Atrial Natriuretic Peptide Inhibits the Expression of Tissue Factor and Plasminogen Activator Inhibitor 1 Induced by Angiotensin II in Cultured Rat Aortic Endothelial Cells

1998 ◽  
Vol 79 (03) ◽  
pp. 631-634 ◽  
Author(s):  
Hajime Tsuji ◽  
Hiromi Nishimura ◽  
Teruhisa Kasahara ◽  
Tatsuya Sugano ◽  
Haruchika Masuda ◽  
...  

SummaryThe pharmacological characteristics of atrial natriuretic peptide (ANP), such as natriuresis, vasodilation, or suppression of smooth muscle cell proliferation, are well investigated. However, this is the first study to report its role on blood coagulation and fibrinolysis mediated by vascular endothelial cells. In this study, the effects of ANP on the enhanced expression of tissue factor (TF) and plasminogen activator inhibitor 1 (PAI-1) by angiotensin II (Ang II) in cultured rat aortic endothelial cells (RAECs) were examined. The expressions of TF and PAI-1 mRNA were detected by northern blotting methods. The activities of TF on the surface of RAECs and PAI-1 in the culture media were measured by chromogenic assay. ANP suppressed mRNA expressions of TF and PAI-1 induced by Ang II in a concentration-dependent manner. This suppression was accompanied by the decreased activities of TF and PAI-1.

2008 ◽  
Vol 36 (05) ◽  
pp. 1005-1015 ◽  
Author(s):  
Jun Yuan ◽  
Xiaoqin Wang ◽  
Taohou Chen ◽  
Gang Chen ◽  
Yanfang Lu

The purpose of this study was to investigate the effect of Salvia miltiorrhiza on the production of plasminogen activator inhibitor-1(PAI-1) induced by angiotensin II (Ang II) in renal mesangial cells. Rat mesangial cells were exposed to 100 nM Ang II. Meanwhile, different concentrations of Salvia miltiorrhiza injection were added to Mesangial Cells. PAI-1 mRNA was measured by semi-quantification reverse transcriptase polymerase chain reaction (RT-PCR) and PAI-1 protein by Western blotting. ELISA was used to detect the expression of transforming growth factor β1 (TGF-β1) in serum free MEM medium. The level of cellular reactive oxygen species (ROS) was measured by confocal laser scanning microscopy. Salvia miltiorrhiza notably attenuated expression of PAI-1 induced by Ang II in a concentration-dependent manner. Meanwhile, it suppressed the production of TGF-β1 and cellular ROS in mesangial cells. These effects were due to Salvia miltiorrhiza's ability of inhibiting the activities of angiotensin II. Therefore, Salvia miltiorrhiza can be used to retard progression of glomerular sclerosis.


1997 ◽  
Vol 77 (06) ◽  
pp. 1189-1195 ◽  
Author(s):  
Hiromi Nishimura ◽  
Hajime Tsuji ◽  
Haruchika Masuda ◽  
Katsumi Nakagawa ◽  
Yoshihumi Nakahara ◽  
...  

SummaryAngiotensin converting enzyme inhibitors (ACE-I) have been reported to prevent the recurrence of cardiovascular events. The mechanism of this decrease, however, can not be completely explained by anti-hypertensive and anti-hypertrophic effects of ACE-I. To investigate the mechanism of this decrease, we studied the regulation of plasminogen activator inhibitor-1 (PAI-1), tissue type plasminogen activator (TPA), tissue factor (TF), and tissue factor pathway inhibitor (TFPI) by angiotensin II (Ang II) in cultured rat aortic endothelial cells. Ang II increased PAI-1 and TF mRNA expression without affecting that of TPA or TFPI. These inductions were accompanied by increases in PAI-1 and TF activities and were inhibited by a type 1 Ang II receptor antagonist. The results suggest that Ang II decreases the antithrombotic properties of endothelial cells which increases the chance of thrombosis. Thus, inhibition of the renin-angiotensin system may be beneficial to prevent thrombus formation in treatment of ischemic heart disease.


Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 721-721
Author(s):  
Kotaro Takeda ◽  
Toshihiro Ichiki ◽  
Tomotake Tokunou ◽  
Satoshi Fujii ◽  
Akira Kitabatake ◽  
...  

P157 Plasminogen activator inhibitor-1 (PAI-1) plays an integral role not only in the regulation of plasminogen activity and fibrinolytic system but also in the pathogenesis of atherosclerosis and hypertension. Because angiotensin II (Ang II) is also involved in these processes, we investigated its role in the intracellular signaling cascade leading to PAI-1 gene expression in vascular smooth muscle cells (VSMC). Ang II increased the PAI-1 mRNA and protein levels through Ang II type 1 receptor. Although PAI-1 mRNA stability was not increased by Ang II, PAI-1 gene promoter activity, which was measured by luciferase assay, was significantly increased by Ang II. This process did not require de novo protein synthesis. BAPTA-AM, genistein and AG1478 completely inhibited the Ang II-induced PAI-1 mRNA upregulation, suggesting that intracellular calcium, tyrosine kinase and epidermal growth factor (EGF) receptor transactivation were involved in this process. However, inhibition of protein kinase C (PKC) by calphostin C, GF109203, or prolonged exposure to PMA failed to abolish the Ang II-induced PAI-1 upregulation, suggesting PKC pathway was not involved. PD98059 suppressed Ang II-induced PAI-1 upregulation, whereas SB203580 did not, suggesting that MEK/ERK1/2 pathway rather than p38 MAP kinase pathway was crucial in this process. Furthermore, adenovirus-mediated expression of dominant negative form of Rho kinase or Rho kinase inhibitor Y27632 also completely suppressed PAI-1 induction by Ang II without affecting Ang II-induced ERK1/2 activation. These data suggest that activation of both MEK/ERK1/2 and Rho kinase pathways will be necessary for the upregulation of PAI-1 gene expression and these two pathways may act synergically to promote PAI-1 gene transcription at least at the downstream of ERK1/2 in VSMC. These findings are important biological and therapeutical implications for the evolution of arterial wall thrombus and the pathogenesis of atherosclerosis by Ang II.


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 ◽  
2004 ◽  
Vol 103 (7) ◽  
pp. 2636-2644 ◽  
Author(s):  
Hong-Chi Chen ◽  
Edward P. Feener

Abstract The MEK1,2 (MAPK/ERK kinase 1 and 2) pathway mediates the up-regulation of plasminogen activator inhibitor-1 (PAI-1) expression in vascular smooth muscle cells by a variety of hormones, including angiotensin II. Transfection of constitutively active MEKK-1, an upstream activator of the mitogen-activated protein (MAP) kinase pathways, was used to isolate an enhancer element located between -89 and -50 bp in PAI-1 promoter that was activated by MEKK-1 and selectively blocked by the MEK1,2 inhibitor PD98059. Mutational analysis revealed that the MEKK-1 response element (MRE) contained 2 cis-acting Sp1- and AP-1—like sequences, located between -75 to -70 and -63 to -52 bp, respectively. Overexpression of Sp1 enhanced MEKK-1—induced MRE promoter activity and a dominant-negative c-Fos blocked this Sp1 response. The combination of Sp1 and c-Jun or c-Fos was required to activate this MRE. Angiotensin II (Ang II) stimulation increased c-Fos, c-Jun, and Sp1 binding to the MRE by 100-, 4.9-, and 1.9-fold, respectively, and these responses were inhibited by PD98059 and AT1 receptor antagonist candesartan. Intravenous Ang II infusion in rats increased aortic c-Fos binding to the MRE. This MRE sequence mediated a 4-fold increase of MEK1,2-dependent PAI-1/luciferase mRNA expression by angiotensin II stimulation. This report identifies the MEK1,2 response element that mediates angiotensin II—stimulated PAI-1 promoter activation and shows that activation of this element requires Sp1 and AP-1 co-activation.


Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Qi Liu ◽  
Xiang Fan ◽  
Helen Brogren ◽  
Ming-Ming Ning ◽  
Eng H Lo ◽  
...  

Aims: Plasminogen activator inhibitor-1 (PAI-1) is the main and potent endogenous tissue-type plasminogen activator (tPA) inhibitor, but an important question on whether PAI-1 in blood stream responds and interferes with the exogenously administered tPA remains unexplored. We for the first time investigated temporal profiles of PAI-1 concentration and activity in circulation after stroke and tPA administration in rats. Methods: Permanent MCAO focal stroke of rats were treated with saline or 10mg/kg tPA at 3 hours after stroke (n=10 per group). Plasma (platelet free) PAI-1 antigen and activity levels were measured by ELISA at before stroke, 3, 4.5 (1.5 hours after saline or tPA treatments) and 24 hours after stroke. Since vascular endothelial cells and platelets are two major cellular sources for PAI-1 in circulation, we measured releases of PAI-1 from cultured endothelial cells and isolated platelets after direct tPA (4 μg/ml) exposures for 60 min in vitro by ELISA (n=4 per group). Results: At 3 hours after stroke, both plasma PAI-1 antigen and activity were significantly increased (3.09±0.67, and 3.42±0.57 fold of before stroke baseline, respectively, all data are expressed as mean±SE). At 4.5 hours after stroke, intravenous tPA administration significantly further elevated PAI-1 antigen levels (5.26±1.24), while as expected that tPA neutralized most elevated PAI-1 activity (0.33±0.05). At 24 hours after stroke, PAI-1 antigen levels returned to the before baseline level, however, there was a significantly higher PAI-1 activity (2.51±0.53) in tPA treated rats. In vitro tPA exposures significantly increased PAI-1 releases into culture medium in cultured endothelial cells (1.65±0.08) and platelets (2.02±0.17). Conclution: Our experimental results suggest that tPA administration may further elevate stroke-increased blood PAI-1 concentration, but also increase PAI-1 activity at late 24 hours after stroke. The increased PAI-1 releases after tPA exposures in vitro suggest tPA may directly stimulate PAI-1 secretions from vascular walls and circulation platelets, which partially contributes to the PAI-1 elevation observed in focal stroke rats. The underlying regulation mechanisms and pathological consequence need further investigation.


2002 ◽  
Vol 87 (2) ◽  
pp. 448-452 ◽  
Author(s):  
Pairunyar Sawathiparnich ◽  
Sandeep Kumar ◽  
Douglas E. Vaughan ◽  
Nancy J. Brown

Recent studies have defined a link between the renin-angiotensin-aldosterone system and fibrinolysis. The present study tests the hypothesis that endogenous aldosterone regulates plasminogen activator inhibitor-1 (PAI-1) production in humans. Hemodynamic parameters, PAI-1 and tissue-type plasminogen activator (t-PA) antigen, potassium, PRA, angiotensin II, and aldosterone were measured in nine male hypertensive subjects after a 3-wk washout, after 2 wk of hydrochlorothiazide (HCTZ; 25 mg plus 20 mmol KCl/d), and after 2 wk of spironolactone (100 mg/d plus KCl placebo). Spironolactone (P = 0.04), but not HCTZ (P = 0.57 vs. baseline; P = 0.1 vs. spironolactone), significantly lowered systolic blood pressure. Angiotensin II increased from baseline during both HCTZ (P = 0.02) and spironolactone (P = 0.02 vs. baseline; P = 0.19 vs. HCTZ) treatments. Although both HCTZ (P = 0.004) and spironolactone (P < 0.001 vs. baseline) increased aldosterone, the effect was greater with spironolactone (P < 0.001 vs. HCTZ). HCTZ increased PAI-1 antigen (P = 0.02), but did not alter t-PA antigen. In contrast, there was no effect of spironolactone on PAI-1 antigen (P = 0.28), whereas t-PA antigen was increased (P = 0.01). There was a significant correlation between PAI-1 antigen and serum aldosterone during both baseline and HCTZ study days (r2 = 0.57; P = 0.0003); however, treatment with spironolactone abolished this correlation (r2 = 0.13; P = 0.33). This study provides evidence that endogenous aldosterone influences PAI-1 production in humans.


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