Effects of oxidized and glycated low-density lipoproteins on transcription and secretion of plasminogen activator inhibitor-1 in vascular endothelial cells

Cardiovasc Pathol. 2006 Jan-Feb;15(1):3-10. doi: 10.1016/j.carpath.2005.08.012.

Abstract

Plasminogen activator inhibitor-1 (PAI-1) is the major physiological inhibitor of fibrinolysis. Elevated levels of PAI-1 were frequently detected in patients with coronary artery disease (CAD) or diabetes. Low-density lipoprotein (LDL) is a classical risk factor of CAD. Oxidation and glycation increase the atherogenecity of LDL. Previous studies demonstrated that oxidized LDL (oxLDL) or glycated LDL (gly-LDL) increased the release of PAI-1 from endothelial cells (ECs). The present study examined the effects of oxLDL and gly-LDL on the transcription, expression, secretion, and subcellular distribution of PAI-1 in cultured human ECs. Treatment with LDL significantly increased the promoter activity, mRNA level, and the release of PAI-1 from ECs by two- to threefold compared to controls. Oxidation or glycation significantly enhanced the effects of LDL on PAI-1 production in ECs compared to LDL (four- to fivefold vs. controls). No significant differences were detected between the effects of oxLDL and gly-LDL. Abundant PAI-1 antigens were detected in the perinuclear region of ECs and overlapped with giantin, a marker of Golgi apparatus. Treatment with brefeldin A disturbed the stack structure of Golgi apparatus and almost completely inhibited the release of PAI-1 from ECs induced by the lipoproteins and at basal conditions. The results suggest that oxidation and glycation enhanced the effects of LDL on the production of PAI-1 in ECs through increasing the transcription of PAI-1. Intact Golgi apparatus is required for PAI-1 generation from ECs induced by LDL or its modified forms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Northern
  • Blotting, Western
  • Cells, Cultured
  • Endothelial Cells / metabolism*
  • Humans
  • Immunohistochemistry
  • Lipoproteins, LDL / metabolism*
  • Plasminogen Activator Inhibitor 1 / physiology*
  • RNA, Messenger / analysis
  • Transcription, Genetic*

Substances

  • Lipoproteins, LDL
  • Plasminogen Activator Inhibitor 1
  • RNA, Messenger