AP-1-dependent induction of plasminogen activator inhibitor-1 by nickel does not require reactive oxygen

2001 ◽  
Vol 281 (3) ◽  
pp. L616-L623 ◽  
Author(s):  
Angeline S. Andrew ◽  
Linda R. Klei ◽  
Aaron Barchowsky
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Airway Epithelial Cells ◽  
Dominant Negative ◽  
Luciferase Reporter ◽  
Mrna Levels ◽  
Reporter Construct ◽  
Luciferase Reporter Construct ◽  
Activator Inhibitor ◽  
Pai 1

Inhalation of nickel dust has been associated with an increased incidence of pulmonary fibrosis. Nickel may promote fibrosis by transcriptionally activating plasminogen activator inhibitor (PAI)-1 and inhibiting fibrinolysis. The current studies examined whether nickel stimulated the PAI-1 promoter though an oxidant-sensitive activator protein (AP)-1 signaling pathway. Addition of nickel to BEAS-2B human airway epithelial cells stimulated intracellular oxidation, induced c-Jun and c-Fos mRNA levels, increased phospho- and total c-Jun protein levels, and elevated PAI-1 mRNA levels over a 24-h time course. Pretreatment of the cells with antioxidants did not affect increased c-Jun protein or PAI-1 mRNA levels. Expression of the dominant negative inhibitor of AP-1, TAM67, prevented nickel-stimulated AP-1 DNA binding, AP-1-luciferase reporter construct activity, and PAI-1 mRNA levels. Overexpression of c-Jun, however, failed to induce the AP-1 luciferase reporter construct or PAI-1 mRNA levels. These data indicated that nickel activated AP-1 through an oxidant-independent pathway and that basal AP-1 is necessary for nickel-induced expression of PAI-1.

scholarly journals The role of plasminogen activator inhibitor-1 in gastric mucosal protection

2013 ◽  
Vol 304 (9) ◽  
pp. G814-G822 ◽  
Author(s):  
Susan Kenny ◽  
Islay Steele ◽  
Suzanne Lyons ◽  
Andrew R. Moore ◽  
Senthil V. Murugesan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Luciferase Reporter ◽  
Gastric Epithelial Cells ◽  
Plasminogen Activator Inhibitor 1 ◽  
Luciferase Reporter Construct ◽  
Plasminogen Activator System ◽  
Activator Inhibitor ◽  
Pai 1

Gastric mucosal health is maintained in response to potentially damaging luminal factors. Aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs) disrupt protective mechanisms leading to bleeding and ulceration. The plasminogen activator system has been implicated in fibrinolysis following gastric ulceration, and an inhibitor of this system, plasminogen activator inhibitor (PAI)-1, is expressed in gastric epithelial cells. In Helicobacter pylori-negative patients with normal gastric histology taking aspirin or NSAIDs, we found elevated gastric PAI-1 mRNA abundance compared with controls; the increase in patients on aspirin was independent of whether they were also taking proton pump inhibitors. In the same patients, aspirin tended to lower urokinase plasminogen activator mRNA. Immunohistochemistry indicated PAI-1 localization to epithelial cells. In a model system using MKN45 or AGS-GR cells transfected with a PAI-1 promoter-luciferase reporter construct, we found no evidence for upregulation of PAI-1 expression by indomethacin, and, in fact, cyclooxygenase products such as PGE2 and PGI2 weakly stimulated expression. Increased gastric PAI-1 mRNA was also found in mice following gavage with ethanol or indomethacin, but plasma PAI-1 was unaffected. In PAI-1−/− mice, gastric hemorrhagic lesions in response to ethanol or indomethacin were increased compared with C57BL/6 mice. In contrast, in PAI-1-H/Kβ mice in which PAI-1 is overexpressed in parietal cells, there were decreased lesions in response to ethanol and indomethacin. Thus, PAI-1 expression is increased in gastric epithelial cells in response to mucosal irritants such as aspirin and NSAIDs probably via an indirect mechanism, and PAI-1 acts as a local autoregulator to minimize mucosal damage.

Induction of plasminogen activator inhibitor 1 by the PPARα ligand, Wy-14,643, is dependent on ERK1/2 signaling pathway

2003 ◽  
Vol 90 (10) ◽  
pp. 611-619 ◽  
Author(s):  
Cristina Banfi ◽  
Johan Auwerx ◽  
Federica Poma ◽  
Elena Tremoli ◽  
Luciana Mussoni
Keyword(s):  
Plasminogen Activator ◽  
Signaling Pathway ◽  
Plasminogen Activator Inhibitor ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Plasminogen Activator Inhibitor 1 ◽  
Luciferase Reporter Construct ◽  
Pparγ Agonist ◽  
Activator Inhibitor ◽  
Pai 1

SummaryImpairment of the fibrinolytic system, mostly due to elevated plasma levels of plasminogen activator inhibitor 1 (PAI-1), is often associated with metabolic disorders such as diabetes mellitus and insulin-resistance syndrome. Moreover, insulin, as we have previously shown, directly stimulates PAI-1 production with a mechanism underlying a complex signaling network which ultimately leads to ERK activation.In this study we have analyzed the effects of agonists of the per-oxisome proliferator-activated receptor (PPAR) alpha and gamma on PAI-1 biosynthesis in HepG2 cells in the presence or absence of insulin. The high affinity PPARα agonist, Wy-14,643, increased basal and insulin-stimulated PAI-1 antigen release with a mechanism involving gene transcription. We then investigated whether the MAP kinase pathway also plays a role in the stimulatory properties of Wy-L4,643. Wy-L4,643 increases phosphorylation of ERK and p38 in a time-dependent manner without affecting that of SAPK/JNK or ERK5. Moreover, the MEK (ERK kinase) inhibitors, PD98059 and UO126, completely prevented PAI-1 induction by Wy-14,643 without inhibiting the activation of a reporter gene carrying the PPRE element. Interestingly, the addition of p38 inhibitor followed by insulin and Wy-14,643 resulted in a greater than additive stimulation of PAI-1 secretion acting through ERK1/2 phosphorylation.In contrast, the synthetic PPARγ agonist, rosiglitazone, did not change PAI-1 level, although this compound induced transcription from the PPRE-driven luciferase reporter construct.In conclusion, Wy-14,643 induces PAI-1 gene expression, in the presence or absence of insulin, with a mechanism which is independent on PPARα activation and requires signaling through the ERK1/2 signaling pathway.

Nickel requires hypoxia-inducible factor-1α, not redox signaling, to induce plasminogen activator inhibitor-1

2001 ◽  
Vol 281 (3) ◽  
pp. L607-L615 ◽  
Author(s):  
Angeline S. Andrew ◽  
Linda R. Klei ◽  
Aaron Barchowsky
Keyword(s):  
Nadph Oxidase ◽  
Plasminogen Activator ◽  
Hypoxia Inducible Factor ◽  
Plasminogen Activator Inhibitor ◽  
Airway Epithelial Cells ◽  
Mrna Levels ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal ◽  
Activator Inhibitor ◽  
Pai 1

Human epidemiological and animal studies have associated inhalation of nickel dusts with an increased incidence of pulmonary fibrosis. At the cellular level, particulate nickel subsulfide inhibits fibrinolysis by transcriptionally inducing expression of plasminogen activator inhibitor (PAI)-1, an inhibitor of the urokinase-type plasminogen activator. Because nickel is known to mimic hypoxia, the present study examined whether nickel transcriptionally activates PAI-1 through the hypoxia-inducible factor (HIF)-1α signaling pathway. The involvement of the NADPH oxidase complex, reactive oxygen species, and kinases in mediating nickel-induced HIF-1α signaling was also investigated. Addition of nickel to BEAS-2B human airway epithelial cells increased HIF-1α protein levels and elevated PAI-1 mRNA levels. Pretreatment of cells with the extracellular signal-regulated kinase inhibitor U-0126 partially blocked HIF-1α protein and PAI-1 mRNA levels induced by nickel, whereas antioxidants and NADPH oxidase inhibitors had no effect. Pretreating cells with antisense, but not sense, oligonucleotides to HIF-1α mRNA abolished nickel-stimulated increases in PAI-1 mRNA. These data indicate that signaling through extracellular signal-regulated kinase and HIF-1α is required for nickel-induced transcriptional activation of PAI-1.

REGULATION OF PLASMINOGEN ACTIVATOR INHIBITOR-1 mRNA IN HUMAN ENDOTHELIAL CELLS

1987 ◽  
Author(s):  
E A van den Berg ◽  
E Sprengers ◽  
M Jaye ◽  
W Burgess ◽  
V W M van Hinsbergh
Keyword(s):  
Endothelial Cells ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Plasminogen Activator ◽  
Cdna Clone ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Human Endothelial Cells ◽  
Activator Inhibitor ◽  
Pai 1

Cultured human endothelial cells (HEC) increase their production of plasminogen activator inhibitor (PAI-1) upon stimulation with endotoxin and IL-1, agents that are known to cause an increase in PAI-1 levels in vivo. In order to study the regulation of PAI-1 synthesis at the mRNA level, we isolated a cDNA clone for the human PAI-1 gene from an endothelial expression cDNA library in λ gt 11 by screening with a PAI-1 specific antibody. Three positive cross-hybridizing clones were isolated. The longest insert (1500 bp) was partially sequenced (1000 bp). The sequence was identical to the PAI-1 sequence recently reported by others. The identity of the cDNA clone was further confirmed by comparison with part of the amino acid sequence of PAI-1. For that purpose t-PA-PAI-1 complex was purified from HEC conditioned medium by immunoadsorption to anti-t-PA IgG, and a suitable peptide was sequenced after comparison of the HPLC elution profiles of CNBr digests of t-PA and t-PA-PAI-1 complex. The amino acid sequence (M)FRQFQADFT completely matches the sequence predicted from the cDNA sequence.By hybridization of the cDNA probe to Northern blots of total cellular RNA from human umbilical vein and artery EC (HUVEC, HUAEC), two transcripts of 2.3 and 3 kb were found. Primary HUAEC, incubated for 18 hours in growth medium, produced considerable although variable levels of PAI-1 activity and contained PAI-1 mRNA levels comparable to those found in subcultured HUAEC. When subcultured HUEC were incubated for 6 h with endotoxin, IL-1 or TNF, a 2-fold increase in PAI-1 mRNA was found with each of these mediators. Stimulation of the cells in the presence of cycloheximide resulted in a further increase of the 3 kb PAI-1 transcript. The 3’ end of this transcript contains a 75 bp AT-rich sequence. Similar 3’ AT-rich sequences have been found in mRNA’s for a number of inflammatory mediators and cellular oncogenes, and in some cases it has been shown that removal of the sequence increased mRNA stability. The influence of cyclohex-imid on the larger PAI-1 transcript might be explained by inhibition of synthesis of a specific nuclease that controls the level of mRNA’s harbouring such an AT rich sequence.

Altered expression of plasminogen activator inhibitor type 1 in placentas from pregnant women with preeclampsia and/or intrauterine fetal growth retardation

Blood ◽  
1994 ◽  
Vol 84 (1) ◽  
pp. 143-150 ◽  
Author(s):  
A Estelles ◽  
J Gilabert ◽  
M Keeton ◽  
Y Eguchi ◽  
J Aznar ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Growth Retardation ◽  
Plasminogen Activator Inhibitor ◽  
Northern Blotting ◽  
Mrna Levels ◽  
Altered Expression ◽  
Normal Placenta ◽  
Activator Inhibitor ◽  
Pai 1

Elevated plasma levels of type 1 plasminogen activator inhibitor (PAI- 1) have been implicated in mediating the fibrin deposition and occlusive lesions that occur within the placental vasculature in preeclampsia (PE) and intrauterine growth retardation (IUGR). In this report we identify the cells within the normal-appearing villous tissue that are responsible for the local production of PAI-1 in women with PE and IUGR. Levels for another fibrinolytic inhibitor (ie, type 2 plasminogen activator inhibitor [PAI-2]) were determined for comparative purposes. Elevated levels of PAI-1 were detected in placenta extracts from PE/IUGR patients (121 +/- 38 ng/mg, n = 8) when compared with the levels in placenta extracts from normal women (43 +/- 17 ng/mg, n = 10) or women with IUGR but not PE (51 +/- 22 ng/mg, n = 11). Immunohistochemical analysis of paraffin sections showed an increased immunoreactivity for PAI-1 in the placental villous syncytiotrophoblasts from PE/IUGR women compared with the immunostaining of placental samples from the normal or IUGR group. In contrast, antigen levels and immunostaining for PAI-2 were reduced in the placentas harvested from not only the PE/IUGR women (209 +/- 144 ng/mg) but also the IUGR group (169 +/- 106 ng/mg) in comparison with the PAI-2 levels in normal placentas (535 +/- 98 ng/mg). To document that the increased immunoreactivity for PAI-1 in PE/IUGR syncytiotrophoblasts was mediated by an increased production of PAI-1 within these cells, in situ hybridization analysis was performed. A strong positive signal for PAI-1 mRNA in villous syncytiotrophoblasts from PE patients (n = 5) was obtained after 2 weeks of exposure to the NTB2 emulsion in comparison with the weak signal for PAI-1 mRNA that required a 10-week exposure of the normal placenta sections (n = 10). Northern blotting for PAI-1 mRNA showed that both transcripts (ie, 3.2 and 2.3 kb) were elevated in samples of two PE patients in comparison with the PAI-1 mRNA transcripts present in a normal placenta and an IUGR placental sample. These results show increased PAI-1 and mRNA levels in placentas from PE patients and raise the possibility that localized elevated levels of PAI-1 may play a role in the initiation of placental damage, as well as in the thrombotic complications associated with this disease.

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.

Physiological testosterone stimulates tissue plasminogen activator and tissue factor pathway inhibitor and inhibits plasminogen activator inhibitor type 1 release in endothelial cellsThis paper is one of a selection of papers in this Special Issue, entitled International Symposium on Recent Advances in Molecular, Clinical, and Social Medicine, and has undergone the Journal's usual peer-review process.

2007 ◽  
Vol 85 (2) ◽  
pp. 246-251 ◽  
Author(s):  
Hong Jin ◽  
Jijin Lin ◽  
Lu Fu ◽  
Yi-Fang Mei ◽  
Geng Peng ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Tissue Plasminogen ◽  
Tissue Factor Pathway ◽  
Inhibitor Type ◽  
Activator Inhibitor Type ◽  
Activator Inhibitor ◽  
Pai 1

There is a striking gender difference in atherosclerotic vascular disease. For decades, testosterone was considered detrimental to the cardiovascular system. Recent studies, however, have presented some alternative results. The aim of this study was to evaluate the effect of testosterone, using physiological and supraphysiological concentrations, on antigen and mRNA levels of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and tissue factor pathway inhibitor (TFPI) released by human umbilical vein endothelial cells and to investigate the cellular mechanism. Cells within 2–3 passages were cultured in 25 cm2 flasks or plated onto 96-well plates with a density of about 1 × 105 cells/mL as recommended. The cells were incubated in the presence or absence of testosterone (3, 30, 3 × 103, 3 × 104 nmol/L) for 48 h. Levels of tPA, PAI-1, and TFPI antigen were assayed with ELISA kits. Reverse transcriptase PCR was carried out to detect tPA, PAI-1, and TFPI mRNA levels. Cells were incubated in androgen-receptor antagonist (flutamide 10 µmol/L) or aromatase inhibitor (aminoglutethimide 50 µmol/L) for 3 h, and then the experiments were repeated. Testosterone at a physiologic concentration (30 nmol/L) increased the antigen levels of tPA and TFPI significantly (P < 0.05). However, tPA and TFPI levels were markedly reduced (P < 0.05) at a larger dose (3 × 104 nmol/L). On the other hand, PAI-1 antigen levels decreased significantly at the testosterone concentrations ranging from 3 to 3 × 104 nmol/L (P < 0.05). The change in the levels of tPA and TFPI were reflected in the corresponding change in mRNA levels. Flutamide attenuated the effect of testosterone at physiological concentration (30 nmol/L). The results demonstrated that testosterone at physiological concentrations may have a beneficial influence on the haemostatic system through enhancement of anticoagulant activity, resulting from stimulation of TFPI and tPA expression and inhibition of PAI-1 secretion by the endothelium.

Fibrin Fragment Induction of Plasminogen Activator Inhibitor Transcription Is Mediated by Activator Protein-1 Through a Highly Conserved Element

Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 2029-2038 ◽  
Author(s):  
Mitchell A. Olman ◽  
James S. Hagood ◽  
Warren L. Simmons ◽  
Gerald M. Fuller ◽  
Charles Vinson ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Transcriptional Activity ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Activator Protein 1 ◽  
Activator Protein ◽  
Activator Inhibitor ◽  
Pai 1 ◽  
D Dimer

Abstract Plasminogen activator inhibitor type-1 (PAI-1), a serine protease inhibitor, affects the processes of fibrinolysis, wound healing, and vascular remodeling. We have demonstrated that PAI-1 transcription is induced by D dimer, a plasmin proteolytic fragment of fibrin, supporting its role in negative feedback on peri-cellular proteolysis. The focus of this study was to define the mechanism of D dimer’s effects on PAI-1 transcription. D dimer increased the binding activity of the transcription factor activator protein-1 components c-fos/junD and c-fos mRNA levels in a time- and concentration-dependent manner to a greater extent than fibrinogen. Both basal and D dimer-induced PAI-1 transcriptional activity were entirely dependent on elements within the −161 to −48 bp region of the PAI-1 gene in fibroblasts. Mutations within the AP-1–like element (−59 to −52 bp) in the PAI-1 gene affected D dimer-induced transcriptional activity, c-fos/junD DNA binding, and basal and c-fos inducible PAI-1 transcriptional activity. Furthermore, expression of either wild-type or mutant c-fos proteins augmented or diminished the response of the PAI-1 promoter (−161 to +26 bp) to D dimer, respectively. D dimer-induced binding of c-fos/junD to the highly conserved and unique AP-1 like element in the PAI-1 gene provides a mechanism whereby specific fibrin fragments control fibrin persistence at sites of inflammation, fibrosis, and neoplasia.

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