Glucose-regulated protein 78 and platelet deposition: effect of rosuvastatin.
OBJECTIVE
To investigate the effect of rosuvastatin on platelet deposition under controlled shear rate conditions and to identify new platelet proteins involved in the interaction with the activating substrate.


RESULTS
Platelet-vessel wall interaction and thrombosis take place under dynamic conditions involving the interaction of the exposed damaged vascular wall with the circulating blood cells and proteins. Blood was perfused over type I collagen at different wall shear rates, and platelet deposition was measured by confocal microscopy. Perfused effluent blood was collected, platelets were sequentially extracted based on differential protein solubility, and proteins were separated by 2D gel electrophoresis. Blockade of 3-hydroxy-3-methylglutaryl-coenzyme A reductase significantly reduced platelet deposition and modulated the expression pattern of 18 proteins in the platelet subproteome. Among them, an increase in platelet surface 78-kDa glucose-regulated protein (GRP78), a stress-inducible multifunctional endoplasmic reticulum protein, was clearly apparent. Immunoprecipitation of platelet GRP78 revealed its interaction with tissue factor. Moreover, blockade of surface GRP78 resulted in a substantial increase in platelet deposition and tissue factor procoagulant activity and in a decrease in clotting time.


CONCLUSIONS
These findings demonstrate that blockade of 3-hydroxy-3-methylglutaryl-coenzyme A reductase reduces platelet deposition and inhibits GRP78 translocation from the platelet surface after shear and collagen activation. For the first time to our knowledge, this study reports on the presence and functional role of GRP78 in platelets and indicates that GRP78 has additional functions beyond those of a molecular chaperone.
Molins
Blanca
B
Cardiovascular Research Center, Consejo Superior de Investigaciones Científicas- Institut Català de Ciències Cardiovasculars, Hospital de Santa Creu i Sant Pau (Universitat Autonoma de Barcelona), Barcelona, Spain.
Peña
Esther
E
Padro
Teresa
T
Casani
Laura
L
Mendieta
Carlos
C
Badimon
Lina
L
D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects*; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D015180:Electrophoresis, Gel, Two-Dimensional; D000091342:Endoplasmic Reticulum Chaperone BiP; D005464:Fluorobenzenes / Q000494:pharmacology*; D006360:Heat-Shock Proteins / Q000097:blood*; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D047468:Immunoprecipitation; D018613:Microscopy, Confocal; D010973:Platelet Adhesiveness / Q000187:drug effects*; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D021381:Protein Transport; D040901:Proteomics / Q000379:methods; D011743:Pyrimidines / Q000494:pharmacology*; D012039:Regional Blood Flow; D000068718:Rosuvastatin Calcium; D013314:Stress, Mechanical; D013449:Sulfonamides / Q000494:pharmacology*; D013552:Swine; D013925:Thromboplastin / Q000378:metabolism
D024042:Collagen Type I; D000091342:Endoplasmic Reticulum Chaperone BiP; D005464:Fluorobenzenes; C000717247:HSPA5 protein, human; D006360:Heat-Shock Proteins; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D011743:Pyrimidines; D013449:Sulfonamides; D000068718:Rosuvastatin Calcium; D013925:Thromboplastin