Autotaxin/Lysopholipase D and Lysophosphatidic Acid Regulate Murine Hemostasis and Thrombosis

doi:10.1074/jbc.M807820200

Autotaxin/Lysopholipase D and Lysophosphatidic Acid Regulate Murine Hemostasis and Thrombosis^*

^{^‡}Division of Cardiovascular Medicine, The Gill Heart Institute, and Departments of ^{^§}Pharmacology and ^{^§§}Biochemistry, University of Kentucky, Lexington, Kentucky 40536-0200, ^{^¶}Department of Systems Biology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030, ^{^∥}Department of Medicine, The University of Chicago, Chicago, Illinois, 60637, ^{^**}Department of Biochemistry, Virginia Commonwealth University School of Medicine, Richmond, Virginia 23298, ^{^‡‡}Division of Cellular Biochemistry, Centre for Biomedical Genetics, The Netherlands Cancer Institute, Plesmanlaan 121, Amsterdam, The Netherlands, and ^{^¶¶}Department of Veterans Affairs Medical Center, Lexington, Kentucky 40511

2 Recipient of an Atorvastatin Research Award from Pfizer. To whom correspondence should be addressed: Division of Cardiovascular Medicine, The Gill Heart Institute, 900 S. Limestone St., 326 CTW Bldg., Lexington, KY 40536-0200. Fax: 859-257-9783; E-mail: SusanSmyth{at}uky.edu.

Abstract

The lipid mediator lysophosphatidic acid (LPA) is a potent regulator of vascular cell function in vitro, but its physiologic role in the cardiovasculature is largely unexplored. To address the role of LPA in regulating platelet function and thrombosis, we investigated the effects of LPA on isolated murine platelets. Although LPA activates platelets from the majority of human donors, we found that treatment of isolated murine platelets with physiologic concentrations of LPA attenuated agonist-induced aggregation. Transgenic overexpression of autotaxin/lysophospholipase D (Enpp2), the enzyme necessary for production of the bulk of biologically active LPA in plasma, elevated circulating LPA levels and induced a bleeding diathesis and attenuation of thrombosis in mice. Intravascular administration of exogenous LPA recapitulated the prolonged bleeding time observed in Enpp2-Tg mice. Enpp2^+/- mice, which have ∼50% normal plasma LPA levels, were more prone to thrombosis. Plasma autotaxin associated with platelets during aggregation and concentrated in arterial thrombus, and activated but not resting platelets bound recombinant autotaxin/lysoPLD in an integrin-dependent manner. These results identify a novel pathway in which LPA production by autotaxin/lysoPLD regulates murine hemostasis and thrombosis and suggest that binding of autotaxin/lysoPLD to activated platelets may provide a mechanism to localize LPA production.

Footnotes

↵³ The abbreviations used are: LPA, lysophosphatidic acid; LPC, lysophosphatidylcholine; lysoPLD, lysophospholipase D; ENPP, ecto-nucleotide pyrophosphatase/phosphodiesterase; HPLC, high performance liquid chromatography; TRITC, tetramethylrhodamine isothiocyanate; WT, wild type; PAR, protein-activated receptor.
↵⁴ F. Fang and G. B. Mills, unpublished data.
↵⁵ H. Y. Chen and S. S. Smyth, unpublished data.
↵⁶ Z. Pamuklar and S. S. Smyth, unpublished data.
↵^* This work was supported, in whole or in part, by National Institutes of Health Grants HL070304, HL078663, and HL074219 (to S. S. S.), CA096496 and GM050388 to A. J. M.), HL79396 (to V. N.), and P30 CA16672 and PO1 CA64602 (to G. B. M.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵ The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. 1-4 and Tables 1 and 2.
↵¹ Both authors contributed equally.
- Received October 9, 2008.
- Revision received January 5, 2009.
The American Society for Biochemistry and Molecular Biology, Inc.