute lung injury, as determined by development of lung edema, pulmonary neutrophil accumulation, histology, and lung IL-6, MIP-2, and TNF-alpha cytokine levels. These proinflammatory effects of the uPA KD appeared to be mediated through activation of Akt and NF-kappaB. The present studies indicate that the uPA KD plays a major role in the development of TLR4-mediated acute inflammatory processes, including lung injury. Blockade of the uPA KD may prevent the development or ameliorate the severity of acute lung injury induced through TLR4-dependent mechanisms, such as would occur in the setting of Gram-negative pulmonary or systemic infection.
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PMID:Involvement of the urokinase kringle domain in lipopolysaccharide-induced acute lung injury. 1701 42

Intra-alveolar fibrin deposition is a common response to localized and diffuse lung infection and acute lung injury (ALI). We hypothesized that the alveolar epithelium modulates intra-alveolar fibrin deposition through activation of protein C. Our objectives [corrected] were to determine whether components of the protein C activation pathway are present in the alveolar compartment in ALI and whether alveolar epithelium is a potential source. In patients with ALI, pulmonary edema fluid levels of endothelial protein C receptor (EPCR) were higher than plasma, suggesting a source in the lung. To determine whether alveolar epithelial cells are a potential source, protein C activation by A549, small airway epithelial, and primary human alveolar epithelial type II cells was measured. All three cell types express thrombomodulin (TM) and EPCR, and activate protein C on the cell surface. Activation of protein C was inhibited by cytomix (TNF-alpha, IL-1beta, and IFN-gamma). Release of EPCR and TM into the conditioned medium was inhibited by the metalloproteinase inhibitors tumor necrosis factor protease inhibitor (TAPI) and GM6001, indicating that the shedding of EPCR and TM from the alveolar epithelium is mediated by a metalloproteinase. These findings provide new evidence that the alveolar epithelium can modulate the protein C pathway and thus could be an important determinant of alveolar fibrin deposition. Local fibrin deposition may be a fundamental mechanism for the lung to localize and confine injury, thus limiting the risk of dissemination of injury or infection to the systemic circulation.
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PMID:Novel role of the human alveolar epithelium in regulating intra-alveolar coagulation. 1709 42

Leukotrienes are increased locally in idiopathic pulmonary fibrosis. Furthermore, a role for these arachidonic acid metabolites has been thoroughly characterized in the animal bleomycin model of lung fibrosis by using different gene knock-out settings. We investigated the efficacy of pharmacological inhibition of leukotrienes activity in the development of bleomycin-induced lung injury by comparing the responses in wild-type mice with mice treated with zileuton, a 5-lipoxygenase inhibitor and MK-571, a cys-leukotrienes receptor antagonist. Mice were subjected to intra-tracheal administration of bleomycin or saline and were assigned to receive either MK-571 at 1 mg/Kg or zileuton at 50 mg/Kg daily. One week after bleomycin administration, BAL cell counts, lung histology with van Gieson for collagen staining and immunohistochemical analysis for myeloperoxidase, IL-1 and TNF-alpha were performed. Following bleomycin administration both MK-571 and zileuton treated mice exhibited a reduced degree of lung damage and inflammation when compared to WT mice as shown by the reduction of:(i) loss of body weight, (ii) mortality rate, (iii) lung infiltration by neutrophils (myeloperoxidase activity, BAL total and differential cell counts), (iv) lung edema, (v) histological evidence of lung injury and collagen deposition, (vi) lung myeloperoxidase, IL-1 and TNF-alpha staining. This is the first study showing that the pharmacological inhibition of leukotrienes activity attenuates bleomycin-induced lung injury in mice. Given our results as well as those coming from genetic studies, it might be considered meaningful to trial this drug class in the treatment of pulmonary fibrosis, a disease that still represents a major challenge to medical treatment.
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PMID:Pharmacological inhibition of leukotrienes in an animal model of bleomycin-induced acute lung injury. 1711 1

Hemorrhagic shock followed by resuscitation (HSR) causes neutrophil sequestration in the lung which leads to acute lung injury (ALI). Neutrophil elastase (NE) is thought to play a pivotal role in the pathogenesis of ALI. This study investigated whether sivelestat, a specific NE inhibitor, can attenuate ALI induced by HSR in rats. Male Sprague-Dawley rats were subjected to hemorrhagic shock by withdrawing blood so as to maintain a mean arterial blood pressure of 30+/-5 mm Hg for 60 min followed by resuscitation with the shed blood. HSR-treated animals received a bolus injection of sivelestat (10 mg/kg) intravenously at the start of resuscitation followed by continuous infusion for 60 min (10 mg/kg/h) during the resuscitation phase, or the vehicle. Lung injury was assessed by pulmonary histology, lung wet-weight to dry-weight (W/D) ratio, myeloperoxidase (MPO) activity, gene expression of tumor necrosis factor (TNF)-alpha and inducible nitric oxide synthase (iNOS), DNA binding activity of nuclear factor (NF)-kappaB, and immunohistochemical analysis of intercellular adhesion molecule (ICAM)-1. HSR treatment induced lung injury, as demonstrated by pulmonary edema with infiltration of neutrophils, the increase in lung W/D ratio, MPO activity, gene expression of TNF-alpha and iNOS, and DNA-binding activity of NF-kappaB, and enhanced expression of ICAM-1. In contrast, sivelestat treatment significantly ameliorated the HSR-induced lung injury, as judged by the marked improvement in all these indices. These results indicate that sivelestat attenuated HSR-induced lung injury at least in part through an inhibition of the inflammatory signaling pathway, in addition to the direct inhibitory effect on NE.
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PMID:A neutrophil elastase inhibitor, sivelestat, ameliorates lung injury after hemorrhagic shock in rats. 1720 97

Carnosine is an endogenously synthesized dipeptide composed of beta-alanine and L-histidine. It acts as a free radical scavenger and possesses antioxidant properties. Carnosine reduces proinflammatory and profibrotic cytokines such as transforming growth factor-beta (TGF-beta), IL-1, and TNF-alpha in different experimental settings. In the present study, we investigated the efficacy of carnosine on the animal model of bleomycin-induced lung injury. Mice were subjected to intratracheal administration of bleomycin and were assigned to receive carnosine daily by an oral bolus of 150 mg/kg. One week after fibrosis induction, bronchoalveolar lavage (BAL) cell counts and TGF-beta levels, lung histology, and immunohistochemical analyses for myeloperoxidase, TGF-beta, inducible nitric oxide synthase, nitrotyrosine, and poly(ADP-ribose) polymerase were performed. Finally, apoptosis was quantified by terminal deoxynucleotidyltransferase-mediated UTP end-labeling assay. After bleomycin administration, carnosine-treated mice exhibited a reduced degree of lung damage and inflammation compared with wild-type mice, as shown by the reduction of 1) body weight, 2) mortality rate, 3) lung infiltration by neutrophils (myeloperoxidase activity and BAL total and differential cell counts), 4) lung edema, 5) histological evidence of lung injury and collagen deposition, 6) lung myeloperoxidase, TGF-beta, inducible nitric oxide synthase, nitrotyrosine, and poly(ADP-ribose) polymerase immunostaining, 7) BAL TGF-beta levels, and 8) apoptosis. Our results indicate that orally administered carnosine is able to prevent bleomycin-induced lung injury likely through its direct antioxidant properties. Carnosine is already available for human use. It might prove useful as an add-on therapy for the treatment of fibrotic disorders of the lung where oxidative stress plays a role, such as for idiopathic pulmonary fibrosis, a disease that still represents a major challenge to medical treatment.
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PMID:Protective effect of orally administered carnosine on bleomycin-induced lung injury. 1722 Mar 73

To clarify the role of macrophage class A scavenger receptors (SR-A, CD204) in oxidative lung injury, we examined lung tissue of SR-A deficient (SR-A(-/-)) and wild-type (SR-A(+/+)) mice in response to hyperoxic treatment. Protein levels of bronchoalveolar lavage fluid (BALF) and pulmonary oedema (wet : dry weight ratios) were higher in SR-A(-/-) mice than those in SR-A(+/+) mice. Cumulative survival was significantly decreased in SR-A(-/-) mice. However, there were no differences in BALF macrophage and neutrophil count between the two groups. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that messenger RNA (mRNA) levels of the inducible nitric oxide synthase (iNOS) were increased during hyperoxic injury, and this increase was more prominent in SR-A(-/-) mice. Expression levels of iNOS in alveolar macrophages after hyperoxia in vivo and in vitro were higher in SR-A(-/-) macrophages compared with SR-A(+/+) macrophages. Immunohistochemistry using anti-nitrotyrosine antibodies revealed distinctive oxidative stress in the injured lung in both groups, but it was more remarkable in the SR-A(-/-) mice. After hyperoxic treatment, pulmonary mRNA levels of tumour necrosis factor-alpha(TNF-alpha) were elevated more rapidly in SR-A(-/-) mice than in SR-A(+/+) mice. Together these results suggest that SR-A expression attenuates hyperoxia-induced lung injury by reducing macrophage activation.
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PMID:Class A scavenger receptor (CD204) attenuates hyperoxia-induced lung injury by reducing oxidative stress. 1737 Feb 94

Ischemia reperfusion (I/R) injury following lung transplantation is exacerbated by the destruction of the endothelial cell barrier leading to pulmonary edema and dysregulated activated lymphocyte migration. Sphingosine 1-phosphate (S1P), a G-coupled protein receptor (GPCR) agonist, has been previously shown to promote endothelial cell tight junction formation and prevent monocyte chemotaxis. We asked if S1P treatment could improve pulmonary function and attenuate I/R injury following syngeneic rat lung transplantation. In comparison to vehicle-treated recipients, S1P administered before reperfusion significantly improved recipient oxygenation following transplantation. Improved graft function was associated with reduced inflammatory signaling pathway activation along with attenuated intragraft levels of MIP-2, TNF-alpha and IL-1beta. Moreover, S1P-treated recipients had significantly less apoptotic endothelial cells, pulmonary edema and graft accumulation of neutrophils than did vehicle-treated recipients. Thus our data show that S1P improves lung tissue homeostasis following reperfusion by enhancing endothelial barrier function and blunting monocytic graft infiltration and inflammation.
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PMID:Sphingosine 1-phosphate inhibits ischemia reperfusion injury following experimental lung transplantation. 1739 Nov 20

Recent in vivo and in vitro work suggests that mesenchymal stem cells (MSC) have anti-inflammatory properties. In this study, we tested the effect of administering MSC directly into the airspaces of the lung 4 h after the intrapulmonary administration of Escherichia coli endotoxin (5 mg/kg). MSC increased survival compared with PBS-treated control mice at 48 h (80 vs 42%; p < 0.01). There was also a significant decrease in excess lung water, a measure of pulmonary edema (145 +/- 50 vs 87 +/- 20 microl; p < 0.01), and bronchoalveolar lavage protein, a measure of endothelial and alveolar epithelial permeability (3.1 +/- 0.4 vs 2.2 +/- 0.8 mg/ml; p < 0.01), in the MSC-treated mice. These protective effects were not replicated by the use of further controls including fibroblasts and apoptotic MSC. The beneficial effect of MSC was independent of the ability of the cells to engraft in the lung and was not related to clearance of the endotoxin by the MSC. MSC administration mediated a down-regulation of proinflammatory responses to endotoxin (reducing TNF-alpha and MIP-2 in the bronchoalveolar lavage and plasma) while increasing the anti-inflammatory cytokine IL-10. In vitro coculture studies of MSC with alveolar macrophages provided evidence that the anti-inflammatory effect was paracrine and was not cell contact dependent. In conclusion, treatment with intrapulmonary MSC markedly decreases the severity of endotoxin-induced acute lung injury and improves survival in mice.
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PMID:Intrapulmonary delivery of bone marrow-derived mesenchymal stem cells improves survival and attenuates endotoxin-induced acute lung injury in mice. 1764 Oct 52

Vitronectin is present in large concentrations in serum and participates in regulation of humoral responses, including coagulation, fibrinolysis, and complement activation. Because alterations in coagulation and fibrinolysis are common in acute lung injury, we examined the role of vitronectin in LPS-induced pulmonary inflammation. Vitronectin concentrations were significantly increased in the lungs after LPS administration. Neutrophil numbers and proinflammatory cytokine levels, including IL-1beta, MIP-2, KC, and IL-6, were significantly reduced in bronchoalveolar lavage fluid from vitronectin-deficient (vitronectin(-/-)) mice, as compared with vitronectin(+/+) mice, after LPS exposure. Similarly, LPS induced increases in lung edema, myeloperoxidase-concentrations, and pulmonary proinflammatory cytokine concentrations were significantly lower in vitronectin(-/-) mice. Vitronectin(-/-) neutrophils demonstrated decreased KC-induced chemotaxis as compared with neutrophils from vitronectin(+/+) mice, and incubation of vitronectin(+/+) neutrophils with vitronectin was associated with increased chemotaxis. Vitronectin(-/-) neutrophils consistently produced more TNF-alpha, MIP-2, and IL-1beta after LPS exposure than did vitronectin(+/+) neutrophils and also showed greater degradation of IkappaB-alpha and increased LPS-induced nuclear accumulation of NF-kappaB compared with vitronectin(+/+) neutrophils. These findings provide a novel vitronectin-dependent mechanism contributing to the development of acute lung injury.
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PMID:Involvement of vitronectin in lipopolysaccaride-induced acute lung injury. 1798 99

The alveolar compartment in acute lung injury contains high levels of tissue factor (TF) procoagulant activity favoring fibrin deposition. We previously reported that the alveolar epithelium can release TF procoagulant activity in response to a proinflammatory stimulus. To test the hypothesis that the alveolar epithelium further modulates intra-alveolar fibrin deposition through secretion of an endogenous inhibitor to TF, tissue factor pathway inhibitor (TFPI), we measured TFPI levels in edema fluid (EF) from patients with acute respiratory distress syndrome. To determine whether the alveolar epithelium can release TFPI, both full-length TFPI and truncated TFPI were measured (ELISA) in pulmonary edema fluid from patients with acute respiratory distress syndrome (ARDS) and a control group of patients with hydrostatic pulmonary edema (HYDRO). TFPI protein was also measured in conditioned media (CM) and cell lysates (CL) from human alveolar epithelial cells (A549) after exposure to cytomix (TNF-alpha, IL-1 beta, IFN-gamma). TFPI protein levels were higher in pulmonary edema fluid from patients with ARDS vs. HYDRO. TFPI protein was increased in CM and did not change in CL after cytomix treatment; TFPI mRNA levels (RT-PCR) did not change. Despite the high levels of TFPI, both the EF and CM retained significant TF procoagulant activity as measured by plasma recalcification time. The majority of intra-alveolar TFPI was in a truncated, inactive form, whereas the majority of TFPI released from cells was full length, suggesting different mechanisms of inactivation. In summary, the alveolar epithelium releases TFPI in response to an inflammatory stimulus but does not increase TFPI gene transcription or protein production. Levels of intra-alveolar TFPI in ARDS are not sufficient to block intra-alveolar TF procoagulant activity due to truncation and inactivation of intra-alveolar TFPI.
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PMID:Intra-alveolar tissue factor pathway inhibitor is not sufficient to block tissue factor procoagulant activity. 1831 Feb 27


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