scholarly journals Identification of the circadian clock-regulated E-box element in the mouse plasminogen activator inhibitor-1 gene

2007 ◽  
Vol 5 (2) ◽  
pp. 428-431 ◽  
Author(s):  
K. OISHI ◽  
H. SHIRAI ◽  
N. ISHIDA
2007 ◽  
Vol 98 (08) ◽  
pp. 296-303 ◽  
Author(s):  
Elitsa Dimova ◽  
Malgorzata Jakubowska ◽  
Thomas Kietzmann

SummaryPlasminogen activator inhibitor-1 (PAI-1) controls the regulation of the fibrinolytic system in blood by inhibiting both urokinase-type and tissue-type plasminogen activators. Enhanced levels of PAI-1 are related to pathological conditions associated with hypoxia or hyperinsulinemia. In this study, we investigated the regulation of PAI-1 expression by glucagon and the cAMP/ PKA/CREB signalling pathway in the liver. Stimulation of the cAMP/PKA/CREB signalling cascade by starvation in vivo or glucagon in vitro induced PAI-1 gene expression in liver. Furthermore, this response was associated with enhanced phosphorylation of CREB. By using EMSAs we found that three promoter elements, the HRE2, E-box 4 and E-box 5, were able to bind CREB but only the HRE2 and E5 appeared to be functionally active. Reporter gene assays confirmed that cAMP induced PAI-1 gene transcription via the same element in both human and rat promoters. Interestingly, although the HRE2 was involved, the glucagon/cAMP pathway had no influence on hypoxia-inducible factor-1 (HIF-1) mRNA and protein levels. Thus, CREB binding to the HIF-1 responsive elements in PAI-1 promoter mediates the glucagon effect in the liver.


2005 ◽  
Vol 173 (4S) ◽  
pp. 255-255 ◽  
Author(s):  
Hugo H. Davila ◽  
Thomas R. Magee ◽  
Freddy Zuniga ◽  
Jacob Rajfer ◽  
Nestor F. GonzalezCadavid

1999 ◽  
Vol 82 (07) ◽  
pp. 104-108 ◽  
Author(s):  
Franck Paganelli ◽  
Marie Christine Alessi ◽  
Pierre Morange ◽  
Jean Michel Maixent ◽  
Samuel Lévy ◽  
...  

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.


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