The Effect of Plasminogen Activator Inhibitor-1 −675 4G/5G Polymorphism on PAI-1 Gene Expression and Adipocyte Differentiation

2007 ◽  
Vol 14 (4) ◽  
pp. 438-446 ◽  
Author(s):  
Duygu Ozel Demiralp ◽  
Huseyin Aktas ◽  
Nejat Akar
Keyword(s):  
Gene Expression ◽  
Insulin Resistance ◽  
Plasminogen Activator ◽  
Adipocyte Differentiation ◽  
Early Stage ◽  
Plasminogen Activator Inhibitor ◽  
Cardiovascular Risks ◽  
Plasminogen Activator Inhibitor 1 ◽  
Promoter Assay ◽  
Activator Inhibitor

Obesity is a complex, multifactorial chronic disease frequently associated with cardiovascular risks, hypertriglyceridemia, low high-density lipoprotein-cholesterol, high blood pressure, and the insulin resistance that appears to be central to the pathogenesis of Type II diabetes. Plasminogen activator inhibitor-1 expression induced in differentiating adipose tissue, but its role in adipogenesis and obesity is poorly understood. Circulating plasminogen activator inhibitor-1 levels are elevated at an early stage of impaired glucose tolerance, resulting in diabetes and metabolic syndrome. Plasminogen activator inhibitor-1 levels are also significantly elevated in the plasma of obese individuals and in adipose tissues of obese mice and humans. Some investigators proposed that the −675 4G/5G polymorphism in plasminogen activator inhibitor-1 promoter caused overexpression of this gene and predisposed carriers to obesity. In this study, we investigated the role of −675 4G/5G polymorphism in plasminogen activator inhibitor-1 promoter in the expression of this gene and the contribution of plasminogen activator inhibitor-1 to adipogenesis. Using a dualluciferase promoter assay, we determined that the −675 4G/5G polymorphism contributes significantly to overexpression of plasminogen activator inhibitor-1 in the course of adipogenesis. The antidiabetic agents troglitazone and ciglitazone inhibited reporter gene expression driven by wild-type and −675 4G/5G mutant promoter, as well as the expression of endogenous plasminogen activator inhibitor-1, indicating that suppression of plasminogen activator inhibitor-1 expression may contribute to antidiabetic effects of these agents. The results indicate that absence of plasminogen activator inhibitor-1 in adipocytes may protect the cells against insulin resistance by promoting glucose uptake and adipocyte differentiation via a decrease in the peroxisome proliferator activated receptor-gamma expression that modulates the adipocyte differentiation.

Plasminogen activator inhibitor-1 modulates adipocyte differentiation

2006 ◽  
Vol 290 (1) ◽  
pp. E103-E113 ◽  
Author(s):  
Xiubin Liang ◽  
Talerngsak Kanjanabuch ◽  
Su-Li Mao ◽  
Chuan-Ming Hao ◽  
Yi-Wei Tang ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Mrna Expression ◽  
Glucose Uptake ◽  
Plasminogen Activator ◽  
Adipocyte Differentiation ◽  
Plasminogen Activator Inhibitor ◽  
Plasmin Activity ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor ◽  
Pai 1

Increased plasminogen activator inhibitor-1 (PAI-1) is linked to obesity and insulin resistance. However, the functional role of PAI-1 in adipocytes is unknown. This study was designed to investigate effects and underlying mechanisms of PAI-1 on glucose uptake in adipocytes and on adipocyte differentiation. Using primary cultured adipocytes from PAI-1+/+ and PAI-1−/− mice, we found that PAI-1 deficiency promoted adipocyte differentiation, enhanced basal and insulin-stimulated glucose uptake, and protected against tumor necrosis factor-α-induced adipocyte dedifferentiation and insulin resistance. These beneficial effects were associated with upregulated glucose transporter 4 at basal and insulin-stimulated states and upregulated peroxisome proliferator-activated receptor-γ (PPARγ) and adiponectin along with downregulated resistin mRNA in differentiated PAI-1−/− vs. PAI-1+/+ adipocytes. Similarly, inhibition of PAI-1 with a neutralizing anti-PAI-1 antibody in differentiated 3T3-L1 adipocytes further promoted adipocyte differentiation and glucose uptake, which was associated with increased expression of transcription factors PPARγ, CCAAT enhancer-binding protein-α (C/EBPα), and the adipocyte-selective fatty acid-binding protein aP2, thus mimicking the phenotype in PAI-1−/− primary adipocytes. Conversely, overexpression of PAI-1 by adenovirus-mediated gene transfer in 3T3-L1 adipocytes inhibited differentiation and reduced PPARγ, C/EBPα, and aP2 expression. This was also associated with a decrease in urokinase-type plasminogen activator mRNA expression, decreased plasmin activity, and increased collagen I mRNA expression. Collectively, these results indicate that absence or inhibition of PAI-1 in adipocytes protects against insulin resistance by promoting glucose uptake and adipocyte differentiation via increased PPARγ expression. We postulate that these PAI-1 effects on adipocytes may, at least in part, be mediated via modulation of plasmin activity and extracellular matrix components.

Bezafibrate Induces Plasminogen Activator Inhibitor-1 Gene Expression in a CLOCK-Dependent Circadian Manner

2010 ◽  
Vol 78 (1) ◽  
pp. 135-141 ◽  
Author(s):  
Katsutaka Oishi ◽  
Satoru Koyanagi ◽  
Naoya Matsunaga ◽  
Koji Kadota ◽  
Eriko Ikeda ◽  
...  
Keyword(s):  
Gene Expression ◽  
Plasminogen Activator ◽  
Plasminogen Activator Inhibitor ◽  
Plasminogen Activator Inhibitor 1 ◽  
Activator Inhibitor

Early genetic responses in rat vascular tissue after simulated diving

2012 ◽  
Vol 44 (24) ◽  
pp. 1201-1207 ◽  
Author(s):  
Ingrid Eftedal ◽  
Arve Jørgensen ◽  
Ragnhild Røsbjørgen ◽  
Arnar Flatberg ◽  
Alf O. Brubakk
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Plasminogen Activator ◽  
Differential Gene Expression ◽  
Vascular Function ◽  
Plasminogen Activator Inhibitor ◽  
Fine Tuning ◽  
Plasminogen Activator Inhibitor 1 ◽  
Differential Gene ◽  
Activator Inhibitor

Diving causes a transient reduction of vascular function, but the mechanisms behind this are largely unknown. The aim of this study was therefore to analyze genetic reactions that may be involved in acute changes of vascular function in divers. Rats were exposed to 709 kPa of hyperbaric air (149 kPa Po2) for 50 min followed by postdive monitoring of vascular bubble formation and full genome microarray analysis of the aorta from diving rats ( n = 8) and unexposed controls ( n = 9). Upregulation of 23 genes was observed 1 h after simulated diving. The differential gene expression was characteristic of cellular responses to oxidative stress, with functions of upregulated genes including activation and fine-tuning of stress-responsive transcription, cytokine/cytokine receptor signaling, molecular chaperoning, and coagulation. By qRT-PCR, we verified increased transcription of neuron-derived orphan receptor-1 ( Nr4a3), plasminogen activator inhibitor 1 ( Serpine1), cytokine TWEAK receptor FN14 ( Tnfrsf12a), transcription factor class E basic helix-loop-helix protein 40 ( Bhlhe40), and adrenomedullin ( Adm). Hypoxia-inducible transcription factor HIF1 subunit HIF1-α was stabilized in the aorta 1 h after diving, and after 4 h there was a fivefold increase in total protein levels of the procoagulant plasminogen activator inhibitor 1 (PAI1) in blood plasma from diving rats. The study did not have sufficient power for individual assessment of effects of hyperoxia and decompression-induced bubbles on postdive gene expression. However, differential gene expression in rats without venous bubbles was similar to that of all the diving rats, indicating that elevated Po2 instigated the observed genetic reactions.

Sign in / Sign up

Export Citation Format

Share Document