title: Atherosclerotic lesion progression changes lysophosphatidic acid homeostasis to favor its accumulation.
abstract: Lysophosphatidic acid (LPA) accumulates in the central atheroma of human atherosclerotic plaques and is the primary platelet-activating lipid constituent of plaques. Here, we investigated the enzymatic regulation of LPA homeostasis in atherosclerotic lesions at various stages of disease progression. Atherosclerotic lesions were induced in carotid arteries of low-density lipoprotein receptor-deficient mice by semiconstrictive collar placement. At 2-week intervals after collar placement, lipids and RNA were extracted from the vessel segments carrying the plaque. Enzymatic-and liquid chromatography-mass spectrometry-based lipid profiling revealed progressive accumulation of LPA species in atherosclerotic tissue preceded by an increase in lysophosphatidylcholine, a precursor in LPA synthesis. Plaque expression of LPA-generating enzymes cytoplasmic phospholipase A(2)IVA (cPLA(2)IVA) and calcium-independent PLA(2)VIA (iPLA(2)VIA) was gradually increased, whereas that of the LPA-hydrolyzing enzyme LPA acyltransferase alpha was quenched. Increased expression of cPLA(2)IVA and iPLA(2)VIA in advanced lesions was confirmed by immunohistochemistry. Moreover, LPA receptors 1 and 2 were 50% decreased and sevenfold upregulated, respectively. Therefore, key proteins in LPA homeostasis are increasingly dysregulated in the plaque during atherogenesis, favoring intracellular LPA production. This might at least partly explain the observed progressive accumulation of this thrombogenic proinflammatory lipid in human and mouse plaques. Thus, intervention in the enzymatic LPA production may be an attractive measure to lower intraplaque LPA content, thereby reducing plaque progression and thrombogenicity.
authors.affiliation: Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands. m.bot@lacdr.leidenuniv.nl
authors.forename: Martine
authors.initials: M
authors.lastname: Bot
authors.forename: Ilze
authors.initials: I
authors.lastname: Bot
authors.forename: Rubén
authors.initials: R
authors.lastname: Lopez-Vales
authors.forename: Chris H A
authors.initials: CH
authors.lastname: van de Lest
authors.forename: Jean Sébastien
authors.initials: JS
authors.lastname: Saulnier-Blache
authors.forename: J Bernd
authors.initials: JB
authors.lastname: Helms
authors.forename: Samuel
authors.initials: S
authors.lastname: David
authors.forename: Theo J C
authors.initials: TJ
authors.lastname: van Berkel
authors.forename: Erik A L
authors.initials: EA
authors.lastname: Biessen
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D000818:Animals; D050197:Atherosclerosis / Q000378:metabolism / Q000473:pathology*; D002339:Carotid Arteries / Q000473:pathology; D004032:Diet; D018450:Disease Progression; D020869:Gene Expression Profiling; D054522:Group VI Phospholipases A2 / Q000378:metabolism; D006706:Homeostasis; D006801:Humans; D008246:Lysophospholipids / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D011973:Receptors, LDL / Q000235:genetics / Q000378:metabolism
chemical_list: D008246:Lysophospholipids; D011973:Receptors, LDL; D000217:Acyltransferases; C018764:2-acylglycerophosphate acyltransferase; D054522:Group VI Phospholipases A2; C032881:lysophosphatidic acid