Summary
Regulation of hemostasis and thrombosis involves numerous plasma factors that contribute
to procoagulant and anticoagulant pathways. Lipid-containing surfaces provide sites
where both procoagulant and anticoagulant enzymes, cofactors and substrates are assembled
to express their activities. Plasma and lipoproteins can contribute to either procoagulant
or anticoagulant reactions. Procoagulant lipids/lipoproteins include triglyceride-rich
particles in plasma and oxidized low density lipoprotein (LDL) which can accelerate
activation of prothrombin, factor X and factor VII. Potentially anticoagulant lipids
and lipoproteins, each of which enhances inactivation of factor Va by activated protein
C, include phosphatidylethanolamine, cardiolipin, the neutral glycosphingolipids glucosylceramide
and Gb3 ceramide (CD77), and high density lipoprotein (HDL). Remarkably, treatment
of hyperlipidemia with statins not only lowers lipids but also provides antithrombotic
effects whose mechanisms remain to be clarified. We hypothesize that procoagulant
and anticoagulant lipids and lipoproteins in plasma may contribute to a Yin-Yang balance
that helps influence the up-regulation and down-regulation of thrombin generation.
Key words
Lipoprotein - glycolipid - glucosylceramide - protein C - prothrombinase