scholarly journals Thrombin Upregulates PAI-1 and Mesothelial–Mesenchymal Transition Through PAR-1 and Contributes to Tuberculous Pleural Fibrosis

2019 ◽  
Vol 20 (20) ◽  
pp. 5076
Author(s):  
Cheng-Ying Hsieh ◽  
Joen-Rong Sheu ◽  
Chih-Hao Yang ◽  
Wei-Lin Chen ◽  
Jie-Heng Tsai ◽  
...  
Keyword(s):  
Pleural Effusion ◽  
Smooth Muscle Actin ◽  
Plasminogen Activator Inhibitor ◽  
Plasminogen Activator Inhibitor 1 ◽  
Mesenchymal Transition ◽  
Pleural Thickening ◽  
Pleural Fibrosis ◽  
Pai 1

Thrombin is an essential procoagulant and profibrotic mediator. However, its implication in tuberculous pleural effusion (TBPE) remains unknown. The effusion thrombin and plasminogen activator inhibitor-1 (PAI-1) levels were measured among transudative pleural effusion (TPE, n = 22) and TBPE (n = 24) patients. Pleural fibrosis, identified as radiological residual pleural thickening (RPT) and shadowing, was measured at 12-month follow-up. Moreover, in vivo and in vitro effects of thrombin on PAI-1 expression and mesothelial–mesenchymal transition (MMT) were assessed. We demonstrated the effusion thrombin levels were significantly higher in TBPE than TPE, especially greater in TBPE patients with RPT > 10mm than those without, and correlated positively with PAI-1 and pleural fibrosis area. In carbon black/bleomycin-treated mice, knockdown of protease-activated receptor-1 (PAR-1) markedly downregulated α-smooth muscle actin (α-SMA) and fibronectin, and attenuated pleural fibrosis. In pleural mesothelial cells (PMCs), thrombin concentration-dependently increased PAI-1, α-SMA, and collagen I expression. Specifically, Mycobacterium tuberculosis H37Ra (MTBRa) induced thrombin production by PMCs via upregulating tissue factor and prothrombin, and PAR-1 silencing considerably abrogated MTBRa−stimulated PAI-1 expression and MMT. Consistently, prothrombin/PAR-1 expression was evident in the pleural mesothelium of TBPE patients. Conclusively, thrombin upregulates PAI-1 and MMT and may contribute to tuberculous pleural fibrosis. Thrombin/PAR-1 inhibition may confer potential therapy for pleural fibrosis.

Anti-thrombotic Effect of a PAI-1 Inhibitor in Rats Given Endotoxin

1996 ◽  
Vol 75 (01) ◽  
pp. 118-126 ◽  
Author(s):  
T Abrahamsson ◽  
V Nerme ◽  
M Strömqvist ◽  
B Åkerblom ◽  
A Legnehed ◽  
...  
Keyword(s):  
Plasminogen Activator Inhibitor ◽  
Rat Plasma ◽  
Clot Lysis ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Fab Fragment ◽  
Dose Dependent Decrease ◽  
Pai 1

SummaryThe aim of this study was to investigate the anti-thrombotic effects of an inhibitor of the plasminogen activator inhibitor-1 (PAI-1) in rats given endotoxin. In studies in vitro, PRAP-1, a Fab-fragment of a polyclonal antibody against human PAI-1, was shown to inhibit PAI-1 activity in rat plasma as well as to stimulate clot-lysis of the euglobulin fraction derived from rat plasma. Endotoxin administered to anaesthetised rats produced a marked increase in plasma PAI-1 activity. To study fibrin formation and lysis in vivo after intravenous (i. v.) injection of the coagulant enzyme batroxobin, 125I-fibrinogen was administered to the animals. The thrombi formed by batroxobin were rapidly lysed in control animals, while the rate of lysis was markedly attenuated in rats given endotoxin. PRAP-1 was administered i.v. (bolus + infusion) to rats given endotoxin and batroxobin and the PAI-1 inhibitor caused a dose-dependent decrease in the 125I-fibrin deposition in the lungs. An immunohistochemical technique was used to confirm this decrease in density of fibrin clots in the tissue. Furthermore, PRAP-1 decreased plasma PAI-1 activity in the rats and this reduction was correlated to the decrease in lung 125I-fibrin deposition at the corresponding time point. It is concluded that in this experimental model the PAI-1 antibody PRAP-1 may indeed inhibit thrombosis in animals exposed to endotoxin.

The Roles of α2-Antiplasmin and Plasminogen Activator Inhibitor 1 (PAI-1) in the Inhibition of Clot Lysis

1993 ◽  
Vol 70 (02) ◽  
pp. 301-306 ◽  
Author(s):  
Linda A Robbie ◽  
Nuala A Booth ◽  
Alison M Croll ◽  
Bruce Bennett
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Fibrin Clot ◽  
Clot Lysis ◽  
Plasminogen Activator Inhibitor 1 ◽  
Dependent Inhibition ◽  
Activator Inhibitor ◽  
Pai 1

SummaryThe relative importance of the two major inhibitors of fibrinolysis, α2-antiplasmin (α2-AP) and plasminogen activator inhibitor (PAI-1), were investigated using a simple microtitre plate system to study fibrin clot lysis in vitro. Cross-linked fibrin clots contained plasminogen and tissue plasminogen activator (t-PA) at concentrations close to physiological. Purified α2-AP and PAI-1 caused dose-dependent inhibition. All the inhibition due to normal plasma, either platelet-rich or poor, was neutralised only by antibodies to α2-AP. Isolated platelets, at a final concentration similar to that in blood, 2.5 × 108/ml, markedly inhibited clot lysis. This inhibition was neutralised only by antibodies to PAI-1. At the normal circulating ratio of plasma to platelets, α2-AP was the dominant inhibitor. When the platelet:plasma ratio was raised some 20-fold, platelet PAI-1 provided a significant contribution. High local concentrations of PAI-1 do occur in thrombi in vivo, indicating a role for PAI-1, complementary to that of α2-AP, in such situations.

scholarly journals Role of plasminogen activator inhibitor-1 in promoting fibrin deposition in rabbits infused with ancrod or thrombin

Blood ◽  
1993 ◽  
Vol 82 (12) ◽  
pp. 3631-3636 ◽  
Author(s):  
C Krishnamurti ◽  
C Bolan ◽  
CA Colleton ◽  
TM Reilly ◽  
BM Alving
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Fibrin Deposition ◽  
Plasminogen Activator Inhibitor 1 ◽  
Elevated Activity ◽  
Activator Inhibitor ◽  
Pai 1

The role of defective fibrinolysis caused by elevated activity of plasminogen activator inhibitor-1 (PAI-1) in promoting fibrin deposition in vivo has not been well established. The present study compared the efficacy of thrombin or ancrod, a venom-derived enzyme that clots fibrinogen, to induce fibrin formation in rabbits with elevated PAI-1 levels. One set of male New Zealand rabbits received intravenous endotoxin to increase endogenous PAI-1 activity followed by a 1-hour infusion of ancrod or thrombin; another set of normal rabbits received intravenous human recombinant PAI-1 (rPAI-1) during an infusion of ancrod or thrombin. Thirty minutes after the end of the infusion, renal fibrin deposition was assessed by histopathology. Animals receiving endotoxin, rPAI-1, ancrod, or thrombin alone did not develop renal thrombi. All endotoxin-treated rabbits developed fibrin deposition when infused with ancrod (n = 4) or thrombin (n = 6). Fibrin deposition occurred in 7 of 7 rabbits receiving both rPAI-1 and ancrod and in only 1 of 6 receiving rPAI-1 and thrombin (P “ .01). In vitro, thrombin but not ancrod was inactivated by normal rabbit plasma and by purified antithrombin III or thrombomodulin. The data indicate that elevated levels of PAI-1 promote fibrin deposition in rabbits infused with ancrod but not with thrombin. In endotoxin-treated rabbits, fibrin deposition that occurs with thrombin infusion may be caused by decreased inhibition of procoagulant activity and not increased PAI-1 activity.

scholarly journals Vitamin D Enhances Radiosensitivity of Colorectal Cancer by Reversing Epithelial-Mesenchymal Transition

2021 ◽  
Vol 9 ◽  
Author(s):  
Xinyue Yu ◽  
Qian Wang ◽  
Baocai Liu ◽  
Ning Zhang ◽  
Guanghui Cheng
Keyword(s):  
Colorectal Cancer ◽  
Vitamin D ◽  
Epithelial Mesenchymal Transition ◽  
Active Form ◽  
Plasminogen Activator Inhibitor ◽  
Biologically Active ◽  
Plasminogen Activator Inhibitor 1 ◽  
Mesenchymal Transition

Colorectal cancer (CRC) is often resistant to conventional therapies. Previous studies have reported the anticancer effects of vitamin D in several cancers, its role in radiotherapy (RT) remains unknown. We found that 1α, 25-dihydroxyvitamin D3 (VD3), the biologically active form of vitamin D, had antitumor effect on CRC and sensitized CRC cells to ionizing radiation (IR). VD3 demonstrated synergistic effect in combination with IR, which were detected by colony formation and cell proliferation assay. Radiosensitivity restoration induced by VD3 was associated with a series of phenotypes, including apoptosis, autophagy, and epithelial-mesenchymal transition (EMT). Using proteomics, “regulation of cell migration” and “cadherin” were found to be obviously enriched GO terms. Moreover, cystatin D and plasminogen activator inhibitor-1 (PAI-1), the differentially expressed proteins, were associated with EMT. Next, we confirmed the contributions of these two genes in enhancing IR sensitivity of CRC cells upon inhibition of EMT. As determined by proteomics, the mechanism underlying such sensitivity involved partially block of JAK/STAT3 signaling pathway. Furthermore, VD3 also elicited sensitization to RT in xenograft CRC models without additional toxicity. Our study revealed that VD3 was able to act in synergy with IR both in vitro and in vivo and could also confer radiosensitivity by regulating EMT, thereby providing a novel insight for elevating the efficacy of therapeutic regimens.

Impairment of adipose tissue development by hypoxia is not mediated by plasminogen activator inhibitor-1

2006 ◽  
Vol 95 (01) ◽  
pp. 174-181 ◽  
Author(s):  
Fabrizio Semeraro ◽  
Gabor Voros ◽  
Désiré Collen ◽  
H. Lijnen
Keyword(s):  
Adipose Tissue ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Development ◽  
Plasminogen Activator Inhibitor 1 ◽  
Adipose Tissue Development ◽  
Activator Inhibitor ◽  
Pai 1

SummaryHypoxia in rodents and humans is associated with a reduction of body fat on the one hand, and with enhanced expression of plasminogen activator inhibitor-1 (PAI-1), the main inhibitor of the fibrinolytic system, on the other hand. It was the objective of this study to investigate whether impairment of adipose tissue development by hypoxia may be mediated by PAI-1. Five week old male wild-type (WT) C57Bl/6 mice were fed a standard (SFD) or high fat (HFD) diet and kept under normoxic or hypoxic (10% O2) conditions. In addition, PAI-1 deficient mice and WT littermates were kept on HFD under normoxia or hypoxia. In vitro, the effect of hypoxia (2% O2) was investigated on differentiation of 3T3-L1 cells into adipocytes. Hypoxia induced a significant reduction of weight gain in WT mice on either SFD or HFD, accompanied by lower weights of subcutaneous (SC) and gonadal (GON) fat. Under hypoxic conditions, adipocytes in the adipose tissues were significantly smaller, whereas blood vessel size and density were larger. Serum PAI-1 levels were enhanced in hypoxic mice on SFD but not on HFD, and overall did not correlate with the observed changes in adipose tissue composition. Furthermore, the effects of hypoxia on adipose tissue in mice on HFD were not affected by deficiency of PAI-1. The inhibiting effect of hypoxia on in vitro preadipocyte differentiation was not mediated by PAI-1 activity. In conclusion, impairment of in vivo adipose tissue development and in vitro differentiation of preadipocytes by hypoxia is not mediated by PAI-1.

Inhibitor-Resistant Tissue-Type Plasminogen Activator: An Improved Thrombolytic Agent In Vitro

1994 ◽  
Vol 71 (01) ◽  
pp. 124-128 ◽  
Author(s):  
R V Shohet ◽  
S Spitzer ◽  
E L Madison ◽  
R Bassel-Duby ◽  
M-J Gething ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Wild Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Tissue Type Plasminogen Activator ◽  
Type Plasminogen Activator ◽  
Pai 1

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.

In vitro and in vivo effects of tPA and PAI-1 on blood vessel tone

Blood ◽  
2004 ◽  
Vol 103 (3) ◽  
pp. 897-902 ◽  
Author(s):  
Taher Nassar ◽  
Sa'ed Akkawi ◽  
Ahuva Shina ◽  
Abdullah Haj-Yehia ◽  
Khalil Bdeir ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Plasminogen Activator ◽  
Density Lipoprotein ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Plasminogen Activator Inhibitor 1 ◽  
Isolated Aorta ◽  
Pai 1

Abstract Tissue type plasminogen activator (tPA) is a key enzyme in the fibrinolytic cascade. In this paper we report that tPA contains 2 independent epitopes that exert opposite effects on blood vessel tone. Low concentrations of tPA (1 nM) inhibit the phenylephrine (PE)–induced contraction of isolated aorta rings. In contrast, higher concentrations (20 nM) stimulate the contractile effect of PE. The 2 putative vasoactive epitopes of tPA are regulated by the plasminogen activator inhibitor-1 (PAI-1) and by a PAI-1–derived hexapeptide that binds tPA. TNK-tPA, a tPA variant in which the PAI-1 docking site has been mutated, stimulates PE-induced vasoconstriction at all concentrations used. The stimulatory, but not the inhibitory, effect of tPA on the contraction of isolated aorta rings was abolished by anti–low-density lipoprotein receptor–related protein/α2-macroglobulin receptor (LRP) antibodies. Administering tPA or TNK-tPA to rats regulates blood pressure and cerebral vascular resistance in a dose-dependent mode. In other in vivo experiments we found that the vasopressor effect of PE is more pronounced in tPA knockout than in wild-type mice. Our findings draw attention to a novel role of tPA and PAI-1 in the regulation of blood vessel tone that may affect the course of ischemic diseases.

scholarly journals HDAC Inhibitor Abrogates LTA−Induced PAI-1 Expression in Pleural Mesothelial Cells and Attenuates Experimental Pleural Fibrosis

2021 ◽  
Vol 14 (6) ◽  
pp. 585
Author(s):  
Wei-Lin Chen ◽  
Mei-Chuan Chen ◽  
Shang-Fu Hsu ◽  
Shih-Hsin Hsiao ◽  
Chi-Li Chung
Keyword(s):  
Mesothelial Cell ◽  
Plasminogen Activator Inhibitor ◽  
Lipoteichoic Acid ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Pleural Thickening ◽  
Gram Positive Bacteria ◽  
Collagen Expression ◽  
Pleural Fibrosis ◽  
Pai 1

Lipoteichoic acid (LTA) stimulates pleural mesothelial cell (PMC) to overproduce plasminogen activator inhibitor-1 (PAI-1), and thus may promote pleural fibrosis in Gram-positive bacteria (GPB) parapneumonic effusion (PPE). Histone deacetylase inhibitor (HDACi) was found to possess anti-fibrotic properties. However, the effects of HDACi on pleural fibrosis remain unclear. The effusion PAI-1 was measured among 64 patients with GPB PPE. Pleural fibrosis was measured as radiographical residual pleural thickening (RPT) and opacity at a 12-month follow-up. The LTA−stimulated human PMCs and intrapleural doxycycline−injected rats were pretreated with or without the pan-HDACi, m-carboxycinnamic acid bis-hydroxamide (CBHA), then PAI-1 and collagen expression and activated signalings in PMCs, and morphologic pleural changes in rats were measured. Effusion PAI-1 levels were significantly higher in GPB PPE patients with RPT > 10 mm (n = 26) than those without (n = 38), and had positive correlation with pleural fibrosis shadowing. CBHA significantly reduced LTA−induced PAI-1 and collagen expression via inhibition of JNK, and decreased PAI-1 promoter activity and mRNA levels in PMCs. Furthermore, in doxycycline−treated rats, CBHA substantially repressed PAI-1 and collagen synthesis in pleural mesothelium and minimized pleural fibrosis. Conclusively, CBHA abrogates LTA−induced PAI-1 and collagen expression in PMCs and attenuates experimental pleural fibrosis. PAI-1 inhibition by HDACi may confer potential therapy for pleural fibrosis.

scholarly journals The pharmacokinetics of plasminogen activator inhibitor-1 in the rabbit

Blood ◽  
1990 ◽  
Vol 76 (8) ◽  
pp. 1514-1520 ◽  
Author(s):  
EJ Mayer ◽  
T Fujita ◽  
SJ Gardell ◽  
RJ Shebuski ◽  
CF Reilly
Keyword(s):  
Plasminogen Activator ◽  
Expression System ◽  
Plasminogen Activator Inhibitor ◽  
Bolus Administration ◽  
Plasminogen Activator Inhibitor 1 ◽  
Main Site ◽  
Activator Inhibitor ◽  
Pai 1

Abstract The pharmacokinetics of the activated and latent forms of plasminogen activator inhibitor-1 (PAI–1) isolated from HT1080 fibrosarcoma cells (HT1080 PAI-1) and a nonglycosylated form of human PAI-1 isolated from a yeast expression system (rPAI-1) were followed in the rabbit. As assessed by an immunologic assay specific for human PAI-1, guanidine HCI activated HT1080 PAI-1 and rPAI-1 entered the total plasma volume following intravenous bolus administration and exhibited a biphasic clearance pattern. The t1/2s of HT1080 PAI-1 for the initial and beta phases equalled 6.0 and 24.8 minutes, respectively. The t1/2s of rPAI-1 for the initial and beta phases equalled 8.8 and 34.0 minutes, respectively. Similar results were obtained by measuring PAI-1 activity in plasma and with trace amounts of 125I-rPAI-1, suggesting that the above pharmacokinetic behavior could also apply to endogenous PAI-1. The liver was the main site of rPAI-1 clearance. Unactivated, latent PAI-1 exhibited a very different pharmacokinetic profile. Over 80% of latent rPAI-1 cleared from the circulation within 10 minutes (t1/2 = 1.7 minutes). The difference in clearance behavior between activated and latent PAI-1 may be related to the ability of activated PAI-1, but not latent PAI-1, to rapidly form high-molecular-weight complexes with plasma binding factors which were observed in vitro and in vivo. Because PAI-1 could potentially tilt the fibrinolytic balance toward a prothrombotic state, its rapid clearance may represent an important control mechanism governing the circulating levels of this key component of the fibrinolytic pathway.

scholarly journals Endothelin-1 Induces Mesothelial Mesenchymal Transition and Correlates with Pleural Fibrosis in Tuberculous Pleural Effusions

2019 ◽  
Vol 8 (4) ◽  
pp. 426 ◽  
Author(s):  
Zhung-Han Wu ◽  
Jie-Heng Tsai ◽  
Cheng-Ying Hsieh ◽  
Wei-Lin Chen ◽  
Chi-Li Chung
Keyword(s):  
Pleural Effusion ◽  
Smooth Muscle Actin ◽  
Mesenchymal Transition ◽  
Pleural Diseases ◽  
Pleural Thickening ◽  
Pleural Fibrosis ◽  
Parapneumonic Pleural Effusion ◽  
Insight Into

Endothelin (ET)-1 is involved in various fibrotic diseases. However, its implication in pleural fibrosis remains unknown. We aimed to study the profibrotic role of ET-1 in tuberculous pleural effusion (TBPE). The pleural effusion ET-1 levels were measured among 68 patients including transudative pleural effusion (TPE, n = 12), parapneumonic pleural effusion (PPE, n = 20), and TBPE (n = 36) groups. Pleural fibrosis, defined as radiological residual pleural thickening (RPT) and shadowing, was measured at 12-month follow-up. Additionally, the effect of ET-1 on mesothelial mesenchymal transition (MMT) and extracellular matrix (ECM) producion in human pleural mesothelial cells (PMCs) was assessed. Our findings revealed that effusion ET-1 levels were significantly higher in TBPE than in TPE and PPE, and were markedly higher in TBPE patients with RPT >10 mm than those with RPT ≤10 mm. ET-1 levels correlated substantially with residual pleural shadowing and independently predicted RPT >10 mm in TBPE. In PMCs, ET-1 time-dependently induced MMT with upregulation of α-smooth muscle actin and downregulation of E-cadherin, and stimulated ECM production; furthermore, ET receptor antagonists effectively abrogated these effects. In conclusion, ET-1 induces MMT and ECM synthesis in human PMCs and correlates with pleural fibrosis in TBPE. This study confers a novel insight into the pathogenesis and potential therapies for fibrotic pleural diseases.

Sign in / Sign up

Export Citation Format

Share Document