Rho-kinase mediates hyperglycemia-induced plasminogen activator inhibitor-1 expression in vascular endothelial cells

Circulation. 2005 Jun 21;111(24):3261-8. doi: 10.1161/CIRCULATIONAHA.105.534024. Epub 2005 Jun 13.

Abstract

Background: Elevated levels of plasminogen activator inhibitor-1 (PAI-1) are associated with myocardial infarction and stroke, especially in patients with diabetes. The induction of PAI-1 expression by hyperglycemia involves oxidative stress and protein kinase C (PKC). However, the mechanism by which hyperglycemia increases PAI-1 expression is unknown.

Methods and results: Compared with normoglycemia, exposure of human endothelial cells to hyperglycemia, but not mannitol, increased Rho-kinase activity in a time- and concentration-dependent manner. This increase was inhibited by a PKC inhibitor, GF109203X, and antioxidants N-acetylcysteine (NAC) and reduced form of glutathione (GSH). This correlated with inhibition of hyperglycemia-induced PAI-1 expression by GF109203X, NAC, and GSH. Hyperglycemia-increased PAI-1 mRNA and protein levels were inhibited by Rho-kinase inhibitors hydroxyfasudil and Y27632 and by a dominant-negative mutant of Rho-kinase. The mechanism for this inhibition occurs at the level of gene transcription because Rho-kinase inhibitors repress hyperglycemia-stimulated PAI-1 promoter activity without affecting mRNA stability. Hyperglycemia failed to stimulate Rho-kinase activity and PAI-1 expression in heterozygous ROCK I-knockout murine endothelial cells.

Conclusions: Hyperglycemia stimulates Rho-kinase activity via PKC- and oxidative stress-dependent pathways, leading to increased PAI-1 gene transcription. These results suggest that inhibition of ROCK I may be a novel therapeutic target for preventing thromboembolic complications of diabetes and cardiovascular disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Cells, Cultured
  • Endothelium, Vascular / cytology
  • Endothelium, Vascular / metabolism*
  • Gene Expression Regulation
  • Humans
  • Hyperglycemia / enzymology
  • Hyperglycemia / metabolism*
  • Intracellular Signaling Peptides and Proteins
  • Mice
  • Mice, Knockout
  • Oxidative Stress
  • Plasminogen Activator Inhibitor 1 / analysis
  • Plasminogen Activator Inhibitor 1 / genetics*
  • Protein Kinase C / metabolism
  • Protein Serine-Threonine Kinases / deficiency
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA Stability
  • RNA, Messenger / analysis
  • rho-Associated Kinases

Substances

  • Antioxidants
  • Intracellular Signaling Peptides and Proteins
  • Plasminogen Activator Inhibitor 1
  • RNA, Messenger
  • Protein Serine-Threonine Kinases
  • rho-Associated Kinases
  • Protein Kinase C