2. Academic Validation
  3. 12(S)-HETrE, a 12-Lipoxygenase Oxylipin of Dihomo-γ-Linolenic Acid, Inhibits Thrombosis via Gαs Signaling in Platelets

12(S)-HETrE, a 12-Lipoxygenase Oxylipin of Dihomo-γ-Linolenic Acid, Inhibits Thrombosis via Gαs Signaling in Platelets

  • Arterioscler Thromb Vasc Biol. 2016 Oct;36(10):2068-77. doi: 10.1161/ATVBAHA.116.308050.
Jennifer Yeung 1,  Benjamin E Tourdot 1,  Reheman Adili 1,  Abigail R Green 1,  Cody J Freedman 1,  Pilar Fernandez-Perez 1,  Johnny Yu 1,  Theodore R Holman 1,  Michael Holinstat 2
Affiliations

Affiliations

  • 1 From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.).
  • 2 From the Department of Pharmacology (J.Y., B.E.T., R.A., M.H.) and Department of Internal Medicine, Division of Cardiovascular Medicine (M.H.), University of Michigan, Ann Arbor; Cardeza Foundation for Hematological Research, Thomas Jefferson University, Philadelphia, PA (J.Y., B.E.T., R.A., P.F.-P., J.Y., M.H.); and Department of Chemistry and Biochemistry, University of California Santa Cruz (A.R.G., C.J.F., T.R.H.). [email protected].
PMID: 27470510 DOI: 10.1161/ATVBAHA.116.308050
Abstract

Objective: Dietary supplementation with polyunsaturated fatty acids has been widely used for primary and secondary prevention of Cardiovascular Disease in individuals at risk; however, the cardioprotective benefits of polyunsaturated fatty acids remain controversial because of lack of mechanistic and in vivo evidence. We present direct evidence that an omega-6 polyunsaturated fatty acid, dihomo-γ-linolenic acid (DGLA), exhibits in vivo cardioprotection through 12-lipoxygenase (12-LOX) oxidation of DGLA to its reduced oxidized lipid form, 12(S)-hydroxy-8Z,10E,14Z-eicosatrienoic acid (12(S)-HETrE), inhibiting platelet activation and thrombosis.

Approach and results: DGLA inhibited ex vivo platelet aggregation and Rap1 activation in wild-type mice, but not in mice lacking 12-LOX expression (12-LOX(-/-)). Similarly, wild-type mice treated with DGLA were able to reduce thrombus growth (platelet and fibrin accumulation) after laser-induced injury of the arteriole of the cremaster muscle, but not 12-LOX(-/-) mice, supporting a 12-LOX requirement for mediating the inhibitory effects of DGLA on platelet-mediated thrombus formation. Platelet activation and thrombus formation were also suppressed when directly treated with 12(S)-HETrE. Importantly, 2 hemostatic models, tail bleeding and arteriole rupture of the cremaster muscle, showed no alteration in hemostasis after 12(S)-HETrE treatment. Finally, the mechanism for 12(S)-HETrE protection was shown to be mediated via a Gαs-linked G-protein-coupled receptor pathway in human platelets.

Conclusions: This study provides the direct evidence that an omega-6 polyunsaturated fatty acid, DGLA, inhibits injury-induced thrombosis through its 12-LOX oxylipin, 12(S)-HETrE, which strongly supports the potential cardioprotective benefits of DGLA supplementation through its regulation of platelet function. Furthermore, this is the first evidence of a 12-LOX oxylipin regulating platelet function in a Gs α subunit-linked G-protein-coupled receptor-dependent manner.

Keywords

blood platelets; eicosanoids; fibrin; lipoxygenase; platelet activation; thrombosis.

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