K domain CR9 of low density lipoprotein (LDL) receptor-related protein 1 (LRP1) is critical for aggregated LDL-induced foam cell formation from human vascular smooth muscle cells
Costales, Paula (Institut d'Investigació Biomèdica Sant Pau)
Fuentes-Prior, Pablo (Institut d'Investigació Biomèdica Sant Pau)
Castellano, José (Hospital de la Santa Creu i Sant Pau (Barcelona, Catalunya))
Revuelta-López, Elena (Hospital de la Santa Creu i Sant Pau (Barcelona, Catalunya))
Corral-Rodríguez, Maria Ángeles (Institut d'Investigació Biomèdica Sant Pau)
Nasarre, Laura (Institut d'Investigació Biomèdica Sant Pau)
Badimon, Lina (Institut d'Investigació Biomèdica Sant Pau)
Llorente-Cortés, Vicenta (Institut d'Investigació Biomèdica Sant Pau)
Universitat Autònoma de Barcelona

Date:	2015
Abstract:	Low density lipoprotein receptor-related protein (LRP1) mediates the internalization of aggregated LDL (AgLDL), which in turn increases the expression of LRP1 in human vascular smooth muscle cells (hVSMCs). This positive feedback mechanism is thus highly efficient to promote the formation of hVSMC foam cells, a crucial vascular component determining the susceptibility of atherosclerotic plaque to rupture. Here we have determined the LRP1 domains involved in AgLDL recognition with the aim of specifically blocking AgLDL internalization in hVSMCs. The capacity of fluorescently labeled AgLDL to bind to functional LRP1 clusters was tested in a receptor-ligand fluorometric assay made by immobilizing soluble LRP1 "minireceptors"(sLRP1-II, sLRP1-III, and sLRP1-IV) recombinantly expressed in CHO cells. This assay showed that AgLDL binds to cluster II. We predicted three well exposed and potentially immunogenic peptides in the CR7-CR9 domains of this cluster (termed P1 (Cys-Glu), P2 (Asp-Cys), and P3 (Gly-Cys)). AgLDL, but not native LDL, bound specifically and tightly to P3-coated wells. Rabbit polyclonal antibodies raised against P3 prevented AgLDL uptake by hVSMCs and were almost twice as effective as anti-P1 and anti-P2 Abs in reducing intracellular cholesteryl ester accumulation. Moreover, anti-P3 Abs efficiently prevented AgLDL-induced LRP1 up-regulation and counteracted the down-regulatory effect of AgLDL on hVSMC migration. In conclusion, domain CR9 appears to be critical for LRP1-mediated AgLDL binding and internalization in hVSMCs. Our results open new avenues for an innovative anti-VSMC foam cell-based strategy for the treatment of vascular lipid deposition in atherosclerosis.
Grants:	Ministerio de Ciencia e Innovación PI11/00747 Ministerio de Ciencia e Innovación SAF2010-15668 Ministerio de Economía y Competitividad PI14/01729 Ministerio de Economía y Competitividad RD12/0042/0027
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Amino Acid Sequence ; Animals ; Atherosclerotic plaque ; Cells, Cultured ; CHO Cells ; Cholesteryl esters ; Cricetinae ; Cricetulus ; Feedback mechanisms ; Fluorometric assay ; Foam Cells ; Human vascular smooth muscle cells ; Humans ; Ligands ; Lipoproteins, LDL ; Low density lipoprotein receptors ; Low Density Lipoprotein Receptor-Related Protein-1 ; Molecular Sequence Data ; Muscle, Smooth, Vascular ; Polyclonal antibody ; Real-Time Polymerase Chain Reaction ; Regulatory effects ; Sequence Homology, Amino Acid
Published in:	Journal of biological chemistry, Vol. 290 Núm. 24 (december 2015) , p. 14852-14865, ISSN 1083-351X

DOI: 10.1074/jbc.M115.638361
PMID: 25918169

14 p, 2.6 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Health sciences and biosciences > Institut de Recerca Sant Pau
Articles > Research articles
Articles > Published articles