Abstract
Statins are widely used to treat dyslipidemia. Effects of statins in addition to low-density lipoprotein lowering include altered platelet aggregation, requiring drug uptake into platelets. Possible candidates for mediating intraplatelet accumulation of statins include members of the organic anion-transporting polypeptide family such as OATP2B1 (SLCO2B1), a high-affinity uptake transporter for atorvastatin. Therefore, we analyzed OATP expression, localization, and function in human platelets. OATP2B1, but not OATP1B1, was detected in platelets and megakaryocytes on transcript and protein levels. Protein localization was almost exclusively confined to the plasma membrane. Moreover, we could demonstrate significant inhibition of estrone sulfate uptake into platelets by atorvastatin as well as direct transport of atorvastatin into platelets using a liquid chromatography-tandem mass spectrometry method. As a consequence of OATP2B1-mediated uptake of atorvastatin, we observed significant atorvastatin-mediated reduction of thrombin-induced Ca2+ mobilization in platelets (37.3 ± 6.7% of control at 15 μM atorvastatin), mechanistically explainable by reduced lipid modification of signal proteins. This effect was reversed by addition of mevalonate. Finally, we demonstrated expression of HMG-CoA reductase, the primary target of atorvastatin, in platelet cytosol. In conclusion, OATP2B1 is an uptake transporter expressed in platelets and is involved in statin-mediated alteration of platelet aggregation.
Footnotes
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The work was supported in part by a grant from the Deutsche Forschungsgemeinschaft [Grant GR 3375/1-1] (to M.G.); and by the German Federal Ministry for Education and Research [Grant 03IP612] (Innoprofile).
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Article, publication date, and citation information can be found at http://dmd.aspetjournals.org.
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doi:10.1124/dmd.108.024570.
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ABBREVIATIONS: HMGCR, 3-hydroxy-3-methylglutaryl coenzyme A reductase; OATP, organic anion transporting polypeptide; SLC, solute carrier; LC, liquid chromatography; MS, mass spectrometry; MS/MS, tandem mass spectrometry; Gp, glycoprotein; PRP, platelet-rich plasma (plasma prepared by centrifugation to separate out red blood cells but not platelets); TBST, Tris-buffered saline containing 0.05% Tween 20 and 1% BSA; BSA, bovine serum albumin; PBS, phosphate-buffered saline; HPLC, high-performance liquid chromatography; RT-PCR, reverse transcription-polymerase chain reaction; PGE1, prostaglandin E1; AFC, N-acetyl-S-farnesyl-l-cysteine; DMSO, dimethyl sulfoxide; CT, cycle threshold.
- Received September 12, 2008.
- Accepted February 18, 2009.
- The American Society for Pharmacology and Experimental Therapeutics
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