scholarly journals Insulin Inhibits the Pro-Inflammatory Transcription Factor Early Growth Response Gene-1 (Egr)-1 Expression in Mononuclear Cells (MNC) and Reduces Plasma Tissue Factor (TF) and Plasminogen Activator Inhibitor-1 (PAI-1) Concentrations

2002 ◽  
Vol 87 (3) ◽  
pp. 1419-1422 ◽  
Author(s):  
Ahmad Aljada ◽  
Husam Ghanim ◽  
Priya Mohanty ◽  
Neeti Kapur ◽  
Paresh Dandona

We have recently demonstrated that an infusion of a low dose of insulin reduces the intranuclear NF-κB (a pro-inflammatory transcription factor) content in MNC while also reducing the p;asma concentration of NF-κB dependent pro-inflammatory cytokines and adhesion molecules. We have now tested the effect of insulin on the pro-inflammatory transcription factor, early growth response-1 (Egr-1) and plasma concentration of tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1), two major proteins whose expression is modulated by Egr-1. Insulin was infused at the rate of 2 IU/h in 5% dextrose (100 mL/h) and KCI (8 mmol/h) for 4 h in the fasting state in ten obese subjects. Blood samples were obtained at 0, 2, 4 and 6 h. MNC were isolated and their total homogenates and nuclear fractions were prepared and Egr-1 was measured by electrophoretic mobility shift assay (EMSA). Plasma TF and PAI-1 were assayed by ELISA. There was a significant fall in Egr-1 at 2 (66 ± 14% of basal level) and 4 h (47± 17% of the basal level; P<0.01). PAI-1 levels (basal = 100%) decreased significantly after insulin infusion at 2 h (57 ± 6.7% of the basal level) and at 4 h (58 ± 8.3% of the basal level; P<0.001). Plasma TF levels (basal = 100%) decreased to 76 ± 7.7% of the basal level at 2 h and to 85 ± 10.4% of the basal level at 4 h (P<0.05). Thus, insulin reduces intranuclear Egr-1 and the expression of TF and PAI-1. These data provide further evidence that insulin has an anti-inflammatory effect including the inhibition of TF and PAI-1 expression. These effects suggest a potential beneficial effect of insulin in thrombin formation and fibrinolysis in atherothrombosis.

2002 ◽  
Vol 88 (12) ◽  
pp. 1060-1065 ◽  
Author(s):  
Ana Pérez-Ruiz ◽  
Ramón Montes ◽  
Francisco Velasco ◽  
Chary López-Pedrera ◽  
José Páramo ◽  
...  

SummaryThe increase in nitric oxide (NO) production in lipopolysaccharide (LPS)-induced sepsis is thought to contribute to the development of shock. However, NO could also play an antithrombotic role. Little is known about the modulating effect of NO on the endothelial overexpression and production of tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) occurring in endotoxemia. We analyzed the effect of N(G)-nitro-L-arginine-methyl-ester (L-NAME), an inhibitor of NO synthases, and S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a NO donor, on the expression and synthesis of TF and PAI-1 by LPS-challenged human umbilical vein endothelial cells (HUVEC): L-NAME enhanced the increase in TF mRNA and antigen levels (P <0.05) observed in LPS-treated HUVEC; SNAP down-regulated the LPSinduced TF increment (p <0.05). However, no effects of NO on regulation of the LPS-dependent increase in PAI-1 could be seen. Thus, NO could play an antithrombotic role in sepsis by down-regulating the endothelial overexpression and production of TF.


Blood ◽  
2001 ◽  
Vol 97 (6) ◽  
pp. 1697-1702 ◽  
Author(s):  
Hidehiko Kawano ◽  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Shinzo Kimura ◽  
Shingo Yano ◽  
...  

Serotonin (5-hydroxytryptamine, or 5-HT), released from activated platelets, not only accelerates aggregation of platelets but also is known to promote mitosis, migration, and contraction of vascular smooth muscle cells (VSMCs). These effects are considered to contribute to thrombus formation and atherosclerosis. The aim of this study was to investigate the effects of 5-HT on the expressions of coagulative and fibrinolytic factors in rat aortic endothelial cells. Endothelial cells were stimulated with various concentrations of 5-HT (0.1∼10 μM), and the expressions of tissue factor (TF), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor-1 (PAI-1), and tissue-type plasminogen activator (TPA) messenger RNAs (mRNAs) were evaluated by Northern blot analysis. The activities of TF and PAI-1 were also measured. TF and PAI-1 mRNA were increased significantly in a concentration- and time-dependent manner. However, TFPI and TPA mRNA expression did not change. The inductions of TF and PAI-1 mRNAs were inhibited by a 5-HT1/5-HT2 receptor antagonist (methiothepin) and a selective 5-HT2A receptor antagonist (MCI-9042). These results indicate that 5-HT increases procoagulant activity and reduces fibrinolytic activities of endothelial cells through the 5-HT2A receptor. It was concluded that the modulation of procoagulant and hypofibrinolytic activities of endothelial cells by 5-HT synergistically promotes thrombus formation at the site of vessel injury with the platelet aggregation, VSMC contraction, and VSMC proliferation.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 5447-5447
Author(s):  
Eriko Morishita ◽  
Keiko Maruyama ◽  
Akiko Sekiya ◽  
Shigeki Ohtake ◽  
Shinji Nakao ◽  
...  

Abstract Objective - Heme oxygenase-1(HO-1), the rate-limiting enzyme of heme degradation, has recently been considered to have protective roles against various pathological conditions. 10 years have passed since we lost the first and the only patient of HO-1 deficiency. Since the patient of HO-1 deficiency showed endothelial cell injury and extremely enhanced coagulation and fibrinolytic parameters, we examined the effect of HO-1 modulation on tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) expression on endothelial cells. Methods and Results - Human umbilical vein endothelial cell (HUVEC) was stimulated with hemin (100mM), HO-1 inducer, and mRNA and protein levels for HO-1, TF and PAI-1 were examined. Total RNA was extracted from HUVEC, and was analyzed by real time RT-PCR. Protein expression levels of HO-1, TF and PAI-1 were measured by ELISA. Hemin stimulation increased HO-1 mRNA levels by 20 times. On the other hand, TF mRNA and antigen levels were minimum even after 8 hours of stimulation. Importantly, hemin stimulation reduced PAI-1 mRNA more than half after 4 hours. After HO-1 induction by hemin (100 mM) for 6 hours, HUVEC cultures were exposed to 10 ng/ml tumor necrosis factor (TNF). Prior exposure to hemin significantly increased HO-1 mRNA by 60 times in 30 minutes after stimulation with TNF. However, TNF alone could not induce HO-1 mRNA and protein levels in HUVEC. Although stimulation with TNF enhanced expressions of both TF and PAI-1 mRNA, they were significantly inhibited more than half by prior treatment with hemin. TF antigen levels were similarly decreased (5.0 to 0.7 pg/ml). PAI-1 antigen levels were also inhibited by prior treatment with hemin (1.8 to 0.1 ng/ml)(3) To see if hemin effect on HUVEC is due to HO-1 production, HO-1 inhibitor tin-protoporphyrin IX (SnPP-IX) was added to the cultures. The inhibitor effect of hemin on TF and PAI-1 productions was cancelled when HUVEC was cocultured with SnPP-IX. Conclusions - These results indicate that hemin exert inhibitory effect on TF and PAI-1 expressions through HO-1 production. Induction of HO-1 may be beneficial in the prevention of thrombosis associated with inflammation.


2021 ◽  
Author(s):  
Marco Leitzke ◽  
Joao-Carlos Correia ◽  
Peter Oskar Dieter Schönknecht

Abstract The current COVID-19 pandemic creates new clinical challenges almost daily, especially in terms of individual prognoses, diagnostics involving newly discovered pathogenic mechanisms, and the appearance of SARS-CoV-2 mutations. In terms of the thromboembolic complications frequently occurring in COVID-19 patients, there is new evidence that pathognomonic COVID-19-associated coagulopathy (CAC) differs considerably from the coagulant malfunction of common disseminated intravascular coagulation. Thus, bleeding is a rare complication in the initial stages of the disease, whereas thrombotic formations can be seen autopticly in the vasculature of several organs. Therefore, it is speculated that most thromboembolic complications are thrombotic rather than embolic, and CAC is more likely to be a pro-coagulant form of coagulopathy. The reasons for these key differences have remained unknown until very recently. The relationship between SARS-CoV-2 infection and the virus-related acceleration of the transcriptional nuclear factor kappa B (NF-κB)-pathway, with the accompanied excessive downstream release of NF-κB-dependent proteins, is undisputed. Therefore, the roles of the NF-κB-transcribed anti-fibrinolytic plasminogen activator inhibitor (PAI 1) and NF-κB-dependent tissue factor (TF) have become worthy of attention. Inappropriate TF action results in enhanced fibrin clot formation, whereas overexpression of PAI 1 prevents appropriate fibrinolytic reactions. CAC is interpreted as critically contributing to overall COVID-19 pathology and is most likely an independent risk factor for mortality.


2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Simone Marquard ◽  
Stefan Thomann ◽  
Sofia M. E. Weiler ◽  
Michaela Bissinger ◽  
Teresa Lutz ◽  
...  

Abstract Background Overexpression and nuclear enrichment of the oncogene yes-associated protein (YAP) cause tumor initiation and support tumor progression in human hepatocellular carcinoma (HCC) via cell autonomous mechanisms. However, how YAP expression in tumor cells affects intercellular communication within the tumor microenvironment is not well understood. Methods To investigate how tumor cell-derived YAP is changing the paracrine communication network between tumor cells and non-neoplastic cells in hepatocarcinogenesis, the expression and secretion of cytokines, growth factors and chemokines were analyzed in transgenic mice with liver-specific and inducible expression of constitutively active YAP (YAPS127A). Transcriptomic and proteomic analyses were performed using primary isolated hepatocytes and blood plasma. In vitro, RNAinterference (RNAi), expression profiling, functional analyses and chromatin immunoprecipitation (ChIP) analyses of YAP and the transcription factor TEA domain transcription factor 4 (TEAD4) were performed using immortalized cell lines. Findings were confirmed in cohorts of HCC patients at the transcript and protein levels. Results YAP overexpression induced the expression and secretion of many paracrine-acting factors with potential impact on tumorous or non-neoplastic cells (e.g. plasminogen activator inhibitor-1 (PAI-1), C-X-C motif chemokine ligand 13 (CXCL13), CXCL16). Expression analyses of human HCC patients showed an overexpression of PAI-1 in human HCC tissues and a correlation with poor overall survival as well as early cancer recurrence. PAI-1 statistically correlated with genes typically induced by YAP, such as connective tissue growth factor (CTGF) and cysteine rich angiogenic inducer 61 (CYR61) or YAP-dependent gene signatures (CIN4/25). In vitro, YAP inhibition diminished the expression and secretion of PAI-1 in murine and human liver cancer cell lines. PAI-1 affected the expression of genes involved in cellular senescence and oncogene-induced senescence was confirmed in YAPS127A transgenic mice. Silencing of TEAD4 as well as treatment with the YAP/TEAD interfering substance Verteporfin reduced PAI-1 expression. ChIP analyses confirmed the binding of YAP and TEAD4 to the gene promoter of PAI-1 (SERPINE1). Conclusions These results demonstrate that the oncogene YAP changes the secretome response of hepatocytes and hepatocyte-derived tumor cells. In this context, the secreted protein PAI-1 is transcriptionally regulated by YAP in hepatocarcinogenesis. Perturbation of these YAP-dependent communication hubs including PAI-1 may represent a promising pharmacological approach in tumors with YAP overexpression.


2005 ◽  
Vol 173 (4S) ◽  
pp. 255-255 ◽  
Author(s):  
Hugo H. Davila ◽  
Thomas R. Magee ◽  
Freddy Zuniga ◽  
Jacob Rajfer ◽  
Nestor F. GonzalezCadavid

1999 ◽  
Vol 82 (07) ◽  
pp. 104-108 ◽  
Author(s):  
Franck Paganelli ◽  
Marie Christine Alessi ◽  
Pierre Morange ◽  
Jean Michel Maixent ◽  
Samuel Lévy ◽  
...  

Summary Background: Type 1 plasminogen activator inhibitor (PAI-1) is considered to be risk factor for acute myocardial infarction (AMI). A rebound of circulating PAI-1 has been reported after rt-PA administration. We investigated the relationships between PAI-1 levels before and after thrombolytic therapy with streptokinase (SK) as compared to rt-PA and the patency of infarct-related arteries. Methods and Results: Fifty five consecutive patients with acute MI were randomized to strep-tokinase or rt-PA. The plasma PAI-1 levels were studied before and serially within 24 h after thrombolytic administration. Vessel patency was assessed by an angiogram at 5 ± 1days. The PAI-1 levels increased significantly with both rt-PA and SK as shown by the levels obtained from a control group of 10 patients treated with coronary angioplasty alone. However, the area under the PAI-1 curve was significantly higher with SK than with rt-PA (p <0.01) and the plasma PAI-1 levels peaked later with SK than with rt-PA (18 h versus 3 h respectively). Conversely to PAI-1 levels on admission, the PAI-1 levels after thrombolysis were related to vessel patency. Plasma PAI-1 levels 6 and 18 h after SK therapy and the area under the PAI-1 curve were significantly higher in patients with occluded arteries (p <0.002, p <0.04 and p <0.05 respectively).The same tendency was observed in the t-PA group without reaching significance. Conclusions: This study showed that the PAI-1 level increase is more pronounced after SK treatment than after t-PA treatment. There is a relationship between increased PAI-1 levels after thrombolytic therapy and poor patency. Therapeutic approaches aimed at quenching PAI-1 activity after thrombolysis might be of interest to improve the efficacy of thrombolytic therapy for acute myocardial infarction.


1988 ◽  
Vol 59 (02) ◽  
pp. 299-303 ◽  
Author(s):  
Grazia Nicoloso ◽  
Jacques Hauert ◽  
Egbert K O Kruithof ◽  
Guy Van Melle ◽  
Fedor Bachmann

SummaryWe analyzed fibrinolytic parameters in 20 healthy men and 20 healthy women, aged from 25 to 59, before and after 10 and 20 min venous occlusion. The 10 min post-occlusion fibrinolytic activity measured directly in diluted unfractionated plasma by a highly sensitive 125I-fibrin plate assay correlated well with the activity of euglobulins determined by the classical fibrin plate assay (r = 0.729), but pre-stasis activities determined with these two methods did not correlate (r = 0.084). The enhancement of fibrinolytic activity after venous occlusion was mainly due to an increase of t-PA in the occluded vessels (4-fold increase t-PA antigen after 10 min and 8-fold after 20 min venous occlusion). Plasminogen activator inhibitor (PAI) activity and plasminogen activator inhibitor 1 (PAI-1)1 antigen levels at rest showed considerable dispersion ranging from 1.9 to 12.4 U/ml, respectively 6.9 to 77 ng/ml. A significant increase of PAI-1 antigen levels was observed after 10 and 20 min venous occlusion. At rest no correlation was found between PAI activity or PAI-1 antigen levels and the fibrinolytic activity measured by 125I-FPA. However, a high level of PAI-1 at rest was associated with a high prestasis antigen level of t-PA and a low fibrinolytic response after 10 min of venous stasis. Since the fibrinolytic response inversely correlated with PAI activity at rest, we conclude that its degree depends mainly on the presence of free PAI.


1992 ◽  
Vol 68 (05) ◽  
pp. 486-494 ◽  
Author(s):  
Malou Philips ◽  
Anne-Grethe Juul ◽  
Johan Selmer ◽  
Bent Lind ◽  
Sixtus Thorsen

SummaryA new assay for functional plasminogen activator inhibitor 1 (PAI-1) in plasma was developed. The assay is based on the quantitative conversion of PAI-1 to urokinase-type plasminogen activator (u-PA)-PAI-l complex the concentration of which is then determined by an ELISA employing monoclonal anti-PAI-1 as catching antibody and monoclonal anti-u-PA as detecting antibody. The assay exhibits high sensitivity, specificity, accuracy, and precision. The level of functional PAI-1, tissue-type plasminogen activator (t-PA) activity and t-PA-PAI-1 complex was measured in normal subjects and in patients with venous thromboembolism in a silent phase. Blood collection procedures and calibration of the respective assays were rigorously standardized. It was found that the patients had a decreased fibrinolytic capacity. This could be ascribed to high plasma levels of PAI-1. The release of t-PA during venous occlusion of an arm for 10 min expressed as the increase in t-PA + t-PA-PAI-1 complex exhibited great variation and no significant difference could be demonstrated between the patients with a thrombotic tendency and the normal subjects.


1994 ◽  
Vol 72 (03) ◽  
pp. 434-437 ◽  
Author(s):  
E Bruckert ◽  
A Ankri ◽  
P Glral ◽  
G Turpin

SummaryPlasminogen activator inhibitor type-1 (PAI-1) is a key determinant of the fibrinolytic capacity. Its activity correlates with most of the characteristic features of insulin resistance syndrome, i. e. obesity, high blood pressure and hyperlipidemia.We measured plasma PAI-1 antigen levels in 131 asymptomatic men (aged 44.2 ± 11 years) who had been referred for hyperlipidemia. Those taking medication and those with a secondary hyperlipidemia were excluded.We confirmed the correlation between PAI-1 levels and the following variables: body mass index, blood pressure, triglyceride concentration, and blood glucose and insulin levels before and after an oral glucose tolerance test. We also found a significant and independent correlation between PAI-1 and the concentration of the hepatic enzymes glutamyl transferase, alanine aminotransferase and aspartate aminotransferase.Mild liver abnormalities (presumably steatosis) may thus be one of the factors accounting for high plasma PAI-1 levels in hyperlipidemic patients.


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