title: LRP5 associates with specific subsets of macrophages: Molecular and functional effects.
abstract: Innate and acquired immunity is involved in the progression of atherosclerosis. The molecular mechanisms ruling monocyte to macrophage (Mø) differentiation are not yet fully understood. Different subtypes of plaque macrophages that have differentiated from monocytes recruited from circulating blood, have been characterized based on surface epitopes. We have recently shown that LRP5, a member of the LDL receptor superfamily supporting Wnt signalling, has an important role in monocyte to macrophage differentiation. The aim of this study was to investigate whether the CD16- and CD16+ macrophage subsets found in human atherosclerotic plaques have a differential LRP5 expression/function and Wnt signalling potential. We show for the first time that LRP5 expression is significantly higher in human CD16+Mø derived from CD14(+)CD16(+) monocytes than in CD16-Mø macrophages derived from CD14(+)CD16(-) monocytes. LRP5 is not found in human healthy vessel or arterial intimal thickening but is found in advanced human atherosclerotic lesions co-localizing only with the CD16+Mø macrophage subset. LRP5 expressing macrophages infiltrate the deep layers of atherosclerotic plaques towards the intima-media boundaries showing increased migratory activity and higher phagocytic activity. The equivalent for human patrolling CD14(+)CD16(+) monocytes in mice, CD115(+)GR1(low) monocytes, also show an increased expression of LRP5. In summary, classical CD14(+)CD16(-)monocytes that differentiate into CD16-Mø do not express LRP5. Instead, human monocytes expressing LRP5 differentiate into CD16+Mø antiinflammatory macrophages. These antiinflammatory macrophages are found in advanced atherosclerotic human plaques. Thus LRP5 is a signature of the anti-inflammatory defensive phenotype of macrophages.
authors.affiliation: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Borrell-Pages
authors.affiliation: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain.
authors.forename: J C
authors.initials: JC
authors.lastname: Romero
authors.affiliation: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Crespo
authors.affiliation: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Juan-Babot
authors.affiliation: Cardiovascular Research Center, CSIC-ICCC, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain. Electronic address: lbadimon@csic-iccc.org.
authors.forename: L
authors.initials: L
authors.lastname: Badimon
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation; D002465:Cell Movement; D058851:GPI-Linked Proteins / Q000235:genetics / Q000276:immunology; D015870:Gene Expression; D006801:Humans; D016130:Immunophenotyping; D018950:Lipopolysaccharide Receptors / Q000235:genetics / Q000276:immunology; D060492:Low Density Lipoprotein Receptor-Related Protein-5 / Q000235:genetics* / Q000276:immunology; D008264:Macrophages / Q000276:immunology* / Q000473:pathology; D010587:Phagocytosis; D010641:Phenotype; D058226:Plaque, Atherosclerotic / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D061251:Primary Cell Culture; D017452:Receptors, IgG / Q000235:genetics / Q000276:immunology
chemical_list: D015415:Biomarkers; C428200:FCGR3B protein, human; D058851:GPI-Linked Proteins; C555482:LRP5 protein, human; D018950:Lipopolysaccharide Receptors; D060492:Low Density Lipoprotein Receptor-Related Protein-5; D017452:Receptors, IgG
keywords: Atherosclerosis; Cell locomotion; Human macrophages; LRP5; Wnt