We have examined spontaneous and lipopolysaccharide (LPS) induced procoagulant activity (PCA) and plasminogen activator activity (PA) in peripheral blood mononuclear cells (PBMC) from ten persons with high, and ten persons with low levels of serum high-density lipoprotein (HDL). PBMC were incubated +/- 100 ng LPS/ml up to 160 h. Additionally, we have measured the release of urokinase (uPA), tissue plasminogen activator (tPA), plasminogen activator inhibitor 1 (PAI-1) and plasminogen activator inhibitor 2 (PAI-2) into the cell culture media. Spontaneous PA was significantly higher in PBMC from persons with low HDL, combined with lower release of uPA to the media and higher uPA-receptor (uPA-R) bound uPA on PBMC. Upon stimulation with LPS, PCA and released PAI-2 increased sharply, while PA and released uPA declined. These changes were not significantly different between the two groups. tPA and PAI-1 were not detected in cell lysates or in cell culture media.
Conclusions: 1) LPS sharply stimulated PBMC PCA (similar in both groups). 2) PBMC from persons with low HDL showed higher spontaneous PA, due to higher uPA-R bound uPA, probably of importance in cell migration during the early events of atherosclerosis.