Extracellular vesicles (EVs) in human blood are a potential source of biomarkers. To which extent anticoagulation affects their concentration, cellular origin and protein composition is largely unexplored. To study this, blood from 23 healthy subjects was collected in acid citrate dextrose (ACD), citrate or EDTA, or without anticoagulation to obtain serum. EVs were isolated by ultracentrifugation or by size-exclusion chromatography (SEC) for fluorescence-SEC. EVs were analyzed by micro flow cytometry, NTA, TEM, Western blot, and protein mass spectrometry. The plasma EV concentration was unaffected by anticoagulants, but serum contained more platelet EVs. The protein composition of plasma EVs differed between anticoagulants, and between plasma and serum. Comparison to other studies further revealed that the shared EV protein composition resembles the “protein corona” of synthetic nanoparticles incubated in plasma or serum. In conclusion, we have validated a higher concentration of platelet EVs in serum than plasma by contemporary EV methods. Anticoagulation should be carefully described (i) to enable study comparison, (ii) to utilize available sample cohorts, and (iii) when preparing/selecting biobank samples. Further, the similarity of the EV protein corona and that of nanoparticles implicates that EVs carry both intravesicular and extravesicular cargo, which will expand their applicability for biomarker discovery.
Bibliographical noteFunding Information:
This study has been supported by the Academy of Finland (grants 287089 (PRMS) and 315227(M. Palviainen)), Magnus Ehrnrooth Foundation (PRMS), Medicinska Underst?dsf?reningen Liv och H?lsa rf. (PRMS) and by the National Research, Development and Innovation Office NKFIH, Hungary (ZV, grants PD 121326 and NVKP_16-1-2016-0007). ZV was supported by the J?nos Bolyai Research Fellowship. DK was supported by the ?NKP-19-3 New National Excellence Program of the Ministry for Innovation and Technology.
© 2020 Palviainen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Copyright 2020 Elsevier B.V., All rights reserved.
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't