Abstract 17261: Inhibition of Fibrinolysis Attenuates Influenza A-induced Lung Injury

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Luisa Morales-Nebreda ◽  
Mesut Eren ◽  
Saul Soberanes ◽  
Recep Nigdelioglu ◽  
Micah Rogel ◽  
...  

Rationale: Influenza A virus (IAV) is the leading cause of death from an infectious cause and ranks 8th in the list of attributable annual mortality in the United States. Currently available antiviral treatments are limited and may become ineffective as resistant strains emerge. The coexistence of hemostatic alterations with inflammatory responses to viral infections support the idea that common molecular mechanisms contribute to the regulation of these systems. Previous studies demonstrated that IAV induces the activation of both coagulation and fibrinolytic pathways, and that the impairment of the latter is mainly attributable to high levels of plasminogen activator inhibitor type I (PAI-1), the major inhibitor of tissue-type plasminogen activator (t-PA). Interferon-α (IFN-α) plays a key role in the control of viral replication and overall shaping of the immune response. We sought to determine whether PAI-1, plays a role in the immune response and morbidity and mortality associated with IAV infection. Methods: Wild-type (C57BL/6J), PAI-1-/-, t-PA-/- and PAI-1 stab (transgenic mice expressing an active form of human PAI-1) mice were treated intratracheally with IAV (A/WSN/33 [H1N1] 500 pfu/mouse in 50μl PBS). We assessed the levels of IFN-α in bronchoalveolar lavage fluid (BALF) on day 2 and 4, and influenza A-induced morbidity (weight loss) and mortality. Results: Compared with wild-type mice, PAI-1-/- mice had increased IAV-induced morbidity and mortality. In contrast, both PAI-1 stab and t-PA-/- mice had improved survival. In wild-type mice, IAV induced a significant elevation IFN-α levels in BALF. PAI-1 stab mice had a 2-fold increase, while PAI-1-/-mice had a 69% reduction in IFN-α levels in BALF compared to wild-type mice. Conclusions: Inhibition of fibrinolysis by means of genetic overexpression of PAI-1 or deletion of t-PA augments the antiviral response and attenuates the morbidity and mortality associated with IAV infection. These results suggest an important functional role for PAI-1 and fibrinolysis in the pathogenesis of influenza A infection. Modulation of the fibrinolytic pathway or PAI-1 may potentially be useful as a target for novel therapeutics in the management of IAV-induced lung injury.

2011 ◽  
Vol 2011 ◽  
pp. 1-11
Author(s):  
Esther K. Wolthuis ◽  
Alexander P. J. Vlaar ◽  
Jorrit-Jan H. Hofstra ◽  
Joris J. T. H. Roelofs ◽  
Vivian de Waard ◽  
...  

Ventilator-induced lung injury (VILI) is associated with inhibition of the fibrinolytic system secondary to increased production of plasminogen activator inhibitor- (PAI-)1. To determine the role of PAI-1 on pulmonary coagulopathy and inflammation during mechanical ventilation, PAI-1 gene-deficient mice and their wild-type littermates were anesthetized (control), or anesthetized, tracheotomized and subsequently ventilated for 5 hours with either low tidal volumes () or high tidal volumes (). VILI was assessed by pulmonary coagulopathy, lung wet-to-dry ratios, total protein level in bronchoalveolar lavage fluid, neutrophil influx, histopathology, and pulmonary and plasma cytokine levels. Ventilation resulted in pulmonary coagulopathy and inflammation, with more injury following ventilation with as compared to . In PAI-1 gene-deficient mice, the influx of neutrophils in the pulmonary compartment was attenuated, while increased levels of pulmonary cytokines were found. Other endpoints of VILI were not different between PAI-1 gene-deficient and wild-type mice. These data indicate that a defect fibrinolytic response attenuates recruitment of neutrophils in VILI.


1999 ◽  
Vol 81 (04) ◽  
pp. 601-604 ◽  
Author(s):  
Hiroyuki Matsuno ◽  
Osamu Kozawa ◽  
Masayuki Niwa ◽  
Shigeru Ueshima ◽  
Osamu Matsuo ◽  
...  

SummaryThe role of fibrinolytic system components in thrombus formation and removal in vivo was investigated in groups of six mice deficient in urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), or plasminogen activator inhibitor-1 (PAI-1) (u-PA-/-, t-PA-/- or PAI-1-/-, respectively) or of their wild type controls (u-PA+/+, t-PA+/+ or PAI-1+/+). Thrombus was induced in the murine carotid artery by endothelial injury using the photochemical reaction between rose bengal and green light (540 nm). Blood flow was continuously monitored for 90 min on day 0 and for 20 min on days 1, 2 and 3. The times to occlusion after the initiation of endothelial injury in u-PA+/+, t-PA+/+ or PAI-1+/+ mice were 9.4 ± 1.3, 9.8 ± 1.1 or 9.7 ± 1.6 min, respectively. u-PA-/- and t-PA-/- mice were indistinguishable from controls, whereas that of PAI-1-/- mice were significantly prolonged (18.4 ± 3.7 min). Occlusion persisted for the initial 90 min observation period in 10 of 18 wild type mice and was followed by cyclic reflow and reocclusion in the remaining 8 mice. At day 1, persistent occlusion was observed in 1 wild type mouse, 8 mice had cyclic reflow and reocclusion and 9 mice had persistent reflow. At day 2, all injured arteries had persistent reflow. Persistent occlusion for 90 min on day 0 was observed in 3 u-PA-/-, in all t-PA-/- mice at day 1 and in 2 of the t-PA-/-mice at day 2 (p <0.01 versus wild type mice). Persistent patency was observed in all PAI-1-/- mice at day 1 and in 5 of the 6 u-PA-/- mice at day 2 (both p <0.05 versus wild type mice). In conclusion, t-PA increases the rate of clot lysis after endothelial injury, PAI-1 reduces the time to occlusion and delays clot lysis, whereas u-PA has little effect on thrombus formation and spontaneous lysis.


1994 ◽  
Vol 71 (01) ◽  
pp. 124-128 ◽  
Author(s):  
R V Shohet ◽  
S Spitzer ◽  
E L Madison ◽  
R Bassel-Duby ◽  
M-J Gething ◽  
...  

SummaryPlatelet-rich clots are inefficiently lysed by current fibrinolytic agents. Platelets contain a great deal of plasminogen activator inhibitor 1 (PAI-1), the principal endogenous inhibitor of tissue-type plasminogen activator (t-PA). We have tested whether PAI-1 resistant t-PAs would be more effective thrombolytic agents in an in vitro model of platelet rich clots. Clots were formed with recalcified human plasma without or with the addition of platelets. The lysis of these clots was followed by the release of incorporated 125I-fibrinogen. Mutant and wild-type t-PA were almost equally effective against clots lacking platelets but the mutant was twice as effective at lysing platelet-rich clots. A mechanism for this effect is suggested by the demonstration that a complex between wild-type t-PA and extruded platelet contents resembles that between purified t-PA and PAI-1 and that the PAI-1 resistant t-PA does not interfere with formation of this adduct. Because of its enhanced ability to lyse platelet-rich clots in vitro, further in vivo work may find that PAI-1 resistant t-PA is a more efficacious therapeutic agent than wild-type t-PA in situations where platelets contribute to the failure of thrombolysis.


1997 ◽  
Vol 77 (02) ◽  
pp. 362-367 ◽  
Author(s):  
H R Lijnen ◽  
E F Wagner ◽  
D Collen

SummaryPlasminogen-dependent and -independent proteolytic activity of murine endothelioma (End) cells that were derived from mice with targeted inactivation of the tissue-type plasminogen activator (t-PA -/-), urokinase-type plasminogen activator (u-PA-/-) or plasminogen activator inhibitor-1 (PAI-1 -/- genes was studied with the use of fibrin and extracellular matrix degradation assays. In a buffer milieu, the activation rate of plasminogen (final concentration 0.25 µM) with wild-type and t-PA-/- End cells (3 X 104 to 4 X 106 cells/ml) was comparable, but it was about 4-fold reduced with u-PA -/- End cells and 3-fold enhanced with PAI-1End cells. Plasminogen activation was markedly reduced by addition of amiloride or of anti-murine u-PA antibodies but not by addition of anti-murine t-PA antibodies, and it was not stimulated by addition of fibrin. Lysis of125I-fibrin labeled matrix in the presence of plasminogen was comparable with wild-type, t-PA-/- and PAI-1-/- End cells (50% lysis in 3 h with 0.7 to 1.5 X 106 cells/ml), but was significantly reduced with u-PA-/- End cells (50% lysis in 20 h with 0.87 X 106 cells/ml). Lysis of3H-proline labeled extracellular matrix in the presence of plasminogen with wild-type, t-PA-/- and PAI-1-/- End cells (20% lysis in 48 h with 3 to 5 X 106 cells/ml) was comparable, but it was virtually abolished with u-PA-/- End cells. In the absence of plasminogen, lysis of both the fibrin and the extracellular matrix by all four cell types was drastically reduced and was virtually abolished by addition of phenylmethylsulfonylfluoride or 1,10 phenanthroline.These data indicate that the proteolytic activity of the transformed murine endothelioma cells, measured in plasminogen activation or matrix degradation assays, is essentially u-PA-related and largely plasminogen-dependent.


1998 ◽  
Vol 274 (2) ◽  
pp. F405-F412 ◽  
Author(s):  
Martin P. Emert ◽  
Christine M. Sorenson ◽  
David P. Basile ◽  
Joseph G. Rogers ◽  
Marc R. Hammerman ◽  
...  

The plasminogen activator inhibitor type 1 (PAI-1) gene encodes the physiological inhibitor of tissue-type and urokinase-type plasminogen activators and is induced by cytokines such as transforming growth factor-β (TGF-β). Studies have identified DNA sequence elements within the first 1.3 kb of the 5′-upstream DNA that mediate cytokine responsiveness in transfected cells in vitro. However, the DNA sequences that mediate PAI-1 expression in vivo have not yet been delineated. To define these regulatory sequences, we generated transgenic mice that expressed a hybrid gene comprising sequences between −1,272 and +75 of the human PAI-1 gene ligated to a LacZ reporter gene. Transgene expression detected in two independent lines was observed only in kidney from embryonic day 13 to adult and was seen primarily in proximal tubule cells of the outer medulla. Transgene expression and activity were unchanged in response to TGF-β and remained restricted to kidney. Thus we have identified a promoter region within the PAI-1 gene that targets transgene expression to kidney but, unlike the native promoter, is unresponsive to TGF-β in the experimental protocol used.


2019 ◽  
Vol 94 (4) ◽  
Author(s):  
J. Oliva ◽  
J. Mettier ◽  
L. Sedano ◽  
M. Delverdier ◽  
N. Bourgès-Abella ◽  
...  

ABSTRACT A novel genus within the Orthomyxoviridae family was identified in the United States and named influenza D virus (IDV). Bovines have been proposed to be the primary host, and three main viral lineages (D/OK-like, D/660-like, and D/Japan-like) have been described. Experimental infections had previously been performed in swine, ferrets, calves, and guinea pigs in order to study IDV pathogenesis. We developed a murine experimental model to facilitate the study of IDV pathogenesis and the immune response. DBA/2 mice were inoculated with 105 50% tissue culture infective dose (TCID50) of D/bovine/France/5920/2014 (D/OK-like). No clinical signs or weight loss were observed. Viral replication was observed mainly in the upper respiratory tract (nasal turbinates) but also in the lower respiratory tract of infected mice, with a peak at 4 days postinfection. Moreover, the virus was also detected in the intestines. All infected mice seroconverted by 14 days postinfection. Transcriptomic analyses demonstrated that IDV induced the activation of proinflammatory genes, such as gamma interferon (IFN-γ) and CCL2. Inoculation of NF-κB-luciferase and Ifnar1−/− mice demonstrated that IDV induced mild inflammation and that a type I interferon response was not necessary in IDV clearance. Adaptation of IDV by serial passages in mice was not sufficient to induce disease or increased pathogenesis. Taken together, present data and comparisons with the calf model show that our mouse model allows for the study of IDV replication and fitness (before selected viruses may be inoculated on calves) and also of the immune response. IMPORTANCE Influenza D virus (IDV), a new genus of Orthomyxoviridae family, presents a large host range and a worldwide circulation. The pathogenicity of this virus has been studied in the calf model. The mouse model is frequently used to enable a first assessment of a pathogen’s fitness, replication, and pathogenesis for influenza A and B viruses. We showed that DBA/2 mice are a relevant in vivo model for the study of IDV replication. This model will allow for rapid IDV fitness and replication evaluation and will enable phenotypic comparisons between isolated viruses. It will also allow for a better understanding of the immune response induced after IDV infection.


1995 ◽  
Vol 74 (05) ◽  
pp. 1305-1309 ◽  
Author(s):  
Paul J Declerck ◽  
Maria Verstreken ◽  
Désiré J Collen

SummaryThree enzyme-linked immunosorbent assays for the quantitation of murine tissue-type plasminogen activator (t-PA), urokinase-type plasminogen aetivator (u-PA) and plasminogen activator inhibitor I (PAI-1), were developed using monoclonal antibodies raised against the autologous proteins in gene-inactivated mice. Dose-response was linear for t-PA and PAI-1 between 5 and 0.1 ng/ml and for u-PA between 50 and 1 ng/ml, with intra-assay, inter-assay and inter-dilution coefficients of variation of 6 to 14%. Assay recoveries of proteins (5 to 100 ng/ml) added to plasma were 73 to 95% for t-PA and PAI-1. Linear correlations (r = 0.65, r = 0.91 and r = 0.92, for t-PA, u-PA and PAI-1 respectively) were found between antigen and activity in plasma, urine and tissue extracts. Levels of t-PA and PAI-1 antigen in murine plasma were 2.5 ± 1.0 ng/ml (mean ± SD, n = 9) and 1.9 ± 0.6 ng/ml (mean ± SD, n = 8), respectively, in wild-type mice and undetectable in gene-inactivated mice. Bradykinin injection in mice provoked a 12-fold increase (p <0.0002) of t-PA and endotoxin injection an 80-fold increase (p <0.005) of PAI-1 levels. u-PA antigen levels in urine from wild-type mice ranged between 0.2 and 8.2 μ;g/ml (1.8 ± 1.9 μg/ml, mean ± SD, n = 17) and were undetectable in gene-inactivated mice.Thus, these assays may be useful for studies on the role of these proteins in tissue remodeling, atherosclerosis, embryogenesis, etc., in established mouse models. Gene-inactivated mice may constitute a general approach for the generation of monoclonal antibodies against the deficient translation products and for the development of specific immunoassays for murine proteins.


1999 ◽  
Vol 82 (11) ◽  
pp. 1497-1503 ◽  
Author(s):  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Haruchika Masuda ◽  
Yasushi Kunieda ◽  
Hidehiko Kawano ◽  
...  

SummaryIn the present study, we demonstrate that brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) interact with angiotensin II (Ang II) in regulative blood coagulation and fibrinolysis by suppressing the expressions of both tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) induced by Ang II. The expressions of TF and PAI-1 mRNA were analyzed by northern blotting methods, and the activities of TF on the surface of rat aortic endothelial cells (RAECs) and PAI-1 in the culture media were respectively measured by chromogenic assay.Both BNP and CNP suppressed the expressions of TF and PAI-1 mRNA induced by Ang II in a time- and concentration-dependent manner via cGMP cascade, which suppressions were accompanied by respective decrease in activities of TF and PAI-1. However, neither the expression of tissue factor pathway inhibitor (TFPI) nor tissue-type plasminogen activator (TPA) mRNA was affected by the treatment of BNP and CNP.


1988 ◽  
Vol 60 (02) ◽  
pp. 328-333 ◽  
Author(s):  
N J de Fouw ◽  
Y F de Jong ◽  
F Haverkate ◽  
R M Bertina

summaryThe effect of purified human activated protein G (APC) on fibrinolysis was studied using a clot iysis system consisting of purified glu-plasminogen, tissue-type plasminogen activator, plasminogen activator inhibitor (released from endothelial cells or blood platelets), fibrinogen, 125T-fibrinogen and thrombin. All proteins were of human origin.In this system APC could increase fibrinolysis in a dose dependent way, without affecting fibrin formation or fibrin crosslinking. However, this profibrinolytic effect of APC could only be observed when plasminogen activator inhibitor (PAI-l) was present. The effect of APC was completely quenched by pretreatment of APC with anti-protein C IgG or di-isopropylfluorophosphate. Addition of the cofactors of APC:protein S, Ca2+-ions and phospholipid-alone or in combination did not enhance the profibrinolytic effect of APC. These observations indicate that human APC can accelerate in vitro clot lysis by the inactivation of PAI-1 activity. However, the neutralization of PAI-1 by APC is independent of the presence or absence of protein S, phospholipid and Ca2+-ions.


1992 ◽  
Vol 68 (06) ◽  
pp. 672-677 ◽  
Author(s):  
Hitoshi Yahara ◽  
Keiji Matsumoto ◽  
Hiroyuki Maruyama ◽  
Tetsuya Nagaoka ◽  
Yasuhiro Ikenaka ◽  
...  

SummaryTissue-type plasminogen activator (t-PA) is a fibrin-specific agent which has been used to treat acute myocardial infarction. In an attempt to clarify the determinants for its rapid clearance in vivo and high affinity for fibrin clots, we produced five variants containing amino acid substitutions in the finger domain, at amino acid residues 7–9, 10–14, 15–19, 28–33, and 37–42. All the variants had a prolonged half-life and a decreased affinity for fibrin of various degrees. The 37–42 variant demonstrated about a 6-fold longer half-life with a lower affinity for fibrin. Human plasma clot lysis assay estimated the fibrinolytic activity of the 37–42 variant to be 1.4-fold less effective than that of the wild-type rt-PA. In a rabbit jugular vein clot lysis model, doses of 1.0 and 0.15 mg/kg were required for about 70% lysis in the wild-type and 37–42 variant, respectively. Fibrinogen was degraded only when the wild-type rt-PA was administered at a dose of 1.0 mg/kg. These findings suggest that the 37–42 variant can be employed at a lower dosage and that it is a more fibrin-specific thrombolytic agent than the wild-type rt-PA.


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