OBJECTIVE: Although lipoprotein-associated phospholipase A2 (Lp-PLA2) has received recent attention as a biomarker of inflammation and risk for acute coronary events, its relative expression in coronary plaque phenotypes, including unstable lesions, has not been established. METHODS AND RESULTS: Coronary segments (n=30) were prospectively collected from 25 sudden coronary death patients for immunolocalization of Lp-PLA2. Lesion morphologies were classified as pathologic intimal thickening, fibroatheromas, thin-cap fibroatheromas (fibrous cap thicknesses <65 microm), and rupture. The expression of Lp-PLA2 was detected using a specific monoclonal antibody. Apoptosis was identified by DNA end-labeling using terminal deoxynucleotidyl transferase (TdT). Lp-PLA2 staining in early plaques was absent or minimally detected. In contrast, thin-cap fibroatheromas and ruptured plaques showed intense Lp-PLA2 expression within necrotic cores and surrounding macrophages including those in the fibrous cap. The degree of macrophage apoptosis was greater in thin-cap fibroatheroma and ruptures compared with less advanced plaques with additional double labeling studies showing Lp-PLA2 present in apoptotic cells in regions of high macrophage density. CONCLUSIONS: Lp-PLA2 is strongly expressed within the necrotic core and surrounding macrophages of vulnerable and ruptured plaques, with relatively weak staining in less advanced lesions. These findings together with the association of Lp-PLA2 in apoptotic macrophages suggest a potential role in promoting plaque instability.
OBJECTIVE: Although lipoprotein-associated phospholipase A2 (Lp-PLA2) has received recent attention as a biomarker of inflammation and risk for acute coronary events, its relative expression in coronary plaque phenotypes, including unstable lesions, has not been established. METHODS AND RESULTS: Coronary segments (n=30) were prospectively collected from 25 sudden coronary deathpatients for immunolocalization of Lp-PLA2. Lesion morphologies were classified as pathologic intimal thickening, fibroatheromas, thin-cap fibroatheromas (fibrous cap thicknesses <65 microm), and rupture. The expression of Lp-PLA2 was detected using a specific monoclonal antibody. Apoptosis was identified by DNA end-labeling using terminal deoxynucleotidyl transferase (TdT). Lp-PLA2 staining in early plaques was absent or minimally detected. In contrast, thin-cap fibroatheromas and ruptured plaques showed intense Lp-PLA2 expression within necrotic cores and surrounding macrophages including those in the fibrous cap. The degree of macrophage apoptosis was greater in thin-cap fibroatheroma and ruptures compared with less advanced plaques with additional double labeling studies showing Lp-PLA2 present in apoptotic cells in regions of high macrophage density. CONCLUSIONS:Lp-PLA2 is strongly expressed within the necrotic core and surrounding macrophages of vulnerable and ruptured plaques, with relatively weak staining in less advanced lesions. These findings together with the association of Lp-PLA2 in apoptotic macrophages suggest a potential role in promoting plaque instability.
Authors: Harald Grallert; Josée Dupuis; Joshua C Bis; Abbas Dehghan; Maja Barbalic; Jens Baumert; Chen Lu; Nicholas L Smith; André G Uitterlinden; Robert Roberts; Natalie Khuseyinova; Renate B Schnabel; Kenneth M Rice; Fernando Rivadeneira; Ron C Hoogeveen; João Daniel Fontes; Christa Meisinger; John F Keaney; Rozenn Lemaitre; Yurii S Aulchenko; Ramachandran S Vasan; Stephen Ellis; Stanley L Hazen; Cornelia M van Duijn; Jeanenne J Nelson; Winfried März; Heribert Schunkert; Ruth M McPherson; Heide A Stirnadel-Farrant; Bruce M Psaty; Christian Gieger; David Siscovick; Albert Hofman; Thomas Illig; Mary Cushman; Jennifer F Yamamoto; Jerome I Rotter; Martin G Larson; Alexandre F R Stewart; Eric Boerwinkle; Jacqueline C M Witteman; Russell P Tracy; Wolfgang Koenig; Emelia J Benjamin; Christie M Ballantyne Journal: Eur Heart J Date: 2011-10-14 Impact factor: 29.983
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Authors: Beth S Sutton; David R Crosslin; Svati H Shah; Sarah C Nelson; Anthony Bassil; A Brent Hale; Carol Haynes; Pascal J Goldschmidt-Clermont; Jeffery M Vance; David Seo; William E Kraus; Simon G Gregory; Elizabeth R Hauser Journal: Hum Mol Genet Date: 2008-01-18 Impact factor: 6.150
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