Impact of statins on modulation by insulin of expression of plasminogen activator inhibitor type-1

Yuki Sato, Jie Dong, Shogo Imagawa, Naoki Ishimori, Tomoo Furumoto, Hiroyuki Tsutsui, Burton E. Sobel, Satoshi Fujii

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)

Abstract

OBJECTIVE: Plasminogen activator inhibitor type-1 (PAI-1) is a physiologic inhibitor of fibrinolysis and a known determinant of cardiovascular risk. That its expression is stimulated by insulin in HepG2 human hepatoma cells has been shown earlier. Others have found that increased expression of PAI-1 is a risk factor for acute myocardial infarction. Pleiotropic (noncholesterol lowering) effects of statins seem to reduce cardiovascular risk. This study was designed to determine whether insulin stimulation of PAI-1 expression is attenuated by statins, and if so to explore mechanisms that are responsible for the attenuation. METHODS: PAI-1 protein in the conditioned media was assayed by western blotting, and PAI-1 mRNA expression was measured by real-time reverse transcriptase polymerase chain reactions. RESULTS: Insulin (0.001-10 μmol/l) increased accumulation of PAI-1 protein in the conditioned media and PAI-1 mRNA expression in HepG2 cells. A transient transfection assay of the human PAI-1 promoter-luciferase construct demonstrated that insulin increased PAI-1 promoter activity. Increased PAI-1 mRNA was attenuated significantly by U0126 and PD98059, specific inhibitors of mitogen-activated protein kinase. In contrast, GF109203X, an inhibitor of the protein kinase C pathway, and LY294002, an inhibitor of phosphatidylinositol 3-kinase, exerted no effects. Simvastatin (10 μmol/l), known to translocate membrane-bound sterol regulatory element-binding protein to nuclei, attenuated PAI-1 mRNA expression induced by insulin. It did not affect baseline PAI-1 mRNA expression. Intraperitoneal injection of insulin (0.1 IU/kg) increased concentrations of PAI-1 antigen in plasma in mice within 3 h, correlating with hepatic PAI-1 mRNA expression. CONCLUSION: Insulin-mediated augmented expression of PAI-1 may be amenable to suppression attributable to pleiotropic effects of statins, potentially diminishing cardiovascular risk in patients with insulin resistance.

Original languageEnglish
Pages (from-to)355-361
Number of pages7
JournalCoronary Artery Disease
Volume19
Issue number5
DOIs
Publication statusPublished - Aug 2008
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Cardiology and Cardiovascular Medicine

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