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Effects of apoptosis and lipid peroxidation on T‐lymphoblastoid phospholipid‐dependent procoagulant activity
Author(s) -
PICKERING W.,
GRAY E.,
GOODALL A. H.,
BARROWCLIFFE T. W.
Publication year - 2008
Publication title -
journal of thrombosis and haemostasis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.947
H-Index - 178
eISSN - 1538-7836
pISSN - 1538-7933
DOI - 10.1111/j.1538-7836.2008.02957.x
Subject(s) - phosphatidylserine , annexin , apoptosis , prothrombinase , chemistry , phospholipid , flow cytometry , thrombin , oxidative stress , lipid peroxidation , annexin a5 , microbiology and biotechnology , annexin a2 , biochemistry , biophysics , immunology , platelet , biology , membrane
Summary. Background: Coagulation has an absolute requirement for macromolecular complexes to be assembled on a negatively charged phospholipid (PL) surface. Previously, we reported that malignant T‐lymphoblastoid cells have the ability to support procoagulant activity (PCA) independently of tissue factor by providing such a surface. Objective: To explore the effect of two pathophysiologic processes, apoptosis and lipid peroxidation (LP), on this PL‐dependent PCA. Methods: Three different assays for PL‐dependent PCA (factor IXa‐initiated FXa and thrombin generation and prothrombinase activity) were used to investigate this PCA after exposing three T‐lymphoblastoid cell lines to either apoptotic stimuli (1 μ m staurosporine) or oxidative stress (4 m m H 2 O 2 and 40 μ m CuSO 4 ). Surface exposure of anionic PL was measured by flow cytometry using annexin A5 FITC and an antibody (3G4) specific for native, but not oxidized, phosphatidylserine (PS). Results and Conclusions: Both apoptosis and LP significantly enhanced the PCA of cells, to a level that was greater than that observed following calcium ionophore treatment, suggesting that the increased activity was not solely due to anionic PL exposure. Whereas cells undergoing apoptosis bound both annexin A5 FITC and 3G4, only annexin A5 FITC bound to cells undergoing LP. This implies that apoptosis increases PCA by causing the translocation of oxidized/native PS to the outer membrane, whereas LP appears to increase the PCA, possibly due to malondialdehyde adducts altering the net charge on the cell surface, which allows PLs other than PS to participate in thrombin generation.