12(S)-hydroxyheptadeca-5Z, 8E, 10E–trienoic acid is a natural ligand for leukotriene B4 receptor 2
Open Access
- 31 March 2008
- journal article
- Published by Rockefeller University Press in The Journal of Experimental Medicine
- Vol. 205 (4), 759-766
- https://doi.org/10.1084/jem.20072329
Abstract
Activated blood platelets and macrophages metabolize prostaglandin H2 into thromboxane A2 and 12(S)-hydroxyheptadeca-5Z, 8E, 10E–trienoic acid (12-HHT) in an equimolar ratio through the action of thromboxane synthase. Although it has been shown that 12-HHT is abundant in tissues and bodily fluids, this compound has long been viewed as a by-product lacking any specific function. We show that 12-HHT is a natural ligand for leukotriene B4 (LTB4) receptor-2 (BLT2), a G protein–coupled receptor that was originally identified as a low-affinity receptor for LTB4. BLT2 agonistic activity in lipid fractions from rat small intestine was identified as 12-HHT using high-performance liquid chromatography and mass spectrometry. Exogenously expressed BLT2 in mammalian cells was activated by synthetic 12-HHT, as assessed by guanosine 5′-O-(3-thio) triphosphate binding, the activation of intracellular signaling pathways, and chemotaxis assay. Displacement analysis using [3H]LTB4 showed that 12-HHT binds to BLT2 with a higher affinity than LTB4. Lipid extracts from cyclooxygenase 1–deficient mice failed to activate BLT2. Bone marrow–derived mast cells (BMMCs) isolated from wild-type mice migrated toward a low concentration of 12-HHT, whereas BMMCs from BLT2-deficient mice did not. We conclude that 12-HHT is a natural lipid agonist of BLT2 in vivo and induces chemotaxis of mast cells.Keywords
This publication has 27 references indexed in Scilit:
- Mast cells: multipotent local effector cells in atherothrombosisImmunological Reviews, 2007
- Identification of the Intracellular Region of the Leukotriene B4 Receptor Type 1 That Is Specifically Involved in Gi ActivationPublished by Elsevier BV ,2007
- Characterization of a Mouse Second Leukotriene B4 Receptor, mBLT2Published by Elsevier BV ,2005
- T-cell trafficking in asthma: lipid mediators grease the wayNature Reviews Immunology, 2004
- Leukotrienes and atherosclerosis: new roles for old mediatorsTrends in Immunology, 2004
- International Union of Pharmacology XXXVII. Nomenclature for Leukotriene and Lipoxin ReceptorsPharmacological Reviews, 2003
- Epoxygenase Pathways of Arachidonic Acid MetabolismJournal of Biological Chemistry, 2001
- Hydroxyeicosanoids Bind to and Activate the Low Affinity Leukotriene B4 Receptor, BLT2Published by Elsevier BV ,2001
- Detection of Endogenous Malondialdehyde-Deoxyguanosine Adducts in Human LiverScience, 1994
- Leukotrienes and Lipoxins: Structures, Biosynthesis, and Biological EffectsScience, 1987