title: Plasminogen activator inhibitor-1 is a major stress-regulated gene: implications for stress-induced thrombosis in aged individuals.
abstract: Plasminogen activator inhibitor-1 (PAI-1) is one of the primary inhibitors of the fibrinolytic system and has been implicated in a variety of thrombotic disorders. In this report, stress-induced changes in murine PAI-1 gene expression were investigated to study the role of this inhibitor in the development of stress-induced hypercoagulability. Restraint stress led to a dramatic induction of plasma PAI-1 antigen and of tissue PAI-1 mRNA with maximum induction in adipose tissues. In situ hybridization analysis of the stressed mice revealed that strong signals for PAI-1 mRNA were localized to hepatocytes, renal tubular epithelial cells, adrenomedullar chromaffin cells, neural cells in the paraaortic sympathetic ganglion, vascular smooth muscle cells, and adipocytes, but not to endothelial cells. These observations indicate that the stress induces the PAI-1 gene expression in a tissue-specific and cell type-specific manner. The induction of PAI-1 mRNA by restraint stress was greater than that observed for heat shock protein, a typical stress protein, suggesting that PAI-1 is one of the most highly induced stress proteins. Importantly, the magnitude of induction of PAI-1 mRNA by stress increased markedly with age, and this increase in PAI-1 correlated with tissue thrombosis in the older stressed mice. Moreover, much less tissue thrombosis was induced by restraint stress in young and aged PAI-1-deficient mice compared with age-matched wild-type mice. These results suggest that the large induction of PAI-1 by stress increases the risk for thrombosis in the older populations, and that the adipose tissue may be involved.
authors.affiliation: First Department of Internal Medicine, Nagoya University School of Medicine, 65 Tsurumai, Showa, Nagoya 466-8550, Japan. kojiy@tsuru.med.nagoya-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Takeshita
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Shimokawa
authors.forename: Hong
authors.initials: H
authors.lastname: Yi
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Isobe
authors.forename: David J
authors.initials: DJ
authors.lastname: Loskutoff
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Saito
mesh_terms: D000375:Aging / Q000235:genetics; D000818:Animals; D005260:Female; D015870:Gene Expression; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D017403:In Situ Hybridization; D007700:Kinetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood / Q000172:deficiency / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012149:Restraint, Physical; D013312:Stress, Physiological / Q000235:genetics*; D013927:Thrombosis / Q000235:genetics*; D014018:Tissue Distribution
chemical_list: D018840:HSP70 Heat-Shock Proteins; D017395:Plasminogen Activator Inhibitor 1; D015800:Protozoan Proteins; D012333:RNA, Messenger; C081884:heat-shock protein 70.1