Effect of atherogenic lipoproteins on PAI-1 synthesis by endothelial cells

M. Camera, L. Mussoni, P. Maderna, L. Sironi, L. Prati, S. Colli, F. Bernini, A. Corsini, E. Tremoli

Research output: Contribution to journalArticle

Abstract

Cultured human umbilical vein endothelial cells (EC) exposed to native and acetylated low density lipoproteins (LDL and acetyl-LDL) show an increased synthesis of PAI-1. Confluent EC monolayers were incubated for 16-18 hours in medium 199 with or without different concentrations of LDL and acetyl-LDL and PAI-1 antigen levels were measured in conditioned medium. LDL and acetyl-LDL increased the release of PAI-1 by EC in a concentration-dependent manner. The effect was specific for PAI-1 because tissue type plasminogen activator (t-PA) and expression of procoagulant activity were not affected by either lipoprotein. The observation that native and acetyl-LDL, which are known to interact with different receptors on EC, exert the same stimulatory effect on PAI-1 release rules out the possibility of an involvement of the LDL receptor in mediating this effect. Experiments carried out incubating native LDL in the presence of a monoclonal antibody against LDL receptor and using binding-defective LDL with a reduced affinity for the LDL receptor (∼50% with respect to normal LDL) further excluded an involvement of the classical LDL receptor in mediating the effect of the lipoproteins on PAI-1 synthesis by EC.

Original languageEnglish
JournalCytotechnology
Volume11
Issue number1 Supplement
DOIs
Publication statusPublished - Jan 1993

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ASJC Scopus subject areas

  • Clinical Biochemistry
  • Cell Biology
  • Biotechnology

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