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Decreasing phosphodiesterase 5 A activity contributes to platelet cGMP accumulation during storage of apheresis‐derived platelet concentrates
Author(s) -
Kobsar Anna,
Putz Evelyn,
Yilmaz Pinar,
Weinig Elke,
Boeck Markus,
Koessler Juergen
Publication year - 2014
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/trf.12360
Subject(s) - chemistry , platelet , phosphorylation , intracellular , platelet activation , phosphodiesterase , phosphoprotein , western blot , microbiology and biotechnology , enzyme , medicine , biochemistry , biology , gene
Background Platelet storage lesion ( PSL ) considerably decreases the quality of platelets (PLTs) in concentrates characterized by a loss of signaling responses to agonists and impaired PLT activation, secretion, and aggregation. To understand the role of inhibitory signaling pathways in the mechanism of PSL , the basal state of the cyclic nucleotide ( CN )‐dependent signaling systems in stored PLTs was investigated. Study Design and Methods Whole blood samples ( WB ) and apheresis‐derived PLT concentrates ( APC s) were obtained from healthy volunteers. Washed PLTs were prepared from WB on D ay 0 and from APC s on D ays 0, 2, and 5. The basal phosphorylation of the vasodilator‐stimulated phosphoprotein ( VASP ) and phosphodiesterase 5 A ( PDE 5 A ) levels were quantified by W estern blot. CN and PDE 5 A activity were measured by enzyme‐linked immunoassay kits. Fibrinogen binding and aggregation were measured in PLT ‐rich plasma of WB or APC samples. Unpaired t test was used for statistical analysis. Results Basal VASP phosphorylation levels were comparable in WB and APC s on D ay 0. VASP phosphorylation increased significantly during storage of APC s, more pronounced at S er 239 than at S er 157 . Similarly, intracellular cGMP , but not cAMP , concentration continuously increased in stored PLTs , whereas PDE 5 A levels and activity significantly decreased accompanied by diminished thrombin receptor activator peptide 6–induced fibrinogen binding and aggregation. Conclusion Storage of APC s leads to intracellular cGMP accumulation that could be caused by degradation of PDE 5 A . Enhanced cGMP level supports subsequent cGMP ‐dependent protein kinase–mediated increase of VASP phosphorylation resulting in reduced fibrinogen binding and aggregation.