title: Low-density lipoprotein mimics blood plasma-derived exosomes and microvesicles during isolation and detection.
abstract: Circulating extracellular vesicles have emerged as potential new biomarkers in a wide variety of diseases. Despite the increasing interest, their isolation and purification from body fluids remains challenging. Here we studied human pre-prandial and 4 hours postprandial platelet-free blood plasma samples as well as human platelet concentrates. Using flow cytometry, we found that the majority of circulating particles within the size range of extracellular vesicles lacked common vesicular markers. We identified most of these particles as lipoproteins (predominantly low-density lipoprotein, LDL) which mimicked the characteristics of extracellular vesicles and also co-purified with them. Based on biophysical properties of LDL this finding was highly unexpected. Current state-of-the-art extracellular vesicle isolation and purification methods did not result in lipoprotein-free vesicle preparations from blood plasma or from platelet concentrates. Furthermore, transmission electron microscopy showed an association of LDL with isolated vesicles upon in vitro mixing. This is the first study to show co-purification and in vitro association of LDL with extracellular vesicles and its interference with vesicle analysis. Our data point to the importance of careful study design and data interpretation in studies using blood-derived extracellular vesicles with special focus on potentially co-purified LDL.
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Barbara W
authors.initials: BW
authors.lastname: Sódar
authors.affiliation: Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, 1083, Hungary.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Kittel
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Krisztina
authors.initials: K
authors.lastname: Pálóczi
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Krisztina V
authors.initials: KV
authors.lastname: Vukman
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Xabier
authors.initials: X
authors.lastname: Osteikoetxea
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Katalin
authors.initials: K
authors.lastname: Szabó-Taylor
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Andrea
authors.initials: A
authors.lastname: Németh
authors.affiliation: Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, 1083, Hungary.
authors.forename: Beáta
authors.initials: B
authors.lastname: Sperlágh
authors.affiliation: Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Baranyai
authors.affiliation: Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Giricz
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Wiener
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117, Hungary.
authors.forename: Lilla
authors.initials: L
authors.lastname: Turiák
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Drahos
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Éva
authors.initials: É
authors.lastname: Pállinger
authors.affiliation: Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, 1117, Hungary.
authors.forename: Károly
authors.initials: K
authors.lastname: Vékey
authors.affiliation: Department of Pharmacology and Pharmacotherapy, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Péter
authors.initials: P
authors.lastname: Ferdinandy
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: András
authors.initials: A
authors.lastname: Falus
authors.affiliation: Department of Genetics, Cell- and Immunobiology, Semmelweis University, Budapest, 1085, Hungary.
authors.forename: Edit Irén
authors.initials: EI
authors.lastname: Buzás
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000737:chemistry; D055354:Exosomes / Q000737:chemistry*; D000067128:Extracellular Vesicles / Q000737:chemistry*; D005260:Female; D006801:Humans; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D019518:Postprandial Period
chemical_list: D015415:Biomarkers; D008077:Lipoproteins, LDL