Abstract 1331: Myocardial Function Alterations Correlate to Cardiac Fibrosis and Upregulation of Profibrotic Signaling in Plasminogen Activator Inhibitor-1 Deficient Mice

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
William Bradham ◽  
Linda Gleaves ◽  
Mousumi Medda ◽  
Douglas Vaughan
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Cardiac Fibrosis ◽  
Plasminogen Activator Inhibitor ◽  
Rt Pcr ◽  
Plasminogen Activator Inhibitor 1 ◽  
Internal Dimension ◽  
Functional Consequences ◽  
Activator Inhibitor ◽  
Pai 1

Cardiac fibrosis is a common sequelae of cardiac injury and has deleterious functional consequences impacting cardiac filling, function and rhythm. Plasminogen activator inhibitor-1 (PAI-1) has been implicated in the pathogenesis of tissue fibrosis in mice. To investigate the longitudinal effect of PAI-1 on cardiac structure and function, M-mode echocardiography was employed to examine cardiac function in PAI-1 deficient (PAI-1 −/− ) and wild-type (WT) control mice in four age groups (6,12,18, 24 months). Eighteen month old PAI-1 −/− mice exhibited reduced left ventricular (LV) diastolic internal dimension ( p =0.0118) and a trend towards increased LV posterior wall (LVPW) thickness, compared to WT. Two year old PAI-1 −/− mice showed increased diastolic and systolic LVPW thickness ( p =0.0127 and p =0.0212, respectively), reduced diastolic and systolic LV internal dimension ( p =0.0486 and p =0.0124), but with preserved LV fractional shortening compared to WT. Histological examination of cardiac sections revealed fibrosis on the anterior epicardial surface of the hearts in 18 month old PKO, which in 26 month old mice had become confluent with extensive (10 –17% by area) epicardial, perivascular, and interstitial distribution (compared to none in WT). Real time polymerase chain reaction (RT-PCR) revealed upregulation of transforming growth factor beta (TGF-β) and fibroblast growth factor 2 in PAI-1 −/− compared to WT ( p =0.0234 and p =0.037, respectively). Immunofluoresence confirmed this finding with bright TGF-β staining localized in the media of intra-myocardial arterioles, and phosphorylated SMAD2/3, the downstream TGF-β signaling mediator, in areas of fibrosis. Thoracic aortic cells from aged (18 –24 month) PKO and WT mice were grown in culture, with RT-PCR revealing 4 fold increased TGF-β and 17 fold increased SMAD3 ( p <0.05 for both) RNA levels in PAI-1 −/− , supplying additional evidence for upregulation of a profibrotic TGF-β/SMAD tissue signaling pathway. The present study is one of the first to elucidate some of the functional consequences and relevant molecular signaling pathways related to aging and PAI-1 deficiency mediated cardiac fibrosis.

scholarly journals Placenta Growth Factor (PlGF), a Novel Inducer of Plasminogen Activator Inhibitor-1 (PAI-1) in Sickle Cell Disease (SCD)

2010 ◽  
Vol 285 (22) ◽  
pp. 16713-16722 ◽  
Author(s):  
Nitin Patel ◽  
Nambirajan Sundaram ◽  
Mingyan Yang ◽  
Catherine Madigan ◽  
Vijay K. Kalra ◽  
...  
Keyword(s):  
Growth Factor ◽  
Sickle Cell Disease ◽  
Plasminogen Activator ◽  
Sickle Cell ◽  
Plasminogen Activator Inhibitor ◽  
Cell Disease ◽  
Placenta Growth Factor ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

scholarly journals Fibroblast-specific plasminogen activator inhibitor-1 depletion ameliorates renal interstitial fibrosis after unilateral ureteral obstruction

2019 ◽  
Vol 34 (12) ◽  
pp. 2042-2050 ◽  
Author(s):  
Lan Yao ◽  
M Frances Wright ◽  
Brandon C Farmer ◽  
Laura S Peterson ◽  
Amir M Khan ◽  
...  
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Ureteral Obstruction ◽  
Interstitial Fibrosis ◽  
Plasminogen Activator Inhibitor ◽  
Unilateral Ureteral Obstruction ◽  
Tubular Epithelium ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Background Plasminogen activator inhibitor-1 (PAI-1) expression increases extracellular matrix deposition and contributes to interstitial fibrosis in the kidney after injury. While PAI-1 is ubiquitously expressed in the kidney, we hypothesized that interstitial fibrosis is strongly dependent on fibroblast-specific PAI-1 (fbPAI-1). Methods Tenascin C Cre (TNC Cre) and fbPAI-1 knockdown (KD) mice with green fluorescent protein (GFP) expressed within the TNC construct underwent unilateral ureteral obstruction and were sacrificed 10 days later. Results GFP+ cells in fbPAI-1 KD mice showed significantly reduced PAI-1 expression. Interstitial fibrosis, measured by Sirius red staining and collagen I western blot, was significantly decreased in fbPAI-1 KD compared with TNC Cre mice. There was no significant difference in transforming growth factor β (TGF-β) expression or its activation between the two groups. However, GFP+ cells from fbPAI-1 KD mice had lower TGF β and connective tissue growth factor (CTGF) expression. The number of fibroblasts was decreased in fbPAI-1 KD compared with TNC Cre mice, correlating with decreased alpha smooth muscle actin (α-SMA) expression and less fibroblast cell proliferation. TNC Cre mice had decreased E-cadherin, a marker of differentiated tubular epithelium, in contrast to preserved expression in fbPAI-1 KD. F4/80-expressing cells, mostly CD11c+/F4/80+ cells, were increased while M1 macrophage markers were decreased in fbPAI-1 KD compared with TNC Cre mice. Conclusion These findings indicate that fbPAI-1 depletion ameliorates interstitial fibrosis by decreasing fibroblast proliferation in the renal interstitium, with resulting decreased collagen I. This is linked to decreased M1 macrophages and preserved tubular epithelium.

scholarly journals Insulin-Like Growth Factor Binding Protein-5 Binds to Plasminogen Activator Inhibitor-I*

Endocrinology ◽  
1997 ◽  
Vol 138 (7) ◽  
pp. 2972-2978 ◽  
Author(s):  
Taek Jeong Nam ◽  
Walker Busby ◽  
David R. Clemmons
Keyword(s):  
Amino Acids ◽  
Extracellular Matrix ◽  
Amino Acid ◽  
Growth Factor ◽  
Heparan Sulfate ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Insulin-like growth factor binding protein-5 (IGFBP-5) has been shown to bind to the extracellular matrix (ECM) of both fibroblasts and smooth muscle cells. The ECM-IGFBP-5 interaction is mediated in part by binding to heparan sulfate containing proteoglycans. Because proteoglycans may not be the only components of ECM that bind to IGFBP-5, we have determined its ability to bind to other ECM proteins. When a partially purified mixture of the proteins that were present in fibroblast conditioned medium was purified by IGFBP-5 affinity chromatography, a 55-kDa protein was eluted. Amino acid sequencing of the amino terminal 28 amino acids showed that it was human plasminogen activator inhibitor-1 (PAI-1). To determine if this interaction was specific, purified human PAI-1 was incubated with IGFBP-5 and the IGFBP-5/PAI-1 complex immunoprecipitated with anti-PAI-1 antiserum. When the precipitate was analyzed by immunoblotting using anti-IGFBP-5 antiserum, the intensity of the IGFBP-5 band was substantially increased compared with controls that did not contain human PAI-1. A synthetic IGFBP-5 peptide that contained the amino acid sequence between positions 201 and 218 inhibited IGFBP-5/PAI-1 interaction. Coincubation of IGFBP-5 mutants that contained substitutions for specific basic residues located between positions 201 and 218 with PAI-1 indicated that some of these amino acids were important for binding. Two mutants that contained neutral substitutions for specific basic amino acids within the glycosaminoglycan binding domain had reduced binding to PAI-1. In contrast, three other mutants that also had substitutions for charged residues in the same region had no reduction in binding. Heparin and heparan sulfate inhibited the IGFBP-5/PAI-1 interaction; however, several other glycosaminoglycans had no effect. PAI-1 was determined to be an important ECM component for binding because approximately 27% of total ECM binding could be inhibited with anti-PAI-1 antiserum. Competitive binding studies with unlabeled IGFBP-5 showed that the dissociation constant of PAI-1 for IGFBP-5 was 9.1 × 10−8m. In summary, IGFBP-5 binds specifically to plasminogen activator inhibitor-1. Because this is present in the extracellular matrix of several cell types, it may be one of the important binding components of ECM. PAI-1 binding partially protects IGFBP-5 from proteolysis, suggesting that it is one of the ECM components that is involved in mediating this effect.

scholarly journals Involvement of miR-30c and miR-301a in immediate induction of plasminogen activator inhibitor-1 by placental growth factor in human pulmonary endothelial cells

2011 ◽  
Vol 434 (3) ◽  
pp. 473-482 ◽  
Author(s):  
Nitin Patel ◽  
Stanley M. Tahara ◽  
Punam Malik ◽  
Vijay K. Kalra
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Placental Growth Factor ◽  
Luciferase Reporter ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

PAI-1 (plasminogen activator inhibitor-1) is a key physiological inhibitor of fibrinolysis. Previously, we have reported PlGF (placental growth factor)-mediated transcriptional up-regulation of PAI-1 (SERPINE1) mRNA expression via activation of HIF-1α (hypoxia-inducible factor-1α) and AP-1 (activator protein-1) in HPMVECs (human pulmonary microvascular endothelial cells), which resulted in elevated PAI-1 in humans with SCA (sickle cell anaemia). In the present study, we have identified the role of post-transcriptional mechanism(s) of PlGF-mediated accumulation of PAI-1 mRNA in HPMVECs by examining the role of microRNAs (miRNAs/miRs) in PlGF-induced PAI-1 mRNA stability. Our results show reduced expression of miR-30c and miR-301a, but not of miR-99a, in response to PlGF, which have evolutionarily conserved binding sites in the 3′-UTR (3′-untranslated region) of PAI-1 mRNA. Transfection of anti-miR-30c or anti-miR-301a oligonucleotides resulted in increased PAI-1 mRNA levels, which were increased further with PlGF stimulation. Conversely, overexpression of pre-miR-30c or pre-miR-301a resulted in an attenuation of PlGF-induced PAI-1 mRNA and protein levels. Luciferase reporter assays using wild-type and mutant 3′-UTR constructs confirmed that the PAI-1 3′-UTR is indeed a direct target of miR-30c and miR-301a. Finally, plasma levels of miR-30c and miR-301a were significantly down-regulated in patients with SCA compared with normal controls. These results provide a post-transcriptional regulatory mechanism of PlGF-induced PAI-1 elevation.

scholarly journals Plasminogen activator inhibitor-1 (PAI-1) is cardioprotective in mice by maintaining microvascular integrity and cardiac architecture

Blood ◽  
2010 ◽  
Vol 115 (10) ◽  
pp. 2038-2047 ◽  
Author(s):  
Zhi Xu ◽  
Francis J. Castellino ◽  
Victoria A. Ploplis
Keyword(s):  
Plasminogen Activator ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Plasminogen Activator Inhibitor ◽  
Transforming Growth Factor Β ◽  
Heart Tissue ◽  
Matrix Remodeling ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

Abstract Although the involvement of plasminogen activator inhibitor-1 (PAI-1) in fibrotic diseases is well documented, its role in cardiac fibrosis remains controversial. The goal of this study was to determine the effect of a PAI-1 deficiency (PAI-1−/−) on the spontaneous development of cardiac fibrosis. PAI-1−/− mice developed pervasive cardiac fibrosis spontaneously with aging, and these mice displayed progressively distorted cardiac architecture and markedly reduced cardiac function. To mechanistically elucidate the role of PAI-1 in cardiac fibrosis, 12-week-old mice were chosen to study the biologic events leading to fibrosis. Although fibrosis was not observed at this early age, PAI-1−/− hearts presented with enhanced inflammation, along with increased microvascular permeability and hemorrhage. A potent fibrogenic cytokine, transforming growth factor-β (TGF-β), was markedly enhanced in PAI-1−/− heart tissue. Furthermore, the expression levels of several relevant proteases associated with tissue remodeling were significantly enhanced in PAI-1−/− hearts. These results suggest that PAI-1 is cardioprotective, and functions in maintaining normal microvasculature integrity. Microvascular leakage in PAI-1−/− hearts may provoke inflammation, and predispose these mice to cardiac fibrosis. Therefore, a PAI-1 deficiency contributes to the development of cardiac fibrosis by increasing vascular permeability, exacerbating local inflammation, and increasing extracellular matrix remodeling, an environment conducive to accelerated fibrosis.

Plasminogen Activator Inhibitor-1 mRNA Is Induced by Hemorrhage in Endothelial and/Mesothelial Cells of the Rat Liver

1995 ◽  
Vol 74 (03) ◽  
pp. 933-937 ◽  
Author(s):  
Masatomo Yamashita ◽  
Daniel N Darlington ◽  
Shiqichi Imafuku ◽  
Dionald S Gann
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Mesothelial Cells ◽  
Sprague Dawley ◽  
Rt Pcr ◽  
Plasminogen Activator Inhibitor 1 ◽  
Treatment Standard ◽  
Activator Inhibitor ◽  
Pai 1

SummaryWe have recently shown that plasminogen activator inhibitor-1 (PAI-I) mRNA is elevated after hemorrhage in various tissues including liver. In this study, we set out to identify the cell types in the liver that are responsible for the increase in PAH mRNA after hemorrhage using in situ reverse transcription-polymerase chain reaction (in situ RT-PCR). Male Sprague-Dawley rats were cannulated and subjected to a 20 ml/kg hemorrhage within 3 min or 300 μg/kg of endotoxin. Pour hours later, the livers were harvested, fixed, frozen, and sectioned. RT-PCR showed an increase of PAI-I mRNA in liver 4 h after hemorrhage or endotoxin-treatment. Standard in situ hybridization could not detect PAI-I mRNA in the livers of either the hemorrhage, endotoxin, or control groups. However, in situ RT-PCR detected PAI-1 mRNA in vascular endothelial cells and capsular mesothelial cells, but not in hepatocytes, in both the hemorrhage and endotoxin groups. No signal was found in the control rats, or when the experimental protocol was modified to 1) omit the RT step, 2) precede the RT step with RNA digestion, or 3) use an irrelevant probe. These results demonstrate that hemorrhage induces PAI-1 mRNA in endothelial and mesothelial cells of liver.

Up-Regulated Expression of Plasminogen Activator Inhibitor-1 in Hep G2 Cells: Interrelationship between Insulin and Insulin-Like Growth Factor 1

1995 ◽  
Vol 73 (02) ◽  
pp. 268-274 ◽  
Author(s):  
F Anfosso ◽  
M C Alessi ◽  
G Nalbone ◽  
N Chomiki ◽  
M Henry ◽  
...  
Keyword(s):  
Growth Factor ◽  
Plasminogen Activator ◽  
Insulin Receptors ◽  
Plasminogen Activator Inhibitor ◽  
Hep G2 ◽  
Hep G2 Cells ◽  
Plasminogen Activator Inhibitor 1 ◽  
G2 Cells ◽  
Activator Inhibitor ◽  
Pai 1

SummaryInsulin resistance represents a situation with a high risk of athero-thrombosis and is accompanied by increased plasma plasminogen activator inhibitor-1 (PAI-1) levels. Fasting insulin level is highly correlated with PAI-1 levels in plasma. It has been shown that insulin increases PAI-1 synthesis by the human hepatoma cell line Hep G2. Moreover when Hep G2 cells expressing a down-regulation of insulin receptors by incubation with 10-7 M insulin, were stimulated by 10-9 M insulin, an overexpression of PAI-1 synthesis was observed despite a reduced number of insulin receptors. Insulin-like growth factor 1 (IGF-1) shares many properties with insulin. The aim of the present study was to evaluate the effect of IGF-1 on PAI-1 synthesis by Hep G2 cells down-regulated either by insulin or IGF-1.Incubation of Hep G2 cells with increasing doses from 10-9 to 10-7 M IGF-1 induced a dose-dependent stimulation of PAI-1 synthesis up to 4.5-fold the control level. When cells were first pre-incubated with 10-7M IGF-1 for 18 h, acid washed, and then stimulated with 10-9 M IGF-1, the expression of IGF-1 receptors was greatly reduced (up to 70%). In contrast PAI-1 secretion was increased 3.4-fold the level of control cells and by 1.9-fold the level of cells first stimulated with 10-9M IGF-1. Both transcripts of PAI-1 mRNA were also increased. The overexpression of PAI-1 synthesis was observed irrespective of the hormone used in the down-regulation step (i.e. 10-9 M insulin or IGF-1) or in the stimulation step (i. e. 10-9 M insulin or IGF-1). The results showed an interrelationship between insulin and IGF-1 on PAI-1 synthesis in down-regulated Hep G2 cells. They also suggest that in the insulin resistant state, IGF-1 would be able to participate in the increase in PAI-1 plasma levels by stimulating down-regulated insulin target cells.

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