Circadian clock molecules CLOCK and CRYs modulate fibrinolytic activity by regulating the PAI-1 gene expression.
J Thromb Haemost
; 4(11): 2478-85, 2006 Nov.
Article
em En
| MEDLINE
| ID: mdl-16970803
ABSTRACT
Disruptions of circadian rhythms are associated with the development of many disorders. However, whether a disruption of the circadian clock can cause anomalies of the hemostatic balance remains unknown. The present study examines coagulation and fibrinolytic activities in circadian clock mutants, a homozygous Clock mutant and Cry1/Cry2 double knockout (Cry1/2-deficient) mice. The euglobulin clot lysis time (ELT) showed circadian variations that peaked at 2100 (early night) in wild-type mice, suggesting that fibrinolytic activity is lowest at this time. The ELT was continuously reduced in Clock mutants, while the ELT was significantly increased and did not differ between day and night (900 and 2100) in Cry1/2-deficient mice. The prothrombin time (PT) and activated partial prothrombin time (APTT) were constant in all genotypes. To identify which factors cause the loss of ELT rhythm, we measured fibrinolytic parameters in Clock mutant and Cry1/2-deficient mice. The robust circadian fluctuation of plasma plasminogen activator inhibitor 1 (PAI-1) that peaked at early night was damped to trough levels in Clock mutant mice. On the other hand, PAI-1 levels in Cry1/2-deficient mice remained equivalent to the peak levels of those in wild-type mice at both 900 and 2100. Circadian changes in plasma PAI-1 levels seemed to be regulated at the level of gene expression, because the plasma PAI-1 levels in Clock mutant and Cry1/2-deficient mice were closely correlated with the level of PAI-1 mRNA transcript in these mice. Plasma plasminogen and hepatic mRNA levels were not rhythmic in wild-type mice, and continuously higher in Clock mutant than in wild-type or Cry1/2-deficient mice. In contrast, the activity and mRNA levels of tissue type plasminogen activator (t-PA), plasma levels and mRNA levels of plasminogen, and plasma levels of alpha2 plasmin inhibitor (alpha2PI) in all genotypes were constant throughout the day. Coagulation parameters such as factor VII, factor X, prothrombin and fibrinogen remained constant throughout the day, and were not affected by clock gene mutations. These results suggest that circadian clock molecules play an important role in hemostatic balance by regulating the fibrinolytic systems.
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Bases de dados:
MEDLINE
Assunto principal:
Transativadores
/
Ritmo Circadiano
/
Inibidor 1 de Ativador de Plasminogênio
/
Fibrinólise
/
Flavoproteínas
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Thromb Haemost
Assunto da revista:
HEMATOLOGIA
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Japão