title: LXR as a novel antithrombotic target.
abstract: Liver X receptors (LXRs) are transcription factors involved in the regulation of cholesterol homeostasis. LXR ligands have athero-protective properties independent of their effects on cholesterol metabolism. Platelets are involved in the initiation of atherosclerosis and despite being anucleate express nuclear receptors. We hypothesized that the athero-protective effects of LXR ligands could be in part mediated through platelets and therefore explored the potential role of LXR in platelets. Our results show that LXR-β is present in human platelets and the LXR ligands, GW3965 and T0901317, modulated nongenomically platelet aggregation stimulated by a range of agonists. GW3965 caused LXR to associate with signaling components proximal to the collagen receptor, GPVI, suggesting a potential mechanism of LXR action in platelets that leads to diminished platelet responses. Activation of platelets at sites of atherosclerotic lesions results in thrombosis preceding myocardial infarction and stroke. Using an in vivo model of thrombosis in mice, we show that GW3965 has antithrombotic effects, reducing the size and the stability of thrombi. The athero-protective effects of GW3965, together with its novel antiplatelet/thrombotic effects, indicate LXR as a potential target for prevention of athero-thrombotic disease.
authors.affiliation: Institute for Cardiovascular and Metabolic Research, University of Reading, Reading, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Spyridon
authors.forename: Leonardo A
authors.initials: LA
authors.lastname: Moraes
authors.forename: Chris I
authors.initials: CI
authors.lastname: Jones
authors.forename: Tanya
authors.initials: T
authors.lastname: Sage
authors.forename: Parvathy
authors.initials: P
authors.lastname: Sasikumar
authors.forename: Giovanna
authors.initials: G
authors.lastname: Bucci
authors.forename: Jonathan M
authors.initials: JM
authors.lastname: Gibbins
mesh_terms: D000818:Animals; D050197:Atherosclerosis / Q000150:complications; D001565:Benzoates / Q000627:therapeutic use*; D001596:Benzylamines / Q000627:therapeutic use*; D002118:Calcium / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D006845:Hydrocarbons, Fluorinated / Q000627:therapeutic use*; D015151:Immunoblotting; D047468:Immunoprecipitation; D008024:Ligands; D000071518:Liver X Receptors; D051379:Mice; D008810:Mice, Inbred C57BL; D057093:Orphan Nuclear Receptors / Q000378:metabolism*; D010974:Platelet Aggregation / Q000187:drug effects; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000378:metabolism; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism; D013449:Sulfonamides / Q000627:therapeutic use*; D013927:Thrombosis / Q000209:etiology / Q000517:prevention & control*; D005466:Fluorocarbons; D000096926:Benzenesulfonamides
chemical_list: D001565:Benzoates; D001596:Benzylamines; D002118:Calcium; D006845:Hydrocarbons, Fluorinated; D008024:Ligands; D000071518:Liver X Receptors; D057093:Orphan Nuclear Receptors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D010980:Platelet Membrane Glycoproteins; D013449:Sulfonamides; C473027:GW 3965; C423915:T0901317; D005466:Fluorocarbons; D000096926:Benzenesulfonamides; C098341:platelet membrane glycoprotein VI