scholarly journals Role of Macrophages and Plasminogen Activator Inhibitor-1 in Delayed Bone Repair Induced by Glucocorticoids in Mice

2022 ◽  
Vol 23 (1) ◽  
pp. 478
Author(s):  
Kiyotaka Okada ◽  
Naoyuki Kawao ◽  
Daisho Nakai ◽  
Rei Wakabayashi ◽  
Yoshitaka Horiuchi ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Bone Repair ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Femoral Bone ◽  
Plasminogen Activator Inhibitor 1 ◽  
Hematopoietic Stem ◽  
Bone Injury ◽  
Activator Inhibitor ◽  
Pai 1

Glucocorticoids delay fracture healing and induce osteoporosis. However, the mechanisms by which glucocorticoids delay bone repair have yet to be clarified. Plasminogen activator inhibitor-1 (PAI-1) is the principal inhibitor of plasminogen activators and an adipocytokine that regulates metabolism. We herein investigated the roles of macrophages in glucocorticoid-induced delays in bone repair after femoral bone injury using PAI-1-deficient female mice intraperitoneally administered with dexamethasone (Dex). Dex significantly decreased the number of F4/80-positive macrophages at the damaged site two days after femoral bone injury. It also attenuated bone injury-induced decreases in the number of hematopoietic stem cells in bone marrow in wild-type and PAI-1-deficient mice. PAI-1 deficiency significantly weakened Dex-induced decreases in macrophage number and macrophage colony-stimulating factor (M-CSF) mRNA levels at the damaged site two days after bone injury. It also significantly ameliorated the Dex-induced inhibition of macrophage phagocytosis at the damaged site. In conclusion, we herein demonstrated that Dex decreased the number of macrophages at the damaged site during early bone repair after femoral bone injury partly through PAI-1 and M-CSF in mice.

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.

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.

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 mRNA in Human Endothelial Cells

1988 ◽  
Vol 60 (01) ◽  
pp. 063-067 ◽  
Author(s):  
E A van den Berg ◽  
E D Sprengers ◽  
M Jaye ◽  
W Burgess ◽  
T Maciag ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasminogen Activator ◽  
Growth Medium ◽  
Cdna Probe ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Human Endothelial Cells ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

SummaryThe plasminogen activator inhibitor (PAI-1) from endothelial cells is a potentially important regulator of plasminogen activator activity. Cultured human endothelial cells increase their PAI-1 production upon stimulation with LPS and TNF, agents that are known to cause an increase in PAI-1 levels in vivo.We isolated a PAI-1 cDNA probe, and by RNA hybridization analysis studied the regulation of PAI-1 mRNA synthesis in human endothelial artery cells. Freshly isolated endothelial cells do not contain detectable amounts of PAI-1 mRNA, but after adherence and incubation for 18 h in growth medium produce considerable amounts of PAI-1 activity and contain PAI-1 mRNA levels comparable to those found in subcultured cells. When subcultured endothelial cells are incubated for 6 h with LPS or TNF, both species of PAI-1 mRNA increase 10 to 20 fold, while PAI-1 activity in the growth medium increases only 1.5 to 2 fold. Stimulation of endothelial cells in the presence of cycloheximide (CHX) results in superinduction of mainly the 3.0 kb PAI-1 mRNA. The 3' end of this mRNA contains a 60 bp AT-rich sequence, that resembles 3' sequences present in a number of other genes superinducible with CHX.

Regulation of the hypoxia-dependent plasminogen activator inhibitor 1 expression by MAP kinases

2003 ◽  
Vol 89 (04) ◽  
pp. 666-673 ◽  
Author(s):  
Kurt Jungermann ◽  
Agnes Görlach ◽  
Thomas Kietzmann
Keyword(s):  
Plasminogen Activator ◽  
Map Kinases ◽  
Hypoxia Inducible Factor ◽  
Plasminogen Activator Inhibitor ◽  
Mrna Levels ◽  
Plasminogen Activator Inhibitor 1 ◽  
Hypoxic Response ◽  
Pi3k Inhibitor Ly294002 ◽  
Activator Inhibitor ◽  
Pai 1

SummaryMitogen-activated protein kinases (MAPKs) and protein kinase B (PKB) mediate growth and stress signals and have been implicated in the hypoxic response. Under hypoxic conditions, the expression of plasminogen activator inhibitor-1 (PAI-1) is mainly controlled by the hypoxia-inducible factor HIF-1. However, the role of MAPKs and PKB in HIF-1-mediated PAI-1 regulation is not clear.Treatment with the p38 inhibitor SB203580 and the PI3K inhibitor LY294002, but not with the MEK1 inhibitor PD98059, abrogated hypoxia-dependent PAI-1 induction in HepG2 cells. Consistently, overexpression of PKB or of the p38 upstream kinases MKK6 and MKK3 and of JNK, but not of ERK, enhanced PAI-1 mRNA levels. In MKK3-,MKK6- and PKB-expressing cells luciferase (Luc) activities from a hypoxia-inducible PAI-1-Luc construct or from a HIF-dependent Luc construct and, concomitantly, HIF-1α protein levels were enhanced. These findings indicate that p38- and PKB-dependent signalling pathways contribute to enhanced PAI-1 levels in the hypoxic response.Theme paper: Part of this paper was originally presented at the joint meetings of the 16th International Congress of the International Society of Fibrinolysis and Proteolysis (ISFP) and the 17th International Fibrinogen Workshop of the International Fibrinogen Research Society (IFRS) held in Munich, Germany, September, 2002.

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.

943: Plasminogen Activator Inhibitor 1 (PAI-1) is Increased in Human Peyronie's Disease

2005 ◽  
Vol 173 (4S) ◽  
pp. 255-255 ◽  
Author(s):  
Hugo H. Davila ◽  
Thomas R. Magee ◽  
Freddy Zuniga ◽  
Jacob Rajfer ◽  
Nestor F. GonzalezCadavid
Keyword(s):  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Peyronie’S Disease ◽  
Plasminogen Activator Inhibitor 1 ◽  
Peyronie's Disease ◽  
Activator Inhibitor ◽  
Pai 1

Relationship of Plasminogen Activator Inhibitor-1 Levels following Thrombolytic Therapy with rt-PA as Compared to Streptokinase and Patency of Infarct Related Coronary Artery

1999 ◽  
Vol 82 (07) ◽  
pp. 104-108 ◽  
Author(s):  
Franck Paganelli ◽  
Marie Christine Alessi ◽  
Pierre Morange ◽  
Jean Michel Maixent ◽  
Samuel Lévy ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Thrombolytic Therapy ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Control Group ◽  
Plasminogen Activator Inhibitor 1 ◽  
Vessel Patency ◽  
Activator Inhibitor ◽  
Pai 1

Summary Background: Type 1 plasminogen activator inhibitor (PAI-1) is considered to be risk factor for acute myocardial infarction (AMI). A rebound of circulating PAI-1 has been reported after rt-PA administration. We investigated the relationships between PAI-1 levels before and after thrombolytic therapy with streptokinase (SK) as compared to rt-PA and the patency of infarct-related arteries. Methods and Results: Fifty five consecutive patients with acute MI were randomized to strep-tokinase or rt-PA. The plasma PAI-1 levels were studied before and serially within 24 h after thrombolytic administration. Vessel patency was assessed by an angiogram at 5 ± 1days. The PAI-1 levels increased significantly with both rt-PA and SK as shown by the levels obtained from a control group of 10 patients treated with coronary angioplasty alone. However, the area under the PAI-1 curve was significantly higher with SK than with rt-PA (p <0.01) and the plasma PAI-1 levels peaked later with SK than with rt-PA (18 h versus 3 h respectively). Conversely to PAI-1 levels on admission, the PAI-1 levels after thrombolysis were related to vessel patency. Plasma PAI-1 levels 6 and 18 h after SK therapy and the area under the PAI-1 curve were significantly higher in patients with occluded arteries (p <0.002, p <0.04 and p <0.05 respectively).The same tendency was observed in the t-PA group without reaching significance. Conclusions: This study showed that the PAI-1 level increase is more pronounced after SK treatment than after t-PA treatment. There is a relationship between increased PAI-1 levels after thrombolytic therapy and poor patency. Therapeutic approaches aimed at quenching PAI-1 activity after thrombolysis might be of interest to improve the efficacy of thrombolytic therapy for acute myocardial infarction.

Sign in / Sign up

Export Citation Format

Share Document