Food deprivation induces adipose plasminogen activator inhibitor-1 (PAI-1) expression without accumulation of plasma PAI-1 in genetically obese and diabetic db/db mice

2007 ◽  
Vol 98 (10) ◽  
pp. 864-870 ◽  
Author(s):  
Katsutaka Oishi ◽  
Naoki Ohkura ◽  
Juzo Matsuda ◽  
Norio Ishida
Keyword(s):  
Plasminogen Activator ◽  
Food Deprivation ◽  
Fibrinolytic Activity ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Wild Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Adipose Tissues ◽  
Activator Inhibitor ◽  
Pai 1

SummaryRelationships between energy intake and fibrinolytic functions have been documented in detail. We evaluated food deprivation (FD) as a means of modulating fibrinolytic activity in genetically obese and diabetic db/db mice and in their lean counterparts. Twelve hours of FD induced considerable gene expression of plasminogen activator inhibitor-1 (PAI-1) in both epididymal (3.8-fold, p<0.05) and intestinal (2.4-fold, p<0.05) adipose tissues without affecting plasma PAI-1 levels in db/db mice, whereas the FD did not affect these parameters in wild-type mice. Importantly, 24 hours of FD increased the plasma PAI-1 content in wild-type (1.9-fold, p<0.01) but not in db/db mice, although adipose PAI-1 mRNA levels were significantly increased in db/db mice. The plasma PAI-1 content significantly correlated with hepatic PAI-1 mRNA levels in wild-type (r=0.84, p<0.01) and in db/db (r=0.63, p<0.01) mice. However, plasma PAI-1 did not correlate with adipose PAI-1 expression in db/db mice, although adipose tissue in general is thought to be the principal site of PAI-1 production in obesity. Hepatic PAI-1 expression was closely correlated with serum levels of free fatty acids in wild-type (r=0.72, p<0.01), but not in db/db mice. Adipose PAI-1 expression significantly correlated with serum corticosterone levels in both genotypes (wild-type, r=0.52, p<0.05; db/db, r=0.51, p<0.01), suggesting that adipose PAI-1 expression is up-regulated by fastinginduced glucocorticoids. The present findings suggested that fasting differentially affects fibrinolytic activity in obese and lean subjects and that PAI-1 expression in the liver as well as in adipose tissues comprises an important determinant of increased risk for cardiovascular disease in obesity.

Regulation of plasminogen activator inhibitor-1 and urokinase by hyaluronan fragments in mouse macrophages

2000 ◽  
Vol 279 (4) ◽  
pp. L707-L715 ◽  
Author(s):  
Maureen R. Horton ◽  
Mitchell A. Olman ◽  
Clare Bao ◽  
Kimberly E. White ◽  
Augustine M. K. Choi ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Alveolar Macrophage ◽  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Upa Mrna ◽  
Activator Inhibitor ◽  
Pai 1

Pulmonary inflammation and fibrosis are characterized by increased turnover and production of the extracellular matrix as well as an impairment of lung fibrinolytic activity. Although fragments of the extracellular matrix component hyaluronan induce macrophage production of inflammatory mediators, the effect of hyaluronan on the fibrinolytic mediators plasminogen activator inhibitor (PAI)-1 and urokinase-type plasminogen activator (uPA) is unknown. This study demonstrates that hyaluronan fragments augment steady-state mRNA, protein, and inhibitory activity of PAI-1 as well as diminish the baseline levels of uPA mRNA and inhibit uPA activity in an alveolar macrophage cell line. Hyaluronan fragments alter macrophage expression of PAI-1 and uPA at the level of gene transcription. Similarly, hyaluronan fragments augment PAI-1 and diminish uPA mRNA levels in freshly isolated inflammatory alveolar macrophages from bleomycin-treated rats. These data suggest that hyaluronan fragments influence alveolar macrophage expression of PAI-1 and uPA and may be a mechanism for regulating fibrinolytic activity during lung inflammation.

Fibrinolysis in Normal Subjects - Comparison Between Plasminogen Activator Inhibitor and Other Components of the Fibrinolytic System

1988 ◽  
Vol 59 (02) ◽  
pp. 299-303 ◽  
Author(s):  
Grazia Nicoloso ◽  
Jacques Hauert ◽  
Egbert K O Kruithof ◽  
Guy Van Melle ◽  
Fedor Bachmann
Keyword(s):  
Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Plasminogen Activator Inhibitor ◽  
Venous Occlusion ◽  
Venous Stasis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Plate Assay ◽  
Fibrin Plate ◽  
Activator Inhibitor ◽  
Pai 1

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.

scholarly journals Plasminogen Activator Inhibitor-1 Regulates LPS Induced Inflammation in Rat Macrophages through Autophagy Activation

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Zhong-Hui Wang ◽  
Wei-Ying Ren ◽  
Lei Zhu ◽  
Li-Juan Hu
Keyword(s):  
Western Blot ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Inflammatory Reactions ◽  
Protein Levels ◽  
Nr8383 Cells ◽  
Activator Inhibitor ◽  
Pai 1

Background. The mechanisms by which plasminogen activator inhibitor-1 (PAI-1) regulates inflammation, especially in acute respiratory distress syndrome (ARDS), are largely unknown.Objective. To assess the relationship between PAI-1 and autophagy in inflammatory reactions induced by LPS in rat NR8383 cells.Methods. ELISA was used to assess the amounts of TNF-α, IL-1β, and PAI-1 in cell culture supernatants; TLR4, MyD88, PAI-1, LC3, Beclin1, and mTOR protein and mRNA levels were determined by western blot and quantitative RT-PCR, respectively; western blot was used to determine NF-κB protein levels. To further evaluate the role of PAI-1, the PAI-1 gene was downregulated and overexpressed using the siRNA transfection technology and the pCDH-PAI-1, respectively. Finally, the GFP Positive Expression Rate Method was used to determine the rate of GFP-LC3 positive NR8383 cells.Results. In LPS-induced NR8383 cells, TNF-α, IL-1β, and PAI-1 expression levels increased remarkably. Upon PAI-1 knockdown, TNF-α, IL-1β, PAI-1, TLR4, MyD88, NF-κB, LC3, and Beclin1 levels were decreased, while mTOR increased. Conversely, overexpression of PAI-1 resulted in increased amounts of TNF-α, IL-1β, PAI-1, TLR4, MyD88, NF-κB, LC3, and Beclin1. However, no significant change was observed in mTOR expression.Conclusions.In NR8383 cells, PAI-1 contributes in the regulation of LPS-induced inflammation, likely by promoting autophagy.

Fluvastatin Inhibits Basal and Stimulated Plasminogen Activator Inhibitor 1, but Induces Tissue Type Plasminogen Activator in Cultured Human Endothelial Cells

2000 ◽  
Vol 84 (07) ◽  
pp. 59-64 ◽  
Author(s):  
Luciana Mussoni ◽  
Cristina Banfi ◽  
Luigi Sironi ◽  
Magda Arpaia ◽  
Elena Tremoli
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
De Novo ◽  
Umbilical Vein ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

SummaryThe effects of fluvastatin, a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) inhibitor, on the biosynthesis of tissue plasminogen activator (t-PA) and of its major physiological inhibitor (plasminogen activator inhibitor type 1, PAI-1) were investigated in cultured human umbilical vein endothelial cells (HUVEC). Fluvastatin (0.1 to 2.5 µM), concentration-dependently reduced the release of PAI-1 antigen by unstimulated HUVEC, subsequent to a reduction in PAI-1 steady-state mRNA levels and de novo protein synthesis. In contrast, it increased t-PA secretion.The drug also reduced PAI-1 antigen secreted in response to 10 µg/ml bacterial lipopolysaccharide (LPS), 100 U/ml tumour necrosis factor α (TNFα) or 0.1 µM phorbol myristate acetate (PMA).Mevalonate (100 µM), a precursor of isoprenoids, added to cells simultaneously with fluvastatin, suppressed the effect of the drug on PAI-1 both in unstimulated and stimulated cells as well as on t-PA antigen. Among intermediates of the isoprenoid pathway, all-trans-geranylgeraniol (5 µM) but not farnesol (10 µM) prevented the effect of 2.5 µM fluvastatin on PAI-1 antigen, which suggests that the former intermediate of the isoprenoid synthesis is responsible for the observed effects.

Effect of Stabilizing versus Destabilizing Interactions on Plasminogen Activator Inhibitor-1

2000 ◽  
Vol 84 (11) ◽  
pp. 871-875 ◽  
Author(s):  
Nele Vleugels ◽  
John Leys ◽  
Isabelle Knockaert ◽  
Paul Declerck
Keyword(s):  
Plasminogen Activator ◽  
Half Life ◽  
Plasminogen Activator Inhibitor ◽  
Reactive Site ◽  
Wild Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
The Stability ◽  
Gate Region ◽  
Activator Inhibitor ◽  
Pai 1

SummaryPlasminogen activator inhibitor-1 (PAI-1) is a unique member of the serpin family, as it spontaneously converts into a latent conformation. However, the exact mechanism of this conversion is not known. Previous studies reported that neutralizing monoclonal antibodies as well as reversal or removal of charges on the s3C-s4C turn results in a destabilization of PAI-1 leading to an accelerated conversion to its latent form.In this study the effect of the reversal or removal of charges in this “gate region” (R186E/R187E, H190E/K191E, H190L/K191L and R356E) on a stable PAI-1-variant (PAI-1-stab) was investigated. Whereas PAI-1-stab has a half-life of 150 ± 66 h, PAI-1-stab-R186ER187E, PAI-1-stab-H190E-K191E, PAI-1-stab-H190L-K191L and PAI-1-stab-R356E have a strongly decreased half-life (p< 0.005 versus PAI-1-stab) of 175 ± 48 min, 75 ± 34 min, 68 ± 38 min and 79 ± 16 min, respectively. Wild-type PAI-1 (wtPAI-1) had a half-life of 55 ± 19 min. These data indicate that the stabilization induced by the mutated residues in PAI-1-stab is counteracted by the additional mutations, resulting in half-lives similar to that of wtPAI-1, thereby suggesting that the stabilizing and destabilizing forces act mainly independently in these mutants. Extrapolation of these data to other (stable) serpins leads to the hypothesis that the s3C-s4C turn and the distal hinge region of the reactive site loop plays a role for the stability of serpins in general.

The upstream stimulatory factor-2a inhibits plasminogen activator inhibitor-1 gene expression by binding to a promoter element adjacent to the hypoxia-inducible factor-1 binding site

Blood ◽  
2001 ◽  
Vol 97 (9) ◽  
pp. 2657-2666 ◽  
Author(s):  
Anatoly Samoylenko ◽  
Ulrike Roth ◽  
Kurt Jungermann ◽  
Thomas Kietzmann
Keyword(s):  
Plasminogen Activator ◽  
Hypoxia Inducible Factor ◽  
Plasminogen Activator Inhibitor ◽  
Wild Type ◽  
Upstream Stimulatory Factor ◽  
Plasminogen Activator Inhibitor 1 ◽  
Hypoxia Inducible Factor 1 ◽  
Stimulatory Factor ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Plasminogen activator inhibitor-1 (PAI-1) expression is induced by hypoxia (8% O2) via the PAI-1 promoter region −175/−159 containing a hypoxia response element (HRE-2) binding the hypoxia-inducible factor-1 (HIF-1) and an adjacent response element (HRE-1) binding a so far unknown factor. The aim of the present study was to identify this factor and to investigate its role in the regulation of PAI-1 expression. It was found by supershift assays that the upstream stimulatory factor-2a (USF-2a) bound mainly to the HRE-1 of the PAI-1 promoter and to a lesser extent to HRE-2. Overexpression of USF-2a inhibited PAI-1 messenger RNA and protein expression and activated L-type pyruvate kinase expression in primary rat hepatocytes under normoxia and hypoxia. Luciferase (Luc) gene constructs driven by 766 and 276 base pairs of the 5′-flanking region of the PAI-1 gene were transfected into primary hepatocytes together with expression vectors encoding wild-type USF-2a and a USF-2a mutant lacking DNA binding and dimerization activity (ΔHU2a). Cotransfection of the wild-type USF-2a vector reduced Luc activity by about 8-fold, whereas cotransfection of ΔHU2a did not influence Luc activity. Mutation of the HRE-1 (−175/−168) in the PAI-1 promoter Luc constructs decreased USF-dependent inhibition of Luc activity. Mutation of the HRE-2 (−165/−158) was less effective. Cotransfection of a HIF-1α vector could compete for the binding of USF at HRE-2. These results indicated that the balance between 2 transcriptional factors, HIF-1 and USF-2a, which can bind adjacent HRE sites, appears to be involved in the regulation of PAI-1 expression in many clinical conditions.

Plasminogen Activator Inhibitor 1: Biosynthesis and mRNA Level Are Increased by Insulin in Cultured Human Hepatocytes

1989 ◽  
Vol 62 (02) ◽  
pp. 723-728 ◽  
Author(s):  
T Kooistra ◽  
P J Bosma ◽  
H A M Töns ◽  
A P van den Berg ◽  
P Meyer ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Insulin Dose ◽  
Mrna Level ◽  
Primary Cultures ◽  
Plasminogen Activator Inhibitor ◽  
Human Hepatocytes ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

SummaryClinical studies have shown that plasma insulin levels are closely related to plasma plasminogen activator inhibitor 1 (PAI-1) levels. To investigate a possible involvement of hepatocytes we have studied the effect of insulin on PAI-1 production by primary cultures of human hepatocytes. We have isolated human hepatocytes from seven left liver lobes. PAI-1 activity measured in 24 hours conditioned medium varied considerably between the various hepatocyte preparations (from 2.9 to 8.5 units per 5 cm2of cells) possibly as a result of interindividual variability in basal PAI-1 production by hepatocytes from different donors. In all cases, however, the relative extent, time profile and dose-dependency of the insulin-induced increase in PAI-1 synthesis were consistent. Up to about 7 nM, insulin dose-dependently increased both PAI-1 activity and PAI-1 antigen production. The increase in PAI-1 synthesis became measurable between 4 and 8 hours after addition of the hormone, and maximally reached twofold control values. The increase in PAI-1 synthesis could be fully explained by a concomitant increase in PAI-1 mRNA levels. The effect of insulin seems fairly specific for the synthesis of PAI-1: overall protein synthesis and mRNA levels of some control proteins (albumin and fibrinogen) did not markedly change after insulin addition. These results, obtained with primary cultures of human hepatocytes, are fully comparable with those obtained with the hepatocellular carcinoma cell line Hep G2. They strengthen the suggestion that the elevated level of PAI-1 in high insulin plasma might be the result of increased hepatic synthesis of PAI-1.

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