title: Cell cholesterol modulates metalloproteinase-dependent shedding of low-density lipoprotein receptor-related protein-1 (LRP-1) and clearance function.
abstract: Low-density lipoprotein receptor-related protein-1 (LRP-1) is a plasma membrane scavenger and signaling receptor, composed of a large ligand-binding subunit (515-kDa α-chain) linked to a shorter transmembrane subunit (85-kDa β-chain). LRP-1 cell-surface level and function are controlled by proteolytic shedding of its ectodomain. Here, we identified ectodomain sheddases in human HT1080 cells and demonstrated regulation of the cleavage by cholesterol by comparing the classical fibroblastoid type with a spontaneous epithelioid variant, enriched ∼ 2-fold in cholesterol. Two membrane-associated metalloproteinases were involved in LRP-1 shedding: a disintegrin and metalloproteinase-12 (ADAM-12) and membrane-type 1 matrix metalloproteinase (MT1-MMP). Although both variants expressed similar levels of LRP-1, ADAM-12, MT1-MMP, and specific tissue inhibitor of metalloproteinases-2 (TIMP-2), LRP-1 shedding from epithelioid cells was ∼4-fold lower than from fibroblastoid cells. Release of the ectodomain was triggered by cholesterol depletion in epithelioid cells and impaired by cholesterol overload in fibroblastoid cells. Modulation of LRP-1 shedding on clearance was reflected by accumulation of gelatinases (MMP-2 and MMP-9) in the medium. We conclude that cholesterol exerts an important control on LRP-1 levels and function at the plasma membrane by modulating shedding of its ectodomain, and therefore represents a novel regulator of extracellular proteolytic activities.
authors.affiliation: Cell Biology Laboratory, de Duve Institute, UCL-75.41, 75 avenue Hippocrate, B-1200 Bruxelles, Belgium.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Selvais
authors.forename: Ludovic
authors.initials: L
authors.lastname: D'Auria
authors.forename: Donatienne
authors.initials: D
authors.lastname: Tyteca
authors.forename: Gwenn
authors.initials: G
authors.lastname: Perrot
authors.forename: Pascale
authors.initials: P
authors.lastname: Lemoine
authors.forename: Linda
authors.initials: L
authors.lastname: Troeberg
authors.forename: Stéphane
authors.initials: S
authors.lastname: Dedieu
authors.forename: Agnès
authors.initials: A
authors.lastname: Noël
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nagase
authors.forename: Patrick
authors.initials: P
authors.lastname: Henriet
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Courtoy
authors.forename: Etienne
authors.initials: E
authors.lastname: Marbaix
authors.forename: Hervé
authors.initials: H
authors.lastname: Emonard
mesh_terms: D051722:ADAM Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000072199:ADAM12 Protein; D015703:Antigens, CD / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism*; D015622:Epithelioid Cells / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000737:chemistry / Q000378:metabolism*; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008565:Membrane Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D045726:Metalloproteases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction
chemical_list: D015703:Antigens, CD; C475476:LRP1 protein, human; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D008565:Membrane Proteins; D034741:RNA, Small Interfering; D002784:Cholesterol; D045726:Metalloproteases; D051722:ADAM Proteins; D000072199:ADAM12 Protein; C000606480:ADAM12 protein, human; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; C507086:MMP14 protein, human; D053511:Matrix Metalloproteinase 14