title: Lipidomic and proteomic characterization of platelet extracellular vesicle subfractions from senescent platelets.
abstract: BACKGROUND
  Platelets (PLTs) in stored PLT concentrates (PLCs) release PLT extracellular vesicles (PL-EVs) induced by senescence and activation, resembling the PLT storage lesion. No comprehensive classification or molecular characterization of senescence-induced PL-EVs exists to understand PL-EV heterogeneity.
  
  
  METHODS
  PL-EVs from 5-day-stored PLCs from healthy individuals were isolated and subfractionated by differential centrifugation, filtration, and density gradient ultracentrifugation into five PLT microvesicle (PL-MV) subfractions (Fraction [F]1-F5) and PLT exosomes (PL-EXs). PL-EV size, concentration, and composition were analyzed by nanoparticle tracking analysis, flow cytometry, and lipid and protein mass spectrometry. Protein data were verified by Western blot.
  
  
  RESULTS
  PL-EVs showed overlapping mean particle sizes of 180 to 260 nm, but differed significantly in composition. Less dense, intermediate, and dense PL-MVs enriched specific lipidomic and proteomic markers related to the plasma membrane, intracellular membranes, PLT granules, mitochondria, and PLT activation. α-Synuclein (81% of total) accumulated in F1 and F2, amyloid-β (Aβ) precursor protein in F3 and F4 (84%), and apolipoprotein (Apo)E (88%) and ApoJ (92%) in F3 to F5. PL-EXs enriched lipid species and proteins, with high abundance of lipid raft, PLT adhesion, and immune response-related markers.
  
  
  CONCLUSIONS
  Differential lipid and protein compositions of PL-EVs suggest their unique cellular origins and functions, partly overlapping with PLT granule secretion. Dense PL-MVs might represent autophagic vesicles released during PLT activation and apoptosis and PL-EXs resemble lipid rafts, with a potential role in PLT aggregation and immunity. Segregation of α-synuclein and Aβ precursor protein, ApoE, and ApoJ into less dense and dense PL-MVs, respectively, show their differential carrier role of neurologic disease-related cargo.
authors.affiliation: Institute for Clinical Chemistry and Laboratory Medicine, University Clinic of Regensburg, Regensburg, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Pienimaeki-Roemer
authors.forename: Katja
authors.initials: K
authors.lastname: Kuhlmann
authors.forename: Alfred
authors.initials: A
authors.lastname: Böttcher
authors.forename: Tatiana
authors.initials: T
authors.lastname: Konovalova
authors.forename: Anne
authors.initials: A
authors.lastname: Black
authors.forename: Evelyn
authors.initials: E
authors.lastname: Orsó
authors.forename: Gerhard
authors.initials: G
authors.lastname: Liebisch
authors.forename: Maike
authors.initials: M
authors.lastname: Ahrens
authors.forename: Martin
authors.initials: M
authors.lastname: Eisenacher
authors.forename: Helmut E
authors.initials: HE
authors.lastname: Meyer
authors.forename: Gerd
authors.initials: G
authors.lastname: Schmitz
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000737:chemistry* / Q000166:cytology; D001793:Blood Preservation; D001798:Blood Proteins / Q000302:isolation & purification*; D015153:Blotting, Western; D055252:Cell-Derived Microparticles / Q000737:chemistry*; D016922:Cellular Senescence; D002498:Centrifugation / Q000379:methods; D004912:Erythrocytes / Q000737:chemistry; D055354:Exosomes / Q000737:chemistry*; D005374:Filtration; D005434:Flow Cytometry; D006801:Humans; D018189:Immunomagnetic Separation; D008055:Lipids / Q000097:blood* / Q000302:isolation & purification; D013058:Mass Spectrometry / Q000379:methods; D008563:Membrane Lipids / Q000097:blood / Q000302:isolation & purification; D008565:Membrane Proteins / Q000097:blood / Q000302:isolation & purification; D053758:Nanoparticles; D009410:Nerve Degeneration; D015539:Platelet Activation; D010983:Plateletpheresis; D051844:alpha-Synuclein / Q000097:blood
chemical_list: D001798:Blood Proteins; D008055:Lipids; D008563:Membrane Lipids; D008565:Membrane Proteins; D051844:alpha-Synuclein