Aspirin Extrusion From Human Platelets Through Multidrug Resistance Protein-4―Mediated Transport: Evidence of a Reduced Drug Action in Patients After Coronary Artery Bypass Grafting

• Published in: Journal of the American College of Cardiology 2011-08, Vol.58 (7), p.752-761
• Main Authors: MATTIELLO, Teresa, GUERRIERO, Raffaella, PULCINELLI, Fabio M, VITTORIA LOTTI, Lavinia, TRIFIRO, Elisabetta, PIA FELLI, Maria, BARBARULO, Alessandro, PUCCI, Bruna, GAZZANIGA, Paola, GAUDIO, Carlo, FRATI, Luigi
• Format: Article
• Language: English
• Subjects: Acids; Adult; Aspirin; Aspirin - pharmacokinetics; Aspirin - pharmacology; Biological and medical sciences; Biological Transport - drug effects; Blood platelets; Blood Platelets - drug effects; Blood Platelets - metabolism; Cardiology; Cardiology. Vascular system; Cells, Cultured; Coronary Artery Bypass; Coronary heart disease; Coronary vessels; Cyclic AMP - pharmacology; Cyclooxygenase 1 - metabolism; Dinoprostone - metabolism; Drug Interactions; Drug Resistance; Extrusion; Female; Fibrinolytic Agents - pharmacokinetics; Fibrinolytic Agents - pharmacology; Heart; Heart surgery; Humans; Male; Medical sciences; Middle Aged; Multidrug Resistance-Associated Proteins - metabolism; Multidrug Resistance-Associated Proteins - pharmacology; Patients; Plasma; Platelet Aggregation; Platelet Aggregation Inhibitors - pharmacokinetics; Platelet Aggregation Inhibitors - pharmacology; Propionates - pharmacology; Prostaglandin-Endoperoxide Synthases - metabolism; Proteins; Quality of life; Quinolines - pharmacology; RNA, Small Interfering - metabolism; Salicylic Acid - pharmacokinetics; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Surgery of the heart; Thromboxane B2 - metabolism; Veins & arteries
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2011.03.049

In this study we investigate: 1) the role of multidrug resistance protein-4 (MRP4), an organic anion unidirectional transporter, in modulating aspirin action on human platelet cyclooxygenase (COX)-1; and 2) whether the impairment of aspirin-COX-1 interaction, found in coronary artery bypass grafting (CABG) patients, could be dependent on MRP4-mediated transport. Platelets of CABG patients present a reduced sensitivity to aspirin despite in vivo and in vitro drug treatment. Aspirin is an organic anion and could be a substrate for MRP4. Intracellular aspirin concentration and drug COX-1 activity, measured by thrombin-induced thromboxane B2 (TxB2) production, were evaluated in platelets obtained from healthy volunteers (HV) and hematopoietic-progenitor cell cultures reducing or not reducing MRP4-mediated transport. Platelet MRP4 expression was evaluated, in platelets from HV and CABG patients, by dot-blot or by immunogold-electromicrographs or immunofluorescence-microscopy analysis. Inhibition of MRP4-mediated transport by dipyridamole or Mk-571 increases aspirin entrapment and its in vitro effect on COX-1 activity (142.7 ± 34.6 pg/10(8) cells vs. 343.7 ± 169.3 pg/10⁸ cells TxB2-production). Platelets derived from megakaryocytes transfected with MRP4 small interfering ribonucleic acid have a higher aspirin entrapment and drug COX-1 activity. Platelets from CABG patients showed a high expression of MRP4 whose in vitro inhibition enhanced aspirin effect on COX-1 (349 ± 141 pg/10⁸ cells vs. 1,670 ± 646 pg/10⁸ cells TxB2-production). Aspirin is a substrate for MRP4 and can be extruded from platelet through its transportation. Aspirin effect on COX-1 is little-related to MRP4-mediated aspirin transport in HV, but in CABG patients with MRP4 over-expression, its pharmacological inhibition enhances aspirin action in an efficient way.